bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comoving Stars in Gaia DR1: An Abundance of Very Wide Separation Comoving Pairs
Authors: Oh Semyeong , Price-Whelan Adrian M. , Hogg David W. , Morton Timothy D. , Spergel David N. 
Published: May 2017

Abstract
The primary sample of the Gaia Data Release 1 is the Tycho-Gaia Astrometric Solution (TGAS): ≈2 million Tycho-2 sources with improved parallaxes and proper motions relative to the initial catalog. This increased astrometric precision presents an opportunity to find new binary stars and moving groups. We search for high-confidence comoving pairs of stars in TGAS by identifying pairs of stars consistent with having the same 3D velocity using a marginalized likelihood ratio test to discriminate candidate comoving pairs from the field population. Although we perform some visualizations using (bias-corrected) inverse parallax as a point estimate of distance, the likelihood ratio is computed with a probabilistic model that includes the covariances of parallax and proper motions and marginalizes the (unknown) true distances and 3D velocities of the stars. We find 13,085 comoving star pairs among 10,606 unique stars with separations as large as 10 pc (our search limit). Some of these pairs form larger groups through mutual comoving neighbors: many of these pair networks correspond to known open clusters and OB associations, but we also report the discovery of several new comoving groups. Most surprisingly, we find a large number of very wide (

pc) separation comoving star pairs, the number of which increases with increasing separation and cannot be explained purely by false-positive contamination. Our key result is a catalog of high-confidence comoving pairs of stars in TGAS. We discuss the utility of this catalog for making dynamical inferences about the Galaxy, testing stellar atmosphere models, and validating chemical abundance measurements.
Resolving the Discrepancy of Distance to M60, a Giant Elliptical Galaxy in Virgo
Authors: Lee Myung Gyoon , Jang In Sung 
Published: May 2017

Abstract
There is a well-known discrepancy in the distance estimation of M60, a giant elliptical galaxy in Virgo; the planetary nebula luminosity function (PNLF) distance moduli for this galaxy are, on average, 0.4 mag smaller than the values based on the surface brightness fluctuation (SBF) in the literature. We present photometry of the resolved stars in an outer field of M60 based on deep F775W and F850LP images in the Hubble Space Telescope obtained as part of the Pure Parallel Program in the archive. Detected stars are mostly old red giants in the halo of M60. With this photometry, we determine a distance to M60 using the tip of the red giant branch (TRGB). A TRGB is detected at F850LP

mag, in the luminosity function of the red giants. This value corresponds to F814W

mag and

mag, where QT is a color-corrected F814W magnitude. From this we derive a distance modulus,

(

Mpc). This value is 0.3 mag larger than the PNLF distances and 0.1 mag smaller than the SBF distances in the previous studies, which indicates that the PNLF distances to M60 reported in the literature have larger uncertainties than the suggested values.
The Evolution and Physical Parameters of WN3/O3s: A New Type of Wolf–Rayet Star*
Authors: Neugent Kathryn F. , Massey Philip , Hillier D. John , Morrell Nidia 
Published: May 2017

Abstract
As part of a search for Wolf–Rayet (WR) stars in the Magellanic Clouds, we have discovered a new type of WR star in the Large Magellanic Cloud (LMC). These stars have both strong emission lines, as well as He ii and Balmer absorption lines and spectroscopically resemble a WN3 and O3V binary pair. However, they are visually too faint to be WN3+O3V binary systems. We have found nine of these WN3/O3s, making up ∼6% of the population of LMC WRs. Using cmfgen, we have successfully modeled their spectra as single stars and have compared the physical parameters with those of more typical LMC WNs. Their temperatures are around 100,000 K, a bit hotter than the majority of WN stars (by around 10,000 K), though a few hotter WNs are known. The abundances are what you would expect for CNO equilibrium. However, most anomalous are their mass-loss rates, which are more like that of an O-type star than a WN star. While their evolutionary status is uncertain, their low mass-loss rates and wind velocities suggest that they are not products of homogeneous evolution. It is possible instead that these stars represent an intermediate stage between O stars and WNs. Since WN3/O3 stars are unknown in the Milky Way, we suspect that their formation depends upon metallicity, and we are investigating this further by a deep survey in M33, which possesses a metallicity gradient.
Advection of Potential Temperature in the Atmosphere of Irradiated Exoplanets: A Robust Mechanism to Explain Radius Inflation
Authors: Tremblin P. , Chabrier G. , Mayne N. J. , Amundsen D. S. , Baraffe I. , Debras F. , Drummond B. , Manners J. , Fromang S. 
Published: May 2017

