Life Sciences Commons^™

Effects Of Elevated Atmospheric Co2 On Root Growth, Turnover And Decomposition In A Scrub Oak Ecosystem, John Joseph Dilustro

Biological Sciences Theses & Dissertations

Atmospheric carbon dioxide levels are increasing and predicted to double this century. The implications of this rise on vegetation structure and function are not well understood. Measurement of root growth response to elevated atmospheric carbon dioxide is critical to understanding soil carbon input. I investigated the effects of elevated carbon dioxide on fine root growth and decomposition using open top chambers with both ambient and elevated (700 PPM) CO₂ treatments in an oak-palmetto scrub ecosystem at Kennedy Space Center, Florida. Minirhizotron tubes were installed in each elevated and control chamber to allow observation of roots. Each tube was sampled …

Investigations On The Use Of Ion Mobility Spectrometry For Clinical Chemistry Applications, Henri Parson Patten

Theses and Dissertations in Biomedical Sciences

The major objective of this research is to examine ion mobility spectrometry as a rapid screening tool for specific application to clinical chemistry research and laboratory use. Methodology was developed for target analytes representing several classes of physiologically active substances, including anesthetics, illicit drugs, and their metabolites. The IMS characteristics of animal tissues and other compounds such as amino acids and proteins were determined. Quality assurance and control procedures were developed for specific quality data objectives. Criteria were established relating to use of IMS for assessing the precision and accuracy of data, qualitative screening, and semi-quantitative analyses.

It was found …

A Taxonomic Evaluation Of The Comatulid Genus Stephanometra (Echinodermata:Crinoidea), Dana Lin Rankin

HCNSO Student Theses and Dissertations

Several genera in the comatulid family Mariametridae are currently ambiguously distinguished on the basis of variations in length and robustness of oral pinnules. Previous descriptions have suggested that at least the genera Stephanometra and Lamprometra are imperfectly distinguishable. A detailed re-examination of morphology coupled with principal component analyses of morphometric data and cladistic analyses provide support for a monophyletic Stephanometra distinct from Lamprometra. A preliminary morphological analysis suggests that Dichrometra and Liparometra should be synonymized with Lamprometra. The six currently recognized species of Stephanometra uniquely share at least one pair of oral pinnules characterized by enlarged size, reduced ambulacral groove …

Studies On The Roles Of Atp In Nitrogenase Catalysis, Wei Wu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrogenase is the enzyme that catalyzes the reduction of nitrogen to ammonia in a reaction requiring MgATP hydrolysis. Two component proteins of nitrogenase are the iron protein (Fe protein) and the molybdenum-iron protein (MoFe protein).

Nitrogenase contains two nucleotide binding sites. During catalysis, the Fe protein binds two MgATP first. The conformational changes induced upon MgATP binding allow the Fe protein to associate with the MoFe protein. After the formation of the Fe protein-MoFe protein complex, a single electron is transferred from the Fe protein to the MoFe protein, an event that is coupled to MgATP hydrolysis in the Fe …

Responses Of Sphagnum And Carex Peatlands To Ultraviolet-B Radiation, And A Meta-Analysis Of Uv-B Effects On Vascular Plants, Peter S. Searles

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The severity of stratospheric ozone depletion in the temperate and polar latitudes has raised concerns about the sensitivity of terrestrial vegetation and ecosystems to solar ultraviolet (UV-B) radiation. This dissertation examined the responses of plants and microbes to solar UV-B for 3 years in Tierra del Fuego, Argentina (55° S). This region is under the influence of the Antarctic "ozone hole" during the austral spring. Additionally, a quantitative review of the UV-B literature was conducted using a set of statistical techniques known as meta-analysis.

