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Root Colonization By Pseudomonas Putida: The Role Of Catalase And Superoxide Dismutase Isozymes, Tawnya Lynn Bowles

Undergraduate Honors Capstone Projects

The fluorescent soil bacterium Pseudomonas putida is an aggressive root colonizer (1) that offers benefits to the host plant by suppressing soilborne pathogens and enhancing plant growth (12,13). Upon introduction in the field through seed inoculation, certain isolates of P. putida have the potential to act as an effective biological control agent (3). P. putida has also been shown to promote the growth of potatoes, sugarbeets, and radishes (13). Fluorescent pseudomonads are effective in protecting plants against pathogens such as Gaeumannomyces graminis var. tritici, a fungus that causes the root disease of wheat called take-all (13).

No Evidence Of Linkage Between 35 Genetic Markers And The Spider Lamb Syndrome Gene In Sheep, Sarah Thornell South

Undergraduate Honors Capstone Projects

Spider Lamb Syndrome (SLS) is a semi-lethal congenital disorder affecting the Suffolk and Hampshire sheep breeds. The clinical manifestations of the syndrome include severe skeletal and muscular abnormalities with long, fine-boned legs, curvature of the spine and nasal septum, minimal muscling and severe muscle atrophy. The affected animals have a difficult time walking and most lambs do not survive past the first six months of life. A single autosomal recessive gene causes the disorder. Researchers believe the SLS gene arose as a single source mutation in a popular Suffolk blood line in the 1970s. Heterozygous carriers of the SLS gene …

Development Of An Enzyme Linked Immunosorbent Assay Capable Of Detecting Antibodies Specific To The Cytomegalovirus, Rachel Bird

Undergraduate Honors Capstone Projects

The cytomegalovirus (CMV) is capable of causing serious illness and death in immunocompromised individuals. The objective of this research is to develop a method of detecting antibodies against CMV. This has lead to the development of an Enzyme linked Immunosorbent Assay (ELISA) that is capable of detecting CMV or anti-CMV antibodies. The process in the development of such an assay involves; 1) the purification of Hyperimmune Rabbit Serum containing anti-CMV antibodies, 2) determination of the appropriate concentrations necessary to provide a clear and concise response to the test, and 3) testing of monoclonal antibodies to determine their specificity towards the …

Effects Of Copper On Oxidative Stress And Growth Of Pseudomonas Putida, Tiffany Marshall

Undergraduate Honors Capstone Projects

Oxygen is an essential compound in all aerobic systems; however, it can also take part in toxic reactions involving active oxygen species (AOS) and transition metals. Most of the time, antioxidant enzymes act as defense mechanisms and keep the production of AOS to a minimum. However, if the defense mechanisms are not adequate, damage may occur and possibly lead to the breakdown of biomolecules such as DNA, lipids, and proteins that are vital to both simple and complex organisms. Oxidative damage could also be a contributing factor to many human pathological conditions including, aging, atherosclerosis, carcinogenesis, diabetes mellitus, lung cancer, …

Association Of The Major Histocompatibility Complex With Autism, Wayne W. Daniels

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The pathogenesis of autism has proven difficult to characterize. However, in many recent studies, it is suggested that the onset of this disorder is the result of multiple etiological factors, which include genetic, immunologic, and viral elements.

Possible immunological influences found in subpopulations of patients with autism include decreased lymphocyte responsiveness, reduced natural killer cell activity, abnormal response to rubella vaccine, abnormal immune response to brain tissue, and decreased plasma levels of the fourth component of complement(C4). These aberrations and others imply a possible autoimmune mechanism in some cases for the development of autism.

C4 deficiencies have been found in …

Competitive Interactions Between A Native And Exotic Trout Species In High Mountain Streams, Heather M. Thomas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Populations of the introduced book trout, Salvelinus fontinalis, have recently become more widespread and abundant in western North American streams, possible at the expense of native Colorado River cutthroat trout, Oncorhynchus clarki pleuriticus. We examined the intensity and potential mechanism of competition between these species.

