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Browsing by Author "Smith, James Joseph"

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    An investigation into hormonal regulation of ovine mammary gland growth during pregnancy
    Smith, James Joseph (Virginia Tech, 1985-05-05)
    Prepartum, multiparous ewes were randomly assigned to experimental groups and sacrificed at 50(n=5), SO(n=4),115(n=5), and 140(n=4) days of gestation. Serum harvested the week prior to slaughter was assayed for progesterone (PG), prolactin (PRL) and growth hormone (GH) concentrations. Mammary tissue obtained at slaughter was assayed for receptor concentrations of progesterone (PGr), prolactin (PRLr) and insulin (Ir). Quantitative biochemical, histological and autoradiographical analyses were used to measure mammary gland growth and indicated no significant glandular growth occurs prior to 8O days of gestation. However, a major phase of parenchymal growth occurred between 8O and 115 days which coincided with significant increases in PG, PGr and PRLr concentrations. Parenchymal growth continued further into late pregnancy. GH and Ir concentrations did not change significantly during pregnancy and were not strongly correlated to growth measurements. These results suggest that mammary gland growth is receptor-mediated and direct or indirect regulation of PGr and PRLr is primarily responsible for the observed growth phenomenon.
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    The Relationship Between School Division Climate and Student Achievement of School Divisions in the Commonwealth of Virginia
    Smith, James Joseph (Virginia Tech, 2005-04-20)
    Researchers and reformers have suggested that school climate is an important aspect of effective schools (Hoy & Hannum, 1997, p. 290). Literature also suggests that effective schools have a positive school climate (Chrispeels, 1990). The purpose of this study is to determine if the climate of schools affects the student achievement in school divisions in the Commonwealth of Virginia. The construct study conducted herein relies exclusively upon data collected by the Virginia Department of Education (VDOE) and reported in the Discipline, Crime and Violence Incidents annual report (DCVI), the Free and Reduced Lunch report, and the Truancy report to form a climate index (CI). A Hierarchical Cluster analysis was used to determine relationships between school division climate, as measured by the CI, and student achievement, as measured by the Virginia Standards of Learning (SOL) Tests, in school divisions in the Commonwealth of Virginia. Based on the CI, there is a relationship between school division climate and student achievement in English/reading, mathematics, history/social science, and science in the Commonwealth of Virginia. Moreover, incidents of disorderly conduct combined with the number of students who receive free and reduced lunch are the best predictors of student achievement.