2,058 research outputs found

    The 1999 Center for Simulation of Dynamic Response in Materials Annual Technical Report

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    Introduction: This annual report describes research accomplishments for FY 99 of the Center for Simulation of Dynamic Response of Materials. The Center is constructing a virtual shock physics facility in which the full three dimensional response of a variety of target materials can be computed for a wide range of compressive, ten- sional, and shear loadings, including those produced by detonation of energetic materials. The goals are to facilitate computation of a variety of experiments in which strong shock and detonation waves are made to impinge on targets consisting of various combinations of materials, compute the subsequent dy- namic response of the target materials, and validate these computations against experimental data

    The Rascal Road: Crime, Prestige, and Development in Papua New Guinea

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    This article critiques analyses that interpret gang crime, or "rascalism," in Papua New Guinea as an underclass phenomenon. Illustrative sketches of gang members' lifestyles and expressed attitudes toward their own criminal behavior are used to demonstrate a variety of social backgrounds and individual reasons for pursuing a criminal career. Themes suggested by these sketches are explored through a discussion of the Melanesian gift economy and common indigenous understandings of the concept of development. That concept tends to be apprehended by Papua New Guineans in terms of the gift economy, with its complex integration of issues of reciprocity, socioeconomic obligation, status, and prestige. Parallels are drawn between the behavior and attitudes of rascals and the ethnographically familiar patterns of behavior by Papua New Guineans associated with the pursuit of status and prestige through the manipulation of relationships of reciprocation and obligation. The "rascal" lifestyle is interpreted as a strategy for pursuing prestige and the appropriation of commodities into a gift economy. Rather than view rascalism as a product of poverty and unemployment generated by processes of development or underdevelopment, it is analytically useful to consider it as an issue of the problematic encounter between a cash economy and an enduring, robust gift economy

    Women in Papua New Guinea's village courts

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    Recently, claims have been made in academic literature that women are disadvantaged, or mistreated, in Papua New Guineas village courts. These claims have the common theme that the male-dominated courts, particularly in the highlands, apply custom or customary law which discriminates against women. Reviewing research-based studies, other literature and my own research findings, I suggest herein that, to the contrary, village courts are an important resource for aggrieved women with limited avenues for seeking justice and recompense. Village courts in PNG were established by the Village Courts Act of 1973, at the end of the colonial era. The legislation provided for magistrates, untrained in law, to be selected by the local community on the criteria of their integrity as adjudicators and good knowledge of local customs (Village Court Secretariat 1975: 1). Despite overwhelming support among Melanesian parliamentarians and progressive legal advisers for the establishment of village courts, there were fears among conservative jurists and other Europeans that these courts would be legally or otherwise corrupt and that village court officials ignorance of the law would result in the application of anachronistic customs. Consequently, when village courts began to be proclaimed in 1975 after a trial period, they became the focus of European officials who were anxious to observe their practice. Some of the first village courts proclaimed were in the Mendi district of the Southern Highlands, and these were almost immediately visited by concerned European officials.AusAI

    Estimating Effects and Making Predictions from Genome-Wide Marker Data

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    In genome-wide association studies (GWAS), hundreds of thousands of genetic markers (SNPs) are tested for association with a trait or phenotype. Reported effects tend to be larger in magnitude than the true effects of these markers, the so-called ``winner's curse.'' We argue that the classical definition of unbiasedness is not useful in this context and propose to use a different definition of unbiasedness that is a property of the estimator we advocate. We suggest an integrated approach to the estimation of the SNP effects and to the prediction of trait values, treating SNP effects as random instead of fixed effects. Statistical methods traditionally used in the prediction of trait values in the genetics of livestock, which predates the availability of SNP data, can be applied to analysis of GWAS, giving better estimates of the SNP effects and predictions of phenotypic and genetic values in individuals.Comment: Published in at http://dx.doi.org/10.1214/09-STS306 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

    Conformations of N-Heterocyclic Carbene Ligands in Ruthenium Complexes Relevant to Olefin Metathesis

