bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elemental high-precision abundances as function of stellar ages: Constrains on the Galactic chemical evolution
Authors: Maia Marcelo Tucci 
Published: August 2018

AbstractSolar twins are a special group of stars that have spectra and stellar parameters very close to the Sun. Also having mass around 1 solar mass and roughly solar chemical composition, these stars follow a similar evolutionary path to the Sun, from the zero age main sequence to the end of their lives. Additional to that, the similarity between themselves permit us to obtain high-precision differential abundance and thus, very precise atmospheric parameters that allows a reliable estimation of their ages using the traditional isochronal method. Taking advantage of this very restrict group of stars we can better understand the effects of nucleosynthesis of chemical elements throughout the Galaxy and with this, finding constrains for its evolution.
Gaia first data release and beyond
Authors: Vallenari Antonella 
Published: August 2018

AbstractThe first Gaia data release took place in 2016, delivering astrometry and photometry for more than 1 billion sources in our Galaxy. After almost one year, Gaia data have already become the reference for astrometry, with applications in a wide range of topics. In this paper we summarize the impressive quality and the known limitations of the data; and we present the extensive validation work that was done by the Gaia Consortium before publication. We review a few results based on Gaia first data release, while looking ahead at the upcoming second data release
Using N-body simulations to understand the chemo-dynamical evolution of the inner Milky Way
Authors: Athanassoula E. 
Published: August 2018

AbstractI present examples of how chemo-dynamical N-body simulations can help understanding the structure and evolution of the inner Galaxy. Such simulations reproduce the observed links between kinematics, morphology and chemistry in the bar/bulge region and explain them by the self-consistent cohabitation of a number of components. Galactic archaeology, applied to simulation snapshots, explains the sequence in which the stars of the various components were formed. The thick disc stars form earlier than those of the thin disc and in a much shorter time scale. The bar in the thick disc is horizontally thicker than that of the thin disc and has a different vertical morphology. The Galaxy’s inner disc scalelength is much smaller than what is expected from nearby galaxies of similar stellar mass.
Getting off the ground: the case of bitcoin
Authors: LUTHER WILLIAM J. 
Published: August 2018

AbstractBy declaring an item legal tender or making it publicly receivable, governments might generate sufficient demand to determine the medium of exchange. How do private actors launch a new money? There are two views in the literature. The first requires offering an item with a use value to some agents that is distinct from its role as a medium of exchange. The second suggests that agents might coordinate on an intrinsically useless item. With these views in mind, I survey the logs from the original bitcoin forum, bitcoin-list. I find that early participants in the bitcoin community understood the importance of coordination and took steps to coordinate users.
Longitudinal Relationships Between Foster Children’s Mental Health Problems and Parental Stress in Foster Mothers and Fathers
Authors: Lohaus Arnold , Kerkhoff Denise , Chodura Sabrina , Möller Christine , Symanzik Tabea , Rueth Jana E. , Ehrenberg Daniela , Job Ann-Katrin , Reindl Vanessa , Konrad Kerstin , Heinrichs Nina 
Published: August 2018

Abstract. This paper focuses on the longitudinal relationships between foster children’s mental health problems and parental stress across a 1-year interval with three measurements. A sample of 94 foster children and a comparison group of 157 biological children and their families participated in this study. The age of the children was between 2 and 7 years. At the initial assessment, the foster children had been in their foster families since 2–24 months. Based on Child Behavior Checklist (CBCL) scores, the results indicated increased internalizing and externalizing mental health problems in the foster children group. Both mental health scores remained rather stable across the longitudinal assessments in foster as well as in biological children. Internalizing as well as externalizing scores were substantially correlated with parental stress in both samples. Moreover, changes in mental health scores were associated with changes in parental stress. However, cross-lagged panel analyses showed no clear pattern of temporal relationships between children’s mental health scores and parental stress. Implications as well as strengths and limitations of the current study are addressed in the Discussion section.
Lithospheric Structure and Tectonic Processes Constrained by Microearthquake Activity at the Central Ultraslow‐Spreading Southwest Indian Ridge (49.2° to 50.8°E)
Authors: Yu Zhiteng , Li Jiabiao , Niu Xiongwei , Rawlinson Nicholas , Ruan Aiguo , Wang Wei , Hu Hao , Wei Xiaodong , Zhang Jie , Liang Yuyang 
Published: August 2018

