Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 20 of 20

Full-Text Articles in Life Sciences

Evolution And Functional Morphology Of The Cephalic Lobes In Batoids, Samantha Lynn Mulvany Dec 2013

Evolution And Functional Morphology Of The Cephalic Lobes In Batoids, Samantha Lynn Mulvany

Graduate Theses and Dissertations

Cephalic lobes are unique structures derived from the anterior pectoral fins, found in select myliobatid stingrays. Many benthic batoids utilize undulatory locomotion and use their pectoral fins for both locomotion and prey capture. Pelagic myliobatids that possess cephalic lobes utilize oscillatory locomotion, using their pectoral fins to locomote and their cephalic lobes for prey capture. Despite differences in habitat usage and locomotor modes, these batoids feed on very similar benthic organisms. The purpose of this study was to 1.) compare the morphology of the cephalic lobes and anterior pectoral fins in lobed and lobeless species, looking at skeletal elements, musculature ...


Use Of Stable Isotope And Trace Metal Signatures To Track The Emigration Of Female Blue Crabs, Callinectes Sapidus, From Tampa Bay, Sky Barrington Williams Jan 2013

Use Of Stable Isotope And Trace Metal Signatures To Track The Emigration Of Female Blue Crabs, Callinectes Sapidus, From Tampa Bay, Sky Barrington Williams

Graduate Theses and Dissertations

The blue crab, Callinectes sapidus, supports a successful fishery in the Atlantic Ocean and throughout the Gulf of Mexico, with a total landing of 8,158,788 lb. and a total value of $10,562,128 for the state of Florida during 2012 (FWC 2012 Annual Landings Summary). An accurate and comprehensive understanding of the blue crab's life history and seasonal migration behavior is essential in defining effective management strategies for the fishery. Tag recapture studies and ultrasonic tracking methods for studying blue crab migrations are costly in terms of time and resources. In this study an alternative approach ...


The Mevalonate Pathway: A Potential Therapeutic Target For Jak2-Driven Myeloproliferative Neoplasms, Lori Nicole Griner Jan 2013

The Mevalonate Pathway: A Potential Therapeutic Target For Jak2-Driven Myeloproliferative Neoplasms, Lori Nicole Griner

Graduate Theses and Dissertations

The Mevalonate Pathway: A Potential Therapeutic Target for JAK2-driven Myeloproliferative Neoplasms

Lori Nicole Griner

Abstract

Myeloproliferative neoplasms (MPNs) are diseases of hematopoietic stem cell origin and are characterized by uncontrolled growth of cells of the myeloid compartment. The Philadelphia chromosome negative classical MPNs, including polycythemia vera, essential thrombocythemia, and myelofibrosis, are diseases of dysregulated JAK2 signaling. In fact, the majority of MPN patients have activating mutations in JAK2 (e.g JAK2-V617F), a tyrosine kinase that contributes to the growth and survival of myeloid cells. While MPNs were first described over sixty years ago, a significant need remains to develop therapeutic ...


Growth And Herbivory Of The Black Mangrove, Avicennia Germinans, Along A Salinity Gradient, Danielle Neveu Jan 2013

Growth And Herbivory Of The Black Mangrove, Avicennia Germinans, Along A Salinity Gradient, Danielle Neveu

Graduate Theses and Dissertations

Coastal communities will be most affected by global climate change and are important to study to understand current and future ecological processes. The current model for global climate change predicts a change in rainfall, which will alter the salinity of coastal systems. Given the presence of eutrophication in many coastal waters, it is important to understand the effects that this increase in nutrients, coupled with changes in salinity, will have on these communities. This study was conducted to understand the effect of salinity increase on the growth and herbivory of the black mangrove, Avicennia germinans, in the presence of increased ...


Predation, Competition, And Nutrient Levels Affect The Survival Of Escherichia Coli, Enterococci And Enteric Pathogens In Aquatic Habitats, Pauline Wanjugi Jan 2013

Predation, Competition, And Nutrient Levels Affect The Survival Of Escherichia Coli, Enterococci And Enteric Pathogens In Aquatic Habitats, Pauline Wanjugi

Graduate Theses and Dissertations

Fecal indicator bacteria (FIB) such as Escherichia coli and enterococci are used to assess microbiological water quality in recreational waters worldwide. FIB are used with the assumption that their presence correlates with that of fecal-associated pathogens in recreational waters. In aquatic habitats, several factors can interfere with the predictive relationship between FIB and pathogens including extended survival of FIB in secondary habitats such as sediment, vegetation and sand. Furthermore, many biotic (e.g. predation from bacterivorous protozoa and competition from indigenous bacteria) and abiotic factors (e.g. temperature, salinity, ultraviolet (UV) light irradiation, and nutrient availability) can influence the fate ...


