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Articles 51091 - 51120 of 52483
Full-Text Articles in Entire DC Network
A Zooplankton Study Of Stumpy Lake, Virginia Beach, Virginia, Jose E. Hernandez
A Zooplankton Study Of Stumpy Lake, Virginia Beach, Virginia, Jose E. Hernandez
Biological Sciences Theses & Dissertations
A one year study was made of the zooplankton composition in Stumpy lake, a reservoir in the city of Virginia Beach, Virginia. Quantitative and qualitative -parameters were investigated under field conditions. The analysis of the data presents information on the monthly dynamics or the zooplankton and other fluctuations in the lake environment. It is the intention or this study to emphasize the seasonal changes in the zooplankton community and their relationship to the ecological factors responsible for these variations.
A Comparative Limnological Survey Of Brackish-Water Lake And A Fresh-Water Lake At Mount Trashmore, Virginia Beach, Virginia, Gene Ramon Cocke
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
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
A Method Of Analyzing Mandibular Movement, Richard B. Mccoy
A Method Of Analyzing Mandibular Movement, Richard B. Mccoy
Loma Linda University Electronic Theses, Dissertations & Projects
Mandibular movement is considered to be a fundamental factor in the study, analysis, and treatment of occlusion. For many years, dentists have realized that dental health depends upon the compatibility of mandibular movements and occlusion. This realization has led to the development of new methods and techniques for recording accurately and scientifically the movements of the mandible. In order for this data to be of scientific value, it must be stored in a usable form which is easily available for analysis.
The purpose of this research project was to develop a procedure for storing and recalling mandibular-movement information. Before such …
Production Of Iodinated Compounds And The Effect On Strobilation In Aurelia Aurita, William J. Welch
Production Of Iodinated Compounds And The Effect On Strobilation In Aurelia Aurita, William J. Welch
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 William J. Welch on May 2, 1973.
Predicting Nitrogen Transformations And Ammonia Volatilization In Warm Desert Soils, G. R. Dutt
Predicting Nitrogen Transformations And Ammonia Volatilization In Warm Desert Soils, G. R. Dutt
Memorandum
No abstract provided.
Effects Of Tubal Ligation And Salpingectomy On Pregnancy, Ottis Murphy Lane
Effects Of Tubal Ligation And Salpingectomy On Pregnancy, Ottis Murphy Lane
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 Ottis Murphy Lane May 1, 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
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
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
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
Seed Reserves Of Desert Soils, Stuart Childs, David W. Goodall
Memorandum
No abstract provided.
Distillation-Condensation Of Water And Nutrient Movement In A Desert Ecosystem, N. Stark
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
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
Proteolytic Activity Of Soil Microorganisms, Robert T. O'Brien
Memorandum
No abstract provided.
Predicting Primary Productivity In Westhampton Lake, Richmond, Virginia., Gary Newton Moore
Predicting Primary Productivity In Westhampton Lake, Richmond, Virginia., Gary Newton Moore
Master's Theses
Several predictive photosynthetic models were tested using light, temperature, nutrient, chlorophyll, and primary productivity data collected from Westhampton Lake, Richmond, Virginia from February-September, 1972. A simple linear model, the Kendall rank correlation coefficient, was used to relate photosynthesis to individual meteorological, physical, chemical, and biological factors. iii Of the parameters measured, only the daily maximum photosynthetic efficiency ((P/chl) max ) was significantly correlated with photosynthesis. Five multiple factor (non-linear) models were tested. In the best fitting model, primary productivity was a function of the maximum observed ratio of photosynthesis/chlorophyll concentration, light intensity, temperature, nutrient concentrations, and chlorophyll concentration. The Pearson …
Mechanisms Of Population Regulation In Confined Colonies Of Peromyscus Maniculatus (Wagner) And The Response To Exploitation, Donna Corn Olsen
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
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 …
The Relationship Of Climatic Factors To Grazing Activities Of Cows On Winter And Spring Ranges, Benton M. Smith
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 …
Impact Of The Black-Tailed Jackrabbits (Lepus Californicus) On Vegetation In Curlew Valley, Northern Utah, Mark Westoby
Impact Of The Black-Tailed Jackrabbits (Lepus Californicus) On Vegetation In Curlew Valley, Northern Utah, Mark Westoby
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The interrelations of black-tailed jackrabbits and the desert-shrub vegetation on which they were feeding were studied in Curlew Valley, Northern Utah. The vegetation was described as a three-cornered continuum, the corners being types dominated respectively by Artemisia tridentata, Atriplex confertifolia, and Sarcobatus vermiculatus.
Jackrabbit diet was studied by microscopic analysis of plant fragments in stomachs from shot animals. The method was inaccurate, apparently because the ratio of identifiable tissues to all ingested tissues was very low, and varied between plant taxa, and seasonally. This problem seems intractable for desert shrub vegetation.
The diet was similar to that …
Mercury, Dieldrin, Ddt, Dde, And Pcb Levels In Tissues From Fish And Wildlife In Utah, Fred A. Smith
Mercury, Dieldrin, Ddt, Dde, And Pcb Levels In Tissues From Fish And Wildlife In Utah, Fred A. Smith
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Fish and wildlife were randomly sampled in Utah from pre-selected x areas and analyzed for levels of total mercury, dieldrin, DDT, and DDE. Levels were well within consumptive tolerance or guideline limits except for mercury levels of fish in Willard Bay Reservoir. PCB's were also identified in a large proportion of samples.
