3,122 research outputs found

    Project risk screening matrix for stream management and restoration

    Get PDF
    The ‘Project Risk Screening Matrix’ derives from a broader effort to assist US government agency staff in reviewing proposed stream management and restoration projects more efficiently and effectively. The River Restoration Analysis Tool (RiverRAT) developed through this effort provides a thorough, comprehensive and auditable approach to review and evaluation of proposed stream actions and projects (www.restorationreview.com). The matrix was initially developed as the first step in applying the RiverRAT, its purpose being to assist reviewers in assessing the risk to natural resources associated with a particular proposal and matching the intensity of their review to the severity of that risk. Hence, the primary application of the matrix to date has been to identify and screen out low risk projects that may be dealt with expeditiously, and so freeing the time and technical resources needed to allow deep reviews of higher risk projects. A second form of screening emerged from this primary function because the matrix proved adept at identifying the minimum level of site and project characterization required to support initial risk assessment. On this basis, proposals lacking adequate information can also be screened out, being referred back to the proponent with a request for additional information. More recently, new and novel versions of the matrix, featuring modification and refinement of one or both of the original axes, have emerged to widen and refine its application to linear infrastructure (e.g. pipelines, roads, and electrical transmission lines), instream structures (e.g. large wood placement and culvert removal), and pre-application, regulatory, decision-support tools

    Project risk screening matrix for stream management and restoration

    Get PDF
    The ‘Project Risk Screening Matrix’ derives from a broader effort to assist US government agency staff in reviewing proposed stream management and restoration projects more efficiently and effectively. The River Restoration Analysis Tool (RiverRAT) developed through this effort provides a thorough, comprehensive and auditable approach to review and evaluation of proposed stream actions and projects (www.restorationreview.com). The matrix was initially developed as the first step in applying the RiverRAT, its purpose being to assist reviewers in assessing the risk to natural resources associated with a particular proposal and matching the intensity of their review to the severity of that risk. Hence, the primary application of the matrix to date has been to identify and screen out low risk projects that may be dealt with expeditiously, and so freeing the time and technical resources needed to allow deep reviews of higher risk projects. A second form of screening emerged from this primary function because the matrix proved adept at identifying the minimum level of site and project characterization required to support initial risk assessment. On this basis, proposals lacking adequate information can also be screened out, being referred back to the proponent with a request for additional information. More recently, new and novel versions of the matrix, featuring modification and refinement of one or both of the original axes, have emerged to widen and refine its application to linear infrastructure (e.g. pipelines, roads, and electrical transmission lines), instream structures (e.g. large wood placement and culvert removal), and pre-application, regulatory, decision-support tools

    High spectral resolution time-resolved optical spectroscopy of V893 Sco

    Get PDF
    We present high resolution time-resolved optical spectra of the high inclination short orbital period dwarf nova V893 Sco. We performed spectral analysis through radial velocity measurements, Doppler mapping, and ratioed Doppler maps. Our results indicate that V893 Sco's accretion disk is dissimilar to WZ Sge's accretion disk, and does not fit any of the current accretion disk models. We derive the system parameters M1 and i, and present evidence for V893 Sco as a very young cataclysmic variable and an ER UMa star. We advance the hypothesis that all ER UMa stars may be newly formed cataclysmic variables.Comment: 23 pages (total), 8 figures, accepted by Ap

    Correlates of Christian Religious Identification and Deidentification Among Sexual and Gender Minorities: A U.S. Probability Sample

    Get PDF
    Using a U.S. nationally representative sample of 1,529 sexual and gender minorities (SGMs), we examined the demographic and developmental correlates of Christian religious deidentification. We found that SGMs who were older, Black, cisgender men, and/or lived in the American South were more likely to identify as Christian in adulthood, relative to other SGMs. Those who were never Christian reported being more out to family and friends at earlier ages than those who were raised Christian. SGMs who were raised Christian, but did not identify as Christian in adulthood reported, more adverse childhood experiences and bullying than other SGMs. Sexual minorities who identified as Christian in adulthood reported more internalized homophobia in adulthood than other sexual minorities. Finally, sexual minorities who were raised Christian, regardless of their adulthood religious identification, reported experiencing more stigma than sexual minorities who were not raised Christian. No differences were noted in measures of adulthood resilience or health. Taken together, results indicate that identifying as Christian—in childhood and/or adulthood—is associated with greater experiences of stigma and stress than not identifying as Christian in adulthood

