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Sex Chromosome Ratios And Aneuploidy Rates In The Zona Pellucida Selected Spermatozoa From Normal And Subfertile Men, Qinuo Fan Van Dyk Oct 1997

Sex Chromosome Ratios And Aneuploidy Rates In The Zona Pellucida Selected Spermatozoa From Normal And Subfertile Men, Qinuo Fan Van Dyk

Theses and Dissertations in Biomedical Sciences

The human hemizona has been demonstrated to select spermatozoa with good motility, normal morphology, and the capacity to undergo the zona-induced acrosomal reaction. The studies conducted here are directed at using the human hemizona to investigate two key questions: (1) whether human X-chromosome bearing spermatozoa (X-sperm) and Y-chromosome bearing spermatozoa (Y-sperm) differ in their functional survival time (assessed by their capacity to bind to the human zona pellucida) after prolonged in vitro incubation, and (2) whether hemizona-bound spermatozoa have a reduced aneuploidy rate compared to unbound (and therefore, unselected) spermatozoa?

In the functional survival study, donor spermatozoa were held in …


Thermophilic Bacterial Activity In A Deep-Sea Sediment From The Pacific Ocean, Fred C. Dobbs, Karen A. Selph Aug 1997

Thermophilic Bacterial Activity In A Deep-Sea Sediment From The Pacific Ocean, Fred C. Dobbs, Karen A. Selph

OES Faculty Publications

Thermophilic bacterial activity was detected in a deep-sea sediment sample from the South Pacific Ocean at 12 degrees S, 135 degrees W, an area of the seafloor distant from known hydrothermal venting. Incubation of sediments amended with C-14-glutamate indicated maximal respiration (evolution of (CO2)-C-14) and assimilation (incorporation of C-14 into acid-precipitated macromolecules) of substrate at 52 degrees C, relative to 4 and 22 degrees C. A parallel experiment at another site (2 degrees S, 140 degrees W) yielded no evidence of thermophily. Thermophilic bacteria may be deposited in deep-sea sediments following their long-distance dispersal from hydrothermal vents (e.g. the East …


Windlass Taping Technique For Symptomatic Relief Of Plantar Fasciitis, Beth Anne Ernst Aug 1997

Windlass Taping Technique For Symptomatic Relief Of Plantar Fasciitis, Beth Anne Ernst

Rehabilitation Sciences Theses & Dissertations

This study investigated the biomechanical and symptomatic effects of a newly described taping technique to support the longitudinal arch in symptomatic plantar fasciitis patients. The subjects were 20 individuals all diagnosed by a physician with unilateral plantar fasciitis, ambulating full weight-bearing without an assistive device.

Measurements were taken pre and post-taping for calcaneal position, tibial position and navicular height, with the subjects serving as their own control. The subjects also reported pain level pre and post tape using a visual analog scale. The statistical analysis performed on the biomechanical data was the t-test, and Wilcoxon matched-pairs signed ranks test was …


Reliability Of The Modified-Modified Schober Method Of Measuring Lumbar Range Of Motion, Mira H. Mariano Aug 1997

Reliability Of The Modified-Modified Schober Method Of Measuring Lumbar Range Of Motion, Mira H. Mariano

Rehabilitation Sciences Theses & Dissertations

The purpose of this study was to determine the reliability of the Modified-modified Schober (MMS) method of measuring lumbar flexion and extension on subjects with low back pain. Thirty patients (19 females, 11 males) between the ages of 18 to 61 years (mean=40.0, SD=l 1.7) were measured by two physical therapists who each had six years of orthopedic experience.

