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Woody Plant Communities Of The Iowa Loess Hills: Expansion From 1855 To 2000, Extant Composition, And Ecological Succession., Melanie I. Trecek-King

Student Work

The Loess Hills of western Iowa are a unique geologic landform historically covered by scattered bur oaks in a matrix of mixed-grass prairie. Since European settlement, however, woody plant encroachment has altered the ecosystem and presently endangers the last substantial prairies remnants in Iowa. Aerial photographs from 2000 and General Land Office field survey notes from the 1850s documented an increase in woody Plant cover from 7% in 1855 to 25% in 2000 for three centuries in the Loess Hills region of western Iowa. Woody Plant species composition along a lowland-ridge-top coenocline on both north and south aspects in centrally …

Insect Communities Of Native And Restored Wet-Mesic Tallgrass Prairies In Central Nebraska: Leafhoppers, Planthoppers, Treehoppers, And Ants., Kristine Trinette Nemec

Student Work

Insect diversity was compared between and among three native and three restored wet-mesic tallgrass prairies along the Platte River in central Nebraska in order to assess both the relative success of restorations and the relationship between insect and plant diversity. Insects were sampled using sweep nets from two transects within each prairie during early June, mid-July, and mid-August 2000. Plant species composition was assessed along each transect in early June and mid-August. A total of 71 leafhopper, 12 planthopper, 3 treehopper, and 11 ant taxa were identified, of which 20 were prairie endemic and 16 were highly remnant-dependent. Eighty-five plant …

The Effect Of Fire Season And Frequency On The Plant Community Of A Restored Tallgrass Prairie., Nathaniel David Birks

Student Work

The effect fire season and frequency was evaluated in 2001 at a 65 ha restored tallgrass prairie in eastern Nebraska using permanent plots established in 1978 and first evaluated in 1979. Treatments included annual and quadrennial burning in spring, summer, and fall as well as unburned plots. Overall, the number of species increased from 28 in 1979 to 30 in 2001, with a shift from ruderal to native species. Shannon diversity (H’) increased significantly across all treatments during this time. Canopy cover of grasses (+19%) and forbs (+18%) increased significantly. However, only forbs showed a significant difference among treatments in …

Direct Evidence For A Membrane Deforming Motif In Endophilin: Implications Beyond Synaptic Vesicle Recycling, Khashayar Farsad

Yale Medicine Thesis Digital Library

Effective neurotransmission is dependent on fast, reproduceable synaptic vesicle recycling. The synaptic vesicle recycling process is a complex event involving both protein-protein, as well as protein-lipid interactions. A central part of the retrieval process of synaptic vesicles lies in the ability of soluble proteins to deform the plasma membrane into a nascent bud which will eventually reform a fully competent synaptic vesicle upon fission. This process involves clathrin-coat proteins, which form a protein scaffold around the vesicle bud, as well as proteins which have more recently been thought to be involved in generating the high curvature membranes present at the …

A Comparison Of Floristic Diversity In Old-Growth Versus Mid-Successional Secondary-Growth Hardwood Forests Of The White Mountain National Forest, New Hampshire, United States, Leslie Marie Teeling-Adams

Doctoral Dissertations

There is currently debate over whether managed forests will ever regain the species diversity of old-growth stands. While succession and response to disturbance of tree species has been extensively researched, little similar effort has focused on understory herbaceous communities. This study conducted large-scale, comprehensive botanical inventories of three old-growth and three mid-successional (80--100 year old) secondary forest stands in New Hampshire's White Mountain National Forest (WMNF). Cluster analysis and TWINSPAN grouped the secondary sites within two steps. Old-growth floras were significantly richer in total, total herbaceous, woodland herbaceous, and unique herbaceous species. Abundance distributions of the two treatment groups were …

Transcriptional Elongation Defects Enhance Upstream Poly (A) Site Utilization And Spt5 Affects Mrna Degradation Through Its Physical And Functional Interaction With Ccr4 -Not Complex, Yajun Cui

Doctoral Dissertations

While a number of proteins are involved in elongational processes, the mechanism of action of most of these factors remains unclear primarily because of the lack of suitable in vivo model systems. We have identified in yeast several genes, each of which contain internal poly (A) sites, whose full-length mRNA formation is reduced by mutations in RNA polymerase II subunit RPB2, elongation factor SPT5, or TFIIS. RPB2 and SPT5 defects also promoted the utilization of upstream poly (A) sites for genes that contain multiple 3 ' poly (A) signaling sequences, supporting a role for elongation in differential poly (A) site …