    Thirty Meter Telescope Site Testing I: Overview

    Get PDF
    As part of the conceptual and preliminary design processes of the Thirty Meter Telescope (TMT), the TMT site testing team has spent the last five years measuring the atmospheric properties of five candidate mountains in North and South America with an unprecedented array of instrumentation. The site testing period was preceded by several years of analyses selecting the five candidates, Cerros Tolar, Armazones and Tolonchar in northern Chile; San Pedro Martir in Baja California, Mexico and the 13 North (13N) site on Mauna Kea, Hawaii. Site testing was concluded by the selection of two remaining sites for further consideration, Armazones and Mauna Kea 13N. It showed that all five candidates are excellent sites for an extremely large astronomical observatory and that none of the sites stands out as the obvious and only logical choice based on its combined properties. This is the first article in a series discussing the TMT site testing project.Comment: Accepted for publication in PASP, April 2009 issu

    Hubble Space Telescope Observations of UV Oscillations in WZ Sagittae During the Decline from Outburst

    Full text link
    We present a time series analysis of Hubble Space Telescope observations of WZ Sge obtained in 2001 September, October, November and December as WZ Sge declined from its 2001 July superoutburst. Previous analysis of these data showed the temperature of the white dwarf decreased from ~29,000 K to ~18,000 K. In this study we binned the spectra over wavelength to yield ultraviolet light curves at each epoch that were then analyzed for the presence of the well-known 27.87 s and 28.96 s oscillations. We detect the 29 s periodicity at all four epochs, but the 28 s periodicity is absent. The origin of these oscillations has been debated since their discovery in the 1970s and competing hypotheses are based on either white dwarf non-radial g-mode pulsations or magnetically-channelled accretion onto a rotating white dwarf. By analogy with the ZZ Ceti stars, we argue that the non-radial g-mode pulsation model demands a strong dependence of pulse period on the white dwarf's temperature. However, these observations show the 29 s oscillation is independent of the white dwarf's temperature. Thus we reject the white dwarf non-radial g-mode pulsation hypothesis as the sole origin of the oscillations. It remains unclear if magnetically-funnelled accretion onto a rapidly rotating white dwarf (or belt on the white dwarf) is responsible for producing the oscillations. We also report the detection of a QPO with period ~18 s in the September light curve. The amplitudes of the 29 s oscillation and the QPO vary erratically on short timescales and are not correlated with the mean system brightness nor with each other.Comment: 20 pages, 3 figures, 1 table; accepted for publication in Ap

    Time-resolved, multi-color photometry and spectroscopy of Virgo 4 (OU Vir): a high orbital inclination, short orbital period dwarf nova

    Full text link
    We present multi-color photometry and time resolved spectroscopy of OU Vir. The analysis of the quiescent light curve shows that OU Vir is characterized by i) strong cycle-to-cycle brightness variations, and ii) hot spot modulated light curve with grazing eclipse of the impact region. Colors are derived both in- and out- of eclipse. The time-resolved spectroscopy allows us to produce the radial velocity curve from the Hα\alpha accretion disk emission line which possibly reveals only weak evidence for hot spot line emission. The hot spot is believed to be a turbulent optically thick region, producing mostly continuum emission.Comment: 8 pages (including figures), 7 figures. To Be published in A&

    High Speed Photometry of SDSS J013701.06-091234.9

    Get PDF
    We present high speed photometry of the Sloan Digital Sky Survey cataclysmic variable SDSS J013701.06-091234.9 in quiescence and during its 2003 December superoutburst. The orbital modulation at 79.71\pm0.01 min is double humped; the superhump period is 81.702\pm0.007 min. Towards the end of the outburst late superhumps with a period of 81.29\pm0.01 min were observed. We argue that this is a system of very low mass transfer rate, and that it probably has a long outburst interval.Comment: 5 pages, 8 figures. Accepted for publication in MNRA

    Religion/Spirituality, Stress, and Resilience Among Sexual and Gender Minorities: The Religious/Spiritual Stress and Resilience Model

    Get PDF
    Although many sexual and gender minorities (SGMs) consider themselves religious or spiritual, the impact of this religiousness or spirituality (RS) on their health is poorly understood. We introduce the religious/spiritual stress and resilience model (RSSR) to provide a robust framework for understanding the variegated ways that RS influences the health of SGMs. The RSSR bridges existing theorizing on minority stress, structural stigma, and RS-health pathways to articulate the circumstances under which SGMs likely experience RS as health promoting or health damaging. The RSSR makes five key propositions: (a) Minority stress and resilience processes influence health; (b) RS influences general resilience processes; (c) RS influences minority-specific stress and resilience processes; (d) these relationships are moderated by a number of variables uniquely relevant to RS among SGMs, such as congregational stances on same-sex sexual behavior and gender expression or an individual’s degree of SGM and RS identity integration; and (e) relationships between minority stress and resilience, RS, and health are bidirectional. In this manuscript, we describe the empirical basis for each of the five propositions focusing on research examining the relationship between RS and health among SGMs. We conclude by describing how the RSSR may inform future research on RS and health among SGMs
    • …
    corecore