Biochemistry, Biophysics, and Structural Biology Commons^™

Enzyme Reactions Using Ureidosuccinate As A Substrate During Pyrimidine Biosynthesis And Degradation In Cl. Oroticum, Penny Amy

Dissertations and Theses

Cells of Clostridium oroticum, an anaerobic bacterium, were grown on orotate as a carbon and energy source. Ureidosuccinase, an inducible enzyme in the pathway for pyrimidine degradation has been shown to convert ureidosuccinate to aspartate, CO₂ and NH₃ as reported by Liebenmm and Kornberg (7). Aspartate and CO₂ were formed in approximately a 1:1 ratio from ureidosuccinase activity.

Ureidosuccinase was found to be a Mn+² requiring enzyme with a pH optimum of approximately pH 6.5. Enzyme activity is labile to O₂, temperature, pH, dilution and high ionic strength. The optimum conditions for storage …

A Diurnal Zooplankton Migration Study In Lake Mead, Robert D. Staker

Publications (WR)

The diurnal vertical movement of zooplankton was first recorded in freshwater lakes by Weismann (1877) in Lake Constance (Bodensee), although Cuvier was credited with observing the migration of Daphniae in 1817 (Gushing, 1955). The migration is best observed in deep oligotrophic lakes and migrations of 50 m per day are described (Worthington, 1931). In addition, two species of chaetognaths are reported to migrate 400 m a day in marine waters off of Lisbon (Waterman and Berry, 1967) while Birge (1895) found little evidence of the phenomenon at all in Lake Mendota, Wisconsin. Most zooplankton that migrate rise at night and …

Final Report On Interrelationships Between Chemical, Physical And Biological Conditions Of The Waters Of Las Vegas Bay Of Lake Mead, James E. Deacon, Richard W. Tew

Publications (WR)

This program was a status study of the interaction between Las Vegas Wash, an enriched stream, and Las Vegas Bay, a wedge shaped arm of one of the world's deeper reservoirs. The program centered primarily on identification and counting of planktonic algae from several points in Las Vegas Bay. Additional work on nutrient enrichment of water samples was conducted to aid in interpretation of algal distribution related to nutrient input. Examination of a variety of physical, chemical, and biological parameters, both at many surface points in the bay, as well as in vertical profile, was also accomplished and further aided …

Proboscipedia, A Homeotic Mutant In Aedes Aegypti (L.) (Diptera: Culicidae), John Roach Roberts Jr.

College of Graduate Studies: Theses & Dissertations (1964–2006)

No abstract provided.

The Comparative Histochemistry Of The Infective Oncospheres Of Oochoristica Osheroffi Meggitt, 1934, And Oochoristica Scelopori Voge And Fox, 1950, (Cyclophyllidea: Linstowiidae) With Notes On The Origins Of The Egg Membranes, Gary R. Coulter

Loma Linda University Electronic Theses, Dissertations & Projects

Infective oncospheres of Oochorlstica osheroffi and Oochoristica scelopori were compared using fifteen histochemical tests. Vital stains were also used.

Carnoy’s-fixed gravid proglottids were vacuum-embedded in a paraffin-piccolyte mixture and cut transversely at 6 microns. Sections were tested for the presence of phosphatases, proteins, sclerotin precursors, nucleic acids, carbohydrates and acid mucopolysaccharides.

Oncospheres were histochemlcally very similar. Heavy concentrations of mucoproteins and glycoproteins were detected in the oncospheral coat of O. scelopori. Acid phosphatase was found in the embryophore of O. osheroffi, but could not be demonstrated in O. scelopori. No evidence of a sclerotized egg capsule was …

Effects Of Insulin, Sodium And D-Glucose On Amino Acid Absorption In The Intestine Of Rats, Andre-Gerard Craan

Dissertations and Theses

Amino acid absorption across rat intestine in vitro was inhibited or stimulated by insulin depending on the hormone serosal concentration.

The absence of sodium ions from the incubating solution resulted in a significant decrease of L-alanine absorption. However, L-alanine was enhanced in a sodium-free medium by the addition of insulin on the serosal side of the intestine.

A sizable decrease in L-alanine and L-lysine absorption was produced by introduction of D-glucose (0.2 % and 2 %) in the Krebs-Ringer's incubating buffer. Nevertheless, the presence of D-glucose did not prevent the stimulatory effect of insulin on amino acid absorption.

