Life Sciences Commons^™

Nitrate Removal From Subsurface Drainage By Denitrifying Bioreactor, Erin Chichlowski

Open Access Theses

Denitrifying bioreactors are an edge-of-field best management practice that reduce nitrate in runoff and subsurface drainage waters with minimum surface foot print and management requirements. The objectives of this study included evaluating a 173 m3 wood chip bioreactor for nitrate reduction and removal rates, the effects on phosphorus, and the impacts of the bioreactor's physical characteristics on effective nitrate reduction During periods of flow, weekly water samples were collected for lab analysis of nitrate+nitrite (nitrate-N), total nitrogen (TN), soluble reactive phosphorus (SRP), and total phosphorus (TP) and measurements were made of water temperature, dissolved oxygen, pH, oxidation reduction potential, temperature, …

Profit-Maximizing Responses To Climate Change In Commodity Agriculture: Does Adaptation Matter?, Sajeev Erangu Purath Mohankumar

Open Access Theses

Accumulation of greenhouse gases in the atmosphere has led to rising temperatures, and is expected to lead to a change in climate. Crop yields are vulnerable to these changes. Adaptation is expected to be key to combating climate change impacts, but the effectiveness of adaptation strategies is not well understood. Hence, there is a need to assess the impacts of climate change on agriculture and devise profitable adaptation strategies to combat its effects. This study uses historical and three projected climate data sets to simulate yields using the crop model Daycent, empirical relationships between weather and agronomic variables that influence …

Producer Perceptions Of Their Use Of Time And Various Areas Of Risk In Their Business, Kendra Marie Hedge

Open Access Theses

Agribusinesses rely on producers choosing their products and services for the success of their business. Agribusinesses can use information regarding how producers rate the importance of certain areas of risk and what takes most of the producers' time to offer specific services to different segments of producers to better meet their needs. An ordered logit model and a multinomial logit model are used to determine factors significant to producers' use of time and importance of various areas of risk. The producers are then segmented into groups based on their risk perceptions. From this research, agribusinesses can recognize that different types …

Quality And Safety Attributes Of Sun-Dried Raisins From Afghanistan, Stacy A. Mccoy

Open Access Theses

Raisins are an important export commodity for Afghanistan, however, Afghan packers are challenged to export to markets seeking high quality products due to limited knowledge regarding their quality and safety. To evaluate this, Afghan raisin samples from pre-, semi-, and post-processed raisins were obtained from a raisin packer in Kabul, Afghanistan. The raisins were analyzed and compared to U.S. standards for processed raisins. The samples tested did not meet U.S. import standards for embedded sand, but the process used to clean the raisins is suitable to maintain food safety standards.

Previous Afghan raisin shipments have been rejected from the U.S. …

Competition Between Private Labels And National Brands: Empirical Evidence From Homescan Data On Fluid Milk Markets, Jeffrey S. Young

Open Access Theses

The purpose of this study is to empirically examine the nature of the pricing relationship between private labels (or "store brands") and national brands. To accomplish this, we control for the exogenous variation in the farm price of a commodity that serves as the main agricultural input common to both private labels and national brands (any shocks to this farm price will pass through to both retail prices - private label and retail). The product of choice is fluid milk, as the farm price of milk comprises a large share of producer and retailer cost.

Two examples of underlying theories …

Market Power Estimation In The Chilean Cattle Market, Rodirgo A. Vasquez Panizza

Open Access Theses

The cattle market in Chile is constituted by cattle slaughtering firms and farmers; the industry demands cattle but also demands beef imports. Based in antecedents of market concentration in this sector, I make a system of equations model based on the NEIO approach to determine market power for the period April 1993 - December 2008. The results show that there is no market power in the aggregated market as well as in the disaggregated market by sex and age type, which is explained because the special features of this market in Chile.

