700 research outputs found

    HIV selfscreening distribution preferences and experiences among men who have sex with men in Mpumalanga Province: Informing policy for South Africa

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    Current research suggests that HIV self-screening (HIVSS) is a feasible and acceptable approach to increase HIV testing among men who have sex with men (MSM). However, few data are available to shape policy around dissemination and implementation. Gaps in knowledge include preferences for distribution of HIVSS kits, potential social harms and benefits of their use, and how much test users would be willing to pay for the kits. The aim was to inform policy recommendations to optimise distribution of HIVSS kits to MSM in South Africa (SA), where there is a high HIV incidence and unmet testing needs. MSM in the high-HIV-prevalence Gert Sibande and Ehlanzeni districts of Mpumalanga Province, SA, were enrolled between October 2015 and May 2017. Participants were provided with their choice of blood or oral fluid HIVSS test kits, receiving 5 kits at enrolment and 4 additional kits at the 3-month follow-up visit. Questionnaires were administered at enrolment, 3 months and 6 months. We analysed participants’ reported social benefits and harms, and their preferences for kit distribution and pricing. Among 127 MSM screened and enrolled, 114 responded to follow-up questionnaires regarding distribution preferences, 49.3% preferred to acquire HIVSS kits at a community-based organisation (CBO) and 42.7% at a clinic, with 8% preferring a pharmacy. Participants with higher education preferred CBO sites for distribution; in other respects preferences were similar by demographic characteristics. Reported social benefits were common, including knowing one’s status, prevention knowledge gained and improved communication with partners. Despite ubiquitous interest in using the kits, the majority of MSM could not afford to purchase test kits. SA guidelines have integrated HIVSS into HIV and testing policy, but little has been published regarding distribution channels of the kits for MSM and other key populations. There is a partnership between the National Department of Health and CBOs that specialise in key population programming to ensure MSM and other populations with unmet testing needs can access affordable test kits. We observed no social harms, and there were multiple social benefits. Consequently, we recommend immediate free or low-cost distribution of HIVSS kits to MSM through community-based initiatives. Future research should continue to assess optimised linkage to care

    HIV self-screening distribution preferences and experiences among men who have sex with men in Mpumalanga Province: Informing policy for South Africa

    Get PDF
    Current research suggests that HIV self-screening (HIVSS) is a feasible and acceptable approach to increase HIV testing among men who have sex with men (MSM). However, few data are available to shape policy around dissemination and implementation. Gaps in knowledge include preferences for distribution of HIVSS kits, potential social harms and benefits of their use, and how much test users would be willing to pay for the kits. The aim was to inform policy recommendations to optimise distribution of HIVSS kits to MSM in South Africa (SA), where there is a high HIV incidence and unmet testing needs. MSM in the high-HIV-prevalence Gert Sibande and Ehlanzeni districts of Mpumalanga Province, SA, were enrolled between October 2015 and May 2017. Participants were provided with their choice of blood or oral fluid HIVSS test kits, receiving 5 kits at enrolment and 4 additional kits at the 3-month follow-up visit. Questionnaires were administered at enrolment, 3 months and 6 months. We analysed participants’ reported social benefits and harms, and their preferences for kit distribution and pricing. Among 127 MSM screened and enrolled, 114 responded to follow-up questionnaires regarding distribution preferences, 49.3% preferred to acquire HIVSS kits at a community-based organisation (CBO) and 42.7% at a clinic, with 8% preferring a pharmacy. Participants with higher education preferred CBO sites for distribution; in other respects preferences were similar by demographic characteristics. Reported social benefits were common, including knowing one’s status, prevention knowledge gained and improved communication with partners. Despite ubiquitous interest in using the kits, the majority of MSM could not afford to purchase test kits. SA guidelines have integrated HIVSS into HIV and testing policy, but little has been published regarding distribution channels of the kits for MSM and other key populations. There is a partnership between the National Department of Health and CBOs that specialise in key population programming to ensure MSM and other populations with unmet testing needs can access affordable test kits. We observed no social harms, and there were multiple social benefits. Consequently, we recommend immediate free or low-cost distribution of HIVSS kits to MSM through community-based initiatives. Future research should continue to assess optimised linkage to care