Net Effects Of Batrachochytrium Dendrobatidis (Bd) And Fungicides On Anurans Across Life Stages, Jenise Brown Jan 2013

Net Effects Of Batrachochytrium Dendrobatidis (Bd) And Fungicides On Anurans Across Life Stages, Jenise Brown

Graduate Theses and Dissertations

Amphibians are declining at alarming rates globally. Multiple factors contribute to these declines, including chemical contaminants and emergent diseases. In recent years, agrochemical use, especially fungicide applications, has increased considerably. Previous studies have demonstrated that these agrochemicals leave application sites and enter wetlands via runoff and have detrimental effects on non-target organisms. For example, exposure to contaminants can have multifarious effects on amphibians, such as reducing their ability to deal with a secondary stressor, such as disease.

A pathogen that is found concomitant with chemical contaminants in aquatic systems is Batrachochytrium dendrobatidis (Bd). Bd has decimated amphibian populations worldwide. Susceptibility ...


An Investigation Of The Factors Leading To Invasion Success Of Non-Native Plants Using A System Of Native, Introduced Non-Invasive, And Invasive Eugenia Congeners In Florida, Kerry Bohl Jan 2013

An Investigation Of The Factors Leading To Invasion Success Of Non-Native Plants Using A System Of Native, Introduced Non-Invasive, And Invasive Eugenia Congeners In Florida, Kerry Bohl

Graduate Theses and Dissertations

The overwhelming majority of plant species introduced into a new range never become invasive. Consequently, identification of factors allowing the small fraction of successful invaders to naturalize, increase in abundance, and displace resident species continues to be a key area of research in invasion biology. Of the considerable number of hypotheses that have been proposed to resolve why some plant species become noxious pests, the enemy release hypothesis (ERH) is one of the most commonly cited. The ERH maintains that invasive plants succeed in a new range because they are no longer regulated by their coevolved natural enemies, and this ...


Ecological Interactions Influencing Avicennia Germinans Propagule Dispersal And Seedling Establishment At Mangrove-Saltmarsh Boundaries, Jennifer Mcclain Peterson Jan 2013

Ecological Interactions Influencing Avicennia Germinans Propagule Dispersal And Seedling Establishment At Mangrove-Saltmarsh Boundaries, Jennifer Mcclain Peterson

Graduate Theses and Dissertations

Mangroves and saltmarshes are ecologically important coastal ecosystems; unfortunately, these low-lying coastal ecosystems are vulnerable to global climate change. As sea-levels rise, mangroves are expected to shift their distribution landward towards higher elevation sites that are occupied by other plants, including saltmarsh taxa. Therefore, mangrove recruits at the leading edge of expansion may interact with diverse assemblages of saltmarsh plants, and these interactions could influence the success of mangrove encroachment into higher tidal-elevation areas. The purpose of the research presented here was to investigate empirically the ecological interactions that may influence the recruitment of the black mangrove, Avicennia germinans, into ...


Resistance And Tolerance To Trematode Parasites In Larval Anurans, Brittany Sears Jan 2013

Resistance And Tolerance To Trematode Parasites In Larval Anurans, Brittany Sears

Graduate Theses and Dissertations

Nearly every species on the planet has at least one parasite, which, by definition, incurs a

cost in the host. Therefore, organisms must resist parasites - preventing or reducing infections -

or tolerate parasites - reducing the costs of infection - in order to maintain their fitness despite

the presence of parasites. Here, I investigated: 1) whether parasitic, larval trematodes (cercariae)

can detect the least resistant tadpole host species, 2) a hypothetical framework for how host life

history impacts the utilization of inflammation and thus, resistance and tolerance, 3) whether a

common anesthesia technique used in experimental infections immunocompromises tadpoles, 4)

the relationship between ...


The Effects Of Scaling On Bite Force And Suction Index In The Eastern Hellbender (Cryptobranchus Alleganiensis), Nicholas Patrick Larghi Jan 2013

The Effects Of Scaling On Bite Force And Suction Index In The Eastern Hellbender (Cryptobranchus Alleganiensis), Nicholas Patrick Larghi

Graduate Theses and Dissertations

The hellbender (Cryptobranchus alleganiensis) is a salamander that grows over a large range of body sizes (2-74 cm total length) making it an ideal organism for examining the effects of body size on morphology and performance. The goal of this study is to investigate the morphology changes over ontogeny and change in

feeding ability. Cryptobranchus feeds on small aquatic insects as juveniles and shifts to crayfish as they get larger. Morphology can be expected to change as an organism grows larger, and because morphology and performance are closely linked, this morphological change can result in a change in feeding ability ...


