38 research outputs found

    Learning the configuration of a landmark array: I. Touch-screen studies with pigeons and humans.

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    Multigroup Ethnic Identity Measure (MEIM) Expansion: Measuring Racial, Religious, and National Aspects of Sense of Ethnic Identity Within the United Kingdom

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    These studies examined the degree to which racial, religious, and national aspects of individuals' sense of ethnic identity stand as interrelated, yet distinct, constructs. Results of exploratory factor analyses in Study 1 (n = 272) revealed that a three-factor model specifying racial, religious, and national identities yielded optimal fit to correlational data from an expanded, 36-item version of the Multigroup Ethnic Identity Measure (MEIM; Roberts et al., 1999), although results left room for improvement in model fit. Subsequently, results of confirmatory factor analyses in Study 2 (n = 291) revealed that, after taking covariance among the items into account, a six-factor model specifying exploration and commitment dimensions within each of the racial, religious, and national identity constructs provided optimal fit. Implications for the utility of Goffman's (1963b) interactionist role theory and Erikson's (1968) ego psychology for understanding the full complexity of felt ethnic identity are discussed

    Productivity, Wages, and Marriage: The Case of Major League Baseball

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    The effect of marriage on productivity and, consequently, wages has been long debated in economics. A primary explanation for the impact of marriage on wages has been through its impact on productivity, however, there has been no direct evidence for this. In this paper, we aim to fill this gap by directly measuring the impact of marriage on productivity using a sample of professional baseball players from 1871 - 2007. Our results show that only lower ability men see an increase in productivity, though this result is sensitive to the empirical specification and weakly significant. In addition, despite the lack of any effect on productivity, high ability married players earn roughly 16 - 20 percent more than their single counterparts. We discuss possible reasons why employers may favor married men

    The James Webb Space Telescope Mission

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    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

    SDSS-III: Massive Spectroscopic Surveys of the Distant Universe, the Milky Way Galaxy, and Extra-Solar Planetary Systems

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    Building on the legacy of the Sloan Digital Sky Survey (SDSS-I and II), SDSS-III is a program of four spectroscopic surveys on three scientific themes: dark energy and cosmological parameters, the history and structure of the Milky Way, and the population of giant planets around other stars. In keeping with SDSS tradition, SDSS-III will provide regular public releases of all its data, beginning with SDSS DR8 (which occurred in Jan 2011). This paper presents an overview of the four SDSS-III surveys. BOSS will measure redshifts of 1.5 million massive galaxies and Lya forest spectra of 150,000 quasars, using the BAO feature of large scale structure to obtain percent-level determinations of the distance scale and Hubble expansion rate at z<0.7 and at z~2.5. SEGUE-2, which is now completed, measured medium-resolution (R=1800) optical spectra of 118,000 stars in a variety of target categories, probing chemical evolution, stellar kinematics and substructure, and the mass profile of the dark matter halo from the solar neighborhood to distances of 100 kpc. APOGEE will obtain high-resolution (R~30,000), high signal-to-noise (S/N>100 per resolution element), H-band (1.51-1.70 micron) spectra of 10^5 evolved, late-type stars, measuring separate abundances for ~15 elements per star and creating the first high-precision spectroscopic survey of all Galactic stellar populations (bulge, bar, disks, halo) with a uniform set of stellar tracers and spectral diagnostics. MARVELS will monitor radial velocities of more than 8000 FGK stars with the sensitivity and cadence (10-40 m/s, ~24 visits per star) needed to detect giant planets with periods up to two years, providing an unprecedented data set for understanding the formation and dynamical evolution of giant planet systems. (Abridged)Comment: Revised to version published in The Astronomical Journa

    Measurement of jet fragmentation in Pb+Pb and pppp collisions at sNN=2.76\sqrt{{s_\mathrm{NN}}} = 2.76 TeV with the ATLAS detector at the LHC

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    Learning the configuration of a landmark array: I. Touch-screen studies with pigeons and humans

