3,242 research outputs found

    Near-IR spectroscopy of PKS1549-79: a proto-quasar revealed?

    Full text link
    We present a near-IR spectrum of the nearby radio galaxy PKS1549-79 (z=0153). These data were taken with the aim of testing the idea that this object contains a quasar nucleus that is moderately extinguished, despite evidence that its radio jet points close to our line-of-sight. We detect broad Paschen Alpha emission (FWHM ~1745 km/s), relatively bright continuum emission, and a continuum slope consistent with a reddened quasar spectrum (3.1 < Av < 7.3), all emitted by an unresolved point source. Therefore we conclude that we have, indeed, detected a hidden quasar nucleus in PKS1549-79. Combined with previous results, these observations are consistent with the idea that PKS1549-79 is a young radio source in which the cocoon of debric left over from the triggering events has not yet been swept aside by circumnuclear outflows.Comment: 6 pages, 4 figures, accepted for publication in MNRA

    Cryptic diversity of the jewel beetles Agrilus viridis (Coleoptera: Buprestidae) hosted on hazelnut

    Get PDF
    The genus Agrilus (Coleoptera: Buprestidae) represents a taxonomic puzzle, since the boundaries between species, subspecies and morphotypes tied to different host plants are sometimes difficult to establish on morphological characteristics alone. Some Agrilus species can cause severe agricultural damage; this makes correct distinctions of the taxon and knowing whether the insects switch from one host plant to another important. This study of mtDNA examined the genetic characteristics of lineages of A. viridis, a jewel beetle recently found causing damage to the hazelnut Corylus avellana in NW Italy. Three mitochondrial markers (a portion of the 12S rDNA and a DNA-fragment including partial NADH dehydrogenase subunit I gene, the tRNA Leucine gene and partial 16S rDNA, and partial  Cytochrome c oxidase) were compared between individuals collected on birch Betula sp., beech Fagus sp., willow Salix sp., alder Alnus sp. and hazelnut. We found a high genetic distance between A. viridis sampled on different host plants, while individuals sampled on the same host plant were similar despite a considerable geographic gap between sampled areas. Our study supports the general pattern for strong ecological separation between populations living on different host plants

    Introduction: Meeting in the Middle

    Get PDF
    Compromise is routinely evoked in everyday language and in scholarly debates across the social sciences. Yet, it has been subjected to relatively little systematic study. The introduction to this inter-disciplinary volume addresses the research gap in three steps. First, we offer three reasons for the study of compromise: its empirical omnipresence in politics, its theoretical potential to bridge the rationalist-constructivist divide, and its normative promise to recognize the plurality of society. Second, we introduce different approaches to the coherence, legitimacy and limits of compromise found in the existing explanatory and normative literatures. We discuss why these literatures need to speak to one another, and identify possible applications in empirical research. Third, we conceptualize compromise as one possible solution to a conflict. Distinct from both dissensus and consensus, all compromises share three characteristics: concessions, non-coercion and continued controversy. However, different types of compromise can be distinguished by how mutual, costly and painful concessions are; by whether all forms of coercion are absent; and by the degree to which the relevant parties’ grounds for conflict are transformed. We conclude by discussing the challenge and appeal of ‘politics as compromise’ in plural and complex societies

    Trouble in Paradise - A disabled person's right to the satisfaction of a self-defined need:Some conceptual and practical problems

    Get PDF
    This paper questions the usefulness of the rights-based approach to ameliorating the social situation of disabled people in Britain and advances two criticisms. First, that rights and self-de? ned needs have been under-theorised by disability theorists to the extent that they have insuf? ciently appreciated the problems that these approaches pose. The paper suggests that rights to appropriate resources to satisfy self-de? ned needs will generate vast numbers of competing rights claims and that the resulting tendency of rights to con? ict has been under-appreciated. Secondly, that there has been little consideration of how these con? icts might be reconciled. The ? rst two sections of the paper look at the concepts of ascribed and self-de? ned needs, respectively, whilst the ? nal one looks at some of the problems of the rights approach and some of the dif? culties of making self-de? ned need the basis of rights claims

    Cognitive representations of disability behaviours in people with mobility limitations : consistency with theoretical constructs

    Get PDF
    Disability is conceptualised as behaviour by psychological theory and as a result of bodily impairment by medical models. However, how people with disabilities conceptualise those disabilities is unclear. The purpose of this study was to examine disability representations in people with mobility disabilities. Thirteen people with mobility disabilities completed personal repertory grids (using the method of triads) applied to activities used to measure disabilities. Ten judges with expertise in health psychology then examined the correspondence between the elicited disability constructs and psychological and medical models of disability. Participants with mobility disabilities generated 73 personal constructs ofdisability. These constructs were judged consistent with the content of two psychological models, namely the theory of planned behaviour and social cognitive theory and with the main medical model of disability, the International Classification of Functioning Disability and Health.Individuals with activity limitations conceptualise activities in a manner that is compatible with both psychological and medical models. This ensures adequate communication in contexts where the medical model is relevant, e.g. clinical contexts, as well as in everyday conversation about activities and behaviours. Finally, integrated models of disability may be of value for theory driven interdisciplinary approaches to disability and rehabilitation

