Life Sciences Commons^™

Predicting Fish Species Diversity In Lotic Freshwaters Of Greece, Eugene G. Maurakis, David V. Grimes

Virginia Journal of Science

Objectives were to test the hypothesis that stream order and stream width alone account for species diversity in drainages of Greece, and to create a mathematical model that predicts fish diversity in small and medium sized freshwater streams in the southern Balkan Peninsula in accord with the stream classification system proposed by the European Environmental Agency (EEA). Thirty-seven species of fishes in 12 families (Petromyzontidae, Anguillidae, Cyprinidae, Moronidae, Centrarchidae, and Blenniidae) were collected in five stream orders (1-5) from 19 river drainages in Greece in 1993 and from 2000-2002. Numbers of species were significantly correlated with stream order (+), width …

Identification Key To Fishes In Fresh Waters Of Greece, Eugene G. Maurakis, Panos S. Economidis

Virginia Journal of Science

The European Environmental Agency formulated a biodiversity initiative in 1996 specifying a freshwater stream-monitoring program to inventory, identify and describe aquatic and terrestrial species in European Union countries. With one of the richest freshwater ichthyofaunas in Europe (126 fish taxa: 97 species and 29 subspecies of primary or secondary freshwater fishes), Greece has two extinct fish species, five listed as critically endangered, and 29 considered endangered and/or vulnerable. There are, however, no published identification guides that are available for identifying fish specimens from fresh waters in Greece. We present an English translation of the only available identification key (in Greek) …

Creating A Geographical Information System For Freshwater Crabs And Fishes In Greece, Eugene G. Maurakis, Walter R.T. Witschey, Panos S. Economidis, Dimitra Bobori

Virginia Journal of Science

A geographical information system (GIS) for freshwater crabs and fishes in Greece was created in response to the European Environmental Agency's (EEA) biodiversity initiative for European Union countries. A total of 1931 collections, made with seines, dipnets, and backpack electroshockers in 32 drainages of Greece, yielded 126 species of fishes and crabs in 2,359 data records including species, latitude, longitude, drainage, prefecture, and locality, 731 also include stream order, elevation, gradient, stream width and depth, pH, temperature, and distance to river mouth. Our GIS indicates current distributions of species, species rich and poor areas, anomalous species distributions, areas warranting further …

Characterization Of Spy1600 A Putative Hyaluronidase Gene In Group A Streptococci, Karin M. Berling

Biological Sciences Theses & Dissertations

Group A Streptococci (GAS), also known as Streptococcus pyogenes, can cause a variety of human diseases ranging from asymptomatic to life threatening. Exactly how a single type of organism is able to inflict such a multitude of diseases remains to be fully understood. One possibility includes the large number of secreted virulence factors expressed by the organism. The recent sequencing of three streptococcal genomes has indicated the existence of several previously unknown genes, some of which may encode possible virulence factors. Among these is Spy1600, which based on its sequence similarities has been proposed to encode a hyaluronidase, a …

Synthesis And Biological Evaluation Of Novel Capacitative Calcium Entry Blockers, Thadigiri Celina Mala

Chemistry & Biochemistry Theses & Dissertations

Studies have shown that 2-aminoethoxydiphenyl borate (2-APB) inhibits thrombin-mediated influx of Ca^{2 +} through store-operated calcium channels in human platelets. Based on this molecule, two sets (boron analogues and the non-boron analogues) were synthesized and characterized by IR, NMR and CHN analysis and evaluated in human platelets to block thrombin-induced [Ca²⁺] elevation.

The synthesis of the non-boron compounds was performed in a simple one step process. According to the literature, some of these compounds were synthesized previously by a complicated two-step process.

