13,048 research outputs found

    Flavor-symmetry Breaking with Charged Probes

    Full text link
    We discuss the recombination of brane/anti-brane pairs carrying D3D3 brane charge in AdS5×S5AdS_5 \times S^5. These configurations are dual to co-dimension one defects in the N=4{\cal N}=4 super-Yang-Mills description. Due to their D3D3 charge, these defects are actually domain walls in the dual gauge theory, interpolating between vacua of different gauge symmetry. A pair of unjoined defects each carry localized (2+1)(2+1) dimensional fermions and possess a global U(N)×U(N)U(N)\times U(N) flavor symmetry while the recombined brane/anti-brane pairs exhibit only a diagonal U(N). We study the thermodynamics of this flavor-symmetry breaking under the influence of external magnetic field.Comment: 21 pages, 10 figure

    Emergence of Arctic-like Rabies Lineage in India

    Get PDF
    Progenitors of Arctic-like rabies viruses, which now circulate extensively in India, may have been responsible for the emergence of the Arctic rabies lineage

    Employment loss and food insecurity - race and sex disparities in the context of COVID-19

    Get PDF
    INTRODUCTION: Applying an intersectional framework, we examined sex and racial inequality in COVID-19-related employment loss (ie, job furlough, layoff, and reduced pay) and food insecurity (ie, quality and quantity of food eaten, food worry, and receipt of free meals or groceries) among residents in Saint Louis County, Missouri. METHODS: We used cross-sectional data from adults aged 18 or older (N = 2,146), surveyed by using landlines or cellular phones between August 12, 2020, and October 27, 2020. We calculated survey-weighted prevalence of employment loss and food insecurity for each group (Black female, Black male, White female, White male). Odds ratios for each group were estimated by using survey-weighted binary and multinomial logistic regression models. RESULTS: Black female residents had higher odds of being laid off, as compared with White male residents (OR = 2.61, 95% CI, 1.24-5.46). Both Black female residents (OR = 4.13, 95% CI, 2.29-7.45) and Black male residents (OR = 2.41, 95% CI, 1.15-5.07) were more likely to receive free groceries, compared with White male residents. Black female (OR = 4.25, 95% CI, 2.28-7.94) and White female residents (OR = 1.93, 95% CI, 1.04-3.60) had higher odds of sometimes worrying about food compared with White male residents. Black women also had higher odds of always or nearly always worrying about food, compared with White men (OR = 2.99, 95% CI, 1.52-5.87). CONCLUSION: Black women faced the highest odds of employment loss and food insecurity, highlighting the disproportionate impact of COVID-19 among people with intersectional disadvantages of being both Black and female. Interventions to reduce employment loss and food insecurity can help reduce the disproportionately negative social effects among Black women

    The First Space-Based Gravitational-Wave Detectors

    Get PDF
    Gravitational waves provide a laboratory for general relativity and a window to energetic astrophysical phenomena invisible with electromagnetic radiation. Several terrestrial detectors are currently under construction, and a space-based interferometer is envisioned for launch early next century to detect test-mass motions induced by waves of relatively short wavelength. Very-long-wavelength gravitational waves can be detected using the plasma in the early Universe as test masses; the motion induced in the plasma by a wave is imprinted onto the cosmic microwave background (CMB). While the signature of gravitational waves on the CMB temperature fluctuations is not unique, the polarization pattern can be used to unambiguously detect gravitational radiation. Thus, forthcoming CMB polarization experiments, such as MAP and Planck, will be the first space-based gravitational-wave detectors.Comment: 5 pages, 3 postscript figure

    Equality of Participation Online Versus Face to Face: Condensed Analysis of the Community Forum Deliberative Methods Demonstration

    Full text link
    Online deliberation may provide a more cost-effective and/or less inhibiting environment for public participation than face to face (F2F). But do online methods bias participation toward certain individuals or groups? We compare F2F versus online participation in an experiment affording within-participants and cross-modal comparisons. For English speakers required to have Internet access as a condition of participation, we find no negative effects of online modes on equality of participation (EoP) related to gender, age, or educational level. Asynchronous online discussion appears to improve EoP for gender relative to F2F. Data suggest a dampening effect of online environments on black participants, as well as amplification for whites. Synchronous online voice communication EoP is on par with F2F across individuals. But individual-level EoP is much lower in the online forum, and greater online forum participation predicts greater F2F participation for individuals. Measured rates of participation are compared to self-reported experiences, and other findings are discussed.Comment: 14 pages, 10 tables, to appear in Efthimios Tambouris, Panos Panagiotopoulos, {\O}ystein S{\ae}b{\o}, Konstantinos Tarabanis, Michela Milano, Theresa Pardo, and Maria Wimmer (Editors), Electronic Participation: Proceedings of the 7th IFIP WG 8.5 International Conference, ePart 2015 (Thessaloniki, August 30-September 2), Springer LNCS Vol. 9249, 201

    Tests of stellar model atmospheres by optical interferometry III: NPOI and VINCI interferometry of the M0 giant gamma Sge covering 0.5 - 2.2 microns

