Life Sciences Commons^™

Conservation Genetics And Systematics Of Several Turtles Species In The Southeastern United States, Joshua Robert Ennen

Dissertations

Chelonians (i.e., turtles) are an imperiled group of reptiles with about 66% of the recognized species listed as threatened by the IUCN. Most chelonian species have a unique set of life history traits (i.e., longevity, delayed sexual maturity, and low juvenile survivorship), which makes their populations exceedingly sensitive to increases in adult and juvenile moralities. With numerous anthropogenic effects (e.g., habitat alteration, exploitation, and over harvesting) negatively influencing mortality rates, chelonians have experienced global precipitous declines and extinctions.

This dissertation focuses on species within two chelonian genera, Gopherus and Graptemys. Although these two genera are vastly different ecologically, they are …

Remote Sensing Of Harmful Algal Blooms In The Mississippi Sound And Mobile Bay: Modelling And Algorithm Formation, Dan Martin Holiday

Dissertations

The incidence and severity of harmful algal blooms have increased in recent decades, as have the economic effects of their occurrence./The diatom Pseudo-nitzschia spp. caused fisheries closures in Mobile Bay during 2005 due to elevated levels of domoic acid. In the previous 4 years Karenia brevis counts of >5,000 cells L"1 have occurred in Mobile Bay and the Mississippi Sound. Population levels of this magnitude had previously been recorded only in 1996. Increases in human populations, urban sprawl, development of shoreline properties, sewage effluent and resultant changes in NP ratios of discharge waters, and decline in forest and marsh lands, …

Experimental Population Dynamics Of Amyloodiniumocellatum In The Spotted Seatrout, Cynoscion Nebulosus, And The Red Snapper, Lutjanus Campechanus, Ignacio Masson

Dissertations

Amyloodinium ocellatum is a parasitic dinoflagellate that infects warm water marine bony fishes and causes high mortalities in aquaculture settings. It has three life history stages: the feeding trophont, the reproductive tomont, and the infective dinospore. This dissertation describes the characteristics of A. ocellatum infections in juvenile spotted seatrout, Cynoscion nebulosus, and red snapper, Lutjanus campechanus, studies the survival and fecundities of the stages in the life cycle of the parasite and presents a population model for A. ocellatum.

At 25°C and 33 ppt, the peak of trophont detachment occurred on day 2 postinfection in spotted seatrout and day 3 …

Maternally Derived Antibodies In Avian Eggs And Offspring: Ecology, Life History, And Development, Brianne Ashley Addison

Dissertations

Mothers can alter offspring phenotypes through a variety of indirect effects, including the deposition of nutrients, hormones, and defense proteins in to the egg. Defense proteins, and antibodies in particular, may be tremendously important for neonatal defense against pathogens and the direction of resources into growth rather than immune responsiveness. Moreover, maternally derived immunoglobulins have been proposed to have an imprinting effect on the development of humoral immunity. In my dissertation, I explored a variety of ecological, life history, and developmental factors that could contribute to the evolution of yolk antibody allocation in a variety of avian species. In the …

Sport As A Vehicle For Socialization And Maintenance Of Cultural Identity: International Students Attending American Universities, James Taylor Allen

Dissertations

Sport can be utilized by immigrants as a vehicle for maintaining cultural identity. Conversely, sport participation provides immigrants with opportunities for adopting an entirely new culture. Previous research also suggests that sport provides individuals with opportunities for attaining social capital. While this can be a beneficial situation for some, sport is also promoting elitism and serving as a powerful mechanism for exclusion. Globalization has led large numbers of foreign nationals to seek educational opportunities in the United States. Due to the increase in the number of international students and the lack of empirical studies, the need to study their participation …

Bridging Functional Genomics And Toxicogenomics Through Dna Microarrays In A Fish Model, Shuzhao Li

Dissertations

In a case study of finding gene expression signatures for environmental stressors in Cyprinodon variegatus, this dissertation examines several important issues of applying DNA microarray technology to fish toxicogenomics. The most relevant disciplines, fish toxicogenomics and computational systems biology are reviewed in Chapter 1. Chapter 2 reviews major aspects of DNA microarray technology.

On DNA microarrays, even for probes that target the same transcript, large variations are seen in the probe signals. These variations are partly dependent and partly independent on probe sequences. Chapter 3 estimates the sequence independent variation by combining experimental and computational approaches. Chapter 4 and …

Reverse Engineering Of Gene Regulatory Networks For Discovery Of Novel Interactions In Pathways Using Gene Expression Data, Tanwir Habib

Dissertations

A variety of chemicals in the environment have the potential to adversely affect the biological systems. We examined the responses of Rat (Rattus norvegicus) to the RDX exposure and female fathead minnows (FHM, Pimephales promelas) to a model aromatase inhibitor, fadrozole, using a transcriptional network inference approach. Rats were exposed to RDX and fish were exposed to 0 or 30mg/L fadrozole for 8 days. We analyzed gene expression changes using 8000 probes microarrays for rat experiment and 15,000 probe microarrays for fish. We used these changes to infer a transcriptional network. The central nervous system is remarkably plastic in its …

Inferring Gene Regulatory Networks From Time Series Microarray Data, Peng Li

Dissertations

The innovations and improvements in high-throughput genomic technologies, such as DNA microarray, make it possible for biologists to simultaneously measure dependencies and regulations among genes on a genome-wide scale and provide us genetic information. An important objective of the functional genomics is to understand the controlling mechanism of the expression of these genes and encode the knowledge into gene regulatory network (GRN). To achieve this, computational and statistical algorithms are especially needed.

