bluuebunny/crossref_metadata_2025_split huggingface dataset:
Food system sustainability and vulnerability: food acquisition during the military occupation of Kuwait
Authors: Alajmi Fahhad , Somerset Shawn M 
Published: January 2015

AbstractObjectiveTo document food acquisition experiences during Iraqi military occupation in Kuwait.DesignRetrospective cross-sectional study.SettingUrban areas in Kuwait during occupation.SubjectsThose living in Kuwait during the period of occupation, and aged between 15 to 50 years at the time of occupation, recruited by snowball sampling. A total of 390 completed questionnaires (response rate 78 %, 202 female and 188 male) were returned.ResultsDuring the occupation, food became increasingly difficult to acquire. Two food systems emerged: (i) an underground Kuwaiti network linked to foods recovered from local food cooperatives and (ii) a black market supplied by food imported through Iraq or stolen locally. Food shortages led to reductions in meal size and frequency. Some respondents (47·7 %) reported not having sufficient income to purchase food and 22·1 % had to sell capital items to purchase food. There was a significant increase (P<0·01) in home production, with 23·1 % of people growing vegetables and 39·0 % raising animals to supplement food needs. Reduction in food wastage also emerged as a significant self-reported behaviour change. Respondents reported deterioration in the quality and availability of fish, milk, and fruit in particular. Despite a decrease in opportunities for physical activity, most respondents reported that they lost weight during the occupation.ConclusionsAlthough the Kuwaiti population fell by about 90 % and domestic food production increased during the 7-month occupation, the local population continued to rely heavily on imported food to meet population needs. The high prevalence of self-reported weight loss indicates the inadequacies of this food supply. High apparent food security in systems which significantly exceed the ecological carrying capacity of the local environment and rely on mass food importation remains vulnerable.
Physics of Mass Loss in Massive Stars
Authors: Puls Joachim , Sundqvist Jon O. , Markova Nevena 
Published: January 2015

AbstractWe review potential mass-loss mechanisms in the various evolutionary stages of massive stars, from the well-known line-driven winds of O-stars and BA-supergiants to the less-understood winds of Red Supergiants. We discuss optically thick winds from Wolf-Rayet stars and Very Massive Stars, and the hypothesis of porosity-moderated, continuum-driven mass loss from stars formally exceeding the Eddington limit, which might explain the giant outbursts from Luminous Blue Variables. We finish this review with a glance on the impact of rapid rotation, magnetic fields and small-scale inhomogeneities in line-driven winds.
Discovery of a Thorne-Żytkow object candidate in the Small Magellanic Cloud
Authors: Levesque Emily M. , Massey Philip , Żytkow Anna N. , Morrell Nidia 
Published: January 2015

AbstractThorne-Żytkow objects (TŻOs) are a theoretical class of star in which a compact neutron star is surrounded by a large, diffuse envelope. Supergiant TŻOs are predicted to be almost identical in appearance to red supergiants (RSGs), with their very red colors and cool temperatures placing them at the Hayashi limit on the H-R diagram. The only features that can be used at present to distinguish TŻOs from the general RSG population are the unusually strong heavy-element and lithium lines present in their spectra. These elements are the unique products of the stars fully convective envelope linking the photosphere with the extraordinarily hot burning region in the vicinity of the neutron star core. We have recently discovered a TŻO candidate in the Small Magellanic Cloud. It is the first star to display the distinctive chemical profile of anomalous element enhancements thought to be characteristic of TŻOs; however, up-to-date models and additional observable predictions (including potential asteroseismological signatures) are required to solidify this discovery. The definitive detection of a TŻO would provide the first direct evidence for a completely new model of stellar interiors, a theoretically predicted fate for massive binary systems, and never-before-seen nucleosynthesis processes that would offer a new channel for heavy-element and lithium production in our universe.
A New Class of Wolf-Rayet Stars: WN3/O3s
Authors: Massey Philip , Neugent Kathryn F. , Morrell Nidia , John Hillier D. 
Published: January 2015

