@article{FruscalzoFrommerLonderoetal.2017, author = {Fruscalzo, Arrigo and Frommer, Julia-Marie and Londero, Ambrogio P. and Henze, Andrea and Schweigert, Florian J. and Nofer, Jerzy-Roch and Steinhard, Johannes and Klockenbusch, Walter and Schmitz, Ralf and Raila, Jens}, title = {First trimester TTR-RBP4-ROH complex and angiogenic factors in the prediction of small for gestational age infant's outcome}, series = {Archives of gynecology and obstetrics}, volume = {295}, journal = {Archives of gynecology and obstetrics}, publisher = {Springer}, address = {Heidelberg}, issn = {0932-0067}, doi = {10.1007/s00404-017-4338-4}, pages = {1157 -- 1165}, year = {2017}, abstract = {To study the role of the TTR-RBP4-ROH complex components (transthyretin, serum retinol binding protein, retinol) and of angiogenic factors PlGF (placental growth factor) and sFlt-1 (soluble fms-like tyrosine kinase-1) in pregnancies complicated by small for gestational age infants (SGA). Case control study conducted on maternal serum collected between 11 + 0 to 13 + 6 weeks of gestation. TTR, RBP4, ROH, PlGF and sFlt-1 were measured in SGA patients (birth weight < 10\%) who delivered at term (n = 37) and before 37 weeks of gestation (n = 17) and in a matched control group with uneventful pregnancies (n = 37). We found decreased RBP4 in SGA patients that delivered fetuses < 3\% and in fetuses delivered after the 37 weeks of gestation compared to controls [1.50 (95\% CI 1.40-1.75) vs 1.62 (95\% CI 1.47-1.98), p < 0.05]. Further, we found lower PlGF and sFlt-1 concentrations in SGA that delivered before 37 weeks of gestation compared to controls (respectively, PIGF and sFlt-1: 39.7 pg/ml (95\% CI 32.3-66.3) vs 62.9 pg/ml (95\% CI 45.2-78.4) and 906 pg/ml (95\% CI 727-1626) vs 1610 pg/ml (95\% CI 1088-212), p < 0.05). First trimester maternal serum RBP4 and angiogenic factors PlGF and sFlt-1 can differently predict the timing of delivery of pregnancies complicated by SGA fetuses.}, language = {en} } @article{GoetzeKroenerBanerjeeetal.2014, author = {Goetze, Jan P. and Kr{\"o}ner, Dominik and Banerjee, Shiladitya and Karasulu, Bora and Thiel, Walter}, title = {Carotenoids as a shortcut for chlorophyll Soret-to-Q band energy flow}, series = {ChemPhysChem : a European journal of chemical physics and physical chemistry}, volume = {15}, journal = {ChemPhysChem : a European journal of chemical physics and physical chemistry}, number = {15}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1439-4235}, doi = {10.1002/cphc.201402233}, pages = {3391 -- 3400}, year = {2014}, abstract = {It is proposed that xanthophylls, and carotenoids in general, may assist in energy transfer from the chlorophyll Soret band to the Q band. Ground-state (1A(g)) and excited-state (1B(u)) optimizations of violaxanthin (Vx) and zeaxanthin (Zx) are performed in an environment mimicking the light-harvesting complex II (LHCII), including the closest chlorophyll b molecule (Chl). Time-dependent density functional theory (TD-DFT, CAM-B3LYP functional) is used in combination with a semi-empirical description to obtain the excited-state geometries, supported by additional DFT/multireference configuration interaction calculations, with and without point charges representing LHCII. In the ground state, Vx and Zx show similar properties. At the 1B(u) minimum, the energy of the Zx 1Bu state is below the Chl Q band, in contrast to Vx. Both Vx and Zx may act as acceptors of Soret-state energy; transfer to the Q band seems to be favored for Vx. These findings suggest that carotenoids may generally mediate Soret-to-Q energy flow in LHCII.}, language = {en} } @article{SchleuningTemplinHuamanetal.2011, author = {Schleuning, Matthias and Templin, Mathias and Huaman, Vicky and Vadillo, Giovana P. and Becker, Thomas and Durka, Walter and Fischer, Markus and Matthies, Diethart}, title = {Effects of inbreeding, outbreeding, and supplemental pollen on the reproduction of a hummingbird-pollinated clonal amazonian herb}, series = {Biotropica : a publication of the Association for Tropical Biology}, volume = {43}, journal = {Biotropica : a publication of the Association for Tropical Biology}, number = {2}, publisher = {Wiley-Blackwell}, address = {Malden}, issn = {0006-3606}, doi = {10.1111/j.1744-7429.2010.00663.x}, pages = {183 -- 191}, year = {2011}, abstract = {Understory herbs are an essential part of tropical rain forests, but little is known about factors limiting their reproduction. Many of these herbs are clonal, patchily distributed, and produce large floral displays of nectar-rich 1-d flowers to attract hummingbird pollinators that may transport pollen over long distances. The aim of this study was to investigate the effects of clonality, cross-proximity, and patchy distribution