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Articles 76951 - 76980 of 78539

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A Comparative Limnological Survey Of Brackish-Water Lake And A Fresh-Water Lake At Mount Trashmore, Virginia Beach, Virginia, Gene Ramon Cocke Jul 1973

A Comparative Limnological Survey Of Brackish-Water Lake And A Fresh-Water Lake At Mount Trashmore, Virginia Beach, Virginia, Gene Ramon Cocke

Biological Sciences Theses & Dissertations

No abstract.


The Prairie Naturalist Volume 5, No.2. June 1973 Jun 1973

The Prairie Naturalist Volume 5, No.2. June 1973

The Prairie Naturalist

SOME ASPECTS OF MINK-WATERFOWL RELATIONSHIPS ON PRAIRIE WETLANDS ▪ Robert T. Eberhardt

SUMMER AND FALL FOODS OF MINK ON THE J. CLARK SALYER NATIONAL WILDLIFE REFUGE ▪ Wayne F. Cowan and James R. Reilly

GIANT CANADA GEESE ▪ S. O. Kolstoe

SOME LICHENS OF BOG AND PAPER BIRCH FROM NORTH DAKOTA ▪ Dennis T. Disrud and Thomas D. Trana

A PALEOCENE FOSSIL LOCALITY IN SOUTHEASTERN SASKATCHEWAN: THE SHORT CREEK SECTION ▪ Paul L. Broughton

NOTE: A new orchid for North Dakota ▪ Robert E. Stewart


Water Resources News, Volume 5, No. 6, June 1973 Jun 1973

Water Resources News, Volume 5, No. 6, June 1973

Water Current Newsletter

From the Desk of the Director
Deadlines for Research Proposals
Dr. Stanton Ware Visits
Regional Research Workshop
Summer Institutes at the University of Nebraska
Seminar Proceedings Available
Nitrogen in Nebraska's Environment
National Water Commission Report Issued
Water Pollution Control Research Fellowships
State Environmental Center Measure Revived
HR 5464 Approved by House


The Growth And Toxicity Of The Florida Red Tide Organism, Gymnodinium Breve, Marion Tilton Doig Iii Jun 1973

The Growth And Toxicity Of The Florida Red Tide Organism, Gymnodinium Breve, Marion Tilton Doig Iii

USF Tampa Graduate Theses and Dissertations

Mass mortalities of marine organisms in the Gulf of Mexico have been associated with blooms of the unarmored dinoflagellate, Gymnodinium breve. This investigation concerns the factors affecting the growth of G. breve and the properties of a toxin produced by the organism.

A modification of the Flask Test of the Provisional Algal Assay Procedure of the Joint Industry/Government Task Force on Eutrophication was used to determine the response of G. breve to various natural waters and enrichments. The growth-promoting potential of natural waters obtained from areas where outbreaks of G. breve frequently occur was greater than that of waters …


Solution Diffusion Coefficients -- New And Improved Methods For Their Determination, Newton C. Fawcett May 1973

Solution Diffusion Coefficients -- New And Improved Methods For Their Determination, Newton C. Fawcett

Chemistry and Chemical Biology ETDs

The previously existing method of determining diffusion coefficients (D values) by diffusion from capillaries is critically reviewed. A differential error analysis of the method is given, and a formula is derived for the upper error bound on D as a function of capillary length, time span of the experiment, and ratio of final to initial diffusant concentrations. It is concluded that when the initial concentration and capillary length are not corrected for convective loss of diffusant solution from the capillary, the errors in concentration and length are additive and can significantly affect the accuracy of D. A new method (the …


Predicting Nitrogen Transformations And Ammonia Volatilization In Warm Desert Soils, G. R. Dutt May 1973

Predicting Nitrogen Transformations And Ammonia Volatilization In Warm Desert Soils, G. R. Dutt

Memorandum

No abstract provided.


