6,971 research outputs found

    Structural Insights into Differences in Drug-binding Selectivity between Two Forms of Human α1-Acid Glycoprotein Genetic Variants, the A and F1*S Forms

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    Human α1-acid glycoprotein (hAGP) in serum functions as a carrier of basic drugs. In most individuals, hAGP exists as a mixture of two genetic variants, the F1*S and A variants, which bind drugs with different selectivities. We prepared a mutant of the A variant, C149R, and showed that its drug-binding properties were indistinguishable from those of the wild type. In this study, we determined the crystal structures of this mutant hAGP alone and complexed with disopyramide (DSP), amitriptyline (AMT), and the nonspecific drug chlorpromazine (CPZ). The crystal structures revealed that the drug-binding pocket on the A variant is located within an eight-stranded ÎČ-barrel, similar to that found in the F1*S variant and other lipocalin family proteins. However, the binding region of the A variant is narrower than that of the F1*S variant. In the crystal structures of complexes with DSP and AMT, the two aromatic rings of each drug interact with Phe-49 and Phe-112 at the bottom of the binding pocket. Although the structure of CPZ is similar to those of DSP and AMT, its fused aromatic ring system, which is extended in length by the addition of a chlorine atom, appears to dictate an alternative mode of binding, which explains its nonselective binding to the F1*S and A variant hAGPs. Modeling experiments based on the co-crystal structures suggest that, in complexes of DSP, AMT, or CPZ with the F1*S variant, Phe-114 sterically hinders interactions with DSP and AMT, but not CPZ. © 2011 by The American Society for Biochemistry and Molecular Biology, Inc

    Analysis of the Shuttle Orbiter reinforced carbon-carbon oxidation protection system

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    Reusable, oxidation-protected reinforced carbon-carbon (RCC) has been successfully flown on all Shuttle Orbiter flights. Thermal testing of the silicon carbide-coated RCC to determine its oxidation characteristics has been performed in convective (plasma Arc-Jet) heating facilities. Surface sealant mass loss was characterized as a function of temperature and pressure. High-temperature testing was performed to develop coating recession correlations for predicting performance at the over-temperature flight conditions associated with abort trajectories. Methods for using these test data to establish multi-mission re-use (i.e., mission life) and single mission limits are presented

    Analysis of satellite-derived Arctic tropospheric BrO columns in conjunction with aircraft measurements during ARCTAS and ARCPAC

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    We derive tropospheric column BrO during the ARCTAS and ARCPAC field campaigns in spring 2008 using retrievals of total column BrO from the satellite UV nadir sensors OMI and GOME-2 using a radiative transfer model and stratospheric column BrO from a photochemical simulation. We conduct a comprehensive comparison of satellite-derived tropospheric BrO column to aircraft in-situ observations of BrO and related species. The aircraft profiles reveal that tropospheric BrO, when present during April 2008, was distributed over a broad range of altitudes rather than being confined to the planetary boundary layer (PBL). Perturbations to the total column resulting from tropospheric BrO are the same magnitude as perturbations due to longitudinal variations in the stratospheric component, so proper accounting of the stratospheric signal is essential for accurate determination of satellite-derived tropospheric BrO. We find reasonably good agreement between satellite-derived tropospheric BrO and columns found using aircraft in-situ BrO profiles, particularly when satellite radiances were obtained over bright surfaces (albedo \u3e0.7), for solar zenith angl

    V618 Sgr: Galactic eclipsing symbiotic nova detected in repeated outbursts

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    V618 Sgr was previously classified as an R CrB-type variable and later as a possible symbiotic star. Our study aims to analyse the nature of this target, which is currently undergoing significant brightening in properties similar to those of known symbiotic novae. We analyse literature information, photometric observations, and 35 new optical spectra. Our findings strongly suggest that V618 Sgr is an eclipsing symbiotic nova currently in outburst. Additionally, since the star has demonstrated at least two similar brightenings in the past, we propose that V618 Sgr could be the first known galactic symbiotic nova observed in repeated outbursts of this type and may host a relatively massive white dwarf.Comment: 6 pages, 6 figures, 1 table; accepted in MNRA

    Consequences of sexual harassment in sport for female athletes

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    Sexual harassment research was first undertaken in the workplace and educational settings. Research on sexual harassment in sport is scarce but has grown steadily since the mid-1980s. Even so, very little is known about the causes and/or characteristics and/or consequences of sexual harassment in sport settings. This article reports on the findings from interviews with 25 elite female athletes in Norway who indicated in a prior survey (N =572) that they had experienced sexual harassment from someone in sport. The consequences of the incidents of sexual harassment that were reported were mostly negative, but some also reported that their experiences of sexual harassment had had no consequences for them. “Thinking about the incidents”, a “destroyed relationship to the coach”, and “more negative view of men in general” were the most often negative consequences mentioned. In addition, a surprising number had chosen to move to a different sport or to drop out of elite sport altogether because of the harassment

    Molecular and morphometric variation in European populations of the articulate brachiopod <i>Terebeatulina retusa</i>

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    Molecular and morphometric variation within and between population samples of the articulate brachiopod &lt;i&gt;Terebratulina&lt;/i&gt; spp., collected in 1985-1987 from a Norwegian fjord, sea lochs and costal sites in western Scotland, the southern English Channel (Brittany) and the western Mediterranean, were measured by the analysis of variation in the lengths of mitochondrial DNA (mtDNA) fragments produced by digestion with nine restriction endonucleases and by multivariate statistical analysis of six selected morphometric parameters. Nucleotide difference within each population sample was high. Nucleotide difference between population samples from the Scottish sites, both those that are tidally contiguous and those that appear to be geographically isolated, were not significantly different from zero. Nucleotide differences between the populations samples from Norway, Brittany, Scotland and the western Mediterranean were also very low. Morphometric analysis confirmed the absence of substantial differentiation

    What Makes Some People Think Astrology Is Scientific?

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    Citizens in both North America and Europe are apt to read horoscope columns in newspapers and magazines. While some people read these casually and purely for entertainment, some believe that astrology has scientific status and can provide real insight into events and personality. Using data from a European survey, this article explores some of the reasons why some people think that astrology is scientific and how astrology is viewed in relation to other knowledge-producing practices. Three hypotheses in particular are tested. The first is that some Europeans lack the necessary scientific literacy to distinguish science from pseudoscience. The second is that people are confused about what astrology actually is. The third is derived from Adorno’s work on authoritarianism and the occult and postulates that those who adhere to authoritarian values are more likely to believe in astrological claims. Support is found for all three hypotheses. </jats:p
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