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Autoradiographic Localization of Carbachol-Induced Second Messenger Response in the Rat Spinal Cord Following Inflammation.

Description: This study examined central mechanisms of persistent pain using an autoradiographic technique to localize phosphoinositide hydrolysis (PI) in the rat spinal cord dorsal horn. The lateral half of laminae I-II showed the highest levels of baseline PI turnover and carbachol-stimulated PI turnover in normal animals as well as after inflammation. Inflammation resulted in increased baseline PI turnover in this region of the ipsilateral (76%) and contralateral (65%) dorsal horns. Carbachol increased PI turnover in this region in normal rats (55%) and following inflammation (ipsilateral: 46%, contralateral: 45%). The absolute magnitudes of these increases were 1.85, 2.71, and 2.51 nCi/mg, respectively. The results of this study demonstrate the involvement of PI turnover in neural mechanisms of persistent pain, and provide evidence for the involvement of cholinergic systems in this process. Because spinal cholinergic systems have been reported to be anti-nociceptive, the present results appear to reflect an upregulation of anti-nociceptive activity in response to inflammation. Thus, the spinal cholinergic system may be a regulatory site within the anti-nociceptive pathway, and may provide an attractive target for the development of new therapeutic agents.
Date: May 2002
Creator: Moore, Jack
Partner: UNT Libraries

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

Description: 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 habitat had significantly changed for select spatial variables.
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Date: August 2002
Creator: Miller, Christopher J.
Partner: UNT Libraries

Neuronal Network Analyses in vitro of Acute Individual and Combined Responses to Fluoxetine and Ethanol

Description: 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
Partner: UNT Libraries

Functional Neural Toxicity and Endocrine Responses in Mice Following Naphthalene Exposure

Description: 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
Partner: UNT Libraries

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
Partner: UNT Libraries

The Teratogenic Effects of Nocodazole and Acrylamide in Mus Musculus

Description: In two separate experiments, weight adjusted doses of nocodazole and acrylamide were injected intraperitoneally at various time intervals into twelve week old female mice. Within the nocodazole experiment, the doses were injected at varying time intervals before and after mating. On day seventeen of gestation, the female mice were sacrificed and their uterine contents examined. Nocodazole induced a significant increase in reproductive pathology per total implants when administered one hour after mating to the (SECxC57BL)F, stock: 5.00% total deads, 70.23% moles, and 3.41% abnormal fetuses. Acrylamide treatment produced a significant reduction in live births when administered six hours after mating: 50.86% moles and 46.46% living fetuses per total implants.
Date: May 1989
Creator: Oliva, Jean L. (Jean Louise)
Partner: UNT Libraries

Biological Control of the Red Imported Fire Ant by the Entomopathogenic Nematode, Steinernema Carpocapsae (Weiser)

Description: Field trials were conducted in 1988 to evaluate the effectiveness of Steinernema (=Neoaplectana) carpocapsae (Weiser) in controlling the fire ant. Infective juveniles (IJ) of the nematode were applied as drench on 235 and 422 mounds, respectively for 2-month summer and 6-week fall evaluation periods. In comparative trials, amidinohydrazone (Amdro) was applied to 249 (summer) and 65 (fall) active mounds, with 245 (summer) and 78 (fall) untreated active as controls. Nematode treatments resulted in an average of 47% control (Abbott's formula) in summer trials and 19-88% control in the fall trials, compared with 39% and 47% control, respectively with amidinohydrazone. Active mounds treated with nematodes or amidinohydrazone had significantly fewer individuals than control mounds in summer trials.
Date: August 1989
Creator: Morris, John R. (John Robert), 1949-
Partner: UNT Libraries

Effects of Long-Term Moderate Ethanol Intake on the Stress Response in Rats

Description: The effect of ethanol on the stress response in rats was examined. Experimental animals were given 0.25 ml of 28 percent ethanol or 0.25 ml of water orally once a day, five days a week, for a period of twelve months and were then subjected to fifteen minute cold stress. Corticosterone levels in ethanol-treated males following stress were significantly lower (22 percent) than in the sham group. Adrenal weights in sham-treated females were significantly higher (15 percent) than in the ethanol group at the end of twelve months. Mortality in sham-treated males was significantly higher (60 percent) than in ethanol-treated males. The effects observed may be due to the sedative action of ethanol on cortical centers controlling the hypothalmus.
Date: December 1984
Creator: Williams, Judy L. (Judy Lee)
Partner: UNT Libraries