Evaluation Of Bacteriophage And Viral Persistence During Alkaline Stabilization In Sludge And Biosolids Intended For Land Application, Jacqueline Joy Brabants

Doctoral Dissertations

The use of lime to reduce or eliminate pathogen content is a cost-effective treatment method currently being employed in many Class B biosolids production plants in the United States. A bench scale model of lime stabilization was designed to evaluate pathogen persistence. The survivability of poliovirus type 1, fecal coliforms, Salmonella, adenovirus type 5, rotavirus Wa, and the male-specific bacteriophage MS-2 was evaluated under lime stabilization conditions in various matrices. Salmonella and fecal coliforms were evaluated at 28°C and poliovirus and MS-2 were evaluated at both 28°C and 4°C for survivability under lime stabilization conditions in a sludge matrix. All …

Spatial Modeling And Visualization Of Habitat Response To Hydrologic Restoration In New England Salt Marshes, Raymond Anthony Konisky

Doctoral Dissertations

Anthropogenic alterations that restrict tidal flows negatively impact 20% of New England salt marshes, but management attempts to restore tides to these sites can be met with unexpected or less than optimal results. Restoration planners may be hindered by a lack of synthesized information regarding important biotic and abiotic factors that determine the distribution of dominant salt marsh plants and invasive species. An ecosystem model was developed to better predict salt marsh habitat response to hydrologic modification as a synthesis of existing models for biomass production, marsh elevation, tidal hydrology, and plant succession. A field experiment was conducted to provide …

Nuclear And Cytoplasmic Genetic Variation In Picea: Dna Markers For Evaluating Past Migration, Introgression And Evolutionary History, Joselle Germano-Presby

Doctoral Dissertations

Mitochondrial and chloroplast haplotypes were identified in range-wide populations of white (Picea glauca), black (P. mariana ) and red spruce (P. rubens). The chloroplast genome exhibited more intraspecific variation than the mitochondrial genome. Red spruce displayed the most total chloroplast genetic diversity (H T = 0.52). Neighbor-joining analysis arranged the chloroplast haplotypes into three monophyletic groups that were nearly 100% species-specific. These results strongly refute a previously proposed progenitor/derivative relationship of black/red spruce. Red and black spruce were estimated to have diverged from their common ancestor ∼0.6--3.5 million years ago. Mitochondrial diversity detected in black spruce was attributed to interspecific …

Satellite Indices Of Fluvial Influence In Coastal Waters, Joseph E. Salisbury Ii.

Doctoral Dissertations

In this dissertation a suite of satellite, discharge and in-situ measurements is used to explore the spatio-temporal distribution of terrestrial constituents in coastal environments. The covariance between riverine delivery of optically active constituents and the corresponding optical variability in neighboring coastal waters for the Mississippi and Orinoco Rivers is documented. From this work, satellite-based indices of fluvial influence (IFI), are developed which contain information on the spatial extent of riverine constituents in coastal waters. The IFI is defined as the correlation between time series of riverine discharge and an ocean color satellite-derived property in the region proximal to a river's …

Factors Associated With Atlantic White -Cedar Seedling Recruitment On Microtopographic And Landscape Scales, Brown Mill Pond, Rye, New Hampshire, Lara Megdane Gengarelly

Doctoral Dissertations

The decline of Atlantic white-cedar (Chamaecyparis thyoides) throughout its range has motivated researchers to investigate cedar seedling recruitment. In this study, conducted at Brown Mill Pond in Rye, New Hampshire, the distribution pattern of cedar seedlings was studied in order to identify which, if any, biological or physical factors observed at a microtopographic scale were associated with seedling presence. On a landscape scale, five previously identified cedar communities were measured for differences in water table level and soil moisture in order to determine associations between stand dynamics and hydrology.

A field survey showed that cedar seedlings were (1) absent from …

Investigations Into The Digestive System Proteases Of Argiope Aurantia (Araneae: Araneidae), Hemolytic Agents Of Spider Venoms, And The Role Of Both In Necrotic Arachnidism, Matthew Joseph Foradori

Doctoral Dissertations

Necrotic arachnidism, or tissue necrosis following spider bites is a widespread problem. Knowledge of the exact mechanism that produces such lesions is still incomplete. Here I have examined spider digestive fluid proteases and spider venom enzymes (e.g., sphingomyelinase D and phospholipase A2) for their potential to cause necrotic lesions, as both are thought to be primary agents.