Abstract
The anomalously large radii of strongly irradiated exoplanets have remained a major puzzle in astronomy. Based on a two-dimensional steady-state atmospheric circulation model, the validity of which is assessed by comparison to three-dimensional calculations, we reveal a new mechanism, namely the advection of the potential temperature due to mass and longitudinal momentum conservation, a process occurring in the Earth’s atmosphere or oceans. In the deep atmosphere, the vanishing heating flux forces the atmospheric structure to converge to a hotter adiabat than the one obtained with 1D calculations, implying a larger radius for the planet. Not only do the calculations reproduce the observed radius of HD 209458b, but also reproduce the observed correlation between radius inflation and irradiation for transiting planets. Vertical advection of potential temperature induced by non-uniform atmospheric heating thus provides a robust mechanism to explain the inflated radii of irradiated hot Jupiters.
Electron Excitation of High Dipole Moment Molecules Re-examined
Authors: Goldsmith Paul F. , Kauffmann Jens 
Published: May 2017

Abstract
Emission from high-dipole moment molecules such as HCN allows determination of the density in molecular clouds, and is often considered to trace the “dense” gas available for star formation. We assess the importance of electron excitation in various environments. The ratio of the rate coefficients for electrons and H2 molecules, ≃105 for HCN, yields the requirements for electron excitation to be of practical importance if

and

, where the numerical factors reflect the critical values

and

. This indicates that in regions where a large fraction of carbon is ionized,

will be large enough to make electron excitation significant. The situation is in general similar for other “high-density tracers,” including HCO+, CN, and CS. But there are significant differences in the critical electron fractional abundance,

, defined by the value required for equal effect from collisions with H2 and e−. Electron excitation is, for example, unimportant for CO and C+. Electron excitation may be responsible for the surprisingly large spatial extent of emission from dense gas tracers in some molecular clouds. The enhanced estimates for HCN abundances and HCN/CO and HCN/HCO+ ratios observed in the nuclear regions of luminous galaxies may be in part a result of electron excitation of high dipole moment tracers. The importance of electron excitation will depend on detailed models of the chemistry, which may well be non-steady state and non-static.
Practical Weak-lensing Shear Measurement with Metacalibration
Authors: Sheldon Erin S. , Huff Eric M. 
Published: May 2017

Abstract

Metacalibration is a recently introduced method to accurately measure weak gravitational lensing shear using only the available imaging data, without need for prior information about galaxy properties or calibration from simulations. The method involves distorting the image with a small known shear, and calculating the response of a shear estimator to that applied shear. The method was shown to be accurate in moderate-sized simulations with galaxy images that had relatively high signal-to-noise ratios, and without significant selection effects. In this work we introduce a formalism to correct for both shear response and selection biases. We also observe that for images with relatively low signal-to-noise ratios, the correlated noise that arises during the metacalibration process results in significant bias, for which we develop a simple empirical correction. To test this formalism, we created large image simulations based on both parametric models and real galaxy images, including tests with realistic point-spread functions. We varied the point-spread function ellipticity at the five-percent level. In each simulation we applied a small few-percent shear to the galaxy images. We introduced additional challenges that arise in real data, such as detection thresholds, stellar contamination, and missing data. We applied cuts on the measured galaxy properties to induce significant selection effects. Using our formalism, we recovered the input shear with an accuracy better than a part in a thousand in all cases.
The Evaporation and Survival of Cluster Galaxy Coronae. I. The Effectiveness of Isotropic Thermal Conduction Including Saturation
Authors: Vijayaraghavan Rukmani , Sarazin Craig 
Published: May 2017

