Biology Commons^™

Invasion Of Mouse Fibroblasts And Macrophages By Human Isolates Of Agrobacterium, Karmon Leigh Kriechbaum

Honors Theses

In the past few decades there has been growing evidence that species of Agrobacterium can be opportunistic animal pathogens. One of these species is Agrobacterium tumefaciens, which for years has been studied as a plant pathogen. The results of one published experiment suggested that an Agrobacterium toxin could kill mice (12). Other strong evidence for Agrobacterium as an opportunistic human pathogen is the over fifty published clinical cases in which humans were infected by Agrobacterium species (3, 13-25). In almost all of these cases the patient was immunocompromised in some way and they often had an invasive procedure such as …

Scientific Investigation Of The Plant Pathogen Agrobacterium Tumefaciens, Casey M. Flanagan, Christopher B. Crowell Ii, Bryan P. Markelz

Honors Theses

A. tumefaciensis a plant pathogen and causative agent of Crown Gall Disease, an ailment that results in the development of tumors in plants. It is a unique organism in that it is the only known non-viral pathogen that transfers its DNA into the host cell. Consequently, the majority of the research conducted on A. tumefaciensinvestigates its mechanism of infection. However, A. tumefaciensis also rare to the bacterial world in that its genome is comprised of two chromosomes: one circular and one linear. Most other bacteria only have one circular chromosome. This area of research has been grossly overlooked and therefore …

Characterizing The Role Of Mapk Phosphates In Plants, Laura Asakura

Honors Theses

Mitogen Activated Protein Kinase (MAPK) pathways e ubiquitous ongst eukaryotes, involved in the signal transduction of various external stimuli to the nucleus. In plants, only MAPK pathways related to pathogen- and stress-related responses have been identified. It has been proposed that another MAPK pathway exists in plants, one that is similar to animal MAPK pathways and postulated to connect the regulation of cell growth and the actions of hormones auxin, cytokinin, and gibberellin. In order to establish whether a link exists between the MAPK pathway and hormone signaling in plants, the role of MAPK phosphatases (MKP) on hormone signaling was …

Method For Identification Of Origins Of Replication And Genes Regulated By Dnaa In Bacteria, Olga G. Troyanskaya

Honors Theses

The study is focused on developing computer programs to identify origin of DNA replication based on analysis of total bacterial genomes, scoring regions for number of DnaA binding sites, AT content, DNA adenine methylase boxes, and integration host factors binding sites. The programs were tested on cyanobacterium Synechocystis, and several potential origins were identified. However, no one definite region could be located. Currently, software is being developed to analyze common motifs around the origins of all bacteria with known origins. Genes whose transcription could be regulated by DnaA were identified by searching for DnaA boxes preceding promoter regions.

The Effect Of Different Warm-Downs On Heart Rate Recovery And Muscular Lactic Acid Removal, Alison Jean Perkins

Honors Theses

Competitive swimmers and coaches have had varying ideas about what exercises constitute an appropriate warm-down. However, there is much agreement about what a warm-down should achieve. A good warm-down should do three things. First, a warm-down should be successful in returning the swimmer's elevated heart rate to the resting heart rate level in a relatively short period of time. Second, the warm-down should flush lactic acid out of the muscles as quickly as possible, and restore blood lactate to baseline levels. Finally the warm-down should contribute to improved athletic performances.

In this experiment, it was expected that a decreasing intensity …

Establishing A Link Between Mapk Pathways And Hormones Signal Transduction In Plants, Marc Meulener

Honors Theses

Mitogen Activated Protein Kinase (MAPK) pathways are ubiquitous among eukaryotes, and are involved in the transduction of various extracellular signals. In mammals, three MAPK pathways have been identified, two of these respond to stress, and one can stimulate growth and differentiation. MAPKs have also been found in plants, and it has been suggested that a MAPK pathway may be involved in the signal transduction of auxin and cytokinin, two plant hormones that stimulate growth and differentiation. However, at this time, there is no conclusive evidence supporting this hypothesis. By studying the effect ofMAPKK's of both plant and animal origin in …

Shrimp Aquaculture: An Analysis Of Its Evolution And Organization; And The Development Of A Shrimp Growth Model, Adam Rana

Honors Theses

This paper examines the impetus for the development and subsequent rise of the shrimp aquaculture industry and continues by exploring a model that seeks to improve shrimp farmers' harvests by identifying specific variables affecting shrimp growth. Evidence reviewed from 1980 through today suggest that technological advancements, reduced prices, and increases in both the supply and demand for shrimp are positively associated with the industry's rapid ascent. The introduction of vertically integrated shrimp farms along with the ability for shrimp farmers to differentiate their products are also correlated with the industry's growth. Variables affecting shrimp growth were also studied to determine …

Sustainable Development In The Third World: An Assessment Of The Conservation Actions In South Africa, Brazil, Malaysia, And Madagascar, Carol Rizkalla

Honors Theses

As a library research project, this thesis has gone beyond research in the library, and it could not have been possible without the aid of several people. First I must thank the organizations which responded to my request for information: the Center for Environmental Information, the Rainforest Action Network, the World Wildlife Fund, and Conservation International Specifically, Jill McLaughlin in the Communications Department of CI was· most gracious in sending me management plans for parks in Brazil and Madagascar. Carla Langeveld of the WWF, was very helpful during my visit to their library, and subsequently in my request for the …

Heat Shock Protein Synthesis In The Gorgonian Leptogorgia Virgulata, Evelyn Afif

Honors Theses

No abstract provided.

