TY  - GEN
A1  - Parsons, R. D.
A1  - Schüssler, F.
A1  - Garrigoux, T.
A1  - Balzer, A.
A1  - Füssling, Matthias
A1  - Hoischen, Clemens
A1  - Holler, M.
A1  - Mitchell, A.
A1  - Pühlhofer, G.
A1  - Rowell, G.
A1  - Wagner, S.
A1  - Bissaldi, E.
A1  - Tam, P. H. T.
T1  - The HESS II GRB Observation Scheme
T2  - AIP conference proceedings / American Institute of Physics
N2  - Gamma-ray bursts (GRBs) are some of the Universe’s most enigmatic and exotic events. However, at energies above 10 GeV their behaviour remains largely unknown. Although space based telescopes such as the Fermi-LAT have been able to detect GRBs in this energy range, their photon statistics are limited by the small detector size. Such limitations are not present in ground based gamma-ray telescopes such as the H.E.S.S. experiment, which has now entered its second phase with the addition of a large 600 m2 telescope to the centre of the array. Such a large telescope allows H.E.S.S. to access the sub 100-GeV energy range while still maintaining a large effective collection area, helping to potentially probe the short timescale emission of these events.
We present a description of the H.E.S.S. GRB observation programme, summarising the performance of the rapid GRB repointing system and the conditions under which GRB observations are initiated. Additionally we will report on the GRB follow-ups made during the 2014-15 observation campaigns.
Y1  - 2017
SN  - 978-0-7354-1456-3
U6  - https://doi.org/10.1063/1.4968980
SN  - 0094-243X
SN  - 1551-7616
VL  - 1792
IS  - 1
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Koebnick, Corinna
A1  - Wagner, K.
A1  - Thielecke, F.
A1  - Dieter, G.
A1  - Hohne, A.
A1  - Franke, A.
A1  - Garcia, Ada
A1  - Meyer, H.
A1  - Hoffmann, I.
A1  - Leitzmann, P.
A1  - Trippo, U.
A1  - Zunft, Hans-Joachim Franz
T1  - An easy-to-use semiquantitative food record validated for energy intake by using doubly labelled water technique
N2  - Background: Estimating dietary intake is important for both epidemiological and clinical studies, but often lacks accuracy. Objective: To investigate the accuracy and validity of energy intake estimated by an easy-to-use semiquantitative food record (EISQFR) compared to total energy expenditure ( TEE) estimated by doubly labelled water technique (EEDLW). Design: TEE was measured in 29 nonobese subjects using the doubly labelled water method over a period of 14 days. Within this period, subjects reported their food consumption by a newly developed semiquantitative food record for 4 consecutive days. Energy intake was calculated using the German Food Code and Nutrition Data Base BLS II.3. Results: A good correlation was observed between EISQFR and EEDLW (r = 0.685, P<0.001). The mean difference between EISQFR and EEDLW was - 1.7 +/- 2.6 MJ/ day ( - 14 +/- 21%, P = 0.002). An underestimation of EISQFR <10% was observed in nine subjects (31%), of 10 - 20% in six subjects (21%), and of >20% in nine subjects (31%). In five subjects (17%), an overestimation of EISQFR was observed. Conclusions: The easy-to-use semiquantitative food record provided good estimates of EI in free-living and nonobese adults without prior detailed verbal instructions. The presented food record has limitations regarding accuracy at the individual level
Y1  - 2005
SN  - 0954-3007
ER  - 
TY  - JOUR
A1  - Koebnick, Corinna
A1  - Wagner, K.
A1  - Thielecke, F.
A1  - Moeseneder, Jutta
A1  - Hoehne, A.
A1  - Franke, A.
A1  - Meyer, H.
A1  - Garcia, Ada
A1  - Trippo, U.