All the compounds synthesized were tested for biological activity and the results showed that they …

Feeding Responses Of Juvenile And Adult Streblospio Benedicti Webster (Spionidae) To Organic Chemicals Bound To Glass Microbeads, Heidi Kathryn Mahon

Biological Sciences Theses & Dissertations

Spionid polychaetes feed at the sediment-water interface using a pair of ciliated palps. Polychaetes select food particles based upon characteristics including size, texture, specific gravity and organic coatings. Juvenile and adult spionids have different stable isotopic carbon signals, indicating the potential to differentiate organic cues ontogenetically. In the present study, the feeding responses of juvenile and adult Streblospio benedicti Webster to seven organic coatings bound (five amino acids and two carbohydrates) to glass microbeads were tested. Juveniles and adults were highly selective for all seven types of organically coated beads. Juveniles were highly selective for threonine; whereas adults were highly …

Mechanical Properties Of The Integument Of The Common Gartersnake, Thamnophis Sirtalis (Serpentes: Colubridae), Gabriel Rivera

Biological Sciences Theses & Dissertations

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. I examined mechanical properties of skin along the body axis in male Thamnophis sirtalis (Colubridae). From each of 11 specimens, I examined nine circumferential strips of skin, each spanning 10 ventral scales, spaced at …

Geographic Variation In The Morphology Of Crotalus Horridus (Serpentes: Viperidae), John Robert Allsteadt

Biological Sciences Theses & Dissertations

The Timber Rattlesnake (Crotalus horridus) occurs in discontinuous populations throughout the eastern and central United States. The species exhibits high levels of polymorphism in morphological traits, especially in coloration and pattern. Previous studies recognized either distinct northern and southern subspecies or three regional morphs (northern, southern, and western), but conflicting data sets and limited geographic sampling of previous studies have left the relationships among those regional variants unclear. In this study, univariate and multivariate statistics, together with a geographic information system, were used to analyze geographic variation in 36 morphological characters recorded from 2,420 specimens of C. horridus …

Aphytophagy In The Miletinae (Lycaenidae): Phylogeny, Ecology, And Conservation, John Mathew

Biological Sciences Theses & Dissertations

Less than 1% of all Lepidoptera are aphytophagous; of these, a considerable proportion is found in the family Lycaenidae. The aphytophagous Lycaenidae are believed to have arisen from a mutualistic template involving ant attendance. With this association firmly in place, it is a relatively simple shift to exploitation, either of the ants themselves, through active carnivory on the brood/trophallactic feeding from adults, or by carnivory on ant-tended homopterans, with little to no interference by the ants. Among lycaenids, aphytophagy has arisen several times; most spectacularly in the subfamily Miletinae, where all of the approximately 150 species are presumed or known …

K+-Induced Smooth Muscle Calcium Sensitization Requires Rhoa Kinase (Rok) Translocation To Caveolae Which Is Inhibited In Non-Neuronal Cell Memory, Nicole Hairrell Urban

Theses and Dissertations in Biomedical Sciences

KC1 causes smooth muscle contraction by elevating intracellular free calcium ([Ca²⁺]i₎, while receptor stimulation activates an additional mechanism termed Ca²⁺- sensitization that can involve activation of ROK and PKC. However, recent studies support the hypothesis that KC1 may also increase Ca²⁺-sensitivity (36). Our data showed that the PKC inhibitor, GF-109203X, did not, while the ROK inhibitor, Y-27632, did inhibit KCl-induced tonic (5’) force and myosin light chain (MLC) phosphorylation in rabbit artery. Y-27632 also inhibited Bay K-8644- and ionomycin-induced MLC phosphorylation and force, but did not inhibit KCl-induced calcium entry or peak …

An Unusually Colored Red-Backed Salamander (Plethodon Cinerus) From Northern Virginia, Joseph C. Mitchell, Thomas K. Pauley, C. Todd Georgel

Virginia Journal of Science

We describe an orange-pink, patternless, translucent morph of the Red-backed Salamander (Plethodon cinereus) found in northern Virginia on 27 September 2001. This is the first description of this unusual phenotype in this terrestrial salamander.

