1,142 research outputs found

    South African healthcare provider perspectives on transitioning adolescents into adult HIV care

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    Background. The first generation of South African (SA) children perinatally infected with HIV is entering adulthood, and there is now a pressing need for systematised transfer of these patients from paediatric to adult care.Objectives. Previous research has investigated the HIV healthcare transition in North America and Europe, yet none has been conducted in SA. Our study is the first to describe the perspectives of healthcare providers overseeing the transition in resource-limited settings.Methods. We approached healthcare providers working in government paediatric HIV clinics and hospitals in the Western Cape Province, SA. Seven physicians and counsellors in adolescent/paediatric care, representing five clinics, were  interviewed, and 43 completed a written survey. Interviews addressed the current state of the transition, barriers and facilitators, and model components. Interviews were assessed for major themes using framework analysis, while logistic regression was applied to survey responses to identify associations with measured covariates.Results. Analysis of interview transcripts revealed several overarching perspectives that were corroborated by survey responses. One barrier identified was the  healthcare providers’ difficulty in letting go of their relationships with the adolescent patients. Since healthcare providers regarded their patients as particularly  vulnerable, they felt a strong and protective attachment towards them. A second barrier identified was a lack of structure and effective communication between adult and paediatric providers; accordingly, healthcare providers feared that they were transferring their adolescents unprepared, to a judgemental, depersonalised and overburdened environment. All interviewees and a majority of survey respondents (>80%) agreed that the formation of adolescent support groups in adult care clinics as well as a later transition age would improve the transition process.Conclusion. This study highlights the need for a systematic healthcare transition for HIV-positive adolescents cared for in the Western Cape, while acknowledging the limitations of the current healthcare infrastructure. Several feasible   recommendations have been identified, including forming support groups and greater involvement of adolescent healthcare providers to facilitate the transition

    Effects of habitat and livestock on nest productivity of the Asian houbara Chlamydotis macqueenii in Bukhara Province, Uzbekistan

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    To inform population support measures for the unsustainably hunted Asian houbara Chlamydotis macqueenii (IUCN Vulnerable) we examined potential habitat and land-use effects on nest productivity in the Kyzylkum Desert, Uzbekistan. We monitored 177 nests across different semi-arid shrub assemblages (clay-sand and salinity gradients) and a range of livestock densities (0–80 km-2). Nest success (mean 51.4%, 95% CI 42.4–60.4%) was similar across four years; predation caused 85% of those failures for which the cause was known, and only three nests were trampled by livestock. Nesting begins within a few weeks of arrival when food appears scarce, but later nests were more likely to fail owing to the emergence of a key predator, suggesting foraging conditions on wintering and passage sites may be important for nest productivity. Nest success was similar across three shrub assemblages and was unrelated to landscape rugosity, shrub frequency or livestock density, but was greater with taller mean shrub height (range 13–67 cm) within 50 m. Clutch size (mean = 3.2 eggs) and per-egg hatchability in successful nests (87.5%) did not differ with laying date, shrub assemblage or livestock density. We therefore found no evidence that livestock density reduced nest productivity across the range examined, while differing shrub assemblages appeared to offer similar habitat quality. Asian houbara appear well-adapted to a range of semi-desert habitats and tolerate moderate disturbance by pastoralism. No obvious in situ mitigation measures arise from these findings, leaving regulation and control as the key requirement to render hunting sustainable

    Alpha-band rhythms in visual task performance: phase-locking by rhythmic sensory stimulation

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    Oscillations are an important aspect of neuronal activity. Interestingly, oscillatory patterns are also observed in behaviour, such as in visual performance measures after the presentation of a brief sensory event in the visual or another modality. These oscillations in visual performance cycle at the typical frequencies of brain rhythms, suggesting that perception may be closely linked to brain oscillations. We here investigated this link for a prominent rhythm of the visual system (the alpha-rhythm, 8-12 Hz) by applying rhythmic visual stimulation at alpha-frequency (10.6 Hz), known to lead to a resonance response in visual areas, and testing its effects on subsequent visual target discrimination. Our data show that rhythmic visual stimulation at 10.6 Hz: 1) has specific behavioral consequences, relative to stimulation at control frequencies (3.9 Hz, 7.1 Hz, 14.2 Hz), and 2) leads to alpha-band oscillations in visual performance measures, that 3) correlate in precise frequency across individuals with resting alpha-rhythms recorded over parieto-occipital areas. The most parsimonious explanation for these three findings is entrainment (phase-locking) of ongoing perceptually relevant alpha-band brain oscillations by rhythmic sensory events. These findings are in line with occipital alpha-oscillations underlying periodicity in visual performance, and suggest that rhythmic stimulation at frequencies of intrinsic brain-rhythms can be used to reveal influences of these rhythms on task performance to study their functional roles

