1,965 research outputs found

    Point-Source/Point-Receiver Materials Testing

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    Conventional measurements in the ultrasonic testing of materials, when used as the basis of a materials characterization procedure, typically rely on one or two piezoelectric transducers operating as source and receiver, attached to a specimen to launch and detect ultrasonic waves in the object to be characterized. Measurements of signal arrival time (or velocity) and amplitude (or attenuation), possibly as a function of frequency, are then correlated with the composition and the macro- and micro-structure of the material, which may include voids, flaws and inclusions distributed through a region of the material. While relative measurements of the time-of-flight and ultrasonic amplitudes do not! present extraordinary measurement challenges, absolute measurements do. It is unfortunate that absolute quantities are often required since they are difficult to obtain reliably with a conventional piezoelectric transducer-based ultrasonic system. For this reason, a considerable effort over the past decade has been undertaken to develop and improve non-contact methods for generating and detecting ultrasonic signals in materials. However, a limiting factor of all the existing non-contact measurement systems is the care required for their use and their reduced sensitivity in comparison to-those utilizing piezoelectric transducers

    Participatory evaluation of drought tolerant maize varieties in the Guinea Savanna of Ghana using mother and baby trial design

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    Maize (Zea mays) is a major food crop in Ghana but grain yields are low as a result of drought and low soil fertility. This study evaluated drought tolerant maize varieties in 2008 and 2009 in the Guinea savanna of Ghana using researcher-managed mother and farmer-managed baby trial design. Mean grain yields ranged between 2574 and 3462 kg/ha for the mother trials and 1460 and 2328 kg/ha for baby trials. Several improved varieties performed better than the best local varieties, but two preferred varieties, TZEE Y POP STR QPM C0 and EVDT W 99 STR QPM CO which produced 35-52% more grain than the best local varieties of similar maturity rating were released in 2010. Farmers have multiple criteria for evaluating maize varieties apart from yield, though yield, larger cob and grain size were the three key criteria used by farmers to select and rank varieties. Researchers should incorporate farmers’ preferences in selecting varieties in the breeding process in order to increase likelihood of adoption of the varieties.Keywords: Drought-tolerant maize, farmer preference, mother and baby, participator

    A model of Bˉ0→D∗+ωπ−\bar{B}^0\to D^{*+}\omega\pi^- decay

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    We suggest a parameterization of the matrix element for Bˉ0→D∗+ωπ−\bar{B}^0\to D^{*+}\omega\pi^- decay using kinematic variables convenient for experimental analysis. The contributions of intermediate ωπ\omega\pi- and D∗∗D^{**}-states up to spin 3 have been taken into account. The angular distributions for each discussed hypothesis have been obtained and analysed using Monte-Carlo simulation.Comment: 24 pages, 9 figures, 1 table; V2: text in some places improved and acknowledgments adde

    No time for change? Impact of contextual factors on the effect of training primary care healthcare workers in Kyrgyzstan and Vietnam on how to manage asthma in children - A FRESH AIR implementation study.

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    BACKGROUND: Training is a common and cost-effective way of trying to improve quality of care in low- and middle-income countries but studies of contextual factors for the successful translation of increased knowledge into clinical change are lacking, especially in primary care. The purpose of this study was to assess the impact of contextual factors on the effect of training rural healthcare workers in Kyrgyzstan and Vietnam on their knowledge and clinical performance in managing pediatric patients with respiratory symptoms. METHODS: Primary care health workers in Kyrgyzstan and Vietnam underwent a one-day training session on asthma in children under five. The effect of training was measured on knowledge and clinical performance using a validated questionnaire, and by direct clinical observations. RESULTS: Eighty-one healthcare workers participated in the training. Their knowledge increased by 1.1 Cohen's d (CI: 0.7 to 1.4) in Kyrgyzstan where baseline performance was lower and 1.5 Cohen's d (CI: 0.5 to 2.5) in Vietnam. Consultations were performed by different types of health care workers in Kyrgyzstan and there was a 79.1% (CI 73.9 to 84.3%) increase in consultations where at least one core symptom of respiratory illness was asked. Only medical doctors participated in Vietnam, where the increase was 25.0% (CI 15.1 to 34.9%). Clinical examination improved significantly after training in Kyrgyzstan. In Vietnam, the number of actions performed generally declined. The most pronounced difference in contextual factors was consultation time, which was median 15 min in Kyrgyzstan and 2 min in Vietnam. DISCUSSION AND CONCLUSION: The effects on knowledge of training primary care health workers in lower middle-income countries in diagnosis and management of asthma in children under five only translated into changes in clinical performance where consultation time allowed for changes to clinical practice, emphasizing the importance of considering contextual factors in order to succeed in behavioral change after training

