3,147 research outputs found
Project risk screening matrix for stream management and restoration
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
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
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
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
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
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
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 H 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
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
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
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