Life Sciences Commons^™

Feeding Behavior And Conditioning In Two Heterotrophic Dinoflagellates, Todd A. Egerton

Biological Sciences Theses & Dissertations

Growth and abundance of heterotrophic dinoflagellate predators are generally attributed to the availability of algal prey. Several species of dinoflagellates feed on a wide variety of food types including fish. However the actual feeding preferences of dinoflagellates have been much less studied. In the few studies that have been carried out on dinoflagellate feeding preference, none have looked at possible factors that may affect preference. I conducted three experiments on the toxic dinoflagellate Pfiesteria piscicida and the related unnamed species Cryptoperidiniopsis brodyi which, (1) calculated the feeding preferences between algal Rhodomonas prey and fish blood cells and identified factors that …

The Immediate Effect Of Cryotherapy At The Ankle Joint On Postural Control, Bradley W. Sage

Human Movement Studies & Special Education Theses & Dissertations

The purpose of this study was to determine the immediate effect of cryotherapy at the ankle joint on measures of static and dynamic postural control. Scores for the chronically unstable ankle were analyzed during a static and dynamic stability test through the use of video analysis. The static test consisted of each subject performing a single leg stance on a multi-axial progressive balance board for one minute. The dynamic test consisted of each subject performing an agility hop test, in which they "hopped" to each of six squares marked on the floor in sequential order. The dependent measure for each …

The Defensin Gene In Dermacentor Variabilis And Ixodes Scapularis, Katherine Corbett Seguin

Biological Sciences Theses & Dissertations

In response to microbial challenge, invertebrates rely on their innate immune response to recognize and destroy harmful pathogens. One of the primary proteins produced by the response and that has been observed in many invertebrates, including insects, mussels, and ticks, is defensin. These proteins are responsible for forming pores in the membranes of invading microbes thereby destroying them. This study examined the gene coding region for defensin in two important tick disease vectors, Dermacentor variabilis and Ixodes scapularis. PCR amplification of the genes from tick chromosomal DNA resulted in the amplification of a 225 base pair amplicon. Sequencing of …

The Antitumor Agent, Arglabin-Dma, Preferentially Induces Apoptosis In Human Colon Tumor Cells, Sung Wook Kwon

Theses and Dissertations in Biomedical Sciences

Arglabin-DMA, an analog of farnesyl pyrophosphate (FPP), reportedly inhibits farnesyltransferase (FTase) directly by competitively blocking the binding of Ras protein and its posttranslational modification, as suggested in previous studies. But, the mechanisms by which Arglabin-DMA inhibits tumor growth in vivo and in vitro are still relatively poorly characterized. To determine the mechanism by which this drug inhibits tumor growth, the effects of Arglabin-DMA in two human colon tumor cell lines (mutant K-ras HCT 116 and wild-type ras HT-29) were explored on cell proliferation, apoptosis, and cell cycle kinetics in vitro. In cell viability studies, we showed that Arglabin-DMA …

Morphological And Molecular Defects In Zebrafish Embryos (Danio Rerio) After Chromated Copper Arsenate Exposure, Kerry Jean Lee

Biological Sciences Theses & Dissertations

This investigation identified the morphological defects caused by different concentrations of chromium, copper, and arsenic (CCA) on the developing zebrafish embryo; in addition to defects caused by the three combined components (complete CCA). A change in the DNA of the developing embryos in response to the three components of CCA and complete CCA was also determined. Early Dania rerio embryos were cultured for five days with various concentrations of CCA components and complete CCA. Morphological defects were assessed with light microscopy and DNA fragmentation was determined by agarose gel electrophoresis. Embryonic exposure of D. rerio to sub lethal concentrations of …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: James River (1985-2004), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Peter L. Morton, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

A marked decline in the water quality of the Chesapeake Bay has occurred over the past several decades. The disappearance of submerged aquatic vegetation in certain regions of the Bay, declines in the abundance of some commercially and recreationally important species, increases in the incidence of low dissolved oxygen events, changes in the Bay's food web, and other ecological problems have been related to the deteriorating water quality. The results of concentrated research efforts in the late 1970s and early 1980s stimulated the establishment of Federal and state directives to better manage the Chesapeake Bay watershed. By way of the …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: Rappahannock River (1985-2004), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Peter L. Morton, Suzanne C. Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