Inference of GRN is a very challenging task for computational biologists because the degree of freedom of the parameters is redundant. Various computational approaches have been proposed for …

The Relationship Between Calcium Intake, Obesity, And Cardiovascular Disease Risk Factors: The Jackson Heart Study, Marjuyua Lartey-Rowser

Dissertations

Cardiovascular disease (CVD) is a major health risk in the United States. Major indicators of CVD risk include obesity, blood lipids, and blood pressure. Modifiable risk factors associated with CVD include body composition (body mass index and waist circumference), serum lipids, and blood pressure. Data suggest calcium intake may play a role in regulation of weight, serum lipids, and blood pressure. The purpose of this study was to assess relationships of dietary calcium intake with weight status, and cardiovascular disease risks in African American population participating in the Jackson Heart Study.

The subjects included 4,267 African American adults ages 21-95 …

Factors Influencing The Environmental Quality Of The Bay Of Saint Louis, Mississippi And Implications For Evolving Coastal Management Policies, Pradnya Ankush Sawant

Dissertations

The Bay of St. Louis, MS is a small northern Gulf of Mexico estuary that has been identified by the Mississippi Department of Environmental Quality (MDEQ) as an impaired waterbody for its designated uses, mainly due to the presence of pollutant pathogens. A systematic study of this estuary was important to understand the behavior and responses of the bay to several natural and anthropogenic forcing factors. A 14- month long study (bimonthly sampling) to evaluate its environmental quality was undertaken from April 2003 to May 2004. Environmental quality was defined as "the health of an ecosystem characterized in terms of …

Sexual Selection In A Species With Exploded Leks: The White-Crowned Manakin (Pipra Pipra), Wendy P. Tori

Dissertations

Understanding what determines male reproductive success is central to sexual selection theory. The main goal of this dissertation was to examine the processes that shape female mate choice and male reproductive success in an exploded lek species: the White-crowned Manakin (Pipra pipra). The first chapter examined if females select males with certain genetic characteristics to gain indirect fitness benefits. Specifically, it tested whether females preferentially mate with unrelated males or males with high overall heterozygosity to increase the genetic diversity of their offspring. The second chapter examined if food resources within territories affect male mating success of territory …

Puf1p-Mediated Mrna Decay And Combinatorial Control Of Mrna Stability By The Yeast Puf Proteins, Randi J. Ulbricht

Dissertations

The stability of a messenger RNA (mRNA) is a highly regulated and important aspect of gene expression. Proteins that regulate mRNA stability often bind to 3' untranslated region (UTR) sequence elements. The eukaryotic Puf proteins are one class of 3'UTR binding proteins that regulate the stability and expression of their target transcripts. Several global genome analyses have identified hundreds of potential mRNA targets of the Saccharomyces cerevisiae Puf proteins, however only three mRNA targets for these proteins have been characterized thus far. After direct testing of nearly forty candidate mRNAs, I have established three of these as true mRNA targets …

Evolution And Maintenance Of Plumage Polymorphism: The Case Of The Red-Footed Booby (Sula Sula), Patricia Carvalho Baiao

Dissertations

The red-footed booby (Sula sula) is considered one of the most polymorphic seabirds, with three recognized major adult plumage types: (1) white; (2) white-tailed brown; and (3) brown, and several degrees of intermediates. The ratio of these color morphs varies among populations, with the white morph typically predominating. However, there are a few populations that present an inversed ratio of color morphs, such as Isla Europa in the Indian Ocean and the Galapagos archipelago, with the white-tailed brown or brown morphs predominating. I studied natural populations of red-footed boobies from three geographic locations, namely, the Galapagos archipelago, Johnston Atoll in …

Closing The Seed Dispersal Loop For Guettarda Viburnoides (Rub.): Connecting Patterns Of Avian Seed Dispersal With Population Growth In A Neotropical Savanna, Andrea Patricia Loayza

