59 research outputs found

    The Relative Influence of Competition and Prey Defenses on the Phenotypic Structure of Insectivorous Bat Ensembles in Southern Africa

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    Deterministic filters such as competition and prey defences should have a strong influence on the community structure of animals such as insectivorous bats that have life histories characterized by low fecundity, low predation risk, long life expectancy, and stable populations. We investigated the relative influence of these two deterministic filters on the phenotypic structure of insectivorous bat ensembles in southern Africa. We used null models to simulate the random phenotypic patterns expected in the absence of competition or prey defences and analysed the deviations of the observed phenotypic pattern from these expected random patterns. The phenotypic structure at local scales exhibited non-random patterns consistent with both competition and prey defense hypotheses. There was evidence that competition influenced body size distribution across ensembles. Competition also influenced wing and echolocation patterns in ensembles and in functional foraging groups with high species richness or abundance. At the same time, prey defense filters influenced echolocation patterns in two species-poor ensembles. Non-random patterns remained evident even after we removed the influence of body size from wing morphology and echolocation parameters taking phylogeny into account. However, abiotic filters such as geographic distribution ranges of small and large-bodied species, extinction risk, and the physics of flight and sound probably also interacted with biotic filters at local and/or regional scales to influence the community structure of sympatric bats in southern Africa. Future studies should investigate alternative parameters that define bat community structure such as diet and abundance to better determine the influence of competition and prey defences on the structure of insectivorous bat ensembles in southern Africa

    Screening and brief interventions for hazardous and harmful alcohol use among patients with active tuberculosis attending primary care clinics in South Africa: a cluster randomized controlled trial protocol

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    <p>Abstract</p> <p>Background</p> <p>In 2008 the World Health Organization (WHO) reported that South Africa had the highest tuberculosis (TB) incidence in the world. This high incidence rate is linked to a number of factors, including HIV co-infection and alcohol use disorders. The diagnosis and treatment package for TB and HIV co-infection is relatively well established in South Africa. However, because alcohol use disorders may present more insidiously, making it difficult to diagnose, those patients with active TB and misusing alcohol are not easily cured from TB. With this in mind, the primary purpose of this cluster randomized controlled trial is to provide screening for alcohol misuse and to test the efficacy of brief interventions in reducing alcohol intake in those patients with active TB found to be misusing alcohol in primary health care clinics in three provinces in South Africa.</p> <p>Methods/Design</p> <p>Within each of the three selected health districts with the highest TB burden in South Africa, 14 primary health care clinics with the highest TB caseloads will be selected. Those agreeing to participate will be stratified according to TB treatment caseload and the type of facility (clinic or community health centre). Within strata from 14 primary care facilities, 7 will be randomly selected into intervention and 7 to control study clinics (42 clinics, 21 intervention clinics and 21 control clinics). At the clinic level systematic sampling will be used to recruit newly diagnosed TB patients. Those consenting will be screened for alcohol misuse using the AUDIT. Patients who screen positive for alcohol misuse over a 6-month period will be given either a brief intervention based on the Information-Motivation-Behavioural Skills (IMB) Model or an alcohol use health education leaflet.</p> <p>A total sample size of 520 is expected.</p> <p>Discussion</p> <p>The trial will evaluate the impact of alcohol screening and brief interventions for patients with active TB in primary care settings in South Africa. The findings will impact public health and will enable the health ministry to formulate policy related to comprehensive treatment for TB and alcohol misuse, which will result in reduction in alcohol use and ultimately improve the TB cure rates.</p> <p>Trial registration number</p> <p>PACTR: <a href="http://apps.who.int/trialsearch/trial.aspx?trialid=PACTR201105000297151">PACTR201105000297151</a></p

    Molecular diet analysis of two african free-tailed bats (molossidae) using high throughput sequencing.

