1,329 research outputs found
Simple model for the phase coexistence and electrical conductivity of alkali fluids
We report the first theoretical model for the alkali fluids which yields a
liquid-vapor phase coexistence with the experimentally observed features and
electrical conductivity estimates which are also in accord with observations.
We have carried out a Monte Carlo simulation for a lattice gas model which
allows an integrated study of the structural, thermodynamic, and electronic
properties of metal-atom fluids. Although such a technique is applicable to
both metallic and nonmetallic fluids, non-additive interactions due to valence
electron delocalization are a crucial feature of the present model.Comment: RevTex, 11 pages, 2 ps figure files appended, submitted to PR
Study of theoretical models for the liquid-vapor and metal-nonmetal transitions of alkali fluids
Theoretical models for the liquid-vapor and metal-nonmetal transitions of
alkali fluids are investigated. Mean-field models are considered first but
shown to be inadequate. An alternate approach is then studied in which each
statistical configuration of the material is treated as inhomogeneous, with the
energy of each ion being determined by its local environment. Nonadditive
interactions, due to valence electron delocalization, are a crucial feature of
the model. This alternate approach is implemented within a lattice-gas
approximation which takes into account the observed mode of expansion in the
materials of interest and which is able to treat the equilibrium density
fluctuations. We have carried out grand canonical Monte Carlo simulations, for
this model, which allow a unified, self-consistent, study of the structural,
thermodynamic, and electronic properties of alkali fluids. Applications to Cs,
Rb, K, and Na yield results in good agreement with observations.Comment: 13 pages, REVTEX, 10 ps figures available by e-mail
Comparative De Novo Transcriptome Assembly of Notophthalmus viridescens RNA-seq Data using Two Commercial Software Programs
Background and Purpose: The reduction of cost and ease of using core laboratories or commercial sequencing companies have allowed biomedical and health researchers alike to employ reference-based genomic or transcriptomic sequencing (RNA-seq) projects to expand their work. Non-reference based data analysis, in cases of inexperienced researchers, become more challenging despite the availability of many open source and commercial software programs. Methods: We performed de novo assembly of RNA-seq data obtained from a non-model organism (Eastern Newt skin) to compare data output of two commercially available software workflows. Results: Our results show that the software packages performed satisfactorily albeit with differences in how the annotated and novel transcripts were identified and listed. Conclusion: Overall, we conclude that the use of commercial software platforms has a clear advantage to that of open source programs because of convenience with data analysis workflows. One caveat is that users need to know the software’s basic algorithm and technical approach, in order to determine the precision and validity of the data output. Thus, it is imperative that researchers fully evaluate the software according to their needs to determine their suitability
2015 Seychelles global school-based student health survey
Introduction : Risky behaviors in school‐aged children, such as unhealthy dietary patterns, lack of physical activity, cigarette smoking, alcohol and substance use, sexual behavior, can impact their health in the short and long terms. This survey aimed to assess the prevalence of selected risk behaviors and protective factors in students aged 13‐15 years.
Methods: The Global School‐based Student Health Survey (GSHS) was conducted in September 2015 in Seychelles. Methods followed the standard methodology of GSHS developed by the World Health Organization, the Centers of Disease Prevention and Control (Atlanta, USA) and other international agencies. A two‐stage cluster sample was used to include a random sample of students in grades S1 to S5, i.e. students aged 11 to 17 years. Students completed a self reported questionnaire, which was anonymous, which included questions from several standard modules of GSHS. In addition, weight and height was measured on the day before the survey and students were asked to report their results in their anonymous response forms
2015 Seychelles Global Youth Tobacco Survey and comparison with GYTS in 2007 and 2002
OBJECTIVES: The Global Youth Tobacco Survey (GYTS) is aimed to assess behaviors, knowledge, beliefs, opinions and other variables related to tobacco use among students of secondary schools aged 13‐15 years in countries worldwide using a standard methodology and questionnaire.
METHODS: We present the main findings of GYTS performed in Seychelles in 2015 and compare results with results of two previous GYTS surveys done in Seychelles in 2007 and 2002 in order to identify trends over time. In each GYTS, a two‐stage cluster sample design was used to produce a representative sample of all students in grades S1, S2, S3, S4 and S5 from all public and private schools in Seychelles. Participants completed a standard self‐administered questionnaire in schools on an anonymous and voluntary basis
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