A1  - Zunft, Hans-Joachim Franz
T1  - Validation of a simplified physical activity record by doubly labeled water technique
N2  - INTRODUCTION: For obtaining reliable information about physical activity in epidemiological studies, validated and easy-to-use instruments are required. Therefore, a new simplified physical activity record based on 15-min recording intervals was developed and validated. SUBJECTS: Nonobese volunteers (n = 31). MEASUREMENTS: Physical activity was recorded over a 7-day period without detailed instructions. Energy expenditure was calculated (EEsPAR) and compared to energy expenditure measured by doubly labelled water technique (EEDLW). RESULTS: A good agreement between EEsPAR (12.1 +/ 3.0) and EEDLW (11.7 +/- 3.3) with a mean difference of 0.33 +/- 1.55 MJ (r = 0.880, P < 0.001) was observed. The absolute difference between EEsPAR and EEDLW was <10% in 65% of the subjects. The difference between EEsPAR and EEDLW was independent of gender, age, body weight, and body mass index. A weak positive association between the difference and total body fat was observed (r = 0.618, P < 0.001), suggesting a slight tendency to overestimate EEsPAR with increasing total body fat. CONCLUSION: The new simplified physical activity protocol needs no detailed instructions, provides valid estimates of physical activity in nonobese free-living adults and can be used in epidemiological studies to assess total daily energy expenditure and physical activity level
Y1  - 2005
SN  - 0307-0565
ER  - 
TY  - GEN
A1  - Hayn, Michael
A1  - Beirle, Steffen
A1  - Hamprecht, Fred A.
A1  - Platt, Ulrich
A1  - Menze, Björn H.
A1  - Wagner, Thomas
T1  - Analysing spatio-temporal patterns of the global NO2-distribution retrieved from GOME satellite observations using a generalized additive model
N2  - With the increasing availability of observational data from different sources at a global level, joint analysis of these data is becoming especially attractive. For such an analysis – oftentimes with little prior knowledge about local and global interactions between the different observational variables at hand – an exploratory, data-driven analysis of the data may be of particular relevance. In the present work we used generalized additive models (GAM) in an exemplary study of spatio-temporal patterns in the tropospheric NO2-distribution derived from GOME satellite observations (1996 to 2001) at global scale. We focused on identifying correlations between NO2 and local wind fields, a quantity which is of particular interest in the analysis of spatio-temporal interactions. Formulating general functional, parametric relationships between the observed NO2 distribution and local wind fields, however, is difficult – if not impossible. So, rather than following a modelbased analysis testing the data for predefined hypotheses (assuming, for example, sinusoidal seasonal trends), we used a GAM with non-parametric model terms to learn this functional relationship between NO2 and wind directly from the data. The NO2 observations showed to be affected by winddominated processes over large areas. We estimated the extent of areas affected by specific NO2 emission sources, and were able to highlight likely atmospheric transport “pathways”. General temporal trends which were also part of our model – weekly, seasonal and linear changes – showed to be in good agreement with previous studies and alternative ways of analysing the time series. Overall, using a non-parametric model provided favorable means for a rapid inspection of this large spatio-temporal NO2 data set, with less bias than parametric approaches, and allowing to visualize dynamical processes of the NO2 distribution at a global scale.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 131 
KW  - Tropospheric nitrogen-dioxide
KW  - Air-pollution
KW  - Anthropogenic sources
KW  - NO2
KW  - Validation
Y1  - 2009
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44999
ER  - 
TY  - JOUR
A1  - Tobie, G.
A1  - Teanby, N. A.
A1  - Coustenis, A.
A1  - Jaumann, Ralf
A1  - Raulin, E.
A1  - Schmidt, J.
A1  - Carrasco, N.
A1  - Coates, Andrew J.
A1  - Cordier, D.
A1  - De Kok, R.
A1  - Geppert, W. D.
A1  - Lebreton, J. -P.
A1  - Lefevre, A.
A1  - Livengood, T. A.
A1  - Mandt, K. E.
A1  - Mitri, G.
A1  - Nimmo, F.
A1  - Nixon, C. A.
A1  - Norman, L.
A1  - Pappalardo, R. T.
A1  - Postberg, F.
A1  - Rodriguez, S.
A1  - SchuizeMakuch, D.
A1  - Soderblom, J. M.
A1  - Solomonidou, A.
A1  - Stephan, K.
A1  - Stofan, E. R.
A1  - Turtle, E. P.
A1  - Wagner, R. J.
A1  - West, R. A.
A1  - Westlake, J. H.
