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Induced Bradycardia Effects on Angiogenesis, Growth and Development in Early Development in Chicken Embryos, Gallus Domesticus

Description: Cardiac performance, angiogenesis and growth was investigated during early chicken development. Heart rate, and thus arterial pulse pressure and cardiac output, were altered with the bradycardic drug ZD7288. Heart rates at 72 h of development of control embryos and those dosed with chicken Ringer were not different at 171 bpm. Acute and chronic application of ZD7288 caused significant bradycardia. Chronic dosing of Ringer and ZD7288 changed neither eye diameter nor development rate. Chronic dosing of ZD7288 did not significantly alter CAM vessel density close to the embryo (2, 3 and 4 mm) but at farther distances (5 and 6 mm) chronic dosing with both Ringer and ZD7288 decreased vessel density by 13 - 16%. Chronic dosing with ZD7288 also reduced body mass by 20%. Thus, lowered heart rate and cardiac output had little effect on vessel density or developmental stage, but did reduce embryo growth.
Date: December 2010
Creator: Ruck, Sylvia A.

Photoactivatable Quantum Dots in Super-Resolution Microscopy of Muscle

Description: Super-resolution 3D imaging was achieved using newly synthesized photoactivatable quantum dot (PAQ dot) probes. Quantum dots were modified with a novel quencher system to make them photoactivatable. The unique properties of these PAQ dots enable single-fluorophore localization in three dimensions using a confocal microscopy optical sectioning method. Myosin and tropomyosin of rabbit myofibrilar bundles were specifically labeled with the newly synthesized PAQ dot. A sufficient number of single quantum dots were photoactivated, localized and reduced to their centroid and then reconstructed to a super-resolution image. The acquired super-resolution image shows a lateral and an axial sub-diffraction resolution and demonstrates ultrafine striations with widths less than 70 nm that are not evident by conventional confocal microscopy. The striations appear to be related to nebulin thin filament binding protein. This newly developed imaging system is cutting edge for its high resolution and localization as well its simplicity and convenience.
Date: December 2010
Creator: Akel, Amal

Expression analysis of the fatty acid desaturase 2-4 and 2-3 genes from Gossypium hirsutum in transformed yeast cells and transgenic Arabidopsis plants.

Description: Fatty acid desaturase 2 (FAD2) enzymes are phosphatidylcholine desaturases occurring as integral membrane proteins in the endoplasmic reticulum membrane and convert monounsaturated oleic acid into polyunsaturated linoleic acid. The major objective of this research was to study the expression and function of two cotton FAD2 genes (the FAD2-3 and FAD2-4 genes) and their possible role in plant sensitivity to environmental stress, since plants may increase the polyunsaturated phospholipids in membranes under environmental stress events, such as low temperature and osmotic stress. Two FAD2 cDNA clones corresponding to the two FAD2 genes have been isolated from a cotton cDNA library, indicating both genes are truly expressed in cotton. Model yeast cells transformed with two cotton FAD2 genes were used to study the chilling sensitivity, ethanol tolerance, and growth rate of yeast cells. The expression patterns of the two FAD2 genes were analyzed by reverse transcription polymerase chain reactions (RT-PCR) and Western blot analyses in cotton plants under different treatment conditions. The coding regions of both FAD2 genes were inserted downstream from the CaMV 35S promoter in the pMDC gateway binary vector system. Five different FAD2/pMDC constructs were transformed into the Arabidopsis fad2 knockout mutant background, and multiple potential transgenic Arabidopsis plant lines harboring the cotton FAD2 genes were generated. The cotton FAD2 genes were amplified by the polymerase chain reaction (PCR) from the genomic DNAs isolated from the transgenic Arabidopsis T1 plant lines. Complementation of the putative transgenic Arabidopsis plants with the two cotton FAD2 genes was demonstrated by gas chromatography analyses of the fatty acid profiles of leaf tissues. The cellular localization of cotton FAD2-4 polypeptides with N-terminal green fluorescence protein (GFP) was visualized by confocal fluorescence microscopy. The phenotype of transgenic Arabidopsis plants transformed with the cotton FAD2-4 gene was compared to Arabidopsis knockout fad2 mutant plants and wild ...
Date: August 2008
Creator: Zhang, Daiyuan

Morphological and physiological developmental consequences of parental effects in the chicken embryo (Gallus gallus domesticus) and the zebrafish larva (Danio rerio).