A marked decline in the water quality of the Chesapeake Bay has occurred over the past several decades. The disappearance of submerged aquatic vegetation in certain regions of the Bay, declines in the abundance of some commercially and recreationally important species, increases in the incidence of low dissolved oxygen events, changes in the Bay's food web, and other ecological problems have been related to the deteriorating water quality. The results of concentrated research efforts in the late 1970s and early 1980s stimulated the establishment of Federal and state directives to better manage the Chesapeake Bay watershed. By way of the …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: York River (1985-2004), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

A marked decline in the water quality of the Chesapeake Bay has occurred over the past several decades. The disappearance of submerged aquatic vegetation in certain regions of the Bay, declines in the abundance of some commercially and recreationally important species, increases in the incidence of low dissolved oxygen events, changes in the Bay's food web, and other ecological problems have been related to the deteriorating water quality. The results of concentrated research efforts in the late 1970s and early 1980s stimulated the establishment of Federal and state directives to better manage the Chesapeake Bay watershed. By way of the …

Comparison Of Aquatic Life Depicted In Illustrations And Plaster Casts Of The Punt Relief From The Temple Of Hatshepsut At Deir El-Bahari, Emily Lord, Eugene G. Maurakis

Virginia Journal of Science

The primary objective of this study is to document differences between image characteristics of two sources (illustrations in Naville, 1898; and images in the cast of the relief at Virginia Museum of Fine Arts (VMFA) of the Punt relief from the temple of Hatshepsut at Deir El-Bahri. Our second is to compare cast images to photographs of the original relief. Characteristics of 30 species in the illustrations were described and compared to descriptions of the corresponding 30 species photographed from the cast at VMFA. The number of differences and similarities were recorded for each pair of corresponding icons and used …

Dietary Supplements And Sports Performance: Amino Acids, Melvin H. Williams

Human Movement Studies & Special Education Faculty Publications

This is the third in a series of six articles to discuss the major classes of dietary supplements (vitamins; minerals; amino acids; herbs or botanicals; metabolites, constituents/extracts, or combinations). The major focus is on efficacy of such dietary supplements to enhance exercise or sport performance.

Dietary Supplements And Sports Performance: Minerals, Melvin H. Williams

Human Movement Studies & Special Education Faculty Publications

Minerals are essential for a wide variety of metabolic and physiologic processes in the human body. Some of the physiologic roles of minerals important to athletes are their involvement in: muscle contraction, normal hearth rhythm, nerve impulse conduction, oxygen transport, oxidative phosphorylation, enzyme activation, immune functions, antioxidant activity, bone health, and acid-base balance of the blood. The two major classes of minerals are the macrominerals and the trace elements. The scope of this article will focus on the ergogenic theory and the efficacy of such mineral supplementation. Journal of the International Society of Sports Nutrition. 2( 1): 43-49, 2005.

Selective Field Effects On Intracellular Vacuoles And Vesicle Membranes With Nanosecond Electric Pulses, Ephrem Tekle, Hammou Oubrahim, Sergey M. Dzekunov, Juergen F. Kolb, Karl H. Schoenbach

Bioelectrics Publications

Electric pulses across intact vesicles and cells can lead to transient increase in permeability of their membranes. We studied the integrity of these membranes in response to external electric pulses of high amplitude and submicrosecond duration with a primary aim of achieving selective permeabilization. These effects were examined in two separate model systems comprising of 1), a mixed population of 1,2-di-oleoyl-sn-glycero-3-phosphocholine phospholipid vesicles and in 2), single COS-7 cells, in which large endosomal membrane vacuoles were induced by stimulated endocytosis. It has been shown that large and rapidly varying external electric fields, with pulses shorter than the charging time of …

Simulations Of Nanopore Formation And Phosphatidylserine Externalization In Lipid Membranes Subjected To A High-Intensity, Ultrashort Electric Pulse, Q. Hu, R. P. Joshi, K. H. Schoenbach

Bioelectrics Publications

A combined MD simulator and time dependent Laplace solver are used to analyze the electrically driven phosphatidylserine externalization process in cells. Time dependent details of nanopore formation at cell membranes in response to a high-intensity (100kV∕cm), ultrashort (10ns) electric pulse are also probed. Our results show that nanosized pores could typically be formed within about 5ns. These predictions are in very good agreement with recent experimental data. It is also demonstrated that defect formation and PS externalization in membranes should begin on the anode side. Finally, the simulations confirm that PS externalization is a nanopore facilitated event, rather than the …

Host Blood Proteins And Peptides In The Midgut Of The Tick Dermacentor Variabilis Contribute To Bacterial Control, Daniel E. Sonenshine, Wayne L. Hynes, Shane M. Ceraul, Robert Mitchell, Tiffany Benzine

