1,473 research outputs found

    Do Teachers’ Race, Gender, and Ethnicity Matter? Evidence From the National Education Longitudinal Study of 1988

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    Using data from the National Educational Longitudinal Study of 1988 (NELS), the authors find that the match between teachers\u27 race, gender, and ethnicity and those of their students had little association with how much the students learned, but in several instances it seems to have been a significant determinant of teachers\u27 subjective evaluations of their students. For example, test scores of white female students in mathematics and science did not increase more rapidly when the teacher was a white woman than when the teacher was a white man, but white female teachers evaluated their white female students more highly than did white male teachers

    Elucidation of the Role of the Exocyst Subunit Sec6p in Exocytosis: A Dissertation

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    Trafficking of protein and lipid cargo through the secretory pathway in eukaryotic cells is mediated by membrane-bound vesicles. Secretory vesicles are targeted to sites of exocytosis on the plasma membrane in part by a conserved multi-subunit protein complex termed the exocyst. In addition to tethering vesicles to the plasma membrane, the exocyst complex and components therein may also add a layer of regulation by directly controlling assembly of the SNARE complex, which is required for membrane fusion, as well as other regulatory factors such as Sec1p. In the past, we have shown that Sec6p interacts with Sec9p in vivo and that that interaction retards binary SNARE complex formation in a SNARE assembly assay. Though many interactions have been mapped using in vitro methods, confirming them in vivoand placing them into the context of a complete model that accounts for all observed interactions (and lack of interactions) has proven difficult. In order to address these problems, I have studied the interactions between Sec6p and other factors involved in exocytosis at the plasma membrane via in vivo methods. My hypothesis was that Sec6p interaction with Sec9p and subsequent inhibition of SNARE complex assembly in vitro was an intermediate state and Sec6p was part of a set of cofactors that accelerated SNARE complex assembly in vivo. To test this hypothesis I showed that the interaction between the plasma membrane t-SNARE Sec9p and the yeast exocyst subunit Sec6p can be observed in vivoand designed point mutations to disrupt that interaction. Interestingly, I also showed that Sec6p:Sec9p interaction involves the free pool of Sec6p rather than the exocyst bound fraction of Sec6p. Point mutations in the N-terminal domain of Sec6p result in temperature sensitive growth and secretion defects, without loss of Sec6p-Sec9p interaction. However, at the non-permissive temperature, the exocyst subunits Sec5p, Sec10p and Sec15p are mislocalized and are absent from the exocyst complex. The resulting subcomplex, containing Sec3p, Sec8p, Exo70p and Exo84p, remains stably assembled and localized at sites of polarized secretion. This subcomplex is likely due to disruption of interaction between Sec6p and Sec5p, and may be similar to that observed at restrictive temperatures in the sec6-54temperature sensitive mutant. Additionally, one of the sec6 temperature sensitive mutants displays a loss of binding to the yeast regulatory protein Sec1p. In vitro binding studies indicate a direct interaction between Sec1p and the free pool of the wild-type Sec6p protein, suggesting close interplay between Sec6p and Sec1p in the regulation of SNARE complexes. A coherent model which incorporates all these interactions has continued to be elusive. However, the results I have found do suggest several hypotheses which should prove testable in the future

    Do Teachers' Race, Gender, and Ethnicity Matter?: Evidence from NELS88

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    Our study uses a unique national longitudinal survey, the National Educational Longitudinal Study of 1988 (NELS), which permits researchers to match individual students and teachers, to analyze issues relating to how a teacher's race, gender, and ethnicity, per se, influence students from both the same and different race, gender, and ethnic groups. In contrast to much of the previous literature, we focus both on how teachers subjectively relate to and evaluate their students and on objectively how much their students learn. On balance, we find that teachers' race, gender, and ethnicity, per se, are much more likely to influence teachers' subjective evaluations of their students than they are to influence how much the students objectively learn. For example, while white female teachers do not appear to be associated with larger increases in test scores for white female students in mathematics and science than white male teachers 'produce', white female teachers do have higher subjective evaluations than their white male counterparts of their white female students. We relate our findings to the more general literature on gender, race, and ethnic bias in subjective performance evaluations in the world of work and trace their implications for educational and labor markets.

    Benzo[a]pyrene-induced DNA adducts and gene expression profiles in target and non-target organs for carcinogenesis in mice

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    Background: Gene expression changes induced by carcinogens may identify differences in molecular function between target and non-target organs. Target organs for benzo[a]pyrene (BaP) carcinogenicity in mice (lung, spleen and forestomach) and three non-target organs (liver, colon and glandular stomach) were investigated for DNA adducts by 32P-postlabelling, for gene expression changes by cDNA microarray and for miRNA expression changes by miRNA microarray after exposure of animals to BaP. Results: BaP-DNA adduct formation occurred in all six organs at levels that did not distinguish between target and non-target. cDNA microarray analysis showed a variety of genes modulated significantly by BaP in the six organs and the overall gene expression patterns were tissue specific. Gene ontology analysis also revealed that BaP-induced bioactivities were tissue specific; eight genes (Tubb5, Fos, Cdh1, Cyp1a1, Apc, Myc, Ctnnb1 and Cav) showed significant expression difference between three target and three non-target organs. Additionally, several gene expression changes, such as in Trp53 activation and Stat3 activity suggested some similarities in molecular mechanisms in two target organs (lung and spleen), which were not found in the other four organs. Changes in miRNA expression were generally tissue specific, involving, in total, 21/54 miRNAs significantly up- or down-regulated. Conclusions: Altogether, these findings showed that DNA adduct levels and early gene expression changes did not fully distinguish target from non-target organs. However, mechanisms related to early changes in p53, Stat3 and Wnt/β-catenin pathways may play roles in defining BaP organotropism

    Survey and monitoring of opium poppy and wheat in Afghanistan: 2003-2009

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    An integrated application of remote-sensing technology was devised and applied in Afghanistan during 2003–2009 providing critical information on cereal and poppy cultivation and poppy eradication. The results influenced UK and international policy and counter-narcotics actions in Afghanistan

    Sexual Aggression in Sport

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    The purpose of this paper is to provide an overview of the sexual aggression in sport literature, including an analysis of interventions delivered to athletes that focus on the role of the coach and wider sporting community. The paper will also discuss the limitations of applying such prevention methods and possible directions for future research. This paper provides an overview of research investigating the prevalence of sexually aggressive behaviour perpetrated by athletes, theoretical explanations of their sexual misconduct, and the application of violence prevention methods delivered to athletes. Research findings are discussed in relation to the prevalence of sexual aggression in sport and the efficacy of prevention methods. This paper provides a valuable overview of the literature that focuses on the topical area of sexual aggression in sports. The paper also considers the application and efficacy of violence prevention and intervention methods delivered to athletes
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