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

Digital Commons Network™

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

Brigham Young University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 63301 - 63330 of 72250

Full-Text Articles in Entire DC Network

The Effects Of Certain Steroids On The Growth Of Slime Mold, Physarum Polycephalum, Ching-Bun Paul Chen Aug 1975

The Effects Of Certain Steroids On The Growth Of Slime Mold, Physarum Polycephalum, Ching-Bun Paul Chen

Theses and Dissertations

The cortex of vertebrate adrenal glands secretes two major groups of hormones--glucocorticoids and mineralocorticoids. Glucocorticoids, which have an oxygen atom at carbon number 11, increase the rate of gluconeogenesis and increase the mobilization of lipids in mammals (Turner and Bagnara 1971). At the same time there is a decrease in protein synthesis. This latter effect may be homologous to a decrease in fibroblast growth in culture in the presence of certain corticosteroids (Ruhmann and Berliner 1965). The main function of mineralocorticoids, on the other hand, is to retain sodium ions. They have little or no gluconeogenic activity. Interestingly, however, these …

Go to article

The Effect Of Recreational Uses On Vegetation And Soil In The Buffalo Campground, Targhee National Forest, Island Park, Idaho, Susan Daines Foster Aug 1975

The Effect Of Recreational Uses On Vegetation And Soil In The Buffalo Campground, Targhee National Forest, Island Park, Idaho, Susan Daines Foster

Theses and Dissertations

The effect of trampling on vegetation and soil, as a result of recreational pressure, was studied in the Buffalo campground of the Targhee National Forest, Idaho. Site deterioration was most evident in the forty-two year old site. The tree stand had matured, but there were few young trees and tree reproduction had been reduced to ten seedlings per acre for Pinus contorta. Only two shrub species were sampled with a combined population of eight individuals per acre. Most of the grass species had been seeded; forbs provided 20% of the ground cover, 13% was bare ground and 71% litter. The …

Go to article

Bionomics Of Two Bark Beetles : Genus Chaetophloeus (Coleoptera : Scolytidae), John Wendell Aaron Aug 1975

Bionomics Of Two Bark Beetles : Genus Chaetophloeus (Coleoptera : Scolytidae), John Wendell Aaron

Theses and Dissertations

Shrubs are important as browse and cover for game animals and songbirds in the desert-shrub and chaparral plant communities in the Great Basin (Plummer, 1968). They also play a major role in soil binding and watershed maintenance (Colby and Weissert, 1975). Therefore, an understanding of the agents which affect the health and survival of the shrubs is important. Insects-have a great impact on the health and reproductive capacity of shrubs. Pollinators, defoliators, borers, etc. must be studied and known for proper management.

Go to article

Ultrastructural Investigations Of The Host-Parasite Interface Of Pumpkin Cotyledons And The Fungus Sclerotinia Sclerotiorum, Mark Edward Richtsteig Aug 1975

Ultrastructural Investigations Of The Host-Parasite Interface Of Pumpkin Cotyledons And The Fungus Sclerotinia Sclerotiorum, Mark Edward Richtsteig

Theses and Dissertations

Pumkin seedlings (Cucurbita maxima) were inoculated with the fungus Sclerotinia sclerotiorum (Lib.) de Bary. Center regions of non-infected and infected cotyledons of various lengths were cut into 1 x 2 mm strips and processed for ultrastructural investigations. Complementary portions of opposing non-infected cotyledons were also processed as control tissue, and contained fewer storage products in cells than cotyledons of comparable size from non-infected plants. Young non-infected cells contained distinct lipid bodies, protein bodies and electron dense inlusions which were translocated out of older cells by abundant plasmodesmata. Initally, infected cells became plasmolyzed, followed by breakdown of the cytoplasm. Host cells …

Go to article

Synthesis And Stereochemistry Of 2,6,10-Triazatricyclo [5.2.1.0⁴ ¹⁰] Decane Derivatives, Susan Elaine Foulger Aug 1975

Synthesis And Stereochemistry Of 2,6,10-Triazatricyclo [5.2.1.0⁴ ¹⁰] Decane Derivatives, Susan Elaine Foulger

