bluuebunny/crossref_metadata_2025_split huggingface dataset:
Statistical Mapping of Freshwater Origin and Fate Signatures as Land/Ocean “Regions of Influence” in the Gulf of Mexico
Authors: Fournier S. , Reager J. T. , Dzwonkowski B. , Vazquez‐Cuervo J. 
Published: July 2019

AbstractHere we present an observation‐based study of the coupled land‐ocean regions of influence for the transformation of precipitation over land into coastal river plume structure in the Gulf of Mexico (GoM). First, we locate the regions on land for which precipitation and runoff generation have the strongest relationship with local river discharge. Then we map, on average, the apparent unique contribution of individual river discharge forcing to specific features of river plume structure across the GoM. To this end, we employ a spatial‐temporal lagged correlation analysis that relates satellite‐based precipitation, soil moisture, and sea surface salinity observations to in situ river discharge for the three primary freshwater input sources for the GoM. On land, we find a likely source region for the northeastern GoM in the southeastern Mississippi basin at 16‐day lead time, a likely source region for the northeastern GoM in the Mobile Bay basin at 3‐day lead time and a likely source region for the Central GoM from the Texas basin region at 4‐day lead time. In the ocean, we find statistically significant regions of distinct contribution for each of the three sources of freshwater on plume structure at lag times from weeks to several months. Though a statistical approach is limited in its interpretability, this result advances progress toward a predictive framework for mapping of the impacts of hydrological flood events from land into the ocean using observations alone.
Characteristics of Atmospheric Turbulence Retrieved From High Vertical‐Resolution Radiosonde Data in the United States
Authors: Ko H.‐C. , Chun H.‐Y. , Wilson R. , Geller M. A. 
Published: July 2019

AbstractIn this study, we estimate atmospheric turbulence in the free atmosphere in terms of the Thorpe scale (LT) and eddy dissipation rate (ε) using U.S. high vertical‐resolution radiosonde data over 4 years (September 2012 to August 2016) at 68 operational stations. In addition, same calculations are conducted for 12 years (October 2005 to September 2017) at four stations among the 68 stations. These high vertical‐resolution radiosonde data have a vertical resolution of approximately 5 m and extend to an altitude of approximately 33 km, and thus, turbulence can be retrieved in the entire troposphere and lower stratosphere. There are thicker and stronger turbulent layers in the troposphere than in the stratosphere, with mean ε values of 1.84 × 10−4 and 1.37 × 10−4 m2/s3 in the troposphere and stratosphere, respectively. The vertical structure of ε exhibits strong seasonal variations, especially in the upper troposphere and lower stratosphere, with the largest ε values in summer and the smallest in winter. In the horizontal distribution of ε, large ε is seen mainly above the mountainous region in the troposphere, but this pattern is not seen in the stratosphere. Although ε is estimated by the square of LT multiplied by the cube of the Brunt‐Väisälä frequency (N), the regions of large ε are matched with large LT regions where N is relatively small. For the time series of ε near the tropopause for 12 years at four stations, an annual variation is prominent at all stations without significant interannual variations. There is, however, a slightly increasing trend of ε at two stations.
The Temporal and Geographic Extent of Seasonal Cold Trapping on the Moon
Authors: Kloos Jacob L. , Moores John E. , Sangha Jasmeer , Nguyen Tue Giang , Schorghofer Norbert 
Published: July 2019

AbstractWe assess the geographic distribution and temporal variability of seasonal shadow at the lunar polar regions and explore its influence on surface water migration and deposition within known permanently shadowed regions (PSRs) in the modern era. At its largest expanse near the winter solstice, seasonally shadowed area more than doubles the permanently shadowed area at both poles. The growth and decay of polar shadow throughout the year enforce distinct seasonal patterns in the poleward migration of water as well as a cyclical variation in the polar surface hydration throughout the year if a continual source of water is assumed. The polar surface water abundance peaks near the hemispheric vernal equinox—significantly offset from the solstice where the seasonal trapping area is most expansive—due to the retention of seasonally trapped water. Owing to their low areal density, lower‐latitude PSRs do not significantly hamper the poleward migration of water, enabling water to reach the high polar latitudes where cold trapping area is densest. We find that northern hemisphere PSRs accumulate more water per unit area than southern hemisphere PSRs and that this disparity is especially prominent beyond 85°. The north/south asymmetry is attributed to differences in the hemispheric PSR size‐frequency distributions; such differences enable unique north/south migration diffusivities, which favor more water reaching the high northern latitudes.
Geostatistical Modeling to Capture Seismic‐Shaking Patterns From Earthquake‐Induced Landslides
Authors: Lombardo Luigi , Bakka Haakon , Tanyas Hakan , van Westen Cees , Mai P. Martin , Huser Raphaël 
Published: July 2019

