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Articles 1741 - 1770 of 2496

Full-Text Articles in Life Sciences

In Utero And In Vitro Sex Ratio Of Bovine Embryos And Calves Originating From The Left And Right Ovaries, Darin Alan Hylan Jan 2007

In Utero And In Vitro Sex Ratio Of Bovine Embryos And Calves Originating From The Left And Right Ovaries, Darin Alan Hylan

LSU Doctoral Dissertations

An asymmetric distribution of the sexes within the left and right uterine horns has been described in multiple polytocous, laboratory species. A series of experiments were conducted to evaluate the sex ratio (% male) of calves gestated in the left and right uterine horns, as well as the sex ratio of embryos originating from the left and right ovaries of cattle. In Experiment 1, the sex ratio of calves and fetuses gestated in the left and right uterine horns was investigated. The sex ratio of calves and fetuses gestated in the right uterine horn was significantly higher compared with the …

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Equine Obesity-Related Hyperleptinemia, Nan Killen Huff Jan 2007

Equine Obesity-Related Hyperleptinemia, Nan Killen Huff

LSU Doctoral Dissertations

Plasma leptin concentrations in obese adult horses have been shown to vary widely, and horses tend to fit into two groups: low leptin (<10 ng/mL) and hyperleptinemic (10 to 50 ng/mL). Observations over time revealed that the hyperleptinemic condition was consistent, possibly indicating a relatively permanent underlying cause. Based on these observations, three experimental approaches were used to further study equine obesity-related hyperleptinemia. The first experiment determined the prevalence of hyperleptinemia among postpartum, lactating mares, evaluated its consequence on their re-breeding success, and investigated correlations between leptin levels in lactating and non-lactating mares. Postpartum mares (n = 198) and non-foaling mares (n = 31) were categorized based on their leptin status: normoleptinemic or hyperleptinemic. Leptin in the lactating mares averaged 4.8 ng/mL, and 11 of the 198 (13%) displayed hyperleptinemia. Leptin in the non-lactating mares averaged 7.5 ng/mL, with 9 mares (29%) displaying hyperleptinemia. Of the 198 lactating mares bred, 81% became pregnant; there was no effect of leptin status on re-breeding success. To study one possible cause for hyperleptinemia in well-fed horses, a second experiment explored polymorphism(s) within exon 2 of the equine leptin gene. The DNA from five hyperleptinemic and five normal mares of high body condition was used to analyze exon 2 of the leptin gene for polymorphisms. Based on the 10 mares tested, there was no polymorphism in exon 2 of the equine leptin gene; therefore, polymorphism is not a likely explanation for the high vs. low leptin difference. The third experiment explored the possible effects of hyperleptinemia on the endocrine and immune systems. Endotoxin was given to mares and geldings to investigate the role and/or regulation of leptin in the pro-inflammatory cytokine response. Of the endpoints measured, only platelet count differed between normal and hyperleptinemic horses. Endotoxin infusion caused the expected pro-inflammatory cytokine and endocrine responses, but leptin status was not a significant factor for any endpoint. It is concluded that hyperleptinemia in mares is not associated with polymorphism in exon 2 of the leptin gene, does not affect re-breeding rates of foaling mares, and does not alter the endotoxin-induced responses of the endocrine and immune systems.

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Chromosomal Stability And Epigenetic Modifications Of Fibroblast Cells Used For Nuclear Transfer, Angelica Maria Giraldo Gomez Jan 2007

Chromosomal Stability And Epigenetic Modifications Of Fibroblast Cells Used For Nuclear Transfer, Angelica Maria Giraldo Gomez

LSU Doctoral Dissertations

Investigations into the importance of the nuclear integrity of the donor cell prior to nuclear transfer (NT) are limited. In Experiment 1, the proliferative characteristics, chromosomal stability and level of histone phosphorylation in cell lines established by explants and enzymatic dissociation at different population doublings (PDs) were investigated. The cells divided at a constant rate and cell cycle length increased only at the end of the proliferative stage. The level of aneuploidies was high and remained elevated throughout the study independent of the technique used to establish the primary culture. High levels of multinucleated cells and abnormal spindle configurations were …

