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Introduction: Oral pre-exposure prophylaxis (PrEP) is a promising new prevention approach for those most at risk of HIV infection. However, there are concerns that behavioural disinhibition, specifically reductions in condom use, might limit PrEP's protective effect. This study uses the case of female sex workers (FSWs) in Johannesburg, South Africa, to assess whether decreased levels of condom use following the introduction of PrEP may limit HIV risk reduction. Methods: We developed a static model of HIV risk and compared HIV-risk estimates before and after the introduction of PrEP to determine the maximum tolerated reductions in condom use with regular partners and clients for HIV risk not to change. The model incorporated the effects of increased STI exposure owing to decreased condom use. Noting that condom use with regular partners is generally low, we also estimated the change in condom use tolerated with clients only, to still achieve 50 and 90% risk reduction on PrEP. The model was parameterized using data from Hillbrow, Johannesburg. Sensitivity analyses were performed to ascertain the robustness of our results. Results: Reductions in condom use could be tolerated by FSWs with lower baseline condom use (65%). For scenarios where 75% PrEP effectiveness is attained, 50% HIV-risk reduction on PrEP would be possible even with 100% reduction in condom use from consistent condom use as high as 70% with clients. Increased exposure to STIs through reductions in condom use had limited effect on the reductions in condom use tolerated for HIV risk not to increase on PrEP. Conclusions: PrEP is likely to be of benefit in reducing HIV risk, even if reductions in condom use do occur. Efforts to promote consistent condom use will be critical for FSWs with high initial levels of condom use, but with challenges in adhering to PrEP. Keywords: HIV; pre-exposure prophylaxis; sexually transmitted infections; mathematical models; behaviour change; risk compensation; condom migration To access the supplementary material to this article please see Supplementary Files under Article Tools online., Introduction Oral pre-exposure prophylaxis (PrEP) is a promising approach to HIV prevention. It is hoped that PrEP might become an effective addition to combined HIV prevention and help to significantly [...]

Background Mathematical models can be powerful policymaking tools. Simple, static models are user-friendly for policymakers. More complex, dynamic models account for time-dependent changes but are complicated to understand and produce. Under which conditions are static models adequate? We compare static and dynamic model predictions of whether behavioural disinhibition could undermine the impact of HIV pre-exposure prophylaxis (PrEP) provision to female sex workers in South Africa. Methods A static model of HIV risk was developed and adapted into a dynamic model. Both models were used to estimate the possible reduction in condom use, following PrEP introduction, without increasing HIV risk. The results were compared over a 20-year time horizon, in two contexts: at epidemic equilibrium and during an increasing epidemic. Results Over time horizons of up to 5 years, the models are consistent. Over longer timeframes, the static model overstates the tolerated reduction in condom use where initial condom use is reasonably high (⁠|$\ge$| 50%) and/or PrEP effectiveness is low (⁠|$\le$| 45%), especially during an increasing epidemic. Conclusions Static models can provide useful deductions to guide policymaking around the introduction of a new HIV intervention over short–medium time horizons of up to 5 years. Over longer timeframes, static models may not sufficiently emphasise situations of programmatic importance, especially where underlying epidemics are still increasing. [ABSTRACT FROM AUTHOR]

A $4 \times 4$ silicon photonic switch based on a voltage-driven Mach–Zehnder interferometer (MZi) was modeled using transfer matrices, whose parameters were determined by fitting smoothed, wavelength-resolved transmission measurements. The model is constructed using voltages that configure each MZi in an intermediate (quadrature point) switch setting. This state is not used during normal operation of the switch. The model is then used to predict bias voltage settings for different switch configurations, such as the conventional through and cross connections, as well as other characteristics, such as crosstalk. [ABSTRACT FROM AUTHOR]

