bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prolonged Fluvial Activity From Channel‐Fan Systems on Mars
Authors: Stucky de Quay Gaia , Kite Edwin S , Mayer David P. 
Published: November 2019

AbstractAlluvial fans on Mars, which are primarily sourced from erosional alcoves incised into crater rims, record a period of increased surface runoff which ended >1 Ga. However, we lack quantitative constraints on the frequency and duration of river‐forming processes and the climatic conditions that accompanied these long‐term habitable episodes. Here we use bedrock erosion and sediment transport models to show that the cumulative time span of wet activity (i.e., nonzero erosion and deposition) was between 100 years to 1 Myr excluding dry years. We use Context Camera (CTX) digital elevation models to compile a data set of >200 channels upstream of depositional fans and determine key fluvial geometry metrics. Results from calculating Mars stream power parameters are compared to great escarpment channels and globally distributed bedrock rivers on Earth. Although Martian channel profile morphologies fall within the range of those on Earth, they are slightly less concave‐up (concavity index,
) and steeper for a given drainage area (reference steepness index,
, for reference drainage area, Ar = 1 ×107 m2). Timescales depend strongly on poorly constrained variables such as erodability and grain size. Channel morphologies, intermittencies, spatial distributions, and orientations collectively suggest an arid climate and a source from snowmelt on steep crater rims, possibly from obliquity‐paced insolation variations or orographic accumulation. Derived timescales are consistent with erosion rates and intermittencies observed in arid environments on Earth and do not support short‐lived or catastrophic triggers for the warm climate conditions (such as impacts or individual volcanic eruptions).
Through the Thick and Thin: New Constraints on Mars Paleopressure History 3.8 – 4 Ga from Small Exhumed Craters
Authors: Warren A. O. , Kite E. S. , Williams J.‐P. , Horgan B. 
Published: November 2019

AbstractMars' climate history depends in part on its atmospheric pressure evolution, but most existing constraints on atmospheric pressure are indirect. Thin atmospheres allow small objects to reach the surface and form impact craters; therefore, ancient impact craters can constrain past atmospheric pressure. To identify ancient craters preserved in sedimentary rocks and exhumed by wind erosion, we use HiRISE orthoimages, anaglyphs, and digital terrain models (DTMs). We compare measured crater populations from two sites to predictions from an atmosphere‐impactor interaction model for atmospheres of different pressures. Our upper limits on continuous atmospheric pressure are 1.9±0.1 bar around 4 Ga and 1.5±0.1 bar at 3.8±0.2 Ga. We demonstrate that atmospheric pressure cannot have been continuously above these upper limits. During the interval 3.8±0.2 Ga, our crater counts require that atmospheric pressure was less than 5% of Earth's modern pressure for at least 104 yrs, or at higher pressure for a correspondingly longer duration of time (at least 105−106 years at 1.5 bar for our Mawrth phyllosilicates and Meridiani Planum data, respectively). Therefore, atmospheric pressure around 4 Ga was either continuously 1.9±0.1 bar or varied between higher (>1.9 bar) and lower (<1.9 bar) pressures. Similarly, atmospheric pressure at 3.8±0.2 Ga was either continuously 1.5±0.1 bar, or varied between higher (>1.5 bar) and lower (<1.5 bar) pressures. Finally, we synthesize all available paleopressure estimates for early Mars to constrain a 2‐component model of Mars' long‐term atmospheric pressure evolution. In our model, atmospheric pressures <1 bar early in Mars' history best fit existing paleopressure constraints.
The Development of an Atmospheric Aerosol/Chemistry‐Climate Model, BCC_AGCM_CUACE2.0, and Simulated Effective Radiative Forcing of Nitrate Aerosols
Authors: An Qi , Zhang Hua , Wang Zhili , Liu Yi , Xie Bing , Liu Qianxia , Wang Zaizhi , Gong Sunling 
Published: November 2019

