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Analysis of the Accumulation, Toxic Effects, and Risk of Persistent Organic Pollutants in Pinnipeds
The present studies determine the accumulation of persistent organic pollutants (POPs) in three pinniped species, evaluate the relationship with relevant biomarkers of exposure, and calculate toxic effect thresholds. Stranded harp and hooded seals were found to be accumulating PBDEs at levels which could pose a based on threshold levels determined in this study. Northern fur seals are accumulating all three classes of POPs (PCBs, PBDEs, and OCPs) with significant relationships being seen with blubber percent lipid. Correlations between contaminant concentrations and expression levels of relevant biomarkers were seen potentially indicating an effect on multiple pathways. Overall risk can be hard to determine due to factors such as sex and age. Broad threshold response values and hazard quotients were calculated for toxic effect endpoints in pinnipeds. Overall these results suggest that certain populations of pinnipeds are at high risk of experiencing toxic effects due to POP exposure, but it is important to understand effects even at lower concentrations. The relationship between exposure, toxic effects, and other stressors, both environmental and physiological, can impact the overall fitness and survival of pinnipeds.
Date:
August 2021
Creator:
Soulen, Brianne K
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
An Analysis of the Seasonal Food Habits of Two Species of Texas Centrarchids
This thesis explores the feeding habits of sunfish and bluegill in Texas lakes. Data gathered for this study is aimed to aid conservation of these pan fish by making a contribution toward a greater life history understanding of each species.
Date:
August 1940
Creator:
Faggard, John M.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Analysis of the Trypanosoma brucei Genome and Identification and Characterization of a Gene Family Encoding Putative EF-Hand Calcium-Binding Proteins
The flagellum of Trypanosoma brucei contains a family of antigenically related EF-hand calcium-binding proteins which are called the calflagins. Genomic Southern blots indicated that multiple copies of calflagin genes occur in T brucei. All of the copies were contained in a single 23 kb Xhol-Xhol fragment. Genomic fragments of 2.5 and 1.7 kb were cloned that encoded calflagin sequences. Two new members of the calflagin family were found from genomic clone sequences. The deduced amino acid sequences of the genomic clones showed the calflagin genes were arranged tandemly along the genomic fragments and were similar to previously described calflagins. The calflagin genes were related by two unrelated 3' flanking sequences. An open reading frame that was unrelated to any calflagin was found at the 5' end of the 2.5 kb genomic fragment. Each encoded protein (~24,000u) contained three EF-hand calcium-binding motifs and one degenerate EF-hand motif. In general, variability among the T. brucei calflagins is greater than related proteins in T. lewisii and T. cruzi. This variability results from amino acid substitutions at the amino and carboxy termini, and duplication of internal segments.
Date:
May 1998
Creator:
DeFord, James H. (James Henry), 1956-
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Anatomical and Morphological Responses of Cardiospermum Halicacabum L. (Balloon Vine), to Four Levels of Water Availability
C. halicacabum (Sapindaceae) is an invasive plant that is considered a nuisance species in Texas riparian environments. Little is known of the tolerance of C. halicacabum to flooding and drought; however, this information may provide insight into the characteristics that contribute to C. halicacabum purported invasiveness. C. halicacabum seedlings (n = 92) were exposed to one of four levels of water availability (flooded, saturated, intermediate and dry) over six weeks under greenhouse conditions. Plant performance was affected by water availability; however, there was no effect on survivorship. Flooded and saturated plants exhibited morphological adaptations; producing adventitious roots, hypertrophy, and aerenchyma tissue. Morphological measures, anatomical responses, and patterns of biomass allocation all indicate that C. halicacabum is able to survive periodic inundation, perform in saturation, and establish and thrive on the drier end of a moisture gradient.
