585 research outputs found
Associations among neighborhood poverty, perceived neighborhood environment, and depressed mood are mediated by physical activity, perceived individual control, and loneliness
Few studies have documented the pathways through which individual level variables mediate the effects of neighborhoods on health. This study used structural equation modeling to examine if neighborhood characteristics are associated with depressive symptoms, and if so, what factors mediated these relationships. Cross-sectional data came from a sample of mostly rural, older adults in North Carolina (n = 1,558). Mediation analysis indicated that associations among neighborhood characteristics and depressive symptoms were mediated by loneliness (standardized indirect effect = −0.19, p < 0.001), physical activity (standardized indirect effect = −0.01, p = 0.003), and perceived individual control (standardized indirect effect = −0.07, p = 0.02) with loneliness emerging as the strongest mediator. Monitoring such individual mediators in formative and process evaluations may increase the precision of neighborhood-based interventions and policies
Identifying critical source areas using multiple methods for effective diffuse pollution mitigation
Diffuse pollution from agriculture constitutes a key pressure on the water quality of freshwaters and is frequently the cause of ecological degradation. The problem of diffuse pollution can be conceptualised with a source-mobilisation-pathway (or delivery)-impact model, whereby the combination of high source risk and strong connected pathways leads to ‘critical source areas’ (CSAs). These areas are where most diffuse pollution will originate, and hence are the optimal places to implement mitigation measures. However, identifying the locations of these areas is a key problem across different spatial scales within catchments. A number of approaches are frequently used for this assessment, although comparisons of these assessments are rarely carried out. We evaluate the CSAs identified via traditional walkover surveys supported by three different approaches, highlighting their benefits and disadvantages. These include a custom designed smartphone app; a desktop geographic information system (GIS) and terrain analysis-based SCIMAP (Sensitive Catchment Integrated Modelling and Analysis Platform) approach; and the use of a high spatial resolution drone dataset as an improved input data for SCIMAP modelling. Each of these methods captures the locations of the CSAs, revealing similarities and differences in the prioritisation of CSA features. The differences are due to the temporal and spatial resolution of the three methods such as the use of static land cover information, the ability to capture small scale features, such as gateways and the incomplete catchment coverage of the walkover survey. The relative costs and output resolutions of the three methods indicate that they are suitable for application at different catchment scales in conjunction with other methods. Based on the results in this paper, it is recommended that a multi-evidence-based approach to diffuse pollution management is taken across catchment spatial scales, incorporating local knowledge from the walkover with the different data resolutions of the SCIMAP approach
Phase diagram of turbulence in superfluid 3He-B
In superfluid 3He-B mutual-friction damping of vortex-line motion decreases
roughly exponentially with temperature. We record as a function of temperature
and pressure the transition from regular vortex motion at high temperatures to
turbulence at low temperatures. The measurements are performed with
non-invasive NMR techniques, by injecting vortex loops into a long column in
vortex-free rotation. The results display the phase diagram of turbulence at
high flow velocities where the transition from regular to turbulent dynamics is
velocity independent. At the three measured pressures 10.2, 29.0, and 34 bar,
the transition is centered at 0.52--0.59Tc and has a narrow width of 0.06Tc
while at zero pressure turbulence is not observed above 0.45Tc.Comment: To be published in J. Low Temp. Phys. (QFS2004 proceedings
Social support needs among patients with advanced breast cancer: Sensitivity trumps substance
Background The importance of social support for cancer patients has been established in previous studies. However, much of the existing research has identified associations between general measures of social support and various health indicators. Nevertheless, some research has begun to suggest the utility of more nuanced understandings of how patients receive and use social support. Objective To examine the roles of nondirective (ie, support that accepts recipients' feelings and is cooperative with their plans) and directive support (ie, support that prescribes "correct" choices and feelings) as well as social support needs and desires among patients with advanced breast cancer. Methods We conducted semi-structured interviews (qualitative method) with 8 patients with stage IV breast cancer to collect qualitative information about the disease-related challenges they faced, the support they received from their families and medical teams, and the appropriateness of directive and nondirective support. In addition, we used the 14-item Hospital Anxiety and Depression Scale (HADS) to assess clinically relevant cut-offs for anxiety and depression and the 16-item Social Support Inventory to assess the provision of nondirective and directive social support to the patients (quantitative method). Results Qualitative findings suggested that there was considerable variability among patients' reports of social support provided by family, friends, and the medical team. From the qualitative data, patients reported directive support as more useful in times of acute need and emphasized the importance of supportive systems rather than supportive persons in providing emotional support. From the quantitative data, patients reported nondirective support as more typical of support received from both family and medical teams than directive support. On the HADS, 1 patient had a score of 9 on the anxiety subscale, above the score of 7 that is for mild anxiety. No patients scored above the criterion for mild depression, also a score of 7. Limitations Very small sample limits the ability to generalize findings. Conclusions The right type of support for patients with advanced breast cancer is contingent on a range of variables, which suggests that the key characteristic of support may not be any particular feature, but the nuanced adjustment of its content and style of delivery to the patient's circumstances. Funding Peers for Progress