A Conceptual Draft Of A Dynamic Hydro-Biological Model For Lake Mead, L. G. Everett, Bureau Of Reclamation

Publications (WR)

Food and energy transformation in an aquatic system must be understood in order to develop a simulation approach. This report provides a comprehensive study of an aquatic ecosystem. The objectives of this report are to show: (1) the biological relationships in an aquatic system (2) the role of nutrients in the biological cycle (3) the role of abiotic factors in a limnetic environment (4) the status of the art of "Eutrophication modeling".

Micronutrients And Biological Patterns In Lake Mead, Hasan K. Qashu, Lorne G. Everett, J. S. Carlson, Bureau Of Reclamation

Publications (WR)

Progressive increases in concentration of dissolved solids in the Colorado River water from Lake Powell to Imperial Dam seem to alter plankton dynamics and biological productivity of the river. Also, changes in biological productivity and micronutrients concentrations occur within the same reservoir. Development of a digital simulation model to predict micronutrients concentrations and biological productivity is necessary for diagnosing changes in plankton population and effluent-carrying capacity of the system. The objectives of the study are: (1) to determine trace metal balance at different locations in Lake Mead, (2) to measure biological productivity and conduct plankton population counts at each sampling …

Purification And Properties Of Triosephosphate Isomerase From Selected Chlorophyta, John C. Meeks

All Master's Theses

It is the purpose of this study to purify and investigate some of the properties of triosephosphate isomerase from two unicellular green algae 1 Ankistrodesmus Braunii and Scenedesmus acuminatus, and one filamentous green alga, Chara sp.

Survey Of The Venezuelan Species Of Ficus, David Walter Hall

College of Graduate Studies: Theses & Dissertations (1964–2006)

This study was undertaken to provide a circumscription of the genus Ficus in Venezuela. The material studied was representative of the collections that have been made throughout the country. A great portion of Venezuela is apparently unexplored botanically. With this in mind I have attempted to do as complete a study as possible with the material available with fully realizing the many limitations. this circumscription is intended as a starting point for future work,not a stopping place.

Comprehensive Survey Of Sedimentation In Lake Mead, 1948-49, W. O. Smith, C. P. Vetter, G. B. Cummings, U.S. Bureau Of Reclamation

Publications (WR)

Reservoirs are becoming an increasingly prominent feature of the American landscape. Built for flood mitigation and to change a fluctuating river into a dependable source of water for irrigation, power, and other purposes, they are predestined, like natural lakes, to be destroyed sometime following their creation. Sedimentation sooner or later robs most lakes and reservoirs of their capacity to store water. The significance of sedimentation in the life of Lake Mead, the largest artificial reservoir in the world, was realized when the plan for the reservoir was conceived, and an aerial survey of the floor was made in 1935 before …

Rationalists In Retreat, W. E. Filmer

Stone-Campbell Books

No abstract provided.

Recent Opinions Of Biologists On Evolution: 2nd Edition, Evolution Protest Movement

Stone-Campbell Books

No abstract provided.

The Study Of The Effects Of Paradichlorbenzene On Drosophila Melanogaster, Dwain J. Paal

Bachelors’ Theses

The object of this investigation was to produce polyploid cells in the salivary glands of Drosophila melanogaster by treatment with paradichlorbenzene. Polyploidy is the condition in which the number of chromosomes in the nucleus is an exact multiple of the somatic or diploid number greater than two. This phenomena has often been referred to as produced by incomplete nuclear division.

Anatomy And Histology Of The Digestive Tract Of A Deep-Sea Fish Coelorhynchus Carminatus, Elly M. Jacobsen

University Studies (University of Nebraska) (1888–1984)

This paper deals with the anatomy and histology of the digestive tube of one of the grenadiers or rat-tails, Coelorhynchus carminatus (Goode), as classified by Jordan & Evermann (1896).1 Many studies on the structure of the digestive tracts of fishes have been made in the past, and pioneer work in the teleost group was done by Valatour in 1861, Pillet in 1894 on the Pleuronectidae, and Gulland in 1898 on the salmon. More recent studies have been made by Greene (1912) on the king salmon, Blake 2 (1930) on the sea bass, and Rogick (1931) on the minnow.

The species …

The Types Of Sterility And Related Phenomena With Special Reference To Convallaria And Tropaeolum Majus, Mary Cecilia

Bachelors’ Theses

The development of superior plants through breeding is one of the chief contributions of America to agriculture. Out of old stock, scientists have developed a large number of new forms with better quality, more productiveness, and greater resistance to disease and adversity. However, the surface has hardly been scratched and possibilities reach in interest are pushing forward the experimentations necessary for success in the science field.

The Natural Factors In The Selection Of Diet., Lamar William Neblett

Electronic Theses and Dissertations

No abstract provided.