on the reproduction of the hummingbird-pollinated Amazonian herb Heliconia metallica. We experimentally pollinated flowers within populations with self-pollen and with pollen of different diversity, crossed flowers between populations, and added supplemental pollen to ramets growing solitarily or in conspecific patches. Only flowers pollinated early in the morning produced seeds. Selfed flowers produced seeds, but seed number and mass were strongly reduced, suggesting partial sterility and inbreeding depression after selfing. Because of pollen competition, flowers produced more seeds after crosses with several than with single donor plants. Crosses between populations mostly resulted in lower seed production than those within populations, suggesting outbreeding depression. Ramets in patches produced fewer seeds than solitary ramets and were more pollen-limited, possibly due to geitonogamy and biparental inbreeding in patches. We conclude that high rates of geitonogamy due to clonality and pollen limitation due to the short receptivity of flowers and patchy distribution constrain the reproduction of this clonal herb. Even in unfragmented rain forests with highly mobile pollinators, outbreeding depression may be a widespread phenomenon in plant reproduction.}, language = {en} } @article{ArmstrongRadouskyAustinetal.2022, author = {Armstrong, Michael R. and Radousky, Harry B. and Austin, Ryan A. and Tschauner, Oliver and Brown, Shaughnessy and Gleason, Arianna E. and Goldman, Nir and Granados, Eduardo and Grivickas, Paulius and Holtgrewe, Nicholas and Kroonblawd, Matthew P. and Lee, Hae Ja and Lobanov, Sergey and Nagler, Bob and Nam, Inhyuk and Prakapenka, Vitali and Prescher, Clemens and Reed, Evan J. and Stavrou, Elissaios and Walter, Peter and Goncharov, Alexander F. and Belof, Jonathan L.}, title = {Highly ordered graphite (HOPG) to hexagonal diamond (lonsdaleite) phase transition observed on picosecond time scales using ultrafast x-ray diffraction}, series = {Journal of applied physics}, volume = {132}, journal = {Journal of applied physics}, number = {5}, publisher = {AIP Publishing}, address = {Melville}, issn = {0021-8979}, doi = {10.1063/5.0085297}, pages = {10}, year = {2022}, abstract = {The response of rapidly compressed highly oriented pyrolytic graphite (HOPG) normal to its basal plane was investigated at a pressure of \& SIM;80 GPa. Ultrafast x-ray diffraction using \& SIM;100 fs pulses at the Materials Under Extreme Conditions sector of the Linac Coherent Light Source was used to probe the changes in crystal structure resulting from picosecond timescale compression at laser drive energies ranging from 2.5 to 250 mJ. A phase transformation from HOPG to a highly textured hexagonal diamond structure is observed at the highest energy, followed by relaxation to a still highly oriented, but distorted graphite structure following release. We observe the formation of a highly oriented lonsdaleite within 20 ps, subsequent to compression. This suggests that a diffusionless martensitic mechanism may play a fundamental role in phase transition, as speculated in an early work on this system, and more recent static studies of diamonds formed in impact events. Published by AIP Publishing.}, language = {en} } @article{BathkeSudhausHolohanetal.2013, author = {Bathke, Hannes and Sudhaus, Henriette and Holohan, E. P. and Walter, T. R. and Shirzaei, M.}, title = {An active ring fault detected at Tendurek volcano by using InSAR}, series = {JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH}, volume = {118}, journal = {JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH}, number = {8}, publisher = {AMER GEOPHYSICAL UNION}, address = {WASHINGTON}, issn = {2169-9313}, doi = {10.1002/jgrb.50305}, pages = {4488 -- 4502}, year = {2013}, abstract = {Although ring faults are present at many ancient, deeply eroded volcanoes, they have been detected at only very few modern volcanic centers. At the so far little studied Tendurek volcano in eastern Turkey, we generated an ascending and a descending InSAR time series of its surface displacement field for the period from 2003 to 2010. We detected a large (similar to 105km(2)) region that underwent subsidence at the rate of similar to 1cm/yr during this period. Source modeling results show that the observed signal fits best to simulations of a near-horizontal contracting sill located at around 4.5km below the volcano summit. Intriguingly, the residual displacement velocity field contains a steep gradient that systematically follows a system of arcuate fractures visible on the volcano\’s midflanks. RapidEye satellite optical images show that this fracture system has deflected Holocene lava flows, thus indicating its presence for at least several millennia. We interpret the arcuate fracture system as the surface expression of an inherited ring fault that has been slowly reactivated during the detected recent subsidence. These results show that volcano ring faults may not only slip rapidly during eruptive or intrusive phases, but also slowly during dormant phases.