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Expression Profiling Of The Spermidine Synthase3 (Spds3) And Spermine Synthase ( Spms) Genes During The Life Of Arabidopsis, Charles F. Rice

Master's Theses and Capstones

Polyamines are low molecular weight nitrogenous compounds found in all living organisms. These omnipresent molecules have been extensively studied in plant systems and have been implicated in a number of physiological responses including growth, development, and stress response. The proposed role of polyamines in vital processes such as cell division and differentiation has sparked enthusiasm in further investigation of this relatively small biosynthetic pathway. Very little is known about the regulation of polyamine biosynthetic genes, an aspect that can elucidate further functions of these ubiquitous compounds. In the following study, the expression profiles of two of these genes, spermidine synthase3 …

The Effects Of Photoperiod And Water Temperature On The Reproductive Development Of Black Sea Bass, Centropristis Striata, Katie Strait

Master's Theses and Capstones

Black sea bass are a potential candidate for marine aquaculture due to their high market value, high demand, and limited seasonal supply. One of the most significant impediments to commercial production of black sea bass is the lack of a year-round supply of eggs and larvae. Further, control of reproductive development is poorly understood in this species. Black sea bass are protogynous hermaphrodites that change sex between 2-5 years of age. It is unclear why adult black sea bass undergo sex change in the wild. Therefore, the first part of study sought to determine if density is involved in sex …

Correlating Sea Otter Density And Behavior To Habitat Attributes In Prince William Sound, Alaska: A Model For Prediction, Heather A. Coletti

Master's Theses and Capstones

As a benthic foraging marine mammal, sea otters ( Enhydra lutris) present a unique opportunity for conducting a quantitative assessment of behavior based on habitat use as well as developing a habitat based density model using GIS because of the sea otter's well defined habitat requirements. Several studies have documented sea otter behavior but none have calculated the probability of occurrence of a particular behavior based on habitat attributes. Previous predictive models of sea otter density have been constructed, however these models have excluded offshore habitat. Seven aerial surveys, that included offshore habitats, were conducted between 1995 and 2005 in …

Gonadal Histology And Reproductive Steroidogenesis Of Anurans Exposed To Potential Endocrine Disrupting Contaminants, Emily May La Fiandra

Doctoral Dissertations

The prevalence of malformed amphibians and the association of high incidences of malformation with the presence of environmental contaminants have raised questions about the effects of environmental contaminants on the development of larval amphibians. The potential endocrine disrupting effects of pesticides suggest that the reproductive and developmental abnormalities observed in larval anurans may be due at least in part to impacts on the hypothalamic-pituitary-gonadal axis. The present studies investigate the effects of exposure to environmental contaminants including DDT and atrazine on the development, gonadal histology and reproductive steroidogenesis of larval anurans.

As previous monitoring at Great Bay National Wildlife Refuge …

Structural Analysis Of Cytokine Signaling Modulators, Cristina Ileana Silvescu

Doctoral Dissertations

The N-linked glycans attached to cytokine receptors modulate signal transduction by interacting with galectin-3 and generating a cell surface lattice. This opposes constitutive endocytosis and reduces the thresholds for cytokine signaling. The preferred ligands for galectin-3 are the poly-N-acetyl lactosaminylated tetra-antennary glycans which are synthesized by Mgat 5 and are present at high levels in tumor cells. A null mutation in Mgat 5 inhibits lattice formation and cancer progression in cells with an oncogenic background. GlcNAc feeding reestablishes lattice formation, cytokine signaling and tumorigenesis.

A MALDI-TOF analysis was employed to identify the N-glycans involved in modulating signal transduction in wild …

Genetics And Physiology Of Motility By Photorhabdus Spp, Brandye A. Michaels

Doctoral Dissertations

Photorhabdus is a bacterial symbiont of soil nematodes and a lethal pathogen of insects. Many pathogenic or symbiotic bacteria utilize various methods of motility to reach favorable conditions, colonize a host, or have motility genes that also regulate virulence expression. It is not known how motility is regulated, or how it may confer an advantage, in the complex life cycle of Photorhabdus..