Elements Of Tanzanian Coastal Planning, James J. Griffin May 1973

Elements Of Tanzanian Coastal Planning, James J. Griffin

Marine Affairs Theses and Major Papers

The purpose of this paper is to examine aspects of a Coastal Zone Plan as it applies to the Republic of Tanzania with its differences from and similarities to, the United States coastal zone planning experience. Possibly, as a result, some feeling for the problem of organizational concepts and approaches, as well as the current need for Tanzanian coastal zone management will emerge.


Nitrogen And Carbon Flux In A Soil-Vegetation Complex In The Desert Biome, D. B. Porcella, J. E. Fletcher, D. L. Sorensen, G. C. Pidge, A. Dogan May 1973

Nitrogen And Carbon Flux In A Soil-Vegetation Complex In The Desert Biome, D. B. Porcella, J. E. Fletcher, D. L. Sorensen, G. C. Pidge, A. Dogan

Memorandum

No abstract provided.


Soil As A Factor In Modelling The Phosphorus Cycle In The Desert Ecosystem, J. J. Jurinak, R. A. Griffin May 1973

Soil As A Factor In Modelling The Phosphorus Cycle In The Desert Ecosystem, J. J. Jurinak, R. A. Griffin

Memorandum

No abstract provided.


Gaseous Losses Of Nitrogen From The Soil Of Semi-Arid Regions, T. C. Tucker, R. L. Westerman May 1973

Gaseous Losses Of Nitrogen From The Soil Of Semi-Arid Regions, T. C. Tucker, R. L. Westerman

Memorandum

No abstract provided.


Seed Reserves Of Desert Soils, Stuart Childs, David W. Goodall May 1973

Seed Reserves Of Desert Soils, Stuart Childs, David W. Goodall

Memorandum

No abstract provided.


The Education Of A Computer: Development Of Computer-Assisted Instruction Of German Grammar, Karen Wintringham May 1973

The Education Of A Computer: Development Of Computer-Assisted Instruction Of German Grammar, Karen Wintringham

Senior Scholar Papers

Characteristic of the acquisition of most skills, the learning of a foreign language requires formalized, systematic training. Computer-assisted instruction provides the necessary individualized drill with accompanying reinforcement. The "BASIC" CAI course, MODALS, represents the culmination of nine months of research and programming of the instruction of German modal auxiliaries; the complex of sixty seven interconnected sub -programs provide drill of all six modals in five different tenses. Subsequent to the in-class introduction of new lecture material concerning the modals, any student may then proceed to the computer terminal, there undertaking further study of the subject. MODALS lacks an answer recording …


The Development Of A Defense System Against Coxsackievirus B5 Infection In Suckling Mice, Neal Shadoff May 1973

The Development Of A Defense System Against Coxsackievirus B5 Infection In Suckling Mice, Neal Shadoff

Senior Scholar Papers

There are many viruses that are able to infect the alimentary tract of man. Little is known, however, about the mechanism of infection itself or the pathophysiology of the gut during infection. 'The research reported here is concerned with the differences in susceptibility among suckling mice of various ages inoculated by the intraperitoneal and intragastric routes. Since the normal mode of entry of many viruses to the gut is via the oral route, Coxsackievirus B5, a human enterovirus which does attack this way, was utilized. It is a non-tumor producing RNA virus that has been shown to act similarly in …


Distillation-Condensation Of Water And Nutrient Movement In A Desert Ecosystem, N. Stark May 1973

Distillation-Condensation Of Water And Nutrient Movement In A Desert Ecosystem, N. Stark

Memorandum

No abstract provided.


Decomposition And Mineralization In An Artemisia Tridentata Community In Northern Nevada, P. L. Comanor, D. C. Prusso May 1973

Decomposition And Mineralization In An Artemisia Tridentata Community In Northern Nevada, P. L. Comanor, D. C. Prusso

Memorandum

No abstract provided.


Proteolytic Activity Of Soil Microorganisms, Robert T. O'Brien May 1973

Proteolytic Activity Of Soil Microorganisms, Robert T. O'Brien

Memorandum

No abstract provided.


