bluuebunny/crossref_metadata_2025_split huggingface dataset:
Not water, sanitation and hygiene practice, but timing of stunting is associated with recovery from stunting at 24 months: results from a multi-country birth cohort study
Authors: Das Subhasish , Fahim Shah Mohammad , Alam Md Ashraful , Mahfuz Mustafa , Bessong Pascal , Mduma Esto , Kosek Margaret , Shrestha Sanjaya K , Ahmed Tahmeed 
Published: May 2020

AbstractObjectives:To measure the role of water, sanitation and hygiene (WASH) practices on recovery from stunting and assess the role of timing of stunting on the reversal of this phenomenonDesign:Data from the MAL-ED multi-country birth cohort study was used for the current analysis. Generalised linear mixed-effects models were used to estimate the probability of reversal of stunting with WASH practice and timing of stunting as the exposures of interest.Setting:Seven different countries across three continents.Participants:A total of 612 children <2 years of age.Results:We found that not WASH practice but timing of stunting had statistically significant association with recovery from stunting. In comparison with the children who were stunted at 6 months, children who were stunted at 12 months had 1·9 times (β= 0·63,P= 0·03) more chance of recovery at 24 months of age. And, children who were stunted at 18 months of age even had higher odds (adjusted OR = 3·01,β= 1·10,P< 0·001) of recovery than children who were stunted at 6 months. Additionally, mother’s height (β= 0·59,P= 0·04) and household income (β= 0·02,P< 0·05) showed statistically significant associations with the outcome.Conclusions:The study provided evidence for the role of timing of stunting on the recovery from the phenomenon. This novel finding indicates that the programmes to promote linear growth should be directed at the earliest possible timepoints in the course of life.
AN ALTERNATIVE APPROACH TO FRÉCHET DERIVATIVES
Authors: ARORA SHANE , BROWNE HAZEL , DANERS DANIEL 
Published: May 2020

AbstractWe discuss an alternative approach to Fréchet derivatives on Banach spaces inspired by a characterisation of derivatives due to Carathéodory. The approach allows many questions of differentiability to be reduced to questions of continuity. We demonstrate how that simplifies the theory of differentiation, including the rules of differentiation and the Schwarz lemma on the symmetry of second-order derivatives. We also provide a short proof of the differentiable dependence of fixed points in the Banach fixed point theorem.
EXTENSIONS OF VECTOR BUNDLES ON THE FARGUES-FONTAINE CURVE
Authors: Birkbeck Christopher , Feng Tony , Hansen David , Hong Serin , Li Qirui , Wang Anthony , Ye Lynnelle 
Published: May 2020

AbstractWe completely classify the possible extensions between semistable vector bundles on the Fargues–Fontaine curve (over an algebraically closed perfectoid field), in terms of a simple condition on Harder–Narasimhan (HN) polygons. Our arguments rely on a careful study of various moduli spaces of bundle maps, which we define and analyze using Scholze’s language of diamonds. This analysis reduces our main results to a somewhat involved combinatorial problem, which we then solve via a reinterpretation in terms of the Euclidean geometry of HN polygons.
The intricate link between galaxy dynamics and intrinsic shape (or why so-called prolate rotation is a misnomer)
Authors: Foster Caroline , Bassett Robert 
Published: May 2020

AbstractMany recent integral field spectroscopy (IFS) survey teams have used stellar kinematic maps combined with imaging to statistically infer the underlying distributions of galaxy intrinsic shapes. With now several IFS samples at our disposal, the method, which was originally proposed by M. Franx and collaborators in 1991, is gaining in popularity, having been so far applied to ATLAS3D, SAMI, MANGA and MASSIVE. We present results showing that a commonly assumed relationship between dynamical and intrinsic shape alignment does not hold in Illustris, affecting our ability to recover accurate intrinsic shape distributions. A further implication is that so-called “prolate rotation”, where the bulk of stars in prolate galaxies are thought to rotate around the projected major axis, is a misnomer.
3D asymmetrical kinematics of mono-age populations from LAMOST and Gaia common red clump stars
Authors: Wang H.-F. , López-Corredoira Martn , Huang Y. , Carlin Jeffrey L. 
Published: May 2020

