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Comparison Of Littoral And Limnetic Zooplankton Communities Of Lake Mead, Patrick Joseph Sollberger

Publications (WR)

Microfaunal communities were studied in littoral (inshore) and limnetic (offshore) areas of the lower basin in Lake Mead to compare species composition and abundance between the two zones. Planktonic forms (zooplankton) dominated inshore and offshore habitats and the occurrence of littoral species was low. Therefore, high similarity in zooplankton species composition was found among all sampling stations. This was perhaps due to two main factors: (i) the physical and chemical environment among the stations were very similar and (ii) the lack of aquatic vegetation in the littoral zone reduced the occurrence of littoral species.

Although species composition did not vary …

Adaptation Of Striped Bass To Sea Water Following Direct Transfer From Freshwater: Morphological, Biochemical, And Physiological Parameters, Judy A. King

Electronic Theses and Dissertations

There has been heightened interest in the biology of striped bass (Morone saxatilis) because of increased pollution in their native spawning grounds and because of their extensive use in landlocked sport fisheries. Their euryhalinity makes them an excellent species for osmoregulation studies. The objective of this research was to study the rate of adaptation of striped bass gills to sea water (3% salt) after direct transfer from freshwater using biochemical (ion transport enzyme levels), physiological (chloride efflux), and ultrastructural methods. Striped bass have specialized osmoregulatory cells located on the interlamellar and afferent surfaces of their gill filaments as shown by …

Role Of Intracellular Ph In Muscle Fatigue, Joseph Mark Metzger, Robert H. Fitts

Biological Sciences Faculty Research and Publications

Intracellular pH of in vitro diaphragm preparations was determined following low- (5 Hz, 1.5 min) and high- (75 Hz, 1 min) frequency stimulation, using glass microelectrodes of the liquid membrane type (pH_m). Results were compared with values obtained by the standard homogenate technique (pH_h). High- and low-frequency stimulation reduced peak tetanic tension to 21 ± 1 (SE) and 71 ± 2% of initial values, respectively. Peak tetanic tension returned to resting values after 10- to 15-min recovery from high- or low-frequency stimulation. Resting pH_m was 7.063 ± 0.011 (n = 72), and after fatiguing …

Reproductive Competence In The Golden Hamster Following Prenatal Alcohol Exposure, Jennifer Jayne Swiatek

Master's Theses

No abstract provided.

The Role Of Iron Nutrition In Regulating Patterns Of Photosynthesis And Nitrogen Metabolism In The Green Alga Scenedesmus Quadricauda, Dennis Raymond Ades

Dissertations and Theses

The influence of iron nutrition on patterns of photosynthetic behavior, nitrogen metabolism, and fixed-carbon allocation is reported for a common freshwater green alga. Cultures of Scenedesmus quadricauda were grown in Fraquil medium in which iron concentrations ranged from 1.0 μM to 0.01 μM (log 10-6 to 10-8 M, respectively). Carbon 14 and nitrogen uptake experiments were conducted at photosynthetically saturating and subsaturating photon flux densities.

The Relationship Of Upwelling To Mussel Production In The Rias On The Western Coast Of Spain, Jack O. Blanton, Kenneth R. Tenore, F. Castillejo, Larry P. Atkinson, Franklin B. Schwing, Amy Lavin

CCPO Publications

We have calculated an upwelling index for each month over a 17-year period (1969-1985) for a point off the western coast of Spain. We interpret April through September values of the index to indicate the flux of nitrate-rich water in the Spanish Rias. The index representing the 6-month upwelling series has been correlated with an index representing the conditions of mussels grown during that season on rafts in Ria de Arosa. Two seasons represent extreme upwelling conditions over the 17-year sampling period: 1977 when the upwelling index was the highest, and 1983 when it was the lowest. A comparison of …

The Effect Of Salt Concentration On Auxin Stability In Culture Media, James R. Dunlap, Stephen Kresovich, Robert E. Mcgee

Faculty Publications

The concentrations of indole-3-acetic acid (IAA), naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D) were followed for 35 days in cell-free liquid medium containing 100, 50, or 0% Murashige-Skoog (MS) salt base. Although the concentrations of NAA or 2,4-D remained constant the level of IAA decreased to only 11% of the original concentration after 35 days in the presence of 100% MS salt base. The observed rate of IAA degradation was accelerated by the presence of MS salts.

