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Articles 39121 - 39150 of 40117
Full-Text Articles in Entire DC Network
The Effects Of Penicillin Upon The Fission Rate Of Dugesia Dorotocephala., John J. Fahsbender
The Effects Of Penicillin Upon The Fission Rate Of Dugesia Dorotocephala., John J. Fahsbender
Theses and Dissertations
Planaria (class Turbellaria) are the highest life forms which exhibit fission (Hyman, 1951). The laboratory planarian, Dugesia, lives in lakes, ponds, streams and springs, where it occupies bottom habitats. Fissioning is an asexual mode of reproduction. The fission plane is usually transverse, forming behind the pharynx, and separation appears to be dependent upon locomotion (Curtis, 1902). The posterior half of the worm adheres to the substratum while the anterior half continues to move forward until the worm snaps in two. Each half then regenerates the missing parts, forming two new smaller worms.
The Effects Of Thiamin Deficiency And Thiamin Antagonists On Cardiac Function In The Rat, D. James B. Sutherland
The Effects Of Thiamin Deficiency And Thiamin Antagonists On Cardiac Function In The Rat, D. James B. Sutherland
Theses and Dissertations
A study was made to determine what biochemical changes were involved in the slowing of the rat heart rate during thiamin deprivation, pyrithiamin or oxythiamin treatment. The appearance of bradycardia during progressive thiamin deficiency was shown to be related to the reduction in myocardial enzymatic activity of pyruvate (PDH) and 2-ketoglutarate (2-KGDH) dehydrogenase, and not due to inanition alone since pair-fed control rats did not show bradycardia until the agonal stage. Bradycardia was not the result of reduced energy since CP, ATP, ADP, and AMP levels remained normal even though PDH and 2-KGDH activity dropped to 20% of normal by …
Distribution And Relationships Of Utah Brome Grasses In Western North America, Jerry B. Anderson
Distribution And Relationships Of Utah Brome Grasses In Western North America, Jerry B. Anderson
Theses and Dissertations
A considerable amount of study material has beccme available since the revision of the genus in 1900 by Shear, and the revision of the section Bromopsis in 1952 by Wagnon. A number of cytological studies have been done in recent years; and Wagnon's work pointed out the need for a comprehensive study of the entire genus. This study is a taxonomic revision of the Genus Bromus for the State of Utah, and contains illustrations and descriptions of the species; synonomy; distribution maps; and discussions of many of the important aspects of the economics, ecology, and historical treatment. I have recognized …
Characterization Of Streptozotocin Induced Small Colony Phenotypes In Bacteria, David M. Zimmer
Characterization Of Streptozotocin Induced Small Colony Phenotypes In Bacteria, David M. Zimmer
Masters Theses
Streptozocin-induced small colony variants of E. coli were characterized and found to have a genetic basis. Both E. coli and S. typhimurium were susceptible to the mutation causing small colonies. Small colony cell lines exhibited a greatly increased generation time and were shown to be non-motile, electron microscopy revealing a complete loss of flagella. The small colony phenotype was revertible by streptozotocin and nitrosoguanidine. The locus responsible for small colony phenotype in one strain of E. coli was found to map within a 19 minute segment of the chromosome between HfrH and HfrC.
A Microtechnique For The Isolation Of Cell Wall Deficient Organisms From Very Small Samples, Lloyd T. Dutcheshen, Philip C. Hessburg
A Microtechnique For The Isolation Of Cell Wall Deficient Organisms From Very Small Samples, Lloyd T. Dutcheshen, Philip C. Hessburg
Henry Ford Hospital Medical Journal
A miniaturized procedure using a modified microtiter plate is described for the isolation of cell wall deficient organisms. It is particularly useful when the volume of a liquid specimen is very small.
Pasteurella Multocida Meningitis: Report Of A Case, Leo J. Bingley Jr.
Pasteurella Multocida Meningitis: Report Of A Case, Leo J. Bingley Jr.
Henry Ford Hospital Medical Journal
No abstract provided.