Water Resources News, Volume 5, No. 5, May 1973 May 1973

Water Resources News, Volume 5, No. 5, May 1973

Water Current Newsletter

From the Desk of the Director
Deadline for Matching Grants Proposals
Institute Activities
Summer Institutes Announced at the University of Nebraska
Increasing Irrigation Efficiency
Black Hills Sciences Field Station
Construction or Destruction?
Low Flood Losses
Center for Environmental Studies
Earth Tremor Control Method
New Commission of Reclamation
Irrigation Considered Low Priority
Salinity Control Bill
Streams Rich in Mineral Content
Who Done It?
Drastic Mineral Depletions Noted
EPA Ordered to Release $6 Billion
Water Prospects in the West


Kinetic Properties Of Partially Purified Isocitrate Dehydrogenase, Devji Dedhia May 1973

Kinetic Properties Of Partially Purified Isocitrate Dehydrogenase, Devji Dedhia

Masters Theses & Specialist Projects

Within the past few years kinetic studies of NADP+- specific isocitrate dehydrogenase have been conducted extensively following isolation from bacteria, yeast and vertebrates. However, the kinetic properties of NADP+ - specific isocitrate dehydrogenase have not been adequately characterized in filamentous fungi. Therefore, the present study was undertaken to examine the kinetic behavior of partially purified NADP+ - specific isocitrate dehydrogenase enzyme isolated from Phycomyces blakesleeanus.

During this study Michaelis constants (Km) and maximum velocities (Vmax) were determined for threo-Ds-isocitrate, NADP+, and Mn2+ as well as the number of binding sites of these …


Internal Water Potential Of An Engelmann Spruce Stand In Relation To Soil And Atmospheric Factors, Richard L. Meyn May 1973

Internal Water Potential Of An Engelmann Spruce Stand In Relation To Soil And Atmospheric Factors, Richard L. Meyn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The primary objective of this study was to determine the degree of correlation between internal water potential of Engelmann spruce trees and selected environmental factors. The secondary objective of the study was to determine the effect of summer precipitation, both in meadow and forested sites, on the soil drying cycle.

Four study plots (each roughly 154 square meters) under spruce cover and two study plots (100 square meters) in a small meadow were established. At each spruce plot, a thermocouple psychrometer was installed at one meter above the ground on the north side of three selected, mature Engelmann spruce trees. …


Bromegrass Productivity In Relation To Precipitation, Shrub Canopy Cover And Soil Nitrogen Content, Lawrence G. Kline May 1973

Bromegrass Productivity In Relation To Precipitation, Shrub Canopy Cover And Soil Nitrogen Content, Lawrence G. Kline

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In seasons of above normal precipitation, populations of annual weedy species increase in great abundance in semi-arid desert plant communities. These increases in biomass tie up a considerable portion of the available nitrogen of such ecosystems and may depress subsequent annual grass germination.

A big sagebrush-annual bromegrass plant community was irrigated to simulate a spring growth period of abundant precipitation amenable to annual bromegras s productivity. Productivity and nitrogen content parameters were monitored throughout the spring and summer to evaluate the short and potential long term effects of this seasonal increase in "precipitation".

Irrigation increased annual bromegrass productivity almost 50 …


Morphological And Ecological Relationships Of Etheostoma Caeruleum And Etheostoma Spectabile In West Central Indiana, Dennis E. Clark May 1973

Morphological And Ecological Relationships Of Etheostoma Caeruleum And Etheostoma Spectabile In West Central Indiana, Dennis E. Clark

All-Inclusive List of Electronic Theses and Dissertations

Etheostoma caeruleum Storer and Jii. spectabile (Agassiz) are closely related members of the family Percidae, subfamily Percinae, tribe Etheostomatinae. This group, consisting mostly of small, brilliantly colored darters, has been partially characterized by Collett ( 1963). Several papers have been published dealing with the biology of these two species. One or both species have been described by Storer (1845), Agassiz (1854), Reeves (1907, but see Trautman, 1930), Trautman (1930, 1957) Knapp (unpublished Ph.D. dissertation), Distler (1968), and others. Trautman (1930, 1957) Gerking (1945), and Hubbs and Lagler (1947) reported that h caeruleum lives in larger and faster streams, whereas JL_ …