Date:
May 2011
Creator:
Dempsey, Matthew Anthony
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Anatomy and Physiology Syllabus for Community Colleges
This syllabus includes both lecture notes and laboratory activities for a two-semester anatomy and physiology community college course. The syllabus is based on a 16-week semester that is comprised of a three-hour lecture section and a one-hour laboratory class each week. Both the lecture course and laboratory are necessary to fulfill the requirement for anatomy and physiology. Laboratory activities coincide with lectures to enhance understanding of each topic by providing visual and hands-on experiments for the concepts learned in the lecture. Laboratory quizzes will be given each week to help students maintain a working knowledge of the material learned in the laboratory. This course is appropriate for the typical anatomy and physiology student and should benefit both students who plan to major in biology and also those who are non-biology majors. Because subject matter in anatomy and physiology is quite difficult, the importance of attendance and good study skills is stressed.
Date:
May 2000
Creator:
Schulz, Leslie
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Animal Contribution to Human Medicine
Access:
Use of this item is restricted to the UNT Community
The use of animal models in research has led to a fierce debate between animal rights activists and scientists. The former claim that little useful information is gained from animal studies and the suffering of animals does not preclude any treatments which may be used to treat human illnesses. Yet, research scientists claim that in vivo animal models are of absolute necessity to developing treatments and cures to disease. To determine the necessity of animal use, one must examine the models currently in research. Have the animal models for disorders such as cystic fibrosis and muscular dystrophy given scientists enough information to develop effective treatments? This paper will examine the role of animal subjects in several disease research protocols, as well as the applicability of the research.
Date:
May 2001
Creator:
Kvernes, Kayce
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Annual Lipid Cycles in the Lizard Cnemidophorus Tigris
Annual lipid cycles were determined for adult male and female Cnemidophorus tigris collected near El Paso, Texas during 1970-1971.
Date:
August 1972
Creator:
Gaffney, Fred G.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Antibacterial Effect of the Oleoresins of One Hundred Common Texas Plants upon Twenty-Five Gram-Negative Mirco-Organisms
This investigation deals with the study of the possible antibiotic effect of oleoresins of one hundred common Texas plants upon twenty-five gram-negative bacterial organisms.
Date:
1949
Creator:
Danhof, Ivan E.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Antibiocity of the Oleoresins of One Hundred Texas Spermatophytes upon Twenty Gram-Positive Bacterial Organisms
This investigation is concerned with the testing, in vitro, of oleoresins from one hundred higher plants common to North and South Central Texas. The plants used were selected in order to obtain a representative collection which might be of value in future research.
Date:
1949
Creator:
Richardson, Lavon P.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
The Antibiotic Activities of Some Members of the Cactaceae Family
This problem has been concerned with, first, the collection of sixteen species of plants belonging to Cactaceae family; second, the drying of these and the extraction of the oleoresins thereof; third, the determination of the extent to which these substances inhibit the growth of ten gram-positive and ten gram-negative bacterial organisms; and fourth, a determination of the possible utilization of these extracts a prophylactic or chemotherapeutic agents.
Date:
1951
Creator:
Gilmore, Derward E.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
The Antibiotic Effect of Pigmented Actinomycetes
This thesis attempts, first, to correlate pigmentation of actinomycetes with the degree of antibiocity; second, to establish the most favorable means of producing a rich luxuriant pigmentation in the individual organism studied by enriching favorable media with specific types of proteins and amino acids.
Date:
1951
Creator:
Cichon, Casimir Joseph
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
The Antibiotic Properties of the Oleoresins of Twenty-Five Common Garden Vegetables
The purpose of this problem is to determine the presence and extent of antibiotic materials as found in the oleoresins of a selected group of garden vegetables. The problem has consisted of, first, the collection and preparation of specimens of twenty-five commonly used garden vegetables; second, the extraction of the oleoresins from these; third, the determination of the inhibitory and other effects of these oleoresins against several strains of selected gram-positive and gram-negative bacteria; and fourth, the evaluation of the potentialities of these oleoresins with regard to their future use as medicinal prophylactics and therapeutics.
