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Articles 38221 - 38250 of 39120

Full-Text Articles in Life Sciences

Phospholipid Inhibitor Inactivation As A Mechanism For The Activation Of Renin By Cadmium Ions, Thomas Emanuel Gallant May 1971

Phospholipid Inhibitor Inactivation As A Mechanism For The Activation Of Renin By Cadmium Ions, Thomas Emanuel Gallant

Senior Scholar Papers

Incubation of bovine kidney homogenates with CdCl or ZnCl2 doubles their renin activity as measured by rat bioassay. It is suggested that the activation of renin by these divalent cations results from their interference with the renin inhibitor system described by Sen et al., (1968). Failure of the inhibitor to reassociate with renin upon removal of cadmium ions by EDTA supports their renin control model. It is suggested that either renin samples prepared directly from tissue without the use of acetone powder preparations contain little phospholipase A or cadmium inactivates phospholipase A. In the absence of active phospholipase A, conversion …


A Monographic Study Of The Genus Aristida In New Mexico, Raymond C. Krehoff May 1971

A Monographic Study Of The Genus Aristida In New Mexico, Raymond C. Krehoff

Biology ETDs

Studies of collections of Aristida from New Mexico indicate that 16 species of this genus occur in the state. These are A. adscensionis L., A. oligantha Michx., A. orcuttiana Vasey, A. ternipes Cav., A. barbata Fourn., A. divaricata Humb. and Bonpl., A. hamulosa Henr., A. glauca (Nees) Walp., A. purpurea Nutt., A. roemeriana Scheele, A. wrightii Nash, A. pansa Woot. and Standl., A. longiseta Steud. (and 2 varieties), A. fendleriana Steud., A. parishii Hitchc., and A. arizonica Vasey. These taxa are treated systematically from a morphological point of view and probable relationships among them are discussed. Distribution of each of …


Phytoplankton Periodicity In Shanty Hollow Lake, Warren County, Kentucky, David Hill May 1971

Phytoplankton Periodicity In Shanty Hollow Lake, Warren County, Kentucky, David Hill

Masters Theses & Specialist Projects

A study of the phytoplankton periodicity and its correlation with chemicophysical parameters, diel variation of the plankton, and the cyclomorphotic variation of Ceratium hirundinella was made in Shanty Hollow Lake, Warren County, Kentucky, from October, 1969, to August, 1970.

Phytoplankton samples were collected at zero and six feet with a Kemmerer sampler (31 October through 8 December) and with a ten -liter Birge-Juday plankton trap (23 December through 9 August). Water samples for the chemicophysical determinations were collected with a Kemmerer sampler. The phytoplankton samples were preserved with 5% formalin until they were enumerated. The chemicophysical determinations (pH, conductivity, dissolved …


The Determination Of The Time Of Ovulation, First Cleavage, Subsequent Cleavage Divisions And Implantation In Female Mice Treated With Gonadotrophins, James William Weldon May 1971

The Determination Of The Time Of Ovulation, First Cleavage, Subsequent Cleavage Divisions And Implantation In Female Mice Treated With Gonadotrophins, James William Weldon

Morehead State Theses and Dissertations

A thesis presented to the faculty of the School of Sciences and Mathematics at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science in Biology by James William Weldon in May of 1971.


Investigation Of Urolithiasis Occurring In Hatchery-Reared Trout In Utah, Ernest H. Dean Jr. May 1971

Investigation Of Urolithiasis Occurring In Hatchery-Reared Trout In Utah, Ernest H. Dean Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The urolithiasis condition investigated occurred at a "hard water" hatchery in Utah after the trout were changed from a meat diet to a commercial pelleted fish feed as a sole sustaining diet in 1961. Numerous diet modifications proved unsuccessful in preventing urolithiasis at the hatchery. It was eventually determined that different commercial diets resulted in varied percentages of trout developing urolithiasis. The urolithic deposits found in the kidney tubules were amorphous and composed of calcium phosphate (apatite) and an organic matrix. Bacterial contamination of the kidneys was not an important factor in the formation of urolithiasis. Rainbow trout containing urolithic …


The Suitability Of Newton Reservoir To Be Either A Coldwater Or A Warmwater Fishery, Jeffrey H. Johnson May 1971

The Suitability Of Newton Reservoir To Be Either A Coldwater Or A Warmwater Fishery, Jeffrey H. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Measurements were made of the water chemistry the distribution and relative abundance of net-plankton, and the reproduction, age and growth, and food habits of largemouth bass in Newton Reservoir, Newton, Utah.

