907 research outputs found

    Understanding why farmers change their farming practices : the role of orienting principles in technology transfer

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    This report presents results from a qualitative study of sheep, beef and dairy farmers in the Temuka, Geraldine area of the South Island, New Zealand. Farmers' accounts of their farming practices, and how they decide to adopt, or not adopt, innovations are analysed to highlight the key orienting principles that guide their decision making. Farmers in each type of production have different orientations to innovation, in large part reflecting the nature of the industry in which they are located. Sheep and beef farmers emphasise profitability and the need to control risk and to farm safely. Dairy farmers emphasise increasing production, increasing efficiency and control by monitoring production. The results are important for alerting researchers and educationalists to the farmers' point of view in the development of effective extension.Funding for this research was received from the Foundation for Research, Science and Technology. The Lotteries Board supported the research by providing technical equipment. The former New Zealand Institute for Social Research and Development initiated this project and it was continued by the AERU in November, 1994

    Numerical analysis of thermal cycling during a multi-stage energy pile thermal response test

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    Energy piles are emerging as convenient alternative to the more traditional borehole heat exchangers (BHEs) to provide heating/cooling to buildings, as they remove the need for special purpose excavations and can accommodate more pipes, thus enhancing energy performance. However, their different aspect ratio compared to BHEs requires different modelling tools and dedicated thermal response testing, to achieve adequate thermal design. In this work, the results of an extended multi-stage thermal response test (TRT) carried out on a single energy pile installed in London Clay are presented in terms of both fluid temperature data and concrete temperature, measured by vibrating wire strain gauges and optic fibre sensors. The results are then explored in detail by means of a finite element numerical code, able to account for both convective heat exchange in the fluid, between the fluid and the solids and transient heat diffusion in the concrete and the ground. Analysis of the TRT field data shows that during the later stages of the test there is clear evidence of cyclic changes in performance. Investigation of these effects using the numerical model raises the possibility that there could be some alteration of the properties of the soil-pile contact during the test. Hypotheses for the observed behaviour are tentatively put forward and discussed with work recommended to further investigate the percieved phenomena

    Unraveling the role of protein dynamics in dihydrofolate reductase catalysis

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    Protein dynamics have controversially been proposed to be at the heart of enzyme catalysis, but identification and analysis of dynamical effects in enzyme-catalyzed reactions have proved very challenging. Here, we tackle this question by comparing an enzyme with its heavy (15N, 13C, 2H substituted) counterpart, providing a subtle probe of dynamics. The crucial hydride transfer step of the reaction (the chemical step) occurs more slowly in the heavy enzyme. A combination of experimental results, quantum mechanics/molecular mechanics simulations, and theoretical analyses identify the origins of the observed differences in reactivity. The generally slightly slower reaction in the heavy enzyme reflects differences in environmental coupling to the hydride transfer step. Importantly, the barrier and contribution of quantum tunneling are not affected, indicating no significant role for “promoting motions” in driving tunneling or modulating the barrier. The chemical step is slower in the heavy enzyme because protein motions coupled to the reaction coordinate are slower. The fact that the heavy enzyme is only slightly less active than its light counterpart shows that protein dynamics have a small, but measurable, effect on the chemical reaction rate

    Infant midnasal stenosis: Reliability of nasal metrics

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    BACKGROUND AND PURPOSE: Midnasal stenosis is a poorly defined entity that may be a component of other conditions of nasal obstruction contributing to respiratory distress in infants. We sought to establish whether midnasal vault narrowing is a component of well-defined syndromes of nasal narrowing, such as bilateral choanal atresia and pyriform aperture stenosis, and to characterize the nasal anatomy of patients with syndromic craniosynostosis. MATERIALS AND METHODS: A convenience sample of patients with pyriform aperture stenosis, bilateral choanal atresia, and Apert and Crouzon syndromes with maxillofacial CT scans was identified. Patients with Pierre Robin Sequence were used as controls. Nasal measurements were performed at the pyriform aperture, choana, and defined midnasal points on axial and coronal CT scans. Intra- and interrater reliability was quantified with the intraclass correlation coefficient. T tests with Bonferroni adjustment were used to assess differences from controls. RESULTS: The study included 50 patients: Eleven had pyriform aperture stenosis, 10 had Apert and Crouzon syndromes, 9 had choanal atresia, and 20 were controls. Measurements in patients with pyriform aperture stenosis and Apert and Crouzon syndromes were narrower than those of controls at all measured points (P .001). Measurements in patients with choanal atresia were only narrow in the posterior half of the nose (P .001). The intra- and interrater reliability of midnasal and pyriform measurements was very good to excellent (intraclass correlation coefficient 0.87). The choanal measurement was good (intraclass correlation coefficient 0.76 – 0.77). CONCLUSIONS: Pyriform aperture stenosis, Apert and Crouzon patients were narrower at all measured points compared to controls. Bilateral choanal atresia patients were only narrower in the posterior half of the nose. More research is needed to evaluate the clinical implications of these radiographic findings

    Termitaria as browsing hotspots for African megaherbivores in miombo woodland

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    Abstract: Thirteen termite mounds and 13 similar-sized control plots were surveyed in central Zimbabwe in order to study large mammalian browsing and vegetation characteristics. The mounds supported almost twice as many tree species as the control plots and the woody vegetation was denser on mounds compared with the woodland plots. Species of woody plants were recorded along with the percentage of branches browsed (cumulative browsing score) by black rhino, Diceros bicornis, elephant, Loxodonta africana and other browsers combined. In addition we measured how the cumulative browsing score on three woody plant species, Acacia nilotica, Colophospermum mopane and Dichrostachys cinerea, which were common both on and off mounds, was related to the distance from mound centre. Both black rhino and elephant cumulative browsing scores were significantly higher on the mound plants compared with the woodland plots. Cumulative browsing score was negatively related to distance from the mound centre for Dichrostachys cinerea, Colophospermum mopane and Acacia nilotica. We propose that termite mound construction in miombo woodland contributes to sustaining populations of megaherbivores and perhaps some woody species in these areas

    Syndromic surveillance to assess the potential public health impact of the Icelandic volcanic ash plume across the United Kingdom, April 2010

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    The Eyjafjallajökull volcano in Iceland erupted on 14 April 2010 emitting a volcanic ash plume that spread across the United Kingdom and mainland Europe. The Health Protection Agency and Health Protection Scotland used existing syndromic surveillance systems to monitor community health during the incident: there were no particularly unusual increases in any of the monitored conditions. This incident has again demonstrated the use of syndromic surveillance systems for monitoring community health in real time
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