Date:
1951
Creator:
Ennis, Arthur F.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Antibiotic Sensitivity of Bacteria Isolated from City Water Distribution Systems
This thesis studies antibiotic sensitivity of bacteria isolated from city water distribution systems.
Date:
August 1958
Creator:
Williams, Catherine
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Antibody Adsorption Used in Identification of Similar Streptomyces Species
This investigation involved the production of specific antisera against known International Streptomyces project strains of Streptomyces.
Date:
January 1970
Creator:
Lassiter, Carroll B.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Antimicrobial and Anti-Platelet Activity in Botanical Extracts of Plants Collected in Northern Thailand
The purpose of my research work was to assess a variety of Northern Thailand plants tissue extracts for antibacterial and anti-platelet aggregation activity. The Minimum Inhibitory Concentration assay method was used to assess antimicrobial activity of plant extracts, while the Zebrafish Platelet Aggregation Assay and the in vitro Whole Human Blood Impedance Aggregation Assay were used to study anti-platelet activity. Forty one plant extracts harvested from the tissues of 26 plants collected from Northern Thailand were assessed. Thirty-four plant extracts were found to have antibacterial activity against the Gram positive bacteria Staphylococcus aureus and/or Bacillus subtilis, while six plant extracts demonstrated activity against the Gram negative bacterium, Escherichia coli. Thirteen plant extracts exhibited anti-platelet aggregation activity better than the positive control. Two crude plant extracts, twigs from Garcinia sp. and twigs from Goniothalamus chilensis were selected for fractionation. Five of the 12 fractions showed anti-platelet activity. Four fractions (two from each plant extract) were selected for further sub-fractionation. Fourteen of 35 sub-fractions were selected for further testing of anti-platelet aggregation activity with 12 sub-fractions demonstrating positive antiplatelet activity. Positive sub-fractions were analyzed using liquid chromatography-mass spectrometry to determine their chemical properties. Three compounds that possessed anti-platelet activity were characterized by …
Date:
May 2019
Creator:
Patcharapinyopong, Thanasan
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
The Application of Chlorine Dioxide to Tastes and Odors in Water Supplies
This problem was undertaken to determine the potentialities of chlorine dioxide as an algaecide and as an agent for the removal of tastes and odors from fresh water.
Date:
1952
Creator:
Hemphill, Louis
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Application of Cultured Neuronal Networks for Use as Biological Sensors in Water Toxicology and Lipid Signaling.
Access:
Use of this item is restricted to the UNT Community
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 …
Date:
August 2004
Creator:
Dian, Emese Emöke
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Application of Fluorescent Antibody Methods for the Enumeration and Identification of Bacillus Cereus
This particular work is proposed as a test of the expedience of using the fluorescent-antibody technique as a method for enumeration and identification of certain strains of B. cereus that have been found to be effective in preventing taste and odor in water supplies resulting from certain Actinomycete blooms.
Date:
August 1969
Creator:
Ferebee, Robert Newton
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Applications of GIS and Remote Sensing for the Characterization of Habitat for Threatened and Endangered Species
Geographic Information Systems (GIS) and remote sensing technologies were used to identify and describe potential habitat for three species endemic to the Southwestern United States; the Golden-cheeked Warbler (Dendroica chrysoparia), the Black-capped Vireo (Vireo atricapillus), and the Texas kangaroo rat (Dipodomys elator). For each species, the computerized classification of digital satellite imagery was integrated with ancillary spatial information (e.g. soils, geology, and land use) to construct a data base to be used for ecological evaluation as well as habitat protection and management measures.
Date:
December 1989
Creator:
Shaw, Denice Marie, 1958-
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Applications of Remote Sensing and GIS to Modeling Fire for Vegetative Restoration in Northern Arizona
An accurate fire model is a useful tool in predicting the behavior of a prescribed fire. Simulation of fire requires an extensive amount of data and can be accomplished best using GIS applications. This paper demonstrates integrative procedures of using of ArcGIS™, ERDAS Imagine™, GPS, and FARSITE© to predict prescribed fire behavior on the Kaibab-Paiute Reservation. ArcGIS was used to create a database incorporating all variables into a common spatial reference system and format for the FARSITE model. ArcGIS Spatial Analyst was then used to select optimal burn sites for simulation. Our predictions will be implemented in future interagency efforts towards vegetative restoration on the reservation.