We investigate earthquake‐induced landslides using a geostatistical model featuring a latent spatial effect (LSE). The LSE represents the spatially structured residuals in the data, which remain after adjusting for covariate effects. To determine whether the LSE captures the residual signal from a given trigger, we test the LSE in reproducing the pattern of seismic shaking from the distribution of seismically induced landslides, without prior knowledge of the earthquake being included in the model. We assessed the landslide intensity, that is, the expected number of landslides per mapping unit, for the area in which landslides triggered by the Wenchuan and Lushan earthquakes overlap. We examined this area to test our method on landslide inventories located in near and far fields of the earthquake. We generated three models for both earthquakes: (i) seismic parameters only (proxy for the trigger); (ii) the LSE only; and (iii) both seismic parameters and the LSE. The three configurations share the same morphometric covariates. This allowed us to study the LSE pattern and assess whether it approximated the seismic effects. Our results show that the LSE reproduced the shaking patterns for both earthquakes. In addition, the models including the LSE perform better than conventional models featuring seismic parameters only. Due to computational limitations we carried out a detailed analysis for a relatively small area (2,112 km2), using a data set with higher spatial resolution. Results were consistent with those of a subsequent analysis for a larger area (14,648 km2) using coarser‐resolution data.
Extensive intraspecific gene order and gene structural variations in upland cotton cultivars
Authors: Yang Zhaoen , Ge Xiaoyang , Yang Zuoren , Qin Wenqiang , Sun Gaofei , Wang Zhi , Li Zhi , Liu Ji , Wu Jie , Wang Ye , Lu Lili , Wang Peng , Mo Huijuan , Zhang Xueyan , Li Fuguang 
Published: July 2019

AbstractMultiple cotton genomes (diploid and tetraploid) have been assembled. However, genomic variations between cultivars of allotetraploid upland cotton (Gossypium hirsutum L.), the most widely planted cotton species in the world, remain unexplored. Here, we use single-molecule long read and Hi-C sequencing technologies to assemble genomes of the two upland cotton cultivars TM-1 and zhongmiansuo24 (ZM24). Comparisons among TM-1 and ZM24 assemblies and the genomes of the diploid ancestors reveal a large amount of genetic variations. Among them, the top three longest structural variations are located on chromosome A08 of the tetraploid upland cotton, which account for ~30% total length of this chromosome. Haplotype analyses of the mapping population derived from these two cultivars and the germplasm panel show suppressed recombination rates in this region. This study provides additional genomic resources for the community, and the identified genetic variations, especially the reduced meiotic recombination on chromosome A08, will help future breeding.
Manganese acting as a high-performance heterogeneous electrocatalyst in carbon dioxide reduction
Authors: Zhang Bingxing , Zhang Jianling , Shi Jinbiao , Tan Dongxing , Liu Lifei , Zhang Fanyu , Lu Cheng , Su Zhuizhui , Tan Xiuniang , Cheng Xiuyan , Han Buxing , Zheng Lirong , Zhang Jing 
Published: July 2019

AbstractDeveloping highly efficient electrocatalysts based on cheap and earth-abundant metals for CO2 reduction is of great importance. Here we demonstrate that the electrocatalytic activity of manganese-based heterogeneous catalyst can be significantly improved through halogen and nitrogen dual-coordination to modulate the electronic structure of manganese atom. Such an electrocatalyst for CO2 reduction exhibits a maximum CO faradaic efficiency of 97% and high current density of ~10 mA cm−2 at a low overpotential of 0.49 V. Moreover, the turnover frequency can reach 38347 h−1 at overpotential of 0.49 V, which is the highest among the reported heterogeneous electrocatalysts for CO2 reduction. In situ X-ray absorption experiment and density-functional theory calculation reveal the modified electronic structure of the active manganese site, on which the free energy barrier for intermediate formation is greatly reduced, thus resulting in a great improvement of CO2 reduction performance.
Long-range spatio-temporal correlations in multimode fibers for pulse delivery
Authors: Xiong Wen , Hsu Chia Wei , Cao Hui 
Published: July 2019