Theses and Dissertations

The synthesis and stereochemical aspects of derivatives of the new ring system 2,6,10-triazatricyclo [5.2.1.04,10] decane are discussed. Sythesis of 2-nitro-2-methyl-1,3-disubstitutedaminopropanes, followed by reduction of these compounds to 2-amino-2-methyl-1,3-disubstituted aminopropanes afforded the necessary starting materials for a cyclization reaction similar to that resulting in already known 2,6-dioxa-10-azatricyclo [5.2.1.04,10] decanes. Reaction of the triamines with 2,5-hexanedione resulted in 2,6-disubstituted-1,4,7-trimethyl-2,6,10-triazatricyclo [5.2.1.04,10] decanes. The stereochemical aspects of this ring system are interesting from the standpoint of nitrogen inversion barriers on nitrogens 2 and 6. Existence of a high inversion barrier for these nitrogens in shown by isolation of different diastereomers of the tricycle. Methods …

Go to article

The Effect Of Lead And Zinc On Selenium Poisoning In Mice, Cynthia Joy Call Aug 1975

The Effect Of Lead And Zinc On Selenium Poisoning In Mice, Cynthia Joy Call

Theses and Dissertations

Trace elements, because they are effective in catalytic amounts, must be held in delicate balance with each other as well as with the macronutrients of the diet. Disturbances of these balances result in deficiency and toxicity symptoms. Toxic doses of selenium, lead, and zinc, for example, are known to cause anemia (1, 2, 3, 4) and growth depression (5, 3) in experimental animals.

Go to article

Macrocyclic Polyether Sulfide Syntheses :|Bthe Preparation Of Thia-Crown-6, 7, And 8 Compounds, Robert Askew Reeder Aug 1975

Macrocyclic Polyether Sulfide Syntheses :|Bthe Preparation Of Thia-Crown-6, 7, And 8 Compounds, Robert Askew Reeder

Theses and Dissertations

Macrocyclic polyether sulfides have been prepared by reacting an oligoethylene glycol dichloride with a dithiol in refluxing basic ethanol. The following new compounds were prepared: 1,5-dithia-(19- crown-6), 3-hydroxy-1,5-dithia-(19-crown-6), 1,4-dithia-(21-crown-7), 3-hydroxy-1,5-dithia-(22-crown-7), and 1,4-dithia-(24-crown-8). One other previously reported macrocyclic polyether sulfide was also prepared. The thesis includes a review of macrocyclic sulfides and other related compounds, the thermodynamics of interaction of several macrocyclic polyether sulfides with Ag^+, Hg^2+, and Pb^2+ ions, and a discussion of the structure of these materials.

Go to article

Habitat Partitioning In A Community Of Passerine Birds, Robert C. Whitmore Aug 1975

Habitat Partitioning In A Community Of Passerine Birds, Robert C. Whitmore

Theses and Dissertations

Habitat partitioning was studied in a community of passerine birds in the Virgin River Valley of southwestern Utah. Ten habitat structure variables were measured for each of 24 species of passerine birds and several multivariate statistical techniques were used to determine the extent of habitat partitioning. Ordinations of species distributions along known environmental gradients were constructed using Principal Component Analysis and Stepwise Discriminant Analysis. Stepwise Discriminant Analysis was also used to determine which habitat variables were important in species separation. It was found that percent canopy cover was the most important variable. Two hundred seventy six pairs of species were …

Go to article

Analysis Of Macroinvertebrate Samples From Ten Rocky Mountain Streams, Fred A. Mangum Aug 1975

Analysis Of Macroinvertebrate Samples From Ten Rocky Mountain Streams, Fred A. Mangum

Theses and Dissertations

This study was an attempt to evaluate the effects on ten Rocky Mountain streams from management activities on U.S. Forest Service lands. Macroinvertebrate and water chemistry data were collected. Data analysis methods included: three diversity indices, a numerical taxonomy system of multivariate statistical analysis, numbers and biomass per selected taxa, percent composition per order, and total numbers and biomass. None of the methods of analysis were found to be adequate if used alone, but by using a combination of dendograms, biomass, and numbers data in addition to the diversity indices (SCI and d) stream stress could be detected. Although organic …