Biological Sciences Faculty Publications

Antimicrobial midgut proteins and peptides that result from blood digestion in feeding American dog ticks Dermacentor variabilis (Say) were identified. Midgut extracts from these ticks showed antimicrobial activity against Micrococcus luteus, regardless of whether they were challenged with peptidoglycan, blood meal components, rabbit blood, Bacillus subtilis, Escherischia coli or Borrelia burgdorferi. However, no peptide band co-migrating with defensin was found in midgut extracts from the challenged ticks. Partial purification of the midgut extracts using C₁₈ Sep Paks and gel electrophoresis showed the presence of 4 distinct bands with rMW 4.1, 5.3, 5.7 and 8.0 kDa identified …

Demonstration Of Toxicity To Fish And To Mammalian Cells By Pfiesteria Species: Comparison Of Assay Methods And Strains, Joann M. Burkholder, Andrew S. Gordon, Peter D. Moeller, J. Mac Law, Kathryn J. Coyne, Alan J. Lewitus, John S. Ramsdell, Harold G. Marshall, Nora J. Deamer, S. Craig Cary, Jason W. Kempton, Steven L. Morton, Parke A. Rublee

Biological Sciences Faculty Publications

Toxicity and its detection in the dinoflagellate fish predators Pfiesteria piscicida and Pfiesteria shumwayae depend on the strain and the use of reliable assays. Two assays, standardized fish bioassays (SFBs) with juvenile fish and fish microassays (FMAs) with larval fish, were compared for their utility to detect toxic Pfiesteria. The comparison included strains with confirmed toxicity, negative controls (noninducible Pfiesteria strains and a related nontoxic cryptoperidiniopsoid dinoflagellate), and P. shumwayae strain CCMP2089, which previously had been reported as nontoxic. SFBs, standardized by using toxic Pfiesteria (coupled with tests confirming Pfiesteria toxin) and conditions conducive to toxicity expression, reliably detected …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: York River (1985-2003), Daniel M. Dauer

Status and Trends for Virginia Chesapeake Bay

The Virginia Chesapeake Bay and its tidal tributaries continue to show some environmental trends indicating progress toward restoration of a more balanced and healthy ecosystem. However, the Bay system remains degraded and some areas and indicators show continuing degradation. Progress in reducing nutrient inputs has made demonstrable improvements and we expect that continued progress toward nutrient reduction goals, along with appropriate fisheries management and chemical contaminant controls, will result in additional improvements to the Bay. Findings from the last 18 years of the monitoring programs are highlighted below. In 1995, the Virginia DEQ instituted changes to its analytical techniques for …

Effect Of Humic Substance Photodegradation On Bacterial Growth And Respiration In Lake Water, Alexandre M. Anesio, William Granéli, George R. Aiken, David J. Kieber, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

This study addresses how humic substance (HS) chemical composition and photoreactivity affect bacterial growth, respiration, and growth efficiency (BGE) in lake water. Aqueous solutions of HSs from diverse aquatic environments representing different dissolved organic matter sources (autochthonous and allochthonous) were exposed to artificial solar UV radiation. These solutions were added to lake water passed through a 0.7-μm pore-size filter (containing grazer-free lake bacteria) followed by dark incubation for 5, 43, and 65 h. For the 5-h incubation, several irradiated HSs inhibited bacterial carbon production (BCP) and this inhibition was highly correlated with H₂O₂ photoproduction. The H_{2 …}

Body-Induced Vortical Flows: A Common Mechanism For Self-Corrective Trimming Control In Boxfishes, Ian K. Bartol, Morteza Gharib, Paul W. Webb, Daniel Weihs, Malcolm S. Gordon

Biological Sciences Faculty Publications

Boxfishes (Teleostei: Ostraciidae) are marine fishes having rigid carapaces that vary significantly among taxa in their shapes and structural ornamentation. We showed previously that the keels of the carapace of one species of tropical boxfish, the smooth trunkfish, produce leading edge vortices (LEVs) capable of generating self-correcting trimming forces during swimming. In this paper we show that other tropical boxfishes with different carapace shapes have similar capabilities. We conducted a quantitative study of flows around the carapaces of three morphologically distinct boxfishes (spotted boxfish, scrawled cowfish and buffalo trunkfish) using stereolithographic models and three separate but interrelated analytical …

Can Otolith Elemental Signatures Record The Capture Site Of Patagonian Toothfish (Dissostichus Eleginoides), A Fully Marine Fish In The Southern Ocean?, J. R. Ashford, C. M. Jones, E. Hofmann, I. Everson, C. Moreno, G. Duhamel, R. Williams

