2024-03-29T00:10:04Zhttps://www.repo.uni-hannover.de/oai/requestoai:www.repo.uni-hannover.de:123456789/582022-12-02T15:04:50Zcom_123456789_1col_123456789_6doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:600ddc:500
Gryshkov, Oleksandr
Pogozhykh, Denys
Hofmann, Nicola
Pogozhykh, Olena
Müller, Thomas
Glasmacher, Birgit
2015-08-19T11:59:00Z
2015-08-19T11:59:00Z
2014-09-26
Gryshkov, Oleksandr; Pogozhykh, Denys; Hofmann, Nicola; Pogozhykh, Olena; Mueller, Thomas; Glasmacher, Birgit: Encapsulating Non-Human Primate Multipotent Stromal Cells in Alginate via High Voltage for Cell-Based Therapies and Cryopreservation. In: PLoS ONE 9 (2014), Nr. 9. DOI: http://dx.doi.org/10.1371/journal.pone.0107911
http://www.repo.uni-hannover.de/handle/123456789/58
http://dx.doi.org/10.15488/40
Alginate cell-based therapy requires further development focused on clinical application. To assess engraftment, risk of mutations and therapeutic benefit studies should be performed in an appropriate non-human primate model, such as the common marmoset (Callithrix jacchus). In this work we encapsulated amnion derived multipotent stromal cells (MSCs) from Callithrix jacchus in defined size alginate beads using a high voltage technique. Our results indicate that i) alginate-cell mixing procedure and cell concentration do not affect the diameter of alginate beads, ii) encapsulation of high cell numbers (up to 10×106 cells/ml) can be performed in alginate beads utilizing high voltage and iii) high voltage (15–30 kV) does not alter the viability, proliferation and differentiation capacity of MSCs post-encapsulation compared with alginate encapsulated cells produced by the traditional air-flow method. The consistent results were obtained over the period of 7 days of encapsulated MSCs culture and after cryopreservation utilizing a slow cooling procedure (1 K/min). The results of this work show that high voltage encapsulation can further be maximized to develop cell-based therapies with alginate beads in a non-human primate model towards human application.
eng
http://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Cross-linking
Cryopreservation
Marmoset
Air flow
Cell staining
Amnion
Flow rate
Cell differentiation
Vernetzung
Kryokonservierung
Callithrix jacchus
Weißbüschelaffe
Marmosetten
Luftstrom
Zellfärbung
Amnion
Flussrate
Durchsatz
Encapsulating Non-Human Primate Multipotent Stromal Cells in Alginate via High Voltage for Cell-Based Therapies and Cryopreservation
Article
Text
oai:www.repo.uni-hannover.de:123456789/2952022-12-02T16:11:40Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Hanschen, Franziska S.
Yim, Bunlong
Winkelmann, Traud
Smalla, Kornelia
Schreiner, Monika
2016-06-13T14:30:48Z
2016-06-13T14:30:48Z
2015-07-17
Hanschen, Franziska S.; Yim, Bunlong; Winkelmann, Traud; Smalla, Kornelia; Schreiner, Monika: Degradation of Biofumigant Isothiocyanates and Allyl Glucosinolate in Soil and Their Effects on the Microbial Community Composition. In: PloS ONE 10 (2015), Nr. 7, e0132931. DOI: http://dx.doi.org/10.1371/journal.pone.0132931
http://www.repo.uni-hannover.de/handle/123456789/295
http://dx.doi.org/10.15488/273
Brassicales species rich in glucosinolates are used for biofumigation, a process based on releasing enzymatically toxic isothiocyanates into the soil. These hydrolysis products are volatile and often reactive compounds. Moreover, glucosinolates can be degraded also without the presence of the hydrolytic enzyme myrosinase which might contribute to bioactive effects. Thus, in the present study the stability of Brassicaceae plant-derived and pure glucosinolates hydrolysis products was studied using three different soils ( model biofumigation). In addition, the degradation of pure 2-propenyl glucosinolate was investigated with special regard to the formation of volatile breakdown products. Finally, the influence of pure glucosinolate degradation on the bacterial community composition was evaluated using denaturing gradient gel electrophoresis of 16S rRNA gene amplified from total community DNA. The model biofumigation study revealed that the structure of the hydrolysis products had a significant impact on their stability in the soil but not the soil type. Following the degradation of pure 2-propenyl glucosinolate in the soils, the nitrile as well as the isothiocyanate can be the main degradation products, depending on the soil type. Furthermore, the degradation was shown to be both chemically as well as biologically mediated as autoclaving reduced degradation. The nitrile was the major product of the chemical degradation and its formation increased with iron content of the soil. Additionally, the bacterial community composition was significantly affected by adding pure 2-propenyl glucosinolate, the effect being more pronounced than in treatments with myrosinase added to the glucosinolate. Therefore, glucosinolates can have a greater effect on soil bacterial community composition than their hydrolysis products.
eng
http://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
enhanced biodegradation
benzyl isothiocyanate
hydrolysis products
broccoli sprouts
model systems
rhizosphere
acid
decomposition
nitriles
sinigrin
Degradation of Biofumigant Isothiocyanates and Allyl Glucosinolate in Soil and Their Effects on the Microbial Community Composition
Article
Text
oai:www.repo.uni-hannover.de:123456789/3082022-12-02T16:11:40Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessddc:590status-type:publishedVersionddc:500
Hoffmann, Holger
Rath, Thomas
2016-06-13T14:56:11Z
2016-06-13T14:56:11Z
2013-10-08
Hoffmann, Holger; Rath, Thomas: Future Bloom and Blossom Frost Risk for Malus domestica Considering Climate Model and Impact Model Uncertainties . In: PloS ONE 8 (2013), Nr. 10, e75033. DOI: http://dx.doi.org/10.1371/journal.pone.0075033
http://www.repo.uni-hannover.de/handle/123456789/308
http://dx.doi.org/10.15488/286
The future bloom and risk of blossom frosts for Malus domestica were projected using regional climate realizations and phenological (= impact) models. As climate impact projections are susceptible to uncertainties of climate and impact models and model concatenation, the significant horizon of the climate impact signal was analyzed by applying 7 impact models, including two new developments, on 13 climate realizations of the IPCC emission scenario A1B. Advancement of phenophases and a decrease in blossom frost risk for Lower Saxony (Germany) for early and late ripeners was determined by six out of seven phenological models. Single model/single grid point time series of bloom showed significant trends by 2021-2050 compared to 1971-2000, whereas the joint signal of all climate and impact models did not stabilize until 2043. Regarding blossom frost risk, joint projection variability exceeded the projected signal. Thus, blossom frost risk cannot be stated to be lower by the end of the 21st century despite a negative trend. As a consequence it is however unlikely to increase. Uncertainty of temperature, blooming date and blossom frost risk projection reached a minimum at 2078-2087. The projected phenophases advanced by 5.5 d K-1, showing partial compensation of delayed fulfillment of the winter chill requirement and faster completion of the following forcing phase in spring. Finally, phenological model performance was improved by considering the length of day.
eng
http://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
phenological models
winter chill
spring frost
fruit-trees
apple
germany
time
europe
trends
damage
Future Bloom and Blossom Frost Risk for Malus domestica Considering Climate Model and Impact Model Uncertainties
Article
Text
oai:www.repo.uni-hannover.de:123456789/3132022-12-02T16:14:10Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:580ddc:500
Shibistova, Olga
Yohannes, Yonas
Boy, Jens
Richter, Andreas
Wild, Birgit
Watzka, Margarete
Guggenberger, Georg
2016-06-13T15:13:59Z
2016-06-13T15:13:59Z
2012-09-26
Shibistova, Olga; Yohannes, Yonas; Boy, Jens; Richter, Andreas; Wild, Birgit et al.: Rate of Belowground Carbon Allocation Differs with Successional Habit of Two Afromontane Trees. In: PloS ONE 7 (2012), Nr. 9, e45540. DOI: http://dx.doi.org/10.1371/journal.pone.0045540
http://www.repo.uni-hannover.de/handle/123456789/313
http://dx.doi.org/10.15488/291
Background: Anthropogenic disturbance of old-growth tropical forests increases the abundance of early successional tree species at the cost of late successional ones. Quantifying differences in terms of carbon allocation and the proportion of recently fixed carbon in soil CO2 efflux is crucial for addressing the carbon footprint of creeping degradation. Methodology: We compared the carbon allocation pattern of the late successional gymnosperm Podocarpus falcatus (Thunb.) Mirb. and the early successional (gap filling) angiosperm Croton macrostachyus Hochst. es Del. in an Ethiopian Afromontane forest by whole tree (CO2)-C-13 pulse labeling. Over a one-year period we monitored the temporal resolution of the label in the foliage, the phloem sap, the arbuscular mycorrhiza, and in soil-derived CO2. Further, we quantified the overall losses of assimilated C-13 with soil CO2 efflux. Principal Findings: C-13 in leaves of C. macrostachyus declined more rapidly with a larger size of a fast pool (64% vs. 50% of the assimilated carbon), having a shorter mean residence time (14 h vs. 55 h) as in leaves of P. falcatus. Phloem sap velocity was about 4 times higher for C. macrostachyus. Likewise, the label appeared earlier in the arbuscular mycorrhiza of C. macrostachyus and in the soil CO2 efflux as in case of P. falcatus (24 h vs. 72 h). Within one year soil CO2 efflux amounted to a loss of 32% of assimilated carbon for the gap filling tree and to 15% for the late successional one. Conclusions: Our results showed clear differences in carbon allocation patterns between tree species, although we caution that this experiment was unreplicated. A shift in tree species composition of tropical montane forests (e. g., by degradation) accelerates carbon allocation belowground and increases respiratory carbon losses by the autotrophic community. If ongoing disturbance keeps early successional species in dominance, the larger allocation to fast cycling compartments may deplete soil organic carbon in the long run.
eng
http://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
high temporal resolution
soil respiration
isotope composition
southern ethiopia
gas-exchange
terrestrial ecosystems
physiological ecology
organic-compounds
tropical forests
fagus-sylvatica
Rate of Belowground Carbon Allocation Differs with Successional Habit of Two Afromontane Trees
Article
Text
oai:www.repo.uni-hannover.de:123456789/4252022-12-02T15:15:02Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessddc:530status-type:publishedVersionddc:500
Armano, M.
Audley, H.
Auger, G.
Baird, J.
Binetruy, P.
Born, Michael
Bortoluzzi, D.
Brandt, N.
Bursi, A.
Caleno, M.
Cavalleri, A.
Cesarini, A.
Cruise, M.
Danzmann, Karsten
Diepholz, I.
Dolesi, R.
Dunbar, N.
Ferraioli, L.
Ferroni, V.
Fitzsimons, E.
Freschi, M.
Gallegos, J.
Marirrodriga, C. Garcia
Gerndt, R.
Gesa, L.I.
Gibert, F.
Giardini, D.
Giusteri, R.
Grimani, C.
Harrison, I.
Heinzel, Gerhard
Hewitson, M.
Hollington, D.
Hueller, M.
Huesler, J.
Inchauspe, H.
Jennrich, O.
Jetzer, P.
Johlander, B.
Karnesis, N.
Kaune, B.
Korsakova, N.
Killow, C.
Lloro, I.
Maarschalkerweerd, R.
Madden, S.
Mance, D.
Martin, V.
Martin-Porqueras, F.
Mateos, I.
McNamara, P.
Mendes, J.
Mendes, L.
Moroni, A.
Nofrarias, M.
Paczkowski, S.
Perreur-Lloyd, M.
Petiteau, A.
Pivato, P.
Plagnol, E.
Prat, P.
Ragnit, U.
Ramos-Castro, J.
Reiche, J.
Perez, J. A. Romera
Robertson, D.
Rozemeijer, H.
Russano, G.
Sarra, P.
Schleicher, A.
Slutsky, J.
Sopuerta, C.F.
Sumner, T.
Texier, D.
Thorpe, J.
Trenkel, C.
Tu, H.B.
Vitale, S.
Wanner, G.
Ward, H.
Waschke, S.
Wass, P.
Wealthy, D.
Wen, S.
Weber, W.
Wittchen, A.
Zanoni, C.
Ziegler, T.
Zweifel, P.
2016-08-12T08:59:20Z
2016-08-12T08:59:20Z
2015
Armano, M.; Audley, Heather; Auger, G.; Baird, J.; Binetruy, P. et al.: Disentangling the magnetic force noise contribution in LISA Pathfinder. In: Journal of Physics Conference Series 610 (2015), 12024. DOI: http://dx.doi.org/10.1088/1742-6596/610/1/012024
http://www.repo.uni-hannover.de/handle/123456789/425
http://dx.doi.org/10.15488/402
Magnetically-induced forces on the inertial masses on-board LISA Path finder are expected to be one of the dominant contributions to the mission noise budget, accounting for up to 40%. The origin of this disturbance is the coupling of the residual magnetization and susceptibility of the test masses with the environmental magnetic field. In order to fully understand this important part of the noise model, a set of coils and magnetometers are integrated as a part of the diagnostics subsystem. During operations a sequence of magnetic excitations will be applied to precisely determine the coupling of the magnetic environment to the test mass displacement using the on-board magnetometers. Since no direct measurement of the magnetic field in the test mass position will be available, an extrapolation of the magnetic measurements to the test mass position will be carried out as a part of the data analysis activities. In this paper we show the first results on the magnetic experiments during an end-to-end LISA Path finder simulation, and we describe the methods under development to map the magnetic field on-board.
eng
https://creativecommons.org/licenses/by/3.0/de/
CC BY 3.0 Unported
LISA Pathfinder
Astronomy
Astrophysics
Physics, Applied
Disentangling the magnetic force noise contribution in LISA Pathfinder
Article
Text
oai:www.repo.uni-hannover.de:123456789/4262022-12-02T15:15:02Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessddc:530status-type:publishedVersionddc:500
Armano, M.
Audley, H.
Auger, G.
Baird, J.
Binetruy, P.
Born, Michael
Bortoluzzi, D.
Brandt, N.
Bursi, A.
Caleno, M.
Cavalleri, A.
Cesarini, A.
Cruise, M.
Danzmann, Karsten
Diepholz, I.
Dolesi, R.
Dunbar, N.
Ferraioli, L.
Ferroni, V.
Fitzsimons, E.
Freschi, M.
Gallegos, J.
Marirrodriga, C. Garcia
Gerndt, R.
Gesa, L.I.
Gibert, F.
Giardini, D.
Giusteri, R.
Grimani, C.
Harrison, I.
Heinzel, Gerhard
Hewitson, M.
Hollington, D.
Hueller, M.
Huesler, J.
Inchauspe, H.
Jennrich, O.
Jetzer, P.
Johlander, B.
Karnesis, N.
Kaune, B.
Korsakova, N.
Killow, C.
Lloro, I.
Maarschalkerweerd, R.
Madden, S.
Mance, D.
Martin, V.
Martin-Porqueras, F.
Mateos, I.
McNamara, P.
Mendes, J.
Mendes, L.
Moroni, A.
Nofrarias, M.
Paczkowski, S.
Perreur-Lloyd, M.
Petiteau, A.
Pivato, P.
Plagnol, E.
Prat, P.
Ragnit, U.
Ramos-Castro, J.
Reiche, J.
Perez, J. A. Romera
Robertson, D.
Rozemeijer, H.
Russano, G.
Sarra, P.
Schleicher, A.
Slutsky, J.
Sopuerta, C.F.
Sumner, T.
Texier, D.
Thorpe, J.
Trenkel, C.
Tu, H.B.
Vitale, S.
Wanner, G.
Ward, H.
Waschke, S.
Wass, P.
Wealthy, D.
Wen, S.
Weber, W.
Wittchen, A.
Zanoni, C.
Ziegler, T.
Zweifel, P.
2016-08-12T08:59:21Z
2016-08-12T08:59:21Z
2015
Armano, M.; Audley, H.; Auger, G.; Baird, J.; Binetruy, P. et al.: A Strategy to Characterize the LISA-Pathfinder Cold Gas Thruster System. In: Journal of Physics Conference Series 610 (2015), 12026. DOI: http://dx.doi.org/10.1088/1742-6596/610/1/012026
http://www.repo.uni-hannover.de/handle/123456789/426
http://dx.doi.org/10.15488/403
The cold gas micro-propulsion system that will be used during the LISA-Pathfinder mission will be one of the most important component used to ensure the "free-fall" of the enclosed test masses. In this paper we present a possible strategy to characterize the effective direction and amplitude gain of each of the 6 thrusters of this system.
eng
https://creativecommons.org/licenses/by/3.0/de/
CC BY 3.0 Unported
LISA Pathfinder
Astronomy
Astrophysics
Physics, Applied
A Strategy to Characterize the LISA-Pathfinder Cold Gas Thruster System
Article
Text
oai:www.repo.uni-hannover.de:123456789/4302022-12-02T15:15:02Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessddc:530status-type:publishedVersionddc:500
Gibert, F.
Nofrarias, M.
Armano, M.
Audley, H.
Auger, G.
Baird, J.
Binetruy, P.
Born, Michael
Bortoluzzi, D.
Brandt, N.
Bursi, A.
Caleno, M.
Cavalleri, A.
Cesarini, A.
Cruise, M.
Danzmann, Karsten
Diepholz, I.
Dolesi, R.
Dunbar, N.
Ferraioli, L.
Ferroni, V.
Fitzsimons, E.
Freschi, M.
Gallegos, J.
Garcia Marirrodriga, C.
Gerndt, R.
Gesa, L.I.
Giardini, D.
Giusteri, R.
Grimani, C.
Harrison, I.
Heinzel, Gerhard
Hewitson, M.
Hollington, D.
Hueller, M.
Huesler, J.
Inchauspe, H.
Jennrich, O.
Jetzer, P.
Johlander, B.
Karnesis, N.
Kaune, B.
Korsakova, N.
Killow, C.
Lloro, I.
Maarschalkerweerd, R.
Madden, S.
Maghami, P.
Mance, D.
Martin, V.
Martin-Porqueras, F.
Mateos, I.
McNamara, P.
Mendes, J.
Mendes, L.
Moroni, A.
Paczkowski, S.
Perreur-Lloyd, M.
Petiteau, A.
Pivato, P.
Plagnol, E.
Prat, P.
Ragnit, U.
Ramos-Castro, J.
Reiche, J.
Perez, J. A. Romera
Robertson, D.
Rozemeijer, H.
Russano, G.
Sarra, P.
Schleicher, A.
Slutsky, J.
Sopuerta, C.F.
Sumner, T.
Texier, D.
Thorpe, J.
Trenkel, C.
Tu, H.B.
Vetrugno, D.
Vitale, S.
Wanner, G.
Ward, H.
Waschke, S.
Wass, P.
Wealthy, D.
Wen, S.
Weber, W.
Wittchen, A.
Zanoni, C.
Ziegler, T.
Zweifel, P.
2016-08-12T08:59:22Z
2016-08-12T08:59:22Z
2015
Gibert, F.; Nofrarias, M.; Armano, M.; Audley, H.; Auger, G. et al.: In-flight thermal experiments for LISA Pathfinder: Simulating temperature noise at the Inertial Sensors. In: Journal of Physics Conference Series 610 (2015), 12023. DOI: http://dx.doi.org/10.1088/1742-6596/610/1/012023
http://www.repo.uni-hannover.de/handle/123456789/430
http://dx.doi.org/10.15488/407
Thermal Diagnostics experiments to be carried out on board LISA Pathfinder (LPF) will yield a detailed characterisation of how temperature fluctuations affect the LTP (LISA Technology Package) instrument performance, a crucial information for future space based gravitational wave detectors as the proposed eLISA. Amongst them, the study of temperature gradient fluctuations around the test masses of the Inertial Sensors will provide as well information regarding the contribution of the Brownian noise, which is expected to limit the LTP sensitivity at frequencies close to 1mHz during some LTP experiments. In this paper we report on how these kind of Thermal Diagnostics experiments were simulated in the last LPF Simulation Campaign (November, 2013) involving all the LPF Data Analysis team and using an end-to-end simulator of the whole spacecraft. Such simulation campaign was conducted under the framework of the preparation for LPF operations.
eng
https://creativecommons.org/licenses/by/3.0/de/
CC BY 3.0 Unported
Astronomy & Astrophysics
Physics, Applied
In-flight thermal experiments for LISA Pathfinder: Simulating temperature noise at the Inertial Sensors
Article
Text
oai:www.repo.uni-hannover.de:123456789/4312022-12-02T15:17:14Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessddc:530status-type:publishedVersionddc:500
Troebs, Michael
Bogan, C.
Barke, S.
Kuehn, G.
Reiche, J.
Heinzel, Gerhard
Danzmann, Karsten
2016-08-12T08:59:22Z
2016-08-12T08:59:22Z
2015
Troebs, M.; Bogan, C.; Barke, S.; Kuehn, G.; Reiche, J. et. al.: Transportable setup for amplifier phase fidelity measurements. In: Journal of Physics Conference Series 610 (2015), 12041. DOI: http://dx.doi.org/10.1088/1742-6596/610/1/012041
http://www.repo.uni-hannover.de/handle/123456789/431
http://dx.doi.org/10.15488/408
One possible laser source for the Laser Interferometer Space Antenna (LISA) consists of an Ytterbium-doped fiber amplifier originally developed for inter-satellite communication, seeded by the laser used for the technology demonstrator mission LISA Pathfinder. LISA needs to transmit clock information between its three spacecraft to correct for phase noise between the clocks on the individual spacecraft. For this purpose phase modulation sidebands at GHz frequencies will be imprinted on the laser beams between spacecraft. Differential phase noise between the carrier and a sideband introduced within the optical chain must be very low. We report on a transportable setup to measure the phase fidelity of optical amplifiers.
eng
https://creativecommons.org/licenses/by/3.0/de/
CC BY 3.0 Unported
interferometer
lisa
Transportable setup for amplifier phase fidelity measurements
Article
Text
oai:www.repo.uni-hannover.de:123456789/4322022-12-02T15:15:03Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessddc:530status-type:publishedVersionddc:500
Wanner, Gudrun
Schuster, Sönke
Tröbs, Michael
Heinzel, Gerhard
2016-08-12T08:59:23Z
2016-08-12T08:59:23Z
2015
Wanner, Gudrun; Schuster, Sönke; Tröbs, Michael; Heinzel, Gerhard: A brief comparison of optical pathlength difference and various definitions for the interferometric phase. In: Journal of Physics Conference Series 610 (2015), 12043. DOI: http://dx.doi.org/10.1088/1742-6596/610/1/012043
http://www.repo.uni-hannover.de/handle/123456789/432
http://dx.doi.org/10.15488/409
To this paper we discuss that the phase readout in low noise laser interferometers can significantly deviate from the underlying optical pathlength difference (OPD). The cross coupling of beam tilt to the interferometric phase readout is compared to the OPD. For such a system it is shown that the amount of tilt to phase readout coupling depends strongly on the involved beams and their parameters, as well as on the detector properties and the precise definition of the phase. The unique single element photodiode phase is therefore compared to three common phase definitions for quadrant diodes. It is shown that neither phase definition globally shows the least amount of cross coupling of angular it
eng
https://creativecommons.org/licenses/by/3.0/de/
CC BY 3.0 Unported
Astronomy
Astrophysics
Physics, Applied
A brief comparison of optical pathlength difference and various definitions for the interferometric phase
Article
Text
oai:www.repo.uni-hannover.de:123456789/4332022-12-02T16:14:10Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Chadwick, A.V.
Duevel, Andre
Heitjans, Paul
Pickup, D.M.
Ramos, S.
Sayle, D.C.
Sayle, T.X.T.
2016-08-12T08:59:23Z
2016-08-12T08:59:23Z
2015
Chadwick, A. V.; Duevel, A.; Heitjans, P.; Pickup, D. M.; Ramos, S. et al.: X-Ray Absorption Spectroscopy and Computer Modelling Study of Nanocrystalline Binary Alkaline Earth Fluorides. In: IOP Conference Series-Materials Science and Engineering 80 (2015) , 12005. DOI: http://dx.doi.org/10.1088/1757-899X/80/1/012005
http://www.repo.uni-hannover.de/handle/123456789/433
http://dx.doi.org/10.15488/410
Nanocrystalline samples of Ba1-xCaxF2 prepared by high-energy milling show an unusually high F-ion conductivity, which exhibit a maximum in the magnitude and a minimum in the activation energy at x = 0.5. Here, we report an X-ray absorption spectroscopy (XAS) at the Ca and Sr K edges and the Ba L-3 edge and a molecular dynamics (MD) simulation study of the pure and mixed fluorides. The XAS measurements on the pure binary fluorides, CaF2, SrF2 and BaF2 show that high-energy ball-milling produces very little amorphous material, in contrast to the results for ball milled oxides. XAS measurements of Ba1-xCaxF2 reveal that for 0 < x < 1 there is considerable disorder in the local environments of the cations which is highest for x = 0.5. Hence the maximum in the conductivity corresponds to the composition with the maximum level of local disorder. The MD calculations also show a highly disordered structure consistent with the XAS results and similarly showing maximum disorder at x = 0.5.
eng
https://creativecommons.org/licenses/by/3.0/de/
CC BY 3.0 Unported
ionic-conductivity
composites
caf2
X-Ray Absorption Spectroscopy and Computer Modelling Study of Nanocrystalline Binary Alkaline Earth Fluorides
Article
Text
oai:www.repo.uni-hannover.de:123456789/4352022-12-02T15:19:58Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Nariaki, Driss
Lekovic, F.
Homenya, Patrick
Costa, B.F.O.
Menzel, M.
Boca, R.
Blumers, M.
Klingelhoefer, G.
Renz, Franz
2016-08-12T09:18:03Z
2016-08-12T09:18:03Z
2014
Nariaki, Driss; Lekovic, F.; Homenya, P.; Costa, B. F. O.; Menzel, M. et al.: Iron(III) Complexes on a Dendrimeric Basis and Various Amine Core Investigated by Mössbauer Spectroscopy. In: Journal of Physics Conference Series 534 (2014) , 12003. DOI: http://dx.doi.org/10.1088/1742-6596/534/1/012003
http://www.repo.uni-hannover.de/handle/123456789/435
http://dx.doi.org/10.15488/412
Dendrimers of various generations were synthesized by the divergent method. Starting from various amine cores (G(0a), G(0b), G(0c)) the generations were built by reaction of the amine with acrylnitrile followed by hydrogenation with DIBAL-H. Treatment with salicylaldehyde creates a fivefold coordination sphere for iron in the molecular periphery. The resulting multinuclear coordination compounds are investigated by Mossbauer spectroscopy.
eng
https://creativecommons.org/licenses/by/3.0/de/
CC BY 3.0 Unported
spectra
Iron(III) Complexes on a Dendrimeric Basis and Various Amine Core Investigated by Mössbauer Spectroscopy
Article
Text
oai:www.repo.uni-hannover.de:123456789/4362022-12-02T15:19:58Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Nariaki, Driss
Lekovic, Faik
Homenya, Patrick
Renz, Franz
2016-08-12T09:18:03Z
2016-08-12T09:18:03Z
2014
Nariaki, Driss; Lekovic, Faik; Homenya, Patrick; Renz, Franz: Mössbauer Spectroscopic Study and Magnetic Investigation of Iron(III) Complexes on a Dendrimeric Basis. In: Journal of Physics Conference Series 534 (2014), 12002. DOI: http://dx.doi.org/10.1088/1742-6596/534/1/012002
http://www.repo.uni-hannover.de/handle/123456789/436
http://dx.doi.org/10.15488/413
The functionalization of the molecular surface of various dendrimer generations with a phosphorous core and external amine groups is obtained by converting those amine groups into the corresponding imines of salicylaldehyde creating multiple coordination sites for the iron atoms. Treatment with iron(III) chloride yields multinuclear iron(III) complexes on a dendrimeric basis. The obtained multinuclear molecular systems exhibit extremely high total spin values. The influence of the generation growth on this type of coordination compounds is investigated by Mossbauer spectroscopy and SQUIDmagnetometry.
eng
https://creativecommons.org/licenses/by/3.0/de/
CC BY 3.0 Unported
ir-spectra
multistability
Mössbauer Spectroscopic Study and Magnetic Investigation of Iron(III) Complexes on a Dendrimeric Basis
Article
Text
oai:www.repo.uni-hannover.de:123456789/4602022-12-02T16:14:09Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Effendi, Yunus
Ferro, Noel
Labusch, Corinna
Geisler, Markus
Scherer, Günther F. E.
