bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pressure‐Induced Coordination Changes in a Pyrolitic Silicate Melt From Ab Initio Molecular Dynamics Simulations
Authors: Solomatova N.V. , Caracas R. 
Published: November 2019

AbstractWith ab initio molecular dynamics simulations on a Na‐, Ca‐, Fe‐, Mg‐, and Al‐bearing silicate melt of pyrolite composition, we examine the detailed changes in elemental coordination as a function of pressure and temperature. We consider the average coordination as well as the proportion and distribution of coordination environments at pressures and temperatures encompassing the conditions at which molten silicates may exist in present‐day Earth and those of the Early Earth's magma ocean. At ambient pressure and 2,000 K, we find that the average coordination of cations with respect to oxygen is 4.0 for Si‐O, 4.0 for Al‐O, 3.7 for Fe‐O, 4.6 for Mg‐O, 5.9 for Na‐O, and 6.2 for Ca‐O. Although the coordination for iron with respect to oxygen may be underestimated, the coordination number for all other cations are consistent with experiments. By 15 GPa (2,000 K), the average coordination for Si‐O remains at 4.0 but increases to 4.1 for Al‐O, 4.2 for Fe‐O, 4.9 for Mg‐O, 8.0 for Na‐O, and 6.8 for Ca‐O. The coordination environment for Na‐O remains approximately constant up to core‐mantle boundary conditions (135 GPa and 4000 K) but increases to about 6 for Si‐O, 6.5 for Al‐O, 6.5 for Fe‐O, 8 for Mg‐O, and 9.5 for Ca‐O. We discuss our results in the context of the metal‐silicate partitioning behavior of siderophile elements and the viscosity changes of silicate melts at upper mantle conditions. Our results have implications for melt properties, such as viscosity, transport coefficients, thermal conductivities, and electrical conductivities, and will help interpret experimental results on silicate glasses.
Near‐Inertial Wave Trapping Near the Base of an Anticyclonic Mesoscale Eddy Under Normal Atmospheric Conditions
Authors: Martínez‐Marrero A. , Barceló‐Llull B. , Pallàs‐Sanz E. , Aguiar‐González B. , Estrada‐Allis S. N. , Gordo C. , Grisolía D. , Rodríguez‐Santana A. , Arístegui J. 
Published: November 2019

AbstractObservational evidence demonstrates the signature of near‐inertial wave (NIW) trapping by a long‐lived westward propagating mesoscale anticyclonic eddy under normal atmospheric conditions. Cross‐eddy sections of density and shipboard acoustic Doppler current profiler data show the downward (upward phase) propagation of NIW packets with vertical wavelengths of 200 m within the eddy, and wave energy amplification in a critical vertical layer located near the base of the anticyclone. Elevated strain variance, enhanced turbulent kinetic energy dissipation rates obtained from a fine‐scale parameterization, and the occurrence of low (≤1) gradient Richardson numbers are consistent with turbulence production and mixing from 400 m to at least the maximum sampling depth of 725 m associated with the trapped NIWs. The observation of NIW packets near the eddy base at two different stages of the survey separated by 10 days and the persistence of low to moderate winds before and during the eddy sampling strongly suggest that our findings may be common in similar open‐ocean anticyclonic eddies under normal wind conditions.
Tracking Atmospheric Rivers Globally: Spatial Distributions and Temporal Evolution of Life Cycle Characteristics
Authors: Guan Bin , Waliser Duane E. 
Published: November 2019