AbstractWith the LAMOST DR4 and Gaia DR2 common red clump giant stars, we investigate the three-dimensional kinematics of Milky Way disk stars in mono-age populations between Galactocentric distances of R = 6 and 15 kpc. We confirm the 3D asymmetrical motions of recent works, and provide time tagging of the Galactic outer disk asymmetrical motions. Radial motions present a north-south asymmetry in the region corresponding to recent density and velocity substructures that were sensitive to the perturbations in the early 6 Gyr. What’s more, we discover a new velocity substructure in the north side corresponding to density dip found recently (“south-middle opposite”) in the radial and azimuthal velocity. Meanwhile, the vertical velocity with clear vertical bulk motions or bending mode motions has no clear asymmetry corresponding to the in-plane asymmetrical features.
Properties of barred galaxies in the MaNGA galaxy survey
Authors: Fraser-McKelvie Amelia , Merrifield Michael , Aragón-Salamanca Alfonso , Masters Karen ,   the MaNGA Survey Team
Published: May 2020

AbstractWe present the initial results of a census of 684 barred galaxies in the MaNGA galaxy survey. This large sample contains galaxies with a wide range of physical properties, and we attempt to link bar properties to key observables for the whole galaxy. We find the length of the bar, when normalised for galaxy size, is correlated with the distance of the galaxy from the star formation main sequence, with more passive galaxies hosting larger-scale bars. Ionised gas is observed along the bars of low-mass galaxies only, and these galaxies are generally star-forming and host short bars. Higher-mass galaxies do not contain Hα emission along their bars, however, but are more likely to host rings or Hα at the centre and ends of the bar. Our results suggest that different physical processes are at play in the formation and evolution of bars in low- and high-mass galaxies.
Study of open cluster NGC 5617 in Gaia era
Authors: Bisht D. , Zhu Qingfeng 
Published: May 2020

AbstractIdentification of member stars in open clusters is still an open question. Thanks to Gaia DR2 data base, which improves our statistics regarding true members in clusters to understand cluster properties much better way. In this paper, we identify the cluster members using proper motion and colour magnitude diagram for NGC 5617. In addition to this, we have determined more precise fundamental parameters as well.
The sequence of spiral arm classes: Observational signatures of persistent spiral density waves in grand-design galaxies
Authors: Bittner A. , Gadotti D. A. , Elmegreen B. G. , Athanassoula E. , Elmegreen D. M. , Bosma A. , Muñoz-Mateos J. 
Published: May 2020

AbstractWe investigate how the properties of spiral arms relate to other fundamental galaxy properties. To this end, we use previously published measurements of those properties, and our own measurements of arm-interarm luminosity contrasts for a large sample of galaxies, using 3.6μm images from the Spitzer Survey of Stellar Structure in Galaxies. Flocculent galaxies are clearly distinguished from other spiral arm classes, especially by their lower stellar mass and surface density. Multi-armed and grand-design galaxies are similar in most of their fundamental parameters, excluding some bar properties and the bulge-to-total luminosity ratio. Based on these results, we discuss dense, classical bulges as a necessary condition for standing spiral wave modes in grand-design galaxies. We further find a strong correlation between bulge-to-total ratio and bar contrast, and a weaker correlation between arm and bar contrasts.
Linear stability of stellar rotating spheres
Authors: Rozier Simon , Fouvry Jean-Baptiste , Breen Philip G. , Varri Anna Lisa , Pichon Christophe , Heggie Douglas C. 
Published: May 2020

AbstractRecent observations of globular clusters encourage to revise some aspects of the traditional paradigm, in which they were considered to be isotropic in velocity space and non-rotating. However, the theory of collisionless spheroids with some kinematic richness has seldom been studied. We present here a further step in this direction, owing to new results regarding the linear stability of rotating Plummer spheres, with varying anisotropy in velocity space and total amount of angular momentum. We extend the well-known radial orbit instability to rotating systems, and discover a new regime of instability in fast rotating, tangentially anisotropic systems.
Galactic mass and anisotropy profile with halo K-giant and blue horizontal branch stars from LAMOST/SDSS andGaia
Authors: Bird Sarah A. , Xue Xiang-Xiang , Liu Chao , Shen Juntai , Flynn Chris , Yang Chengqun 
Published: May 2020