2016-08-29T08:04:52Z
2016-08-29T08:04:52Z
2015-01
Effendi, Yunus; Ferro, Noel; Labusch, Corinna; Geisler, Markus; Scherer, Guenther F. E.: Complementation of the embryo-lethal T-DNA insertion mutant of AUXIN-BINDING-PROTEIN 1 (ABP1) with abp1 point mutated versions reveals crosstalk of ABP1 and phytochromes. In: Journal of Experimental Botany 66 (2015), Nr. 1, S. 403-418. DOI: http://dx.doi.org/10.1093/jxb/eru433
http://www.repo.uni-hannover.de/handle/123456789/460
http://dx.doi.org/10.15488/437
The function of the extracytoplasmic AUXIN-BINDING-PROTEIN1 (ABP1) is largely enigmatic. We complemented a homozygous T-DNA insertion null mutant of ABP1 in Arabidopsis thaliana Wassilewskia with three mutated and one wild-type (wt) ABP1 cDNA, all tagged C-terminally with a strepII-FLAG tag upstream the KDEL signal. Based on in silico modelling, the abp1 mutants were predicted to have altered geometries of the auxin binding pocket and calculated auxin binding energies lower than the wt. Phenotypes linked to auxin transport were compromised in these three complemented abp1 mutants. Red light effects, such as elongation of hypocotyls in constant red (R) and far-red (FR) light, in white light supplemented by FR light simulating shade, and inhibition of gravitropism by R or FR, were all compromised in the complemented lines. Using auxin-or light-induced expression of marker genes, we showed that auxininduced expression was delayed already after 10 min, and light-induced expression within 60 min, even though TIR1/AFB or phyB are thought to act as receptors relevant for gene expression regulation. The expression of marker genes in seedlings responding to both auxin and shade showed that for both stimuli regulation of marker gene expression was altered after 10-20 min in the wild type and phyB mutant. The rapidity of expression responses provides a framework for the mechanics of functional interaction of ABP1 and phyB to trigger interwoven signalling pathways.
eng
http://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
auxin-binding protein1 (abp1)
abp1 mutants
early auxin-regulated genes
early light-regulated genes
gravitropism
phototropism
phytochrome
hypocotyl elongation
shade avoidance
arabidopsis thaliana
shade avoidance-response
arabidopsis-thaliana
cell expansion
signal-transduction
negative regulator
plant development
gene-expression
red-light
transport
Complementation of the embryo-lethal T-DNA insertion mutant of AUXIN-BINDING-PROTEIN 1 (ABP1) with abp1 point mutated versions reveals crosstalk of ABP1 and phytochromes
Article
Text
oai:www.repo.uni-hannover.de:123456789/4612022-12-02T16:14:10Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Bauerfeind, Martin Andreas
Winkelmann, Traud
Franken, Philipp
Druege, Uwe
2016-08-29T08:04:52Z
2016-08-29T08:04:52Z
2015-07-28
Bauerfeind, Martin Andreas; Winkelmann, Traud; Franken, Philipp; Druege, Uwe: Transcriptome, carbohydrate, and phytohormone analysis of Petunia hybrida reveals a complex disturbance of plant functional integrity under mild chilling stress. In: Frontiers in Plant Science 6 (2015), 583. DOI: http://dx.doi.org/10.3389/fpls.2015.00583
http://www.repo.uni-hannover.de/handle/123456789/461
http://dx.doi.org/10.15488/438
Cultivation of chilling-tolerant ornamental crops at lower temperature could reduce the energy demands of heated greenhouses. To provide a better understanding of how sub-optimal temperatures (12 degrees C vs. 16 degrees C) affect growth of the sensitive Petunia hybrida cultivar 'SweetSunshine Williams', the transcriptome, carbohydrate metabolism, and phytohormone homeostasis were monitored in aerial plant parts over 4 weeks by use of a microarray, enzymatic assays and GC-MS/MS. The data revealed three consecutive phases of chilling response. The first days were marked by a strong accumulation of sugars, particularly in source leaves, preferential up-regulation of genes in the same tissue and down-regulation of several genes in the shoot apex, especially those involved in the abiotic stress response. The midterm phase featured a partial normalization of carbohydrate levels and gene expression. After 3 weeks of chilling exposure, a new stabilized balance was established. Reduced hexose levels in the shoot apex, reduced ratios of sugar levels between the apex and source leaves and a higher apical sucrose/hexose ratio, associated with decreased activity and expression of cell wall invertase, indicate that prolonged chilling induced sugar accumulation in source leaves at the expense of reduced sugar transport to and reduced sucrose utilization in the shoot. This was associated with reduced levels of indole-3-acetic acid and abscisic acid in the apex and high numbers of differentially, particularly up-regulated genes, especially in the source leaves, including those regulating histones, ethylene action, transcription factors, and a jasmonate-ZIM-domain protein. Transcripts of one Jumonji C domain containing protein and one expansin accumulated in source leaves throughout the chilling period. The results reveal a dynamic and complex disturbance of plant function in response to mild chilling, opening new perspectives for the comparative analysis of differently tolerant cultivars.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
petunia
cold
carbohydrate metabolism
sugars
invertase
gene expression
microarray
plant hormones
freezing tolerance
arabidopsis-thaliana
abscisic-acid
suboptimal temperature
carbon metabolism
cold-acclimation
expression
seedlings
growth
auxin
Transcriptome, carbohydrate, and phytohormone analysis of Petunia hybrida reveals a complex disturbance of plant functional integrity under mild chilling stress
Article
Text
oai:www.repo.uni-hannover.de:123456789/4622022-12-02T16:14:10Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Dong, Peng
Georget, Erika S.
Aganovic, Kemal
Heinz, Volker
Mathys, Alexander
2016-08-29T08:04:52Z
2016-08-29T08:04:52Z
2015-07-14
Dong, Peng; Georget, Erika S.; Aganovic, Kemal; Heinz, Volker; Mathys, Alexander: Ultra high pressure homogenization (UHPH) inactivation of Bacillus amyloliquefaciens spores in phosphate buffered saline (PBS) and milk. In: Frontiers in Plant Science 6 (2015) , 712. DOI: http://dx.doi.org/10.3389/fmicb.2015.00712
http://www.repo.uni-hannover.de/handle/123456789/462
http://dx.doi.org/10.15488/439
Ultra high pressure homogenization (UHPH) opens up new areas for dynamic high pressure assisted thermal sterilization of liquids. Bacillus amyloliquefaciens spores are resistant to high isostatic pressure and temperature and were suggested as potential surrogate for high pressure thermal sterilization validation. B. amyloliquefaciens spores suspended in PBS buffer (0.01 M, pH 7.0), low fat milk (1.5%, pH 6.7), and whole milk (3.5%, pH 6.7) at initial concentration of similar to 10(6) CFU/mL were subjected to UHPH treatments at 200, 300, and 350 MPa with an inlet temperature at similar to 80 degrees C. Thermal inactivation kinetics of B. amyloliquefaciens spores in PBS and milk were assessed with thin wall glass capillaries and modeled using first-order and Weibull models. The residence time during UHPH treatments was estimated to determine the contribution of temperature to spore inactivation by UHPH. No sublethal injury was detected after UHPH treatments using sodium chloride as selective component in the nutrient agar medium. The inactivation profiles of spores in PBS buffer and milk were compared and fat provided no clear protective effect for spores against treatments. Treatment at 200 MPa with valve temperatures lower than 125 degrees C caused no reduction of spores. A reduction of 3.5 log(10)CFU/mL of B. amyloliquefaciens spores was achieved by treatment at 350 MPa with a valve temperature higher than 150 degrees C. The modeled thermal inactivation and observed inactivation during UHPH treatments suggest that temperature could be the main lethal effect driving inactivation.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
ultra high pressure homogenization
bacterial spore
bacillus amyloliquefaciens
inactivation
milk
fat content
dynamic high-pressure
electric-fields pef
fat globule size
raw bovine-milk
uv-c light
escherichia-coli
microbial inactivation
thermal inactivation
listeria-monocytogenes
bacterial-spores
Ultra high pressure homogenization (UHPH) inactivation of Bacillus amyloliquefaciens spores in phosphate buffered saline (PBS) and milk
Article
Text
oai:www.repo.uni-hannover.de:123456789/4632022-12-02T16:11:40Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Dossa, Gerbert Sylvestre
Sparks, Adam
Cruz, Casiana Vera
Oliva, Ricardo
2016-08-29T08:04:52Z
2016-08-29T08:04:52Z
2015-05-05
Dossa, Gerbert S.; Sparks, Adam; Cruz, Casiana Vera; Oliva, Ricardo: Decision tools for bacterial blight resistance gene deployment in rice-based agricultural ecosystems. In: Frontiers in Plant Science 6 (2015), 305. DOI: http://dx.doi.org/10.3389/fpls.2015.00305
http://www.repo.uni-hannover.de/handle/123456789/463
http://dx.doi.org/10.15488/440
Attempting to achieve long-lasting and stable resistance using uniformly deployed rice varieties is not a sustainable approach. The real situation appears to be much more complex and dynamic, one in which pathogens quickly adapt to resistant varieties. To prevent disease epidemics, deployment should be customized and this decision will require interdisciplinary actions. This perspective article aims to highlight the current progress on disease resistance deployment to control bacterial blight in rice. Although the model system rice-Xanthomonas oryzae pv. oryzae has distinctive features that underpin the need for a case-by-case analysis, strategies to integrate those elements into a unique decision tool could be easily extended to other crops.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
customized deployment
forward breeding
tal effectors
r-genes
genome editing
oryzae pv. oryzae
triggers disease resistance
tal effectors
susceptibility gene
plant-pathogens
iii effectors
crispr/cas9
biology
system
asia
Decision tools for bacterial blight resistance gene deployment in rice-based agricultural ecosystems
Article
Text
oai:www.repo.uni-hannover.de:123456789/4642022-12-02T16:11:40Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Kuligowska, Katarzyna
Lütken, Henrik
Christensen, Brian
Skovgaard, Ib
Linde, Marcus
Winkelmann, Traud
Müller, Renate
2016-08-29T08:04:53Z
2016-08-29T08:04:53Z
2015-01-21
Kuligowska, Katarzyna; Luetken, Henrik; Christensen, Brian; Skovgaard, Ib; Linde, Marcus et al.: Evaluation of reproductive barriers contributes to the development of novel interspecific hybrids in the Kalanchoe genus . In: BMC Plant Biology 15 (2015), 15. DOI: http://dx.doi.org/10.1186/s12870-014-0394-0
http://www.repo.uni-hannover.de/handle/123456789/464
http://dx.doi.org/10.15488/441
Background: Interspecific hybridization is a useful tool in ornamental breeding to increase genetic variability and introduce new valuable traits into existing cultivars. The successful formation of interspecific hybrids is frequently limited by the presence of pre- and post-fertilization barriers. In the present study, we investigated the nature of hybridization barriers occurring in crosses between Kalanchoe species and evaluated possibilities of obtaining interspecific hybrids. Results: The qualitative and quantitative analyses of pollen tube growth in situ were performed following intra-and interspecific pollinations. They revealed occurrence of pre-fertilization barriers associated with inhibition of pollen germination on the stigma and abnormal growth of pollen tubes. Unilateral incongruity related to differences in pistil length was also observed. The pollen quality was identified as a strong factor influencing the number of pollen tubes germinating in the stigma. In relation to post-fertilization barriers, endosperm degeneration was a probable barrier hampering production of interspecific hybrids. Moreover, our results demonstrate the relation of genetic distance estimated by AFLP marker analysis of hybridization partners with cross-compatibility of Kalanchoe species. At the same time, differences in ploidy did not influence the success of interspecific crosses. Conclusions: Our study presents the first comprehensive analysis of hybridization barriers occurring within Kalanchoe genus. Reproductive barriers were detected on both, pre- and post-fertilization levels. This new knowledge will contribute to further understanding of reproductive isolation of Kalanchoe species and facilitate breeding of new cultivars. For the first time, interspecific hybrids between K. nyikae as maternal plant and K. blossfeldiana as well as K. blossfeldiana and K. marnieriana were generated.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
aflp markers
chromosome number
cross-compatibility
endosperm development
genetic distance
pollen tube growth
pre-zygotic barrier
post-zygotic barrier
hybridization
pollen
rhododendron
compatibility
crossability
cultivars
crosses
genera
Evaluation of reproductive barriers contributes to the development of novel interspecific hybrids in the Kalanchoe genus
Article
Text
oai:www.repo.uni-hannover.de:123456789/4652022-12-02T16:11:40Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Matschegewski, Claudia
Zetzsche, Holger
Hasan, Yaser
Leibeguth, Lena
Briggs, William
Ordon, Frank
Uptmoor, Ralf
2016-08-29T08:04:53Z
2016-08-29T08:04:53Z
2015-09-10
Matschegewski, Claudia; Zetzsche, Holger; Hasan, Yaser; Leibeguth, Lena; Briggs, William et al.: Genetic variation of temperature-regulated curd induction in cauliflower: elucidation of floral transition by genome-wide association mapping and gene expression analysis. In: Frontiers in Plant Science 6 (2015), 720. DOI: http://dx.doi.org/10.3389/fpls.2015.00720
http://www.repo.uni-hannover.de/handle/123456789/465
http://dx.doi.org/10.15488/442
Cauliflower (Brassica oleracea var. botrytis) is a vernalization-responsive crop. High ambient temperatures delay harvest time. The elucidation of the genetic regulation of floral transition is highly interesting for a precise harvest scheduling and to ensure stable market supply. This study aims at genetic dissection of temperature-dependent curd induction in cauliflower by genome-wide association studies and gene expression analysis. To assess temperature dependent curd induction, two greenhouse trials under distinct temperature regimes were conducted on a diversity panel consisting of 111 cauliflower commercial parent lines, genotyped with 14,385 SNPs. Broad phenotypic variation and high heritability (0.93) were observed for temperature-related curd induction within the cauliflower population. GWA mapping identified a total of 18 QTL localized on chromosomes O1, O2, O3, O4, O6, O8, and O9 for curding time under two distinct temperature regimes. Among those, several QTL are localized within regions of promising candidate flowering genes. Inferring population structure and genetic relatedness among the diversity set assigned three main genetic clusters. Linkage disequilibrium (LD) patterns estimated global LD extent of r(2) = 0.06 and a maximum physical distance of 400 kb for genetic linkage. Transcriptional profiling of flowering genes FLOWERING LOCUS C (BoFLC) and VERNALIZATION 2 (BoVRN2) was performed, showing increased expression levels of BoVRN2 in genotypes with faster curding. However, functional relevance of BoVRN2 and BoFLC2 could not consistently be supported, which probably suggests to act facultative and/or might evidence for BoVRN2/BoFLC-independent mechanisms in temperature regulated floral transition in cauliflower. Genetic insights in temperature-regulated curd induction can underpin genetically informed phenology models and benefit molecular breeding strategies toward the development of thermo-tolerant cultivars.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
genome-wide association study (gwas)
quantitative trait loci (qtl)
transcriptional profiling
single nucleotide polymorphism (snp)
linkage disequilibrium (ld)
vernalization
cauliflower
curd induction
quantitative trait loci
maize inbred lines
flowering-time
brassica-oleracea
linkage disequilibrium
structured populations
sequence polymorphism
qtl analysis
vernalization
arabidopsis
Genetic variation of temperature-regulated curd induction in cauliflower: elucidation of floral transition by genome-wide association mapping and gene expression analysis
Article
Text
oai:www.repo.uni-hannover.de:123456789/4672022-12-02T16:11:40Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Winkelmann, Traud
Ratjens, Svenja
Bartsch, Melanie
Rode, Christina
Niehaus, Karsten
Bednarz, Hanna
2016-08-29T08:04:56Z
2016-08-29T08:04:56Z
2015-08-04
Winkelmann, Traud; Ratjens, Svenja; Bartsch, Melanie; Rode, Christina; Niehaus, Karsten; Bednarz, Hanna: Metabolite profiling of somatic embryos of Cyclamen persicum in comparison to zygotic embryos, endosperm, and testa. In: Frontiers in Plant Science 6 (2015) , 597. DOI: http://dx.doi.org/10.3389/fpls.2015.00597
http://www.repo.uni-hannover.de/handle/123456789/467
http://dx.doi.org/10.15488/444
Somatic embryogenesis has been shown to be an efficient in vitro plant regeneration system for many crops such as the important ornamental plant Cyclamen persicum, for which this regeneration pathway of somatic embryogenesis is of interest for the vegetative propagation of parental lines as well as elite plants. However, somatic embryogenesis is not commercially used in many crops due to several unsolved problems, such as malformations, asynchronous development, deficiencies in maturation and germination of somatic embryos. In contrast, zygotic embryos in seeds develop and germinate without abnormalities in most cases. Instead of time-consuming and labor-intensive experiments involving tests of different in vitro culture conditions and plant growth regulator supplements, we follow a more directed approach. Zygotic embryos served as a reference and were compared to somatic embryos in metabolomic analyses allowing the future optimization of the in vitro system. The aims of this study were to detect differences in the metabolite profiles of torpedo stage somatic and zygotic embryos of C. persicum. Moreover, major metabolites in endosperm and testa were identified and quantified. Two sets of extracts of two to four biological replicates each were analyzed. In total 52 metabolites were identified and quantified in the different tissues. One of the most significant differences between somatic and zygotic embryos was that the proline concentration in the zygotic embryos was about 40 times higher than that found in somatic embryos. Epicatechin, a scavenger for reactive oxygen species, was found in highest abundance in the testa. Sucrose, the most abundant metabolite was detected in significantly higher concentrations in zygotic embryos. Also, a yet unknown trisaccharide, was significantly enriched in zygotic embryos.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
in vitro propagation
proline
ornamental plant
seeds
somatic embryogenesis
seed development
arabinogalactan proteins
tissue-cultures
energy status
embryogenesis
plants
growth
acid
mill
oligosaccharides
Metabolite profiling of somatic embryos of Cyclamen persicum in comparison to zygotic embryos, endosperm, and testa
Article
Text
oai:www.repo.uni-hannover.de:123456789/4682022-12-02T16:14:10Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Zhang, Chao
Koepke, Jürgen
Kirchner, Clemens
Götze, Niko
Behrens, Harald
2016-08-29T08:04:57Z
2016-08-29T08:04:57Z
2014-09-11
Zhang, Chao; Koepke, Jürgen; Kirchner, Clemens; Götze, Niko; Behrens, Harald: Rapid hydrothermal cooling above the axial melt lens at fast-spreading mid-ocean ridge. In: Scientific Reports 4 (2015), 6342. DOI: http://dx.doi.org/10.1038/srep06342
http://www.repo.uni-hannover.de/handle/123456789/468
http://dx.doi.org/10.15488/445
Axial melt lenses sandwiched between the lower oceanic crust and the sheeted dike sequences at fast-spreading mid-ocean ridges are assumed to be the major magma source of oceanic crust accretion. According to the widely discussed "gabbro glacier'' model, the formation of the lower oceanic crust requires efficient cooling of the axial melt lens, leading to partial crystallization and crystal-melt mush subsiding down to lower crust. These processes are believed to be controlled by periodical magma replenishment and hydrothermal circulation above the melt lens. Here we quantify the cooling rate above melt lens using chemical zoning of plagioclase from hornfelsic recrystallized sheeted dikes drilled from the East Pacific at the Integrated Ocean Drilling Program Hole 1256D. Weestimate the cooling rate using a forward modelling approach based on CaAl-NaSi interdiffusion in plagioclase. The results show that cooling from the peak thermal overprint at 1000-10506 degrees C to 6006 degrees C are yielded within about 10-30 years as a result of hydrothermal circulation above melt lens during magma starvation. The estimated rapid hydrothermal cooling explains how the effective heat extraction from melt lens is achieved at fast-spreading mid-ocean ridges.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
east pacific rise
lower oceanic-crust
magma chamber
oman ophiolite
evolution
model
roof
plagioclase
constraints
diffusion
Rapid hydrothermal cooling above the axial melt lens at fast-spreading mid-ocean ridge
Article
Text
oai:www.repo.uni-hannover.de:123456789/4692022-12-02T16:11:40Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Baessler, Bettina
Schaarschmidt, Frank
Stehning, Christian
Schnackenburg, Bernhard
Maintz, David
Bunck, Alexander C.
2016-08-29T08:04:57Z
2016-08-29T08:04:57Z
2015-08-01
Baessler, Bettina; Schaarschmidt, Frank; Stehning, Christian; Schnackenburg, Bernhard; Maintz, David; Bunck, Alexander C.: Cardiac T2-mapping using a fast gradient echo spin echo sequence - first in vitro and in vivo experience. In: Journal of Cardiovascular Magnetic Resonance 17 (2015), 67. DOI: http://dx.doi.org/10.1186/s12968-015-0177-2
http://www.repo.uni-hannover.de/handle/123456789/469
http://dx.doi.org/10.15488/446
Background: The aim of this study was the evaluation of a fast Gradient Spin Echo Technique (GraSE) for cardiac T2-mapping, combining a robust estimation of T2 relaxation times with short acquisition times. The sequence was compared against two previously introduced T2-mapping techniques in a phantom and in vivo. Methods: Phantom experiments were performed at 1.5 T using a commercially available cylindrical gel phantom. Three different T2-mapping techniques were compared: a Multi Echo Spin Echo (MESE; serving as a reference), a T2-prepared balanced Steady State Free Precession (T2prep) and a Gradient Spin Echo sequence. For the subsequent in vivo study, 12 healthy volunteers were examined on a clinical 1.5 T scanner. The three T2-mapping sequences were performed at three short-axis slices. Global myocardial T2 relaxation times were calculated and statistical analysis was performed. For assessment of pixel-by-pixel homogeneity, the number of segments showing an inhomogeneous T2 value distribution, as defined by a pixel SD exceeding 20 % of the corresponding observed T2 time, was counted. Results: Phantom experiments showed a greater difference of measured T2 values between T2prep and MESE than between GraSE and MESE, especially for species with low T1 values. Both, GraSE and T2prep resulted in an overestimation of T2 times compared to MESE. In vivo, significant differences between mean T2 times were observed. In general, T2prep resulted in lowest (52.4 +/- 2.8 ms) and GraSE in highest T2 estimates (59.3 +/- 4.0 ms). Analysis of pixel-by-pixel homogeneity revealed the least number of segments with inhomogeneous T2 distribution for GraSE-derived T2 maps. Conclusions: The GraSE sequence is a fast and robust sequence, combining advantages of both MESE and T2prep techniques, which promises to enable improved clinical applicability of T2-mapping in the future. Our study revealed significant differences of derived mean T2 values when applying different sequence designs. Therefore, a systematic comparison of different cardiac T2-mapping sequences and the establishment of dedicated reference values should be the goal of future studies.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
cardiovascular magnetic resonance
t2-mapping
parametric imaging
cardiovascular magnetic-resonance
acute myocardial-infarction
t2
edema
heart
risk
area
Cardiac T2-mapping using a fast gradient echo spin echo sequence - first in vitro and in vivo experience
Article
Text
oai:www.repo.uni-hannover.de:123456789/4702022-12-02T15:19:58Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Chen, Tsu-Wei
Nguyen, Thi My Nguyet
Kahlen, Katrin
Stuetzel, Hartmut
2016-08-29T08:04:57Z
2016-08-29T08:04:57Z
2014-12
Chen, Tsu-Wei; Thi My Nguyet Nguyen; Kahlen, Katrin; Stuetzel, Hartmut: Quantification of the effects of architectural traits on dry mass production and light interception of tomato canopy under different temperature regimes using a dynamic functional-structural plant model. In: Journal of Experimental Botany 65 (2014), S. 6399-6410. DOI: http://dx.doi.org/10.1093/jxb/eru356
http://www.repo.uni-hannover.de/handle/123456789/470
http://dx.doi.org/10.15488/447
There is increasing interest in evaluating the environmental effects on crop architectural traits and yield improvement. However, crop models describing the dynamic changes in canopy structure with environmental conditions and the complex interactions between canopy structure, light interception, and dry mass production are only gradually emerging. Using tomato (Solanum lycopersicum L.) as a model crop, a dynamic functional-structural plant model (FSPM) was constructed, parameterized, and evaluated to analyse the effects of temperature on architectural traits, which strongly influence canopy light interception and shoot dry mass. The FSPM predicted the organ growth, organ size, and shoot dry mass over time with high accuracy (>85%). Analyses of this FSPM showed that, in comparison with the reference canopy, shoot dry mass may be affected by leaf angle by as much as 20%, leaf curvature by up to 7%, the leaf length: width ratio by up to 5%, internode length by up to 9%, and curvature ratios and leaf arrangement by up to 6%. Tomato canopies at low temperature had higher canopy density and were more clumped due to higher leaf area and shorter internodes. Interestingly, dry mass production and light interception of the clumped canopy were more sensitive to changes in architectural traits. The complex interactions between architectural traits, canopy light interception, dry mass production, and environmental conditions can be studied by the dynamic FSPM, which may serve as a tool for designing a canopy structure which is 'ideal' in a given environment.
eng
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
canopy photosynthesis
dynamic model
functional-structural plant model
light interception
plant architecture
temperature
tomato
cucumber canopies
growth-models
photosynthesis
simulation
efficiency
environment
absorption
mechanisms
tolerance
expansion
Quantification of the effects of architectural traits on dry mass production and light interception of tomato canopy under different temperature regimes using a dynamic functional-structural plant model
Article
Text
oai:www.repo.uni-hannover.de:123456789/4722022-12-02T16:11:42Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Effendi, Yunus
Jones, Alan M.
Scherer, Günther F.E.
2016-08-29T13:44:50Z
2016-08-29T13:44:50Z
2013-11
Effendi, Yunus; Jones, Alan M.; Scherer, Guenther F. E.: AUXIN-BINDING-PROTEIN1 (ABP1) in phytochrome-B-controlled responses. In: Journal of Experimental Botany 64 (2013), Nr. 16, S. 5065-5074. DOI: http://dx.doi.org/10.1093/jxb/ert294
http://www.repo.uni-hannover.de/handle/123456789/472
http://dx.doi.org/10.15488/449
The auxin receptor ABP1 directly regulates plasma membrane activities including the number of PIN-formed (PIN) proteins and auxin efflux transport. Red light (R) mediated by phytochromes regulates the steady-state level of ABP1 and auxin-inducible growth capacity in etiolated tissues but, until now, there has been no genetic proof that ABP1 and phytochrome regulation of elongation share a common mechanism for organ elongation. In far red (FR)-enriched light, hypocotyl lengths were larger in the abp1-5 and abp1/ABP1 mutants, but not in tir1-1, a null mutant of the TRANSPORT-INHIBITOR-RESPONSE1 auxin receptor. The polar auxin transport inhibitor naphthylphthalamic acid (NPA) decreased elongation in the low R: FR light-enriched white light (WL) condition more strongly than in the high red: FR light-enriched condition WL suggesting that auxin transport is an important condition for FR-induced elongation. The addition of NPA to hypocotyls grown in R-and FR-enriched light inhibited hypocotyl gravitropism to a greater extent in both abp1 mutants and in phyB-9 and phyA-211 than the wild-type hypocotyl, arguing for decreased phytochrome action in conjunction with auxin transport in abp1 mutants. Transcription of FR-enriched light-induced genes, including several genes regulated by auxin and shade, was reduced 3-5-fold in abp1-5 compared with Col and was very low in abp1/ABP1. In the phyB-9 mutant the expression of these reporter genes was 5-15-fold lower than in Col. In tir1-1 and the phyA-211 mutants shade-induced gene expression was greatly attenuated. Thus, ABP1 directly or indirectly participates in auxin and light signalling.
eng
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
auxin-binding protein1 (abp1)
early auxin-regulated genes
elongation
gravitropism
phototropism
phytochrome
shade avoidance
auxin-binding protein-1
shade-avoidance-response
light-regulated growth
arabidopsis-thaliana
hypocotyl elongation
signal-transduction
cucumis seedlings
indoleacetic-acid
plant development
genomic analysis
AUXIN-BINDING-PROTEIN1 (ABP1) in phytochrome-B-controlled responses
Article
Text
oai:www.repo.uni-hannover.de:123456789/4762022-12-02T16:10:14Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Yang, Zhong-Bao
Eticha, Dejene
Fuehrs, Hendrik
Heintz, Dimitri
Ayoub, Daniel
Van Dorsselaer, Alain
Schlingmann, Barbara
Rao, Idupulapati Madhusudana
Braun, Hans-Peter
Horst, Walter Johannes
2016-08-29T13:44:51Z
2016-08-29T13:44:51Z
2013-12
Yang, Zhong-Bao; Eticha, Dejene; Fuehrs, Hendrik; Heintz, Dimitri; Ayoub, Daniel et al.: Proteomic and phosphoproteomic analysis of polyethylene glycol-induced osmotic stress in root tips of common bean (Phaseolus vulgaris L.). In: Journal of Experimental Botany 64 (2013), Nr. 18, S. 5569-5586. DOI: http://dx.doi.org/10.1093/jxb/ert328
http://www.repo.uni-hannover.de/handle/123456789/476
http://dx.doi.org/10.15488/453
Previous studies have shown that polyethylene glycol (PEG)-induced osmotic stress (OS) reduces cell-wall (CW) porosity and limits aluminium (Al) uptake by root tips of common bean (Phaseolus vulgaris L.). A subsequent transcriptomic study suggested that genes related to CW processes are involved in adjustment to OS. In this study, a proteomic and phosphoproteomic approach was applied to identify OS-induced protein regulation to further improve our understanding of how OS affects Al accumulation. Analysis of total soluble proteins in root tips indicated that, in total, 22 proteins were differentially regulated by OS; these proteins were functionally categorized. Seventy-seven per- cent of the total expressed proteins were involved in metabolic pathways, particularly of carbohydrate and amino acid metabolism. An analysis of the apoplastic proteome revealed that OS reduced the level of five proteins and increased that of seven proteins. Investigation of the total soluble phosphoproteome suggested that dehydrin responded to OS with an enhanced phosphorylation state without a change in abundance. A cellular immunolocalization analysis indicated that dehydrin was localized mainly in the CW. This suggests that dehydrin may play a major protective role in the OS-induced physical breakdown of the CW structure and thus maintenance of the reversibility of CW extensibility during recovery from OS. The proteomic and phosphoproteomic analyses provided novel insights into the complex mechanisms of OS-induced reduction of Al accumulation in the root tips of common bean and highlight a key role for modification of CW structure.
eng
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
apoplast
cell wall
common bean
dehydrin
phosphoproteomics
proteomics
root tips
low water potentials
cell-wall proteome
maize primary root
nadp(+)-dependent isocitrate dehydrogenase
s-adenosylmethionine synthetase
ionically bound proteins
salt-responsive proteins
dehydrin-like proteins
arabidopsis-thaliana
elongation zone
Proteomic and phosphoproteomic analysis of polyethylene glycol-induced osmotic stress in root tips of common bean (Phaseolus vulgaris L.)
