bluuebunny/crossref_metadata_2025_split huggingface dataset:
The evolution of pitch angles of spiral arms
Authors: Pringle J E , Dobbs C L 
Published: October 2019

ABSTRACTIn spiral galaxies, the pitch angle, α, of the spiral arms is often proposed as a discriminator between theories for the formation of the spiral structure. In Lin–Shu density wave theory, α stays constant in time, being simply a property of the underlying galaxy. In other theories (e.g. tidal interaction, and self-gravity), it is expected that the arms wind up in time, so that to a first approximation $\cot \alpha \propto t$. For these theories, it would be expected that a sample of galaxies observed at random times should show a uniform distribution of $\cot \alpha$. We show that a recent set of measurements of spiral pitch angles (Yu & Ho) is broadly consistent with this expectation.
The second-degree gravity coefficients of Phobos from two Mars Express flybys
Authors: Yang X , Yan J G , Andert T , Ye M , Pätzold M , Hahn M , Jin W T , Li F , Barriot J P 
Published: October 2019

ABSTRACT
Several close spacecraft flybys of Phobos have been performed over the past 40 yr in order to determine the gravity field of this tiny Martian moon. In this work, the second-degree coefficients of the gravity field of Phobos were derived from the radio tracking data of two combined Mars Express flybys (2010 and 2013), by applying a least squares regularized inverse technique, that introduces as an a priori the gravity field retrieved from a shape model based on constant density hypothesis. A gravitational mass estimate of $(7.0765\pm 0.0075)\times 10^5 \, \mathrm{m^3\, s}^{-2}$ and second-degree gravity coefficients C20 = −0.1378 ± 0.0348 and C22 = 0.0166 ± 0.0153(3σ) were derived. The estimated C20 value, in contrast to the value of C20 computed from the shape model under the constant density assumption, supports an inhomogeneous distribution inside Phobos at a confidence interval of 95 per cent (1.96σ). This result indicates a denser mass in the equatorial region or lighter mass in polar areas.
X-shooter observations of strong H2-bearing DLAs at high redshift
Authors: Balashev S A , Klimenko V V , Noterdaeme P , Krogager J-K , Varshalovich D A , Ivanchik A V , Petitjean P , Srianand R , Ledoux C 
Published: October 2019

ABSTRACT
We present results from spectroscopic observations with X-shooter at the Very Large Telescope of seven H2-bearing damped Lyman-α systems (DLAs) at high redshifts (zabs ∼ 2.5–3). These DLAs were originally selected from the presence of strong H2 lines directly seen at the DLA redshift in low-resolution low signal-to-noise ratio SDSS spectra. We confirm the detection of molecular hydrogen in all of them. We measure the column densities of H i, H2 in various rotational levels, and metal species, and associated dust extinction. The metallicities, obtained from undepleted species, are in the range log Z = −0.8 to −0.2. We discuss the chemical enrichment in these clouds and compare their properties with that of other molecular-rich systems selected by other means. In particular, we show that three different methods of pre-selection of H2-bearing DLAs in the SDSS have their own biases but complement each other mostly in terms of chemical enrichment. We use the rotational excitation of H2 molecules together with the fine-structure energy levels of neutral carbon to constrain the physical conditions in the gas with the help of numerical modelling as well as analytical expressions for the surface density at which atomic to molecular conversion happens. We find that the H2-bearing medium revealed by the studied DLAs has typical values for the kinetic temperature, hydrogen density, and UV radiation field of T ∼ 100 K, nH ∼ 100 cm−3, and IUV , respectively, about twice the intensity of the Draine field. Detailed studies combining different selections should therefore bring important clues to understand the H i-H2 transition at high redshift.
Primordial power spectrum and cosmology from black-box galaxy surveys
Authors: Leclercq Florent , Enzi Wolfgang , Jasche Jens , Heavens Alan 
Published: October 2019