AbstractBeneath ultraslow‐spreading ridges, the oceanic lithosphere remains poorly understood. Using recordings from a temporary array of ocean bottom seismometers, we here report an ~17‐days‐long microearthquake study on two segments (27 and 28) of the ultraslow‐spreading Southwest Indian Ridge (49.2° to 50.8°E). A total of 214 locatable microearthquakes are recorded; seismic activity appears to be concentrated within the west median valley at Segment 28 and adjacent nontransform discontinuities. Earthquakes reach a maximum depth of ~20 km beneath the seafloor, and they mainly occur in the mantle, implying a cold and thick brittle lithosphere. The relatively uniform brittle/ductile boundary beneath Segment 28 suggests that there is no focused melting in this region. The majority of earthquakes is located below the Moho interface, and a 5‐km‐thick aseismic zone is present beneath Segment 28 and adjacent nontransform discontinuities. At the Dragon Flag hydrothermal vent field along Segment 28, the presence of a detachment fault has been inferred from geomorphic features and seismic tomography. Our seismicity data show that this detachment fault deeply penetrates into the mantle with a steeply dipping (~65°) interface, and it appears to rotate to a lower angle in the upper crust, with ~55° of rollover. There is a virtual seismic gap beneath magmatic Segment 27, which may be connected to the presence of an axial magma chamber beneath the spreading center and focused melting; in this scenario, the increased magma supply produces a broad, elevated temperature environment, which suppresses earthquake generation.
The Development of Late‐Stage Continental Breakup: Seismic Reflection and Borehole Evidence from the Danakil Depression, Ethiopia
Authors: Bastow Ian D. , Booth Adam D. , Corti Giacomo , Keir Derek , Magee Craig , Jackson Christopher A.‐L. , Warren John , Wilkinson Jason , Lascialfari Matteo 
Published: August 2018

AbstractDuring continental breakup, the locus of strain shifts from a broad region of border faulting and ductile plate stretching to a narrow zone of magma intrusion in a young ocean basin. Recent studies of volcanic rifts and margins worldwide suggest this shift occurs subaerially, before the onset of seafloor spreading. We test this hypothesis using recently acquired seismic reflection and borehole data from the Danakil Depression, Ethiopia, a unique region of transition between continental rifting and seafloor spreading. Our data, located near Dallol, ~30 km northwest of the Erta'Ale Volcanic Segment, reveal a remarkably thick (>1‐km) sequence of young (~100‐ka) evaporites in a basin bound by a major (≤400‐m‐throw), east‐dipping normal fault. To generate such a large amount of subsidence in such a relatively short time, we propose that upper‐crustal extension in Danakil is currently dominated by faulting, not magmatic intrusion. Given the region's markedly thinned crust (~15‐km‐thick), relative to elsewhere in Afar where magma‐assisted rifting dominates and maintains crustal thickness at ~25 km, mechanical extension in Danakil is likely coupled with ductile extension of the lower‐crust and mantle lithosphere. Despite proximity to the voluminous lavas of the active Erta'Ale Volcanic Segment, evidence for igneous material in the upper ~2 km of the 6‐ to 10‐km‐wide basin is limited. Late‐stage stretching was likely aided by thermal/strain‐induced lithospheric weakening following protracted magma‐assisted rifting. Basin formation immediately prior to the onset of seafloor spreading may also explain the accumulation of thick marine‐seepage‐fed evaporite sequences akin to those observed, for example, along the South Atlantic rifted margins.
Discrimination in Tree Stems O2 Uptake and the Dole Effect
Authors: Hilman Boaz , Angert Alon 
Published: August 2018

