15,318 research outputs found

    Transport phenomena in ionized gases as an initial value problem

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    Transport phenomena in ionized gases as initial value proble

    Plasma diffusion as an initial value problem

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    Plasma diffusion as initial value proble

    Past and Ongoing Tsetse and Animal Trypanosomiasis Control Operations in Five African Countries: A Systematic Review

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    Background Control operations targeting Animal African Trypanosomiasis and its primary vector, the tsetse, were covering approximately 128,000 km2 of Africa in 2001, which is a mere 1.3% of the tsetse infested area. Although extensive trypanosomiasis and tsetse (T&T) control operations have been running since the beginning of the 20th century, Animal African Trypanosomiasis is still a major constraint of livestock production in sub-Saharan Africa. Methodology/Principal Findings We performed a systematic review of the existing literature describing T&T control programmes conducted in a selection of five African countries, namely Burkina Faso, Cameroon, Ethiopia, Uganda and Zambia, between 1980 and 2015. Sixty-eight documents were eventually selected from those identified by the database search. This was supplemented with information gathered through semi-structured interviews conducted with twelve key informants recruited in the study countries and selected based on their experience and knowledge of T&T control. The combined information from these two sources was used to describe the inputs, processes and outcomes from 23 major T&T control programmes implemented in the study countries. Although there were some data gaps, involvement of the target communities and sustainability of the control activities were identified as the two main issues faced by these programmes. Further, there was a lack of evaluation of these control programmes, as well as a lack of a standardised methodology to conduct such evaluations. Conclusions/Significance Past experiences demonstrated that coordinated and sustained control activities require careful planning, and evidence of successes, failures and setbacks from past control programmes represent a mine of information. As there is a lack of evaluation of these programmes, these data have not been fully exploited for the design, analyses and justification of future control programmes

    Viking '75 spacecraft design and test summary. Volume 3: Engineering test summary

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    The engineering test program for the lander and the orbiter are presented. The engineering program was developed to achieve confidence that the design was adequate to survive the expected mission environments and to accomplish the mission objective

    Viking '75 spacecraft design and test summary. Volume 1: Lander design

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    The Viking Mars program is summarized. The design of the Viking lander spacecraft is described

    Hydrogenation of Si from SiNx(H) films: Characterization of H introduced into the Si

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    A promising method to introduce H into multicrystalline Si solar cells in order to passivate bulk defects is by the postdeposition annealing of a H-rich, SiNx surface layer. It has previously been difficult to characterize the small concentration of H that is introduced by this method. Infrared spectroscopy has been used together with marker impurities in the Si to determine the concentration and depth of H introduced into Si from an annealed SiNx film

    Integrated cost-benefit analysis of tsetse control and herd productivity to inform control programs for animal African trypanosomiasis

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    Animal African trypanosomiasis (AAT) and its tsetse vector are responsible for annual losses estimated in billions of US dollars ($). Recent years have seen the implementation of a series of multinational interventions. However, actors of AAT control face complex resource allocation decisions due to the geographical range of AAT, diversity of ecological and livestock systems, and range of control methods available. The study presented here integrates an existing tsetse abundance model with a bio-economic herd model that captures local production characteristics as well as heterogeneities in AAT incidence and breed. These models were used to predict the impact of tsetse elimination on the net value of cattle production in the districts of Mambwe, in Zambia, and Faro et Déo in Cameroon. The net value of cattle production under the current situation was used as a baseline, and compared with alternative publicly funded control programmes. In Zambia, the current baseline is AAT control implemented privately by cattle owners (Scenario Z0). In Cameroon, the baseline (Scenario C0) is a small-scale publicly funded tsetse control programme and privately funded control at farm level. The model was run for 10 years, using a discount rate of 5%

    X-ray spectra of Hercules X-1. 2: Intrinsic beam

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    The X-ray spectrum of Hercules X-1 was observed in the energy range 2-24 keV with sufficient temporal resolution to allow detailed study of spectral correlations with the 1.24 sec pulse phase. A region of spectral hardening which extends over approximately the 1/10 pulse phase may be associated with the underlying beam. The pulse shape stability and its asymmetry relative to this intrinsic beam are discussed

    Characteristics of Magnetoplasmas Semiannual Status Report No. 12, May 1 - Oct. 31, 1965

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    Magnetoplasma characteristics - anomalous diffusion across magnetic field, heat conduction in plasma, cesium plasma generator, and electron velocity distribution function in magnetoplasma

    Evaluation of a recreational team game for seniors: Lifeball - a case study

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    The objective of this project was to assess changes in physical activity, social isolation and loneliness of Lifeball participants as a result of participation in Lifeball. Lifeball is a team game based on walking, ball passing and goal shooting. Newly enrolled Lifeball players (n = 95) aged 50 years and over were recruited from Lifeball clubs in Western Australia. Subjects completed a questionnaire on their physical activity levels and perceptions of their psychosocial health and well-being. The questionnaire was administered at baseline and after 3 months of participation in Lifeball. There was no significant change to overall physical activity levels. However, it appears Lifeball was used to replace other recreational pursuits that the subjects were involved in. There was a positive shift in variables associated with social isolation and loneliness. Lifeball provides alternative physical activity opportunities and may help reduce social isolation and loneliness
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