918 research outputs found

    The emission of radiation from diatomic gases. III. Numerical emissivity calculations for carbon monoxide for low optical densities at 300°K and atmospheric pressure

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    Numerical emissivity calculations at 300°K and atmospheric pressure for nonoverlapping rotational lines have been carried out for CO using a dispersion formula for the line-shape representation. Use of the best available experimental data on integrated absorption and rotational line-width leads to calculated emissivities which are in excellent agreement with extrapolated empirical data published by Hottel and Ullrich. In particular, the theoretical dependence of emissivity on optical density, for small optical densities at 300°K, has been shown to follow experimental observations with satisfactory precision.For small optical densities the calculated emissivity is found to be proportional to the square root of the assumed rotational line-width, thus emphasizing the need for accurate line-width determinations at elevated temperatures. The limits of validity of the treatment utilizing nonoverlapping rotational lines are defined by examining overlapping between adjacent weak and strong rotational lines.The calculation of emissivities can be simplified by the use of approximate treatments. Thus absolute values of the emissivity can be predicted within 10 percent by utilizing a treatment for nonoverlapping, equally spaced, and equally intense lines, together with empirically determined values for the equivalent mean integrated absorption of the rotational lines of CO. A better analytic solution, which does not involve the assumptions of equal spacing and equal intensity of the rotational lines, has been obtained by utilizing asymptotic relations for large values of modified Bessel functions

    Working With Refugees in the U.S.: Trauma-Informed and Structurally Competent Social Work Approaches

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    Social workers, government, and non-governmental organizations in the United States have been inadequately prepared to address the impact of trauma faced by refugees fleeing persecution. Compounding their initial trauma experiences, refugees often undergo further traumatic migration experiences and challenges after resettlement that can have long-lasting effects on their health and mental health. Micro and macro social work practitioners must understand the impact of these experiences in order to promote policies, social work training, and clinical practice that further the health and well-being of refugees and society. Social workers are in a unique position to provide multi-dimensional, structurally competent care and advocacy for diverse refugee populations. The experiences of Cambodian refugees will be used to examine these issues. We will explore the benefits of an ecological perspective in guiding interventions that support refugees, and will apply the framework of structural competence to highlight multidimensional implications for social work with refugee populations

    The Serendipitous Discovery of a Group or Cluster of young Galaxies at z=2.40 in Deep Hubble Space Telescope WFPC2 Images

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    We report the serendipitous discovery of a group or cluster of young galaxies at zz\simeq2.40 in a 24-orbit HST/WFPC2 exposure of the field around the weak radio galaxy 53W002. Potential cluster members were identified on ground-based narrow-band redshifted Lyα\alpha images and confirmed via spectroscopy. In addition to the known weak radio galaxy 53W002 at z=2.390, two other objects were found to have excess narrow-band Lyα\alpha emission at zz\simeq2.40. Both have been spectroscopically confirmed, and one clearly contains a weak AGN. They are located within one arcminute of 53W002, or 0.23h1001\sim0.23h_{100}^{-1}Mpc (qoq_o=0.5) at zz\simeq2.40, which is the physical scale of a group or small cluster of galaxies. Profile fitting of the WFPC2 images shows that the objects are very compact, with scale lengths \simeq0\farcs 1 (0.39h1001\simeq0.39h_{100}^{-1}kpc), and are rather faint (luminosities < L*), implying that they may be sub-galactic sized objects. We discuss these results in the context of galaxy and cluster evolution and the role that weak AGN may play in the formation of young galaxies.Comment: Accepted for publication in The Astrophysical Journal (Letters). 13 pages of gzip compressed and uuencoded PS. Figures are available at http://www.phys.unsw.edu.au/~spd/bib.htm

    Socially Isolated Cambodians in the US: Recommendations for Health Promotion

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    Cambodian genocide survivors experience health disparities associated with their traumatic experiences. Cambodian community organizations in the United States are severely challenged to serve these survivors. Community leaders have identified a sub-set of community members of particular concern: those at either end of the age spectrum (elders and young people) who are socially isolated. As part of a larger community-based participatory research project, we conducted a focus group with seven Cambodian community leaders from six cities that sought to better understand the phenomenon of social isolation of Cambodian elders and young people in order to inform health promotion efforts. Cambodian leaders expressed keen concern for those community members who rarely seem to leave their homes or interact with the Cambodian community. Prominent themes identified by leaders related to isolation were: a generational pattern; benefits of extended family; health concerns; the impact of stigma and fear; lack of sufficient resources; and cultural influences. In addition, leaders identified several possible solutions to address the phenomenon of social isolation in their communities. Health promotion efforts in this population should identify isolated individuals and enhance their social connectedness and support networks as part of a larger integrated effort

    Population-based study of the association of variants in mismatch repair genes with prostate cancer risk and outcomes.

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    BACKGROUND: Mismatch repair (MMR) gene activity may be associated with prostate cancer risk and outcomes. This study evaluated whether single nucleotide polymorphisms (SNP) in key MMR genes are related to prostate cancer outcomes. METHODS: Data from two population-based case-control studies of prostate cancer among Caucasian and African-American men residing in King County, Washington were combined for this analysis. Cases (n = 1,458) were diagnosed with prostate cancer in 1993 to 1996 or 2002 to 2005 and were identified through the Seattle-Puget Sound Surveillance Epidemiology and End Results cancer registry. Controls (n = 1,351) were age-matched to cases and were identified through random digit dialing. Logistic regression was used to assess the relationship between haplotype-tagging SNPs and prostate cancer risk and disease aggressiveness. Cox proportional hazards regression was used to assess the relationship between SNPs and prostate cancer recurrence and prostate cancer-specific death. RESULTS: Nineteen SNPs were evaluated in the key MMR genes: five in MLH1, 10 in MSH2, and 4 in PMS2. Among Caucasian men, one SNP in MLH1 (rs9852810) was associated with overall prostate cancer risk [odds ratio, 1.21; 95% confidence interval (95% CI), 1.02, 1.44; P = 0.03], more aggressive prostate cancer (odds ratio, 1.49; 95% CI, 1.15, 1.91; P < 0.01), and prostate cancer recurrence (hazard ratio, 1.83; 95% CI, 1.18, 2.86; P < 0.01), but not prostate cancer-specific mortality. A nonsynonymous coding SNP in MLH1, rs1799977 (I219V), was also found to be associated with more aggressive disease. These results did not remain significant after adjusting for multiple comparisons. CONCLUSION: This population-based case-control study provides evidence for a possible association with a gene variant in MLH1 in relation to the risk of overall prostate cancer, more aggressive disease, and prostate cancer recurrence, which warrants replication

    A Mutation in the Myostatin Gene Increases Muscle Mass and Enhances Racing Performance in Heterozygote Dogs

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    Double muscling is a trait previously described in several mammalian species including cattle and sheep and is caused by mutations in the myostatin (MSTN) gene (previously referred to as GDF8). Here we describe a new mutation in MSTN found in the whippet dog breed that results in a double-muscled phenotype known as the “bully” whippet. Individuals with this phenotype carry two copies of a two-base-pair deletion in the third exon of MSTN leading to a premature stop codon at amino acid 313. Individuals carrying only one copy of the mutation are, on average, more muscular than wild-type individuals (p = 7.43 × 10−6; Kruskal-Wallis Test) and are significantly faster than individuals carrying the wild-type genotype in competitive racing events (Kendall's nonparametric measure, τ = 0.3619; p ≈ 0.00028). These results highlight the utility of performance-enhancing polymorphisms, marking the first time a mutation in MSTN has been quantitatively linked to increased athletic performance
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