AbstractThe difference in δ18O between the atmospheric O2 and seawater is named the Dole effect (DE). Interpretation of past DE variations, a proxy for monsoonal intensity, is based on current understanding of global O2 fluxes. One such O2 flux that was poorly studied is the discrimination in O2 uptake by tree stems (Dstem). Stems differ from leaves in their lower gas permeability, which reduces the internal [O2] and poses diffusion limitations to local respiration. Diffusion limitations are expected to lower the effective discrimination below enzymatic values (17–30‰). Given fixed permeability, the lowest internal [O2] and thus the greatest diffusional effect are expected in high O2 influx. Dstem and O2 influx values were obtained by measurements of stem‐chamber air and a numerical model that resolves the gas exchange in the chamber. According to 101 results of temperate, Mediterranean, and tropical trees, the global Dstem is 19.2‰. Assuming basal O2 diffusion limitation in the stems, the results indicate involvement of the alternative oxidase respiration, with enzymatic discrimination factor of above 20‰. Small seasonal variations in Dstem were uncoupled from the O2 influx rates that tracked the temperature changes. This indicates a possible adjustment between the aeration capability of the stems and O2 uptake rate, which helps to maintain sufficient O2 supply. The mean Dstem value agrees with the assumed discrimination for leaf respiration, thus supporting current DE understanding. The small Dstem seasonal variations give an indication that climate variations on millennial and interglacial scales did not have a strong effect on Dstem values.
The Effect of Air‐Sea Flux Products, Shortwave Radiation Depth Penetration, and Albedo on the Upper Ocean Overturning Circulation
Authors: Groeskamp Sjoerd , Iudicone Daniele 
Published: August 2018

AbstractWater mass transformation quantifies transport of matter between different density classes of the World Ocean. We present the first observationally based quantification of transformation rates due to air‐sea buoyancy fluxes, which considers different parameterizations of shortwave radiation depth penetration, including the influence of albedo and the Chlorophyll a concentration. The results provide a range of solutions that can be used to compare model‐based transformation rates against. We compared two air‐sea flux products with limited representation of ice dynamics at high latitudes. We find that variations in the air‐sea heat fluxes due to Chlorophyll a and its horizontal distribution are as important for water mass transformation rates than differences between the freshwater flux products. An accurate representation of the effects and spatial distribution of Chlorophyll a is required to obtain realistic transformation rates.
Toward Low‐Level Turbulence Forecasting at Eddy‐Resolving Scales
Authors: Muñoz‐Esparza Domingo , Sharman Robert , Sauer Jeremy , Kosović Branko 
Published: August 2018

AbstractMicroscale turbulence in the atmospheric boundary layer (ABL) is characterized by significant spatiotemporal variability. Consequently, a change in the turbulence forecasting paradigm needs to occur, moving beyond average turbulence estimates at mesoscale grid resolutions (several kilometers) to eddy‐resolving forecasts. To that end, the viability of dynamic downscaling to large‐eddy simulation scales is evaluated. We present for the first time, multiday dynamic downscaling from currently available numerical weather prediction forecasts to a high‐resolution grid spacing of 25 m. It is found that these eddy‐resolving forecasts can realistically reproduce turbulence levels and peak events in the bulk of the daytime ABL, adequately capturing turbulence variability at subminute intervals. Moreover, probability distributions of turbulence quantities are in very good agreement when compared to in situ sonic‐anemometer observations. These results demonstrate the feasibility of eddy‐resolving forecasts to derive accurate probabilistic estimates of turbulence in the ABL and provide a path toward real‐time large‐eddy simulation scale prediction.
Sand Grain Sizes and Shapes in Eolian Bedforms at Gale Crater, Mars
Authors: Weitz Catherine M. , Sullivan Robert J. , Lapotre Mathieu G. A. , Rowland Scott K. , Grant John A. , Baker Mariah , Yingst R. Aileen 
Published: August 2018

AbstractWe measured sand sizes and shapes on diverse eolian bedforms in Gale crater to help constrain models of eolian sediment transport on Mars. All grains are subangular to rounded with circularities of ~0.93–0.97, indicating an extensive abrasion history. There are two types of active bedforms based on grain size: (1) ripples composed of 50‐ to 150‐μm grains and (2) ripples that also include 250‐ to 500‐μm grains along their crests, in some cases with small amounts of even coarser grains (up to 1.4 mm). The smallest grain sizes (50–150 μm) are volumetrically the most abundant at all active bedforms. Inactive bedforms have surfaces of 350‐ to 2,000‐μm grains with finer‐grained interiors, consistent with observations made by rovers at other landing sites. Grains coarser than ~300 μm are less prone to mobilization driven by smaller saltating grains, making bedforms with concentrations of coarser grains more susceptible to surface stabilization and inactivity.
Effect of Flood Hydrograph Duration, Magnitude, and Shape on Bed Load Transport Dynamics
Authors: Phillips C. B. , Hill K. M. , Paola C. , Singer M. B. , Jerolmack D. J. 
Published: August 2018