Scanning Electron Microscopy Of The Irradiated Mouse Bladder Urothelium, Jon B. Reitan, Kari Feren

Scanning Electron Microscopy

The luminal surface of mouse bladder urothelium was studied by scanning microscopy 1 year after irradiation with 0, 10 and 20 Gy respectively. The controls that were anaesthetized only displayed surface characteristics indistinguishable from normal urothelium.

Irradiation with 10 Gy did not result in marked overall changes in the scanning electron microscopic features of the luminal aspect, but in some areas alterations comparable to the alterations after 20 Gy were observed. After irradiation with 20 Gy focal hyperplastic areas, superficial early ulceration and dedifferentiation of cover cells were seen. The dedifferentiation to featureless cells is probably not associated with increased …

Detection Of Abnormal Milk With Impedance Microbiology Instrumentation, Fahad Ali Abdulghany Khayat

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mastitic milk was detected by obtaining conductance measurements using an impedance microbiology Bactometer® 120 SC instruments. Conductance readings taken after 30 min at 25'C separated normal and abnormal milks when readings differed by more than 3% from the variance among instrument module wells. Samples blended from four quarters of a cow indicated milk from one quarter was abnormal if the salt level in the abnormal quarter raised the blend conductivity above that of normal samples and variance among the wells. Either solid or liquid substrates that contained bacterial stimulants could be used to accelerate bacterial acid production or to reduce …

Functional Aspects Of Renal Glomeruli Based On Scanning Electron Microscopy Of Corrosion Casts, With Special Emphasis On Reptiles And Birds, H. Ditrich, H. Splechtna

Scanning Electron Microscopy

The glomerular complexity of several species of birds and reptiles is investigated in this study by scanning electron microscopy of vascular corrosion casts. Comparing these results with those of a freshwater teleost and a mammalian species, a trend towards small, simple glomeruli of the avian type, beginning with large, well vascularized glomeruli resembling the type found in fish, can be observed in reptiles.

A close correlation between glomerular size and habitat can be established comparing related species having a similar physiological mode of renal function.

Entirely different from this sauropsidian evolutionary line of development is the highly complex, large differentiation …

Lipofuscin Accumulation In Cultured Non-Dividing Cells As A Function Of Time And Oxygen Tension, Anders Brunmark, V. Peter Collins, Howard Thaw, Ulf Brunk

Scanning Electron Microscopy

Cultivated human glial cells, kept in a state of density-dependent inhibition of growth, accumulate age-pigment (lipofucsin) within their lysosomal vacuomes with the same characteristics as the corresponding pigment observed in vivo. The rate of formation and accumulation of lipofuscin is greatly accelerated under the conditions of routine cell cultivation in comparison to the in vivo event. Lipofuscin is generally considered to be composed of polymerized products of lipid peroxidation and thus it would be reasonable to suggest that factors which influence lipid peroxidation would also alter the rate of lipofuscin formation. Human glial cells were grown in the presence …

Prezygotic Male Reproductive Effort In Insects: Why Do Males Provide More Than Sperm, James S. Quinn, Scott K. Sakaluk

Faculty Publications – Biological Sciences

Males' incentives for providing benefits to females and/or their offspring are ambiguous during the period prior to zygote formation. The benefits may function to increase the number of available eggs fertilized by a male and/or enhance the production and survival of his offspring. In some cases, male prezygotic investment may be an adaptation to secure fertilizations despite the fact that it incidentally benefits the female or her offspring. More often, the benefits to offspring production and survival are not simply incidental and probably account, in part, for the magnitude of the male investment. Regardless of the adaptive significance of male …

Assessment Of Fawn Breeding In A South Carolina Deer Herd, Olin E. Rhodes Jr., James M. Novak, Michael H. Smith, Paul E. Johns

