241 research outputs found

    Disordered Eating Behavior Frequency and Body Mass Index Comparison among Racially Diverse Sorority Women: The Strong Bodies and Strong Minds Unite Sisters! Study

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    Objective: The purpose of this study was to describe and compare the frequency of disordered eating behaviors (DEB) among primarily Caucasian and primarily Minority sorority women. A secondary purpose was to describe weight status of sorority women by comparing Body Mass Index (BMI) categories, using guidelines from the Centers of Disease Control and Prevention (CDC), among the two sorority groups. Method: Sorority women (primarily Caucasian, n=291; primarily Minority, n=44) completed an online survey designed to assess lifestyle habits, body image, and eating attitudes. We focused upon differences in Eating Disorder Examination-Questionnaire (EDE-Q) global and subscale scores and BMI scores, calculated from self-reported height and weight, between primarily Caucasian and primarily Minority sorority women. Results: The mean global scores for primarily Caucasian sororities was 1.98 ± 1.30; for primarily Minority sororities, 1.72 ± 1.40 (p≤0.23). The reported mean BMI of the primarily Caucasian sororities was 22.34 ± 2.66 compared to the reported mean BMI of the primarily Minority sororities at 26.99 ± 5.96 (p≤ 0.001). The prevalence of overweight, based upon self-report height and weight, among primarily Caucasian sorority women was 12.71% compared to the prevalence of overweight among primarily Minority sorority women at 31.82% (p≤ 0.001). The prevalence of obesity among primarily Caucasian sorority women was 1.37%, compared to primarily Minority sorority women at 22.73% (p≤ 0.001)

    The dynamic electric polarizability of a particle bound by a double delta potential

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    In this paper we derive an expression for the dynamic electric polarizability of a particle bound by a double delta potential for frequencies below and above the absolute value of the particle's ground state energy. The derived expression will be used to study some of the fundamental features of the system and its representation of real systems. In addition we derive a general expression of the dynamic electric polarizability for a potential of multi-delta functions.Comment: 11 pages, 5 figure

    Monte Carlo simulation of size-effects on thermal conductivity in a 2-dimensional Ising system

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    A model based on microcanonical Monte Carlo method is used to study the application of the temperature gradient along a two-dimensional (2D) Ising system. We estimate the system size effects on thermal conductivity, KK, for a nano-scale Ising layer with variable size. It is shown that KK scales with size as K=cLα K=cL^\alpha where α\alpha varies with temperature. Both the Metropolis and Cruetz algorithms have been used to establish the temperature gradient. Further results show that the average demon energy in the presence of an external magnetic field is zero for low temperatures.Comment: 10 pages, 7 figures, to appear in Physica

    Systematically improvable optimized atomic basis sets for {\it ab inito} calculations

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    We propose a unique scheme to construct fully optimized atomic basis sets for density-functional calculations. The shapes of the radial functions are optimized by minimizing the {\it spillage} of the wave functions between the atomic orbital calculations and the converged plane wave calculations for dimer systems. The quality of the bases can be systematically improved by increasing the size of the bases within the same framework. The scheme is easy to implement and very flexible. We have done extensive tests of this scheme for wide variety of systems. The results show that the obtained atomic basis sets are very satisfactory for both accuracy and transferability

    Complete d-Band Dispersion and the Mobile Fermion Scale in NaxCoO2

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    We utilize fine-tuned polarization selection coupled with excitation-energy variation of photoelectron signal to image the \textit{complete d}-band dispersion relation in sodium cobaltates. A hybridization gap anticrossing is observed along the Brillouin zone corner and the full quasiparticle band is found to emerge as a many-body entity lacking a pure orbital polarization. At low dopings, the quasiparticle bandwidth (Fermion scale, many-body \textit{EF_F} \sim 0.25 eV) is found to be smaller than most known oxide metals. The low-lying density of states is found to be in agreement with bulk-sensitive thermodynamic measurements for nonmagnetic dopings where the 2D Luttinger theorem is also observed to be satisfied.Comment: 4+ pages, 5 Fig

    Quantum Thermodynamic Cycles and quantum heat engines

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    In order to describe quantum heat engines, here we systematically study isothermal and isochoric processes for quantum thermodynamic cycles. Based on these results the quantum versions of both the Carnot heat engine and the Otto heat engine are defined without ambiguities. We also study the properties of quantum Carnot and Otto heat engines in comparison with their classical counterparts. Relations and mappings between these two quantum heat engines are also investigated by considering their respective quantum thermodynamic processes. In addition, we discuss the role of Maxwell's demon in quantum thermodynamic cycles. We find that there is no violation of the second law, even in the existence of such a demon, when the demon is included correctly as part of the working substance of the heat engine.Comment: 17 pages, 9 figures, 4 table