AbstractLong-range correlations play an essential role in wave transport through disordered media, but have rarely been studied in other complex systems. Here we discover spatio-temporal intensity correlations for an optical pulse propagating through a multimode fiber with strong random mode coupling. Positive long-range correlation arises from multiple scattering in fiber mode space and depends on the statistical distribution of arrival times. By optimizing the incident wavefront of a pulse, we maximize the power transmitted at a selected time, and such control is significantly enhanced by the long-range spatio-temporal correlation. We provide an explicit relation between the correlation and the power enhancement, which agrees with experimental results. Our work shows that multimode fibers provide a fertile ground for studying complex wave phenomena. The strong spatio-temporal correlation can be employed for efficient power delivery at a well-defined time.
High-pressure synthesis of ultraincompressible hard rhenium nitride pernitride Re2(N2)(N)2 stable at ambient conditions
Authors: Bykov Maxim , Chariton Stella , Fei Hongzhan , Fedotenko Timofey , Aprilis Georgios , Ponomareva Alena V. , Tasnádi Ferenc , Abrikosov Igor A. , Merle Benoit , Feldner Patrick , Vogel Sebastian , Schnick Wolfgang , Prakapenka Vitali B. , Greenberg Eran , Hanfland Michael , Pakhomova Anna , Liermann Hanns-Peter , Katsura Tomoo , Dubrovinskaia Natalia , Dubrovinsky Leonid 
Published: July 2019

AbstractHigh-pressure synthesis in diamond anvil cells can yield unique compounds with advanced properties, but often they are either unrecoverable at ambient conditions or produced in quantity insufficient for properties characterization. Here we report the synthesis of metallic, ultraincompressible (K0 = 428(10) GPa), and very hard (nanoindentation hardness 36.7(8) GPa) rhenium nitride pernitride Re2(N2)(N)2. Unlike known transition metals pernitrides Re2(N2)(N)2 contains both pernitride N24− and discrete N3− anions, which explains its exceptional properties. Re2(N2)(N)2 can be obtained via a reaction between rhenium and nitrogen in a diamond anvil cell at pressures from 40 to 90 GPa and is recoverable at ambient conditions. We develop a route to scale up its synthesis through a reaction between rhenium and ammonium azide, NH4N3, in a large-volume press at 33 GPa. Although metallic bonding is typically seen incompatible with intrinsic hardness, Re2(N2)(N)2 turned to be at a threshold for superhard materials.
Beyond 100 THz-spanning ultraviolet frequency combs in a non-centrosymmetric crystalline waveguide
Authors: Liu Xianwen , Bruch Alexander W. , Lu Juanjuan , Gong Zheng , Surya Joshua B. , Zhang Liang , Wang Junxi , Yan Jianchang , Tang Hong X. 
Published: July 2019

AbstractUltraviolet frequency combs enable applications ranging from precision spectroscopy to atomic clocks by addressing electronic transitions of atoms and molecules. Access to ultraviolet light via integrated nonlinear optics is usually hampered by the strong material dispersion and large waveguide attention in ultraviolet regions. Here we demonstrate a simple route to chip-scale ultraviolet comb generators, simultaneously showing a gap-free frequency span of 128 terahertz and high conversion efficiency. This process relies on adiabatic quadratic frequency translation of a near-visible supercontinuum sourced by an ultrafast fiber laser. The simultaneous cubic and quadratic nonlinear processes are implemented in single-crystalline aluminum nitride thin films, where chirp-modulated taper waveguides are patterned to ensure a broad phase matching. The heterodyne characterization suggests that both the near-visible and ultraviolet supercontinuum combs maintain high coherence. Our approach is also adaptable to other non-centrosymmetric photonic platforms for ultrafast nonlinear optics with scalable bandwidth.
Metagenomics and transcriptomics data from human colorectal cancer
Authors: Visnovska Tina , Biggs Patrick J. , Schmeier Sebastian , Frizelle Frank A. , Purcell Rachel V. 
Published: July 2019

