Prevalence of consensual male–male sex and sexual violence, and associations with HIV in South Africa: A population-based cross-sectional study

Background: In sub-Saharan Africa the population prevalence of men who have sex with men (MSM) is unknown, as is the population prevalence of male-on-male sexual violence, and whether male-on-male sexual violence may relate to HIV risk. This paper describes lifetime prevalence of consensual male–male sexual behavior and male-on-male sexual violence (victimization and perpetration) in two South African provinces, socio-demographic factors associated with these experiences, and associations with HIV serostatus. Methods and Findings: In a cross-sectional study conducted in 2008, men aged 18–49 y from randomly selected households in the Eastern Cape and KwaZulu-Natal provinces provided anonymous survey data and dried blood spots for HIV serostatus assessment. Interviews were completed in 1,737 of 2,298 (75.6%) of enumerated and eligible households. From these households, 1,705 men (97.1%) provided data on lifetime history of same-sex experiences, and 1,220 (70.2%) also provided dried blood spots for HIV testing. 5.4% (n = 92) of participants reported a lifetime history of any consensual sexual activity with another man; 9.6% (n = 164) reported any sexual victimization by a man, and 3.0% (n = 51) reported perpetrating sexual violence against another man. 85.0% (n = 79) of men with a history of consensual sex with men reported having a current female partner, and 27.7% (n = 26) reported having a current male partner. Of the latter, 80.6% (n = 21/26) also reported having a female partner. Men reporting a history of consensual male–male sexual behavior are more likely to have been a victim of male-on-male sexual violence (adjusted odds ratio [aOR] = 7.24; 95% CI 4.26–12.3), and to have perpetrated sexual violence against another man (aOR = 3.10; 95% CI 1.22–7.90). Men reporting consensual oral/anal sex with a man were more likely to be HIV+ than men with no such history (aOR = 3.11; 95% CI 1.24–7.80). Men who had raped a man were more likely to be HIV+ than non-perpetrators (aOR = 3.58; 95% CI 1.17–10.9). Conclusions: In this sample, one in 20 men (5.4%) reported lifetime consensual sexual contact with a man, while about one in ten (9.6%) reported experience of male-on-male sexual violence victimization. Men who reported having had sex with men were more likely to be HIV+, as were men who reported perpetrating sexual violence towards other men. Whilst there was no direct measure of male–female concurrency (having overlapping sexual relationships with men and women), the data suggest that this may have been common. These findings suggest that HIV prevention messages regarding male–male sex in South Africa should be mainstreamed with prevention messages for the general population, and sexual health interventions and HIV prevention interventions for South African men should explicitly address male-on-male sexual violence

Probing Photochemically and Thermally Induced Isomerization Reactions in α-Pyrone

The isomerization dynamics of α-pyrone dissolved in CH₃CN have been probed by femtosecond 267 nm pump/broadband infrared (IR) probe spectroscopy. A novel experimental setup allowed the populations of the parent molecule and ring-opened photoproducts to be monitored over pump/probe time delays ranging between 2 ps and 100 μs within a single experiment, and at 5 different temperatures between 0 and 40 °C. The photochemically prepared α-pyrone­(S₁) molecules decay rapidly (<10 ps) through internal conversion to the S₀ potential energy surface, with an initial quantum yield for parent molecule re-formation of ∼60%. Probing the antisymmetric ketene stretch region (2100–2150 cm^–1) confirms the presence of at least two ring-opened photoproducts, which are assumed to have an <i>E</i>-configuration with respect to the central CC double bond. These ketenes are observed to undergo two distinct, thermally driven, isomerization processes which occur on the nanosecond and microsecond time scales, respectively. The former reaction is ascribed to thermalization of the initially prepared <i>E-</i>isomer populations, while the slower (microsecond) process involves rotation around the central CC double bond leading to formation of <i>Z</i>-isomers. Subsequent rapid <i>Z</i> → <i>Z</i> isomerizations (occurring on a nanosecond time scale) result in ring-closure and a second, longer time recovery of parent molecule population. By determining rates as a function of the sample temperature, barrier heights of 0.23(3) eV and 0.43(2) eV are obtained for the <i>E</i> → <i>E</i> and <i>E</i> → <i>Z</i> transformations, respectively

Molecular photofragmentation dynamics in the gas and condensed phases

Exciting a molecule with an ultraviolet photon often leads to bond fission, but the final outcome of the bond cleavage is typically both molecule and phase dependent. The photodissociation of an isolated gas-phase molecule can be viewed as a closed system: Energy and momentum are conserved, and the fragmentation is irreversible. The same is not true in a solution-phase photodissociation process. Solvent interactions may dissipate some of the photoexcitation energy prior to bond fission and will dissipate any excess energy partitioned into the dissociation products. Products that have no analog in the corresponding gas-phase study may arise by, for example, geminate recombination. Here, we illustrate the extent to which dynamical insights from gas-phase studies can inform our understanding of the corresponding solution-phase photochemistry and how, in the specific case of photoinduced ring-opening reactions, solution-phase studies can in some cases reveal dynamical insights more clearly than the corresponding gas-phase study. </jats:p

Setting a common standard in clinical skills assessment: The experience of the California Consortium for the Assessment of Clinical Competence

Objective or purpose of innovation: To identify common clinical skills competency thresholds across schools by centralizing standard setting for a multi-institutional assessment. Background and/or theoretical framework and importance to the field: The California Consortium for the Assessment of Clinical Competence (CCACC) comprises 10 medical schools that administer a common multi-station clinical skills assessment (CPX). Previously, each institution determined their own, largely norm-referenced passing thresholds for the examination. With the elimination of USMLE Step 2 CS, there is a recognized need for robust clinical skills assessment beyond the individual institutional level. A collaboratively developed, multi-institutional examination with passing thresholds established via a rigorous process offers greater validity evidence for summative decisions made based on its results. Accordingly, the CCACC undertook centralized, criterion-based standard setting for the CPX. Design: Passing thresholds for the six core CPX cases were determined via two methods: modified Angoff, using expert raters from multiple institutions, and borderline regression, using global encounter ratings assigned by standardized patients. Results from the two methods were compared to each other and to institutions’ prior thresholds. Outcomes: Both methods yielded the same cumulative cut score based on averages across all cases (70%), but exhibited variation between individual cases, suggesting case-specificity. Compared with prior thresholds, some institutions’ pass rates would have been higher using the common criterion-referenced cut score, while others would have been lower. Innovation’s strengths and limitations: This study demonstrates the feasibility of centralizing standard setting across multiple institutions using two criterion-based methods. Standardized patient ratings may generate similar passing thresholds to those determined by clinicians. Further studies are necessary to determine whether these findings generalize to other case types and how best to apply centralized standards within each institution’s context. Feasibility and generalizability: The CCACC’s standard setting approaches may be applied across other institutions sharing an assessment, allowing for comparison of learner performance to a common standard. Given the similar results, the choice of method may be determined by resource availability