AbstractThe Tracking Atmospheric Rivers Globally as Elongated Targets (tARget) algorithm is further developed to Version 3, adding the capability to track atmospheric river (AR) life cycles along with other refinement. The results indicate AR genesis is more frequent toward the western boundaries of midlatitude ocean basins and nearby upstream land areas (~1 month−1) compared to the eastern boundaries (~0.5 month−1) and least frequent in tropical and polar areas (reaching toward 0). AR termination is more frequent toward the northeastern sectors of North Pacific/Atlantic and adjacent downstream land areas and in the Southern Ocean near Antarctica (~1 month−1) compared to the adjacent ocean sectors (~0.5 month−1) and least frequent in tropical areas and interior Antarctica where AR genesis is similarly infrequent. ARs tend to be longer‐lived when the genesis (termination) occurs toward the western (eastern) boundaries of midlatitude ocean basins and adjacent land areas (maximum lifetime >72 hr) compared to the opposite side of the ocean basins (24–72 hr) and when terminated at high latitudes. AR travel speed is higher in the midlatitude ocean basins and strongly steered by the zonal wind around 650 hPa. AR tracks are nearly linear in most cases, with the overall travel direction closely correlated with the direction of integrated water vapor transport (r = 0.69) although being more zonal than the latter. Temporally, ARs tend to be longer/stronger around the middle of the life cycle. Seasonal variations in AR life cycle characteristics are also examined. The handling of AR separations/mergers contributes the largest sensitivity in tracking result compared to selection/resolution of input data.
Land–Sea Contrast in the Diurnal Variation of Precipitation from Landfalling Tropical Cyclones
Authors: Tang Xiaodong , Cai Qichao , Fang Juan , Tan Zhe‐Min 
Published: November 2019

AbstractRecent composite analysis of landfalling tropical cyclones (TCs) suggests a rain rate peak in the early morning, which contradicts the typically observed peak in convective precipitation over land seen in the late afternoon to early evening. We conducted a set of idealized simulations of TCs and analyzed observational data from TC Bebinca (2018), which stalled near the shoreline of southern China. We show a distinct land–sea contrast in the diurnal variation of TC precipitation and an 8–12 hr offset between the peak precipitation time over land compared with that over the sea in a TC that stalls at the shoreline. The highest land surface temperature and maximum low‐level buoyancy during the afternoon led to peak precipitation over land at this time. However, the peak precipitation over the sea in the early morning was generated by the increase in relative humidity caused by nighttime radiative cooling and enhanced instability.
Spatiotemporal Variability and Sources of DIC in Permafrost Catchments of the Yangtze River Source Region: Insights From Stable Carbon Isotope and Water Chemistry
Authors: Song Chunlin , Wang Genxu , Mao Tianxu , Huang Kewei , Sun Xiangyang , Hu Zhaoyong , Chang Ruiying , Chen Xiaopeng , Raymond Peter A. 
Published: November 2019

AbstractRiverine dissolved inorganic carbon (DIC) exports play a central role in the regional and global carbon cycles. Here, we investigated the spatiotemporal variability and sources of DIC in eight catchments in the Yangtze River source region (YRSR) with variable permafrost coverage and seasonally thawed active layers. The YRSR catchments are DIC‐rich (averagely 25 mg C L−1) and export 3.51 g m−2 yr−1 of DIC. The seasonal changes of temperature, active layer, flow path, and discharge can alter DIC and stable carbon isotope of DIC (δ13C‐DIC). The most depleted δ13C‐DIC values were found in the thawed period, suggesting the soil‐respired CO2 during the active layer thaw period can promote bicarbonate production via H2CO3 weathering. Spatially, δ13C‐DIC values increased downstream, likely due to CO2 outgassing and changed permafrost coverage and runoff. We found that evaporite dissolution and silicate weathering in the seasonally thawed active layer contributed 44.2% and 30.9% of stream HCO3‐, respectively, while groundwater and rainwater contributed 16.7% and 7.3% of HCO3‐, respectively. Pure carbonate rock weathering played a negligible role in DIC production. These results were compatible with δ13C‐DIC source approximation results. Silicate weathering increased from initial thaw to thawed period, reflecting the active layer thaw and subsequent hydrology change impacts. Silicate weathering consumed 1.25 × 1010 mol of CO2 annually, while evaporite dissolution may produce CO2 and neutralize this CO2 sink. This study provides new understanding of the riverine DIC export processes of the YRSR. As permafrost degrades, the quantity, sources, and sinks of riverine DIC may also change spatiotemporally.
A New Automated Method for Improved Flood Defense Representation in Large‐Scale Hydraulic Models
Authors: Wing Oliver E. J. , Bates Paul D. , Neal Jeffrey C. , Sampson Christopher C. , Smith Andrew M. , Quinn Niall , Shustikova Iuliia , Domeneghetti Alessio , Gilles Daniel W. , Goska Radoslaw , Krajewski Witold F. 
Published: November 2019

