706 research outputs found

    Anomie, Deviant Behavior, and the Olympics

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    Criminal and deviant behavior is known to occur in all places, settings, and times. The Olympics, both Summer and Winter, are not immune to deviant behavior. This paper focuses on the specific types of deviant and criminal acts arising out of the Olympic settings and the anomic factors that possibly lead to deviance in this particular arena. The way that athletes are conformists, innovators, ritualists, and retreatists is considered along with the way that norm confusion influences the Olympic event. Also considered is the role of norm saturation in confusing the way actors interpret appropriate behavior in this setting. Implications are provided

    Freezing by Monte Carlo Phase-Switch

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    We describe a Monte Carlo procedure which allows sampling of the disjoint configuration spaces associated with crystalline and fluid phases, within a single simulation. The method utilises biased sampling techniques to enhance the probabilities of gateway states (in each phase) which are such that a global switch (to the other phase) can be implemented. Equilibrium freezing-point parameters can be determined directly; statistical uncertainties prescribed transparently; and finite-size effects quantified systematically. The method is potentially quite general; we apply it to the freezing of hard spheres.Comment: 5 pages, 2 figure

    Stacking Entropy of Hard Sphere Crystals

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    Classical hard spheres crystallize at equilibrium at high enough density. Crystals made up of stackings of 2-dimensional hexagonal close-packed layers (e.g. fcc, hcp, etc.) differ in entropy by only about 10−3kB10^{-3}k_B per sphere (all configurations are degenerate in energy). To readily resolve and study these small entropy differences, we have implemented two different multicanonical Monte Carlo algorithms that allow direct equilibration between crystals with different stacking sequences. Recent work had demonstrated that the fcc stacking has higher entropy than the hcp stacking. We have studied other stackings to demonstrate that the fcc stacking does indeed have the highest entropy of ALL possible stackings. The entropic interactions we could detect involve three, four and (although with less statistical certainty) five consecutive layers of spheres. These interlayer entropic interactions fall off in strength with increasing distance, as expected; this fall-off appears to be much slower near the melting density than at the maximum (close-packing) density. At maximum density the entropy difference between fcc and hcp stackings is 0.00115+/−0.00004kB0.00115 +/- 0.00004 k_B per sphere, which is roughly 30% higher than the same quantity measured near the melting transition.Comment: 15 page

    Postpartum glucose follow-up and lifestyle management after gestational diabetes mellitus:general practitioner and patient perspectives

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    BACKGROUND: Incidence of type 2 diabetes is high after gestational diabetes mellitus (GDM). We aimed to evaluate the adherence to follow-up six-weeks postpartum visits in secondary care after GDM and glucose monitoring in primary care longer than 12-14 months after delivery and the years thereafter. In addition, we examined the women's lifestyle after delivery. METHODS: A cross-sectional follow-up survey among women with a history of GDM and their general practitioners (GP). Rates of attendance at the six-weeks postpartum visit and glucose testing were obtained from hospital records, over the period 2011-2012. Rates of annual follow-up postpartum glucose testing were assessed by a survey among their GP's. Lifestyle of the women on diet and exercise was assessed by questionnaire in 2015. RESULTS: In total 197 women were eligible for the study. Of these, 156 (79%) attended the six-weeks postpartum visit at the diabetes outpatient clinic and in 145 (93%) of these women glucose testing was performed. In total 77 (39%) women responded to the invitation to participate in this study and filled in the lifestyle questionnaire. About one third of the women met the recommendations for sufficient physical activity. A majority of them did not fulfil the Dutch guidelines on healthy diet - fruit intake 35.1%, vegetables intake 7.8%. Of the 74 invited GP's, 61 responded (82%), only 12 (20%) reported that they had performed a follow-up glucose testing within >12-14 months postpartum. Of these women, five were tested only in the first year of follow-up, five also in the second year, and two were tested for three consecutive years. CONCLUSIONS: Despite the high attendance rate of six-weeks postpartum visit and glucose testing, we observed low rates of longer-term follow-up regarding postpartum glucose testing. Moreover, we found a suboptimal adherence to healthy lifestyle for women with a history of GDM

    Free energies of crystalline solids: a lattice-switch Monte Carlo method

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    We present a method for the direct evaluation of the difference between the free energies of two crystalline structures, of different symmetry. The method rests on a Monte Carlo procedure which allows one to sample along a path, through atomic-displacement-space, leading from one structure to the other by way of an intervening transformation that switches one set of lattice vectors for another. The configurations of both structures can thus be sampled within a single Monte Carlo process, and the difference between their free energies evaluated directly from the ratio of the measured probabilities of each. The method is used to determine the difference between the free energies of the fcc and hcp crystalline phases of a system of hard spheres.Comment: 5 pages Revtex, 3 figure

