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 Degree Discipline: Biology
 Collection: UNT Theses and Dissertations
Use of Geographic Information System and Remote Sensing Technologies to Describe Mosquito Population Dynamics in the Ray Roberts Greenbelt, Denton County, Texas

Use of Geographic Information System and Remote Sensing Technologies to Describe Mosquito Population Dynamics in the Ray Roberts Greenbelt, Denton County, Texas

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Date: May 2003
Creator: Bolling, Bethany G.
Description: A population survey was conducted from April through September 2002 on mosquito species occurring on the Ray Roberts Greenbelt, a riparian corridor used for public recreation on the Elm Fork of the Trinity River, in Denton County, Texas. ArcGIS software was used to set up a stratified random sampling design based on habitat parameters. Multivariate analyses of sampling data and climatic variables were used to describe spatial and temporal patterns of mosquito species. A total of 33 species were collected during this study belonging to the following genera: Aedes, Anopheles, Coquillettidia, Culex, Mansonia, Ochlerotatus, Orthopodomyia, Psorophora, Toxorhynchites, and Uranotaenia. Seasonal distributions of the dominant species revealed population fluctuations. Aedes vexans was the primary species collected in April and May, occurring in low numbers throughout the rest of the sampling period. Psorophora columbiae reached its highest population density in June, with a smaller peak occurring in late July. Present from May through the end of September, Culex erraticus was the most abundant species collected with major peaks in mid-June and the end of July. Abundance of Culex salinarius followed the same general trend as that for Cx. erraticus, but with smaller numbers. The specimens were tested for a variety of arboviruses ...
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Determination of Dissociation Constants for GABAA Receptor Antagonists using Spontaneously Active Neuronal Networks in vitro

Determination of Dissociation Constants for GABAA Receptor Antagonists using Spontaneously Active Neuronal Networks in vitro

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Date: December 2005
Creator: Oli-Rijal, Sabnam
Description: Changes in spontaneous spike activities recorded from murine frontal cortex networks grown on substrate-integrated microelectrodes were used to determine the dissociation constant (KB) of three GABAA antagonists. Neuronal networks were treated with fixed concentrations of GABAA antagonists and titrated with muscimol, a GABAA receptor agonist. Muscimol decreased spike activity in a concentration dependent manner with full efficacy (100% spike inhibition) and a 50% inhibitory concentration (IC50) of 0.14 ± 0.05 µM (mean ± SD, n=6). At 10, 20, 40 and 80 µM bicuculline, the muscimol IC50 values were shifted to 4.3 ± 1.8 µM (n=6), 6.8 ± 1.7 µM (n=6), 19.3 ± 3.54 µM (n=10) and 43.5 µM (n=2), respectively (mean ± SD). Muscimol titration in the presence of 10, 20, 40 µM of gabazine resulted in IC50s values of 20.1 (n=2), 37.17 (n=4), and 120.45 (n=2), respectively. In the presence of 20, 80, and 160 µM of TMPP (trimethylolpropane phosphate) the IC50s were 0.86 (n=2), 3.07 (n=3), 6.67 (n=2) µM, respectively. Increasing concentrations of GABAA antagonists shifted agonist log concentration-response curves to the right with identical efficacies, indicating direct competition for the GABAA receptor. A Schild plot analysis with linear regression resulted in slopes of 1.18 ± 0.18, 1.29 ...
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Pyrimidine Enzyme Specific Activity at Four Different Phases of Growth in Minimal and Rich Media, and Concomitant Virulence Factors Evaluation in Pseudomonas aeruginosa

Pyrimidine Enzyme Specific Activity at Four Different Phases of Growth in Minimal and Rich Media, and Concomitant Virulence Factors Evaluation in Pseudomonas aeruginosa

