The predominant relationship between sexual environment characteristics and HIV-serodiscordant condomless anal sex among HIV-positive men who have sex with men (MSM)

In some studies, situational factors have been shown to be stronger predictors of condomless sex than individual risk factors. Cross-sectional relationships between condomless anal sex (CAS) with HIV-serodiscordant partners and risk factors across ecological levels (individual, sexual environment) were examined using a sample (N = 60) of HIV-positive men who have sex with men (MSM) who reported multiple recent episodes of CAS. Negative binomial regressions were used to evaluate the association of contextual risk factors (e.g., substance use during sex, transactional sex, public sex, sex at a sex party) with recent condomless sex, controlling for demographics and mental health. Results demonstrated that sexual environment factors, particularly sex under the influence of drugs or alcohol (B = .019, p < .05), transactional sex (B = .035, p < .01), and public sex (B = .039, p < .01) explained a large proportion of the variance in CAS. Only sex at a sex party was not related to CAS (p = .39). For each additional sexual environment in which men engaged, their rates of CAS increased (B = .39, p < .01). Secondary prevention interventions that are tailored to the proximal sexual environment could be maximally effective, particularly if they address substance use and other challenging sexual situations.We are very grateful to the participants for their time and efforts in the study. Support for the current study came from a feasibility grant (PI: Conall O'Cleirigh) from the Harvard University Center for AIDS Research (Parent Grant: P30AI060354, PI: Bruce Walker, MD) awarded to Dr. Conall O'Cleirigh. Investigator support for Dr. Steven Safren also came from NIH Grant K24MH094214. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. (P30AI060354 - Harvard University Center for AIDS Research; K24MH094214 - NIH)Accepted manuscrip

Adolescent HIV Pre Exposure Prophylaxis Prescribing Practices Among Family Medicine Physicians: Limited Immediate Uptake

This study aims to: Examine the adolescent PrEP prescribing practices and knowledge of family medicine physicians. Begin to identify areas that might be key targets for interventions which may lead to increased adolescent PrEP prescribing uptake.https://jdc.jefferson.edu/fmposters/1005/thumbnail.jp

Adolescent HIV Pre-Exposure Prophylaxis Prescribing Practices Among Family Medicine Physicians: Limited Immediate Uptake

Introduction: In the United States, individuals aged 13-24 made up 21% of new HIV infections in 2016. In 2018, the FDA approved tenofovir/emtricitabine as HIV pre-exposure prophylaxis (PrEP) for adolescents aged 15-17. In 2019, we examined adolescent PrEP prescribing practices among family medicine physicians at an academic family medicine practice. Methods: Physicians were invited to complete an online questionnaire assessing PrEP knowledge, attitudes, and prescribing practices. Differences in PrEP knowledge and attitudes among providers who prescribe PrEP to adolescents versus those who do not were examined using independent samples t-tests. Results: 50 out of 99 surveys were completed. Respondents were 90% White, 84% heterosexual, 50% attendings, 50% residents/fellows, and 2% HIV specialists. All respondents had heard of PrEP before the survey, 76% had prescribed PrEP and 70% reported being aware of the FDA approval of PrEP for adolescents. While 86% reported treating patients aged 15-17, only 6% reported having prescribed PrEP to this demographic. Physicians who reported prescribing PrEP to adolescents reported greater comfort assessing for indications for PrEP, t(48)= -2.23, p \u3c 0.05, greater PrEP knowledge, t(47)= -3.34, p \u3c 0.005, and felt PrEP was safer, t(48)= -2.09, p \u3c 0.05, compared to physicians who had not. Conclusion: Despite universal awareness of PrEP, high rates of prescribing to adults, and awareness of FDA approval of PrEP for adolescents, PrEP prescribing to adolescents in our sample remains limited. Differences between providers who have and have not prescribed PrEP to adolescents suggest targeted training may boost prescribing to this demographic

Psychological morbidity and autonomic reactivity to emotional stimulus in parental cancer: a study with children caregivers