The Effects Of Intense Submicrosecond Electrical Pulses On Cells, Jingdong Deng, Karl H. Schoenbach, E. Stephen Buescher, Pamela S. Hair, Paula M. Fox, Stephen J. Beebe

Bioelectrics Publications

A simple electrical model for living cells predicts an increasing probability for electric field interactions with intracellular substructures of both prokaryotic and eukaryotic cells when the electric pulse duration is reduced into the submicrosecond range. The validity of this hypothesis was verified experimentally by applying electrical pulses (durations 100 μs– 60 ns, electric field intensities 3–150 kV/cm) to Jurkat cells suspended in physiologic buffer containing propidium iodide. Effects on Jurkat cells were assessed by means of temporally resolved fluorescence and light microscopy. For the longest applied pulses, immediate uptake of propidium iodide occurred consistent with electroporation as the cause of …

Keys To The Mammals And Mammal Skulls Of The Northern Coastal Plain Of Virginia, John F. Pagels, A. Scott Bellows, Joseph C. Mitchell

Virginia Journal of Science

This publication is designed to function as a tool for the identification of mammal species that occur on the Coastal Plain of northern Virginia. We provide whole-body and skull keys to the 40 species that occur in this region. Baseline data for this work were collected during several studies conducted on Fort A.P. Hill, Caroline County. The intended audience includes interested naturalists, teachers, students, field biologists, and natural resource managers.

The Quantitative Assessment Of Osteoinductivity Of Human Demineralized Bone Matrix And Cdna Array Analysis Of Osteogenic Differentiation In Human Periosteal Cells, Sittisak Honsawek

Theses and Dissertations in Biomedical Sciences

Demineralized bone matrix (DBM) has been extensively utilized in orthopeadic, periodontal, and maxillofacial applications. DBM comprises bone morphogenetic proteins (BMPs) that are essential regulators for endochondral bone formation. The current study was undertaken to establish the quantitative in vitro assays for determining the osteoinductive potential of human DBM and the use of cDNA gene expression array technology for examining gene expression profiles during osteoblast differentiation in human periosteal cells.

BMP-4 is one of the most osteoinductive factors and has been investigated for clinical applications. For this reason, BMP-4 was designated as the osteoinductive protein for use in the quantitative in …

Characterization Of Mouse Prostate Tumor-Infiltrating Leukocytes, Daniel Alan Holterman

Theses and Dissertations in Biomedical Sciences

Prostate cancer is the most common form of non-cutaneous cancer among men in the United States and the second most common cause of cancer-related death among men with approximately 189,000 new cases diagnosed and 30,200 deaths of the disease in 2002. Prostate cancer can be a treatable disease but once it becomes metastatic there are no acceptable therapies. For this reason, immunotherapy has been attempted but the results have been disappointing. The TRAMP model was used to evaluate specific interactions between an intact murine immune system and a prostate tumor that expressed a naturally processed weak tumor antigen. Vaccination trials …

Hyaluronate Lyase Gene Of Streptococcus Pyogenes: Molecular Characterization And Regulation, Sheryl Lynne Walton

Theses and Dissertations in Biomedical Sciences

Streptococcus pyogenes causes an assortment of diseases ranging from pharyngitis to necrotizing fasciitis. This bacterium has the ability to elaborate several extracellular products capable of causing tissue damage; one of which is a hyaluronate lyase. Little information is available regarding the regulation of streptococcal hyaluronidase. As such, the expression of hylA in the hyaluronate lyase-producing strain ATCC 10403 and in strains that do not produce detectable enzyme was analyzed by RT-PCR and quantitative PCR. Hyaluronate lyase transcript was detected throughout growth for all strains; however, expression of hylA in the enzymatically inactive strains, 71698 and SF370, was determined …