The Synthesis Of Imidazo [4, 5-C] Pyridazines And Pyridazino-As-Triazines, Dennis King Chesney May 1973

The Synthesis Of Imidazo [4, 5-C] Pyridazines And Pyridazino-As-Triazines, Dennis King Chesney

Chemistry and Chemical Biology ETDs

The preparation of the first examples of imidazo[4, 5-c]­pyridazine-2, 7-dithiones is described herein. Several of the S-methyl and S-benzyl derivatives have been prepared and the conditions required for the selective monoalkylation of the 2, 7-dithione have been determined. Several new derivatives of imidazo[4, 5-c]pyridazine and imidazo[4, 5-c]pyridazine-2 or 7-thione are also described. The preparation of several examples of the previously unknown heterocyclic ring systems, 1, 2-dihydropyridazino[4, 5-c]­-as-triazine and 3, 4-dihydropyridazino[4, 3-e]-as-triazine, is described. The preparation, isolation, and structure determination of the products from the reaction of methylamine with 3, 4, 5-tri­chloropyridazine are described. It was found that the reaction of …


Reproduction In The Red Squirrel (Tamiasciurus Hudsonicus) In Colorado, Richard A. Dolbeer May 1973

Reproduction In The Red Squirrel (Tamiasciurus Hudsonicus) In Colorado, Richard A. Dolbeer

United States Department of Agriculture Wildlife Services: Staff Publications

Information on reproduction of the red squirrel (Tamiasciumrs hudsonicus) can be gleaned from studies in the northeastern United States (Klugh, 1927; Hamilton, 1939; Layne, 1954) and in western Canada (Miller, 1970; Smith, 1968; Kemp and Keith, 1971; Wood, 1967). However, there is a paucity of information on reproduction from the mountainous regions of the western United States. This paper presents reproductive information on the red squirrel from Colorado and helps fill this void. In addition, the reproductive strategy of red squirrels is briefly compared with that of snowshoe hares.


A Measure Of The Amount Of Phosphate Adsorption And The Rate Of Release Of Indigenous Phosphate From A Desert Soil, Robert Lindsey Evans May 1973

A Measure Of The Amount Of Phosphate Adsorption And The Rate Of Release Of Indigenous Phosphate From A Desert Soil, Robert Lindsey Evans

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The capacity of a calcareous desert soil, Thiokol silt loam, to retain natural, as well as added, orthophosphate-P was measured by equilibrium adsorption employing a batch technique and evaluated using the two-slope Langmuir adsorption isotherm. From these data, corrected to account for indigenous soil P, a hypothesis was formulated as to the nature of retention of P by the soil, including the identification of two interfacial reactions involving P, and a value calculated for the adsorption maximum as defined by the Langmuir isotherm equation for P with soil at each of two soil depths and three constant temperatures within the …


Effects Of Exercise On Serum Lactate Dehydrogenase Activity Of Catchable-Size Hatchery Rainbow Trout, Salmo Gairdneri, Gerlad T. Klar May 1973

Effects Of Exercise On Serum Lactate Dehydrogenase Activity Of Catchable-Size Hatchery Rainbow Trout, Salmo Gairdneri, Gerlad T. Klar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Effects of exercise and the relative condition of exercised fish were viii evaluated for two strains of rainbow trout. Circular tanks fitted with a paddle were used to continuously exercise the fish and a stamina tunnel was used to evaluate the condition of exercised trout. Trout were exercised continuously at one fish-length per second and one-half fish length per second. Serum LDH activity in Shephard-of-the-Hills (Missouri) rainbow trout acclimated to 10 C increased two fold during the first four days of exercise. Serum LDH activity returned to control levels by the tenth day of exercise. Serum LDH activity in Shephard-of-the-Hills …