Each subject was evaluated twice, in random order, by each tester using the MMS method. Trials 1 and 2 were used to calculate intratester reliability for each tester and intertester reliability was calculated between the two testers. Intraclass correlation coefficients (ICCs) …


The Effects Of Estrogen On Dorsal Root Ganglion Neurons, Sheila A. Scoville Jul 1997

The Effects Of Estrogen On Dorsal Root Ganglion Neurons, Sheila A. Scoville

Theses and Dissertations in Biomedical Sciences

Skin sensation is mediated by dorsal root ganglion (DRG) neurons. Data indicates that skin sensitivity in female rats is estrogen-dependent. Some DRG neurons have estrogen receptors (ERs) which are regulated by estrogen. In these cells, nerve growth factor (NGF) and estrogen receptors colocalize. Regulation of NGF receptors and neuronal sensitivity to NGF may allow estrogen to regulate NGF-dependent genes. The goals of the present study were to determine which DRG neurons express the ER gene and to analyze the effects of long-term estrogen administration on the interrelated expression of tyrosine kinase A (trkA), preprotachykinin (PPT), and 68kD neurofilament (NF) genes …


Endothelial Nitric Oxide Synthase And Growth Factor Regulation Of Flow-Mediated Vascular Remodeling, David Anthony Tulis Jul 1997

Endothelial Nitric Oxide Synthase And Growth Factor Regulation Of Flow-Mediated Vascular Remodeling, David Anthony Tulis

Theses and Dissertations in Biomedical Sciences

This study was designed to characterize structural remodeling of male Wistar rat mesenteric arteries exposed to elevated blood flow in vivo for 1, 3, or 7 days. A series of arterial ligations induced blood flow increases in ileal and second-order branch arteries compared to same animal control vessels. Neither mean carotid nor local mesenteric arterial pressures changed significantly pre- to post-ligation. The primary flow-mediated force in both vessels was shear stress with possible involvement of acute stretch-induced wall stress in the ileal artery. Significant luminal expansion and medial wall hypertrophy occurred in the ileal and second-order arteries in a time-dependent …


Systematics Of The Freshwater Amphipod Genus Crangonyx (Crangonyctidae) In North America, Jun Zhang Jul 1997

Systematics Of The Freshwater Amphipod Genus Crangonyx (Crangonyctidae) In North America, Jun Zhang

Biological Sciences Theses & Dissertations

The systematics of the amphipod genus Crangonyx of North America (north of Mexico) is revised, based on available collections (ca. 2240) and literature dealing with the genus. A grand total of 42 North America species of Crangonyx are recognized in the present study, 24 of them new to science. All species are described or redescribed and figured, utilizing external morphological features. Keys to both species groups and individual species are given. Phylogenetic trees are built using computer programs (PAUP, Hennig86, MacClade) based on 26 characters. Wagner parsimony produced 18 parsimonious trees and Fitch parsimony produced 45 trees. The consensus tree …


The Annual Reproductive Cycle Of Oryzomys Palustris In A Virginia Tidal Marsh, Erin A. Dreelin Jul 1997

The Annual Reproductive Cycle Of Oryzomys Palustris In A Virginia Tidal Marsh, Erin A. Dreelin

Biological Sciences Theses & Dissertations

The objectives of my study were to determine when the marsh rice rat (Oryzomys palustris) begins and ends reproduction during the year, if there are seasonal changes in litter size, and the weight at which sexual maturity is reached. Monthly samples of rice rats were trapped from May 1995 to May 1996 in Northampton County, Virginia. Rice rats were trapped with Fitch live traps, euthanized in the field, and brought to the lab for necropsy. Data from two other studies of rice rats in Northampton County were also examined. Potential breeders did not reproduce with equal intensity throughout the …


Comparison Of The Dichlorination Of Organic N-Chloramines By Caroate And By Bisulfite: A Kinetic Study, Said H. Lubbad Jul 1997

Comparison Of The Dichlorination Of Organic N-Chloramines By Caroate And By Bisulfite: A Kinetic Study, Said H. Lubbad

Chemistry & Biochemistry Theses & Dissertations

Bisulfite is commonly used to dechlorinate chlorinated municipal wastewater. However, several studies suggest that bisulfite is not effective in dechlorinating N-chlorinated amino components of wastewater. The purpose of this study was to investigate the effectiveness of an alternate dechlorinating agent, caroate (peroxysulfate), and to compare its rate of dechlorination of three different types of chloramines with that of bisulfite.

