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Full-Text Articles in Life Sciences

Environmental Ecology And Life History Variation Of Perkinsus Marinus, Lydia M. Bienlien Jan 2022

Environmental Ecology And Life History Variation Of Perkinsus Marinus, Lydia M. Bienlien

Dissertations, Theses, and Masters Projects

Marine resources provide a growing world population with the opportunity to increase food security, particularly through aquaculture. Oysters are prominent aquacultured species, but marine diseases are a threat to the growth and sustainability of oyster culture. Perkinsus marinus is the most important oyster pathogen of the Atlantic and Gulf coasts of the U.S., where it causes substantial mortality. Despite being one of the most well-studied protozoan parasites of bivalve molluscs, much is still unknown about P. marinus. This research investigated multiple characteristics of P. marinus.In Chapter Two, the environmental ecology of P. marinus was explored through tidal sampling and year-long …


The Effect Of Slow Release Cortisol Implant On Humoral Immune Responses And Infection Prevalence Following Experimental Challenge With Flavobacterium Psycrophilum In Rainbow Trout (Oncorhynchus Mykiss), Fatima Quddos Jan 2020

The Effect Of Slow Release Cortisol Implant On Humoral Immune Responses And Infection Prevalence Following Experimental Challenge With Flavobacterium Psycrophilum In Rainbow Trout (Oncorhynchus Mykiss), Fatima Quddos

Dissertations, Theses, and Masters Projects

Pacific salmon migrate long distances to spawn as part of their life cycle. During this journey from sea to their natal stream, they undergo major endocrine, physiological and immune changes. Cortisol, the primary stress hormone, gradually increases during the journey. Persistent high cortisol levels have deleterious health effects, including suppression of the antibody response. However, pathogens encountered during their journey may stimulate antibody responses to overcome the infection. My main research question focuses on how salmonids balance the immunosuppressive effects of high cortisol levels with activation of the antibody response. A recent field study from our lab showed a transient …


The Development Of Fiddler Crabs (Uca Spp.) As A Comparative Model System For The Parasitic Dinoflagellate, Hematodinium Perezi And Its Natural Host The Blue Crab, Callinectes Sapidus, Patricia Anne O'Leary Jan 2018

The Development Of Fiddler Crabs (Uca Spp.) As A Comparative Model System For The Parasitic Dinoflagellate, Hematodinium Perezi And Its Natural Host The Blue Crab, Callinectes Sapidus, Patricia Anne O'Leary

Dissertations, Theses, and Masters Projects

Herein, I have completed several experiments which encompass developing fiddler crabs as a model system, as well as sentinel and temperature studies to investigate biotic and abiotic factors in parasite transmission. My studies show which factors prevent, delay, or accelerate transmission and progression of H. perezi. The fiddler crab experiments by chapter are as follows: Chapter 1. I screened adult and juvenile fiddler crab populations for naturally occurring H. perezi infections at endemic and non-endemic sites. No natural infections were found in the adult or juvenile populations (Chapter 1 and 3). I completed inoculation trials with U. minax, U. pugnax, …


Reproductive Investment In Crassostrea Virginica As An Indicator Of A Tolerance Response To Perkinsus Marinus, Lauren Irene Huey Jan 2018

Reproductive Investment In Crassostrea Virginica As An Indicator Of A Tolerance Response To Perkinsus Marinus, Lauren Irene Huey

Dissertations, Theses, and Masters Projects

The Chesapeake Bay region values oysters for the ecosystem services, lucrative fishery, and historical significance that the species embodies; however, over the last half century, oyster abundances have been reduced to historical lows. Two protozoan parasites, Perkinsus marinus and Haplosporidium nelsoni, have been major influences on oyster populations, especially in high-salinity regions. Today, the population is recovering; catches have increased and oysters have expanded spatially. to investigate the cause of the recovery, three measurements were made on slides of oysters from a histological archive collected during summer at Wreck Shoal in the James River from 1988–2017: oocyte diameter, oocyte density, …


Impact Of The Parasitic Nematode Anguillicoloides Crassus On American Eels (Anguilla Rostrata) In Chesapeake Bay, Zoemma Taudel Warshafsky Jan 2017

Impact Of The Parasitic Nematode Anguillicoloides Crassus On American Eels (Anguilla Rostrata) In Chesapeake Bay, Zoemma Taudel Warshafsky