Feeding experiments in laboratory stream channels showed that cutthroat trout feeding efficiency decreases in the presence of a brook trout. Decreased feeding efficiency appeared to be due to interference, as cutthroat trout were inactive in the presence of the brook trout. Evidence for interference competition in the feeding experiments was also given by the …

Reversal Of Cell Fate Determination In Caenorhabditis Elegans Vulval Development, Susan Euling, Victor Ambros

Dartmouth Scholarship

In Caenorhabditis elegans, the fates of the multipotent vulval precursor cells (VPCs) are specified by intercellular signals, The VPCs divide in the third larval stage (L3) of the wild type, producing progeny of determined cell types, In lin-28 mutants, vulva development is similar to wild-type vulva development except that it occurs precociously, in the second larval stage (L2), Consequently, when lin-28 hermaphrodites temporarily arrest development at the end of L2 in the dauer larva stage, these otherwise determined VPC progeny become reprogrammed back to the multipotent, signal- sensitive state of VPCs. Our results indicate that VPC fate determination by intercellular …

Habitat Edge And Nest Predation In House Wrens, Daniel Moore '96

Honors Projects

I studied the effect of habitat edge on nest predation rates ina population of House Wrens (Troglodytes aedon) which bred in nest boxes in central Illinois from 1986-1994. Each nest box was classified according to its distance from the nearest habitat edge, and edges were classified into either abrupt, gradual or riverine edge-types. Nest predation rates varied significantly annually for the the two major nest predator classes, apparent avian and snake, and Raccoon (Procyon lotor). Neither predator class showed significant differences in nest predation rates in relation to distance from the nearest edge. There was no significant effect of edge-type …

Imaging Molecular Structure Of Channels And Receptors With An Atomic Force Microscope, Ratneshwar Lal

Scanning Microscopy

Biological membranes contain specialized protein macromolecules such as channels, pumps and receptors. Physiologically, membranes and their constituent macromolecules are the interface surfaces toward which most of the regulatory biochemical and other signals are directed. Yet very little is known about these surfaces. The structure of biological membranes has been analyzed primarily using imaging techniques that are limited in their resolution of surface topology. An atomic force microscope (AFM) developed by Binnig, Quate and Gerber, can image molecular structures on specimen surfaces with subnanometer resolution, under diverse environmental conditions. Also, AFM can manipulate surfaces with molecular precision: it can nanodissect, translocate, …

Immunolesions Using Site Specific Injections Of 192-Lgg Saporin Into The Basal Forebrain Fail To Affect Radial Arm Maze Performance In The Male Rat, Lesley J. Hickman '96

Honors Projects

In this study I investigated the effects of 192-lgG saporin injections into the medial septal area.(MSA) and nucleus basalis magnocel/ularis (NBM) on radial arm maze performance in the male rat. The results of the present study reveal that combined injections of 192-lgG saporin into the basal forebrain failed to disrupt RAM performance when compared to vehicle-injected controls. In addition, intraperitoneal injections using a muscarinic receptor blocker, scopolamine, failed to reveal a compensatory response of the cholinergic basal forebrain that may have explained the lack of behavioral effects of 192IgG saporin. Consequently, the results of this study suggest that a selective …

Potential Influences Of Biotic And Abiotic Factors On Patterns Of Activity In Galapagos Snakes: Locomotory Performance Or Prey Abundance?, Marco A. Altamirano

Biology ETDs

Biotic and abiotic factors were considered as the potential factors influencing the activity pattern of Galapagos snakes. Three hypothesis are tested in this study in order to examine the causes of variation in snake activity. The first hypothesis (variation in the number of snakes active throughout the day is caused by distribution and abundance of their prey) is rejected because snakes and lizards have different patterns of activity. Moreover, Chi-square Goodness-of-Fit test and 2 x 2 Contingency tables show significant differences between these patterns of activity. However there are hours of the day when lizard activity could influence snake activity. …

In Vitro Systems And Cultured Cells As Specimens For X-Ray Microanalysis, Godfried M. Roomans, Jarin Hongpaisan, Zhengzhu Jin, Ann-Christin Mörk, Ailing Zhang

Scanning Microscopy

In vitro systems and cultured cells are recognized as useful systems in many areas of biomedical research, including X-ray microanalysis. To be reliable, in an vitro system should have an elemental composition close to that of the tissue in situ, react in the same way to stimuli, and retain the in situ regulation of ion transport. In the present paper, four of the most commonly used in vitro systems will be reviewed: incubated tissue slices (liver and pancreas), isolated glands (submandibular gland acini, sweat glands), primary cell cultures (sweat glands, endometrium), and cell lines (the colon cancer cell line …

Estrogen Levels In House Wren (Troglodytes Aedon) Egg Yolks, V. Brook Waggoner '96

Honors Projects

Estrogen, when present in early embryonic development, regulates sexual differentiation in the avian nestling and adult. In this study, I developed a procedure to extract and quantify levels (by radioimmunoassay) of the estrogen, 17[beta]-estradiol, in house wren (Troglodytes aedon) egg yolk. Levels of 17[beta]-estradiol found in one clutch of eggs increased with the order of laying, indicating female house wrens may be capable of regulating the levels of 17[beta]-estradiol received by the offspring. Since the attraction of mates is often aided by the display of sex differences, maternal control of 17[beta]-estradiol levels in the embryo may influence the future reproductive …

