Digital Commons Network^™

Cartilage Regeneration On A Large Articular Surface Facilitated By Stress Shielding, Charles L. Mcdowell, Jennifer S. Wayne, Robert Tuten, Hunter H. Mcguire Jr.

Virginia Journal of Science

An animal model for the study of articular cartilage regeneration in-vivo facilitated by stress-shielding is introduced. The object of the model is to test the hypothesis that some form of cartilaginous tissue will grow upon a large joint surface in vivo with the joint in normal motion. The model utilizes the known capability of immature cells to differentiate. The source of cells is bleeding subchondral bone. In addition, the model provides a mechanically shielded environment in which cell differentiation and maturation can occur. The study showed that a substantial amount of tissue will grow in the animal model only when …

Segmental Distribution Of Common Synaptic Inputs To Spinal Motoneurons During Fictive Swimming In The Lamprey, James T. Buchanan, Stefan Kasicki

Biological Sciences Faculty Research and Publications

These experiments were designed to measure the degree of shared synaptic inputs coming to pairs of myotomal motoneurons during swimming activity in the isolated spinal cord of the lamprey. In addition, the experiments measured the decrease in the degree of shared synaptic inputs with the distance between the motoneurons to assess the segmental distribution of these shared inputs. Intracellular microelectrode recordings of membrane potential were made simultaneously on pairs of myotomal motoneurons during swimming activity induced with an excitatory amino acid. The swim cycle oscillations of motoneuron membrane potentials were removed with a digital notch filter, thus leaving the fast …

Molecular Systematics & Evolution Of The Ctenosaura Hemilopha Complex (Squamata: Iguanidae), Michael Ray Cryder

Loma Linda University Electronic Theses, Dissertations & Projects

Molecular variation within Ctenosaura hemilopha and among other Ctenosaura species are used to identify species boundaries, assess suitable systematic characters, identify evolutionary patterns within C. hemilopha mitochondrial DNA sequences and reconstruct species and area relationships among the various taxa. The molecular evolution of the C. hemilopha complex is analyzed using 1109 base pairs of mitochondrial DNA sequence from the cytochrome b and cytochrome oxidase III genes. Samples come from 22 individuals representing each of the five allopatric populations.

The results of a parsimony analysis showed a strongly supported, partially resolved set of relationships. The strict consenses tee formed in this …

Comparing The Tadpoles Of Hyla Geographica And Hyla Semilineata, Anne D'Heursel, Rafael O. De Sá

Biology Faculty Publications

External morphology, internal oral anatomy, and chondrocranial anatomy were examined for tadpoles of Hyla geographica from the Amazon rainforest, Brazil, and Hyla semilineata from the Atlantic rainforest, Brazil. Here, we provide morphological larval data to help diagnose these closely related species. Scanning electron microscopy analysis of buccal morphology showed the most distinctive features between these species: the distance between the lingual papillae in the buccal floor of H. geographica is three times greater than that distance in H. semilineata, and the relative size of the lingual papillae in H. geographica is less than half their size in H. semilineata. Although …

Host-Driven Population Dynamics In An Herbivorous Insect, Tiina Ylioja, Heikki Roininen, Matthew P. Ayres, Matti Rousi, Peter W. Price

Dartmouth Scholarship

Understanding the nature and relative importance of endogenous (density-dependent) and exogenous (density-independent) effects on population dynamics remains a central problem in ecology. Evaluation of these forces has been constrained by the lack of long time series of population densities and largely limited to populations chosen for their unique dynamics (e.g., outbreak insects). Especially in herbivore populations, the relative contributions of bottom-up and top-down effects (resources and natural enemies, respectively) have been difficult to compare because population data have rarely been combined with resource measurements. The feeding scars of a wood-mining herbivorous insect (Phytobia betulae Kangas; Diptera: Agromyzidae) of birch …

Conservation Implications Of Dietary Dilution From Debris Ingestion: Sublethal Effects In Post-Hatchling Loggerhead Sea Turtles, Shannon J. Mccauley, Karen A. Bjomdal