Real-Time Study Of Multidrug Resistance Mechanism In Pseudomonas Aeruginosa Using Nanoparticle Optics And Single Live Cell Imaging, Sophia Vasou Kyriacou

Chemistry & Biochemistry Theses & Dissertations

This thesis centers on the study of the xenobiotic efflux system in Pseudomonas aeruginosa, which is a ubiquitous bacterium. It resists many structurally and functionally diverse substrates due to expression of Mex-extrusion pumps, including MexAB-OprM, MexCD-OprJ, MexEF-OprN and MexXY-OprM systems. Despite extensive research, the structure and mechanism of multidrug resistance is unclear (1-9). For example, (i) how do MexA, MexB and OprM proteins assemble to extrude antibiotics? (ii) What is the antibiotic susceptibility of MexA, MexB, and OprM proteins? (iii) How do substrates cross the outer membrane of P. aeruginosa? (iv) Where are antibiotics accumulated inside the cell? This thesis …

The Ecological Ramifications Of Disease And Density In The Caribbean Spiny Lobster, Panulirus Argus, Donald C. Behringer Jr.

Biological Sciences Theses & Dissertations

In 1999, I discovered the first virus known to be pathogenic to any species of lobster. HLV-PA is a pathogenic herpes-like virus that infects juvenile Caribbean spiny lobster, Panulirus argus, in the waters off south Florida (USA), and it alters the behavior and ecology of this species in fundamental ways. Gross signs of HLV-PA infection are lethargy, morbidity, cessation of molting, and discolored, “milky” hemolymph that does not clot. HLV-PA infects the hemocytes of host lobsters, specifically the hyalinocytes and semi-granulocytes, but not the granulocytes. When hemolymph from infected donors was injected into healthy juvenile lobsters, 90% of the …

Hybridization Between The Watersnakes Nerodia Sipedon And Nerodia Fasciata, In The Carolinas: A Morphological And Molecular Approach, Konrad Mebert

Biological Sciences Theses & Dissertations

A few traditionally applied diagnostic characters of color pattern were compared with an additional set of morphological and genetic characters to evaluate differences between Nerodia sipedon and N. fasciata and to study the dynamics across their hybrid zone in the Carolinas. Many of the morphological characters exhibited significant interspecific differences, although only the number of dorsally complete crossbands (CBa) was diagnostic by itself. A discriminant function analysis of morphological characters was successful in separating both taxa. Species-specific nuclear markers, identified by the AFLP (Amplified Fragment Length Polymorphism) technique were nearly fixed and served as diagnostic markers. They revealed extensive introgression …

Male Reproductive Dynamics In The Caribbean Spiny Lobster Panulirus Argus, Jamie S. Heisig

Biological Sciences Theses & Dissertations

The population size structure of the Caribbean Spiny Lobster, Panulirus argus, in the Florida Keys, Florida (USA) has undergone a dramatic shift as a result of fishing pressure on the large individuals of the population. Male lobsters are affected most by fishing because of sexual dimorphism in size and other studies have shown that male size has direct impacts on reproductive output (i.e., number of fertilized eggs/clutch) that are independent of female size. To assess more precisely the impact of male size on fertilization success, I conducted laboratory experiments and field observations to examine various male reproductive attributes over …

Comparison Of Methods For Dna Isolation From Food Samples For Detection Of Shiga Toxin-Producing Escherichia Coli By Real-Time Pcr, Loree C. Heller, Carisa R. Davis, K. Kealy Peak, David Wingfield, Andrew C. Cannons, Philip T. Amuso, Jacqueline Cattani

Bioelectrics Publications

In this study, food samples were intentionally contaminated with Escherichia coli O157:H7, and then DNA was isolated by using four commercial kits. The isolated DNA samples were compared by using real-time PCR detection of the Shiga toxin genes. The four kits tested worked similarly.

