Biology Commons^™

Role Of Pseudomonas Produced Hydrogen Cyanide In Biological Control Of Plant-Parasitic Nematodes, Haytham Aly

Dissertations

Plant-parasitic nematodes are among the most devastating pests world-wide, causing extensive damage to important agriculture crops. The management of nematodes is challenging. Current methods used for nematode control rely mostly on using chemical nematicides and naturally resistant plants. Because of serious health and environmental problems associated with chemical control and over use of resistant plants resulting in resistant breaking strains of nematodes, alternative nematode-control methods are needed. Several potential nematode-biocontrol agents, including bacteria and fungi, have been studied for their antagonistic effect toward plant-parasitic nematodes. However, a concise picture about the biological agent’s mechanisms used to antagonize nematodes remains elusive. …

The Role Of The Nascent Polypeptide-Associated Complex In Caenorhabditis Elegans, Paul T. Arsenovic

Masters Theses, 2010-2019

The nascent polypeptide-associated complex (NAC) is a highly conserved protein complex known to play an important role in the development of metazoan organisms, but its molecular function is not well understood. Recent evidence from experiments using Saccharomyces cerevisiae as model supported the hypothesis that the NAC is either a chaperone or a component of the cytosolic chaperone network that interacts with nascent peptides emerging from the ribosome. We tested this model in C. elegans and found that the homologues of the NAC , icd-1 and icd-2, behave like chaperones in the worm. Lack of icd-1 or icd-2 altered the worms …

Effects Of The Exotic Shrub Lonicera Maackii On The Plant Animal Interactions In The Invaded Habitat, Humberto De Paula Dutra

Dissertations

Invasive plants are an economical, political, social, and ecological problem. Some invasive species are a serious concern for society because some of them are diseases, some are agricultural pests, and some become major threats to the ecosystems. Most studies with invasive species are limited because they measure only the impact of the invasion via direct pathways. Unfortunately, the potential for non-native plant species to alter ecosystem functions via indirect pathways mediated by interactions with animals just recently became broadly recognized. This research investigates the interactions of Amur honeysuckle with native fauna and how these interactions indirectly affect other trophic levels …

A Floristic Survey Of The Lichens Of The Spring Mountains, Nevada, Usa, Monica W. Proulx

Theses and Dissertations

This thesis is the culmination of a graduate research project involving a floristic survey of the lichens of the Spring Mountain National Recreation Area (SMNRA), Humboldt-Toiyabe National Forest, Nevada. The project was based on extensive collections made between 1997 and 2007 as part of an air pollution biomonitoring program and a baseline established by Larry St. Clair (BYU). The Spring Mountains are a sky island mountain range in the Mojave Desert located less than an hour northwest of Las Vegas. A floristic survey of the lichen communities in the Spring Mountains represents a major addition to our understanding of the …

Selectivity Of Prey Capture Based On Prey Size In The Venus Fly Trap (Dionaea Muscipula Ellis), Jessica Humenik

Honors Theses

Venus fly traps (Dionaea muscipula Ellis) are carnivorous plants that live in nutrient poor soils and must digest insects to supplement their diets. When a Venus fly trap captures an insect, the plant's traps do not fully close for several minutes, which may allow small prey to escape. It would be beneficial for the plant to consume a large, nutrient-rich prey item as opposed to a small prey item. We tested the hypothesis that Venus fly traps select larger prey by offering plants small and large crickets. A Kruskal-Wallis test and Wilcoxon signed rank test were used to test significance …

Lesson Not Learned: Deepwater Horizon Research And Media Coverage Exposes Gaps In Knowledge And Risky Protocol Within The Oil Industry, Lauren Haller

Honors Theses

An insatiable thirst for oil has led poorly coordinated, risk-prone megasystems deeper into the ocean in search of new oil reserves. Profit-driven agendas at the corporate level have a top-down effect within these megasystems. Cost-cutting and risk-downplaying leaves the field employees unprepared to handle emergencies. A series of costly mistakes led to the 2010 BP Deepwater Horizon oil spill, which caused extensive damage to an already fragile ecosystem in the Gulf of Mexico. The wealth and political influence of the oil industry overpowers lax regulatory agencies and legislation-even though media and research has exposed frustrating parallels between the Deepwater Horizon …

