1,046 research outputs found

    Blatant benevolence and conspicuous consumption: When romantic motives elicit strategic costly signals

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    Conspicuous displays of consumption and benevolence might serve as “costly signals ” of desirable mate qualities. If so, they should vary strategically with manipulations of mating-related motives. The authors examined this possibility in 4 experiments. Inducing mating goals in men increased their willingness to spend on conspicuous luxuries but not on basic necessities. In women, mating goals boosted public—but not private—helping. Although mating motivation did not generally inspire helping in men, it did induce more helpfulness in contexts in which they could display heroism or dominance. Conversely, although mating motivation did not lead women to conspicuously consume, it did lead women to spend more publicly on helpful causes. Overall, romantic motives seem to produce highly strategic and sex-specific self-presentations best understood within a costly signaling framework. Key words: costly signaling, altruism, conspicuous consumption, mating goals, self-presentation We should often blush at our noblest deeds if the world were to see all their underlying motives.—Francois de La Rochefoucauld On Valentine’s Day 2003, America’s leading authority on phi-lanthropy announced that real estate mogul Donald Trump had pledged $1 million to charity (Foundation Center, 2003). A fe

    Drum vortons in high density QCD

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    Recently it was shown that high density QCD supports of number of topological defects. In particular, there are U(1)_Y strings that arise due to K^0 condensation that occurs when the strange quark mass is relatively large. The unique feature of these strings is that they possess a nonzero K^+ condensate that is trapped on the core. In the following we will show that these strings (with nontrivial core structure) can form closed loops with conserved charge and currents trapped on the string worldsheet. The presence of conserved charges allows these topological defects, called vortons, to carry angular momentum, which makes them classically stable objects. We also give arguments demonstrating that vortons carry angular momentum very efficiently (in terms of energy per unit angular momentum) such that they might be the important degrees of freedom in the cores of neutron stars.Comment: 11 pages, accepted for publication in Physical Review

    miR-23~27~24 clusters control effector T cell differentiation and function

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    Coordinated repression of gene expression by evolutionarily conserved microRNA (miRNA) clusters and paralogs ensures that miRNAs efficiently exert their biological impact. Combining both loss- and gain-of-function genetic approaches, we show that the miR-23~27~24 clusters regulate multiple aspects of T cell biology, particularly helper T (Th) 2 immunity. Low expression of this miRNA family confers proper effector T cell function at both physiological and pathological settings. Further studies in T cells with exaggerated regulation by individual members of the miR-23~27~24 clusters revealed that miR-24 and miR-27 collaboratively limit Th2 responses through targeting IL-4 and GATA3 in both direct and indirect manners. Intriguingly, although overexpression of the entire miR-23 cluster also negatively impacts other Th lineages, enforced expression of miR-24, in contrast to miR-23 and miR-27, actually promotes the differentiation of Th1, Th17, and induced regulatory T cells, implying that under certain conditions, miRNA families can fine tune the biological effects of their regulation by having individual members antagonize rather than cooperate with each other. Together, our results identify a miRNA family with important immunological roles and suggest that tight regulation of miR-23~27~24 clusters in T cells is required to maintain optimal effector function and to prevent aberrant immune responses

    The SAMPLE Experiment and Weak Nucleon Structure

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    One of the key elements to understanding the structure of the nucleon is the role of its quark-antiquark sea in its ground state properties such as charge, mass, magnetism and spin. In the last decade, parity-violating electron scattering has emerged as an important tool in this area, because of its ability to isolate the contribution of strange quark-antiquark pairs to the nucleon's charge and magnetism. The SAMPLE experiment at the MIT-Bates Laboratory, which has been focused on s-sbar contributions to the proton's magnetic moment, was the first of such experiments and its program has recently been completed. In this paper we give an overview of some of the experimental aspects of parity-violating electron scattering, briefly review the theoretical predictions for strange quark form factors, summarize the SAMPLE measurements, and place them in context with the program of experiments being carried out at other electron scattering facilities such as Jefferson Laboratory and the Mainz Microtron.Comment: 61 pages, review articl

    Stroke in Patients With Acute Coronary Syndromes: Incidence and Outcomes in the Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) Trial