    Gap structure in the electron-doped Iron-Arsenide Superconductor Ba(Fe0.92Co0.08)2As2: low-temperature specific heat study

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    We report the field and temperature dependence of the low-temperature specific heat down to 400 mK and in magnetic fields up to 9 T of the electron-doped Ba(Fe0.92Co0.08)2As2 superconductor. Using the phonon specific heat obtained from pure BaFe2As2 we find the normal state Sommerfeld coefficient to be 18 mJ/mol.K^2 and a condensation energy of 1.27 J/mol. The temperature dependence of the electronic specific heat clearly indicate the presence of the low-energy excitations in the system. The magnetic field variation of field-induced specific heat cannot be described by single clean s- or d-wave models. Rather, the data require an anisotropic gap scenario which may or may not have nodes. We discuss the implications of these results.Comment: New Journal of Physics in press, 10 pages, 5 figure

    Suffix-specific RNAi Leads to Silencing of F Element in Drosophila melanogaster

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    Separate conserved copies of suffix, a short interspersed Drosophila retroelement (SINE), and also divergent copies in the 3′ untranslated regions of the three genes, have already been described. Suffix has also been identified on the 3′ end of the Drosophila non-LTR F element, where it forms the last conserved domain of the reverse transcriptase (RT). In our current study, we show that the separate copies of suffix are far more actively transcribed than their counterparts on the F element. Transcripts from both strands of suffix are present in RNA preparations during all stages of Drosophila development, providing the potential for the formation of double-stranded RNA and the initiation of RNA interference (RNAi). Using in situ RNA hybridization analysis, we have detected the expression of both sense and antisense suffix transcripts in germinal cells. These sense and antisense transcripts are colocalized in the primary spermatocytes and in the cytoplasm of the nurse cells, suggesting that they form double-stranded RNA. We performed further analyses of suffix-specific small RNAs using northern blotting and SI nuclease protection assays. Among the total RNA preparations isolated from embryos, larvae, pupae and flies, suffix-specific small interfering RNAs (siRNAs) were detected only in pupae. In wild type ovaries, both the siRNAs and longer suffix-specific Piwi-interacting RNAs (piRNAs) were observed, whereas in ovaries of the Dicer-2 mutant, only piRNAs were detected. We further found by 3′ RACE that in pupae and ovaries, F element transcripts lacking the suffix sequence are also present. Our data provide direct evidence that suffix-specific RNAi leads to the silencing of the relative LINE (long interspersed element), F element, and suggests that SINE-specific RNA interference could potentially downregulate a set of genes possessing SINE stretches in their 5′ or 3′ non-coding regions. These data also suggest that double stranded RNAs possessing suffix are processed by both RNAi and an additional silencing mechanism

    Spectroscopic scanning tunneling microscopy insights into Fe-based superconductors

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    In the first three years since the discovery of Fe-based high Tc superconductors, scanning tunneling microscopy (STM) and spectroscopy have shed light on three important questions. First, STM has demonstrated the complexity of the pairing symmetry in Fe-based materials. Phase-sensitive quasiparticle interference (QPI) imaging and low temperature spectroscopy have shown that the pairing order parameter varies from nodal to nodeless s\pm within a single family, FeTe1-xSex. Second, STM has imaged C4 -> C2 symmetry breaking in the electronic states of both parent and superconducting materials. As a local probe, STM is in a strong position to understand the interactions between these broken symmetry states and superconductivity. Finally, STM has been used to image the vortex state, giving insights into the technical problem of vortex pinning, and the fundamental problem of the competing states introduced when superconductivity is locally quenched by a magnetic field. Here we give a pedagogical introduction to STM and QPI imaging, discuss the specific challenges associated with extracting bulk properties from the study of surfaces, and report on progress made in understanding Fe-based superconductors using STM techniques.Comment: 36 pages, 23 figures, 229 reference

