TY  - JOUR
A1  - Kollmann, Peter
A1  - Roussos, Elias
A1  - Clark, George
A1  - Cooper, John F.
A1  - Sturner, Steven J.
A1  - Kotova, Anna
A1  - Regoli, Leonardo
A1  - Shprits, Yuri
A1  - Aseev, Nikita
A1  - Krupp, Norbert
T1  - Spectra of Saturn's proton belts revealed
JF  - Icarus
N2  - Saturn is permanently surrounded by 6 discrete proton radiation belts that are rigidly separated by the orbits of its inner moons and dense rings. These radiation belts are ideal environments to study the details of radial diffusion and the CRAND source process, yet progress has been hindered by the fact that the energy spectra are not known with certainty: Reanalysis of the response functions of the LEMMS instrument on-board the Cassini orbiter has shown that measurements of less than or similar to 10 MeV protons may be easily contaminated by greater than or similar to 10 MeV protons and that many available measurements characterize a very broad energy range, so that the calculation of an energy-resolved spectrum is not as straightforward as previously assumed. Here we use forward modeling of the measurements based on the instrument response and combine this technique where useful with numerical modeling of the proton belt physics in order to determine Saturn's spectra with higher certainty. We find significant proton intensities up to approximate to 1 GeV. While earlier studies reported on proton spectra roughly following a power law with exponent approximate to -2, our more advanced analysis shows harder spectra with exponent approximate to -1. The observed spectra provide independent confirmation that Saturn's proton belts are sourced by CRAND and are consistent with the provided protons being subsequently cooled in the tenuous gas originating from Saturn or Enceladus. The intensities at Saturn are found to be lower than at Jupiter and Earth, which is also consistent with the source of Saturn being exclusively CRAND, while the other planets can draw from additional processes. Our new spectra can be used in the future to further our understanding of Saturn's proton belts and the respective physical processes that occur at other magnetized planets in general. Also, the spectra have applications for several topics of planetary science, such as space weathering of Saturn's moons and rings, and can be useful to constrain properties of the main rings through their production of secondary particles.
KW  - Radiation belts
KW  - Saturn
KW  - CRAND
KW  - Proton
Y1  - 2022
U6  - https://doi.org/10.1016/j.icarus.2021.114795
SN  - 0019-1035
SN  - 1090-2643
VL  - 376
PB  - Elsevier
CY  - San Diego
ER  - 
TY  - JOUR
A1  - Rosa, Angelika D.
A1  - Dewaele, Agnès
A1  - Garbarino, Gaston
A1  - Svitlyk, Volodymyr
A1  - Morard, Guillaume
A1  - De Angelis, Filippo
A1  - Krstulovic, Marija
A1  - Briggs, Richard
A1  - Irifune, Tetsuo
A1  - Mathon, Olivier
A1  - Bouhifd, Mohamed Ali
T1  - Martensitic fcc-hcp transformation pathway in solid krypton and xenon and its effect on their equations of state
JF  - Physical review / publ. by The American Institute of Physics. B
N2  - The martensitic transformation is a fundamental physical phenomenon at the origin of important industrial applications. However, the underlying microscopic mechanism, which is of critical importance to explain the outstanding mechanical properties of martensitic materials, is still not fully understood. This is because for most martensitic materials the transformation is a fast process that makes in situ studies extremely challenging. Noble solids krypton and xenon undergo a progressive pressure-induced face-centered cubic (fcc) to hexagonal close-packed (hcp) martensitic transition with a very wide coexistence domain. Here, we took advantage of this unique feature to study the detailed transformation progress at the atomic level by employing in situ x-ray diffraction and absorption spectroscopy. We evidenced a four-stage pathway and suggest that the lattice mismatch between the fcc and hcp forms plays a key role in the generation of strain. We also determined precisely the effect of the transformation on the compression behavior of these materials.