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    BACKGROUND: The incidence of stroke in patients with acute coronary syndromes has not been clearly defined because few trials in this patient population have been large enough to provide stable estimates of stroke rates. METHODS AND RESULTS: We studied the 10 948 patients with acute coronary syndromes without persistent ST-segment elevation who were randomly assigned to placebo or the platelet glycoprotein IIb/IIIa receptor inhibitor eptifibatide in the Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trial to determine stroke rates, stroke types, clinical outcomes in patients with stroke, and independent baseline clinical predictors for nonhemorrhagic stroke. Stroke occurred in 79 (0.7%) patients, with 66 (0.6%) nonhemorrhagic, 6 intracranial hemorrhages, 3 cerebral infarctions with hemorrhagic conversion, and 4 of uncertain cause. There were no differences in stroke rates between patients who received placebo and those assigned high-dose eptifibatide (odds ratios and 95% confidence intervals 0.82 [0.59, 1.14] and 0.70 [0.49, 0.99], respectively). Of the 79 patients with stroke, 17 (22%) died within 30 days, and another 26 (32%) were disabled by hospital discharge or 30 days, whichever came first. Higher heart rate was the most important baseline clinical predictor of nonhemorrhagic stroke, followed by older age, prior anterior myocardial infarction, prior stroke or transient ischemic attack, and diabetes mellitus. These factors were used to develop a simple scoring nomogram that can predict the risk of nonhemorrhagic stroke. CONCLUSIONS: Stro

    Design of Experiments for Screening

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    The aim of this paper is to review methods of designing screening experiments, ranging from designs originally developed for physical experiments to those especially tailored to experiments on numerical models. The strengths and weaknesses of the various designs for screening variables in numerical models are discussed. First, classes of factorial designs for experiments to estimate main effects and interactions through a linear statistical model are described, specifically regular and nonregular fractional factorial designs, supersaturated designs and systematic fractional replicate designs. Generic issues of aliasing, bias and cancellation of factorial effects are discussed. Second, group screening experiments are considered including factorial group screening and sequential bifurcation. Third, random sampling plans are discussed including Latin hypercube sampling and sampling plans to estimate elementary effects. Fourth, a variety of modelling methods commonly employed with screening designs are briefly described. Finally, a novel study demonstrates six screening methods on two frequently-used exemplars, and their performances are compared

    The G0 Experiment: Apparatus for Parity-Violating Electron Scattering Measurements at Forward and Backward Angles

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    In the G0 experiment, performed at Jefferson Lab, the parity-violating elastic scattering of electrons from protons and quasi-elastic scattering from deuterons is measured in order to determine the neutral weak currents of the nucleon. Asymmetries as small as 1 part per million in the scattering of a polarized electron beam are determined using a dedicated apparatus. It consists of specialized beam-monitoring and control systems, a cryogenic hydrogen (or deuterium) target, and a superconducting, toroidal magnetic spectrometer equipped with plastic scintillation and aerogel Cerenkov detectors, as well as fast readout electronics for the measurement of individual events. The overall design and performance of this experimental system is discussed.Comment: Submitted to Nuclear Instruments and Method

    Observation of a Narrow Resonance of Mass 2.46 GeV/c^2 Decaying to D_s^*+ pi^0 and Confirmation of the D_sJ^* (2317) State

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    Using 13.5 inverse fb of e+e- annihilation data collected with the CLEO II detector we have observed a narrow resonance in the Ds*+pi0 final state, with a mass near 2.46 GeV. The search for such a state was motivated by the recent discovery by the BaBar Collaboration of a narrow state at 2.32 GeV, the DsJ*(2317)+ that decays to Ds+pi0. Reconstructing the Ds+pi0 and Ds*+pi0 final states in CLEO data, we observe peaks in both of the corresponding reconstructed mass difference distributions, dM(Dspi0)=M(Dspi0)-M(Ds) and dM(Ds*pi0)=M(Ds*pi0)-M(Ds*), both of them at values near 350 MeV. We interpret these peaks as signatures of two distinct states, the DsJ*(2317)+ plus a new state, designated as the DsJ(2463)+. Because of the similar dM values, each of these states represents a source of background for the other if photons are lost, ignored or added. A quantitative accounting of these reflections confirms that both states exist. We have measured the mean mass differences = 350.0 +/- 1.2 [stat] +/- 1.0 [syst] MeV for the DsJ*(2317) state, and = 351.2 +/- 1.7 [stat] +/- 1.0 [syst] MeV for the new DsJ(2463)+ state. We have also searched, but find no evidence, for decays of the two states via the channels Ds*+gamma, Ds+gamma, and Ds+pi+pi-. The observations of the two states at 2.32 and 2.46 GeV, in the Ds+pi0 and Ds*+pi0 decay channels respectively, are consistent with their interpretations as (c anti-strange) mesons with orbital angular momentum L=1, and spin-parities of 0+ and 1+.Comment: 16 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, version to be published in Physical Review D; minor modifications and fixes to typographical errors, plus an added section on production properties. The main results are unchanged; they supersede those reported in hep-ex/030501
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