Mechanisms Of Population Regulation In Confined Colonies Of Peromyscus Maniculatus (Wagner) And The Response To Exploitation, Donna Corn Olsen May 1973

Mechanisms Of Population Regulation In Confined Colonies Of Peromyscus Maniculatus (Wagner) And The Response To Exploitation, Donna Corn Olsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wild-trapped and laboratory-reared Peromyscus maniculatus (Wagner) were raised as confined colonies indoors with various stocking densities ranging from 0.026 to 0.100 mice per sq. ft. in pens of 40, 77, and 154 sq. ft. The animals were individually tagged and all pens were censused at weekly or semi-monthly intervals to record animals present, body weights, food consumption, and overt reproductive condition. At the termination of each experiment, all mice were necropsied and organ weights of gonads and adrenals recorded. Histological sections were made of the testes and ovaries. Half the colonies were subjected to density-independent exploitation by removal of 50% …


Field Measurements Of Photosynthesis And Leaf Growth Rates Of Three Alpine Plant Species, Douglas A. Johnson May 1973

Field Measurements Of Photosynthesis And Leaf Growth Rates Of Three Alpine Plant Species, Douglas A. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Leaf photosynthetic measurements using a portable 14Co2 field system were carried out and correlative leaf relative growth rates, RGR, were determined at different leaf positions of three alpine plant species throughout the growing season. Initially there was a period of high leaf RGR associated with a period of increasing photosynthetic activity. Following this stage was a long period of no net change in length of the living leaf. During this period, photosynthetic activity generally increased to a maximum level and then decreased steadily. The final ontogenetic stage was a period of negative leaf RGR denoting leaf senescence which …


Trout Movements In A Small Mountain Stream, Thomas Mark Twedt May 1973

Trout Movements In A Small Mountain Stream, Thomas Mark Twedt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Five groups of 400 hatchery rainbow trout, (Salmo gairdneri), were stocked in a small, mountain stream at 3-week intervals from June to September, 1972. A fish trap captured any fish moving out of a 500 m study section.

Fish began moving at high levels during the first day of each stocking and continued at high rates for 5-8 days (Early Phase), after which movement decreased to low levels for 6-9 days (Late Phase). Early Phase fish moved primarily at night, possibly due to their disoriented state and high subjectivity to stream conditions. Fish moving during Late Phase did …


The Relationship Of Climatic Factors To Grazing Activities Of Cows On Winter And Spring Ranges, Benton M. Smith May 1973

The Relationship Of Climatic Factors To Grazing Activities Of Cows On Winter And Spring Ranges, Benton M. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this research was to investigate the effects of climatic variations upon the daily activities of grazing cattle. The activities of individual cows on a partially seeded salt desert shrub range were observed and recorded during three grazing periods. Two of the periods were during consecutive winters and the other during the spring. Climatic variations during the second winter period were quantified and compared to changes in the daily activity patterns of the cattle.

Distinctly different daily routines of cattle activities were evident for the winter and spring seasons. In the spring, the cattle grazed, traveled, and drank …


Autecological Life History Studies Of Two Geraniums, Geranium Richardsonii And Geranium Nervosum, Becky Lee Green May 1973

Autecological Life History Studies Of Two Geraniums, Geranium Richardsonii And Geranium Nervosum, Becky Lee Green

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two perennial species of wild geranium (Geranium nervosum Rydb. and G. richardsonii Fisch, and Trautv, [Geraniaceae]) which grow throughout the mountainous regions of western North America were studied to determine the factors influencing the life stage development and distribution of these plants. Attempts were also made to provide some information to assist in the taxonomy of this genus.

Geranium richardsonii is found in wet meadows and along streambanks throughout its distribution. Geranium nervosum frequents rocky hillsides and drier meadows throughout its range.

Seeds of G. nervosum had 65%, germination in the stratification pretreatment. Geranium richardsonii seeds required scarification to …