Accessing Nuclear Structure For Field Emission, In Lens, Scanning Electron Microscopy (Feisem), T. D. Allen, G. R. Bennion, S. A. Rutherford, S. Reipert, A. Ramalho, E. Kiseleva, M. W. Goldberg

Scanning Microscopy

Scanning electron microscopy (SEM) has had a shorter time course in biology than conventional transmission electron microscopy (TEM) but has nevertheless produced a wealth of images that have significantly complemented our perception of biological structure and function from TEM information. By its nature, SEM is a surface imaging technology, and its impact at the subcellular level has been restricted by the considerably reduced resolution in conventional SEM in comparison to TEM. This restriction has been removed by the recent advent of high-brightness sources used in lensfield emission instruments (FEISEM) which have produced resolution of around 1 nanometre, which is not …

Angiogenesis In The Gonadal Capillary Network Of The Chick Embryo, F. J. Pérez-Aparicio, A. Carretero, M. Navarro, J. Ruberte

Scanning Microscopy

Seventy-one chick embryos of both sexes at the 35 Hamburger and Hamilton (H-H) developmental stage were processed for scanning electron microscopy of vascular corrosion casts and of critical point dried specimens, as well as transmission electron- and light microscopy, in order to study the angiogenic structures. The gonadal subepithelial capillary network was located at the level of the tunica albuginea under the covering epithelium. The casts showed a densely-meshed capillary network and numerous sprouting (nodular protrusions or capillary sprouts) and non-sprouting (enlarged vessels and angiogenic holes) angiogenic structures that were randomly distributed and mixed. Four types of angio-genic holes were …

Micrographic Fracture Characterization Of Gallium Arsenide Wafers, H. E. Belsinger Jr., L. D. T. Topoleski, B. Wilner

Scanning Microscopy

Single crystal gallium arsenide (GaAs) specimens were loaded to failure. Scanning electron microscope examination of fracture surfaces showed that GaAs fails in a brittle manner on {110} planes. Features on these fracture surfaces were used to identify preexisting (critical) flaws that potentially initiated fracture when loaded by tensile stresses. Critical flaws in each specimen were identified by comparison to an intentionally damaged control. The size and shape of critical defects were consistent with existing failure models.

Tc-Mapping And Investigation Of Water-Initiated Modification Of Yba2cu3o7-X Thin Films By Low Temperature Scanning Electron Microscopy, A. V. Bobyl, M. E. Gaevski, S. G. Konnikov, D. V. Shantsev, V. A. Solov'ev, R. A. Suris

Scanning Microscopy

The T_c -mapping method using low temperature scanning electron microscopy (LTSEM) has been developed to study the spatial distribution of the critical temperature in high temperature superconducting (HTSC) films with a spatial resolution approaching 2 μm. To achieve so high a spatial resolution, a numerical deconvolution method was applied that eliminated distorting effects associated with the thermal diffusion and with the contribution from the absorbed beam current. The T_c -mapping method was used to investigate modification by water of YBa₂Cu₃O_7-x films grown on (100) MgO and (110) LaAIO₃ substrates. The rate of …

Climatic And Geomorphic Controls On Semi-Fluvial Ecosystems, Max Aldon “Tad” Crocker Jr.

Biology ETDs

In most climatic regions, the growth of ecological knowledge for terrestrial and limnological components of landscapes have roughly occurred in tandem. But at a time when the world's deserts are increasingly used for human development, and particularly so along water courses, knowledge of how stream ecosystems function within semi-add landscapes has seriously lagged the productive history of terrestrial research there. How terrestrial and limnological components interact within semi-arid landscapes will elude a useful scientific understanding of semi-arid landscapes and will preclude wise landscape management policies as long as semi-arid fluvial ecosystems in general, and ephemeral streams in particular, remain poorly …

Crystallization During Volume Reduction Of Solutions With An Ion-Composition Corresponding To That In The Distal Tubuli, Inge Hojgaard, Anne-Marie Fornander, Mari-Anne Nilsson, Hans Goran Tiselius

Scanning Microscopy

The effect of macromolecules on the crystallization in solutions with an ion-composition and a pH corresponding to that of urine in the distal part of the distal tubuli was examined by recording the number and volume of crystals in a Coulter Multisizer and by studying the crystal morphology with scanning electron microscopy at different degrees of evaporation. The experiments were carried out with 100 ml samples of salt solutions with and without different concentrations of dialysed urine (dU) from normal subjects. Addition of dU resulted in a greater number of crystals and a reduction in the mean crystal volume (MCV). …