Bio-Optical Properties Of The Labrador Sea, Glenn F. Cota, W. Glen Harrison, Trevor Platt, Shubha Sathyendranath, Venetia Stuart

CCPO Publications

Three cruises were conducted during fall and spring in the Labrador Sea to investigate the effects of bio-optical properties on satellite retrievals of phytoplankton chlorophyll in this important high-latitude ecosystem. Taxon-specific and regional differences were found. Diatoms had similar to 1.5 lower chlorophyll-specific absorption but significantly higher reflectance ratios than prymnesiophytes. Particulate absorption at 443 nm for total, phytoplankton, and "detrital'' fractions was related to chlorophyll, but values were lower than reported for lower latitudes. Decreased particulate absorption is attributed primarily to pigment packaging, while low backscattering to scattering ratios result from a lower relative abundance of bacteria and picophytoplankton …

Chemical Composition Of Some Components Of The Arrestment Pheromone Of The Black-Legged Tick, Ixodes Scapularis (Acari : Ixodidae) And Their Use In Tick Control, Daniel E. Sonenshine, Trevor Adams, Sandra A. Allan, John Mclaughlin, Francis X. Webster

Biological Sciences Faculty Publications

Chemical analysis (high-performance liquid chromatography) and bioassay demonstrated the presence of compounds that seem to be components of the Ixodes scapularis arrestment pheromone. Only two purines, guanine and xanthine, were found in acidified saline extracts made from cast skins after molting of fed nymphs, fed larvae, and fecal/excretory exudates deposited by unfed adults on substrates in their environment. The ratio of guanine to xanthine was 10.6:1 in an extract from the nymphal skins versus 0.95:1 in an extract from the larval skins. Guanine, xanthine, and traces of a third purine, tentatively identified as 8-azaguanine, were found in extracts made from …

Multiple Transporters Associated With Malaria Parasite Responses To Chloroquine And Quinine, Jianbing Mu, Michael T. Ferdig, Xiaorong Feng, Deirdre A. Joy, Junhui Duan, Tetsuya Furuya, G. Subramanian, L. Aravind, Roland A. Cooper, John C. Wootton, Momia Xiong, Xin-Zhuan Su

Biological Sciences Faculty Publications

Mutations and/or overexpression of various transporters are known to confer drug resistance in a variety of organisms. In the malaria parasite Plasmodium falciparum, a homologue of P-glycoprotein, PfMDR1, has been implicated in responses to chloroquine (CO), quinine (ON) and other drugs, and a putative transporter, PfCRT, was recently demonstrated to be the key molecule in CO resistance. However, other unknown molecules are probably involved, as different parasite clones carrying the same pfcrt and pfmdr1 alleles show a wide range of quantitative responses to CO and ON. Such molecules may contribute to increasing incidences of ON treatment failure, the molecular basis …

An Arthropod Defensin Expressed By The Hemocytes Of The American Dog Tick, Dermacentor Variabilis (Acari: Ixodidae), Shane M. Ceraul, Daniel E. Sonenshine, Robert E. Ratzlaff, Wayne L. Hynes

Biological Sciences Faculty Publications

Both soluble and cell-mediated components are involved in the innate immune response of arthropods. Injection of Borrelia burgdorferi, the Lyme disease agent, results in the secretion of defensin into the hemolymph of the ixodid tick, Dermacentor variabilis. The presence of the peptide is observed as early as 15 min post-challenge and remains present through 18 h post-challenge. As observed in insects and soft ticks, the transcript for defensin is detected as early as 1 h post-challenge in D. variabilis. RT-PCR resulted in an amplicon of 624 bp with a 225 bp region that translates to a 74 …

Algal Composition And Abundance In The Neuston Surface Micro Layer From A Lake And Pond In Virginia (U.S.A.), Lubomira Burchardt, Harold G. Marshall

