bluuebunny/crossref_metadata_2025_split huggingface dataset:
MESSENGER Gamma Ray Spectrometer and Epithermal Neutron Hydrogen Data Reveal Compositional Differences Between Mercury's Hot and Cold Poles
Authors: Wilson Jack T. , Lawrence David J. , Peplowski Patrick N. , Feldman William C. 
Published: February 2019

AbstractThe presence of hydrogen, most likely in the form of water ice, is well established in Mercury's permanently shaded polar craters. But lower concentrations that may exist away from the poles have not previously been well constrained. In this work we use data from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) Gamma‐Ray and Neutron Spectrometer to produce the first map of the absolute hydrogen abundance in Mercury's northern hemisphere. We find a mean abundance of
ppm and a latitudinal trend that agrees with earlier results showing enhanced hydrogen contained within Mercury's radar bright craters. Additionally, we observe a middle‐ and low‐latitude variation in hydrogen abundance that is correlated most strongly with temperature 20 cm beneath Mercury's surface.
The Role of Lithospheric Flexure in the Landscape Evolution of the Wilkes Subglacial Basin and Transantarctic Mountains, East Antarctica
Authors: Paxman Guy J. G. , Jamieson Stewart S. R. , Ferraccioli Fausto , Bentley Michael J. , Ross Neil , Watts Anthony B. , Leitchenkov German , Armadillo Egidio , Young Duncan A. 
Published: February 2019

AbstractReconstructions of the bedrock topography of Antarctica since the Eocene‐Oligocene Boundary (approximately 34 Ma) provide important constraints for modeling Antarctic ice sheet evolution. This is particularly important in regions where the bedrock lies below sea level, since in these sectors the overlying ice sheet is thought to be most susceptible to past and future change. Here we use 3‐D flexural modeling to reconstruct the evolution of the topography of the Wilkes Subglacial Basin (WSB) and Transantarctic Mountains (TAM) in East Antarctica. We estimate the spatial distribution of glacial erosion beneath the East Antarctic Ice Sheet, and restore this material to the topography, which is also adjusted for associated flexural isostatic responses. We independently constrain our post‐34 Ma erosion estimates using offshore sediment stratigraphy interpretations. Our reconstructions provide a better‐defined topographic boundary condition for modeling early East Antarctic Ice Sheet history. We show that the majority of glacial erosion and landscape evolution occurred prior to 14 Ma, which we interpret to reflect more dynamic and erosive early ice sheet behavior. In addition, we use closely spaced 2‐D flexural models to test previously proposed hypotheses for a flexural origin of the TAM and WSB. The pre‐34 Ma topography shows lateral variations along the length of the TAM and WSB that cannot be explained by uniform flexure along the front of the TAM. We show that some of these variations may be explained by additional flexural uplift along the south‐western flank of the WSB and the Rennick Graben in northern Victoria Land.
Reconstruction of Global Lightning Activity Based on Schumann Resonance Measurements: Model Description and Synthetic Tests
Authors: Prácser E. , Bozóki T. , Sátori G. , Williams E. , Guha A. , Yu H. 
Published: February 2019

AbstractAn inversion algorithm for multistation Schumann resonance measurements is presented and tested in this paper. The location and intensity of the lightning activity is estimated in absolute unit (C2 km2/s) from the Schumann resonance electromagnetic field components measured at distant observation sites on the globe. We summarize the main steps of the forward modeling for single and multiple sources and describe the main characteristics of the applied inversion. The applicability of the inversion algorithm is tested via synthetic data.
Development of an Intrawedge Tectonic Mélange by Out‐of‐Sequence Thrusting, Buttressing, and Intraformational Rheological Contrast, Mt. Massico Ridge, Apennines, Italy
Authors: Smeraglia Luca , Aldega Luca , Billi Andrea , Carminati Eugenio , Di Fiore Fabrizio , Gerdes Axel , Albert Richard , Rossetti Federico , Vignaroli Gianluca 
Published: February 2019

