168 research outputs found

    K Giants in Baade's Window. II. The Abundance Distribution

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    This is the second in a series of papers in which we analyze spectra of over 400 K and M giants in Baade's Window, including most of the stars with proper motions measured by Spaenhauer et al. [AJ, 103, 297 (1992)]. In our first paper, we measured line--strength indices of Fe, Mg, CN and Hβ\beta and calibrated them on the system of Faber et al. [ApJS, 57, 711 (1985)]. Here, we use the ⟨Fe⟩\langle{\rm Fe}\rangle index to derive an abundance distribution in [Fe/H] for 322 stars with effective temperatures between 3900 K and 5160 K. Our derived values of [Fe/H] agree well with those measured from high--resolution echelle spectra (e.g., McWilliam \& Rich [ApJS, 91, 749 (1994)]) for the small number of stars in common. We find a mean abundance ⟨[Fe/H]⟩=−0.11±0.04\langle{\rm [Fe/H]}\rangle = -0.11 \pm 0.04 for our sample of Baade's Window K giants. More than half the sample lie in the range −0.4<-0.4 < \feh\ <+0.3<+0.3. We estimate line--of--sight distances for individual stars in our sample and confirm that, in Baade's Window, most K giants with V<15.5V < 15.5 are foreground disk stars, but the great majority (more than 80\%) with V>16V > 16 belong to the bulge. We also compare the metallicities derived from the CN and Mg2_2 indices to those from iron. Most of the metal--rich stars in our sample appear to be CN--weak, in contrast to the situation in metal--rich globular clusters and elliptical galaxies. The metal--poor half of our sample ([Fe/H] <0< 0) shows evidence for a mild Mg overenhancement ([Mg/Fe] ∼+0.2\sim +0.2); but this is not seen in the more metal--rich stars ([Fe/H] ≥\geq 0). The K giants in Baade's Window therefore share some, but not all, of the characteristics of stars in elliptical galaxies as inferred from their integrated light.Comment: Accepted for publication in the Astronomical Journal, tentatively scheduled for July, 1996. LaTex source which generates 40 pages of text (no figures or tables). Complete (text + 15 figs + 5 tables) preprint in gzip/tar format is also available at ftp://bessel.mps.ohio-state.edu/pub/terndrup/kg2.tar.gz (227 kbyte

    Nonsteroidal Anti-Inflammatory Agents in the Therapy for Experimental Pneumococcal Meningitis

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    An increased inflammatory mass in the subarachnoid space during bacterial meningitis may correlate with a poor outcome of disease. Using a rabbit model of pneumococcal meningitis, we sought to reduce this inflammatory process. The ability of the pneumococcal cell wall to cause death and to generate leukocytosis and abnormal chemistry in cerebrospinal fluid was prevented when animals were treated with inhibitors of the cyclooxygenase pathway of arachidonate metabolism. Bacterial lysis by ampicillin led to release of cell wall that caused a significant, transient increase in meningeal inflammation. This inflammatory burst was also prevented by administering cyclooxygenase inhib-itors concurrently with the antibioti

    JTEC panel report on machine translation in Japan

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    The goal of this report is to provide an overview of the state of the art of machine translation (MT) in Japan and to provide a comparison between Japanese and Western technology in this area. The term 'machine translation' as used here, includes both the science and technology required for automating the translation of text from one human language to another. Machine translation is viewed in Japan as an important strategic technology that is expected to play a key role in Japan's increasing participation in the world economy. MT is seen in Japan as important both for assimilating information into Japanese as well as for disseminating Japanese information throughout the world. Most of the MT systems now available in Japan are transfer-based systems. The majority of them exploit a case-frame representation of the source text as the basis of the transfer process. There is a gradual movement toward the use of deeper semantic representations, and some groups are beginning to look at interlingua-based systems

    Semantic Lexicon Acquisition for Learning Natural Language Interfaces

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    viii List of Tables xii List of Figures xiii Chapter 1 Introduction 1 Chapter 2 Background 6 2.1 Chill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.2 The Work of Jeff Siskind . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Chapter 3 Lexicon Learning and Wolfie 11 3.1 Problem Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.2 Potential Approaches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.3 The Wolfie Algorithm and an Example . . . . . . . . . . . . . . . . . . . . . . . . . 18 3.4 Generating Candidate Lexicon Items . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 3.5 Finding the Best Pair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3.6 Constraining Remaining Candidates . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Chapter 4 Wolfie Experimental Results: Learning for Database-Query Parsing 30 4..

