3,056 research outputs found
The Bath Environment, the Bathing Task, and the Older Adult: A Review and Future Directions for Bathing Disability Research
Purpose. To review existing research studies to identify optimal intervention strategies for remediation and prevention of bathing disability and future directions for bathing disability research.
Method. Bathing disability, defined as problems in the interaction between the person and the environment during bathing performance, is examined through a comprehensive, narrative literature review.
Results. Most studies focus on the relationship between the person and the environment (such as assistive device use and environmental hazards) while fewer studies focus on analysis of the bathing task or the interaction of the person, environment, and bathing task. Of intervention studies, most do not focus solely on remediation of bathing disability and outcomes vary widely.
Conclusions. In order to help remediate and prevent bathing disability, it will be necessary to better understand and measure the person-environment-occupation interaction involved in bathing as it relates to specific groups of older adults
Pulsational Analysis of the Cores of Massive Stars and its Relevance to Pulsar Kicks
The mechanism responsible for the natal kicks of neutron stars continues to
be a challenging problem. Indeed, many mechanisms have been suggested, and one
hydrodynamic mechanism may require large initial asymmetries in the cores of
supernova progenitor stars. Goldreich, Lai, & Sahrling (1997) suggested that
unstable g-modes trapped in the iron (Fe) core by the convective burning layers
and excited by the -mechanism may provide the requisite asymmetries.
We perform a modal analysis of the last minutes before collapse of published
core structures and derive eigenfrequencies and eigenfunctions, including the
nonadiabatic effects of growth by nuclear burning and decay by both neutrino
and acoustic losses. In general, we find two types of g-modes: inner-core
g-modes, which are stabilized by neutrino losses and outer-core g-modes which
are trapped near the burning shells and can be unstable. Without exception, we
find at least one unstable g-mode for each progenitor in the entire mass range
we consider, 11 M_{\sun} to 40 M_{\sun}. More importantly, we find that the
timescales for growth and decay are an order of magnitude or more longer than
the time until the commencement of core collapse. We conclude that the
-mechanism may not have enough time to significantly amplify core
g-modes prior to collapse.Comment: 32 pages including 12 color figures and 2 tables, submitted to Ap
“Life at the River is a Living Hell:” a qualitative study of trauma, mental health, substance use and HIV risk behavior among female fish traders from the Kafue Flatlands in Zambia
Abstract
Background
In Western settings, the relationship between trauma history, posttraumatic stress disorder, substance use, and HIV risk behavior, is well established. Although female fish traders in Zambia are affected by HIV at rates estimated to be 4–14 times higher than the national prevalence, no studies have examined the co-occurring issues of trauma, substance use and HIV risk behavior among this vulnerable population. The current study examined: 1) trauma history, trauma symptoms and HIV risk behaviors and 2) the relationship between these co-occurring issues among female fish traders from the Kafue Flatlands in Zambia.
Methods
Twenty individual semi-structured qualitative interviews and a focus group discussion (n = 12 participants) were conducted with female fish traders in the Kafue Flatlands of Zambia. Template analysis was used to examine the data.
Results
The findings indicate that female fish traders in Zambia are at risk of multiple and ongoing traumatic events and daily stressors, severe mental health symptoms (including western conceptualizations of disorders such as anxiety, depression, post-traumatic stress disorder (PTSD) and complicated grief, as well as local idioms of distress), substance abuse, and HIV sexual risk behaviors. The results suggest a relationship between trauma and HIV sexual risk behavior in this population.
Conclusions
The indication of these co-occurring issues demonstrates the need for HIV prevention intervention efforts, which account for trauma, mobility, and psychosocial outcomes in order to reduce HIV sexual risk behavior among female fish traders in Zambia.http://deepblue.lib.umich.edu/bitstream/2027.42/136165/1/12905_2017_Article_369.pd
The S-Star Cluster at the Center of the Milky Way: On the nature of diffuse NIR emission in the inner tenth of a parsec
Sagittarius A*, the super-massive black hole at the center of the Milky Way,
is surrounded by a small cluster of high velocity stars, known as the S-stars.
We aim to constrain the amount and nature of stellar and dark mass associated
with the cluster in the immediate vicinity of Sagittarius A*. We use
near-infrared imaging to determine the -band luminosity function
of the S-star cluster members, and the distribution of the diffuse background
emission and the stellar number density counts around the central black hole.
This allows us to determine the stellar light and mass contribution expected
from the faint members of the cluster. We then use post-Newtonian N-body
techniques to investigate the effect of stellar perturbations on the motion of
S2, as a means of detecting the number and masses of the perturbers. We find
that the stellar mass derived from the -band luminosity
extrapolation is much smaller than the amount of mass that might be present
considering the uncertainties in the orbital motion of the star S2. Also the
amount of light from the fainter S-cluster members is below the amount of
residual light at the position of the S-star cluster after removing the bright
cluster members. If the distribution of stars and stellar remnants is strongly
enough peaked near Sagittarius A*, observed changes in the orbital elements of
S2 can be used to constrain both their masses and numbers. Based on simulations
of the cluster of high velocity stars we find that at a wavelength of 2.2
m close to the confusion level for 8 m class telescopes blend stars will
occur (preferentially near the position of Sagittarius A*) that last for
typically 3 years before they dissolve due to proper motions.Comment: 14 pages, 11 figures, minor changes to match the published version in
Astronomy & Astrophysic
Cosmological thermodynamics and deflationary gas universe
We establish a general thermodynamic scheme for cosmic fluids with internal
self-interactions and discuss equilibrium and non-equilibrium aspects of such
systems in connection with (generalized) symmetry properties of the
cosmological dynamics. As an example we construct an exactly solvable gas
dynamical model of a ``deflationary'' transition from an initial de Sitter
phase to a subsequent Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) period.
We demonstrate that this dynamics represents a manifestation of a conformal
symmetry of an ``optical'' metric, characterized by a specific effective
refraction index of the cosmic medium.Comment: 12 pages, to appear in PR
The physical scale of the far-infrared emission in the most luminous submillimetre galaxies II: evidence for merger-driven star formation
We present high-resolution 345 GHz interferometric observations of two
extreme luminous (L_{IR}>10^{13} L_sun), submillimetre-selected galaxies (SMGs)
in the COSMOS field with the Submillimeter Array (SMA). Both targets were
previously detected as unresolved point-sources by the SMA in its compact
configuration, also at 345 GHz. These new data, which provide a factor of ~3
improvement in resolution, allow us to measure the physical scale of the
far-infrared in the submillimetre directly. The visibility functions of both
targets show significant evidence for structure on 0.5-1 arcsec scales, which
at z=1.5 translates into a physical scale of 5-8 kpc. Our results are
consistent with the angular and physical scales of two comparably luminous
objects with high-resolution SMA followup, as well as radio continuum and CO
sizes. These relatively compact sizes (<5-10 kpc) argue strongly for
merger-driven starbursts, rather than extended gas-rich disks, as the preferred
channel for forming SMGs. For the most luminous objects, the derived sizes may
also have important physical consequences; under a series of simplifying
assumptions, we find that these two objects in particular are forming stars
close to or at the Eddington limit for a starburst.Comment: 9 pages, 3 Figures, submitted to MNRA
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