AbstractThe Mt. Massico ridge (central southern Apennines, Italy) is characterized by a ~150‐m‐thick tectonic mélange located at the base of a Tortonian‐lower Messinian heterogeneous clastic succession consisting of layered sandstones, limestones, marls, and claystones with intercalated mass wasting deposits and isolated olistoliths, which deposited above Meso‐Cenozoic limestones. Geological mapping and structural analyses, integrated with illite‐smectite paleothermal indicators and U‐Pb dating of syntectonic calcite veins and slickenfibers, allowed us to unravel (1) the tectonic evolution of the Mt. Massico ridge and (2) the development of the intrawedge tectonic mélange in the framework of the Apennine accretionary wedge evolution. Results show that after thrusting and folding of Meso‐Cenozoic limestones during late Tortonian times (7.0 ± 1.6 Ma), late Messinian‐early Pliocene out‐of‐sequence thrusting (5.1 ± 3.7 Ma) juxtaposed ~3,300‐m‐thick, imbricate thrust sheets above the Tortonian‐lower Messinian clastic succession. During out‐of‐sequence thrusting, the base of the weak clastic deposits acted as a décollement horizon due to the rheological contrast and mechanical buttress with the underlying competent Mesozoic‐Cenozoic limestones. Heterogeneous deformation along the base of the clastic succession was accommodated by ductile pressure solution of claystones and marls, by brittle stratal disruption and fracturing/veining of competent olistoliths and primary foliation (i.e., sandstones and limestones strata), thus leading to the development of a tectonic mélange. The compressional phase was followed by extensional tectonics after the late Pliocene (minimum age 2.9 ± 0.5 Ma). We conclude that out‐of‐sequence thrusting, buttressing, and intraformational rheological contrast can be fundamental factors for the development of intrawedge tectonic mélange.
Modeling Runoff and Nitrogen Loads From a Watershed at Different Levels of Impervious Surface Coverage and Connectivity to Storm Water Control Measures
Authors: Bell Colin D. , Tague Christina L. , McMillan Sara K. 
Published: February 2019

AbstractUrban development of watersheds increases runoff and nitrogen loads by adding urban impervious surfaces and increasing the hydrologic connectivity of these surfaces to streams. Storm water control measures (SCMs) are designed to disrupt this connectivity by retaining water in biologically active depressions where nitrogen retention, transformation, and removal occur. This work applies a mechanistic, spatially distributed, hydroecological model (RHESSys) to a suburban watershed in Charlotte, NC, with 15% total imperviousness (TI) and 33% watershed area mitigated by SCMs. We developed emergent relationships between watershed‐scale predictors (TI and connectivity to SCMs) and water and nitrogen response variables (storm water runoff ratios and nitrogen load by species). Results showed that annual runoff ratios were insensitive to increases in connectivity to SCMs (varying by ~1% of rainfall) because SCMs did not substantially increase evaporation but that runoff ratios increased by an average 0.2% per 1% increase in TI due to decreases in transpiration in the watershed. Generally, nitrate loads increased with TI but decreased as more surfaces were mitigated by SCMs. However, these nitrate reductions corresponded to increased export of dissolved organic nitrogen and ammonium. Together, these results indicate that SCMs act as both removers and transformers of nitrogen at the watershed scale. SCMs showed a net assimilation of nitrogen in warm months and net release in cool months, which offset the timing of nitrogen export relative to inputs. This work highlights that using a hydroecological, process‐based model reveals both the emergent relationships between watershed condition and response and the processes controlling those relationships.
The Climatic Water Balance and Topography Control Spatial Patterns of Atmospheric Demand, Soil Moisture, and Shallow Subsurface Flow
Authors: Hoylman Zachary H. , Jencso Kelsey G. , Hu Jia , Holden Zachary A. , Martin Justin T. , Gardner W. Payton 
Published: February 2019

AbstractCatchment hydrometeorology and the organization of shallow subsurface flow are key drivers of active contributing areas and streamflow generation. However, understanding how the climatic water balance and complex topography contribute to these processes from hillslope to catchment scales remains difficult. We compared time series of vapor pressure deficits and soil moisture to the climatic water balance and topographic variables across six zero‐order catchments in the Lubrecht Experimental Forest (Montana, USA). We then evaluated how local hydrometeorology (volumetric water content and atmospheric vapor pressure deficit) affected the spatial occurrence of shallow subsurface flow. Generalized linear mixed model analysis revealed significant, temporally stable (monthly and seasonal average) patterns of hydrometeorology that can be predicted by the topographic wetness index and the dynamic climatic water deficit (CWD = potential evapotranspiration − actual evapotranspiration). Intracatchment patterns were significantly correlated to the topographic wetness index, while intercatchment patterns were correlated to spatiotemporal variance in the CWD during each time period. Spatial patterns of shallow subsurface flow were related to the hydrometeorological conditions of the site. We observed persistent shallow subsurface flow in convergent hillslope positions, except when a catchment was positioned in locations with high CWDs (low elevations and southerly aspects). Alternatively, we observed persistent subsurface flow across all hillslope positions (even 70‐m upslope from the hollow) when catchments were positioned in locations with especially low CWDs (northerly aspects and high elevations). These results highlight the importance of considering the superposition of the catchment‐scale climatic water balance and hillslope‐scale topography when characterizing hydrometeorology and shallow subsurface flow dynamics.
Evaluation of Groundwater Levels in the Arapahoe Aquifer Using Spatiotemporal Regression Kriging
Authors: Ruybal Christopher J. , Hogue Terri S. , McCray John E. 
Published: February 2019

