422 research outputs found

    Genetic relationships between three indigenous cattle breeds in Mozambique

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    This study provides the first account of genetic relationships between three indigenous cattle breeds from Mozambique. Forty-two blood group factors and six blood proteins revealed genetic variation of 84% (Angone), 88% (Bovine de Tete) and 90% (Landim) at the loci studied. Average heterozygosity values ranged from 33% for Angone and Bovine de Tete to 35% for the Landim. The genetic distance was greatest between the Landim and both the Bovine de Tete and the Angone breeds, whereas the smallest genetic distance was observed between the Bovine de Tete and the Angone. These results show the intermediate relationship of Bovine de Tete with the Angone and Landim breeds and show that the Bovine de Tete is an admixture of taurine and indicus genes. (South African Journal of Animal Science, 2000, 30(2): 92-97

    Exploring the anthelmintic properties of Australian native shrubs with respect to their potential role in livestock grazing systems

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    We measured in vitro anthelmintic activity in extracts from 85 species of Australian native shrub, with a view to identifying species able to provide a degree of worm control in grazing systems. Approximately 40% of the species showed significant activity in inhibiting development of Haemonchus contortus larvae. The most active extracts showed IC50 values of 60–300 mg/ml. Pre-incubation with polyvinylpolypyrrolidine removed the activity from some extracts, implicating tannins as the bioactive agent, while in other cases the pre-incubation had no effect, indicating the presence of other anthelmintic compounds. Plant reproductive maturity (onset of flowering or fruiting) was associated with increasing anthelmintic activity in some species. Variability was observed between plants of the same species growing in different environments, while variation between individual plants of the same species within a single field suggests the existence of distinct chemotypes. Significant activity against adult H. contortus worms in vitro was also demonstrated in a limited number of extracts tested against this life stage. Our study indicates that there is potential for Australian native shrubs to play an anthelmintic role in grazing systems, and highlights some plant biology factors which will need to be considered in order to maximize any anthelmintic effects.A. C. Kotze, J. O’Grady, J. Emms, A. F. Toovey, S. Hughes, P. Jessop, M. Bennell P. E. Vercoe and D. K. Revel

    A radiological evaluation of alveolar bone regeneration between the left and right mandibles and maxillae of the Chacma baboon

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    There is a lack of information in comparing the healing rate between the left and right sides of the maxilla and mandible. Osteogenesis of alveolar bone was evaluated with digital radiology by comparing differences in bone density (BD) at different time points within the left and right maxilla and mandible. Alveolar bone defects were created in five healthy Chacma baboons. Standardised x-ray images were acquired over time and the densities of the selected trauma areas were measured pre-operatively, post-operatively and at 3 and 6 weeks post-operatively. Differences in densities were statistically tested. There was no significant difference when the grey scale averages of the combined first and fourth quadrants (right side) and combined second and third quadrants (left side) were compared pre-operatively (t = 0.70), immediately post-operatively (t = 0.34), 3 weeks post-operatively (t = 0.40) and 6 weeks post-operatively (t = 0.66). There was also no significant difference between the values for the first and second quadrants (maxilla) pre-operatively (t = 0.37), immediately post-operatively (t = 0.30), 3 weeks post-operatively (t = 0.30) and 6 weeks post-operatively (t = 0.38); the third and fourth quadrants (mandible) were also not significantly different pre-operatively (t = 0.29), immediately post-operatively (t = 0.69), 3 weeks post-operatively (t = 0.07) and 6 weeks postoperatively (t = 0.06). However, the results showed an increased predisposition of the right side to regenerate faster than the left side and indicated sufficient information to investigate the effect of laterality and preferred side of mastication on the rate of healing and alveolar BD in the maxilla and mandible.The Dental Research Education and Development Trust of the South African Dental Associationhttp://www.jsava.co.zaam2016Maxillo-Facial and Oral Surger

