4,433 research outputs found

    Dark Matter Halo Properties vs. Local Density and Cosmic Web Location

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    We study the effects of the local environmental density and the cosmic web environment (filaments, walls, and voids) on key properties of dark matter halos using the Bolshoi-Planck LCDM cosmological simulation. The z = 0 simulation is analysed into filaments, walls, and voids using the SpineWeb method and also the VIDE package of tools, both of which use the watershed transform. The key halo properties that we study are the specific mass accretion rate, spin parameter, concentration, prolateness, scale factor of the last major merger, and scale factor when the halo had half of its z = 0 mass. For all these properties, we find that there is no discernible difference between the halo properties in filaments, walls, or voids when compared at the same environmental density. As a result, we conclude that environmental density is the core attribute that affects these properties. This conclusion is in line with recent findings that properties of galaxies in redshift surveys are independent of their cosmic web environment at the same environmental density at z ~ 0. We also find that the local web environment of the Milky Way and the Andromeda galaxies near the centre of a cosmic wall does not appear to have any effect on the properties of these galaxies' dark matter halos except for their orientation, although we find that it is rather rare to have such massive halos near the centre of a relatively small cosmic wall.Comment: 23 page

    Risk of Cancer among Commercially Insured HIV-Infected Adults on Antiretroviral Therapy.

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    The objective of this study was to explore the cancer incidence rates among HIV-infected persons with commercial insurance who were on antiretroviral therapy and compare them with those rates in the general population. Paid health insurance claims for 63,221 individuals 18 years or older, with at least one claim with a diagnostic code for HIV and at least one filled prescription for an antiretroviral medication between January 1, 2006, and September 30, 2012, were obtained from the LifeLink® Health Plan Claims Database. The expected number of cancer cases in the general population for each gender-age group (<30, 30-39, 40-49, 50-59, and >60 years) was estimated using incidence rates from the Surveillance Epidemiology and End Results (SEER) program. Standardized incidence ratios (SIRs) were estimated using their 95% confidence intervals (CIs). Compared to the general population, incidence rates for HIV-infected adults were elevated (SIR, 95% CI) for Kaposi sarcoma (46.08; 38.74-48.94), non-Hodgkin lymphoma (4.22; 3.63-4.45), Hodgkin lymphoma (9.83; 7.45-10.84), and anal cancer (30.54; 25.62-32.46) and lower for colorectal cancer (0.69; 0.52-0.76), lung cancer (0.70; 0.54, 0.77), and prostate cancer (0.54; 0.45-0.58). Commercially insured, treated HIV-infected adults had elevated rates for infection-related cancers, but not for common non-AIDS defining cancers

    The quantum Hall plateau transition at order 1/N

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    The localization behavior of noninteracting two-dimensional electrons in a random potential and strong magnetic field is of fundamental interest for the physics of the quantum Hall effect. In order to understand the emergence of power-law delocalization near the discrete extended-state energies En=ωc(n+1/2)E_n = \hbar \omega_c (n+{1/2}), we study a generalization of the disorder-averaged Liouvillian framework for the lowest Landau level to NN flavors of electron densities (N=1 for the physical case). We find analytically the large-N limit and 1/N corrections for all disorder strengths: at N=N = \infty this gives an estimate of the critical conductivity, and at order 1/N an estimate of the localization exponent ν\nu. The localization properties of the analytically tractable N1N \gg 1 theory seem to be continuously connected to those of the exact quantum Hall plateau transition at N=1N = 1.Comment: 4 pages, 4 figures; improved text, 1 corrected referenc

    Phase transitions with four-spin interactions

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    Using an extended Lee-Yang theorem and GKS correlation inequalities, we prove, for a class of ferromagnetic multi-spin interactions, that they will have a phase transition(and spontaneous magnetization) if, and only if, the external field h=0h=0 (and the temperature is low enough). We also show the absence of phase transitions for some nonferromagnetic interactions. The FKG inequalities are shown to hold for a larger class of multi-spin interactions

    Getting that female glance: Patterns and consequences of male nonverbal behavior in courtship contexts

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    Abstract Females apparently are the choosier sex in courtship contexts, but there still is limited information about female selection criteria in real courtship settings. Given that a female knows little about a heretofore unacquainted male, upon what dimensions can (and do) females base their initial courtship decisions? Here, we report findings from observational studies that investigated male nonverbal behavior in a bar context. Study 1 documented the body movements of males prior to making contact with a female. It was found that males who successfully made bcontactQ courtship initiation with females exhibited different body language in this precontact phase than did males who did not make contact with females, including significantly more glancing behaviors, space-maximization movements, intrasexual touching, and less closed-body movements. The findings from a second withinsubject study comparing the behavior of men in a bar when women were present or not present supported the initial study's findings and showed that males' emphasis on these behaviors increases in a mate-relevant context. We suggest that certain aspects of male nonverbal behavior in courtship contexts can serve as self-presentation and mate-value signals

    Utilization of a ts-sacB selection system for the generation of a Mycobacterium avium serovar-8 specific glycopeptidolipid allelic exchange mutant

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    BACKGROUND: Mycobacterium avium are ubiquitous environmental organisms and a cause of disseminated infection in patients with end-stage AIDS. The glycopeptidolipids (GPL) of M. avium are proposed to participate in the pathogenesis of this organism, however, establishment of a clear role for GPL in disease production has been limited by the inability to genetically manipulate M. avium. METHODS: To be able to study the role of the GPL in M. avium pathogenesis, a ts-sacB selection system, not previously used in M. avium, was employed as a means to achieve homologous recombination for the rhamnosyltransferase (rtfA) gene of a pathogenic serovar 8 strain of M. avium to prevent addition of serovar-specific sugars to rhamnose of the fatty acyl-peptide backbone of GPL. The genotype of the resultant rtfA mutant was confirmed by polymerase chain reaction and southern hybridization. Disruption in the proximal sugar of the haptenic oligosaccharide resulted in the loss of serovar specific GPL with no change in the pattern of non-serovar specific GPL moieties as shown by thin layer chromatography and gas chromatography/mass spectrometry. Complementation of wild type (wt) rtfA in trans through an integrative plasmid restored serovar-8 specific GPL expression identical to wt serovar 8 parent strain. RESULTS: In this study, we affirm our results that rtfA encodes an enzyme responsible for the transfer of Rha to 6d-Tal and provide evidence of a second allelic exchange mutagenesis system suitable for M. avium. CONCLUSION: We report the second allelic exchange system for M. avium utilizing ts-sacB as double-negative and xylE as positive counter-selection markers, respectively. This system of allelic exchange would be especially useful for M. avium strains that demonstrate significant isoniazid (INH) resistance despite transformation with katG. Through the construction of mutants in GPL or other mycobacterial components, their roles in M. avium pathogenesis, biosynthesis, or drug resistance can be studied in a consistent manner

    Fermions scattering in a three dimensional extreme black hole background

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    The absorption cross section for scattering of fermions off an extreme BTZ black hole is calculated. It is shown that, as in the case of scalar particles, an extreme BTZ black hole exhibits a vanishing absorption cross section, which is consistent with the vanishing entropy of such object. Additionally, we give a general argument to prove that the particle flux near the horizon is zero. Finally we show that the {\it reciprocal space} introduced previously in \cite{gm} gives rise to the same result and, therefore, it could be considered as the space where the scattering process takes place in an AdS spacetime.Comment: 15 pages, RevTex4. Revised version. To be published in Class. Quantum. Gra
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