The bulk correlation length and the range of thermodynamic Casimir forces at Bose-Einstein condensation
The relation between the bulk correlation length and the decay length of
thermodynamic Casimir forces is investigated microscopically in two
three-dimensional systems undergoing Bose-Einstein condensation: the perfect
Bose gas and the imperfect mean-field Bose gas. For each of these systems, both
lengths diverge upon approaching the corresponding condensation point from the
one-phase side, and are proportional to each other. We determine the
proportionality factors and discuss their dependence on the boundary
conditions. The values of the corresponding critical exponents for the decay
length and the correlation length are the same, equal to 1/2 for the perfect
gas, and 1 for the imperfect gas
Examining the Support Peer Supporters Provide Using Structural Equation Modeling: Nondirective and Directive Support in Diabetes Management
Background: Little research has examined the characteristics of peer support. Pertinent to such examination may be characteristics such as the distinction between nondirective support (accepting recipients’ feelings and cooperative with their plans) and directive (prescribing “correct” choices and feelings). Purpose: In a peer support program for individuals with diabetes, this study examined (a) whether the distinction between nondirective and directive support was reflected in participants’ ratings of support provided by peer supporters and (b) how nondirective and directive support were related to depressive symptoms, diabetes distress, and Hemoglobin A1c (HbA1c). Methods: Three hundred fourteen participants with type 2 diabetes provided data on depressive symptoms, diabetes distress, and HbA1c before and after a diabetes management intervention delivered by peer supporters. At post-intervention, participants reported how the support provided by peer supporters was nondirective or directive. Confirmatory factor analysis (CFA), correlation analyses, and structural equation modeling examined the relationships among reports of nondirective and directive support, depressive symptoms, diabetes distress, and measured HbA1c. Results: CFA confirmed the factor structure distinguishing between nondirective and directive support in participants’ reports of support delivered by peer supporters. Controlling for demographic factors, baseline clinical values, and site, structural equation models indicated that at post-intervention, participants’ reports of nondirective support were significantly associated with lower, while reports of directive support were significantly associated with greater depressive symptoms, altogether (with control variables) accounting for 51% of the variance in depressive symptoms. Conclusions: Peer supporters’ nondirective support was associated with lower, but directive support was associated with greater depressive symptoms
Monotonicity of quantum ground state energies: Bosonic atoms and stars
The N-dependence of the non-relativistic bosonic ground state energy is
studied for quantum N-body systems with either Coulomb or Newton interactions.
The Coulomb systems are "bosonic atoms," with their nucleus fixed, and the
Newton systems are "bosonic stars". In either case there exists some third
order polynomial in N such that the ratio of the ground state energy to the
respective polynomial grows monotonically in N. Some applications of these new
monotonicity results are discussed
Topological quantization and degeneracy in Josephson-junction arrays
We consider the conductivity quantization in two-dimensional arrays of
mesoscopic Josephson junctions, and examine the associated degeneracy in
various regimes of the system. The filling factor of the system may be
controlled by the gate voltage as well as the magnetic field, and its
appropriate values for quantization is obtained by employing the Jain hierarchy
scheme both in the charge description and in the vortex description. The
duality between the two descriptions then suggests the possibility that the
system undergoes a change in degeneracy while the quantized conductivity
remains fixed.Comment: To appear in Phys. Rev.
The Milky Way Bulge: Observed properties and a comparison to external galaxies
The Milky Way bulge offers a unique opportunity to investigate in detail the
role that different processes such as dynamical instabilities, hierarchical
merging, and dissipational collapse may have played in the history of the
Galaxy formation and evolution based on its resolved stellar population
properties. Large observation programmes and surveys of the bulge are providing
for the first time a look into the global view of the Milky Way bulge that can
be compared with the bulges of other galaxies, and be used as a template for
detailed comparison with models. The Milky Way has been shown to have a
box/peanut (B/P) bulge and recent evidence seems to suggest the presence of an
additional spheroidal component. In this review we summarise the global
chemical abundances, kinematics and structural properties that allow us to
disentangle these multiple components and provide constraints to understand
their origin. The investigation of both detailed and global properties of the
bulge now provide us with the opportunity to characterise the bulge as observed
in models, and to place the mixed component bulge scenario in the general
context of external galaxies. When writing this review, we considered the
perspectives of researchers working with the Milky Way and researchers working
with external galaxies. It is an attempt to approach both communities for a
fruitful exchange of ideas.Comment: Review article to appear in "Galactic Bulges", Editors: Laurikainen
E., Peletier R., Gadotti D., Springer Publishing. 36 pages, 10 figure
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