ABSTRACT
We propose a new, likelihood-free approach to inferring the primordial matter power spectrum and cosmological parameters from arbitrarily complex forward models of galaxy surveys where all relevant statistics can be determined from numerical simulations, i.e. black boxes. Our approach, which we call simulator expansion for likelihood-free inference (selfi), builds upon approximate Bayesian computation using a novel effective likelihood, and upon the linearization of black-box models around an expansion point. Consequently, we obtain simple ‘filter equations’ for an effective posterior of the primordial power spectrum, and a straightforward scheme for cosmological parameter inference. We demonstrate that the workload is computationally tractable, fixed a priori, and perfectly parallel. As a proof of concept, we apply our framework to a realistic synthetic galaxy survey, with a data model accounting for physical structure formation and incomplete and noisy galaxy observations. In doing so, we show that the use of non-linear numerical models allows the galaxy power spectrum to be safely fitted up to at least kmax = 0.5 h Mpc−1, outperforming state-of-the-art backward-modelling techniques by a factor of ∼5 in the number of modes used. The result is an unbiased inference of the primordial matter power spectrum across the entire range of scales considered, including a high-fidelity reconstruction of baryon acoustic oscillations. It translates into an unbiased and robust inference of cosmological parameters. Our results pave the path towards easy applications of likelihood-free simulation-based inference in cosmology. We have made our code pyselfi and our data products publicly available at http://pyselfi.florent-leclercq.eu.
Observational constraints on the magnetic field of the bright transient Be/X-ray pulsar SXP 4.78
Authors: Semena Andrey N , Lutovinov Alexander A , Mereminskiy Ilya A , Tsygankov Sergey S , Shtykovsky Andrey E , Molkov Sergey V , Poutanen Juri 
Published: October 2019

ABSTRACT
We report results of the spectral and timing analysis of the Be/X-ray pulsar SXP 4.78 using the data obtained during its recent outburst with NuSTAR, Swift, Chandra, and NICER observatories. Using an overall evolution of the system luminosity, spectral analysis, and variability power spectrum we obtain constraints on the neutron star magnetic field strength. We found a rapid evolution of the variability power spectrum during the rise of the outburst, and absence of the significant changes during the flux decay. Several low frequency quasi-periodic oscillation features are found to emerge on the different stages of the outburst, but no clear clues on their origin were found in the energy spectrum and overall flux behaviour. We use several indirect methods to estimate the magnetic field strength on the neutron star surface and found that most of them suggest magnetic field B ≲ 2 × 1012 G. The strictest upper limit comes from the absence of the cyclotron absorption features in the energy spectra and suggests relatively weak magnetic field B &lt; 6 × 1011 G.)
The total stellar halo mass of the Milky Way
Authors: Deason Alis J , Belokurov Vasily , Sanders Jason L 
Published: October 2019

ABSTRACT
We measure the total stellar halo luminosity using red giant branch (RGB) stars selected from Gaia data release 2. Using slices in magnitude, colour, and location on the sky, we decompose RGB stars belonging to the disc and halo by fitting two-dimensional Gaussians to the Galactic proper motion distributions. The number counts of RGB stars are converted to total stellar halo luminosity using a suite of isochrones weighted by age and metallicity, and by applying a volume correction based on the stellar halo density profile. Our method is tested and calibrated using Galaxia and N-body models. We find a total luminosity (out to 100 kpc) of $L_{\rm halo} = 7.9 \pm 2.0 \times 10^8\, \mathrm{L}_\odot$ excluding Sgr, and $L_{\rm halo} = 9.4 \pm 2.4 \times 10^8\, \mathrm{L}_\odot$ including Sgr. These values are appropriate for our adopted stellar halo density profile and metallicity distribution, but additional systematics related to these assumptions are quantified and discussed. Assuming a stellar mass-to-light ratio appropriate for a Kroupa initial mass function (M⋆/L = 1.5), we estimate a stellar halo mass of $M^\star _{\rm halo} = 1.4 \pm 0.4\times 10^9 \, \mathrm{M}_\odot$. This mass is larger than previous estimates in the literature, but is in good agreement with the emerging picture that the (inner) stellar halo is dominated by one massive dwarf progenitor. Finally, we argue that the combination of a ${\sim}10^9\, \mathrm{M}_\odot$ mass and an average metallicity of 〈[Fe/H]〉 ∼ −1.5 for the Galactic halo points to an ancient (∼10 Gyr) merger event.
GPU empowered pipelines for calculating genome-wide kinship matrices with ultra-high dimensional genetic variants and facilitating 1D and 2D GWAS
Authors: Zhang Wenchao , Dai Xinbin , Xu Shizhong , Zhao Patrick X 
Published: October 2019