    The Proper Motion of NGC 6522 in Baade's Window

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    We have detected seven stars with a common proper motion which are located within 2.5 arcminutes of the globular cluster NGC 6522 in the Baade's Window field of the Galactic bulge. We argue that these stars are members of the cluster, and derive a weighted mean proper motion and heliocentric radial velocity of mu_l = 1.4 +/- 0.2 mas/yr, mu_b = -6.2 +/- 0.2 mas/yr, v = -28.5 +/- 6.5 km/s. We rederive the distance to NGC 6522 (0.91 +/- 0.04 R_0, where R_0 is the Galactocentric distance) and metallicity ([Fe/H] = -1.28 +/- 0.12), making use of recent revisions in the foreground extinction toward the cluster (A_V = 1.42 +/- 0.05). We find the spatial velocity of the cluster and conclude that the cluster stays close to the Galactic center, and may have experienced significant bulge/disk shocking during its lifetime.Comment: submitted to AJ, 21 pages, 5 figure

    Exploring the beliefs, experiences and impacts of HIV-related self-stigma amongst adolescents and young adults living with HIV in Harare, Zimbabwe: A qualitative study

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    Background: HIV-related self-stigma is a significant barrier to HIV management. However, very little research has explored this phenomenon, particularly in sub-Saharan Africa. This study explored the beliefs, experiences, and impacts of HIV self-stigma amongst adolescents and young adults (AYALHIV) in Harare, Zimbabwe to inform future interventions. It aimed to capture the lived experience of self-stigmatization among AYALHIV and its impact on their social context using Corrigan et al (2009) self-stigma framework of 'awareness', 'agreement', and 'application'. Methods: Virtual semi-structured key informant interviews were conducted between June and July 2020 with adolescents and young adults (Female = 8; Male = 8) living with HIV (18-24 years) in Harare, Zimbabwe. We conducted the interviews with a purposive sample of AYALHIV enrolled in Africaid's 'Zvandiri' program which provides HIV support services. Interviews were mainly conducted in English and with three in Shona, the main indigenous language. Audio-recorded qualitative data were transcribed, translated into English (where necessary) and deductively coded using Corrigan et al.'s self-stigma framework. The outbreak of SARS-CoV-2 coincided with the commencement of data collection activities, which impacted on both the sample size and a shift from in-person to virtual interviewing methods. Results: Sixteen respondents (50% male) took part in the interviews. The mean age of respondents was 22 years. All respondents reported HIV-related self-stigma either occasionally or frequently. Three main themes of self-stigmatizing experiences emerged: disclosure, relationships, and isolation. These themes were then analyzed within the self-stigma development framework by Corrigan et al. (2009) known as 'the three As': awareness, agreement, and application of self-stigmatizing thoughts. Respondents' experiences of self-stigma reportedly led to poor well-being and decreased mental and physical health. Gendered experiences and coping mechanisms of self-stigma were reported. Data suggested that context is key in the way that HIV is understood and how it then impacts the way people living with HIV (PLHIV) live with, and experience, HIV. Conclusions: HIV-related negative self-perceptions were described by all respondents in this study, associated with self-stigmatizing beliefs that adversely affected respondents' quality of life. Study findings supported Corrigan et al.'s framework on how to identify self-stigma and was a useful lens through which to understand HIV-related self-stigma among young people in Harare. Study findings highlight the need for interventions targeting PLHIV and AYALHIV to be context relevant if they are to build individual resilience, while working concurrently with socio-political and systemic approaches that challenge attitudes to HIV at the wider societal levels. Finally, the gendered experiences of self-stigma point to the intersecting layers of self-stigma that are likely to be felt by particularly marginalized populations living with HIV and should be further explored

    Genetic Organisation, Mobility and Predicted Functions of Genes on Integrated, Mobile Genetic Elements in Sequenced Strains of Clostridium difficile

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    Background: Clostridium difficile is the leading cause of hospital-associated diarrhoea in the US and Europe. Recently the incidence of C. difficile-associated disease has risen dramatically and concomitantly with the emergence of 'hypervirulent' strains associated with more severe disease and increased mortality. C. difficile contains numerous mobile genetic elements, resulting in the potential for a highly plastic genome. In the first sequenced strain, 630, there is one proven conjugative transposon (CTn), Tn5397, and six putative CTns (CTn1, CTn2 and CTn4-7), of which, CTn4 and CTn5 were capable of excision. In the second sequenced strain, R20291, two further CTns were described.Results: CTn1, CTn2 CTn4, CTn5 and CTn7 were shown to excise from the genome of strain 630 and transfer to strain CD37. A putative CTn from R20291, misleadingly termed a phage island previously, was shown to excise and to contain three putative mobilisable transposons, one of which was capable of excision. In silico probing of C. difficile genome sequences with recombinase gene fragments identified new putative conjugative and mobilisable transposons related to the elements in strains 630 and R20291. CTn5-like elements were described occupying different insertion sites in different strains, CTn1-like elements that have lost the ability to excise in some ribotype 027 strains were described and one strain was shown to contain CTn5-like and CTn7-like elements arranged in tandem. Additionally, using bioinformatics, we updated previous gene annotations and predicted novel functions for the accessory gene products on these new elements.Conclusions: The genomes of the C. difficile strains examined contain highly related CTns suggesting recent horizontal gene transfer. Several elements were capable of excision and conjugative transfer. The presence of antibiotic resistance genes and genes predicted to promote adaptation to the intestinal environment suggests that CTns play a role in the interaction of C. difficile with its human host
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