    The gray matter volume of the amygdala is correlated with the perception of melodic intervals: a voxel-based morphometry study

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    Music is not simply a series of organized pitches, rhythms, and timbres, it is capable of evoking emotions. In the present study, voxel-based morphometry (VBM) was employed to explore the neural basis that may link music to emotion. To do this, we identified the neuroanatomical correlates of the ability to extract pitch interval size in a music segment (i.e., interval perception) in a large population of healthy young adults (N = 264). Behaviorally, we found that interval perception was correlated with daily emotional experiences, indicating the intrinsic link between music and emotion. Neurally, and as expected, we found that interval perception was positively correlated with the gray matter volume (GMV) of the bilateral temporal cortex. More important, a larger GMV of the bilateral amygdala was associated with better interval perception, suggesting that the amygdala, which is the neural substrate of emotional processing, is also involved in music processing. In sum, our study provides one of first neuroanatomical evidence on the association between the amygdala and music, which contributes to our understanding of exactly how music evokes emotional responses

    Does a SLAP lesion affect shoulder muscle recruitment as measured by EMG activity during a rugby tackle?

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    Background: The study objective was to assess the influence of a SLAP lesion on onset of EMG activity in shoulder muscles during a front on rugby football tackle within professional rugby players. Methods: Mixed cross-sectional study evaluating between and within group differences in EMG onset times. Testing was carried out within the physiotherapy department of a university sports medicine clinic. The test group consisted of 7 players with clinically diagnosed SLAP lesions, later verified on arthroscopy. The reference group consisted of 15 uninjured and full time professional rugby players from within the same playing squad. Controlled tackles were performed against a tackle dummy. Onset of EMG activity was assessed from surface EMG of Pectorialis Major, Biceps Brachii, Latissimus Dorsi, Serratus Anterior and Infraspinatus muscles relative to time of impact. Analysis of differences in activation timing between muscles and limbs (injured versus non-injured side and non injured side versus matched reference group). Results: Serratus Anterior was activated prior to all other muscles in all (P = 0.001-0.03) subjects. In the SLAP injured shoulder Biceps was activated later than in the non-injured side. Onset times of all muscles of the noninjured shoulder in the injured player were consistently earlier compared with the reference group. Whereas, within the injured shoulder, all muscle activation timings were later than in the reference group. Conclusions: This study shows that in shoulders with a SLAP lesion there is a trend towards delay in activation time of Biceps and other muscles with the exception of an associated earlier onset of activation of Serratus anterior, possibly due to a coping strategy to protect glenohumeral stability and thoraco-scapular stability. This trend was not statistically significant in all cases

    Interaction of hope and optimism with anxiety and depression in a specific group of cancer survivors: a preliminary study

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    <p>Abstract</p> <p>Background</p> <p>Anxiety and depression have been identified as a common psychological distress faced by the majority of cancer patients. With the increasing number of cancer cases, increasing demands will be placed on health systems to address effective psychosocial care and therapy. The objective of this study was to assess the possible role of hope and optimism on anxiety and depression. We also wanted to investigate if there is a specific component of hope that could play a role in buffering anxiety and depression amongst cancer patients.</p> <p>Methods</p> <p>A retrospective cross sectional study was conducted in the outpatient station of the Oral and Maxillofacial Surgery at the University of Hong Kong, Hong Kong SAR, PR-China. Fifty patients successfully treated for OC cancer were recruited after their informed consents had been obtained during the review clinic. During their regular follow-up controls in the outpatient clinic the patients compiled the hospital anxiety and depression scale (HADS), hope scale (HS) and the life orientation scale-revised (LOT-R).</p> <p>Results</p> <p>Hope was negatively correlated with depression (<it>r </it>= -.55, <it>p </it>< .001) and anxiety (r = -.38, <it>p </it>< .05). Similar pattern was found between optimism and the latter adjustment outcomes (depression: <it>r </it>= -.55, <it>p </it>< .001; anxiety: <it>r </it>= -.35, <it>p </it>< .05). Regression analyses indentified that both hope and optimism were significant predictors of depression. Hope and optimism had equal association with depression (hope: <it>β </it>= .40 versus optimism: <it>β </it>= .38). Hope and optimism together were significantly predictive of anxiety, whereas neither hope nor optimism alone was significant individual predictors of anxiety.</p> <p>Conclusions</p> <p>Hope and optimism both negatively correlated with patients' level of anxiety and depression. Besides theoretical implications, this study brings forward relevant findings related to developing specific clinical psychological care in the field of oncology that to date has not been researched specifically in the field of oncology. The results of this study will help guide the direction of future prospective studies in the field of oncology. This will contribute significantly to increasing patients quality of life as well enabling health care facilities to provide all cancer patients a more holistic cancer care.</p