This study presents two experiments employing a naming task that test the modulation of stress assignment by syllable structure in Spanish. The first replicates the findings of a previous study in which words containing arguably heavy penultimate diphthongs provoke higher error rates than putatively light monophthong controls when marked for antepenultimate stress. This result is interpreted as support for quantity sensitivity in the language. This experiment also replicates a subtler finding of differential patterning between rising and falling diphthong in their interaction with Spanish stress, suggesting gradient sensitivity to patterns in the lexicon. The second experiment presents the results of an identical task with Spanish-English heritage speakers in which the general effect of syllable weight is replicated, while the effect of diphthong type does not emerge. An analysis of error types suggests that varying levels of reading proficiency among heritage speakers may have led to the lack of the latter result, while still revealing sensitivity to frequencies in the lexicon. The combined results are offered as further evidence of quantity sensitivity among both monolingual and bilingual speakers of Spanish and provide further data in the understudied subfield of heritage phonotactics. [ABSTRACT FROM AUTHOR]

Context. Due to their important ecological roles, predators are increasingly being suggested as targets for biodiversity studies investigating how they respond to landscape change and transformation. But there is limited literature investigating our capacity to accurately monitor changes in their occupancy. Aims. To test the efficacy of playback surveys for monitoring owls as a basis for investigating change in owl occupancy over time. We ask whether playback is an effective tool, and whether it can be optimised to improve its utility. Methods. Using the urban-forest interface of Melbourne, Australia, as a case study, we used playback techniques to survey for the presence of three owl species: the powerful owl (Ninox strenua); southern boobook (Ninox boobook); and eastern barn owl (Tyto javanica). Sites were repeat surveyed at least 16 times throughout the year and occupancy models were developed to establish how season and temperature influence nightly detection probabilities of owls. Key results. All three species of owl were detected through playback survey approaches, but the detection probabilities varied greatly between species and across seasons and temperature conditions. Eastern barn owls are poor candidates for playback surveys due to their low detection probabilities. The southern boobook and powerful owl are responsive to playback, but detection probabilities are influenced by season and/or temperature conditions. To optimise survey approaches, southern boobooks should be surveyed during spring and summer and the powerful owl should be surveyed on nights where the minimum temperature is near 20°C. Conclusions. Although there is considerable interest in using predators such as owls to monitor biodiversity impacts associated with landscape change, poor detection rates can limit their utility. However, optimising survey approaches that consider shifting detection probabilities under different conditions such as time of year or temperature may improve the utility of predators as surrogates in biodiversity monitoring. Implications. Optimising survey approaches for owls considerably reduces the window of opportunity in which to conduct surveys. To counter this, the intensity of survey effort needs to be increased during key periods. The use of highly trained citizen science teams may be one effective way of delivering such an approach. [ABSTRACT FROM AUTHOR]

We report on the flip chip packaging of Micro-Electro-Mechanical System (MEMS)-based digital silicon photonic switching device and the characterization results of 12 × 12 switching ports. The challenges in packaging N 2 electrical and 2N optical interconnections are addressed with single-layer electrical redistribution lines of 25 μm line width and space on aluminum nitride interposer and 13° polished 64-channel lidless fiber array (FA) with a pitch of 127 μm. 50 μm diameter solder spheres are laser-jetted onto the electrical bond pads surrounded by suspended MEMS actuators on the device before fluxless flip-chip bonding. A lidless FA is finally coupled near-vertically onto the device gratings using a 6-degree-of-freedom (6-DOF) alignment system. Fiber-to-grating coupler loss of 4.25 dB/facet, 10–11 bit error rate (BER) through the longest optical path, and 0.4 μs switch reconfiguration time have been demonstrated using 10 Gb/s Ethernet data stream. [ABSTRACT FROM PUBLISHER]