Biological Sciences

Ingestion of anthropogenic debris by marine species has been documented extensively; fewer studies have attempted to quantify the sublethal effects caused by debris ingestion. One potential sublethal effect is reduced nutrient gains from diets diluted by consumption of debris. Post-hatchling and juvenile loggerhead sea turtles (Caretta caretta) consume substantial quantities of debris. We evaluated the effects of dietary dilution on voluntary intake in post-hatchling loggerheads to assess their ability to compensate for the presence of inert diluents in their diet by increasing dry mass intakes to maintain nutrient gains. Mean daily intakes of dry mass did not increase …

Reactive Oxygen Species Generated By Depletion Of Cellular Glutathione Mediate Cadmium Cytotoxicity, Jun Xu

Masters Theses

Studies were put forth to test whether or not reactive oxygen species, which are influenced by the cellular level of reduced glutathione, mediate the toxicity of cadmium. Cadmium has been a focal point in the health care community in the past few years because it has been shown to induce the development of tumors, interfere with cellular signaling, and cause damage to organs, tissues, and biomolecules. Although various studies and theories have been proposed, little direct evidence, especially from studies utilizing primary cells in culture, has accumulated to show the mechanism by which the cadmium induced toxicity occurs.

Our studies …

Avian Communities Of Large Reclaimed Mine Grasslands In Southwestern Indiana, Travis L. Devault

All-Inclusive List of Electronic Theses and Dissertations

Many bird species native to the tallgrnss prairie region oCthc central U.S. have declined drastically since European settlement due lo the destruction and alteration of grassland habitat. In this study, the breeding bird communities or 21 large reclaimed surface coal mine grasslands in a seven-county area or southwestern Indiana were examined with respect to species and guild composition, density, variation among sites, and grassland size. In addition, the vegetation characteristics of nine large mine grasslands were described and related to the presence and abundance or eight grasslund bird species common to the study areas. The immense size of mine grasslands …

Two-Metal-Ion Catalysis In Adenylyl Cyclase, John J.G. Tesmer, Roger K. Sunahara, Roger A. Johnson, Gilles Gosselin, Alfred G. Gilman, Stephen R. Sprang

Biological Sciences Faculty Publications

Adenylyl cyclase (AC) converts adenosine triphosphate (ATP) to cyclic adenosine monophosphate, a ubiquitous second messenger that regulates many cellular functions. Recent structural studies have revealed much about the structure and function of mammalian AC but have not fully defined its active site or catalytic mechanism. Four crystal structures were determined of the catalytic domains of AC in complex with two different ATP analogs and various divalent metal ions. These structures provide a model for the enzyme- substrate complex and conclusively demonstrate that two metal ions bind in the active site. The similarity of the active site of AC to those …

The Rise And Fall Of African American Midwifery In The South, Nicole M. Bernard

Electronic Dissertations and Theses

The purpose of this thesis is to give insight into the role played by the African American midwife in the rural south, including Louisiana, Alabama, Texas, and Florida. The African American midwife was responsible for prenatal care, delivery, and a certain degree of postnatal care for the mother and the infant. During slavery, she was all that the slaves had. The African American midwife also aided in delivery of some of the whites as well in a time when blacks were considered to be no more than animals. This proves that the African American midwife was more than a savage …

Different Proctolin Neurons Elicit Distinct Motor Patterns From A Multifunctional Neuronal Network, Dawn M. Blitz, Andrew E. Christie, Melissa J. Coleman, Brian J. Norris, Eve Marder, Michael P. Nusbaum

WM Keck Science Faculty Papers

Distinct motor patterns are selected from a multifunctional neuronal network by activation of different modulatory projection neurons. Subsets of these projection neurons can contain the same neuromodulator(s), yet little is known about the relative influence of such neurons on network activity. We have addressed this issue in the stomatogastric nervous system of the crab Cancer borealis. Within this system, there is a neuronal network in the stomatogastric ganglion (STG) that produces many versions of the pyloric and gastric mill rhythms. These different rhythms result from activation of different projection neurons that innervate the STG from neighboring ganglia and modulate STG …