Article
Text
oai:www.repo.uni-hannover.de:123456789/4772022-12-02T16:10:16Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Scherer, Günther F.E.
Labusch, Corinna
Effendi, Yunus
2016-08-29T13:44:51Z
2016-08-29T13:44:51Z
2012
Scherer, Guenther F. E.; Labusch, Corinna; Effendi, Yunus: Phospholipases and the network of auxin signal transduction with ABP1 and TIR1 as two receptors: a comprehensive and provocative model. In: Frontiers in Plant Science 3 (2012), 56. DOI: http://dx.doi.org/10.3389/fpls.2012.00056
http://www.repo.uni-hannover.de/handle/123456789/477
http://dx.doi.org/10.15488/454
Three types of phospholipases, phospholipase D, secreted phospholipase A2, and patatin-related phospholipase A (pPLA) have functions in auxin signal transduction. Potential linkage to auxin receptors ABP1 or TIR1, their rapid activation or post-translational activation mechanisms, and downstream functions regulated by these phospholipases is reviewed and discussed. Only for pPLA all aspects are known at least to some detail. Evidence is gathered that all these signal reactions are located in the cytosol and seem to merge on regulation of PIN-catalyzed auxin efflux transport proteins. As a consequence, auxin concentration in the nucleus is also affected and this regulates the E3 activity of this auxin receptor. We showed that ABP1, PIN2, and pPLA, all outside the nucleus, have an impact on regulation of auxin-induced genes within 30 min. We propose that regulation of PIN protein activities and of auxin efflux transport are the means to coordinate ABP1 and TIR1 activity and that no physical contact between components of the ABP1-triggered cytosolic pathways and TIR1-triggered nuclear pathways of signaling is necessary to perform this.
eng
https://creativecommons.org/licenses/by-nc/3.0/
CC BY-NC 3.0 Unported
auxin-binding-protein1
auxin signal transduction
patatin-related phospholipase a
phospholipase d
pin-formed protein
secreted phospholipase a,,transport-inhibitor-resistant1
Phospholipases and the network of auxin signal transduction with ABP1 and TIR1 as two receptors: a comprehensive and provocative model
Article
Text
oai:www.repo.uni-hannover.de:123456789/4792022-12-02T16:14:10Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Yang, Zhong-Bao
Eticha, Dejene
Albacete, Alfonso
Madhusudana Rao, Idupulapati
Roitsch, Thomas
Horst, Walter Johannes
2016-08-29T13:44:52Z
2016-08-29T13:44:52Z
2012-05
Yang, Zhong-Bao; Eticha, Dejene; Albacete, Alfonso; Madhusudana Rao, Idupulapati; Roitsch, Thomas; Horst, Walter Johannes: Physiological and molecular analysis of the interaction between aluminium toxicity and drought stress in common bean (Phaseolus vulgaris). In: Journal of Experimental Botany 63 (2012), S. 3109-3125. DOI: http://dx.doi.org/10.1093/jxb/ers038
http://www.repo.uni-hannover.de/handle/123456789/479
http://dx.doi.org/10.15488/456
Aluminium (Al) toxicity and drought are two major factors limiting common bean (Phaseolus vulgaris) production in the tropics. Short-term effects of Al toxicity and drought stress on root growth in acid, Al-toxic soil were studied, with special emphasis on Al-drought interaction in the root apex. Root elongation was inhibited by both Al and drought. Combined stresses resulted in a more severe inhibition of root elongation than either stress alone. This result was different from the alleviation of Al toxicity by osmotic stress (-0.60 MPa polyethylene glycol) in hydroponics. However, drought reduced the impact of Al on the root tip, as indicated by the reduction of Al-induced callose formation and MATE expression. Combined Al and drought stress enhanced up-regulation of ACCO expression and synthesis of zeatin riboside, reduced drought-enhanced abscisic acid (ABA) concentration, and expression of NCED involved in ABA biosynthesis and the transcription factors bZIP and MYB, thus affecting the regulation of ABA-dependent genes (SUS, PvLEA18, KS-DHN, and LTP) in root tips. The results provide circumstantial evidence that in soil, drought alleviates Al injury, but Al renders the root apex more drought-sensitive, particularly by impacting the gene regulatory network involved in ABA signal transduction and cross-talk with other phytohormones necessary for maintaining root growth under drought.
eng
https://creativecommons.org/licenses/by-nc/3.0/
CC BY-NC 3.0 Unported
abscisic acid
aluminum
callose
common bean
cytokinin
drought
gene expression
root growth
low water potentials
abscisic-acid accumulation
root-growth
shoot growth
arabidopsis-thaliana
gene-expression
9-cis-epoxycarotenoid dioxygenase
ethylene biosynthesis
callose formation
endogenous aba
Physiological and molecular analysis of the interaction between aluminium toxicity and drought stress in common bean (Phaseolus vulgaris)
Article
Text
oai:www.repo.uni-hannover.de:123456789/4822022-12-02T16:10:16Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Schippers, Axel
Kock, Dagmar
Hoeft, Carmen
Koeweker, Gerrit
Siegert, Michael
2016-08-29T13:44:52Z
2016-08-29T13:44:52Z
2012
Schippers, Axel; Kock, Dagmar; Hoeft, Carmen; Koeweker, Gerrit; Siegert, Michael: Quantification of microbial communities in subsurface marine sediments of the Black Sea and off Namibia. In: Frontiers in Microbiology 3 (2012), 16. DOI: http://dx.doi.org/10.3389/fmicb.2012.00016
http://www.repo.uni-hannover.de/handle/123456789/482
http://dx.doi.org/10.15488/459
Organic-rich subsurface marine sediments were taken by gravity coring up to a depth of 10 m below seafloor at six stations from the anoxic Black Sea and the Benguela upwelling system off Namibia during the research cruises Meteor 72-5 and 76-1, respectively. The quantitative microbial community composition at various sediment depths was analyzed using total cell counting, catalyzed reporter deposition fluorescence in situ hybridization (CARD FISH) and quantitative real-time PCR (Q-PCR). Total cell counts decreased with depths from 10(9) to 10(10) cells/mL at the sediment surface to 10(7)-10(9) cells/mL below one meter depth. Based on CARD FISH and Q-PCR analyses overall similar proportions of Bacteria and Archaea were found. The down-core distribution of prokaryotic and eukaryotic small subunit ribosomal RNA genes (16S and 18S rRNA) as well as functional genes involved in different biogeochemical processes was quantified using Q-PCR. Crenarchaeota and the bacterial candidate division JS-1 as well as the classes Anaerolineae and Caldilineae of the phylum Chloroflexi were highly abundant. Less abundant but detectable in most of the samples were Eukarya as well as the metal and sulfate-reducing Geobacteraceae (only in the Benguela upwelling influenced sediments). The functional genes cbbL, encoding for the large subunit of RuBisCO, the genes dsrA and aprA, indicative of sulfate-reducers as well as the mcrA gene of methanogens were detected in the Benguela upwelling and Black Sea sediments. Overall, the high organic carbon content of the sediments goes along with high cell counts and high gene copy numbers, as well as an equal abundance of Bacteria and Archaea.
eng
https://creativecommons.org/licenses/by-nc/3.0/
CC BY-NC 3.0 Unported
benguela upwelling
black sea
card-fish
deep biosphere
real-time pcr
sediments
subsurface
Quantification of microbial communities in subsurface marine sediments of the Black Sea and off Namibia
Article
Text
oai:www.repo.uni-hannover.de:123456789/4832022-12-02T16:10:16Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Siegert, Michael
Krueger, Martin
Teichert, Barbara
Wiedicke, Michael
Schippers, Axel
2016-08-30T10:20:22Z
2016-08-30T10:20:22Z
2011
Siegert, Michael; Krueger, Martin; Teichert, Barbara; Wiedicke, Michael; Schippers, Axel: Anaerobic oxidation of methane at a marine methane seep in a forearc sediment basin off Sumatra, Indian Ocean. In: Frontiers in Microbiology 2 (2011), 249. DOI: http://dx.doi.org/10.3389/fmicb.2011.00249
http://www.repo.uni-hannover.de/handle/123456789/483
http://dx.doi.org/10.15488/460
A cold methane seep was discovered in a forearc sediment basin off the island Sumatra, exhibiting a methane-seep adapted microbial community. A defined seep center of activity, like in mud volcanoes, was not discovered. The seep area was rather characterized by a patchy distribution of active spots. The relevance of anaerobic oxidation of methane (AOM) was reflected by C-13-depleted isotopic signatures of dissolved inorganic carbon. The anaerobic conversion of methane to CO2 was confirmed in a C-13-labeling experiment. Methane fueled a vital microbial community with cell numbers of up to 4 x 10(9) cells cm(-3) sediment. The microbial community was analyzed by total cell counting, catalyzed reporter deposition fluorescence in situ hybridization (CARD FISH), quantitative real-time PCR (qPCR), and denaturing gradient gel electrophoresis (DGGE). CARD FISH cell counts and qPCR measurements showed the presence of Bacteria and Archaea, but only small numbers of Eukarya. The archaeal community comprised largely members of ANME-1 and ANME-2. Furthermore, members of the Crenarchaeota were frequently detected in the DGGE analysis. Three major bacterial phylogenetic groups (delta-Proteobacteria, candidate division OP9, and Anaerolineaceae) were abundant across the study area. Several of these sequences were closely related to the genus Desulfococcus of the family Desulfobacteraceae, which is in good agreement with previously described AOM sites. In conclusion, the majority of the microbial community at the seep consisted of AOM-related microorganisms, while the relevance of higher hydrocarbons as microbial substrates was negligible.
eng
https://creativecommons.org/licenses/by-nc/3.0/
CC BY-NC 3.0 Unported
dgge
quantitative pcr
card-fish
methane seep
stable isotopes
aom
hydrocarbon-dependent methanogenesis
Anaerobic oxidation of methane at a marine methane seep in a forearc sediment basin off Sumatra, Indian Ocean
Article
Text
oai:www.repo.uni-hannover.de:123456789/4852022-12-02T15:19:58Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Lavrentieva, Antonina
Majore, Ingrida
Kasper, Cornelia
Hass, Ralf
2016-08-30T10:20:24Z
2016-08-30T10:20:24Z
2010-06-16
Lavrentieva, Antonina; Majore, Ingrida; Kasper, Cornelia; Hass, Ralf: Effects of hypoxic culture conditions on umbilical cord-derived human mesenchymal stem cells. In: Cell Communication and Signaling 8 (2010) , 18. DOI: http://dx.doi.org/10.1186/1478-811X-8-18
http://www.repo.uni-hannover.de/handle/123456789/485
http://dx.doi.org/10.15488/462
Following cultivation of distinct mesenchymal stem cell (MSC) populations derived from human umbilical cord under hypoxic conditions (between 1.5% to 5% oxygen (O-2)) revealed a 2- to 3-fold reduced oxygen consumption rate as compared to the same cultures at normoxic oxygen levels (21% O-2). A simultaneous measurement of dissolved oxygen within the culture media from 4 different MSC donors ranged from 15 mu mol/L at 1.5% O-2 to 196 mu mol/L at normoxic 21% O-2. The proliferative capacity of the different hypoxic MSC populations was elevated as compared to the normoxic culture. This effect was paralleled by a significantly reduced cell damage or cell death under hypoxic conditions as evaluated by the cellular release of LDH whereby the measurement of caspase 3/7 activity revealed little if any differences in apoptotic cell death between the various cultures. The MSC culture under hypoxic conditions was associated with the induction of hypoxia-inducing factor-alpha (HIF-1 alpha) and an elevated expression of energy metabolism-associated genes including GLUT-1, LDH and PDK1. Concomitantly, a significantly enhanced glucose consumption and a corresponding lactate production could be observed in the hypoxic MSC cultures suggesting an altered metabolism of these human stem cells within the hypoxic environment.
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
adipose-tissue
bone-marrow
oxygen concentration
reactive oxygen
metabolism
growth
consumption
responses
damage
dna
Effects of hypoxic culture conditions on umbilical cord-derived human mesenchymal stem cells
Article
Text
oai:www.repo.uni-hannover.de:123456789/4862022-12-02T16:10:15Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Yang, Zhong-Bao
Eticha, Dejene
Rao, Idupulapati Madhusudana
Horst, Walter Johannes
2016-08-30T10:20:24Z
2016-08-30T10:20:24Z
2010-07
Yang, Zhong-Bao; Eticha, Dejene; Rao, Idupulapati Madhusudana; Horst, Walter Johannes: Alteration of cell-wall porosity is involved in osmotic stress-induced enhancement of aluminium resistance in common bean (Phaseolus vulgaris L.). In: Journal of Experimental Botany 61 (2010), Nr. 12 , S. 3245-3258. DOI: http://dx.doi.org/10.1093/jxb/erq146
http://www.repo.uni-hannover.de/handle/123456789/486
http://dx.doi.org/10.15488/463
Aluminium (Al) toxicity and drought are the two major abiotic stress factors limiting common bean production in the tropics. Using hydroponics, the short-term effects of combined Al toxicity and drought stress on root growth and Al uptake into the root apex were investigated. In the presence of Al stress, PEG 6000 (polyethylene glycol)-induced osmotic (drought) stress led to the amelioration of Al-induced inhibition of root elongation in the Al-sensitive genotype VAX 1. PEG 6000 (>> PEG 1000) treatment greatly decreased Al accumulation in the 1 cm root apices even when the roots were physically separated from the PEG solution using dialysis membrane tubes. Upon removal of PEG from the treatment solution, the root tips recovered from osmotic stress and the Al accumulation capacity was quickly restored. The PEG-induced reduction of Al accumulation was not due to a lower phytotoxic Al concentration in the treatment solution, reduced negativity of the root apoplast, or to enhanced citrate exudation. Also cell-wall (CW) material isolated from PEG-treated roots showed a low Al-binding capacity which, however, was restored after destroying the physical structure of the CW. The comparison of the Al(3+), La(3+), Sr(2+), and Rb(+) binding capacity of the intact root tips and the isolated CW revealed the specificity of the PEG 6000 effect for Al. This could be due to the higher hydrated ionic radius of Al(3+) compared with other cations (Al(3+) >> La(3+) > Sr(2+) > Rb(+)). In conclusion, the results provide circumstantial evidence that the osmotic stress-inhibited Al accumulation in root apices and thus reduced Al-induced inhibition of root elongation in the Al-sensitive genotype VAX 1 is related to the alteration of CW porosity resulting from PEG 6000-induced dehydration of the root apoplast.
eng
https://creativecommons.org/licenses/by-nc/2.5/
CC BY-NC 2.5 Unported
aluminium
apoplast
drought stress
intercellular space
organic acids
polyethylene glycol
root elongation
low water potentials
triticum-aestivum l
apical root-zone
drought tolerance
abscisic-acid
pore-size
polyethylene glycol-6000
pectin methylesterase
nutrient solution
soybean roots
Alteration of cell-wall porosity is involved in osmotic stress-induced enhancement of aluminium resistance in common bean (Phaseolus vulgaris L.)
Article
Text
oai:www.repo.uni-hannover.de:123456789/4872022-12-02T16:10:16Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Blazejak, Anna
Schippers, Axel
2016-08-30T10:20:24Z
2016-08-30T10:20:24Z
2011
Blazejak, Anna; Schippers, Axel: Real-time PCR quantification and diversity analysis of the functional genes aprA and dsrA of sulfate-reducing prokaryotes in marine sediments of the Peru continental margin and the Black Sea. In: Frontiers in Microbiology 2 (2011), 253. DOI: http://dx.doi.org/10.3389/fmicb.2011.00253
http://www.repo.uni-hannover.de/handle/123456789/487
http://dx.doi.org/10.15488/464
Sulfate-reducing prokaryotes (SRP) are ubiquitous and quantitatively important members in many ecosystems, especially in marine sediments. However their abundance and diversity in subsurface marine sediments is poorly understood. In this study, the abundance and diversity of the functional genes for the enzymes adenosine 5'-phosphosulfate reductase (aprA) and dissimilatory sulfite reductase (dsrA) of SRP in marine sediments of the Peru continental margin and the Black Sea were analyzed, including samples from the deep biosphere (ODP site 1227). For aprA quantification a Q-PCR assay was designed and evaluated. Depth profiles of the aprA and dsrA copy numbers were almost equal for all sites. Gene copy numbers decreased concomitantly with depth from around 10(8)/g sediment close to the sediment surface to less than 10(5)/g sediment at 5 mbsf. The 16S rRNA gene copy numbers of total bacteria were much higher than those of the functional genes at all sediment depths and used to calculate the proportion of SRP to the total Bacteria. The aprA and dsrA copy numbers comprised in average 0.5-1% of the 16S rRNA gene copy numbers of total bacteria in the sediments up to a depth of ca. 40 mbsf. In the zone without detectable sulfate in the pore water from about 40-121 mbsf (Peru margin ODP site 1227), only dsrA (but not aprA) was detected with copy numbers of less than 10(4)/g sediment, comprising ca. 14% of the 16S rRNA gene copy numbers of total bacteria. In this zone, sulfate might be provided for SRP by anaerobic sulfide oxidation. Clone libraries of aprA showed that all isolated sequences originate from SRP showing a close relationship to aprA of characterized species or form a new cluster with only distant relation to aprA of isolated SRP. For dsrA a high diversity was detected, even up to 121 m sediment depth in the deep biosphere.
eng
https://creativecommons.org/licenses/by-nc/3.0/
CC BY-NC 3.0 Unported
deep biosphere
real-time pcr
subsurface
odp
sulfate-reducing prokaryotes
apra
dsra
Real-time PCR quantification and diversity analysis of the functional genes aprA and dsrA of sulfate-reducing prokaryotes in marine sediments of the Peru continental margin and the Black Sea
Article
Text
oai:www.repo.uni-hannover.de:123456789/4882022-12-02T16:10:15Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Nehmann, Julia B.
Kajari-Schröder, Sarah
Bahnemann, Detlef W.
2016-08-30T10:20:24Z
2016-08-30T10:20:24Z
2012-07-17
Nehmann, Julia B.; Kajari-Schroeder, Sarah; Bahnemann, Detlef W.: Analysis methods for meso- and macroporous silicon etching baths. In: Nanoscale Research Letters 7 (2012), 398. DOI: http://dx.doi.org/10.1186/1556-276X-7-398
http://www.repo.uni-hannover.de/handle/123456789/488
http://dx.doi.org/10.15488/465
Analysis methods for electrochemical etching baths consisting of various concentrations of hydrofluoric acid (HF) and an additional organic surface wetting agent are presented. These electrolytes are used for the formation of meso- and macroporous silicon. Monitoring the etching bath composition requires at least one method each for the determination of the HF concentration and the organic content of the bath. However, it is a precondition that the analysis equipment withstands the aggressive HF. Titration and a fluoride ion-selective electrode are used for the determination of the HF and a cuvette test method for the analysis of the organic content, respectively. The most suitable analysis method is identified depending on the components in the electrolyte with the focus on capability of resistance against the aggressive HF.
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
chemical analysis
silicon etching
bath composition
organic content
hydrofluoric acid
titrimetric determination
fluoride
Analysis methods for meso- and macroporous silicon etching baths
Article
Text
oai:www.repo.uni-hannover.de:123456789/4922022-12-02T16:14:10Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Kai, Hiroomi
Hirashima, Keita
Matsuda, Osamu
Ikegami, Hidetoshi
Winkelmann, Traud
Nakahara, Takao
Iba, Koh
2016-08-30T10:20:26Z
2016-08-30T10:20:26Z
2012-06
Kai, Hiroomi; Hirashima, Keita; Matsuda, Osamu; Ikegami, Hidetoshi; Winkelmann, Traud et al.: Thermotolerant cyclamen with reduced acrolein and methyl vinyl ketone. In: Journal of Experimental Botany 63 (2012), Nr. 11, S. 4143-4150. DOI: http://dx.doi.org/10.1093/jxb/ers110
http://www.repo.uni-hannover.de/handle/123456789/492
http://dx.doi.org/10.15488/469
Reduced levels of trienoic fatty acids (TAs) in chloroplast membranes induce thermotolerance in several plant species, but the underlying mechanisms remain unclear. TA peroxidation in plant cell membranes generates cytotoxic, TA-derived compounds containing alpha,beta-unsaturated carbonyl groups. The relationship between low TA levels and the amounts of cytotoxic TA-derived compounds was examined using thermotolerant transgenic cyclamen (Cyclamen persicum Mill.) with low TA contents. Changes in the levels of the cytotoxic TA-derived acrolein (ACR), methyl vinyl ketone (MVK), (E)-2-hexenal, 4-hydroxy-2-nonenal, and malondialdehyde were analysed in the leaf tissues of wild-type (WT) and thermotolerant transgenic cyclamen under heat stress. Levels of ACR and MVK in the WT increased in parallel with the occurrence of heat-induced tissue damage, whereas no such changes were observed in the thermotolerant transgenic lines. Furthermore, exogenous ACR and MVK infiltrated into leaves to concentrations similar to those observed in heat-stressed WT leaves caused similar disease symptoms. These results suggest that thermotolerance in transgenic cyclamen depends on reduced production rates of ACR and MVK under heat stress, due to the low level of TAs in these plants.
eng
https://creativecommons.org/licenses/by-nc/3.0/
CC BY-NC 3.0 Unported
acrolein
cyclamen persicum mill
methyl vinyl ketone
thermotolerance
trienoic fatty acids
chloroplast omega-3-fatty-acid desaturase
fatty-acid desaturation
lipid-peroxidation
transgenic tobacco
liquid-chromatography
arabidopsis-thaliana
botrytis-cinerea
high-temperature
plant tolerance
stress
Thermotolerant cyclamen with reduced acrolein and methyl vinyl ketone
Article
Text
oai:www.repo.uni-hannover.de:123456789/4952022-12-02T16:14:10Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Henckel, Kolja
Küster, Helge
Stutz, Leonhard J.
Goesmann, Alexander
2016-08-31T09:19:32Z
2016-08-31T09:19:32Z
2010
Henckel, Kolja; Küster, Helge; Stutz, Leonhard J.; Goesmann, Alexander: MediPlEx - a tool to combine in silico & experimental gene expression profiles of the model legume Medicago truncatula. In: BMC Research Notes 3 (2010), 262. DOI: http://dx.doi.org/10.1186/1756-0500-3-262
http://www.repo.uni-hannover.de/handle/123456789/495
http://dx.doi.org/10.15488/471
Background: Expressed Sequence Tags (ESTs) are in general used to gain a first insight into gene activities from a species of interest. Subsequently, and typically based on a combination of EST and genome sequences, microarray-based expression analyses are performed for a variety of conditions. In some cases, a multitude of EST and microarray experiments are conducted for one species, covering different tissues, cell states, and cell types. Under these circumstances, the challenge arises to combine results derived from the different expression profiling strategies, with the goal to uncover novel information on the basis of the integrated datasets. Findings: Using our new analysis tool, MediPlEx (MEDIcago truncatula multiPLe EXpression analysis), expression data from EST experiments, oligonucleotide microarrays and Affymetrix GeneChips® can be combined and analyzed, leading to a novel approach to integrated transcriptome analysis. We have validated our tool via the identification of a set of well-characterized AM-specific and AM-induced marker genes, identified by MediPlEx on the basis of in silico and experimental gene expression profiles from roots colonized with AM fungi. Conclusions: MediPlEx offers an integrated analysis pipeline for different sets of expression data generated for the model legume Medicago truncatula. As expected, in silico and experimental gene expression data that cover the same biological condition correlate well. The collection of differentially expressed genes identified via MediPlEx provides a starting point for functional studies in plant mutants.
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
Medicago truncatula
legume biology
Expressed Sequence Tags
MediPlEx - a tool to combine in silico & experimental gene expression profiles of the model legume Medicago truncatula
Medizinische und gesundheitsökonomische Bewertung der Radiochirurgie zur Behandlung von Hirnmetastasen
Article
Text
oai:www.repo.uni-hannover.de:123456789/4962022-12-02T16:10:15Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Mrosk, Cornelia
Forner, Susanne
Hause, Gerd
Kuester, Helge
Kopka, Joachim
Hause, Bettina
2016-08-31T09:19:32Z
2016-08-31T09:19:32Z
2009-09
Mrosk, Cornelia; Forner, Susanne; Hause, Gerd; Kuester, Helge; Kopka, Joachim; Hause, Bettina: Composite Medicago truncatula plants harbouring Agrobacterium rhizogenes-transformed roots reveal normal mycorrhization by Glomus intraradices. In: Journal of Experimental Botany 60 (2009), Nr. 13, S. 3797-3807. DOI: http://dx.doi.org/10.1093/jxb/erp220
http://www.repo.uni-hannover.de/handle/123456789/496
http://dx.doi.org/10.15488/472
Composite plants consisting of a wild-type shoot and a transgenic root are frequently used for functional genomics in legume research. Although transformation of roots using Agrobacterium rhizogenes leads to morphologically normal roots, the question arises as to whether such roots interact with arbuscular mycorrhizal (AM) fungi in the same way as wild-type roots. To address this question, roots transformed with a vector containing the fluorescence marker DsRed were used to analyse AM in terms of mycorrhization rate, morphology of fungal and plant subcellular structures, as well as transcript and secondary metabolite accumulations. Mycorrhization rate, appearance, and developmental stages of arbuscules were identical in both types of roots. Using Mt16kOLI1Plus microarrays, transcript profiling of mycorrhizal roots showed that 222 and 73 genes exhibited at least a 2-fold induction and less than half of the expression, respectively, most of them described as AM regulated in the same direction in wild-type roots. To verify this, typical AM marker genes were analysed by quantitative reverse transcription-PCR and revealed equal transcript accumulation in transgenic and wild-type roots. Regarding secondary metabolites, several isoflavonoids and apocarotenoids, all known to accumulate in mycorrhizal wild-type roots, have been found to be up-regulated in mycorrhizal in comparison with non-mycorrhizal transgenic roots. This set of data revealed a substantial similarity in mycorrhization of transgenic and wild-type roots of Medicago truncatula, validating the use of composite plants for studying AM-related effects.
eng
http://creativecommons.org/licenses/by-nc/2.0/uk/
CC BY-NC 2.0 UK
agrobacterium rhizogenes
arbuscular mycorrhiza
composite plants
glomus intraradices
isoflavanoids
transcript profiling
transmission electron microscopy
time rt-pcr
arbuscular-mycorrhizal
phosphate transporter
rna interference
provide insights
lotus-japonicus
gene-expression
hairy roots
nod factor
symbiosis
Composite Medicago truncatula plants harbouring Agrobacterium rhizogenes-transformed roots reveal normal mycorrhization by Glomus intraradices
Article
Text
oai:www.repo.uni-hannover.de:123456789/4972022-12-02T16:14:10Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Wild, Birgit
Gentsch, Norman
Capek, Petr
Diakova, Katerina
Alves, Ricardo J. Eloy
Barta, Jiri
Gittel, Antje
Hugelius, Gustaf
Knoltsch, Anna
Kuhry, Peter
Lashchinskiy, Nikolay
Mikutta, Robert
Palmtag, Juri
Schleper, Christa
Schnecker, Jörg
Shibistova, Olga
Takriti, Mounir
Torsvik, Vigdis L.