Adipogenic And Myogenic Stem Cells In Brown Fat: A Study Of Progenitors And Regenerative Capacity, Xin Yang

Open Access Theses

Brown adipose tissue (BAT) utilizes stored lipids to generate heat, therefore reducing body fat content and favoring a leaner body composition. Recent identification of metabolically active BAT in adult humans has sparked broad interests in understanding the developmental origin and postnatal homeostasis of BAT. However, the stem cell population that gives rise to BAT during development and maintains BAT mass at postnatal stage has not been characterized. In addition, whether adult BAT has the capacity to regenerate after injury or to proliferate in response to cold is flargely unknown. Furthermore, although BAT and skeletal muscle are known to share a …

Uncertainty, Irreversibility, And Investment In Secondgeneration Biofuels, Tanner Joseph Mccarty

Open Access Theses

The present study formalizes and quantifies the importance of uncertainty for investment in a corn-stover based cellulosic biofuel plant. Using a real options model we recover prices of gasoline that would trigger entry into the market and calculate the portion of that entry trigger price required to cover cost and the portion that corresponds to risk premium. We then discuss the effect of managerial flexibility on the entry risk premium and the prices of gasoline that would trigger mothballing, reactivation, and exit. Results show that the risk premium required by plants to enter the second-generation biofuel market is likely to …

Management Of Root Knot Nematode (Meloidogyne Incognita ) In Indiana Soybeans, David Edgardo Perla Martinez

Open Access Theses

The aim of this project was to evaluate different strategies for management of Root Knot Nematode (RKN) on soybean and tomato in Indiana. Seed treatments were evaluated under field and greenhouse conditions, but no effect on RKN populations was observed. Soybean lines evaluated for resistance to RKN under greenhouse conditions showed that six lines may be resistant to RKN. Four different commercial mustard cover crops were evaluated for their bio-fumigant impact on RKN populations in the production of tomato. Euruca sativa, Cv. Nemat was a poor host of RKN. A positive impact on the vigor of the tomato plants followed …

Differences In Carbon Dioxide Evolution From Samples Of Shelled Corn Subjected To Various Storage Treatments, Cininta Alp Pertiwi

Open Access Theses

Shelled corn was collected from two sources - commercial grain elevators and corn harvested from Purdue University farms and then frozen until tested. Using a carbon dioxide (CO₂) test kit manufactured by Woods End Laboratories, CO₂ evolution measurements were conducted on shelled corn from both sources, after the samples were re-wetted to approximately 21% moisture content, placed in a 473 ml glass jar, and incubated at room temperature for 72 hours. The CO₂ test kit uses a gel that changes color in response to a change in the level of CO₂ in the surrounding air. …

The Effects Of Radar On Avian Behavior: Implications For Wildlife Management At Airports, Eleanor R. Sheridan

Open Access Theses

Airports are areas with a high availability of resources for wildlife to forage, breed, and roost. Airports also have different types of radars to assist with air traffic control as well as tracking of wildlife that could become a risk for aircraft. The effect of radar electromagnetic radiation on wildlife behavior is not well understood. The goal of this study was to determine if bird behavior is affected by radar in two contexts: static radar (e.g., surveillance radar) and approaching radar (e.g., aircraft weather radar). We used brown-headed cowbirds as a model species. In the static radar context, we performed …

Abcb11 Functions With B1 And B19 To Regulate Rootward Auxin Transport, Jesica Elyse Reemmer

Open Access Theses

Auxin transport is essential for the architecture and development of erect plants. In a network of transporters directing auxin flows, ATP-Binding Cassette (ABC) transporters are a ubiquitous family of proteins that actively transport important substrates, including auxins, across the plasma membrane. ABCB1 and ABCB19 have been shown to account for the majority of rootward auxin transport, but residual fluxes to the root tip in Arabidopsis b1b19 double mutants implies the involvement of at least one additional auxin transporter in this process. Of specific interest, the severe dwarfism seen in abcb1abcb19 is strikingly reminiscent of that seen in mutants defective in …

Ems Induced Mutations In Dhurrin Metabolism And Their Impacts On Sorghum Growth And Development, Jenae Lavon Skelton

