2,409 research outputs found
Psychometric precision in phenotype definition is a useful step in molecular genetic investigation of psychiatric disorders
Affective disorders are highly heritable, but few genetic risk variants have been consistently replicated in molecular genetic association studies. The common method of defining psychiatric phenotypes in molecular genetic research is either a summation of symptom scores or binary threshold score representing the risk of diagnosis. Psychometric latent variable methods can improve the precision of psychiatric phenotypes, especially when the data structure is not straightforward. Using data from the British 1946 birth cohort, we compared summary scores with psychometric modeling based on the General Health Questionnaire (GHQ-28) scale for affective symptoms in an association analysis of 27 candidate genes (249 single-nucleotide polymorphisms (SNPs)). The psychometric method utilized a bi-factor model that partitioned the phenotype variances into five orthogonal latent variable factors, in accordance with the multidimensional data structure of the GHQ-28 involving somatic, social, anxiety and depression domains. Results showed that, compared with the summation approach, the affective symptoms defined by the bi-factor psychometric model had a higher number of associated SNPs of larger effect sizes. These results suggest that psychometrically defined mental health phenotypes can reflect the dimensions of complex phenotypes better than summation scores, and therefore offer a useful approach in genetic association investigations
Quantification of the SF₆ lifetime based on mesospheric loss measured in the stratospheric polar vortex
Sulfur hexafluoride (SF₆) is a greenhouse gas with one of the highest radiative efficiencies in the atmosphere as well as an important indicator of transport time scales in the stratosphere. The current widely used estimate of the atmospheric lifetime of SF₆ is 3200 years. In this study we use in situ measurements in the 2000 Arctic polar vortex that sampled air with up to 50% SF₆ loss to calculate an SF₆ lifetime. Comparison of these measurements with output from the Whole Atmosphere Community Climate Model (WACCM) shows that WACCM transport into the vortex is accurate and that an important SF₆ loss mechanism, believed to be electron attachment, is missing in the model. Based on the measurements and estimates of the size of the vortex, we calculate an SF₆ lifetime of 850 years with an uncertainty range of 580–1400 years. The amount of SF₆ loss is shown to be consistent with that of HFC‐227ea, which has a lifetime of 670–780 years, adding independent support to our new SF₆ lifetime estimate. Based on the revised lifetime the global warming potential of SF₆ will decrease only slightly for short time horizons (<100 years) but will decrease substantially for time horizons longer than 2000 years. Also, the use of SF6 measurements as an indicator of transport time scales in the stratosphere clearly must account for potential influence from polar vortex air
Examining the Relationships among the Coaching Climate, Life Skills Development and Well-Being in Sport
Using Benson and Saito's framework for positive youth development, we investigated the relationships between the coaching climate, young people's perceived life skills development within sport, and their psychological well-being. British youth sport participants (N=326, Mage=13.81, range=11–18 years) completed a survey assessing the coaching climate, participants' perceived life skills development (teamwork, goal setting, time management, emotional skills, interpersonal communication, social skills, leadership, and problem solving and decision making) and psychological well-being (self-esteem, positive affect, and satisfaction with life). In all analyses, the coaching climate was positively related to young peoples' perceived development of life skills within sport and their psychological well-being. Total life skills development (a summative score of all eight life skills scores) was positively related to all three psychological well-being indicators – providing support for the "pile-up" effect – and partially mediated the relationships between the coaching climate and participants' psychological well-being. Interpretation of the results indicated that coaches should foster the development of multiple life skills in youth sport participants, as they are associated with participants' psychological well-being. One way this can be achieved is through autonomy-supportive coaching behaviours
Association of treatment satisfaction and psychopathological sub-syndromes among involuntary patients with psychotic disorders
Publisher's version: http://www.springerlink.com/content/rx24036274667t10
A meta-analytic review of stand-alone interventions to improve body image
Objective
Numerous stand-alone interventions to improve body image have been developed. The
present review used meta-analysis to estimate the effectiveness of such interventions, and
to identify the specific change techniques that lead to improvement in body image.
Methods
The inclusion criteria were that (a) the intervention was stand-alone (i.e., solely focused on
improving body image), (b) a control group was used, (c) participants were randomly
assigned to conditions, and (d) at least one pretest and one posttest measure of body
image was taken. Effect sizes were meta-analysed and moderator analyses were conducted.
A taxonomy of 48 change techniques used in interventions targeted at body image
was developed; all interventions were coded using this taxonomy.
Results
The literature search identified 62 tests of interventions (N = 3,846). Interventions produced
a small-to-medium improvement in body image (d+ = 0.38), a small-to-medium reduction in
beauty ideal internalisation (d+ = -0.37), and a large reduction in social comparison tendencies
(d+ = -0.72). However, the effect size for body image was inflated by bias both within
and across studies, and was reliable but of small magnitude once corrections for bias were
applied. Effect sizes for the other outcomes were no longer reliable once corrections for
bias were applied. Several features of the sample, intervention, and methodology moderated
intervention effects. Twelve change techniques were associated with improvements in
body image, and three techniques were contra-indicated.