Four N-chlorinated amino compounds were investigated: N-chlorodiethylamine, chloroalanylphenylalanine, N-chloroglycylphenylalanine, and N-[2-(N'-chloroimino)­ propanoyl]phenylalanine. These compounds were selected from different families of chloramines to study the effect of structure on dechlorination by both caroate and bisulfite. At pH …


Interaction Of Acth And Estradiol In The Regulation Of Growth, Differentiation, And Steroidogenic Maturation Of The Baboon Fetal Adrenal Gland, Maria Gomez Leavitt Jul 1997

Interaction Of Acth And Estradiol In The Regulation Of Growth, Differentiation, And Steroidogenic Maturation Of The Baboon Fetal Adrenal Gland, Maria Gomez Leavitt

Theses and Dissertations in Biomedical Sciences

The present study determined whether the growth of, as well as ACTH receptor and P-450 enzyme messenger ribonucleic acid and/or protein levels in the baboon fetal adrenal are dependent upon fetal pituitary ACTH during mid and late gestation and the mechanism by which placental estrogen modulates ACTH actions. Administration of betamethasone (3mg/day) to baboon mothers on days 60-99 of gestation and to the fetus (0.6 mg/, n = 4) or to the fetus (0.6mg) and mother (6 mg/ml; n = 4) every other day between days 150-164 of gestation (term = 184 days) decreased (P $53β-hydroxysteroid dehydrogenase-isomerase (3β-HSD(+)ctochrome P450 17α-hydroxylase, …


Mark-Recapture Creel Survey And Survival Models, Shampa Saha Jul 1997

Mark-Recapture Creel Survey And Survival Models, Shampa Saha

Mathematics & Statistics Theses & Dissertations

In this dissertation, we consider a model based approach to the estimation of exploitation rate of a fish population by combining mark-recapture procedures with a creel survey. We also consider the analysis of a proportional hazards survival model for randomly censored observations, known as the Koziol-Green model. The model assumes that the lifetime survivor function is a power of the censored time survivor function.

In Chapter 2, we introduce the model based approach to the estimation of the exploitation rate of a fish population by combining mark-recapture procedures with a creel survey. We assume that in the beginning of a …


Fluorescence In Situ Hybridization Analysis Of Human Embryos Derived From In Vitro And In Vivo Matured Oocytes, Constance Descisciolo Jul 1997

Fluorescence In Situ Hybridization Analysis Of Human Embryos Derived From In Vitro And In Vivo Matured Oocytes, Constance Descisciolo

Theses and Dissertations in Biomedical Sciences

Despite adequate hormonal stimulation, oocytes collected for the purpose of in vitro fertilization and embryo transfer display several levels of nuclear maturity. Preovulatory or mature oocytes, technically those that are Metaphase I or II, are inseminated shortly after aspiration and assessed for fertilization the following day. Prophase I oocytes, also called germinal vesicle-bearing or immature oocytes, require a 24-36 hour period in culture before being exposed to spermatozoa. During this time, the majority of Prophase I oocytes complete nuclear maturation in vitro, progressing from germinal vesicle breakdown through first polar body extrusion. If inseminated, many in vitro matured oocytes fertilize …


Ecological Relationships Between The Marsh Rice Rat (Oryzomys Palustris) And The Meadow Vole (Microtus Pennsylvanicus) In Two Virginia Tidal Marshes, Christopher P. Bloch Jul 1997

Ecological Relationships Between The Marsh Rice Rat (Oryzomys Palustris) And The Meadow Vole (Microtus Pennsylvanicus) In Two Virginia Tidal Marshes, Christopher P. Bloch

Biological Sciences Theses & Dissertations

Small mammals were trapped for 23 months on two live trap grids in tidal marshes in Northampton County, on the Eastern Shore of Virginia, to examine ecological relationships between the marsh rice rat (Oryzomys palustris) and the meadow vole (Microtus pennsylvanicus). Population density, survival rates, capture probability, recruitment, residence time, and home range size were calculated for each species. Patterns of reproductive activity and fluctuations in mean weight were also observed.