AbstractOur new survey for Wolf-Rayet stars in the Magellanic Clouds is only 15% complete but has already found 9 new Wolf-Rayet (WR) stars in the Large Magellanic Cloud (LMC). This suggests that the total WR population in the LMC may be underestimated by 10-40%. Eight of the nine are of the WN subtype, demonstrating that the “observed” WC to WN ratio is too large, and is biased towards WC stars. The ninth is another rare WO star, the second we have found in the LMC in the past two years. Five (and possibly six) of the 8 WNs are of a new class of WRs, which pose a significant challenge to our understanding. Naively we would classify these stars as “WN3+O3V,” but there are several reasons why such a pairing is unlikely, not the least of which is that the absolute visual magnitudes of these stars are faint, with MV ~ -2.3 to -3.1. We have performed a preliminary analysis with the atmospheric code CMFGEN, and we find that (despite the faint visual magnitudes) the bolometric luminosities of these stars are normal for early-type WNs. Our fitting suggests that these stars are evolved, with significantly enriched N and He. Their effective temperatures are also normal for early-type WNs. What is unusual about these stars is that they have a surprisingly small mass-loss rate compared to other early-type WNs. How these stars got to be the way they are (single star evolution? binary evolution?) remains an open question. For now, we are designating this class as WN3/O3, in analogy to the late-type WN “slash” stars.
Linking 1D Stellar Evolution to 3D Hydrodynamic Simulations
Authors: Cristini A. , Hirschi R. , Georgy C. , Meakin C. , Arnett D. , Viallet M. 
Published: January 2015

AbstractIn this contribution we present initial results of a study on convective boundary mixing (CBM) in massive stellar models using the GENEVA stellar evolution code (Eggenbergeret al.2008). Before undertaking costly 3D hydrodynamic simulations, it is important to study the general properties of convective boundaries, such as the: composition jump; pressure gradient; and “stiffness”. Models for a 15M⊙star were computed. We found that for convective shells above the core, the lower (in radius or mass) boundaries are “stiffer” according to the bulk Richardson number than the relative upper (Schwarzschild) boundaries. Thus, we expect reduced CBM at the lower boundaries in comparison to the upper. This has implications on flame front propagation and the onset of novae.
Delta-slow solution to explain B supergiant stars' winds
Authors: Haucke M. , Araya I. , Arcos C. , Curé M. , Cidale L. , Kanaan S. , Venero R. , Kraus M. 
Published: January 2015

AbstractA new radiation-driven wind solution called δ-slow was found by Curé et al. (2011) and it predicts a mass-loss rate and terminal velocity slower than the fast solution (m-CAK, Pauldrach et al. 1986). In this work, we present our first synthetic spectra based on the δ-slow solution for the wind of B supergiant (BSG) stars. We use the output of our hydrodynamical code HYDWIND as input in the radiative transport code FASTWIND (Puls et al. 2005). In order to obtain stellar and wind parameters, we try to reproduce the observed Hα, Hβ, Hγ, Hδ, Hei 4471, Hei 6678 and Heii 4686 lines. The synthetic profiles obtained with the new hydrodynamical solutions are in good agreement with the observations and could give us clues about the parameters involved in the radiation force.
Fundamental parameters of B type stars
Authors: Nieva María-Fernanda 
Published: January 2015

AbstractFundamental parameters of 26 well-studied sharp-lined single early B-type stars in OB associations and in the field within a distance of ≤400 pc from the Sun are compared to high-precision data from detached eclipsing binaries (DEBs). Fundamental parameters are derived from accurate and precise atmospheric parameters determined earlier by us from non-LTE analyses of high-quality spectra, utilising the new Geneva stellar evolution models in the mass-range ~6 to 18 M⊙ at metallicity Z = 0.014. Evolutionary masses, radii and luminosities are determined to better than typically 5%, 10%, and 20% uncertainty, respectively, facilitating the mass-radius and mass-luminosity relationships to be recovered for single core hydrogen-burning objects with a similar precision as derived from DEBs. Good agreement between evolutionary and spectroscopic masses is found. Absolute visual and bolometric magnitudes are derived to typically ~0.15-0.20 mag uncertainty. Metallicities are constrained to better than 15-20% uncertainty and tight constraints on evolutionary ages of the stars are provided. The spectroscopic distances and ages of individual sample stars agree with independently derived values for the host OB associations. The accuracy and precision achieved in the determination of fundamental stellar parameters from the quantitative spectroscopy of single early B-type stars comes close (within a factor 2-4) to data derived from DEBs.
Revisiting the Hunter diagram with the Geneva Stellar Evolution Code
Authors: Simoniello R. , Meynet G. , Ekström S. , Georgy C. , Granada A. 
Published: January 2015

