2,634 research outputs found

    A Study of single and multiphoton events in e+ e- collisions at center-of-mass energies of 161-GeV and 172-GeV

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    Events from electron-positron collisions where photons are the only particles detected in the final state are studied using the data collected by the ALEPH detector at LEP. The data consist of 11.1 pb \sp{-1} at s=161\sqrt{s} = 161 GeV, 1.1 pb\sp{-1} at 170 GeV and 9.5 pb\sp{-1} at 172 GeV. The \rm e\sp+e\sp-\to\nu\bar\nu\gamma(\gamma) and \rm e\sp+e\sp-\to\gamma\gamma(\gamma) cross sections are measured. The data are in good agreement with predictions based on the Standard Model, and are used to set upper limits on anomalous photon production. Searches for supersymmetric particles in channels with one or more photons and missing energy have been performed. Cross-section upper limits are derived for two different Supersymmetry models. A lower limit of 71 GeV/c\sp2 at 95ib/zoneinfo/MET.L. is set on the mass of the lightest neutralino \rm\chi\sbsp{1}{0}\ (M\sb{\tilde e\sb{R}} = 1.5M\sb{\chi\sbsp{1}{0}} and \tau\sb{\chi\sbsp{1}{0}}\le 3 ns) for the Gauge-Mediated Supersymmetry Breaking model. Constraints on compositeness models and excited electrons are studied using the differential cross section for \rm e\sp+e\sp-\to\gamma\gamma(\gamma) events

    Outbreeding depression and inheritance in three generations of geographically distinct southeast Alaska coho salmon (Oncorhynchus kisutch) populations

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    Thesis (M.S.) University of Alaska Fairbanks, 2009I observed no fitness losses among Fâ‚‚ hybrids of three Southeast Alaska coho salmon (Oncorhynchus kisutch) populations relative to parental controls. Marine survival did not differ among groups in one generation, but was greater for hybrids than controls in another, although the power of these tests was low. Increases in fluctuating asymmetry, which can signal losses in fitness, were not observed. Line cross analyses of length suggested additive and additive plus dominance gene action, and two of three analyses suggested epistasis. In contrast, meristic characters exhibited little variability; and in most cases tests failed to reject a simple additive model. Half- and full-sib analyses provided no evidence of quantitative genetic variation for any trait although the power to detect these effects was low. Comparisons of population divergence measured by quantitative traits (Qst) and molecular markers (Fst) that length is an adaptive trait and that bilateral meristics are highly conserved. Although we did not observe losses in fitness, the power of our tests was low, the among-population differences were unique to our experiment and so results of this study should be interpreted with caution

    Hyperon Production in Z Decays

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    Can Jury Trial Innovations Improve Juror Understanding of DNA Evidence?

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    A single spot of blood on a pink windowsill will tell investigators who broke a windowpane, turned a lock, and kidnapped 2-year-old Molly Evans from her bedroom in the middle of the night. An expert witness will testify that the DNA profile of the blood evidence recovered from the windowsill was entered into CODIS, an electronic database of DNA profiles. That process yielded a “hit,” identifying the defendant as the most likely source of the blood inside Molly’s room. But will jurors be able to understand the expert’s intricate analysis and use it to reach a verdict? And what—if any—steps can be taken to increase jurors’ comprehension of complex DNA evidence? Questions such as these prompted an NIJ-funded study on the impact of jury trial innovations upon mock jurors’ understanding of contested mitochondrial DNA (mtNDA) evidence. By examining how jurors in different experimental conditions performed on a Juror Comprehension Scale both before and after deliberations, researchers were able to assess whether four specific innovations improved jurors’ understanding of this complex evidence and identify which innovations worked best

    Synthesis and characterization of La<sub>0.8</sub>Sr<sub>1.2</sub>Co<sub>0.5</sub>M<sub>0.5</sub>O<sub>4-?</sub> (M=Fe, Mn)