    Continuity of care of outpatients with schizophrenia in Pretoria

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    Objective. To study the needs of outpatients suffering from schizophrenia and their primary caregivers. Methods. A qualitative descriptive design was selected to study the needs of a non-probability purposive sample of 50 outpatients with schizophrenia and their primary caregivers. Data were collected on their compliance-related needs as well as psychosocial and aftercare treatment needs. Results. Compliance needs: Eighty-three per cent of the participants supported their medication treatment and aftercare, but needed more information on the illness than they had received or had managed to gather. Psychosocial needs: Participants had difficulty in accepting the illness and in understanding its consequences for their everyday functioning. Ninety-seven per cent of patients were aware that their illness had affected the health of their primary caregiver. The majority of participants had lost friendships since the diagnosis of schizophrenia. Eighty-eight of the primary caregivers supported the patient financially, despite the fact that many were over 60 years of age. Aftercare treatment needs: A strong need was expressed for services such as day-care centres, workshops, and psycho-educational and social work services. Conclusions. As South African health policy is moving towardsde-institutionalisation and treating mental health as part of primary care, support must be improved for sufferers of schizophrenia and their primary caregivers. Many people are prepared to face up to the challenge of caring for a mentally ill family member, yet are faced with significant needs that should be addressed

    IGR J19552+0044: A new asynchronous short period polar: "Filling the gap between intermediate and ordinary polars"

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    Based on XMM--Newton X-ray observations IGR J19552+0044 appears to be either a pre-polar or an asynchronous polar. We conducted follow-up optical observations to identify the sources and periods of variability precisely and to classify this X-ray source correctly. Extensive multicolor photometric and medium- to high-resolution spectroscopy observations were performed and period search codes were applied to sort out the complex variability of the object. We found firm evidence of discording spectroscopic (81.29+/-0.01m) and photometric (83.599+/-0.002m) periods that we ascribe to the white dwarf (WD)\ spin period and binary orbital period, respectively. This confirms that IGR J19552+0044 is an asynchronous polar. Wavelength-dependent variability and its continuously changing shape point at a cyclotron emission from a magnetic WD with a relatively low magnetic field below 20 MG. The difference between the WD spin period and the binary orbital period proves that IGR J19552+0044 is a polar with the largest known degree of asynchronism (0.97 or 3%).Comment: 9 pages, 10 figures, A&A accepte

    The Genetic Structure and History of Africans and African Americans.

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    Africa is the source of all modern humans, but characterization of genetic variation and of relationships among populations across the continent has been enigmatic. We studied 121 African populations, four African American populations, and 60 non-African populations for patterns of variation at 1327 nuclear microsatellite and insertion/deletion markers. We identified 14 ancestral population clusters in Africa that correlate with self-described ethnicity and shared cultural and/or linguistic properties. We observed high levels of mixed ancestry in most populations, reflecting historical migration events across the continent. Our data also provide evidence for shared ancestry among geographically diverse hunter-gatherer populations (Khoesan speakers and Pygmies). The ancestry of African Americans is predominantly from Niger-Kordofanian (approximately 71%), European (approximately 13%), and other African (approximately 8%) populations, although admixture levels varied considerably among individuals. This study helps tease apart the complex evolutionary history of Africans and African Americans, aiding both anthropological and genetic epidemiologic studies

    Urban forest invertebrates : how they shape and respond to the urban environment

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    Invertebrates comprise the most diversified animal group on Earth. Due to their long evolutionary history and small size, invertebrates occupy a remarkable range of ecological niches, and play an important role as "ecosystem engineers" by structuring networks of mutualistic and antagonistic ecological interactions in almost all terrestrial ecosystems. Urban forests provide critical ecosystem services to humans, and, as in other systems, invertebrates are central to structuring and maintaining the functioning of urban forests. Identifying the role of invertebrates in urban forests can help elucidate their importance to practitioners and the public, not only to preserve biodiversity in urban environments, but also to make the public aware of their functional importance in maintaining healthy greenspaces. In this review, we examine the multiple functional roles that invertebrates play in urban forests that contribute to ecosystem service provisioning, including pollination, predation, herbivory, seed and microorganism dispersal and organic matter decomposition, but also those that lead to disservices, primarily from a public health perspective, e.g., transmission of invertebrate-borne diseases. We then identify a number of ecological filters that structure urban forest invertebrate communities, such as changes in habitat structure, increased landscape imperviousness, microclimatic changes and pollution. We also discuss the complexity of ways that forest invertebrates respond to urbanisation, including acclimation, local extinction and evolution. Finally, we present management recommendations to support and conserve viable and diverse urban forest invertebrate populations into the future.Peer reviewe
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