Y1  - 2022
U6  - https://doi.org/10.1103/PhysRevB.105.144103
SN  - 2469-9950
SN  - 2469-9969
VL  - 105
IS  - 14
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Kutzschbach, Martin
A1  - Wunder, Bernd
A1  - Wannhoff, Iris
A1  - Wilke, Franziska Daniela Helena
A1  - Couffignal, Frédéric
A1  - Rocholl, Alexander
T1  - Raman spectroscopic quantification of tetrahedral boron in synthetic aluminum-rich tourmaline
JF  - American mineralogist : an international journal of earth and planetary materials
N2  - The Raman spectra of five B-[4]-bearing tourmalines of different composition synthesized at 700 degrees C/4.0 GPa (including first-time synthesis of Na-Li-B-[4]-tourmaline, Ca-Li-B-[4]-tourmaline, and Ca-bearing square-B-[4]-tourmaline) reveal a strong correlation between the tetrahedral boron content and the summed relative intensity of all OH-stretching bands between 3300-3430 cm(-1). The band shift to low wavenumbers is explained by strong O3-H center dot center dot center dot O5 hydrogen bridge bonding. Applying the regression equation to natural B-[4]-bearing tourmaline from the Koralpe (Austria) reproduces the EMPA-derived value perfectly [EMPA: 0.67(12) B-[4] pfu vs. Raman: 0.66(13) B-[4] pfu]. This demonstrates that Raman spectroscopy provides a fast and easy-to-use tool for the quantification of tetrahedral boron in tourmaline. The knowledge of the amount of tetrahedral boron in tourmaline has important implications for the better understanding and modeling of B-isotope fractionation between tourmaline and fluid/melt, widely used as a tracer of mass transfer processes.
KW  - Tourmaline
KW  - high pressure
KW  - synthesis
KW  - tetrahedral boron
KW  - Raman
KW  - SIMS
KW  - Lithium
KW  - Beryllium and Boron: Quintessentially Crustal
Y1  - 2021
U6  - https://doi.org/10.2138/am-2021-7758
SN  - 0003-004X
SN  - 1945-3027
VL  - 106
IS  - 6
SP  - 872
EP  - 882
PB  - Mineralogical Society of America
CY  - Washington, DC [u.a.]
ER  - 
TY  - JOUR
A1  - Wilhelmi, Ilka
A1  - Neumann, Alexander
A1  - Jähnert, Markus
A1  - Ouni, Meriem
A1  - Schürmann, Annette
T1  - Enriched alternative splicing in islets of diabetes-susceptible mice
JF  - International journal of molecular sciences
N2  - Dysfunctional islets of Langerhans are a hallmark of type 2 diabetes (T2D). We hypothesize that differences in islet gene expression alternative splicing which can contribute to altered protein function also participate in islet dysfunction. RNA sequencing (RNAseq) data from islets of obese diabetes-resistant and diabetes-susceptible mice were analyzed for alternative splicing and its putative genetic and epigenetic modulators. We focused on the expression levels of chromatin modifiers and SNPs in regulatory sequences. We identified alternative splicing events in islets of diabetes-susceptible mice amongst others in genes linked to insulin secretion, endocytosis or ubiquitin-mediated proteolysis pathways. The expression pattern of 54 histones and chromatin modifiers, which may modulate splicing, were markedly downregulated in islets of diabetic animals. Furthermore, diabetes-susceptible mice carry SNPs in RNA-binding protein motifs and in splice sites potentially responsible for alternative splicing events. They also exhibit a larger exon skipping rate, e.g., in the diabetes gene Abcc8, which might affect protein function. Expression of the neuronal splicing factor Srrm4 which mediates inclusion of microexons in mRNA transcripts was markedly lower in islets of diabetes-prone compared to diabetes-resistant mice, correlating with a preferential skipping of SRRM4 target exons. The repression of Srrm4 expression is presumably mediated via a higher expression of miR-326-3p and miR-3547-3p in islets of diabetic mice. Thus, our study suggests that an altered splicing pattern in islets of diabetes-susceptible mice may contribute to an elevated T2D risk.
KW  - alternative splicing
KW  - epigenetic
KW  - MicroRNA
KW  - RNAseq
KW  - diabetes
KW  - beta-cell
KW  - failure
Y1  - 2021
U6  - https://doi.org/10.3390/ijms22168597
SN  - 1422-0067
VL  - 22
IS  - 16
PB  - Molecular Diversity Preservation International
CY  - Basel
ER  - 
TY  - JOUR
A1  - Farkas, Márton Pál
A1  - Hofmann, Hannes
A1  - Zimmermann, Günter
A1  - Zang, Arno
A1  - Bethmann, Falko
A1  - Meier, Peter
A1  - Cottrell, Mark
A1  - Josephson, Neal
T1  - Hydromechanical analysis of the second hydraulic stimulation in well PX-1 at the Pohang fractured geothermal reservoir, South Korea
JF  - Geothermics : an international journal of geothermal research and its applications
N2  - In this study, we investigate numerically the hydro-mechanical behavior of fractured crystalline rock due to one of the five hydraulic stimulations at the Pohang Enhanced Geothermal site in South Korea. We use the commercial code FracMan (Golder Associates) that enables studying hydro-mechanical coupled processes in fractured media in three dimensions combining the finite element method with a discrete fracture network. The software is used to simulate fluid pressure perturbation at fractures during hydraulic stimulation. Our numerical simulation shows that pressure history matching can be obtained by partitioning the treatment into separate phases. This results in adjusted stress-aperture relationships. The evolution of aperture adjustment implies that the stimulation mechanism could be a combination of hydraulic fracturing and shearing. The simulated extent of the 0.01 MPa overpressure contour at the end of the treatment equals to similar to 180 m around the injection point.