Abstract
Genome-wide association study (GWAS) is a powerful approach that has revolutionized the field of quantitative genetics. Two-dimensional GWAS that accounts for epistatic genetic effects needs to consider the effects of marker pairs, thus quadratic genetic variants, compared to one-dimensional GWAS that accounts for individual genetic variants. Calculating genome-wide kinship matrices in GWAS that account for relationships among individuals represented by ultra-high dimensional genetic variants is computationally challenging. Fortunately, kinship matrix calculation involves pure matrix operations and the algorithms can be parallelized, particular on graphics processing unit (GPU)-empowered high-performance computing (HPC) architectures. We have devised a new method and two pipelines: KMC1D and KMC2D for kinship matrix calculation with high-dimensional genetic variants, respectively, facilitating 1D and 2D GWAS analyses. We first divide the ultra-high-dimensional markers and marker pairs into successive blocks. We then calculate the kinship matrix for each block and merge together the block-wise kinship matrices to form the genome-wide kinship matrix. All the matrix operations have been parallelized using GPU kernels on our NVIDIA GPU-accelerated server platform. The performance analyses show that the calculation speed of KMC1D and KMC2D can be accelerated by 100–400 times over the conventional CPU-based computing.
Nicotine Standards in the United States
Authors: Stanton Cassandra A , Hatsukami Dorothy K 
Published: October 2019

Implications
This Special Issue on nicotine standards in the United States will address many of the questions raised in the Advance Notice of Proposed Rulemaking (ANPRM) through a series of policy commentaries and timely empirical studies across a variety of topic areas within the proposed comprehensive nicotine standards plan. The questions addressed in this issue include: (1) the threshold dose of nicotine (and other constituents) that would lead to minimally addictive cigarettes; (2) the effects of a nicotine product standard in smokers with co-morbidity, youth and young adult smokers, and menthol smokers; (3) a step-down or targeted data approach to reducing nicotine in cigarettes; (4) perceptions and communications about product standards; and (5) requirements associated with the implementation of a nicotine product standard.
Conceptual study on parasitic low-energy RI beam production with in-flight separator BigRIPS and the first stopping examination for high-energy RI beams in the parasitic gas cell
Authors: Sonoda T , Katayama I , Wada M , Iimura H , Sonnenschein V , Iimura S , Takamine A , Rosenbusch M , Kojima T M , Ahn D S , Fukuda N , Kubo T , Nishimura S , Shimizu Y , Suzuki H , Takeda H , Tanigaki M , Tomita H , Yoshida K , Ishiyama H 
Published: October 2019

Abstract
An in-flight separator performs the important role of separating a single specific radioactive isotope (RI) beam from the thousands of RI beams produced by in-flight fission as well as projectile fragmentation. However, when looking at ``separation'' from a different viewpoint, more than 99% of simultaneously produced RI beams are just eliminated in the focal plane slits or elsewhere in the separator. In order to enhance the effective usability of the RIKEN in-flight separator BigRIPS, we have been developing an innovative method: parasitic laser ion source (PALIS), which implements parasitic low-energy RI beam production by saving eliminated RI beams during BigRIPS experiments. In this paper, we present the expected benefits and feasibility for the PALIS concept and the results of the first stopping examination for high-energy RI beams in the gas cell.
Headteachers’ and chairs of governors’ perspectives on adolescent obesity and its prevention in English secondary school settings
Authors: Booth E , Halliday V , Cooper R J 
Published: October 2019

ABSTRACT

Background
Secondary schools are an important setting for preventing obesity in adolescence. Headteachers and chairs of governors are identified in national guidance as crucial stakeholders for school-based preventative action. Despite this, their views remain unexplored and unrepresented.

Methods
A sequential mixed method study was conducted. Semi-structured interviews were undertaken with a purposive sample of 22 secondary school headteachers and chairs of governors in England. Data were thematically analysed and informed the development of a descriptive cross-sectional survey, completed by 127 participants from the same population.

