274 research outputs found

    Old age and fear of crime: cross-national evidence for a decreased impact of neighbourhood disadvantage in older age

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    Fear of crime among older people has been a frequent topic in ageing research, criminology and urban studies. The ‘environmental docility hypothesis’ assumes that older people are more vulnerable to adverse neighbourhood conditions than younger age groups. Yet, few studies have tested this influential hypothesis using samples of respondents covering the complete adult lifespan. Looking at fear of crime, we investigated the person–environment interaction of age and neighbourhood disadvantage, using two independent surveys comprising 12,620 respondents aged 25–90 years residing in 435 neighbourhoods in four cities in Germany and Australia. We used multi-level analysis and cross-level interactions to model age-differential effects of neighbourhood disadvantage on fear. Contrary to the hypothesis, we found a weakening of neighbourhood effects on fear with age. The strong effect of neighbourhood disadvantage on fear of crime dropped by around half from the youngest (25 years) to the oldest age (90 years) in both countries. Younger people were almost as fearful as older people in the most disadvantaged neighbourhoods, but older people were considerably more fearful than younger ages in better-off neighbourhoods. We found limited empirical support for the assumption that this diminished association between neighbourhood disadvantage and fear can be explained by the stronger neighbourhood attachment of older people. The limitations of the analysis and potential future directions of research are discussed

    Overly honest data repository development

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    After a year of development, the library at the University of Illinois at Urbana-Champaign has launched a repository, called the Illinois Data Bank (https://databank.illinois.edu/), to provide Illinois researchers with a free, self-serve publishing platform that centralizes, preserves, and provides persistent and reliable access to Illinois research data. This article presents a holistic view of development by discussing our overarching technical, policy, and interface strategies. By openly presenting our design decisions, the rationales behind those decisions, and associated challenges this paper aims to contribute to the library community’s work to develop repository services that meet growing data preservation and sharing needs.Ope

    A Determination of the Centre-of-Mass Energy at LEP2 using Radiative 2-fermion Events

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    Using e+e- -> mu+mu-(gamma) and e+e- -> qqbar(gamma) events radiative to the Z pole, DELPHI has determined the centre-of-mass energy, sqrt{s}, using energy and momentum constraint methods. The results are expressed as deviations from the nominal LEP centre-of-mass energy, measured using other techniques. The results are found to be compatible with the LEP Energy Working Group estimates for a combination of the 1997 to 2000 data sets.Comment: 20 pages, 6 figures, Accepted by Eur. Phys. J.

    Discovery of a Modified Tetrapolar Sexual Cycle in Cryptococcus amylolentus and the Evolution of MAT in the Cryptococcus Species Complex

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    Sexual reproduction in fungi is governed by a specialized genomic region called the mating-type locus (MAT). The human fungal pathogenic and basidiomycetous yeast Cryptococcus neoformans has evolved a bipolar mating system (a, α) in which the MAT locus is unusually large (>100 kb) and encodes >20 genes including homeodomain (HD) and pheromone/receptor (P/R) genes. To understand how this unique bipolar mating system evolved, we investigated MAT in the closely related species Tsuchiyaea wingfieldii and Cryptococcus amylolentus and discovered two physically unlinked loci encoding the HD and P/R genes. Interestingly, the HD (B) locus sex-specific region is restricted (∼2 kb) and encodes two linked and divergently oriented homeodomain genes in contrast to the solo HD genes (SXI1α, SXI2a) of C. neoformans and Cryptococcus gattii. The P/R (A) locus contains the pheromone and pheromone receptor genes but has expanded considerably compared to other outgroup species (Cryptococcus heveanensis) and is linked to many of the genes also found in the MAT locus of the pathogenic Cryptococcus species. Our discovery of a heterothallic sexual cycle for C. amylolentus allowed us to establish the biological roles of the sex-determining regions. Matings between two strains of opposite mating-types (A1B1×A2B2) produced dikaryotic hyphae with fused clamp connections, basidia, and basidiospores. Genotyping progeny using markers linked and unlinked to MAT revealed that meiosis and uniparental mitochondrial inheritance occur during the sexual cycle of C. amylolentus. The sexual cycle is tetrapolar and produces fertile progeny of four mating-types (A1B1, A1B2, A2B1, and A2B2), but a high proportion of progeny are infertile, and fertility is biased towards one parental mating-type (A1B1). Our studies reveal insights into the plasticity and transitions in both mechanisms of sex determination (bipolar versus tetrapolar) and sexual reproduction (outcrossing versus inbreeding) with implications for similar evolutionary transitions and processes in fungi, plants, and animals