AbstractThe execution of hydraulic models at large spatial scales has yielded a step change in our understanding of flood risk. Yet their necessary simplification through the use of coarsened terrain data results in an artificially smooth digital elevation model with diminished representation of flood defense structures. Current approaches in dealing with this, if anything is done at all, involve either employing incomplete inventories of flood defense information or making largely unsubstantiated assumptions about defense locations and standards based on socioeconomic data. Here, we introduce a novel solution for application at scale. The geomorphometric characteristics of defense structures are sampled, and these are fed into a probabilistic algorithm to identify hydraulically relevant features in the source digital elevation model. The elevation of these features is then preserved during the grid coarsening process. The method was shown to compare favorably to surveyed U.S. levee crest heights. When incorporated into a continental‐scale hydrodynamic model based on LISFLOOD‐FP and compared to local flood models in Iowa (USA), median correspondence was 69% for high‐frequency floods and 80% for low‐frequency floods, approaching the error inherent in quantifying extreme flows. However, improvements versus a model with no defenses were muted, and risk‐based deviations between the local and continental models were large. When simulating an event on the Po River (Italy), built and tested with higher quality data, the method outperformed both undefended and even engineering‐grade models. As such, particularly when employed alongside model components of commensurate quality, the method here generates improved‐accuracy simulations of flood inundation.
Microbial succession during wheat bran fermentation and colonisation by human faecal microbiota as a result of niche diversification
Authors: De Paepe Kim , Verspreet Joran , Courtin Christophe M , Van de Wiele Tom 
Published: November 2019

Abstract
The human gut can be viewed as a flow-through system with a short residence time, a high turnover rate and a spatial gradient of physiological conditions. As a consequence, the gut microbiota is exposed to highly fluctuating environmental determinants presented by the host and diet. Here, we assessed the fermentation and colonisation of insoluble wheat bran by faecal microbiota of three individuals at an unprecedented sampling intensity. Time-resolved 16S rRNA gene amplicon sequencing, revealed a dynamic microbial community, characterised by abrupt shifts in composition, delimiting states with a more constant community, giving rise to a succession of bacterial taxa alternately dominating the community over a 72 h timespan. Early stages were dominated by Enterobacteriaceae and Fusobacterium species, growing on the carbohydrate-low, protein rich medium to which wheat bran was supplemented. The onset of wheat bran fermentation, marked by a spike in short chain fatty acid production with an increasing butyrate proportion and an increased endo-1,4-β-xylanase activity, corresponded to donor-dependent proportional increases of Bacteroides ovatus/stercoris, Prevotella copri and Firmicutes species, which were strongly enriched in the bran-attached community. Literature and database searches provided novel insights into the metabolic and growth characteristics underlying the observed succession and colonisation, illustrating the potency of a time-resolved analysis to increase our understanding of gut microbiota dynamics upon dietary modulations.
Polygenic burden associated to oligodendrocyte precursor cells and radial glia influences the hippocampal volume changes induced by aerobic exercise in schizophrenia patients
Authors: Papiol Sergi , Keeser Daniel , Hasan Alkomiet , Schneider-Axmann Thomas , Raabe Florian , Degenhardt Franziska , Rossner Moritz J. , Bickeböller Heike , Cantuti-Castelvetri Ludovico , Simons Mikael , Wobrock Thomas , Schmitt Andrea , Malchow Berend , Falkai Peter 
Published: November 2019