For the field studies in Tierra del Fuego, plots were established in a Sphagnum moss peatland …

Green Sea Turtle (Chelonia Mydas) Hatchlings Success: The Effects Of Artificial Lights And Other Human Impacts, Hui-Yu Tracy Liang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Sea turtles appeared more than 200 million years ago in the late Triassic period. They grow very slowly, taking an average of 25 years to reach sexual maturity, with a life span averaging 40-50 years. From May to October green sea turtles (Chelonia mydas) emerge during the night and follow light cues toward the sea. Recently, beachfront development has increased hatchling mortality rate. When hatchlings emerge from nest, high densities of artificial lights lead them toward the land where they either desiccate and die, or are preyed upon. Short-wavelength high intensity light and the distance of artificial light are the …

Diffusion Problems In Wound Healing And A Scattering Approach To Immune System Interactions, Julia Suzanne Arnold

Mathematics & Statistics Theses & Dissertations

A theoretical model for the existence of a Critical Size Defect (CSD) in certain animals is the focus of the majority of this dissertation. Adam [1] recently developed a one-dimensional model of this phenomenon, and chapters I–V address the exist the CSD in a two-dimensional model and a three-dimensional model. The two dimensional (or 1-d circular) model is the more appropriate for a study of CSD's. In that model we assume a circular wound of uniform depth and develop a time-independent form of the diffusion equation relevant to the study of the CSD phenomenon. It transpires that the range of …

A Longitudinal Assessment Of Temperament In Octopus Bimaculoides, David Loyd Sinn

Dissertations and Theses

Cephalopods, including Octopus spp., are highly intelligent molluscs that play major roles in many marine food webs, both as top-level feeders (Ambrose, 1984) as well as by constituting a major source of protein for the animals above them (Lang, Hochberg, Ambrose, & Engle, 1997). They also are fascinating organisms for behavioral studies, with elaborate repertoires of behavior based on plasticity and learning (Wells, 1962a; 1962b; 1978) which in complexity rivals that of the vertebrates. The study of individual differences in behavior is a facet of behavioral research that has recently gained attention in the literature (Gosling & John, 1999). Traditionally, …

Chromate Dissociation From Primer Paint In Simulated Lung Fluid, Tiffany J. R. Morgan

Theses and Dissertations

OSHA has proposed a new strontium chromate exposure standard that would potentially cause Air Force paint facilities to be in violation of the proposed standard if adopted. This proposed reduction make the continued use of chromate containing primer paints very difficult. There is currently no acceptable replacements for chromate containing primer paints on AF aircraft. This study suggests that paint particles with chromate bound in primer paint may be unavailable for bodily absorption if inhaled and a reduced standard for painting applications may be unnecessary. Primer paint overspray was collected into simulated lung fluid (SLF) and allowed 6 hr, 24 …

Mapping The Boulder City Wetlands Using A Global Positioning System (Gps) And A Geographic Information System (Gis), Jennifer Lea Bishop

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Boulder City Wetlands is a constructed wetlands park located in Boulder City, Nevada, approximately 23 miles southeast of Las Vegas, Nevada. Currently, a baseline study of water quality is being conducted in the Boulder City Wetlands. This baseline study of the wetlands is an important step in understanding the development of the Boulder City Wetlands over time. As wastewater is eventually introduced into the existing community tap water running through the wetlands, it is expected that the nitrogen within the water will enhance the growth of vegetation in the surrounding area. Comparing the vegetation growth over time is only …

Bioremediation Of Tributyltin Contaminated Sediment Using Spartina Alterniflora In A Created Tidal Wetland, Britt-Anne Anderson

Dissertations, Theses, and Masters Projects

No abstract provided.

Organic Matter Composition Of Sediments And The History Of Eutrophication And Anoxia In The Mesohaline Chesapeake Bay, Andrew R. Zimmerman

Dissertations, Theses, and Masters Projects

To evaluate the effects of anthropogenic alteration of the Chesapeake Bay (CB) watershed since European settlement, the historical progression of eutrophication and anoxia in the mesohaline region of CB was reconstructed. Lipid biomarker and carbon and nitrogen stable isotopic and elemental composition of CB surficial sediments were examined seasonally in order to identify the present sources of organic matter to CB sediments and the processes controlling their distribution. Temporal variability in surficial sediment composition could be linked to seasonal changes in phytoplankton community composition and biomass while spatial variation was dominated by the delivery of alloclithonous versus autochthonous sources of …

Effects Of Polychlorinated Biphenyl Exposure On Development And Sexual Differentiation In Ranid Tadpoles, Mary J. Rybitski