The Translocation Of Barramundi. A Discussion Paper., Makaira Pty Ltd

Fisheries Management Papers

There is recognisable economic benefit to the translocation of barramundi, but there is also a need to ensure the translocation will not adversely impact upon the genetic diversity, introduce disease or impact on the natural environment and biodiversity. This discussion paper has been prepared to provide information to assist in the assessment of the possible impact of translocation of barramundi into and within Western Australia, for the purposed of recreational stock enhancement, aquaculture development and domestic stocking. In contemplating the translocation any aquatic species, signigicant economic and social benefits must be balanced with biological and environmental risks; that is, the …

Cullin-3 Targets Cyclin E For Ubiquitination And Controls S Phase In Mammalian Cells, Jeffrey D. Singer, Mark Gurian-West, Bruce Clurman, James M. Roberts

Biology Faculty Publications and Presentations

Cyclin E is an unstable protein that is degraded in a ubiquitin- and proteasome- dependent pathway. Two factors stimulate cyclin E ubiquitination in vivo: when it is free of its CDK partner, and when it is phosphorylated on threonine 380. We pursued the first of these pathways by using a two-hybrid screen to identify proteins that could bind only to free cyclin E. This resulted in the isolation of human Cul-3, a member of the cullin family of E3 ubiquitin–protein ligases. We found that Cul-3 was bound to cyclin E but not to cyclin E-Cdk2 complexes in mammalian cells, and …

Estructura Del Condrocráneo Y Esqueleto Visceral De Larvas De Pseudis Minuta (Anura, Pseudidae, E. O. Lavilla, Rafael O. De Sá

Biology Faculty Publications

The chondrocranium and visceral skeleton of Pseudis minuta tadpoles are described, based on a series of five larvae in stages 31 - 35 of Gosner (1960). Among their striking characters are the presence of peculiar articular surfaces between cornua trabeculae and suprarostral cartilage, the incomplete development of the orbital cartilage, the high fenestration of the floor of the cavum cranii, the fusion of posterior foramina, and the fusion of spicules 3 and 4 in the hyobranchial skeleton.

Capillary Density Of Skeletal Muscle: A Contributing Mechanism For Exercise Intolerance In Class Ii–Iii Chronic Heart Failure Independent Of Other Peripheral Alterations, Brian D. Duscha, William E. Kraus, Steven J. Keteyian, Martin J. Sullivan, Howard J. Green, Fred H. Schachat, Anne M. Pippen, Clinton A. Brawner, Jason M. Blank, Brian H. Annex

Biological Sciences

No abstract provided.

The Mayfly Newsletter, Peter M. Grant

The Mayfly Newsletter

The Mayfly Newsletter is the official newsletter of the Permanent Committee of the International Conferences on Ephemeroptera.

The Winogradsky Column & Biofilms: Models For Teaching Nutrient Cycling & Succession In An Ecosystem, Delia Castro Anderson, Rosalina V. Hairston

Faculty Publications

No abstract provided.

Use Of Anal Gland Secretion To Distinguish The Two Beaver Species Castor Canadensis And C. Fiber, Frank Rosell, Lixing Sun

Biology Faculty Scholarship

Introduced North American beavers Castor canadensis pose a potential threat to the continuing recovery of Eurasian beaver C. fiber populations in several European countries. For management purposes, it is necessary to be able to identify and distinguish the two species. This, however, is difficult because the two species are morphologically, ecologically and behaviorally similar. To find a method for species identification, we examined the possibility of using anal gland secretion (AGS) collected from the two beaver species. We asked 20 inexperienced volunteers to inspect the color and viscosity of the AGS. When we provided the volunteers with the sex of …

The Timing And Pattern Of Myogenesis In Hymenochirus Boettgeri, Matthew T. Smetanick, Rafael O. De Sá, Gary P. Radice

Biology Faculty Publications

Differences in the relative timing of homologous developmental events among closely related species, known as heterochronies, may provide valuable clues in understanding evolutionary relationships (McKinney, 1988; McNamara, 1995). Examining the timing of myogenic events is a relatively easy and effective method for finding heterochronic events. For example, whether muscle proteins and myofibrils appear before or after multinucleation can be determined through histological techniciques (Kielbowna, 1981). Simple observations of live specimens can pinpoint functional landmarks such as first twitch (spontaneous or due to external stimuli) and first heartbeat.

