3,345 research outputs found

    Farmers' perceptions of the lay health worker on farms in the Western Cape, South Africa

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    This study is focussed on farms situated in the Boland health district of the Cape Winelands, South Africa. The aim was to explore, understand, and describe the perceptions of farmers of having a trained lay health worker (LHW) on the farm. A qualitative study design was applied. Data were collected during six in-depth interviews and two focus group discussions with participating farmers. The results show that farmers remained positive about the concept of having a trained LHW on the farm, but became frustrated with the lack of recognition of their and the LHWs' contribution by the public health service. Farmers who are willing to participate and remain active are key to introducing a farm community-based LHW intervention. Sustainable LHW interventions are dependent on public health sector support and recognition of all role players.Farm Management,

    Stock Selection Strategies in Emerging Markets

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    Recent empirical evidence suggests that value and momentum strategies generate significant excess returns in emerging markets. We confirm these results and extend them in several directions. First, we examine a broader range of stock selection strategies, including strategies based on analysts' earnings revisions. We also consider multivariate strategies, whereby stocks are selected on multiple characteristics, and find that this enhances the overall performance. Excess returns also increase if country selection is incorporated into the strategies, but the risk of the strategies increases proportionally. Second, we test whether the strategies can be implemented successfully in practice by a large institutional investor, facing a lack of liquidity, restrictions on foreign ownership and substantial transaction costs. We find that even under such more realistic circumstances the strategies earn significant excess returns. Third, we examine several popular explanations for the excess returns. We find no evidence of higher market risk or lower liquidity of the strategies. Instead, based on the developments of earnings and earnings revisions after portfolio formation, we find that the results are consistent with behavioral explanations

    Measurement of the Fermi Constant by FAST

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    An initial measurement of the lifetime of the positive muon to a precision of 16 parts per million (ppm) has been performed with the FAST detector at the Paul Scherrer Institute. The result is tau_mu = 2.197083 (32) (15) microsec, where the first error is statistical and the second is systematic. The muon lifetime determines the Fermi constant, G_F = 1.166353 (9) x 10^-5 GeV^-2 (8 ppm).Comment: 15 pages, 6 figure

    Testing refinements by refining tests

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    One of the potential benefits of formal methods is that they offer the possibility of reducing the costs of testing. A specification acts as both the benchmark against which any implementation is tested, and also as the means by which tests are generated. There has therefore been interest in developing test generation techniques from formal specifications, and a number of different methods have been derived for state based languages such as Z, B and VDM. However, in addition to deriving tests from a formal specification, we might wish to refine the specification further before its implementation. The purpose of this paper is to explore the relationship between testing and refinement. As our model for test generation we use a DNF partition analysis for operations written in Z, which produces a number of disjoint test cases for each operation. In this paper we discuss how the partition analysis of an operation alters upon refinement, and we develop techniques that allow us to refine abstract tests in order to generate test cases for a refinement. To do so we use (and extend existing) methods for calculating the weakest data refinement of a specification

    The Development of Novel Organotin Anti-Tumor Drugs: Structure and Activity

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    An overview of the development of anti-tumor organotin derivatives in selected classes of compounds is presented and discussed. High to very high in vitro activity has been found, sometimes equaling that of doxorubicin. Solubility in water is an important issue, dominating the in vivo testing of compounds with promising in vitro properties. The cytotoxicity of the compounds was increased by the presence of a bulky group, an active substituent or one or more polar substituents. Polar substituents may also improve the water solubility. Although organotin derivatives constitute a separate class of compounds, the comparison with cisplatin is inevitable. Among the observed toxicities, neurotoxicity, known from platinum cytostatics, and gastrointestinal toxicity, typical for many oncology drugs, have been detected. Further research to develop novel, useful organotin anti-tumor compounds should be carried out

    Gravity induced over a smooth soliton

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    I consider gravity induced over a smooth (finite thickness) soliton. Graviton kinetic term is coupled to bulk scalar that develops solitonic vacuum expectation value. Couplings of Kaluza-Klein modes to soliton-localized matter are suppressed, giving rise to crossover distance rc=MP2/M3r_c=M_{P}^2/M_{*}^3 between 4D and 5D behavior. This system can be viewed as a finite thickness brane regularization of the model of Dvali, Gabadadze and Porrati.Comment: 12 pages, 2 figure

    Multidrug-Resistant Mycobacterium tuberculosis, Southwestern Colombia

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    Using spoligotyping, we identified 13 genotypes and 17 orphan types among 160 Mycobacterium tuberculosis isolates from patients in Valle del Cauca, Colombia. The Beijing genotype represented 15.6% of the isolates and was correlated with multidrug-resistant tuberculosis, female sex of the patients, and residence in Buenaventura and may represent a new public health threat
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