The digestive fluid of Argiope aurantia was examined for its ability to cleave a variety of extra-cellular matrix proteins, including collagen, elastin, and fibronectin. Having confirmed that the fluid has collagenases, the digestive fluid was injected into the skin of rabbits to observe …

Assessment Of The Fate Of Cryptosporidium Parvum, Giardia Lamblia And Ascaris Lumbricoides In Class A Composting And Class B Lime Stabilization Biosolids Treatment Processes, Christine L. Bean

Doctoral Dissertations

The management of biosolids in the United States has become an issue of public health concern in regard to disposal. Congress created the Clean Water Act in 1972 to protect waters in the United States and as a result, no longer can human waste be dumped into oceans or rivers. Means of disposal of biosolids are focused on land application today. The practice of land application takes into consideration the classification of the biosolids material and management practices to control access to and growth of crops on the land. Biosolids are classified as either Class A or Class B depending …

Calcium -Dependent Protein Kinases Are Myristoylated And Associated With Different Membranes In Arabidopsis Thaliana, Sheen Xun Lu

Doctoral Dissertations

In plants, calcium-dependent protein kinases (CDPKs) are the predominant calcium-stimulated kinases and are known to be involved in many cellular processes. CDPK enzymatic activity previously has been detected in many locations in plant cells, including the membrane fraction. However, little is known about the subcellular locations of individual CDPKs or the mechanisms involved in targeting them to those locations. Arabidopsis contains 34 genes that are predicted to encode CDPKs and 28 of the predicted CDPK proteins have potential myristoylation motifs at their amino termini. Myristate is a 14-carbon saturated fatty acid that is attached co-translationally to the amino-terminal glycine of …

Age, Growth, And Reproductive Biology, Of The Winter Skate, Leucoraja Ocellata, In The Western Gulf Of Maine, James Antoni Sulikowski

Doctoral Dissertations

This study describes the age, growth and reproductive biology of the winter skate, Leucoraja ocellata, in the Western Gulf of Maine. Age was estimated by enumerating annular bands within the vertebral centra. Precision of the age estimates was evaluated using the Index of Average Percent Error and the annual nature of growth band formation was documented using marginal increment analyses. Growth was assessed with the use of the von Bertalanffy growth equation. Age and size at maturity was estimated by measuring morphological and histological changes in the reproductive tract and circulating steroid hormone concentrations. Maturity ogives for males predict that …

Factors Affecting Plant Community Composition And Dynamics In The Ossipee Pine Barrens, New Hampshire, Lauren Fredrick Howard

Doctoral Dissertations

Forty-one 0.25 ha sites were sampled in the Ossipee Pine Barrens to identify and describe tree community types and investigate factors controlling forest composition and dynamics. Every site had three site-time assemblages (STA's) representing past, present, and future trees. Past (1952) vegetation was calculated based on reverse growth estimates of current stems and stumps. Future (2052) vegetation was predicted by current sapling (<10 cm dbh and ≥1 m tall) relative densities.

Cluster analysis produced three community types from 121 STA's: pitch pine, mixed pine-hardwoods, and red maple. Pitch pine communities comprised 63% of sites in 1952, but declined since. Mixed pine-hardwoods peaked at 58% in 2002, but were …

Characterization Of Prokaryotic Diversity In A Chlorinated Solvent-Contaminated Bedrock Aquifer Using Denaturing Gradient Gel Electrophoresis, Ribosomal Dna Sequencing, And Real Time Pcr, Walid Naser

Doctoral Dissertations

A culture-independent molecular phylogenetic approach was implemented to investigate spatial and temporal variations in microbial diversity and abundance in a chlorinated solvent-contaminated bedrock aquifer. Core and groundwater samples were collected from several boreholes and included the following samples: (1) groundwater that was associated with the core, (2) open fractures and (3) partially mineralized sealed fractures (PMSF) exposed by striking the core with a surface-sterilized geology hammer. DNA representing the attached and unattached microbial communities was extracted from these samples, and the 16S rRNA gene was amplified with primers specific for Bacteria, Archaea, sulfate reducers, Geobacteraceae family, Dehalorespirers (Dehalococcoides sp. and …

Biology, Culture, And Environment: The Struggle For Hegemony In Arizona, Sondra Kae Cosgrove

