971 research outputs found

    Quenched QCD at finite density

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    Simulations of quenched QCDQCD at relatively small but {\it nonzero} chemical potential μ\mu on 32×16332 \times 16^3 lattices indicate that the nucleon screening mass decreases linearly as μ\mu increases predicting a critical chemical potential of one third the nucleon mass, mN/3m_N/3, by extrapolation. The meson spectrum does not change as μ\mu increases over the same range, from zero to mπ/2m_\pi/2. Past studies of quenched lattice QCD have suggested that there is phase transition at μ=mπ/2\mu = m_\pi/2. We provide alternative explanations for these results, and find a number of technical reasons why standard lattice simulation techniques suffer from greatly enhanced fluctuations and finite size effects for μ\mu ranging from mπ/2m_\pi/2 to mN/3m_N/3. We find evidence for such problems in our simulations, and suggest that they can be surmounted by improved measurement techniques.Comment: 23 pages, Revte

    Clinical trial of tailored activity and eating newsletters with older rural women.

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    BACKGROUND: Unhealthy diet and lack of physical activity increase rural midlife and older women\u27s risk of chronic diseases and premature death, and they are behind urban residents in meeting Healthy People 2010 objectives. OBJECTIVES: The objective of this study was to compare a tailored intervention based on the Health Promotion Model with a generic intervention to increase physical activity and healthy eating among rural women. METHODS: In a randomized-by-site, community-based, controlled, clinical trial, Wellness for Women, 225 women aged 50 to 69 years were recruited in two similar rural areas. Over 12 months, women received by mail either 18 generic newsletters or 18 newsletters computer tailored on Health Promotion Model behavior-specific cognitions (benefits, barriers, self-efficacy, and interpersonal support), activity, and eating. Outcomes at 6 and 12 months included behavioral markers and biomarkers of physical activity and eating. Data were analyzed by repeated-measures analysis of variance and chi-square tests (alpha \u3c .05). RESULTS: Both groups significantly increased stretching and strengthening exercise and fruit and vegetable servings and decreased percentage of calories from fat, whereas only the tailored group increased moderate or greater intensity activity and decreased percentage of calories from saturated fat from baseline to 6 months. Both groups increased stretching and strengthening exercise, whereas only the tailored group increased moderate or greater intensity activity and fruit and vegetable servings and decreased percentage of calories from fat from baseline to 12 months. Both groups had several changes in biomarkers over the study. A higher proportion of women receiving tailored newsletters met Healthy People 2010 criteria for moderate or greater intensity activity, fruit and vegetable servings, and percentage of calories from fat at 12 months. DISCUSSION: Mailed computer-tailored and generic print newsletters facilitated the adoption of change in both activity and eating over 6 months. Tailored newsletters were more efficacious in facilitating change over 12 months

    Directional Microwave Emission from Femtosecond-laser Illuminated Linear Arrays of Superconducting Rings

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    We examine the electromagnetic emission from two photo-illuminated linear arrays composed of inductively charged superconducting ring elements. The arrays are illuminated by an ultrafast infrared laser that triggers microwave broadband emission detected in the 1–26 GHz range. Based on constructive interference from the arrays a narrowing of the forward radiation lobe is observed with increasing element count and frequency demonstrating directed GHz emission. Results suggest that higher frequencies and a larger number of elements are achievable leading to a unique pulsed array emitter concept that can span frequencies from the microwave to the terahertz (THz) regime

    Maintenance of activity and eating change after a clinical trial of tailored newsletters with older rural women.

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    BACKGROUND: In the Wellness for Women Project, a randomized-by-site 1-year controlled clinical trial, the efficacy of generic newsletters and newsletters tailored on Health Promotion Model behavior-specific cognitions, eating behavior, and activity behavior were compared among 225 women aged 50 to 69 years. OBJECTIVES: The purpose of this study was to compare the maintenance of change in healthy eating and physical activity over the 12 months following the tailored versus generic mailed newsletter intervention. METHODS: Outcomes at 18 and 24 months included behavioral markers and biomarkers of physical activity and eating. Data were analyzed using the multivariate approach to repeated measures analysis of variance and generalized estimating equations (alpha \u3c.05). RESULTS: At 18 months, the tailored group maintained levels of all eating and activity behaviors, whereas the generic group maintained levels of fruit and vegetable servings, a moderate or greater activity, stretching exercise, lower body strength and flexibility but increased saturated fat intake and declined in weekly strength exercise and cardiorespiratory fitness. At 24 months, both groups maintained or returned to 12-month levels of all eating behaviors,moderate or greater activity, stretching exercise, and flexibility but declined in cardiorespiratory fitness; the tailored group maintained levels of strength exercise and lower body strength, whereas the generic group decreased in both. A greater proportion of women who received tailored newsletters continued to achieve most Healthy People 2010 criteria for eating and activity. DISCUSSION: Mailed tailored print newsletters were more efficacious than generic newsletters in facilitating maintenance of change in eating and activity for 6 months postintervention. Both tailored and generic newsletters facilitated the maintenance of change in eating behaviors and in moderate or greater physical activity and stretching exercise, whereas tailored newsletters were more efficacious in maintaining change in strength exercise for 12 months postintervention