Urich, Tim
Watzka, Margarete
Santruckova, Hana
Guggenberger, Georg
Richter, Andreas
2016-08-31T09:19:32Z
2016-08-31T09:19:32Z
2016
Wild, Birgit; Gentsch, Norman; Capek, Petr; Diakova, Katerina; Alves, Ricardo J. Eloy et al.: Plant-derived compounds stimulate the decomposition of organic matter in arctic permafrost soils. In: Scientific Reports 6 (2016), 25607. DOI: http://dx.doi.org/10.1038/srep25607
http://www.repo.uni-hannover.de/handle/123456789/497
http://dx.doi.org/10.15488/473
Arctic ecosystems are warming rapidly, which is expected to promote soil organic matter (SOM) decomposition. In addition to the direct warming effect, decomposition can also be indirectly stimulated via increased plant productivity and plant-soil C allocation, and this so called "priming effect" might significantly alter the ecosystem C balance. In this study, we provide first mechanistic insights into the susceptibility of SOM decomposition in arctic permafrost soils to priming. By comparing 119 soils from four locations across the Siberian Arctic that cover all horizons of active layer and upper permafrost, we found that an increased availability of plant-derived organic C particularly stimulated decomposition in subsoil horizons where most of the arctic soil carbon is located. Considering the 1,035 Pg of arctic soil carbon, such an additional stimulation of decomposition beyond the direct temperature effect can accelerate net ecosystem C losses, and amplify the positive feedback to global warming.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Soil Organic Matter
Soil Organic Carbon Mineralization
SOC
SOM
Plant-derived compounds stimulate the decomposition of organic matter in arctic permafrost soils
Article
Text
oai:www.repo.uni-hannover.de:123456789/5002022-12-02T15:19:58Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Walter, Johanna-Gabriela
Petersen, Svea
Stahl, Frank
Scheper, Thomas
Barcikowski, Stephan
2016-08-31T09:19:34Z
2016-08-31T09:19:34Z
2010
Walter, Johanna G.; Petersen, Svea; Stahl, Frank; Scheper, Thomas; Barcikowski, Stephan: Laser ablation-based one-step generation and bio-functionalization of gold nanoparticles conjugated with aptamers. In: Journal of Nanobiotechnology 8 (2010), 21. DOI: http://dx.doi.org/10.1186/1477-3155-8-21
http://www.repo.uni-hannover.de/handle/123456789/500
http://dx.doi.org/10.15488/476
Background: Bio-conjugated nanoparticles are important analytical tools with emerging biological and medical applications. In this context, in situ conjugation of nanoparticles with biomolecules via laser ablation in an aqueous media is a highly promising one-step method for the production of functional nanoparticles resulting in highly efficient conjugation. Increased yields are required, particularly considering the conjugation of cost-intensive biomolecules like RNA aptamers. Results: Using a DNA aptamer directed against streptavidin, in situ conjugation results in nanoparticles with diameters of approximately 9 nm exhibiting a high aptamer surface density (98 aptamers per nanoparticle) and a maximal conjugation efficiency of 40.3%. We have demonstrated the functionality of the aptamer-conjugated nanoparticles using three independent analytical methods, including an agglomeration-based colorimetric assay, and solid-phase assays proving high aptamer activity. To demonstrate the general applicability of the in situ conjugation of gold nanoparticles with aptamers, we have transferred the method to an RNA aptamer directed against prostate-specific membrane antigen (PSMA). Successful detection of PSMA in human prostate cancer tissue was achieved utilizing tissue microarrays. Conclusions: In comparison to the conventional generation of bio-conjugated gold nanoparticles using chemical synthesis and subsequent bio-functionalization, the laser-ablation-based in situ conjugation is a rapid, one-step production method. Due to high conjugation efficiency and productivity, in situ conjugation can be easily used for high throughput generation of gold nanoparticles conjugated with valuable biomolecules like aptamers.
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
PSMA
AuNP
DNA
RNA
Laser ablation-based one-step generation and bio-functionalization of gold nanoparticles conjugated with aptamers
Article
Text
oai:www.repo.uni-hannover.de:123456789/5072022-12-02T16:11:40Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:570ddc:500
Wild, Birgit
Schnecker, Jörg
Knoltsch, Anna
Takriti, Mounir
Mooshammer, Maria
Gentsch, Norman
Mikutta, Robert
Alves, Ricardo J. Eloy
Gittel, Antje
Lashchinskiy, Nikolay
Richter, Andreas
2016-09-01T09:05:32Z
2016-09-01T09:05:32Z
2015-05
Wild, Birgit; Schnecker, Joerg; Knoltsch, Anna; Takriti, Mounir; Mooshammer, Maria et al.: Microbial nitrogen dynamics in organic and mineral soil horizons along a latitudinal transect in western Siberia. In: Global Biogeochemical Cycles 29 (2015), Nr. 5, S. 567-582. DOI: http://dx.doi.org/10.1002/2015GB005084
http://www.repo.uni-hannover.de/handle/123456789/507
http://dx.doi.org/10.15488/483
Soil N availability is constrained by the breakdown of N-containing polymers such as proteins to oligopeptides and amino acids that can be taken up by plants and microorganisms. Excess N is released from microbial cells as ammonium (N mineralization), which in turn can serve as substrate for nitrification. According to stoichiometric theory, N mineralization and nitrification are expected to increase in relation to protein depolymerization with decreasing N limitation, and thus from higher to lower latitudes and from topsoils to subsoils. To test these hypotheses, we compared gross rates of protein depolymerization, N mineralization and nitrification (determined using N-15 pool dilution assays) in organic topsoil, mineral topsoil, and mineral subsoil of seven ecosystems along a latitudinal transect in western Siberia, from tundra (67 degrees N) to steppe (54 degrees N). The investigated ecosystems differed strongly in N transformation rates, with highest protein depolymerization and N mineralization rates in middle and southern taiga. All N transformation rates decreased with soil depth following the decrease in organic matter content. Related to protein depolymerization, N mineralization and nitrification were significantly higher in mineral than in organic horizons, supporting a decrease in microbial N limitation with depth. In contrast, we did not find indications for a decrease in microbial N limitation from arctic to temperate ecosystems along the transect. Our findings thus challenge the perception of ubiquitous N limitation at high latitudes, but suggest a transition from N to C limitation of microorganisms with soil depth, even in high-latitude systems such as tundra and boreal forest.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
tundra
permafrost
boreal forest
protein depolymerization
arctic tundra
terrestrial ecosystems
carbon availability
forest ecosystems
alaskan tundra
use efficiency
plant-growth
n uptake
permafrost
matter
Microbial nitrogen dynamics in organic and mineral soil horizons along a latitudinal transect in western Siberia
Article
Text
oai:www.repo.uni-hannover.de:123456789/5112022-12-02T16:14:09Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:610ddc:570ddc:500
Schadzek, Patrik
Schlingmann, Barbara
Schaarschmidt, Frank
Lindner, Julia
Koval, Michael
Heisterkamp, Alexander
Ngezahayo, Anaclet
Preller, Matthias
2016-09-01T09:05:34Z
2016-09-01T09:05:34Z
2016
Schadzek, Patrik; Schlingmann, Barbara; Schaarschmidt, Frank; Lindner, Julia; Koval, Michael et al.: Data of the molecular dynamics simulations of mutations in the human connexin46 docking interface. In: Data in Brief 7 (2016), S. 93-99. DOI: http://dx.doi.org/10.1016/j.dib.2016.01.067
http://www.repo.uni-hannover.de/handle/123456789/511
http://dx.doi.org/10.15488/487
The structure of hCx26 derived from the X-ray analysis was used to generate a homology model for hCx46. Interacting connexin molecules were used as starting model for the molecular dynamics (MD) simulation using NAMD and allowed us to predict the dynamic behavior of hCx46wt and the cataract related mutant hCx46N188T as well as two artificial mutants hCx46N188Q and hCx46N188D. Within the 50 ns simulation time the docked complex composed of the mutants dissociate while hCx46wt remains stable. The data indicates that one hCx46 molecule forms 5-7 hydrogen bonds (HBs) with the counterpart connexin of the opposing connexon. These HBs appear essential for a stable docking of the connexons as shown by the simulation of an entire gap junction channel and were lost for all the tested mutants. The data described here are related to the research article entitled "The cataract related mutation N188T in human connexin46 (hCx46) revealed a critical role for residue N188 in the docking process of gap junction channels" (Schadzek et al., 2015) [1].
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Cataract
Connexin
Dye transfer
Hemichannel docking
Molecular dynamics
Structural modeling
Data of the molecular dynamics simulations of mutations in the human connexin46 docking interface
Article
Text
oai:www.repo.uni-hannover.de:123456789/5122022-12-02T16:10:15Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Sandor, Marko
Rüdinger, Ferdinand
Solle, Dörte
Bienert, Roland
Grimm, Christian
Groß, Sven
Scheper, Thomas
2016-09-01T09:05:34Z
2016-09-01T09:05:34Z
2013
Sandor, Marko; Rüdinger, Ferdinand; Solle, Dörte; Bienert, Roland; Grimm et al.: NIR-spectroscopy for bioprocess monitoring & control. In: BMC Proceedings 7 (2013), Suppl. 6, P29. DOI: http://dx.doi.org/10.1186/1753-6561-7-S6-P29
http://www.repo.uni-hannover.de/handle/123456789/512
http://dx.doi.org/10.15488/488
The Ingold port adaption of a free beam NIR spectrometer is tailored for optimal bioprocess monitoring and control. The device shows an excellent signal to noise ratio dedicated to a large free aperture and therefore a large sample volume. This can be seen particularly in the batch trajectories which show a high reproducibility. The robust and compact design withstands rough process environments as well as SIP/CIP cycles. Robust free beam NIR process analyzers are indispensable tools within the PAT/QbD framework for realtime process monitoring and control. They enable multiparametric, non-invasive measurements of analyte concentrations and process trajectories. Free beam NIR spectrometers are an ideal tool to define golden batches and process borders in the sense of QbD. Moreover, sophisticated data analysis both quantitative and MSPC yields directly to a far better process understanding. Information can be provided online in easy to interpret graphs which allow the operator to make fast and knowledge-based decisions. This finally leads to higher stability in process operation, better performance and less failed batches.
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
NIR-spectroscopy
TCC
PAT/QbD
Cell technology
NIR-spectroscopy for bioprocess monitoring & control
Article
Text
oai:www.repo.uni-hannover.de:123456789/5132022-12-02T16:14:10Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Robben, Lars
Merzlyakova, Elena
Heitjans, Paul
Gesing, Thorsten M.
2016-09-01T09:05:34Z
2016-09-01T09:05:34Z
2016
Robben, Lars; Merzlyakova, Elena; Heitjans, Paul; Gesing, Thorsten M.: Symmetry reduction due to gallium substitution in the garnet Li6.43(2)Ga0.52(3)La2.67(4)Zr2O12. In: Acta crystallographica. Section E, Crystallographic Communications 72 (2016) Pt. 3, S. 287-289. DOI: http://dx.doi.org/10.1107/S2056989016001924
http://www.repo.uni-hannover.de/handle/123456789/513
http://dx.doi.org/10.15488/489
Single-crystal structure refinements on lithium lanthanum zirconate (LLZO; Li7La3Zr2O12) substituted with gallium were successfully carried out in the cubic symmetry space group I [Formula: see text]3d. Gallium was found on two lithium sites as well as on the lanthanum position. Due to the structural distortion of the resulting Li6.43(2)Ga0.52(3)La2.67(4)Zr2O12 (Ga-LLZO) single crystals, a reduction of the LLZO cubic garnet symmetry from Ia[Formula: see text] d to I [Formula: see text]3d was necessary, which could hardly be analysed from X-ray powder diffraction data.
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
crystal structure
garnet
lithium lanthanum zirconate (LLZO)
symmetry reduction
Symmetry reduction due to gallium substitution in the garnet Li6.43(2)Ga0.52(3)La2.67(4)Zr2O12
Article
Text
oai:www.repo.uni-hannover.de:123456789/5152022-12-02T15:17:14Zcom_123456789_1col_123456789_7doc-type:Articleddc:540doc-type:Textopen_accessddc:530status-type:publishedVersionddc:570ddc:500
Peise, Jan
Kruse, I.
Lange, K.
Lücke, Bernd
Pezze, L.
Arlt, Jan J.
Ertmer, Wolfgang
Hammerer, Klemens
Santos, Luis
Smerzi, A.
Klempt, Carsten
2016-09-01T09:05:35Z
2016-09-01T09:05:35Z
2015
Peise, J.; Kruse, I.; Lange, K.; Lucke, B.; Pezze, L. et al.: Satisfying the Einstein-Podolsky-Rosen criterion with massive particles. In: Nature Communications 6 (2015), 8984. DOI: http://dx.doi.org/10.1038/ncomms9984
http://www.repo.uni-hannover.de/handle/123456789/515
http://dx.doi.org/10.15488/491
In 1935, Einstein, Podolsky and Rosen (EPR) questioned the completeness of quantum mechanics by devising a quantum state of two massive particles with maximally correlated space and momentum coordinates. The EPR criterion qualifies such continuous-variable entangled states, where a measurement of one subsystem seemingly allows for a prediction of the second subsystem beyond the Heisenberg uncertainty relation. Up to now, continuous-variable EPR correlations have only been created with photons, while the demonstration of such strongly correlated states with massive particles is still outstanding. Here we report on the creation of an EPR-correlated two-mode squeezed state in an ultracold atomic ensemble. The state shows an EPR entanglement parameter of 0.18(3), which is 2.4 s.d. below the threshold 1/4 of the EPR criterion. We also present a full tomographic reconstruction of the underlying many-particle quantum state. The state presents a resource for tests of quantum nonlocality and a wide variety of applications in the field of continuous-variable quantum information and metrology.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Physical sciences
Atomic and molecular physics
Satisfying the Einstein-Podolsky-Rosen criterion with massive particles
Article
Text
oai:www.repo.uni-hannover.de:123456789/5162022-12-02T16:11:40Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Ogada, Pamella Akoth
Moualeu, Dany Pascal
Poehling, Hans-Michael
2016-09-01T09:05:35Z
2016-09-01T09:05:35Z
2016
Ogada, Pamella Akoth; Moualeu, Dany Pascal; Poehling, Hans-Michael: Predictive Models for Tomato Spotted Wilt Virus Spread Dynamics, Considering Frankliniella occidentalis Specific Life Processes as Influenced by the Virus. In: PLoS ONE 11 (2016), Nr. 5, e0154533. DOI: http://dx.doi.org/10.1371/journal.pone.0154533
http://www.repo.uni-hannover.de/handle/123456789/516
http://dx.doi.org/10.15488/492
Several models have been studied on predictive epidemics of arthropod vectored plant viruses in an attempt to bring understanding to the complex but specific relationship between the three cornered pathosystem (virus, vector and host plant), as well as their interactions with the environment. A large body of studies mainly focuses on weather based models as management tool for monitoring pests and diseases, with very few incorporating the contribution of vector's life processes in the disease dynamics, which is an essential aspect when mitigating virus incidences in a crop stand. In this study, we hypothesized that the multiplication and spread of tomato spotted wilt virus (TSWV) in a crop stand is strongly related to its influences on Frankliniella occidentalis preferential behavior and life expectancy. Model dynamics of important aspects in disease development within TSWV-F. occidentalis-host plant interactions were developed, focusing on F. occidentalis' life processes as influenced by TSWV. The results show that the influence of TSWV on F. occidentalis preferential behaviour leads to an estimated increase in relative acquisition rate of the virus, and up to 33% increase in transmission rate to healthy plants. Also, increased life expectancy; which relates to improved fitness, is dependent on the virus induced preferential behaviour, consequently promoting multiplication and spread of the virus in a crop stand. The development of vector-based models could further help in elucidating the role of tri-trophic interactions in agricultural disease systems. Use of the model to examine the components of the disease process could also boost our understanding on how specific epidemiological characteristics interact to cause diseases in crops. With this level of understanding we can efficiently develop more precise control strategies for the virus and the vector.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Plants
viral vectors
life expectancy
death rates
desease vectors
population dynamics
tomato spotted wilt virus
Predictive Models for Tomato Spotted Wilt Virus Spread Dynamics, Considering Frankliniella occidentalis Specific Life Processes as Influenced by the Virus
Article
Text
oai:www.repo.uni-hannover.de:123456789/5172022-12-02T16:11:40Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:570ddc:500
Nyasani, Johnson O.
Subramanian, Sevgan
Poehling, Hans-Michael
Maniania, Nguya K.
Ekesi, Sunday
Meyhöfer, Rainer
2016-09-01T09:05:36Z
2016-09-01T09:05:36Z
2015
Nyasani, Johnson O.; Subramanian, Sevgan; Poehling, Hans-Michael; Maniania, Nguya K.; Ekesi, Sunday; Meyhofer, Rainer: Optimizing Western Flower Thrips Management on French Beans by Combined Use of Beneficials and Imidacloprid. In: Insects 6 (2015), Nr. 1, S. 279-296. DOI: http://dx.doi.org/10.3390/insects6010279
http://www.repo.uni-hannover.de/handle/123456789/517
http://dx.doi.org/10.15488/493
Western flower thrips (WFT), Frankliniella occidentalis (Pergande), is an important pest of vegetable crops worldwide and has developed resistance to many insecticides. The predatory mites Neoseiulus (=Amblyseius) cucumeris (Oudemans), the entomopathogenic fungus Metarhizium anisopliae (Metsch.), and an insecticide (imidacloprid) were tested for their efficacy to reduce WFT population density and damage to French bean (Phaseolus vulgaris L.) pods under field conditions in two planting periods. Metarhizium anisopliae was applied as a foliar spray weekly at a rate of one litre spray volume per plot while imidacloprid was applied as a soil drench every two weeks at a rate of two litres of a mixture of water and imidacloprid per m(2). Neoseiulus cucumeris was released every two weeks on plant foliage at a rate of three mites per plant. Single and combined treatment applications reduced WFT population density by at least three times and WFT damage to French bean pods by at least 1.7 times compared with untreated plots. The benefit-cost ratios in management of WFT were profitable with highest returns realized on imidacloprid treated plots. The results indicate that M. anisopliae, N. cucumeris, and imidacloprid have the potential for use in developing an integrated pest management program against WFT on French beans.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Amblyseius
benefit-cost ratio
Frankliniella occidentalis
entomopathogenic fungus
neonicotinoid
Phaseolus vulgaris
predatory mite
Optimizing Western Flower Thrips Management on French Beans by Combined Use of Beneficials and Imidacloprid
Article
Text
oai:www.repo.uni-hannover.de:123456789/5192022-12-02T15:12:31Zcom_123456789_1col_123456789_7doc-type:Articleddc:540doc-type:Textopen_accessddc:530status-type:publishedVersionddc:570ddc:500
Abdelkhalek, Daniela
Syllwasschy, Mareike
Cerf, Nicolas J.
Fiurasek, Jaromir
Schnabel, Roman
2016-09-01T09:06:11Z
2016-09-01T09:06:11Z
2016
Abdelkhalek, Daniela; Syllwasschy, Mareike; Cerf, Nicolas J.; Fiurasek, Jaromir; Schnabel, Roman: Efficient entanglement distillation without quantum memory. In: Nature Communications 7 (2016), 11720. DOI: http://dx.doi.org/10.1038/ncomms11720
http://www.repo.uni-hannover.de/handle/123456789/519
http://dx.doi.org/10.15488/495
Entanglement distribution between distant parties is an essential component to most quantum communication protocols. Unfortunately, decoherence effects such as phase noise in optical fibres are known to demolish entanglement. Iterative (multistep) entanglement distillation protocols have long been proposed to overcome decoherence, but their probabilistic nature makes them inefficient since the success probability decays exponentially with the number of steps. Quantum memories have been contemplated to make entanglement distillation practical, but suitable quantum memories are not realised to date. Here, we present the theory for an efficient iterative entanglement distillation protocol without quantum memories and provide a proof-of-principle experimental demonstration. The scheme is applied to phase-diffused two-mode-squeezed states and proven to distil entanglement for up to three iteration steps. The data are indistinguishable from those that an efficient scheme using quantum memories would produce. Since our protocol includes the final measurement it is particularly promising for enhancing continuous-variable quantum key distribution.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Physical sciences
Theoretical physics
Applied physics
Optical physics
Efficient entanglement distillation without quantum memory
Article
Text
oai:www.repo.uni-hannover.de:123456789/5222022-12-02T16:14:09Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:580ddc:500
Moualeu-Ngangue, Dany Pascal
Chen, Tsu-Wei
Stützel, Hartmut
2016-09-02T08:00:18Z
2016-09-02T08:00:18Z
2016
Moualeu-Ngangue, Dany P.; Chen, Tsu-Wei; Stützel, Hartmut: A Modeling Approach to Quantify the Effects of Stomatal Behavior and Mesophyll Conductance on Leaf Water Use Efficiency. In: Frontiers in Plant Science 7 (2016), 875. DOI: http://dx.doi.org/10.3389/fpls.2016.00875
http://www.repo.uni-hannover.de/handle/123456789/522
http://dx.doi.org/10.15488/498
Water use efficiency (WUE) is considered as a determinant of yield under stress and a component of crop drought resistance. Stomatal behavior regulates both transpiration rate and net assimilation and has been suggested to be crucial for improving crop WUE. In this work, a dynamic model was used to examine the impact of dynamic properties of stomata on WUE. The model includes sub-models of stomatal conductance dynamics, solute accumulation in the mesophyll, mesophyll water content, and water flow to the mesophyll. Using the instantaneous value of stomatal conductance, photosynthesis, and transpiration rate were simulated using a biochemical model and Penman-Monteith equation, respectively. The model was parameterized for a cucumber leaf and model outputs were evaluated using climatic data. Our simulations revealed that WUE was higher on a cloudy than a sunny day. Fast stomatal reaction to light decreased WUE during the period of increasing light (e.g., in the morning) by up to 10.2% and increased WUE during the period of decreasing light (afternoon) by up to 6.25%. Sensitivity of daily WUE to stomatal parameters and mesophyll conductance to CO2 was tested for sunny and cloudy days. Increasing mesophyll conductance to CO2 was more likely to increase WUE for all climatic conditions (up to 5.5% on the sunny day) than modifications of stomatal reaction speed to light and maximum stomatal conductance.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Water use efficiency (WUE)
Light regulation
mesophyll conductance
sap flow dynamics
stomatal behavior
water use efficiency
A Modeling Approach to Quantify the Effects of Stomatal Behavior and Mesophyll Conductance on Leaf Water Use Efficiency
Article
Text
oai:www.repo.uni-hannover.de:123456789/5272022-12-02T15:19:58Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:580ddc:500
Klie, Maik
Debener, Thomas
2016-09-02T08:00:21Z
2016-09-02T08:00:21Z
2011
Klie, Maik; Debener, Thomas: Identification of superior reference genes for data normalisation of expression studies via quantitative PCR in hybrid roses (Rosa hybrida). In: BMC Research Notes 4 (2011), 518. DOI: http://dx.doi.org/10.1186/1756-0500-4-518
http://www.repo.uni-hannover.de/handle/123456789/527
http://dx.doi.org/10.15488/503
Background: Gene expression studies are a prerequisite for understanding the biological function of genes. Because of its high sensitivity and easy use, quantitative PCR (qPCR) has become the gold standard for gene expression quantification. To normalise qPCR measurements between samples, the most prominent technique is the use of stably expressed endogenous control genes, the so called reference genes. However, recent studies show there is no universal reference gene for all biological questions. Roses are important ornamental plants for which there has been no evaluation of useful reference genes for gene expression studies. Results: We used three different algorithms (BestKeeper, geNorm and NormFinder) to validate the expression stability of nine candidate reference genes in different rose tissues from three different genotypes of Rosa hybrida and in leaves treated with various stress factors. The candidate genes comprised the classical "housekeeping genes" (Actin, EF-1α, GAPDH, Tubulin and Ubiquitin), and genes showing stable expression in studies in Arabidopsis (PP2A, SAND, TIP and UBC). The programs identified no single gene that showed stable expression under all of the conditions tested, and the individual rankings of the genes differed between the algorithms. Nevertheless the new candidate genes, specifically, PP2A and UBC, were ranked higher as compared to the other traditional reference genes. In general, Tubulin showed the most variable expression and should be avoided as a reference gene. Conclusions: Reference genes evaluated as suitable in experiments with Arabidopsis thaliana were stably expressed in roses under various experimental conditions. In most cases, these genes outperformed conventional reference genes, such as EF1-α and Tubulin. We identified PP2A, SAND and UBC as suitable reference genes, which in different combinations may be used for normalisation in expression analyses via qPCR for different rose tissues and stress treatments. However, the vast genetic variation found within the genus Rosa, including differences in ploidy levels, might also influence expression stability of reference genes, so that future research should also consider different genotypes and ploidy levels.
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
Rosa hybrida
qPCR
PCR
Identification of superior reference genes for data normalisation of expression studies via quantitative PCR in hybrid roses (Rosa hybrida)
Article
Text
oai:www.repo.uni-hannover.de:123456789/5282022-12-02T16:11:41Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:580ddc:500
Kahlen, Katrin
Chen, Tsu-Wei
2016-09-02T08:00:22Z
2016-09-02T08:00:22Z
2015
Kahlen, Katrin; Chen, Tsu-Wei: Predicting Plant Performance Under Simultaneously Changing Environmental Conditions-The Interplay Between Temperature, Light, and Internode Growth. In: Frontiers in Plant Science 6 (2015), 1130. DOI: http://dx.doi.org/10.3389/fpls.2015.01130
http://www.repo.uni-hannover.de/handle/123456789/528
http://dx.doi.org/10.15488/504
Plant performance is significantly influenced by prevailing light and temperature conditions during plant growth and development. For plants exposed to natural fluctuations in abiotic environmental conditions it is however laborious and cumbersome to experimentally assign any contribution of individual environmental factors to plant responses. This study aimed at analyzing the interplay between light, temperature and internode growth based on model approaches. We extended the light-sensitive virtual plant model L-Cucumber by implementing a common Arrhenius function for appearance rates, growth rates, and growth durations. For two greenhouse experiments, the temperature-sensitive model approach resulted in a precise prediction of cucumber mean internode lengths and number of internodes, as well as in accurately predicted patterns of individual internode lengths along the main stem. In addition, a system's analysis revealed that environmental data averaged over the experimental period were not necessarily related to internode performance. Finally, the need for a species-specific parameterization of the temperature response function and related aspects in modeling temperature effects on plant development and growth is discussed.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Arrhenius
cucumber
modeling
morphogenesis
plant development
plant growth
virtual plant
Predicting Plant Performance Under Simultaneously Changing Environmental Conditions-The Interplay Between Temperature, Light, and Internode Growth
Article
Text
oai:www.repo.uni-hannover.de:123456789/5302022-12-02T16:11:40Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Hong, Hui
Samborskyy, Markiyan
Lindner, Frederick
Leadlay, Peter F.