T1  - Science goals and mission concept for the future exploration of Titan and Enceladus
JF  - Planetary and space science
KW  - Titan
KW  - Enceladus
KW  - Atmosphere
KW  - Surface
KW  - Ocean
KW  - Interior
KW  - Missions
Y1  - 2014
U6  - https://doi.org/10.1016/j.pss.2014.10.002
SN  - 0032-0633
VL  - 104
SP  - 59
EP  - 77
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Wolf, Thomas J. A.
A1  - Holzmeier, Fabian
A1  - Wagner, Isabella
A1  - Berrah, Nora
A1  - Bostedt, Christoph
A1  - Bozek, John
A1  - Bucksbaum, Philip H.
A1  - Coffee, Ryan
A1  - Cryan, James
A1  - Farrell, Joe
A1  - Feifel, Raimund
A1  - Martinez, Todd J.
A1  - McFarland, Brian
A1  - Mucke, Melanie
A1  - Nandi, Saikat
A1  - Tarantelli, Francesco
A1  - Fischer, Ingo
A1  - Gühr, Markus
T1  - Observing Femtosecond Fragmentation Using Ultrafast X-ray-Induced Auger Spectra
JF  - Applied Sciences
N2  - Molecules often fragment after photoionization in the gas phase. Usually, this process can only be investigated spectroscopically as long as there exists electron correlation between the photofragments. Important parameters, like their kinetic energy after separation, cannot be investigated. We are reporting on a femtosecond time-resolved Auger electron spectroscopy study concerning the photofragmentation dynamics of thymine. We observe the appearance of clearly distinguishable signatures from thymine′s neutral photofragment isocyanic acid. Furthermore, we observe a time-dependent shift of its spectrum, which we can attribute to the influence of the charged fragment on the Auger electron. This allows us to map our time-dependent dataset onto the fragmentation coordinate. The time dependence of the shift supports efficient transformation of the excess energy gained from photoionization into kinetic energy of the fragments. Our method is broadly applicable to the investigation of photofragmentation processes.
KW  - ultrafast dynamics
KW  - Auger electron spectroscopy
KW  - photofragmentation
KW  - photochemistry
Y1  - 2017
U6  - https://doi.org/10.3390/app7070681
SN  - 2076-3417
VL  - 7
IS  - 7
PB  - MDPI
CY  - Basel
ER  - 
TY  - GEN
A1  - Wolf, Thomas J. A.
A1  - Holzmeier, Fabian
A1  - Wagner, Isabella
A1  - Berrah, Nora
A1  - Bostedt, Christoph
A1  - Bozek, John
A1  - Bucksbaum, Philip H.
A1  - Coffee, Ryan
A1  - Cryan, James
A1  - Farrell, Joe
A1  - Feifel, Raimund
A1  - Martinez, Todd J.
A1  - McFarland, Brian
A1  - Mucke, Melanie
A1  - Nandi, Saikat
A1  - Tarantelli, Francesco
A1  - Fischer, Ingo
A1  - Gühr, Markus
T1  - Observing Femtosecond Fragmentation Using Ultrafast X-ray-Induced Auger Spectra
N2  - Molecules often fragment after photoionization in the gas phase. Usually, this process can only be investigated spectroscopically as long as there exists electron correlation between the photofragments. Important parameters, like their kinetic energy after separation, cannot be investigated. We are reporting on a femtosecond time-resolved Auger electron spectroscopy study concerning the photofragmentation dynamics of thymine. We observe the appearance of clearly distinguishable signatures from thymine′s neutral photofragment isocyanic acid. Furthermore, we observe a time-dependent shift of its spectrum, which we can attribute to the influence of the charged fragment on the Auger electron. This allows us to map our time-dependent dataset onto the fragmentation coordinate. The time dependence of the shift supports efficient transformation of the excess energy gained from photoionization into kinetic energy of the fragments. Our method is broadly applicable to the investigation of photofragmentation processes.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 386 
KW  - Auger electron spectroscopy
KW  - photochemistry
KW  - photofragmentation
KW  - ultrafast dynamics
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-402692
ER  - 
TY  - JOUR
A1  - Former, C.
A1  - Wagner, H.
A1  - Richert, R.
