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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

The Relations hip of Climatic Factors to Grazing Activities of Cows on Winter and Spring Ranges

Smith, Benton M. 01 May 1973 (has links)
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 more each day than they did during the winter months. The increase in these activities was attributed to the more temperate climatic conditions and the higher energy demands of lactation. Air temperature, changes in barometric pressure, windspeed, precipitation, snow depth, and radiation all influenced cattle activities in the winter. Decreasing air temperature and rapid fluctuations in barometric pressure both correlated significantly with increased grazing time. Increasing windspeed and greater snow depth caused the cattle to travel less distance daily. The cattle ceased grazing during snowstorms. They oriented themselves at right angles to the sun while standing and lying. The modifications which occurred in daily activity patterns were shown to be apparently directed toward the conservation of energy during periods of climatic stress.
212

The Cache County Snowmobiler: An Empirical Study

Dierker, Michael William 01 May 1977 (has links)
Snowmobiling is one of the major outdoor winter sports in Cache County, Utah. Despite its popularity, it has run into several problems, among which the most noticeable is its conflict with other winter recreationists, namely, cross-country skiers and snowshoers. In order to resolve this conflict, one must first understand more about each group involved. As such, the purpose of this research was to obtain information on the snowmobiler in Cache County, Utah. Specifically, the objectives of the study were: (1) to identify the attitudes of the snowmobiler toward leisure and the environment; (2) to identify and compare occupations, SES, and social characteristics with studies in other regions; (3) to identify and compare aspects such as when, where, and why they go snowmobiling and the areas preferred by them with studies in other regions; and (4) to identify their other leisure-time activities. To collect the data, the names of the Cache County snowmobilers were obtained from tax assessment receipts at the Cache County Courthouse. From a total list of 501 names, a sample of 250 was selected by a simple random procedure. A questionnaire composed of Burdge's Leisure Orientation Scale, an environmental orientation scale, and usage, ownership, and demographic questions was sent to the sample population with a 59 percent usable return rate. The data was then analyzed by the following SPSS programs to meet the objective of the study: marginals, t-test, and chi square. Analysis of the data revealed the following major characteristics of the Cache County, Utah snowmobilers: (1) They are typically male, married with between three and four children per family, have a high school education or above, have a median income above the median income for Utah of $9,320.00, and hold either a blue- or white-collar occupation. (2) They hold a slight preservationist orientation toward the environment. (3) They have a moderately strong leisure orientation. (4) They snowmobile primarily on weekends with friends or family with the primary area of use being the Cache National Forest. (5) The main reason for buying or still owning a snowmobile was "snowmobiling for pleasure." Upon comparison with the findings of this research with studies conducted in other regions, the conclusion is reached that the Cache County, Utah snowmobilers are much like their counterparts in other regions of the country.
213

Winter Ecology of Waterfowl on the Great Salt Lake, Utah

Vest, Josh L. 01 May 2013 (has links)
I designed a suite of studies in coordination with Utah Division of Wildlife Resources (UDWR) to evaluate waterfowl use of the GSL in winter and ecological aspects associated with GSL use. These studies provided insight into key information gaps previously identified by UDWR regarding management of GSL resources. Population surveys indicated total duck abundance was low when GSL surface elevations were low and wetland resources diminished because of persistent drought in the system. Also, ducks appear to use hypersaline parts of GSL more when freshwater habitats are limited from either drought or ice conditions. Common goldeneye, northern shoveler, and green-winged teal exhibited the most use of hypersaline areas. Dietary evaluations indicated all three species feed on hypersaline invertebrates from GSL to meet energetic and nutritional needs in winter. Brine shrimp cysts were important foods for northern shoveler and green-winged teal. Fat levels of ducks are important determinants of survival and fitness. Fat reserves of goldeneye were generally lower in the winter when both GSL and wetland habitat resources were lower. Results suggest brine fly larvae productivity, freshwater habitat availability, and temperature and wind speed likely play a more prominent role in goldeneye fat reserves than osmoregulation. Also, common goldeneye and northern shoveler using the GSL apparently accumulated biologically concerning amounts of mercury and selenium during winter. However, further research is needed to evaluate the effect of these elements on GSL ducks.
214

