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Articles 1 - 24 of 24

Full-Text Articles in Life Sciences

Virginia's Pelagic Recreational Fishery: Biological, Socioeconomic And Fishery Components, Eleanor A. Bochenek Jan 1989

Virginia's Pelagic Recreational Fishery: Biological, Socioeconomic And Fishery Components, Eleanor A. Bochenek

Dissertations, Theses, and Masters Projects

Catch, effort, fleet size and boat owner expenditure data were collected on Virginia's recreational marlin/tuna fishery for the 1983-1985 seasons. Logbooks, dockside interviews and a telephone survey were evaluated to determine which method was the most efficient and effective for collecting and estimating catch and effort for Virginia's pelagic recreational fishery. In 1984, logbooks were used to collect catch and effort data and fishing effort was estimated using Bochenek's method. Very few fishermen returned their logbooks and as a result this data is probably less reliable than the data collected in other years. Due to the ...


Pcb Congener Analysis With Hall Electrolytic Conductivity Detection, Robert D. Edstrom Jan 1989

Pcb Congener Analysis With Hall Electrolytic Conductivity Detection, Robert D. Edstrom

Dissertations, Theses, and Masters Projects

This work reports the development of an analytical methodology for the analysis of PCB congeners based on integrating relative retention data provided by other researchers. The retention data were transposed into a multiple retention marker system which provided good precision in the calculation of relative retention indices for PCB congener analysis. Analytical run times for the developed methodology were approximately one hour using a commercially available GC capillary column. A Tracor Model 700A Hall Electrolytic Conductivity Detector (HECD) was employed in the GC detection of Aroclor standards and environmental samples. Responses by the HECD provided good sensitivity and were reasonably ...


The Influence Of Tributyltin On Various Aspects Of Activation And Reactive Oxygen Formation In Oyster Toadfish (Opsanus Tau) Macrophages, Charles D. Rice Jan 1989

The Influence Of Tributyltin On Various Aspects Of Activation And Reactive Oxygen Formation In Oyster Toadfish (Opsanus Tau) Macrophages, Charles D. Rice

Dissertations, Theses, and Masters Projects

The effects of tributyltin (TBT) on phorbol myristate acetate (PMA)- and calcium ionophore (A23187)-stimulated peritoneal macrophages from oyster toadfish (Opsanus tau) were evaluated in a luminol-dependent chemiluminescence (CL) assay. PMA-stimulated CL responses were increased by in vitro exposure to 50 ug/L TBT, but depressed to baseline values by 500 ug/L TBT. A23187-stimulated CL increased with 5 ug/L and 50 ug/L TBT, and depressed by 500 ug/L TBT. Responses stimulated by synergistic doses of PMA and A23187 were increased by 50 ug/L TBT and depressed by 500 ug/L TBT. Enhanced PMA- and A23187-stimulated ...


Nitrogen And Phosphorus Cycling Strategies In Two Tidal Freshwater Macrophytes, Peltandra Virginica And Spartina Cynosuroides, Paul Milton. Booth Jr Jan 1989

Nitrogen And Phosphorus Cycling Strategies In Two Tidal Freshwater Macrophytes, Peltandra Virginica And Spartina Cynosuroides, Paul Milton. Booth Jr

Dissertations, Theses, and Masters Projects

Monotypic stands of the macrophytes Peltandra virginica and Spartina cynosuroides, which shared a common boundary, were studied at Sweethall Marsh, a tidal freshwater marsh located on the Pamunkey River within the Chesapeake Bay estuarine system, Virginia. Compartmental models indicate that both Peltandra and Spartina take up, internally cycle, and release to the environment, significant levels of nitrogen and phosphorus. Models also suggest that Peltandra and Spartina and their associated sediment compartments are capable of regulating nitrogen and phosphorus fluxes through their uptake and storage capacity. Nitrogen use efficiency was significantly higher in the shoots and roots of Spartina compared to ...


Recruitment And Growth Of Juvenile Crassostrea Virginica (Gmelin) In Relation To Tidal Zonation, George Curtis Roegner Jan 1989

Recruitment And Growth Of Juvenile Crassostrea Virginica (Gmelin) In Relation To Tidal Zonation, George Curtis Roegner

Dissertations, Theses, and Masters Projects

No abstract provided.


Effect Of Nitrogen And Phosphorus Enrichment On Lipid And Fatty Acid Composition Of Estuarine Microplankton, Jia Chen Jan 1989

Effect Of Nitrogen And Phosphorus Enrichment On Lipid And Fatty Acid Composition Of Estuarine Microplankton, Jia Chen

Dissertations, Theses, and Masters Projects

No abstract provided.