Dissertations, Theses, and Masters Projects

American eels are infected by the introduced parasitic nematode, Anguillicoloides crassus, which can cause significant damage to their swimbladders. Despite the high prevalence and severe damage caused by A. crassus, the population level effects on American eels are not well understood. The prevalence and swimbladder damage in young glass eels and elvers are relatively unstudied, despite the potential for this parasite to cause tissue damage. Additionally, the effects of environmental, temporal, and spatial variables have been debated in previous studies without consensus. Also, the potential for eels to recover from infection and tissue damage has been speculated but not definitively …


Influence Of Perkinsus Marinus Infection And Oyster Health On Levels Of Human-Pathogenic Vibrios In Oysters, Lydia M. Bienlien Jan 2016

Influence Of Perkinsus Marinus Infection And Oyster Health On Levels Of Human-Pathogenic Vibrios In Oysters, Lydia M. Bienlien

Dissertations, Theses, and Masters Projects

The eastern oyster Crassostrea virginica is an ecologically and commercially important species whose natural populations have been devastated by overharvesting, habitat destruction, and disease, but the rapid growth of oyster aquaculture has shown potential to restore the economic significance of this species. A key threat to the growth and sustainability of oyster aquaculture is the association of human-pathogenic Vibrio bacteria with product marketed for raw consumption. Two Vibrio species, Vibrio vulnificus and Vibrio parahaemolyticus, are the causes of the highest rates of seafood consumption-related mortality and gastrointestinal illness, respectively. Identification of the factors influencing V. vulnificus and V. parahaemolyticus prevalence …


A Novel Test Of The Immunocompetence Handicap Hypothesis, Jessica H. Ebers Jan 2014

A Novel Test Of The Immunocompetence Handicap Hypothesis, Jessica H. Ebers

Dissertations, Theses, and Masters Projects

No abstract provided.


Sublethal Effects Of Methylmercury On The Songbird Immune Response: An Experimental Study, Catherine Ann Lewis Jan 2012

Sublethal Effects Of Methylmercury On The Songbird Immune Response: An Experimental Study, Catherine Ann Lewis

Dissertations, Theses, and Masters Projects

No abstract provided.


Molecular Genetic Studies Of Hematodinium Sp., A Parasitic Dinoflagellate Of The Blue Crab, Callinectes Sapidus, Katrina M. Pagenkopp Lohan Jan 2011

Molecular Genetic Studies Of Hematodinium Sp., A Parasitic Dinoflagellate Of The Blue Crab, Callinectes Sapidus, Katrina M. Pagenkopp Lohan

Dissertations, Theses, and Masters Projects

Economically viable fisheries for the American blue crab, Callinectes sapidus, occur in the USA from Delaware Bay to the Gulf of Mexico. Unfortunately, a number of factors, including overexploitation, degraded habitats, and disease, have contributed to the decline of blue crab populations in the USA. In April 2008, the Secretary of Commerce declared the blue crab fishery in the Chesapeake Bay a "commercial fishery disaster." One factor potentially contributing to the decline of blue crab populations in high salinity waters is infection with Hematodinium sp., a parasitic dinoflagellate, which can cause significant mortalities in blue crab populations. Since the first …


The Development And Application Of An Antibody-Based Biosensor For The Detection Of The Petroleum-Derived Compounds, Candace Rae Spier Jan 2011

The Development And Application Of An Antibody-Based Biosensor For The Detection Of The Petroleum-Derived Compounds, Candace Rae Spier

Dissertations, Theses, and Masters Projects

Petroleum is one of the most important natural resources, but can also be problematic to environmental and human health. Petroleum is comprised of thousands of compounds, including polycyclic aromatic hydrocarbons (PAHs) and heterocycles, some of which are toxic and/or carcinogenic. Traditional analytical methods for environmental monitoring of low-level PAHs are time-consuming labor-intensive, and often laboratory-bound. Efforts to achieve timely, sensitive, and accurate analysis of PAHs in the field have become a priority for environmental research and monitoring. Antibody-based biosensors are presently being developed for environmental analysis. Anti-PAH antibody molecules can be coupled with electronic transducers to provide new biosensor technology …


Role Of Apolipoprotein A-1 In Defense Against Bacteria By Striped Bass (Morone Saxatilis), L. Danielle Johnston Jan 2006

Role Of Apolipoprotein A-1 In Defense Against Bacteria By Striped Bass (Morone Saxatilis), L. Danielle Johnston

Dissertations, Theses, and Masters Projects

No abstract provided.