AbstractWe produced a model grid of rotating main and post-main sequence stars with the Geneva Stellar Evolution Code (GENEC). The initial chemical composition is tailored to compare with observations of early OB type stars in the Large Magellanic Cloud (LMC) and the grid covers stellar masses in the range of 7 ≤ M/M⊙ ≤ 15 and initial velocity between 0 km s−1 ≤ v sin(i) ≤ 300 km s−1. The model grid has been used to determine the changes in the surface Nitrogen abundances during the star evolution and the results have been compared with observations.
Photometric Variability of OB-type stars as a New Window on Massive Stars
Authors: Kourniotis M. , Bonanos A. Z. , Soszyński I. , Poleski R. , Krikelis G. ,   the OGLE team
Published: January 2015

AbstractWe present the first systematic study of 4646 spectroscopically confirmed early-type massive stars in the Small Magellanic Cloud (SMC), using variability as a tool to confine the physics of OB-type massive stars. We report the discovery of ∼100 massive eclipsing systems which are useful for the accurate determination of the fundamental parameters of massive stars and we evaluate the frequency of multiplicity. In addition, we explore the occurrence of the Oe/Be phenomenon and provide a large number of candidate non-radial pulsators, which can be further studied via asteroseismology. The results of this work (Kourniotis et al. 2014) will contribute to a better understanding of the role of metallicity in triggering processes associated to matter ejections and/or disk formation, which in turn affect mass loss and stellar rotation.
Rotation and the Cepheid Mass Discrepancy
Authors: Anderson Richard I. , Ekström Sylvia , Georgy Cyril , Meynet Georges , Mowlavi Nami , Eyer Laurent 
Published: January 2015

AbstractWe recently showed that rotation significantly affects most observable Cepheid quantities, and that rotation, in combination with the evolutionary status of the star, can resolve the long-standing Cepheid mass discrepancy problem. We therefore provide a brief overview of our results regarding the problem of Cepheid masses. We also briefly mention the impact of rotation on the Cepheid period-luminosity(-color) relation, which is crucial for determining extragalactic distances, and thus for calibrating the Hubble constant.
The BinaMIcS project: understanding the origin of magnetic fields in massive stars through close binary systems
Authors: Alecian E. , Neiner C. , Wade G. A. , Mathis S. , Bohlender D. , Cébron D. , Folsom C. , Grunhut J. , Le Bouquin J.-B. , Petit V. , Sana H. , Tkachenko A. , ud-Doula A. ,   the BinaMIcS collaboration
Published: January 2015

AbstractIt is now well established that a fraction of the massive (M> 8M⊙) star population hosts strong, organised magnetic fields, most likely of fossil origin. The details of the generation and evolution of these fields are still poorly understood. The BinaMIcS project takes an important step towards the understanding of the interplay between binarity and magnetism during the stellar formation and evolution, and in particular the genesis of fossil fields, by studying the magnetic properties of close binary systems. The components of such systems are most likely formed together, at the same time and in the same environment, and can therefore help us to disentangle the role of initial conditions on the magnetic properties of the massive stars from other competing effects such as age or rotation. We present here the main scientific objectives of the BinaMIcS project, as well as preliminary results from the first year of observations from the associated ESPaDOnS and Narval spectropolarimetric surveys.
Discovery of Secular Evolution of the Atmospheric Abundances of Ap Stars
Authors: Bailey J. D. , Landstreet J. D. , Bagnulo S. 
Published: January 2015

AbstractThe stars of the middle main-sequence have relatively quiescent outer layers, and unusual chemical abundance patterns may develop in their atmospheres, revealing the action of such subsurface phenomena as gravitational settling and radiatively driven levitation of trace elements, and their competition with mixing processes such as turbulent diffusion. We report the discovery of the time evolution of such chemical tracers through the main-sequence lifetime of magnetic chemically peculiar stars.
A Simple Mean-Field Diagnostic from Stokes V Spectra
Authors: Gayley K. G. , Owocki S. P. 
Published: January 2015

AbstractIt is shown that the diagnostics from an observed circularly polarized line in a rapidly rotating star are directly interpretable, not in terms of the observed Stokes V profiles, but in terms of its antiderivative with respect to wavelength (in velocity units if preferred). This also leads to a new mean-field diagnostic that is just as easily obtained as the standard “center of gravity” approach, and is less susceptible to cancellation if the line-of-sight field changes sign over the face of the star.
Multiple, short-lived “stellar prominences” on O stars: the supergiant λ Cephei
Authors: Henrichs H. F. , Sudnik N. 
Published: January 2015