Dissertations, Theses, and Masters Projects

The effects of AroclorRTM1242 exposure on developing amphibians were examined by exposing southern leopard frogs, Rana sphenocephala, to a contaminated diet throughout the larval period. Treatment groups consisted of an untreated control, a solvent control, 17beta-estradiol, and three PCB doses (10, 100, and 1000 mug/g). PCB accumulation and biotransformation were examined. Effects of PCB exposure on metamorphosis and sexual differentiation were assessed. PCB accumulation was not statistically different between the egg masses. Levels of PCBs in the tissues differed in a dose related manner. Within treatments, body weight appeared to be the major factor correlated with PCB concentration. Congener patterns …

Applications Of The Atomic Force Microscope Within The Fields Of Haematology And Cytogenetics, Margaret O'Reilly-Crowley

Theses

Atomic force microscopy [AFM] has become a rapidly developing interdisciplinary field of research in recent years. The technique, including instrumentation and specimen preparation methods, is now more sophisticated and its application has increased dramatically. The key advantage of AFM is in providing three-dimensional images of samples imaged. Both size and shape of samples imaged can be obtained allowing their subsequent quantification. Red blood cells [RBCs] and chromosomes were imaged in this work. A brief overview of the current status of biomedical AFM, has been presented in the review.

Measurement of mean cell volume [MCV] of immobilised red blood cells with …

The Human Factor In Size Selectivity In The Sea Scallop, Placopecten Magellanicus Fishery, Arman O. Kaltayev

Dissertations, Theses, and Masters Projects

No abstract provided.

Synoptic Scale Climatic Forcing Of Multispecies Fish Recruitment Patterns In Chesapeake Bay, Robert J. Wood

Dissertations, Theses, and Masters Projects

Five fishery independent data sets were used to investigate multispecies fish recruitment patterns in Chesapeake Bay (1966--1997). Despite differences in sampling gear, sampled habitat, collection methods, and sampling sites, the strongest multispecies recruitment patterns within each data set (revealed by separate principal components analyses) depict a negative relationship between recruitment of spring spawning anadromous fishes and fall-winter continental shelf spawning species. This pattern dominates both low and high frequency components of the multispecies data. Because these two species groups utilize freshwater and oligohaline reaches of the Bay and its tributaries as springtime nursery areas, this Chesapeake Bay Anadromous-Shelf Spawner (CBASS) …

Biology Of The Spotted Seatrout, Cynoscion Nebulosus, In The Chesapeake Bay Region, Thomas F. Ihde

Dissertations, Theses, and Masters Projects

No abstract provided.

Seasonal Residence, Movement, And Activity Patterns Of Adult Tautog, Tautoga Onitis, In Lower Chesapeake Bay, Michael D. Arendt

Dissertations, Theses, and Masters Projects

No abstract provided.

Maturation And Repeat Spawning By American Shad In The York River, Virginia, Kristin L. Maki

Dissertations, Theses, and Masters Projects

No abstract provided.

A Determination Of Parentage, Mating System, And Genetic Diversity In A Captive Population Of The Straw-Colored Fruit Bat (Eidolon Helvum), Jan Zinck

Dissertations and Theses

Small populations tend to lose genetic variability. The magnitude of this loss is influenced by the number of founding individuals, the genetic diversity of the founders, and the species mating system. Genetic variability is the basis of adaptive evolution, and the loss of genetic variability may have harmful effects on development, growth, and survival. Therefore, a primary management goal for small, captive populations is the retention of genetic variability. Of considerable importance to conservation biology is the determination of parentage, from which mating, genetic, and demographic information can be derived. Microsatellites provide a robust molecular evolutionary tool for the study …

The Growth And Distribution Of The Green Alga Cladophora At Presqu'ile Provincial Park: Implications For Management (Ontario), Dolf Craig Dejong

Theses and Dissertations (Comprehensive)

The Green alga genus Caldophora is one of the most abundant kinds of algae worldwide, found in both freshwater and marine environments. It prefers nutrient-rich waters and requires a rocky substrate and water movement for growth. When water temperatures reach 22 to 26 C, the alga dies and washes into shore in large mats. Dead Cladophora produces a terrible odour, reduces property values and can alter the taste of drinking water. At Presqu’ile Provincial Park, maximum Cladophora sloughing occurred July 22 1999, the same time as peak summer park visitation begins. This results in the fouling of the Park’s beaches …

Predicting Milk And Soft Drink Consumption Among Female Adolescents Using The Theory Of Planned Behavior, Nada Osman Kassem