An Inheritance Study of Sedimentation Values in Three Winter Wheat Crosses

Baker, Douglas J. 01 May 1969 (has links)
Three crosses were used to study the inheritance of the sedimentation properties in hard red winter wheat. The parents of the three crosses were the variety Delmar, and the breeding lines 217-61- 7-14 and 217 - 19- 5. Delmar has high sedimentation properties, 217-6 1-7-14 is intermediate, and 217-19-5 has very poor sedimentation qualities. Sedimentation tests were run on five replications of the parents and 300 samples of the F3 populations in each cross. A semi-micro sedimentation test (a one-fourth scale test) was run on 200 F2 plants and the F1's from each cross. The distributions from each cross were analyzed and the type of gene action and possible number of genes involved were estimated. There were two general trends apparent in the progeny of all three crosses. (1) In the F2 generation there were more low parental types than high parental types recovered. This situation was reversed in each of the F3 populations where more high parental types were recovered than the low parental types (2) All three F3means were about 10 units higher than their respective F2 means. The type of gene action appeared to be mainly additive but with some partial dominance for the high parent in each cross . Depending on the cross, from one to three genes were estimated to be functioning in the determination of the sedimentation properties.
215

A Research Study of Lamb Feeding in Winter Dry Lots at Monroe, Utah

Henderson, George R. 01 May 1930 (has links)
By reason of the topography of the land, Utah is and probably will remain a livestock grazing state. As far as agriculture is concerned over 90 percent of the area is suitable for grazing only. This grazing range is used by cattle and sheep.
216

The Genetic Architecture of Grain Quality and its Temporal Relationship with Growth and Development in Winter Malting Barley (Hordeum vulgare)

Loeb, Amelia 26 June 2023 (has links)
This thesis explores the genetic architecture of malting quality within the Virginia Tech barley breeding program, and discusses implications for imposing selection on complex traits that are difficult to phenotype. Malting quality measures are destructive, and can not be performed before selection must be made for advancement of breeding lines in winter barley. A growing body of evidence suggests that malt quality is influenced by malting regime, growing environment, line genotype, and the interactions between them. We aim to better understand the genetic effect on malt quality in two manners: first, as it relates to the genetic architecture regulating malt quality parameters, and second the relationship between genetic growth patterns to end-use malting traits. This study included two years of breeding trial data of two and six-row winter malt barley across two locations. Results of a genome-wide association scan and genomic prediction of malt quality traits indicated that they are largely quantitative traits with complex inheritance. Previous studies have identified quantitative trait loci and genes regulating malt quality traits in markedly different germplasm. Heritability of traits ranged from 0.27 to 0.72, while mean predictive abilities ranged from 0.45 to 0.74. Thus, selection on genomic estimated breeding values (gEBVs) should perform similarly to selection on single phenotypic observations of quality, but can be done within the same season. This indicates that genomic selection may be a viable method to accelerate genetic improvement of malting quality traits. The use of gEBVs requires that lines be genotyped with genome-wide markers, somewhat limiting the number of candidate individuals. Selection on growth and development traits genetically correlated with quality measures could allow for selection among a much greater number of candidates if high-throughput phenotypes can be collected on many ungenotyped indivduals. Growth and development was quantified by the near-infrared vegetation index (NDVI) extracted from aerial images captured from multiple time points throughout the growing season. Estimates of genetic correlation identified time points throughout the season when quality traits are related to growth and development. We demonstrated that aerial imagery can discern growth patterns in barley and suggest ways it can be incorporated into the breeding pipeline. / Master of Science / Malt barley (Hordeum vulgare) is the preferred source of fermentable sugar used to brew beer. Currently, the majority of malt barley used in the United States is grown in the upper mid-west or imported from Europe. The east coast could become a producing region if high quality, disease resistant varieties were available to growers. The Virginia Tech small grains breeding program began breeding locally adapted malt barley in 2010. This project aims to improve the breeding process by incorporating information from genomic sequencing, malt quality and aerial imagery. Malt barley differs from that used for animal feed or human food because specific quantities of starches, proteins, and enzymes are necessary in the brewing process. The quantity of these molecules are determined through lab analysis and determine the grain's suitability for particular brewing styles. This analysis is timeconsuming and costly because it involves a three-step process of malting the grain, brewing with the malt, and analyzing the wort. The wort is the liquid sugar solution which is produced by heating the malt with water to a high temperature in a process called 'mashing'. Lab quality analysis for the thousands of lines evaluated in a breeding program in any given year is unfeasible. However, by understanding the genetic regulation of malt quality traits, breeders can employ techniques like genomic selection to improve these traits in a shorter amount of time. Additionally, this work identifies relationships between growth and quality. The grain is the result of the plant's growth throughout the entirety of the season. Measuring growth repeatedly through time was previously difficult until the advent of aerial imagery. Images captured from drones have been used to quantify growth in a variety of plants, but is not extensively done in malt barley. Relating growth to quality will help breeders understand genetic patterns of growth and development which may be advantageous in the production of high quality malt barley.
217

