634 research outputs found

    Objective Ultrasonic Characterization of Welding Defects Using Physically Based Pattern Recognition Techniques

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    Computer-based methods for analysing ultrasonic data to distinguish between different defect types have been based on a variety of techniques such as adaptive learning [1], artificial intelligence [2] and statistical pattern recognition [3]. The uncertain classification reliability of these techniques when applied to a range of realistic defect types has, however, often been a significant practical limitation to their use

    Previous Experiences with Epilepsy and Effectiveness of Information to Change Public Perception of Epilepsy

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    Differences with regard to the effectiveness of health information and attitude change are suggested between people with direct, behavioral experiences with a health topic and people with indirect, nonbehavioral experiences. The effects of three different methods of health education about epilepsy, frequently used in health education practice, are assessed in a pretest posttest design with control groups, controlling for experiences with epilepsy. Subjects were 132 students from teacher-training colleges. After all treatments, attitudes, and knowledge about epilepsy were changed in a positive way. Treatments were found to be equally effective. Before treatment, direct behavioral experiences were related to knowledge and a more positive attitude towards epilepsy. After treatment, subjects with direct behavioral experiences with epilepsy showed less change of attitude and knowledge as compared with subjects with indirect experiences. Direct experiences appear to restrain the processing of new information and attitude change

    Negative phenotypic and genetic associations between copulation duration and longevity in male seed beetles

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    Reproduction can be costly and is predicted to trade-off against other characters. However, while these trade-offs are well documented for females, there has been less focus on aspects of male reproduction. Furthermore, those studies that have looked at males typically only investigate phenotypic associations, with the underlying genetics often ignored. Here, we report on phenotypic and genetic trade-offs in male reproductive effort in the seed beetle, Callosobruchus maculatus. We find that the duration of a male's first copulation is negatively associated with subsequent male survival, phenotypically and genetically. Our results are consistent with life-history theory and suggest that like females, males trade-off reproductive effort against longevity

    Bias in the prediction of genetic gain due to mass and half-sib selection in random mating populations

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    The prediction of gains from selection allows the comparison of breeding methods and selection strategies, although these estimates may be biased. The objective of this study was to investigate the extent of such bias in predicting genetic gain. For this, we simulated 10 cycles of a hypothetical breeding program that involved seven traits, three population classes, three experimental conditions and two breeding methods (mass and half-sib selection). Each combination of trait, population, heritability, method and cycle was repeated 10 times. The predicted gains were biased, even when the genetic parameters were estimated without error. Gain from selection in both genders is twice the gain from selection in a single gender only in the absence of dominance. The use of genotypic variance or broad sense heritability in the predictions represented an additional source of bias. Predictions based on additive variance and narrow sense heritability were equivalent, as were predictions based on genotypic variance and broad sense heritability. The predictions based on mass and family selection were suitable for comparing selection strategies, whereas those based on selection within progenies showed the largest bias and lower association with the realized gain

    Mechanical Circulatory Support as a Bridge to Transplant or for Destination Therapy

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    Mechanical circulatory support (MCS) frequently is used to treat medically refractory end-stage heart failure. Initially designed to be a bridge to transplantation, MCS also has proven itself as a durable therapy for patients who are not transplant candidates. As outcomes for patients with MCS have improved, research interest in device development has flourished, with many new device types under investigation. In addition to improvement of MCS devices, investigational work continues to achieve appropriate patient selection and complication management

