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Full-Text Articles in Life Sciences
Population Ecology And Reproductive Biology Of The Diamondback Watersnake, Nerodia Rhombifer (Serpentes: Colubridae), In Southernmost Texas, Ruben D. Zamora
Population Ecology And Reproductive Biology Of The Diamondback Watersnake, Nerodia Rhombifer (Serpentes: Colubridae), In Southernmost Texas, Ruben D. Zamora
Theses and Dissertations - UTB/UTPA
Nerodia rhombifer is a polytypic, semi-aquatic snake with a broad geographical distribution ranging from the American Midwest southward to Chiapas, Mexico. Although relatively abundant throughout much of its range, few ecological studies of the species have been conducted. This study provides basic population ecology information in a subtropical habitat. Population data were obtained in a mark-recapture study at Santa Ana National Wildlife Refuge, Hidalgo County, Texas, from August 1995 to December 1998. Specimens taken elsewhere in Hidalgo County provided information on the reproductive biology. This study provides the first absolute density estimates from anywhere within the species’ range. Quantitative information …
Built Environment: Does Geographical Proximity Play A Role In Exercise Frequency And Adherence?, Nancy Anzaldua
Built Environment: Does Geographical Proximity Play A Role In Exercise Frequency And Adherence?, Nancy Anzaldua
Theses and Dissertations - UTB/UTPA
Built environment has been identified as a factor affecting exercise adherence. The author conducted a cross-sectional descriptive study to examine the relationship of distance traveled and its relationship to frequency of exercise and level of adherence. Surveys with demographic and contextual information were collected from 260 participants. Demographic data was mapped using Geographic Information Systems software and data analyses were performed on geographical trends, participants' use facilities and participants' proximity to their respective place of exercise. Trends among participants across the various bands were determined. The author found strong support to show geographical proximity as an important factor in frequency …
The Influence Of Environmental Factors On The Activity And Movement Of Bufo Nebulifer (Coastal Plain Toad) In A Disturbed Area, Crystal Salinas
The Influence Of Environmental Factors On The Activity And Movement Of Bufo Nebulifer (Coastal Plain Toad) In A Disturbed Area, Crystal Salinas
Theses and Dissertations - UTB/UTPA
Toads in the family Bufonidae are poorly studied in southern Texas. Bufo nebulifir, a native bufonid, has been studied in its northern and southern range limits (east Texas and northern Mexico). South Texas' sub-tropical climate could impact the length of the activity period for B. nebulifer in yet unrecorded ways. This study resolves whether environmental factors correlate to Bufo nebulifer's activity, presence, and movement, using a mark-recapture method. The study was conducted for one year during February 2008 to March 2009. Environmental factors, especially rainfall and temperature were significantly correlated (PB. nebulifer . The active period of B. …
Genetic And Phenotypic Characterization Of Plant Pathogen Inhibitory Streptomyces Isolates, Uylissa A. Rodriguez
Genetic And Phenotypic Characterization Of Plant Pathogen Inhibitory Streptomyces Isolates, Uylissa A. Rodriguez
Theses and Dissertations - UTB/UTPA
Streptomyces are Gram-positive, filamentous bacteria that are readily isolated from soil and produce diverse secondary metabolites such as pigments and antibiotics. A survey of indigenous soil microbes from Rio Grande Valley agricultural soils revealed several isolates with broad inhibitory abilities against a range of soil-borne plant pathogens. The goal of this study was to characterize eleven of these potential biocontrol isolates both biochemically and genetically. Nutrient utilization profiles, 16S rDNA sequencing, and the presence of genes involved in antibiotic biosynthesis pathways (strBl, strR, strF, strN, strS and KS) on plasmids or the chromosome were investigated. Nutrient utilization profiling revealed that …
Evaluation Of Streptomycetes For Biological Control Of Gummy Stem Blight Disease Of Cantaloupe, Shima Chaudhary
Evaluation Of Streptomycetes For Biological Control Of Gummy Stem Blight Disease Of Cantaloupe, Shima Chaudhary
Theses and Dissertations - UTB/UTPA
Studies were conducted to evaluate the efficacy of Streptomyces isolates for the biological control of gummy stem blight (GSB) in cantaloupes (Cucumis melo var. ‘Primo’) in south Texas. Plants were monitored for seedling emergence, lesions, mortality and plant growth under laboratory, greenhouse and field conditions. Comparison of treatment groups indicated a significant reduction in plant mortality and enhanced growth of infected plants exposed to three Streptomyces isolates (MA1F4#2, WI1B#5, and MA2A4 #2), which appear to be most effective when used in combination. In all three experiments, GSB infection was associated with a significant reduction in reflectance of near-infrared wavelengths (700-1,100 …
Phenotypic And Genetic Differences In Soil Bacterial Communities Among Successional Stages, Rowena A. G. Hamlet
Phenotypic And Genetic Differences In Soil Bacterial Communities Among Successional Stages, Rowena A. G. Hamlet
Theses and Dissertations - UTB/UTPA
The association between soil microbes and plants can influence plant growth and survival as well as alter soil microbial community dynamics. The purpose of this study was to determine how the length of this interaction between plants and bacteria affects the bacterial soil community structure. Soil microbial communities associated with plant communities at different successional stages at the Santa Ana National Wildlife Refuge were investigated. The study sites included three revegetated sites (4 months, 21 months, and 221 months since revegetation) and a control site (native brush, never revegetated). Five soil samples were randomly collected at each site. Soil microbial …
Hispanic Youth Physical Activity Participation: A Study Of Psychological And Social Influence, Mary Lou Trinidad
Hispanic Youth Physical Activity Participation: A Study Of Psychological And Social Influence, Mary Lou Trinidad
Theses and Dissertations - UTB/UTPA
This study seeks to identity barriers that influenced middle school students from engaging in daily physical activity at least 60 minutes outside of their physical education classes in the Rio Grande Valley. Statistical significance of the study will be determined at the 95% level of confidence. The researcher offers the null hypothesis of no difference between the doers and non-doers The participants of this study were 79 middle school students ages 12-15. The participants were given an open-ended questionnaire. Cross tabulation analyses was conducted to determine difference using the Mann-Whitney U Test. Data from the research questions was analyzed by …
Stress Responses To Salinity In A Native Fresh Water Snake (Nerodia Rhombifer), Joana A. Cordoba
Stress Responses To Salinity In A Native Fresh Water Snake (Nerodia Rhombifer), Joana A. Cordoba
Theses and Dissertations - UTB/UTPA
Salinity stress at 0 ppt, 9 ppt, 18 ppt, and 27 ppt was investigated in Nerodia rhombifer, a fresh water snake. The purpose of this study was to establish if exposure to salinity could elicit a hormonal response in the form of corticosterone. Salinity treatment 27 ppt was lethal for 50% of the snakes. Factors such as population and gender differences were not significant, p=0.748 and p=0.135, respectively. Exposure to the different salinities did not significantly affect the overall mass of the animal, p=0.951. A significant increase in circulating corticosterone was noted in salinity treatments 0 ppt and 18 ppt, …