Structure, Dynamics, And Evolution Of The Intrinsically Disordered P53 Transactivation Domain, Wade Michael Borcherds Jan 2013

Structure, Dynamics, And Evolution Of The Intrinsically Disordered P53 Transactivation Domain, Wade Michael Borcherds

Graduate Theses and Dissertations

in numerous disease states, including cancers and neurodegenerative diseases. All proteins are dynamic in nature, occupying a range of conformational flexibilities. This inherent flexibility is required for their function, with ordered proteins and IDPs representing the least flexible, and most flexible, respectively. As such IDPs possess little to no stable tertiary or secondary structure, they instead form broad ensembles of heterogeneous structures, which fluctuate over multiple time scales. Although IDPs often lack stable secondary structure they can assume a more stable structure in the presence of their binding partners in a coupled folding binding reaction.

The phenomenon of the dynamic ...


Phenotypic Characterization Of The Pancreatic-Derived Factor (Pander) Knockout Mouse On Pure C57bl/6 Background, Shari Moak Jan 2013

Phenotypic Characterization Of The Pancreatic-Derived Factor (Pander) Knockout Mouse On Pure C57bl/6 Background, Shari Moak

Graduate Theses and Dissertations

PANcreatic-DERived Factor (PANDER), or FAM3B, is a 235-amino acid protein strongly expressed within and secreted from the endocrine pancreas. Research surrounding PANDER has revealed a large role for the protein in maintaining glucose homeostasis, as evidenced by several Ad-PANDER overexpressing murine models, our lab's pancreas-specific PANDER transgenic overexpressor, and most recently our mixed genetic C57/129J PANDER knockout (PANKO) mouse. However, PANDER's overall role in glycemic regulation and glucose homeostasis has yet to be studied in a purebred C57BL/6J PANDER knockout model. Here we present the first phenotypic characterization of our global PANDER knockout mouse on a ...


Innate Immune Responses To Respiratory Syncytial Virus: Age-Associated Changes, Terianne Maiko Wong Jan 2013

Innate Immune Responses To Respiratory Syncytial Virus: Age-Associated Changes, Terianne Maiko Wong

Graduate Theses and Dissertations

Respiratory syncytial virus (RSV) infection causes ~64 million cases of respiratory disease and 200,000 deaths annually worldwide, yet there is no broadly effective prophylactic or treatment regimen. RSV can produce acute respiratory illness in patients of all ages but strikes the age extremes, infants and the elderly, with highest frequency presumably due to innate immune deficiencies. A higher morbidity and mortality has been reported for the elderly above 65 years of age, which has been attributed to immune senescence. Efforts to generate an effective vaccine have thus far been unsuccessful.

The innate immune system provides the first line of ...


Investigation Of Hsf1 Interacting Partners Via A Genome-Wide Yeast Two-Hybrid Screen, Jamie Elizabeth Mendez Jan 2013

Investigation Of Hsf1 Interacting Partners Via A Genome-Wide Yeast Two-Hybrid Screen, Jamie Elizabeth Mendez

Graduate Theses and Dissertations

Heat shock factor 1 (HSF1) is the master transcriptional regulator of the heat shock response (HSR), an evolutionarily conserved cellular stress response. HSF1 promotes the expression of a variety of molecular chaperones that aid in restoring protein homeostasis upon exposure to proteoxic stress. However, all of the proteins responsible for regulating the HSR together with HSF1 are unknown. A genome-wide yeast two hybrid screen was performed to identify new S. cerevisiae Hsf1 protein interacting partners. Two GAL4 DNA binding domain-Hsf1 fusion proteins (baits) were constructed with mutations in the Hsf1 C-terminal activation domain to dampen Hsf1 mediated auto-activation of the ...


Drug Resistance Mechanisms To Gamma-Secretase Inhibitors In Human Colon Cancer Cells, Cindy R. Timme Jan 2013

Drug Resistance Mechanisms To Gamma-Secretase Inhibitors In Human Colon Cancer Cells, Cindy R. Timme

Graduate Theses and Dissertations

Colorectal cancer is the third leading cause of cancer-related mortality. Much progress has been achieved in combating this disease with surgical resection and chemotherapy in combination with targeted drugs. However, most metastatic patients develop drug resistance so new modalities of treatment are needed.