Go to article

Steady State Fluidics: The Static Matching Of Fluidic Amplifiers And Loads, Frank J. Redd Aug 1975

Steady State Fluidics: The Static Matching Of Fluidic Amplifiers And Loads, Frank J. Redd

Theses and Dissertations

"Fluidics" is the title applied to a relatively new technology which is concerned with the control of fluid power and the processing of information through the use of the fluid mechanical properties of the fluid medium itself. The absence of moving parts and the relatively low sensitivity to enviromental conditions suggest the probability that fluidic systems will prove to be faster and more reliable than the mechanically controlled (valves, diaphragms, springs, etc.) fluid systems which they are designed to replace.

Go to article

Timpanogos Flora, Kelly W. Allred Aug 1975

Timpanogos Flora, Kelly W. Allred

Theses and Dissertations

A comprehensive floristic study of Mt. Timpanogos, Utah County, Utah, was undertaken. The Mt. Timpanogos area is a much used facility in recreation, biology, watershed development, livestock management, and education. It is also representative of a major segment of the overall flora of Utah. This study adds to the ever-increading knowledge of the flora of Utah, and provides a means of identifying the flora of this region, which is basic to any future management.

Go to article

Two New Species Of The Genus Cycadeoidea From The Lower Cretaceous Of Utah, H. Blaine Furniss Jul 1975

Two New Species Of The Genus Cycadeoidea From The Lower Cretaceous Of Utah, H. Blaine Furniss

Theses and Dissertations

Cyadeoidea medullara and C. cleavelandii, two new species of the genus Cycadeoidea, have been recovered from the Lower Cretaceous Cedar Mountain Formation of Utah. They have been described in histologic detail and relationships with similar species are set forth. Monoecism and pollination mechanisms have been discussed in connection with C. medullara. This data contributes to our knowledge of the diverse composition of Lower Cretaceous floras in Utah.

Go to article

A Paleocene Flora From The Fort Union Formation Near Baggs, Carbon County, Wyoming, John L. Roth Jul 1975

A Paleocene Flora From The Fort Union Formation Near Baggs, Carbon County, Wyoming, John L. Roth

Theses and Dissertations

A well-preserved Paleocene flora of 39 species from the Fort Union Formation near Baggs, Carbon County, Wyoming has been studied. This is the first study of the plant megafossils in this area. The most abundant species collected are: Carya antiquorum Platanus nobilis, Cercidiphyllum arcticum and Platanus raynoldsi. Together they represent 74% of the flora. The flora has been dated as Upper Middle Torrejonian. This report is also the first paleoecological study of any North American Paleocene flora. Two methods were used to determine the paleoclimatic conditions of the flora. The first was an analysis of leaf margin characteristics, comparing them …

Go to article

The Subfamily Leeuwenhoekinae In The Neotropics (Acarina: Trombiculidae), Jack T. Reed, James M. Brennan Jul 1975

The Subfamily Leeuwenhoekinae In The Neotropics (Acarina: Trombiculidae), Jack T. Reed, James M. Brennan

Brigham Young University Science Bulletin, Biological Series

Neotropical representatives of the subfamily Leeuwenhoekinae are reviewed. The genus Odontacarus comprises 66 percent of the chiggers examined, and 82 percent of this genus were identified as O. tubercularis (Brennan). The following genera are redescribed: Albeckia Veracammen-Grandjean and Watkins, Leeuwenhoekia Oudemans, Odontacarus Ewing, Sasacarus Brennan and Jones, Wagenaaria Brennan, and Whartonia Ewing. New taxa are: Odontacarus comosus comosus, O. c. novemsetus, O. dienteslargus, O. pugnosus, O. schoenesetosus, O. sunnianae, O. tiptoni, O. tuberculohirsutus, O. vanderhammeni, O. vergrandi, Sasacarus furmani panamensis, and Whartonia angulascuta. Odontacarus fieldi Brennan and Jones, 1961, and O. cayolargoensis Brennan, 1959, are synonymized under O. tubercularis Brennan, …

Go to article

End Matter, Vol. 20 No. 1 Jul 1975

End Matter, Vol. 20 No. 1

Brigham Young University Science Bulletin, Biological Series

No abstract provided.