The Reproductive Consequences of Carriers of Methylenebisacrylamide-Induced Balanced Reciprocal Translocations in Mus Musculus

Description: N,N'-methylenebisacrylamide (MBA) was studied because of its effectiveness in inducing heritable translocations in germ cells of male mice. The health impact of translocations was studied through anatomical analysis of the progeny of semisterile translocation carriers. As expected, the semisterility of translocation carriers resulted primarily from embryonic death during periimplantation stages due to unbalanced chromosome sperm segregants. Among conceptuses that survived to mid- and late-gestation stages, there was an increased incidence of developmental anomalies including fetal death and phenotypic defects. These abnormalities are associated with unbalanced chromosome complements that allow survival to the later stages of development.
Date: May 1989
Creator: Kile, Joanna L. (Joanna Le)
Partner: UNT Libraries

Changes in Heterozygosity Through Time in American Standardbred and American Saddlebred Horses (1960-1990)

Description: Observed and expected heterozygosity (H) levels for ten electrophoretic blood marker loci and expected H for seven red blood cell (RBC) anitgen/antibody loci were examined for 20 years in American Standardbred and 30 years in American Saddlebred horses. Standardbreds were classed by gait, Trotter and Pacer, and evaluated separately in most analyses. 4,404 Trotters and 12,271 Pacers were found to have statistically highly significant losses of mean total observed H through time for the ten electrophoretic loci (P<0.005), although in Trotters the loss was more extreme (P<<0.001). Loss of H in 5984 Saddlebreds was not significant (P=0.259). Correlations of RBC expected H through time showed decreases in all three groups.
Date: May 1992
Creator: King, Judith A. (Judith Ann), 1955-
Partner: UNT Libraries

Characterization of the OCT Plasmid-Encoded Mercury Resistance Genetic Locus in Pseudomonas putida

Description: A 17.1 Kb genetic element encoding for mercury resistance (OCT-Hg^r) was shown to translocate from its original location on the OCT plasmid to the resistance plasmid, RPl, in Pseudomonas putida. Analysis of RPl-Hg^r recombinant plasmids revealed that insertion of mercury resistance genes into RPl could occur at a variety of sites, with all recombinants having common EcoRI restriction fragments of 9.4, 3.8, 2.3, and 1.6 Kb, derived from the insertion. Hybridization analysis suggested the existence of extensive homology between this insertion and the prototypic mercury resistance transposon, Tn501, as well as the location of a similar merA sequence. Although the overall size was shown to be quite different from Tn501, striking physical similarities are shared between these two elements.
Date: May 1989
Creator: Armbruster, Steven C. (Steven Christopher)
Partner: UNT Libraries

Genetic Variation in a Population of the Plains Woodrat Neotoma micropus

Description: Neotoma micropus from Jack County, Texas, were studied over a 9-month period. Loci from blood and saliva were used to determine genetic variation within the population. Deviations from Hardy-Weinberg equilibrium were found at one locus. The average temporal F over all seven loci was 0.040. Genetic structuring was subtle, fluctuated on a seasonal basis, and was due to differential migration or predation on genotypes. Heterozygotes tended to move more than homozygotes, and a greater proportion of heterozygotes were lost from the population during each season. Genetic variation was maintained in the population by immigrant individuals. This differential in dispersal of genotypes fits current models of reorganization within the genome of populations.
Date: August 1988
Creator: Stewart, John E. B. (John Edward Bakos)
Partner: UNT Libraries