    Get PDF
    Aims: We present a comparison of the visual and NIR intensity profile of the M0 giant gamma Sagittae to plane-parallel ATLAS 9 as well as to plane-parallel & spherical PHOENIX model atmospheres. Methods: We use previously described visual interferometric data obtained with the NPOI in July 2000. We apply the recently developed technique of coherent integration, and thereby obtain visibility data of more spectral channels and with higher precision than before. In addition, we employ new measurements of the K-band diameter of gamma Sagittae obtained with the instrument VINCI at the VLTI in 2002. Results: The spherical PHOENIX model leads to a precise definition of the Rosseland angular diameter and a consistent high-precision diameter value for our NPOI and VLTI/VINCI data sets of Theta_Ross=6.06 pm 0.02 mas, with the Hipparcos parallax corresponding to R_Ross=55 pm 4 R_sun, and with the bolometric flux corresponding to an effective temperature T_eff=3805 pm 55 K. Our visual visibility data close to the first minimum and in the second lobe constrain the limb-darkening effect and are generally consistent with the model atmosphere predictions. The visual closure phases exhibit a smooth transition between 0 and pi. Conclusions: The agreement between the NPOI and VINCI diameter values increases the confidence in the model atmosphere predictions from optical to NIR wavelengths as well as in the calibration and accuracy of both interferometric facilities. The consistent night-by-night diameter values of VINCI give additional confidence in the given uncertainties. The closure phases suggest a slight deviation from circular symmetry, which may be due to surface features, an asymmetric extended layer, or a faint unknown companion.Comment: 12 pages, 9 figures, accepted by A&A. Also available from http://www.aanda.org/articles/aa/pdf/forth/aa5853_06.pd

    Indication, from Pioneer 10/11, Galileo, and Ulysses Data, of an Apparent Anomalous, Weak, Long-Range Acceleration

    Get PDF
    Radio metric data from the Pioneer 10/11, Galileo, and Ulysses spacecraft indicate an apparent anomalous, constant, acceleration acting on the spacecraft with a magnitude ∼8.5×10−8\sim 8.5\times 10^{-8} cm/s2^2, directed towards the Sun. Two independent codes and physical strategies have been used to analyze the data. A number of potential causes have been ruled out. We discuss future kinematic tests and possible origins of the signal.Comment: Revtex, 4 pages and 1 figure. Minor changes for publicatio

    Carbon Abundances of Three Carbon-Enhanced Metal-Poor Stars from High-Resolution Gemini-S/bHROS Spectra of the 8727A [C I] Line

    Full text link
    We present the results from an analysis of the 8727ang forbidden [C I] line in high-resolution Gemini-S/bHROS spectra of three CEMP stars. We find the [C/Fe] ratios based on the [C I] abundances of the two most Fe-rich stars in our sample (HIP 0507-1653: [Fe/H] = -1.42 and HIP 0054-2542: [Fe/H] = -2.66) to be in good agreement with previously determined CH and C_2 line-based values. For the most Fe-deficient star in our sample (HIP 1005-1439: [Fe/H] = -3.08), however, the [C/Fe] ratio is found to be 0.34 dex lower than the published molecular-based value. We have carried out 3D local thermodynamic equilibrium (LTE) calculations for [C I], and the resulting corrections are found to be modest for all three stars, suggesting that the discrepancy between the [C I] and molecular-based C abundances of HIP 1005-1439 is due to more severe 3D effects on the molecular lines. Carbon abundances are also derived from C I high-excitation lines and are found to be 0.45-0.64 dex higher than the [C I]-based abundances. Previously published non-LTE C I abundance corrections bring the [C I] and C I abundances into better agreement; however, targeted NLTE calculations for CEMP stars are clearly needed. We have also derived the abundances of N, K, and Fe for each star. The Fe abundances agree well with previously derived values, and the K abundances are similar to those of C-normal metal-poor stars. Nitrogen abundances have been derived from resolved lines of the CN red system. The abundances are found to be approximately 0.44 dex larger than literature values, which have been derived from CN blue bands near 3880 and 4215 ang. We discuss evidence that suggests that analyses of the CN blue system bands underestimate the N abundances of metal-poor giants.Comment: Accepted for publication in AJ; 42 pages, 6 figures, 7 table

    Oldest known pantherine skull and evolution of the tiger

    Get PDF
    The tiger is one of the most iconic extant animals, and its origin and evolution have been intensely debated. Fossils attributable to extant pantherine species-lineages are less than 2 MYA and the earliest tiger fossils are from the Calabrian, Lower Pleistocene. Molecular studies predict a much younger age for the divergence of modern tiger subspecies at <100 KYA, although their cranial morphology is readily distinguishable, indicating that early Pleistocene tigers would likely have differed markedly anatomically from extant tigers. Such inferences are hampered by the fact that well-known fossil tiger material is middle to late Pleistocene in age. Here we describe a new species of pantherine cat from Longdan, Gansu Province, China, Panthera zdanskyi sp. nov. With an estimated age of 2.55–2.16 MYA it represents the oldest complete skull of a pantherine cat hitherto found. Although smaller, it appears morphologically to be surprisingly similar to modern tigers considering its age. Morphological, morphometric, and cladistic analyses are congruent in confirming its very close affinity to the tiger, and it may be regarded as the most primitive species of the tiger lineage, demonstrating the first unequivocal presence of a modern pantherine species-lineage in the basal stage of the Pleistocene (Gelasian; traditionally considered to be Late Pliocene). This find supports a north-central Chinese origin of the tiger lineage, and demonstrates that various parts of the cranium, mandible, and dentition evolved at different rates. An increase in size and a reduction in the relative size of parts of the dentition appear to have been prominent features of tiger evolution, whereas the distinctive cranial morphology of modern tigers was established very early in their evolutionary history. The evolutionary trend of increasing size in the tiger lineage is likely coupled to the evolution of its primary prey species
    • …
    corecore