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GABAá´€ Receptors in Rat Whisker Barrel Cortex: Effects of Sensory Deprivation
The GABAergic system in adult sensory cortex is affected by sensory deprivation, but little is known about how this predominant inhibitory system is affected during ontogeny. The present study investigates developmental effects of whisker trimming on GABAa receptors in rat barrel cortex. Rats trimmed for 6 wk beginning at birth and adulthood showed similar decreases in [3H]muscimol binding in deprived relative to non-deprived barrels, suggesting absence of a critical period.
Date:
August 1995
Creator:
Salazar, Eduardo, 1962-
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Effects of Copper on Immune Responses of Largemouth Bass, Micropterus salmoides
Copper exposures of 400 μg/L for 5,10 and 15 days resulted in no significant differences in antibody titers of largemouth bass, Micropterus salmoides injected with Aeromonas hydrophila compared to control-injected bass. Twenty days of exposure did significantly increase titers. The control group had significantly lower antibody titers than either control-injected or copper-exposed.
Date:
August 1994
Creator:
Connell, Patrice M. (Patrice Michelle)
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Upper and Lower Temperature Tolerances of Three Freshwater Game-Fish Species Exposed to Cycling Temperatures
A total of 670 critical thermal maxima (CTMax) and minima (CTMin) were determined for three freshwater fishes acclimated to three constant temperatures and a diel regimen cycling between the lowest and highest acclimation temperatures. In all species temperature tolerance was directly related to acclimation temperature and slopes relating these variables indicate that acclimation temperature has a greater influence on tolerance of low rather than high temperatures. CTMax and CTMin values generated following exposure to 32 days of oscillating temperatures indicate that in general, fishes had temperature tolerance acclimation states consistent with the average temperature and not either the highest or lowest temperature of the diel cycle.
Date:
August 1995
Creator:
Currie, Rebecca J. (Rebecca Jean)
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Heat Shock Proteins in Ascaris suum
Ascaris suum were exposed to a number of stressors, including heavy metals and both high (40°C) and low (18°C) temperatures. The 70kD and 90kD heat shock proteins (HSPs) in the different A. suum tissues were analyzed by Western blot and quantitated by Macintosh Image Program.
Date:
August 1995
Creator:
Chao, Sheng-Hao
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Site Directed Mutagenesis of β-Ketoadipate Succinyl-Coenzyme A Transferase II from Acinetobacter Calcoaceticus
The role of specific amino acid residues in β-ketoadipate succinyl-coenzyme A transferase II from Acinetobacter calcoaceticus was investigated. A 1412 base pair BamiHI-EcoRI fragment carrying the catIJ genes was amplified by polymerase chain reaction and inserted into pUCl9 to generate the plasmid pCATEl9. Escherichia coli DH5α (pCATEl9) carrying only the catlJ genes expressed 3-fold higher enzyme activity than the parent strain. Two mutants were constructed by site directed mutagenesis so that glutamate was replaced by a glutamine at positions Gln155 and Gln193 in the ß subunit of the primary amino acid sequence of the CoA transferase. Both mutants produced transferase that was catalytically active suggesting that Glu155 and Glu193 do not participate directly in catalysis.
Date:
August 1993
Creator:
Sheng, Mei
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Nicotinic Acetylcholine Receptor α3 mRNA in Rat Visual System After Monocular Deprivation
In situ hybridization was used to examine effects of monocular enucleation on nicotinic acetylcholine receptor subunit cc3 mRNA in the rat dLGNand visual cortex. After 28 days postoperative, there were no significant differences in α3 mRNA density between the contralateral (deprived) and ipsilateral (non-deprived) sides. The lack of obvious effects of visual deprivation on α3 mRNA density suggests that other factors, possibly intrinsic to dLGNand visual cortex, govern the postnatal expression of α3 mRNA.
Date:
August 1997
Creator:
Taylor, James H. (James Harvey), 1970-
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Underwater Optical Properties of Lake Texoma (Oklahoma-Texas) Using Secchi Disk, Submarine Photometer, and High-Resolution Spectroscopy
The underwater optical climate of Lake Texoma was measured at eleven fixed stations from August 1996 to August 1997. Secchi transparency and submarine photometry characterized seasonal and spatial values of secchi depth (SD), vertical attenuation coefficient (η''), and depth of euphotic zone (Zeu). Indices of Zeu:SD and η'' × SD were compared with universally applied values derived from inland and coastal waters. Turbidity explained 76% of the variation (p = 0.0001) of η'' among water quality parameters, including chlorophyll-α. Using a spectroradiometer, spectral signatures of chlorophyll-α and turbidity were located. Stations with low turbidity exhibited a distinct green reflectance peak around 590-610 nanometers, indicating presence of chlorophyll-α. Stations with high turbidity exhibited a reflectance peak shift towards the red spectrum, making it difficult to detect the chlorophyll signature. Derivative analysis of the reflectance signal at 590-610, and 720-780 nanometers allowed discrimination of this chlorophyll signature from those of turbidity (0.66 ≤ r^2 ≤ 0.99).