The Stabilizing Efects Of Disulfide Bonds On Limulus And Octopus Hemocyanin, Danielle Mercatante

Honors Theses

Hemocyanin is a large molecular weight, oxygen carrying protein that is present in the hemolymph of mollusks and arthropods . Limulus, horseshoe crab, hemocyanin is made up of 48 hexamer subunits ( consisting of seven different repeating subunits) each of which have oxygen binding dinuclear copper active centers. Octopus hemocyanin is composed of a single kind of polypeptide chain that has seven functional units, or oxygen binding domains.

The goals of research conducted by Gregory Cole and Danielle Mercatante during the fall of 1996 and spring of 1997 were to gain a biochemical understanding of the structure of Limulus and …

Internal Oral Anatomy: A Comparative Analysis Of The Phyllomedusinae (Anura:Hylidae), Erin B. Hines

Honors Theses

The internal oral anatomy of phyllomedusines has only been described for Agalychnis callydrias using light microscopy. Herein, we compare the internal oral anatomy of the genera Phyllomedusa, Agalychnis, Pachymedusa, and Phasmahyla, using SEM methodology. Tadpoles of ten species were prepared using standard SEM techniques; these larvae ranged from Gosner stages 34-39. Phasmahyla has a unique prenarial arena with three well developed pre-narial arena papillae, whereas the other genera possess the prenarial arena papillae in a semicircular arrangement with the opening directed posteriorly. Pachymedusa differs from Phyllomedusa and Agalychnis by having a low, straight-edge, median ridge; also, its buccal floor arena …

Ubiquitin-Mediated Proteolysis During Gametogenis In Chlamydomonas Reinhardtii, Hall Thomas Mcgee

Honors Theses

Scientists in the field of cell biology have focused considerable attention on a unicellular species of green algae known as Chlamydomonas reinhardtii. This organism is relatively common in bodies of fresh water and some types of soil, but most of the attention is due to its value as a model for biochemical studies. This laboratory has undertaken a broad study of the species including exploration into a special class of proteins, called heat shock proteins, and certain biochemical processes of the organism. The work herein described is a part of this latter study, and also a preliminary step in a …

The Effects Of Thyroid Hormone On Myosin Heavy Chain A-7 Production In Xenopus Laevis Tail And Leg Muscles, Andrew R. Noble

Honors Theses

The present research examines the expression of myosin heavy chain genes in muscle fibers in Xenopus laevis. Characteristically different muscle fibers are expressed before and after metamorphosis. The embryonic myosin proteins that are synthesized during the tadpole stages are replaced with adult myosin heavy chains at metamorphosis. At least one of the adult myosin genes, called A-7, is expressed only in the adult animals, not in tadpoles. The controlling factor or trigger for the expression of this adult gene still remains unknown. There are a number of possible explanations for the A-7 regulation at metamorphosis, including changes in particular hormone …

Use Of Solid-Phase Resins In Pesticide Monitoring, Jenny Bittinger

Honors Theses

The feasibility of using solid-phase resins for monitoring concentrations of pesticides in water was examined. Efforts were made to ascertain relationships between concentrations of a pesticide (methoxychlor) in water and on a resin (AXD-2) under laboratory conditions. Solutions of pesticide in water were drawn through columns of resin. Methylene Chloride was used to absorb the pesticide from the resin. Gas chromatography and ultraviolet spectrophotometry were used to measure concentrations of pesticide.

Description Of The Form Of Wing-Flashing Behavior In Northern Mockingbirds (Mimus Polyglottos), Lyn M. Harper, Kathryn J. Schneider

Honors Theses

The purpose of this study was to describe the form and location of wing-flashing behavior in mockingbirds and to identify differences in flashing between young and adult birds through film analysis techniques and observation. Subjects consisted of 50 mockingbirds from the University of Richmond campus. Analyses of the data suggested that there were three types of wing-flashes based on degree of wing extension. Flashes were most likely to occur in direct sunlight and in grass. No significant differences in the form of flashes between adult and juvenile mockingbirds were found. It is hoped that this study will provide insight into …

The Effect Of Bilateral Adrenalectomy On The Electrocardiogram Of Meriones Unguiculatus, Jeff A. Brown

Honors Theses

The effects of adrenalectomy on the heart rate and electrical potentials of the heart of the Mongolian gerbil were studied (using an EKG) in an attempt to determine in hyperkalemia is the cause of its short survival time following adrenal ablation.

The Distribution Of The Ctenophore, Mnemiopsis Leidyi (A. Agassiz), In A Vertical Thermal Gradient, James J. Leder Iii

Honors Theses

The distribution of organisms in an estuary is affected by a plethora of environmental factors. The ctenophore, Mnemiopsis leidyi, is found to exists over a wide range of these factors, temperature and salinity in particular, allowing it to occupy the estuary year round and make use of low salinity areas unavailable to most marine organisms.

Wood Anatomy And Relationships Of Neowawraea (Euphorbiaceae), Dörthe S. Brandt, W. John Hayden

Honors Theses

Wood anatomy of three specimens of Neowawraea phyllanthoides Rock, a rare and endangered member of Euphorbiaceae endemic to the Hawaiian Islands, is described and compared with woods of other genera of subfamily Phyllanthoideae. Neowawraeahas often been associated or synonymized with Drypetes Vahl. Wood of Neowawraea is diffuse porous, perforation plates are simple, imperforate tracheary elements are thin-walled septate fiber-tracheids, rays are heterocellular and crystalliferous, and axial xylem parenchyma is restricted to a few scanty paratracheal and terminal cells. In several respects these results differ from earlier published descriptions of the wood of this taxon; these earlier descriptions are shown …