Browsing by Subject "Ecology and Evolutionary Biology"
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Item Scientific Proceedings of the Royal Dublin Society; Unsound Mendelian Developments Especially as Regards the Presence and Absence Theory(The Royal Dublin Society; Williams and Norgate, 1912-12-01) Wilson, JamesItem Scientific Proceedings of the Royal Dublin Society; AN EXAMPLE OF THE MULTIPLE COUPLINGOF MENDELIAN FACTORS .(The Royal Dublin Society; Williams and Norgate, 1913-03-01) Wilson, JamesItem Scientific Proceedings of the Royal Dublin Society; Inter-Alternative as Opposed to Coupled Mendelian Factors: A Solution of the Agouti-Black Colour in Rabbits(The Royal Dublin Society; Williams and Norgate, 1915-01-01) Wilson, JamesItem Secondary Science Curriculum: Developing a Browser-Based Constructive Ecosystem(2004-08-01) Barrier, Ame R.; Reeves, Rustin; Shores, Jay H.; Rudick, Victoria L.Barrier, Ame R., Secondary Science Curriculum: Developing a Browser-Based Constructivist Ecosystem. Master of Science Education (Biomedical Sciences), August, 2004, 46pp, 1 software program, bibliography, 33 titles. The internship practicum report explores current research on the plausibility of incorporating technology based on guided inquiry into K-12 classrooms to increase student science achievement. Part of the practicum report is browser-based software designed for teaching an ecosystems unit and includes the materials for use in a guided inquiry classroom. Can browser-based science instruction designed along a guided inquiry approach increase student achievement in science education and be quantified when compared to didactic classroom methods? The practicum report and the materials developed are designed to provide a means for the eventual testing of technology infused guided inquiry against traditional didactic teaching in the K-12 science classroom and begin to answer this question.Item Sexually Dimorphic Anxiety-Like Interoceptive Discriminative Stimuli(1997-12-01) Jung, Marianna E.; Walls, Cleatus; Downey, H. Fred; Forster, MichaelJung, Marianna E., Sexually Dimorphic Anxiety-Like Interoceptive Discriminative Stimuli. Doctor of Philosophy (Biomedical Sciences), December 1997, 150 pp, introduction, 2 chapters, discussion, bibliography, 109 titles. This study compared gender differences in the anxiogenic stimuli induced by either a GABA-A antagonist, pentylenetetrazol (PTZ) or by a 5-HT1b/2 agonist, m-chlorophenylpiperazine (m-CPP) before and during ethanol withdrawal (EW). Rats were trained to discriminate either PTZ (16mg/kg, IP) or m-CPP (1.2 mg/kg, IP) from saline in a two lever choice task for food reward. Male and female rats were gonadectomized or sham-operated, and ovariectomized (OVX) female rats were tested during replacement treatment with 17β estradiol (2.5 mg, 21 day release, sc). The dose-response for the discrimination of the interoceptive stimulus (IDS) produced by PTZ (0-16 mg/kg) or m-CPP (0 to 1.2 mg/kg) was measured under all hormonal conditions. For m-CPP trained rats, latency to first lever-press response was also tested. Results: sham and estradiol-replaced female rats had higher ED50s for discrimination of the PTZ or m-CPP IDS than intact males or OVX rats. There is a dose-related impairment of operant responding after mCPP injection. Sham and estradiol replaced OVX rats showed an increased delay to the initiation of response after m-CPP injection as compared to sham or castrated male rats or OVX rats that showed no effect at the doses tested. Rats then received a chronic ethanol diet (6.5%) for 10 days. At twelve hours of ethanol withdrawl, they were tested for lever selection after saline injection. Fewer sham female and estradiol-replaced female rats responded on the drug lever during acute EW as compared to sham male, castrated or OVX rats. In general, the anxiogenic drug lever selection of OVX rats resembled that of male rats but was restored toward that of sham female rats by estradiol replacement. Castration did not alter the response of male rats to either PTZ or mCPP. Serum β –estradiol concentrations were determined by radioimmunoassay for sham, OVX, and estradiol-replaced female rats. The concentration was significantly higher in hormone-replaced female rats than in OVX. The estradiol concentration in sham female rats showed a cyclic pattern over 4 consecutive days, but this pattern did not correlate with any difference in IDS. Blood ethanol concentration (BEC) was determined using head space gas chromatography. BEC was higher in intact female rats than in intact male rats after ethanol injection (2 g/kg, ip), but did not differ during EW. Conclusions: females produce less anxiogenic IDS in response to either GABA inhibition or 5-HT1b/2 activation, but are more impaired by m-CPP in their ability to initiate operant responses than male rats. In addition, fewer intact females developed a spontaneous IDS during EW than males which is not the result of lower BEC. Estrogen appears to play a trophic role in altering responsiveness to anxiogenic stimuli.Item Single Nucleotide Polymorphisms and Haplotype Analyses of Complex Medical Disorders(2008-05-01) Gonzalez, Suzanne