2016-09-02T08:00:23Z
2016-09-02T08:00:23Z
2016
Hong, Hui; Samborskyy, Markiyan; Lindner, Frederick; Leadlay, Peter F.: An Amidinohydrolase Provides the Missing Link in the Biosynthesis of Amino Marginolactone Antibiotics . In: Angewandte Chemie (Int. Edition) 55 (2016), Nr. 3, S. 1118-1123. DOI: http://dx.doi.org/10.1002/anie.201509300
http://www.repo.uni-hannover.de/handle/123456789/530
http://dx.doi.org/10.15488/506
Desertomycin A is an aminopolyol polyketide containing a macrolactone ring. We have proposed that desertomycin A and similar compounds (marginolactones) are formed by polyketide synthases primed not with gamma-aminobutanoyl-CoA but with 4-guanidinylbutanoyl-CoA, to avoid facile cyclization of the starter unit. This hypothesis requires that there be a final-stage de-amidination of the corresponding guanidino-substituted natural product, but no enzyme for such a process has been described. We have now identified candidate amidinohydrolase genes within the desertomycin and primycin clusters. Deletion of the putative desertomycin amidinohydrolase gene dstH in Streptomyces macronensis led to the accumulation of desertomycin B, the guanidino form of the antibiotic. Also, purified DstH efficiently catalyzed the in vitro conversion of desertomycin B into the A form. Hence this amidinohydrolase furnishes the missing link in this proposed naturally evolved example of protective-group chemistry.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
amidinohydrolases
biosynthesis
marginolactones
polyketide synthases
streptomyces
An Amidinohydrolase Provides the Missing Link in the Biosynthesis of Amino Marginolactone Antibiotics
Article
Text
oai:www.repo.uni-hannover.de:123456789/5312022-12-02T16:14:10Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Hohnjec, Natalija
Czaja-Hasse, Lisa F.
Hogekamp, Claudia
Kuster, Helge
2016-09-02T08:00:23Z
2016-09-02T08:00:23Z
2015
Hohnjec, Natalija; Czaja-Hasse, Lisa F.; Hogekamp, Claudia; Kuster, Helge: Pre-announcement of symbiotic guests: transcriptional reprogramming by mycorrhizal lipochitooligosaccharides shows a strict co-dependency on the GRAS transcription factors NSP1 and RAM1. In: BMC Genomics 16 (2015), 994. DOI: http://dx.doi.org/10.1186/s12864-015-2224-7
http://www.repo.uni-hannover.de/handle/123456789/531
http://dx.doi.org/10.15488/507
BACKGROUND: More than 80 % of all terrestrial plant species establish an arbuscular mycorrhiza (AM) symbiosis with Glomeromycota fungi. This plant-microbe interaction primarily improves phosphate uptake, but also supports nitrogen, mineral, and water aquisition. During the pre-contact stage, the AM symbiosis is controled by an exchange of diffusible factors from either partner. Amongst others, fungal signals were identified as a mix of sulfated and non-sulfated lipochitooligosaccharides (LCOs), being structurally related to rhizobial nodulation (Nod)-factor LCOs that in legumes induce the formation of nitrogen-fixing root nodules. LCO signals are transduced via a common symbiotic signaling pathway (CSSP) that activates a group of GRAS transcription factors (TFs). Using complex gene expression fingerprints as molecular phenotypes, this study primarily intended to shed light on the importance of the GRAS TFs NSP1 and RAM1 for LCO-activated gene expression during pre-symbiotic signaling. RESULTS: We investigated the genome-wide transcriptional responses in 5 days old primary roots of the Medicago truncatula wild type and four symbiotic mutants to a 6 h challenge with LCO signals supplied at 10(-7/-8) M. We were able to show that during the pre-symbiotic stage, sulfated Myc-, non-sulfated Myc-, and Nod-LCO-activated gene expression almost exclusively depends on the LysM receptor kinase NFP and is largely controled by the CSSP, although responses independent of this pathway exist. Our results show that downstream of the CSSP, gene expression activation by Myc-LCOs supplied at 10(-7/-8) M strictly required both the GRAS transcription factors RAM1 and NSP1, whereas those genes either co- or specifically activated by Nod-LCOs displayed a preferential NSP1-dependency. RAM1, a central regulator of root colonization by AM fungi, controled genes activated by non-sulfated Myc-LCOs during the pre-symbiotic stage that are also up-regulated in areas with early physical contact, e.g. hyphopodia and infecting hyphae; linking responses to externally applied LCOs with early root colonization. CONCLUSIONS: Since both RAM1 and NSP1 were essential for the pre-symbiotic transcriptional reprogramming by Myc-LCOs, we propose that downstream of the CSSP, these GRAS transcription factors act synergistically in the transduction of those diffusible signals that pre-announce the presence of symbiotic fungi.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Arbuscular mycorrhiza
GRAS transcription factor
Lipochitooligosaccharide
Medicago GeneChip
NSP1
Pre-symbiotic signaling
RAM1
Transcriptional reprogramming
Pre-announcement of symbiotic guests: transcriptional reprogramming by mycorrhizal lipochitooligosaccharides shows a strict co-dependency on the GRAS transcription factors NSP1 and RAM1
Article
Text
oai:www.repo.uni-hannover.de:123456789/5322023-10-24T07:04:24Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Alkio, Merianne
Jonas, Uwe
Declercq, Myriam
van Nocker, Steven
Knoche, Moritz
2016-09-02T08:00:25Z
2016-09-02T08:00:25Z
2014
Alkio, Merianne; Jonas, Uwe; Declercq, Myriam; van Nocker, Steven; Knoche, Moritz: Transcriptional dynamics of the developing sweet cherry (Prunus avium L.) fruit: sequencing, annotation and expression profiling of exocarp-associated genes. In: Horticulture Research 1 (2014), 11. DOI: http://dx.doi.org/10.1038/hortres.2014.11
http://www.repo.uni-hannover.de/handle/123456789/532
http://dx.doi.org/10.15488/508
The exocarp, or skin, of fleshy fruit is a specialized tissue that protects the fruit, attracts seed dispersing fruit eaters, and has large economical relevance for fruit quality. Development of the exocarp involves regulated activities of many genes. This research analyzed global gene expression in the exocarp of developing sweet cherry (Prunus avium L., 'Regina'), a fruit crop species with little public genomic resources. A catalog of transcript models (contigs) representing expressed genes was constructed from de novo assembled short complementary DNA (cDNA) sequences generated from developing fruit between flowering and maturity at 14 time points. Expression levels in each sample were estimated for 34 695 contigs from numbers of reads mapping to each contig. Contigs were annotated functionally based on BLAST, gene ontology and InterProScan analyses. Coregulated genes were detected using partitional clustering of expression patterns. The results are discussed with emphasis on genes putatively involved in cuticle deposition, cell wall metabolism and sugar transport. The high temporal resolution of the expression patterns presented here reveals finely tuned developmental specialization of individual members of gene families. Moreover, the de novo assembled sweet cherry fruit transcriptome with 7760 full-length protein coding sequences and over 20 000 other, annotated cDNA sequences together with their developmental expression patterns is expected to accelerate molecular research on this important tree fruit crop.
eng
http://creativecommons.org/licenses/by-nc-nd/3.0/
CC BY-NC-ND 3.0 Unported
Prunus avium L.
sweet cherry
DNA
Transcriptional dynamics of the developing sweet cherry (Prunus avium L.) fruit: sequencing, annotation and expression profiling of exocarp-associated genes
Article
Text
oai:www.repo.uni-hannover.de:123456789/5332022-12-02T15:12:31Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessddc:530status-type:publishedVersionddc:500
Gehring, Tobias
Handchen, Vitus
Duhme, Jörg
Furrer, Fabian
Franz, Torsten
Pacher, Christoph
Werner, Reinhard F.
Schnabel, Roman
2016-09-06T07:57:59Z
2016-09-06T07:57:59Z
2015
Gehring, Tobias; Handchen, Vitus; Duhme, Jorg; Furrer, Fabian; Franz, Torsten et al.: Implementation of continuous-variable quantum key distribution with composable and one-sided-device-independent security against coherent attacks. In: Nature Communications 6 (2015), 8795. DOI: http://dx.doi.org/10.1038/ncomms9795
http://www.repo.uni-hannover.de/handle/123456789/533
http://dx.doi.org/10.15488/509
Secret communication over public channels is one of the central pillars of a modern information society. Using quantum key distribution this is achieved without relying on the hardness of mathematical problems, which might be compromised by improved algorithms or by future quantum computers. State-of-the-art quantum key distribution requires composable security against coherent attacks for a finite number of distributed quantum states as well as robustness against implementation side channels. Here we present an implementation of continuous-variable quantum key distribution satisfying these requirements. Our implementation is based on the distribution of continuous-variable Einstein–Podolsky–Rosen entangled light. It is one-sided device independent, which means the security of the generated key is independent of any memoryfree attacks on the remote detector. Since continuous-variable encoding is compatible with conventional optical communication technology, our work is a step towards practical implementations of quantum key distribution with state-of-the-art security based solely on telecom components.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Physical sciences
Optical physics
Theoretical physics
Applied physics
QKD
EPR
Implementation of continuous-variable quantum key distribution with composable and one-sided-device-independent security against coherent attacks
Article
Text
oai:www.repo.uni-hannover.de:123456789/5342022-12-02T15:19:58Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Fromm, Steffanie
Senkler, Jennifer
Eubel, Holger
Peterhansel, Christoph
Braun, Hans-Peter
2016-09-06T07:57:59Z
2016-09-06T07:57:59Z
2016
Fromm, Steffanie; Senkler, Jennifer; Eubel, Holger; Peterhansel, Christoph; Braun, Hans-Peter: Life without complex I: proteome analyses of an Arabidopsis mutant lacking the mitochondrial NADH dehydrogenase complex. In: Journal of Experimental Botany 67 (2016), Nr. 10, S. 3079-3093. DOI: http://dx.doi.org/10.1093/jxb/erw165
http://www.repo.uni-hannover.de/handle/123456789/534
http://dx.doi.org/10.15488/510
The mitochondrial NADH dehydrogenase complex (complex I) is of particular importance for the respiratory chain in mitochondria. It is the major electron entry site for the mitochondrial electron transport chain (mETC) and therefore of great significance for mitochondrial ATP generation. We recently described an Arabidopsis thaliana double-mutant lacking the genes encoding the carbonic anhydrases CA1 and CA2, which both form part of a plant-specific 'carbonic anhydrase domain' of mitochondrial complex I. The mutant lacks complex I completely. Here we report extended analyses for systematically characterizing the proteome of the ca1ca2 mutant. Using various proteomic tools, we show that lack of complex I causes reorganization of the cellular respiration system. Reduced electron entry into the respiratory chain at the first segment of the mETC leads to induction of complexes II and IV as well as alternative oxidase. Increased electron entry at later segments of the mETC requires an increase in oxidation of organic substrates. This is reflected by higher abundance of proteins involved in glycolysis, the tricarboxylic acid cycle and branched-chain amino acid catabolism. Proteins involved in the light reaction of photosynthesis, the Calvin cycle, tetrapyrrole biosynthesis, and photorespiration are clearly reduced, contributing to the significant delay in growth and development of the double-mutant. Finally, enzymes involved in defense against reactive oxygen species and stress symptoms are much induced. These together with previously reported insights into the function of plant complex I, which were obtained by analysing other complex I mutants, are integrated in order to comprehensively describe 'life without complex I'.
eng
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Arabidopsis thaliana
carbonic anhydrase
complex I
mitochondrial metabolism
photosynthesis
proteomics
respiratory chain
Life without complex I: proteome analyses of an Arabidopsis mutant lacking the mitochondrial NADH dehydrogenase complex
Article
Text
oai:www.repo.uni-hannover.de:123456789/5362022-12-02T16:14:10Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Donner, Jannik
Reck, Michael
Bergmann, Simone
Kirschning, Andreas
Müller, Rolf
Wagner-Döbler, Irene
2016-09-06T07:58:00Z
2016-09-06T07:58:00Z
2016
Donner, Jannik; Reck, Michael; Bergmann, Simone; Kirschning, Andreas; Muller, Rolf; Wagner-Dobler, Irene: The biofilm inhibitor Carolacton inhibits planktonic growth of virulent pneumococci via a conserved target. In: Scientific Reports 6 (2016), 29677. DOI: http://dx.doi.org/10.1038/srep29677
http://www.repo.uni-hannover.de/handle/123456789/536
http://dx.doi.org/10.15488/512
New antibacterial compounds, preferentially exploiting novel cellular targets, are urgently needed to fight the increasing resistance of pathogens against conventional antibiotics. Here we demonstrate that Carolacton, a myxobacterial secondary metabolite previously shown to damage Streptococcus mutans biofilms, inhibits planktonic growth of Streptococcus pneumoniae TIGR4 and multidrug-resistant clinical isolates of serotype 19A at nanomolar concentrations. A Carolacton diastereomer is inactive in both streptococci, indicating a highly specific interaction with a conserved cellular target. S. mutans requires the eukaryotic-like serine/threonine protein kinase PknB and the cysteine metabolism regulator CysR for susceptibility to Carolacton, whereas their homologues are not needed in S. pneumoniae, suggesting a specific function for S. mutans biofilms only. A bactericidal effect of Carolacton was observed for S. pneumoniae TIGR4, with a reduction of cell numbers by 3 log units. The clinical pneumonia isolate Sp49 showed immediate growth arrest and cell lysis, suggesting a bacteriolytic effect of Carolacton. Carolacton treatment caused a reduction in membrane potential, but not membrane integrity, and transcriptome analysis revealed compensatory reactions of the cell. Our data show that Carolacton might have potential for treating pneumococcal infections.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Carolacton
S. pneumoniae TIGR4
Medical Microbiology
Infection Research
The biofilm inhibitor Carolacton inhibits planktonic growth of virulent pneumococci via a conserved target
Article
Text
oai:www.repo.uni-hannover.de:123456789/5372022-12-02T15:19:58Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Dondrup, Michael
Albaum, Stefan P.
Griebel, Thasso
Henckel, Kolja
Junemann, Sebastian
Kahlke, Tim
Kleindt, Christiane K.
Küster, Helge
Linke, Burkhard
Mertens, Dominik
Mittard-Runte, Virginie
Neuweger, Heiko
Runte, Kai J.
Tauch, Andreas
Tille, Felix
Pühler, Alfred
Goesmann, Alexander
2016-09-06T07:58:00Z
2016-09-06T07:58:00Z
2009
Dondrup, Michael; Albaum, Stefan P.; Griebel, Thasso; Henckel, Kolja; Junemann, Sebastian; Kahlke, Tim; Kleindt, Christiane K.; Küster, Helge; Linke, Burkhard; Mertens, Dominik et al.: EMMA 2 - a MAGE-compliant system for the collaborative analysis and integration of microarray data. In: BMC Bioinformatics 10 (2009), 50. DOI: http://dx.doi.org/10.1186/1471-2105-10-50
http://www.repo.uni-hannover.de/handle/123456789/537
http://dx.doi.org/10.15488/513
Background: Understanding transcriptional regulation by genome-wide microarray studies can contribute to unravel complex relationships between genes. Attempts to standardize the annotation of microarray data include the Minimum Information About a Microarray Experiment (MIAME) recommendations, the MAGE-ML format for data interchange, and the use of controlled vocabularies or ontologies. The existing software systems for microarray data analysis implement the mentioned standards only partially and are often hard to use and extend. Integration of genomic annotation data and other sources of external knowledge using open standards is therefore a key requirement for future integrated analysis systems. Results: The EMMA 2 software has been designed to resolve shortcomings with respect to full MAGE-ML and ontology support and makes use of modern data integration techniques. We present a software system that features comprehensive data analysis functions for spotted arrays, and for the most common synthesized oligo arrays such as Agilent, Affymetrix and NimbleGen. The system is based on the full MAGE object model. Analysis functionality is based on R and Bioconductor packages and can make use of a compute cluster for distributed services. Conclusion: Our model-driven approach for automatically implementing a full MAGE object model provides high flexibility and compatibility. Data integration via SOAP-based web-services is advantageous in a distributed client-server environment as the collaborative analysis of microarray data is gaining more and more relevance in international research consortia. The adequacy of the EMMA 2 software design and implementation has been proven by its application in many distributed functional genomics projects. Its scalability makes the current architecture suited for extensions towards future transcriptomics methods based on high-throughput sequencing approaches which have much higher computational requirements than microarrays.
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
Molecular Biotechnology
Genome Research
MAGE-ML
EMMA 2 - a MAGE-compliant system for the collaborative analysis and integration of microarray data
Article
Text
oai:www.repo.uni-hannover.de:123456789/5392022-12-02T16:14:10Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Cordero, R.R.
Damiani, A.
Seckmeyer, Gunther
Jorquera, J.
Caballero, M.
Rowe, P.
Ferrer, J.
Mubarak, Riyad
Carrasco, J.
Rondanelli, R.
Matus, M.
Laroze, D.
2016-09-06T07:58:01Z
2016-09-06T07:58:01Z
2016
Cordero, R. R.; Damiani, A.; Seckmeyer, Gunther; Jorquera, J.; Caballero, M. et al.: The Solar Spectrum in the Atacama Desert. In: Scientific Reports 6 (2016) , 22457. DOI: http://dx.doi.org/10.1038/srep22457
http://www.repo.uni-hannover.de/handle/123456789/539
http://dx.doi.org/10.15488/515
The Atacama Desert has been pointed out as one of the places on earth where the highest surface irradiance may occur. This area is characterized by its high altitude, prevalent cloudless conditions and relatively low columns of ozone and water vapor. Aimed at the characterization of the solar spectrum in the Atacama Desert, we carried out in February-March 2015 ground-based measurements of the spectral irradiance (from the ultraviolet to the near infrared) at seven locations that ranged from the city of Antofagasta (on the southern pacific coastline) to the Chajnantor Plateau (5,100 m altitude). Our spectral measurements allowed us to retrieve the total ozone column, the precipitable water, and the aerosol properties at each location. We found that changes in these parameters, as well as the shorter optical path length at high-altitude locations, lead to significant increases in the surface irradiance with the altitude. Our measurements show that, in the range 0-5100 m altitude, surface irradiance increases with the altitude by about 27% in the infrared range, 6% in the visible range, and 20% in the ultraviolet range. Spectral measurements carried out at the Izana Observatory (Tenerife, Spain), in Hannover (Germany) and in Santiago (Chile), were used for further comparisons.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Atacama Desert
ozone
Atmospheric chemistry
Atmospheric dynamics
The Solar Spectrum in the Atacama Desert
Article
Text
oai:www.repo.uni-hannover.de:123456789/5402022-12-02T16:11:40Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Ciazela, Jakub
Siepak, Marcin
2016-09-06T07:58:01Z
2016-09-06T07:58:01Z
2016
Ciazela, Jakub; Siepak, Marcin: Environmental factors affecting soil metals near outlet roads in Poznan, Poland: impact of grain size, soil depth, and wind dispersal. In: Environmental Monitoring and Assessment 188 (2016), Nr. 6, 323. DOI: http://dx.doi.org/10.1007/s10661-016-5284-5
http://www.repo.uni-hannover.de/handle/123456789/540
http://dx.doi.org/10.15488/516
We determined the Cd, Cr, Cu, Ni, Pb, and Zn concentrations in soil samples collected along the eight main outlet roads of Poznan. Samples were collected at distances of 1, 5, and 10 m from the roadway edges at depth intervals of 0-20 and 40-60 cm. The metal content was determined in seven grain size fractions. The highest metal concentrations were observed in the smallest fraction (<0.063 mm), which were up to four times higher than those in sand fractions. Soil Pb, Cu, and Zn (and to a lesser extent Ni, Cr, and Cd) all increased in relation to the geochemical background. At most sampling sites, metal concentrations decreased with increasing distance from roadway edges and increasing depth. In some locations, the accumulation of metals in soils appears to be strongly influenced by wind direction. Our survey findings should contribute in predicting the behavior of metals along outlet road, which is important by assessing sources for further migration of heavy metals into the groundwater, plants, and humans.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Soil pollution
Soil metal
Road transport
Grain size
Environmental factors affecting soil metals near outlet roads in Poznan, Poland: impact of grain size, soil depth, and wind dispersal
Article
Text
oai:www.repo.uni-hannover.de:123456789/5412022-12-02T16:11:40Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Chen, Tsu-Wei
Nguyen, Thi M.N.
Kahlen, Katrin
Stützel, Hartmut
2016-09-06T07:58:01Z
2016-09-06T07:58:01Z
2015
Chen, Tsu-Wei; Nguyen, Thi M. N.; Kahlen, Katrin; Stutzel, Hartmut: High temperature and vapor pressure deficit aggravate architectural effects but ameliorate non-architectural effects of salinity on dry mass production of tomato. In: Frontiers in Plant Science 6 (2015), 887. DOI: http://dx.doi.org/10.3389/fpls.2015.00887
http://www.repo.uni-hannover.de/handle/123456789/541
http://dx.doi.org/10.15488/517
Tomato (Solanum lycopersicum L.) is an important vegetable crop and often cultivated in regions exposed to salinity and high temperatures (HT) which change plant architecture, decrease canopy light interception and disturb physiological functions. However, the long-term effects of salinity and HT combination (S+HT) on plant growth are still unclear. A dynamic functional-structural plant model (FSPM) of tomato was parameterized and evaluated for different levels of S+HT combinations. The evaluated model was used to quantify the contributions of morphological changes (architectural effects) and physiological disturbances (non-architectural effects) on the reduction of shoot dry mass under S+HT. The model predicted architectural variables with high accuracy (>85%), which ensured the reliability of the model analyses. HT enhanced architectural effects but reduced non-architectural effects of salinity on dry mass production. The stronger architectural effects of salinity under HT could not be counterbalanced by the smaller non-architectural effects. Therefore, long-term influences of HT on shoot dry mass under salinity were negative at the whole plant level. Our model analysis highlights the importance of plant architecture at canopy level in studying the plant responses to the environments and shows the merits of dynamic FSPMs as heuristic tools.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
dynamicfunctional-structuralplantmodel
canopyarchitecture
canopyphotosynthesis
allometric relationship
tomato
hightemperature
salinity
stresscombination
High temperature and vapor pressure deficit aggravate architectural effects but ameliorate non-architectural effects of salinity on dry mass production of tomato
Article
Text
oai:www.repo.uni-hannover.de:123456789/5422022-12-02T16:14:09Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Butenschön, Holger
Vinokurov, Nikolai
Baumgardt, Ingmar
Pietrusiewicz, K. Michal
2016-09-06T07:58:01Z
2016-09-06T07:58:01Z
2009
Butenschon, Holger; Vinokurov, Nikolai; Baumgardt, Ingmar; Pietrusiewicz, K. Michal: (SP,SP)-(–)-(E)-1,2-Bis(methylphenylphosphinoyl)ethene. In: Acta Crystallographica. Section E: Structure Reports Online 65 (2009), Nr. 3, o517. DOI: http://dx.doi.org/10.1107/S1600536809004632
http://www.repo.uni-hannover.de/handle/123456789/542
http://dx.doi.org/10.15488/518
The title compound, C(16)H(18)O(2)P(2), possesses two stereogenic P atoms and shows a distorted s-cis conformation of each O=P-C=C moiety. This has been suggested on the basis of the stereochemical result of 1,3-dipolar cyclo-additions with nitro-nes and is now confirmed by the present crystal structure analysis. There are two crystallographically independent molecules in the asymmetric unit.
eng
https://creativecommons.org/licenses/by/2.0/uk
CC BY 2.0 UK
single-crystal
X-ray study
(SP,SP)-(–)-(E)-1,2-Bis(methylphenylphosphinoyl)ethene
Article
Text
oai:www.repo.uni-hannover.de:123456789/5432022-12-02T16:16:26Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Baessler, Bettina
Schaarschmidt, Frank
Schnackenburg, Bernhard
Stehning, Christian
Giolda, Agathe D.
Maintz, David
Bunck, Alexander
2016-09-06T07:58:01Z
2016-09-06T07:58:01Z
2015
Baessler, Bettina; Schaarschmidt, Frank; Schnackenburg, Bernhard; Stehning, Christian; Giolda, Agathe D. Et al.: Reproducibility of three different cardiac T2-mapping sequences at 1.5T and impact of cofactors on T2-relaxation times. In: Journal of Cardiovascular Magnetic Resonance 17 (2015), Suppl. 1, W12. DOI: http://dx.doi.org/10.1186/1532-429X-17-S1-W12
http://www.repo.uni-hannover.de/handle/123456789/543
http://dx.doi.org/10.15488/519
Background: The high interindividual variability of myocardial T2 relaxation times appears to be one of the main challenges for the clinical application of cardiac T2-mapping. This study therefore aimed to evaluate potential underlying causes for this variability, analyzing the reproducibility of three different cardiac T2-mapping sequences and evaluating the influence of cofactors on T2 relaxation times. Methods: 30 healthy volunteers were examined three times on a clinical 1.5T scanner (scan 1: in the morning; scan 2: in the evening of the same day; scan 3: in the evening 2-3 weeks later). In each examination three different T2-mapping sequences were acquired at three slices in short axis view: Multi Echo Spin Echo (MESE), T2-prepared balanced Steady State Free Precession (T2prep; [1]) and Gradient Spin Echo (GraSE). Repeated measurements were performed for T2prep and GraSE. Segmented T2-maps were generated for each slice according to the AHA 17-segment model. Intra- and inter-observer reproducibility was tested in a subgroup of 10 randomly selected subjects, where manual ROIs were drawn independently to measure T2 values of each segment blinded to the other results. Results: Overall, we observed no systematic difference of T2 times due to diurnal effects and on long-term analysis. Differentiated analysis of variance components for all sequences, however, revealed a greater variance of T2 times over multiple time points than for repeated measurements within the same scan. Our study revealed a low intra-observer and inter-observer variability of manual ROI-definition and the acquired T2 times for each sequence. The coefficients of variation and intraclass correlation coefficients for intra-observer variability were: 1.3% and 0.89 for T2prep, 1.5% and 0.93 for GraSE, 3.1% and 0.83 for MESE; and for inter-observer variability: 3.3% and 0.66 for T2prep, 2.0% and 0.83 for GraSE, 3.6% and 0.77 for MESE. With respect to the influence of potential cofactors on T2 times, we observed a negative effect of the cofactor heart rate on mean T2 values, yet this effect proved to be not significant. Conversely, we found significant and positive relation between mean T2 times and the cofactors age, weight and height (p < 0.005, p < 0.05 and p < 0.05) in single linear regression models. Using multiple regression models, we observed significant relations between mean T2 times and age (p < 0.005), gender (p < 0.01), and either weight or height (p < 0.005), for given values of the remaining cofactors. Conclusions: Intra- and inter-observer reproducibility of all tested T2-mapping sequnces is high, thereby confirming previous studies. According to our study, the high interindividual variability of myocardial T2 relaxation times is most likely due to proband-related effects such as age, gender, weight and height and other cofactors intraindividually varying with time.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
T2-mapping
radiology
Reproducibility of three different cardiac T2-mapping sequences at 1.5T and impact of cofactors on T2-relaxation times
Article
Text
oai:www.repo.uni-hannover.de:123456789/5442022-12-02T16:14:10Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Baessler, Bettina
Schaarschmidt, Frank
Dick, Anastasia
Stehning, Christian
Schnackenburg, Bernhard
Michels, Guido
Maintz, David
Bunck, Alexander C.