Abstract
We simulate the evolution of cluster galaxy hot interstellar medium (ISM) gas that is a result of the effects of ram pressure and thermal conduction in the intracluster medium (ICM). At the density and temperature of the ICM, the mean free paths of ICM electrons are comparable to the sizes of galaxies, therefore electrons can efficiently transport heat that is due to thermal conduction from the hot ICM to the cooler ISM. Galaxies consisting of dark matter halos and hot gas coronae are embedded in an ICM-like “wind tunnel” in our simulations. In this paper, we assume that thermal conduction is isotropic and include the effects of saturation. We find that as heat is transferred from the ICM to the ISM, the cooler denser ISM expands and evaporates. This process is significantly faster than gas loss due to ram pressure stripping; for our standard model galaxy, the evaporation time is 160 Myr, while the ram pressure stripping timescale is 2.5 Gyr. Thermal conduction also suppresses the formation of shear instabilities, and there are no stripped ISM tails since the ISM evaporates before tails can form. Observations of long-lived X-ray emitting coronae and ram pressure stripped X-ray tails in galaxies in group and cluster environments therefore require that thermal conduction is suppressed or offset by some additional physical process. The most likely process is anisotropic thermal conduction that is due to magnetic fields in the ISM and ICM, which we simulate and study in the next paper in this series.
La France, paradis pour les entrepreneurs ?
Authors: Cavarretta Fabrice 
Published: May 2017

La France, écosystème pour entreprendre : nombreux domaines d’excellence, capital humain de qualité, argent disponible. Il y a certes l’Administration, les charges et le droit du travail, mais aux USA, il faut payer cher des lawyers et le fisc traque ceux qui réussissent...
A model study of warming-induced phosphorus–oxygen feedbacks in open-ocean oxygen minimum zones on millennial timescales
Authors: Niemeyer Daniela , Kemena Tronje P. , Meissner Katrin J. , Oschlies Andreas 
Published: May 2017

Abstract. Observations indicate an expansion of oxygen minimum zones (OMZs) over the past 50 years, likely related to ongoing deoxygenation caused by reduced oxygen solubility, changes in stratification and circulation, and a potential acceleration of organic matter turnover in a warming climate. The overall area of ocean sediments that are in direct contact with low-oxygen bottom waters also increases with expanding OMZs. This leads to a release of phosphorus from ocean sediments. If anthropogenic carbon dioxide emissions continue unabated, higher temperatures will cause enhanced weathering on land, which, in turn, will increase the phosphorus and alkalinity fluxes into the ocean and therefore raise the ocean's phosphorus inventory even further. A higher availability of phosphorus enhances biological production, remineralisation and oxygen consumption, and might therefore lead to further expansions of OMZs, representing a positive feedback. A negative feedback arises from the enhanced productivity-induced drawdown of carbon and also increased uptake of CO2 due to weathering-induced alkalinity input. This feedback leads to a decrease in atmospheric CO2 and weathering rates. Here, we quantify these two competing feedbacks on millennial timescales for a high CO2 emission scenario. Using the University of Victoria (UVic) Earth System Climate Model of intermediate complexity, our model results suggest that the positive benthic phosphorus release feedback has only a minor impact on the size of OMZs in the next 1000 years. The increase in the marine phosphorus inventory under assumed business-as-usual global warming conditions originates, on millennial timescales, almost exclusively (> 80 %) from the input via terrestrial weathering and causes a 4- to 5-fold expansion of the suboxic water volume in the model.
Sand quarry wetlands provide high-quality habitat for native amphibians
Authors: Sievers Michael 
Published: May 2017

