Elasticity of Stiff Polymer Networks

We study the elasticity of a two-dimensional random network of rigid rods (``Mikado model''). The essential features incorporated into the model are the anisotropic elasticity of the rods and the random geometry of the network. We show that there are three distinct scaling regimes, characterized by two distinct length scales on the elastic backbone. In addition to a critical rigidiy percolation region and a homogeneously elastic regime we find a novel intermediate scaling regime, where elasticity is dominated by bending deformations.Comment: 4 pages, 4 figure

The Legacy of the U. S. Public Health Service Study of Untreated Syphilis in African American Men at Tuskegee on the Affordable Care Act and Health Care Reform Fifteen Years after President Clinton's Apology

http://dx.doi.org/10.1080/10508422.2012.73080

Demonstartion of density dependence of x-ray flux in a laser-driven hohlraum

Experiments have been conducted using laser-driven cylindrical hohlraums whose walls are machined from Ta{sub 2}O{sub 5} foams of 100 mg/cc and 4 g/cc densities. Measurements of the radiation temperature demonstrate that the lower density walls produce higher radiation temperatures than the high density walls. This is the first experimental demonstration of the prediction that this would occur [M. D. Rosen and J. H. Hammer, Phys. Rev. E 72, 056403 (2005)]. For high density walls, the radiation front propagates subsonically, and part of the absorbed energy is wasted by the flow kinetic energy. For the lower wall density, the front velocity is supersonic and can devote almost all of the absorbed energy to heating the wall

Personal stigma and use of mental health services among people with depression in a general population in Finland

Background - A minority of people suffering from depression seek professional help for themselves. Stigmatizing attitudes are assumed to be one of the major barriers to help seeking but there is only limited evidence of this in large general population data sets. The aim of this study was to analyze the associations between mental health attitude statements and depression and their links to actual use of mental health services among those with depression. Methods - We used a large cross-sectional data set from a Finnish population survey (N = 5160). Attitudes were measured by scales which measured the belief that people with depression are responsible for their illness and their recovery and attitudes towards antidepressants. Desire for social distance was measured by a scale and depression with the Composite International Diagnostic Interview Short Form (CIDI-SF) instrument. Use of mental health services was measured by self-report. Results - On the social discrimination scale, people with depression showed more social tolerance towards people with mental problems. They also carried more positive views about antidepressants. Among those with depression, users of mental health services, as compared to non-users, carried less desire for social distance to people with mental health problems and more positive views about the effects of antidepressants. More severe depression predicted more active use of services. Conclusions - Although stronger discriminative intentions can reduce the use of mental health services, this does not necessarily prevent professional service use if depression is serious and views about antidepressant medication are realistic.peerReviewe

Modulation of ATP/ADP Concentration at the Endothelial Cell Surface by Flow: Effect of Cell Topography

Determining how flow affects the concentration of the adenine nucleotides ATP and ADP at the vascular endothelial cell (EC) surface is essential for understanding flow-induced mobilization of intracellular calcium. Previously, mathematical models were formulated to describe the ATP/ADP concentration at the EC surface; however, all previous models assumed the endothelium to be flat. In the present study we investigate the effect of surface undulations on ATP/ADP concentration at the EC surface. The results demonstrate that under certain geometric and flow conditions, the ATP + ADP concentration at the EC surface is considerably lower for a wavy cell surface than for a flat surface. Because ECs in regions of disturbed arterial flow are expected to have larger undulations than cells in non-disturbed flow zones, our findings suggest that ECs in regions of flow disturbance would exhibit lower ATP + ADP concentrations at their surfaces, which may lead to impaired calcium signaling. If validated experimentally, the present results may contribute to our understanding of endothelial cell dysfunction observed in regions of disturbed flow

Measuring factors that influence the utilisation of preventive care services provided by general practitioners in Australia

Background: Relatively little research attention has been given to the development of standardised and psychometrically sound scales for measuring influences relevant to the utilisation of health services. This study aims to describe the development, validation and internal reliability of some existing and new scales to measure factors that are likely to influence utilisation of preventive care services provided by general practitioners in Australia.----- Methods: Relevant domains of influence were first identified from a literature review and formative research. Items were then generated by using and adapting previously developed scales and published findings from these. The new items and scales were pre-tested and qualitative feedback was obtained from a convenience sample of citizens from the community and a panel of experts. Principal Components Analyses (PCA) and internal reliability testing (Cronbach's alpha) were then conducted for all of the newly adapted or developed scales utilising data collected from a self-administered mailed survey sent to a randomly selected population-based sample of 381 individuals (response rate 65.6 per cent).----- Results: The PCA identified five scales with acceptable levels of internal consistency were: (1) social support (ten items), alpha 0.86; (2) perceived interpersonal care (five items), alpha 0.87, (3) concerns about availability of health care and accessibility to health care (eight items), alpha 0.80, (4) value of good health (five items), alpha 0.79, and (5) attitudes towards health care (three items), alpha 0.75.----- Conclusion The five scales are suitable for further development and more widespread use in research aimed at understanding the determinants of preventive health services utilisation among adults in the general population