Sensitivity Of Vertebrate Embryos To Heavy Metals As A Criterion Of Water Quality, Wesley J. Birge, John J. Just
Sensitivity Of Vertebrate Embryos To Heavy Metals As A Criterion Of Water Quality, Wesley J. Birge, John J. Just
KWRRI Research Reports
Embryonic and/or larval stages of the leopard frog (Rana pipiens), domestic fowl (Gallus domesticus) and the goldfish (Carassiua auratus) were treated with cadmium chloride, mercuric chloride, lead chloride, zinc chloride and sodium arsenite. The principal objectives were (1) to determine the sensitivity of vertebrate embryos to certain metals which are of consequence in water pollution, and (2) to ascertain the suitalility of vertebrate embryos as bioassay organisms for monitoring metallic pollutants within water resources. Vertebrate embryos are found to be highly sensitive to the toxic effects of all the metals studied. Concentrations of mercury as low as 10 ppb, with …
Control Of Pantothenate Accumulation In Agrobacterium Tumefaciens, Tsuneo Kaneshiro, Larry O. Arthur, Kenneth W. Nickerson
Control Of Pantothenate Accumulation In Agrobacterium Tumefaciens, Tsuneo Kaneshiro, Larry O. Arthur, Kenneth W. Nickerson
Papers in Microbiology
Two pantothenate-requiring mutants of Agrobacterium tumefaciens have been isolated. One of them (strain WMP-1) is unusual in that growth levels equivalent to the parent strain are achieved only when the medium is additionally supplemented with aspartate or another compound related to the tricarboxylic acid cycle. Extracts of cells grown on limiting aspartate were found to contain four times more 14IC-pantothenate than th6se grown at optimal aspartate concentrations. This difference was found in both the perchloric acid-soluble and -insoluble fractions, presumably the coenzyme A pool and acyl carrier protein, respectively. These findings are discussed in terms of membrane integrity and …
A Proposed Mechanism Of Action For In Vitro Excystation Of Two Species Of Coccidia, William Ronald Jolley
A Proposed Mechanism Of Action For In Vitro Excystation Of Two Species Of Coccidia, William Ronald Jolley
Theses and Dissertations
Excystation of coccidian oocysts is accomplished in vitro by altering wall permeability with CO2 and a reducing agent, then activating the enclosed sporozoites with a solution of trypsin and bile. Elucidation of the mechanism of action of the CO2-reducing agent treatment was the basic intent of this study. Oocysts of Eimeria stiedae (rabbit) and E. tenella (chicken) were tested for the presence of an excystation-associated enzyme by incubating sporulated oocysts in fluids extracted from variously treated oocysts, and by carbon-14 labelling; the effect of CO2 -reducing agent treatment on oocyst walls was investigated by titration with acid or base for …
Regulating Growth Of An Aquatic Plant: Lemna Perpusilla, Willard L. Koukkari, Stanley H. Duke
Regulating Growth Of An Aquatic Plant: Lemna Perpusilla, Willard L. Koukkari, Stanley H. Duke
Journal of the Minnesota Academy of Science
Growth rates of Lemna perpusilla 6746 can be regulated in axenic cultures by 6-benzylaminopurine (BA) . Concentrations of 10-BM BA significantly enhanced growth, while levels of 10-7M and Higher were inhibitory. These effects of BA on growth were evident when calculated as either fresh weight of frond number.
Ribosomes Of Acid-Fast Bacilli - Immunogenicity, Serology, And In-Vitro Correlates Of Delayed-Hypersensitivity, Robert E. Baker, Walter E. Hill, C. L. Larson
Ribosomes Of Acid-Fast Bacilli - Immunogenicity, Serology, And In-Vitro Correlates Of Delayed-Hypersensitivity, Robert E. Baker, Walter E. Hill, C. L. Larson
Biological Sciences Faculty Publications
No abstract provided.
Evidence For An Ambidirectional Magnesium-Activated, Sodium-Potassium Dependent Adenosine Triphosphatase, John Dale Hempel
Evidence For An Ambidirectional Magnesium-Activated, Sodium-Potassium Dependent Adenosine Triphosphatase, John Dale Hempel
Master's Theses
Controversy exists as to whether the Na-K ATPases of euryhaline fishes are the same enzyme.This study demonstrates that the phosphorylated enzyme from gills of Fundulus heteroclitus adapted to freshwater and salt water migrate to the same position in SDS polyacrylamide gels. Similar behavior of the enzyme from both sources in different ionic media is also shown. Additionally, the possible ability or the enzyme to couple an osmoregulatory influx to an excretory efflux in freshwater fish is demonstrated. The term "ambidirectional" is proposed for this enzyme, and its place in certain membrane models is discussed.