Open Access Theses

Sorghum is the fifth most important grain crop in the world. It is a staple food, feed, and silage crop in many developing countries in the semi-arid tropics. One factor that can impact sorghum forage quality is dhurrin content. Dhurrin is a cyanogenic glucoside naturally produced in the plant. When tissues containing dhurrin are crushed, hydrogen cyanide (HCN) is released during dhurrin decomposition. HCN is toxic to humans and livestock. While there is natural genetic diversity for the concentration of dhurrin within sorghum lines, there have been no naturally occurring dhurrin-free genotypes identified to date. ^ We have identified ethyl …

An Analysis Of Marketing Margins In The Us Beef Industry, John A. Tobin

Open Access Theses

The US beef industry has undergone significant structural changes in the last 30 years at the wholesale and retail levels. Meanwhile producer prices have failed to keep pace with increases in the price of beef received by wholesalers and retailers, resulting in concerns being raised about market power being exercised in the beef industry by stakeholders. ^ This study uses marketing margins to determine what factors affect margins, test for differences among different procurement methods of purchasing cattle, and test for differences among different cuts of beef. This paper extends previous research providing more detail regarding the factors that may …

Effectiveness Of Field Days On Promoting The Adoption Of Recommended Improved Maize Varieties By Small Holder Farmers In Lilongwe District, Malawi, Yakosa Charity Zgawa Tegha

Open Access Theses

The study described the contribution of field days to promoting the adoption of improved maize varieties by small holder farmers of Chitsime and Mpingu Extension Planning Areas (EPAs) in Lilongwe District, Malawi. Sixty farmers from two EPAs where the field days had been conducted were randomly selected. Data were collected through personal interviews because literacy was a problem among farmers. The results of the study showed that 31 (51.7%) of the farmers interviewed were female. Use of other methods such as radio, mobile van, leaflets, posters, village meetings and messages sent to farmers’ cellphones helped to popularize the improved maize …

Characterization Of Water-Solid Interactions In Crystalline Ingredients And Development Of Deliquescence Measurement Recommendations, Matthew C. Allan

Open Access Theses

There are five major mechanisms of water-solid interactions. The primary focus of this thesis was on two of these: deliquescence and hydrate formation. Many crystalline food ingredients are deliquescent compounds (e.g., NaCl, sucrose, and ascorbic acid) and some are both deliquescent and hydrate formers (e.g., glucose, thiamine HCl, citric acid). Deliquescence is the first order phase transformation of a crystalline solid to a solution above a critical relative humidity (RH) known as the deliquescence point (RH0). A crystalline hydrate is a pseudo-polymorph in which water is incorporated into the crystal structure, altering the molecular formula and the physical properties.^ To …

Evolution Of Food Quality Demand In The Food Service Industry In China: The Case Of Duck, Rachel Alison Carnegie

Open Access Theses

Booming economic growth and rising consumer incomes have impacted food preferences and purchasing behavior in China. At the same time, several internationally publicized food safety incidents, particularly in the animal husbandry sector, have heightened awareness of and concern for food safety and quality in meat and dairy. Rising quality demand and safety concerns have been studied at length in the food retail sector, but also appear to be important in the food service industry. This research uses data from a survey of duck restaurant managers and consumers in Beijing, Shanghai, Chengdu, and Guangzhou to determine preferences and willingness to pay …

Price Impacts Of Increased Peruvian Table Grape Supply, Jacob W. Iest

Open Access Theses

In the last decade, Peru has begun to structure its economy and complete infrastructure projects to promote agricultural export growth. Bolstered by the signing of the Peru Trade Promotion Agreement (PTPA) with the U.S., table grape production has increased significantly since 2006. Peru has a climatic advantage for a quality harvest from November to March, which overlaps the end of the U.S. growing season. With this supply increase expected to continue, U.S. producers and marketers question the effect Peru will have on "late-season" table grape prices in North America.