Faculty Research & Creative Activity

Annual variation in breeding success among female white-tailed deer (Odocoileus virginianus) fawns on the Savannah River Plant (1967 to 1985) was determined from direct counts of pregnancy in spring-collected fawn females and evidence of lactation and measurements of udder thickness in fall-harvested 1. 5-yearolds. Percent lactation in 1.5-year-old females collected during September and October gave the best estimate of fawn breeding in the previous year. The overall mean fawn breeding estimate from September and October was 41 % , and the yearly variation in fawn breeding was significant. An estimate of the average yearly contribution to recruitment was 43 fetuses …

The Effect Of Sewage Effluent Removal On The Water Quality Of Lake Howell, Florida, Patricia L. Smith

Retrospective Theses and Dissertations

In April, 1983, sewage effluent discharge from the Maitland and Winter Park sewage treatment plants was diverted from Lake Howell to the Iron Bridge Regional Sewage Treatment Plant. The sewage treatment plants of the cities of Winter Park and Maitland had been discharging into Lake Howell since 1927 and 1962, respectively. These point sources had contributed 95% of the total phosphorus and 69% of the total nitrogen budgets for Lake Howell. Physico-chemical parameters were monitored monthly for two years chemical parameters were monitored monthly for two years from January, 1983 through December, 1984. Annual mean values fro chlorophyll_a, …

The Effect Of Food On Reproduction In The Sailfin Molly, Poecilia Iatipinna (Poeciliidae, Rebecca B. Smith

Retrospective Theses and Dissertations

Sailfin molly populations often experience a midsummer slump in reproduction, and it has been suggested that this slump is caused by food shortage. A food supplementation experiment on a natural population of mollies was done in 1983. Excess food did not directly affect the fecundity of females in the field. A laboratory experiment was designed to determine the food level on reproduction in females. Ration had the greatest effect on somatic condition and growth, indirectly influencing fecundity. Two explanations for this strategy are suggested. A significant difference in brood size and size of young was observed between the field and …

Arthropod Species Diversity, Composition And Trophic Structure At The Soil Level Biotope Of Three Northeastern Illinois Prairie Remnants, With Botanical Characterization For Each Site, Dean George Stathakis

Master's Theses

No abstract provided.

Metabolism Of N⁶- Δ ²-Isopentenyladenine In Saccharomyces Cerevisiae, Kast Carol Anne Van

Master's Theses

No abstract provided.

Fiber Number And Type Composition In Extensor Digitorum Longus, Soleus, And Diaphragm Muscles With Aging In Fisher 344 Rats, Thomas J. Eddinger, Richard L. Moss, Robert G. Cassens

Biological Sciences Faculty Research and Publications

Histochemical (M-ATPase) fiber typing was done on extensor digitorum longus, (EDL), soleus (SOL), and diaphragm (DIA) muscles of barrier-reared Fisher 344 rats obtained at four different ages (3, 9, 28, and 30 months) from the colonies of the National Institute of Aging. In the EDL there are no differences in the percent of type I fibers among the four age groups. The percent of type IIa and IIb fibers also showed no difference between the 3 and 30 month age groups. There was no apparent trend for an increase or decrease in the percent of type IIa or IIb fibers …

Factors Influencing Cellulolytic Activity Of The Soil Fungus, Aspergillus Candidus, Jacobo Ortega, Ernest J. Baca

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Effects of pH, incubation time, nitrogen source and carbohydrate source upon production of carboxymethyl cellulase by Aspergillus candidus grown in liquid medium were studied. Maximal cellulase activity per unit of protein occurred in culture fluids with a pH of 5.5, after 10 days of cultivation of the fungus. Ammonium nitrate supported the highest production of the enzyme. However, in the nitrogen-source test, highest accumulation of extracellular protein was found in fluids from cultures with urea as the nitrogen source. Cotton fibers produced the greatest gain in cellulase activity when the carbohydrate source was incremented from 0.5 to 1.0 percent. The …

The Trend In Canopy Composition In A Young Mesic Forest, Zhenchang Li

Masters Theses

Brewer Woods, a young disturbed mesic sugar maple-beech (Acer saccharum-Fagus grandifolia) forest in Kalamazoo Co., Michigan, was investigated by point-quarter and transition matrix methods. The results indicate that this forest is dominated by sugar maple in both canopy and understory composition. Beech is the second most important species. Fourteen species were found as canopy trees or replacements. The hypothesis that a young forest is more diverse than comparable climax forests such as Warren Woods and Hueston Woods was supported. Its successional trend is that sugar maple will become more abundant at the expense of the other species. Beech is a …

Going To Extremes: Why Do Sanderlings Migrate To The Neotropics?, J. P. Myers, John L. Maron, Michel Sallaberry A.