Results
Unhealthy dietary and sedentary behaviours were viewed as a more significant problem than adolescent obesity. Obesity was perceived as complex and multi-causal, and a range of stakeholders were deemed to have responsibility for its prevention, most notably parents. Support was identified for the role of secondary schools, although this was not an explicit priority and extensive internal and external barriers exist, which hinder preventative action.

Conclusions
Whilst secondary school settings in England remain an important setting for the prevention of adolescent obesity, it is crucial for policy makers and public health professionals to recognize the factors affecting school leaders’ ability and willingness to contribute to this agenda.
Further insights in the Tardigrada microbiome: phylogenetic position and prevalence of infection of four new Alphaproteobacteria putative endosymbionts
Authors: Guidetti Roberto , Vecchi Matteo , Ferrari Agnese , Newton Irene L G , Cesari Michele , Rebecchi Lorena 
Published: October 2019

Abstract
Data from a previous study showed that microbiomes of six tardigrade species are species-specific and distinct from associated environmental microbes. We here performed a more in-depth analyses of those data, to identify and characterize new potential symbionts. The most abundant bacterial operational taxonomic units (OTUs) found in tardigrades are classified, and their prevalence in other environments is assessed using public databases. A subset of OTUs was selected for molecular phylogenetic analyses based on their affiliation with host-associated bacterial families in tardigrades. Almost 22.6% of the most abundant OTUs found do not match any sequence at 99% identity in the IMNGS database. These novel OTUs include four putative tardigrade endosymbionts from Alphaproteobacteria (Anaplasmataceae and Candidatus Tenuibacteraceae), which are characterized by 16S rRNA gene analysis and investigated for their infection rates in: Echiniscus trisetosus, Richtersisus coronifer and Macrobiotus macrocalix. These putative endosymbionts have an infection prevalence between 9.1% and 40.0%, and are, therefore, likely secondary symbionts, not essential for tardigrade survival and reproduction. Using fluorescence in situ hybridization (FISH), we detected bacteria on the cuticle and within the ovary of E. trisetosus, suggesting possible vertical transmission. This study highlights the great contribution in biodiversity discovery that neglected phyla can provide in microbiome and symbiosis studies.
Improving Care Transitions to Drive Patient Outcomes
Authors: Campagna Vivian , Nelson Sheila A. , Krsnak Jean 
Published: October 2019

Purpose:
The purpose of this article is to examine how case managers can support positive outcomes during care transitions by focusing on the goals of the Triple Aim (D. Berwick, T. Nolan, & J. Whittington, 2008) and Coleman's Four Pillars (E. Coleman, C. Parry, S. Chalmers, & S. Min, 2006). Case managers can play a pivotal role to ensure high-quality transitions by assessing patients and identifying those who are at high risk; coordinating care and services among providers and settings; reconciling medications; and facilitating education of patients and their support systems to improve self-management. These activities are congruent with an underlying value of case management as defined by the Code of Professional Conduct for Case Managers: “improving client [i.e., patient] health, wellness and autonomy through advocacy, communication, education, identification of service resources, and service facilitation” (Commission for Case Manager Certification [CCMC], Code, Rev. 2015).

Case Management Primary Practice Settings:
Case managers across health or human services must assess for, identify, and understand the vulnerability of patients during care transitions and must adopt best practices to support successful care transitions. This includes case managers in acute care, primary care, rehabilitation, home health, community-based, and other settings.

Implications for Case Management Practice:
Two frameworks that support care transitions are the Triple Aim of improving the individual's experience of care, advancing the health of populations, and reducing the costs of care (D. Berwick, T. Nolan, & J. Whittington, 2008), and Coleman's “Four Pillars” of care transition activities of medication management, patient-centered health records, follow-up visits with providers and specialists, and patient knowledge about red flags that indicate worsening conditions or drug reactions (E. Coleman, C. Parry, S. Chalmers, & S. Min, 2006). From a case management perspective, these approaches and their goals are interrelated. As an advocate for the individual and at the hub of the care team, the professional case manager engages in important activities such as facilitating communication across multiple providers and care settings, arranging “warm handoffs,” undertaking medication reconciliation, and engaging in follow-up, particularly with high-risk patients. To support successful transitions of care, case managers must adopt best practices and advocate within their organizations for systematic approaches to care transitions to improve outcomes.
Bone morphogenetic protein signaling regulates Id1 mediated neural stem cell quiescence in the adult zebrafish brain via a phylogenetically conserved enhancer module
Authors: Zhang Gaoqun , Ferg Marco , Lübke Luisa , Takamiya Masanari , Beil Tanja , Gourain Victor , Diotel Nicolas , Strähle Uwe , Rastegar Sepand 
Published: October 2019