    Measurement of flavor asymmetry of light-quark sea in the proton with Drell-Yan dimuon production in p+pp+p and p+dp+d collisions at 120 GeV

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    Evidence for a flavor asymmetry between the uˉ\bar u and dˉ\bar d quark distributions in the proton has been found in deep-inelastic scattering and Drell-Yan experiments. The pronounced dependence of this flavor asymmetry on xx (fraction of nucleon momentum carried by partons) observed in the Fermilab E866 Drell-Yan experiment suggested a drop of the dˉ(x)/uˉ(x)\bar d\left(x\right) / \bar u\left(x\right) ratio in the x>0.15x > 0.15 region. We report results from the SeaQuest Fermilab E906 experiment with improved statistical precision for dˉ(x)/uˉ(x)\bar d\left(x\right) / \bar u\left(x\right) in the large xx region up to x=0.45x=0.45 using the 120 GeV proton beam. Two different methods for extracting the Drell-Yan cross section ratios, σpd/2σpp\sigma^{pd} /2 \sigma^{pp}, from the SeaQuest data give consistent results. The dˉ(x)/uˉ(x)\bar{d}\left(x\right) / \bar{u}\left(x\right) ratios and the dˉ(x)−uˉ(x)\bar d\left(x\right) - \bar u\left(x\right) differences are deduced from these cross section ratios for 0.13<x<0.450.13 < x < 0.45. The SeaQuest and E866/NuSea dˉ(x)/uˉ(x)\bar{d}\left(x\right) / \bar{u}\left(x\right) ratios are in good agreement for the x≲0.25x\lesssim 0.25 region. The new SeaQuest data, however, show that dˉ(x)\bar d\left(x\right) continues to be greater than uˉ(x)\bar u\left(x\right) up to the highest xx value (x=0.45x = 0.45). The new results on dˉ(x)/uˉ(x)\bar{d}\left(x\right) / \bar{u}\left(x\right) and dˉ(x)−uˉ(x)\bar{d}\left(x\right) - \bar{u}\left(x\right) are compared with various parton distribution functions and theoretical calculations

    The Mating Type Locus (MAT) and Sexual Reproduction of Cryptococcus heveanensis: Insights into the Evolution of Sex and Sex-Determining Chromosomal Regions in Fungi

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    Mating in basidiomycetous fungi is often controlled by two unlinked, multiallelic loci encoding homeodomain transcription factors or pheromones/pheromone receptors. In contrast to this tetrapolar organization, Cryptococcus neoformans/Cryptococcus gattii have a bipolar mating system, and a single biallelic locus governs sexual reproduction. The C. neoformans MAT locus is unusually large (>100 kb), contains >20 genes, and enhances virulence. Previous comparative genomic studies provided insights into how this unusual MAT locus might have evolved involving gene acquisitions into two unlinked loci and fusion into one contiguous locus, converting an ancestral tetrapolar system to a bipolar one. Here we tested this model by studying Cryptococcus heveanensis, a sister species to the pathogenic Cryptococcus species complex. An extant sexual cycle was discovered; co-incubating fertile isolates results in the teleomorph (Kwoniella heveanensis) with dikaryotic hyphae, clamp connections, septate basidia, and basidiospores. To characterize the C. heveanensis MAT locus, a fosmid library was screened with C. neoformans/C. gattii MAT genes. Positive fosmids were sequenced and assembled to generate two large probably unlinked MAT gene clusters: one corresponding to the homeodomain locus and the other to the pheromone/receptor locus. Strikingly, two divergent homeodomain genes (SXI1, SXI2) are present, similar to the bE/bW Ustilago maydis paradigm, suggesting one or the other homeodomain gene was recently lost in C. neoformans/C. gattii. Sequencing MAT genes from other C. heveanensis isolates revealed a multiallelic homeodomain locus and at least a biallelic pheromone/receptor locus, similar to known tetrapolar species. Taken together, these studies reveal an extant C. heveanensis sexual cycle, define the structure of its MAT locus consistent with tetrapolar mating, and support the proposed evolutionary model for the bipolar Cryptococcus MAT locus revealing transitions in sexuality concomitant with emergence of a pathogenic clade. These studies provide insight into convergent processes that independently punctuated evolution of sex-determining loci and sex chromosomes in fungi, plants, and animals
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