Date:
August 1998
Creator:
Rolbiecki, David A. (David Alan)
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
The Role of Gabergic Inhibition in Modulating Receptive Field Size of Cuneate Neurons
A blockade of GABAergic inhibition increases the receptive field(RF) size of most somatosensory cortex (SI) and some ventrobasal thalamus (VB) neurons. The results suggest RF size of cuneate neurons may be modulated through GABAa and GABAb receptors, independent of firing frequency.
Date:
August 1997
Creator:
Tennison, Cullen F.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Life History and Secondary Production of Caenis latipennis Banks (Ephemeroptera: Caenidae) in Honey Creek, Oklahoma
A study of the life history and secondary production of Caenis latipennis, a caenid mayfly, was conducted on Honey Creek, OK. from August 1999 through September 2000. The first instar nymph was described. Nymphs were separated into five development classes. Laboratory egg and nymph development rates, emergence, fecundity, voltinism, and secondary production were analyzed. C. latipennis eggs and nymphs take 132 and 1709 degree days to develop. C. latipennis had an extended emergence with five peaks. Females emerged, molted, mated, and oviposited in an estimated 37 minutes. Mean fecundity was 888.4 ± 291.9 eggs per individual (range 239 -1576). C. latipennis exhibited a multivoltine life cycle with four overlapping generations. Secondary production was 6,052.57 mg/m2/yr.
Date:
August 2001
Creator:
Taylor, Jason M.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
A Correlation of Humus with Water Content and Crop Rotation in San Saba and Denton Clays, Denton County, Texas
A study of the humus content and the water content of San Saba clay and Denton clay. Studies show that the physical properties of soil are conducive to moisture retention and the availability of moisture to plants.
Date:
August 1939
Creator:
Culwell, John Walton
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Neuronal Network Analyses in vitro of Acute Individual and Combined Responses to Fluoxetine and Ethanol
Embryonic murine neuronal networks cultured on microelectrode arrays were used to quantify acute electrophysiological effects of fluoxetine and ethanol. Spontaneously active frontal cortex cultures showed highly repeatable, dose-dependent sensitivities to both compounds. Cultures began to respond to fluoxetine at 3 µM and were shut off at 10-16 µM. EC50s mean ± S.D. for spike and burst rates were 4.1 ± 1.5 µM and 4.5 ± 1.1 µM (n=14). The fluoxetine inhibition was reversible and without effect on action potential wave shapes. Ethanol showed initial inhibition at 20 mM, with spike and burst rate EC50s at 52.0 ± 17.4 mM and 56.0 ± 17.0 mM (n=15). Ethanol concentrations above 100 -140 mM led to cessation of activity. Although ethanol did not change the shape and amplitude of action potentials, unit specific effects were found. The combined application of ethanol and fluoxetine was additive. Ethanol did not potentiate the effect of fluoxetine.
Date:
August 2002
Creator:
Xia,Yun
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Use of Satellite Imagery and GIS to Model Brood-Rearing Habitat for Rio Grande Wild Turkey Populations Occurring in the Western Cross Timbers Region of Texas
Access:
Use of this item is restricted to the UNT Community
Remote sensing and GIS have become standard tools for evaluating spatial components of wildlife habitats. These techniques were implemented to evaluate Rio Grande wild turkey (Meleagris gallopavo) poult-rearing habitat in the Western Cross Timbers region of Texas. Texas Parks and Wildlife (TPWD) random roving turkey counts for 1987-1989 and 1998-2000 were selected, indicating locations where hens with poults were observed. Satellite imagery from 1988 and 1999 was classified and then processed with Patch Analyst. To add robustness, stream, road and census population densities were also evaluated for each turkey location. Analysis of the 1988 canopy cover image, comparing observed locations with randomly-selected habitat cells (N = 20) indicated significant differences (p <.05) for patch edge variables. Mean patch edge was significantly greater for habitat locations where hens with poults were observed than for those selected at random. Spatial data for 1999 did not indicate a significant difference (p < .05) between sampling groups (observed vs. random, N = 30). Significant differences (p <.05) did occur for turkey locations observed in both 1988 and 1999 (N = 7). This demonstrates the adaptability of wild turkey hens, as habitats change over time, hens continued to visit the same locations even though the …
Date:
August 2002
Creator:
Miller, Christopher J.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Functional Neural Toxicity and Endocrine Responses in Mice Following Naphthalene Exposure
Polycyclic aromatic hydrocarbons (PAHs) are a well studied and diverse class of environmental toxicants. PAHs act via the aryl hydrocarbon receptor (AhR), and studies have suggested that PAHs may elicit neurological and estrogenic effects. Doses of PAHs between 50 to 150 ppm may elicit neurotoxicity in rodent models. The present study investigated the effects of naphthalene on in vivo steroidogenesis in Swiss Webster male mice, and in vitro neural function of Balb-C/ICR mice frontal cortex neurons. These data suggest that naphthalene may not elicit steroidogenic effects at concentrations ranging from 0.2 to 25 mg/kg/day, following a 7 day subcutaneous dosing regime. In addition, naphthalene may cause functional toxicity of frontal cortex neurons at concentrations of 32 to 160 ppm naphthalene.