AbstractGroundwater monitoring is fundamental to understanding system dynamics, trends in storage, and the long‐term sustainability of an aquifer. Water‐level data are the key source of information used to understand the response. However, groundwater‐level data are often irregularly sampled, leading to temporal gaps in the record, and are not adequately distributed spatially across an aquifer. This presents challenges when spatially interpolating potentiometric surfaces and creating groundwater maps due to data availability. We present a spatiotemporal kriging methodology to improve spatial and temporal confidence in groundwater‐level predictions at unsampled locations. The space–time data set consists of a trend and residual component modeled with a linear regression and utilize a sum‐metric model to represent spatiotemporal covariances. The Arapahoe aquifer is used as a case study to demonstrate the benefits of spatiotemporal kriging over spatial kriging across a sparsely gauged and irregularly sampled aquifer. The Arapahoe aquifer is a major source of water for many residents along the Rocky Mountain Front Range in Colorado. The results show superior performance of spatiotemporal kriging to predict groundwater levels over the traditional spatial kriging. Spatiotemporal kriging represents realistic temporal and spatial changes in water levels and avoids some of the problems inherent to spatial kriging. This study demonstrates the power of spatiotemporal kriging to help inform system dynamics in irregularly sampled aquifers.
Dihydroartemisinin inhibits prostate cancer via JARID2/miR-7/miR-34a-dependent downregulation of Axl
Authors: Paccez Juliano D. , Duncan Kristal , Sekar Durairaj , Correa Ricardo G. , Wang Yihong , Gu Xuesong , Bashin Manoj , Chibale Kelly , Libermann Towia A. , Zerbini Luiz F. 
Published: February 2019

AbstractAxl expression is deregulated in several cancer types, predicts poor overall patient survival and is linked to resistance to drug therapy. Here, we evaluated a library of natural compounds for inhibitors of Axl and identified dihydroartemisinin, the active principle of the anti-malarial drug artemisinin, as an Axl-inhibitor in prostate cancer. Dihydroartemisinin blocks Axl expression leading to apoptosis, decrease in cell proliferation, migration, and tumor development of prostate cancer cells. Dihydroartemisinin treatment synergizes with docetaxel, a standard of care in metastatic prostate cancer increasing overall survival of mice with human xenografts. Dihydroartemisinin control of miR-34a and miR-7 expression leads to inhibition of Axl expression in a process at least partially dependent on regulation of chromatin via methylation of histone H3 lysine 27 residues by Jumonji, AT-rich interaction domain containing 2 (JARID2), and the enhancer of zeste homolog 2. Our discovery of a previously unidentified miR-34a/miR-7/JARID2 pathway controlling dihydroartemisinin effects on Axl expression and inhibition of cancer cell proliferation, migration, invasion, and tumor formation provides new molecular mechanistic insights into dihydroartemisinin anticancer effect on prostate cancer with potential therapeutic implications.
Expanding the repertoire of miRNAs and miRNA-offset RNAs expressed in multiple myeloma by small RNA deep sequencing
Authors: Agnelli Luca , Bisognin Andrea , Todoerti Katia , Manzoni Martina , Taiana Elisa , Galletti Serena , Cutrona Giovanna , Gaffo Enrico , Bortoluzzi Stefania , Neri Antonino 
Published: February 2019

