1,835 research outputs found

    Fe II and Mg II in Luminous, Intermediate-Redshift Narrow-line Seyfert 1 Galaxies from the Sloan Digital Sky Survey

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    We present results from analysis of spectra from a sample of ~900 quasars from the Sloan Digital Sky Survey. These objects were selected for their intermediate redshift (1.2<z<1.8), placing MgII and UV FeII in the optical band pass, relatively narrow MgII lines, and moderately good signal-to-noise-ratio spectra. Using a maximum likelihood analysis, we discovered that there is a significant dispersion in the FeII/MgII ratios in the sample. Using simulations, we demonstrate that this range, and corresponding correlation between FeII equivalent width and FeII/MgII ratio, are primarily a consequence of a larger dispersion of FeII equivalent width (EW) relative to MgII EW. This larger dispersion in FeII EW could be a consequence of a range in iron abundance, or in a range of FeII excitation. The latter possibility is supported by evidence that objects with weak (zero) CII]\lambda 2325 equivalent width are likely to have large FeII/MgII ratios. We discuss physical effects that could produce a range of FeII/MgII ratio.Comment: Accepted for publication in ApJ. Spectral fitting and analysis substantially revise

    Green Apparel Consumption: An Empirical Examination of Behavior versus Attitudes

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    The research reports empirical findings that contrast apparel consumers who behave in pro-environment purchasing behavior with those who do behave in pro-environmental purchasing behavior, in an effort to better understand the attitude-behavior gap commonly recognized among consumer researchers in the ethical consumption research stream. A large cross-section of U.S. Consumer data (N=1,846) provides the sample data for analyses.Demographics, product preferences, attribution behavior and intentions are contrasted between the two groups using appropriate statistical tests. Distinctly different profiles of the two consumer groups emerge, suggesting a number of directions for future research with academic and practical implications

    Mosquito net coverage in years between mass distributions: a case study of Tanzania, 2013.

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    BACKGROUND: The Government of Tanzania is the main source of long-lasting insecticidal nets (LLINs) for its population. Mosquito nets (treated and untreated) are also available in the commercial market. To sustain investments and health gains in the fight against malaria, it is important for the National Malaria Control Programme to monitor LLIN coverage especially in the years between mass distributions and to understand what households do if their free nets are deemed unusable. The aim of this paper was to assess standard LLIN indicators by wealth status in Tanzania in 2013, 2 years after the last mass campaign in 2011, and extend the analysis to untreated nets (UTNs) to investigate how households adapt when nets are not continuously distributed. METHODS: Between October-December 2013, a household survey was conducted in 3398 households in eight districts in Tanzania. Using the Roll Back Malaria indicators, the study analysed: (1) household net ownership; (2) access to nets; (3) population net use and (4) net use:access ratio. Outcomes were calculated for LLINs and UTNs. Results were analysed by socio-economic quintiles and by district. RESULTS: Only three of the eight districts had household LLIN ownership of more than 80%. In 2013, less than a quarter of the households had one LLIN for every two people and only half of the population had access to an LLIN. Only the wealthier quintiles increased their net ownership and access to levels above 80% through the addition of UTNs. Overall net use of the population was low (LLINs: 32.8%; UTNs: 9.5%) and net use:access ratio was below target level (LLINs: 0.66; UTN: 0.50). Both measures varied significantly by district. CONCLUSIONS: Two years after the last mass campaign, the percentage of households or population with access to LLINs was low. These findings indicate the average rate at which households in Tanzania lose their nets is higher than the rate at which they acquire new nets. The wealthiest households topped up their household net ownership with UTNs. Efforts to make LLINs available through commercial markets should be promoted, so those who can afford to buy nets purchase LLINs rather than UTNs. Net use was low around 40% and mostly explained by lack of access to nets. However, the use:access ratio was poor in Mbozi and Kahama districts warranting further investigations to understand other barriers to net use