A Vegetative Analysis of and Distribution of the Grasses of North Central Texas

Description: Accurate identification is fundamental in any study of grasses by farmers, ranchers, range specialists, ecologists, or students interested in the changes taking place in the grass habitat. Frequently it is convenient, and sometimes it is necessary, to identify the grasses by their vegetative characters. Some are readily recognized at a glance by their habitat and certain characters well known to the experienced observer. In other cases, identification is more difficult; and, perhaps with a few, it is impossible to be certain of the species from vegetative characters. However, this may also be true when the characters of the floral parts alone are considered. The inflorescence, used in most keys and descriptions, is often available only for a short period of time. Identification by the characters of the vegetation can be used throughout the growing season, even if grazing or mowing has removed or prevented the development of the floral parts. There have been other studies of grass identification related to vegetative characters, but they have been local and have not covered North Central Texas. This paper provides a means of identifying grasses by their vegetative characters. It can be used by the scientist, the technician, and the layman interested in the grasses of North Central Texas. A key using technical terminology is provided for use by the ecologist, range specialist, plant taxonomist, and student in these areas of study. For the ranchman, farmer, greens keeper, gardener, or nurseryman, a key with symbols is given that can be used without a technical knowledge of taxonomic botany. The distribution maps and diagnoses will aid any user of the keys. They will also make available additional information that may be useful in the establishment of a numerical classification and identification of plants--grasses in particular.
Date: August 1970
Creator: Smith, David Lawrence, 1932-
Partner: UNT Libraries

The Effect of Nine Diet and Water Combinations on the Culture Health of Ceriodaphnia Dubia

Description: Culture health of Ceriodaphnia dubia was evaluated for organisms cultured using all combinations of three foods and three waters. Criteria used to assess health of cultures included adult and neonate weights, time required to produce first broods, neonate production, adult survival, and resistance to hexavalent chromium. Diet/water combinations which produced the most neonates were not found to produce adults which were more resistant to chromium than those which produced fewer neonates. Of those evaluated, a diet of Selenastrum capricornutum and a yeast-trout chow-cereal leaf mixture was best for culturing and testing Ceriodaphnia. The best synthetic water tested was a mixture of nine parts reconstituted hard water and one part bottled mineral water.
Date: May 1990
Creator: Patterson, Paul W. (Paul William)
Partner: UNT Libraries

Sediment Characteristics and Bioavailability of Sorbed Neutral Organic Compounds

Description: Several sediment characteristics were analyzed to determine their suitability for use as potential normalization factors for the bioavailability of neutral organic compounds sorbed to sediments. Percent organic carbon, cation exchange capacity and particle surface area were measured sediment characteristics that varied sufficiently to encompass the range in observed sediment toxicity. Laboratory sediment toxicity test data using fluoranthene suggest that there is no biologically significant correlation between sediment toxicity and sediment characteristics (organic carbon, cation exchange capacity, particle size distribution, particle surface area). Fluoranthene amended sediments with similar organic carbon contents do not yield similar toxicities due to sorbed fluoranthene and thus do not support the organic carbon normalization approach for evaluating sediment quality or for sediment criteria development.
Date: December 1989
Creator: Suedel, Burton C. (Burton Craig)
Partner: UNT Libraries

Structural Analysis of the Genes Encoding the Oxalocrotonate Branch of the Pseudomonas putida TOL Plasmid pDKI meta-cleavage Pathway and the Expression of the xy1G Gene Product in Escherichia coli

Description: Three overlapping DNA fragments from the lower operon of Pseudomonas putida TOL plasmid pDK1, covering the xy1IH genes and downstream flanking region, were cloned into pUC19. They include a 2.8 kbp XhoI fragment, a 2.7 kbp PstI fragment and a 2.0 kbp EcoRI-HindIII fragment. They were subjected to DNA sequence analysis. The xy1I (4-oxalocrotonate decarboxylase) and xy1H (4-oxalocrotonate tautomerase) genes were found to possess coding regions of 792 and 189 nucleotides, respectively. A possible transcriptional terminator resembling E. coli rho-independent terminators was identified downstream of the translational stop of xy1H. An additional stem and loop structure was found in the intergenic region between xy1I and xy1H. The individual ORF's of the oxalocrotonate branch (xy1G, xy1I and xy1H) have been cloned into pUC18/19. The expression of the xy1G gene in E. coli was successfully assayed spectrophotometrically.
Date: December 1992
Creator: Luo, Xuebin
Partner: UNT Libraries