There were considerable differences in population dynamics between the two sites. At Grid 2, where vegetative cover was more abundant, population densities of rice rats and meadow voles …


Stomach Content Analysis Of Stranded Bottlenose Dolphins, Tursiops Truncatus, In Virginia, 1987-1996, John Mcgurk Jul 1997

Stomach Content Analysis Of Stranded Bottlenose Dolphins, Tursiops Truncatus, In Virginia, 1987-1996, John Mcgurk

Biological Sciences Theses & Dissertations

I examined the stomach contents from 94 bottlenose dolphins, Tursiops truncatus, that were stranded along the Virginia coastline from 1987 through 1996. Samples from 1987 through 1991 were obtained from the National Museum of Natural History (NMNH) and samples from 1992 through 1996 were collected by the Virginia Marine Science Museum (VMSM) Stranding Team. Prey species were identified using fish otoliths and cephalopod beaks.

The dolphins examined fed on 23 species of fish and one genus of cephalopods. The primary prey species was Atlantic croaker (Micropogonias undulatus); secondary species were weakfish (Cynoscion regalia), spot (Leiostomus xanthurus), silver perch (Bairdiella chrysoura), …


Effect Of Cocaine On Rabbit Renin Angiotensin System: Cocaine Detection In Adult And Fetal Tissue And Adult Plasma Using Ion Mobility Spectrometry, Barbara Belinda Guinn Jul 1997

Effect Of Cocaine On Rabbit Renin Angiotensin System: Cocaine Detection In Adult And Fetal Tissue And Adult Plasma Using Ion Mobility Spectrometry, Barbara Belinda Guinn

Biological Sciences Theses & Dissertations

Ion mobility spectrometry (IMS) was used to detect cocaine and/or the metabolite ecgonine methyl ester (EME) in tissue and plasma samples from male, maternal, and fetal New Zealand White (NZW) rabbits. EME was consistently detected in all adult plasma samples 5 minutes after the injection of cocaine hydrochloride (cocaine•HCI, 2 mg/kg). EME was also in the liver, kidneys, testicles, and ovaries. Five minutes after the injection of cocaine•HCI, the male arterial pressure (MAP) increased from a mean control value of 79 ± 3.2 mmHg to 88 ± 4.1 mmHg, and the pCO2 increased from a control value of28 ± …


Type Ii Estrogen Binding-Site Agonist: The Synthesis And Biological Evaluation Of The Enantiomers Of Methyl-Para-Hydroxyphenyllactate (Mehpla), Lester G. Pretlow Jul 1997

Type Ii Estrogen Binding-Site Agonist: The Synthesis And Biological Evaluation Of The Enantiomers Of Methyl-Para-Hydroxyphenyllactate (Mehpla), Lester G. Pretlow

Theses and Dissertations in Biomedical Sciences

The function of the type II estrogen binding site (EBS) has yet to be determined. However, a high affinity ligand for the binding site has been identified through HPLC and GC-MS. This ligand, MeHPLA, bears a structural relationship to a group of compounds called "phytoestrogens" which, along with MeHPLA, have been observed to suppress the cellular proliferation of estrogen sensitive MCF-7 breast cancer cells in vitro. Additionally, MeHPLA has been observed to suppress the growth of rat uteri in vivo. The high affinity of MeHPLA for the type II EBS suggests that this interaction is responsible for the observed suppression …


The Cellular And Molecular Dynamics Of The Queuosine Modification In Transfer Rna: Definition, Modulation, Deficiencies And Effect Of The Queuosine Modification System, Rana C. Morris Jul 1997

The Cellular And Molecular Dynamics Of The Queuosine Modification In Transfer Rna: Definition, Modulation, Deficiencies And Effect Of The Queuosine Modification System, Rana C. Morris

Theses and Dissertations in Biomedical Sciences

The presence of the queuosine modification in the wobble position of tRNAasn, tRNasp, tRNAhis, and tRNAtyr is associated with a decrease in cellular growth rate, an increase in the ability to withstand environmental stress, and differentiation of pleuripotent cells into mature phenotypes. The loss of this normal modification is strongly correlated with neoplastic transformation and tumor progression of a wide variety of cancers.