2016-09-06T07:58:01Z
2016-09-06T07:58:01Z
2015
Baessler, Bettina; Schaarschmidt, Frank; Dick, Anastasia; Stehning, Christian; Schnackenburg, Bernhard et al.: Mapping tissue inhomogeneity in acute myocarditis: a novel analytical approach to quantitative myocardial edema imaging by T2-mapping. In: Journal of Cardiovascular Magnetic Resonance 17 (2015), 115
http://www.repo.uni-hannover.de/handle/123456789/544
http://dx.doi.org/10.15488/520
BACKGROUND: The purpose of the present study was to investigate the diagnostic value of T2-mapping in acute myocarditis (ACM) and to define cut-off values for edema detection. METHODS: Cardiovascular magnetic resonance (CMR) data of 31 patients with ACM were retrospectively analyzed. 30 healthy volunteers (HV) served as a control. Additionally to the routine CMR protocol, T2-mapping data were acquired at 1.5 T using a breathhold Gradient-Spin-Echo T2-mapping sequence in six short axis slices. T2-maps were segmented according to the 16-segments AHA-model and segmental T2 values as well as the segmental pixel-standard deviation (SD) were analyzed. RESULTS: Mean differences of global myocardial T2 or pixel-SD between HV and ACM patients were only small, lying in the normal range of HV. In contrast, variation of segmental T2 values and pixel-SD was much larger in ACM patients compared to HV. In random forests and multiple logistic regression analyses, the combination of the highest segmental T2 value within each patient (maxT2) and the mean absolute deviation (MAD) of log-transformed pixel-SD (madSD) over all 16 segments within each patient proved to be the best discriminators between HV and ACM patients with an AUC of 0.85 in ROC-analysis. In classification trees, a combined cut-off of 0.22 for madSD and of 68 ms for maxT2 resulted in 83% specificity and 81% sensitivity for detection of ACM. CONCLUSIONS: The proposed cut-off values for maxT2 and madSD in the setting of ACM allow edema detection with high sensitivity and specificity and therefore have the potential to overcome the hurdles of T2-mapping for its integration into clinical routine.
eng
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Cardiovascular magnetic resonance
Tissue characterization
Acute myocarditis
T2-mapping
Myocardial edema
Mapping tissue inhomogeneity in acute myocarditis: a novel analytical approach to quantitative myocardial edema imaging by T2-mapping
Article
Text
oai:www.repo.uni-hannover.de:123456789/5472022-12-02T15:17:13Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Gross, Günter
2016-09-12T13:13:52Z
2016-09-12T13:13:52Z
2016
Gross, Günter: Dispersion of traffic exhausts emitted from a stationary line source versus individual moving cars – a numerical comparison. In: Meteorologische Zeitschrift 25 (2016), Nr. 4, S. 479-487. DOI: http://dx.doi.org/10.1127/metz/2016/0797
http://www.repo.uni-hannover.de/handle/123456789/547
http://dx.doi.org/10.15488/523
A three-dimensional microscale model was used to study the effects of moving vehicles on air pollution in the close vicinity of a road. The numerical results are compared to general findings from wind tunnel experiments and field observations. It was found that the model is suitable to capture the main flow characteristics within an urban street canyon, in particular the modifications relating to running traffic. A comparison of the results for a stationary line source approach and for multiple single moving sources demonstrates significant differences. For a street in a flat terrain, the near-road concentrations are underestimated by up to a factor of two if the emissions are approximated by a stationary line source. This underestimation decreases with increasing distance, and becomes negligible 30–50 m away from the road. For an urban canyon situation, the line source assumption is a conservative approximation for the concentrations at the leeside of the street, while on the opposite pavement and wall, a systematic underestimation was found. Also, the effects of different traffic situations have been studied and discussed.
eng
https://creativecommons.org/licenses/by-nc/3.0/
CC BY-NC 3.0 Unported
Micro-scale simulation
running traffic
vehicle dispersion
urban canyon concentration
Dispersion of traffic exhausts emitted from a stationary line source versus individual moving cars – a numerical comparison
Article
Text
oai:www.repo.uni-hannover.de:123456789/5512022-12-02T16:14:10Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Labusch, Corinna
Effendi, Yunus
Fulda, Martin
Scherer, Günther F.E.
2016-09-12T13:13:52Z
2016-09-12T13:13:52Z
2016
Labusch, Corinna; Effendi, Yunus; Fulda, Martin; Scherer, Gunther F. E.: Transcription of TIR1-Controlled Genes Can be Regulated within 10 Min by an Auxin-Induced Process. Can TIR1 be the Receptor? In: Frontiers in Plant Science 7 (2016), 995. DOI: http://dx.doi.org/10.3389/fpls.2016.00995
http://www.repo.uni-hannover.de/handle/123456789/551
http://dx.doi.org/10.15488/527
ABP1 and TIR1/AFBs are known as auxin receptors. ABP1 is linked to auxin responses several of which are faster than 10 min. TIR1 regulates auxin-induced transcription of early auxin genes also within minutes. We use transcription of such TIR1-dependent genes as indicator of TIR1 activity to show the rapid regulation of TIR1 by exogenous auxin. To this end, we used quantification of transcription of a set of fifteen early auxin-induced reporter genes at t = 10 and t = 30 min to measure this as a TIR1-dependent auxin response. We conducted this study in 22 mutants of auxin transporters (pin5, abcb1, abcb19, and aux1/lax3), protein kinases and phosphatases (ibr5, npr1, cpk3, CPK3-OX, d6pk1, d6pkl1-1, d6pkl3-2, d6pkl1-1/d6pkl2-2, and d6pkl1-1/d6pkl3-2), of fatty acid metabolism (fad2-1, fad6-1, ssi2, lacs4, lacs9, and lacs4/lacs9) and receptors (tir1, tir1/afb2, and tir1/afb3) and compared them to the wild type. After 10 min auxin application, in 18 out of 22 mutants mis-regulated expression of at least one reporter was found, and in 15 mutants transcription of two-to-three out of five selected auxin reporter genes was mis-regulated. After 30 min of auxin application to mutant plants, mis-regulation of reporter genes ranged from one to 13 out of 15 tested reporter genes. Those genes chosen as mutants were themselves not regulated in their expression by auxin for at least 1 h, excluding an influence of TIR1/AFBs on their transcription. The expression of TIR1/AFB genes was also not modulated by auxin for up to 3 h. Together, this excludes a feedback or feedforward of these mutant genes/proteins on TIR1/AFBs output of transcription in this auxin-induced response. However, an auxin-induced response needed an as yet unknown auxin receptor. We suggest that the auxin receptor necessary for the fast auxin-induced transcription modulation could be, instead, ABP1. The alternative hypothesis would be that auxin-induced expression of a protein, initiated by TIR1/AFBs receptors, could initiate these responses and that this unknown protein regulated TIR1/AFB activities within 10 min.
eng
http://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
AUXIN-BINDING PROTEIN 1
early auxin-induced genes
auxin transport mutants
auxin receptor mutants
fatty acid-metabolism mutants
protein kinase mutants
protein phosphatase mutants
TRANSPORT INHIBITOR RESPONSE 1
Transcription of TIR1-Controlled Genes Can be Regulated within 10 Min by an Auxin-Induced Process. Can TIR1 be the Receptor?
Article
Text
oai:www.repo.uni-hannover.de:123456789/5572022-12-02T15:19:58Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Sambale, Franziska
Wagner, S.
Stahl, Frank
Khaydarov, R.R.
Scheper, Thomas
Bahnemann, Detlef W.
2016-09-29T11:44:59Z
2016-09-29T11:44:59Z
2015
Sambale, F.; Wagner, S.; Stahl, F.; Khaydarov, R. R.; Scheper, T.; Bahnemann, Detlef W.: Investigations of the Toxic Effect of Silver Nanoparticles on Mammalian Cell Lines. In: Journal of Nanomaterials 2015 (2015), 136765. DOI: http://dx.doi.org/10.1155/2015/136765
http://www.repo.uni-hannover.de/handle/123456789/557
http://dx.doi.org/10.15488/533
Silver nanoparticles are widely used for many applications. In this study silver nanoparticles have been tested for their toxic effect on fibroblasts (NIH-3T3), on a human lung adenocarcinoma epithelial cell line (A-549), on PC-12-cells, a rat adrenal pheochromocytoma cell line, and on HEP-G2-cells, a human hepatocellular carcinoma cell line. The viability of the cells cultivated with different concentrations of silver was determined by the MTT assay, a photometric method to determine cell metabolism. Dose-response curves were extrapolated and IC50, total lethal concentration (TLC), and no observable adverse effect concentration (NOAEC) values were calculated for each cell line. As another approach, ECIS (electric-cell-substrate-impedance-sensing) an automated method to monitor cellular behavior in real-time was applied to observe cells cultivated with silver nanoparticles. To identify the type of cell death the membrane integrity was analyzed by measurements of the lactate dehydrogenase releases and by determination of the caspase 3/7 activity. To ensure that the cytotoxic effect of silver nanoparticles is not traced back to the presence of Ag+ ions in the suspension, an Ag+ salt (AgNO3) has been examined at the same concentration of Ag+ present in the silver nanoparticle suspension that is assuming that the Ag particles are completely available as Ag+ ions.
eng
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
in-vitro cytotoxicity
textile fabrics
antibacterial
nanosilver
colloids
growth
ions
Investigations of the Toxic Effect of Silver Nanoparticles on Mammalian Cell Lines
Article
Text
oai:www.repo.uni-hannover.de:123456789/5582022-12-02T16:14:10Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Pan, Jia Hong
Bahnemann, Detlef W.
Wang, Qing
Wang, Chuanyi
Zhang, Xiwang
2016-09-29T11:44:59Z
2016-09-29T11:44:59Z
2014
Pan, Jia Hong; Bahnemann, Detlef W.; Wang, Qing; Wang, Chuanyi; Zhang, Xiwang: Solar Energy Conversion by Nanostructured TiO2. In: International Journal of Photoenergy 2014 (2014), 704729. DOI: http://dx.doi.org/10.1155/2014/704729
http://www.repo.uni-hannover.de/handle/123456789/558
http://dx.doi.org/10.15488/534
Research in solar energy conversion and the associated photoactive materials has attracted continuous interest. Due to its proper electronic band structure, high quantum efficiency, and photonic and chemical innerness, TiO2 has been demonstrated as a versatile oxide semiconductor capable of efficiently utilizing sunlight to produce electrical and chemical energy. Its outstanding physicochemical performances have led to an array of advanced photocatalytic and photoelectrochemical applications including environmental photocatalysis, dye/semiconductor-sensitized solar cell, and solar fuel productions.
eng
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
solar energy
TiO2
Solar Energy Conversion by Nanostructured TiO2
Article
Text
oai:www.repo.uni-hannover.de:123456789/5592022-12-02T16:10:15Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Kamil, Ahmed M.
Hussein, Falah H.
Halbus, Ahmed F.
Bahnemann, Detlef W.
2016-09-29T11:45:02Z
2016-09-29T11:45:02Z
2014
Kamil, Ahmed M.; Hussein, Falah H.; Halbus, Ahmed F.; Bahnemann, Detlef W.: Preparation, Characterization, and Photocatalytic Applications of MWCNTs/TiO2 Composite. In: International Journal of Photoenergy 2014 (2014), 475713. DOI: http://dx.doi.org/10.1155/2014/475713
http://www.repo.uni-hannover.de/handle/123456789/559
http://dx.doi.org/10.15488/535
The multiwall carbon nanotubes (MWCNTs)/titanium dioxide (P25) composite in different ratios was prepared using simple evaporation and drying process. The composite was characterized by Raman spectroscopy, X-ray diffraction (XRD), UV-visible diffuse reflectance spectroscopy, and scanning electron microscopy (SEM). The photocatalytic activity of this composite was investigated using degradation of the Bismarck brown R dye (BBR). An optimal MWCNTs/TiO2 ratio of 0.5% (w/w) was found to achieve the maximum rate of BBR degradation. It was observed that the composite exhibits enhanced photocatalytic activity compared with TiO2. The enhancement in photocatalytic activity performance of the MWCNTs/P25 composite is explained in terms of recombination of photogenerated electron-hole pairs. In addition, MWCNTs act as a dispersing support to control the morphology of TiO2 particles in the MWCNTs/TiO2 composite.
eng
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
walled carbon nanotubes
mechanical-properties
raman-spectra
tio2
nanocomposites
spectroscopy
degradation
films
Preparation, Characterization, and Photocatalytic Applications of MWCNTs/TiO2 Composite
Article
Text
oai:www.repo.uni-hannover.de:123456789/5602022-12-02T15:19:58Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Karam, Faiq F.
Hussein, Falah H.
Baqir, Sadiq J.
Halbus, Ahmed F.
Dillert, Ralf
Bahnemann, Detlef W.
2016-09-29T11:45:02Z
2016-09-29T11:45:02Z
2014
Karam, Faiq F.; Hussein, Falah H.; Baqir, Sadiq J.; Halbus, Ahmed F.; Dillert, Ralf; Bahnemann, Detlef W.: Photocatalytic Degradation of Anthracene in Closed System Reactor. In: International Journal of Photoenergy 2014 (2014), 503825. DOI: http://dx.doi.org/10.1155/2014/503825
http://www.repo.uni-hannover.de/handle/123456789/560
http://dx.doi.org/10.15488/536
Polycyclic aromatic hydrocarbons (PAHs) represent a large class of persistent organic pollutants in an environment of special concern because they have carcinogenic and mutagenic activity. In this paper, we focus on and discuss the effect of different parameters, for instance, initial concentration of Anthracene, temperature, and light intensity, on the degradation rate. These parameters were adjusted at pH 6.8 in the presence of the semiconductor materials (TiO2) as photocatalysts overUVlight. The main product of Anthracene photodegradation is 9,10-Anthraquinone which isidentified and compared with the standard compound by GC-MS. Our results indicate that the optimum conditions for the best rate of degradation are 25 ppm concentration of Anthracene, regulating the reaction vessel at 308.15 K and 2.5 mW/cm(2) of light intensity at 17 5mg/100 mL of titanium dioxide (P25).
eng
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
polycyclic aromatic-hydrocarbons
dyeing waste-water
titanium-dioxide
soil surfaces
uv-light
fluorescence detection
tio2
irradiation
extraction
pahs
Photocatalytic Degradation of Anthracene in Closed System Reactor
Article
Text
oai:www.repo.uni-hannover.de:123456789/5612022-12-02T16:14:10Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Ahmed, Luma M.
Ivanova, Irina
Hussein, Falah H.
Bahnemann, Detlef W.
2016-09-29T11:45:02Z
2016-09-29T11:45:02Z
2014
Ahmed, Luma M.; Ivanova, Irina; Hussein, Falah H.; Bahnemann, Detlef W.: Role of Platinum Deposited on TiO2 in Photocatalytic Methanol Oxidation and Dehydrogenation Reactions. In: International Journal of Photoenergy 2014 (2014), 503516. DOI: http://dx.doi.org/10.1155/2014/503516
http://www.repo.uni-hannover.de/handle/123456789/561
http://dx.doi.org/10.15488/537
Titania modified nanoparticles have been prepared by the photodeposition method employing platinum particles on the commercially available titanium dioxide (Hombikat UV 100). The properties of the prepared photocatalysts were investigated by means of the Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM), and UV-visible diffuse spectrophotometry (UV-Vis). XRD was employed to determine the crystallographic phase and particle size of both bare and platinised titanium dioxide. The results indicated that the particle size was decreased with the increasing of platinum loading. AFM analysis showed that one particle consists of about 9 to 11 crystals. UV-vis absorbance analysis showed that the absorption edge shifted to longer wavelength for 0.5% Pt loading compared with bare titanium dioxide. The photocatalytic activity of pure and Pt-loaded TiO2 was investigated employing the photocatalytic oxidation and dehydrogenation of methanol. The results of the photocatalytic activity indicate that the platinized titanium dioxide samples are always more active than the corresponding bare TiO2 for both methanol oxidation and dehydrogenation processes. The loading with various platinum amounts resulted in a significant improvement of the photocatalytic activity of TiO2. This beneficial effect was attributed to an increased separation of the photogenerated electron-hole charge carriers.
eng
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
layered double hydroxides
visible-light photoactivity
sol-gel preparation
exposed 001 facets
titanium-dioxide
nanoparticles
anatase
catalysts
water
microspheres
Role of Platinum Deposited on TiO2 in Photocatalytic Methanol Oxidation and Dehydrogenation Reactions
Article
Text
oai:www.repo.uni-hannover.de:123456789/5632022-12-02T15:19:58Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Menendez-Flores, Victor M.
Friedmann, Donia
Bahnemann, Detlef W.
2016-09-29T11:45:04Z
2016-09-29T11:45:04Z
2008
Menendez-Flores, Victor M.; Friedmann, Donia; Bahnemann, Detlef W.: Durability of Ag-TiO(2) Photocatalysts Assessed for the Degradation of Dichloroacetic Acid. In: International Journal of Photoenergy 2008 (2008), 280513. DOI: http://dx.doi.org/10.1155/2008/280513
http://www.repo.uni-hannover.de/handle/123456789/563
http://dx.doi.org/10.15488/539
The stability of Ag-TiO(2) photocatalysts was examined for the photocatalytic degradation of dichloroacetic acid (DCA) as a function of the recycling times. The photocatalytic activity was investigated by measuring the rate of H(+) ions released during the photodegradation of DCA and confirmed by measuring the total organic carbon removal. The photodegradation reactions were studied at pH 3 and pH 10 for a series of Ag-TiO(2) photocatalysts as different with Ag loadings. All the Ag-TiO(2) and bare TiO(2) photocatalysts showed a decrease in photocatalytic activity on recycling for the DCA photodegradation reaction. The decrease in activity can be attributed to poisoning of active sites by Cl(-) anions formed during the photocatalytic DCA degradation. The photocatalytic activity was, however, easily recovered by a simple washing technique. The reversibility of the poisoning is taken as evidence to support the idea that the recycling of Ag-P25 TiO(2) photocatalysts does not have a permanent negative effect on their photocatalytic performance for the degradation of DCA. The choice of the preparation procedure for the Ag-TiO2 photocatalysts is shown to be of significant importance for the observed changes in the photocatalytic activity of the Ag-TiO2 particles. Copyright (C) 2008 Victor M. Menendez-Flores et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
eng
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
water detoxification
titanium-dioxide
ag+ ions
silver
tio2
clusters
quartz
mineralization
deposition
particles
Durability of Ag-TiO(2) Photocatalysts Assessed for the Degradation of Dichloroacetic Acid
Article
Text
oai:www.repo.uni-hannover.de:123456789/5642022-12-02T16:14:09Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Leong, Kah Hon
Sim, Lan Ching
Bahnemann, Detlef W.
Jang, Min
Ibrahim, Shaliza
Saravanan, Pichiah
2016-09-29T11:45:04Z
2016-09-29T11:45:04Z
2015
Leong, Kah Hon; Sim, Lan Ching; Bahnemann, Detlef W.; Jang, Min; Ibrahim, Shaliza; Saravanan, Pichiah: Reduced graphene oxide and Ag wrapped TiO2 photocatalyst for enhanced visible light photocatalysis. In: APL Materials 3 (2015), Nr. 10, 104503. DOI: http://dx.doi.org/10.1063/1.4926454
http://www.repo.uni-hannover.de/handle/123456789/564
http://dx.doi.org/10.15488/540
A well-organised reduced graphene oxide (RGO) and silver (Ag) wrapped TiO2 nano-hybrid was successfully achieved through a facile and easy route. The inherent characteristics of the synthesized RGO-Ag/TiO2 were revealed through crystalline phase, morphology, chemical composition, Raman scattering, UV-visible absorption, and photoluminescence analyses. The adopted synthesis route significantly controlled the uniform formation of silver nanoparticles and contributed for the absorption of light in the visible spectrum through localized surface plasmon resonance effects. The wrapped RGO nanosheets triggered the electron mobility and promoted visible light shift towards red spectrum. The accomplishment of synergised effect of RGO and Ag well degraded Bisphenol A under visible light irradiation with a removal efficiency of 61.9%.
eng
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Silver
visible light
surface plasmons
charge carriers
surface charge
Reduced graphene oxide and Ag wrapped TiO2 photocatalyst for enhanced visible light photocatalysis
Article
Text
oai:www.repo.uni-hannover.de:123456789/5652022-12-02T15:19:58Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Ganesh Babu, S.
Vinoth, R.
Surya Narayana, P.
Bahnemann, Detlef W.
Neppolian, B.
2016-09-29T11:45:04Z
2016-09-29T11:45:04Z
2015
Ganesh Babu, S.; Vinoth, R.; Surya Narayana, P.; Bahnemann, Detlef W.; Neppolian, B.: Reduced graphene oxide wrapped Cu2O supported on C3N4: An efficient visible light responsive semiconductor photocatalyst. In: APL Materials 3 (2015), Nr. 11, 104415. DOI: http://dx.doi.org/10.1063/1.4928286
http://www.repo.uni-hannover.de/handle/123456789/565
http://dx.doi.org/10.15488/541
Herein, Cu 2O spheres were prepared and encapsulated with reduced graphene oxide (rGO). The Cu 2O–rGO–C3N4 composite covered the whole solar spectrum with significant absorption intensity. rGO wrapped Cu 2O loading caused a red shift in the absorption with respect to considering the absorption of bare C3N4. The photoluminescence study confirms that rGO exploited as an electron transport layer at the interface of Cu 2O and C3N4 heterojunction. Utmost, ∼2 fold synergistic effect was achieved with Cu 2O–rGO–C3N4 for the photocatalytic reduction of 4-nitrophenol to 4-aminophenol in comparison with Cu 2O–rGO and C3N4. The Cu 2O–rGO–C3N4 photocatalyst was reused for four times without loss in its activity.
eng
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Visible light
band gap
x-ray diffraction
copper
heterojunctions
Reduced graphene oxide wrapped Cu2O supported on C3N4: An efficient visible light responsive semiconductor photocatalyst
Article
Text
oai:www.repo.uni-hannover.de:123456789/5662022-12-02T15:19:58Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Dillert, Ralf
Taffa, Dereje H.
Wark, Michael
Bredow, Thomas
Bahnemann, Detlef W.
2016-09-29T11:45:04Z
2016-09-29T11:45:04Z
2015
Dillert, Ralf; Taffa, Dereje H.; Wark, Michael; Bredow, Thomas; Bahnemann, Detlef W.: Research Update: Photoelectrochemical water splitting and photocatalytic hydrogen production using ferrites (MFe2O4) under visible light irradiation. In: APL Materials 3 (2015), Nr. 12, 104001. DOI: http://dx.doi.org/10.1063/1.4931763
http://www.repo.uni-hannover.de/handle/123456789/566
http://dx.doi.org/10.15488/542
The utilization of solar light for the photoelectrochemical and photocatalytic production of molecular hydrogen from water is a scientific and technical challenge. Semiconductors with suitable properties to promote solar-driven water splitting are a desideratum. A hitherto rarely investigated group of semiconductors are ferrites with the empirical formula MFe2O4 and related compounds. This contribution summarizes the published results of the experimental investigations on the photoelectrochemical and photocatalytic properties of these compounds. It will be shown that the potential of this group of compounds in regard to the production of solar hydrogen has not been fully explored yet.
eng
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Electrodes
ferrities
visible light
illumination
photoelectric conversion
Research Update: Photoelectrochemical water splitting and photocatalytic hydrogen production using ferrites (MFe2O4) under visible light irradiation
Article
Text
oai:www.repo.uni-hannover.de:123456789/5692022-12-02T15:02:17Zcom_123456789_1col_123456789_3ddc:550doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Taubenböck, H.
Goseberg, Nils
Setiadi, N.
Lämmel, G.
Moder, F.
Oczipka, M.
Klüpfel, H.
Wahl, R.
Schlurmann, Torsten
Strunz, G.
Birkmann, J.
Nagel, K.
Siegert, F.
Lehmann, F.
Dech, S.
Gress, A.
Klein, R.
2016-10-28T09:05:25Z
2016-10-28T09:05:25Z
2009
Taubenböck, H.; Goseberg, N.; Setiadi, N.; Lämmel, G.; Moder, F.: "Last-Mile" preparation for a potential disaster - Interdisciplinary approach towards tsunami early warning and an evacuation information system for the coastal city of Padang, Indonesia. In: Natural Hazards and Earth System Science 9 (2009), Nr. 4 , S. 1509-1528. DOI: http://dx.doi.org/10.5194/nhess-9-1509-2009
http://www.repo.uni-hannover.de/handle/123456789/569
http://dx.doi.org/10.15488/545
Extreme natural events, like e.g. tsunamis or earthquakes, regularly lead to catastrophes with dramatic consequences. In recent years natural disasters caused hundreds of thousands of deaths, destruction of infrastructure, disruption of economic activity and loss of billions of dollars worth of property and thus revealed considerable deficits hindering their effective management: Needs for stakeholders, decision-makers as well as for persons concerned include systematic risk identification and evaluation, a way to assess countermeasures, awareness raising and decision support systems to be employed before, during and after crisis situations. The overall goal of this study focuses on interdisciplinary integration of various scientific disciplines to contribute to a tsunami early warning information system. In comparison to most studies our focus is on high-end geometric and thematic analysis to meet the requirements of smallscale, heterogeneous and complex coastal urban systems. Data, methods and results from engineering, remote sensing and social sciences are interlinked and provide comprehensive information for disaster risk assessment, management and reduction. In detail, we combine inundation modeling, urban morphology analysis, population assessment, socioeconomic analysis of the population and evacuation modeling. The interdisciplinary results eventually lead to recommendations for mitigation strategies in the fields of spatial planning or coping capacity.
eng
http://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
coastal zone
coping strategy
decision support system
disaster management
early warning system
natural hazard
risk assessment
stakeholder
strategic approach
tsunami
Indonesia
"Last-Mile" preparation for a potential disaster - Interdisciplinary approach towards tsunami early warning and an evacuation information system for the coastal city of Padang, Indonesia
Article
Text
oai:www.repo.uni-hannover.de:123456789/5702022-12-02T16:14:09Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Breznica-Selmani, Pranvera
Mladenovska, Kristina
Kavrakovski, Zoran
Mikhova, Bozhana
Draeger, Gerald
Popovski, Emil
2016-10-28T09:05:26Z
2016-10-28T09:05:26Z
2015
Breznica-Selmani, P.; Mladenovska, K.; Kavrakovski, Z.; Mikhova, B.; Draeger, Gerald et al.: [(3-Chlorobenzamido)methyl]triethylammonium chloride. In: MolBank 2015 (2015), Nr. 2, M851. DOI: http://dx.doi.org/10.3390/M851
http://www.repo.uni-hannover.de/handle/123456789/570
http://dx.doi.org/10.15488/546
We report the synthesis of [(3-chlorobenzamido)methyl]triethylammonium chloride in a reaction of N-(chloromethyl)-3-chlorobenzamide and triethylamine in dry acetone. The structure of the newly synthesized compound was characterized with1H-NMR,13C-NMR, FTIR and Mass spectroscopy.
eng
http://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Benzamidomethylation
N-(chloromethyl)-3-chlorobenzamide
[(3-Chlorobenzamido)methyl]triethylammonium chloride
Article
Text
oai:www.repo.uni-hannover.de:123456789/5712022-12-02T16:14:09Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Cludius-Brandt, Stephan
Kupracz, Lukas
Kirschning, Andreas
2016-10-28T09:05:29Z
2016-10-28T09:05:29Z
2013
Cludius-Brandt, Stephan; Kupracz, Lukas; Kirschning, Andreas: [3 + 2]-Cycloadditions of nitrile ylides after photoactivion of vinyl azides under flow conditions. In: Beilstein Journal of Organic Chemistry 9 (2013), 1745. DOI: http://dx.doi.org/10.3762/bjoc.9.201
http://www.repo.uni-hannover.de/handle/123456789/571
http://dx.doi.org/10.15488/547
The photodenitrogenation of vinyl azides to 2H-azirines by using a photoflow reactor is reported and compared with thermal formation of 2H-azirines. Photochemically, the ring of the 2H-azirines was opened to yield the nitrile ylides, which underwent a [3 + 2]-cycloaddition with 1,3-dipolarophiles. When diisopropyl azodicarboxylate serves as the dipolarophile, 1,3,4-triazoles become directly accessible starting from the corresponding vinyl azide.
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
Azirines
Cycloaddition
Flow chemistry
Flow reactors
Inductive heating
Nitrile ylides
Photochemistry
Vinyl azides
[3 + 2]-Cycloadditions of nitrile ylides after photoactivion of vinyl azides under flow conditions
Article
Text
oai:www.repo.uni-hannover.de:123456789/5762022-12-02T15:15:03Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessddc:530status-type:publishedVersionddc:500
Burgess, C.P.
Van Nierop, L.
Parameswaran, Susha L.
Salvio, A.
Williams, M.