Survival and Habitat Selection of American Black Ducks in Tennessee

Newcomb, Kira Cristina 13 December 2014 (has links)
American black duck (Anas rubripes) populations declined throughout North America from 1950–1990, but the breeding population since has stabilized. However, limited information exists on black ducks in the Mississippi Flyway, where wintering populations continue to decline. I radiomarked 111 female black ducks at Tennessee National Wildlife Refuge (TNWR) in winters 2010–2012 to estimate winter survival and investigate patterns of habitat selection. Winter survival (83–85%) was greater than or comparable to previous estimates for black duck populations in North America. Interval survival increased 0.6% with a 100 g increase in body mass, but survival differed between years and waterfowl hunting seasons relative to body mass. Black ducks selected habitats on TNWR and emergent/scrub-shrub wetlands throughout winter regardless of hunting season or time of day. High winter survival rates and consistent use of TNWR suggest the refuge provides an important complex of habitats for black ducks wintering in Tennessee.
218

Winter Cover Crops, Fall Applied Poultry Litter, and N Fertilization Effects on Soil Quality and Health Indicators

Boupai, Apisit 11 August 2017 (has links)
Soil quality and health indicators are necessary to monitor and improve the agricultural sustainability. This experiment was conducted at Mississippi State, MS between 2015 and 2016. Soil samples were taken to determine bulk density, enzymatic activity, and total C and N. Results indicated greater bulk density, total C and N, and enzymatic activity for inter-row position than for within the corn row which was disturbed by strip-tillage. Soil bulk density tended to increase with soil depth; however, total C and N and total microbial activity decreased with depth both years. Total soil C and N increased from 2015 to 2016. Enzymatic activity was greatest at corn planting and decreased up thru four weeks apparently due to total C and N decomposition. Total C and N were related to bulk density and enzymatic activity because increase in soil C and N decreased the bulk density and increased the enzymatic activity values.
219

Winter cycling in Eskilstuna municipality: motivators and barriers experienced by commuters

Wang, Wenjing January 2022 (has links)
Many cities focus on cycling due to the multiple advantages including individual, societal, and economic advantages. Eskilstuna municipality in Sweden is one of the cases that aim to develop cycling, but the question is if the municipality has managed in developing winter cycling because of the special winter weather characteristics, cold, windy, snowy, and dark. This study focuses on the experiences of commuters when commuting in winter in Eskilstuna municipality. The goal of this study is to identify and analyze the motivators and barriers that influence winter cycle commuting, and the research result can contribute to improving the cycling rate in Eskilstuna municipality. The researcher examined the issues in Eskilstuna municipality through qualitative analysis from the focus group interview and interview and document analysis. Factors such as prioritized cycle lanes, the construction of new cycle lanes, preference for wellbeing, social influence (such as cycling culture and cycle-friendly atmosphere), the good function of the cycle (including the cycle, the tire, the cycle lights), good private economy situation were identified as motivators to cycling to work in winter. By contrast, issues that are related to lack of infrastructure maintenance and lack of cycle lanes, the darkness, the snow, limitation in practices of the policy, and cleanness as a social norm were identified as barriers. However, some factors were identified as irrelevant factors such as low temperature, showing room, parking space, and scenery.
220

Variation in Winter Estuarine Habitat Use by Bluefish in Northeastern Florida with Implications for Growth and Condition

Murt, John S 01 January 2009 (has links) (PDF)
Age and growth were determined from otoliths for 181 juvenile bluefish, Pomatomus saltatrix, collected using a variety of gear in northeast Florida during 2003 and 2005. Three distinct cohorts were identified recruiting to the near shore waters during spring, summer and fall. Growth rates were high regardless of cohort or season. To compare pre- and post-recruitment growth rates, models were fit to individual growth trajectories using change point analysis. Post-estuarine growth rates were generally higher. Growth rates and hatching times were within the range of those obtained in other bluefish studies conducted at higher latitudes. As this is the only area where winter recruitment of bluefish has been observed, coastal Florida habitats may be essential for the bluefish stock and will need to be carefully monitored in future studies. A technique to estimate the lipid content of bluefish was developed using fat stage (subjectively assigned based on mesenteric fat around the stomach), fish length, and fish weight. A highly significant relationship was observed between fat stage and lipid content in a generalized linear model. The visual lipid content technique provides rapid results, is inexpensive and could be easily implemented into current fisheries sampling methods. Total lipids were also extracted from potential bluefish prey species collected during sampling. Prey lipids ranged from 0.88% to 19.52%. Regular prey species from the MAB; Atlantic silverside and bay anchovy contained 3.49% and 3.19% mean lipids respectively. Highest lipid content was observed in mullet (Mugil spp.) (19.52%) and was significantly higher than other available prey species. A previous study indentified a decline in bluefish lipids as winter progressed as well as a prey preference for mullet. We propose mullet are the preferred prey choice due to their high lipid content.

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