    Electrochemical Generation of Superoxide in Room-Temperature Ionic Liquids

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    We have demonstrated that superoxide ion can be generated electrochemically in room-temperature ionic-liquid solvents. In the absence of impurities, cyclic voltammetry showed that the super oxide ion is stable in these solvents. Similar superoxide ion chemistry has previously been demonstrated in volatile and environmentally suspect aprotic solvents such as dimethyl formamide and acetonitrile. However, ionic liquids are nonvolatile and should minimize the problems of secondary solvent waste. It is proposed that the resultant superoxide ion can be used to perform low temperature oxidation of wastes. Low-temperature oxidation of waste solvents can provide a much needed alternative to high-temperature waste incinerators, whose use is greatly complicated by regulatory requirements and locating suitable sites

    Intrinsic Electric Dipole Moments of Paramagnetic Atoms: Rubidium and Cesium

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    The electric dipole moment (EDM) of paramagnetic atoms is sensitive to the intrinsic EDM contribution from that of its constituent electrons and a scalar--pseudo-scalar (S-PS) electron-nucleus interactions. The electron EDM and the S-PS EDM contribution to atomic EDM scales as Z^3. Thus, the heavy paramagnetic atomic systems will exhibit large enhancement factors. However, the nature of the coupling is so small that it becomes an interest of high precision atomic experiments. In this work, we have computed the EDM enhancement factors of the ground states of Rb and Cs due to both the electron EDM and the S-PS EDM using the relativistic coupled-cluster (RCC) theory. The importance of obtaining the precise enhancement factors and the experimental results in deducing a reliable limit on the electron EDM is emphasized.Comment: 4 pages, 1 figur

    Formation of the double helix: a mutational study

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    To investigate the mechanisms by which oligonucleotides hybridize to target molecules, the binding of two oligodeoxynucleotide probes to RNA targets was measured over a broad range of temperatures. Mutations were then scanned across each DNA/RNA hybrid to map, at single base resolution, sequences important for hybridization. Despite being unrelated in sequence, each hybrid formed by a similar mechanism. In the absence of secondary structure, two stretches of bases, termed nucleation regions, cooperated with one another by a looping mechanism to nucleate hybridization. Mutations inside each nucleation region strongly decreased hybridization rates, even at temperatures well below the melting temperature (Tm) of the hybridized duplex. Surprisingly, nucleation regions were detected in a RNA target but not a corresponding DNA target. When either nucleation region was sequestered in secondary structure, the hybridization rate fell and the mechanism of hybridization changed. Single-stranded bases within the nucleation region of the probe and target first collided to form a double helix. If sufficiently G + C rich, the double helix then propagated throughout the oligonucleotide by a strand invasion process. On the basis of these results, general mechanisms for the hybridization of oligonucleotides to complementary and mutant targets are proposed

    Anthropogenic Disturbance and Population Viability of Woodland Caribou in Ontario

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    One of the most challenging tasks in wildlife conservation and management is to clarify how spatial variation in land cover due to anthropogenic disturbance influences wildlife demography and long‐term viability. To evaluate this, we compared rates of survival and population growth by woodland caribou (Rangifer tarandus caribou) from 2 study sites in northern Ontario, Canada that differed in the degree of anthropogenic disturbance because of commercial logging and road development, resulting in differences in predation risk due to gray wolves (Canis lupus). We used an individual‐based model for population viability analysis (PVA) that incorporated adaptive patterns of caribou movement in relation to predation risk and food availability to predict stochastic variation in rates of caribou survival. Field estimates of annual survival rates for adult female caribou in the unlogged ( x̄ = 0.90) and logged ( x̄ = 0.76) study sites recorded during 2010–2014 did not differ significantly (P \u3e 0.05) from values predicted by the individual‐based PVA model (unlogged:  x̄ = 0.87; logged:  x̄ = 0.79). Outcomes from the individual‐based PVA model and a simpler stage‐structured matrix model suggest that substantial differences in adult survival largely due to wolf predation are likely to lead to long‐term decline of woodland caribou in the commercially logged landscape, whereas the unlogged landscape should be considerably more capable of sustaining caribou. Estimates of population growth rates (λ) for the 2010–2014 period differed little between the matrix model and the individual‐based PVA model for the unlogged (matrix model  x̄ = 1.01; individual‐based model x̄ = 0.98) and logged landscape (matrix model x̄ = 0.88; individual‐based model x̄ = 0.89). We applied the spatially explicit PVA model to assess the viability of woodland caribou across 14 woodland caribou ranges in Ontario. Outcomes of these simulations suggest that woodland caribou ranges that have experienced significant levels of commercial forestry activities in the past had annual growth rates 0.96. These differences were strongly related to regional variation in wolf densities. Our results suggest that increased wolf predation risk due to anthropogenic disturbance is of sufficient magnitude to cause appreciable risk of population decline in woodland caribou in Ontario. © 2020 The Authors. The Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society
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