Studies On The Secretory Process Of Rabbit Parotid, John David Castle
Studies On The Secretory Process Of Rabbit Parotid, John David Castle
Student Theses and Dissertations
An in vitro incubation system which allows the labeling and isolation of secretion granules - and their subsequent resolution into membrane and content subfractions - has been developed by using dissected lobules of rabbit parotid glands. The system can be used to study a series of aspects related to the last phases of the secretory cycle (concentration, storage, discharge). The work reported in this thesis characterizes the system and presents data concerning the relative rates of synthesis of membrane and content proteins. The dissected lobules can be maintained in vitro in a tissue culture medium for 9 to 10 hr …
Protozoan Symbionts From The Anemone Bunodosoma Cavernata From Galveston Island, Texas, Philip J. Phillips
Protozoan Symbionts From The Anemone Bunodosoma Cavernata From Galveston Island, Texas, Philip J. Phillips
Gulf and Caribbean Research
The anemone Bunodosoma cavernata is a common inhabitant of the Texas coast and cursory observation revealed a large complement of protozoan associates. These included Saprodinium, Euplotes, Paraeuplotes, Vorticella, Cohnilembus, Anophrys, Uronema and Vahlkampfia.
Approximately forty anemones were collected from jetty rocks on Galveston Island on 3 November 1970. Note was made within one day of protozoans found on the external surfaces, in the coelenteron and in surrounding sea water. The anemones were kept until 7 December 1970 under varying conditions and bi-weekly note was made of the associated protozoan fauna.
The Eriophyoidea Of South Dakota, Magdalena Lopez Briones
The Eriophyoidea Of South Dakota, Magdalena Lopez Briones
Electronic Theses and Dissertations
This paper presents the results of the taxonomic investigation of the Eriophyoidea in South Dakota. Information is given on the morphology, discussion of variation within a population, distribution, damage in host plants, economic importance and techniques of collecting and preparing specimens. There are 42 previously described species included in this study. Of the 48 species studied, six are new. Species described are: Aculops maximilianae, Diptacus pengsonae, Eriophyes arceosae, Eriophyes taylori, Tegonotus lindenus, and Tetra mcdanieli.
Biology Of The Flea Beetle, Altica Carduorum Guer. (Coleoptera: Chrysomelidae) On Canada Thistle, Cirsium Arvense (L.) Scop., In South Dakota, Burton Danis Schaber
Biology Of The Flea Beetle, Altica Carduorum Guer. (Coleoptera: Chrysomelidae) On Canada Thistle, Cirsium Arvense (L.) Scop., In South Dakota, Burton Danis Schaber
Electronic Theses and Dissertations
A laboratory colony of Altica carduorum Guer. was established from a stock colony of 50 adult beetles. They had an average previposition period of 7 days when exposed to a regular cycle of 16 hr. of light (24° C) and 8 hr. of darkness (12.75° C). Under these conditions, females laid an average of 259.3 ± 9.7 eggs, and longevity averaged 100 days. The eggs are laid on the underside of leaves along edges of leaf veins throughout June. Adults fed and overwintered in the soil, and some beetles emerged the following spring and laid viable eggs. Laboratory studies indicate …
Studies On Muropeptide Amino Acids Of Rhizobium Japonicum, Mohammed Alauddin
Studies On Muropeptide Amino Acids Of Rhizobium Japonicum, Mohammed Alauddin
Masters Theses
The isolation of Rhizobium japonicum cell walls was performed by ultrasonication and the enzymatic digestion with DNase, RNase and pronase separately. Crude cell walls were washed with M NaCl and 5% SDS and were isolated by 20,000 g centrifugation. Muropeptide amino acids were freed by hydrolysis at 121C for 10 minutes in 6N HCl.
Detection of Rhizobium japonicum murein layer amino acids was done by 2-dimensional instant thin layer chromatography on silica gel plates. The solvents found most favorable, were n-butanol: acetic acid: water and n-propanol: 34% ammonium hydroxide. Amino acid spots were developed by spraying ninhydrin on the chromatograms, …
Morphological And Physiological Effects Of 2,4-D On Gram-Negative And Gram-Positive Bacteria, John H. Rupnow
Morphological And Physiological Effects Of 2,4-D On Gram-Negative And Gram-Positive Bacteria, John H. Rupnow
Masters Theses
Manometric, spectrophotometric, photomicrographic and quantitative biochemical techniques were employed to determine the morphological and physiological effects of 2,4-D on Gram-positive and Gram-negative bacteria.
The growth and motility of Gram-positive bacteria appeared to be more adversely affected than the growth and motility of Gram-negative species. The terminal oxidation, lysis, and chain length of both Gram-positive and Gram-negative bacteria did not appear to be affected by the concentrations used. The average cell size of both Gram-positive and Gram-negative bacteria was observed to increase after exposure to 1000 ppm 2,4-D. The normal leakage of amino acid and ultraviolet light absorbing cell constituents appeared …
Biological Aspects Of Speciation In Three Sympatric Euzonus Species At Dillon Beach, California (Polychaeta: Opheliidae), Steven Rhoads Parke
Biological Aspects Of Speciation In Three Sympatric Euzonus Species At Dillon Beach, California (Polychaeta: Opheliidae), Steven Rhoads Parke
University of the Pacific Theses and Dissertations
In the present study, information concerning morphology, ecology, fertilization and larval development of three sympatric species of Eusonus is presented. Morphological similarities are reviewed in part I. These similarities correspond with significant lack of variation found in larval development (part IV). Despite these similarities, as well as the ability to cross fertilize their species, the ecological and reproductive isolating mechanisms presented in part II and II provide a positive indication of the existence of three biologically distinct species. A comparative discussion reviews the efficacy of morphological criteria in differentiating the three closely related Euzonus species.