    Differential Interactions of the Autonomous Pathway RRM Proteins and Chromatin Regulators in the Silencing of Arabidopsis Targets

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    We have recently shown that two proteins containing RRM-type RNA-binding domains, FCA and FPA, originally identified through their role in flowering time control in Arabidopsis, silence transposons and other repeated sequences in the Arabidopsis genome. In flowering control, FCA and FPA function in the autonomous pathway with conserved chromatin regulators, the histone demethylase FLD and the MSI1-homologue FVE, a conserved WD-repeat protein found in many chromatin complexes. Here, we investigate how the RRM proteins interact genetically with these chromatin regulators at a range of loci in the Arabidopsis genome. We also investigate their interaction with the DNA methylation pathway. In several cases the RRM protein activity at least partially required a chromatin regulator to effect silencing. However, the interactions of the autonomous pathway components differed at each target analysed, most likely determined by certain properties of the target loci and/or other silencing pathways. We speculate that the RNA-binding proteins FCA and FPA function as part of a transcriptome surveillance mechanism linking RNA recognition with chromatin silencing mechanisms

    Improved Heterosis Prediction by Combining Information on DNA- and Metabolic Markers

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    Background: Hybrids represent a cornerstone in the success story of breeding programs. The fundamental principle underlying this success is the phenomenon of hybrid vigour, or heterosis. It describes an advantage of the offspring as compared to the two parental lines with respect to parameters such as growth and resistance against abiotic or biotic stress. Dominance, overdominance or epistasis based models are commonly used explanations. Conclusion/Significance: The heterosis level is clearly a function of the combination of the parents used for offspring production. This results in a major challenge for plant breeders, as usually several thousand combinations of parents have to be tested for identifying the best combinations. Thus, any approach to reliably predict heterosis levels based on properties of the parental lines would be highly beneficial for plant breeding. Methodology/Principal Findings: Recently, genetic data have been used to predict heterosis. Here we show that a combination of parental genetic and metabolic markers, identified via feature selection and minimum-description-length based regression methods, significantly improves the prediction of biomass heterosis in resulting offspring. These findings will help furthering our understanding of the molecular basis of heterosis, revealing, for instance, the presence of nonlinear genotype-phenotype relationships. In addition, we describe a possible approach for accelerated selection in plant breeding

    RNA Is an Integral Component of Chromatin that Contributes to Its Structural Organization

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    Chromatin structure is influenced by multiples factors, such as pH, temperature, nature and concentration of counterions, post-translational modifications of histones and binding of structural non-histone proteins. RNA is also known to contribute to the regulation of chromatin structure as chromatin-induced gene silencing was shown to depend on the RNAi machinery in S. pombe, plants and Drosophila. Moreover, both in Drosophila and mammals, dosage compensation requires the contribution of specific non-coding RNAs. However, whether RNA itself plays a direct structural role in chromatin is not known. Here, we report results that indicate a general structural role for RNA in eukaryotic chromatin. RNA is found associated to purified chromatin prepared from chicken liver, or cultured Drosophila S2 cells, and treatment with RNase A alters the structural properties of chromatin. Our results indicate that chromatin-associated RNAs, which account for 2%–5% of total chromatin-associated nucleic acids, are polyA− and show a size similar to that of the DNA contained in the corresponding chromatin fragments. Chromatin-associated RNA(s) are not likely to correspond to nascent transcripts as they are also found bound to chromatin when cells are treated with α-amanitin. After treatment with RNase A, chromatin fragments of molecular weight >3.000 bp of DNA showed reduced sedimentation through sucrose gradients and increased sensitivity to micrococcal nuclease digestion. This structural transition, which is observed both at euchromatic and heterochromatic regions, proceeds without loss of histone H1 or any significant change in core-histone composition and integrity
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