4,612 research outputs found
THE ASSOCIATIONS BETWEEN SEXUAL VICTIMIZATION AND HEALTH OUTCOMES AMONG LGBQA COLLEGE STUDENTS: EXAMINING THE MODERATING ROLE OF SOCIAL SUPPORT
Sexual victimization is a prevailing public health concern that differentially impacts sexual minority populations (i.e., people who identify as lesbian, gay, bisexual, asexual, or queer) compared with their heterosexual and cisgender counterparts (McCauley et al., 2018). Studies have shown that sexual violence is associated with depressive symptoms, post-traumatic stress disorder symptoms, and alcohol use (Aosved et al., 2011; Bedard-Gilligan et al, 2011; Carey et al., 2018) among heterosexual college students. However, we know less about the potential effects of sexual victimization on health outcomes among sexual minority college students. Understanding these relations are especially important because sexual minority college students often experience unique challenges and are at increased risk of sexual victimization in comparison to their counterparts (Cantor et al., 2015; Edwards et al., 2015). Moreover, few studies to date have examined the moderating role of social support in buffering the links between sexual victimization and health outcomes. Guided by the minority stress framework (Meyer, 2003), the current study examined the extent to which sexual victimization influences health outcomes (i.e., depressive symptoms, post-traumatic stress disorder symptoms, and alcohol use disorder) among sexual minority college students. Furthermore, we examined whether social support moderated the association between sexual victimization and each health outcome. The current study included 234 students who identified as being part of the Queer community (e.g., Gay, Lesbian, Asexual, and Queer) from a larger university-wide study (i.e., Spit for Science; Dick et al., 2014). The participants in the present study were 18-22 years old (M = 18.46, SD = .412) and majority female (i.e., 74%). Fifty-six percent of the participants self- identified as White, 16% as Black or African American, 13% as Asian, and 15% as American Indian, Latinx, Pacific Islander, or Multiracial. Students provided online self-reports of their sexual victimization experiences (Blake et al., 1990), social support (Hays et al., 1995), depressive symptoms (Derogatis et al., 1973), post-traumatic stress disorder symptoms (Weathers et al., 2013) and alcohol use (DSM-V). We used a series of regression models in Mplus v 7.2 (Muthén & Muthén, 1998–2014) to test our research questions, with multiple imputation to handle missing data. Findings indicated that sexual victimization was positively related to depressive symptoms (b = .21, p = .00), post- traumatic stress disorder symptoms (b = .43, p = .00), and alcohol use disorder (b = .45, p = .00). Furthermore, social support significantly moderated the association between sexual victimization and depressive symptoms, however, in a direction contrary to hypotheses. Specifically, greater sexual victimization was associated with greater depressive symptoms among sexual minority college students with higher levels of social support (b = .29, p = .00), and the association was not significant for sexual minority college students with lower levels of social support (b = .13, p = .26; Figure 1). Discussion will center on the detrimental effects of sexual victimization on health outcomes among sexual minority college students, as well as providing potential explanations and future directions for the nuanced ways social support functions in the lives of sexual minority college students.https://scholarscompass.vcu.edu/gradposters/1079/thumbnail.jp
Time Variability in the X-ray Nebula Powered by Pulsar B1509-58
We use new and archival Chandra and ROSAT data to study the time variability
of the X-ray emission from the pulsar wind nebula (PWN) powered by PSR B1509-58
on timescales of one week to twelve years. There is variability in the size,
number, and brightness of compact knots appearing within 20" of the pulsar,
with at least one knot showing a possible outflow velocity of ~0.6c (assuming a
distance to the source of 5.2 kpc). The transient nature of these knots may
indicate that they are produced by turbulence in the flows surrounding the
pulsar. A previously identified prominent jet extending 12 pc to the southeast
of the pulsar increased in brightness by 30% over 9 years; apparent outflow of
material along this jet is observed with a velocity of ~0.5c. However, outflow
alone cannot account for the changes in the jet on such short timescales.