The 2.67 Ga Hackett River volcanogenic massive sulfide (VMS) deposits located in the northeastern Slave province, Nunavut, Canada, are among the largest undeveloped massive sulfide resources in Canada and are silver rich compared to other such deposits of similar age, with Ag grades up to 3,000 g/t. The deposits are hosted by the Ignerit Formation of the felsic to intermediate calc-alkaline Hackett River Group metavolcanic rocks that are part of the province-wide supracrustal Yellowknife Supergroup. One of the most economically significant of the Hackett River deposits is the Hackett River Main zone (Main zone), which consists of two parts: a stratigraphically lower chalcopyrite-rich stringer zone and an upper massive to semimassive polymetallic sulfide lens. The mineralization is subdirided into five types based on mineralogy, textures, and approximate stratigraphie position: (1) disseminated footwall sulfides, (2) copper-rich stringer sulfides, (3) pyrite-poor sphalerite-pyrrhotite-chalcopyrite mineralization at the top of the stringer zone, (4) mineralization in calc-silicate-altered calcareous tuff units, and (5) sphalerite-pyrite massive sulfide. In type 1 mineralization, disseminated pyrite, pyrrhotite, and sphalerite contain negligible Ag and in type 2, Bi-Ag-(Pb) sulfides, Ag-Bi-Se-enriched galena and chaicopyrite are the dominant Ag hosts. Within type 3, Ag-ricli tetraliedrite (freibergite) and galena are the main Ag hosts. In type 4, Ag is hosted in disseminated electrum and freibergite, and within type 5 mineralization, freibergite hosts 99% of the Ag. Overall within the Main zone, Ag-rich freibergite contains 79.4% of the Ag, whereas chaicopyrite hosts 6.3% and galena contains 1.8%. Trace minerals such as electrum host the remainder of the Ag, and these have a limited spatial distribution. Zone refining is the most important control on the distribution of Ag within the Main zone and the principal controls on Ag residence are mineralizing fluid temperature, deposit-scale relative redox conditions, sulfidation state, location of the mineralization relative to the hydrothermal conduit, and the ratio of Bi to Sb in the mineralizing fluid available for coupled substitution. Within the freibergite and chaicopyrite, Ag directly substitutes for Cu and replaces Pb in galena by coupled substitution with Bi and, to a lesser extent, Sb. Lower temperatures ca. 250°C, the most reducing conditions favored incorporation in Ag-Bi-rieh galena (plus Se) and Bi-bearing sulfides or Ag-rich chaicopyrite under lesser reducing conditions. [ABSTRACT FROM AUTHOR]

Presents an article on loving a male-to-female transsexual husband. Influence of religion on sexual abstinence; Desire of the partner to have a sex change; Challenges in loving such husband.

Emerging technologies use cell plasma membrane vesicles or "blebs" as an intermediate to form molecularly complete, planar cell surface mimetics that are compatible with a variety of characterization tools and microscopy methods. This approach enables direct incorporation of membrane proteins into supported lipid bilayers without using detergents and reconstitution and preserves native lipids and membrane species. Such a system can be advantageous as in vitro models of in vivo cell surfaces for study of the roles of membrane proteins as drug targets in drug delivery, host-pathogen interactions, tissue engineering, and many other bioanalytical and sensing applications. However, the impact of methods used to induce cell blebbing (vesiculation) on protein and membrane properties is still unknown. This study focuses on characterization of cell blebs created under various bleb-inducing conditions and the result on protein properties (orientation, mobility, activity, etc.) and lipid scrambling in this platform. The orientation of proteins in the cell blebs and planar bilayers is revealed using a protease cleavage assay. Lipid scrambling in both cell blebs and planar bilayers is indicated through an annexin V binding assay. To quantify protein confinement, immobility, etc., incorporation of GPI-linked yellow fluorescent protein (GPI-YFP) was used in conjunction with single-molecule tracking (SMT) microscopy. Finally, to investigate the impact of the bleb induction method on protein activity and expression level, cell blebs expressing human aminopeptidase N (hAPN) were analyzed by an enzyme activity assay and immunoblotting. This work enriches our understanding of cell plasma membrane bleb bilayers as a biomimetic platform, reveals conditions under which specific properties are met, and represents one of the few ways to make molecularly complete supported bilayers directly from cell plasma membranes.