    Implementation of a Journal Prototype for Pregnant and Parenting Adolescents

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    Teenage pregnancy and childbearing remain pressing public health issues that have garnered attention from public health officials and social services agencies. This paper reports on the initial implementation and formative evaluation of a journaling program used as a means of communicating health information to pregnant and parenting adolescents (young women age 15-19) while also providing participants with a means of self-expression. The journaling prototype was implemented in a community-based agency in the Midwest by Family Support Specialists (FSSs) who made home visits on a monthly basis to assist pregnant and parenting adolescents (n = 52) with successful family planning and public health education. A mixed method approach of qualitative (analysis of journals, field notes, and responses of semi-structured interviews with FSSs) and quantitative (questionnaires from pregnant and parenting adolescent respondents) data with purposive sampling was employed to evaluate the implementation of the journaling intervention. Twenty of the 52 study participants were pregnant when the journaling intervention was implemented, while 32 were not pregnant, but recently had a child and were currently parenting. Two core themes emerged from analysis of the data after the implementation of the journals: (1) usefulness of the journal and responsiveness to participants' information needs and (2) functionality challenges. The results offer practical starting points to tailor the implementation of journaling in other contexts. Further, areas for improvement emerged regarding the distribution timeline for the journal and the content of the journal itself. As such, we discuss the lessons learned through this collaborative project and suggest opportunities for future phases of the journal intervention

    Associations of less healthy snack food consumption with infant weight-for-length z-score trajectories: Findings from the Nurture cohort study

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    Little is known about the impact of less healthy snack foods on weight trajectories during infancy. This secondary analysis of data from the Nurture cohort explored prospective associations of less healthy snack foods with infant weight trajectories. Pregnant women were recruited and, upon delivery of a single live infant, 666 mothers agreed to participate. Mothers completed sociodemographic and infant feeding questionnaires, and infant anthropometrics were collected during home visits at 3, 6, 9, and 12 months. Less healthy snack food consumption was assessed by asking how frequently baby snacks and sweets were consumed each day during the previous three months. Multilevel growth curve models explored associations of baby snacks and sweets with infant weight-for-length (WFL) z-scores. On average, mothers were 27 years old, 71.5% were non-Hispanic Black, and 55.4% had household incomes of ≤$20,000/year. Consumption of less healthy snack foods increased during infancy with a median intake of 3.0 baby snacks/day and 0.7 sweets/day between 10 and 12 months. Growth curve models showed that infants who consumed sweets \u3e2 times/day had significantly higher WFL z-scores during the second half of infancy compared to infants who never consumed sweets. Less healthy snacks may contribute to the risk of obesity during infancy and promoting healthy snack food choices during this critical time is important

    HST STIS Ultraviolet Spectral Evidence for Outflow in Extreme Narrow-line Seyfert 1 Galaxies: I. Data and Analysis

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    We present HST STIS observations of two extreme NLS1s, IRAS 13224-3809 and 1H 0707-495. The spectra are characterized by very blue continua, broad, strongly blueshifted high-ionization lines (including \ion{C}{4} and \ion{N}{5}), and narrow, symmetric intermediate- (including \ion{C}{3}], \ion{Si}{3}], \ion{Al}{3}) and low-ionization (e.g., \ion{Mg}{2}) lines centered at their rest wavelengths. The emission-line profiles suggest that the high-ionization lines are produced in a wind, and the intermediate- and low-ionization lines are produced in low-velocity gas associated with the accretion disk or base of the wind. In this paper, we present the analysis of the spectra from these two objects; in a companion paper we present photoionization analysis and a toy dynamical model for the wind. The highly asymmetric profile of \ion{C}{4} suggests that it is dominated by emission from the wind, so we develop a template for the wind from the \ion{C}{4} line. We model the bright emission lines in the spectra using a combination of this template, and a narrow, symmetric line centered at the rest wavelength. We also analyzed a comparison sample of HST spectra from 14 additional NLS1s, and construct a correlation matrix of emission line and continuum properties. A number of strong correlations were observed, including several involving the asymmetry of the \ion{C}{4} line.Comment: 26 pages, 10 figures, accepted for publication in ApJ with no change
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