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  Partner: UNT Libraries
 Degree Discipline: Biology
Effects of X-Irradiation on Water and Ion Flux in Isolated Roots

Effects of X-Irradiation on Water and Ion Flux in Isolated Roots

Date: January 1967
Creator: Wall, Malcolm J.
Description: Due to the relatively small amount of work concerning radiation, it was thought feasible to use ionizing radiation as a tool to study the relationship between water and salt flux in isolated root systems. Moreover, the more quantitative potometric method lends itself well to such a study, since the two processes can be followed simultaneously. the aims of this study, therefore, were 1) to determine effects of X-irradiation on water, calcium and potassium flux in excised onion roots; 2) to determine the dose levels required for producing permeability changes; 3) to investigate the nature of radiation damage to root systems; and 4) to attempt to shed light on the relation between water transport and ion movement in root systems.
Contributing Partner: UNT Libraries
Electron Microscopy of Vesicles Present in Bacterial Lysates of Escherichia Coli

Electron Microscopy of Vesicles Present in Bacterial Lysates of Escherichia Coli

Date: August 1966
Creator: Shaw, James Elwood
Description: It is the purpose of this thesis to report further studies on the vesicles appearing in phage lysates of Escherichia coli, phage attachment to these vesicles, and the presence of similar vesicles in lysozyme and penicillin lysed cultures.
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Enallagma civile (Odonata: Coengrionidae) life history and production in a west Texas playa

Enallagma civile (Odonata: Coengrionidae) life history and production in a west Texas playa

Date: May 2002
Creator: Booker, Jennifer Suzanne
Description: A life history and productivity study of Enallagma civile was conducted in a playa that was located in the southern High Plains of Texas. Other odonates were also studies to identify their contributions to the habitat.
Contributing Partner: UNT Libraries
Endocannabinoid System in a Planarian Model

Endocannabinoid System in a Planarian Model

Date: December 2010
Creator: Mustonen, Katie Lynn
Description: In this study, the presence and possible function of endocannabinoid ligands in the planarian is investigated. The endocannabinoids ananadamide (AEA) and 2-arachidonoylglycerol (2-AG) and entourage NAE compounds palmitoylethanolamide (PEA), stearoylethanolamide (SEA) and oleoylethanolamide (OEA) were found in Dugesia dorotocephala. Changes in SEA, PEA, and AEA levels were observed over the initial twelve hours of active regeneration. Exogenously applied AEA, 2-AG and their catabolic inhibition effected biphasic changes in locomotor velocity, analogous to those observed in murines. The genome of a close relative, Schmidtea mediterranea, courtesy of the University of Utah S. med genome database, was explored for cannabinoid receptors, none were found. A putative fatty acid amide hydrolase (FAAH) homolog was found in Schmidtea mediterranea.
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Endocrine Disruption of Levonorgestrel in Early-life Stages of Fathead Minnows, Pimephales Promelas

Endocrine Disruption of Levonorgestrel in Early-life Stages of Fathead Minnows, Pimephales Promelas

Date: August 2013
Creator: Overturf, Matthew D.
Description: Pharmaceuticals have routinely been detected in the environment resulting in a growing concern about whether these drugs could elicit effects on aquatic organisms. The concerns are centered on the highly conserved nature of mammalian therapeutic targets in fish. These pharmaceuticals are found at very low levels in the environment, which can result in sub-lethal effects in aquatic organisms. Therefore, 28 d early-life stage studies were conducted on six pharmaceuticals to assess their impacts on survival and growth fathead minnow larvae. Two pharmaceuticals tested, carbamazepine and fenofibrate, resulted in no alterations to survival and growth. However, amiodarone, clozapine, dexamethasone, and levonorgestrel (LNG) reduced survival at concentrations tested with LNG being the most potent at 462 ng/L. Survival was increased with amiodarone and clozapine; however LNG significantly decreased growth at 86 ng/L. Therefore, the most potent pharmaceutical tested was the synthetic progestin LNG with survival and growth impacts at concentrations less than 1 μg/L. Further analysis was conducted by measuring specific endocrine related mRNA transcript profiles in FHM larvae following the 28 d ELS exposure to LNG. Transcripts of 3β-HSD, 20β-HSD, and FSH were significantly down-regulated following 28 d exposure to both 16.3 and 86.9 ng/L LNG. Also, CYP19a expression was significantly ...
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Endogenous Levels of Indole-3-Acetic Acid in Synchronously Grown Chlorella Pyrenoidosa