The Involvement Of 26s Proteasome Complex In Selenium Toxicity, Melissa Sabbagh

Honors Theses

Plants that hyperaccumulate elements like selenium to potentially toxic levels may use proteasome complexes to reduce toxicity. The 26S proteasome complex may be a pathway that these plants take to rid themselves of selenium toxicity by destroying damaged proteins caused by selenium. A method to test this hypothesis is to use a hyperaccumulator of selenium Stanleya pinnata and nonhyperaccumulators Populous tremula and Arabdopsis thaliana to evaluate their proteasome abundance without and with selenium. To compare these species western blots were made to show the differences in proteasome abundance. Also to compare the amount of oxidized and an ubiquinated protein in …

Aging Of Florida Blue Crabs, Callinectes Sapidus, Through The Biochemical Extraction Of Lipofuscin, Claire Elizabeth Crowley

USF Tampa Graduate Theses and Dissertations

The blue crab, Callinectes sapidus, represents an ecologically and economically important component of marine and estuarine ecosystems. In Florida, blue crab landings accounted for $9.6 million dollars during the 2010 fishing season. Accurate stock assessments for this valuable fishery are essential. Age is a critical biological component of accurate stock assessments; however, blue crabs and other crustaceans are especially difficult to age because of the complex nature of discrete growth. Biochemical extraction of an aging pigment, lipofuscin, was developed using blue crab eyestalks. The current study investigated the effects of freezing preservation on lipofuscin extracts and examined whether the …

Elucidating Matrix Protein Import And Beta-Oxidation Pathways In Plant Peroxisomes, Bibi Rafeiza Khan

Dissertations

Plant peroxisomes function in fatty acid β-oxidation, jasmonic acid (JA) synthesis, and conversion of indole-3-butyric acid (IBA) to indole-3-acetic acid (IAA). Peroxisomes lack genetic material; proteins required for peroxisomal processes are imported posttranslationally. The PEX5 and PEX7 receptors import proteins containing one of two peroxisomal targeting signals (PTS1 or PTS2). I took a genetic approach to better understand protein import and to elucidate the role of Acyl-CoA Oxidase (ACX) enzymes in the model plant Arabidopsis thaliana. ACX enzymes catalyze the first step in β-oxidation. There are six ACX genes in Arabidopsis and each ACX enzyme acts on specific chain-length targets, …

Species Level Differences In The Ecology Of Two Neotropical Tadpole Species: Responses To Nonlethal Predators And The Roles Of Competition And Resource Use, Zacharia Costa

Theses and Dissertations

Closely related species at the same trophic level are often considered to be ecologically equivalent. However, it is clear that individuals species can have unique functional roles that drive community and ecosystem processes. In this study we examine the growth responses of two Neotropical hylid tadpole species, Agalychnis callidryas and Dendropsophus ebraccatus, to intraspecific and interspecific competition. We also look at density-dependent effects of each on phytoplankton, periphyton and zooplankton, as well as their responses to a caged dragonfly predator through ontogeny. Intraspecific competition affected both species similarly, and their effects on resources were qualitatively similar but quantitatively different. Predators …

Evaluation Of Brook Trout (Salvelinus Fontinalis) Introductions And Re-Introductions Into Four Virginia Blue Ridge Mountain Streams, Michael Isel Iii

Theses and Dissertations

Approximately 100 brook trout were transplanted into each of four Virginia streams in September 2008. Garth Run and Kinsey Run were re-introductions, and Wildcat Hollow and Sweet Run were new introductions. Single pass electrofishing (EF) surveys were conducted with a backpack electrofisher five times during the study. Selected trout > 70 mm but < 100 mm and all trout > 100 mm received a Biomark® 134.2 kHz passive integrated transponder (PIT) tag to identify individual fish upon recapture. Trout were present in all streams almost three years post introductions. Catches decreased across the first four surveys. Young of year catch rates severely decreased from June 2009 (n = …

Factors Controlling Dissolved Organic Carbon Lability And Ecological Fate In The East Branch Swift River, Massachusettes, Hall Eric

Theses and Dissertations

Fluvial systems have been estimated to transform, transport, or store 2.75 petagrams (Pg) of Organic Carbon (OC) per year. Although approximately 1Pg per year of terrestrial carbon is fluxed to the atmosphere through inland waters, little is known about the factors regulating its eventual ecological fate. 28 day lability incubations were conducted concurrent with the measurement of several environmental parameters including discharge, nutrient concentration, DO13C, and DOC:DON at several sites along Bigelow Brook and the East Branch of the Swift River, Massachusetts. Temporal and spatial variation of DOC, DOC:DON and DO13C were explored. Two distinct DOC consumption rates, short and …

An Evaluation Of Disturbance-Induced Nutrient Changes And Climate Responses Of Loblolly Pine Xylem, Rebecca Lynne Stratton

Doctoral Dissertations

Dendrochronological techniques are currently limited to the identification of visible fire scars. However, through the development of new dendrochemical techniques, the potential exists to provide insight into a broader array of pyric ecosystems. In addition, the ability to identify historic climate-growth responses provides a better understanding of the conditions under which historic fire regimes occurred.