AbstractMicroarray analysis of the multiple myeloma (MM) miRNome has unraveled the differential expression of miRNAs in cytogenetic subgroups, their involvement in the tumor biology and their effectiveness in prognostic models. Herein, the small RNA transcriptional landscape in MM has been investigated exploiting the possibilities offered by small RNA-seq, including accurate quantification of known mature species, discovery and characterization of isomiRs, and miRNA-offset RNAs (moRNAs). Matched small RNA-seq and miRNA GeneChip® microarray expression profiles were obtained in a representative panel of 30 primary MM tumors, fully characterized for genomic aberrations and mutations. RNA-seq and microarray gave concordant estimations of known species. Enhanced analysis of RNA-seq data with the miR&moRe pipeline led to the characterization of 655 known and 17 new mature miRNAs and of 74 moRNAs expressed in the considered cohort, 5 of which (moR-150-3p, moR-24-2-5p, moR-421-5p, moR-21-5p, and moR-6724-5p) at high level. Ectopic expression of miR-135a-3p in t(4;14) patients, upregulation of moR-150-3p and moR-21-5p in t(14;16)/t(14;20) samples, and of moR-6724-1-5p in patients overexpressing CCND1 were uncovered and validated by qRT-PCR. Overall, RNA-seq offered a more complete overview of small non-coding RNA in MM tumors, indicating specific moRNAs that demand further investigations to explore their role in MM biology.
The flavonoid 4,4′-dimethoxychalcone promotes autophagy-dependent longevity across species
Authors: Carmona-Gutierrez Didac , Zimmermann Andreas , Kainz Katharina , Pietrocola Federico , Chen Guo , Maglioni Silvia , Schiavi Alfonso , Nah Jihoon , Mertel Sara , Beuschel Christine B. , Castoldi Francesca , Sica Valentina , Trausinger Gert , Raml Reingard , Sommer Cornelia , Schroeder Sabrina , Hofer Sebastian J. , Bauer Maria A. , Pendl Tobias , Tadic Jelena , Dammbrueck Christopher , Hu Zehan , Ruckenstuhl Christoph , Eisenberg Tobias , Durand Sylvere , Bossut Noélie , Aprahamian Fanny , Abdellatif Mahmoud , Sedej Simon , Enot David P. , Wolinski Heimo , Dengjel Jörn , Kepp Oliver , Magnes Christoph , Sinner Frank , Pieber Thomas R. , Sadoshima Junichi , Ventura Natascia , Sigrist Stephan J. , Kroemer Guido , Madeo Frank 
Published: February 2019

AbstractAgeing constitutes the most important risk factor for all major chronic ailments, including malignant, cardiovascular and neurodegenerative diseases. However, behavioural and pharmacological interventions with feasible potential to promote health upon ageing remain rare. Here we report the identification of the flavonoid 4,4′-dimethoxychalcone (DMC) as a natural compound with anti-ageing properties. External DMC administration extends the lifespan of yeast, worms and flies, decelerates senescence of human cell cultures, and protects mice from prolonged myocardial ischaemia. Concomitantly, DMC induces autophagy, which is essential for its cytoprotective effects from yeast to mice. This pro-autophagic response induces a conserved systemic change in metabolism, operates independently of TORC1 signalling and depends on specific GATA transcription factors. Notably, we identify DMC in the plant Angelica keiskei koidzumi, to which longevity- and health-promoting effects are ascribed in Asian traditional medicine. In summary, we have identified and mechanistically characterised the conserved longevity-promoting effects of a natural anti-ageing drug.
Magnetic field alignment of stable proton-conducting channels in an electrolyte membrane
Authors: Liu Xin , Li Yi , Xue Jiandang , Zhu Weikang , Zhang Junfeng , Yin Yan , Qin Yanzhou , Jiao Kui , Du Qing , Cheng Bowen , Zhuang Xupin , Li Jianxin , Guiver Michael D. 
Published: February 2019

AbstractProton exchange membranes with short-pathway through-plane orientated proton conductivity are highly desirable for use in proton exchange membrane fuel cells. Magnetic field is utilized to create oriented structure in proton exchange membranes. Previously, this has only been carried out by proton nonconductive metal oxide-based fillers. Here, under a strong magnetic field, a proton-conducting paramagnetic complex based on ferrocyanide-coordinated polymer and phosphotungstic acid is used to prepare composite membranes with highly conductive through-plane-aligned proton channels. Gratifyingly, this strategy simultaneously overcomes the high water-solubility of phosphotungstic acid in composite membranes, thereby preventing its leaching and the subsequent loss of membrane conductivity. The ferrocyanide groups in the coordinated polymer, via redox cycle, can continuously consume free radicals, thus helping to improve the long-term in situ membrane durability. The composite membranes exhibit outstanding proton conductivity, fuel cell performance and durability, compared with other types of hydrocarbon membranes and industry standard Nafion® 212.
Specialized rainforest hunting by Homo sapiens ~45,000 years ago
Authors: Wedage Oshan , Amano Noel , Langley Michelle C. , Douka Katerina , Blinkhorn James , Crowther Alison , Deraniyagala Siran , Kourampas Nikos , Simpson Ian , Perera Nimal , Picin Andrea , Boivin Nicole , Petraglia Michael , Roberts Patrick 
Published: February 2019