}, language = {en} } @article{EiblHainzlVeselyetal.2019, author = {Eibl, Eva P. S. and Hainzl, Sebastian and Vesely, Nele I. K. and Walter, Thomas R. and Jousset, Philippe and Hersir, Gylfi Pall and Dahm, Torsten}, title = {Eruption interval monitoring at strokkur Geyser, Iceland}, series = {Geophysical research letters}, volume = {47}, journal = {Geophysical research letters}, number = {1}, publisher = {American Geophysical Union}, address = {Washington}, issn = {0094-8276}, doi = {10.1029/2019GL085266}, pages = {10}, year = {2019}, abstract = {Geysers are hot springs whose frequency of water eruptions remain poorly understood. We set up a local broadband seismic network for 1 year at Strokkur geyser, Iceland, and developed an unprecedented catalog of 73,466 eruptions. We detected 50,135 single eruptions but find that the geyser is also characterized by sets of up to six eruptions in quick succession. The number of single to sextuple eruptions exponentially decreased, while the mean waiting time after an eruption linearly increased (3.7 to 16.4 min). While secondary eruptions within double to sextuple eruptions have a smaller mean seismic amplitude, the amplitude of the first eruption is comparable for all eruption types. We statistically model the eruption frequency assuming discharges proportional to the eruption multiplicity and a constant probability for subsequent events within a multituple eruption. The waiting time after an eruption is predictable but not the type or amplitude of the next one.
Plain Language Summary Geysers are springs that often erupt in hot water fountains. They erupt more often than volcanoes but are quite similar. Nevertheless, it is poorly understood how often volcanoes and also geysers erupt. We created a list of 73,466 eruption times of Strokkur geyser, Iceland, from 1 year of seismic data. The geyser erupted one to six times in quick succession. We found 50,135 single eruptions but only 1 sextuple eruption, while the mean waiting time increased from 3.7 min after single eruptions to 16.4 min after sextuple eruptions. Mean amplitudes of each eruption type were higher for single eruptions, but all first eruptions in a succession were similar in height. Assuming a constant heat inflow at depth, we can predict the waiting time after an eruption but not the type or amplitude of the next one.}, language = {en} } @article{HeslopWinkelAnthonyetal.2019, author = {Heslop, J. K. and Winkel, Matthias and Anthony, K. M. Walter and Spencer, R. G. M. and Podgorski, D. C. and Zito, P. and Kholodov, A. and Zhang, M. and Liebner, Susanne}, title = {Increasing organic carbon biolability with depth in yedoma permafrost}, series = {Journal of geophysical research : Biogeosciences}, volume = {124}, journal = {Journal of geophysical research : Biogeosciences}, number = {7}, publisher = {American Geophysical Union}, address = {Washington}, issn = {2169-8953}, doi = {10.1029/2018JG004712}, pages = {2021 -- 2038}, year = {2019}, abstract = {Permafrost thaw subjects previously frozen organic carbon (OC) to microbial decomposition, generating the greenhouse gases (GHG) carbon dioxide (CO2) and methane (CH4) and fueling a positive climate feedback. Over one quarter of permafrost OC is stored in deep, ice-rich Pleistocene-aged yedoma permafrost deposits. We used a combination of anaerobic incubations, microbial sequencing, and ultrahigh-resolution mass spectrometry to show yedoma OC biolability increases with depth along a 12-m yedoma profile. In incubations at 3 degrees C and 13 degrees C, GHG production per unit OC at 12-versus 1.3-m depth was 4.6 and 20.5 times greater, respectively. Bacterial diversity decreased with depth and we detected methanogens at all our sampled depths, suggesting that in situ microbial communities are equipped to metabolize thawed OC into CH4. We concurrently observed an increase in the relative abundance of reduced, saturated OC compounds, which corresponded to high proportions of C mineralization and positively correlated with anaerobic GHG production potentials and higher proportions of OC being mineralized as CH4. Taking into account the higher global warming potential (GWP) of CH4 compared to CO2, thawed yedoma sediments in our study had 2 times higher GWP at 12-versus 9.0-m depth at 3 degrees C and 15 times higher GWP at 13 degrees C. Considering that yedoma is vulnerable to processes that thaw deep OC, our findings imply that it is important to account for this increasing GHG production and GWP with depth to better understand the disproportionate impact of yedoma on the magnitude of the permafrost carbon feedback.