This study provides the groundwork for the identification of a dendrochemical nutrient fire signature in xylem and identifies the climate-radial growth responses of loblolly pine (Pinus taeda L.) on five sites in the Piedmont of South Carolina. Changes in N, P, K, Ca, Mg, …

Riparian Ecosystem Response To Hemlock Woolly Adelgid (Adelges Tsugae) Induced Eastern Hemlock (Tsuga Canadensis) Mortality In The Great Smoky Mountains National Park, Usa, Misty Dawn Huddleston

Doctoral Dissertations

An invasive insect, hemlock woolly adelgid (HWA), has initiated widespread hemlock decline and mortality in the Great Smoky Mountains National Park (GSMNP). Riparian hemlock mortality impacts on vegetative and aquatic systems of first-order, headwater streams were evaluated. Reference sites for this study were representative of the best available conditions within the GSMNP, with initial stages of HWA presence. Impacted sites were defined as areas with over 90 percent hemlock mortality. Impacted streams had decreased canopy coverage and increased light availability. Residual red maple, yellow birch, and sweet birch capitalized on the loss of hemlock, with increases in relative basal area …

Characterization Of An S-Layer-Like Protein And Select Antimicrobial Factors Of The Novel Species Lactobacillus Coleohominis, Nicole Ann Marie Ayala

Theses & Dissertations

Lactobacilli in the vaginal tract have been reported be protective against infections with vaginal pathogenic microorganisms through the production of antimicrobial factors, competition for adherence to vaginal epithelium, and coaggregation with pathogens to aid in their clearing. In addition, the antimicrobial factors produced by certain species of lactobacilli have even been shown to interrupt the replication or alter the function of select viruses. Vaginal lactobacilli have been investigated for their antimicrobial characteristics, but little is known about the novel species L coleohominis. recently described in vaginal isolates (Nikolaitchouk et al. 2001). It was hypothesized that L coleohominis, found …

Environmental Regulation Of Dormancy Loss In Seeds Of Lomatium Dissectum, Melissa Dawn Scholten

Boise State University Theses and Dissertations

Lomatium dissectum (Nutt.) Mathias & Constance is a perennial plant found across much of western North America. For disturbed lands within this range, there is interest in using L. dissectum in restoration. A problem in the propagation of L. dissectum is that at the time of dispersal the seeds are dormant. Thus, prior to usage in restoration projects the type of dormancy and the procedures necessary to release dormancy in these seeds must be determined. Determining the type of dormancy and the treatments necessary to break dormancy in L. dissectum seeds was the primary focus of this study. To approach …

Relative Importance Of Environmental Variables For Spawning Cues And Tributary Use By An Adfluvial Lake Sucker, Brian A. Hines

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The endangered June sucker (Chasmistes liorus mictus), which is only found in Utah Lake, UT, historically spawned in all streams flowing into the lake, but due to human-caused changes their spawning is restricted to the Provo River. The purpose of this study was to gain a better understanding of the spawning and early life-history of the
June sucker for recovery purposes. My specific objectives were to determine:

1. what environmental factors attract or deter June suckers to certain Utah Lake tributaries for spawning,
2. what cues June suckers to migrate upstream to spawn,
3. if June suckers use more than one …

Influence Of Detritus Levels And Organic Pollution On Interspecific Resource Competition, Oviposition Behavior, And Larval Survival Of Two Tire-Inhabiting Mosquito Species (Diptera: Culicidae), David Wayne Allgood

Master's Theses

Mosquitoes (Diptera: Culicidae) are vectors of disease in the adult stage, but understanding the factors affecting distributions of the immature stages is important to the understanding and control of adult populations. Discarded automobile tires comprise important larval mosquito habitats. The Asian tiger mosquito (Aedes albopictus) and the southern house mosquito (Culex quinquefasciatus) are two medically important species commonly found in tires, but factors affecting their larval distributions in tires have not been studied, nor have their interspecific interactions. I investigated the effects of chemicals associated with organic pollution on oviposition preferences and larval survival of both …

Tick Infestations And Their Consequences For Migratory Songbirds During Spring Stopover, Johnny Michael Sellers Jr.