The Competition Of Pityopsis Ruthii With Liatris Microcephala And Andropogon Temarius, Helen Lee

Capstone Research Projects

Pityopsis ruthii (Small) Small, currently listed as an endangered species by the State of Tennessee and the U.S. Fish and Wildlife Service, is a perennial plant belonging to the family Asteraceae. The distribution of P. ruthii is limited to soil that has accumulated in cracks and crevices of phyllite or graywacke boulders along the Ocoee and Hiwassee Rivers. Analysis of both the soil and the boulders indicate neither the absence nor the presence of any unusual nutrient. P. ruthii is most likely restricted to this habitat mainly because of its inability to compete with other more vigorously growing associates. The …

Radioimmunoassay Analysis Of Testosterone Levels In Clutches Of House Wrens (Troglodytes Aedon) Egg Yolks, Kimberly A. Fryzel '96

Honors Projects

Recent evidence indicates that variation in intensity of aggressiveness and competitive ability among nestlings of a clutch may be attributed, at least partly, to differences in maternally deposited yolk testosterone that affects embryonic development (Schwabl 1993). We developed a radioimmunoassay (RIA) for measuring yolk testosterone levels in house wren (Troglodytes aedon) eggs. This procedure was used in initial studies to determine whether yolk testosterone varies within a clutch of house wren eggs. The analysis revealed the presence of higher levels of testosterone in yolks of eggs laid later in the clutch sequence. Because later laid eggs tend to hatch later …

Coordinate Cell Cycle Control Of A Caulobacter Dna Methyltransferase And The Flagellar Genetic Hierarchy, Craig Stephens, Gary Zweiger, Lucy Shapiro

Biology

The expression of the Caulobacter ccrM gene and the activity of its product, the M.Ccr II DNA methyltransferase, are limited to a discrete portion of the cell cycle (G. Zweiger, G. Marczynski, and L. Shapiro, J. Mol. Biol. 235:472-485, 1994). Temporal control of DNA methylation has been shown to be critical for normal development in the dimorphic Caulobacter life cycle. To understand the mechanism by which ccrM expression is regulated during the cell cycle, we have identified and characterized the ccrM promoter region. We have found that it belongs to an unusual promoter family used by several Caulobacter class II …

Mioc Transcription, Initiation Of Replication, And The Eclipse In Escherichia Coli, Joseph A. Bogan, Charles E. Helmstetter

Biomedical Engineering and Sciences Faculty Publications

The potential role of mioC transcription as a negative regulator of initiation of chromosome replication in Escherichia coli was evaluated. When initiation was aligned by a shift of dnaC2(Ts) mutants to nonpermissive temperature (40°C), mioC transcript levels measured at the 5' end or reading through oriC disappeared within one mass doubling. Upon return to permissive temperature (30°C), the transcripts reappeared coordinately about 15 min after the first synchronized initiation and then declined sharply again 10 min later, just before the second initiation. Although these observations were consistent with the idea that mioC transcription might have to be terminated prior to …

Dna Representation Of Variegating Heterochromatic P-Element Inserts In Diploid And Polytene Tissues Of Drosophila Melanogaster, Lori L. Wallrath, Vamsi P. Guntur, L Rosman, Sarah C.R. Elgin

Biology Faculty Research

Position-effect variegation (PEV) is the mosaic expression of a euchromatic gene brought into juxtaposition with heterochromatin. Fourteen different transformed Drosophila melanogaster lines with variegating P-element inserts were used to examine the DNA levels of these transgenes. Insert sites include pericentric, telomeric and fourth chromosome regions. Southern blot analyses showed that the heterochromatic hsp26 transgenes are underrepresented 1.3- to 33-fold in polytene tissue relative to the endogenous euchromatic hsp26 gene. In contrast, the heterochromatic hsp26 transgenes are present in approximately the same copy number as the endogenous euchromatic hsp26 gene in diploid tissue. It appears unlikely that DNA loss could account …

The Evaluation Of Succinylcholine Chloride For Harmful Effects Upon Early-Stage Mouse Embryos, Francis Warren Prescott