Date:
August 2010
Creator:
Colbert, Crystal
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Molecular systematics of Baird's pocket gopher (Geomys breviceps)
Baird's pocket gopher (Geomys breviceps) is found in eastern Texas, eastern Oklahoma, central and western Arkansas, and western Louisiana. The cytochrome-b gene was sequenced and analyzed for 16 pocket gophers from throughout the range of the species. Similar phylogenetic trees were obtained using maximum-parsimony, maximum-likelihood, neighbor-joining, and Bayesian analyses. Two major clades were formed with northern individuals belonging to clade I and southern individuals belonging to clade II. G. b. sagittalis was paraphyletic in relation to G. b. breviceps in all analyses. Based on inconsistencies between the taxonomic classification and systematic relationships within Baird's pocket gopher, a taxonomic restructuring appears warranted.
Date:
August 2010
Creator:
Bodine, Deanna Martinez
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
The Food and Growth of the Largemouthed Black Bass (Huro Salmoides) in North Texas
This thesis describes the growth and feeding habits of large mouth bass (Huro salmoides) as observed in North Texas.
Date:
August 1939
Creator:
Hill, Jackson F.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
A Limnological Study of Lake Worth
This thesis presents the results of a three year study devoted to discovering the life and phenomena found in Lake Worth near Fort Worth, Texas.
Date:
August 1939
Creator:
Johns, William Barnette
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
A Study of the Early Maturation Stages in the Male and Female Homophron Americanum
This thesis presents the results of an investigation conducted to determine the maturation stages and chromosomal composition of the Homophron americanum (Sand Beetle) found in North Texas.
Date:
August 1938
Creator:
Lipscomb, Joe Lloyd
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Correlation of Humus and Water Content on Saba Clay, Denton, Texas
This study is an attempt to determine the relationship between humus and the water found in it and how both effect soil in Denton county, Texas.
Date:
August 1938
Creator:
Wilson, Clyde Byron
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Preliminary Report on the Status of the Mourning Dove in Throckmorton County, Texas
This thesis presents the results of an examination conducted to determine the status of mourning doves in Throckmorton County, Texas.
Date:
August 1940
Creator:
Jackson, Alfred S.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
The Life History and Ecology of Camelobaetidius Mexicanus (Ephemeroptera: Baetidae) from Honey Creek, Oklahoma
The primary objective of this study is to describe the life history of Camelobaetidius mexicanus living in Honey Creek in south central Oklahoma. Specific objectives were to determine emergence phenology and behavior, describe nupital flight and female oviposition, measure subimaginal and imaginal life spans, examine egg morphology and time to hatching, describe larval microdistribution, analyze gut contents and to determine voltinism from nymphal head capsule widths and adult emergence.
Date:
August 1995
Creator:
Wagner, Paul F.
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
Bottom Fauna of Lake Worth
This thesis describes the vertical distribution, quality, and quantity of the fauna found at the bottom of Lake Worth in Texas.
Date:
August 1940
Creator:
Jenkins, Jesse Denney
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
To Determine the Status of Sex Education of High School Seniors
The average level of sexual knowledge and attitudes about sexual situations among surveyed high school seniors in Gregg County, Texas are presented in this thesis.
Date:
August 1940
Creator:
Knowles, Winlon
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
The Evolution, Applications, and Statistical Interpretations of DNA Typing in Forensic Science
This thesis examines the evolution, applications, and statistical interpretations of DNA typing as a tool in the field of forensic science as well as in our criminal justice system. The most controversial aspect of DNA typing involves the determination of how likely it is that two people share the same DNA profile. This involves the use of population genetics and databases of allelic frequencies as well as some assumptions about population structuring.
Date:
August 1997
Creator:
Schober, Cassandra C. (Cassandra Carolyn)
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library