Description: Cardiac, metabolic and growth response of early-stage chicken embryos to perturbations in yolk environment was investigated. Also, effects of parental hypoxia exposure on hypoxia resistance, thermal tolerance and body length of zebrafish larvae were investigated. In the first study, thyroxine, triiodothyronine and testosterone produced differential effects on heart rate and development rate of chicken embryos during the first 4 days of development. Triiodothyronine caused a dose-dependent increase in heart rate when applied at 40 or 70 hours of age, while thyroxine caused a dose-dependent increase in heart rate when applied at 40 hours only. Testosterone and propyl-thiouracil (deiodinase antagonist) did not have an effect on heart rate. Development rate was not changed by thyroxine, triiodothyronine, testosterone or propyl-thiouracil, which suggested that heart rate changes did not result from changes in embryo maturity. In the second study, chicken embryos exposed to yolks of different bird species during early-stage embryonic development showed changes in heart rate, mass-specific oxygen consumption and body mass that scaled with the egg mass, incubation period length, and yolk triiodothyronine and testosterone levels of the species from which yolk was derived. In the third study, this phenomenon was investigated between layer and broiler chickens. Heart rate, oxygen consumption and body mass of broiler and layer embryos were significantly changed by a breed-specific change in yolk environment. Yolk triiodothyronine and testosterone concentrations of broiler and layer eggs did not suggest that these hormones were responsible for physiological and morphological changes observed. The final study demonstrated that hypoxia resistance and body lengths, but not thermal tolerance of zebrafish larvae was increased by parental hypoxia exposure.
Date: August 2008
Creator: Ho, Dao H.

The impact of invertebrates to four aquatic macrophytes: Potamogeton nodosus, P. illinoensis, Vallisneria americana and Nymphaea mexicana.

Description: This research investigated the impact of invertebrates to four species of native aquatic macrophytes: V. americana, P. nodosus, P. illinoensis, and N. mexicana. Two treatments were utilized on each plant species, an insecticide treatment to remove most invertebrates and a non-treated control. Ten herbivore taxa were collected during the duration of the study including; Synclita, Paraponyx, Donacia, Rhopalosiphum, and Hydrellia. Macrophyte biomass differences between treatments were not measured for V. americana or N. mexicana. The biomasses of P. nodosus and P. illinoensis in non-treated areas were reduced by 40% and 63% respectively. This indicated that herbivory, once thought to be insignificant to aquatic macrophytes, can cause substantial reductions in biomass.
Date: August 2008
Creator: Nachtrieb, Julie Graham

Molecular cloning and analysis of the genes for cotton palmitoyl-acyl carrier protein thioesterase (PATE) and Δ-12 fatty acid desaturase (FAD2-3) and construction of sense and anti-sense PATE plasmid vectors for altering oilseed composition of transgenic cotton plants.

Description: A cotton PATE cDNA clone has a 1.7-kb insert with an coding region for 410 amino acids, lacking codons for the three N-terminal amino acids. The predicted amino acid sequence of the PATE preprotein has a characteristic stromal-targeting domain and a 63% identity to the Arabidopsis FatB1 thioesterase sequence. A cotton genomic clone containing a 17.4-kb DNA segment was found to encompass a palmitoyl-ACP thioesterase (FatB1) gene. The gene spans 3.6 kb with six exons and five introns. The six exons are identical in nucleotide sequence to the open reading frame of the corresponding cDNA, and would encode a preprotein of 413 amino acids. The preprotein is identified as a FatB thioesterase from its deduced amino acid sequence similarity to those of other FatB thioesterase preproteins. A 5'-flanking region of 914 bp was sequenced, with the potential promoter/enhancer elements including basic helix-loop-helix elements (E box). Alkaline blot hybridization of cotton genomic DNA suggests the presence at least two FatB1 thioesterase genes in cotton. Four plasmid constructs for both constitutive and seed-specific anti-sense RNA suppression and gene-transgene co- suppression of PATE gene expression were successfully generated. Two overlapping cotton genomic clones were found to encompass a Δ-12 fatty acid desaturase (FAD2-3) gene. The continuous FAD2-3 coding region is 1,155 bp and would encode a protein of 384 amino acids. The FAD2-3 gene has one large intron of 2,967 bp entirely within its 5'-untranslated region. Several potential promoter/enhancer elements, including several light responsive motifs occur in the 5'-flanking region. Yeast cells transformed with a plasmid construct containing the cotton FAD2-3 coding region accumulate an appreciable amount of linoleic acid (18:2), not normally present in wild-type yeast cells, indicating that the gene encodes a functional FAD2 enzyme.
Date: May 2002
Creator: Nampaisansuk, Mongkol

