Systematics of Lecythidoideae (Lecythidaceae) with emphasis on Bertholletia, Corythophora, Eschweilera, and Lecythis
Year of Dissertation:
2010
Phylogenetic analyses based on morphological and DNA sequence data were generated to test the monophyly of Eschweilera and Lecythis and to investigate the relationships of these two genera and their close relatives (Bertholletia and Corythophora). The final results were applied to questions of taxonomic rearrangements and character evolution in traits related to pollination.
The Sustainable Management and Conservation Santalum yasi (Sandalwood) in Fiji and Tonga: A Combined Ecological and Genetic Approach
Year of Dissertation:
2009
Valued internationally for the aromatic oil found within its heartwood, Sandalwood (Santalum, Santalaceae) is one of the most heavily exploited groups of plants across its range. While historically, most oil has been harvested from Santalum album in Southeast Asia and India, the decrease of S. album sources has caused a widening gap between supply and demand, which creates profitable market opportunities and increasing harvest pressure for alternative sandalwood oil sources. Santalum yasi, a quality alternative, has been harvested extensively in Fiji and Tonga, yet is vastly under-studied. The absence of basic data on population dynamics and genetic variation for remnant populations remains a major constraint to the sustainable management of this culturally and economically valued resource. This dissertation focuses on the ecological and genetic data and analyses that can aid in developing sustainable management strategies.
Origin and development of hematopoietic tumors in sumoylation mutants of Drosophila melanogaster
Year of Dissertation:
2010
The larval hematopoietic system of Drosophila melanogaster consists of freely circulating cells, the sessile population, and the hematopoietic organ called the lymph gland. Most hemocytes function as macrophages and play a significant role in innate immunity. Hemocytes also remodel tissues, aiding in development of the organism. Constitutive activation of immune signaling pathways, as well as various mutations in genes which are not linked to immune pathways, result in the overabundance of circulating hemocytes and tumor formation. Many aspects of tumor development, such as the identity of the affected hematopoietic population and mechanisms of tumor growth are either not characterized or not well understood. The overall goal of this project was to understand the origin and development of hematopoietic tumor formation in Ubc9 mutants.
Effects of endophyte infection, environmental stress and competition on Lolium perenne populations from the Mediterranean region
Year of Dissertation:
2012
No
The role of ubiquitin-mediated proteolysis in Drosophila glia development
Year of Dissertation:
2009
Advisor:
Tadmiri Venkatesh
Biological processes are dynamic, requiring both simple and complex mechanisms that enable cells to adapt with the ever-changing environment. Ubiquitination is one of many posttranslational modifications that result in a change in cellular activity. Mono-ubiquitination, the addition of a single ubiquitin moeity leads to endocytosis and membrane trafficking, while the addition of a multiple ubiquitin chains primarily results in protein degradation. Rap/Fzr acts as an activator of the E3 ubiquitin ligase, Anaphase Promoting Complex (APC) which has been studied for its role in the timely degradation of cell cycle regulators. My thesis work focuses on novel roles Rap/Fzr during nervous system development and specifically investigates its role during glia development. My results show that Rap/Fzr regulates glia development through its interaction with
Effects of The Enzyme Inhibitor Prohexadione-calcium on Hops Determined by LC-TOF-MS
Year of Dissertation:
2011
Humulus lupulus L. (hops) is an agricultural crop valued for its inflorescences, commonly known as hop cones, which produce a diverse collection of secondary metabolites. Hop cones are most valued for their terpenophenolic contents, which are essential to beer production, and the subject of biomedical research. We studied two hop cultivars, Willamette and Zeus, over five stages of development, which were characterized by detailed flower morphology, gross cone measurements, and phytochemical quantitation. By combining morphological observations with phytochemical quantitation we produced an index to inform our developmentally dependent experiments. In order to understand these developmental processes and in an attempt to induce agronomically positive effects, we perturbed hop morphological and phytochemical development using enzyme inhibition.
The investigation of the antidiabetic Dominican traditional medicinal plants Costus spicatus Sw. and Momordica charantia L.
Year of Dissertation:
2011
Diabetes is a serious disease affecting many people throughout the world, and is expected to increase in the coming decades. Traditional medicine is used in many places around the globe, including the Dominican Republic, for the treatment of diabetes along with modern medicines. Fieldwork conducted in the Dominican community by the Institute of Economic Botany identified Costus species and Momordica charantia L. as being widely used for diabetes treatment, thus pointing to these plants for further investigation.
Down Regulation of Neuronatin by MicroRNA-151 Overcomes Inhibition of Axonal Growth by Myelin-based Inhibitors
Year of Dissertation:
2010
Down Regulation of Neuronatin by microRNA-151 Overcomes Inhibition of Axonal Growth by Myelin-based Inhibitors
The Behavioral Effects of Exposure to the Endocrine Disrupting Chemical, Ethinyl Estradiol, on Fourspine Stickleback (Apeltes quadracus)
Year of Dissertation:
2009
There is growing evidence that endocrine disrupting chemicals polluting the environment have the potential to affect animal health and behavior. Ethinyl estradiol (EE2), the active ingredient in contraceptive pills and hormone-replacement therapies, is a particularly potent endocrine disrupting chemical found in our waterways. In this study, adult male and female fish were used to investigate the effects of a 60 day EE2 exposure on 1) ecologically relevant behaviors, 2) gonadal state, and 3) male reproductive coloration. Exposure to levels of EE2 documented in the environment (10, 70 and 100 ng/L) detrimentally altered fish behavior. Fish exposed to EE2 were less active, more aggressive, and avoided an artificial predator less often. 100 days in clean water reversed some but not all of these behavioral changes. In both males and females, gonads in exposed groups differed from controls, and included the presence of ovotestes found only in males exposed to EE2. Reproductive coloration in males was not affected by exposure. This is the first report of long-lasting behavioral aberrations caused by EE2 exposure in adult fish.
Diet and feeding strategies of redbreast sunfish (Lepomis aurtitus) and bluegill sunfish (Lepomis macrochirus) in two suburban lakes.
Year of Dissertation:
2013
This is a study of the feeding habits of two species of sunfish, Lepomis auritus (Linnaeus, 1758), redbreast sunfish, and Lepomis macrochirus Rafinesque, 1819, bluegill sunfish, co-occurring in two suburban lakes with different degrees of shoreline development. Since it has been well-documented that other animal species change their dietary habits during or just prior to breeding season, it seemed sensible to determine if sunfish also exhibited this behavior. The two study lakes are close in proximity in Putnam County, New York. Lake Mahopac is a more urbanized setting, close to road traffic, surrounded by homes, and has little to no vegetation due to the introduction of grass carp. Long Pond is in a more pristine setting with one side being entirely wooded. It is not close to any main roads and there are few houses on the perimeter. The vegetation is for the most part undisturbed except for a small amount removed from its beach areas. Despite the lack of vegetation, Lake Mahopac still has as much species diversity as Long Pond. Unfortunately the bluegill population in Lake Mahopac has suffered from the lack of weed beds, which are necessary for successful breeding, which has resulted in a steady decline in numbers.