UNLV Retrospective Theses & Dissertations

This is an examination of the various cultural groups who have attempted to extend hegemony control over what is now the state of Arizona. Each chapter focuses on the ways different societies adapted to the region's challenging environment; paying particular attention to those that sought to integrate their neighbors into their own socioeconomic systems, whether by force or through negotiation. The rise and fall of the indigenous Hohokam civilization marks the first phase in this struggle for hegemony, while conflicts between Spaniards and Indians characterize the second. The third, and so far, final cycle concludes with Euro-Americans seizing the region …

The Relationship Between Anthropogenic Disturbance And The Distribution Of A Nonindigenous Species, Echinogammarus Ischnus Stebbing, 1898 (Amphipoda: Gammaridae), At Great Lakes Coastal Margins, Misun Kang

Electronic Theses and Dissertations

Invasive species are becoming increasingly common components of Great Lakes zoobenthic communities. Elton (1958) proposed that biotic resistance against exotic species establishment is greater in intact communities than in those disturbed by human activities. However, Baltz and Moyle (1993) suggested that if abiotic conditions are appropriate, invasion is likely, regardless of the biota already present. I tested these hypotheses by investigating the distribution of Echinogammarus ischnus Stebbing, 1898, an exotic amphipod, at U.S. Great Lakes coastal margin sites influenced by varying degrees of anthropogenic stress. Thirty-nine sites supporting Gammarus fasciatus Say, 1818, a common amphipod with habitat preferences similar to …

The Impacts Of Polycyclic Aromatic Hydrocarbons On Brown Bullhead (Ameiurus Nebulosus) Apoptosis Regulation., Christopher Ronald Lindholm Busch

Electronic Theses and Dissertations

In this study, it is hypothesized that the apoptotic pathways in the brown bullhead are altered by the presence of PAHs with a final outcome of elevated tumor formation. To evaluate the impact of PAHs on the apoptotic process, three separate, but related, studies were completed to characterise apoptosis in brown bullhead. First, the impact of known apoptotic inducers (staurosporine, cycloheximide, and TNF-alpha) on cell death in brown bullhead fibroblasts was characterized (Chapter 1). Secondly, fibroblasts were exposed to PAHs to examine how exposure to an environmentally relevant genotoxic substance alters the apoptotic pathway (Chapter 2). Finally, bullheads from various …

Propagule Pressure: A Null Model For Biological Invasions., Robert I. Colautti

Electronic Theses and Dissertations

I begin with a review of recent attempts to identify characteristics of species 'invasiveness' (i.e., the ability to invade) and habitat 'invasibility' (i.e., the susceptibility to invasion), and find little support for an emerging consensus on species- or habitat-specific characteristics. Moreover, I find that few studies consider hypotheses based on the concept of 'propagule pressure' (i.e., introduction effort), despite its potential as a confounding factor. Another barrier to generalizations may be the divergent use of operationally important terms like 'invasive', 'naturalized', or 'nuisance'. I therefore introduce a framework that conceptualizes biological invasions as a series of obligatory stages. This stage-based …

Factors Regulating Biomass And Contaminant Uptake By Round Gobies (Neogobius Melanostomus) In Western Lake Erie., Victoria Ann. Lee

Electronic Theses and Dissertations

Round gobies, an invasive fish from the Ponto-Caspian region of Eastern Europe arrived in the western basin of Lake Erie in 1993. A bioenergetics model was developed for round gobies to quantify the flow of energy and contaminants from the benthos to pelagic fishes. Weight and temperature dependent coefficients for metabolism and consumption were derived. Food consumption increased with temperature up to 26°C before sharply decreasing and decreased with increasing fish weight. Oxygen consumption was inversely related to body mass and increased exponentially with temperature. Additional parameters were obtained from the literature to describe specific dynamic action, egestion and excretion. …

Zoobenthic Succession In Constructed Wetlands Of The Fort Mcmurray Oil Sands Region: Developing A Measure Of Zoobenthic Recovery (Alberta)., Christel Lynn. Leonhardt