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    Given the diversity of prey consumed by insectivorous bats, it is difficult to discern the composition of their diet using morphological or conventional PCR-based analyses of their faeces. We demonstrate the use of a powerful alternate tool, the use of the Roche FLX sequencing platform to deep-sequence uniquely 5' tagged insect-generic barcode cytochrome c oxidase I (COI) fragments, that were PCR amplified from faecal pellets of two free-tailed bat species Chaerephon pumilus and Mops condylurus (family: Molossidae). Although the analyses were challenged by the paucity of southern African insect COI sequences in the GenBank and BOLD databases, similarity to existing collections allowed the preliminary identification of 25 prey families from six orders of insects within the diet of C. pumilus, and 24 families from seven orders within the diet of M. condylurus. Insects identified to families within the orders Lepidoptera and Diptera were widely present among the faecal samples analysed. The two families that were observed most frequently were Noctuidae and Nymphalidae (Lepidoptera). Species-level analysis of the data was accomplished using novel bioinformatics techniques for the identification of molecular operational taxonomic units (MOTU). Based on these analyses, our data provide little evidence of resource partitioning between sympatric M. condylurus and C. pumilus in the Simunye region of Swaziland at the time of year when the samples were collected, although as more complete databases against which to compare the sequences are generated this may have to be re-evaluated.This study was supported by Bat Conservation International, Etatsraad Georg Bestle og Hustrus Mindelegat and the Oticon Fonden (KB and CN), the Danish Council for Independent Research Natural Sciences ‘Skou’ award (MTPG), and a Natural Sciences and Engineering Research Council of Canada post-doctoral fellowship (ELC). These funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. This study was also supported by the Royal Swaziland Sugar Corporation, who provided field assistance and therefore had a role in data collection

    Baseline Predictors of Sputum Culture Conversion in Pulmonary Tuberculosis: Importance of Cavities, Smoking, Time to Detection and W-Beijing Genotype

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    Background: Time to detection (TTD) on automated liquid mycobacterial cultures is an emerging biomarker of tuberculosis outcomes. The M. tuberculosis W-Beijing genotype is spreading globally, indicating a selective advantage. There is a paucity of data on the association between baseline TTD and W-Beijing genotype and tuberculosis outcomes. Aim: To assess baseline predictors of failure of sputum culture conversion, within the first 2 months of antitubercular therapy, in participants with pulmonary tuberculosis. Design: Between May 2005 and August 2008 we conducted a prospective cohort study of time to sputum culture conversion in ambulatory participants with first episodes of smear and culture positive pulmonary tuberculosis attending two primary care clinics in Cape Town, South Africa. Rifampicin resistance (diagnosed on phenotypic susceptibility testing) was an exclusion criterion. Sputum was collected weekly for 8 weeks for mycobacterial culture on liquid media (BACTEC MGIT 960). Due to missing data, multiple imputation was performed. Time to sputum culture conversion was analysed using a Cox-proportional hazards model. Bayesian model averaging determined the posterior effect probability for each variable. Results: 113 participants were enrolled (30.1% female, 10.5% HIV-infected, 44.2% W-Beijing genotype, and 89% cavities). On Kaplan Meier analysis 50.4% of participants underwent sputum culture conversion by 8 weeks. The following baseline factors were associated with slower sputum culture conversion: TTD (adjusted hazard ratio (aHR) = 1.11, 95% CI 1.02; 1.2), lung cavities (aHR = 0.13, 95% CI 0.02; 0.95), ever smoking (aHR = 0.32, 95% CI 0.1; 1.02) and the W-Beijing genotype (aHR = 0.51, 95% CI 0.25; 1.07). On Bayesian model averaging, posterior probability effects were strong for TTD, lung cavitation and smoking and moderate for W-Beijing genotype. Conclusion: We found that baseline TTD, smoking, cavities and W-Beijing genotype were associated with delayed 2 month sputum culture. Larger studies are needed to confirm the relationship between the W-Beijing genotype and sputum culture conversion.Publisher's versio

    The Association between Household Socioeconomic Position and Prevalent Tuberculosis in Zambia: A Case-Control Study