Cannibalism Experiments With The Blue Crab (Callinectes Sapidus Rathbun): Potential Effects Of Size And Abundance, Christopher A. Peery Jan 1989

Cannibalism Experiments With The Blue Crab (Callinectes Sapidus Rathbun): Potential Effects Of Size And Abundance, Christopher A. Peery

Dissertations, Theses, and Masters Projects

No abstract provided.


Mitochondrial Dna Variation In Striped Bass, Morone Saxatilis, From The Rappahannock River, Virginia, Carol Furman Jan 1989

Mitochondrial Dna Variation In Striped Bass, Morone Saxatilis, From The Rappahannock River, Virginia, Carol Furman

Dissertations, Theses, and Masters Projects

No abstract provided.


Effects Of Selected Nitrogen-Containing Aromatic Compounds (Ncacs) On Physiological Properties In Escherichia Coli, W. James Catallo Iii Jan 1989

Effects Of Selected Nitrogen-Containing Aromatic Compounds (Ncacs) On Physiological Properties In Escherichia Coli, W. James Catallo Iii

Dissertations, Theses, and Masters Projects

This research examined the effects of quinoline and 4-azafluorene on respiratory electron transport rate (ET), outer membrane permeability and topology, oxygen consumption, and viable cell density in Escherichia coli cell suspensions. ET was estimated spectrophotometrically using INT (2-(p-iodophenyl)-3-(p-nitrophenyl)-5-(phenyl)-2H-tetrazolium chloride, which is reduced in vivo to a red colored formazan (INTF). Both test compounds caused anomalous dose-response behavior in INT assays: in a defined window of doses, ET rates near or above the controls were observed. These doses showed altered INT reduction kinetics, decreased cellular oxygen demand, and decreased viable cell densities. Experiments with E ...


Heterotrophic Bacterial Production: Relationships To Biological And Abiological Factors In Estuarine Environments, Eric Thor Koepfler Jan 1989

Heterotrophic Bacterial Production: Relationships To Biological And Abiological Factors In Estuarine Environments, Eric Thor Koepfler

Dissertations, Theses, and Masters Projects

Section 1. Ecotoxicological effects of creosote contamination on benthic bacterial communities in the Elizabeth River, Virginia were investigated using both structural and functional microbial parameters. Results indicated that cell specific and total heterotrophic bacterial production parameters were depressed in a dose dependent manner with increasing sediment PAH concentrations. Toxicity effects upon production were modified by temporal trends associated with temperature as well as spatial sediment characteristics. of the parameters employed, the tritiated thymidine production assay was found to be the most sensitive for detection of ecotoxicological effects. Section 2. Bacterial abundance and production were examined during a destratification event in ...


Comparative Ecology Of The Parasites Of The Spot, Leiostomus Xanthurus Lacepede, And The Atlantic Croaker, Micropogonias Undulatus Linnaeus (Sciaenidae), In The Cape Hatteras Region, Dennis A. Thoney Jan 1989

Comparative Ecology Of The Parasites Of The Spot, Leiostomus Xanthurus Lacepede, And The Atlantic Croaker, Micropogonias Undulatus Linnaeus (Sciaenidae), In The Cape Hatteras Region, Dennis A. Thoney

Dissertations, Theses, and Masters Projects

Parasite communities of spot, Leiostomus xanthurus, and Atlantic croaker, Micropogonias undulatus, were examined to determine if (1) their structure changed with host age, (2) geographical location affected community structure, (3) food habits affected community structure, and (4) their parasite communities are predictable. Juvenile fish were collected monthly from Chesapeake Bay and Pamlico Sound. Adult fish were collected offshore north of Cape Hatteras in fall, and offshore south of Cape Hatteras in spring and fall. A total of 21 parasitic species occurred in juvenile spot and 19 in juvenile croaker from Chesapeake Bay and Pamlico Sound. The parasite communities of juvenile ...


Structure And Function Of Crustacean Hemocyaninis, John Edwin Reese Jan 1989

Structure And Function Of Crustacean Hemocyaninis, John Edwin Reese

Dissertations, Theses, and Masters Projects

No abstract provided.


Vascular Flora Of Northwestern Highland County, Virginia, Theresa Alee Theodose Jan 1989

Vascular Flora Of Northwestern Highland County, Virginia, Theresa Alee Theodose

Dissertations, Theses, and Masters Projects

No abstract provided.