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Date: December 2005
Creator: Azad, Kamran Nikkhah
Description: Pseudomonas aeruginosa is a Gram-negative rod, aerobic, non-fermenting, oxidase positive, pigment producing, and nutritionally versatile bacterium. Infections by P. aeruginosa are the most important cause of morbidity and mortality in immunocompromised patients, given virulence factor production that suppresses antibiotic therapy and promotes persistent infection. This research is the first comprehensive report of the pyrimidine biosynthetic pathway for all phases of growth in minimal and rich media coupled with the evaluation of virulence factor production of P. aeruginosa in comparison to four other bacterial species (Pseudomonas putida, Pseudomonas fluorescens, Burkholderia cepacia, and Escherichia coli wild-type strains). Cellular growth and passing genetic information to the next generation depend on the synthesis of purines and pyrimidines, the precursors of DNA and RNA. The pyrimidine biosynthetic pathway is essential and found in most organisms, with the exception of a few parasites that depend upon the pyrimidine salvage pathway for growth. Both the pyrimidine biosynthetic and salvage enzymes are targets for chemotherapeutic agents. In our laboratory, research on pyrimidine auxotrophic mutants showed the role of the pyrimidine biosynthetic pathway and its intermediates on P. aeruginosa metabolism and impaired virulence factors production. The present research shows that pyrimidine enzymes are active in all phases of growth, ...
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A Physiological Age-Grading System for Female Hydrellia pakistanae  Deonier (Diptera: Ephydridae)

A Physiological Age-Grading System for Female Hydrellia pakistanae Deonier (Diptera: Ephydridae)

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Date: December 2002
Creator: Lenz, Jennifer Marie
Description: Conflicting opinions about the effectiveness of H. pakistanae as a biological control agent for hydrilla prompt researchers to find a method for assessing the fly's success. Developing a physiological age-grading system for the fly using ovarian morphology to detect changes in reproductive activity is useful for evaluating reproductive status of the fly in field populations. Changes in the appearance of follicular relics in ovaries with oviposition provide a reliable method to estimate fecundity. Characteristics of follicular relics were used to develop a system with eight physiological age classes, three nulliparous and five parous. Changes that occur in the fat body were used to assist in classification of nulliparous females or those with low egg counts.
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A Multimedia Atlas of Dissection for Comparative Anatomy of the Vertebrates

A Multimedia Atlas of Dissection for Comparative Anatomy of the Vertebrates

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Date: August 1999
Creator: Curran, Anthony A.
Description: Traditional methods of teaching the laboratory course for Comparative Anatomy of the Vertebrates could be improved by applying current computer technology to construct an interactive, multimedial atlas of dissection. Five specimens used in comparative anatomy courses at most institutions were chosen as representative members of the Phylum Chordata: amphioxus, lamprey, dogfish shark, mud puppy, and cat. Specimens were dissected according to the modified method of Wischnitzer, 1993, and each stage was photographed with a Kodak DC120 digital zoom camera. These images were processed on a Power Macintosh 7600 computer with Adobe Photoshop v. 5.0. The atlas was constructed from these images using Macromedia Authorware v. 4.0.3. Each image contains a series of interactive objects that display a highlight and descriptive text as the cursor passes over each object.
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A laboratory course in experimental genetics for the biology major.

A laboratory course in experimental genetics for the biology major.

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Date: December 2001
Creator: Lux, Melissa McNeil
Description: This manual has been designed for a class of twenty- four students concurrently enrolled in the lecture course. The laboratory aids in the learning process and fosters an interest in the science of genetics. This manual and the experiments contained within are both informative and fun. The manual correlates with and expands upon the genetics course. Each investigation, with the exception of the Drosophila melanogaster project, can be completed in a 3-4 hour timeframe. This manual provides a “hands on” experience of theories simply discussed in the lecture course. This manual is intended to be a one-source manual where each investigation is designed to include an adequate introduction. Special attention has been given for each investigation with both the student and instructor in mind.
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Integrating Concepts in Modern Molecular Biology into a High School Biology Curriculum

Integrating Concepts in Modern Molecular Biology into a High School Biology Curriculum

