54 research outputs found

    Sex differences in self- and teachers' reports of self-esteem in preadolescents

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    The short form of the Coopersmith Self-Esteem Inventory was administered to 952 fourth- and fifth-grade children (482 males, 470 females) from 41 classes. The children's teachers completed Coopersmith's Behavior Rating Form, a measure of self-esteem-related behavior. In the self-ratings, girls were significantly lower than boys; in the teachers' ratings, girls were significantly higher. In 32 of the 41 classes, boys ranked higher in their self-ratings than in the teacher ratings; the reverse was true for girls — a highly significant difference. This pattern of findings did not occur in the 8 classes which had male teachers. Issues concerning the measurement and conceptualization of self-esteem are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45616/1/11199_2004_Article_BF00287338.pd

    Overcoming real-world obstacles in 21 cm power spectrum estimation: A method demonstration and results from early Murchison Widefield Array data

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    We present techniques for bridging the gap between idealized inverse covariance weighted quadratic estimation of 21 cm power spectra and the real-world challenges presented universally by interferometric observation. By carefully evaluating various estimators and adapting our techniques for large but incomplete data sets, we develop a robust power spectrum estimation framework that preserves the so-called "Epoch of Reionization (EoR) window" and keeps track of estimator errors and covariances. We apply our method to observations from the 32-tile prototype of the Murchinson Widefield Array to demonstrate the importance of a judicious analysis technique. Lastly, we apply our method to investigate the dependence of the clean EoR window on frequency—especially the frequency dependence of the so-called “wedge" feature—and establish upper limits on the power spectrum from z ¼ 6.2 to z ¼ 11:7. Our lowest limit is ?ðkÞ < 0.3 Kelvin at 95% confidence at a comoving scale k ¼ 0.046 Mpc-1 and z ¼ 9.5

    Designing the climate observing system of the future

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    © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Earth's Future 6 (2018): 80–102, doi:10.1002/2017EF000627.Climate observations are needed to address a large range of important societal issues including sea level rise, droughts, floods, extreme heat events, food security, and freshwater availability in the coming decades. Past, targeted investments in specific climate questions have resulted in tremendous improvements in issues important to human health, security, and infrastructure. However, the current climate observing system was not planned in a comprehensive, focused manner required to adequately address the full range of climate needs. A potential approach to planning the observing system of the future is presented in this article. First, this article proposes that priority be given to the most critical needs as identified within the World Climate Research Program as Grand Challenges. These currently include seven important topics: melting ice and global consequences; clouds, circulation and climate sensitivity; carbon feedbacks in the climate system; understanding and predicting weather and climate extremes; water for the food baskets of the world; regional sea-level change and coastal impacts; and near-term climate prediction. For each Grand Challenge, observations are needed for long-term monitoring, process studies and forecasting capabilities. Second, objective evaluations of proposed observing systems, including satellites, ground-based and in situ observations as well as potentially new, unidentified observational approaches, can quantify the ability to address these climate priorities. And third, investments in effective climate observations will be economically important as they will offer a magnified return on investment that justifies a far greater development of observations to serve society's needs

    Low frequency observations of linearly polarized structures in the interstellar medium near the south Galactic pole

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    This is an author-created, un-copyedited version of an article published in The Astrophysical Journal. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at https://doi.org/10.3847/0004-637X/830/1/38We present deep polarimetric observations at 154 MHz with the Murchison Widefield Array (MWA), covering 625 deg^2 centered on RA=0 h, Dec=-27 deg. The sensitivity available in our deep observations allows an in-band, frequency-dependent analysis of polarized structure for the first time at long wavelengths. Our analysis suggests that the polarized structures are dominated by intrinsic emission but may also have a foreground Faraday screen component. At these wavelengths, the compactness of the MWA baseline distribution provides excellent snapshot sensitivity to large-scale structure. The observations are sensitive to diffuse polarized emission at ~54' resolution with a sensitivity of 5.9 mJy beam^-1 and compact polarized sources at ~2.4' resolution with a sensitivity of 2.3 mJy beam^-1 for a subset (400 deg^2) of this field. The sensitivity allows the effect of ionospheric Faraday rotation to be spatially and temporally measured directly from the diffuse polarized background. Our observations reveal large-scale structures (~1 deg - 8 deg in extent) in linear polarization clearly detectable in ~2 minute snapshots, which would remain undetectable by interferometers with minimum baseline lengths >110 m at 154 MHz. The brightness temperature of these structures is on average 4 K in polarized intensity, peaking at 11 K. Rotation measure synthesis reveals that the structures have Faraday depths ranging from -2 rad m^-2 to 10 rad m^-2 with a large fraction peaking at ~+1 rad m^-2. We estimate a distance of 51+/-20 pc to the polarized emission based on measurements of the in-field pulsar J2330-2005. We detect four extragalactic linearly polarized point sources within the field in our compact source survey. Based on the known polarized source population at 1.4 GHz and non-detections at 154 MHz, we estimate an upper limit on the depolarization ratio of 0.08 from 1.4 GHz to 154 MHz.Peer reviewedFinal Accepted Versio

    From empirics to empiricists

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    Catálogo Taxonômico da Fauna do Brasil: setting the baseline knowledge on the animal diversity in Brazil

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    The limited temporal completeness and taxonomic accuracy of species lists, made available in a traditional manner in scientific publications, has always represented a problem. These lists are invariably limited to a few taxonomic groups and do not represent up-to-date knowledge of all species and classifications. In this context, the Brazilian megadiverse fauna is no exception, and the Catálogo Taxonômico da Fauna do Brasil (CTFB) (http://fauna.jbrj.gov.br/), made public in 2015, represents a database on biodiversity anchored on a list of valid and expertly recognized scientific names of animals in Brazil. The CTFB is updated in near real time by a team of more than 800 specialists. By January 1, 2024, the CTFB compiled 133,691 nominal species, with 125,138 that were considered valid. Most of the valid species were arthropods (82.3%, with more than 102,000 species) and chordates (7.69%, with over 11,000 species). These taxa were followed by a cluster composed of Mollusca (3,567 species), Platyhelminthes (2,292 species), Annelida (1,833 species), and Nematoda (1,447 species). All remaining groups had less than 1,000 species reported in Brazil, with Cnidaria (831 species), Porifera (628 species), Rotifera (606 species), and Bryozoa (520 species) representing those with more than 500 species. Analysis of the CTFB database can facilitate and direct efforts towards the discovery of new species in Brazil, but it is also fundamental in providing the best available list of valid nominal species to users, including those in science, health, conservation efforts, and any initiative involving animals. The importance of the CTFB is evidenced by the elevated number of citations in the scientific literature in diverse areas of biology, law, anthropology, education, forensic science, and veterinary science, among others

    Self-Concept in Gifted Children: Differential Impact in Boys and Girls

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    Gifted 9-12-year-old children were compared with non-gifted children on three paper and pencil measures of self-concept. Additional personality and behavioral information on each child was provided by his/her mother and teacher. Giftedness seemed to be an advantage for girls but not for boys. Gifted girls described themselves as having a more positive self-concept and a more internal locus of control than did non-gifted girls. No such differences were found with boys. In fact, gifted boys gave some evidence of lower self-satisfaction, particularly in areas of physical strength and aggressiveness, when compared to non-gifted boys. Mothers and teachers similarly reported fewer problem areas for gifted girls but no such differences between gifted and non-gifted boys. The findings are discussed in the context of cultural sex-role expectations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66764/2/10.1177_001698628703100102.pd
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