AbstractThis study developed a next‐generation atmospheric aerosol/chemistry‐climate model, the BCC_AGCM_CUACE2.0. Then, the performance of the model for nitrate was evaluated, and the nitrate direct radiative forcing (DRF) and effective radiative forcing (ERF) due to aerosol‐radiation interactions were simulated for the present day (2010), near‐term future (2030), and middle‐term future (2050) under the Representative Concentration Pathway 4.5, 6.0, and 8.5 scenarios relative to the preindustrial era (1850). The model reproduced the distributions and seasonal changes in nitrate loading well, and simulated surface concentrations matched observations in Europe, North America, and China. Current global mean annual loading of nitrates was predicted to increase by 1.50 mg m−2relative to 1850, with the largest increases occurring in East Asia (9.44 mg m−2), Europe (4.36 mg m−2), and South Asia (3.09 mg m−2). The current global mean annual ERF of nitrates was −0.28 W m−2relative to 1850. Due to global reductions in pollutant emissions, the nitrate ERF values were predicted to decrease to −0.17, −0.20, and −0.24 W m−2in 2030 and −0.07, −0.18, and −0.19 W m−2in 2050 for Representative Concentration Pathway 4.5, 6.0, and 8.5 relative to 1850, respectively. Although global mean nitrate values showed a declining trend, future nitrate loading remained high in East Asia and South Asia.
A Steady‐State Model for the Relationship Between Humidity, Instability, and Precipitation in the Tropics
Authors: Singh Martin S. , Warren Robert A. , Jakob Christian 
Published: November 2019

AbstractA simple steady‐state model for the thermodynamic structure of a convecting atmosphere under the influence of large‐scale dynamics is derived based on a bulk‐plume representation of convection. Given profiles of the large‐scale vertical velocity and convective mass flux, the model predicts the steady‐state temperature and environmental relative humidity profiles as a function of the convective entrainment rate and a parameter representing the importance of condensate reevaporation. The bulk‐plume model determines the environmental relative humidity through a balance between the moistening effect of convective detrainment and the drying effect of subsidence in the cloud environment. As the convective mass flux is increased, the importance of detrainment moistening increases, leading to a higher environmental relative humidity. Since the precipitation rate also increases with the convective mass flux, this leads to a steady state in which the precipitation is a strongly increasing function of environmental relative humidity. The bulk‐plume model also predicts that the atmospheric stability increases with large‐scale upward motion, with the tropospheric lapse rate being most unstable under large‐scale descent, when the environmental relative humidity is low. The above relationships are reproduced in a set of simulations with a cloud‐system resolving model (CRM) run to equilibrium with imposed large‐scale vertical velocity profiles. The results provide insight to the steady‐state limit of the well‐known problem of determining the relationships between large‐scale conditions and the convective state of the atmosphere.
Evaluation of CNRM Earth System Model, CNRM‐ESM2‐1: Role of Earth System Processes in Present‐Day and Future Climate
Authors: Séférian Roland , Nabat Pierre , Michou Martine , Saint‐Martin David , Voldoire Aurore , Colin Jeanne , Decharme Bertrand , Delire Christine , Berthet Sarah , Chevallier Matthieu , Sénési Stephane , Franchisteguy Laurent , Vial Jessica , Mallet Marc , Joetzjer Emilie , Geoffroy Olivier , Guérémy Jean‐François , Moine Marie‐Pierre , Msadek Rym , Ribes Aurélien , Rocher Matthias , Roehrig Romain , Salas‐y‐Mélia David , Sanchez Emilia , Terray Laurent , Valcke Sophie , Waldman Robin , Aumont Olivier , Bopp Laurent , Deshayes Julie , Éthé Christian , Madec Gurvan 
Published: November 2019

AbstractThis study introduces CNRM‐ESM2‐1, the Earth system (ES) model of second generation developed by CNRM‐CERFACS for the sixth phase of the Coupled Model Intercomparison Project (CMIP6). CNRM‐ESM2‐1 offers a higher model complexity than the Atmosphere‐Ocean General Circulation Model CNRM‐CM6‐1 by adding interactive ES components such as carbon cycle, aerosols, and atmospheric chemistry. As both models share the same code, physical parameterizations, and grid resolution, they offer a fully traceable framework to investigate how far the represented ES processes impact the model performance over present‐day, response to external forcing and future climate projections. Using a large variety of CMIP6 experiments, we show that represented ES processes impact more prominently the model response to external forcing than the model performance over present‐day. Both models display comparable performance at replicating modern observations although the mean climate of CNRM‐ESM2‐1 is slightly warmer than that of CNRM‐CM6‐1. This difference arises from land cover‐aerosol interactions where the use of different soil vegetation distributions between both models impacts the rate of dust emissions. This interaction results in a smaller aerosol burden in CNRM‐ESM2‐1 than in CNRM‐CM6‐1, leading to a different surface radiative budget and climate. Greater differences are found when comparing the model response to external forcing and future climate projections. Represented ES processes damp future warming by up to 10% in CNRM‐ESM2‐1 with respect to CNRM‐CM6‐1. The representation of land vegetation and the CO2‐water‐stomatal feedback between both models explain about 60% of this difference. The remainder is driven by other ES feedbacks such as the natural aerosol feedback.
Middle to Late Miocene Age for the End of Amphibolite‐Facies Mylonitization of the Alpine Schist, New Zealand: Implications for Onset of Transpression Across the Alpine Fault
Authors: Ring Uwe , Glodny Johannes , Angiboust Samuel , Little Tim , Lang Karl A. 
Published: November 2019