AbstractIn the telencephalon of adult zebrafish, the inhibitor of DNA binding 1 (id1) gene is expressed in radial glial cells (RGCs), behaving as neural stem cells (NSCs), during constitutive and regenerative neurogenesis. Id1 controls the balance between resting and proliferating states of RGCs by promoting quiescence. Here, we identified a phylogenetically conserved cis-regulatory module (CRM) mediating the specific expression of id1 in RGCs. Systematic deletion mapping and mutation of conserved transcription factor binding sites in stable transgenic zebrafish lines reveal that this CRM operates via conserved smad1/5 and 4 binding motifs (SBMs) under both homeostatic and regenerative conditions. Transcriptome analysis of injured and uninjured telencephala as well as pharmacological inhibition experiments identify a crucial role of bone morphogenetic protein (BMP) signaling for the function of the CRM. Our data highlight that BMP signals control id1 expression and thus NSC proliferation during constitutive and induced neurogenesis.
Deciphering the combinatorial interaction landscape
Authors: Cappuccio Antonio , Jensen Shane T. , Hartmann Boris , Sealfon Stuart C. , Soumelis Vassili , Zaslavsky Elena 
Published: October 2019

AbstractFrom cellular activation to drug combinations, the control of biological systems involves multiple stimuli that can elicit complex nonlinear interactions. To elucidate the functions and logic of stimulus interactions, we developed SAIL (Synergistic/Antagonistic Interaction Learner). SAIL uses a machine learning classifier trained to categorize interactions across a complete taxonomy of possible combinatorial effects. The strategy resolves the most informative interactions, and helps infer their functions and regulatory mechanisms. SAIL-predicted interaction mechanisms controlling key immune functions were experimentally validated. SAIL can integrate results from multiple datasets to derive general properties of how cells respond to multiple stimuli. Using public immunological datasets, we assembled a fine-grained landscape of ∼30000 interactions. Analysis of the landscape shows the context-dependent functions of individual modulators, and reveals a probabilistic algebra that links the separate and combined stimulus effects. SAIL is available through a user friendly interface to resolve the effect of stimulus and drug combinations.
The persistence in time of distributional patterns in marine megafauna impacts zonal conservation strategies
Authors: Lambert C. , Dorémus G. , Ridoux V. 
Published: October 2019

AbstractThe main type of zonal conservation approach corresponds to Marine Protected Areas (MPAs), which are spatially defined and generally static entities aiming at the protection of some target populations by the implementation of a management plan. For highly mobile species the relevance of an MPA over time might be hampered by temporal variations in distributions or home ranges. In the present work, we used habitat model-based predicted distributions of cetaceans and seabirds within the Bay of Biscay from 2004 to 2017 to characterise the aggregation and persistence of mobile species distributional patterns and the relevance of the existing MPA network. We explored the relationship between population abundance and spatial extent of distribution to assess the aggregation level of species distribution. We used the smallest spatial extent including 75% of the population present in the Bay of Biscay to define specific core areas of distributions, and calculated their persistence over the 14 studied years. We inspected the relevance of the MPA network with respect to aggregation and persistence. We found that aggregation and persistence are two independent features of marine megafauna distributions. Indeed, strong persistence was shown in both aggregated (bottlenose dolphins, auks) and loosely distributed species (northern gannets), while some species with aggregated distributions also showed limited year-to-year persistence in their patterns (black-legged kittiwakes). We thus have demonstrated that both aggregation and persistence have potential impact on the amount of spatio-temporal distributional variability encompassed within static MPAs. Our results exemplified the need to have access to a minimal temporal depth in the species distribution data when aiming to designate new site boundaries for the conservation of mobile species.