AbstractDefining the distinctive capacities of Homo sapiens relative to other hominins is a major focus for human evolutionary studies. It has been argued that the procurement of small, difficult-to-catch, agile prey is a hallmark of complex behavior unique to our species; however, most research in this regard has been limited to the last 20,000 years in Europe and the Levant. Here, we present detailed faunal assemblage and taphonomic data from Fa-Hien Lena Cave in Sri Lanka that demonstrates specialized, sophisticated hunting of semi-arboreal and arboreal monkey and squirrel populations from ca. 45,000 years ago, in a tropical rainforest environment. Facilitated by complex osseous and microlithic technologies, we argue these data highlight that the early capture of small, elusive mammals was part of the plastic behavior of Homo sapiens that allowed it to rapidly colonize a series of extreme environments that were apparently untouched by its hominin relatives.
Revisiting the distribution of oceanic N2 fixation and estimating diazotrophic contribution to marine production
Authors: Tang Weiyi , Wang Seaver , Fonseca-Batista Debany , Dehairs Frank , Gifford Scott , Gonzalez Aridane G. , Gallinari Morgane , Planquette Hélène , Sarthou Géraldine , Cassar Nicolas 
Published: February 2019

AbstractMarine N2 fixation supports a significant portion of oceanic primary production by making N2 bioavailable to planktonic communities, in the process influencing atmosphere-ocean carbon fluxes and our global climate. However, the geographical distribution and controlling factors of marine N2 fixation remain elusive largely due to sparse observations. Here we present unprecedented high-resolution underway N2 fixation estimates across over 6000 kilometers of the western North Atlantic. Unexpectedly, we find increasing N2 fixation rates from the oligotrophic Sargasso Sea to North America coastal waters, driven primarily by cyanobacterial diazotrophs. N2 fixation is best correlated to phosphorus availability and chlorophyll-a concentration. Globally, intense N2 fixation activity in the coastal oceans is validated by a meta-analysis of published observations and we estimate the annual coastal N2 fixation flux to be 16.7 Tg N. This study broadens the biogeography of N2 fixation, highlights the interplay of regulating factors, and reveals thriving diazotrophic communities in coastal waters with potential significance to the global nitrogen and carbon cycles.
Suppression of autophagic activity by Rubicon is a signature of aging
Authors: Nakamura Shuhei , Oba Masaki , Suzuki Mari , Takahashi Atsushi , Yamamuro Tadashi , Fujiwara Mari , Ikenaka Kensuke , Minami Satoshi , Tabata Namine , Yamamoto Kenichi , Kubo Sayaka , Tokumura Ayaka , Akamatsu Kanako , Miyazaki Yumi , Kawabata Tsuyoshi , Hamasaki Maho , Fukui Koji , Sango Kazunori , Watanabe Yoshihisa , Takabatake Yoshitsugu , Kitajima Tomoya S. , Okada Yukinori , Mochizuki Hideki , Isaka Yoshitaka , Antebi Adam , Yoshimori Tamotsu 
Published: February 2019

AbstractAutophagy, an evolutionarily conserved cytoplasmic degradation system, has been implicated as a convergent mechanism in various longevity pathways. Autophagic activity decreases with age in several organisms, but the underlying mechanism is unclear. Here, we show that the expression of Rubicon, a negative regulator of autophagy, increases in aged worm, fly and mouse tissues at transcript and/or protein levels, suggesting that an age-dependent increase in Rubicon impairs autophagy over time, and thereby curtails animal healthspan. Consistent with this idea, knockdown of Rubicon extends worm and fly lifespan and ameliorates several age-associated phenotypes. Tissue-specific experiments reveal that Rubicon knockdown in neurons has the greatest effect on lifespan. Rubicon knockout mice exhibits reductions in interstitial fibrosis in kidney and reduced α-synuclein accumulation in the brain. Rubicon is suppressed in several long-lived worms and calorie restricted mice. Taken together, our results suggest that suppression of autophagic activity by Rubicon is one of signatures of aging.