The Timing And Pattern Of Myogenesis In Hymenochirus Boettgeri, Matthew T. Smetanick, Rafael O. De Sá

Biology Faculty Publications

Differences in the relative timing of homologous developmental events among closely related species, known as heterochronies, may provide valuable clues in understanding evolutionary relationships (McKinney, 1988; McNamara, 1995). Examining the timing of myogenic events is a relatively easy and effective method for finding heterochronic events. For example, whether muscle proteins and myofibrils appear before or after multinucleation can be determined through histological techniques (Kielbowna, 1981). Simple observations of live specimens can pinpoint functional landmarks such as first twitch (spontaneous or due to external stimuli) and first heartbeat.

Dissolved Organic Carbon Cycling In A Subtropical Seagrass-Dominated Lagoon, Susan Ziegler, Ronald Benner

Faculty Publications

The cycling of dissolved organic matter (DOM) and its significance to ecosystem metabolism was studled over a 16 mo period in a Thalassia testudjnum dominated meadow. The benthos was usually net autotrophic (annual gross primary production to respiration ratio [P:R] = 1.3) while water column respiration (R) exceeded gross primary production (annual P:R = 0.3). Net fluxes of dissolved organic carbon (DOC) from the benthos primarily occurred in the light (0 to 18 mmol C m^-2 d^-1) and from seagrass-dominated areas, suggesting that release of DOC was mainly due to seagrass exudation. Net benthic DOC fluxes measured …

The Effect Of Acute Exposure To Glyphosate On Reproductive Potential And Embryo Development Of Pseudosuccinea Columella Snail, Ambika N. Osborn

Electronic Dissertations and Theses

Glyphosate (Roundup) is one of the most commonly used broad spectrum herbicides used with little to no toxicity to higher animals or the environment (Smith and Ochme, 1992). Due to its widespread use, there is a continuous contamination of the environment in both soil and water, with this herbicide. This study was developed to determine the effects of sublethal concentrations of glyphosate on development and survivability of Pseudosuccinea columella snails (intermediate host of Fasciola hepatica). This was assessed by acutely exposing third generation snails to varying concentrations (0.01-1ppm) of glyphosate. The snails were kept on artificial spring water to which …

Isolation, Cloning, And Identification Of Syringomycin E Action Genes Of Saccharomyces Cerevisiae, Stephen D. Stock

Biology

Members of the syringomycin family of antifungal cyclic lipodepsipeptides are produced by Pseudomonas syringae pv. syringae strains as secondary metabolites. These metabolites are potent antifungal agents effective against a broad range of fungi. The antifungal mechanism of action of these compounds has been investigated using syringomycin E and Saccharomyces cerevisiae as a model fungal system. Mutants resistant to the growth inhibitory effects of syringomycin E were isolated after mutagenesis with nitrosoguanidine. These mutants were screened for the production of ergosterol and by complementation with syr2 mutants to eliminate mutants belonging to known syringomycin E-resistant complementation groups. From a total of …

Estimating Total Body Fat In Sharp-Shinned And Cooper's Hawks: Techniques And Application, John P. Delong

Biology

I evaluated the use of three direct methods (fat scoring, condition indices, and multiple regression of external morphological variables) and one indirect method to estimate total body fat (TBF) in Sharp-shinned Hawks (Accipiter striatus) and Cooper's Hawks (A. cooperii). All three direct methods explained a reasonable amount of variation in actual TBF values (r² ≥ 0.82), and all three methods required the use of four equations to account for the categories of species, age, and sex. Indirect methods are those that predict lean mass and subtract the lean mass estimate from the actual body …

The Roles Of Superoxide Dismutases Of A Plant-Beneficial Bacterium, Pseudomonas Putida, And A Phytopathogenic Bacterium, Pseudomonas Syringae Pv. Syringae B728a, During Plant Colonization, Young Cheol Kim