Date:
August 2003
Creator:
Hardison, Tanya
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
The aquatic insect communities of Holbrook Creek and Cochetopa Creek in Colorado.
The first objective for this problem in lieu of thesis project was to gather, identify to the lowest practical taxonomic level and organize all available aquatic insects collected from high altitude Colorado aquatic systems during the summers of 1994, 1996, 1998, and 2002 for the University of North Texas Environmental Science Field Course (BIOL 5650). The curated collection will be housed in the Elm Fork Natural History Museum, located at the University of North Texas. The second objective was to provide a summary and discussion of the occurrence and distribution of the aquatic insects collected from Mt. Blanca in 1994, 1996, and 1998 and to create a taxa list of aquatic insects collected from Cochetopa Creek during the summer of 2002.
Date:
December 2003
Creator:
Wallace, Mark Allen
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Aquatic Vegetation Nutrient Budgets and Sedimentation in a Southwestern Reservoir
During four growing seasons, aquatic vascular plant production and distribution were studied in Pat Mayse Lake, Texas, a 2425 hectare oligo-mesotrophic reservoir. The dominant macrophyte population was Myriophyllum spicatum L. Growth rates and regrowth rates of mechanically harvested Myriophyllum beds were found to be dissimilar. Based on estimates of watermilfoil nutrient content, there were insufficient nutrients in the entire population to alter the trophic status of this reservoir should all of the nutrients be instantaneously released. Sediments were the primary nutrient (nitrogen and phosphorus) sink. Bank erosion and solids transport from the watershed appear to contribute most of the sediments and a lake-wide mean sedimentation rate of 2.5 cm/year was estimated from sediment trap and core sample data.
Date:
May 1986
Creator:
Clifford, Philip A. (Philip Alan)
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Aryl Hydrocarbon Hydroxylase and Sixteen Alpha Hydroxylase in Cultured Human Lymphocytes
Cultured human lymphocytes may be assayed for aryl hydrocarbon hydroxylase (AHH) in whole cell preparations. The optimum assay conditions are pH 8.5, and 1.5 mM Mg++. The reaction is linear with time and cell number, and is inhibited by CO. Estradiol may inhibit induction of AHH by 3-methylcholanthrene, but is a poor competitor for the enzyme. A Caucasian population was assayed for AHH activity. The distribution was lognormal; no difference was found in cultured cells from males and females or smokers and nonsmokers. Cells from relatives of lung cancer patients showed higher activity. An American Indian population showed no difference from the Caucasian population in enzyme level. No linkage was found between AHH and 16a-hydroxylase.
Date:
December 1975
Creator:
Coomes, Marguerite L.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Aspartate Transcarbamoylase of Aeromonas Hydrophila
This study focused on the enzyme, aspartate transcarbamoylase (ATCase) from A. hydrophila, a Gram-negative bacterium found in fresh water. The molecular mass of the ATCase holoenzyme from A. hydrophila is 310 kDa. The enzyme is likely composed of 6 catalytic polypeptides of 34 kDa each and 6 regulatory polypeptides of 17 kDa each. The velocity-substrate curve for A. hydrophila ATCase is sigmoidal for both aspartate and carbamoylphosphate. The Km for aspartate was the highest to date for an enteric bacterium at 97.18 mM. The Km for carbamoylphosphate was 1.18 mM. When heated to 60 ºC, the specific activity of the enzyme dropped by more than 50 %. When heated to 100 ºC, the enzyme showed no activity. The enzyme's activity was inhibited by ATP, CTP or UTP.
Date:
December 2000
Creator:
Higginbotham, Leah
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library