    The Minimal Autoinhibited Unit of the Guanine Nucleotide Exchange Factor Intersectin

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    Intersectin-1L is a member of the Dbl homology (DH) domain guanine nucleotide exchange factors (GEF) which control Rho-family GTPase signaling. Intersectin-1L is a GEF that is specific for Cdc42. It plays an important role in endocytosis, and is regulated by several partners including the actin regulator N-WASP. Intact intersectin-1L shows low Cdc42 exchange activity, although the isolated catalytic DH domain shows high activity. This finding suggests that the molecule is autoinhibited. To investigate the mechanism of autoinhibition we have constructed a series of domain deletions. We find that the five SH3 domains of intersectin are important for autoinhibition, with the fifth domain (SH3(E)) being sufficient for the bulk of the autoinhibitory effect. This SH3 domain appears to primarily interact with the DH domain. We have determined the crystal structure of the SH3(E)-DH domain construct, which shows a domain swapped arrangement in which the SH3 from one monomer interacts with the DH domain of the other monomer. Analytical ultracentrifugation and gel filtration, however, show that under biochemical concentrations, the construct is fully monomeric. Thus we propose that the actual autoinhibited structure contains the related intramolecular SH3(E)-DH interaction. We propose a model in which this intramolecular interaction may block or distort the GTPase binding region of the DH domain

    Specialized Learning in Antlions (Neuroptera: Myrmeleontidae), Pit-Digging Predators, Shortens Vulnerable Larval Stage

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    Unique in the insect world for their extremely sedentary predatory behavior, pit-dwelling larval antlions dig pits, and then sit at the bottom and wait, sometimes for months, for prey to fall inside. This sedentary predation strategy, combined with their seemingly innate ability to detect approaching prey, make antlions unlikely candidates for learning. That is, although scientists have demonstrated that many species of insects possess the capacity to learn, each of these species, which together represent multiple families from every major insect order, utilizes this ability as a means of navigating the environment, using learned cues to guide an active search for food and hosts, or to avoid noxious events. Nonetheless, we demonstrate not only that sedentary antlions can learn, but also, more importantly, that learning provides an important fitness benefit, namely decreasing the time to pupate, a benefit not yet demonstrated in any other species. Compared to a control group in which an environmental cue was presented randomly vis-à-vis daily prey arrival, antlions given the opportunity to associate the cue with prey were able to make more efficient use of prey and pupate significantly sooner, thus shortening their long, highly vulnerable larval stage. Whereas “median survival time,” the point at which half of the animals in each group had pupated, was 46 days for antlions receiving the Learning treatment, that point never was reached in antlions receiving the Random treatment, even by the end of the experiment on Day 70. In addition, we demonstrate a novel manifestation of antlions' learned response to cues predicting prey arrival, behavior that does not match the typical “learning curve” but which is well-adapted to their sedentary predation strategy. Finally, we suggest that what has long appeared to be instinctive predatory behavior is likely to be highly modified and shaped by learning

    Raising the profile of pilot and feasibility studies in relation to the development, evaluation and implementation of patient-reported outcome measures.

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    This editorial introduces a new special series on the pilot and feasibility testing of patient-reported outcome measures (PROMs) in the on-line open access journal Pilot and Feasibility Studies. Pilot and feasibility studies are typically implemented to address issues of uncertainty before undertaking a larger definitive study such as a randomised controlled trial or large scale survey. This editorial considers the role that such pilot and feasibility testing plays in relation to the development, evaluation and implementation of PROMs. This is often an essential element of PROM research but is typically overlooked-especially within current methodological guidance, reporting space and also debate. This editorial aims to open up a dialogue about the role of pilot and feasibility testing in relation to PROMs. It highlights some of the areas in PROMs research where these types of studies have been carried out and discusses the ways in which the PROM community may be better supported and encouraged to integrate this element of the research process into their PROM-based work

    Exceptional river gorge formation from unexceptional floods

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    An understanding of rates and mechanisms of incision and knickpoint retreat in bedrock rivers is fundamental to perceptions of landscape response to external drivers, yet only sparse field data are available. Here we present eye witness accounts and quantitative surveys of rapid, amphitheatre-headed gorge formation in unweathered granite from the overtopping of a rock-cut dam spillway by small-moderate floods (~100–1,500 m3 s−1). The amount of erosion demonstrates no relationship with flood magnitude or bedload availability. Instead, structural pattern of the bedrock through faults and joints appears to be the primary control on landscape change. These discontinuities facilitate rapid erosion (>270 m headward retreat; ~100 m incision; and ~160 m widening over 6 years) principally through fluvial plucking and block topple. The example demonstrates the potential for extremely rapid transient bedrock erosion even when rocks are mechanically strong and flood discharges are moderate. These observations are relevant to perceived models of gorge formation and knickpoint retreat
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