2016-10-28T09:05:31Z
2016-10-28T09:05:31Z
2013
Burgess, C.P.; Van Nierop, L.; Parameswaran, S.; Salvio, A.; Williams, M.: Accidental SUSY: Enhanced bulk supersymmetry from brane back-reaction. In: Journal of High Energy Physics 2013 (2013), Nr. 2, S. 1-64. DOI: http://dx.doi.org/10.1007/JHEP02(2013)120
http://www.repo.uni-hannover.de/handle/123456789/576
http://dx.doi.org/10.15488/552
We compute how bulk loops renormalize both bulk and brane effective interactions for codimension-two branes in 6D gauged chiral supergravity, as functions of the brane tension and brane-localized flux. We do so by explicitly integrating out hyper- and gauge-multiplets in 6D gauged chiral supergravity compactified to 4D on a flux-stabilized 2D rugby-ball geometry, specializing the results of a companion paper, arXiv:1210.3753 , to the supersymmetric case. While the brane back-reaction generically breaks supersymmetry, we show that the bulk supersymmetry can be preserved if the amount of brane- localized flux is related in a specific BPS-like way to the brane tension, and verify that the loop corrections to the brane curvature vanish in this special case. In these systems it is the brane-bulk couplings that fix the size of the extra dimensions, and we show that in some circumstances the bulk geometry dynamically adjusts to ensure the supersymmetric BPS-like condition is automatically satisfied. We investigate the robustness of this residual supersymmetry to loops of non-supersymmetric matter on the branes, and show that supersymmetry- breaking effects can enter only through effective brane-bulk interactions involving at least two derivatives. We comment on the relevance of this calculation to proposed applications of codimension-two 6D models to solutions of the hierarchy and cosmological constant problems.
eng
http://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Flux compactifications
Large Extra Dimensions
Renormalization Group
Supergravity Models
Accidental SUSY: Enhanced bulk supersymmetry from brane back-reaction
Article
Text
oai:www.repo.uni-hannover.de:123456789/5782023-09-20T07:05:22Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Behrend, Anne
Borchert, Thomas
Spiller, Monika
Hohe, Annette
2016-10-28T09:05:31Z
2016-10-28T09:05:31Z
2013
Behrend, A.; Borchert, T.; Spiller, Monika; Hohe, A.: AFLP-based genetic mapping of the "bud-flowering" trait in heather (Calluna vulgaris). In: BMC Genetics 14 (2013) , 64. DOI: http://dx.doi.org/10.1186/1471-2156-14-64
http://www.repo.uni-hannover.de/handle/123456789/578
http://dx.doi.org/10.15488/554
Background: Calluna vulgaris is one of the most important landscaping plants produced in Germany. Its enormous economic success is due to the prolonged flower attractiveness of mutants in flower morphology, the so-called bud-bloomers. In this study, we present the first genetic linkage map of C. vulgaris in which we mapped a locus of the economically highly desired trait " flower type" .Results: The map was constructed in JoinMap 4.1. using 535 AFLP markers from a single mapping population. A large fraction (40%) of markers showed distorted segregation. To test the effect of segregation distortion on linkage estimation, these markers were sorted regarding their segregation ratio and added in groups to the data set. The plausibility of group formation was evaluated by comparison of the " two-way pseudo-testcross" and the " integrated" mapping approach. Furthermore, regression mapping was compared to the multipoint-likelihood algorithm. The majority of maps constructed by different combinations of these methods consisted of eight linkage groups corresponding to the chromosome number of C. vulgaris.Conclusions: All maps confirmed the independent inheritance of the most important horticultural traits " flower type" , " flower colour" , and " leaf colour". An AFLP marker for the most important breeding target " flower type" was identified. The presented genetic map of C. vulgaris can now serve as a basis for further molecular marker selection and map-based cloning of the candidate gene encoding the unique flower architecture of C. vulgaris bud-bloomers.
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
Bud-bloomer
Flower architecture
Linkage map
ML mapping
Molecular marker
amplified fragment length polymorphism
article
bud
Calluna
calluna vulgaris
chromosome number
controlled study
flower
flowering
gene locus
gene mapping
genetic linkage
genetic trait
inheritance
nonhuman
segregation distortion
Algorithms
Amplified Fragment Length Polymorphism Analysis
Calluna
Flowers
Genetic Linkage
Likelihood Functions
Calluna
Calluna vulgaris
AFLP-based genetic mapping of the " bud-flowering" trait in heather (Calluna vulgaris)
Article
Text
oai:www.repo.uni-hannover.de:123456789/5812022-12-02T16:14:09Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Grau, Jan
Reschke, Maik
Erkes, Annett
Streubel, Jana
Morgan, Richard D.
Wilson, Geoffrey G.
Koebnik, Ralf
Boch, Jens
2016-10-28T09:54:26Z
2016-10-28T09:54:26Z
2016
Grau, J.; Reschke, Maik; Erkes, A.; Streubel, Jana; Morgan, R.D. et al.: AnnoTALE: Bioinformatics tools for identification, annotation, and nomenclature of TALEs from Xanthomonas genomic sequences. In: Scientific Reports 6 (2016), 21077. DOI: http://dx.doi.org/10.1038/srep21077
http://www.repo.uni-hannover.de/handle/123456789/581
http://dx.doi.org/10.15488/557
Transcription activator-like effectors (TALEs) are virulence factors, produced by the bacterial plant-pathogen Xanthomonas, that function as gene activators inside plant cells. Although the contribution of individual TALEs to infectivity has been shown, the specific roles of most TALEs, and the overall TALE diversity in Xanthomonas spp. is not known. TALEs possess a highly repetitive DNA-binding domain, which is notoriously difficult to sequence. Here, we describe an improved method for characterizing TALE genes by the use of PacBio sequencing. We present 'AnnoTALE', a suite of applications for the analysis and annotation of TALE genes from Xanthomonas genomes, and for grouping similar TALEs into classes. Based on these classes, we propose a unified nomenclature for Xanthomonas TALEs that reveals similarities pointing to related functionalities. This new classification enables us to compare related TALEs and to identify base substitutions responsible for the evolution of TALE specificities.
eng
http://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
bioinformatics
classification
DNA transcription
gene expression
gene expression regulation
genome
nomenclature
nucleic acid base substitution
transcription initiation
transcription regulation
Xanthomonas
AnnoTALE: Bioinformatics tools for identification, annotation, and nomenclature of TALEs from Xanthomonas genomic sequences
Article
Text
oai:www.repo.uni-hannover.de:123456789/5822022-12-02T16:10:15Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:570ddc:500
Ude, Christian
Schmidt-Hager, Jörg
Findeis, Michael
John, Gernot Thomas
Scheper, Thomas
Beutel, Sascha
2016-10-28T09:54:26Z
2016-10-28T09:54:26Z
2014
Ude, Christian; Schmidt-Hager, Jörg; Findeis, M.; John, G.T.; Scheper, Thomas et al.: Application of an online-biomass sensor in an optical multisensory platform prototype for growth monitoring of biotechnical relevant microorganism and cell lines in single-use shake flasks. In: Sensors (Basel, Switzerland) 14 (2014), Nr. 9, S. 17390-17405. DOI: http://dx.doi.org/10.3390/s140917390
http://www.repo.uni-hannover.de/handle/123456789/582
http://dx.doi.org/10.15488/558
In the context of this work we evaluated a multisensory, noninvasive prototype platform for shake flask cultivations by monitoring three basic parameters (pH, pO2 and biomass). The focus lies on the evaluation of the biomass sensor based on backward light scattering. The application spectrum was expanded to four new organisms in addition to E. coli K12 and S. cerevisiae [1]. It could be shown that the sensor is appropriate for a wide range of standard microorganisms, e.g., L. zeae, K. pastoris, A. niger and CHO-K1. The biomass sensor signal could successfully be correlated and calibrated with well-known measurement methods like OD600, cell dry weight (CDW) and cell concentration. Logarithmic and Bleasdale-Nelder derived functions were adequate for data fitting. Measurements at low cell concentrations proved to be critical in terms of a high signal to noise ratio, but the integration of a custom made light shade in the shake flask improved these measurements significantly. This sensor based measurement method has a high potential to initiate a new generation of online bioprocess monitoring. Metabolic studies will particularly benefit from the multisensory data acquisition. The sensor is already used in labscale experiments for shake flask cultivations.
eng
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
animal
biochemical oxygen demand
cell count
cell proliferation
cell size
CHO cell line
Cricetulus
densitometry
device failure analysis
devices
equipment design
online system
photometry
physiology
refractometry
system analysis
Animals
Biological Oxygen Demand Analysis
Cell Count
Cell Proliferation
Cell Size
CHO Cells
Cricetulus
Densitometry
Equipment Design
Equipment Failure Analysis
Online Systems
Photometry
Refractometry
Systems Integration
Application of an online-biomass sensor in an optical multisensory platform prototype for growth monitoring of biotechnical relevant microorganism and cell lines in single-use shake flasks
Article
Text
oai:www.repo.uni-hannover.de:123456789/5852022-12-02T16:11:41Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Schäfer, K.
Grant, R.H.
Emeis, S.
Raabe, A.
Heide, Carolin von der
Schmid, H.P.
2016-10-28T09:54:27Z
2016-10-28T09:54:27Z
2012
Schäfer, K.; Grant, R.H.; Emeis, S.; Raabe, A.; Von Der Heide, C. et al.: Areal-averaged trace gas emission rates from long-range open-path measurements in stable boundary layer conditions. In: Atmospheric Measurement Techniques 5 (2012), Nr. 7, S. 1571-1583. DOI: http://dx.doi.org/10.5194/amt-5-1571-2012
http://www.repo.uni-hannover.de/handle/123456789/585
http://dx.doi.org/10.15488/561
Measurements of land-surface emission rates of greenhouse and other gases at large spatial scales (10 000 m2) are needed to assess the spatial distribution of emissions. This can be readily done using spatial-integrating micro-meteorological methods like flux-gradient methods which were evaluated for determining land-surface emission rates of trace gases under stable boundary layers. Non-intrusive path-integrating measurements are utilized. Successful application of a flux-gradient method requires confidence in the gradients of trace gas concentration and wind, and in the applicability of boundary-layer turbulence theory; consequently the procedures to qualify measurements that can be used to determine the flux is critical. While there is relatively high confidence in flux measurements made under unstable atmospheres with mean winds greater than 1 m s-1, there is greater uncertainty in flux measurements made under free convective or stable conditions. The study of N2O emissions of flat grassland and NH3 emissions from a cattle lagoon involves quality-assured determinations of fluxes under low wind, stable or night-time atmospheric conditions when the continuous "steady-state" turbulence of the surface boundary layer breaks down and the layer has intermittent turbulence. Results indicate that following the Monin-Obukhov similarity theory (MOST) flux-gradient methods that assume a log-linear profile of the wind speed and concentration gradient incorrectly determine vertical profiles and thus flux in the stable boundary layer. An alternative approach is considered on the basis of turbulent diffusivity, i.e. the measured friction velocity as well as height gradients of horizontal wind speeds and concentrations without MOST correction for stability. It is shown that this is the most accurate of the flux-gradient methods under stable conditions.
eng
http://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
concentration (composition)
emission inventory
flux measurement
friction
grassland
land surface
micrometeorology
nitrous oxide
spatial distribution
trace gas
turbulent boundary layer
vertical profile
wind velocity
Bos
Areal-averaged trace gas emission rates from long-range open-path measurements in stable boundary layer conditions
Article
Text
oai:www.repo.uni-hannover.de:123456789/5862022-12-02T16:14:09Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:580ddc:500
Brüggenwirth, Martin
Fricke, Heiko
Knoche, Moritz
2016-10-28T09:54:27Z
2016-10-28T09:54:27Z
2014
Brüggenwirth, Martin; Fricke, Heiko; Knoche, Moritz: Biaxial tensile tests identify epidermis and hypodermis as the main structural elements of sweet cherry skin. In: AoB PLANTS 6 (2014), plu019. DOI: http://dx.doi.org/10.1093/aobpla/plu019
http://www.repo.uni-hannover.de/handle/123456789/586
http://dx.doi.org/10.15488/562
The skin of developing soft and fleshy fruit is subjected to considerable growth stress, and failure of the skin is associated with impaired barrier properties in water transport and pathogen defence. The objectives were to establish a standardized, biaxial tensile test of the skin of soft and fleshy fruit and to use it to characterize and quantify mechanical properties of the sweet cherry (Prunus avium) fruit skin as a model. A segment of the exocarp (ES) comprising cuticle, epidermis, hypodermis and adhering flesh was mounted in the elastometer such that the in vivo strain was maintained. The ES was pressurized from the inner surface and the pressure and extent of associated bulging were recorded. Pressure: strain responses were almost linear up to the point of fracture, indicating that the modulus of elasticity was nearly constant. Abrading the cuticle decreased the fracture strain but had no effect on the fracture pressure. When pressure was held constant, bulging of the ES continued to increase. Strain relaxation upon releasing the pressure was complete and depended on time. Strains in longitudinal and latitudinal directions on the bulging ES did not differ significantly. Exocarp segments that released their in vivo strain before the test had higher fracture strains and lower moduli of elasticity. The results demonstrate that the cherry skin is isotropic in the tangential plane and exhibits elastic and viscoelastic behaviour. The epidermis and hypodermis, but not the cuticle, represent the structural 'backbone' in a cherry skin. This test is useful in quantifying the mechanical properties of soft and fleshy fruit of a range of species under standardized conditions.
eng
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Biomechanics
fracture
mechanical properties
Prunus avium
rheology
skin
stiffness
strain
Biaxial tensile tests identify epidermis and hypodermis as the main structural elements of sweet cherry skin
Article
Text
oai:www.repo.uni-hannover.de:123456789/5882022-12-02T16:10:15Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Minuth, Tobias
Boysen, Mike M. K.
2016-10-28T09:54:27Z
2016-10-28T09:54:27Z
2010
Minuth, Tobias; Boysen, Mike M. K.: Bis(oxazolines) based on glycopyranosides - Steric, configurational and conformational influences on stereoselectivity. In: Beilstein Journal of Organic Chemistry 6 (2010), 23. DOI: http://dx.doi.org/10.3762/bjoc.6.23
http://www.repo.uni-hannover.de/handle/123456789/588
http://dx.doi.org/10.15488/564
In previous studies we found that the asymmetric induction of bis(oxazolines) based on D-glucosamine strongly depended on the steric demand of the 3-O-substituents. To further probe the impact of the 3-position of the pyranose scaffold, we prepared 3-epimerised and 3-defunctionalised versions of these ligands as well as a 3-O-formyl derivative. Application of these new ligands in asymmetric cyclopropanation revealed strong steric and configurational effects of position 3 on asymmetric induction, further dramatic effects of the pyranose conformation were also observed.
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
Asymmetric synthesis
Carbohydrates
Copper
Cyclopropanation
Ligand design
Bis(oxazolines) based on glycopyranosides - Steric, configurational and conformational influences on stereoselectivity
Article
Text
oai:www.repo.uni-hannover.de:123456789/5902022-12-02T16:10:15Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Kirschning, Andreas
2016-10-28T09:54:28Z
2016-10-28T09:54:28Z
2011
Kirschning, Andreas: Chemistry in flow systems II. In: Beilstein Journal of Organic Chemistry 7 (2011) , S. 1046-1047. DOI: http://dx.doi.org/10.3762/bjoc.7.119
http://www.repo.uni-hannover.de/handle/123456789/590
http://dx.doi.org/10.15488/566
[No abstract available]
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
Flow chemistry
Chemistry in flow systems II
Article
Text
oai:www.repo.uni-hannover.de:123456789/5912022-12-02T16:10:15Zcom_123456789_1col_123456789_8doc-type:Articleddc:540doc-type:Textopen_accessstatus-type:publishedVersionddc:500
Kirschning, Andreas
2016-10-28T09:54:28Z
2016-10-28T09:54:28Z
2013
Kirschning, Andreas: Chemistry in flow systems III. In: Beilstein Journal of Organic Chemistry 9 (2013), S. 1696-1697. DOI: http://dx.doi.org/10.3762/bjoc.9.193
http://www.repo.uni-hannover.de/handle/123456789/591
http://dx.doi.org/10.15488/567
[No abstract available]
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
Flow chemistry
Chemistry in flow systems III
Article
Text
oai:www.repo.uni-hannover.de:123456789/5922022-12-02T16:11:40Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:610ddc:500
Burblies, Niklas
Schulze, Jennifer
Schwarz, Hans-Christoph
Kranz, Katharina
Motz, Damian
Vogt, Carla
Lenarz, Thomas
Warnecke, Athanasia
Behrens, Peter
2016-10-28T09:54:28Z
2016-10-28T09:54:28Z
2016
Burblies, Niklas; Schulze, Jennifer; Schwarz, H.-C.; Kranz, K.; Motz, D. Et al.: Coatings of different carbon nanotubes on platinum electrodes for neuronal devices: Preparation, cytocompatibility and interaction with spiral ganglion cells. In: PLoS ONE 11 (2016), Nr. 7, e0158571. DOI: http://dx.doi.org/10.1371/journal.pone.0158571
http://www.repo.uni-hannover.de/handle/123456789/592
http://dx.doi.org/10.15488/568
Cochlear and deep brain implants are prominent examples for neuronal prostheses with clinical relevance. Current research focuses on the improvement of the long-term functionality and the size reduction of neural interface electrodes. A promising approach is the application of carbon nanotubes (CNTs), either as pure electrodes but especially as coating material for electrodes. The interaction of CNTs with neuronal cells has shown promising results in various studies, but these appear to depend on the specific type of neurons as well as on the kind of nanotubes. To evaluate a potential application of carbon nanotube coatings for cochlear electrodes, it is necessary to investigate the cytocompatibility of carbon nanotube coatings on platinum for the specific type of neuron in the inner ear, namely spiral ganglion neurons. In this study we have combined the chemical processing of as-delivered CNTs, the fabrication of coatings on platinum, and the characterization of the electrical properties of the coatings as well as a general cytocompatibility testing and the first cell culture investigations of CNTs with spiral ganglion neurons. By applying a modification process to three different as-received CNTs via a reflux treatment with nitric acid, long-term stable aqueous CNT dispersions free of dispersing agents were obtained. These were used to coat platinum substrates by an automated spray-coating process. These coatings enhance the electrical properties of platinum electrodes, decreasing the impedance values and raising the capacitances. Cell culture investigations of the different CNT coatings on platinum with NIH3T3 fibroblasts attest an overall good cytocompatibility of these coatings. For spiral ganglion neurons, this can also be observed but a desired positive effect of the CNTs on the neurons is absent. Furthermore, we found that the well-established DAPI staining assay does not function on the coatings prepared from single-wall nanotubes. © 2016 Burblies et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
eng
http://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
platinum
neurons
carbon nanotubes
thin film
cell cultures
fibroblasts
Coatings of different carbon nanotubes on platinum electrodes for neuronal devices: Preparation, cytocompatibility and interaction with spiral ganglion cells
Article
Text
oai:www.repo.uni-hannover.de:123456789/5932022-12-02T16:11:41Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:580ddc:500
Guretzki, Sebastian
Papenbrock, Jutta
2016-10-31T07:58:54Z
2016-10-31T07:58:54Z
2013
Guretzki, S.; Papenbrock, Jutta: Comparative analysis of methods analyzing effects of drought on the herbaceous plant Lablab purpureas. In: Journal of Applied Botany and Food Quality 89 (2013), Nr. 1 , S. 47-54. DOI: http://dx.doi.org/10.5073/JABFQ.2013.086.007
http://www.repo.uni-hannover.de/handle/123456789/593
http://dx.doi.org/10.15488/569
Due to the changing climatic conditions, there is an enlargement of land areas with insufficient rainfall and therefore a reduction in the cultivated area for common crops. Hence, it is now important to find plants that are adapted to these drought conditions. The focus of our research was to apply and compare different methods to quantify the impact of drought stress on plants. Lablab purpureus is considered to be drought tolerant. Therefore, we used L. purpureus genotypes from three continents CPI 36903 (Europe), CPI 52508 (Africa) and HA-4 (Asia) as examples for our study. All genotypes were screened for their tolerance to drought stress by various methods to obtain quantitative data on the drought stress tolerance of individual genotypes and to find out which methods are especially suitable for the measurement of drought tolerance. Classical methods such as leaf size, plant height, biomass, and plant water content were investigated. In addition, by chlorophyll fluorescence measurement effects of drought on the photosynthetic system were examined. Infrared thermography was used in order to make the changes in leaf temperature in plants stressed by drought compared to unstressed plants visible. The methods were complemented by the measurement of leaf conductivity. Results indicate a difference in the usability of the methods for the determination of drought stress. Finally, a set of methods is assembled based on suitability for drought tolerance analysis in plants. The methods include classical growth parameters, including dry weight biomass, plant water content (PWC) and leaf size determination, as well as height measurements of the plants. The stomata behavior is analyzed by leaf conductivity and infrared thermography, both methods complete the set for drought tolerance identification. Based on the results of these methods a ranking of the examined genotypes with respect to their drought tolerance is created.
eng
https://creativecommons.org/licenses/by-sa/4.0/
CC BY-SA 4.0 Unported
adaptation
biomass
climate conditions
comparative study
data set
drought stress
genotype
herb
measurement method
tolerance
Lablab
Lablab purpureus
Comparative analysis of methods analyzing effects of drought on the herbaceous plant Lablab purpureas
Article
Text
oai:www.repo.uni-hannover.de:123456789/6022022-12-02T16:10:15Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:570ddc:500
Vanz, Ana Leticia
Nimtz, Manfred
Rinas, Ursula
2016-10-31T07:59:01Z
2016-10-31T07:59:01Z
2014
Vanz, Ana Leticia.; Nimtz, M.; Rinas, Ursula: Decrease of UPR- and ERAD-related proteins in Pichia pastoris during methanol-induced secretory insulin precursor production in controlled fed-batch cultures. In: Microbial Cell Factories 13 (2014), Nr. 1, 23. DOI: http://dx.doi.org/10.1186/1475-2859-13-23
http://www.repo.uni-hannover.de/handle/123456789/602
http://dx.doi.org/10.15488/578
Background: Pichia pastoris is a popular yeast preferably employed for secretory protein production. Secretion is not always efficient and endoplasmic retention of proteins with aberrant folding properties, or when produced at exaggerated rates, can occur. In these cases production usually leads to an unfolded protein response (UPR) and the induction of the endoplasmic reticulum associated degradation (ERAD). P. pastoris is nowadays also an established host for secretory insulin precursor (IP) production, though little is known about the impact of IP production on the host cell physiology, in particular under industrially relevant production conditions. Here, we evaluate the cellular response to aox1 promoter-controlled, secretory IP production in controlled fed-batch processes using a proteome profiling approach.Results: Cells were first grown in a batch procedure using a defined medium with a high glycerol concentration. After glycerol depletion IP production was initiated by methanol addition which was kept constant through continuous methanol feeding. The most prominent changes of the intracellular proteome after the onset of methanol feeding were related to the enzymes of central carbon metabolism. In particular, the enzymes of the methanol dissimilatory pathway - virtually absent in the glycerol batch phase - dominated the proteome during the methanol fed-batch phase. Unexpectedly, a strong decrease of UPR and ERAD related proteins was also observed during methanol-induced IP production. Compared to non-producing control strains grown under identical conditions the UPR down-regulation was less pronounced indicating that IP production elicits a detectable but non prominent UPR response which is repressed by the general culture condition-dependent UPR down-regulation after the shift from glycerol to methanol.Conclusions: The passage of IP through the secretory pathway using an optimized IP vector and growing the strain at fed-batch conditions with a high initial glycerol concentration does not impose a significant burden on the secretory machinery even under conditions leading to an extracellular accumulation of ~ 3 g L-1 IP. The glycerol batch pre-induction culture conditions are associated with a high constitutive - recombinant protein production independent - induction of the UPR and ERAD pathways probably preconditioning the cells for effective IP secretion in the methanol fed-batch phase.
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
Endoplasmic reticulum associated degradation (ERAD)
Insulin precursor
Methanol metabolism
Pichia pastoris
Proteome
Two-dimensional gel electrophoresis
Unfolded protein response (UPR)
Batch Cell Culture Techniques
Endoplasmic Reticulum-Associated Degradation
Glycerol
Methanol
Pichia
Proinsulin
Proteome
Recombinant Proteins
Secretory Pathway
Unfolded Protein Response
Decrease of UPR- and ERAD-related proteins in Pichia pastoris during methanol-induced secretory insulin precursor production in controlled fed-batch cultures
Article
Text
oai:www.repo.uni-hannover.de:123456789/6072022-12-02T16:10:15Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:570ddc:500
Schmidt, Simone
Stahl, Frank
Mutz, Kai-Oliver
Scheper, Thomas
Hahn, Andreas
Schuchardt, Jan Philipp
2016-10-31T10:06:38Z
2016-10-31T10:06:38Z
2012
Schmidt, Simone; Stahl, Frank; Mutz, Kai-Oliver; Scheper, Thomas; Hahn, Andreas et al.: Different gene expression profiles in normo- and dyslipidemic men after fish oil supplementation: Results from a randomized controlled trial. In: Lipids in Health and Disease 11 (2012), 105. DOI: http://dx.doi.org/10.1186/1476-511X-11-105
http://www.repo.uni-hannover.de/handle/123456789/607
http://dx.doi.org/10.15488/583
Background: Epidemiological studies have suggested the benefits of omega-3 polyunsaturated fatty acids (n-3 PUFAs) on cardiovascular health, but only limited data are available describing n-3 PUFA regulated pathways in humans. The aim of this study was to investigate the effects of n-3 PUFA administration on whole genome expression profiles in the blood of normo- and dyslipidemic subjects. Methods. Differentially expressed genes were detected after four hours, one week and twelve weeks of supplementation with either fish oil (FO) or corn oil in normo- and dyslipidemic men using whole genome microarrays. Results: Independent of the oil, a significantly higher number of genes was regulated in dyslipidemic subjects compared to normolipidemic subjects. Pathway analyses discovered metabolisms dominantly affected by FO after twelve weeks of supplementation, including the lipid metabolism, immune system and cardiovascular diseases. Several pro-inflammatory genes, in particular, were down-regulated in dyslipidemic subjects, indicating the immune-modulatory and anti-inflammatory capability of FO and its bioactive FAs, eicosapentaenoic acid and docosahexaenoic acid. Conclusions: This is the first study showing significant differences in gene expression profiles between normo- and dyslipidemic men after FO supplementation. Further studies need to clarify the exact role of n-3 PUFAs in pathways and metabolisms which were identified as being regulated after FO supplementation in this study. Trial registration. ClinicalTrials.gov (ID: NCT01089231).
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
Cardiovascular disease
Dyslipidemia
Gene regulation
Genome microarrays
Hypertriglyceridemia
Lipid metabolism
Omega-3 fatty acids
Omega-3 index
Pathway analysis
cholesterol
docosahexaenoic acid
fish oil
high density lipoprotein
icosapentaenoic acid
low density lipoprotein
membrane lipid
omega 3 fatty acid
triacylglycerol
adult
antiinflammatory activity
article
cardiovascular disease
clinical article
controlled study
diet supplementation
double blind procedure
down regulation
dyslipidemia
erythrocyte membrane
gene expression profiling
gene expression regulation
human
immune system
immunomodulation
lipid blood level
lipid composition
lipid metabolism
microarray analysis
nucleotide sequence
randomized controlled trial
Adult
Corn Oil
Double-Blind Method
Dyslipidemias
Erythrocyte Membrane
Fatty Acids
Fatty Acids, Omega-3
Fish Oils
Humans
Immune System
Lipid Metabolism
Lipids
Male
Middle Aged
Oligonucleotide Array Sequence Analysis
RNA
Transcriptome
Zea mays
Different gene expression profiles in normo- and dyslipidemic men after fish oil supplementation: Results from a randomized controlled trial
Article
Text
oai:www.repo.uni-hannover.de:123456789/6082022-12-02T16:14:09Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:570ddc:500
Hass, Ralf
Kasper, Cornelia
Böhm, Stefanie
Jacobs, Roland
2016-10-31T10:06:39Z
2016-10-31T10:06:39Z
2011
Hass, R.; Kasper, Cornelia; Böhm, Stefanie; Jacobs, R.: Different populations and sources of human mesenchymal stem cells (MSC): A comparison of adult and neonatal tissue-derived MSC. In: Cell Communication and Signaling 9 (2011), 12. DOI: http://dx.doi.org/10.1186/1478-811X-9-12
http://www.repo.uni-hannover.de/handle/123456789/608
http://dx.doi.org/10.15488/584
The mesenchymal stroma harbors an important population of cells that possess stem cell-like characteristics including self renewal and differentiation capacities and can be derived from a variety of different sources. These multipotent mesenchymal stem cells (MSC) can be found in nearly all tissues and are mostly located in perivascular niches. MSC have migratory abilities and can secrete protective factors and act as a primary matrix for tissue regeneration during inflammation, tissue injuries and certain cancers. These functions underlie the important physiological roles of MSC and underscore a significant potential for the clinical use of distinct populations from the various tissues. MSC derived from different adult (adipose tissue, peripheral blood, bone marrow) and neonatal tissues (particular parts of the placenta and umbilical cord) are therefore compared in this mini-review with respect to their cell biological properties, surface marker expression and proliferative capacities. In addition, several MSC functions including in vitro and in vivo differentiation capacities within a variety of lineages and immune-modulatory properties are highlighted. Differences in the extracellular milieu such as the presence of interacting neighbouring cell populations, exposure to proteases or a hypoxic microenvironment contribute to functional developments within MSC populations originating from different tissues, and intracellular conditions such as the expression levels of certain micro RNAs can additionally balance MSC function and fate.