AbstractWe report five new Rb‐Sr muscovite‐based isochron ages, which are the first to constrain the timing of amphibolite‐facies mylonitization of the Alpine Schist in the Southern Alps of New Zealand. The ages range from 13.1 ± 4.3 to 8.9 ± 3.2 Ma (2σ uncertainties) for mylonite directly above the Alpine Fault. The weighted mean age of 10.74 ± 0.57 Ma is within uncertainty of a published 40Ar/39Ar illite/mica upper‐intercept age of 11.5 ± 0.5 Ma measured at the same locality. The end of amphibolite‐facies mylonitization occurred at metamorphic conditions of ~560–570 °C and ~0.9–1.1 GPa as derived from pseudosection analysis in the NCTiKFMASH system. We interpret Miocene metamorphism to reflect transpressional crustal thickening and formation of a thick crustal root supporting early Southern Alps topography at or prior to 10.74 ± 0.57 Ma. Additional ~2–1 Ma Rb‐Sr biotite, 40Ar/39Ar muscovite, and 40Ar/39Ar biotite ages reflect isotopic closure during rapid cooling along the Alpine Fault in the Pleistocene. The Miocene mylonitization ages and the Pleistocene cooling ages define a distinct two‐stage cooling and exhumation history for the Alpine Schist with initial cooling of ~10 °C/Myr and exhumation rates of 2–4 km/Myr. Final cooling since ~2 Ma was >100 °C/Myr at exhumation rates of ~5–6 km/Myr. We interpret the two‐phase cooling history by movement of the mylonite through a strongly nonlinear thermal structure. An older 60.5 ± 0.7 Ma metamorphic event is also preserved as a Rb‐Sr crystallization age of a predeformational muscovite‐plagioclase assemblage in a sheared pegmatite.
Using a Paleosurface to Constrain Low‐Temperature Thermochronological Data: Tectonic Evolution of the Cuevas Range, Central Andes
Authors: Zapata S. , Sobel E. R. , del Papa C. , Jelinek A. R. , Glodny J. 
Published: November 2019

AbstractDispersion of low‐temperature thermochronologic data from nine samples collected on a deformed paleosurface preserved on the Cuevas range (Central Andes) can be exploited to unravel complex thermal histories. The nine samples yielded data that have both intersample and intrasample dispersions; the data set includes apatite fission‐track ages (180–110 Ma), mean track lengths (11–13 μm), apatite helium (10–250 Ma), and zircon helium ages (180–348 Ma). We ran inverse thermal history models for each sample that reveal spatial variations of the Miocene reheating along the paleosurface. Next, we ran a multiple‐sample joint model to infer a common form for thermal history for all samples. Our results suggest that initial exhumation during the Famatinian orogeny was followed by a residence between ~2.5 and 7.0 km depth during the Paleozoic and the Triassic. The onset of Mesozoic rifting was responsible for an increase of the geothermal gradient and extensive horst exhumation, which brought the basement of the Cuevas range close to the surface (~1–2 km) in the Late Jurassic. Between the Late Cretaceous and the Paleocene, the combination of low relief, a humid climate, and low erosion rates (0.006–0.030 km/Ma) facilitated the development of the Cuevas paleosurface. During the Miocene, this paleosurface experienced differential reheating with a high geothermal gradient (>25 °C/km) due to the sedimentary cover and local magmatic heat sources. During the Andean orogeny, in the Pliocene, the Cuevas paleosurface was deformed, exhumed, and uplifted.
Generalization of Hop Distance‐Time Scaling and Particle Velocity Distributions via a Two‐Regime Formalism of Bedload Particle Motions
Authors: Wu Zi , Furbish David , Foufoula‐Georgiou Efi 
Published: November 2019