AbstractA major uncertainty in the determination of the mass profile of the Milky Way using stellar kinematics in the halo is the poorly determined anisotropy parameter,, whereσris the Galactocentric radial velocity dispersion, andσθandσφare the tangential components of the velocity dispersion. We have used a sample of over 24,000 Galactic halo K giant and blue horizontal branch stars from the LAMOST stellar spectroscopic survey and SDSS/SEGUE, combined with proper motions fromGaiaData Release 2, to measureβ(rgc) over a wide range of Galactocentric distancesrgcfrom 5 to 80 kpc. Kinematic substructures have been carefully removed to reveal the underlying diffuse stellar halo prior to measuringβ. We find that orbits are generally radial (β > 0) andβis constant out to distances of about 40 kpc, with a dependence on metallicity of the stars, such thatβdeclines with lower metallicity. Similar behavior is seen in both the K giant and BHB samples.
Kinematic asymmetry of galaxy pairs
Authors: Feng Shuai , Shen Shi-Yin , Yuan Fang-Ting 
Published: May 2020

AbstractThe interaction between galaxies is believed to be the main origin of the peculiarities of galaxies. It can disturb not only the morphology but also the kinematics of galaxies. These disturbed and asymmetric features are the indicators of galaxy interaction. We study the velocity field of ionized gas in galaxy pairs based on MaNGA survey. Using the kinemetry package, we fit the velocity field and quantify the degree of kinematic asymmetry. We find that the fraction of high kinematic asymmetry is much higher for galaxy pairs with dp⩽30h−1kpc. Moreover, compared to a control sample of single galaxies, we find that the star formation rate is enhanced in paired galaxies with high kinematic asymmetry. For paired galaxies with low kinematic asymmetry, no significant SFR enhancement has been found. The galaxy pairs with high kinematic asymmetry are more likely to be real interacting galaxies rather than projected pairs.
Lithium enrichment in the Galaxy: A study using the GALAH and Gaia surveys
Authors: Deepak  , Reddy Bacham E. 
Published: May 2020

AbstractHere, we explore the enrichment of Lithium in the Galaxy using a large sample of stars common among large spectroscopic surveys such as the GALAH and astrometric survey by the Gaia satellite. For this study we used about 60,000 low mass (M⩽ 2M⊙) dwarfs from the GALAH survey. Further, we discuss Li enrichment among giant stars based on a sample of 52,000 low mass giants, of which 335 are Li-rich with A(Li) ⩾ 1.80 ± 0.14 dex, culled from the GALAH survey. These low mass giants appears to be one of the promising source of Li enrichment in the Galaxy as their atmospheric Li can be added to the ISM through mass loss.
The high transverse velocity stars in Gaia-LAMOST
Authors: Amarante João A. S. , Smith Martin C. , Boeche Corrado 
Published: May 2020

AbstractAlthough the stellar halo accounts for just ∼1% of the total stellar mass of the Milky Way, the kinematics of halo stars can tell us a lot about the origins and evolution of our Galaxy. It has been shown that the high transverse velocity stars in Gaia DR2 reveal a double sequence in the Hertzsprung-Russell (HR) diagram, indicating a duality in the local halo within 1 kpc. We fit these stars by updating the popular Besançon/Galaxia model, incorporating the latest observational results for the stellar halo. We are able to obtain a good match to the Gaia data and provide new constraints on the properties of the disc and halo. In particular, we show that the thick disc contribution to this high velocity tail is small, but not negligible, and likely has an influence on the red sequence of the HR diagram.
The GIST pipeline: A multi-purpose tool for the analysis and visualisation of (integral-field) spectroscopic data
Authors: Bittner A. , Falcón-Barroso J. , Nedelchev B. , Dorta A. , Gadotti D. A. , Sarzi M. , Molaeinezhad A. , Iodice E. , Rosado-Belza D. , de Lorenzo-Cáceres A. , Fragkoudi F. , Galán-de Anta P. M. , Husemann B. , Méndez-Abreu J. , Neumann J. , Pinna F. , Querejeta M. , Sánchez-Blázquez P. , Seidel M. K. 
Published: May 2020

