TY  - JOUR
A1  - Boëchat, Iola G.
A1  - Weithoff, Guntram
A1  - Krüger, Angela
A1  - Gücker, Björn
A1  - Adrian, Rita
T1  - A biochemical explanation for the success of the mixotrophy in the flagellate Ochromonas sp.
N2  - We report the influence of different nutritional modes-autotrophy, mixotrophy, and heterotrophy-on the fatty acid and sterol composition of the freshwater flagellate Ochromonas sp. and discuss the ecological significance of our results with respect to the resource competition theory (rct). Polyunsaturated fatty acids (PUFAs) are the most efficient biochemical variable distinguishing between nutritional modes of Ochromonas sp. Decreasing concentrations of PUFAs were observed in the order autotrophs, mixotrophs, heterotrophs. In mixotrophs and heterotrophs, concentrations of saturated fatty acids were higher than those of monounsaturated fatty acids and PUFAs as a result of bacterivory. Stigmasterol was the main sterol in Ochromonas sp., regardless of nutritional mode. Mixotrophs showed higher growth rates than heterotrophs, which could not be explained by rct. Heterotrophs, in turn, exhibited higher growth rates than autotrophs, which were cultured under the same light conditions as mixotrophs. Mixotrophs can synthesize PUFAs, which are important for many physiological functions such as membrane permeability and growth. Thus, mixotrophy facilitated efficient growth as well as the ability to synthesize complex and essential biomolecules. These strong synergetic effects are due to the combination of biochemical benefits of heterotrophic and autotrophic metabolic pathways and cannot be predicted by rct.
Y1  - 2007
UR  - http://www.aslo.org/lo/
U6  - https://doi.org/10.4319/lo.2007.52.4.1624
SN  - 0024-3590
ER  - 
TY  - JOUR
A1  - Krüger, Frank
A1  - Kulikova, Galina
A1  - Landgraf, Angela
T1  - Magnitudes for the historical 1885 (Belovodskoe), the 1887 (Verny) and the 1889 (Chilik) earthquakes in Central Asia determined from magnetogram recordings
JF  - Geophysical journal international
N2  - Six large magnitude earthquakes in Central Asia which occurred at the end of the 19th century were recorded on early magnetographs in Great Britain. Scalar seismic moment estimates of the 1911 Chon-Kemin, the 1902 Atushi and the 1907 Karatag earthquakes in Central Asia were recently determined by historical seismogram modelling. For those events, we find agreement between moment magnitudes estimated from seismograms and from magnetograms. This supports the assumption of linear scaling of magnetogram amplitudes as function of M-0, which we then use to estimate the moment magnitudes for earlier large-magnitude events, that is, the 1885 Belovodskoe, 1887 Verny and 1889 Chilik earthquakes. The magnetometer data imply that the Chilik earthquake had M(W)7.9, slightly smaller than the Chon-Kemin event with M(W)8.0. The Verny earthquake, however, for which we estimate M(W)7.7, is likely larger than listed in catalogues (M7.3). Similarly, we find a larger magnitude M(W)7.6 (instead of the previous M6.9) for the Belovodskoe earthquake, but this remains uncertain due to measurement imprecision.
KW  - Earthquake source observations
KW  - Seismicity and tectonics
KW  - Intraplate processes
Y1  - 2018
U6  - https://doi.org/10.1093/gji/ggy377
SN  - 0956-540X
SN  - 1365-246X
VL  - 215
IS  - 3
SP  - 1824
EP  - 1840
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Krüger, Frank
A1  - Kulikova, Galina
A1  - Landgraf, Angela
T1  - Instrumental magnitude constraints for the 11 July 1889, Chilik earthquake
JF  - Seismicity, fault rupture and earthquake hazards in slowly deforming regions
N2  - A series of large-magnitude earthquakes above 6.9 occurred in the northern Tien-Shan between 1885 and 1911. The Chilik earthquake of 11 July 1889, has been listed with a magnitude of 8.3, based on sparse macroseismic intensities, constrained by reported damage. Despite the existence of several juvenile fault scarps in the epicentral region, that are possibly associated with the 1889 earthquake, no through-going surface rupture having the dimensions expected for a magnitude 8.3 earthquake has been located - a puzzling dilemma. Could the magnitude have been overestimated? This would have major implications not only for the understanding of the earthquake series, but also for regional hazard estimates. Fortunately, a fragmentary record from an early Rebeur-Paschwitz seismometer exists for the Chilik event, recorded in Wilhelmshaven (Germany). To constrain the magnitude, we compare the late coda waves of this record with those of recent events from Central Asia, recorded on modern instruments in Germany and filtered with Rebeur-Paschwitz instrument characteristics. Additional constraints come from disturbances of historic magnetograms that exist from the Chilik and the 1911 Chon-Kemin earthquakes. Scaling of these historic records confirm a magnitude of about 8 for the 1889 Chilik earthquake, pointing towards a lower crustal contribution to the fault area.
Y1  - 2017
SN  - 978-1-86239-745-3
SN  - 978-1-86239-964-8
U6  - https://doi.org/10.1144/SP432.8
SN  - 0305-8719
VL  - 432
SP  - 41
EP  - 72
PB  - The Geological Society
CY  - London
ER  - 
TY  - GEN
A1  - Donner, Stefanie
A1  - Strecker, Manfred
A1  - Rößler, Dirk
A1  - Ghods, Abdolreza
A1  - Krüger, Frank
A1  - Landgraf, Angela
A1  - Ballato, Paolo
T1  - Earthquake source models for earthquakes in Northern Iran
N2  - The complex system of strike-slip and thrust faults in the Alborz Mountains, Northern Iran, are not well understood yet. Mainly structural and geomorphic data are available so far. As a more extensive base for seismotectonic studies and seismic hazard analysis we plan to do a comprehensive seismic moment tensor study also from smaller magnitudes (M < 4.5) by developing a new algorithm. Here, we present first preliminary results.
KW  - Elburs
KW  - Iran
KW  - Momententensor
KW  - Seismotektonik
KW  - Alborz
KW  - Iran
KW  - moment tensor
KW  - seismotectonics
Y1  - 2009
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-32581
ER  - 
TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Heydenreich, Matthias
A1  - Koch, Andreas
A1  - Krtitschka, Angela
A1  - Krüger, Tobias
A1  - Linker, Torsten
T1  - NMR spectroscopic conformational analysis of 4-methylene-cyclohexyl pivalateThe effect of sp(2) hybridization
JF  - Magnetic resonance in chemistry
N2  - The conformational equilibrium of the axial/equatorial conformers of 4-methylene-cyclohexyl pivalate is studied by dynamic NMR spectroscopy in a methylene chloride/freon mixture. At 153K, the ring interconversion gets slow on the nuclear magnetic resonance timescale, the conformational equilibrium (-G degrees) can be examined, and the barrier to ring interconversion (G(#)) can be determined. The structural influence of sp(2) hybridization on both G degrees and G(#) of the cyclohexyl moiety can be quantified.
KW  - 4-methylene-cyclohexyl pivalate
KW  - conformational analysis
KW  - dynamic NMR spectroscopy
KW  - exo-methylene conformational effect at cyclohexane
KW  - quantum chemical calculations
Y1  - 2017
U6  - https://doi.org/10.1002/mrc.4630
SN  - 0749-1581
SN  - 1097-458X
VL  - 55
SP  - 1073
EP  - 1078
PB  - Wiley
CY  - Hoboken
ER  -