TY - JOUR A1 - Fruscalzo, Arrigo A1 - Frommer, Julia-Marie A1 - Londero, Ambrogio P. A1 - Henze, Andrea A1 - Schweigert, Florian J. A1 - Nofer, Jerzy-Roch A1 - Steinhard, Johannes A1 - Klockenbusch, Walter A1 - Schmitz, Ralf A1 - Raila, Jens T1 - First trimester TTR-RBP4-ROH complex and angiogenic factors in the prediction of small for gestational age infant’s outcome JF - Archives of gynecology and obstetrics N2 - 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. KW - Low birth weight KW - Small for gestational age KW - Pregnancy KW - First trimester KW - Marker KW - RBP4 KW - TTR KW - Retinol KW - Vitamin A KW - sFlt-1 KW - PlGF Y1 - 2017 U6 - https://doi.org/10.1007/s00404-017-4338-4 SN - 0932-0067 SN - 1432-0711 VL - 295 SP - 1157 EP - 1165 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Goetze, Jan P. A1 - Kröner, Dominik A1 - Banerjee, Shiladitya A1 - Karasulu, Bora A1 - Thiel, Walter T1 - Carotenoids as a shortcut for chlorophyll Soret-to-Q band energy flow JF - ChemPhysChem : a European journal of chemical physics and physical chemistry N2 - 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. KW - carotenoids KW - chlorophyll KW - density functional calculations KW - energy transfer KW - xanthophylls Y1 - 2014 U6 - https://doi.org/10.1002/cphc.201402233 SN - 1439-4235 SN - 1439-7641 VL - 15 IS - 15 SP - 3391 EP - 3400 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Schleuning, Matthias A1 - Templin, Mathias A1 - Huaman, Vicky A1 - Vadillo, Giovana P. A1 - Becker, Thomas A1 - Durka, Walter A1 - Fischer, Markus A1 - Matthies, Diethart T1 - Effects of inbreeding, outbreeding, and supplemental pollen on the reproduction of a hummingbird-pollinated clonal amazonian herb JF - Biotropica : a publication of the Association for Tropical Biology N2 - 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. KW - clonality KW - geitonogamy KW - Heliconiaceae KW - hummingbird pollination KW - Peru KW - pollen limitation KW - pollination experiment KW - rain forest understory Y1 - 2011 U6 - https://doi.org/10.1111/j.1744-7429.2010.00663.x SN - 0006-3606 VL - 43 IS - 2 SP - 183 EP - 191 PB - Wiley-Blackwell CY - Malden ER - TY - JOUR A1 - Armstrong, Michael R. A1 - Radousky, Harry B. A1 - Austin, Ryan A. A1 - Tschauner, Oliver A1 - Brown, Shaughnessy A1 - Gleason, Arianna E. A1 - Goldman, Nir A1 - Granados, Eduardo A1 - Grivickas, Paulius A1 - Holtgrewe, Nicholas A1 - Kroonblawd, Matthew P. A1 - Lee, Hae Ja A1 - Lobanov, Sergey A1 - Nagler, Bob A1 - Nam, Inhyuk A1 - Prakapenka, Vitali A1 - Prescher, Clemens A1 - Reed, Evan J. A1 - Stavrou, Elissaios A1 - Walter, Peter A1 - Goncharov, Alexander F. A1 - Belof, Jonathan L. T1 - Highly ordered graphite (HOPG) to hexagonal diamond (lonsdaleite) phase transition observed on picosecond time scales using ultrafast x-ray diffraction JF - Journal of applied physics N2 - 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. Y1 - 2022 U6 - https://doi.org/10.1063/5.0085297 SN - 0021-8979 SN - 1089-7550 VL - 132 IS - 5 PB - AIP Publishing CY - Melville ER - TY - JOUR A1 - Bathke, Hannes A1 - Sudhaus, Henriette A1 - Holohan, E. P. A1 - Walter, T. R. A1 - Shirzaei, M. T1 - An active ring fault detected at Tendurek volcano by using InSAR JF - JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH N2 - 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. KW - Tendurek volcano KW - caldera subsidence KW - arcuate fracture system KW - fault reactivation Y1 - 2013 U6 - https://doi.org/10.1002/jgrb.50305 SN - 2169-9313 VL - 118 IS - 8 SP - 4488 EP - 4502 PB - AMER GEOPHYSICAL UNION CY - WASHINGTON ER - TY - JOUR A1 - Eibl, Eva P. S. A1 - Hainzl, Sebastian A1 - Vesely, Nele I. K. A1 - Walter, Thomas R. A1 - Jousset, Philippe A1 - Hersir, Gylfi Pall A1 - Dahm, Torsten T1 - Eruption interval monitoring at strokkur Geyser, Iceland JF - Geophysical research letters N2 - 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. Y1 - 2019 U6 - https://doi.org/10.1029/2019GL085266 SN - 0094-8276 SN - 1944-8007 VL - 47 IS - 1 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Heslop, J. K. A1 - Winkel, Matthias A1 - Anthony, K. M. Walter A1 - Spencer, R. G. M. A1 - Podgorski, D. C. A1 - Zito, P. A1 - Kholodov, A. A1 - Zhang, M. A1 - Liebner, Susanne T1 - Increasing organic carbon biolability with depth in yedoma permafrost BT - ramifications for future climate change JF - Journal of geophysical research : Biogeosciences N2 - 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. KW - permafrost KW - carbon KW - yedoma KW - Alaska KW - FT-ICR MS KW - microbes Y1 - 2019 U6 - https://doi.org/10.1029/2018JG004712 SN - 2169-8953 SN - 2169-8961 VL - 124 IS - 7 SP - 2021 EP - 2038 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Eibl, Eva P. S. A1 - Müller, Daniel A1 - Walter, Thomas R. A1 - Allahbakhshi, Masoud A1 - Jousset, Philippe A1 - Hersir, Gylfi Páll A1 - Dahm, Torsten T1 - Eruptive cycle and bubble trap of Strokkur Geyser, Iceland JF - Journal of geophysical research : JGR. B: Solid earth N2 - 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. KW - bubble trap KW - eruptive cycle KW - geyser KW - hydrothermal systems KW - source KW - location KW - tremor Y1 - 2021 U6 - https://doi.org/10.1029/2020JB020769 SN - 2169-9313 SN - 2169-9356 VL - 126 IS - 4 PB - Wiley CY - Hoboken, NJ ER - TY - JOUR A1 - Garbusow, Maria A1 - Schad, Daniel A1 - Sebold, Miriam A1 - Friedel, Eva A1 - Bernhardt, Nadine A1 - Koch, Stefan P. A1 - Steinacher, Bruno A1 - Kathmann, Norbert A1 - Geurts, Dirk E. M. A1 - Sommer, Christian A1 - Mueller, Dirk K. A1 - Nebe, Stephan A1 - Paul, Soeren A1 - Wittchen, Hans-Ulrich A1 - Zimmermann, Ulrich S. A1 - Walter, Henrik A1 - Smolka, Michael N. A1 - Sterzer, Philipp A1 - Rapp, Michael A. A1 - Huys, Quentin J. M. A1 - Schlagenhauf, Florian A1 - Heinz, Andreas T1 - Pavlovian-to-instrumental transfer effects in the nucleus accumbens relate to relapse in alcohol dependence JF - Addiction biology N2 - 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. KW - human Pavlovian-to-instrumental transfer KW - nucleus accumbens KW - relapse in alcohol use disorder Y1 - 2016 U6 - https://doi.org/10.1111/adb.12243 SN - 1355-6215 SN - 1369-1600 VL - 21 SP - 719 EP - 731 PB - Wiley-Blackwell CY - Hoboken ER -