AbstractMany OB stars show unexplained cyclical variability in their winds and in many optical lines, which are formed at the base of the wind. For these stars no dipolar magnetic fields have been detected. We propose that these cyclical variations are caused by the presence of multiple, transient, short-lived, corotating magnetic loops, which we call “stellar prominences”. We present a simplified model representing these prominences as corotating spherical blobs and fit the rapid variability in the Heiiλ4686 line of the O supergiant λ Cep for time-resolved spectra obtained in 1989. Our conclusions are: (1) From model fits we find that the life time of the prominences varies, and is between 2–7 h. (2) The adopted inclination angle is 68° with a rotation period of ≈ 4.1 d (but not well constrained). (3) The contribution of non-radial pulsations is negligible (4) Similar behavior is observed in at least 4 other O stars. We propose that prominences are a common phenomenon among O stars.
Observing programs, what are the priorities?
Authors: Meynet Georges , Henrichs Huib 
Published: January 2015

AbstractThis brief note reflects the exchanges that were made between the participants during the general discussion on the observing programs. Because of time constraints only two questions have been addressed: 1) What is the priority between large programs and detailed observations of one or only a few objects? 2) Large surveys implies some automatic pipelines: what is their reliability? Elements of answers are given below. One interesting unexpected outcome of this discussion was the realization that a recent and up-to-date textbook on spectral synthesis is missing, while it would be an extremely useful tool for the community.
EBV-driven B-cell lymphoproliferative disorders: from biology, classification and differential diagnosis to clinical management
Authors: Ok Chi Young , Li Ling , Young Ken H 
Published: January 2015

AbstractEpstein–Barr virus (EBV) is a ubiquitous herpesvirus, affecting >90% of the adult population. EBV targets B-lymphocytes and achieves latent infection in a circular episomal form. Different latency patterns are recognized based on latent gene expression pattern. Latent membrane protein-1 (LMP-1) mimics CD40 and, when self-aggregated, provides a proliferation signal via activating the nuclear factor-kappa B, Janus kinase/signal transducer and activator of transcription, phosphoinositide 3-kinase/Akt (PI3K/Akt) and mitogen-activated protein kinase pathways to promote cellular proliferation. LMP-1 also induces BCL-2 to escape from apoptosis and gives a signal for cell cycle progression by enhancing cyclin-dependent kinase 2 and phosphorylation of retinoblastoma (Rb) protein and by inhibiting p16 and p27. LMP-2A blocks the surface immunoglobulin-mediated lytic cycle reactivation. It also activates the Ras/PI3K/Akt pathway and induces Bcl-xL expression to promote B-cell survival. Recent studies have shown that ebv-microRNAs can provide extra signals for cellular proliferation, cell cycle progression and anti-apoptosis. EBV is well known for association with various types of B-lymphocyte, T-lymphocyte, epithelial cell and mesenchymal cell neoplasms. B-cell lymphoproliferative disorders encompass a broad spectrum of diseases, from benign to malignant. Here we review our current understanding of EBV-induced lymphomagenesis and focus on biology, diagnosis and management of EBV-associated B-cell lymphoproliferative disorders.
Methanogenic food web in the gut contents of methane-emitting earthwormEudrilus eugeniaefrom Brazil
Authors: Schulz Kristin , Hunger Sindy , Brown George G , Tsai Siu M , Cerri Carlos C , Conrad Ralf , Drake Harold L 
Published: January 2015