A1  - Neher, Dieter
A1  - Müllen, K.
T1  - Orientation and dynamics of chainlike dipole arrays: Donor-acceptor-substituted oligophenylenevinylenes in a polymer matrix
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Ribeiro, Dimas M.
A1  - Araujo, Wagner L.
A1  - Fernie, Alisdair R.
A1  - Schippers, Jos H. M.
A1  - Müller-Röber, Bernd
T1  - Action of Gibberellins on growth and metabolism of arabidopsis plants Associated with high concentration of carbon dioxide
JF  - Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants
N2  - Although the positive effect of elevated CO2 concentration [CO2] on plant growth is well known, it remains unclear whether global climate change will positively or negatively affect crop yields. In particular, relatively little is known about the role of hormone pathways in controlling the growth responses to elevated [CO2]. Here, we studied the impact of elevated [CO2] on plant biomass and metabolism in Arabidopsis (Arabidopsis thaliana) in relation to the availability of gibberellins (GAs). Inhibition of growth by the GA biosynthesis inhibitor paclobutrazol (PAC) at ambient [CO2] (350 mu mol CO2 mol(-1)) was reverted by elevated [CO2] (750 mu mol CO2 mol(-1)). Thus, we investigated the metabolic adjustment and modulation of gene expression in response to changes in growth of plants imposed by varying the GA regime in ambient and elevated [CO2]. In the presence of PAC (low-GA regime), the activities of enzymes involved in photosynthesis and inorganic nitrogen assimilation were markedly increased at elevated [CO2], whereas the activities of enzymes of organic acid metabolism were decreased. Under ambient [CO2], nitrate, amino acids, and protein accumulated upon PAC treatment; however, this was not the case when plants were grown at elevated [CO2]. These results suggest that only under ambient [CO2] is GA required for the integration of carbohydrate and nitrogen metabolism underlying optimal biomass determination. Our results have implications concerning the action of the Green Revolution genes in future environmental conditions.
Y1  - 2012
U6  - https://doi.org/10.1104/pp.112.204842
SN  - 0032-0889
VL  - 160
IS  - 4
SP  - 1781
EP  - 1794
PB  - American Society of Plant Physiologists
CY  - Rockville
ER  - 
TY  - JOUR
A1  - Ribeiro, Dimas M.
A1  - Araujo, Wagner L.
A1  - Fernie, Alisdair R.
A1  - Schippers, Jos H. M.
A1  - Müller-Röber, Bernd
T1  - Translatome and metabolome effects triggered by gibberellins during rosette growth in Arabidopsis
JF  - Journal of experimental botany
N2  - Although gibberellins (GAs) are well known for their growth control function, little is known about their effects on primary metabolism. Here the modulation of gene expression and metabolic adjustment in response to changes in plant (Arabidopsis thaliana) growth imposed on varying the gibberellin regime were evaluated. Polysomal mRNA populations were profiled following treatment of plants with paclobutrazol (PAC), an inhibitor of GA biosynthesis, and gibberellic acid (GA(3)) to monitor translational regulation of mRNAs globally. Gibberellin levels did not affect levels of carbohydrates in plants treated with PAC and/or GA(3). However, the tricarboxylic acid cycle intermediates malate and fumarate, two alternative carbon storage molecules, accumulated upon PAC treatment. Moreover, an increase in nitrate and in the levels of the amino acids was observed in plants grown under a low GA regime. Only minor changes in amino acid levels were detected in plants treated with GA(3) alone, or PAC plus GA(3). Comparison of the molecular changes at the transcript and metabolite levels demonstrated that a low GA level mainly affects growth by uncoupling growth from carbon availability. These observations, together with the translatome changes, reveal an interaction between energy metabolism and GA-mediated control of growth to coordinate cell wall extension, secondary metabolism, and lipid metabolism.
KW  - Gibberellin
KW  - growth
KW  - paclobutrazol
KW  - primary metabolism
KW  - translatome
Y1  - 2012
U6  - https://doi.org/10.1093/jxb/err463
SN  - 0022-0957
VL  - 63
IS  - 7
SP  - 2769
EP  - 2786
PB  - Oxford Univ. Press
CY  - Oxford
ER  -