Immunohistochemical characterization of neuronal cilia in the rat central nervous system.

Description: An anti-G"11 antibody was used to label neuronal cilia throughout the rat central nervous system. Immunoreactive cilia were observed in every examined region of the rat CNS, but not in monkey or mouse tissue. Antibodies to G"q and G"q/11 failed to label cilia. Immunoreactive cilia were observed as early as postnatal day 0 in spinal tissue, and postnatal day 3 in hypothalamic tissue. There was a statistically significant negative correlation between a region's mean cilium length and that region's distance to the nearest ventricle; regions nearest ventricles were those with the longest cilia. This correlation suggests neuronal cilia may function as chemosensors, detecting substances as they move out from the cerebrospinal fluid and into the extracellular space of the brain.
Date: May 2002
Creator: Hughes, Rhome

College Freshman Biology Two Semester Course: Integrating Deep Processing Teaching Techniques

Description: Development of a college level freshman biology course was undertaken in response to government reports that American students have fallen behind students of other countries in the area of the sciences. Teaching strategies were investigated to accomplish two objectives, to define essential academic material to include in the course and to investigate teaching techniques that would increase deep processing of the information. An active process that consisted of applying the cognitive information to solving problems or developing answers to questions was defined as critical thinking. Critical thinking was incorporated into the course by the use of case studies.
Date: May 2002
Creator: Blevins, Mary Jean

Food, Feeding Selectivity, and Ecological Efficiencies of Fundulus notatus (Rafinesque) (Osteichthyes; Cyprinodontidae)

Description: This study was made to further define the trophic dynamics of Fundulus notatus by determining its ration composition under natural conditions, measuring feeding selectivity under various laboratory conditions of prey-species composition and availability, and determining the efficiencies with which F. notatus utilizes ingested chironomid larvae.
Date: August 1970
Creator: Atmar, Gerald Legare

Carbon Flux in Reservoir Sediments

Description: The central objective of the study was to fractionate sedimenting organic materials according to their source (allochthonous or autochthonous) and ultimately to determine the degree of biodegradability of contributions from either source with particular reference to activities at the mud-water interface.
Date: May 1973
Creator: Newton, Charles Eugene

Interactions of N-Acylethanolamine Metabolism and Abscisic Acid Signaling in Arabidopsis Thaliana Seedlings

Description: N-Acylethanolamines (NAEs) are endogenous plant lipids hydrolyzed by fatty acid amide hydrolase (FAAH). When wildtype Arabidopsis thaliana seeds were germinated and grown in exogenous NAE 12:0 (35 µM and above), growth was severely reduced in a concentration dependent manner. Wildtype A. thaliana seeds sown on exogenous abscisic acid (ABA) exhibited similar growth reduction to that seen with NAE treatment. AtFAAH knockouts grew and developed similarly to WT, but AtFAAH overexpressor lines show markedly enhanced sensitivity to ABA. When low levels of NAE and ABA, which have very little effect on growth alone, were combined, there was a dramatic reduction in seedling growth in all three genotypes, indicating a synergistic interaction between ABA and NAE. Notably, this synergistic arrest of seedling growth was partially reversed in the ABA insensitive (abi) mutant abi3-1, indicating that a functional ABA signaling pathway is required for the full synergistic effect. This synergistic growth arrest results in an increased accumulation of NAEs, but no concomitant increase in ABA levels. The combined NAE and ABA treatment induced a dose-dependent increase in ABI3 transcript levels, which was inversely related to growth. The ABA responsive genes AtHVA22B and RD29B also had increased expression in both NAE and ABA treatment. The abi3-1 mutant showed no expression of ABI3 and AtHVA22B, but RD29B expression remained similar to wildtype seedlings, suggesting an alternate mechanism for NAE and ABA interaction. Taken together, these data suggest that NAE metabolism acts through ABI3-dependent and independent pathways in the negative regulation of seedling development.
Date: August 2010
Creator: Cotter, Matthew Q.

