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Comparing Organic And Conventional Yield Responses To Climate Variations, Joost Wilken Meyer Dec 2021

Comparing Organic And Conventional Yield Responses To Climate Variations, Joost Wilken Meyer

Graduate Theses and Dissertations

This thesis compares the responses of organic yields and conventional yields towards climate variations. To achieve this objective, weather variables such as growing season weather conditions (average temperature, precipitation, cloud cover, relative humidity, drought index), weather anomalies, the occurrence of severe or extreme droughts and excessive rainfalls, are combined with 23 data sets gathered from previous studies that compare organic and conventional yields from the same location and time periods. To narrow the scope, the thesis focuses on soybean, maize, and wheat production in Europe and North America. Study-level fixed-effects models are used to control for any time-invariant factors such …


Investigation Of Factors Influencing Recombination Versus Disproportionation Of Complex Radicals Formed By C-N Homolysis Of Breslow Type Intermediates And Related Compounds, Taylor Burnett Jul 2021

Investigation Of Factors Influencing Recombination Versus Disproportionation Of Complex Radicals Formed By C-N Homolysis Of Breslow Type Intermediates And Related Compounds, Taylor Burnett

Graduate Theses and Dissertations

Electron rich enamines are capable of C-N bond homolysis and subsequent recombination and/or disproportionation. It is unclear what causes these radicals to undergo recombination or disproportionation. Density Functional Theory (DFT) calculations do not provide a transition state for the recombination and disproportionation processes and therefore they cannot be used to predict the favorable reaction. Breslow intermediates formed by deprotonation of thiazolium salts and reaction with aromatic aldehydes are examples of electron rich enamines. These breslow intermediates can undergo C-N bond homolysis to form a radical pair the either recombine or disproportionate. Upon investigation of the factors influencing recombination and disproportionation, …


Poultry Labeling: Knowledge, Perceptions, And Preferences Among Adolescents, Eleni L. Parsons Aug 2019

Poultry Labeling: Knowledge, Perceptions, And Preferences Among Adolescents, Eleni L. Parsons

Graduate Theses and Dissertations

The purpose of this study was to determine the knowledge, perceptions, and preferences of adolescents in regard to the labeling of poultry products. The theory of planned behavior (TPB) and Elaboration Likelihood Model (ELM) were used to display the relationship of perceptions, attitude, and behavior intentions. Quantitative data was collected in a descriptive research design. The population included youth, aged 14 – 18 years, involved in the Arkansas 4-H State O’Rama competition (N = 400). The sample (n = 80) ensured a 90% confidence interval of the population. Data was collected by administering paper surveys that addressed four product labels …


Consumers’ Willingness To Pay For Hydroponic Lettuce, Daniel Gilmour May 2018

Consumers’ Willingness To Pay For Hydroponic Lettuce, Daniel Gilmour

Graduate Theses and Dissertations

With continued advances in hydroponic plant production technology, an increasing number of farms have begun using hydroponic techniques to grow leaf lettuce and other food crops in a controlled environment. Recent controversy about the ongoing inclusion of hydroponics in the USDA organic program has highlighted uncertainty about marketing for hydroponic crops. In November 2017, the National Organic Standards Board voted not to recommend that hydroponic farms be banned from applying for organic certification. Since then, continued controversy has led a group of organic producers to start an additional independent certification program that would exclude hydroponic crops. While hydroponic production may …


Seasonality And Management Of Spotted Wing Drosophila On Berry Crops And Wild Hosts In Arkansas, Lizabeth Rubi Herrera Dec 2017

Seasonality And Management Of Spotted Wing Drosophila On Berry Crops And Wild Hosts In Arkansas, Lizabeth Rubi Herrera

Graduate Theses and Dissertations

Spotted wing drosophila (SWD), Drosophila suzukii (Matsumura) is a serious invasive pest of small fruit production in North and South America and Europe since 2008. The primary control method is to apply insecticides every 5-7 days. Therefore, it is necessary to develop control tactics that are less chemical dependent to enhance an integrated approach for SWD management. The objectives of this study were to monitor SWD populations in different crop systems and adjacent landscape habitats; identify wild hosts of SWD; evaluate the effectiveness of insect exclusion netting in tunnels to prevent blackberry and blueberry infestations, and compare effects of netted …


Studies Toward The Total Synthesis Of Antascomicin B, David Ross Clay Aug 2012

Studies Toward The Total Synthesis Of Antascomicin B, David Ross Clay

Graduate Theses and Dissertations

The following dissertation describes synthetic efforts toward the synthesis of the C21-C34 fragment of antascomicin B. Our initial enzymatic approach is detailed as well as an asymmetric transfer hydrogenation (ATH) strategy that will be used in the eventual total synthesis of the molecule. Several investigations into anomalies observed during (ATH) reactions are also discussed.


Purchaser Preferences On Carbon Labels: Conventional Vs. Organic Milk, Mustafa Ozkan Aug 2011

Purchaser Preferences On Carbon Labels: Conventional Vs. Organic Milk, Mustafa Ozkan

Graduate Theses and Dissertations

Over the past several years, there has been growing attention concerning global warming/climate change and how humans are contributors. It is known that agricultural production is a main contributor of greenhouse gas emissions and the livestock sector is particularly significant because it is quoted as having between 3 and 18% of greenhouse gas emissions measured in CO2 equivalent pending different assumptions. Due to this, carbon footprint labeling has been described as a potential tool to inform consumers about greenhouse gases associated with food products and assist them with the necessary information to purchase products that help reduce greenhouse gas emissions. …