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    BACKGROUND: Although historically tuberculosis (TB) has been associated with poverty, few analytical studies from developing countries have tried to: 1. assess the relative impact of poverty on TB after the emergence of HIV; 2. explore the causal mechanism underlying this association; and 3. estimate how many cases of TB could be prevented by improving household socioeconomic position (SEP). METHODS AND FINDINGS: We undertook a case-control study nested within a population-based TB and HIV prevalence survey conducted in 2005-2006 in two Zambian communities. Cases were defined as persons (15+ years of age) culture positive for M. tuberculosis. Controls were randomly drawn from the TB-free participants enrolled in the prevalence survey. We developed a composite index of household SEP combining variables accounting for four different domains of household SEP. The analysis of the mediation pathway between household SEP and TB was driven by a pre-defined conceptual framework. Adjusted Population Attributable Fractions (aPAF) were estimated. Prevalent TB was significantly associated with lower household SEP [aOR = 6.2, 95%CI: 2.0-19.2 and aOR = 3.4, 95%CI: 1.8-7.6 respectively for low and medium household SEP compared to high]. Other risk factors for prevalent TB included having a diet poor in proteins [aOR = 3.1, 95%CI: 1.1-8.7], being HIV positive [aOR = 3.1, 95%CI: 1.7-5.8], not BCG vaccinated [aOR = 7.7, 95%CI: 2.8-20.8], and having a history of migration [aOR = 5.2, 95%CI: 2.7-10.2]. These associations were not confounded by household SEP. The association between household SEP and TB appeared to be mediated by inadequate consumption of protein food. Approximately the same proportion of cases could be attributed to this variable and HIV infection (aPAF = 42% and 36%, respectively). CONCLUSIONS: While the fight against HIV remains central for TB control, interventions addressing low household SEP and, especially food availability, may contribute to strengthen our control efforts

    The elusive archaeology of Kongo urbanism: the case of Kindoki, Mbanza Nsundi (Lower Congo, DRC)

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    We present here results, analyses and an in-depth historical contextualisation of the fieldwork undertaken in 2012 and 2013 at the Kindoki site in the Lower Congo (DRC). This site is linked with Mbanza Nsundi, one of the Kongo Kingdom's provincial capitals, which turns out to be archaeologically 'elusive'. Pinpointing its location proved to be particularly challenging. To this end, a historically-informed excavation methodology was developed that was never implemented in Central Africa before. We combined a strategy of systematic test pits with a large-scale 50 m grid approach. A cemetery was identified on Kindoki Hill with distinct but contemporaneous quarters of a 16th-17thcenturies settlement on both sides. The cemetery itself contains mainly 18th-century burials, in all likelihood of successive Nsundi rulers. The foreign, especially Portuguese, ceramics excavated on the hilltop and the hundreds of Venetian and likely Bavarian beads found in the graves are indicative of Mbanza Nsundi's connection to trade routes linking the Atlantic coast with the Pool region. The most striking discovery is that of a previously unknown type of comb-impressed pottery, from a pit with a calibrated radiocarbon date AD 1294-1393 (2 sigma). This suggests that a settlement had been developing at Kindoki since at least the 14th century, which allows us, for the very first time, to spatially bridge Kongo history and 'prehistory'. For the entire Lower Congo region only three 14C dates posterior to AD 1000 were available before the start of the KongoKing project, twelve have been added for just Kindoki

    The mammals of Angola

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    Scientific investigations on the mammals of Angola started over 150 years ago, but information remains scarce and scattered, with only one recent published account. Here we provide a synthesis of the mammals of Angola based on a thorough survey of primary and grey literature, as well as recent unpublished records. We present a short history of mammal research, and provide brief information on each species known to occur in the country. Particular attention is given to endemic and near endemic species. We also provide a zoogeographic outline and information on the conservation of Angolan mammals. We found confirmed records for 291 native species, most of which from the orders Rodentia (85), Chiroptera (73), Carnivora (39), and Cetartiodactyla (33). There is a large number of endemic and near endemic species, most of which are rodents or bats. The large diversity of species is favoured by the wide range of habitats with contrasting environmental conditions, while endemism tends to be associated with unique physiographic settings such as the Angolan Escarpment. The mammal fauna of Angola includes 2 Critically Endangered, 2 Endangered, 11 Vulnerable, and 14 Near-Threatened species at the global scale. There are also 12 data deficient species, most of which are endemics or near endemics to the countryinfo:eu-repo/semantics/publishedVersio

    Exploring how Chinese primary school psychological counsellors understand and use therapeutic stories

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    Psychological counsellors in western countries have used stories and storytelling for therapeutic purposes for decades. However, the development of the profession of school counselling in China is at an early stage and little research has been done on using therapeutic stories in Chinese primary school settings. This exploratory study presents qualitative data on using therapeutic stories collected from interviews with Chinese psychological counsellors who work with primary school students. Findings from a grounded theory analysis revealed that therapeutic stories were used by the participants in various therapeutic approaches. A spectrum of therapist directiveness was developed to integrate different ways of using therapeutic stories
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