Biological Sciences Faculty Publications

A comparative study was conducted that characterized the algae within the neuston, ca 2 mm below the surface, and the algae in the water column from two freshwater habitats. There were significant differences in total algal abundance and the abundance of diatoms, cyanoprokaryotes, and chlorophytes between the neuston and water column algae of these two regions during each season and at both sites. The pond neuston was dominated by chlorophytes, with total algal abundance ranging seasonally from 0.6 to 59.6 x 10^-3 cells ml^-1 compared to water column algal concentrations of 4.1 to 40.4 x 10-3 cells ml-1. …

Experimental Mycobacteriosis In Striped Bass Morone Saxatilis, D. T. Gauthier, M. W. Rhodes, W. K. Vogelbein, H. Kator, C. A. Ottinger

Biological Sciences Faculty Publications

Striped bass Morone saxatilis were infected intraperitoneally with approximately 10⁵ Mycobacterium marinum, M. shottsii sp. nov., or M. gordonae. Infected fish were maintained in a flow-through freshwater system at 18 to 21°C, and were examined histologically and bacteriologically at 2, 4, 6, 8, 17, 26, 36 and 45 wk post-infection (p.i.). M. marinum caused acute peritonitis, followed by extensive granuloma development in the mesenteries, spleen and anterior kidney. Granulomas in these tissues underwent a temporal progression of distinct morphological stages, culminating in well-circumscribed lesions surrounded by normal or healing tissue. Mycobacteria were cultured in high numbers from …

Enhancement Of Disease And Pathology By Synergy Of Trichuris Suis And Campylobacter Jejuni In The Colon Of Immunologically Naive Swine, Linda S. Mansfield, David T. Gauthier, Sheila R. Abner, Kathryn M. Jones, Stacey R. Wilder, Joseph F. Urban

Biological Sciences Faculty Publications

Campylobacter jejuni, a leading cause of bacterial gastroenteritis, has different age distribution and disease expression in developing and developed countries, which may be due to the endemnicity of infection and the age of acquisition of immunity. Differences in disease expression are not solely dependent on the C jejuni strain or virulence attributes. Another modulating factor in developing countries may be endemic nematode infections such as Trichuris, which drive type 2 cytokine responses and down-regulate type I immune responses. In this study, three-day-old germfree pigs given dual infections with Trichuris suis and C jejuni had more frequent, more severe …

Hydrodynamic Stability Of Swimming In Ostraciid Fishes: Role Of The Carapace In The Smooth Trunkfish Lactophrys Triqueter (Teleostei : Ostraciidae), Ian K. Bartol, Morteza Gharib, Daniel Weihs, Paul W. Webb, Jay R. Hove, Malcolm S. Gordon

Biological Sciences Faculty Publications

The hydrodynamic bases for the stability of locomotory motions in fishes are poorly understood, even for those fishes, such as the rigid-bodied smooth trunkfish Lactophrys triqueter, that exhibit unusually small amplitude recoil movements during rectilinear swimming. We have studied the role played by the bony carapace of the smooth trunkfish in generating trimming forces that self-correct for instabilities. The flow patterns, forces and moments on and around anatomically exact, smooth trunkfish models positioned at both pitching and yawing angles of attack were investigated using three methods: digital particle image velocimetry (DPIV), pressure distribution measurements, and force balance measurements. Models …

Recognizing Toxic Species In Aquatic Habitats: A Potential Concern In Lake Management, Mikolaj Kokocinski, Harold G. Marshall

Biological Sciences Faculty Publications

The importance of distinguishing toxic and non-toxic algal species is becoming a more common problem for management decisions associated with various freshwater and estuarine habitats. An example is given where two dinoflagellates, originally unidentified as closely resembling the toxin producing Pfiesteria spp., have been compared to these species. In order to clarify any relationship to Pfiesteria spp., scanning electron microscopy was used to determine the plate tabulation patterns of these dinoflagellates and make comparisons to the tabulation present in Pfiesteria spp. The results indicated significant differences in the plate tabulations of these taxa to distinguish them from Pfiesteria …