AbstractThe anoxic saccharide-rich conditions of the earthworm gut provide an ideal transient habitat for ingested microbes capable of anaerobiosis. It was recently discovered that the earthworm Eudrilus eugeniae from Brazil can emit methane (CH4) and that ingested methanogens might be associated with this emission. The objective of this study was to resolve trophic interactions of bacteria and methanogens in the methanogenic food web in the gut contents of E. eugeniae. RNA-based stable isotope probing of bacterial 16S rRNA as well as mcrA and mrtA (the alpha subunit of methyl-CoM reductase and its isoenzyme, respectively) of methanogens was performed with [13C]-glucose as a model saccharide in the gut contents. Concomitant fermentations were augmented by the rapid consumption of glucose, yielding numerous products, including molecular hydrogen (H2), carbon dioxide (CO2), formate, acetate, ethanol, lactate, succinate and propionate. Aeromonadaceae-affiliated facultative aerobes, and obligate anaerobes affiliated to Lachnospiraceae, Veillonellaceae and Ruminococcaceae were associated with the diverse fermentations. Methanogenesis was ongoing during incubations, and 13C-labeling of CH4 verified that supplemental [13C]-glucose derived carbon was dissimilated to CH4. Hydrogenotrophic methanogens affiliated with Methanobacteriaceae and Methanoregulaceae were linked to methanogenesis, and acetogens related to Peptostreptoccocaceae were likewise found to be participants in the methanogenic food web. H2 rather than acetate stimulated methanogenesis in the methanogenic gut content enrichments, and acetogens appeared to dissimilate supplemental H2 to acetate in methanogenic enrichments. These findings provide insight on the processes and associated taxa potentially linked to methanogenesis and the turnover of organic carbon in the alimentary canal of methane-emitting E. eugeniae.
Quorum sensing-regulated chitin metabolism provides grazing resistance to Vibrio cholerae biofilms
Authors: Sun Shuyang , Tay Qi Xiang Martin , Kjelleberg Staffan , Rice Scott A , McDougald Diane 
Published: January 2015

Abstract
Association of Vibrio cholerae with chitinous surfaces of zooplankton is important for its persistence in marine environments, as it provides accessibility to nutrients and resistance to stresses. Predation by heterotrophic protists has a major impact on the survival of V. cholerae. V. cholerae forms biofilms as its main defensive strategy, and quorum sensing (QS) additionally regulates the production of antiprotozoal factors. The role of chitin and QS regulation in V. cholerae grazing resistance was investigated by exposing V. cholerae wild-type (WT) and QS mutant biofilms grown on chitin flakes to the bacteriotrophic, surface-feeding flagellate Rhynchomonas nasuta. V. cholerae formed more biofilm biomass on chitin flakes compared with nonchitinous surfaces. The growth of R. nasuta was inhibited by WT biofilms grown on chitin flakes, whereas the inhibition was attenuated in QS mutant biofilms. The chitin-dependent toxicity was also observed when the V. cholerae biofilms were developed under continuous flow or grown on a natural chitin source, the exoskeleton of Artemia. In addition, the antiprotozoal activity and ammonium concentration of V. cholerae biofilm supernatants were quantified. The ammonium levels (3.5 mm) detected in the supernatants of V. cholerae WT biofilms grown on chitin flakes were estimated to reduce the number of R. nasuta by &gt;80% in add-back experiments, and the supernatant of QS mutant biofilms was less toxic owing to a decrease in ammonium production. Transcriptomic analysis revealed that the majority of genes involved in chitin metabolism and chemotaxis were significantly downregulated in QS mutant biofilms when grown on chitin compared with the WT biofilms.
DNA sequencing using polymerase substrate-binding kinetics
Authors: Previte Michael John Robert , Zhou Chunhong , Kellinger Matthew , Pantoja Rigo , Chen Cheng-Yao , Shi Jin , Wang BeiBei , Kia Amirali , Etchin Sergey , Vieceli John , Nikoomanzar Ali , Bomati Erin , Gloeckner Christian , Ronaghi Mostafa , He Molly Min 
Published: January 2015

AbstractNext-generation sequencing (NGS) has transformed genomic research by decreasing the cost of sequencing. However, whole-genome sequencing is still costly and complex for diagnostics purposes. In the clinical space, targeted sequencing has the advantage of allowing researchers to focus on specific genes of interest. Routine clinical use of targeted NGS mandates inexpensive instruments, fast turnaround time and an integrated and robust workflow. Here we demonstrate a version of the Sequencing by Synthesis (SBS) chemistry that potentially can become a preferred targeted sequencing method in the clinical space. This sequencing chemistry uses natural nucleotides and is based on real-time recording of the differential polymerase/DNA-binding kinetics in the presence of correct or mismatch nucleotides. This ensemble SBS chemistry has been implemented on an existing Illumina sequencing platform with integrated cluster amplification. We discuss the advantages of this sequencing chemistry for targeted sequencing as well as its limitations for other applications.