This thesis is a study of the effects of an increase …

Two Essays On Large Agricultural Producer Buying Behaviors, Jacqueline K. Holland

Open Access Theses

The trend of consolidation of large farms into high volume operations has continued over the past 30 years. Large farm management is a juggling act of a variety of biological processes, financial management, technology adaptation, and human resource development activities. This research looks to provide insights into the underlying management psychology of those large farmers to serve not only as a benchmark for other producers, but to provide customer information to agribusinesses so these firms can strengthen their relationships with their large farmer customers. The first part of this analysis will use Best-Worst modeling to examine five predetermined success factors …

Physical And Chemical Attributes Of A Genetically Modified Fruit Pectin, Carl Patrick Littrell

Open Access Theses

Pectin is an important polymer used in the food industry as a thickening and gelling agent. Though pectin is ubiquitous in plants, chemical and structural differences among pectin molecules prevent most from being viable for industrial use. Enzymes found naturally in fruit cell walls during the ripening process impair many desirable attributes of fruit pectins, rendering them unsuitable for industrial applications. Pectin methylesterase (PME) is one such enzyme whose expression can be altered during ripening through the use of recombinant genetic engineering. Reduction in levels of PME results in increased degree of methylation and molecular size of pectin, greatly increasing …

Field To Flight: A Techno-Economic Analysis Of Stover To Aviation Biofuels Supply Chain, Amanda C. Bittner

Open Access Theses

Greenhouse gas emissions have been a growing concern. The transportation sector contributes to one-third of GHG emissions in the United States from fossil fuel burning. The Renewable Fuel Standard set a requirement for 16 billion gallons (ethanol equivalent) of cellulosic biofuels to be used in the market. Aviation biofuels can help to meet both of these problems as well as improve U.S. energy security.

Investment in the biofuel industry carries a lot of risk. The biofuel industry is run by the private sector, but can be incentivized by government. Cellulosic biofuels carry even more risk than first generation biofuels, because …

Changes In Tundra Plant And Soil Organic Geochemical Composition In Response To Long-Term Increased Winter Precipitation In N. Alaska, Olivia Miller

Open Access Theses

Tundra ecosystem soils store half of the global soil organic carbon (SOC) pool and have the potential to release large amounts of greenhouse gases, primarily CH₄ and CO₂. As climates warm and permafrost thaws, the emissions of these gases as organic matter decomposition rates increase may become increasingly important to the chemistry of the atmosphere. Increases in precipitation that accompany warming, may shift tundra vegetative composition from moss/graminoid- to shrub-dominated systems. These vegetation shifts may result in important feedback effects as altered plant and litter chemistry may affect SOC storage in soils. Questions investigated include: 1) How …

Supplemental, End-Of-Day, And Sole-Source Lighting From Light-Emitting Diodes Influences Growth, Morphology, And Quality Of Annual Bedding Plant Seedlings, Wesley C. Randall

Open Access Theses

Annual bedding plants make up the largest sector of the U.S. floriculture industry. High-quality annual bedding plant seedlings are compact, fully rooted transplants with a large stem caliper and high root dry mass. However, production usually occurs in late winter or early spring when the daily light integral (DLI) is as low as 1 to 5 mol·m^–2·d ^–1 in northern latitudes. Therefore, supplemental lighting (SL) is often used to increase the DLI to a recommended 10 to 12 mol·m ^–2·d^–1. The objectives of this study were to: 1) quantify the effects of SL from three …

Fact Or Fiction: Random Mating In Field Populations Of Western Corn Rootworm (Diabrotica Virgifera Virgifera Leconte) Emerging On Bt And Refuge Corn Plants, Steven Joel Smith

Open Access Theses

The western corn rootworm, or WCR, (Diabrotica virgifera virgifera LeConte) is the most significant pest of field corn (Zea mays) in the United States, and has recently expanded its range into Europe. Since 2004, hybrid corn containing Bt toxins targeting the corn rootworm complex have been heavily adopted and are now the primary control measure for this pest in North American corn production. ^ The evolution of resistance is an ongoing concern, and to ensure Bt products will retain their usefulness, insect resistance management (IRM) tactics using various refuge structures have been adopted. One of the key …