History Of Extension, Cooperative Extension Service, South Dakota State University, Epsilon Sigma Phi, South Dakota Chapter
History Of Extension, Cooperative Extension Service, South Dakota State University, Epsilon Sigma Phi, South Dakota Chapter
SDSU Extension Publications Archive
The College had been doing a certain amount of Extension work since 1901, 13 years before the Smith-Lever Act was passed. This work consisted mainly of holding farmers' institutes, addressing farmers' meetings and judging at county fairs. During this 13-year period (1901-1914), four different superintendents were employed. Stacy Cochran served for two years. The work was discontinued for two years, and in 1905 it was reestablished under M. F. Greeley. He was succeeded in a short time by A. E. Chamberlain. The last man to hold the position before the work finally merged into Extension work was H. F. Stoner …
Isolation And Characterization Of Two Bacteriophages Infecting The Myxobacterium Cytophaga Succinicans, Kenneth Wayne Lee
Isolation And Characterization Of Two Bacteriophages Infecting The Myxobacterium Cytophaga Succinicans, Kenneth Wayne Lee
All Master's Theses
Two bacteriophages which infect the myxobacterium Cytophaga succinicans, strains 14 and 16, were isolated from fish hatchery effluent. Each was submitted to a detailed study. These phages have a limited host range, even within the genus Cytophaga. The turbid plaques formed by these phages are similar in appearance to those produced by coliphage Lambda, and average 0.85 mm in diameter. Both phages have a latent period of 195 minutes and a rise period of an additional 165 minutes. Phage 0CS-16 has a burst size of 137 and phage 0CS-14 has a burst of 45. Sodium ion at a concentration of …
Karyology And Sex In Clematis Ligusticifolia Nutt. (Ranunculaceae), Darrel A. White
Karyology And Sex In Clematis Ligusticifolia Nutt. (Ranunculaceae), Darrel A. White
All Master's Theses
An investigation was conducted to determine the relationship between sex and karyology in Clematis ligusticifolia Nutt. (Ranunculaceae), a dioecious perennial.
Chromosome number and karyology of this species are discussed and a review of some of the major works of previous investigators of sex determinism in dioecious angiosperms is included.
The Effects Of Aging And Transformation On The Dna, Rna, Protein, And Hydroxyproline Content Of Fibroblasts (Wi 38) In Culture, James Michael Eichner
The Effects Of Aging And Transformation On The Dna, Rna, Protein, And Hydroxyproline Content Of Fibroblasts (Wi 38) In Culture, James Michael Eichner
University of the Pacific Theses and Dissertations
The study of the aging process is the investigation as to how the passage of time affects cells, organs, and organisms. Aging is a very complex and incompletely understood phenomenon. This is reflected by the number of theories attributing aging to a variety of causative factors such as: (1) the somatic mutations occurring spontaneously or produced by ionizing radiation, which are thought to have some effect on again but are not responsible for the normal process; (2) the alteration of macromolecules as the cells of an organism age forming neoantigens and functioning in the autoimmune reactions; the Cross-linkage theory which …
Biology And Ecology Of False Wireworms In South Dakota (Coleoptera: Tenebrionidae), Carrol Otto Calkins
Biology And Ecology Of False Wireworms In South Dakota (Coleoptera: Tenebrionidae), Carrol Otto Calkins
Electronic Theses and Dissertations
False wireworms were important pests of wheat on the Great Plains during the early 20th century. Until recently, they were of little importance; however, they are now occasionally appearing in damaging proportions. The purpose of studying the biological and ecological aspects of these insects in South Dakota was to understand the factors responsible for their demise and the circumstances that could affect the recurrence of damaging populations. The more common species of false wireworms found in South Dakota during this study were Eleodes suturalis (Say), E. opaca (Say), E. hispilabris (Say), E. tricostata (Say), E. extricata (Say), E. obsoleta (Say), …
Floristic Study Of Crawford County, Illinois, Loy R. Phillippe
Floristic Study Of Crawford County, Illinois, Loy R. Phillippe
Masters Theses
A two year inventory of the flora of Crawford County resulted in a collection of 809 species and has brought the present known vegetation to 918 species encompasing 470 genera in 127 families. A total of 388 species not previously reported were either collected during this study or previously deposited within the herbarium of Eastern Illinois University. An annotated checklist of each species is given followed by a brief note concerning the habitat in which it was collected, the collector's initials, and collecting number. During the search for these specimens a number of interesting natural areas were noted. An account …
Seasonal Variation In The Tubular And Interstitial Areas Of The Testes In Sternotherus Odoratus L., Robert Hans Spaet
Seasonal Variation In The Tubular And Interstitial Areas Of The Testes In Sternotherus Odoratus L., Robert Hans Spaet
Masters Theses
Seasonal changes within the tubular and interstitial areas of the testes in Sternotherus odoratus are investigated, histologically and histochemically. Forty specimens were collected in Illinois, Tennessee and Louisiana between May, 1969 and August, 1972.
