Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 10 of 10
Full-Text Articles in Entire DC Network
Impacts Of Invasive Phragmites Australis On Diamondback Terrapin Nesting, Cassandra Cook
Impacts Of Invasive Phragmites Australis On Diamondback Terrapin Nesting, Cassandra Cook
Dissertations, Theses, and Masters Projects
The diamondback terrapin (Malaclemys terrapin) is a species of turtle found exclusively in brackish water habitats. Terrapins are currently facing population threats including by-catch mortality in crab pots, predation, and habitat loss. The expansion of the exotic, invasive reed Phragmites australis is causing widespread structural and functional changes to coastal ecosystems throughout North America, which could negatively impact the nesting success of female terrapins by invading preferred nesting habitats. I examined the extent to which Phragmites affects nesting of a breeding population of diamondback terrapins at Fisherman Island National Wildlife Refuge on the eastern shore of Virginia, where Phragmites has …
A Test For Heritable Variation In A Wild Population In Response To Endocrine Disrupting Events, Emily Van Den Blink
A Test For Heritable Variation In A Wild Population In Response To Endocrine Disrupting Events, Emily Van Den Blink
Dissertations, Theses, and Masters Projects
Endocrine disrupting chemicals (EDCs) are a pervasive threat to the health of both human and wildlife populations. EDCs bind to hormone receptors and mimic or block their action, causing disrupted growth, metabolism and reproduction. Fertility affected by EDCs might be compensated if some individuals are genetically resistant. Genetic resistance in a variable population might cause hormonal feedback pathways to be more resilient to disruption. The effects of EDCs on fertility will be studied using a naturally variable population. A wild population of neonatal male mice, Peromyscus leucopus, was treated with testosterone propionate during a critical developmental period. Genetic variation was …
Differences In Sockeye Salmon Antibody Composition: Testing The Immunological Imprinting Hypothesis, Maxwell Elliott Chappell
Differences In Sockeye Salmon Antibody Composition: Testing The Immunological Imprinting Hypothesis, Maxwell Elliott Chappell
Dissertations, Theses, and Masters Projects
Anadromous fish such as sockeye salmon return to their natal streams to spawn, during which they undergo significant physiological changes including the release of cortisol, a known immunosuppressive hormone. Our lab has proposed the Immunological Imprinting Hypothesis, which suggests that juvenile anadromous fish respond to pathogens specific to their natal site by producing protective long lived plasma cells (LLPCs) that constitutively produce antibodies against those pathogens. These LLPCs are believed to be highly cortisol resistant. Thus, fish returning to their natal streams have immunological protection from pathogens found at that specific location. I investigated the Immunological Imprinting Hypothesis through analysis …
Floristic Change Spanning 45 Years Of Global Change In The College Woods, Williamsburg, Va, Caitlin Cyrus
Floristic Change Spanning 45 Years Of Global Change In The College Woods, Williamsburg, Va, Caitlin Cyrus
Dissertations, Theses, and Masters Projects
The College Woods, located in Williamsburg, VA, is a natural preserve of approximately 960 acres owned by the College of William & Mary. The Woods supports a relatively diverse flora in a mature coastal-plain forest which has been under long-term biological study by members of the College. This thesis contributes to the ongoing investigation of the Woods by documenting floristic and vegetation changes that have occurred over the last 45 years amidst a rising and uncontrolled white-tailed deer population. Three main research questions are addressed: (1) How has floristic diversity, composition, and species abundance changed since the last floristic survey …
Dietary Mercury Exposure In Male Zebra Finches Does Not Decrease Their Attractiveness To Females, Virginia Greene
Dietary Mercury Exposure In Male Zebra Finches Does Not Decrease Their Attractiveness To Females, Virginia Greene
Dissertations, Theses, and Masters Projects
Choosing a high-quality mate contributes strongly to increased reproductive success in birds. Female birds assess quality in males, in part, via condition-dependent signals such as male songs and plumage. The production of attractive signals can be disrupted by environmental stressors, however, including environmental toxins. Mercury, a globally-increasing pollutant, is one such toxin. Mercury exposure has been shown to affect song, plumage, bill color, and mating behaviors in male birds, but the effect of these changes on the outcome of female mate choice is unknown. These effects on condition-dependent signals indicate that mercury could potentially alter males’ attractiveness to females, as …