Loma Linda University Electronic Theses, Dissertations & Projects

A total of 756 female adolescents, aged 13 to 18 years, from five public high schools in Antelope Valley Union High School District located in North Los Angeles County participated in this study between February 1999 and March 1999. The ethnic composition was 53.3% White/Anglo Americans, 19.3% Hispanics or Latinos and 10.2% Black/African Americans. The constructs of the Theory of Planned Behavior (attitude, subjective norm, and perceived behavioral control and their underlying beliefs) were assessed to determine the predictors of low-fat milk and regular soda consumption. A cross-sectional design with group-administered questionnaires was utilized.

Most participants (89.6%, n = 636) …

The Habitat Utilization Of Juvenile Hawksbill Sea Turtles (Eretmochelys Imbricata) At Buck Island Reef National Monument, St Croix, U.S Virgin Islands, Roy A. Pemberton

Dissertations, Theses, and Masters Projects

No abstract provided.

Application Of Genetic Markers To Provide Species Identification And Define Stock Structure: Analyses Of Selected Marine Fishes Of The Mid -Atlantic Bight, Jan F. Cordes

Dissertations, Theses, and Masters Projects

Molecular markers and techniques were employed to develop a genetic key for the forensic identification of 16 species of Chesapeake Bay sportfishes and to investigate the stock structure of one of those species, the weakfish Cynoscion regalis. Regions within the ATP synthetase 6 (ATPase 6), Cytochrome b , cytochrome c oxidase I, NADH dehydrogenase 4 (ND4), and 12S/16S ribosomal RNA mitochondrial genes were amplified using the polymerase chain reaction (PCR) and digested with a bank of restriction endonucleases to find a genetic marker that exhibited complete interspecific differentiation and low intraspecific variation. Complete separation of all sixteen species was accomplished …

Photosynthetic Response And Nutrient Uptake Dynamics Of Phytoplankton In The Ross Sea, Antarctica, Christina Marie Van Hilst

Dissertations, Theses, and Masters Projects

No abstract provided.

A Framework For Construction And Analysis Of Juvenile Abundance Indices For American Shad (Alosa Sapidissima) In The York River, Virginia, Mary Lynn Aiken

Dissertations, Theses, and Masters Projects

No abstract provided.

Characterization Of Iron-Bearing Solids Used By Naturally-Occurring Microbes In The Anaerobic Degradation Of Hydrocarbons, David C. Powell

Dissertations, Theses, and Masters Projects

No abstract provided.

Population Dynamics Of The Smooth Dogfish, Mustelus Canis, In The Northwest Atlantic, Christina L. Conrath

Dissertations, Theses, and Masters Projects

No abstract provided.

Carbon Dynamics In A Tidal Freshwater Marsh, Scott C. Neubauer

Dissertations, Theses, and Masters Projects

The sources and fates of carbon in a tidal freshwater marsh (Sweet Hall marsh; Pamunkey River, Virginia) were determined to understand the role that these marshes play with respect to estuarine carbon cycling. A carbon gas flux model, based on measured carbon dioxide and methane fluxes, was developed to calculate annual rates of macrophyte and microalgal photosynthesis and community and belowground respiration. Because carbon fluxes out of marsh sediments may underestimate true belowground respiration if sediment-produced gases are transported through plant tissues, gross nitrogen mineralization was used as a proxy for belowground carbon respiration. Annual community respiration exceeded gross photosynthesis, …

Assessment Of Spawning And Nursery Habitat Suitability For American Shad (Alosa Sapidissima) In The Mattaponi And Pamunkey Rivers, Donna Marie Bilkovic

Dissertations, Theses, and Masters Projects

Delineation of essential fish habitat is particularly difficult for migratory fish which utilize large expanses of habitat throughout their life history. This study's main objective was the development and evaluation of habitat assessment tools for the early life stages of American shad (Alosa sapidissima) in two coastal plain rivers. to accomplish this, shad spawning and larval nursery habitats were delineated in the Mattaponi and Pamunkey rivers using presence of eggs and larvae (1997--1999) as evidence of habitat use. A watershed habitat assessment protocol was developed and used to rate habitat based on hydrographic, physical habitat, shoreline and land use parameters. …