Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Brigham Young University

1973

Articles 31 - 37 of 37

Full-Text Articles in Life Sciences

Distribution And Relationships Of Utah Brome Grasses In Western North America, Jerry B. Anderson Apr 1973

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 …


Transforming Ability Of Bacillus Subtilis Dna Taken Up By Barley Embryos, Christine Tolman Ence Apr 1973

Transforming Ability Of Bacillus Subtilis Dna Taken Up By Barley Embryos, Christine Tolman Ence

Theses and Dissertations

Purified Bacillus subtilis DNA taken up by one-day-old barley embryos and permanently fixed within the barley cell is shown to have maintained its biological activity in B. subtilis transformation. Cesuim chloride density gradient centrifugation of DNA isolated from the roots of barley embryos after the uptake and incorporation of radioactive, bromouracil-labelled B. subtilis DNA indicates the presence of the bacterial DNA in several discreet bands of well-defined density, whose density is changed by sonication. These preliminary findings concerning the fate of bacterial DNA taken up by barley roots are discussed in terms of the recombination model of Ledoux and Huart …


Reproduction And Development Of Ferrissia Rivularis (Say) (Basommatophora: Ancylidae) And The Effects Of Maleic Hydrazide On Its Development And Fecundity, Yuan-Hsu Kang Apr 1973

Reproduction And Development Of Ferrissia Rivularis (Say) (Basommatophora: Ancylidae) And The Effects Of Maleic Hydrazide On Its Development And Fecundity, Yuan-Hsu Kang

Theses and Dissertations

Ferrissia rivularis was selected for research because of its local accessibility and because essentially nothing was known of its reproduction and development. Reproductive and developmental biology is first described herein from the natural environment. This is then compared with the effects created by experimental exposure to a selected herbicide, maleic hydrazide, which might be a potential threat to certain invertebrates in the natural environment.


The Effects Of Penicillin Upon The Fission Rate Of Dugesia Dorotocephala., John J. Fahsbender Apr 1973

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 Apr 1973

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 …


A Taxonomic Investigation Of The Algae Of The Brigham Young University Campus, Provo, Utah, Cheng Mou-Sheng Apr 1973

A Taxonomic Investigation Of The Algae Of The Brigham Young University Campus, Provo, Utah, Cheng Mou-Sheng

Theses and Dissertations

A taxonomic investigation of the algal flora of the Brigham Young University campus was conducted from October 1971 to August 1972. This algal flora consisted of 27 genera and 36 species of Chlorophyta, 2 genera and 2 species of Euglenophyta, 32 genera and 106 species of Bacillariophyceae (including 16 genera and 33 species of soil diatoms), 1 genus and 2 species of Chrysophyta excluding diatoms and 6 genera and 14 species of Cyanophyta. Diatoms were the predominent algae in this study. Chlorococcum humicola, Vaucheria geminata, Amphora normani, Hantzschia amphioxys and Oscillatoria sancta were prominent in the greenhouses. In the arboretum …


A Proposed Mechanism Of Action For In Vitro Excystation Of Two Species Of Coccidia, William Ronald Jolley Jan 1973

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 …