Magnetohydrodynamic sausage or kink instabilities are feasible explanations for
the jet variability with timescale of ~1.3-2 years. An arc structure, located
30"-45" north of the pulsar, shows transverse structural variations and appears
to have moved inward with a velocity of ~0.03c over three years. The overall
structure and brightness of the diffuse PWN exterior to this arc and excluding
the jet has remained the same over the twelve year span. The photon indices of
the diffuse PWN and possibly the jet steepen with increasing radius, likely
indicating synchrotron cooling at X-ray energies.Comment: accepted to ApJ, 14 pages, 8 figure
Estimating volcanic deformation source parameters with a finite element inversion: The 2001-2002 unrest at Cotopaxi volcano, Ecuador
Image states in metal clusters
The existence of image states in small clusters is shown, using a quantum-mechanical many-body approach. We present image state energies and wave functions for spherical jellium clusters up to 186 atoms, calculated in the GW approximation, where G is the Green's function and W is the dynamically screened Coulomb interaction, which by construction contains the dynamic long-range correlation effects that give rise to image effects. In addition, we find that image states are also subject to quantum confinement. To extrapolate our investigations to clusters in the mesoscopic size range, we propose a semiclassical model potential, which we test against our full GW results
The Medical Home and Care Coordination in Disaster Recovery: Hypothesis for Interventions and Research
In postdisaster settings, health care providers encounter secondary surges of unmet primary care and mental health needs that evolve throughout disaster recovery phases. Whatever a community’s predisaster adequacy of health care, postdisaster gaps are similar to those of any underserved region. We hypothesize that existing practice and evidence supporting medical homes and care coordination in primary care for the underserved provide a favorable model for improving health in disrupted communities. Elements of medical home services can be offered by local or temporary providers from outside the region, working out of mobile clinics early in disaster recovery. As repairs and reconstruction proceed, local services are restored over weeks or years. Throughout recovery, major tasks include identifying high-risk patients relative to the disaster and underlying health conditions, assisting displaced families as they transition through housing locations, and tracking their evolving access to health care and community services as they are restored. Postdisaster sources of financial assistance for the disaster-exposed population are often temporary and evolving, requiring up-to-date information to cover costs of care until stable services and insurance coverage are restored. Evidence to support disaster recovery health care improvement will require research funding and metrics on structures, processes, and outcomes of the disaster recovery medical home and care coordination, based on adaptation of standard validated methods to crisis environments
The Three-Dimensional Structure of Cassiopeia A
We used the Spitzer Space Telescope's Infrared Spectrograph to map nearly the
entire extent of Cassiopeia A between 5-40 micron. Using infrared and Chandra
X-ray Doppler velocity measurements, along with the locations of optical ejecta
beyond the forward shock, we constructed a 3-D model of the remnant. The
structure of Cas A can be characterized into a spherical component, a tilted
thick disk, and multiple ejecta jets/pistons and optical fast-moving knots all
populating the thick disk plane. The Bright Ring in Cas A identifies the
intersection between the thick plane/pistons and a roughly spherical reverse
shock. The ejecta pistons indicate a radial velocity gradient in the explosion.