The Effectiveness Of Virtual And On-Site Dairy Farm Field Trips To Increase Student Knowledge In Science, Social Studies, And Health And Wellness Standards, Abby M. Sweet

Open Access Theses

The integration of agriculture into the curriculum can be difficult for educators when materials and resources are not aligned with state learning standards. However, online educational tools, such as virtual field trips that are aligned with state learning standards, can allow for educators to bring the experience of a field trip to the classroom, as well as complement curriculum in the classroom. Virtual field trips also assist with removing many barriers that prevent educators from taking their students on an on-site field trip. ^ This study sought to describe the effectiveness of a virtual and on-site dairy farm field trip …

Furniture Design And Product Development Principles Considering End-Of-Life Options And Design For Environment Strategies, Mesut Uysal

Open Access Theses

During last decades, environmental issues come into prominence and some governmental or organizational regulations are legislated to reduce environmental impacts of products within their life cycle. At the same time, costumers consider not only price, quality, branding, uniqueness, availability but also environmental impact, safety, and overall sustainability of products they select. Therefore, producers are addressing environmental impact of products they are producing and also making changes to their production process. This project is addressing End-of-Life (EoL) Options of wooden furniture. ^ Although wood is eco-friendly and natural material, its technological process, use and disposal might have ecological problem and challenge. …

Crystallization Inhibitor Properties Of Polymers And Effects On The Chemical And Physical Stability Of L-Ascorbic Acid During Preparation And Storage, Belinda Christina

Open Access Theses

Crystalline L-ascorbic acid (VitC) is an essential nutrient solid that is widely used in food applications for fortification, antioxidant, and label claim purposes. VitC is known as one of the most unstable vitamins, and its content must be declared on food labels. Interest has been increasing in creating amorphous solid structures for improving the solubility and/or dissolution rates of crystalline compounds. One of the most promising methods studied to prevent the crystallization of an amorphous solid is the use of polymers in dispersions, although the specific polymer properties that lead to the best physical stability for a particular type of …

Shrinkage Prediction During Pasta Dehydration, Gina Michelle Bressani

Open Access Theses

Shrinkage models from different fields of study were reviewed. Pasta was used as a model to further develop the hypothesis of predicting shrinkage in terms of the rate of relaxation and the rate of moisture loss. An extended literature review of pasta properties, such as isotherms, diffusivity, glass transition, rheological properties, and shrinkage was conducted. Isotherm and glass transition models were developed from the literature data acquired. Creep was tested with a 25 mm-diameter flat plate at 20 to 40°C at varying moisture content. Viscoelastic properties for the Burgers model for creep were determined, where higher moisture content samples resulted …

Comparative Analysis Of The True Profitability Between Genetic Multiplication And Terminal Pig Production, Nicholas H. Dekryger

Open Access Theses

In the agriculture industry today, farmers and agribusinesses must continually deal numerous uncertainties and consequential financials burdens. Market prices, both in grains and livestock, have varied quiet substantially over the past five years creating difficulties in risk management and sales. As a means to combat the uncertainty facing the agriculture industry, solid business strategies must be implemented in order to absorb any external impact. Using part of the strategy outlined in The Breakthrough Imperative, an analysis was done on the strategy used by Belstra Group Farms with the goal to determine the true profitability of gilt multiplication.

A model was …

Understanding Childhood Malnutrition In Nepal: A Hierarchical Regression Approach, Timothy M. Smith

Open Access Theses

This thesis investigates the determinants of childhood malnutrition in Nepal, with a particular emphasis on the importance of district characteristics relative to household and child characteristics. Using a new dataset constructed from child and household data from the 2006 and 2011 Nepal Demographic and Health Survey (DHS) and community characteristics aggregated from the 2004 and 2010 Nepal Living Standards Survey (NLSS), we estimate a variety of hierarchical regression models, which allow us to partition variance in height-for-age Z-scores between the levels of different hierarchical specifications, and then to partition that variance further, between group-level parameters.

Our findings suggest that the …