Many of the histological and macroscopic observations made by Risley (1938) on the spermatogenic cycle of S. odoratus in Michigan are confirmed. Contrary to his findings, fluctuations in interstitial cell nuclear diameters are observed during spermatogenesis. Greatest diameters coincide with what Risley has considered " . . . period of most active breeding." Sertoli cell nuclear diameters undergo similar fluctuations being greatest during spring breeding and …
Morphometric Variation In Aphelenchus Avenae Bastian, 1865 With Varied Nutrition And Time, John P. Kline
Morphometric Variation In Aphelenchus Avenae Bastian, 1865 With Varied Nutrition And Time, John P. Kline
Masters Theses
The effect of varied time, nutritional media, and species of fungus on taxonomic characters (L, a, b1, c, and V) of Aphelenchus avenae was investigated. The effect of these ecological conditions on morphometrics was variable; however, these characters varied significantly with increased time, decreased nutritional media, and species of fungus. The greatest number of morphometric changes occurred with increased time, and the fewest with species of fungus. With changing environmental conditions, “V” values were the most stable character.
Tissue Culture Of Camptotheca Acuminata Decaisne (Nyssaceae), Ron Charles Cooke
Tissue Culture Of Camptotheca Acuminata Decaisne (Nyssaceae), Ron Charles Cooke
University of the Pacific Theses and Dissertations
Camptotheca acuminata Decaisne (Nyssaceae) is endemic to China. The plant was brought to the United States only on a few occasions and thus can be considered rare in this country. A search of the plant kingdom for species that produced anticancer substances revealed that ethanolic extracts of Camptotheca acuminata had such a property. The active constituent was identified eventually. Further testing and possible marketing of the active principle, and alkaloid, (camptothecin) depended on a combination of factors: obtaining the plant from China, organization of a mass planting program in the United States or chemical synthesis of the drug.
Due to …
The Effect Of The Herbicide Glyphosate On The Growth Of Selenastrum Capricornutum, Judith Susan Eisen
The Effect Of The Herbicide Glyphosate On The Growth Of Selenastrum Capricornutum, Judith Susan Eisen
Undergraduate Honors Capstone Projects
The herbicide glyphosate (MON-0139), an isopropylamine salt of N- (phosphonemethyl)glycine, was tested to determine its effects on the growth of the fresh water green alga Selenastrum capricornutum. Experiments were carried out to determine algicidal, algistatic, and inhibitory concentrations of the compound.
Concentrations from 5 ppm to 1000 ppm were inhibitory to the growth of the alga, but the effects were algistatic, rather than algicidal. At concentrations from 0.1 ppm to 1.0 ppm the growth of the alga was stimulated by the presence of the herbicide, while at concentrations from 0.001 ppm to 0.05 ppm the effects of the herbicide were …
The Molecular Nature And Replication Of R Factor 222 In Proteus Mirabilis, Dennis Jon Kopecko
The Molecular Nature And Replication Of R Factor 222 In Proteus Mirabilis, Dennis Jon Kopecko
Theses and Dissertations
The molecular nature and replicative behavior of R factor 222 was examined in Proteus mirabilis . In deoxyribonucleic acid (DNA} from R+ P. mirabilis , R factor 222 was identified by CsCl density gradient centrifugation as 2 satellite DNA bands at densities corresponding to 50 and 58 moles percent guanine plus cytosine (% GC) . Replication of the 50 and 58% GC components of R factor 222 in P. mirabilis was analyzed during growth in the presence and absence of chloramphenicol (CAM} and after shifting exponentialand stationary- phase cells to conditions which inhibit host protein or DNA synthesis . CAM …