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Low Crude Protein, Amino Acid-Supplemented Diets, And The Glycine Requirement In Low Crude Protein Diets For Broilers, April Marie Waguespack Jan 2007

Low Crude Protein, Amino Acid-Supplemented Diets, And The Glycine Requirement In Low Crude Protein Diets For Broilers, April Marie Waguespack

LSU Master's Theses

The purpose of this research was to determine the optimal level of crystalline amino acid (AA) supplementation that supports maximum growth performance in broilers, and to determine the Gly requirement in broilers. Treatments were replicated with a minimum of 7 pens with 6 broilers per pen. Experiments (Exp.) were conducted from 0- to 18- days (d) post-hatching in brooder batteries. Three Exp. were conducted to determine the maximum level of L-Lys•HCl that could be supplemented to corn-soybean meal (C-SBM) diets without negatively affecting growth performance of broilers. The results of these Exp. indicate that broilers can achieve maximum growth performance …

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Pathology And Seedling Nutrition Of Spartina Alterniflora (Smooth Cordgrass), Clark Lane Robertson Jan 2007

Pathology And Seedling Nutrition Of Spartina Alterniflora (Smooth Cordgrass), Clark Lane Robertson

LSU Master's Theses

Transplants of Spartina alterniflora Loisel. (smooth cordgrass, Poaceae) are effective in stabilizing and protecting vulnerable coastal wetlands from erosion. However, the expense and labor associated with propagation and transplanting restrict the widespread use of S. alterniflora in coastal restoration and protection projects. As an alternative, seeding of S. alterniflora by aircraft has been proposed as a more useful and economical approach for revegetating denuded marsh sites. However, a period of stalled growth, which lasts for 12 or more weeks, has been observed in smooth cordgrass seedlings, and this increases their susceptibility to being washed away by inundating tides. This stalled …

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Louisiana Agriculture Fall, 2006, Lsu Agcenter Oct 2006

Louisiana Agriculture Fall, 2006, Lsu Agcenter

Louisiana Agriculture

No abstract provided.

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Louisiana Agriculture Summer, 2006, Lsu Agcenter Jul 2006

Louisiana Agriculture Summer, 2006, Lsu Agcenter

Louisiana Agriculture

No abstract provided.

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Calcium Intake, Bone Mineral Density, And Percent Body Fat Of University Students, Beth Peterson May 2006

Calcium Intake, Bone Mineral Density, And Percent Body Fat Of University Students, Beth Peterson

Honors Capstones

No abstract provided.

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Louisiana Agriculture Spring, 2006, Lsu Agcenter Apr 2006

Louisiana Agriculture Spring, 2006, Lsu Agcenter

Louisiana Agriculture

No abstract provided.

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Louisiana Agriculture Winter, 2006, Lsu Agcenter Jan 2006

Louisiana Agriculture Winter, 2006, Lsu Agcenter

Louisiana Agriculture

No abstract provided.

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Evaluation Of Bovine Spermatid Sex Ratio By Fluorescent In Situ Hybridization, Michael Alan Stout Jan 2006

Evaluation Of Bovine Spermatid Sex Ratio By Fluorescent In Situ Hybridization, Michael Alan Stout

LSU Master's Theses

The objective of this study was to use fluorescent in situ hybridization (FISH) to determine if a skew in the sex ratio was present at the level of the bovine round spermatid. Paraffin embedded bovine testicular tissue obtained from biopsies were used to perform FISH, and the seminiferous tubules were examined. Our findings show that the skew does exist within the round spermatids. Analysis of variance on X- and Y-chromosome bearing round spermatids as affected by sex, slide, picture set, and tubule was performed. Sex showed that the variation in round spermatid sex ratio differed between slides (P = 0.0001). …

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Strain To Strain Differences In The Growth, Survival And Adaptation Of Vibrio Vulnificus And Vibrio Parahaemolyticus In Broth, Veronica Elaine Burnham Jan 2006

Strain To Strain Differences In The Growth, Survival And Adaptation Of Vibrio Vulnificus And Vibrio Parahaemolyticus In Broth, Veronica Elaine Burnham