AbstractWe introduce the Galaxy IFU Spectroscopy Tool (GIST), a convenient, all-in-one and multi-purpose tool for the analysis and visualisation of already reduced (integral-field) spectroscopic data. In particular, the pipeline performs all steps from read-in and preparation of data to its scientific analysis and visualisation in publication-quality plots. The code measures stellar kinematics and non-parametric star formation histories using the pPXF routine (Cappellari & Emsellem 2004; Cappellari 2017), performs an emission-line analysis with the GandALF procedure (Sarzi et al. 2006; Falcón-Barroso et al. 2006), and determines absorption line-strength indices and their corresponding single stellar population equivalent population properties (Kuntschner et al.2006; Martín-Navarro et al. 2018). The dedicated visualisation routine Mapviewer facilitates the access of all data products in a sophisticated graphical user interface with fully interactive plots.
Transverse bar/bulge kinematics with Gaia and VVV
Authors: Sanders Jason L. , Evans N. Wyn , Smith Leigh , Lucas Philip 
Published: May 2020

AbstractWe present new results on the Galactic bar/bulge transverse velocity structure using Gaia and the VISTA Variables in Via Lactea (VVV) survey. Gaia is complemented in high extinction regions by the multi-epoch infrared VVV observations for which derived relative proper motions can be tied to Gaia’s absolute frame. We extract kinematic maps (both 2D and 3D) of the Galactic bar/bulge, from which we measure the pattern speed of the bar using a novel technique. We focus on the evidence of an X-shaped bulge from the kinematic maps.
The shape of the dark matter halo revealed from a hypervelocity star
Authors: Hattori Kohei , Valluri Monica 
Published: May 2020

AbstractA recently discovered young, high-velocity giant star J01020100-7122208 is a good candidate of hypervelocity star ejected from the Galactic center, although it has a bound orbit. If we assume that this star was ejected from the Galactic center, it can be used to constrain the Galactic potential, because the deviation of its orbit from a purely radial orbit informs us of the torque that this star has received. Based on this assumption, we estimate the flattening of the Galactic dark matter halo by using the Gaia DR2 data and the circular velocity data. Our Bayesian analysis shows that the orbit of J01020100-7122208 favors a prolate halo within ~ 10 kpc from the Galactic center. The posterior distribution of the density flattening q shows a broad distribution at q ≳ 1 and peaks at q ≃ 1.5. Also, 98.5% of the posterior distribution is located at q > 1, highly disfavoring an oblate halo.
The VVV Survey: Globular Clusters and more
Authors: Minniti Dante , Navarro María Gabriela 
Published: May 2020

AbstractIn the efforts to map the Milky Way structure, the central regions have remained very difficult to probe. The VISTA Variables in the Vía Láctea Survey (VVV) is a near-IR variability Survey that scans 560 sq.deg. across the Milky Way bulge and an adjacent section of the southern mid-plane. The main goal of the VVV Survey is to build a 3D map of the structure of the inner Galaxy and characterize its stellar populations. This survey has discovered different kinds of objects, such as globular clusters, Microlensing events, RR Lyrae stars, Cepheids, WITs, among others. The extension of the Survey (VVVX) is observing until 2020, tripling the areal coverage, and complementing the variability studies done by the VVV Survey.
Can bars erode cuspy halos?
Authors: Kataria Sandeep Kumar , Das Mousumi , Mcgaugh Stacy 
Published: May 2020

AbstractOne of the major and widely known small scale problem with the Lambda CDM model of cosmology is the “core-cusp” problem. In this study we investigate whether this problem can be resolved using bar instabilities. We see that all the initial bars are thin (b/a < 0.3) in our simulations and the bar becomes thick ( b /a > 0.3) faster in the high resolution simulations. By increasing the resolution, we mean a larger number of disk particles. The thicker bars in the high resolution simulations transfer less angular momentum to the halo. Hence, we find that in the high resolution simulations it takes around 7 Gyr for the bar to remove inner dark matter cusp which is too long to be meaningful in galaxy evolution timescales. Physically, the reason is that as the resolution increases, the bar buckles faster and becomes thicker much earlier on.
The puzzle of unbarred galaxies
Authors: Shen Juntai 
Published: May 2020