    Domain-Wall Free-Energy of Spin Glass Models:Numerical Method and Boundary Conditions

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    An efficient Monte Carlo method is extended to evaluate directly domain-wall free-energy for randomly frustrated spin systems. Using the method, critical phenomena of spin-glass phase transition is investigated in 4d +/-J Ising model under the replica boundary condition. Our values of the critical temperature and exponent, obtained by finite-size scaling, are in good agreement with those of the standard MC and the series expansion studies. In addition, two exponents, the stiffness exponent and the fractal dimension of the domain wall, which characterize the ordered phase, are obtained. The latter value is larger than d-1, indicating that the domain wall is really rough in the 4d Ising spin glass phase.Comment: 9 pages Latex(Revtex), 8 eps figure

    Generalizing with perceptrons in case of structured phase- and pattern-spaces

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    We investigate the influence of different kinds of structure on the learning behaviour of a perceptron performing a classification task defined by a teacher rule. The underlying pattern distribution is permitted to have spatial correlations. The prior distribution for the teacher coupling vectors itself is assumed to be nonuniform. Thus classification tasks of quite different difficulty are included. As learning algorithms we discuss Hebbian learning, Gibbs learning, and Bayesian learning with different priors, using methods from statistics and the replica formalism. We find that the Hebb rule is quite sensitive to the structure of the actual learning problem, failing asymptotically in most cases. Contrarily, the behaviour of the more sophisticated methods of Gibbs and Bayes learning is influenced by the spatial correlations only in an intermediate regime of α\alpha, where α\alpha specifies the size of the training set. Concerning the Bayesian case we show, how enhanced prior knowledge improves the performance.Comment: LaTeX, 32 pages with eps-figs, accepted by J Phys

    Temperature and density extrapolations in canonical ensemble Monte Carlo simulations

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    We show how to use the multiple histogram method to combine canonical ensemble Monte Carlo simulations made at different temperatures and densities. The method can be applied to study systems of particles with arbitrary interaction potential and to compute the thermodynamic properties over a range of temperatures and densities. The calculation of the Helmholtz free energy relative to some thermodynamic reference state enables us to study phase coexistence properties. We test the method on the Lennard-Jones fluids for which many results are available.Comment: 5 pages, 3 figure

    Gestational Diabetes Mellitus:current knowledge and unmet needs

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    Gestational diabetes mellitus (GDM) is a global health concern, not only because its prevalence is high and on the increase, but also because of the potential implications for the health of mothers and their offspring. Unfortunately, there is considerable controversy in the literature surrounding the diagnosis and treatment of GDM, as well as the possible long-term consequences for the offspring. As a result, worldwide there is a lack of uniformly accepted diagnostic criteria and the advice regarding the treatment of GDM, including diet, insulin therapy, and the use of oral blood glucose-lowering agents, is highly variable. In this review we provide an overview of the important issues in the field of GDM, including diagnostic criteria, different treatment regimens available, and the long-term consequences of GDM in the offspring

    Thermal conductivity measurement of liquids in a microfluidic device

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    A new microfluidic-based approach to measuring liquid thermal conductivity is developed to address the requirement in many practical applications for measurements using small (microlitre) sample size and integration into a compact device. The approach also gives the possibility of high-throughput testing. A resistance heater and temperature sensor are incorporated into a glass microfluidic chip to allow transmission and detection of a planar thermal wave crossing a thin layer of the sample. The device is designed so that heat transfer is locally one-dimensional during a short initial time period. This allows the detected temperature transient to be separated into two distinct components: a short-time, purely one-dimensional part from which sample thermal conductivity can be determined and a remaining long-time part containing the effects of three-dimensionality and of the finite size of surrounding thermal reservoirs. Identification of the one-dimensional component yields a steady temperature difference from which sample thermal conductivity can be determined. Calibration is required to give correct representation of changing heater resistance, system layer thicknesses and solid material thermal conductivities with temperature. In this preliminary study, methanol/water mixtures are measured at atmospheric pressure over the temperature range 30–50°C. The results show that the device has produced a measurement accuracy of within 2.5% over the range of thermal conductivity and temperature of the tests. A relation between measurement uncertainty and the geometric and thermal properties of the system is derived and this is used to identify ways that error could be further reduced
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