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    The structure of ruthenium-based olefin metathesis catalyst 3 and model π-complex 5 in solution and in the solid state are reported. The N-tolyl ligands, due to their lower symmetry than the traditional N-mesityl substituents, complicate this analysis, but ultimately provide explanation for the enhanced reactivity of 3 relative to standard catalyst 2. The tilt of the N-tolyl ring provides additional space near the ruthenium center, which is consistent with the enhanced reactivity of 3 toward sterically demanding substrates. Due to this tilt, the more sterically accessible face bears the two methyl substituents of the N-aryl rings. These experimental studies are supported by computational studies of these complexes by DFT. The experimental data provides a means to validate the accuracy of the B3LYP and M06 functionals. B3LYP provides geometries that match X-ray crystal structural data more closely, though it leads to slightly less (0.5 kcal mol^(−1)) accuracy than M06 most likely because it underestimates attractive noncovalent interactions

    The use of epigenetic phenomena for the improvement of sheep and cattle

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    This review considers the evidence for inheritance across generations of epigenetic marks and how this phenomenon could be exploited in the cattle and sheep industries. Epigenetic marks are chemical changes in the chromosomes that affect the expression of genes and hence the phenotype of the cell and are passed on during mitosis so that the daughter cells have the same chemical changes or epigenetic marks as the parent cell. Although most epigenetic marks are wiped clean in the process of forming a new zygote, some epigenetic marks (epimutations) may be passed on from parent to offspring. The inheritance of epigenetic marks across generations is difficult to prove as there are usually alternative explanations possible. There are few well documented cases, mainly using inbred strains of mice. The epimutations are unstable and revert to wild type after a few generations. Although, there are no known cases in sheep or cattle, it is likely that inherited epimutations occur in these species but it is unlikely that they explain a large part of the inherited or genetic variation. There is limited evidence in mice and rats that an environmental treatment can cause a change in the epigenetic marks of an animal and that this change can be passed on the next generation. If inherited epimutations occur in sheep and cattle, they will already be utilized to some extent by existing genetic improvement programs. It would be possible to modify the statistical models used in the calculation of estimated breeding values to better recognize the variance controlled by epimutations, but it would probably have, at best, a small effect on the rate on genetic (inherited) gain achieved. Although not a genetic improvement, the inheritance of epigenetic marks caused by the environment experienced by the sire offers a new opportunity in sheep and cattle breeding. However, at present we do not know if this occurs or, if it does, what environmental treatment might have a beneficial effect

    Addition of H_2O and O_2 to Acetone and Dimethylsulfoxide Ligated Uranyl(V) Dioxocations

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    Gas-phase complexes of the formula [UO_2(lig)]^+ (lig = acetone (aco) or dimethylsulfoxide (dmso)) were generated by electrospray ionization (ESI) and studied by tandem ion-trap mass spectrometry to determine the general effect of ligand charge donation on the reactivity of UO_2^+ with respect to water and dioxygen. The original hypothesis that addition of O_2 is enhanced by strong σ-donor ligands bound to UO_2^+ is supported by results from competitive collision-induced dissociation (CID) experiments, which show near exclusive loss of H_2O from [UO_2(dmso)(H_2O)(O_2)]^+, whereas both H_2O and O_2 are eliminated from the corresponding [UO_2(aco)(H_2O)(O_2)]^+ species. Ligand-addition reaction rates were investigated by monitoring precursor and product ion intensities as a function of ion storage time in the ion-trap mass spectrometer: these experiments suggest that the association of dioxygen to the UO_2^+ complex is enhanced when the more basic dmso ligand was coordinated to the metal complex. Conversely, addition of H_2O is favored for the analogous complex ion that contains an aco ligand. Experimental rate measurements are supported by density function theory calculations of relative energies, which show stronger bonds between UO_2^+ and O_2 when dmso is the coordinating ligand, whereas bonds to H_2O are stronger for the aco complex
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