We characterized motility in Photorhabdus and found that the bacterium was motile both by swimming (movement in liquid) and swarming (movement on surfaces) under appropriate conditions. Both types of motility utilized the same peritrichous flagella and shared genetic …

Remote Detection Of Forest Structure In The White Mountains Of New Hampshire: An Integration Of Waveform Lidar And Hyperspectral Remote Sensing Data, Jeanne Elizabeth Anderson

Doctoral Dissertations

The capability of waveform lidar, used singly and through integration with high-resolution spectral data, to describe and predict various aspects of the structure of a northern temperate forest is explored. Waveform lidar imagery was acquired in 1999 and 2003 over Bartlett Experimental Forest in the White Mountains of central New Hampshire using NASA's airborne Laser Vegetation Imaging Sensor (LVIS). High-resolution spectral imagery from 1997 and 2003 was likewise acquired using NASA's Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). USDA Forest Service Northeastern Research Station (USFS NERS) 2001-2003 inventory data was used to define basal area, above-ground biomass, quadratic mean stem diameter and …

Cichlids As A Model For The Evolution Of Visual Sensitivity, Tyrone Clifford Spady

Doctoral Dissertations

The cichlid fishes of East Africa are the most ecologically diverse radiation of recent vertebrates. These highly visual fish live in habitats ranging from turbid rivers to clear lakes. They have evolved to exploit an astounding array of foraging strategies. The combination of phenotypic diversity and varied environmental conditions makes the cichlid system ideal for the examination of the relationship between ecology and the evolution of visual sensitivity. In this dissertation, I explore several aspects of this relationship. In Chapter 1, I compare the opsin gene sequences from 17 African cichlid species that have evolved in either clear or turbid …

Physiological Bases Of Parental Care In The Burying Beetles, Nicrophorus Orbicollis, Stefania Carmen Panaitof

Doctoral Dissertations

Burying beetles, Nicrophorus orbicollis, have extended biparental care. They bury and prepare small vertebrate carcasses as food for their young. While females provide the most care, single males show a remarkable behavioral compensation after a mate loss. Here, I integrate behavioral and physiological analyses of parental behavior in burying beetles by exploring how hormonal and social factors may interact to mediate brood care.

In Chapter I, I establish Juvenile Hormone (JH) profiles during a breeding bout and show that after larvae hatch, JH titers of single males and paired females are similar. JH titers of single males also respond to …

Improving Estimation Of Gross Primary Productivity Of Terrestrial Ecosystems, Qingyuan Zhang

Doctoral Dissertations

The MOderate Resolution Imaging Spectroradiometer (MODIS) provides an unprecedented opportunity to monitor and quantify seasonal changes of vegetation and phenology. MODIS has the potential to improve the estimation, which is based on the algorithms for the NOAA Advanced Very High Resolution Radiometer (AVHRR), of biophysical/biochemical variables of vegetation. My doctoral study improves estimation of gross primary productivity (GPP) through two aspects: first, my study improved the detection of vegetation phenology by distinguishing MODIS contaminated observations and contamination-free observations, and secondly, I inverted the fraction of absorbed photosynthetically active radiation (PAR) by chlorophyll using radiative transfer models and daily MODIS data. …

Functional Analysis Of The Caf1 Protein, Takbum Ohn

Doctoral Dissertations

The CAF1 protein is a component of the CCR4-NOT deadenylase complex. While yeast CAF1 displays deadenylase activity, this activity is not required for its function in vivo, and CCR4 is the primary deadenylase in the complex. In order to identify CAF1-specific functional regions required for deadenylation in vivo, we targeted for mutagenesis six regions of CAF1 that are specifically conserved among CAF1 orthologs. Defects in three regions of the CAF1 protein (residues 173-175, residues 255-257 and residues 340-342, alleles caf1-1, caf1-3 and caf1-6, respectively) were found to dramatically reduce the rate of deadenylation in vivo and to result in typical …

Patterns And Process During The Diversification Of The Cichlid Fishes In Lake Malawi, Africa, Michael R. Kidd

Doctoral Dissertations

The 500-1000 cichlid species endemic to Lake Malawi constitute one of the most rapid and extensive radiations of vertebrates ever discovered. The objective of this dissertation was to test the assumptions and predictions of several recently published models of cichlid speciation. First, a novel assay of female choice was used to evaluate the role of visual cues during conspecific recognition. The results of this experiment demonstrate that females are able to identify conspecific mates using only visual cues. Second, the assumptions of a recent model of speciation via intrasexual selection were tested by comparing aggressive behavior during territorial contests among …

Cellular Uptake And Actions Of Bilberry Anthocyanins In Retinal Pigment Epithelial Cells, Paul Everett Milbury Jr.