Adenylate Energy Charge Determinations of Soil Bacteria Grown in Soil Extract Medium

Description: The adenylate energy charge values of twenty bacteria isolated from soil and cultured in a medium consisting of soil and distilled water were determined by the luciferin-luciferase bioluminescense method. The purpose of this study was to examine the growth and energy charge values of these organisms in soil extract medium, and to determine what effect the addition of glucose has on their energy charge values. Three of the organisms employed in this study showed energy charge values similar to those reported for bacteria grown in enriched media. The remainder of the isolates demonstrated low energy charge values, and scant growth in the soil medium.
Date: August 1988
Creator: Rodriguez, Luis A. (Luis Antonio)
Partner: UNT Libraries

Responses of Pristina leidyi Smith 1896 (Naididae: Oligochaeta) to Cadmium, Vanadium, and Some Environmental Factors

Description: Concern over sediment toxicity has increased the need for toxicity test information with organisms that inhabit sediments. Oligochaetes are exposed to toxicants through feeding and direct body contact with aquatic sediments. Chronic testing with oligochaetes has historically focused on tubificids with test lengths of one year or more to encompass several generations. Most naidid oligochaetes have generation times of three to seven days and could provide chronic information in a matter of weeks. The cosmopolitan distributed naidid, Pristina leidyi, was evaluated for use as a toxicity test organism. Results of research conducted includes culture methods, effects of temperature on reproduction, growth rates in a reference sediment, acute toxicity tests, and chronic toxicity tests.
Date: May 1990
Creator: Smith, David P. (David Paul), 1956-
Partner: UNT Libraries

Dalbergia and Albizia: Plantlet Production via Tissue Culture, Karyological Evaluation, and Seed Anatomy with Scanning Electron Microscopy

Description: A publication by the National Academy of Sciences, USA (1979) outlined some of the research need for a great variety of economically important woody species whose remaining genetic resources need urgently to be collected and conserved. A viable regeneration system was established via tissue and cell suspension culture for Albizia falcataria and A. lebbeck, two important wood yielding leguminous tree species. The culture medium was standardized after several trials to obtain callus from the leaflet explants of these two tree species. The optimum use of casein hydrolysate (w/v) and coconut milk (v/v) in addition to 6-Benzylaminopurine and Indole-3-butyric acid could induce morphogenesis and somatic embryogenesis in the cultured tissue. This reports the first observation on somatic embryogenesis ofA. lebbeck using leaflets as the explants. Scanning Electron Microscopy and histological studies were done on the different stages plant development following standard techniques. Embryogenesis in suspension culture followed regeneration of plantlets in A. lebbeck. In A.falcaaria the regenerative process followed via organogenesis from the shoot buds developed on the leaf explants. After hardening the regenerated plants were transferred to the greenhouse. Some of the trees grew more than 25 feet tall within a few months outside the greenhouse. Karyotype of the three leguminous trees Albizia lebbeck, A. falcataria, and Dalbergia sissoo was analyzed. In D. sissoo, various chromosomal anomalies were observed in the cultured tissue. The abnormality indices and ploidy level varied with the age and the frequency of the subculture. In the aged culture the regenerative potential declined but was reinstated to some extent with the addition of two complex growth factors, coconut milk and casein hydrolysate. Seed anatomy of 26 species of 4 leguminous genera was studied with SEM. The main distinguishing anatomical features observed in the seed sections were uniseriate or multiseriate epidermis, epidermal projections, and number of rows ...
Date: December 1998
Creator: Ghosh, Nabarun
Partner: UNT Libraries

Biogeographic Relationships of Pocket Gophers (Geomys breviceps and Geomys bursarius) in the Southeastern Portion of Their Ranges