LSU Master's Theses

Vibrio vulnificus and Vibrio parahaemolyticus are natural inhabitants of estuarine environments of the Gulf of Mexico. V. vulnificus is the leading cause of death, while V. parahaemolyticus is a leading cause of foodborne gastroenteritis from the consumption of seafood in the United States. Refrigeration is commonly used as a preservation method to control the growth of microorganisms in food. The ability of some microorganisms to adapt, as a survival response when exposed to a downshift in temperature, could compromised efforts to use low temperature storage to reduce the risk of foodborne illnesses. Limited research is available on the growth characteristics …

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Trade Creation And Trade Diversion Effects In The Eu-South Africa Free Trade Agreement, Gregory Emeka Kwentua Jan 2006

Trade Creation And Trade Diversion Effects In The Eu-South Africa Free Trade Agreement, Gregory Emeka Kwentua

LSU Master's Theses

This study examines trade creation and trade diversion effects in the EUSAFTA using the standard gravity model of bilateral trade flows. The estimation of the gravity equation was carried out using the OLS analysis. In order to ascertain the overall trade creation and trade diversion effects explanatory variables such as GDP, distance and dummy variables were incorporated into the estimation equation to explain bilateral trade flows and exports respectively. The main focus was on the estimation of trade creation and trade diversion effects, resulting from participation in selected regional and preferential trade agreements like EU, COMESA, SACU and EUSAFTA. Additionally, …

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Application Of Ozonated Water Technology For Improving Quality And Safety Of Peeled Shrimp Meat, Amrish Suresh Chawla Jan 2006

Application Of Ozonated Water Technology For Improving Quality And Safety Of Peeled Shrimp Meat, Amrish Suresh Chawla

LSU Master's Theses

Ozone is an effective sanitizing agent against a broad spectrum of pathogenic and spoilage organisms. Optimization of treatment applications of ozonated water is needed for increased use in the food industry. An experimental apparatus and process has been developed to digitally measure ozone concentrations in processing water at the point of product application. Two application methods were evaluated. Ozone concentrations were measured rapidly at the point of product application. Shrimp samples were either sprayed or soaked for 20, 40 or 60 seconds with similar volumes of water with dissolved ozone levels of 1, 2, or 3 ppm. Microbial destruction using …

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Cost-Efficacy Of Wetland Preservation And Restoration In Coastal Louisiana, Christiane Aust Jan 2006

Cost-Efficacy Of Wetland Preservation And Restoration In Coastal Louisiana, Christiane Aust

LSU Master's Theses

Louisiana faces a tremendous crisis of coastal wetland loss, where an estimated 1,900 square miles of coastal land has been lost in the past century. The Coastal Wetlands Planning, Protection, and Restoration Act (CWPPRA) has been the largest single source of restoration funding, providing approximately $560 million for more than 155 restoration projects since 1991. Recently reauthorized by Congress to the year 2019, current spending under CWPPRA constitutes less than 10% of the funding required to sustain coastal Louisiana as it exists today. A descriptive analysis of selected projects (n=109) was conducted to analyze the economic efficiency associated with various …

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Quality Characterization Of Cholesterol-Free Mayonnaise-Type Spreads Containing Rice Bran Oil, Karen Melissa Garcia Jan 2006

Quality Characterization Of Cholesterol-Free Mayonnaise-Type Spreads Containing Rice Bran Oil, Karen Melissa Garcia

LSU Master's Theses

Traditional mayonnaise is manufactured with soybean oil (SBO) and egg-yolk containing ingredients. About 1/4 of American consumers have some forms of cardiovascular disease, accounting for >40% of all deaths in USA. Rice bran oil (RBO), a healthy lipid source, has cholesterol-lowering effects, and could be used to replace SBO in mayonnaise preparation. To take advantage of the health benefits associated with RBO, food products containing RBO need to be developed and characterized. Cholesterol-free mayonnaise-type spreads containing RBO were developed using a constrained mixture design. Two studies were performed to determine sensory attributes driving acceptance and purchase intent and to optimize …

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Estradiol Interactions With Dopamine Antagonists In Mares: Prolactin Secretion And Reproductive Traits, Kristian Kandis Kelley Jan 2006

Estradiol Interactions With Dopamine Antagonists In Mares: Prolactin Secretion And Reproductive Traits, Kristian Kandis Kelley