Doctoral Dissertations

Inflammation and oxidative stress play a significant role in the pathogenesis of age-related macular degeneration (AMD). In AMD, retinal pigment epithelium (RPE) cells are damaged by oxidative stress and die via the process of apoptosis. Anthocyanins from fruits and berries, such as bilberry (Vaccinium myrtillus), possess significant antioxidant activity in vitro and have been used in "traditional medicine" to treat AMD. It is not clear whether intracellular concentrations of anthocyanins are sufficient to quench radical species and mitigate oxidative stress in vivo. In this research project, human RPE cells in vitro were used to establish an oxidative stress model in …

Transposable Elements: What Have You Done For Me Lately? A Genomics Based Investigation Into The Potential Functional Roles Of Transposable Elements Using The Model Organism Caenorhabditis Elegans, Sarah Prescott Kenick

Doctoral Dissertations

The genomes of all organisms contain discrete DNA sequences present as disperse repetitive elements called transposons. Transposons have the unique ability to move to new chromosomal locations. Problems of uncontrolled movement of transposons can result in mutations, rearrangement, and even broken chromosomes. Often termed "selfish parasites" that invade a host genome, there is a longstanding question of whether they have a functional role. As a first step in an effort to investigate this question, I identified and annotated 276 full length and partial elements in the C.elegans genome. I determined the genomic location of each and looked for patterns resulting …

Ecological Patterns, Community Classification, And A Comparison Of Approaches For Predicting Biological And Habitat Reference Conditions In New Hampshire Streams, Brian R. Frappier

Doctoral Dissertations

Reference conditions play a vital role in many challenges facing both conservation and natural resources management. This dissertation sought to establish minimally-impacted reference conditions for stream biota and habitat in New Hampshire and explore alternative statistical methodologies to predict reference conditions for biological and habitat assessments. The fish, stream-dwelling salamander, macroinvertebrate and periphyton assemblages as well as the co-occurring physical habitat and riparian conditions of 76 minimally-impacted first to fourth order streams in New Hampshire were estimated using USEPA Environmental Monitoring and Assessment Program protocols over a four year period. Several statistical approaches and data standardizations for classifying multi-taxonomic assemblages …

Analysis Of The Role Of Poly(A) -Binding Protein (Pab1) In The Mrna Degradation Process In Yeast, Gang Yao

Doctoral Dissertations

The mRNA deadenylation process influences multiple aspects of protein synthesis and is known to be the major factor controlling mRNA decay rates. My data demonstrates that yeast PAB1 plays both positive and negative roles in controlling deadenylation, and I have identified particular regions of PAB1 involved in controlling different aspects of the mRNA degradative process. I have found that yeast PAB1 does not play a simple, obstructionist role in regulating CCR4 deadenylation. Instead, PAB1-PAB1 protein interactions, as mediated by the PAB1 proline-rich region (P domain) and the RRM1 domain, are required for the CCR4 deadenylase activity. The P and RRM1 …

Uptake And Growth Effects Of Polycyclic Aromatic Hydrocarbons In Wetland Plants, Alison Watts

Doctoral Dissertations

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants in estuarine environments, but little is known about the distribution and fate of PAHs in wetland sediments and plants. The effect of PAHs on common salt marsh plants, and the PAH distribution within the plants, sediment, and atmosphere were evaluated to determine if PAHs were transported from the sediment into the plants, and if the PAHs affected plant growth. Four salt marsh plant species, Spartina alterniflora, Phragmites australis, Solidago sempervirens and Distichlis spicata were grown in pots of PAH contaminated sediment containing mean total PAH concentrations of 355 mg/kg (ppm). During the growing …

Tropical Forest Structure: Ground Measurements Of Coarse Necromass And Satellite Observations Of Crown Geometry, Michael W. Palace

Doctoral Dissertations

Forests are structurally diverse, but these structures derive from the same processes of disturbance and growth. Understanding forest structure can help unlock the history, function, and future of a forested ecosystem. Components of forest structure include tree size distributions, foliage distributions and variation in canopy density, and coarse woody debris (coarse necromass). Tropical rainforests are structurally the most complex of all ecosystems. In addition to having high biological diversity, Amazon forests are marked by complex vegetation dynamics and a diverse forest stand structures, which play an important role in the interactions of water and carbon between the biosphere and atmosphere. …

A Molecular And Morphological Investigation Of The Red Seaweed Genus Porphyra (Bangiales, Rhodophyta) In The Northwest Atlantic, Troy Lee Bray

Doctoral Dissertations

To evaluate the possible occurrence of cryptic Porphyra taxa in the Northwest Atlantic, extensive field collections were made during winter and spring periods when relatively few previous collections had been made. Approximately 100 different sites extending from Chance Harbor, New Brunswick, Canada to Rye, New York, USA, were sampled during multiple years (2001-2005). Historical specimens from several herbaria (NHA, FH, BM, WTU, MICH, US) were also examined for possible cryptic taxa. A combination of morphological and molecular tools was used to screen both recent and historical collections.