Electronic Theses and Dissertations

This study investigated the effect of oil sands process material (OSPM) on the zoobenthic community of constructed wetlands in the Fort McMurray oil sands region. The unique characteristics of OSPM-affected wetlands may modify the successional trajectory of invertebrate communities compared to that of high or low-conductivity reference wetlands. The zoobenthic community of 31 wetlands, aged 0 to 30 years, was simultaneously sampled, allowing inference into the chronological sequence of change that results with wetland succession. Wetlands were categorised a priori into one of three classes: low conductivity (<700 muS/cm) or high conductivity (700--2,500 muS/cm) reference wetlands or OSPM-affected wetlands (700--4,000 muS/cm) containing tailings and/or water from bitumen extraction. Invertebrate communities in each wetland were assessed using core, artificial substrate, and sweep net sampling methods. Principal components analysis and discriminant function analysis were used to classify each OSPM-affected wetland as being "equivalent to young" or "equivalent to mature" reference wetlands. Restoration of mined areas to pre-mining conditions of diversity and abundance of habitat types, using wetlands as a component of a reclamation strategy, is a viable option. (Abstract shortened by UMI.)Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2003 .L46. Source: Masters Abstracts International, Volume: 42-02, page: 0520. Adviser: J. H. Ciborowski. Thesis (M.Sc.)--University of Windsor (Canada), 2003.

Parallel Stochastic Context-Free Grammar Training For Trna Secondary Structure Prediction., Kaiyuan. Shi

Electronic Theses and Dissertations

In this thesis, parallel computing methods are used to construct a stochastic context-free grammar for analyzing the secondary structure of tRNA molecules. Stochastic context-free grammars are basically probabilistic languages that parse a sequence/molecule and output its probability of whether or not it belongs to the sequence family modeled by the grammar and at the same time predict the molecule's secondary structure. Stochastic context-free grammars can be converted from corresponding context-free grammars, by assigning probabilities to the grammar's production rules. The use of stochastic context-free grammars to analyze the secondary structure of RNA molecules was limited due to time and space …

Primary Production And Phytoplankton Dynamics In Western Lake Erie., Mark Alan John. Fitzpatrick

Electronic Theses and Dissertations

Primary production studies have had a profound impact on the management of the Great Lakes, culminating with the Great Lakes Water Quality Agreement of 1972 between Canada and the United States. The current study examined primary production and phytoplankton dynamics in western Lake Erie with application to water quality and fisheries management practices. Annual primary production, estimated using a 14carbon tracer and both in situ and constant light incubations, ranged from 320--370 g C m-2 y-1 during the study period and was similar to the 340 g C m-2 y -1 reported in the basin for 1970. Phytoplankton standing crop, …

Enhancing The Yield Of Target Tissue And Secondary Metabolites In Calendula Officinalis L., A Medicinal Plant., Christie Lynn. Stewart

Electronic Theses and Dissertations

Medicinal crops can be usefully studied in controlled hydroponic systems in which various factors can be manipulated to increase target plant tissue yield and secondary metabolite production. In this project floral tissue and other plant organs of the medicinal plant Calendula officinalis and four important secondary metabolites: quercetin, rutin, isorhamnetin-3-O-glucoside and isorhamnetin-3-rutinoside were quantified under contrasting conditions in terms of phosphorus concentration, rate of nutrient supply and simulated foliar herbivory in a factorial experimental design. The objectives were to identify conditions that will maximize the yield of target plant tissue, maximize the production of secondary metabolites and minimize the variation …

Effects Of Land-Use Patterns And Land Ownership On Biodiversity In The Natural Areas Of The Niagara Escarpment World Biosphere Reserve (Ontario)., Rosamonde Ellen. Page

Electronic Theses and Dissertations

Existing under the protection of provincial legislation, the natural areas and biodiversity of the Niagara Escarpment World Biosphere Reserve have been particularly well-studied. I mapped land ownership and land-use patterns in the land matrix surrounding each of the 98 designated natural areas of the Reserve area, and then analysed their effects on estimates of biodiversity. Increasing percentages of recreational land-use surrounding a natural area were associated with degradative effects on rare plant species, as well as species with endangered or threatened status. Numbers of provincially rare plant species and endangered or threatened species were positively related to increasing amounts of …

An Electro-Olfactogram Investigation Of The Responses Of Female Round Gobies (Neogobius Melanostomus) To Conspecific Odours And Putative Sex Pheromones., Andrea Jane Belanger

Electronic Theses and Dissertations

The round goby is an aggressive and prolific bottom dwelling fish species that threatens native economically and ecologically important fish in the Great Lakes. Its reproductive success may be mediated by the use of sex pheromones, with males attracting reproductive females to nests for spawning. As steroids have repeatedly been shown to function as conspecific signalling molecules (pheromones) mediating reproductive processes in teleosts, round goby males may release specific steroidal compounds to function as attractants to reproductive females. In this study, measurement of olfactory epithelial activity through electrolfactogram (EOG) analysis has shown that odors released by reproductive round goby males …