    Solutions of Several Coupled Discrete Models in terms of Lame Polynomials of Order One and Two

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    Coupled discrete models abound in several areas of physics. Here we provide an extensive set of exact quasiperiodic solutions of a number of coupled discrete models in terms of Lame polynomials of order one and two. Some of the models discussed are (i) coupled Salerno model, (ii) coupled Ablowitz-Ladik model, (iii) coupled saturated discrete nonlinear Schrodinger equation, (iv) coupled phi4 model, and (v) coupled phi6 model. Furthermore, we show that most of these coupled models in fact also possess an even broader class of exact solutions.Comment: 31 pages, to appear in Pramana (Journal of Physics) 201

    Meditation on the Soles of the Feet Practice Provides Some Control of Aggression for Individuals with Alzheimer’s Disease

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    Alzheimer’s disease is a progressive neurodegenerative condition that affects cognition, mental and physical health, and functionality of older people. As the disease progresses from the mild to moderate stage, there is a concomitant increase in several behavioral variables, chiefly agitation, anger, and aggression. Currently, there are no evidence-based treatments for these behaviors in this population. Three individuals with moderate Alzheimer’s disease were taught an informal mindfulness practice, meditation on the Soles of the Feet (SoF), as a self-management strategy within a multiple-baseline design across participants. All three were able to learn and use the SoF practice to manage their verbal and physical aggression. Their use of the SoF practice was correlated with decreased perceived psychological stress for their spouses and caregivers, as well as for the participants, but to a much smaller degree. In terms of social validity, the participants, their spouses, and caregivers rated the SoF practice as acceptable, effective, with no unintended effects, and indicated that they would recommend the practice to others. However, they also rated SoF as effortful for the participants because it involves the participants remembering to use the practice with rising anger, a requirement particularly challenging for those with memory problems. The SoF practice may enable individuals in the early stages of dementia to manage their anger and aggression. The data were derived from an internally valid experimental design, suggestive of initial proof-of-concept, but needs to be replicated before any clinical implications can be imputed from this study

    Nanoclusters and nanolines: the effect of molybdenum oxide substrate stoichiometry on iron self-assembly

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    The growth of Fe nanostructures on the stoichiometric MoOâ‚‚/Mo(110) and oxygen-rich MoOâ‚‚+x /Mo(110) surfaces has been studied using low-temperature scanning tunnelling microscopy (STM) and density functional theory calculations. STM results indicate that at low coverage Fe nucleates on the MoOâ‚‚/Mo(110) surface, forming small, well-ordered nanoclusters of uniform size, each consisting of five Fe atoms. These five-atom clusters can agglomerate into larger nanostructures reflecting the substrate geometry, but they retain their individual character within the structure. Linear Fe nanocluster arrays are formed on the MoOâ‚‚/Mo(110) surface at room temperature when the surface coverage is greater than 0.6 monolayers. These nanocluster arrays follow the direction of the oxide rows of the strained MoOâ‚‚/Mo(110) surface. Slightly altering the preparation procedure of MoOâ‚‚/Mo(110) leads to the presence of oxygen adatoms on this surface. Fe deposition onto the oxygen-rich MoOâ‚‚+x /Mo(110) surface results in elongated nanostructures that reach up to 24 nm in length. These nanolines have a zigzag shape and are likely composed of partially oxidised Fe formed upon reaction with the oxygen-rich surface

    The XVth World Congress of Psychiatric Genetics, October 7–11, 2007: Rapporteur summaries of oral presentations

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    The World Congress of Psychiatric Genetics (WCPG) has become an annual event since the early 1990's sponsored by the International Society of Psychiatric Genetics (ISPG). Each year the latest published and unpublished findings are aired for discussion by representatives of the majority of research programs on this topic world-wide. The 2007 congress was held in New York City and attracted over 1000 researchers. The topics emphasized included results from whole genome association studies, the significance of copy number variation and the important contributions of epigenetic events to psychiatric disorders. There were over 20 oral sessions devoted to these and other topics of interest. Young investigator recipients of travel awards served as rapporteurs to summarize sessions and these summaries follow.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58040/1/30711_ftp.pd
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