Biological Sciences Faculty Publications

Sanderlings (Calidris alba) breed within a small latitudinal range in the arctic while spreading in winter virtually throughout temperate and tropical marine beaches of the world. This paper examines spatial variation in Sanderlings nonbreeding density across the New World, documents annual cycle differences between populations wintering in California and those wintering in Peru and Chile, and then explores demographic and ecological factors underlying Sanderlings migration to different wintering grounds. Densities during the nonbreeding season are higher on the Pacific coast than on the Atlantic at all censused latitudes in the New World, and reach a peak in southwestern …

Seasonal Changes In Feeding Success, Activity Patterns, And Weights Of Nonbreeding Sanderlings (Calidris Alba), John L. Maron, J. P. Myers

Biological Sciences Faculty Publications

Seasonal changes in Sanderling (Calidris alba) feeding success, time budgets, and weights were followed throughout the nonbreeding season at Bodega Bay, California. Sanderlings spent more time roosting in fall than in winter, and in fall adults spent more time roosting than juveniles. Sanderling prey capture rates were high in fall and spring and declined through winter. Sanderling weights paralleled seasonal changes in feeding success and activity patterns: birds were heaviest in fall and spring and lightest in winter. These results reflect lowered food availability in winter and imply that birds may have difficulty balancing their energy budgets during …

Acetylcholinesterase In The Neonatal Rat Brain: The Effects Of Prenatal Ethanol Exposure, Linda M. Boland

Biological Sciences Theses & Dissertations

Acetylcholinesterase (AChE) activity in the neonatal rat brain was determined by histochemical localization and quantitative biochemical analysis. AChE-positive perikarya were concentrated in the neostriatum, globus pallidus, medial habenular nucleus, amygdaloid complex, various hypothalamic nuclei, gigantocellular and paragigantocellular reticular nuclei, raphe nuclei, locus coeruleus, and motor nuclei of cranial nerves III-VII and IX-XII. Some areas stained differently or not at all when compared with the adult rat brain. The effects of prenatal ethanol exposure on regional AChE activity were assessed by comparing enzyme levels in offspring exposed via maternal consumption of a liquid diet containing 35 percent ethanol derived calories. This …

Microbial Degradation Of The Leachable And Lignocellulosic Components Of Leaves And Wood From Rhizophora Mangle In A Tropical Mangrove Swamp, Ronald Benner, Robert E. Hodson

Faculty Publications

Preparations of uniformly [¹⁴C] labeled mangrove leaves and specifically radiolabeled [¹⁴C-lignin] lignocelluloses and [¹⁴C -polysaccharide]lignocelluloses from mangrove leaves and wood were used in experiments to determine the microbial rates of mineralization of the leachable and lignocellulosic components of mangrove detritus in aerobic and anaerobic sediments of a tropical mangrove swamp. The bulk of the leachable fraction from mangrove leaves was mineralized relatively rapidly and was assimilated into microbial biomass with high efficiency (30 %). In contrast, rates of mineralization of the lignocellulosic component of mangrove leaves and wood were 10fold lower than mineralization rates …

Early Development Of The Vertebrate Limb: An Introduction To Morphogenetic Tissue Interactions Using Scanning Electron Microscopy, Robert O. Kelley

Scanning Electron Microscopy

The developing limbs of most vertebrates serve as a model system for studies of morphogenesis, pattern formation, cell and tissue interactions and cell differentiation. Mesoderm in the flank of the embryo induces overlying ectoderm to form a thickened, stratified or pseudo-stratified epithelium which becomes the highly specialized apical ectodermal ridge. In turn, the apical ridge specifies individual limb parts (first from structures proximal to the body axis, then to more distal components) and is required for those elements to form. If the ridge is removed, subsequent limb development ceases and no further limb parts appear. The series of ectodermal-mesodermal interactions …