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    The M4+-containing K2NiF4-type phases La0.8Sr1.2Co0.5Fe0.5O4 and La0.8Sr1.2Co0.5Mn0.5O4 have been synthesized by a sol-gel procedure and characterized by X-ray powder diffraction, thermal analysis, neutron powder diffraction and Mössbauer spectroscopy. Oxide ion vacancies are created in these materials via reduction of M4+ to M3+ and of Co3+ to Co2+. The vacancies are confined to the equatorial planes of the K2NiF4-type structure. A partial reduction of Mn3+ to Mn2+ also occurs to achieve the oxygen stoichiometry in La0.8Sr1.2Co0.5Mn0.5O3.6. La0.8Sr1.2Co0.5Fe0.5O3.65 contains Co2+ and Fe3+ ions which interact antiferromagnetically and result in noncollinear magnetic order consistent with the tetragonal symmetry. Competing ferromagnetic and antiferromagnetic interactions in La0.8Sr1.2Co0.5Fe0.5O4, La0.8Sr1.2Co0.5Mn0.5O4 and La0.8Sr1.2Co0.5Mn0.5O3.6 induce spin glass properties in these phases

    Science in the Jury Box: Jurors\u27 Views and Understanding of Mitochondrial DNA Evidence

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    This article describes parts of an unusually realistic experiment on the comprehension of expert testimony on mitochondrial DNA (mtDNA) sequencing in a criminal trial for robbery. Specifically, we examine how jurors who responded to summonses for jury duty evaluated portions of videotaped testimony involving probabilities and statistics. Although some jurors showed susceptibility to classic fallacies in interpreting conditional probabilities, the jurors as a whole were not overwhelmed by a 99.98% exclusion probability that the prosecution presented. Cognitive errors favoring the defense were more prevalent than ones favoring the prosecution. These findings lend scant support to the legal argument that mtDNA evidence (with modest exclusion probabilities) should be excluded because jurors are prone to overvalue such evidence. The article also introduces a new method for inferring the perceived probability of guilt that satisfies the burden of persuasion for most jurors

    Testing Jury Reforms

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    DNA evidence has become a key law enforcement tool and is increasingly presented in criminal trials in Delaware and elsewhere. The integrity of the criminal trial process turns upon the jury\u27s ability to understand DNA evidence and to evaluate properly the testimony of experts. How well do they do? Can we assist them in the process

    Statistics in the Jury Box: How Jurors Respond to Mitochondrial DNA Match Probabilities

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    This article describes parts of an unusually realistic experiment on the comprehension of expert testimony on mitochondrial DNA (mtDNA) sequencing in a criminal trial for robbery. Specifically, we examine how jurors who responded to summonses for jury duty evaluated portions of videotaped testimony involving probabilities and statistics. Although some jurors showed susceptibility to classic fallacies in interpreting conditional probabilities, the jurors as a whole were not overwhelmed by a 99.98% exclusion probability that the prosecution presented. Cognitive errors favoring the defense were more prevalent than ones favoring the prosecution. These findings lend scant support to the legal argument that mtDNA evidence (with modest exclusion probabilities) should be excluded because jurors are prone to overvalue such evidence. The article also introduces a new method for inferring the perceived probability of guilt that satisfies the burden of persuasion for most jurors

    Science in the Jury Box: Jurors\u27 Views and Understanding of Mitochondrial DNA Evidence

    Get PDF
    This article describes parts of an unusually realistic experiment on the comprehension of expert testimony on mitochondrial DNA (mtDNA) sequencing in a criminal trial for robbery. Specifically, we examine how jurors who responded to summonses for jury duty evaluated portions of videotaped testimony involving probabilities and statistics. Although some jurors showed susceptibility to classic fallacies in interpreting conditional probabilities, the jurors as a whole were not overwhelmed by a 99.98% exclusion probability that the prosecution presented. Cognitive errors favoring the defense were more prevalent than ones favoring the prosecution. These findings lend scant support to the legal argument that mtDNA evidence (with modest exclusion probabilities) should be excluded because jurors are prone to overvalue such evidence. The article also introduces a new method for inferring the perceived probability of guilt that satisfies the burden of persuasion for most jurors
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