A bacterial challenge assay was developed utilizing the earthworm, Lumbricus terrestris, in order to assess potential immunotoxic effects from exposure to specific polychlorinated biphenyl congeners. Earthworms were inoculated with Aeromonous hydrophila, establishing a 10-day LD50. In vitro assays for effects of PCBs on phagocytosis agreed with mammalian studies, demonstrating potent suppression of phagocytosis by the non-coplanar PCB congener 138 and no suppression by the coplanar congener 126. However, when the effects of the two PCB congeners were evaluated for suppression of resistance to a whole animal infection challenge assay, coplanar PCB 126 decreased the ability of L. terrestris to withstand infection while non-coplanar PCB 138 did not.

Superior swimming stamina in adult fish is presumably passed on to their offspring, but the ontogeny of the appearance of superior stamina and the requisite enhanced cardio-respiratory support for locomotion in larval fishes has not been determined. Is the expression of the suite of parental traits enabling superior swimming stamina in their offspring dependent upon their achieving juvenile/adult morphology, or does it appear earlier in their larvae? To answer this, adults were classified into three groups based on swimming stamina, followed by measurement of length, mass, and width. Larval offspring from the two parental groups -high stamina larvae (HSL) and low stamina larvae (LSL)- were reared at 27°C in aerated water (21% O2). Routine and active heart rate, routine and active mass specific oxygen consumption were recorded through 21dpf, and cost of transport (COT) and factorial aerobic scope were derived from oxygen consumption measurements. Routine heart rate at 2dpf of LSL was 164 ± 1 b·min-1, compared to only 125 ± 2 b·min-1 for HSL. Routine heart rate subsequently peaked at 203 ± 1 b·min-1 at 5dpf in the HSL group, compared to 207 ± 1 b·min-1, at 4dpf in the LSP larvae. Active heart rate at 5 dpf of …

Established interspecific metabolic allometric relationships do not adequately describe the complexity and variable physiological states of developing animals. Consequently, intraspecific allometric relationships of oxygen consumption and carbon dioxide production as a function of body mass; the respiratory quotient; the function of the silk cocoon; and body composition were investigated for each distinct developmental stage of the silkworm, Bombyx mori. Whole animal O2 consumption in Bombyx ranged from 0.00064 + 0.000047 ml O2 .hr-1 at larval instar I to 0.77 + 0.06 ml O2 .hr-1 in pre-pupal, falling to 0.21+ 0.01 ml O2 .hr-1 in the pupae. Those instars having a significant relationship between O2 consumption as a function of body mass, the slope of the line relating O2 consumption to body mass varied between 0.99 and 1.02, while across all instars the slope was 0.82. Developmental allometry should be presented for individual developmental stages because the individual allometric exponents of the stages can be significantly different from the overall allometric exponent throughout development and in some cases, the overall allometric exponent can be a statistical artifact. The first larval instar of Bombyx mori has the lowest cross sectional area of high metabolic tissue of the midgut (27%) and had one …

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 …

Raptor rehabilitation has become commonplace globally, yet studies on the survival and adaptation of great horned owls (Bubo virginianus) after release has been neglected to an appreciable extent. The primary objective of this study is to provide quantitative data on the success of rehabilitated and released great horned owls in the North Texas region. Owls (N=12) were rehabilitated and released onto the Ray Roberts Greenbelt Corridor in Denton County, Texas, and monitored using radio telemetry to evaluate home range (November 2002 - February 2005). With approximately 75% of the birds released for this study surviving until transmitter battery failure, it is believed that the rehabilitation process was successful for these birds.

This thesis describes the development of an optimized method for culturing dissociated, monolayer neuronal networks from murine frontal cortex and midbrain. It is presented as a guidebook for use by cell culture specialists and laboratory personnel who require updated and complete procedures for use with microelectrode array (MEA) recording technology. Specific cell culture protocols, contamination prevention and control, as well common problems encountered within the cell culture facility, are discussed. This volume offers value and utility to the rapidly expanding fields of MEA recording and neuronal cell culture. Due to increasing interest in determining the mechanisms underlying Parkinson's disease, the newly developed procedures for mesencephalon isolation and culture on MEAs are an important research contribution.

The rapid development of once-rural landscapes often produces detrimental effects on surface water quality entering local reservoirs through vulnerable stream channels. This study presents a methodology that incorporates geographic information systems (GIS) and remote sensing techniques for the creation of a stream corridor evaluation mechanism, coined the water quality corridor management (WQCM) model. Specifically, the study focuses on determining the viability of the WQCM model in assessing the stream corridor conditions within a northern Denton County pilot study region. These results will aid in the prediction and evaluation of the quality of stream water entering reservoirs that serve as the primary drinking water source for local municipalities.

The chicken ductus arteriosi (DA) are two embryonic blood vessels that shunt blood away from the non-ventilated lungs and towards the body and chorioallantoic membrane. I show that prostaglandins have a diminished role in maintaining chicken DA patency and nitric oxide inhibits oxygen induced contraction of the day 19 proximal DA in a time dependent manner. The pathways governing oxygen induced contraction in the chicken DA are similar to those found in mammals and include contributions from ROS, Kv channels, L-type Ca2+ channels, and the Rho kinase pathway. Longer exposure to high oxygen generates increased oxygen induced constriction of the day 19 DA that may be mediated through the Rho kinase pathway.

Honors thesis written by a student in the UNT Honors College discussing mutations in the Tg737 gene in mice and how this affects neuronal cilia in mice.

Thesis written by a student in the UNT Honors College discussing the problems and variables associated with assessing the total number of neurons in a network from cell seeding concentrations and measurements of network area.

Thesis written by a student in the UNT Honors College discussing independence and maneuverability related to regular exercise among noninstitutionalized elderly adults.