LSU Master's Theses

Two experiments studied the effects of pretreatment with estradiol benzoate before treatment with a dopamine antagonist on prolactin secretion and reproductive traits in mares during 1) the seasonal anovulatory period and 2) the normal breeding season. Experiment 1 was performed in winter with 17 mares selected for low follicular activity. Nine mares received estradiol benzoate injections every other day for a total of 10 injections; 8 mares received similar injections of vehicle. Ten days after onset of injections, all mares were placed on a daily injections of sulpiride (250 mg) for 45 d or until ovulation. Plasma prolactin concentrations were …

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Analysis Of Trade In The Western Hemisphere Utilizing A Gravity Model Framework, Brian Matthew Hilbun Jan 2006

Analysis Of Trade In The Western Hemisphere Utilizing A Gravity Model Framework, Brian Matthew Hilbun

LSU Master's Theses

With the recent proliferation of Regional Trade Agreements (RTAs) the tendency world-wide has been seemingly toward trade liberalization. This thesis is primarily concerned with the impacts RTAs have had in the Western Hemisphere regarding agricultural trade flows. Utilizing the framework of the Gravity Model, agricultural trade flows for 24 Western Hemisphere Nations were examined. In the course of the study it was expected that if RTAs were to have an effect it would be a positive Trade Creation Effect and a negative Trade Diversion Effect with positive effects for GDP of importer/exporter and population size of importer/exporter and a negative …

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Econometric Essays On Specification And Estimation Of Demand Systems, Anil Kumar Sulgham Jan 2006

Econometric Essays On Specification And Estimation Of Demand Systems, Anil Kumar Sulgham

LSU Doctoral Dissertations

This dissertation focuses on two research themes related to econometric estimation of linear almost ideal demand systems (LAIDS) for U.S. meats. The first theme addresses whether nonstationarity (unit-roots and cointegration) contributes to a dynamic specification of LAIDS models. The results of the effect of nonstationarity are reported in two case studies. The second theme explores the relationship between age and household size with budget shares to specify semiparametric LAIDS model. The results are reported in a third case study that compares parametric and semiparametric models estimates of price and expenditure elasticities. The first case study conducts a comparative analysis of …

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A Novel Yogurt Product With Lactobacillus Acidophilus, Senthil Ganesh Jan 2006

A Novel Yogurt Product With Lactobacillus Acidophilus, Senthil Ganesh

LSU Master's Theses

Health benefits of Lactobacillus acidophilus include providing immune support for infections or cancer, providing a healthy replacement of good bacteria in the intestinal tract following antibiotic therapy, reducing occurrence of diarrhea in humans, aiding in lowering cholesterol and improving the symptoms of lactose intolerance. Consumer demand exists for new dairy products. There are several types of yogurt like stir curd, set curd and drinkable yogurt and they all need to be refrigerated. Moreover there are very few dairy products that can be stored at room temperature and not many dairy foods are finger foods. A novel yogurt product like a …

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Color And Tenderness In Chilled Or Frozen Pork Loin Chops After Antioxident Dipping And Modified Atmosphere Packaging, Dennis Michael Price Jan 2006

Color And Tenderness In Chilled Or Frozen Pork Loin Chops After Antioxident Dipping And Modified Atmosphere Packaging, Dennis Michael Price

LSU Master's Theses

The objective of this research was to evaluate color and tenderness in chilled or frozen pork loin chops after antioxidant dipping and modified atmosphere packaging. Loin chops were dipped in 0.3 M calcium chloride, 2.0 % sodium ascorbate, 0.2 M calcium ascorbate, or 0.3 M calcium ascorbate. Non-dipped chops served as controls. Chops were packaged in high oxygen (80% O2 / 20% CO2) or no oxygen (80% N2 / 20% CO2) and stored chilled (4° C) for 7 days or frozen (-18° C) for 21 days. After storage, chops were displayed under continuous fluorescent lighting for 3 or 6 days. …

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A Comparative Study Of Household Demand For Meats By U.S. Hispanics, Carlos Ignacio Garcia Jan 2006

A Comparative Study Of Household Demand For Meats By U.S. Hispanics, Carlos Ignacio Garcia