KW  - Enhanced Geothermal System
KW  - Pohang geothermal reservoir
KW  - hydraulic
KW  - stimulation
KW  - PX-1
KW  - FracMan
Y1  - 2021
U6  - https://doi.org/10.1016/j.geothermics.2020.101990
SN  - 0375-6505
SN  - 1879-3576
VL  - 89
PB  - Elsevier
CY  - Amsterdam [u.a.]
ER  - 
TY  - JOUR
A1  - Sedaghatmehr, Mastoureh
A1  - Thirumalaikumar, Venkatesh P.
A1  - Kamranfar, Iman
A1  - Schulz, Karina
A1  - Müller-Röber, Bernd
A1  - Sampathkumar, Arun
A1  - Balazadeh, Salma
T1  - Autophagy complements metalloprotease FtsH6 in degrading plastid heat shock protein HSP21 during heat stress recovery
JF  - The journal of experimental botany : an official publication of the Society for Experimental Biology and of the Federation of European Societies of Plant Physiology
N2  - Moderate and temporary heat stresses prime plants to tolerate, and survive, a subsequent severe heat stress. Such acquired thermotolerance can be maintained for several days under normal growth conditions, and can create a heat stress memory. We recently demonstrated that plastid-localized small heat shock protein 21 ( HSP21) is a key component of heat stress memory in Arabidopsis thaliana. A sustained high abundance of HSP21 during the heat stress recovery phase extends heat stress memory. The level of HSP21 is negatively controlled by plastid-localized metalloprotease FtsH6 during heat stress recovery. Here, we demonstrate that autophagy, a cellular recycling mechanism, exerts additional control over HSP21 degradation. Genetic and chemical disruption of both metalloprotease activity and autophagy trigger superior HSP21 accumulation, thereby improving memory. Furthermore, we provide evidence that autophagy cargo receptor ATG8-INTERACTING PROTEIN1 (ATI1) is associated with heat stress memory. ATI1 bodies co-localize with both autophagosomes and HSP21, and their abundance and transport to the vacuole increase during heat stress recovery. Together, our results provide new insights into the module for control of the regulation of heat stress memory, in which two distinct protein degradation pathways act in concert to degrade HSP21, thereby enabling cells to recover from the heat stress effect at the cost of reducing the heat stress memory.
KW  - Arabidopsis thaliana
KW  - ATI1
KW  - FtsH6
KW  - heat stress
KW  - HSP21
KW  - plastid
KW  - selective autophagy
KW  - stress memory
KW  - stress recovery
Y1  - 2021
U6  - https://doi.org/10.1093/jxb/erab304
SN  - 0022-0957
SN  - 1460-2431
VL  - 72
IS  - 21
SP  - 7498
EP  - 7513
PB  - Oxford University Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Schaerer, Daniel
A1  - Izotov, Yuri I.
A1  - Worseck, Gábor
A1  - Berg, Danielle
A1  - Chisholm, John
A1  - Jaskot, Anne
A1  - Nakajima, Kimihiko
A1  - Ravindranath, Swara
A1  - Thuan, Trinh X.