Abstract. Anthropogenic disturbances to habitats influence the fitness of individual animals, the abundance of their populations, and the composition of their communities. Wetlands in particular are frequently degraded and destroyed, impacting the animals that inhabit these important ecosystems. The creation of wetlands during and following sand extraction processes is inevitable, and thus, sand quarries have the potential to support aquatic animals. To determine how amphibians utilise these wetlands, I conducted nocturnal call surveys at wetlands within the Kables Sands quarry, New South Wales, Australia, and within surrounding reference wetlands, and quantified levels of developmental instability (DI) as a proxy for fitness. Whilst quarry and reference wetlands were largely similar in terms of environmental characteristics, quarry wetlands consistently harboured more amphibian species and individuals. Using unsigned asymmetry as a measure of DI, frogs from the quarry sites exhibited significantly lower levels of DI compared to reference wetlands, indicating that quarry wetlands may be comparatively higher quality. Levels of DI within quarry wetlands also compared favourably to data from healthy frog populations extracted from the literature. Further enhancing the suitability of quarry wetlands would require minimal effort, with potentially significant increases in local and regional biodiversity. Documenting species presence and quantifying individual fitness by measuring limb lengths is an economically and logistically feasible method to assess the health of quarry wetlands. Overall, the methods outlined here provide a powerful, yet simple, tool to assess the overall health and suitability of quarry wetlands that could be easily adopted at quarries throughout the world.
Qualificação dos dados hidrológicos disponíveis na base HIDROWEB/ANA: estações fluviométricas do estado de Goiás
Authors: Roza dos Santos Júnio Gregório , Vespucci Ariel Godinho , Bayer Maximiliano 
Published: May 2017

ResumoO presente artigo pretende realizar uma qualificação dos dados das estações fluviométricas do estado de Goiás, no Brasil, registradas na base de dados hidrológicos HidroWeb. A partir de três parâmetros: periodicidade, continuidade e atualidade, elaborou-se um Índice de Qualidade que permitiu mensurar o nível de confiabilidade dos registros de cota e vazão hídrica armazenados no portal. Dessa forma o índice possibilitou classificar as estações em satisfatórias, razoáveis e insatisfatórias. E assim, concluiu-se que 66,37% ou 274 das 413 estações fluviométricas do estado se enquadram como insatisfatórias, pois não fornecem séries históricas longas e contínuas, prejudicando assim o planejamento de uso dos recursos hídricos, tornando o monitoramento das águas superficiais um desafio.Palavras-chave: HidroWeb, estações fluviométricas, dados hidrológicos, Índice de Qualidade. AbstractThis paper aims to realize a qualification of stations fluviometric data of the state of Goiás in Brazil, registered in hydrological database HidroWeb. From three parameters: periodicity, continuity and topicality, a Quality Index was drawn up that has allowed us to measure the reliability's level of quota and water flow records stored in the database. Thus, the index has enabled us to classify the stations as satisfactory, moderate and unsatisfactory. Therefore, we concluded that there 66.37% or 274 of 413 fluviometric stations in the state are classified as unsatisfactory, because they don't produce historical and continuous series, affecting like this the use of water resources planning and makes a challenge the surface water monitoring.Keywords: HidroWeb, fluviometric stations, hydrilogicals data, Quality Index. ResumenEste artículo tiene como objetivo realizar una calificación de los datos de las estaciones fluviométricas en el estado de Goiás, que hacen parte de la base HIDROWEB. A partir de la selección de tres parámetros: la periodicidad, la continuidad y la actualidad de los datos, se elaboró un Índice de Calidad que permite medir el nivel de confiabilidad de los registros de cota y caudal de agua almacenados en el portal. Así, la aplicación de este índice posibilitó clasificar las estaciones hidrológicas en estaciones en satisfactorias, razonables e insatisfactorias. Los resultados permiten concluir que 66,37% o 274 de 413 estaciones fluviométricas del estado presentan informaciones insatisfactorias, perjudicando así, la planificación y gestión de los recursos hídricos. De esta manera, el monitoreo de aguas superficiales se convierte en un desafío. Palabras clave: HidroWeb, estaciones fluviométricas, datos hidrológicos, Índice de Calidad.
Relationship between Bioimpedance-determined Body Composition and Peritoneal Transport in Peritoneal Dialysis
Authors: da Costa Bernardo M. , Del Peso Gloria , Bajo Maria Auxiliadora , Carreño Gilda , Ferreira Marta , Ferreira Carina , Selgas Rafael 
Published: May 2017

