3,961 research outputs found
Minority Stress: A Model for Understanding Sexual Minority Adolescents’ Mental Health
Taken together, the three papers included in this dissertation offer an investigation of sexual minority adolescents’ stress as a predictor of adverse mental health outcomes (Paper 1), as being influenced by school and home climates (Paper 2), and as a measurable model for stress across levels (Paper 3). Results from this series of studies generally support theory and findings from other studies in that minority stress was found to be a meaningful predictor of mental health in sexual minority youth and that school and home climates were found to be important for understanding sexual minority youth wellbeing. However, the current set of papers went beyond confirming past research and offered new contributions to the literature by identifying differences in the levels at which minority stress’ predicts mental health (Paper 1), showing how school and home climates both influence sexual minority youths’ wellbeing and that school climates offer a better explanation for the wellbeing of sexual minority adolescents (Paper 2), and providing support for the measurement of minority stress for adolescents. Findings from this series of studies may help support the knowledge and measurement necessary for informing mental health providers’ practice to reduce mental health disparities in sexual minority youth
The Moderating Role of Psychological Inflexibility in the Relationship Between Minority Stress, Substance Misuse, and Suicidality in LGB+ Adolescents
Adolescence is a difficult time, especially for those who do not identify as heterosexual (e.g., gay, lesbian, bisexual, asexual, pansexual; LGB+). Increased rates of substance abuse and suicidality are well documented outcomes that tend to be worse in the LGB+ adolescent community than in mainstream groups. Minority stress, the effect of unique stressors experienced by those in the LGB+ community explained by external and societal influences, has been accepted within the research community as a theory used to explain the health disparities seen in this group. This study proposed a possible further explanation, in addition to minority stress, that helps clarify the relationship between minority stress and negative outcomes, and that is changeable through Acceptance and Commitment Therapy (ACT). Psychological inflexibility, a rigid reaction to life events that is inconsistent with values and often promotes avoidant behavior, and five of its six key sub-processes (experiential avoidance, cognitive fusion, lack of values, preoccupation with the past or future, and inaction) was posited as influencing the strength of the relationship between minority stress and substance misuse or suicidality.
Interactions with both global psychological inflexibility and its sub-processes were examined using statistical models to explore relationships between minority stress and both suicidality and substance misuse in the LGB+ adolescent community. A sample of 152 LGB+ adolescents participated. Significant interactions were found in models of substance misuse but not suicidality, with global psychological inflexibility, cognitive fusion, and obstruction of valued living as moderators that strengthened the relationship between minority stress and substance misuse.
Implications based on results suggest that psychological inflexibility as a mechanism of change in LGB+ adolescents is worth further study. Additional examination into the effectiveness of ACT in LGB+ populations struggling with minority stress’ effects and/or substance misuse should be conducted to advance the understanding of these results
Properties of cage rearrangements observed near the colloidal glass transition
We use confocal microscopy to study the motions of particles in concentrated
colloidal systems. Near the glass transition, diffusive motion is inhibited, as
particles spend time trapped in transient ``cages'' formed by neighboring
particles. We measure the cage sizes and lifetimes, which respectively shrink
and grow as the glass transition approaches. Cage rearrangements are more
prevalent in regions with lower local concentrations and higher disorder.