Some ejecta pistons are bipolar with oppositely-directed flows about the
expansion center while some ejecta pistons show no such symmetry. Some ejecta
pistons appear to maintain the integrity of the nuclear burning layers while
others appear to have punched through the outer layers. The ejecta pistons
indicate a radial velocity gradient in the explosion. In 3-D, the Fe jet in the
southeast occupies a "hole" in the Si-group emission and does not represent
"overturning", as previously thought. Although interaction with the
circumstellar medium affects the detailed appearance of the remnant and may
affect the visibility of the southeast Fe jet, the bulk of the symmetries and
asymmetries in Cas A are intrinsic to the explosion.Comment: Accepted to ApJ. 54 pages, 21 figures. For high resolution figures
and associated mpeg movie and 3D PDF files, see
http://homepages.spa.umn.edu/~tdelaney/pape
Non-universal Voronoi cell shapes in amorphous ellipsoid packings
In particulate systems with short-range interactions, such as granular matter
or simple fluids, local structure plays a pivotal role in determining the
macroscopic physical properties. Here, we analyse local structure metrics
derived from the Voronoi diagram of configurations of oblate ellipsoids, for
various aspect ratios and global volume fractions . We focus
on jammed static configurations of frictional ellipsoids, obtained by
tomographic imaging and by discrete element method simulations. In particular,
we consider the local packing fraction , defined as the particle's
volume divided by its Voronoi cell volume. We find that the probability
for a Voronoi cell to have a given local packing fraction shows the
same scaling behaviour as function of as observed for random sphere
packs. Surprisingly, this scaling behaviour is further found to be independent
of the particle aspect ratio. By contrast, the typical Voronoi cell shape,
quantified by the Minkowski tensor anisotropy index ,
points towards a significant difference between random packings of spheres and
those of oblate ellipsoids. While the average cell shape of all cells
with a given value of is very similar in dense and loose jammed sphere
packings, the structure of dense and loose ellipsoid packings differs
substantially such that this does not hold true. This non-universality has
implications for our understanding of jamming of aspherical particles.Comment: 6 pages, 5 figure
Multiple Gluon Effects in at FNAL Energies: Semi-Analytical Results
We apply our Yennie-Frautschi-Suura exponentiated cross section formulas for
the parton processes q + {^(} \bar q {^)}{^\prime} \ra q{^\prime}{^\prime} +
{^(} \bar q {^)}{^\prime}{^\prime}{^\prime} + n(G) to the process q + \bar q
\ra t + \bar t + n(G) at FNAL energies, where G is a QCD gluon. We use
semi-analytical methods to compute the ratio ,
where is our soft gluon YFS exponentiated cross section and
is the Born cross section. For TeV, we get
, respectively, for for example. These results are
not inconsistent with the recent observations by CDF and D0.Comment: 6 pages, latex replaces postscript at archiver's reques
Application of Stem Cell Derived Neuronal Cells to Evaluate Neurotoxic Chemotherapy
The generation of induced pluripotent stem cells (iPSCs) and differentiation to cells composing major organs has opened up the possibility for a new model system to study adverse toxicities associated with chemotherapy. Therefore, we used human iPSC-derived neurons to study peripheral neuropathy, one of the most common adverse effects of chemotherapy and cause for dose reduction. To determine the utility of these neurons in investigating the effects of neurotoxic chemotherapy, we measured morphological differences in neurite outgrowth, cell viability as determined by ATP levels and apoptosis through measures of caspase 3/7 activation following treatment with clinically relevant concentrations of platinating agents (cisplatin, oxaliplatin and carboplatin), taxanes (paclitaxel, docetaxel and nab-paclitaxel), a targeted proteasome inhibitor (bortezomib), an antiangiogenic compound (thalidomide), and 5-fluorouracil, a chemotherapeutic that does not cause neuropathy. We demonstrate differential sensitivity of neurons to mechanistically distinct classes of chemotherapeutics. We also show a dose-dependent reduction of electrical activity as measured by mean firing rate of the neurons following treatment with paclitaxel. We compared neurite outgrowth and cell viability of iPSC-derived cortical (iCell® Neurons) and peripheral (Peri.4U) neurons to cisplatin, paclitaxel and vincristine. Goshajinkigan, a Japanese herbal neuroprotectant medicine, was protective against paclitaxel-induced neurotoxicity but not oxaliplatin as measured by morphological phenotypes. Thus, we have demonstrated the utility of human iPSC-derived neurons as a useful model to distinguish drug class differences and for studies of a potential neuroprotectant for the prevention of chemotherapy-induced peripheral neuropathy
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