Samples for chemical analysis were collected weekly from three sites and from several depths at each site. Plankton collections were made on a monthly basis. Data were compared with data in the literature and analyzed for possible ecological implications.

Physical and chemical investigations of the water indicated favorable conditions for a warmwater fishery.

The study of the surface net-plankton revealed a predominance of blue-green algae.

The substratum of the …


An Electrophysiological Study Of The Oral Plate Sensory Organs Of The Honey Bee (Apis Mellifera L.), Rodney R. Seeley May 1971

An Electrophysiological Study Of The Oral Plate Sensory Organs Of The Honey Bee (Apis Mellifera L.), Rodney R. Seeley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The oral plate sense organs of the honey bee, Apis mellifera L., have been investigated employing an electrophysiological technique which allows simultaneous stimulation and recording.

The results of the study present evidence that the four bipolar sense cells innervating the sensory papillae on the oral surface of the hypopharynx are chemoreceptors. The sensory papillae respond to cations, glucose, water, and amino acids. Evidence for the absence of a mechanosensory cell is presented. The data concerning the sensory structures agree with the current theories of chemoreception.


Effects Of Dmso And Propham On Mitosis In Root Tips Of Secale Cereale, Max Rosequist May 1971

Effects Of Dmso And Propham On Mitosis In Root Tips Of Secale Cereale, Max Rosequist

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

DMSO (dimethyl sulfoxide) and propham (isopropyl carbanilate) were investigated to determine their effect singly and in combination on mitoses in rye (Secale cereale) root tip cells. Root tips were prepared for observation by the paraffin and aceto-carmine squash methods. Results showed DMSO caused the following abnormalities: arrested metaphases, multipolar spindles, multinucleate cells, stickiness, shortened chromosomes, and mitotic inhibition. Cells from propham treated root tips exhibited the same abnormalities as those treated with DMSO. In addition, propham treatments resulted in polyploid cells and chromosome granulation. In combination, DMSO and propham caused all the abnormalities mentioned above except polyploidy. In …


Isolation And Characterization Of Autosomal Male Sterile Mutants In Drosophila Melanogaster, Lynn J. Romrell May 1971

Isolation And Characterization Of Autosomal Male Sterile Mutants In Drosophila Melanogaster, Lynn J. Romrell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In order to study the genetic control of spermiogenesis, recessive, male-sterile, autosomal mutants of Drosophila melanogaster were induced with ethyl methanesulfonate. A total of 31 mutants were recovered, 15 of which were located on the second chromosome and 16 on the third chromosome. Eight second- and 6 third-chromosome mutants demonstrating sterility in all homozygous males were used for further analysis.

Complementation tests showed that 2 of the 8 second chromosome mutants (and none of the 6 third chromosome mutants) were noncomplementing, indicating that two of the mutants produced were alleles of the same locus. Mapping of the second chromosome mutants …


Ribose 5'-Phosphate Aminotransferase Of Salmonella Typhimurium, Gulamnabi Y. Vahora May 1971

Ribose 5'-Phosphate Aminotransferase Of Salmonella Typhimurium, Gulamnabi Y. Vahora

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ribose-5 '-phosphate aminotransferase, an alternate first enzyme in the purine de novo pathway, has been purified about 800-fold from Salmonella typhimurium (pur D-55 ). The enzyme is distinct from ribosylpyrophosphate-5'-phosphate amidotransferase (E C 2.4.2.14), has an approximate molecular weight of 229,000, and requires ribose-5'-phosphate, ATP and either ammonium ion, carbamyl phosphate or L-glutamine, to synthesize 5'-phosphoribosylamine (PRA). A coupled assay system, employing a S. typhimurium (pur G-310) extract as the coupling-agent source, was used to measure the enzyme. PRA production in this system was inhibited by higher ribose-5' -phosphate concentrations and longer (over 10 minutes) incubation periods. It …


A Comparison Of The In Vitro Viability Of Ova From Hormone-Treated Mice With Ova From Spontaneous Ovulations, Henry H. Lyon Apr 1971

A Comparison Of The In Vitro Viability Of Ova From Hormone-Treated Mice With Ova From Spontaneous Ovulations, Henry H. Lyon

Morehead State Theses and Dissertations

A thesis presented to the faculty of the School of Science and Mathematics at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science in Biology by Henry H. Lyon on April 23, 1971.