AbstractNearly two thirds of spiral galaxies are either strongly or weakly barred, yet a significant fraction of disc galaxies do not have a bar. Now we understand that there are at least three ways of making bars, i.e., bar instability, tidal interaction, and secular bar growth by orbit trapping of a seed bar. However, the reverse problem of avoiding bar formation in unbarred galaxies may be more challenging than we thought. It is shocking that we still do not understand how the bar instability is avoided in real galaxies such as M33, and this puzzle may be central to the outstanding issue of what determines the distribution of bar strengths in galaxies.
No preferred alignments of angular momentum vectors of galaxies in the SDSS supercluster S[202-001+0084]
Authors: Malla Janak R. , Saurer Walter , Aryal Binil 
Published: May 2020

AbstractWe present spatial orientation of angular momentum vectors of 3038 galaxies in the SDSS supercluster S[202-002+0084] having mean redshift 0.084. The selection effects in the database are removed using random simulation method. The observed distributions of angular momentum vectors of galaxies are compared with expected theoretical distribution using chi-square, auto-correlation and Fourier tests. No preferred alignments of angular momentum vectors of galaxies are noticed in the supercluster S[202-001+0084], supporting hierarchy model.
A MUSE study of the fast bar in the weakly-interacting galaxy NGC 4264
Authors: Cuomo Virginia , Corsini Enrico Maria , Aguerri Alfonso J. L. , Debattista Victor P. 
Published: May 2020

AbstractWe present surface photometry and stellar kinematics of NGC 4264, a lenticular galaxy in the region of the Virgo Cluster undergoing a tidal interaction with its neighbour, NGC 4261. We measured the bar radius and strength from SDSS imaging and the bar pattern speed from MUSE integral-field spectroscopy. We find that NGC 4264 hosts a strong and large bar, which is rotating fast. The accurate measurement of the bar rotation rate allows us to exclude that the formation of the bar was triggered by the ongoing interaction.
The early merger that made the galaxy’s stellar halo
Authors: Evans N. Wyn 
Published: May 2020

AbstractThe last two years have seen widespread acceptance of the idea that the Milky Way halo was largely created in an early (8-10 Gyr ago) and massive (>1010Mȯ) merger. The roots of this idea pre-date the Gaia mission, but the exquisite proper motions available from Gaia have made the hypothesis irresistible. We trace the history of this idea, reviewing the series of papers that led to our current understanding.
Variability in pension products: a comparison study between The Netherlands and Denmark
Authors: Balter Anne G. , Kallestrup-Lamb Malene , Rangvid Jesper 
Published: May 2020

AbstractThe Danish and the Dutch pension systems are often referred to as “among the best in the world”. We compare pension systems and pension products in Denmark and The Netherlands. We focus on the shifts that have taken place in both countries, from pension products with relatively low levels of risk for the participant to pension products with more risk but also higher expected return. We end by drawing lessons that are relevant for discussions in many countries.
An ultra-wideband, polarization insensitive metamaterial absorber based on multiple resistive film layers with wide-incident-angle stability
Authors: Deng Guangsheng , Lv Kun , Sun Hanxiao , Hong Yuan , Zhang Xiaoying , Yin Zhiping , Li Ying , Yang Jun 
Published: May 2020

AbstractIn this work, we propose a broadband, polarization-insensitive and wide incident angle stable metamaterial absorber (MA) based on the resistive film. The absorber consists of a three-layer structure with each layer of dielectric substrate printed with different shapes of resistive film. The multilayer structure not only extends the absorption bandwidth but also maintains high absorption under large wave incident angles. Numerical simulation shows that the absorptivity of a normal incident wave is above 90% in the frequency range 2.34–18.95 GHz, corresponding to a relative absorption bandwidth of 156%. Moreover, the whole MA structure has a total thickness of 11.3 mm, corresponding to 0.09 λ0 at its lowest absorption frequency. Due to the high symmetry of the structure, the absorber has good polarization insensitivity. In addition, for both transverse electric and transverse magnetic incidence, the proposed absorber achieves an absorptivity of more than 80% at incident angles of up to 45° and thus has good stability for wide incident angles. The absorption principle of the absorber is analyzed by the surface current and power loss density distribution. Parameter analysis is also performed for bandwidth optimization. Due to its advantages of wideband absorption with high efficiency, the proposed absorber has the potential to be applied to the energy-harvesting and electromagnetic stealth fields.