    Social representations and the politics of participation

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    Recent work has called for the integration of different perspectives into the field of political psychology (Haste, 2012). This chapter suggests that one possible direction that such efforts can take is studying the role that social representations theory (SRT) can play in understanding political participation and social change. Social representations are systems of common-sense knowledge and social practice; they provide the lens through which to view and create social and political realities, mediate people's relations with these sociopolitical worlds and defend cultural and political identities. Social representations are therefore key for conceptualising participation as the activity that locates individuals and social groups in their sociopolitical world. Political participation is generally seen as conditional to membership of sociopolitical groups and therefore is often linked to citizenship. To be a citizen of a society or a member of any social group one has to participate as such. Often political participation is defined as the ability to communicate one's views to the political elite or to the political establishment (Uhlaner, 2001), or simply explicit involvement in politics and electoral processes (Milbrath, 1965). However, following scholars on ideology (Eagleton, 1991; Thompson, 1990) and social knowledge (Jovchelovitch, 2007), we extend our understanding of political participation to all social relations and also develop a more agentic model where individuals and groups construct, develop and resist their own views, ideas and beliefs. We thus adopt a broader approach to participation in comparison to other political-psychological approaches, such as personality approaches (e.g. Mondak and Halperin, 2008) and cognitive approaches or, more recently, neuropsychological approaches (Hatemi and McDermott, 2012). We move away from a focus on the individual's political behaviour and its antecedents and outline an approach that focuses on the interaction between psychological and political phenomena (Deutsch and Kinnvall, 2002) through examining the politics of social knowledge

    Perception and valuations of community-based education and service by alumni at Makerere University College of Health Sciences

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    <p>Abstract</p> <p>Background</p> <p>Training of health professionals can be deliberately structured to enhance rural recruitment by exposing the trainees to the realities of rural life and practice through Community-Based Education and Service (COBE) programs. Few studies have surveyed the alumni of these programs to establish their post-university views and whether the positive impact of COBE programs endures into the post-university life. This study surveyed the alumni of COBE at Makerere to obtain their perceptions of the management and administration of COBE and whether COBE had helped develop their confidence as health workers, competence in primary health care and willingness and ability to work in rural communities.</p> <p>Objectives</p> <p>• To assess the efficiency of the management and administration of COBES.</p> <p>• To obtain the views of the impact of COBES on its alumni.</p> <p>Methods</p> <p>A mixed qualitative and quantitative study was conducted using focus group discussions (FGD) and a telephone administered questionnaire. From a total of 300 COBES alumni 150 were contacted. Twenty four Alumni (13 females and 11 males) were purposefully selected by discipline, gender and place of work, and invited for the focus group discussion. The discussions were transcribed and analyzed using a manifest content analysis table. The thematic issues from the FGDs were used to develop a structured questionnaire which was administered by telephone by the authors. The data were entered into Microsoft excel template and exported to Stata for analysis. The findings of the telephone survey were used to cross-match the views expressed during the focus group discussions.</p> <p>Results</p> <p>The alumni almost unanimously agree that the initial three years of COBES were very successful in terms of administration and coordination. COBES was credited for contributing to development of confidence as health workers, team work, communication skills, competence in primary health care and willingness to work in rural areas. The COBES alumni also identified various challenges associated with administration and coordination of COBES at Makerere.</p> <p>Conclusions</p> <p>This study has established that the positive impact of COBES endures with the alumni of the program. Health planners should take advantage of the impact of COBES and provide it with more support.</p

    Emergent global patterns of ecosystem structure and function from a mechanistic general ecosystem model

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    Anthropogenic activities are causing widespread degradation of ecosystems worldwide, threatening the ecosystem services upon which all human life depends. Improved understanding of this degradation is urgently needed to improve avoidance and mitigation measures. One tool to assist these efforts is predictive models of ecosystem structure and function that are mechanistic: based on fundamental ecological principles. Here we present the first mechanistic General Ecosystem Model (GEM) of ecosystem structure and function that is both global and applies in all terrestrial and marine environments. Functional forms and parameter values were derived from the theoretical and empirical literature where possible. Simulations of the fate of all organisms with body masses between 10 µg and 150,000 kg (a range of 14 orders of magnitude) across the globe led to emergent properties at individual (e.g., growth rate), community (e.g., biomass turnover rates), ecosystem (e.g., trophic pyramids), and macroecological scales (e.g., global patterns of trophic structure) that are in general agreement with current data and theory. These properties emerged from our encoding of the biology of, and interactions among, individual organisms without any direct constraints on the properties themselves. Our results indicate that ecologists have gathered sufficient information to begin to build realistic, global, and mechanistic models of ecosystems, capable of predicting a diverse range of ecosystem properties and their response to human pressures
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