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
gamma interferon
Jagged1
mycophenolic acid
rapamycin
toll like receptor 3
adipogenesis
age distribution
binding affinity
cell differentiation
cell function
cell hypoxia
cell interaction
cell lineage
cell migration
cell population
cellular immunity
density gradient centrifugation
graft versus host reaction
human
immunogenicity
immunomodulation
immunoregulation
in vitro study
in vivo study
low drug dose
mesenchymal stem cell
microenvironment
nonhuman
osteoblast
oxidative stress
placenta
plasticity
priority journal
protein expression
review
synapse
tissue distribution
umbilical cord
Different populations and sources of human mesenchymal stem cells (MSC): A comparison of adult and neonatal tissue-derived MSC
Article
Text
oai:www.repo.uni-hannover.de:123456789/6102022-12-02T15:19:59Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Sharifi, Monir
Wallacher, Dirk
Wark, Michael
2016-10-31T10:06:39Z
2016-10-31T10:06:39Z
2012
Sharifi, Monir; Wallacher D.; Wark M.: Distribution of functional groups in periodic Mesoporous organosilica materials studied by small-angle neutron scattering with in situ adsorption of nitrogen. In: Beilstein Journal of Nanotechnology 3 82012), Nr. 1, S. 428-437. DOI: http://dx.doi.org/10.3762/bjnano.3.49
http://www.repo.uni-hannover.de/handle/123456789/610
http://dx.doi.org/10.15488/586
Periodic mesoporous materials of the type (R'O) 3Si-R-Si(OR') 3 with benzene as an organic bridge and a crystal-like periodicity within the pore walls were functionalized with SO 3H or SO 3 - groups and investigated by small-angle neutron scattering (SANS) with in situ nitrogen adsorption at 77 K. If N 2 is adsorbed in the pores the SANS measurements show a complete matching of all of the diffraction signals that are caused by the long-range ordering of the mesopores in the benzene-PMO, due to the fact that the benzene-PMO walls possess a neutron scattering length density (SLD) similar to that of nitrogen in the condensed state. However, signals at higher q-values (>1 1/Å) are not affected with respect to their SANS intensity, even after complete pore filling, confirming the assumption of a crystal-like periodicity within the PMO material walls due to π-π interactions between the organic bridges. The SLD of pristine benzene-PMO was altered by functionalizing the surface with different amounts of SO3H-groups, using the grafting method. For a low degree of functionalization (0.81 mmol SO 3H·g -1) and/or an inhomogeneous distribution of the SO 3H-groups, the SLD changes only negligibly, and thus, complete contrast matching is still found. However, for higher amounts of SO 3H-groups (1.65 mmol SO 3H·g -1) being present in the mesopores, complete matching of the neutron diffraction signals is no longer observed proving that homogeneously distributed SO 3H-groups on the inner pore walls of the benzene-PMO alter the SLD in a way that it no longer fits to the SLD of the condensed N 2.
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
Contrast matching
Crystal-like periodicity
Distribution of functional groups
Pmo
Sans
Surface functionalization
Contrast matching
Crystal-like periodicity
Pmo
Sans
Surface Functionalization
Benzene
Functional groups
Mesoporous materials
Neutron diffraction
Neutron scattering
Nitrogen
Pore pressure
Quay walls
Silica
Silicon
Gas adsorption
Distribution of functional groups in periodic Mesoporous organosilica materials studied by small-angle neutron scattering with in situ adsorption of nitrogen
Article
Text
oai:www.repo.uni-hannover.de:123456789/6122022-12-02T16:11:40Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:570ddc:500
Schmidt, Simone
Willers, Janina
Riecker, Sabine
Möller, Katharina
Schuchardt, Jan Philipp
Hahn, Andreas
2016-10-31T10:06:39Z
2016-10-31T10:06:39Z
2015
Schmidt, Simone; Willers, Janina; Riecker, Sabine; Möller, Katharina; Schuchardt, Jan Philipp et al.: Effect of omega-3 polyunsaturated fatty acids on the cytoskeleton: An open-label intervention study. In: Lipids in Health and Disease 14 (2015), 4: DOI: http://dx.doi.org/10.1186/1476-511X-14-4
http://www.repo.uni-hannover.de/handle/123456789/612
http://dx.doi.org/10.15488/588
Background: Omega-3 polyunsaturated fatty acids (n-3 PUFAs) show beneficial effects on cardiovascular health and cognitive functions, but the underlying molecular mechanisms are not completely understood. Because of the fact that cytoskeleton dynamics affect almost every cellular process, the regulation of cytoskeletal dynamics could be a new pathway by which n-3 PUFAs exert their effects on cellular level. Methods: A 12-week open-label intervention study with 12 healthy men was conducted to determine the effects of 2.7 g/d n-3 PUFA on changes in mRNA expression of cytoskeleton-associated genes by quantitative real-time PCR in whole blood. Furthermore, the actin content in red blood cells was analyzed by immunofluorescence imaging. Results: N-3 PUFA supplementation resulted in a significant down-regulation of cytoskeleton-associated genes, in particular three GTPases (RAC1, RHOA, CDC42), three kinases (ROCK1, PAK2, LIMK), two Wiskott-Aldrich syndrome proteins (WASL, WASF2) as well as actin related protein 2/3 complex (ARPC2, ARPC3) and cofilin (CFL1). Variability in F-actin content between subjects was high; reduced actin content was only reduced within group evaluation. Conclusions: Reduced cytoskeleton-associated gene expression after n-3 PUFA supplementation suggests that regulation of cytoskeleton dynamics might be an additional way by which n-3 PUFAs exert their cellular effects. Concerning F-actin, this analysis did not reveal unmistakable results impeding a generalized conclusion.
eng
http://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Cytoskeleton
F-actin
Gene-expression
GTPases
n-3 PUFA
Omega-3 index
Red blood cells
Effect of omega-3 polyunsaturated fatty acids on the cytoskeleton: An open-label intervention study
Article
Text
oai:www.repo.uni-hannover.de:123456789/6142022-12-02T15:12:30Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
McKenzie, R.L.
Weinreis, C.
Johnston, P.V.
Liley, B.
Shiona, H.
Kotkamp, M.
Smale, D.
Takegawa, N.
Kondo, Y.
2016-10-31T10:06:40Z
2016-10-31T10:06:40Z
2008
McKenzie, R.L.; Weinreis, C.; Johnston, P.V.; Liley, B.; Shiona, H. et al.: Effects of urban pollution on UV spectral irradiances. In: Atmospheric Chemistry and Physics 8 (2008), Nr. 18, S. 5683-5697. DOI: http://dx.doi.org/10.5194/acp-8-5683-2008
http://www.repo.uni-hannover.de/handle/123456789/614
http://dx.doi.org/10.15488/590
Spectral measurements of UV irradiances at Tokyo are compared with corresponding measurements at a pristine site (Lauder New Zealand) to identify the causes of the reductions in urban UV irradiances, and to quantify their effects. Tropospheric extinctions in Tokyo were found to be up to ∼40% greater than at Lauder. Most of these differences can be explained by differences in cloud and aerosols, but ozone differences are also important in the summer. Examining spectral signatures of tropospheric transmission of both sites shows that reductions due to mean NO2 and SO2 amounts are generally small. However, at times the amount of NO2 can be 10 times higher than the mean amount, and on these days it can decrease the UVA irradiance up to 40%. If SO2 shows comparable day to day variability, it would contribute to significant reductions in UVB irradiances. The results indicate that at Tokyo, interactions between the larger burden of tropospheric ozone and aerosols also have a significant effect. These results have important implications for our ability to accurately retrieve surface UV irradiances at polluted sites from satellites that use backscattered UV. Supplementary data characterising these boundary layer effects are probably needed.
eng
http://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
atmospheric pollution
backscatter
boundary layer
irradiance
nitrogen dioxide
ozone
pollution effect
pristine environment
satellite data
spectral analysis
sulfur dioxide
troposphere
ultraviolet radiation
Asia
Eurasia
Far East
Honshu
Japan
Kanto
Tokyo [Kanto]
Effects of urban pollution on UV spectral irradiances
Article
Text
oai:www.repo.uni-hannover.de:123456789/6202022-12-02T15:19:58Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:570ddc:500
Terefe-Ayana, Diro
Kaufmann, Helgard
Linde, Marcus
Debener, Thomas
2016-10-31T13:37:19Z
2016-10-31T13:37:19Z
2012
Terefe-Ayana, Diro; Kaufmann, Helgard; Linde, Marcus; Debener, Thomas: Evolution of the Rdr1 TNL-cluster in roses and other Rosaceous species. In: BMC Genomics 13 (2012), Nr. 1, 409. DOI: http://dx.doi.org/10.1186/1471-2164-13-409
http://www.repo.uni-hannover.de/handle/123456789/620
http://dx.doi.org/10.15488/596
Background: The resistance of plants to pathogens relies on two lines of defense: a basal defense response and a pathogen-specific system, in which resistance (R) genes induce defense reactions after detection of pathogen-associated molecular patterns (PAMPS). In the specific system, a so-called arms race has developed in which the emergence of new races of a pathogen leads to the diversification of plant resistance genes to counteract the pathogens' effect. The mechanism of resistance gene diversification has been elucidated well for short-lived annual species, but data are mostly lacking for long-lived perennial and clonally propagated plants, such as roses. We analyzed the rose black spot resistance gene, Rdr1, in five members of the Rosaceae: Rosa multiflora, Rosa rugosa, Fragaria vesca (strawberry), Malus x domestica (apple) and Prunus persica (peach), and we present the deduced possible mechanism of R-gene diversification.Results: We sequenced a 340.4-kb region from R. rugosa orthologous to the Rdr1 locus in R. multiflora. Apart from some deletions and rearrangements, the two loci display a high degree of synteny. Additionally, less pronounced synteny is found with an orthologous locus in strawberry but is absent in peach and apple, where genes from the Rdr1 locus are distributed on two different chromosomes. An analysis of 20 TIR-NBS-LRR (TNL) genes obtained from R. rugosa and R. multiflora revealed illegitimate recombination, gene conversion, unequal crossing over, indels, point mutations and transposable elements as mechanisms of diversification.A phylogenetic analysis of 53 complete TNL genes from the five Rosaceae species revealed that with the exception of some genes from apple and peach, most of the genes occur in species-specific clusters, indicating that recent TNL gene diversification began prior to the split of Rosa from Fragaria in the Rosoideae and peach from apple in the Spiraeoideae and continued after the split in individual species. Sequence similarity of up to 99% is obtained between two R. multiflora TNL paralogs, indicating a very recent duplication.Conclusions: The mechanisms by which TNL genes from perennial Rosaceae diversify are mainly similar to those from annual plant species. However, most TNL genes appear to be of recent origin, likely due to recent duplications, supporting the hypothesis that TNL genes in woody perennials are generally younger than those from annuals. This recent origin might facilitate the development of new resistance specificities, compensating for longer generation times in woody perennials.
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
apple
article
chromosome analysis
controlled study
Fragaria
Fragaria vesca
gene cluster
gene conversion
gene deletion
gene duplication
gene locus
gene rearrangement
gene sequence
genetic recombination
genetic similarity
genetic variability
nonhuman
nucleotide sequence
peach
phylogeny
plant gene
point mutation
promoter region
R gene
Rdr1 gene
Rosa multiflora
Rosa rugosa
Rosaceae
rose
Rosoideae
sequence alignment
species difference
Spiraeoideae
strawberry
TNL gene
transposon
Chromosomes
Cluster Analysis
Contig Mapping
Evolution, Molecular
Fragaria
Genes, Plant
Genetic Loci
Malus
Phylogeny
Plant Proteins
Prunus
Repressor Proteins
Rosa
Fragaria
Fragaria vesca
Fragaria x ananassa
Malus x domestica
Prunus persica
Rosa
Rosa multiflora
Rosa rugosa
Rosaceae
Rosoideae
Evolution of the Rdr1 TNL-cluster in roses and other Rosaceous species
Article
Text
oai:www.repo.uni-hannover.de:123456789/6272022-12-02T15:19:58Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:570ddc:500
Majore, Ingrida
Moretti, Pierre
Hass, Ralf
Kasper, Cornelia
2016-10-31T13:37:22Z
2016-10-31T13:37:22Z
2009
Majore, Ingrida; Moretti, Pierre; Hass, R.; Kasper, Cornelia: Identification of subpopulations in mesenchymal stem cell-like cultures from human umbilical cord. In: Cell Communication and Signaling 7 (2009), 6. DOI: http://dx.doi.org/10.1186/1478-811X-7-6
http://www.repo.uni-hannover.de/handle/123456789/627
http://dx.doi.org/10.15488/603
Background: A variety of cell types can be identified in the adherent fraction of bone marrow mononuclear cells including more primitive and embryonic-like stem cells, mesenchymal stem cells (MSC), lineage-committed progenitors as well as mature cells such as osteoblasts and fibroblasts. Different methods are described for the isolation of single bone marrow stem cell subpopulations - beginning from ordinary size sieving, long term cultivation under specific conditions to FACS-based approaches. Besides bone marrow-derived subpopulations, also other tissues including human umbilical cord (UC) have been recently suggested to provide a potential source for MSC. Although of clinical importance, these UC-derived MSC populations remain to be characterized. It was thus the aim of the present study to identify possible subpopulations in cultures of MSC-like cells obtained from UC. We used counterflow centrifugal elutriation (CCE) as a novel strategy to successfully address this question. Results: UC-derived primary cells were separated by CCE and revealed differentially-sized populations in the fractions. Thus, a subpopulation with an average diameter of about 11 μm and a small flat cell body was compared to a large sized subpopulation of about 19 μm average diameter. Flow cytometric analysis revealed the expression of certain MSC stem cell markers including CD44, CD73, CD90 and CD105, respectively, although these markers were expressed at higher levels in the small-sized population. Moreover, this small-sized subpopulation exhibited a higher proliferative capacity as compared to the total UC-derived primary cultures and the large-sized cells and demonstrated a reduced amount of aging cells. Conclusion: Using the CCE technique, we were the first to demonstrate a subpopulation of small-sized UC-derived primary cells carrying MSC-like characteristics according to the presence of various mesenchymal stem cell markers. This is also supported by the high proliferative capacity of these MSC-like cells as compared to whole primary culture or other UC-derived subpopulations. The accumulation of a self-renewing MSC-like subpopulation by CCE with low expression levels of the aging marker senescence-associated β-galactosidase provides a valuable tool in the regenerative medicine and an alternative to bone-marrow-derived MSC.
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
Counterflow Centrifugal Elutriation
CCE
mesenchymal stem cells
MSC
Identification of subpopulations in mesenchymal stem cell-like cultures from human umbilical cord
Article
Text
oai:www.repo.uni-hannover.de:123456789/6322022-12-02T15:19:58Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:570ddc:500
Schuchardt, Jan Philipp
Schneider, Inga
Meyer, Henrike
Neubronner, Juliane
Schacky, C. von
Hahn, Andreas
2016-11-02T08:33:43Z
2016-11-02T08:33:43Z
2011
Schuchardt, Jan Philipp; Schneider, Inga; Meyer, Henrike; Neubronner, Juliane; Von Schacky, C. et al.: Incorporation of EPA and DHA into plasma phospholipids in response to different omega-3 fatty acid formulations - A comparative bioavailability study of fish oil vs. krill oil. In: Lipids in Health and Disease 10 (2011), 145. DOI: http://dx.doi.org/10.1186/1476-511X-10-145
http://www.repo.uni-hannover.de/handle/123456789/632
http://dx.doi.org/10.15488/608
Background: Bioavailability of omega-3 fatty acids (FA) depends on their chemical form. Superior bioavailability has been suggested for phospholipid (PL) bound omega-3 FA in krill oil, but identical doses of different chemical forms have not been compared. Methods. In a double-blinded crossover trial, we compared the uptake of three EPA+DHA formulations derived from fish oil (re-esterified triacylglycerides [rTAG], ethyl-esters [EE]) and krill oil (mainly PL). Changes of the FA compositions in plasma PL were used as a proxy for bioavailability. Twelve healthy young men (mean age 31 y) were randomized to 1680 mg EPA+DHA given either as rTAG, EE or krill oil. FA levels in plasma PL were analyzed pre-dose and 2, 4, 6, 8, 24, 48, and 72 h after capsule ingestion. Additionally, the proportion of free EPA and DHA in the applied supplements was analyzed. Results: The highest incorporation of EPA+DHA into plasma PL was provoked by krill oil (mean AUC 0-72 h: 80.03 34.71%*h), followed by fish oil rTAG (mean AUC 0-72 h: 59.78 36.75%*h) and EE (mean AUC 0-72 h: 47.53 38.42%*h). Due to high standard deviation values, there were no significant differences for DHA and the sum of EPA+DHA levels between the three treatments. However, a trend (p = 0.057) was observed for the differences in EPA bioavailability. Statistical pair-wise group comparison's revealed a trend (p = 0.086) between rTAG and krill oil. FA analysis of the supplements showed that the krill oil sample contained 22% of the total EPA amount as free EPA and 21% of the total DHA amount as free DHA, while the two fish oil samples did not contain any free FA. Conclusion: Further studies with a larger sample size carried out over a longer period are needed to substantiate our findings and to determine differences in EPA+DHA bioavailability between three common chemical forms of LC n-3 FA (rTAG, EE and krill oil). The unexpected high content of free EPA and DHA in krill oil, which might have a significant influence on the availability of EPA+DHA from krill oil, should be investigated in more depth and taken into consideration in future trials.
eng
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
absorption
bioavailability
ethyl esters
fish oil
krill oil
re-esterified triacylglycerides
uptake
docosahexaenoic acid
edible oil
fish oil
icosapentaenoic acid
krill oil
nko
omega 3 fatty acid
phospholipid
unclassified drug
docosahexaenoic acid
fish oil
icosapentaenoic acid
phospholipid
adult
area under the curve
article
body weight
controlled study
crossover procedure
diet supplementation
double blind procedure
drug bioavailability
drug blood level
drug formulation
human
human experiment
intermethod comparison
male
maximum plasma concentration
normal human
phospholipid blood level
randomized controlled trial
time to maximum plasma concentration
animal
blood
chemistry
clinical trial
comparative study
controlled clinical trial
Euphausiacea
Euphausiacea
Adult
Animals
Area Under Curve
Chemistry, Pharmaceutical
Docosahexaenoic Acids
Double-Blind Method
Eicosapentaenoic Acid
Euphausiacea
Fish Oils
Humans
Male
Phospholipids
Incorporation of EPA and DHA into plasma phospholipids in response to different omega-3 fatty acid formulations - A comparative bioavailability study of fish oil vs. krill oil
Article
Text
oai:www.repo.uni-hannover.de:123456789/6352022-12-02T15:19:58Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:570ddc:500
Kaufmann, Helgard
Qiu, X.
Wehmeyer, Juliane
Debener, Thomas
2016-11-02T08:33:45Z
2016-11-02T08:33:45Z
2012
Kaufmann, Helgard; Qiu, X.; Wehmeyer, Juliane; Debener, Thomas: Isolation, molecular characterization, and mapping of four rose MLO orthologs. In: Frontiers in Plant Science 3 (2012), 244. DOI: http://dx.doi.org/10.3389/fpls.2012.00244
http://www.repo.uni-hannover.de/handle/123456789/635
http://dx.doi.org/10.15488/611
Powdery mildew is a major disease of economic importance in cut and pot roses. As an alternative to conventional resistance breeding strategies utilizing single-dominant genes or QTLs, mildew resistance locus o (MLO)-based resistance might offer some advantages. In dicots such as Arabidopsis, pea, and tomato, loss-of-function mutations in MLO genes confer high levels of broad-spectrum resistance. Here, we report the isolation and characterization of four MLO homologs from a large rose EST collection isolated from leaves. These genes are phylogenetically closely related to other dicot MLO genes that are involved in plant powdery mildew interactions. Therefore, they are candidates for MLO genes involved in rose powdery mildew interactions. Two of the four isolated genes contain all of the sequence signatures considered to be diagnostic for MLO genes. We mapped all four genes to three linkage groups and conducted the first analysis of alternative alleles. This information is discussed in regards to a reverse genetics approach aimed at the selection of rose plants that are homozygous for loss-of-function in one or more MLO genes.
eng
http://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Mildew resistance locus o
Podosphaera pannosa
Powdery mildew
Rosaceae
Tetraploid
Isolation, molecular characterization, and mapping of four rose MLO orthologs
Article
Text
oai:www.repo.uni-hannover.de:123456789/6362022-12-02T16:10:14Zcom_123456789_1col_123456789_8ddc:550doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Weymann, D.
Geistlinger, H.
Well, R.
Heide, Carolin von der
Flessa, H.
2016-11-02T08:33:57Z
2016-11-02T08:33:57Z
2010
Weymann, D.; Geistlinger, H.; Well, R.; Von Der Heide, C.; Flessa, H.: Kinetics of N2O production and reduction in a nitrate-contaminated aquifer inferred from laboratory incubation experiments. In: Biogeosciences 7 (2010), Nr. 6, S 1953-1972. DOI: http://dx.doi.org/10.5194/bg-7-1953-2010
http://www.repo.uni-hannover.de/handle/123456789/636
http://dx.doi.org/10.15488/612
Knowledge of the kinetics of N2O production and reduction in groundwater is essential for the assessment of potential indirect emissions of the greenhouse gas. In the present study, we investigated this kinetics using a laboratory approach. The results were compared to field measurements in order to examine their transferability to the in situ conditions. The study site was the unconfined, predominantly sandy Fuhrberger Feld aquifer in northern Germany. A special characteristic of the aquifer is the occurrence of the vertically separated process zones of heterotrophic denitrification in the near-surface groundwater and of autotrophic denitrification in depths beyond 2-3 m below the groundwater table, respectively. The kinetics of N2O production and reduction in both process zones was studied during long-term anaerobic laboratory incubations of aquifer slurries using the 15N tracer technique. We measured N2O, N2, NO3-, NO2-, and SO42- concentrations as well as parameters of the aquifer material that were related to the relevant electron donors, i.e. organic carbon and pyrite. The laboratory incubations showed a low denitrification activity of heterotrophic denitrification with initial rates between 0.2 and 13 μg N kg-1 d-1. The process was carbon limited due to the poor availability of its electron donor. In the autotrophic denitrification zone, initial denitrification rates were considerably higher, ranging between 30 and 148 μg N kg-1 d-1, and NO3- as well as N2O were completely removed within 60 to 198 days. N2O accumulated during heterotrophic and autotrophic denitrification, but maximum concentrations were substantially higher during the autotrophic process. The results revealed a satisfactory transferability of the laboratory incubations to the field scale for autotrophic denitrification, whereas the heterotrophic process less reflected the field conditions due to considerably lower N2O accumulation during laboratory incubation. Finally, we applied a conventional model using first-order-kinetics to determine the reaction rate constants k1 for N2O production and k2 for N2O reduction, respectively. The goodness of fit to the experimental data was partly limited, indicating that a more sophisticated approach is essential to describe the investigated reaction kinetics satisfactorily.
eng
http://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
denitrification
electron
greenhouse gas
groundwater pollution
nitrogen dioxide
reaction kinetics
unconfined aquifer
Germany
Kinetics of N2O production and reduction in a nitrate-contaminated aquifer inferred from laboratory incubation experiments
Article
Text
oai:www.repo.uni-hannover.de:123456789/6372022-12-02T15:15:01Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:500
Dipankar, Anurag
Stevens, Björn
Heinze, Rieke
Moseley, Christopher
Zängl, Günther
Giorgetta, Marco
Brdar, Slavko
2016-11-02T08:33:58Z
2016-11-02T08:33:58Z
2015
Dipankar, A.; Stevens, B.; Heinze, Rieke; Moseley, C.; Zängl, G. et al.: Large eddy simulation using the general circulation model ICON. In: Journal of Advances in Modeling Earth Systems 7 (2015), Nr. 3, S. 963-986. DOI: http://dx.doi.org/10.1002/2015MS000431
http://www.repo.uni-hannover.de/handle/123456789/637
http://dx.doi.org/10.15488/613
ICON (ICOsahedral Nonhydrostatic) is a unified modeling system for global numerical weather prediction (NWP) and climate studies. Validation of its dynamical core against a test suite for numerical weather forecasting has been recently published by Zängl et al. (2014). In the present work, an extension of ICON is presented that enables it to perform as a large eddy simulation (LES) model. The details of the implementation of the LES turbulence scheme in ICON are explained and test cases are performed to validate it against two standard LES models. Despite the limitations that ICON inherits from being a unified modeling system, it performs well in capturing the mean flow characteristics and the turbulent statistics of two simulated flow configurations - one being a dry convective boundary layer and the other a cumulus-topped planetary boundary layer.
eng
https://creativecommons.org/licenses/by-nc-nd/3.0/
CC BY-NC-ND 3.0 Unported
climate prediction
cloud topped boundary layer
convective boundary layer
large eddy simulation
numerical weather forecast
turbulence
Atmospheric thermodynamics
Boundary layer flow
Boundary layers
Forecasting
Turbulence
Weather forecasting
Climate prediction
Cloud-topped boundary layer
Convective boundary layers
Dry convective boundary layer
Numerical weather forecasting
Numerical weather forecasts
Numerical weather prediction
Planetary boundary layers
Large eddy simulation
climate prediction
convective boundary layer
cumulus
general circulation model
global climate
large eddy simulation
model validation
weather forecasting
Large eddy simulation using the general circulation model ICON
Article
Text
oai:www.repo.uni-hannover.de:123456789/6382022-12-02T15:12:31Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessddc:530status-type:publishedVersionddc:500
Barclay, Luke
Gregory, Ruth
Parameswaran, Susha L.
Tasinato, Gianmassimo
Zavala, Ivonne
2016-11-02T08:33:58Z
2016-11-02T08:33:58Z
2012
Barclay, L.; Gregory, R.; Parameswaran, Susha; Tasinato, G.; Zavala, I.: Lifshitz black holes in IIA supergravity. In: Journal of High Energy Physics 2012 (2012), Nr. 5, 122. DOI: http://dx.doi.org/10.1007/JHEP05(2012)122
http://www.repo.uni-hannover.de/handle/123456789/638
http://dx.doi.org/10.15488/614
We compute string theoretic black hole solutions having Lifshitz asymptotics with a general dynamical exponent z > 1. We start by constructing solutions in a flux compactification of six dimensional supergravity, then uplift them to massive type IIA supergravity. Alongside the Lifshitz black holes we study the simpler anti-de Sitter solutions, of which there are a 1-parameter family in this supergravity, and compare and contrast their properties. The black holes are characterized by a two-form and scalar charge, and we numerically explore their configuration space and thermodynamical aspects.
eng
http://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
AdS-CFT correspondence
Black Holes in String Theory
Gauge-gravity correspondence
Holography and condensed matter physics (AdS/CMT)
Lifshitz black holes in IIA supergravity
Article
Text
oai:www.repo.uni-hannover.de:123456789/6432022-12-02T16:11:40Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:570ddc:500
Santiago, Julia
Brandt, Benjamin
Wildhagen, Mari
Hohmann, Ulrich
Hothorn, Ludwig A.
Butenko, Melinka A.
Hothorn, Michael
2016-11-02T08:33:59Z
2016-11-02T08:33:59Z
2016
Santiago, J.; Brandt, B.; Wildhagen, M.; Hohmann, U.; Hothorn, Ludwig A. et al.: Mechanistic insight into a peptide hormone signaling complex mediating floral organ abscission. In: eLife 5 (2016), e15075. DOI: http://dx.doi.org/10.7554/eLife.15075
http://www.repo.uni-hannover.de/handle/123456789/643
http://dx.doi.org/10.15488/619
Plants constantly renew during their life cycle and thus require to shed senescent and damaged organs. Floral abscission is controlled by the leucine-rich repeat receptor kinase (LRR-RK) HAESA and the peptide hormone IDA. It is unknown how expression of IDA in the abscission zone leads to HAESA activation. Here we show that IDA is sensed directly by the HAESA ectodomain. Crystal structures of HAESA in complex with IDA reveal a hormone binding pocket that accommodates an active dodecamer peptide. A central hydroxyproline residue anchors IDA to the receptor. The HAESA co-receptor SERK1, a positive regulator of the floral abscission pathway, allows for high-affinity sensing of the peptide hormone by binding to an Arg-His-Asn motif in IDA. This sequence pattern is conserved among diverse plant peptides, suggesting that plant peptide hormone receptors may share a common ligand binding mode and activation mechanism.
eng
http://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
biophysics and structural biology
plant biology
A. thaliana
floral abscission
membrane signaling
peptide hormone
plant development
protein complexes
receptor kinase
Mechanistic insight into a peptide hormone signaling complex mediating floral organ abscission
Article
Text
mods///ddc:500/100