Sequences from the plastid-encoded, ribulose-1, 5-bisphosphate carboxylase-oxygenase large subunit (rbcL) gene and rbcL- …

Studies Of Flower Color In Anagallis Monelli L, Andrea Quintana Pinilla

Master's Theses and Capstones

One of the main goals for plant breeders in the floriculture industry is to develop plants with new attributes. Characteristics such as flower size, growth habit, resistance to pests and diseases, flower size, and particularly flower color are among the most important traits to breed and improve. One of the best ways to make a plant popular in the market is to offer a wide variety of flower colors. A. monelli is an ornamental plant used for hanging baskets and as a bedding plant, and until recently, cultivars available were only blue- or orange-flowered. Recent breeding research on this species …

Abiotic Retention Of Nitrogen And Dissolved Organic Matter By Forest Mineral Soils, Naoko Watanabe

Master's Theses and Capstones

The effect of NO3- deposition on NH4 +, DON, and DOC retention as well as abiotic NO3 - retention via the hypothesized "ferrous wheel" mechanism was examined in oxic and anoxic tropical and oxic temperate soils using sorption isotherm experiments. Adsorption of NH4+, DON, and DOC by mineral soils was examined in forest floor extracts with DOC levels of 0-50 mg/L. Experimental treatments included no added NO3-, 4mg/L of added NO3-, or 4 mg/L of NO3 - and 2 mg/L of Fe3+. Ferric iron was added since it would likely increase DOC retention in the context of podzolization, and it …

Assessing The Suitability Of The Eelgrass (Zostera Marina L) Deep Edge As An Indicator Of Water Clarity In Estuarine Systems, David Omer Rivers

Master's Theses and Capstones

The suitability of the seagrass deep edge as an indicator of water clarity was assessed by examining the sensitivity and specificity of this indicator to changes in light. Indicator specificity was assessed by examining the extent to which seasonal variation in environmental parameters affected the location of the deep edge at five eelgrass meadows in the Great Bay Estuary, New Hampshire. The mean location of the eelgrass deep edge was seasonally stable at three sites, confirming its suitability as an indicator. At two sites, the deep edge responded to long-term light reduction and changes in deep edge location of 1.3 …

Effects Of Forest Clear Cutting On Spotted Salamander ( Ambystoma Maculatum) Migration, Jessica Susannah Veysey

Master's Theses and Capstones

Upland buffer zones are a proposed management tool for vernal-pool-breeding amphibians. Substantial validation of buffers, via experimental upland habitat disturbance, is lacking. Specifically, no studies have examined immediate effects of clear cutting on spotted salamander (Ambystoma maculatum ) migration. I used clear cutting to experimentally manipulate upland buffer widths at 11 vernal pools. I then radiotracked 40 adult spotted salamanders at these pools, and modeled their migration with mixed-effects regression. Mean maximum distance from the pool was 106.0 +/- 15.4 m (range = 1.6 to 427.6 m). At clear cut-treatment pools, mean percent of time in the cut was 27.2 …

Salmonella Enterica Serovar Typhimurium Promotes Apoptosis In Activated Neutrophils, Christopher C. Wrocklage

Master's Theses and Capstones

Apoptosis is an extremely important and highly regulated function in neutrophils. As the most abundant, but shortest-lived white blood cells, they must initiate this process in the absence of pathogens and selectively release their potent cytotoxic components when pathogens are present. Many pathogens are able to modulate this process in neutrophils, either for the host's benefit or for their own. Previous work has shown that transmigration across a T84 intestinal epithelial crypt cell monolayer increases the ability of neutrophils to bind and kill Salmonella enterica serovar Typhimurium (S. Typhimurium).

The goal of this work was to see how S. Typhimurium …

The Development And Utilization Of Est (Expressed Sequence Tag) Resources In The Diploid Strawberry Model System, Robin Leigh Brese

Master's Theses and Capstones

Enhancement of genomic resources is needed for the cultivated octoploid strawberry Fragaria x ananassa (2n=8x=56). A diploid (2n=2x=14) relative, Fragaria vesca, has been used as a model system for strawberry genomics because of its small (~200 Mb) basic genome size, ancestry to the octoploid strawberries and availability of inbred lines, among other favorable features.