CCPO Publications

Otolith chemistry has been successfully used to reconstruct the environmental history experienced by estuarine-dependent teleost fish, including movement between estuaries and coastal areas. However, application has been more limited in species exposed exclusively to oceanic waters, where gradients in physical and chemical properties are less extreme. To test whether otolith elemental signatures record spatial information in an oceanic species, we sampled otoliths from Patagonian toothfish (Dissostichus eleginoides) and used an inductively coupled plasma mass spectrometer (ICP-MS) coupled to a laser ablation system to target the outer otolith edges corresponding to the period immediately before capture. Using multivariate analysis …

The Role Of Feeding Behavior In Sustaining Copepod Populations In The Tropical Ocean, J. D. Wiggert, A. G. E. Haskell, G.-A. Paffenhofer, E. E. Hofmann, J. M. Klinck

CCPO Publications

A fundamental question regarding marine copepods is how the many species coexist and persist in the oligotrophic environment (i.e. Hutchinson’s paradox). This question is addressed with a stochastic, object-oriented Lagrangian model that explicitly simulates the distinct foraging behaviors of three prominent tropical species: Clausocalanus furcatus, Paracalanus aculeatus and Oithona plumifera. The model also individually tracks all prey cells. Each particle’s motion combines sinking, turbulent diffusion and active swimming when applicable. The model successfully simulates observed size partitioned carbon uptake rates. Based on the model results, the wide-ranging translational ambit employed by C. furcatus is best suited for the acquisition …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: Rappahannock River (1985-2003), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

The Virginia Chesapeake Bay and its tidal tributaries continue to show some environmental trends indicating progress toward restoration of a more balanced and healthy ecosystem. However, the Bay system remains degraded and some areas and indicators show continuing degradation. Progress in reducing nutrient inputs has made demonstrable improvements and we expect that continued progress toward nutrient reduction goals, along with appropriate fisheries management and chemical contaminant controls, will result in additional improvements to the Bay. Findings from the last 18 years of the monitoring programs are highlighted below. In 1995, the Virginia DEQ instituted changes to its analytical techniques for …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: James River (1985-2003), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

The Virginia Chesapeake Bay and its tidal tributaries continue to show some environmental trends indicating progress toward restoration of a more balanced and healthy ecosystem. However, the Bay system remains degraded and some areas and indicators show continuing degradation. Progress in reducing nutrient inputs has made demonstrable improvements and we expect that continued progress toward nutrient reduction goals, along with appropriate fisheries management and chemical contaminant controls, will result in additional improvements to the Bay. Findings from the last 18 years of the monitoring programs are highlighted below.

In 1995, the Virginia DEQ instituted changes to its analytical techniques for …

Circulation, Mixing And The Distribution Of Remineralized Nutrients, Larry P. Atkinson, John Huthnance, Jose L. Blanco

CCPO Publications

No abstract provided.

Tumor Response Tcf-4/Β-Catenin Regulatory Elements For Enhancing Cancer Gene Therapies, Saurabh Kumar Gupta

Theses and Dissertations in Biomedical Sciences

Mutations in the adenomatous polyposis coli gene are frequently associated with progression of colon carcinoma and most other types of epithelial carcinomas. This usually results in stabilization of β-catenin protein levels, followed by transactivation of Tcf-4/β-catenin responsive genes. The effectiveness of a Tcf-4/β-catenin transcriptional enhancer element in combination with a c-fos or carcinoembryonic antigen promoter was tested for its ability to act as a tumor specific regulator of gene expression in a panel of human tumor and normal cell lines. Luciferase reporter assays indicated enhanced activity of the Tcf-4/β-catenin transcriptional element only in tumor cell lines, with minimal activities in …

Landscape Ecology Of Birds On Mount Leconte, Great Smoky Mountains National Park, Andreas P. Damalas

Biological Sciences Theses & Dissertations

Landbirds form a significant component of wildlife resources in the Great Smoky Mountains National Park. The present study explored how forest structure and composition of deciduous-coniferous ecotones influenced diversity, richness, and relative abundance of bird species and how bird species responded to the spruce-fir community.