A1  - Verhamme, Anne
T1  - Strong Lyman continuum emitting galaxies show intense C IV λ 1550 emission
JF  - Astronomy and astrophysics
N2  - Using the Space Telescope Imaging Spectrograph, we have obtained ultraviolet spectra from similar to 1200 to 2000 angstrom of known Lyman continuum (LyC) emitting galaxies at low redshift (z similar to 0.3-0.4) with varying absolute LyC escape fractions ( f(esc) similar to 0.01-0.72). Our observations include in particular the galaxy J1243+4646, which has the highest known LyC escape fraction at low redshift. While all galaxies are known Lyman alpha emitters, we consistently detect an inventory of additional emission lines, including C IV lambda 1550, He II lambda 1640, O III] lambda 1666, and C III] lambda 1909, whose origin is presumably essentially nebular. C IV lambda 1550 emission is detected above 4 sigma in six out of eight galaxies, with equivalent widths of EW(C IV) = 12-15 angstrom for two galaxies, which exceeds the previously reported maximum emission in low-z star-forming galaxies. We detect C IV lambda 1550 emission in all LyC emitters with escape fractions f(esc) > 0.1 and find a tentative increase in the flux ratio C IV lambda 1550 /C III] lambda 1909 with f(esc). Based on the data, we propose a new criterion to select and classify strong leakers (galaxies with f(esc) > 0.1): C IV lambda 1550 /C III] lambda 1909 greater than or similar to 0.75. Finally, we also find He II lambda 1640 emission in all the strong leakers with equivalent widths from 3 to 8 angstrom rest frame. These are among the highest values observed in star-forming galaxies and are primarily due to a high rate of ionizing photon production. The nebular He II lambda 1640 emission of the strong LyC emitters does not require harder ionizing spectra at >54 eV compared to those of typical star-forming galaxies at similarly low metallicity.
KW  - galaxies: starburst
KW  - galaxies: high-redshift
KW  - dark ages, reionization
KW  - first stars
KW  - ultraviolet: galaxies
Y1  - 2022
U6  - https://doi.org/10.1051/0004-6361/202243149
SN  - 0004-6361
SN  - 1432-0746
VL  - 658
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Birukov, Anna
A1  - Glintborg, Dorte
A1  - Schulze, Matthias B.
A1  - Jensen, Tina K.
A1  - Kuxhaus, Olga
A1  - Andersen, Louise B.
A1  - Kräker, Kristin
A1  - Polemiti, Elli
A1  - Jensen, Boye L.
A1  - Jørgensen, Jan S.
A1  - Dechend, Ralf
A1  - Andersen, Marianne S.
T1  - Elevated blood pressure in pregnant women with gestational diabetes according to the WHO criteria: importance of overweight
JF  - Journal of hypertension
N2  - Objective: Hypertension before and during early pregnancy has been associated with an increased risk of gestational diabetes mellitus (GDM) in retrospective analyses. We aimed to investigate the prospective blood pressure trackings in a population-based cohort of pregnant women, who were stratified according to their metabolic status in early third trimester. Methods: We recorded blood pressure longitudinally during pregnancy in 1230 women from the Odense Child Cohort, Denmark. Fasting glucose and insulin were measured at gestational weeks 28-30. Metabolic status was evaluated according to the WHO 2013 threshold for GDM (GDM-WHO: fasting plasma glucose >= 5.1 mmol/l), insulin and homeostatic model assessment of insulin resistance (HOMA-IR). Relationships between metabolic status in third trimester and blood pressure trajectories were evaluated with adjusted linear mixed models. Trajectory was defined as blood pressure records in pregnancy per 4 weeks interval. Results: Prevalence of GDM-WHO was 40% (498/1230). GDM-WHO was associated with 1.46 (0.22-2.70) mmHg higher SBP and 1.04 (0.07-2.01) mmHg higher DBP trajectories in the overall cohort. The associations were driven by differences in the overweight group, with 3.14 (1.05-5.25) mmHg higher SBP and 1.94 (0.42-3.47) mmHg higher DBP per 4 weeks in women with GDM-WHO compared with women without GDM-WHO. GDM-WHO was not associated with blood pressure in women with normal weight. Blood pressure trajectories were elevated across quartiles of insulin resistance. Conclusion: GDM-WHO is associated with higher blood pressure in pregnancy, and there appears to be a stronger effect in overweight women.
KW  - blood pressure
KW  - gestational diabetes mellitus
KW  - insulin resistance
KW  - overweight
KW  - pregnancy
KW  - WHO
Y1  - 2022
U6  - https://doi.org/10.1097/HJH.0000000000003196
SN  - 0263-6352
SN  - 1473-5598
VL  - 40
IS  - 8
SP  - 1614
EP  - 1623
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Zech, Hilmar G.
A1  - Reichert, Markus
A1  - Ebner-Priemer, Ulrich W.
A1  - Tost, Heike
A1  - Rapp, Michael A.
A1  - Heinz, Andreas
A1  - Dolan, Raymond J.
A1  - Smolka, Michael N.
A1  - Deserno, Lorenz
T1  - Mobile data collection of cognitive-behavioral tasks in substance use disorders: Where are we now?