Master's Theses

Migratory birds face a number of challenges during their seasonal movement from tropical/sub-tropical Central and South America to more temperate North America. Maintaining health during migration is of particular concern. This study seeks to understand how haematophageous ectoparasites, such as ticks (Ixodida), impact host body condition as they feed on passerines during migration. We hypothesized that foraging location would impact tick acquisition by migrants and that tick burdens during migration would negatively impact body condition. We surveyed 2,064 birds during spring 2009 and 2010 and found that 2.4% of the surveyed birds were infested with one or more …

Thermal Tolerance Of Age-0 Gulf Of Mexico Striped Bass (Morone Saxatilis): Ontogenetic And Genetic Effects, Corey Robert Anderson

Master's Theses

Striped bass, Morone saxatilis, were historically abundant in the Gulf of Mexico region but were largely extirpated from most Gulf rivers by the early 1960s. Since 1967 hatchery stocking has supported populations in Mississippi rivers and to date there is no evidence of natural reproduction. Intolerance of striped bass to high water temperature is a potential factor negatively impacting Gulf striped bass survival and reproductive fitness, and may be a limiting factor to reintroduction of the species in Mississippi. This work contributed to restoration efforts by establishing molecular tools necessary for genetic monitoring of striped bass restoration, and evaluating …

Factors Related To Nest Survival And Over-Winter Survival Of A Northern Bobwhite (Colinus Virginianus) Population In Southwest Florida, Steven Kenneth Brinkley

Masters Theses

The northern bobwhite (Colinus virginianus) is a gallinaceous upland game bird dependent on early successional grassland habitat for reproduction and survival. Bobwhite populations have been declining range-wide for nearly a half century. The habitat of Babcock-Webb Wildlife Management Area (BWWMA) in southwest Florida is mostly virgin, early successional grassland and pine flatwoods. Although BWWMA is located in the far southern end of the bobwhite range, the area is a popular public land for bobwhite hunting. The BWWMA bobwhite population has declined evidenced by a dramatic decrease in harvest over the last 20 years. The two objectives of my …

Effect Of Voluntary Exercise And Diet On The Unfolded Protein Response In The Brain Of Mice, Yu Ho Kim

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The medical costs for many chronic diseases are increasing dramatically and placing a major financial burden on nations and individuals in both developed and developing countries. A number of chronic diseases, such as obesity, type 2 diabetes and some neurodegenerative diseases are all attenuated by a history of physical activity suggesting that they may be interconnected in some way. It has been suggested that cellular stress is a major factor promoting these chronic diseases.

Cellular stress occurs in a specific compartment within the cell, the endoplasmic reticulum, whose normal function is in the synthesis and folding of proteins into the …

The Role Of Receptor Tyrosine Kinase Axl In Pancreatic Ductal Adenocarcinoma And Its Regulation By Hematopoietic Progenitor Kinase 1, Xianzhou Song

Dissertations & Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDA) is one of the most aggressive malignancies with less than 5% of five year survival rate. New molecular markers and new therapeutic targets are urgently needed for patients with PDA. Oncogenic receptor tyrosine kinase Axl has been reported to be overexpressed in many types of human malignancies, including diffuse glioma, melanoma, osteosarcoma, and carcinomas of lung, colon, prostate, breast, ovary, esophagus, stomach, and kidney. However, the expression and functions of Axl in PDA are unclear. We hypothesized that Axl contributes to the development and progression of PDA. We examined Axl expression in 54 human PDA samples …

The Biogeography Of Marbled Godwit (Limosa Fedoa) Populations In North America, Bridget E. Olson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The mission of the U.S. Fish and Wildlife Service (USFWS) is working with others to conserve, protect, and enhance fish, wildlife, plants, and their habitats for the continuing benefit of the American people. Toward fulfillment of that mission, a priority of the USFWS is conservation and management of migratory birds. Effective conservation actions to ensure the continued existence of a species on the landscape cannot be designed without first understanding basic life history characteristics of a species. It is common in the case of migratory birds, that we lack understanding of some of their elemental biological traits.

The Marbled Godwit, …

Movement Ecology Of An Intercontinental Migratory Bird During Spring Stopover, Emily Beth Cohen

Dissertations

Movement ecology is a component of nearly all aspects of animal behavior and an animal’s decision to move is likely influenced by a complex combination of exogenous and endogenous factors. Therefore, an examination of the causes and consequences of organismal movement provides a conceptual framework for understanding complex behavioral strategies. My dissertation research is focused on the movement ecology of an intercontinental migratory songbird during spring migration. I adopted experimental approaches to study the factors influencing how a songbird migrant, red-eyed vireos (Vireo olivaceus), makes decisions in unfamiliar landscapes from the initiation of spring stopover.