The "normal" system for formation of the queuosine modification in tRNA was studied in human fibroblast cell cultures and in mouse, rat and human liver tissues. The queuosine modification system …


Speciation Of Selenium In Serum, Alice Tsapayi-Musapatike Jul 1997

Speciation Of Selenium In Serum, Alice Tsapayi-Musapatike

Chemistry & Biochemistry Theses & Dissertations

We investigated the separation of selenoprotein P and extracellular (serum) glutathione peroxidase using a concanavalin A affinity column. We were able to show that the method does not adequately separate serum glutathione peroxidase from selenoprotein P because human glutathione peroxidase binds strongly to the column. We also found that albumin can interfere with measurement serum of glutathione peroxidase activity when hydrogen peroxide is used as the substrate. When t-butyl hydroperoxide was used as the substrate, less than 10% of the measured activity was due to the presence of albumin. We also found that the pH of the elution buffer plays …


The Effect Of Growth Hormone Release On Plasma And Erythrocyte Selenium And Zinc Levels In Children, Maria Estela Legal De Reid Jul 1997

The Effect Of Growth Hormone Release On Plasma And Erythrocyte Selenium And Zinc Levels In Children, Maria Estela Legal De Reid

Chemistry & Biochemistry Theses & Dissertations

Research studies have suggested that selenium may be important in the release of growth hormone, GH. A selenium-containing amino-acid residue, selenocysteine, has been identified as part of the active site of the three isoenzymes (Type I, II and III iodothyronine 5' -deiodinase) responsible for the synthesis of active thyroid hormone, T3, which is reported to stimulate GH secretion. The importance of zinc in growth is well- documented because of its involvement in transcription and expression of GH and its intermediary, insulin growth factor I or IGF- I. Thus, selenium and zinc levels in plasma may be altered in response …


Cγ- And Cα-Subunits Provide The Specificity For Camp/Pka Function, Wei Qing Zhang Apr 1997

Cγ- And Cα-Subunits Provide The Specificity For Camp/Pka Function, Wei Qing Zhang

Theses and Dissertations in Biomedical Sciences

The Cα and Cγ of the cAMP-dependent protein kinase (PKA) are two highly homologous (83% amino acid identity), yet functionally distinct isozymes in vitro for substrate and pseudosubstrate specificity, and in intact cells for cell phenotypes (Beebe, 1992).

To determine the molecular mechanisms underlying the distinct functions in cell phenotypes, in vitro experiments were designed to make a detailed comparison of Cγ and Cα for substrate and pseudosubstrate specificity. To this end, Cγ and Cα were expressed m mammalian cells, bacteria and Sf9 insect cells using baculovirus. Abundant expression of active enzyme was cell system specific. Cγ and Cα expressed …


Active And Passive Settling By Marine Benthic Nematodes, Rodney Duane Bertelsen Apr 1997

Active And Passive Settling By Marine Benthic Nematodes, Rodney Duane Bertelsen

Biological Sciences Theses & Dissertations

This study investigates whether active processes participate in the settlement of marine benthic nematodes. The settling rates of three estuarine benthic nematode taxa were examined in a linear flume using two treatments defined by the type of sediment bed placed in the flume. One treatment bed contained sediments rendered "unattractive" by boiling. The other treatment bed contained unaltered "attractive" sediment. Preliminary still water choice experiments confirmed the attractive and unattractive properties of these sediment treatments with each taxon. Recolonization trays placed in the field confirmed that each taxon did disperse in the water column. One taxon (Theristus sp?) exhibited significantly …


Ecology Of The Early Life History Of The Caribbean Spiny Lobster, Panulirus Argus: Recruitment, Predation, And Habitat Requirements, Charles A. Acosta Apr 1997

Ecology Of The Early Life History Of The Caribbean Spiny Lobster, Panulirus Argus: Recruitment, Predation, And Habitat Requirements, Charles A. Acosta