Dynamics Of The Host-Parasite Interaction: In Vitro Correlates Of Crassostrea-Induced Modulation Of Perkinsus Marinus Function, Christopher G. Earnhart Jan 2004

Dynamics Of The Host-Parasite Interaction: In Vitro Correlates Of Crassostrea-Induced Modulation Of Perkinsus Marinus Function, Christopher G. Earnhart

Dissertations, Theses, and Masters Projects

Perkinsus marinus is an alveolate protozoan parasite of the eastern oyster (Crassostrea virginica) which is responsible for much of the decline in United States oyster populations. Perkinsus marinus can be cultured in vitro, but is rapidly attenuated in the process. Supplementation of a protein-free medium with oyster products altered proliferation, changed protease expression in the parasite extracellular products (ECP), induced morphological forms typically seen in vivo, and partially reversed parasite attenuation. Supplements derived from dissected oyster tissues were used to determine if these changes could be differentially elicited. These supplements, with the exception of adductor muscle, reduced proliferation. Whole oyster …


The Specific Immune Response In Rainbow Trout: Somatic Hypermutation And Vh Gene Utilization, Teresa D. Lewis Jan 2000

The Specific Immune Response In Rainbow Trout: Somatic Hypermutation And Vh Gene Utilization, Teresa D. Lewis

Dissertations, Theses, and Masters Projects

The study of antibody responses in prominent aquaculture species such as the rainbow trout, Oncorhynchus mykiss, can facilitate vaccine development and contribute to producing useful paradigms of adaptive immunity in lower vertebrates. Thus, it is essential to identify genes responsible for antibody responses. In the mouse model, hybridoma technology allows for the association of monoclonal antibodies possessing various affinities for antigen with specific VH sequences, gene family utilization, and other molecular events (i.e. somatic hypermutation) that occur during the specific immune response. The absence of a comparable hybridoma technology in piscine systems has limited similar studies of fish immunogenetics to …


The Parasite Fauna Of The Wreckfish, Polyprion Americanus, In The North Atlantic Ocean: Application To Host Biology And Stock Identification, Colleen Jill Fennessy Jan 1998

The Parasite Fauna Of The Wreckfish, Polyprion Americanus, In The North Atlantic Ocean: Application To Host Biology And Stock Identification, Colleen Jill Fennessy

Dissertations, Theses, and Masters Projects

No abstract provided.


Guided Imagery As A Psychoneuroimmunological Intervention For Hiv-Positive Individuals, Christopher Dale Keene Jan 1996

Guided Imagery As A Psychoneuroimmunological Intervention For Hiv-Positive Individuals, Christopher Dale Keene

Dissertations, Theses, and Masters Projects

No abstract provided.


An Ultra Structural Study Of Sporogenesis, Vegatative Morphology, And Host-Parasite Interactions In Choreonema Thuretii (Corallinales, Rhodophyta), Elizabeth Anne Lapointe Jan 1995

An Ultra Structural Study Of Sporogenesis, Vegatative Morphology, And Host-Parasite Interactions In Choreonema Thuretii (Corallinales, Rhodophyta), Elizabeth Anne Lapointe

Dissertations, Theses, and Masters Projects

No abstract provided.


Effects Of Methyl Parathion On The Cellular Immune Responses In Giant Black Tiger Shrimp, Penaeus Monodon, Nantarika. Bodhipaksha Jan 1994

Effects Of Methyl Parathion On The Cellular Immune Responses In Giant Black Tiger Shrimp, Penaeus Monodon, Nantarika. Bodhipaksha

Dissertations, Theses, and Masters Projects

The effects of an organophosphorus pesticide, methyl parathion, on cellular immune defense mechanisms of the giant black tiger shrimp (Penaeus monodon) were studied. Animals were exposed for 96 hours at concentrations equal to, above and below the LC&\sb{lcub}50{rcub}& (3 ppb). Phagocytes were obtained from the heart and circulating hemolymph. Cellular immune responses, including chemotaxis, phagocytosis and the respiratory burst were examined. Chemotactic activity was determined by means of a modified Boyden double chamber technique. There was a dose-dependent decrease in the chemotactic activities of both circulating hemocytes and cardiac phagocytes. Phagocytic activity (percent phagocytosis) was examined by the microscopic enumeration …