Conclusions
The findings show that interventions engender only small improvements in body image, and
underline the need for large-scale, high-quality trials in this area. The review identifies effective
techniques that could be deployed in future interventions
A cross-sectional study of vascular risk factors in a rural South African population : data from the Southern African Stroke Prevention Initiative (SASPI)
Background: Rural sub-Saharan Africa is at an early stage of economic and health transition. It is
predicted that the 21st century will see a serious added economic burden from non-communicable disease
including vascular disease in low-income countries as they progress through the transition. The stage of
vascular disease in a population is thought to result from the prevalence of vascular risk factors. Already
hypertension and stroke are common in adults in sub-Saharan Africa. Using a multidisciplinary approach
we aimed to assess the prevalence of several vascular risk factors in Agincourt, a rural demographic
surveillance site in South Africa.
Methods: We performed a cross sectional random sample survey of adults aged over 35 in Agincourt
(population ≈ 70 000). Participants were visited at home by a trained nurse who administered a
questionnaire, carried out clinical measurements and took a blood sample. From this we assessed
participants' history of vascular risk, blood pressure using an OMRON 705 CP monitor, waist
circumference, body mass index (BMI), ankle brachial index (ABI), and total and HDL cholesterol.
Results: 402 people (24% men) participated. There was a high prevalence of smoking in men, but the
number of cigarettes smoked was small. There was a striking difference in mean BMI between men and
women (22.8 kg/m2 versus 27.2 kg/m2), but levels of blood pressure were very similar. 43% of participants
had a blood pressure greater than 140/90 or were on anti-hypertensive treatment and 37% of participants
identified with measured high blood pressure were on pharmacological treatment. 12% of participants had
an ABI of < 0.9, sugesting the presence of sub-clinical atheroma. 25.6% of participants had a total
cholesterol level > 5 mmol/l.
Conclusion: We found a high prevalence of hypertension, obesity in women, and a suggestion of
subclinical atheroma despite relatively favourable cholesterol levels in a rural South African population.
South Africa is facing the challenge of an emerging epidemic of vascular disease. Research to establish the
social determinates of these risk factors and interventions to reduce both individual and population risk
are required
Assessing students' experiences of teaching-learning environments and approaches to learning.:Validation of a questionnaire used in different countries and varying contexts.
Protecting eyewitness evidence: Examining the efficacy of a self-administered interview tool
Given the crucial role of eyewitness evidence, statements should be obtained as soon as possible after an incident. This is not always achieved due to demands on police resources. Two studies trace the development of a new tool, the Self-Administered Interview (SAI), designed to elicit a comprehensive initial statement. In Study 1, SAI participants reported more correct details than participants who provided a free recall account, and performed at the same level as participants given a Cognitive Interview. In Study 2, participants viewed a simulated crime and half recorded their statement using the SAI. After a delay of 1 week, all participants completed a free recall test. SAI participants recalled more correct details in the delayed recall task than control participants
Variational Methods for Biomolecular Modeling
Structure, function and dynamics of many biomolecular systems can be
characterized by the energetic variational principle and the corresponding
systems of partial differential equations (PDEs). This principle allows us to
focus on the identification of essential energetic components, the optimal
parametrization of energies, and the efficient computational implementation of
energy variation or minimization. Given the fact that complex biomolecular
systems are structurally non-uniform and their interactions occur through
contact interfaces, their free energies are associated with various interfaces
as well, such as solute-solvent interface, molecular binding interface, lipid
domain interface, and membrane surfaces. This fact motivates the inclusion of
interface geometry, particular its curvatures, to the parametrization of free
energies. Applications of such interface geometry based energetic variational
principles are illustrated through three concrete topics: the multiscale
modeling of biomolecular electrostatics and solvation that includes the
curvature energy of the molecular surface, the formation of microdomains on
lipid membrane due to the geometric and molecular mechanics at the lipid
interface, and the mean curvature driven protein localization on membrane
surfaces. By further implicitly representing the interface using a phase field
function over the entire domain, one can simulate the dynamics of the interface
and the corresponding energy variation by evolving the phase field function,
achieving significant reduction of the number of degrees of freedom and
computational complexity. Strategies for improving the efficiency of
computational implementations and for extending applications to coarse-graining
or multiscale molecular simulations are outlined.Comment: 36 page
Stress related epigenetic changes may explain opportunistic success in biological invasions in Antipode mussels
Different environmental factors could induce epigenetic changes, which are likely involved in the biological invasion process. Some of these factors are driven by humans as, for example, the pollution and deliberate or accidental introductions and others are due to natural conditions such as salinity. In this study, we have analysed the relationship between different stress factors: time in the new location, pollution and salinity with the methylation changes that could be involved in the invasive species tolerance to new environments. For this purpose, we have analysed two different mussels’ species, reciprocally introduced in antipode areas: the Mediterranean blue mussel Mytilus galloprovincialis and the New Zealand pygmy mussel Xenostrobus securis, widely recognized invaders outside their native distribution ranges. The demetylathion was higher in more stressed population, supporting the idea of epigenetic is involved in plasticity process. These results can open a new management protocols, using the epigenetic signals as potential pollution monitoring tool. We could use these epigenetic marks to recognise the invasive status in a population and determine potential biopollutants
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