A Conceptual Draft Of A Dynamic Hydro-Biological Model For Lake Mead, L. G. Everett, Bureau Of Reclamation Apr 1971

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".


A Determination By Thin-Layer Chromatography Of The Chemical Nature Of The Poison Produced By The Bryozoan Lophopodella Carteri (Hyatt), John Michael Dolan Apr 1971

A Determination By Thin-Layer Chromatography Of The Chemical Nature Of The Poison Produced By The Bryozoan Lophopodella Carteri (Hyatt), John Michael Dolan

Master's Theses

A study was undertaken to isolate and characterize by thin-layer chromatography the poisonous principle produced by the freshwater bryozoan, Lophopodella carteri (Hyatt).

The bryozoan homogenate was divided into a lipid and non-lipid portion and each was assayed for toxicity. Only the lipid extract was lethal to fishes. The lipid part was divided into six classes by thin-layer chromatography. When tested, four of the six classes were toxic. Thin­ layer chroatography was used to subdivide each class into fractions. Assays showed toxicity in nine of fourteen fractions.

Evidence indicates that the poisonous princi ple is a lipid and the large number …


Cause And Control Of A Common Market Disease Of Lettuce, William Palmore Mar 1971

Cause And Control Of A Common Market Disease Of Lettuce, William Palmore

Masters Theses & Specialist Projects

Head lettuce, Lactuta sativa var. capitata, is susceptible to a number of economically important diseases, the most frequent being russet spot, rib discoloration, and vascular browning (28), which have been shown by Ceponis and Friedman (7) to be caused by Pseudomonas marginalis. Pseudomonads are common plant pathogens and cause such diseases as halo blight in beans (20), bacterial blight in soybeans (20), and bacterial wilt of the bird-of-paradise (27) and tobacco (24).

Plants that develop symptoms similar to russet of lettuce are oats, infected by Pseudomonas cichorii, and tobacco infected with Pseudomonas tobaci (34). In general, russet symptoms …


Immunologic Enhancement Of Murine Sarcoma I Tumor System, Fung-Win Shen Jan 1971

Immunologic Enhancement Of Murine Sarcoma I Tumor System, Fung-Win Shen

Biology ETDs

The purpose of this project was to study the mechanism of imnunologic enhancement in the mouse a t the cellular level. The Sarcoma I (Sal, H-2a) murine tumor system was employed as the model for this study. Sal, indigenous to the A/J (H-2a) strain of mouse, grows progressively in its syngeneic host but is rejected by non-H-2a mice. However, the SaI tumor can be induced to grow progressively in C57BL/KsJ (Ks, H-2d) mice by passive administration of Ks anti-Sal serum at the time of Sal tumor implantation. This phenomenon is termed immunologic enhancement. Hereafter, mice pretreated …


Molecular Weight Distribution Of Proteins Synthesized In Single, Identified Neurons Of Aplysia, David L. Wilson Jan 1971

Molecular Weight Distribution Of Proteins Synthesized In Single, Identified Neurons Of Aplysia, David L. Wilson

Biology Articles and Papers

Parietovisceral ganglia from Aplysia californica were incubated in medium containing leucine-3H. Single, identified nerve cell somas were isolated from the ganglia, and their proteins extracted and separated by electrophoresis on 5% SDS-polyacrylamide gels. The distribution of total or newly synthesized proteins from the single neurons was determined by staining or slicing and liquid scintillation counting of the gels. Experiments showed that: (a) a number of proteins were being synthesized in abundance in the nerve cells; (b) different, identified neurons showed reproducibly different labeling patterns in the gels; (c) cells R2 and R15, …


A History And Distributional List Of Ellis County, Kansas, Birds, Charles A. Ely Jan 1971

A History And Distributional List Of Ellis County, Kansas, Birds, Charles A. Ely

Fort Hays Studies Series

This paper marks a century of Ornithology in Ellis County most of it centered around Hays and Ellis. This paper is an attempt to collect the scattered observations of numerous birders and to encourage others to record their observations for posterity.