I simulated the …

The Study Of The Parasitic Fauna In Sciaenops Ocellatus, Lower Laguna Madre, Texas, Veronica Abrigo

Theses and Dissertations - UTB/UTPA

Parasitological investigations provide information on ecosystem health because parasite prevalence and abundance are influenced by biotic and abiotic environmental changes. This survey classified the parasitic fauna of red drum, Sciaenops ocellatus, in the Lower Laguna Madre, TX. Fish (n = 239) were collected from four study sites (May 2005 - June 2006). Parasite identification consisted of digenean and monogenean trematodes, cestodes, larval nematodes, copepods, and protozoans. Parasite prevalence and host length was positively correlated from South Bay (r=0.473), Port Isabel (r=0.533), Arroyo(r=0.314), and Port Mansfield (r=0.630). Significant differences (p<0.001) between zone and parasite prevalence from Arroyo site indicated a higher prevalence of protozoa and monogeneans and reduced prevalence of digeneans. Statistical analyses indicated the greatest difference between Port Isabel and Arroyo sites ( divided by 2= 48.195; p<0.001; df= 14), and the least difference between South Bay and Arroyo sites ( divided by 2= 20.847; p= 1.06; df= 14).

Characterization And Antibiotic Resistance Profile Of Staphylococci In The Lower Rio Grande Valley, Diana E. Trevino

Theses and Dissertations - UTB/UTPA

Staphylococci from part of the natural flora of humans and some, like Staphylococcus aureus, appear to be evolving antibiotic resistance. The Lower Rio Grande Valley (LRGV) is an area of interest due to its proximity to the US/Mexico border where antibiotics could recently be purchased without prescription. Two libraries from community association (CA-S) and environmental association (E-S) have been collected and the staphylococci isolated. We hypothesize that their SCCmec type, which aids the staphylococci in antibiotic resistance, will not display classically defined association schemes and will surface in many species of staphylococci. This study generates antibiotic resistance profiles via antibiotic …

Effect Of Pesticides On Salicylic Acid Binding Protein 2 (Sabp2) And Plant Defense, Joannes Petrus Yuh

Electronic Theses and Dissertations

Tobacco SABP2 has been shown to display high affinity for salicylic acid (SA) and methylsalicylate (MeSA) and plays an important role in SAR signal development. Using biochemical approach, SABP2 has been shown to demonstrate strong esterase activity in converting MeSA to SA. Recent study shows that tetra fluoroacetophenone, a synthetic analog of SA, competitively inhibits SABP2 esterase activity as well as suppresses SAR signal development in tobacco mosaic virus (TMV)-infected tobacco plants. Not much has been studied on the effect of pesticides on plant defenses. Because both AChE and SABP2 are esterase-like proteins belonging to α/β hydroxylase superfamily, we hypothesize …

Shrubs As Sentinels Of Ordnance Contamination: Using Plant Physiology And Remote Sensing To Detect Tnt In Soils, Kathryn Rubis

Theses and Dissertations

Methods for rapid, safe and effective detection of unmapped buried ordnance are vital to the protection of humans and environmental quality throughout the world. This study aimed to investigate the use of phytosensing and to understand the physiological response of woody plants to 2,4,6-trinitrotoluene (TNT) contamination. Baccharis halimifolia were potted in soils containing various concentrations of TNT and physiological responses were observed over a 9-week experimental period. Measurements included the collection of remotely sensed data, such as hyperspectral reflectance and chlorophyll fluorescence, and traditional plant-level physiological data. In accordance with the hypothesis, low levels of TNT improved physiological response in …

Association Of Glpq With Serum-Resistance In Salmonella Typhimurium, Kristie Carlotta Mitchell

Master's Theses and Doctoral Dissertations

Salmonella typhimurium is a leading cause of infectious human gastroenteritis and systemic disease when it escapes into the bloodstream. The human serum complement system is central in fighting systemic bacterial infections. S. typhimurium exhibits resistance to killing by complement (serum-resistance), a trait conferred by several known virulence genes. This study investigates a potential chromosomal complement-resistance gene in S. typhimurium tagged by TnphoA insertional transposon mutagenesis. S. typhimurium strain EM876 has a chromosomal TnphoA insertion and reduced serum-resistance. Inverse PCR and subsequent DNA sequence analysis reveal the insertion to be in the gene glpQ. glpQ codes for a …