AbstractHippocampal volume decrease is a structural hallmark of schizophrenia (SCZ), and convergent evidence from postmortem and imaging studies suggests that it may be explained by changes in the cytoarchitecture of the cornu ammonis 4 (CA4) and dentate gyrus (DG) subfields. Increasing evidence indicates that aerobic exercise increases hippocampal volume in CA subfields and improves cognition in SCZ patients. Previous studies showed that the effects of exercise on the hippocampus might be connected to the polygenic burden of SCZ risk variants. However, little is known about cell type-specific genetic contributions to these structural changes. In this secondary analysis, we evaluated the modulatory role of cell type-specific SCZ polygenic risk scores (PRS) on volume changes in the CA1, CA2/3, and CA4/DG subfields over time. We studied 20 multi-episode SCZ patients and 23 healthy controls who performed aerobic exercise, and 21 multi-episode SCZ patients allocated to a control intervention (table soccer) for 3 months. Magnetic resonance imaging-based assessments were performed with FreeSurfer at baseline and after 3 months. The analyses showed that the polygenic burden associated with oligodendrocyte precursor cells (OPC) and radial glia (RG) significantly influenced the volume changes between baseline and 3 months in the CA4/DG subfield in SCZ patients performing aerobic exercise. A higher OPC- or RG-associated genetic risk burden was associated with a less pronounced volume increase or even a decrease in CA4/DG during the exercise intervention. We hypothesize that SCZ cell type-specific polygenic risk modulates the aerobic exercise-induced neuroplastic processes in the hippocampus.
The complex genetics and biology of human temperament: a review of traditional concepts in relation to new molecular findings
Authors: Cloninger C. Robert , Cloninger Kevin M. , Zwir Igor , Keltikangas-Järvinen Liisa 
Published: November 2019

AbstractRecent genome-wide association studies (GWAS) have shown that temperament is strongly influenced by more than 700 genes that modulate associative conditioning by molecular processes for synaptic plasticity and long-term learning and memory. The results were replicated in three independent samples despite variable cultures and environments. The identified genes were enriched in pathways activated by behavioral conditioning in animals, including the two major molecular pathways for response to extracellular stimuli, the Ras-MEK-ERK and the PI3K-AKT-mTOR cascades. These pathways are activated by a wide variety of physiological and psychosocial stimuli that vary in positive and negative valence and in consequences for health and survival. Changes in these pathways are orchestrated to maintain cellular homeostasis despite changing conditions by modulating temperament and its circadian and seasonal rhythms. In this review we first consider traditional concepts of temperament in relation to the new genetic findings by examining the partial overlap of alternative measures of temperament. Then we propose a definition of temperament as the disposition of a person to learn how to behave, react emotionally, and form attachments automatically by associative conditioning. This definition provides necessary and sufficient criteria to distinguish temperament from other aspects of personality that become integrated with it across the life span. We describe the effects of specific stimuli on the molecular processes underlying temperament from functional, developmental, and evolutionary perspectives. Our new knowledge can improve communication among investigators, increase the power and efficacy of clinical trials, and improve the effectiveness of treatment of personality and its disorders.
Genetic risk scores for major psychiatric disorders and the risk of postpartum psychiatric disorders
Authors: Bauer Anna E. , Liu Xiaoqin , Byrne Enda M. , Sullivan Patrick F. , Wray Naomi R. , Agerbo Esben , Nyegaard Mette , Grove Jakob , Musliner Katherine L. , Ingstrup Katja G. , Johannsen Benedicte M. W. , Mægbæk Merete L. , Wang Yunpeng , Nordentoft Merete , Mors Ole , Børglum Anders D. , Werge Thomas , Hougaard David M. , Mortensen Preben Bo , Munk-Olsen Trine , Meltzer-Brody Samantha 
Published: November 2019

AbstractPostpartum psychiatric disorders are heritable, but how genetic liability varies by other significant risk factors is unknown. We aimed to (1) estimate associations of genetic risk scores (GRS) for major depression (MD), bipolar disorder (BD), and schizophrenia (SCZ) with postpartum psychiatric disorders, (2) examine differences by prior psychiatric history, and (3) compare genetic and familial risk of postpartum psychiatric disorders. We conducted a nested case-control study based on Danish population-based registers of all women in the iPSYCH2012 cohort who had given birth before December 31, 2015 (n = 8850). Cases were women with a diagnosed psychiatric disorder or a filled psychotropic prescription within one year after delivery (n = 5829 cases, 3021 controls). Association analyses were conducted between GRS calculated from Psychiatric Genomics Consortium discovery meta-analyses for MD, BD, and SCZ and case-control status of a postpartum psychiatric disorder. Parental psychiatric history was associated with postpartum psychiatric disorders among women with previous psychiatric history (OR, 1.14; 95% CI 1.02–1.28) but not without psychiatric history (OR, 1.08; 95% CI: 0.81–1.43). GRS for MD was associated with an increased risk of postpartum psychiatric disorders in both women with (OR, 1.44; 95% CI: 1.19–1.74) and without (OR, 1.88; 95% CI: 1.26–2.81) personal psychiatric history. SCZ GRS was only minimally associated with postpartum disorders and BD GRS was not. Results suggest GRS of lifetime psychiatric illness can be applied to the postpartum period, which may provide clues about distinct environmental or genetic elements of postpartum psychiatric disorders and ultimately help identify vulnerable groups.
EASIX for prediction of survival in lower-risk myelodysplastic syndromes
Authors: Merz Almuth , Germing Ulrich , Kobbe Guido , Kaivers Jennifer , Jauch Anna , Radujkovic Aleksandar , Hummel Manuela , Benner Axel , Merz Maximilian , Dreger Peter , Luft Thomas 
Published: November 2019