AbstractBed load sediment transport is an inherently challenging process to measure within a river, which is further complicated by the typically transient nature of the hydrograph. Here we use laboratory experiments to explore how sediment flux under transient—unsteady and intermittent—flow differ from those under steady flow. For a narrow unimodal sediment distribution, we calculated fluid stress and measured sediment flux for a range of hydrograph durations, magnitudes, shapes, and sequences. Within a hydrograph, we find considerable variability in sediment flux for a given stress above the threshold for motion. However, cumulative bed load flux resulting from a flood scales linearly with the integrated excess transport capacity (flow impulse). This scaling indicates that, to first order, flow magnitude, duration, shape, and sequence are only relevant to bed load flux in terms of their contribution to the total flow impulse, in agreement with prior field results. The flood impulse represents a quantitative parameter through which the effects of transient flow on coarse sediment transport may be parsed.
Enlarging Rainfall Area of Tropical Cyclones by Atmospheric Aerosols
Authors: Zhao Chuanfeng , Lin Yanluan , Wu Fang , Wang Yang , Li Zhanqing , Rosenfeld Daniel , Wang Yuan 
Published: August 2018

AbstractThe size of a tropical cyclone (TC), measured by the area of either rainfall or wind, is an important indicator for the potential damage by TC. Modeling studies suggested that aerosols tend to enhance rainfall in the outer rainbands, which enlarges the eyewall radius and expands the extent of rainfall area. However, no observational evidence has yet been reported. Using TC rainfall area and aerosol optical depth (AOD) data, we find that aerosols have a distinguishable footprint in the TC size. Other dynamical factors for TC size, such as relative SST and Coriolis parameter, are also quantified and discussed. We show that, on average, TC rainfall size increases 9–20 km for each 0.1 increase of AOD in the western North Pacific. This finding implies that anthropogenic aerosol pollution can increase not only TC rainfall rate, but also TC rainfall area, resulting in potentially more destructive flooding affecting larger areas.
On the Role of Thermospheric Winds and Sporadic E Layers in the Formation and Evolution of Electrified MSTIDs in Geomagnetic Conjugate Regions
Authors: Narayanan V. L. , Shiokawa K. , Otsuka Y. , Neudegg D. 
Published: August 2018

AbstractThe electrified medium‐scale traveling ionospheric disturbances (EMSTIDs) occurring as geomagnetically conjugate features in the middle latitude F region ionosphere are studied using multi‐instrument observations. Airglow imaging of OI 630 nm emission over Sata, Japan, and Darwin, Australia, are used to identify the occurrence of EMSTIDs. Thermospheric wind measurements made with the Fabry‐Perot interferometer observations of OI 630 nm from Shigaraki, Japan, and Darwin, Australia, are used along with ionosonde observations over Yamagawa, Japan, and Darwin, Australia, to study the thermospheric and ionospheric characteristics. These are the first results from such multi‐instrument observations simultaneously made from geomagnetic conjugate locations. Our results show that the amplitudes of the EMSTIDs are often different between the hemispheres. Thermospheric meridional winds appear to control the EMSTID amplitudes in the respective hemisphere. However, EMSTIDs are generated only when there is significant sporadic E activity with foEs often reaching greater than 6 MHz and (foEs − fbEs) reaching above 5 MHz at least for a short duration occurred. Existence of strong sporadic E activity on one of the hemispheres is found to be sufficient enough for generation of EMSTIDs in the conjugate F regions. These results conclusively indicate the importance of sporadic E layers in the generation of EMSTIDs. Further, it shows the significance of interhemispheric coupling between the E and F region ionospheres in the formation of EMSTIDs while their amplitudes in the respective hemispheres appear to have control of thermospheric neutral winds in the same hemisphere.
Wind‐Driven Coastal Upwelling and Downwelling in the Shelfbreak East Greenland Current
Authors: Håvik Lisbeth , Våge Kjetil 
Published: August 2018

AbstractThe East Greenland Current is a major pathway for freshwater export from the Arctic Ocean and for the transport of dense overflow waters toward the North Atlantic. We use moored measurements from the East Greenland Current north of Denmark Strait from October 2011 to April 2012 to analyze the wind‐driven variability of the shelfbreak branch of this current system. By combining the moored data with atmospheric reanalysis data we found that coastal upwelling and downwelling take place in the shelfbreak East Greenland Current throughout winter. In total, upwelling and downwelling events occur around five times per month, and these events modulate the volume transport and redistribute water masses. Specifically, we find that upwelling may lead to a deposition of dense water masses on the shelf and to an offshore transport of freshwater, while downwelling events are associated with a considerable increase in along‐stream freshwater transport. Based on wind patterns and wind‐driven ocean variability along the east Greenland coast, the integrated effect of these episodes is expected to be substantial.
Improving Multitarget Tracking in Synthetic Aperture Radar Within a High‐Density Clutter, Using a Technique Based on the Promoted PHD Filtering and MTI Filter
Authors: Daryasafar N. , Sadeghzadeh R. A. , Naser‐Moghadasi M. 
Published: August 2018