Biological Sciences Theses & Dissertations

Recruitment variability of the early life history stages of marine benthic organisms can have profound consequences on population dynamics. I studied factors affecting recruitment success of postlarvae and early juveniles of the Caribbean spiny lobster. I examined patterns in postlarval supply, investigated wind forcing as a potential transport mechanism for recruiting postlarvae, and quantified predation on postlarvae in south Florida, USA. In an eight-year time series, spiny lobster postlarval supply occurred year-round between the new and first quarter lunar phases. The major annual peak occurred around March corresponding to spawning activity ten months earlier, and a smaller non-seasonal peak occurred …


Microzooplankton Dynamics In Lower Chesapeake Bay And Its Major Tributaries, Gyung Soo Park Apr 1997

Microzooplankton Dynamics In Lower Chesapeake Bay And Its Major Tributaries, Gyung Soo Park

Biological Sciences Theses & Dissertations

This study identified the temporal and spatial variability of microzooplankton density and biomass at 14 stations located within Chesapeake Bay and four rivers. Microzooplankton are defined as those heterotrophic organisms which range from 20 to 200 $\mu$m in size, and in this study were mainly composed of copepod nauplii, rotifers, and ciliates. Ciliates were the most abundant microzooplankton, comprising more than 90% of the total density, with copepod nauplii representing approximately 50% of the total microzooplankton biomass (carbon content). Rotifers contributed less than 5% for both density and biomass of the total microzooplankton.

Maximum ciliate abundance occurred from spring to …


Influence Of Physics On The Distribution Of Ichthyoplankton Across The Chesapeake Bay Plume, Christian S. Reiss Apr 1997

Influence Of Physics On The Distribution Of Ichthyoplankton Across The Chesapeake Bay Plume, Christian S. Reiss

OES Theses and Dissertations

Most marine fish have retained pelagic larval stages that are spawned away from juvenile habitats. Physical and biological processes on a number of scales may affect larval survival. Mesoscale features like estuarine or riverine plumes and fronts are thought to affect larval survival by transporting larvae to juvenile habitats or by retaining larvae in favorable developmental habitats. It is likely that these features are major contributors in the regulation of shelf-spawned estuarine-dependent taxa.

This study examined how physical oceanographic features affected the spatial distribution of ichthyoplankton across the Chesapeake Bay Plume. Larval surveys were conducted across the shelf and within …


Changes In Spinal Height Supine And Walking In Subjects With And Without Lower Back Pain, Dave Gregory Apr 1997

Changes In Spinal Height Supine And Walking In Subjects With And Without Lower Back Pain, Dave Gregory

Rehabilitation Sciences Theses & Dissertations

Purpose: The purpose of this study was to develop and test a device that could be used in clinical situations to measure spinal height in subjects with lower back pain.

Introduction: Spinal height measurement provides information on the impact of spinal loading on the intervertebral disc. The stadiometer is presently the most accurate device for this purpose but users of the device must be trained to be measured. This excludes untrainable subjects such as those with lower back pain. For this study, a new ins1rument was developed combining aspects of the stadiometer and other devices to produce a simpler method …


The Effects Of Organic Matter Rich Topsoil On The Germination Growth And Metal Uptake Of Corn (Zea Mays) Grown In Flue Dust Contaminated Soil, Christopher Allen Impellitteri Apr 1997

The Effects Of Organic Matter Rich Topsoil On The Germination Growth And Metal Uptake Of Corn (Zea Mays) Grown In Flue Dust Contaminated Soil, Christopher Allen Impellitteri

OES Theses and Dissertations

The large biomass of corn (Zea mays) and promising results from a previous experiment (Chlopecka and Adriano, 1995) concerning metal uptake by corn indicate that corn may be a good candidate for phytoremediation of trace metal contaminated soil. Appling soil (acid, thermic, typic paleudult) was treated with increasing levels of a metal rich flue dust based on Zn concentration (0, 150, 300, 600, 1200, and 2400 mg/kg). Four replicates at each Zn treatment level were either limed to pH 6.3-6.5 and covered with a two inch thick layer of organic matter rich topsoil (OM), unlimed and covered with …


A Modeling Study Of The Effects Of Size- And Depth-Dependent Predation On Larval Survival, Margaret M. Dekshenieks, Eileen E. Hofmann, John M. Klinck, Eric N. Powell Jan 1997

