886 research outputs found

    Calculations of Neutron Reflectivity in the eV Energy Range from Mirrors made of Heavy Nuclei with Neutron-Nucleus Resonances

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    We evaluate the reflectivity of neutron mirrors composed of certain heavy nuclei which possess strong neutron-nucleus resonances in the eV energy range. We show that the reflectivity of such a mirror for some nuclei can in principle be high enough near energies corresponding to compound neutron-nucleus resonances to be of interest for certain scientific applications in non-destructive evaluation of subsurface material composition and in the theory of neutron optics beyond the kinematic limit.Comment: 18 pages, 5 figures, 1 tabl

    Neighborhood Environment Perceptions and the Likelihood of Smoking and Alcohol Use

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    Citation: Jitnarin, N., Heinrich, K. M., Haddock, C. K., Hughey, J., Berkel, L., & Poston, W. S. C. (2015). Neighborhood Environment Perceptions and the Likelihood of Smoking and Alcohol Use. International Journal of Environmental Research and Public Health, 12(1), 784-799. doi:10.3390/ijerph120100784Neighborhood characteristics are important correlates for a variety of health outcomes. Among several health risk behaviors, smoking and alcohol use have significant consequences. Perceptions of neighborhood problems are associated with depressive symptoms, lower physical activity, and lower quality of life. However, it is unclear which perceived aspects of neighborhoods might be related to smoking and drinking. We examined whether perceived neighborhood characteristics were associated with smoking and drinking patterns using data from US metropolitan Midwestern area adults. Participants completed surveys including sociodemographic characteristics, neighborhood perceptions, behavioral and psychological health. For men, negative perceptions of neighborhood infrastructures were significant predictors for smoking and binge drinking. Among women, no perceived environmental factors were associated with smoking or drinking. However, education was a significant negative predictor for smoking. As age increased, the likelihood of using cigarettes, heavy and binge drinking in women decreased significantly. Depression was a positive predictor for smoking and heavy drinking in men and women, respectively. These findings indicate that the perceived neighborhood infrastructure was predictive of health behaviors among men, even after adjusting for key confounders. Closer attention may need to be paid to the role of neighborhood environmental characteristics along with individual-level characteristics in influencing unhealthy behaviors

    A Model To Measure Supination And Pronation Of The Foot Over Different Levels Of Physiological Stress Using An In-Shoe Force Monitoring System

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    The purpose of this study was to create a diagnostic model of supination and pronation of the foot using vertical ground reaction forces. A size adjustable capacitive transducer retaining 960 individual pressure cells was used to assess orthopaedic parameters of gait cyale timing and vertical ground reaction forces. A pilot sample of five males were used for this model. The subjects were exposed to six experimental conditions. These being; a) a walk, b) jog, c) walk on treadmill, and d) three levels of perceived exertion (mild, moderate and hard running). Perceived exertion was measured with the Borg (RPE) scale. All subjects were measured in the same brand of athletic shoe to control for intershoe differences. The ptonation/supination model was determined by medial/lateral force and timing measurements of the calcaneus, forefoot prominence, arch, the first and fifth metatarsal heads and the toe off (end of gait cycle). Results indicated bi-Iateral differences in the medial and lateral force measurements of the calcaneus. Timing in this area was slightly different. Medial to lateral timing pronation was evidenced in the treadmill walking and moderate running condition. As well, the loading of the first and fifth metatarsal heads as a percentage of the gait cycle did not change over the running conditions. The preliminary results of five subjects provides for limited support of a vertical ground reaction model to assess pronation and supination. Further research with techniques such as high speed photography will allow for clarification of this model

    DYNAMIC MEASUREMENT OF FORCE WITHIN THE SHOE DURING CONDITIONS OF PERCEIVED EXERTION

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    INTRODUCTION Athletics and recreation are becoming a very large component of modem day society. Now, more than ever, more people are becoming very active and involved in recreational pursuits that include aerobics and running/jogging. The resultant increase in activity has lead to a noted increase in injuries (Nigg, 1985; Mckenzie et al., 1985). James et al (cited in Cavanagh, 1990), in a study of 180 injured runners identified three categories of running injury problem areas. These areas being: a) training errors; b)anatomic factors (biomechanics); and c) shoes and surfaces. Two thirds of these injuries were accounted for by training errors (increased mileage or increased intensity). Training errors concerning sudden increases in mileage or intensity tend to subject the body to new or greater than expected physiological stressors. Voloshin and Wosk (1981), have investigated the relationship between heel strike shock wave transmission and joint degeneration in walking subjects. Taken one step further, the implications of damage to the muscle-skeletal system by running is noted by Cavanagh (1990). This combined with the Nigg et al. (1983) data that suggests a relationship between the hardness of the athletic (running) surface and the incidence of injury has serious implications for the recreational runner/athlete. Clarke et al. (1985) have highlighted the possible injurious force involved in tibial accelerations that are the result of the runner taking longer strides. Since most people retain a constant stride frequency, as velocity increases, the athlete tends to increase their stride length. The resultant increase in stride length increases impact forces at the joint. This combined with the increase of ground reaction forces with higher running speeds (Munro et al., 1987) identifies high impact forces as a major factor to be considered when investigating the causal nature of running injuries. Research into the type of shoe and ground reaction forces has been equivocal. Nigg and Bahlsen (1988) have stated that shoes with the hardest mid soles elicit the lowest maximal vertical forces. Conversely other research has indicated that shoe hardness is related to higher (vertical) loading rates. Listed above are a number of factors involved in the prediction of running injuries. Further research is needed to discover the causative factors involved in etiology of sport medicine running injuries. An analysis of running shoes, in particular the vertical ground reaction forces, may account for dynamic patterns of gait. Running at different levels of perceived exertion may elicit clues as to the biomechanics patterns that may be injurious to runners. For example, the gait of a runner at the beginning of the run may be markedly different from the gait at the end of the run. Variables such as intensity and distance will greatly affect the athlete's form as they become more tired. Thus, the number of running injuries (2/3 of Clarke's population) as a result of improper training may be the function of bad form (gait mechanics). An analysis under different levels of exertion will identify patterns of pressure with the foot that may have implications for the construction and design of athletic footwear as well as training methods for runners. This study was an attempt to understand the dynamic of in-shoe vertical ground reaction forces within the shoe under differing levels of perceived exertion. Research in the area of running shoe forces may lead to the development of a better product that will decrease the rate and type of running injuries