AbstractColorectal cancer is a heterogenous and mostly sporadic disease, the development of which is associated with microbial dysbiosis. Recent advances in subtype classification have successfully stratified the disease using molecular profiling. To understand potential relationships between molecular mechanisms differentiating the subtypes of colorectal cancer and composition of gut microbial community, we classified a set of 34 tumour samples into molecular subtypes using RNA-sequencing gene expression profiles and determined relative abundances of bacterial taxonomic groups. To identify bacterial community composition, 16S rRNA amplicon metabarcoding was used as well as whole genome metagenomics of the non-human part of RNA-sequencing data. The generated data expands the collection of the data sources related to the disease and connects molecular aspects of the cancer with environmental impact of microbial community.
Pax 6 Controls Neural Crest Potential of Limbal Niche Cells to Support Self-Renewal of Limbal Epithelial Stem Cells
Authors: Chen Szu-Yu , Cheng Anny M. S. , Zhang Yuan , Zhu Ying-Ting , He Hua , Mahabole Megha , Tseng Scheffer C. G. 
Published: July 2019

AbstractOn ocular surface, corneal epithelial stem cells (SC) reside in limbus between cornea and conjunctiva. Pax6, an evolutionally conserved transcription factor essential for eye development, is expressed in post-natal corneal and limbal epithelia progenitors (LEPC) but not in underlying stroma. Because Pax6 is transiently expressed in developing corneal stroma and a subset of limbal and corneal stromal progenitors, we examined the role of Pax6 in limbal niche cells (LNC) in maintaining the phenotype of neural crest (NC) progenitors to support LEPC. Our results showed that nuclear Pax6 staining was found in freshly isolated LNC but not corneal stromal cells. Serial passaged LNC resulted in gradual loss of nuclear Pax6 (46 kDa) staining and neural crest progenitor status defined by the expression of embryonic SCs and NC markers, neurosphere formation, and differentiation into neurons, oligodendrocytes and astrocytes. Gain of function of 46 kDa Pax6 in late-passaged LNC resulted in nuclear Pax6 staining and promotion of the aforementioned NC progenitor status. In an in vitro reunion assay, early passaged LNC and late passaged LNC with overexpression of Pax6 inhibited the expression of corneal epithelial differentiation marker and promoted holoclone by LEPC. Therefore, expression of nuclear 46 kDa Pax6 in LNC plays an important developmental role in maintaining NC progenitor status to support self-renewal of corneal epithelial SCs in the limbal niche.
Selection of reference genes for flowering pathway analysis in the masting plants, Celmisia lyallii and Chionochloa pallens, under variable environmental conditions
Authors: Samarth  , Jameson Paula E. 
Published: July 2019

AbstractMast flowering is characterised by mass synchronised flowering at irregular intervals over a wide geographical area. An understanding of the molecular drivers of mast flowering requires expression analysis of key developmentally regulated gene(s). Reverse transcription-quantitative PCR is the gold standard technique used to assess expression of target gene(s) and to validate high-throughput sequencing data. Selection and validation of appropriate reference gene(s), used as normalisation factors in transcript abundance analysis, is an essential step to avoid ambiguous expression results. Eight candidate reference genes were assessed to select the best internal normalisation factors in naturally growing masting plantsChionochloa pallensandCelmisia lyallii. Statistical packages geNorm, Normfinder, BestKeeper, ΔCtand RefFinder were used to determine the expression stability in plants translocated to different altitudes and sampled across the season.GAPDHandPP2ainCelmisiaandExPandTHPinChionochloawere found to be the best pairs of reference genes for normalisation of the gene expression data. Our study revealed environmentally-induced changes in reference gene expression, information that will be utilised as we investigate flowering phenology of masting plants under global climatic change.
Sorption, persistence, and leaching of the allelochemical umbelliferone in soils treated with nanoengineered sorbents
Authors: Real Miguel , Gámiz Beatriz , López-Cabeza Rocío , Celis Rafael 
Published: July 2019