The Effects Of Exogenous Triiodothyronine On Reproductively Inhibited Prairie Deer Mice (Peromyscus Maniculatus Bairdii) From Laboratory Populations, Paul Sumpter Hogg Jan 1989

The Effects Of Exogenous Triiodothyronine On Reproductively Inhibited Prairie Deer Mice (Peromyscus Maniculatus Bairdii) From Laboratory Populations, Paul Sumpter Hogg

Dissertations, Theses, and Masters Projects

No abstract provided.


Aspects Of Volume Regulation In Two Estuarine Invertebrates: Glycera Dibranchiata (Annelida) And Modiolus Demissus (Mollusca), Ana Marie Beardsley Jan 1989

Aspects Of Volume Regulation In Two Estuarine Invertebrates: Glycera Dibranchiata (Annelida) And Modiolus Demissus (Mollusca), Ana Marie Beardsley

Dissertations, Theses, and Masters Projects

No abstract provided.


Anion And Urea Sensitivity Of Three Elasmobranch Hemoglobins, David Allen Scholnick Jan 1989

Anion And Urea Sensitivity Of Three Elasmobranch Hemoglobins, David Allen Scholnick

Dissertations, Theses, and Masters Projects

No abstract provided.


Nutritional Influences On Aging In Aspergillus Ornatus, Jaydeep Shantilal Shah Jan 1989

Nutritional Influences On Aging In Aspergillus Ornatus, Jaydeep Shantilal Shah

Dissertations, Theses, and Masters Projects

No abstract provided.


Distribution Of The Heterogeneous Hemocyanin Subunits Of Callinestes Sapidus (Rathbun) Along A Salinity Gradient, Julie Sayre Rainer Jan 1989

Distribution Of The Heterogeneous Hemocyanin Subunits Of Callinestes Sapidus (Rathbun) Along A Salinity Gradient, Julie Sayre Rainer

Dissertations, Theses, and Masters Projects

No abstract provided.


Caching By Carolina Chickadees: Minimizing Starvation Risk Vs Maximizing Harvest Rate, Lynn R. Walter Jan 1989

Caching By Carolina Chickadees: Minimizing Starvation Risk Vs Maximizing Harvest Rate, Lynn R. Walter

Dissertations, Theses, and Masters Projects

No abstract provided.


Recent Vegetation And Area Changes In A Tidal Marsh Located At Pope's Creek, Virginia, Julia K. Wilcox Jan 1989

Recent Vegetation And Area Changes In A Tidal Marsh Located At Pope's Creek, Virginia, Julia K. Wilcox

Dissertations, Theses, and Masters Projects

No abstract provided.


The Influence Of Salinity On The Swimming Behavior Of Larval Crassostrea Virginica (Gmelin), Kevin J. Mccarthy Jan 1989

The Influence Of Salinity On The Swimming Behavior Of Larval Crassostrea Virginica (Gmelin), Kevin J. Mccarthy

Dissertations, Theses, and Masters Projects

No abstract provided.


The Effect Of Tissue Culture Medium Composition On Fragile X Expression, Jennifer Anne Hyman Jan 1989

The Effect Of Tissue Culture Medium Composition On Fragile X Expression, Jennifer Anne Hyman

Dissertations, Theses, and Masters Projects

No abstract provided.


Reproductive And Metabolic Characteristics In Peromyscus Leucopus Noveboracensis From Laboratory Populations And Females During Release From Reproductive Inhibition, Holly Anne Lavoie Jan 1989

Reproductive And Metabolic Characteristics In Peromyscus Leucopus Noveboracensis From Laboratory Populations And Females During Release From Reproductive Inhibition, Holly Anne Lavoie

Dissertations, Theses, and Masters Projects

No abstract provided.


Uptake Kinetics And Toxicity Of Diazinon In The American Oyster, Crassostrea Virginica Gmelin, Ruth L. Williams Jan 1989

Uptake Kinetics And Toxicity Of Diazinon In The American Oyster, Crassostrea Virginica Gmelin, Ruth L. Williams

Dissertations, Theses, and Masters Projects

Several aspects of effects of the organophosphate pesticide diazinon on the American oyster Crassostrea virginica Gmelin were investigated. Uptake of diazinon directly from water was compared with uptake of diazinon sorbed to either fine sediment or algae; the primary route of assimilation seems to be from the water. Concentrations of diazinon between 0.91 and 2.03 mg/L inhibit shell growth during 96 hours of exposure; there is a sharp threshold of effect for this response which is probably an indirect one caused by lack of food during shell closure. Acetylcholinesterase inhibition is significant in oyster heart tissue at ...