Thyroid Hormone Receptor Nucleocytoplasmic Transport, Zhang Jibo
Thyroid Hormone Receptor Nucleocytoplasmic Transport, Zhang Jibo
Dissertations, Theses, and Masters Projects
The thyroid hormone receptor α1 (TRα1) and the thyroid hormone receptor β1 (TRβ1) are transcription factors that modulate the expression of target genes that are important in metabolism and development in response to thyroid hormone. Although primarily localized to the nucleus, prior studies have shown that TRα1 and TRβ1 shuttle rapidly between the nucleus and cytoplasm, and that nuclear import of TRα1 is directed by two nuclear localization signal (NLS) motifs: NLS-1 in the hinge domain, and NLS-2 in the N-terminal A/B domain. In contrast, TRβ1 lacks NLS-2. Previous studies also characterized two nuclear export signal (NES) motifs, NES-H3/H6 and …
Does Sound Help Prevent Birds From Flying Into Objects?, Nicole Ingrassia
Does Sound Help Prevent Birds From Flying Into Objects?, Nicole Ingrassia
Dissertations, Theses, and Masters Projects
Bird strike is the often fatal collision between a bird and a surface, such as a window or tower. Collisions kill millions of birds each year in the US alone, and cost industries millions of dollars per year. as more buildings, wind turbines, communication towers and other structures are built, bird strikes and its associated costs are predicted to increase. Researchers have explored mitigative measures to alleviate bird strikes but to date none have solved this growing problem. Recent research suggests that current technologies fail because their design does not take into account birds' sensory ecology, including habituation to loud …
Density Dependence And Clonal Integration In Common Milkweed, Asclepias Syriaca, Mary Danielle Seward
Density Dependence And Clonal Integration In Common Milkweed, Asclepias Syriaca, Mary Danielle Seward
Dissertations, Theses, and Masters Projects
The density of individuals in a population has the potential to affect growth and death rates of that population. This effect of density is called density dependence and can be negatively or positively related to a vital rate. In most populations, increasing density leads to lower growth rates, which is negative density dependence. Positive density dependence, or Allee effects, occurs when increasing density leads to an increase in a vital rate, such as increasing survival in large herds. However, in clonal plants, there is the potential for the effects of density to be ameliorated. Clonal plants produce genetically identical progeny …
Factors Affecting Temporal Variation In Occupancy Of Two Common Species Of Butterflies In Woodlands Of The Eastern United States, Papilio Glaucus And Eurytides Marcellus., Angela Louise Zappalla
Factors Affecting Temporal Variation In Occupancy Of Two Common Species Of Butterflies In Woodlands Of The Eastern United States, Papilio Glaucus And Eurytides Marcellus., Angela Louise Zappalla
Dissertations, Theses, and Masters Projects
Identifying key factors of habitat quality and the extents at which they operate is invaluable to the understanding of the biology of a species. Key factors defining habitat quality for many common butterfly species have yet to be determined. Diverse methods are used to define habitat quality for butterflies. Some of these, such as mark-release-recapture or distance sampling, can be difficult to implement. Occupancy modeling is less invasive and generally less expensive than these other methods. Occupancy modeling is based on repeated presence-absence surveys. Occupancy is the probability that a species is present at a given site after accounting for …
The Effect Of Methylmercury On The Auditory Brainstem Response In Domestic Zebra Finches (Taeniopygia Guttata), Sarah Elizabeth Wolf
The Effect Of Methylmercury On The Auditory Brainstem Response In Domestic Zebra Finches (Taeniopygia Guttata), Sarah Elizabeth Wolf
Dissertations, Theses, and Masters Projects
With global urbanization on the rise, human activities continue to threaten the functionality of auditory communication in birds through induced change to vocalizations, the acoustic landscape, and hearing ability. One human-associated pollutant potentially affecting auditory communication is mercury, which is released into the environment through industrial emissions and is correlated with markers of global climate change. Already, mercury has been implicated in mammalian high-frequency hearing impairment; however, the effect of mercury on avian hearing ability is unknown. In this study, we examined whether dietary mercury exposure affected hearing ability in domestic zebra finches using the auditory brainstem response (ABR), which …