Biology

Both Pseudomonas putida and Pseudomonas syringae produced manganese-superoxide dismutase (MnSOD) and iron-superoxide dismutase (FeSOD). Genes sodB, encoding FeSOD, and sodA, encoding MnSOD, were cloned. The sodB genes were transcribed as monocistronic transcripts, expressed throughout growth phases when iron was available. The sodA genes were part of polycistronic operons, and transcripts of the operons were induced only in iron-deficient conditions. The effect of mutations in the SOD genes was observed during root colonization by Pseudomonas putida. The sodB and sodAsodB mutants were impaired in root colonization in mixed inoculations with wild-type. Growth of the sodB and sodAsodB mutants …

Roles Of Plasma Membrane Lipids In Syringomycin E Action In Saccharomyces Cerevisiae, Rungrach Wangspa

Biology

The bacterium Pseudomonas syringae pv. syringae produces an antifungal secondary metabolite, syringomycin E. Yeast growth inhibition by this lipodepsipeptide involves sterol and sphingolipids of the plasma membrane. Using a sterol auxotroph of Saccharomyces cerevisiae, strain FY-14, it was shown that the predominant sterol in yeast, ergosterol, is not required for the mechanism of action of this metabolite. With ergosterol, cholesterol, β-sitosterol or stigmasterol as the bulk sterol, strain FY-14 was sensitive to syringomycin E with the last two conferring the highest degree of sensitivity. The type of growth-promoting sterol influenced cellular sensitivity to syringomycin E. Growth-promoting ergosterol afforded the …

Ecology Of The Malay Civet (Viverra Tangalunga) In A Logged And An Unlogged Forest In Sabah, East Malaysia, Christina P. Colon

Publications and Research

Malay civets in a dipterocarp rain forest were studied from December, 1995, through June, 1997, in the Ulu Segama Forest Reserve in Sabah, East Malaysia. To investigate the basic ecology of this species and explore the potential impact of selective logging, data on home range, activity and diet were collected on study animals in an unlogged and a selectively logged forest, and comparisons made.

Density in the unlogged forest was 1/0.46 km² , and 1/1.07 km² in the logged forest. Mean home range size based on a 95% minimum convex polygon was 110 ha. and did not differ …

Interaction Between Winter Dominance And Territory Defense In Male Pronghorn Antelope, Antilocapra Americana, Charles William Gunnels Iv

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In a territorial population of pronghorn from Antelope Island, UT, interaction between male dominance and territory defense was examined. High-ranking males were more likely to defend territories. Closely ranked animals engaged in more dominance interactions than distantly ranked individuals, and middle-ranked animals were involved in disproportionately more interactions than either high- or low-ranking animals. Large males possessed large horns and prongs as well as small cheek patches. Results from a factor analysis suggested that large males defended territories with a high density of sage. However, in this study, we did not observe pronghorn feed on sage during the territorial season. …

Commissural Interneurons In Rhythm Generation And Intersegmental Coupling In The Lamprey Spinal Cord, James T. Buchanan

Biological Sciences Faculty Research and Publications

Commissural interneurons in rhythm generation and intersegmental coupling in the lamprey spinal cord. To test the necessity of spinal commissural interneurons in the generation of the swim rhythm in lamprey, longitudinal midline cuts of the isolated spinal cord preparation were made. Fictive swimming was then induced by bath perfusion with an excitatory amino acid while recording ventral root activity. When the spinal cord preparation was cut completely along the midline into two lateral hemicords, the rhythmic activity of fictive swimming was lost, usually replaced with continuous ventral root spiking. The loss of the fictive swim rhythm was not due to …

Analysis Of Intraguild Predation With A Consideration Of Adaptive Foraging, Toshinori Okuyama

School of Biological Sciences: Dissertations, Theses, and Student Research

Identification of interactive units in food webs is particularly important in population and community ecology. Intraguild predation has gained much attention recently with the recognition of its prevalence in the field, although its significance has not been fully studied. Nature contains much more complex interactions than a simple food chain. Yet, much theory still focuses on the trophic levels connected in a single linear chain. In this thesis, I study intraguild predation including the consideration of animal behavior whose importance is also often neglected in population and community ecology.

First, the concepts of intraguild predation and animal behavior are introduced. …