None of the chukars, 6 percent of the pheasants, 4 percent of the waterfowl, and none of the fish sampled, excluding Willard Bay Reservoir, were above the 0.5 ppm guideline level for mercury established by the Food and Drug Administration. Seventy-seven percent of the fish sampled from Willard …
Economic (Linear Programming) Model Of The Farming Region Served By The D.M.D.A. Irrigation Company, Delta, Utah, Francisco Zarzalejo
Economic (Linear Programming) Model Of The Farming Region Served By The D.M.D.A. Irrigation Company, Delta, Utah, Francisco Zarzalejo
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The main objectives of the study are to create a linear programming model of the study area in order to estimate changes in benefits when water delivery system losses are assumed to be affected by shifting between rotation, demand and continuous flow management systems,
Approximately 7,000 acres are included in the program model and the estimated potential "gains" or benefits from distribution system loss "savings" due to more efficient delivery range from $6,000 to _ $12,000 per season. This result is influenced by the facts that the - loss estimates are hypothetical and the system studied is in an area …
Internal Water Potential Of An Engelmann Spruce Stand In Relation To Soil And Atmospheric Factors, Richard L. Meyn
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. …
Trout Movements In A Small Mountain Stream, Thomas Mark Twedt
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 …
Habitat Selection By Large Wild Ungulates And Some Aspects Of The Energy Flow In A Sub-Tropical African Savanna Woodland Ecosystem, Stanley M. Hirst
Habitat Selection By Large Wild Ungulates And Some Aspects Of The Energy Flow In A Sub-Tropical African Savanna Woodland Ecosystem, Stanley M. Hirst
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
A study of habitat selection by large wild ungulates was carried out on a 50 cm2 area in the sub-tropical Lowveld region of eastern Transvaal province, South Africa. Estimations were made of herbaceous forage net productivity and ungulate secondary productivity on the same area.
Fourteen vegetation types, varying in composition and structure from open savanna to dense woodland, were delineated by association analysis. Structural and vegetational characteristics which were considered to influence ungulate distribution were measured within each vegetation type.
The study area supported resident populations of seven ungulate species during the wet season; drv season densities were higher …
Autecological Life History Studies Of Two Geraniums, Geranium Richardsonii And Geranium Nervosum, Becky Lee Green
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 …
Effects Of Exercise On Serum Lactate Dehydrogenase Activity Of Catchable-Size Hatchery Rainbow Trout, Salmo Gairdneri, Gerlad T. Klar
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 …
Bromegrass Productivity In Relation To Precipitation, Shrub Canopy Cover And Soil Nitrogen Content, Lawrence G. Kline
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 …
A Comparison Of Consumer's Surplus And Monopoly Revenue Estimates Of Recreational Value For Two Utah Waterfowl Marshes, C. Holden Brink
A Comparison Of Consumer's Surplus And Monopoly Revenue Estimates Of Recreational Value For Two Utah Waterfowl Marshes, C. Holden Brink
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Demand curves were estimated for waterfowl hunting and nonconsumptive recreational use from use rate and variable expenditure data collected at the Bear River Migratory Bird Refuge and the Farmington Bay Waterfowl Management Area during fiscal 1969. Consumer's surplus and monopoly revenue estimates were then derived from the demand functions. Adjusted estimates of consumer's surplus for waterfowl hunting amounted to $7,260 per year at Bear River and $11,400 per year at Farmington Bay. For nonconsumptive recreation annual consumer's surplus was estimated to be $18,700 at Bear River and $3,760 at Farmington Bay. Monopoly revenue estimates were between one-half and one-fourth the …
Fish Production And Movements In The Lower Logan River, Utah, Eric P. Bergersen
Fish Production And Movements In The Lower Logan River, Utah, Eric P. Bergersen
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Following the abatement of domestic sewage pollution xii in the lower Logan River , the fish population was investigated in terms of abundance, growth, fecundity, production, mortality, age class structure, species diversity, distribution and movements during 1970 and 1971.
Three general groupings of fish were identified in the study area on the basis of species composition, abundance and distribution using a cluster analysis technique. These were located in 1) the tributary stream (7-Mile Creek) which previously transported sewage to the river and 2) above and 3) below 7-Mile Creek in the main stream of the Logan River. A "transition" population …
Criteria For Recreation Site Selection On Flood Control Reservoirs-Case Studies, Kenneth B. Mclaughlin
Criteria For Recreation Site Selection On Flood Control Reservoirs-Case Studies, Kenneth B. Mclaughlin
Electronic Theses and Dissertations
Stephen F. Austin State University was awarded a contract in August 1971 to select the 1,200 acres best suited for recreation area development on three proposed flood control reservoirs. At that time, there was no central publication which could be used as a guide for such a project. This thesis was written to help correct this situation. The nine factors that were used in initial site selection are soils, topography, access, wind, vegetation, land ownership, distribution of the sites, bridges and open-water and cove locations. Once the sites were selected, they were evaluated and assigned priorities for development according to …