In this study, a cDNA library was constructed from developing flower buds of Fragaria vesca ssp. vesca cv. 'Yellow Wonder'. A cDNA library of 7680 clones was created using the CLONTECH SMART cDNA Library Construction kit. Sequencing and bioinformatic analyses of 3298 clones resulted in 2717 …

Microvascular Endothelial Cells Of The Bovine Corpus Luteum: A Comparative Study Of The Estrous Cycle And Pregnancy, Jessica A. Cherry

Master's Theses and Capstones

Endothelial cells derived from the corpus luteum (CLENDOs) exhibit a diverse array of characteristics that seemingly complement their wide-ranging properties in luteal function and fate. Reproductive status of the animal (i.e., non-pregnant vs. pregnant) may contribute to the phenotypic/physiologic diversity of microvascular endothelial cells, but information in this regard is limited. Here, structural and functional attributes of CLENDOs derived from the estrous cycle (Days 9-12) were compared with those of pregnancy (Day 60). Initially, lectin binding properties were examined in the cells. Using fluorescent-tagged lectins for Bandeiraea simplicifolia I or concanavalin A, flow cytometric analysis indicated that lectin-binding on CLENDOs …

The Expression Of Heat Shock Protein 70, Heat Shock Protein 90 And Heat Shock Factor 1 Within The Bovine Midcycle Corpus Luteum After Stimulation With Temperature In Vitro And Pgf2alpha In Vitro And In Vivo, Melissa N. Kopka

Master's Theses and Capstones

Environmental and biological stressors affect cellular function. Heat shock proteins (HSPs) are molecular chaperones that safeguard cells against these stressors by protecting endogenous proteins from degradation. Heat shock factors (HSF) are their transcriptional regulators. In the present study, we evaluated whether heat (Experiment 1) or prostaglandin F2alpha (PGF2alpha; Experiments 2 and 3) induces the expression of HSP 70, HSP 90 and HSF1 in the bovine corpus luteum (CL). In summary, in vitro heat treatment elicited a later response in luteal cells by increasing HSP 70 expression at 24 hrs, while in vivo PGF2alpha treatment leads to an earlier response by …

Effects Of Stz Induced Hyperglycemia And Hyperlipemia On Ppargamma And Abca1 In A Hamster Model Of Atherogenesis, Craig Lamarca

Master's Theses and Capstones

Diabetes mellitus accelerates atherogenesis, but the exact mechanisms involved are unknown. This study examined the effects of hyperglycemia on the inflammatory transcription factor peroxisome proliferator activated receptor gamma (PPARgamma), known to be involved in atherogenesis, and the ATP binding cassette A1 (ABCA1) protein that is a downstream product of PPARgamma. ABCA1 is a membrane bound transporter that is involved in reverse cholesterol transport via high density lipoprotein cholesterol (HDL-C). Hamsters were divided into two groups; hyperlipemic animals fed a high fat/high cholesterol control diet (C) and hyperlipemic/hyperglycemic animals that received the high fat diet and were administered streptozotocin. Half of …

Temporal Expression Of Protein Mediators During Pgf2alpha-Induced Luteolysis In Sheep, Bryon F. Ricketts

Master's Theses and Capstones

To study dynamic in vivo biochemical changes within the corpus luteum (CL) during luteolysis, a physiological model mimicking the onset of natural luteolysis was established, in which sheep received sequential systemic pulses of PGF2alpha (20ug/min/lhr) at mid-luteal phase of the estrous cycle. We previously demonstrated that after one pulse of PGF2alpha, the protein levels of extracellular matrix (ECM) regulators, tissue inhibitors of metalloproteinases (TIMPs) -1 and -2 decreased dramatically within one hour of PGF2alpha infusion, while matrix metalloproteinase (MMP)-2 activity increased 4 hrs post infusion. In summary, the early and dramatic decrease in TIMP-1 and TIMP-2 proteins, accompanied by an …

Patterns And Processes Of Soil Carbon Dynamics In A Northeastern United States Forest, Sarah K. Silverberg

Master's Theses and Capstones

Forest soils represent a substantial component of the terrestrial carbon cycle and are an important research area for a number of carbon cycle science initiatives. Whereas patterns of aboveground productivity have been relatively well measured and are increasingly included in regional-scale model analyses, belowground estimates are still highly uncertain and progress has been hampered by methodological difficulties. The lack of data poses a problem because belowground measurements are needed to create complete carbon budgets for terrestrial ecosystems at local, regional and global scales. Ecosystem carbon balances will help identify how and where carbon is being stored, as well as how …