Characterization Of Anti-Tumor Immunity In Oyster Toadfish (Opsanus Tau), And The Effects Of 7,12 -Dimethylbenz(A)Anthracene On This Immune Response, Kenneth R. Seeley Jan 1993

Characterization Of Anti-Tumor Immunity In Oyster Toadfish (Opsanus Tau), And The Effects Of 7,12 -Dimethylbenz(A)Anthracene On This Immune Response, Kenneth R. Seeley

Dissertations, Theses, and Masters Projects

Cell-mediated lysis of cultured tumor target cells by nonspecific cytotoxic cells (NCC) was examined in the oyster toadfish (Opsanus tau), an estuarine teleost. NCC activity was evaluated in cells taken from the head kidney, peripheral blood, spleen and peritoneal cavity. NCC activity was a property of plastic nonadherent cells which lacked phagocytic activity, indicating that in terms of their functional capacity, the cells which mediate nonspecific cytoxic immune responses in oyster toadfish do not appear to be monocytes or macrophages. However, light and electron microscopic examination of these cells revealed that morphologically, they resemble monocytes and macrophages. A new technique …


Immunological Identification Of A Centrin Homologue In The Red Alga Gracilaria Tikvahiae, Christopher Lee Dassler Jan 1991

Immunological Identification Of A Centrin Homologue In The Red Alga Gracilaria Tikvahiae, Christopher Lee Dassler

Dissertations, Theses, and Masters Projects

No abstract provided.


Seasonal Immune Response In Juvenile Summer Flounder Paralichthys Dentatus To The Hemoflagellate Trypanoplasma Bullocki In The Lower Chesapeake Bay, Linda Jane Frizzell Jan 1985

Seasonal Immune Response In Juvenile Summer Flounder Paralichthys Dentatus To The Hemoflagellate Trypanoplasma Bullocki In The Lower Chesapeake Bay, Linda Jane Frizzell

Dissertations, Theses, and Masters Projects

No abstract provided.


Antibody Production In Spot (Leiostomus Xanthurus Lacepede): A Model To Test The Impact Of Elizabeth River Sediments On The Humoral Immune System Of Fish, Catherine Nancy Pourreau Jan 1984

Antibody Production In Spot (Leiostomus Xanthurus Lacepede): A Model To Test The Impact Of Elizabeth River Sediments On The Humoral Immune System Of Fish, Catherine Nancy Pourreau

Dissertations, Theses, and Masters Projects

No abstract provided.


An Analysis Of Parasite Communities Of The Atlantic Croaker, Micropogonias Undulatus (Linnaeus), Within The Chesapeake Bay, David A. Benner Jan 1980

An Analysis Of Parasite Communities Of The Atlantic Croaker, Micropogonias Undulatus (Linnaeus), Within The Chesapeake Bay, David A. Benner

Dissertations, Theses, and Masters Projects

No abstract provided.


Reproductive Biology Of The Egg Parasite Gryon Parkeri (Fouts) (Hymenoptera: Scelionidae), Richard Lee Lampman Jan 1980

Reproductive Biology Of The Egg Parasite Gryon Parkeri (Fouts) (Hymenoptera: Scelionidae), Richard Lee Lampman

Dissertations, Theses, and Masters Projects

No abstract provided.


Ectoparasites Of Fishes Of The Antarctic Peninsular Area, Ervin Lynn Suydam Jan 1972

Ectoparasites Of Fishes Of The Antarctic Peninsular Area, Ervin Lynn Suydam

Dissertations, Theses, and Masters Projects

No abstract provided.


Aspects Of The Ecology, Life History, And Host-Parasite Relationship Of Loxothylacus Panopaei (Sacculinidae) In Chesapeake Bay, Seth Jerome Daugherty Jan 1969

Aspects Of The Ecology, Life History, And Host-Parasite Relationship Of Loxothylacus Panopaei (Sacculinidae) In Chesapeake Bay, Seth Jerome Daugherty

Dissertations, Theses, and Masters Projects

No abstract provided.


Some Endoparasites Of The Herpetofauna Of Dominica, West Indies, And Their Use As Clues To Host Zoogeography, Eugene William Nicholls Jan 1968

Some Endoparasites Of The Herpetofauna Of Dominica, West Indies, And Their Use As Clues To Host Zoogeography, Eugene William Nicholls

Dissertations, Theses, and Masters Projects

No abstract provided.