Neighboring rearranging particles typically move in parallel directions,
although a nontrivial fraction move in anti-parallel directions, usually from
pairs of particles with initial separations corresponding to the local maxima
and minima of the pair correlation function , respectively.Comment: 5 pages, 4 figures; text & figures revised in v
Local molecular field theory for the treatment of electrostatics
We examine in detail the theoretical underpinnings of previous successful
applications of local molecular field (LMF) theory to charged systems. LMF
theory generally accounts for the averaged effects of long-ranged components of
the intermolecular interactions by using an effective or restructured external
field. The derivation starts from the exact Yvon-Born-Green hierarchy and shows
that the approximation can be very accurate when the interactions averaged over
are slowly varying at characteristic nearest-neighbor distances. Application of
LMF theory to Coulomb interactions alone allows for great simplifications of
the governing equations. LMF theory then reduces to a single equation for a
restructured electrostatic potential that satisfies Poisson's equation defined
with a smoothed charge density. Because of this charge smoothing by a Gaussian
of width sigma, this equation may be solved more simply than the detailed
simulation geometry might suggest. Proper choice of the smoothing length sigma
plays a major role in ensuring the accuracy of this approximation. We examine
the results of a basic confinement of water between corrugated wall and justify
the simple LMF equation used in a previous publication. We further generalize
these results to confinements that include fixed charges in order to
demonstrate the broader impact of charge smoothing by sigma. The slowly-varying
part of the restructured electrostatic potential will be more symmetric than
the local details of confinements.Comment: To be published in J Phys-Cond Matt; small misprint corrected in Eq.
(12) in V
Vacuum Energy Density for Massless Scalar Fields in Flat Homogeneous Spacetime Manifolds with Nontrivial Topology
Although the observed universe appears to be geometrically flat, it could
have one of 18 global topologies. A constant-time slice of the spacetime
manifold could be a torus, Mobius strip, Klein bottle, or others. This global
topology of the universe imposes boundary conditions on quantum fields and
affects the vacuum energy density via Casimir effect. In a spacetime with such
a nontrivial topology, the vacuum energy density is shifted from its value in a
simply-connected spacetime. In this paper, the vacuum expectation value of the
stress-energy tensor for a massless scalar field is calculated in all 17
multiply-connected, flat and homogeneous spacetimes with different global
topologies. It is found that the vacuum energy density is lowered relative to
the Minkowski vacuum level in all spacetimes and that the stress-energy tensor
becomes position-dependent in spacetimes that involve reflections and
rotations.Comment: 25 pages, 11 figure
Reconstructing the global topology of the universe from the cosmic microwave background
If the universe is multiply-connected and sufficiently small, then the last
scattering surface wraps around the universe and intersects itself. Each circle
of intersection appears as two distinct circles on the microwave sky. The
present article shows how to use the matched circles to explicitly reconstruct
the global topology of space.Comment: 6 pages, 2 figures, IOP format. To be published in the proceedings of
the Cleveland Cosmology and Topology Workshop 17-19 Oct 1997. Submitted to
Class. Quant. Gra
Circles in the Sky: Finding Topology with the Microwave Background Radiation
If the universe is finite and smaller than the distance to the surface of
last scatter, then the signature of the topology of the universe is writ large
on the microwave background sky. We show that the microwave background will be
identified at the intersections of the surface of last scattering as seen by
different ``copies'' of the observer. Since the surface of last scattering is a
two-sphere, these intersections will be circles, regardless of the background
geometry or topology. We therefore propose a statistic that is sensitive to all
small, locally homogeneous topologies. Here, small means that the distance to
the surface of last scatter is smaller than the ``topology scale'' of the
universe.Comment: 14 pages, 10 figures, IOP format. This paper is a direct descendant
of gr-qc/9602039. To appear in a special proceedings issue of Class. Quant.
Grav. covering the Cleveland Topology & Cosmology Worksho
Exact Polynomial Eigenmodes for Homogeneous Spherical 3-Manifolds
Observational data hints at a finite universe, with spherical manifolds such
as the Poincare dodecahedral space tentatively providing the best fit.
Simulating the physics of a model universe requires knowing the eigenmodes of
the Laplace operator on the space. The present article provides explicit
polynomial eigenmodes for all globally homogeneous 3-manifolds: the Poincare
dodecahedral space S3/I*, the binary octahedral space S3/O*, the binary
tetrahedral space S3/T*, the prism manifolds S3/D_m* and the lens spaces
L(p,1).Comment: v3. Final published version. 27 pages, 1 figur
- …