663 research outputs found
Examination of offsite radiological emergency protective measures for nuclear reactor accidents involving core melt
"Date published: June 1978. --Reissued: October 1979."MITNE series handwritten on title-page"SAND78-0454."Originally issued as a Ph. D. thesis by the first author and supervised by the second and third author, MIT, Dept. of Nuclear Engineering, 1978Originally issued as anIncludes bibliographical referencesEvacuation, sheltering followed by population relocation, and iodine prophylaxis are evaluated as offsite public protective measures in response to nuclear reactor accidents involving core-melt. Evaluations were conducted using a modified version of the Reactor Safety Study consequence model. Models representing each measure were developed and are discussed. Potential PWR core-melt radioactive material releases are separated into two categories, "Melt-through" and "Atmospheric," based upon the mode of containment failure. Protective measures are examined and compared for each category in terms of projected doses to the whole body and thyroid. Measures for "Atmospheric" accidents are also examined in terms of their influence on the occurrence of public health effects. For "Melt-through" accidents, few, if any, early public health effects are likely, and doses in excess of Protective Action Guides (PAGs) are "confined" to areas within 10 miles of the reactor.Evacuation appears to provide the largest reduction in whole body dose for this category. However, sheltering, particularly when basements are readily available, may be an acceptable alternative. Both evacuation and iodine prophylaxis can substantially reduce the dose to the thyroid. For "Atmospheric" accidents, PAGs are likely to be exceeded at very large distances, and significant numbers of early public health effects are possible. However, most early fatalities occur within 10 miles of the reactor. Within 5 miles, evacuation appears to be more effective than sheltering in reducing the number of early health effects. Beyond 5 miles, this distinction is less, or not, apparent. Within 10 miles, early health effects are strongly influenced by the speed and efficiency with which protective measures are implemented. Outside of 10 miles, they are not.The projected total number of thyroid nodules is not substantially reduced unless iodine prophylaxis is administered over very large areas (distances). The qualitative effects of weather conditions on the above conclusions are also briefly discussed.Prepared for Office of Nuclear Regulatory Research, Probabilistic Staff, U.S. Nuclear Regulatory Commission, under Interagency Agreement DOE-40-550-75 NRC FIN no. A103
Procedural Signaling, Party Loyalty, and Traceability in the U.S. House of Representatives
In this article, we take advantage of a new source of data providing updates from the Majority Leader’s Office that signal the leadership’s positions on floor votes. We offer a more nuanced explanation of voting in the U.S. House as our findings suggest that not all procedural votes are created equal. While the most liberal members of the party vote with the leadership on procedural votes at high rates and nearly 100 percent of the time when signaled by the majority leader, moderate members are significantly less likely to support the party and are not responsive to these signals.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
Generating Computational Models for Serious Gaming
Westera, W. (2013, 25 October). Generating computational models for serious gaming. Presentation at the GALA Serious Gaming Conference, Paris, France.Many serious games include computational models that simulate dynamic systems. These models promote enhanced interaction and responsiveness. Under the social web paradigm more and more usable game authoring tools become available that enable prosumers to create their own games, but the inclusion of dynamic simulations remains a specialist’s job involving knowledge of mathematics, numerical modeling and programming. This presentation explains a methodology for specifying and running a specific subset of computational models without the need of bothering with mathematical equations. The methodology comprises a knowledge elicitation procedure for identifying and specifying the required model components, whereupon the mathematical model is automatically generated. The approach is based on the fact that many games focus on optimisation problems that are covered by a general class of linear programming models. The presentation thus sketches the principles of a creativity tool that removes barriers for harvesting the creative potential of teachers and students
Spectrum of Neutral Helium in Strong Magnetic Fields
We present extensive and accurate calculations for the excited state spectrum
of spin-polarized neutral helium in a range of magnetic field strengths up to
G. Of considerable interest to models of magnetic white dwarf stellar
atmospheres, we also present results for the dipole strengths of the low lying
transitions among these states. Our methods rely on a systematically saturated
basis set approach to solving the Hartree--Fock self-consistent field
equations, combined with an ``exact'' stochastic method to estimate the
residual basis set truncation error and electron correlation effects. We also
discuss the applicability of the adiabatic approximation to strongly magnetized
multi-electron atoms.Comment: 19 pages, 7 figures, 10 table
Strain Relaxation Mechanisms and Local Structural Changes in Si_{1-x}$Ge_{x} Alloys
In this work, we address issues pertinent to the understanding of the
structural and electronic properties of Si_{1-x} Ge_{x}alloys, namely, (i) how
does the lattice constant mismatch between bulk Si and bulk Ge manifests itself
in the alloy system? and (ii) what are the relevant strain release mechanisms?