JF  - Neuropsychobiology
N2  - Introduction: Over the last decades, our understanding of the cognitive, motivational, and neural processes involved in addictive behavior has increased enormously. A plethora of laboratory-based and cross-sectional studies has linked cognitive-behavioral measures to between-subject differences in drinking behavior. However, such laboratory-based studies inevitably suffer from small sample sizes and the inability to link temporal fluctuations in task measures to fluctuations in real-life substance use. To overcome these problems, several existing behavioral tasks have been transferred to smartphones to allow studying cognition in the field. Method: In this narrative review, we first summarize studies that used existing behavioral tasks in the laboratory and self-reports of substance use with ecological momentary assessment (EMA) in the field. Next, we review studies on psychometric properties of smartphone-based behavioral tasks. Finally, we review studies that used both smartphone-based tasks and self-reports with EMA in the field. Results: Overall, studies were scarce and heterogenous both in tasks and in study outcomes. Nevertheless, existing findings are promising and point toward several methodological recommendations: concerning psychometrics, studies show that - although more systematic studies are necessary - task validity and reliability can be improved, for example, by analyzing several measurement sessions at once rather than analyzing sessions separately. Studies that use tasks in the field, moreover, show that power can be improved by choosing sampling schemes that combine time-based with event-based sampling, rather than relying on time-based sampling alone. Increasing sampling frequency can further increase power. However, as this also increases the burden to participants, more research is necessary to determine the ideal sampling frequency for each task. Conclusion: Although more research is necessary to systematically study both the psychometrics of smartphone-based tasks and the frequency at which task measures fluctuate, existing studies are promising and reveal important methodological recommendations useful for researchers interested in implementing behavioral tasks in EMA studies.
KW  - Ecological momentary assessment
KW  - Behavioral tasks
KW  - Smartphone
KW  - Substance use
KW  - Addiction
Y1  - 2022
U6  - https://doi.org/10.1159/000523697
SN  - 0302-282X
SN  - 1423-0224
VL  - 81
IS  - 5
SP  - 438
EP  - 450
PB  - Karger
CY  - Basel
ER  - 
TY  - JOUR
A1  - Ciarniello, Mauro
A1  - Fulle, Marco
A1  - Raponi, Andrea
A1  - Filacchione, Gianrico
A1  - Capaccioni, Fabrizio
A1  - Rotundi, Alessandra
A1  - Rinaldi, Giovanna
A1  - Formisano, Michelangelo
A1  - Magni, Gianfranco
A1  - Tosi, Federico
A1  - De Sanctis, Maria Cristina
A1  - Capria, Maria Teresa
A1  - Longobardo, Andrea
A1  - Beck, Pierre
A1  - Fornasier, Sonia
A1  - Kappel, David
A1  - Mennella, Vito
A1  - Mottola, Stefano
A1  - Rousseau, Batiste
A1  - Arnold, Gabriele
T1  - Macro and micro structures of pebble-made cometary nuclei reconciled by seasonal evolution
JF  - Nature astronomy
N2  - Comets evolve due to sublimation of ices embedded inside porous dust, triggering dust emission (that is, erosion) followed by mass loss, mass redistribution and surface modifications. Surface changes were revealed by the Deep Impact and Stardust NExT missions for comet 9P/Tempel 1 (ref.(1)), and a full inventory of the processes modifying cometary nuclei was provided by Rosetta while it escorted comet 67P/Churyumov-Gerasimenko for approximately two years(2-4). Such observations also showed puzzling water-ice-rich spots that stood out as patches optically brighter and spectrally bluer than the average cometary surfaces(5-9). These are up to tens of metres large and indicate macroscopic compositional dishomogeneities apparently in contrast with the structural homogeneity above centimetre scales of pebble-made nuclei(10). Here we show that the occurrence of blue patches determines the seasonal variability of the nucleus colour(4,11,12) and gives insight into the internal structure of comets. We define a new model that links the centimetre-sized pebbles composing the nucleus(10) and driving cometary activity(13,14) to metre-sized water-ice-enriched blocks embedded in a drier matrix. The emergence of blue patches is due to the matrix erosion driven by CO2-ice sublimation that exposes the water-ice-enriched blocks, which in turn are eroded by water-ice sublimation when exposed to sunlight. Our model explains the observed seasonal evolution of the nucleus and reconciles the available data at micro (sub-centimetre) and macro (metre) scales.
KW  - Asteroids, comets and Kuiper belt
KW  - Planetary science
Y1  - 2022
U6  - https://doi.org/10.1038/s41550-022-01625-y
SN  - 2397-3366
VL  - 6
IS  - 5
SP  - 546
EP  - 553
PB  - Nature Research
CY  - Berlin
ER  -