Using a form of the variable-circular plot method, I conducted audio-visual censuses of diurnal birds on Mount LeConte. I established 212 geo-referenced census points on six trails, which were used as gradient-oriented transects (gradsects). I measured habitat characteristics at the same census points. I used forest community types for each point on gradsects to delineate …

Mechanical Properties Of The Integument Of The Common Gartersnake, Thamnophis Sirtalis (Serpentes: Colubridae), Gabriel Rivera, Alan H. Savitzky, Jeffrey A. Hinkley

Biological Sciences Faculty Publications

The evolution of the ophidian feeding mechanism has involved substantial morphological restructuring associated with the ability to ingest relatively large prey. Previous studies examining the morphological consequences of macrophagy have concentrated on modifications of the skull and cephalic musculature. Although it is evident that macrophagy requires highly compliant skin, the mechanical properties of the ophidian integument have received limited attention, particularly in the context of feeding. We examined mechanical properties of skin along the body axis in Thamnophis sirtalis (Colubridae). Data were collected from tensile tests and were analyzed using a multivariate analysis of variance (MANOVA) and post-hoc multiple comparison …

3,4-Methylenedioxymethamphetamine Activates Nuclear Factor- Κb, Increases Intracellular Calcium, And Modulates Gene Transcription In Rat Heart Cells, David A. Tiangco, Frank A. Lattanzio Jr., Christopher J. Osgood, Stephen J. Beebe, Julie A. Kerry, Barbara Y. Hargrave

Biological Sciences Faculty Publications

3,4-Methylenedioxymethamphetamine (MDMA) is an illicit psychoactive drug that has gained immense popularity among teenagers and young adults. The cardiovascular toxicological consequences of abusing this compound have not been fully characterized. The present study utilized a transient transfection/dual luciferase genetic reporter assay, fluorescence confocal microscopy, and gene expression macroarray technology to determine nuclear factor-κB (NF-κB) activity, intracellular calcium balance, mitochondrial depolarization, and gene transcription profiles, respectively, in cultured rat striated cardiac myocytes (H9c2) exposed to MDMA. At concentrations of 1×10⁻³ M and 1×10⁻² M, MDMA significantly enhanced NF-κB reporter activity compared with 0 M (medium only) control. This …

A Defensin-Like Gene Expressed In The Black-Legged Tick, Ixodes Scapularis (Acari: Ixodidae), Wayne L. Hynes, S. M. Ceraul, S. M. Todd, K. C. Seguin, Daniel E. Sonenshine

Biological Sciences Faculty Publications

The black-legged tick Ixodes scapularis linnaeus (Acari: Ixodidae) is an important vector of microbial pathogens. Knowledge of the tick's innate immune response, particularly defensin and other antimicrobial peptides, is important for understanding how microbes survive in this tick. A defensin gene (slnA) from I. scapularis was obtained by reverse transcription-polymerase chain reaction (RT-PCR) using mRNA extracted from tissues of female ticks. RT-PCR indicated the gene was expressed in the midgut, haemocytes, and fat-body, although no evidence of a peptide was found. Sequencing a cloned cDNA fragment revealed a 225 bp open reading frame encoding a 74 amino acid pre-prodefensin, including …

Phytoplankton Development Within Tidal Freshwater Regions Of Two Virginia Rivers, Usa, Harold G. Marshall, Lubomira Burchardt

Biological Sciences Faculty Publications

Phytoplankton composition and the range of seasonal patterns of abundance are presented for the tidal freshwater regions in two Virginia rivers based on data accumulated monthly from 1986 through 1999. Diatoms dominated the flora during spring, summer, and fall, whereas, other taxonomic categories were more representative when the river flow rates decreased, allowing for a more stable water system and increased residency time within this tidal region during summer and early fall. This summer/fall period was associated with increased water temperatures, higher productivity rates and chlorophyll levels, increased total phytoplankton abundance and species diversity. The major components of the summer …

In Vivo Role Of 20-Hydroxyecdysone In The Regulation Of The Vitellogenin Mrna And Egg Development In The American Dog Tick, Dermacentor Variabilis (Say), Deborah M. Thompson, Sayed M.S. Khalil, Laura A. Jeffers, Usha Ananthapadadmanaban, Daniel E. Sonenshine, Robert D. Mitchell, Christopher J. Osgood, Charles S. Apperson, R. Michael Roe

Biological Sciences Faculty Publications

Injection of the hormone 20-hydroxyecdysone (20-E) into partially fed (virgin) female adults of the American dog tick, Dermacentor variabilis, while they are attached and feeding on the rabbit host, initiated the expression of the vitellogenin (Vg) gene, and Vg protein secretion and uptake by the ovary. The induction of egg production by 20-E in this bioassay was dose dependent in the range of 1-50 times the concentration normally found in a replete, vitellogenic female. Ticks examined 4d after the 50x treatment were still attached to the host, had numerous enlarged vitellin-filled (brown) oocytes in their ovaries, but had not …