To provide answers to these questions, we have carried out an in-depth study of
the changes in the local geometric and electronic structures arising from the
strain relaxation in Si_{1-x} Ge_{x} alloys using an ab initio molecular
dynamics scheme. The optimized lattice constant, while exhibiting a general
trend of linear dependence on the composition (Vegard's law), shows a negative
deviation from Vegard's law in the vicinity of x=0.5. We delineate the
mechanisms responsible for each one of the above features. We show that the
radial-strain relaxation through bond stretching is responsible for the overall
trend of linear dependence of the lattice constant on the composition. On the
other hand, the negative deviation from Vegard's law is shown to arise from the
angular-strain relaxation.Comment: 21 pages, 7 figure
Progress report no. 7
Statement of responsibility on title-page reads: editor: M.J. Driscoll; contributors: D.C. Aldrich, M.J. Driscoll, O.K. Kadiroglu, S. Keyvan, H.U.R. Khan, D.D. Lanning, R. Morton, J. Pasztor, T.J. Reckart, A.A. Salehi, J.I. Shin, A.T. Supple, D.J. Wargo, and S.S. WuIncludes bibliographical referencesProgress report; September 30, 1976U.S. Atomic Energy Commission contracts: E(11-1) 225
Large-scale genome-wide association studies and meta-analyses of longitudinal change in adult lung function.
BACKGROUND: Genome-wide association studies (GWAS) have identified numerous loci influencing cross-sectional lung function, but less is known about genes influencing longitudinal change in lung function.
METHODS: We performed GWAS of the rate of change in forced expiratory volume in the first second (FEV1) in 14 longitudinal, population-based cohort studies comprising 27,249 adults of European ancestry using linear mixed effects model and combined cohort-specific results using fixed effect meta-analysis to identify novel genetic loci associated with longitudinal change in lung function. Gene expression analyses were subsequently performed for identified genetic loci. As a secondary aim, we estimated the mean rate of decline in FEV1 by smoking pattern, irrespective of genotypes, across these 14 studies using meta-analysis.
RESULTS: The overall meta-analysis produced suggestive evidence for association at the novel IL16/STARD5/TMC3 locus on chromosome 15 (P  =  5.71 × 10(-7)). In addition, meta-analysis using the five cohorts with ≥3 FEV1 measurements per participant identified the novel ME3 locus on chromosome 11 (P  =  2.18 × 10(-8)) at genome-wide significance. Neither locus was associated with FEV1 decline in two additional cohort studies. We confirmed gene expression of IL16, STARD5, and ME3 in multiple lung tissues. Publicly available microarray data confirmed differential expression of all three genes in lung samples from COPD patients compared with controls. Irrespective of genotypes, the combined estimate for FEV1 decline was 26.9, 29.2 and 35.7 mL/year in never, former, and persistent smokers, respectively.
CONCLUSIONS: In this large-scale GWAS, we identified two novel genetic loci in association with the rate of change in FEV1 that harbor candidate genes with biologically plausible functional links to lung function
Identification of Susceptibility Pathways for the Role of Chromosome 15q25.1 in Modifying Lung Cancer Risk
Genome-wide association studies (GWAS) identified the chromosome 15q25.1 locus as a leading susceptibility region for lung cancer. However, the pathogenic pathways, through which susceptibility SNPs within chromosome 15q25.1 affects lung cancer risk, have not been explored. We analyzed three cohorts with GWAS data consisting 42,901 individuals and lung expression quantitative trait loci (eQTL) data on 409 individuals to identify and validate the underlying pathways and to investigate the combined effect of genes from the identified susceptibility pathways. The KEGG neuroactive ligand receptor interaction pathway, two Reactome pathways, and 22 Gene Ontology terms were identified and replicated to be significantly associated with lung cancer risk, with P values less than 0.05 and FDR less than 0.1. Functional annotation of eQTL analysis results showed that the neuroactive ligand receptor interaction pathway and gated channel activity were involved in lung cancer risk. These pathways provide important insights for the etiology of lung cancer
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