Calcium Oxalate Urolithiasis In The Rat: Is It A Model For Human Stone Disease? A Review Of Recent Literature, S. R. Khan, R. L. Hackett

Scanning Electron Microscopy

Calcium oxalate stone disease is the most common human urinary stone disease in the Western Hemisphere. To understand different aspects of the disease, calcium oxalate urolithiasis in the rat is used as a model. Spontaneous calcium oxalate urolithiasis is very rare in rats. Thus the disease is experimentally induced and the rats are generally made hyperoxaluric either by administration of excess oxalate, exposure to the toxin ethylene glycol, or various nutritional manipulations. All the experimental models show renal injury associated with crystal deposition. Calcium oxalate crystals are in most cases intraluminal in renal tubules and often attached to the basal …

The Growth Of Fetal Human Sensory Ganglion Neurons In Culture: A Scanning Electron Microscopic Study, Seung U. Kim, Kookmin M. Kim, Giuseppe Moretto, James H. Kim

Scanning Electron Microscopy

Sensory neurons of 8-week human fetal dorsal root ganglia were dissociated into single cells by trypsinization and cultured on coverslips for 4 months, in either serum-containing or serum-free chemically defined media. At different times the cultures were fixed and prepared for scanning electron microscopy. Fetal sensory neurons in culture regenerated axons within 24 hours which were characterized by axonal growth cones at their tips and the neuronal perikarya assumed spherical or a bonnet-like morphology.

Effects Of Temperature And Crowding On The Pathogenicity Of Edwardsiella Ictaluri In Channel Catfish (Ictalurus Punctatus), Sharon L. Johnson, Lawrence W. Hinck

Journal of the Arkansas Academy of Science

Channel catfish were injected with Edwardsiella ictaluri and stocked at increasing temperatures and densities. Bacteriological examination of kidney, liver and spleen revealed the greatest numbers of organisms in fish from the highest temperature and stocking density tested. Survival time was the shortest for fish held at the highest temperature and stocking density. Increased temperature and crowding were directly proportional to the number of organisms recovered from the organs and inversely proportional to fish survival time.

Concanavalin A-Binding Enzymes Of Crotalus Scutulatus Scutulatus Venom, Michael W. Hinson, C. K. Childs, Bob D. Johnson, Dewey H. Sifford

Journal of the Arkansas Academy of Science

Crotalus scutulatus scutulatus crude venom was separated into two fractions by Concanavalin A Sepharose 4B affinity chromatography. The proteins binding to Con A exhibited phosphomonoesterase (orthophosphoric monoester phosphohydrolase EC 3.1.3.2), phosphodiesterase, 5'-nucleotidase (5'-ribonucleotide phosphohydrolase EC 3.1.3.5), phospholipase A(phosphatidate 2-acylhydrolase EC 3.1.1 .4), hyaluronidase (hyaluronate glycanohydrolase EC 3.2.1 d), N-benzoyl-L-arginine ethyl esterase, p-toluenesulfonyl-L-arginine methyl esterase, L-amino acid oxidase (L-amino acid: 02 oxidoreductase [deaminating] EC 1.4.3.2), and caseinolytic activities. Thrombin-like and NAD nucleosidase (5'-ribonucleotide phosphohydrolase EC 3.1.3.5) activities were not observed. The crude venom and the fraction containing the glycoproteins which bound to Con A were fractionated by DEAE Sephadex A-50 ion …

Cell Volume Regulation Studies With The Electron Microprobe, Mary Jo Ingram, F. Duane Ingram

Scanning Electron Microscopy

Lumbricals from the hind feet of young rats are dissected free, stretched to approximately 125% of resting length, and mounted on individual, simple plastic forms. After recovery in physiological saline, the isolated muscles are incubated for periods of 40 to 60 min. in one of a series of hypertonic bathing solutions. The composition of each bathing solution is identical, except for osmolality which is increased with lactose. At least one muscle from each animal is incubated in a control solution to serve as a control muscle for that particular set of 5 to 8 muscles. Mounted muscles are removed from …