LSU Master's Theses

The general objective of this research project was to study the consumption behavior of U.S. Hispanics for meat products. A comprehensive review of literature on the studies of U.S. Hispanic consumers was performed by means of a systematic survey; different sources of information useful in studying Hispanic consumers were documented. The simultaneous increase in population and income of Hispanics in the United States is attractive to food companies, and makes more relevant the study of their consumer behavior patterns for discovering future market opportunities. Censored incomplete demand systems of the LinQuad form were used for recognizing the consumption patterns by …

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Cryopreservation And Intracytoplasmic Sperm Injection With Bovine Epididymal Spermatozoa, Carlos Andres Guerrero Jan 2006

Cryopreservation And Intracytoplasmic Sperm Injection With Bovine Epididymal Spermatozoa, Carlos Andres Guerrero

LSU Doctoral Dissertations

Recently, interest in the preservation of epididymal sperm as a potential source of valuable genes for genome resource banks has escalated. The development of a successful protocol to recover and cryopreserve sperm harvested from the epididymides would salvage germplasm from genetically valuable males that are injured and can no longer mate or have unexpectedly died and can be used as a model for the preservation of male gametes from endangered species. In a series of experiments, epididymal sperm was successfully harvested, cryopreserved and used for intracytoplasmic sperm injection. In Experiment I, ethylene glycol was found to cause significantly (P<0.05) less osmotic damage to bovine sperm during a one step addition and/or removal at 4°C as compared with glycerol in all concentrations evaluated. Furthermore, prolonged exposure (5 days at 4°C) of ethylene glycol was found to be less toxic than glycerol to sperm. In Experiment II, it was demonstrated that glycerol was more effective than ethylene glycol in providing protection against freezing injury during the cryopreservation process in the concentrations evaluated. In Experiment III, it was demonstrated that epididymal sperm retrieval using seminal plasma is beneficial to enhance sperm overall and progressive motility characteristics and to protect it from morphological abnormalities derived from the freezing process. In Experiment IV, a one step dilution process for removal of glycerol from cryopreserved epididymal sperm was found to significantly affect plasma membrane integrity and mitochondrial function of sperm previously exposed to seminal plasma. However, seminal plasma exposure did not have any significant detrimental effect on acrosome integrity. Furthermore, it was demonstrated that the longevity and survivability in vitro during a 4-hour incubation period at 37°C of post-thaw epididymal sperm exposed to seminal plasma prior to cryopreservation was not compromised when compared with the control extended sperm. In Experiment V, we have demonstrated that fertilization, blastocyst and fetal development could be achieved with cryopreserved bovine epididymal sperm by intracytoplasmic sperm injection (ICSI). To our knowledge, this is the first report in the United States and second in the world to use bovine epididymal sperm for ICSI. We achieved far markedly improved blastocyst rates over those results recently reported in the first study originating in Japan.

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Evaluation On Antioxidant Activities Of The Soybean Oils And Gums, Xianglong Yuan Jan 2006

Evaluation On Antioxidant Activities Of The Soybean Oils And Gums, Xianglong Yuan

LSU Master's Theses

In this study crude soy oil was extracted from the soy flour by hexane solvent. The crude oil was refined using a refining procedure similar to the one in edible oil industries, which included degumming, neutralizing, and bleaching. As the result, the eight groups of the oils and the gums were obtained. The compositions of fatty acids and tocopherols in the eight groups of samples were analyzed using GC-FID and HPLC, respectively. The antioxidant activities of the samples were analyzed by two chemical models, cholesterol and DHA. The results showed that ã- and ä-tocopherols may not be the main antioxidants …

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College Student's Motivation For Physical Activity, Lori Lynn Delong Jan 2006

College Student's Motivation For Physical Activity, Lori Lynn Delong

LSU Doctoral Dissertations

The purpose of this study was to examine college students' motivations to be physically active by merging the perspectives of self-determination theory and the transtheoretical model. The secondary purpose was to examine the effects of a required physical activity course on college students' levels of physical activity. The premise is that both the theory and model can be used to help predict physical activity outcomes. Participants were 277 male and female students at a small private college. Motivation, self-determination, stage of change, self-efficacy, decisional balance, and leisure time activity levels were assessed using an online survey. Results revealed that activity …

