4,567 research outputs found

    Minimal Flavor Violation with Axion-like Particles

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    We revisit the flavor-changing processes involving an axion-like particle (ALP) in the context of generic ALP effective lagrangian with a discussion of possible UV completions providing the origin of the relevant bare ALP couplings. We focus on the minimal scenario that ALP has flavor-conserving couplings at tree level, and the leading flavor-changing couplings arise from the loops involving the Yukawa couplings of the Standard Model fermions. We note that such radiatively generated flavor-changing ALP couplings can be easily suppressed in field theoretic ALP models with sensible UV completion. We discuss also the implication of our result for string theoretic ALP originating from higher-dimensional pp-form gauge fields, for instance for ALP in large volume string compactification scenario.Comment: 41 pages, 3 figures; v3: a discussion on general extended Higgs sector added in sec. 2, version published in JHE

    Characterization of slow and fast phase nystagmus

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    A current literature review of the analog and digital process of vestibular and optical kinetic nystagmus reveals little agreement in the methods used by various labs. The strategies for detection of saccade (fast phase velocity component of nystagmus) vary between labs, and most of the process have not been evaluated and validated with a standard database. A survey was made of major vestibular labs in the U.S. that perform computer analyses of vestibular and optokinetic reflexes to stimuli, and a baseline was established from which to standardize data acquisition and analysis programs. The concept of an Error Index was employed as the criterium for evaluating the performance of the vestibular analysis software programs. The performance criterium is based on the detection of saccades and is the average of the percentages of missed detections and false detections. Evaluation of the programs produced results for lateral gaze with saccadic amplitude of one, two, three, five, and ten degrees with various signal-to-noise ratios. In addition, results were obtained for sinusoidal pursuit of 0.05, 0.10, and 0.50 Hz with saccades from one to ten degrees at various signal-to-noise ratios. Selection of the best program was made from the performance in the lateral gaze with three degrees of saccadic amplitude and in the 0.10 Hz sinusoid with three degrees of saccadic amplitude

    Synthesis and Application of Pheromones for Integrated Pest Management in Vietnam

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    The negative impacts of conventional pesticides on health, environment, and organisms have involved strong development of integrated pest management (IPM) strategies. The use of insect pheromones becomes an effectively alternative selection in agricultural and forest pest control. Pheromone researches in Vietnam started in the last few decades and in addition to technical factors, recent achievements in the Vietnamese agriculture have an important direct link to the pheromone developments. In this chapter, we review the pheromone researches related to synthesis and field trials of several especial insect pheromones, in which Vietnamese scientists have mainly participated or collaborated with foreign research groups. First, we will discuss an overview of popular insect pheromones in Vietnam, a lot of species of which are also found around the world, as an important reference for scientists who would have especial consideration in this field. Further, synthetic routes of pheromones are summarized with various structures including chiral, racemic, mono- and poly-olefinic pheromones where some schemes have become standard methodologies for synthesis of similar structural compounds. Finally, field evaluations of the pheromones of numerous species are discussed in detail

    Evaluation of the learning outcomes of a year-long postgraduate training course in community geriatrics for primary care doctors

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    There are increasing expectations on primary care doctors to shoulder a bigger share of care for patients with common geriatric problems in the community. This study aims to examine the outcomes of a postgraduate training course in geriatrics for primary care doctors. A questionnaire developed by the research team was sent to the course graduates (years 2001-2007). Ninety-eight replies were received with a response rate of 52.4% (98/187). Difference in the ratings by the respondents before and after taking the course was analyzed using the nonparametric Wilcoxon signed rank test. Most respondents felt more rewarding and had participated more in geriatric care, and the majority had improvement in their communication skills with elderly patients after taking the course. Moreover, the graduates are more confident in diagnosing and managing common geriatric problems, and deciding to which specialty to refer the elderly patients. Of the referrals, there was a significant increase to private geriatricians and a significant reduction to other specialists. The average number of elderly patients seen per day had also increased. However, little change was observed about making nursing home visits, the frequency of which remained low. Many graduates expressed difficulties in conducting nursing home visits. © 2010 Elsevier Ireland Ltd.postprin

    Energy-Efficient Multiprocessor Scheduling for Flow Time and Makespan

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    We consider energy-efficient scheduling on multiprocessors, where the speed of each processor can be individually scaled, and a processor consumes power sαs^{\alpha} when running at speed ss, for α>1\alpha>1. A scheduling algorithm needs to decide at any time both processor allocations and processor speeds for a set of parallel jobs with time-varying parallelism. The objective is to minimize the sum of the total energy consumption and certain performance metric, which in this paper includes total flow time and makespan. For both objectives, we present instantaneous parallelism clairvoyant (IP-clairvoyant) algorithms that are aware of the instantaneous parallelism of the jobs at any time but not their future characteristics, such as remaining parallelism and work. For total flow time plus energy, we present an O(1)O(1)-competitive algorithm, which significantly improves upon the best known non-clairvoyant algorithm and is the first constant competitive result on multiprocessor speed scaling for parallel jobs. In the case of makespan plus energy, which is considered for the first time in the literature, we present an O(ln11/αP)O(\ln^{1-1/\alpha}P)-competitive algorithm, where PP is the total number of processors. We show that this algorithm is asymptotically optimal by providing a matching lower bound. In addition, we also study non-clairvoyant scheduling for total flow time plus energy, and present an algorithm that achieves O(lnP)O(\ln P)-competitive for jobs with arbitrary release time and O(ln1/αP)O(\ln^{1/\alpha}P)-competitive for jobs with identical release time. Finally, we prove an Ω(ln1/αP)\Omega(\ln^{1/\alpha}P) lower bound on the competitive ratio of any non-clairvoyant algorithm, matching the upper bound of our algorithm for jobs with identical release time

    Reliable protein folding on non-funneled energy landscapes: the free energy reaction path

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    A theoretical framework is developed to study the dynamics of protein folding. The key insight is that the search for the native protein conformation is influenced by the rate r at which external parameters, such as temperature, chemical denaturant or pH, are adjusted to induce folding. A theory based on this insight predicts that (1) proteins with non-funneled energy landscapes can fold reliably to their native state, (2) reliable folding can occur as an equilibrium or out-of-equilibrium process, and (3) reliable folding only occurs when the rate r is below a limiting value, which can be calculated from measurements of the free energy. We test these predictions against numerical simulations of model proteins with a single energy scale.Comment: 13 pages, 9 figure
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