}, language = {en} } @article{EiblMuellerWalteretal.2021, author = {Eibl, Eva P. S. and M{\"u}ller, Daniel and Walter, Thomas R. and Allahbakhshi, Masoud and Jousset, Philippe and Hersir, Gylfi P{\´a}ll and Dahm, Torsten}, title = {Eruptive cycle and bubble trap of Strokkur Geyser, Iceland}, series = {Journal of geophysical research : JGR. B: Solid earth}, volume = {126}, journal = {Journal of geophysical research : JGR. B: Solid earth}, number = {4}, publisher = {Wiley}, address = {Hoboken, NJ}, issn = {2169-9313}, doi = {10.1029/2020JB020769}, pages = {20}, year = {2021}, abstract = {The eruption frequency of geysers can be studied easily on the surface. However, details of the internal structure including possible water and gas filled chambers feeding eruptions and the driving mechanisms often remain elusive. We used a multidisciplinary network of seismometers, video cameras, water pressure sensors and one tiltmeter to study the eruptive cycle, internal structure, and mechanisms driving the eruptive cycle of Strokkur geyser in June 2018. An eruptive cycle at Strokkur always consists of four phases: (1) Eruption, (2) post-eruptive conduit refilling, (3) gas filling of the bubble trap, and (4) regular bubble collapse at shallow depth in the conduit. For a typical single eruption 19 +/- 4 bubble collapses occur in Phase 3 and 8 +/- 2 collapses in Phase 4 at a mean spacing of 1.52 +/- 0.29 and 24.5 +/- 5.9 s, respectively. These collapses release latent heat to the fluid in the bubble trap (Phase 3) and later to the fluid in the conduit (Phase 4). The latter eventually reaches thermodynamic conditions for an eruption. Single to sextuple eruptions have similar spacings between bubble collapses and are likely fed from the same bubble trap at 23.7 +/- 4.4 m depth, 13-23 m west of the conduit. However, the duration of the eruption and recharging phase linearly increases likely due to a larger water, gas and heat loss from the system. Our tremor data provides documented evidence for a bubble trap beneath a pool geyser.}, language = {en} } @article{GarbusowSchadSeboldetal.2016, author = {Garbusow, Maria and Schad, Daniel and Sebold, Miriam and Friedel, Eva and Bernhardt, Nadine and Koch, Stefan P. and Steinacher, Bruno and Kathmann, Norbert and Geurts, Dirk E. M. and Sommer, Christian and Mueller, Dirk K. and Nebe, Stephan and Paul, Soeren and Wittchen, Hans-Ulrich and Zimmermann, Ulrich S. and Walter, Henrik and Smolka, Michael N. and Sterzer, Philipp and Rapp, Michael A. and Huys, Quentin J. M. and Schlagenhauf, Florian and Heinz, Andreas}, title = {Pavlovian-to-instrumental transfer effects in the nucleus accumbens relate to relapse in alcohol dependence}, series = {Addiction biology}, volume = {21}, journal = {Addiction biology}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {1355-6215}, doi = {10.1111/adb.12243}, pages = {719 -- 731}, year = {2016}, abstract = {In detoxified alcohol-dependent patients, alcohol-related stimuli can promote relapse. However, to date, the mechanisms by which contextual stimuli promote relapse have not been elucidated in detail. One hypothesis is that such contextual stimuli directly stimulate the motivation to drink via associated brain regions like the ventral striatum and thus promote alcohol seeking, intake and relapse. Pavlovian-to-Instrumental-Transfer (PIT) may be one of those behavioral phenomena contributing to relapse, capturing how Pavlovian conditioned (contextual) cues determine instrumental behavior (e.g. alcohol seeking and intake). We used a PIT paradigm during functional magnetic resonance imaging to examine the effects of classically conditioned Pavlovian stimuli on instrumental choices in n=31 detoxified patients diagnosed with alcohol dependence and n=24 healthy controls matched for age and gender. Patients were followed up over a period of 3 months. We observed that (1) there was a significant behavioral PIT effect for all participants, which was significantly more pronounced in alcohol-dependent patients; (2) PIT was significantly associated with blood oxygen level-dependent (BOLD) signals in the nucleus accumbens (NAcc) in subsequent relapsers only; and (3) PIT-related NAcc activation was associated with, and predictive of, critical outcomes (amount of alcohol intake and relapse during a 3 months follow-up period) in alcohol-dependent patients. These observations show for the first time that PIT-related BOLD signals, as a measure of the influence of Pavlovian cues on instrumental behavior, predict alcohol intake and relapse in alcohol dependence.}, language = {en} }