    Understanding Outcomes in a Randomized Controlled Trial of a Ward-based Intervention on Psychiatric Inpatient Wards: A Qualitative Analysis of Staff and Patient Experiences.

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    OBJECTIVE: Team formulation is advocated to improve quality of care in mental health care and evidence from a recent U.K.-based trial supports its use in inpatient settings. This study aimed to identify the effects of formulation on practice from the perspectives of staff and patient participating in the trial, including barriers and enhancers to implementing the intervention. METHOD: We carried out semistructured interviews with 57 staff and 20 patients. Data were analyzed using thematic analysis. RESULTS: Main outcomes were: improved staff understanding of patients, better team collaboration and increased staff awareness of their own feelings. Key contextual factors were as follows: overcoming both staff and patient anxiety, unwelcome expert versus collaborative stance, competing demands, and management support. CONCLUSION: Team formulation should be implemented to improve quality of care in inpatient settings and larger definitive trials should be carried out to assess the effect of this intervention on patient outcomes

    Effects of the soil microbiome on the demography of two annual prairie plants

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    This work is licensed under a Creative Commons Attribution 4.0 International License.1. Both mutualistic and pathogenic soil microbes are known to play important roles in shaping the fitness of plants, likely affecting plants at different life cycle stages. 2. In order to investigate the differential effects of native soil mutualists and pathogens on plant fitness, we compared survival and reproduction of two annual tallgrass prairie plant species (Chamaecrista fasciculata and Coreopsis tinctoria) in a field study using 3 soil inocula treatments containing different compositions of microbes. The soil inocula types included fresh native whole soil taken from a remnant prairie containing both native mutualists and pathogens, soil enhanced with arbuscular mycorrhizal (AM) fungi derived from remnant prairies, and uninoculated controls. 3. For both species, plants inoculated with native prairie AM fungi performed much better than those in uninoculated soil for all parts of the life cycle. Plants in the native whole prairie soil were either generally similar to plants in the uninoculated soil or had slightly higher survival or reproduction. 4. Overall, these results suggest that native prairie AM fungi can have important positive effects on the fitness of early successional plants. As inclusion of prairie AM fungi and pathogens decreased plant fitness relative to prairie AM fungi alone, we expect that native pathogens also can have large effects on fitness of these annuals. Our findings support the use of AM fungi to enhance plant establishment in prairie restorations.National Science Foundation (NSF DEB‐1556664)National Science Foundation (DEB‐1738041)National Science Foundation (OIA 1656006

    The Two-Nucleon Potential from Chiral Lagrangians

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    Chiral symmetry is consistently implemented in the two-nucleon problem at low-energy through the general effective chiral lagrangian. The potential is obtained up to a certain order in chiral perturbation theory both in momentum and coordinate space. Results of a fit to scattering phase shifts and bound state data are presented, where satisfactory agreement is found for laboratory energies up to about 100 Mev.Comment: Postscript file; figures available by reques

    Vasomotion and Neurovascular Coupling in the Visual Thalamus In Vivo

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    Spontaneous contraction and relaxation of arteries (and in some instances venules) has been termed vasomotion and has been observed in an extensive variety of tissues and species. However, its functions and underlying mechanisms are still under discussion. We demonstrate that in vivo spectrophotometry, measured simultaneously with extracellular recordings at the same locations in the visual thalamus of the cat, reveals vasomotion, measured as an oscillation (0.14hz) in the recorded oxyhemoglobin (OxyHb) signal, which appears spontaneously in the microcirculation and can last for periods of hours. During some non-oscillatory periods, maintained sensory stimulation evokes vasomotion lasting ∼30s, resembling an adaptive vascular phenomenon. This oscillation in the oxyhaemoblobin signal is sensitive to pharmacological manipulation: it is inducible by chloralose anaesthesia and it can be temporarily blocked by systemic administration of adrenaline or acetylcholine (ACh). During these oscillatory periods, neurovascular coupling (i.e. the relationship between local neural activity and the rate of blood supply to that location) appears significantly altered. This raises important questions with regard to the interpretation of results from studies currently dependent upon a linear relationship between neural activity and blood flow, such as neuroimaging
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