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Date: August 2003
Creator: Parker, Timothy P.
Description: More so than any other science in the past several decades, Biology has seen an explosion of new information and monumental discoveries that have had a profound impact on much more than the science itself. Much of this has occurred at the molecular level. Many of these modern concepts, ideas, and technologies, as well as their historical context, can be easily understood and appreciated at the high school level. Moreover, it is argued here that the integration of this is critical for making biology relevant as a modern science. A contemporary high school biology curriculum should adequately reflect this newly acquired knowledge and how it has already has already begun to revolutionize medicine, agriculture, and the study of biology itself. This curriculum provides teachers with a detailed framework for integrating molecular biology into a high school biology curriculum. It is not intended to represent the curriculum for an entire academic year, but should be considered a significant component. In addition to examining key concepts and discoveries, it examines modern molecular techniques, their applications, and their relevance to science and beyond. It also provides several recommended labs and helpful protocols.
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Application of cultured neuronal networks for use as biological sensors in water toxicology and lipid signaling.

Application of cultured neuronal networks for use as biological sensors in water toxicology and lipid signaling.

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Date: August 2004
Creator: Dian, Emese Emöke
Description: This dissertation research explored the capabilities of neuronal networks grown on substrate integrated microelectrode arrays in vitro to be applied to toxicological research and lipid signaling. Chapter 1 details the effects of chlorine on neuronal network spontaneous electrical activity and pharmacological sensitivity. This study demonstrates that neuronal networks can maintain baseline spontaneous activity, and respond normally to pharmacological manipulations in the present of three times the chlorine present in drinking water. The findings suggest that neuronal networks may be used as biological sensors to monitor the quality of water and the presence of novel toxicants that cannot be detected by conventional sensors. Chapter 2 details the neuromodulatory effects of N-acylethanolamides (NAEs) on the spontaneous electrical activity of neuronal networks. NAEs are a group of lipids that can mimic the effects of marijuana and can be derived from a variety of plant sources including soy lecithin. The most prominent NAEs in soy lecithin, palmitoylethanolamide (PEA) and linoleoylethanolamide (LEA), were tested individually and were found to significantly inhibit neuronal spiking and bursting activity. These effects were potentiated by a mixture of NAEs as found in a HPLC enriched fraction from soy lecithin. Cannabinoid receptor-1 (CB1-R) antagonists and other cannabinoid pathway modulators indicated ...
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Evaluation of virulence in wild type and pyrimidine auxotrophs of  Pseudomonas aeruginosa using the eukaryotic model system  Caenorhabditis elegans.

Evaluation of virulence in wild type and pyrimidine auxotrophs of Pseudomonas aeruginosa using the eukaryotic model system Caenorhabditis elegans.

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Date: August 2004
Creator: Anvari, Sara
Description: The human opportunistic pathogen, Pseudomonas aeruginosa PAO1, has been shown to kill the nematode Caenorhabditis elegans. C. elegans has been a valuable model for the study of bacterial pathogenesis, and has reinforced the notion that common virulence and host defense mechanisms exist. Recently, the pyrimidine pathway was shown to regulate virulence levels. Therefore, mutations in the pyrimidine pathway of PAO1 showed decrease virulence in the nematode. When starving the nematode, bacterial resistance was also shown to increase. It was hypothesized that starvation induced the DAF pathway, which regulates the transcription of genes involved with the antibacterial defense mechanism. Further research will be conducted to test this theory by performing RNAi experiments for the genes functioning in the antibacterial defense mechanism.
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Chemotactic Response of Lumbricus terrestris Coelomocytes to Larval and Adult Stages of Rhabditis pellio

Chemotactic Response of Lumbricus terrestris Coelomocytes to Larval and Adult Stages of Rhabditis pellio

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Date: December 1999
Creator: Medrano, Jennifer Centurion
Description: Experiments were performed to assess the suitability of Rhabditis pellio, a nematode found in earthworms, as a challenge organism for use in development of a biomarker assay to determine the potential of chemicals to suppress the immunocompetence of the non-specific immune system. To accomplish this goal, information on the life cycle of R. pellio was determined; including effects of incubation time and temperature on growth rates; along with information on the immune response elicited in the earthworm, Lumbricus terrestris. Immune parameters measured were coelomocyte migration toward and attachment to R. pellio larvae and adults. Preliminary background information showed that R. pellio has potential as a challenge organism for development of a biomarker assay.
Contributing Partner: UNT Libraries
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