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    Pigeons and humans searched on a touch-screen monitor for an unmarked goal located relative to an array of landmarks presented in varied screen locations. After training with the goal centered in various square arrays of 4 landmarks, humans, but not pigeons, transferred accurately to arrays with novel elements. Humans searched in the middle of expanded arrays, whereas pigeons preserved the distance and direction to a single landmark. When trained with the goal centered below 2 identical horizontally aligned landmarks, humans responded to horizontal expansions or contractions of the array by shifting their search vertically, preserv-ing angles from landmarks to goal. Pigeons did not adjust their search vertically. Humans trained with a single landmark adjusted search distance when landmark size was changed. Both pigeons and humans use the configuration of a landmark array, but the underlying processes seem to differ. Experimental work has demonstrated that many animal species can encode the location of an important place in terms of nearby visual landmarks (see Gallistel, 1990, and Collett, 1992, for reviews). In several investigations of landmark use, a goal was located near an array of two or more local landmarks, with a directionally stable frame of reference provided by other cues (e.g., Cartwright &amp; Collett

    Absence of stearoyl-CoA desaturase-1 does not promote DSS-induced acute colitis

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    Absence of stearoyl-CoA desaturase-1 (SCD1) in mice leads to chronic inflammation of the skin and increased susceptibility to atherosclerosis, while also increasing plasma inflammatory markers. A recent report suggested that SCD1 deficiency also increases disease severity in a mouse model of inflammatory bowel disease, induced by dextran sulfate sodium (DSS). However, SCD1-deficient mice are known to consume increased amounts of water, which would also be expected to increase the intake of DSS-treated water. The aim of this study was to determine the effect of SCD1 deficiency on DSS-induced acute colitis with DSS dosing adjusted to account for genotype differences in fluid consumption. Wild-type controls were treated with 3.5% DSS for 5 days to induce moderately severe colitis, while the concentration of DSS given to SCD1-deficient mice was lowered to 2.5% to control for increased fluid consumption. Colonic inflammation was assessed by clinical and histological scoring. Although SCD1-deficient mice consumed a total intake of DSS that was greater than that of wild-type controls, colonic inflammation, colon length and fecal blood were not altered by SCD1-deficiency in DSS-induced colitis, while diarrhea and total weight loss were modestly improved. Despite SCD1 deficiency leading to chronic inflammation of the skin and increased susceptibility to atherosclerosis, it does not accelerate inflammation in the DSS-induced model of acute colitis when DSS intake is controlled. These observations suggest that SCD1 deficiency does not play a significant role in colonic inflammation in this model. [The original version of this article, along with updated information and services is located on the World Wide Web at: http://dx.doi.org/10.1016/j.bbalip.2009.08.001]Medicine, Faculty ofMedical Genetics, Department ofReviewedFacultyResearcherOthe

    Identification and functional analysis of a naturally occurring E89K mutation in the ABCA1 gene of the WHAM chicken

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    The Wisconsin hypoalpha mutant (WHAM) chicken has a >90% reduction in plasma HDL due to hypercatabolism. by the kidney of lipid-poor apoA-I. The WHAM chickens have a recessive white skin phenotype caused by a single-gene mutation that maps to the chicken Z-chromosome. This corresponds to human 9q31.1, a chromosomal segment that contains the ATP-binding cassette protein-1 (ABCA1) gene, which is mutated in Tangier Disease and familial hypoalphalipoproteinemia. Complete sequencing of the WHAM ABCA1 cDNA identified a missense mutation near the N-terminus of the protein (E89K). The substitution of this evolutionary conserved glutamate residue for lysine in the mouse ABCA1 transporter leads to complete loss of function, resulting principally from defective intracellular trafficking and very little ABCA1 reaching the plasma membrane. The WHAM chicken is a naturally occurring animal model for Tangier Disease.-Attie, A. D., Y. Hamon, A. R. Brooks-Wilson, M. P. Gray-Keller, M. L. E. MacDonald, V. Rigot, A. Tebon, L.-H. Zhang, J. D. Mulligan, R. R. Singaraja J.J. Bitgood, M. E. Cook, J.J. P. Kastelein, G. Chimini, and M. R. Hayden. Identification and functional analysis of a naturally occurring E89K mutation in the ABCA1 gene of the WHAM chicke
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