AbstractTo date, there is no consensus on the probability distribution of particle velocities during bedload transport, with some studies suggesting an exponential‐like distribution while others a Gaussian‐like distribution. Yet, the form of this distribution is key for the determination of sediment flux and the dispersion characteristics of tracers in rivers. Combining theoretical analysis of the Fokker‐Planck equation for particle motions, numerical simulations of the corresponding Langevin equation, and measurements of motion in high‐speed imagery from particle‐tracking experiments, we examine the statistics of bedload particle trajectories, revealing a two‐regime distance‐time (L‐Tp) scaling for the particle hops (measured from start to stop). We show that particles of short hop distances scale as L ~
giving rise to the Weibull‐like front of the hop distance distribution, while particles of long hop distances transition to a different scaling regime of L ~ Tp leading to the exponential‐like tail of the hop distance distribution. By demonstrating that the predominance of mostly long hop particles results in a Gaussian‐like velocity distribution, while a mixture of both short and long hop distance particles leads to an exponential‐like velocity distribution, we argue that the form of the probability distribution of particle velocities can depend on the physical environment within which particle transport occurs, explaining and unifying disparate views on particle velocity statistics reported in the literature.
Statistical Inference Over Persistent Homology Predicts Fluid Flow in Porous Media
Authors: Moon Chul , Mitchell Scott A. , Heath Jason E. , Andrew Matthew 
Published: November 2019

AbstractWe statistically infer fluid flow and transport properties of porous materials based on their geometry and connectivity, without the need for detailed We summarize structure by persistent homology and then determines the similarity of structures using image analysis and statistics. Longer term, this may enable quick and automated categorization of rocks into known archetypes. We first compute persistent homology of binarized 3D images of material subvolume samples. The persistence parameter is the signed Euclidean distance from inferred material interfaces, which captures the distribution of sizes of pores and grains. Each persistence diagram is converted into an image vector. We infer structural similarity by calculating image similarity. For each image vector, we compute principal components to extract features. We fit statistical models to features estimates material permeability, tortuosity, and anisotropy. We develop a Structural SIMilarity index to determine statistical representative elementary volumes.
Morphodynamic Modeling of Sediment Pulse Dynamics
Authors: Morgan Jacob A. , Nelson Peter A. 
Published: November 2019

AbstractSediment pulses, defined as discrete, temporary increases in sediment supply, enter channels through both natural and anthropogenic means. The movement of the resultant deposit (sediment wave) in coarse‐bedded channels is generally characterized by some combination of translation and dispersion; however, how sediment waves evolve over time is still poorly understood, potentially hampering restoration efforts that involve the introduction of sediment to channels. Here we use a one‐dimensional morphodynamic model to explore how different pulse characteristics affect sediment wave movement. Our one‐dimensional model uses the standard step backwater method to compute hydrodynamics and determines morphodynamics by computing bedload transport and retaining vertical grain size stratigraphy. We explore the effect of pulse mass, initial wave spread, and composition (grain size) on subsequent sediment wave dynamics. Our results suggest higher relative rates of sediment wave dispersion to advection for larger pulses, waves with a smaller initial spread, and pulses composed of coarser material. In all simulations sediment wave celerity and spreading rates decayed through time as a power function. Waves of smaller total mass decayed at faster rates than those of larger mass. Simulations also show that sediment pulses attain a terminal amplitude, suggesting that some sediment waves may not completely disperse. Larger terminal amplitudes were associated with larger pulses and pulses composed of coarser grains.
Genetic causes of primary aldosteronism
Authors: Seidel Eric , Schewe Julia , Scholl Ute I. 
Published: November 2019