Dissertations

This study connects data on frugivore activity, post-dispersal seed fate and plant population demography using stage-specific demographic modeling to examine the role of individual dispersers for plant population dynamics of the fleshy-fruited Neotropical tree Guettarda viburnoides (Rubiaceae) in northeastern Bolivian savannas. Detailed information on frugivory and seed dispersal of G. viburnoides reveals that the endocarps of this plant are dispersed mainly by two species of birds: Cyanocorax cyanomelas and Pteroglossus castanotis, which are defined as the quantitatively important dispersers of G. viburnoides. These two species differ in several qualitative aspects of seed dispersal: 1) They select fruits of …

Tritrophic Interactions In Forests: Direct And Indirect Interactions Between Birds, Insect Herbivores, And Oaks, Nicholas Anthony Barber

Dissertations

This study examines direct and indirect relationships between three trophic levels to determine effects on plant damage, herbivore abundance and community structure, and bird distribution in forest ecosystems. Exclusion experiments on white oak (Quercus alba) revealed that bird predation effects to not vary spatially despite variation in abundance of both birds and insects. Using a leaf quality manipulation, I demonstrated that bird impacts do not differ with host plant quality. Rather, birds and plant traits had additive effects on herbivore damage. Bottom-up effects of leaf quality were also more important than top-down effects of birds in structuring the insect herbivore …

Oceanic-Atmospheric Modes Of Variability And Their Effect On River Flow And Blue Crab (Callinectes Sapidus) Abundance In The Northcentral Gulf Of Mexico, Guillermo Humberto Sanchez-Rubio

Dissertations

Oceanic-atmospheric modes of variability occur on interdecadal, multidecadal, decadal, and interannual timescales and their influence on climate around the world has been confirmed. The present study investigates Mississippi River and Pascagoula River flows in response to the influence of one or more of the four oceanic-atmospheric modes of variability: the Pacific Decadal Oscillation (PDO), the Atlantic Multidecadal Oscillation (AMO), the North Atlantic Oscillation (NAO), and the El Nino Southern Oscillation (ENSO). These modes of variability are present in phases: PDO warm (PDOw) and cold (PDOc), AMO warm (AMOw) and cold (AMOc), NAO positive (NAOp) and negative (NAOn), and ENSO warm …

The Effects Of Dolphin Education Programs On Visitors' Conservation-Related Knowledge, Attitude And Behavior, Lance Joseph Miller

Dissertations

Zoological institutions typically exhibit dolphins in educational programs such as dolphin shows and interaction programs. The goal of these programs is to entertain visitors while increasing their conservation-related knowledge, attitude and behavior towards dolphins and the marine environment. The purpose of the current study was to examine dolphin shows and interaction programs in terms of their effectiveness in meeting these goals. A multi-institutional study was conducted at six different facilities throughout the United States. A repeated measures design was used to examine the knowledge, attitude and behavior of visitors before, immediately after and three months following participation in dolphin shows …

The Effects Of Climate Variability On The Structure Of The Phytoplankton Community In Tumaco Bay, Colombia, Ingrid Garcia-Hansen Honkala

Dissertations

Spatiotemporal variability in the diatom and dinoflagellate community structure and chlorophyll a (chl a) concentrations in Tumaco Bay during the 1993-2005 period was related clearly to seasonal and interannual variability in environmental conditions due to the migration of the Inter-tropical Convergence Zone (ITZC) and the influence of El Nino Southern Oscillation (ENSO) events. A total of 134 species of diatoms that belong to 57 genera, and 78 species of dinoflagellates that belong to 25 genera were identified during the survey. The diatom community was the dominant group in the waters of the bay, being the most abundant with the greatest …

Regulation Of Transglutaminase By 5-Ht2a Receptor Signaling And Calmodulin, Ying Dai

Dissertations

Transglutaminase (TGase), nature’s biological glue, catalyzes the post-translational modification of proteins by formation of intra- and intermolecular protein cross-links or by primary amine incorporation. TGase has various physiological functions, such as skin-barrier formation and blood clot stabilization, whereas increasing evidence indicates they may also involved in neurodegenerative diseases including Huntington’s disease (HD), Alzheimer disease’s, and progressive supranuclear palsy. Mutant huntingtin (htt) and small G proteins (e.g. Rac 1) are potential substrates of TGases. The purpose of this dissertation was to characterize the mechanisms by which 5-HT2A receptor signaling and calmodulin (CaM) regulate TGase-catalyzed transamidation of Rac1 and htt in cultured …

A Rat Model Examining Behavioral And Neurochemical Effects Of Passive Exposure To Aggression On Observers, Hideo Suzuki

Dissertations

Previous studies have consistently reported that passive exposure to aggression is a risk of aggressive inclinations for a human witness. However, it is unclear whether a witness' aggressiveness is semi-permanently socialized or temporarily primed. Furthermore, a neurochemical mechanism of passive exposure to aggression also remains unaddressed in clinical literature. The present research used a rat model to clarify the behavioral and neurochemical effects of passive exposure to aggression. First, rats were screened for their aggressiveness after they were acutely or chronically exposed to aggression or non-aggression. It was found that observer rats chronically exposed to aggression exhibited more aggression than …