Use of In-Stream Water Quality Measurements and Geospatial Parameters to Predict Consumer Surfactant Toxic Units in the Upper Trinity River Watershed, Texas

Description: Surfactants are used in a wide assortment of "down-the-drain" consumer products, yet they are often discharged in wastewater treatment plant effluent into receiving water, potentially causing environmental harm. The objective of this project was to predict surfactant toxic units and in-stream nutrients in the upper Trinity River watershed. Surface and pore water samples were collected in late summer 2005. General chemistries and surfactant toxic units were calculated. GIS models of anthropogenic and natural factors were collected and analyzed according to subwatersheds. Multiple regression analyses using the Maximum R2 improvement method were performed to predict surfactant toxic units and in-stream nutrients using GIS and in-stream values. Both geospatial and in-stream parameters generated multiple regression models for surfactant surface and pore water toxic units, as well as in-stream nutrients, with high R2 values. Thus, GIS and in-stream parameter modeling have the potential to be reliable and inexpensive method of predicting surfactant toxic units and nutrient loading in the upper Trinity River watershed.
Date: May 2008
Creator: Johnson, David Richard

Comparative biochemistry and genetic analysis of nucleoside hydrolase in Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas fluorescens.

Description: The pyrimidine salvage enzyme, nucleoside hydrolase, is catalyzes the irreversible hydrolysis of nucleosides into the free nucleic acid base and D-ribose. Nucleoside hydrolases have varying degrees of specificity towards purine and pyrimidine nucleosides. In E. coli, three genes were found that encode homologues of several known nucleoside hydrolases in protozoa. All three genes (designated yaaF, yeiK, and ybeK) were amplified by PCR and cloned. Two of the gene products (yeiK and ybeK) encode pyrimidine-specific nucleoside hydrolases, while the third (yaaF) encodes a nonspecific nucleoside hydrolase. All three were expressed at low levels and had different modes of regulation. As a comparative analysis, the homologous genes of Pseudomonas aeruginosa and P. fluorescens (designated nuh) were cloned. Both were determined to encode nonspecific nucleoside hydrolases. The nucleoside hydrolases of the pseudomonads exhibited markedly different modes of regulation. Both have unique promoter structures and genetic organization. Furthermore, both pseudomonad nucleoside hydrolase were found to contain an N-terminal extension of 30-35 amino acids that is shown to act as a periplasmic-signaling sequence. These are the first two nucleoside hydrolases, to date,that have been conclusively demonstrated to be exported to the periplasmic space. The physiological relevance of this is explained.
Date: December 2002
Creator: Fields, Christopher J.

Integrating life cycle analysis and the ecological footprint calculator to foster sustainable behaviors

Description: Many tools have been developed to assess global, national or regional sustainable development policies. However, as governments develop sustainable policies, individuals must also feel empowered to affect their personal impact on the planet. This thesis integrates three sustainability concepts that lend themselves to individual sustainability: The natural step, life cycle assessment, and the ecological footprint. TNS serves to provide the meaning and substance toward sustainable development. LCA helps provide the framework for assessing sustainability. The EF calculator determines the driving components and measures the qualitative decisions made through TNS and LCA. From the analysis of the household footprint calculator a simplified footprint calculator was developed to assist individuals and communities in setting benchmarks and goals as they move away from over-consumption and towards a sustainable lifestyle.
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Date: December 2002
Creator: Anderle, Kathryn

Evaluation of a Common Carp (Cyprinus carpio L.) Exclusion and Trapping Device for Use in Aquatic Plant Founder Colony Establishment