Randomized trial of achieving healthy lifestyles in psychiatric rehabilitation: the ACHIEVE trial

<p>Abstract</p> <p>Background</p> <p>Overweight and obesity are highly prevalent among persons with serious mental illness. These conditions likely contribute to premature cardiovascular disease and a 20 to 30 percent shortened life expectancy in this vulnerable population. Persons with serious mental illness need effective, appropriately tailored behavioral interventions to achieve and maintain weight loss. Psychiatric rehabilitation day programs provide logical intervention settings because mental health consumers often attend regularly and exercise can take place on-site. This paper describes the Randomized Trial of Achieving Healthy Lifestyles in Psychiatric Rehabilitation (ACHIEVE). The goal of the study is to determine the effectiveness of a behavioral weight loss intervention among persons with serious mental illness that attend psychiatric rehabilitation programs. Participants randomized to the intervention arm of the study are hypothesized to have greater weight loss than the control group.</p> <p>Methods/Design</p> <p>A targeted 320 men and women with serious mental illness and overweight or obesity (body mass index ≥ 25.0 kg/m²) will be recruited from 10 psychiatric rehabilitation programs across Maryland. The core design is a randomized, two-arm, parallel, multi-site clinical trial to compare the effectiveness of an 18-month behavioral weight loss intervention to usual care. Active intervention participants receive weight management sessions and physical activity classes on-site led by study interventionists. The intervention incorporates cognitive adaptations for persons with serious mental illness attending psychiatric rehabilitation programs. The initial intensive intervention period is six months, followed by a twelve-month maintenance period in which trained rehabilitation program staff assume responsibility for delivering parts of the intervention. Primary outcomes are weight loss at six and 18 months.</p> <p>Discussion</p> <p>Evidence-based approaches to the high burden of obesity and cardiovascular disease risk in person with serious mental illness are urgently needed. The ACHIEVE Trial is tailored to persons with serious mental illness in community settings. This multi-site randomized clinical trial will provide a rigorous evaluation of a practical behavioral intervention designed to accomplish and sustain weight loss in persons with serious mental illness.</p> <p>Trial Registration</p> <p>Clinical Trials.gov NCT00902694</p

HIV infection and sexual risk among men who have sex with men and women (MSMW): A systematic review and meta-analysis

Objectives: To estimate the number of men who have sex with men and women who are HIV-positive in the United States, and to compare HIV prevalence rates between men who have sex with men and women, men who have sex with men only, and men who have sex with women exclusively. Methods: Following PRISMA guidelines, we conducted a systematic review and meta-analysis of reports referencing HIV prevalence and men who have sex with men and women. We searched PubMed and Ovid PsycINFO for peer-reviewed, U.S.-based articles reporting on HIV prevalence among men who have sex with men and women. We conducted event rate, effect size, moderation and sensitivity analyses. Results: We estimate that 1.0% of U.S. males are bisexually-behaving, and that 121,800 bisexually-behaving men are HIV-positive. Men who have sex with men and women are less than half as likely to be HIV-positive as men who have sex with men only (16.9% vs. 33.3%; OR = 0.41, 95% CI: 0.31, 0.54), but more than five times as likely to be HIV-positive as men who have sex with women exclusively (18.3% vs. 3.5%; OR = 5.71, 95% CI: 3.47, 9.39). They are less likely to engage in unprotected receptive anal intercourse than men who have sex with men only (15.9% vs. 35.0%; OR = 0.36, 95% CI: 0.28, 0.46). Men who have sex with men and women in samples with high racial/ethnic minority proportions had significantly higher HIV prevalence than their counterparts in low racial/ethnic minority samples. Conclusions: This represents the first meta-analysis of HIV prevalence in the U.S. between men who have sex with men and women and men who have sex with men only. Data collection, research, and HIV prevention and care delivery specifically tailored to men who have sex with men and women are necessary to better quantify and ameliorate this population's HIV burden. © 2014 Friedman et al