    The role of the global cryosphere in the fate of organic contaminants

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    The cryosphere is an important component of global organic contaminant cycles. Snow is an efficient scavenger of atmospheric organic pollutants while a seasonal snowpack, sea ice, glaciers and ice caps are contaminant reservoirs on time scales ranging from days to millennia. Important physical and chemical processes occurring in the various cryospheric compartments impact contaminant cycling and fate. A variety of interactions and feedbacks also occur within the cryospheric system, most of which are susceptible to perturbations due to climate change. In this article, we review the current state of knowledge regarding the transport and processing of organic contaminants in the global cryosphere with an emphasis on the role of a changing climate. Given the complexity of contaminant interactions with the cryosphere and limitations on resources and research capacity, interdisciplinary research and extended collaborations are essential to close identified knowledge gaps and to improve our understanding of contaminant fate under a changing climate

    Vancomycin-intermediate Staphylococcus aureus in a home health-care patient.

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    In June 2000, vancomycin-intermediate Staphylococcus aureus (VISA) was isolated from a 27-year-old home health-care patient following a complicated cholecystectomy. Two VISA strains were identified with identical MICs to all antimicrobials tested except oxacillin and with closely related pulsed-field gel electrophoresis types. The patient was treated successfully with antimicrobial therapy, biliary drainage, and reconstruction. Standard precautions in the home health setting appear successful in preventing transmission

    Crystal structure of dichlorido(4,11-dimethyl-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane)iron(III) hexafluoridophosphate

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    The title compound, [FeCl₂(C₁₄H₃₀N₄)]PF₆, contains Fe³⁺ coordinated by the four nitro­gen atoms of an ethyl­ene cross-bridged cyclam macrocycle and two cis chloride ligands in a distorted octa­hedral environment. In contrast to other similar compounds this is a monomer. Inter­molecular C-H...Cl inter­actions exist in the structure between the complex ions. Comparison with the mononuclear Fe²⁺ complex of the same ligand shows that the smaller Fe³⁺ ion is more fully engulfed by the cavity of the bicyclic ligand. Comparison with the μ-oxido dinuclear complex of an unsubstituted ligand of the same size demonstrates that the methyl groups of 4,11-dimethyl-1,4,8,11-tetra­aza­bicyclo­[6.6.2]hexa­decane prevent dimerization upon oxidation

    Simplivariate Models: Uncovering the Underlying Biology in Functional Genomics Data

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    One of the first steps in analyzing high-dimensional functional genomics data is an exploratory analysis of such data. Cluster Analysis and Principal Component Analysis are then usually the method of choice. Despite their versatility they also have a severe drawback: they do not always generate simple and interpretable solutions. On the basis of the observation that functional genomics data often contain both informative and non-informative variation, we propose a method that finds sets of variables containing informative variation. This informative variation is subsequently expressed in easily interpretable simplivariate components

    Simplivariate Models: Ideas and First Examples

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    One of the new expanding areas in functional genomics is metabolomics: measuring the metabolome of an organism. Data being generated in metabolomics studies are very diverse in nature depending on the design underlying the experiment. Traditionally, variation in measurements is conceptually broken down in systematic variation and noise where the latter contains, e.g. technical variation. There is increasing evidence that this distinction does not hold (or is too simple) for metabolomics data. A more useful distinction is in terms of informative and non-informative variation where informative relates to the problem being studied. In most common methods for analyzing metabolomics (or any other high-dimensional x-omics) data this distinction is ignored thereby severely hampering the results of the analysis. This leads to poorly interpretable models and may even obscure the relevant biological information. We developed a framework from first data analysis principles by explicitly formulating the problem of analyzing metabolomics data in terms of informative and non-informative parts. This framework allows for flexible interactions with the biologists involved in formulating prior knowledge of underlying structures. The basic idea is that the informative parts of the complex metabolomics data are approximated by simple components with a biological meaning, e.g. in terms of metabolic pathways or their regulation. Hence, we termed the framework ‘simplivariate models’ which constitutes a new way of looking at metabolomics data. The framework is given in its full generality and exemplified with two methods, IDR analysis and plaid modeling, that fit into the framework. Using this strategy of ‘divide and conquer’, we show that meaningful simplivariate models can be obtained using a real-life microbial metabolomics data set. For instance, one of the simple components contained all the measured intermediates of the Krebs cycle of E. coli. Moreover, these simplivariate models were able to uncover regulatory mechanisms present in the phenylalanine biosynthesis route of E. coli
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