Description: The focus of this study was to design and evaluate a trapping system that would reduce populations of common carp within water bodies in conjunction with establishment of native aquatic macrophytes founder colonies. A pond study and field study were conducted. A pond study was performed at the Lewisville Aquatic Ecosystem Research Facility, located in Lewisville, Texas, followed by a field study within a constructed wetland located in southern Dallas, Texas. For the pond study, twelve funnel traps were constructed (four reps of each type: control, dual-walled and ring cage). Two anti-escape devices were tested with funnels including steel fingers and hinged flaps. Ring cage and dual-walled treatments were planted using native pondweeds, while controls were left unplanted (additional bait and a drift fence scenarios were also tested). Common carp were introduced into the study pond. Chi-square statistical analyses were utilized and showed ring cage treatments using fingers as well as the use of a drift fence to be most effective. Following completion of the pond study, the two most effective treatments (controls and ring cages) were tested within the Dallas, Texas wetland; no carp were caught during the field test.
Date: May 2008
Creator: Williams, Paul Edwin

Biochemical Identification of Molecular Components Required for Cyanide Assimilation in Pseudomonas fluorescens NCIMB 11764

Description: Utilization of cyanide as a nutritional nitrogen source in P. fluorescens NCIMB 11764 was shown to involve a novel metabolic mechanism involving nonenzymatic neutralization outside of cells prior to further enzymatic oxidation within. Several cyanide degrading enzymes were produced by NCIMB 11764 in response to growth or exposure to cyanide, but only one of these cyanide, oxygenase (CNO), was shown to be physiologically required for assimilation of cyanide as a growth substrate.
Date: May 1998
Creator: Chen, Jui-Lin

Effects of 5-hydroxytryptamine on Mouse Lumbar Motor Activity During Postnatal Development

Description: The lumbar motor activity in isolated spinal cords of 72 postnatal Balb/C mice aged 2, 5, 10 and 21 days (PN2-21) was electroneurographically recorded (ENG) via bilateral ventral roots following treatment with three different concentrations (25, 100 and 200 pM) of the neurotransmitter, 5-hydroxytryptamine (5-HT), i.e., serotonin, to determine its effects on spinal pattern generation.
Date: December 1998
Creator: Lowe-Chatham, Janice E. (Janice Elaine)

Comparison of Risk Assessment-Predicted Ecologically Safe Concentrations of Azinphos-Methyl and Fenvalerate to Observed Effects on Estuarine Organisms in a South Carolina Tidal Stream Receiving Agricultural Runoff

Description: A prospective ecological risk assessment method was developed evaluating the cumulative probabilistic impact of chemical stressors to aquatic organisms. This method was developed in response to the need to evaluate the magnitude, duration and episodic nature of chemical stressors on aquatic communities under environmental exposure scenarios. The method generates a probabilistic expression of the percent of an ecosystem's species at risk from a designated chemical exposure scenario.
Date: August 1997
Creator: Morton, Michael Gerard, 1957-

Biology and Energetics of Tropisternus Lateralis Nimbatus (SAY) (Coleoptera: Hydrophilidae) in a Playa on the Southern High Plains of Texas and Aquatic Coleoptera Diversity from Seven Playas on the Southern High Plains of Texas

Description: A study of the biology of Tropisternus lateralis, a hydrophilid beetle, was conducted during the flood period of a single playa on the Southern High Plains of Texas from early June 1995 through early September 1995. Mechanism of colonization, tolerance/avoidance to drought, larval density, and secondary production were analyzed. T. lateralis colonized playas from surrounding aquatic habitats and avoided drought through aerial dispersion. Once in the playa, larval density increased over time. Secondary production was 1.31 g/m2/.25 yr. In addition, aquatic Coleoptera diversity was studied in seven playas on the Southern High Plains of Texas. A total of twenty three species were identified from the study region. Nine species not reported in playa literature were identified.
Date: December 1997
Creator: Cook, Robert E. (Robert Edward), 1969-

Lipids and Phospholipase Activity of Vibrio Cholerae

Description: One purpose of this investigation is to determine the fatty acid and lipid content of typical Vibrio cholerae cells. The comparison of cholera lipid constituents with those of closely-related bacteria might be of taxonomic value. Furthermore, chemical characterization of the cholera vibrio could provide useful criteria for identification of these disease-producing microorganisms.
Date: August 1972
Creator: Brian, Buford Leo