Literature suggests that parental cancer can provoke aversive emotional arousal in adult children, who may perceive caregiving as a traumatic experience. Limited research has been conducted on emotional and physiological impact of family caregiving for cancer patients undergoing chemotherapy. The aim of the present study was to examine psychological and physiological responses in parental cancer’s caregivers. Two matched groups of adult children, with 78 participants each (parental cancer vs. control), completed psychological measures of distress, post-traumatic stress disorder (PTSD) symptoms, and burden. Additionally, each participant visualised standardised pictures with different emotional valences, while cardiovascular (heart rate) and electrodermal responses (skin conductance) were recorded. Between-group analysis showed significant differences on all psychological variables, and on skin conductance for all types of pictures. However, for the heart rate responses, differences were found only for pictures with unpleasant emotional arousal. In the parental cancer group, the heart rate peak response stood out as a predictor of PTSD symptoms, after controlling for distress and burden. This study highlights the important role of psychophysiological measures of family caregiving in oncology. Physiological responses may explain a higher prevalence of PTSD symptoms. Therefore, biofeedback combined with targeted psychosocial interventions for relaxation could be of great clinical value for this populationFundação para a Ciência e a Tecnologia (FCT

Tracking Rotational Diffusion of Colloidal Clusters

We describe a novel method of tracking the rotational motion of clusters of colloidal particles. Our method utilizes rigid body transfor- mations to determine the rotations of a cluster and extends conventional proven particle tracking techniques in a simple way, thus facilitating the study of rotational dynamics in systems containing or composed of colloidal clusters. We test our method by measuring dynamical properties of simulated Brownian clusters under conditions relevant to microscopy experiments. We then use the technique to track and describe the motions of a real colloidal cluster imaged with confocal microscopy.Comment: 14 pages, 6 figures. Submitted to Optics Expres

Symbolic management and the glass cliff. Evidence from the boardroom careers of female and male directors

This paper uses archival board data to demonstrate that women who take positions as directors of UK companies have shorter tenures than their male counterparts. We show that female directors face a much higher risk of dismissal as they approach nine years of service on the board when their long service deprives them of the all-important classifi- cation as ‘independent’. At this point, their position on the board becomes precarious. Male directors do not suffer the same increase in boardroom exit. This gender-specific difference is shown to be clearly linked to the independence status. It is argued that these observations are consistent with the notion that female directors are being used in the symbolic management of corporate governance and that at nine years, when the cloak of independence disappears, women directors are then exposed to the biases that arise from role congruity issues

Fabrication of polyhedral particles from spherical colloids and their self-assembly into rotator phases

Particle shape is a critical parameter that plays an important role in self-assembly, for example, in designing targeted complex structures with desired properties. In the last decades an unprecedented range of monodisperse nanoparticle systems with control over the shape of the particles have become available. In contrast, the choice of micron-sized colloidal building blocks of particles with flat facets, i.e., particles with polygonal shapes, is significantly more limited. This can be attributed to the fact that, contrary to nanoparticles, the larger colloids are significantly harder to synthesize as single crystals. Herein, we demonstrate that the simplest building block, such as the micron-sized polymeric spherical colloidal particle, is already enough to fabricate particles with regularly placed flat facets, including completely polygonal shapes with sharp edges. As an illustration that the yields are high enough for further self-assembly studies we demonstrate the formation of 3D rotator phases of fluorescently labelled, micron-sized and charged rhombic dodecahedron particles. Our method for fabricating polyhedral particles opens a new avenue for designing new materials.Comment: 5 pages, published in Angewandte Chemie International Editio

The internal structure of poly(methyl methacrylate) latexes in nonpolar solvents

Hypothesis: Poly(methyl methacrylate) (PMMA) latexes in nonpolar solvents are an excellent model system to understand phenomena in low dielectric media, and understanding their internal structure is critical to characterizing their performance in both fundamental studies of colloidal interactions and in potential industrial applications. Both the PMMA cores and the poly(12-hydroxystearic acid) (PHSA) shells of the latexes are known to be penetrable by solvent and small molecules, but the relevance of this for the properties of these particles is unknown. Experiments: These particles can be prepared in a broad range of sizes, and two PMMA latexes dispersed in n-dodecane (76 and 685 nm in diameter) were studied using techniques appropriate to their size. Small-angle scattering (using both neutrons and X-rays) was used to study the small latexes, and analytical centrifugation was used to study the large latexes. These studies enabled the calculation of the core densities and the amount of solvent in the stabilizer shells for both latexes. Both have consequences on interpreting measurements using these latexes. Findings: The PHSA shells are highly solvated (∼85% solvent by volume), as expected for effective steric stabilizers. However, the PHSA chains do contribute to the intensity of neutron scattering measurements on concentrated dispersions and cannot be ignored. The PMMA cores have a slightly lower density than PMMA homopolymer, which shows that only a small free volume is required to allow small molecules to penetrate into the cores. Interestingly, the observations are essentially the same, regardless of the size of the particle; these are general features of these polymer latexes. Despite the latexes being used as a model physical system, the internal chemical structure is complex and must be fully considered when characterizing them