AbstractA method is presented in this paper for simultaneous multitarget tracking in the presence of high‐density clutter through the received data by synthetic aperture radar (SAR) by the use of the promoted Gaussian mixture probability hypothesis density filtering. Simultaneous tracking of several moving targets in an environment with high density of clutters is a special feature of probability hypothesis density (PHD) filtering that has turned it into a powerful system for tracking moving targets in SAR. Moving targets are desirably tracked by applying range cell migration compensation on the raw data received by SAR. As simulation results revealed, applying moving target indicator (MTI) filter before tracking process could improve performance of the promoted PHD filtering in multitarget tracking in SAR radar. In other words, application of MTI filter to decrease the clutter would significantly reduce the computational loads of the processor in tracking moving targets through the reduction of observations that enter the processor. The main parameters for assessing the performance of the proposed algorithm in this paper, the extracted state of moving targets over time in the presence of noise for different values of clutter's density, are considered in received observations. By increasing clutter density, the tracking process will be carried out with poorer performance using the promoted Gaussian mixture probability hypothesis density and Sequential Monte Carlo‐PHD filterings.
Systematic identification of non-coding pharmacogenomic landscape in cancer
Authors: Wang Yue , Wang Zehua , Xu Jieni , Li Jiang , Li Song , Zhang Min , Yang Da 
Published: August 2018

AbstractEmerging evidence has shown long non-coding RNAs (lncRNAs) play important roles in cancer drug response. Here we report a lncRNA pharmacogenomic landscape by integrating multi-dimensional genomic data of 1005 cancer cell lines and drug response data of 265 anti-cancer compounds. Using Elastic Net (EN) regression, our analysis identifies 27,341 lncRNA-drug predictive pairs. We validate the robustness of the lncRNA EN-models using two independent cancer pharmacogenomic datasets. By applying lncRNA EN-models of 49 FDA approved drugs to the 5605 tumor samples from 21 cancer types, we show that cancer cell line based lncRNA EN-models can predict therapeutic outcome in cancer patients. Further lncRNA-pathway co-expression analysis suggests lncRNAs may regulate drug response through drug-metabolism or drug-target pathways. Finally, we experimentally validate that EPIC1, the top predictive lncRNA for the Bromodomain and Extra-Terminal motif (BET) inhibitors, strongly promotes iBET762 and JQ-1 resistance through activating MYC transcriptional activity.
Deubiquitinase Usp12 functions noncatalytically to induce autophagy and confer neuroprotection in models of Huntington’s disease
Authors: Aron Rebecca , Pellegrini Pasquale , Green Edward W. , Maddison Daniel C. , Opoku-Nsiah Kwadwo , Oliveira Ana Osório , Wong Jinny S. , Daub Aaron C. , Giorgini Flaviano , Muchowski Paul , Finkbeiner Steven 
Published: August 2018

AbstractHuntington’s disease is a progressive neurodegenerative disorder caused by polyglutamine-expanded mutant huntingtin (mHTT). Here, we show that the deubiquitinase Usp12 rescues mHTT-mediated neurodegeneration in Huntington’s disease rodent and patient-derived human neurons, and in Drosophila. The neuroprotective role of Usp12 may be specific amongst related deubiquitinases, as the closely related homolog Usp46 does not suppress mHTT-mediated toxicity. Mechanistically, we identify Usp12 as a potent inducer of neuronal autophagy. Usp12 overexpression accelerates autophagic flux and induces an approximately sixfold increase in autophagic structures as determined by ultrastructural analyses, while suppression of endogenous Usp12 slows autophagy. Surprisingly, the catalytic activity of Usp12 is not required to protect against neurodegeneration or induce autophagy. These findings identify the deubiquitinase Usp12 as a regulator of neuronal proteostasis and mHTT-mediated neurodegeneration.