Go to article

A List Of Venezuela Chiggers, Particularly Of Small Mammalian Hosts (Acarina: Trombiculidae), James M. Brennan, Jack T. Reed Jul 1975

A List Of Venezuela Chiggers, Particularly Of Small Mammalian Hosts (Acarina: Trombiculidae), James M. Brennan, Jack T. Reed

Brigham Young University Science Bulletin, Biological Series

Detailed or summarized records of 136 species in 38 genera with a key to the latter are provided. Of 86 described forms, 49 are new for Venezuela; the remaining undescribed taxa are coded for purposes of this report. A classified host-parasite list is appended.

Go to article

No. 047 Newsletter - Association For Asian Studies. Committee On East Asian Libraries, Thomas C. Kuo Jul 1975

No. 047 Newsletter - Association For Asian Studies. Committee On East Asian Libraries, Thomas C. Kuo

Journal of East Asian Libraries

No abstract provided.

Go to article

Poems By Iris Corry, Iris Corry Jul 1975

Poems By Iris Corry, Iris Corry

BYU Studies

No abstract provided.

Go to article

Rey L. Pratt And The Mexican Mission, Dale F. Beecher Jul 1975

Rey L. Pratt And The Mexican Mission, Dale F. Beecher

BYU Studies

No abstract provided.

Go to article

End Matter, Byu Studies Jul 1975

End Matter, Byu Studies

BYU Studies

No abstract provided.

Go to article

Introductory Pages, Byu Studies Jul 1975

Introductory Pages, Byu Studies

BYU Studies

No abstract provided.

Go to article

The Neophyte, Roger Ladd Memmott Jul 1975

The Neophyte, Roger Ladd Memmott

BYU Studies

No abstract provided.

Go to article

Moral Free Agency, Daniel H. Ludlow Jul 1975

Moral Free Agency, Daniel H. Ludlow

BYU Studies

No abstract provided.

Go to article

Religion And Communism In The Soviet Union And Eastern Europe, Robert R. King Jul 1975

Religion And Communism In The Soviet Union And Eastern Europe, Robert R. King

BYU Studies

No abstract provided.

Go to article

A Newly Discovered 1838 Wilford Woodruff Letter, Robert H. Slover Jul 1975

A Newly Discovered 1838 Wilford Woodruff Letter, Robert H. Slover

BYU Studies

No abstract provided.

Go to article

Jesse Gause, Counselor To The Prophet, Robert J. Woodford Jul 1975

Jesse Gause, Counselor To The Prophet, Robert J. Woodford

BYU Studies

No abstract provided.

Go to article

A Believing People: Literature Of The Latter-Day Saints Richard H. Cracroft And Neal E. Lambert, Eugene England Jul 1975

A Believing People: Literature Of The Latter-Day Saints Richard H. Cracroft And Neal E. Lambert, Eugene England

BYU Studies

No abstract provided.

Go to article

The Restoration Movement: Essays In Mormon History F. Mark Mckiernan, Alma R. Blair, And Paul M. Edwards, Chad J. Flake Jul 1975

The Restoration Movement: Essays In Mormon History F. Mark Mckiernan, Alma R. Blair, And Paul M. Edwards, Chad J. Flake

BYU Studies

No abstract provided.

Go to article

The Pearl Of Great Price: Comprehensive Concordance Thomas A. Curtis And Jeffrey Hill, James R. Harris Jul 1975

The Pearl Of Great Price: Comprehensive Concordance Thomas A. Curtis And Jeffrey Hill, James R. Harris

BYU Studies

No abstract provided.

Go to article

The Golden Legacy: A Folk History Of J. Golden Kimball Thomas E. Cheney, Peter L. Crawley Jul 1975

The Golden Legacy: A Folk History Of J. Golden Kimball Thomas E. Cheney, Peter L. Crawley

BYU Studies

No abstract provided.

Go to article

First Prev Next Last