Description: This research utilized population genetic analyses (protein starch-gel electrophoresis and DNA sequencing of the cytochrome b mtDNA gene), host-parasite specificity (lice coevolution), remote sensing of satellite data, and geographic information systems (GIS) to characterize newly discovered populations of pocket gophers (genus: Geomys) in Arkansas. These populations are isolated and occur in seemingly unsuitable habitat in the Ozark Mountains of Arkansas. Analyses of electrophoretic and ectoparasite data suggested the populations in the Ozark Mountains represented isolates allied to Geomys bursarius, a species not known to occur in Arkansas. Comparison of mitochondrial DNA sequence data of the cytochrome b gene with that of other taxa and morphometric analyses confirmed that these populations are most closely allied to G. bursarius occurring to the north in Missouri. Moreover, these mtDNA sequence analyses indicated a degree of differentiation typical of that between other subspecies of pocket gophers. Therefore, these populations represent a distinct genetic entity in an intermediate stage of speciation and should be designated as a new subspecies, Geomys bursarius ozarkensis. Molecular clock analysis revealed a time of lineage divergence for this new subspecies as approximately 511,000 YBP. Due to the isolated nature and limited distribution of this subspecies, an evaluation of critical habitat needs was initiated. Remote sensing and GIS technologies were used to identify and describe suitable habitat Computerized classification of satellite imagery of suitable vegetation, integrated with ancillary digital information on soil associations, roads, and water systems, revealed that human activity had played a positive role in the establishment and dispersal of pocket gophers in this area. This research represents an initial combination of classical systematic tools with remote sensing and GIS to investigate biogeographic patterns and evolution. This project establishes a framework for using an interdisciplinary approach to studying organisms with limited distributions, determining evolutionary status, and providing recommendations for ...
Date: August 1998
Creator: Elrod, Douglas Allen
Partner: UNT Libraries

Mutagenic Potential of Tetramethylthiuram Disulfide (42-S Thiram) on the Germ Cell Stages of Drosophila melanogaster

Description: Tetramethylthiuram disulfide (42-S Thiram), a carbamate fungicide was studied for its mutagenic potential on the germ cell stages of wild-type male Drosophila melanogaster. The mutagenicity was tested using the sex-linked recessive lethal assay (SLRL). Any lethals induced in the F2 generation were evidenced by the absence of wild-type males. Although there was an increase in mutation rates in the 42-S Thiram treated wild-type males over the control wild-type males, it was not significantly higher. According to the laboratory conditions in this preliminary study, tetramethylthiuram disulfide failed to produce mutagenic effect.
Date: December 1990
Creator: Lowe-Chatham, Janice E. (Janice Elaine)
Partner: UNT Libraries

Teratogenic and Mutagenic Potential of Triethylenemelamine, Ethyl Methanesulfonate, and N-Ethyl-N-Nitrosourea for Causing Fetal Anomalies in Mus Musculus

Description: In five separate experiments, weight-adjusted doses of TEM, EMS, and ENU were injected intraperitoneally into twelve week-old female mice six hours after mating. On day seventeen of gestation, the females were sacrificed and their uterine contents were examined. The effect of each agent was determined by its ability to cause malformations and death to the developing embryos. All treatment groups showed statistically significant elevated levels of malformations in comparison to their corresponding control groups. The reproductive damage induced in these experiments cannot be singularly attributed to teratogenesis or mutagenesis but a combination of the two.
Date: December 1987
Creator: Gans, Murry J. (Murry Joe)
Partner: UNT Libraries

Endogenous Nucleotide Pools in Growing Cells of Azotobacter Vinelandii

Description: The objective of this investigation was to examine the changes in the nucleotide pools of Azotobacter vinelandii during the growth cycle. Endogenous ribonucleotides were extracted from A. vinelandii using trichloroacetic acid (TCA; 12% w/v). The 5' mono-, di- and triphosphates of adenine, guanine, uracil and cytosine were separated and quantified by anion-exchange high performance liquid chromatography. Results indicated that the adenylate energy charge of A. vinelandii paralleled the growth rate during exponential phase and that it declined rapidly as the stationary phase was reached. In addition, the amount of each nucleotide in A. vinelandii tended to increase in the logarithmic phase and decrease in the stationary phase in a similar manner to the energy charge.
Date: August 1987
Creator: Lee, Yick-Shun
Partner: UNT Libraries