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Examination Of The Constructs Of The Transtheoretical Model In Patients With Heart Failure: A Focus On Physical Activity Readiness, Tracie Rena Parish Jan 2006

Examination Of The Constructs Of The Transtheoretical Model In Patients With Heart Failure: A Focus On Physical Activity Readiness, Tracie Rena Parish

LSU Doctoral Dissertations

The goal of this research was to gain greater understanding about the management of heart failure patients. A particular focus was to evaluate exercise tolerance and behavior. The major findings of the first study included: (1) evidence that few heart failure patients receive adequate information regarding physical activity; (2) performance on a six-minute walk test were ~42% lower, and SF-36 scores were also lower in heart failure patients compared to controls; (3) stability in hemodynamic measures and distance walked on the 6-minute walk test were adequate, and (4) home exercise resulted in 19% improvement in maximum walking distance and 30% …

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Self-Determination In Physical Education: Designing Class Environments To Promote Active Lifestyles, Charity Leigh Bryan Jan 2006

Self-Determination In Physical Education: Designing Class Environments To Promote Active Lifestyles, Charity Leigh Bryan

LSU Doctoral Dissertations

The purpose of this study was to investigate the relationships between self-determination, perceptions of the motivational climate, attitude, perceived ability, engagement in physical activity, and health-related fitness indicators. Two structural models related to engagement/intention to engage in physical activity and health-related fitness were tested. The premise of both models is that perceived competence predicts the outcome variables (engagement or health-related fitness), with self-determination, attitude, and motivational climate predicting perceived competence. Participants were 827 sixth, seventh, and eighth graders. Motivation, perceptions of the climate, attitude, perceived competence, and self-reported physical activity levels were assessed using surveys. Pedometers were used to record …

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Measuring The Degree Of Market Power In The Export Demand For Soybean Complex, Dwi Susanto Jan 2006

Measuring The Degree Of Market Power In The Export Demand For Soybean Complex, Dwi Susanto

LSU Doctoral Dissertations

Previous studies on market power hypothesis strictly assumed that the data used in the analysis were a stationary process. This assumption has been argued that not all time series exhibit a stationary process such that conventional asymptotic theory cannot be applied. This study adopts the “New Empirical Industrial Organization” (NEIO) approach developed by Bresnahan (1982) and Lau (1982) to measure the degree of market power in the export market for soybean complex. The non-stationary properties of the data were accommodated by formulating the model in an error correction framework (ECM) developed by Bårdsen (1989) and applied by Steen and Salvanes …

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Validity Of The Yale Physical Activity Survey For Older Adults, Angela Nickole Solomito Pugh Jan 2006

Validity Of The Yale Physical Activity Survey For Older Adults, Angela Nickole Solomito Pugh

LSU Master's Theses

The purpose of this study is to determine the validity of the Yale Physical Activity Survey (YPAS) in a population of oldest-old adults residing in Southeastern Louisiana. Methods: Participants were older adults (n=273) in two distinct age groups; 60-81 years of age (YOUNG-OLD) AND 29-103 years of age (OLDEST-OLD). YPAS estimates of physical activity will be compared to physical function as measured by the continuous scale physical function performance test. Results: The OLDEST-OLD demonstrated lower physical function scores and reported less physical activity (and more time sitting) in comparison to the YOUNG-OLD. The correlation between Total Time Summary Index and …

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Exchange Rate Effects On Bilateral Agricultural Trade Analysis On The Dr-Cafta, Jennifer Eileen Bocock Jan 2006

Exchange Rate Effects On Bilateral Agricultural Trade Analysis On The Dr-Cafta, Jennifer Eileen Bocock

LSU Master's Theses

Economic theory states that the exchange rates influences movements in agricultural prices and are in an important determinant of the agricultural sector trade. This paper reviewed the theory and economic models under which exchange rate fluctuations create shifts in the excess supply and demand between countries in the international market along with a history of relations between the United States and the DR-CAFTA region. The theory is econometrically tested through the OLS method to examine to what extent the real exchange rates between the United States and less developed countries were constant with accepted theory. The agricultural trade movements were …

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