AbstractPrimary aldosteronism is characterized by at least partially autonomous production of the adrenal steroid hormone aldosterone and is the most common cause of secondary hypertension. The most frequent subforms are idiopathic hyperaldosteronism and aldosterone-producing adenoma. Rare causes include unilateral hyperplasia, adrenocortical carcinoma and Mendelian forms (familial hyperaldosteronism). Studies conducted in the last eight years have identified somatic driver mutations in a substantial portion of aldosterone-producing adenomas, including the genesKCNJ5(encoding inwardly rectifying potassium channel GIRK4),CACNA1D(encoding a subunit of L-type voltage-gated calcium channel CaV1.3),ATP1A1(encoding a subunit of Na+/K+-ATPase),ATP2B3(encoding a Ca2+-ATPase), andCTNNB1(encoding ß-catenin). In addition, aldosterone-producing cells were recently reported to form small clusters (aldosterone-producing cell clusters) beneath the adrenal capsule. Such clusters accumulate with age and appear to be more frequent in individuals with idiopathic hyperaldosteronism. The fact that they are associated with somatic mutations implicated in aldosterone-producing adenomas also suggests a precursor function for adenomas. Rare germline variants ofCYP11B2(encoding aldosterone synthase),CLCN2(encoding voltage-gated chloride channel ClC-2),KCNJ5,CACNA1H(encoding a subunit of T-type voltage-gated calcium channel CaV3.2), andCACNA1Dhave been reported in different subtypes of familial hyperaldosteronism. Collectively, these studies suggest that primary aldosteronism is largely due to genetic mutations in single genes, with potential implications for diagnosis and therapy.
Microfluidics-assisted multiplexed biomarker detection for in situ mapping of immune cells in tumor sections
Authors: Migliozzi Daniel , Pelz Benjamin , Dupouy Diego G. , Leblond Anne-Laure , Soltermann Alex , Gijs Martin A. M. 
Published: November 2019

AbstractBecause of the close interaction between tumors and the immune system, immunotherapies are nowadays considered as the most promising treatment against cancer. In order to define the diagnosis and the subsequent therapy, crucial information about the immune cells at the tumor site is needed. Indeed, different types or activation status of cells may be indicative for specific and personalized treatments. Here, we present a quantitative method to identify ten different immuno-markers in the same tumor cut section, thereby saving precious samples and enabling correlative analysis on several cell families and their activation status in a tumor microenvironment context. We designed and fabricated a microfluidic chip with optimal thermomechanical and optical properties for fast delivery of reagents on tissue slides and for fully automatic imaging by integration with an optical microscope. The multiplexing capability of the system is enabled by an optimized cyclic immunofluorescence protocol, with which we demonstrated quantitative sequential immunostaining of up to ten biomarkers on the same tissue section. Furthermore, we developed high-quality image-processing algorithms to map each cell in the entire tissue. As proof-of-concept analyses, we identified coexpression and colocalization patterns of biomarkers to classify the immune cells and their activation status. Thanks to the quantitativeness and the automation of both the experimental and analytical methods, we believe that this multiplexing approach will meet the increasing clinical need of personalized diagnostics and therapy in cancer pathology.
Intrinsic connectomes are a predictive biomarker of remission in major depressive disorder
Authors: Korgaonkar Mayuresh S. , Goldstein-Piekarski Andrea N. , Fornito Alexander , Williams Leanne M. 
Published: November 2019

Abstract
Although major depressive disorder (MDD) is associated with altered functional coupling between disparate neural networks, the degree to which such measures are ameliorated by antidepressant treatment is unclear. It is also unclear whether functional connectivity can be used as a predictive biomarker of treatment response. Here, we used whole-brain functional connectivity analysis to identify neural signatures of remission following antidepressant treatment, and to identify connectomic predictors of treatment response. 163 MDD and 62 healthy individuals underwent functional MRI during pre-treatment baseline and 8-week follow-up sessions. Patients were randomized to escitalopram, sertraline or venlafaxine-XR antidepressants and assessed at follow-up for remission. Baseline measures of intrinsic functional connectivity between each pair of 333 regions were analyzed to identify pre-treatment connectomic features that distinguish remitters from non-remitters. We then interrogated these connectomic differences to determine if they changed post-treatment, distinguished patients from controls, and were modulated by medication type. Irrespective of medication type, remitters were distinguished from non-remitters by greater connectivity within the default mode network (DMN); specifically, between the DMN, fronto-parietal and somatomotor networks, the DMN and visual, limbic, auditory and ventral attention networks, and between the fronto-parietal and somatomotor networks with cingulo-opercular and dorsal attention networks. This baseline hypo-connectivity for non-remitters also distinguished them from controls and increased following treatment. In contrast, connectivity for remitters was higher than controls at baseline and also following remission, suggesting a trait-like connectomic characteristic. Increased functional connectivity within and between large-scale intrinsic brain networks may characterize acute recovery with antidepressants in depression.