Biological Sciences Theses & Dissertations

Succinylcholine (SCh) chloride is a depolarizing neuromuscular blocking agent used to paralyze patients for surgical procedures. Over 1,800 clinical observations of newborn infants have demonstrated that succinylcholine does not cross the placenta in quantities detrimental to fetuses (Kolstad, et al., 1957, Bakhoum, et al., 1957, Hodges, et al., 1959, Duffield, et al., 1958, Dennis, et al., 1954, 1956, McNab, 1955, Coleman, et al., 1956, Lund, 1953). Later investigations which involved comparison of blood levels of SCh in the mother to those in fetuses bolstered the finding that SCh fails to cross the placenta in significant amounts (Moya and Kvisselgaard, 1961, …

Heterochromatin And Gene Regulation In Drosophila, Sarah C.R. Elgin

Biology Faculty Research

We have recently learned more about the biochemistry of heterochromatin and about how heterochromatic environments affect gene function. New findings have emphasized the distinctions between telomeric and pericentric heterochromatin in Drosophila and have suggested a mosaic structure within pericentric heterochromatin. Theories concerning the mechanism of inactivation of euchromatic genes in heterochromatic environments have been tested using transgenes inserted into heterochromatin. The current data support a competition/chromatin structure model, in which multiprotein repressor complexes compete with transcriptional activators to assemble an active or inactive chromatin structure.

The Role Of Nitric Oxide In The Modulation Of The Leukocyte-Endothelial Cell Interactions During Ischemia And Reperfusion, Fernando López-Neblina

Masters Theses

Nitric oxide (NO) is involved in several metabolic pathways and physiological phenomena. The role of NO in inflammation after ischemia and reperfusion (I/R) is controversial. The early phases of inflammation include the leukocyte-endothelial (L/EC) cell interactions which have been divided in rolling, activation, adhesion and migration.

The first experiment was to demonstrate the role of NO in a model of renal I/R. We demonstrated that exogenous NO improves survival and renal function tests after renal I/R, while endogenous NO does not appear to be an important contributor to renal I/R. We also demonstrated that NO modulate the infiltration of neutrophils …

Effects Of Insulin And Insulin-Mimetics On Mrna Levels Of C-Fos And C-Jun In Primary Rat Hepatocytes In Culture, Guangmin Li

Masters Theses

Insulin is capable of regulating cellular and metabolic processes as well as gene expression. Selenate and vanadate are two compounds that have been found to mimic the action of insulin in several tissue and cell types. cFos and cJun are the products of immediate early responsive genes c-fos and c-jun. They are members of the family of the AP-1 (Activator Protein-1) transcription factors. AP-1 transcription factors bind as cJun.cJun homodimer or cJun.cFos heterodimer to the TRE found in the promoter regions of several genes. AP-1 is characterized by its ability to alter gene expression in response to various peptide …

Effects Of High-Molecular-Weight Dissolved Organic Matter On Nitrogen Dynamics In The Mississippi River Plume, Wayne S. Gardner, Ronald Benner, Rainer M.W. Amon, James B. Cotner Jr., Joann F. Cavaletto, Jeffrey R. Johnson

Faculty Publications

The dynamics of N and its interactions with labile dissolved organic C (DOC), bacteria, and phytoplankton were studied to determine potential effects of dissolved organic matter (DOM) and light on N dynamics in surface waters of the Mississippi River (USA) plume in the Gulf of Mexico. Bacterial uptake of added labeled N compounds ( ¹⁵NH₄⁺ or ¹⁵N-labeled dissolved free amino acids. DFAA) was stimulated more by high-molecular-weight (HMW, >l kDa) DOM than by low-molecular-weight (LMW, < l kDa) DOM. An index that inversely indicated the presence of labile DOC was defined as the fraction of assimilated Amino acid-¹⁵N that was Recovered as ¹⁵N -Ammonium (ANRA), following the additions of high-levels (4 µM) of ¹⁵N -DFAA. …

Mutagenicity Of Acridines In A Reversion Assay Based On Tetracycline Resistance In Plasmid Pbr322 In Escherichia Coli, George R. Hoffman, Suzanne M. Deschênes, Teresa Manyin, Robert P. P. Fuchs

Biology Faculty Publications

The mutagenicity of a series of acridine compounds was studied in an assay based on the reversion of mutations in the tetracycline-resistance gene (tet) of plasmid pBR322 in Escherichia coli. Mutations that restore the tetracycline-resistant phenotype were detected in tetracycline-sensitive strains carrying mutant plasmids. Mutations that revert by +2, +1, −1, and −2 frameshift mutations and by base-pair substitutions were used to analyze the mutagenicity of two simple acridines, two acridine mustards, and a nitroacridine. The simple acridines (9-aminoacridine and quinacrine) effectively induced −1 frameshifts and weakly induced +1 frameshifts. The acridine mustards (quinacrine mustard and ICR-191) …