Endogenous Levels of Indole-3-Acetic Acid in Synchronously Grown Chlorella Pyrenoidosa

Date: August 1971
Creator: Grotbeck, Laurence Merritt
Description: The purpose of this study was to determine the endogenous levels of indole-3-acetic acid throughout the life cycle of Chlorella pyrenoidosa, and to show a correlation between onset of cell division and IAA levels.
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Enzyme Assays Using Earthworms for Assessing Innate and Nonspecific Immunotoxicity of Xenobiotics

Enzyme Assays Using Earthworms for Assessing Innate and Nonspecific Immunotoxicity of Xenobiotics

Date: May 1992
Creator: Chen, Shing-Chong
Description: Principal objectives of my research were to: (1) report for the first time that coelomocytes are able to reduce NBT dye and confirm the presence of lysozyme-like activity in earthworm; (2) develop a standard methodology for determination of NBT reduction and lysozyme-like activity in earthworms; (3) compare NBT reduction and lysozyme-like activity in earthworms with those of murine and human cells and fluids; and (4) demonstrate the sensitivity of earthworm NBT reduction and lysozyme-like activity as the assays using matrics in refuse-derived fuel fly ash (RDFF) and CuSO4.
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The Eosinophil Response in Mice Infected with Trichinella spiralis or Trichinella pseudospiralis as Indicated by Phospholipase B Activity

The Eosinophil Response in Mice Infected with Trichinella spiralis or Trichinella pseudospiralis as Indicated by Phospholipase B Activity

Date: December 1992
Creator: Hsu, Shing-Chien
Description: The host eosinophil response was compared in mice infected with either T. spiralis or T. pseudospiralis by determination of levels of splenic and intestinal phospholipase B, a marker enzyme for eosinophils. Primary infection of naive mice and challenge infection of homologously sensitized mice with T. pseudospiralis resulted in significantly lower tissue phospholipase B activities than infection with T. spiralis. Mice homologously challenged with T. pseudospiralis did exhibit an anamnestic eosinophil response compared to mice given a primary T. pseudospiralis infection. This anamnestic response, however, was significantly lower than the eosinophil response seen in sensitized mice given a homologous T. spiralis challenge. Mice sensitized to T. spiralis or T. pseudospiralis and heterologous challenge demonstrated an elevated eosinophil response compared to mice given a primary infection with either parasite. The heterologous challenge response, however, was not as intense as found for sensitized mice given a homologous challenge.
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Establishing genetic and physiological baselines for the black-tailed prairie dog (Cynomys ludovicianus).

Establishing genetic and physiological baselines for the black-tailed prairie dog (Cynomys ludovicianus).

Date: May 2007
Creator: Biggs, Cindy Dawn
Description: The black-tailed prairie dog (Cynomys ludovicianus) has experienced dramatic declines over much of its historical range due to habitat loss, plague, poisonings, and shootings. Many populations now occur as isolated genetic relicts. A multiple locus genetic profile was obtained using microsatellite analyses of six polymorphic nucleotide repeats from 319 black-tailed prairie dogs collected from 16 colonies throughout the state of Texas. This assessment revealed that existing populations have sufficient variation at all six loci to verify the usefulness of this approach as a primary genetic tool in conservation and preservation. The data reveals regional-dependent frequency patterns as well as support for founder/bottleneck effects for several of the 16 sites. Although the prairie dog population in Texas as a whole may appear genetically diverse, considerable genetic divergence has already occurred among the subpopulations (FST = 0.164). Isolation by distance is supported by genic differentiation analysis (P < 0.001) and pairwise correlation analysis between genetic distance and geographic distance (P < 0.001). Prairie dogs from six (COC, LUBA, LUBC, LUBD, LUBE, and TAR) of the original 16 sites have been relocated or exterminated, or were in the process of being relocated. Results indicated the following colonies (COT, DAL, HOW, and HUD) are ...
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Eutrophic Levels of Different Areas of a Reservoir: A Comparative Study

Eutrophic Levels of Different Areas of a Reservoir: A Comparative Study

Date: August 1970
Creator: Hendricks, Albert C.
Description: It was the purpose of this investigation to attempt to demonstrate if differences in eutrophic levels existed among selected areas of Garza-Little Elm, and to demonstrate the role that sediments play in affecting eutrophication.
Contributing Partner: UNT Libraries