A Study Of The Endogenous Electron Donors For Nitrogen Fixation By Cell-Free Extracts Of Klebsiella Pneumoniae M5al (Aerobacter Aerogenes M5al), Elisabeth Yi-Jan Wu Jan 1971

A Study Of The Endogenous Electron Donors For Nitrogen Fixation By Cell-Free Extracts Of Klebsiella Pneumoniae M5al (Aerobacter Aerogenes M5al), Elisabeth Yi-Jan Wu

Electronic Theses and Dissertations

Biological nitrogen fixation, the mechanism of the enzymatic conversion of the inert nitrogen gas into amino acids in the cytoplasm of the microorganism has puzzled many scientists for decades. The recent discovery of some free-living nitrogen-fixing bacteria has encouraged the investigation of this mechanism. A big step taken in the rapid elucidation of this mechanism was the first reproducible cell-free nitrogen-fixing system from Clostridium pasteurianum successfully obtained by Carnahan et al. (9) in 1960. In the following decade, reproducible cell-free systems were demonstrated with the strict aerobe, Azotobacter vinelandii (4), facultative anaerobic Bacillus polymyxa (16) and Klebsiella pneumoniae (31) and …


Micronutrients And Biological Patterns In Lake Mead, Hasan K. Qashu, Lorne G. Everett, J. S. Carlson, Bureau Of Reclamation Jan 1971

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 …


The Effect Of Las Vegas Wash Effluent Upon The Water Quality In Lake Mead, D. A. Hoffman, P. R. Tramutt, F. C. Heller, Bureau Of Reclamation Jan 1971

The Effect Of Las Vegas Wash Effluent Upon The Water Quality In Lake Mead, D. A. Hoffman, P. R. Tramutt, F. C. Heller, Bureau Of Reclamation

Publications (WR)

This study developed from observations made during an earlier study on Lake Mead which was reported in CHE-70, Water Quality Study of Lake Mead. Results from that study indicated that poor-quality water was flowing into the Las Vegas Bay reach of Boulder Basin, Lake Mead. Also reports of deteriorating water quality, resulting in taste and odors in domestic water supplies taken from Boulder Basin as well as a reduction in the attractiveness of Las Vegas Bay for recreational uses caused by aquatic plants and algae blooms, indicated a need for a concentrated study concerning the effects of flows from Las …


Combined Microspectrophotometry And Autoradiography Of Late Interphase Nuclei In Physarum Polycephalum, Joseph K. Vlchek Jan 1971

Combined Microspectrophotometry And Autoradiography Of Late Interphase Nuclei In Physarum Polycephalum, Joseph K. Vlchek

Master's Theses

No abstract provided.


Seasonal Changes In Morphology Of The Gonads Of The Bluegill Lepomis Macrochirus, Alan C. Roman Jan 1971

Seasonal Changes In Morphology Of The Gonads Of The Bluegill Lepomis Macrochirus, Alan C. Roman

Master's Theses

No abstract provided.


Notes On The Algae Of Arkansas. 1. Chrysococcus, Kephyrion, Kephyriopsis, Pseudokephyrion And Stenokalyx, Richard L. Meyer Jan 1971

Notes On The Algae Of Arkansas. 1. Chrysococcus, Kephyrion, Kephyriopsis, Pseudokephyrion And Stenokalyx, Richard L. Meyer

Journal of the Arkansas Academy of Science

The genera Chrysococcus, Kephyrion, Pseudokephyrion and Stonokalyx have received some consideration by investigators in Europe and in the boreal forest and tundra-range regions of the United States. Many of the species are considered to be cold-water stenotherms, thus occurring more frequently in northern habitats. In the present paper 4 species of Chrysococcus, 4 species of Kephyroin, 2 species of Pseudokephyrion and 2 species of Stenokalyx from Arkansas are discussed.


A Variation Of The Standard Steepest Ascent Search Procedure For Response Surface Experiments, George Whitfield Cobb Jan 1971

A Variation Of The Standard Steepest Ascent Search Procedure For Response Surface Experiments, George Whitfield Cobb

Theses and Dissertations

The results of this chapter lead to a modification of the standard stopping rule which breathes new life into the method of steepest ascent, but which is unfortunately not sufficient to effect a total resuscitation. As expected, there is no uniformly optimum stopping rule, nor even a uniformly best test statistic; both the optimum statistic and the optimum test level depend on the model parameters y1 and y2. One can, however, adopt a compromise rule which works reasonably well for all parameter combinations by testing at the 25% level with the statistic zn = 1/2(yn -yn-2). In many cases the …


The In Vitro Synthesis Of Melanin In The Avian Pineal When Treated With D, L-Dopa, Bernadette Ann Nowicki Jan 1971

The In Vitro Synthesis Of Melanin In The Avian Pineal When Treated With D, L-Dopa, Bernadette Ann Nowicki

Master's Theses

No abstract provided.