AbstractCoumarins represent an important family of allelochemicals with fungicidal, bactericidal, insecticidal, nematicidal, and herbicidal properties. Like for other allelochemicals, the short persistence of coumarins in soils can reduce their biological activity and hamper their application as environmentally friendly agrochemicals. We evaluated the sorption of the coumarin umbelliferone by eight soils and six sorbent materials, and then selected two nanoengineered sorbents, hexadecyltrimethylammonium-modified Arizona montmorillonite (SA-HDTMA) and olive-mill waste biochar (BC), to assess the effect of their addition to two distinct soils on umbelliferone sorption, persistence, and leaching. Umbelliferone was sorbed to a greater extent by the acid soils (A1-A2, Kd > 4.0 L kg−1) than by the alkaline soils (B1-B6, Kd < 0.5 L kg−1). The addition of BC and SA-HDTMA at a rate of 4% to alkaline soil (B2) increased the umbelliferone sorption Kd value from 0.3 to 1.6–2.0 L kg−1, whereas their addition to acid soil (A1) increased the Kd value from 4.6 to 12.2–19.0 L kg−1. Incubation experiments showed that BC had more impact than SA-HDTMA on the persistence of umbelliferone in the soils, increasing its half-life from 0.3-2.5 to 1.2–14.4 days, depending on the soil. Furthermore, the addition of BC to the top 0–5 cm of soil columns reduced leaching of umbelliferone and led to accumulation of umbelliferone residues in the top 0–5 cm soil layer. The addition of nanoengineered materials, such as organoclays and biochars, could thus be a suitable strategy to increase the persistence and reduce the mobility of coumarins in the rhizosphere with the aim of prolonging their biological activity.
Respiratory influence on cerebrospinal fluid flow – a computational study based on long-term intracranial pressure measurements
Authors: Vinje Vegard , Ringstad Geir , Lindstrøm Erika Kristina , Valnes Lars Magnus , Rognes Marie E. , Eide Per Kristian , Mardal Kent-Andre 
Published: July 2019

AbstractCurrent theories suggest that waste solutes are cleared from the brain via cerebrospinal fluid (CSF) flow, driven by pressure pulsations of possibly both cardiac and respiratory origin. In this study, we explored the importance of respiratory versus cardiac pressure gradients for CSF flow within one of the main conduits of the brain, the cerebral aqueduct. We obtained overnight intracranial pressure measurements from two different locations in 10 idiopathic normal pressure hydrocephalus (iNPH) patients. The resulting pressure gradients were analyzed with respect to cardiac and respiratory frequencies and amplitudes (182,000 cardiac and 48,000 respiratory cycles). Pressure gradients were used to compute CSF flow in simplified and patient-specific models of the aqueduct. The average ratio between cardiac over respiratory flow volume was 0.21 ± 0.09, even though the corresponding ratio between the pressure gradient amplitudes was 2.85 ± 1.06. The cardiac cycle was 0.25 ± 0.04 times the length of the respiratory cycle, allowing the respiratory pressure gradient to build considerable momentum despite its small magnitude. No significant differences in pressure gradient pulsations were found in the sleeping versus awake state. Pressure gradients underlying CSF flow in the cerebral aqueduct are dominated by cardiac pulsations, but induce CSF flow volumes dominated by respiration.
Uncovering biomarker genes with enriched classification potential from Hallmark gene sets
Authors: Targonski Colin A. , Shearer Courtney A. , Shealy Benjamin T. , Smith Melissa C. , Feltus F. Alex 
Published: July 2019

AbstractGiven the complex relationship between gene expression and phenotypic outcomes, computationally efficient approaches are needed to sift through large high-dimensional datasets in order to identify biologically relevant biomarkers. In this report, we describe a method of identifying the most salient biomarker genes in a dataset, which we call “candidate genes”, by evaluating the ability of gene combinations to classify samples from a dataset, which we call “classification potential”. Our algorithm, Gene Oracle, uses a neural network to test user defined gene sets for polygenic classification potential and then uses a combinatorial approach to further decompose selected gene sets into candidate and non-candidate biomarker genes. We tested this algorithm on curated gene sets from the Molecular Signatures Database (MSigDB) quantified in RNAseq gene expression matrices obtained from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) data repositories. First, we identified which MSigDB Hallmark subsets have significant classification potential for both the TCGA and GTEx datasets. Then, we identified the most discriminatory candidate biomarker genes in each Hallmark gene set and provide evidence that the improved biomarker potential of these genes may be due to reduced functional complexity.