Notch signaling plays a vital role in intestinal homeostasis, self-renewal, and cell fate decisions during post-development and is activated in colorectal adenocarcinomas. Under debate is its role in carcinomas and metastatic disease. In theory, blocking Notch activation using gamma-secretase inhibitors (GSIs) may show efficacy alone or in combination with chemotherapy in the treatment of colon cancer.

In ...


Partial Characterization Of Pf13_0027: A Putative Phosphatase Of Plasmodium Falciparum, Christopher Campbell Jan 2013

Partial Characterization Of Pf13_0027: A Putative Phosphatase Of Plasmodium Falciparum, Christopher Campbell

Graduate Theses and Dissertations

Signal transduction and stage-specific gene expression are essential components of Plasmodium falciparum development. In this study, the putative phosphatase PF13_0027 is investigated as a critical component of intraerythrocytic development contributing to maturation of the late trophozoite. This putative phosphatase was identified during the course of a large-scale insertional mutagenesis project by insertion of the piggyBac (pB) element, containing a human dihydrofolate reductase (hDHFR) drug selection cassette into the open reading frame (ORF) preventing expression and attenuating parasite development. PF13_0027 codes for a protein with a rhodanese (RHD) and dual specificity phosphatase (DUSP) in a tandem arrangement typically identified with mitogen-activated ...


The Role Of Molecular Chaperones In The Etiology And Treatment Of Psychiatric Diseases In The Elderly, John Clarence O'Leary Jan 2013

The Role Of Molecular Chaperones In The Etiology And Treatment Of Psychiatric Diseases In The Elderly, John Clarence O'Leary

Graduate Theses and Dissertations

The elderly are at increased risk for developing psychiatric diseases, which include Alzheimer's disease, depression, anxiety and suicide. The probability of multiple disease comorbidity is also increased in the elderly. At the cellular level, the loss of protein homeostasis is often at the root of disease emergence, and thus the scientific community is searching for ways to help maintain this balance. A vast group of proteins that are paramount to balancing and counterbalancing protein levels is the molecular chaperone protein group, which has evolved a tremendous variety of functions in the cell. They aid in protein trafficking, folding, receptor ...


Associational Resistance And Competition In The Asphondylia - Borrichia - Iva System, Keith Stokes Jan 2013

Associational Resistance And Competition In The Asphondylia - Borrichia - Iva System, Keith Stokes

Graduate Theses and Dissertations

Indirect ecological effects such as associational resistance and resource competition have the potential to affect ecological interactions and influence the structure of ecological communities. Although resource competition is commonly studied, the effects of associational resistance are not as evident if studies are not designed to detect them. Additionally, the relative strengths of different ecological mechanisms ought to be measured in studies, rather than the strength of singular mechanisms. This permits proper attribution of causes and effects in community structure and detection of higher order interactions in a way that naïve reductionism will not.

In a series of experiments, I looked ...


Understanding Amphibian Decline: The Role Of Pesticides And The Pathogenic Chytrid Fungus On Amphibians And Aquatic Communities, Taegan A. Mcmahon Jan 2013

Understanding Amphibian Decline: The Role Of Pesticides And The Pathogenic Chytrid Fungus On Amphibians And Aquatic Communities, Taegan A. Mcmahon

Graduate Theses and Dissertations

Amphibians are the most threatened taxon on the planet. Declines have been associated with over-exploitation, habitat loss, pollution, and pathogenic diseases, but of these factors, pollution and disease have been relatively under-studied. Here, I investigated: 1) the impacts of commonly used pesticides on aquatic communities, 2) the effect of these pesticides on amphibian susceptibility to the pathogenic chytrid fungus, Batrachochytrium dendrobatidis (Bd), and 3) whether there are non-amphibian hosts of Bd and 4) how to best quantify the survival of Bd through ontogeny of the host.

In my first research chapter, I quantified the effects of environmentally relevant concentrations of ...


Environmental Effects On The Biomechanics And Motor Physiology Of Elastically Powered Movements In Chameleons, Christopher Van Anderson Jan 2013

Environmental Effects On The Biomechanics And Motor Physiology Of Elastically Powered Movements In Chameleons, Christopher Van Anderson

Graduate Theses and Dissertations

Environmental temperature exhibits profound effects on the activity and ecology of ectotherms through its impact on muscle contractile physiology. While the performance of locomotor behaviors powered by muscle contraction directly decreases by at least 33% over a 10°C drop in body temperature, chameleons are known to feed, presumably with high performance, at body temperatures where sympatric lizard species remain inactive. I propose that ballistic movements that are powered by the recoil of preloaded elastic and collagenous tissues are less thermally dependent than movements that rely on direct muscular power. Despite the reduced thermal sensitivity of the elastic-recoil powered movement ...