D.; Arthur Eisenberg; Robert Luedtke; Rustin ReevesGonzalez, Suzanne D., Doctor of Philosophy. Cell Biology and Genetics. Single Nucleotide Polymorphisms and Haplotype Analyses of Complex Medical Disorders. Number of Pages: 129. Number of Tables: 25. Number of Illustrations: 5. Number of Titles Included in References: 197. There has been great difficulty in identifying genes involved in complex disorders. The complex genetic basis of these diseases indicates that either several genes act together to cause disease, or genetic heterogeneity is present in the population. This dissertation was aimed at developing new assays to identify polymorphisms in novel candidate genes that potentially contribute to two classes of common complex disorders: psychiatric diseases and metabolic disorders. Genotyping assays were developed to investigate single nucleotide polymorphisms (SNPs) and haplotypes in complex genetic disorders using multiplexed SNP panels, restriction fragment length polymorphism technology, and cycle sequencing platforms. An introduction to the study is provided in Chapter 1. Manuscripts focus on association studies of candidate genes in Bipolar Disorder and Schizophrenia (Chapter 2), Type 2 Diabetes, Hypertension and Metabolic Syndrome (Chapter 3), and baseline blood pressure in African Americans (Chapter 4). The summary of these manuscripts (Chapter 5) describes the significant associations made between SNPs/haplotypes in psychiatric and metabolic complex genetic disorders. Significant genetic associations of SNPs within the PHLPP gene were detected among schizophrenics (Chapter 2). The G allele of SNP rs8087170 was associated with the control population with the T allele of SNP rs12966002 was found only in schizophrenics. A significant variance was detected at SNP rs12457020 between bipolar and schizophrenic datasets, as there was a 10 fold increase in the A allele in the bipolar group. Significant associations of ATP1A2 5’ SNPs C-1489T and G-1253A were detected in metabolic syndrome and hypertensive groups (Chapter 3). Haplotypes based on these 3 SNPs were significantly associated with metabolic syndrome and hypertensive populations. Four linked ATP1A2 SNPs, G3756C, G3853A, C3913T and C3915T, were associated with baseline blood pressure (Chapter 4). Haplotypes associated with blood pressure in an ethnic specific manner. GGCC associated with lower blood pressures, while haplotype GGTT associated with higher blood pressures in African Americans. These studies provide new mechanisms to identify mutations and provide evidence supporting the pathophysiology of these disorders.Item The Population Abundance and Associated Geographic and Demographic Factors of the Dengue Vectors, Aedes Aegypti and Aedes Albopictus in Dallas County, TX, USA(2007-05-01) Stahl, Matthew S.; Sue Lurie; Joon-Hak LeeStahl, Matthew S., The Population Abundance and Associated Geographic and Demographic factors of the Dengue Vectors Aedes aegypti and Aedes albopictus in Dallas County, TX. Master of Public Health (Environmental Health), May 2007, 40 pp., 7 figures, 2 tables, bibliography, 72 titles. The risk for dengue outbreak was assessed in North Central Texas in 2006 in response to increased case numbers in Texas and Mexican states in 2005. Data were collected from 54 sites in Dallas County, TX using oviposition traps and estimates from U.S. Census and Sourcebook America databases. Higher vegetation and shade displayed more Aedes species; standing water also showed more Aedes albopictus. Lower home values and lower incomes corresponded to more Aedes aegypti; lower household density displayed more Aedes albopictus. Other socio-economic and demographic factors did not have significant association with abundance. The methodology of this study may serve as a model for assessment of dengue vector abundance in other regions.Item The Relationship Between Atrazine Exposure and Breast and Ovarian Cancer Incidence Rates in Texas Agricultural Statistical Districts(2006-05-01) Hull, Kimberly M.; Terrance Gratton; Eric Johnson; Sejong BaeHull, Kimberly M., The Relationship Between Atrazine Exposure and Breast and Ovarian Cancer Incidence Rates in Texas Agricultural Statistical Districts. Masters of Public Health (Environmental Health), May 2006, 95pp., 16 tables, 7 illustrations, reference, 74 titles. The herbicide, atrazine, is suspected to cause cancer primarily through drinking water. This ecological study analyzed relationships between potential atrazine exposures and female breast and ovarian cancer incidence rates in Texas Agricultural Statistical Districts. Atrazine exposures are: atrazine usage, rural population, and public water systems. Study results indicate an inverse relationship between four atrazine exposures and breast and ovarian cancer incidence rates (county level). There is a positive relationship between surface water systems and ovarian cancer incidences rates (county level). There also is an inverse relationship between one atrazine usage index and ovarian cancer incidence rates (district level). Study results are similar to other atrazine and cancer studies; correlations prevent statements of causal inference.