    The 5.25 & 5.7 μ\mum Astronomical Polycyclic Aromatic Hydrocarbon Emission Features

    Full text link
    Astronomical mid-IR spectra show two minor PAH features at 5.25 and 5.7 μ\mum (1905 and 1754 cm1^{\rm - 1}) that hitherto have been little studied, but contain information about the astronomical PAH population that complements that of the major emission bands. Here we report a study involving both laboratory and theoretical analysis of the fundamentals of PAH spectroscopy that produce features in this region and use these to analyze the astronomical spectra. The ISO SWS spectra of fifteen objects showing these PAH features were considered for this study, of which four have sufficient S/N between 5 and 6 μ\mum to allow for an in-depth analysis. All four astronomical spectra show similar peak positions and profiles. The 5.25 μ\mum feature is peaked and asymmetric, while the 5.7 μ\mum feature is broader and flatter. Detailed analysis of the laboratory spectra and quantum chemical calculations show that the astronomical 5.25 and 5.7 μ\mum bands are a blend of combination, difference and overtone bands primarily involving CH stretching and CH in-plane and CH out-of-plane bending fundamental vibrations. The experimental and computational spectra show that, of all the hydrogen adjacency classes possible on PAHs, solo and duo hydrogens consistently produce prominent bands at the observed positions whereas quartet hydrogens do not. In all, this a study supports the picture that astronomical PAHs are large with compact, regular structures. From the coupling with primarily strong CH out-of-plane bending modes one might surmise that the 5.25 and 5.7 μ\mum bands track the neutral PAH population. However, theory suggests the role of charge in these astronomical bands might also be important.Comment: Accepted ApJ, 40 pages in pre-print, 14 figures, two onlin

    Assessing the influence of the Responsibility to Protect on the UN Security Council during the Arab Spring

    Get PDF
    This article challenges those perspectives which assert first, that the Security Council’s engagement with the Responsibility to Protect (R2P) during the Arab Spring evidences a generally positive trend, and second, that the response to the Arab Spring, particularly Syria, highlights the need for veto restraint. With respect to the first point, the evidence presented in this article suggests that the manner in which R2P has been employed by the Security Council during this period evidences three key trends: first, a willingness to invoke R2P only in the context of Pillar I; second, a pronounced lack of consensus surrounding Pillar III; and third, the persistent prioritisation of national interests over humanitarian concerns. With respect to veto restraint, this article argues that there is no evidence that this idea will have any significant impact on decision-making at the Security Council; the Council’s response to the Arab Spring suggests that national interests continue to trump humanitarian need

    First-Trimester Circulating 25-Hydroxyvitamin D Levels and Development of Gestational Diabetes Mellitus

    Get PDF
    OBJECTIVE-To investigate the association between first-trimester maternal serum levels of 25-hydroxyvitamin D (25-OH-D) as measured by liquid chromatography-tandem mass spectrometry and development of gestational diabetes mellitus (GDM). RESEARCH DESIGN AND METHODS-We conducted a case-control study involving 248 women in the first-trimester of pregnancy, 90 of whom developed GDM and 158 remained normoglycemic. RESULTS-Although booking 25-OH-D levels correlated negatively with 2-h glucose postoral glucose tolerance test and positively with HDL cholesterol, as well as with ethnicity, obesity, and smoking (all P &lt; 0.05), there were no statistically significant differences in baseline maternal mean 25-OH-D levels between those who subsequently developed GDM, 18.9 ng/mL (SD 10.7) and those who remained normoglycemic, 19.0 ng/mL (10.7) (P = 0.874), even after adjustment for possible confounders including sampling month (P = 0.784). CONCLUSIONS-Our large and well-phenotyped prospective study did not find evidence of an association between first-trimester maternal levels of 25-OH-D and subsequent development of GDM

    Label-free electrochemical monitoring of DNA ligase activity

    Get PDF
    This study presents a simple, label-free electrochemical technique for the monitoring of DNA ligase activity. DNA ligases are enzymes that catalyze joining of breaks in the backbone of DNA and are of significant scientific interest due to their essential nature in DNA metabolism and their importance to a range of molecular biological methodologies. The electrochemical behavior of DNA at mercury and some amalgam electrodes is strongly influenced by its backbone structure, allowing a perfect discrimination between DNA molecules containing or lacking free ends. This variation in electrochemical behavior has been utilized previously for a sensitive detection of DNA damage involving the sugar-phosphate backbone breakage. Here we show that the same principle can be utilized for monitoring of a reverse process, i.e., the repair of strand breaks by action of the DNA ligases. We demonstrate applications of the electrochemical technique for a distinction between ligatable and unligatable breaks in plasmid DNA using T4 DNA ligase, as well as for studies of the DNA backbone-joining activity in recombinant fragments of E. coli DNA ligase
    corecore