Purpose In peritoneal dialysis (PD) patients, body fluid homeostasis is dependent on peritoneal elimination of water and solutes. Patients with less favorable peritoneal transport parameters should be more overhydrated. Despite this, the association between faster transport and overhydration (OH) is weak, and the factors that influence hydration status are still poorly characterized. Modified peritoneal equilibration tests (PET) offer us new parameters that might correlate better with hydration status, like free water transport (FWT). The aim of this study was thus to establish the relationships between new peritoneal transport parameters and body composition parameters estimated by bioimpedance spectroscopy (BIS). Methods Prospective observational study on incident PD patients with a baseline and 1-year follow-up evaluation. Results 61 patients were included in the baseline evaluation, 19 of whom had a 1-year follow-up evaluation; 67.2% were fluid overloaded. There was a negative correlation between D/P creatinine and FWT (r = -0.598, p = 0.000). The fraction of FWT was negatively correlated with OH (r = -0.302, p = 0.018). Peritoneal protein losses (PPL) were also correlated with OH (r = 0.287, p = 0.028). There were no significant differences in OH according to small-solute transport status or fluid output parameters. After 1 year, we observed a significant worsening of renal function and an improvement in 24-hour ultrafiltration (UF) and hydration status, but we detected no differences in peritoneal transport of water or solutes that could explain these changes. Conclusions There is a poor relationship between kidney/peritoneal function parameters and body composition parameters. The fraction of FWT and PPL may be underestimated markers of peritoneal health and of its contribution to the hydration status.
Dynamic Mechanical Analysis of Carbon Nanotube-Reinforced Nanocomposites
Authors: Her Shiuh-Chuan , Lin Kuan-Yu 
Published: May 2017

Background To predict the mechanical properties of multiwalled carbon nanotube (MWCNT)–reinforced polymers, it is necessary to understand the role of the nanotube-polymer interface with regard to load transfer and the formation of the interphase region. The main objective of this study was to explore and attempt to clarify the reinforcement mechanisms of MWCNTs in epoxy matrix. Methods Nanocomposites were fabricated by adding different amounts of MWCNTs to epoxy resin. Tensile test and dynamic mechanical analysis (DMA) were conducted to investigate the effect of MWCNT contents on the mechanical properties and thermal stability of nanocomposites. Results Compared with the neat epoxy, nanocomposite reinforced with 1 wt% of MWCNTs exhibited an increase of 152% and 54% in Young's modulus and tensile strength, respectively. Conclusions Dynamic mechanical analysis demonstrates that both the storage modulus and glass transition temperature tend to increase with the addition of MWCNTs. Scanning electron microscopy (SEM) observations reveal that uniform dispersion and strong interfacial adhesion between the MWCNTs and epoxy are achieved, resulting in the improvement of mechanical properties and thermal stability as compared with neat epoxy.
Urinary Artificial Sphincter ZSI 375 for Treatment of Stress Urinary Incontinence in Men: 5 and 7 Years Follow-Up Report
Authors: Llorens Christophe , Pottek Tobias 
Published: May 2017

Study Design This is a retrospective, non-randomised study. Objectives The aim of this study was to evaluate safety and efficacy of artificial urinary sphincter ZSI 375 inserted in male patients with stress urinary incontinence (SUI). Methods Between May 2009 and January 2017, 45 men with SUI underwent ZSI 375 device insertion. Operations were performed in two French centres by one surgeon. Complications and pad used to manage continence were recorded. Results From May 2009 to January 2012, 45 patients with a mean age of 70.42 years underwent placement of the ZSI 375 device in France. The most common cause for incontinence was radical prostatectomy (RP, 33/45 ­patients, 73.33%). The minimal period of incontinence was 6 months. Twenty-seven out of 45 patients (60.00%) had a severe incontinence (at least four pads per day), 13 patients (28.89%) had moderate incontinence (three pads per day) and five patients (11.11%) had two pads per day. With a long follow-up, the ZSI 375 device was considered to be successful in 73.33% patients after 5 years (60 months) and 72% of patients after 7 years (84 months). The infection rate was 2.2 % affecting one in 45 patients. Six out of 45 patients presented a urethral erosion (13.33%). Mechanical failure with a revision occurred in three patients (6.67%). Conclusions The ZSI 375 device is a safe and effective device to treat severe SUI in men.