Taxonomic Studies On The Genus Podocotyle (Trematoda: Opecoelidae), Paul Clinton Edmiston Jan 1971

Taxonomic Studies On The Genus Podocotyle (Trematoda: Opecoelidae), Paul Clinton Edmiston

University of the Pacific Theses and Dissertations

The original intent of this study was to reinvestigate and confirm the validity of thirteen species of Podocotyle reported from Dillon Beach, California. Eight species were described by Park (1937) and five described by Johnson (1949-unpublished). Among these species basic similarities were evident in such features as: cirrus sac, seminal vesicle, body shape, extent and distribution of vitellaria, which indicated the possibility of conspecificity. Because four of these species (Podocotly blennicottusi, P. california, P. pedunculata, and P. pacifica) were also reported from fishes of the Pacific Northwest coast by Ching (1960), Pratt and McCauley (1961), Arai (1969), and Hall and …


Temperature Induced Changes In The Territorial Dynamics Of Cyprinodon Macularius Baird And Girard, Don Victor Plantz Jr. Jan 1971

Temperature Induced Changes In The Territorial Dynamics Of Cyprinodon Macularius Baird And Girard, Don Victor Plantz Jr.

University of the Pacific Theses and Dissertations

Behavior is qualitatively and quantitatively modified by the environment. Thus, any consideration of behavior must take into consideration the environmental conditions present. The present study evaluates the interrelationship between one environmental condition (temperature) and a measurable behavioral phenomenon (territoriality).


Radio-Biotelemetry Studies Of Circadian Body Temperature Rhythms And Activity Levels [Of The] Zebra Finch (Peophilia Guttata), Vaughan Arthur Langman Jan 1971

Radio-Biotelemetry Studies Of Circadian Body Temperature Rhythms And Activity Levels [Of The] Zebra Finch (Peophilia Guttata), Vaughan Arthur Langman

University of the Pacific Theses and Dissertations

The object of this study was to determine the normal thermoregulatory patterns of zebra finches (Poephilia guttat) in as near a normal physiological and behavioral state as possible. Surface body temperature and level of activity were the two primary channels of information. Radiobioelemetry allowed the reduction of external disturbance during long periods of continuous recording.


Lichens Of The Genus Parmelia From Columbia, Costa Rica, And Guatemala, Donald G. Flenniken Jan 1971

Lichens Of The Genus Parmelia From Columbia, Costa Rica, And Guatemala, Donald G. Flenniken

Dissertations and Theses @ UNI

During the summer of 1969 a total of eighty-four species of lichens belonging to four subgenera were collected in Colombia, Costa Rica, and Guatemala. Twelve of these are described as new. The subgenus Amphigymnia is represented by thirty-six species, three of which are described as new. The subgenus Parmelia is represented by forty-one species, eight of which are described as new. The subgenera Everniiformes and Xanthoparmelia are represented by two and five species, respectively, with no new taxa recognized. The lichen product strepsiline, previously known only in the lichen Cladonia strepsilis (Ach.) Vain., was found by microchemical tests in Parmelia …


The Effects Of Para-Chlorophenylalanine On A Conditioned Emotional Response In Rats, Roy J. Hartmann Dec 1970

The Effects Of Para-Chlorophenylalanine On A Conditioned Emotional Response In Rats, Roy J. Hartmann

Theses & Dissertations

The initial intent of this study was to investigate p-CPA's actions on conditioned "anxiety" (CER) in rats in order to ascertain whether the derived effects were qualitatively similar to those previously reported for "conflict" behavior. Specifically, the goals of this study were to determine if p-CPA would reinstate lever-pressing behavior that had been suppressed by a series of tone-shock pairings. If a change in behavior did occur, would the reintroduction of serotonin, through the use of 5-HTP, return the behavior to pre-drug control levels.