AbstractPatients with myelodysplastic syndromes (MDS) are at risk of early death from cardiovascular complications due to the link between clonal hematopoiesis and endothelial dysfunction. EASIX (Endothelial Activation and Stress Index) has been established to predict endothelial complications after allogeneic transplantation. We investigated the impact of EASIX measured at first diagnosis on survival of patients with lower- and higher-risk MDS (no allogeneic transplantation) in two independent institutions: n = 192 (training cohort) and n = 333 (validation cohort). Serum markers of endothelial cell distress were measured and correlated to EASIX. While no effects of EASIX on survival were observed in higher-risk patients, EASIX was associated with shorter survival in patients with lower-risk MDS in both cohorts (univariate: Cohort I: hazard ratio (HR): 1.46; 95% confidence interval (CI) 1.24–1.71; p-value < 0.001/Cohort II: HR 1.31 [1.17–1.48]; p-value < 0.001). Multivariate Cox regression analysis and prediction error analyses confirmed that EASIX remained a significant predictor of survival after adjustment for age, sex, cytogenetic abnormalities and bone marrow blasts in lower-risk patients. The model of the training cohort could be validated. Serum levels of Angiopioetin-2 correlated significantly with EASIX. We introduce EASIX as an easily accessible and independent predictor for survival in patients with lower-risk MDS.
Human papillomavirus as a driver of head and neck cancers
Authors: Sabatini Maria Elisa , Chiocca Susanna 
Published: November 2019

Abstract
The human papillomavirus (HPV) family includes more than 170 different types of virus that infect stratified epithelium. High-risk HPV is well established as the primary cause of cervical cancer, but in recent years, a clear role for this virus in other malignancies is also emerging. Indeed, HPV plays a pathogenic role in a subset of head and neck cancers—mostly cancers of the oropharynx—with distinct epidemiological, clinical and molecular characteristics compared with head and neck cancers not caused by HPV. This review summarises our current understanding of HPV in these cancers, specifically detailing HPV infection in head and neck cancers within different racial/ethnic subpopulations, and the differences in various aspects of these diseases between women and men. Finally, we provide an outlook for this disease, in terms of clinical management, and consider the issues of ‘diagnostic biomarkers’ and targeted therapies.
Engaging chromatin: PRC2 structure meets function
Authors: Chammas Paul , Mocavini Ivano , Di Croce Luciano 
Published: November 2019

AbstractPolycomb repressive complex 2 (PRC2) is a key epigenetic multiprotein complex involved in the regulation of gene expression in metazoans. PRC2 is formed by a tetrameric core that endows the complex with histone methyltransferase activity, allowing it to mono-, di- and tri-methylate histone H3 on lysine 27 (H3K27me1/2/3); H3K27me3 is a hallmark of facultative heterochromatin. The core complex of PRC2 is bound by several associated factors that are responsible for modulating its targeting specificity and enzymatic activity. Depletion and/or mutation of the subunits of this complex can result in severe developmental defects, or even lethality. Furthermore, mutations of these proteins in somatic cells can be drivers of tumorigenesis, by altering the transcriptional regulation of key tumour suppressors or oncogenes. In this review, we present the latest results from structural studies that have characterised PRC2 composition and function. We compare this information with data and literature for both gain-of function and loss-of-function missense mutations in cancers to provide an overview of the impact of these mutations on PRC2 activity.