A Modeling Study Of The Effects Of Size- And Depth-Dependent Predation On Larval Survival, Margaret M. Dekshenieks, Eileen E. Hofmann, John M. Klinck, Eric N. Powell

CCPO Publications

The form of the predation pressure experienced by larval stages of marine invertebrates is largely unknown. However, it is believed that the type, timing and rate of larval predation are critical in determining recruitment to adult populations. In this study, a time and depth-dependent model of the growth and behavior of larvae of the Eastern oyster, Crassostrea virginica, was used to investigate the effects of different forms of size-and depth-dependent predation on larval survivorship. The simulated larval survival for a cohort experiencing size-dependent predation showed that the greatest percent of the cohort survived to competent settlement size when the …


Detection Of Harmful Algal Blooms Using Photopigments And Absorption Signatures: A Case Study Of The Florida Red Tide Dinoflagellate, Gymnodinium Breve, David F. Millie, Oscar M. Schofield, Gary J. Kirkpatrick, Geir Johnson, Patricia A. Tester, Btyan T. Vintard Jan 1997

Detection Of Harmful Algal Blooms Using Photopigments And Absorption Signatures: A Case Study Of The Florida Red Tide Dinoflagellate, Gymnodinium Breve, David F. Millie, Oscar M. Schofield, Gary J. Kirkpatrick, Geir Johnson, Patricia A. Tester, Btyan T. Vintard

OES Faculty Publications

The utility of photopigments and absorption signatures to detect and enumerate the red tide dinoflagellate, Gymnodinium breve, was evaluated in laboratory cultures and in natural assemblages. The carotenoid, gyroxanthindiester, was an adequate biomarker for G. breve biomass; water‐column concentrations corresponded with cell standing crops and chlorophyll a concentrations during bloom events in Sarasota Bay, Florida. Unlike other carotenoids, the relative abundance of gyroxanthin‐diester did not change throughout a range of physiological states in culture and the gyroxanthin‐diester: chlorophyll a ratio exhibited little variability in a natural assemblage during bloom senescence. Stepwise discriminant analysis indicated that wavelengths indicative of in vivo …


Problems With The Interpretation Of Mark-Release-Recapture Data In Subterranean Termites (Isoptera: Rhinotermitidae), Anthony D. Curtis, Deborah A. Waller Jan 1997

Problems With The Interpretation Of Mark-Release-Recapture Data In Subterranean Termites (Isoptera: Rhinotermitidae), Anthony D. Curtis, Deborah A. Waller

Biological Sciences Faculty Publications

The Lincoln index (Peterson method) is frequently used to estimate animal population size in mark-release-recapture studies. We tested the accuracy of this method to estimate termite colony size using logs infested with termites that were maintained in the laboratory. Termites were fed paper towels dyed either with 0.05% or 0.1% (w/w) of the dye marker Nile blue and released into their host logs in the laboratory. Following recapture a week later, estimates of termite population size for termites dyed with 0.05% Nile blue, and were approximately 3 times greater for termites dyed with 0.1% Nile blue. Concentrations of 0.1% Nile …


Regulation Of Algal Blooms In Antarctic Shelf Waters By The Release Of Iron From Melting Sea Ice, Peter N. Sedwick, Giacomo R. Ditullio Jan 1997

Regulation Of Algal Blooms In Antarctic Shelf Waters By The Release Of Iron From Melting Sea Ice, Peter N. Sedwick, Giacomo R. Ditullio

OES Faculty Publications

During summer 1995-96, we measured iron in the water column and conducted iron-enrichment bottle-incubation experiments at a station in the central Ross Sea (76°30'S, 170°40'W), first, in the presence of melting sea ice, and 17 days later, in ice-free conditions. We observed a striking temporal change in mixed-layer dissolved iron concentrations at this station, from 0.72-2.3 nM with sea ice present, to 0.16-0.17 nM in ice-free conditions. These changes were accompanied doubling of algal (diatom) biomass. Our incubation experiments suggest that conditions were iron-replete in the presence of sea ice, and iron-deficient in the absence of sea ice. We surmise …