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2013

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Target Validation For Neurofibromatosis Type 2 Therapeutics., Alejandra Guinart Jan 2013

Target Validation For Neurofibromatosis Type 2 Therapeutics., Alejandra Guinart

Electronic Theses and Dissertations

Neurofibromatosis type 2 (NF2) is a benign tumor disease of the nervous system. Development of bilateral vestibular schwannomas is characteristic of NF2; however patients frequently present schwannomas on other nerves, as well as meningiomas and ependymomas. Currently, there are no drug therapies for NF2. There is an urgent need for development of NF2 therapeutics and this dissertation presents two independent potential therapeutic targets. The disease is caused by mutations in the NF2 gene that encodes a tumor suppressor called merlin. Loss of merlin function is associated with increased activity of Rac and p21-activated kinases (PAK) and deregulation of cytoskeletal organization ...


Wetland Diversity In A Disturbance-Maintained Landscape: Effects Of Fire And A Fire Surrogate On Aquatic Amphibian Survival And Species Depauperateness., Joyce Klaus Jan 2013

Wetland Diversity In A Disturbance-Maintained Landscape: Effects Of Fire And A Fire Surrogate On Aquatic Amphibian Survival And Species Depauperateness., Joyce Klaus

Electronic Theses and Dissertations

Disturbance is one of the central concepts explaining how diversity arises and is perpetuated in ecological time. A good model system for testing hypotheses related to disturbance is the longleaf pine ecosystem in the southeastern U.S. because in this ecosystem frequent, low-severity fires acts as a disturbance that maintains a unique vegetation structure and high species richness. Vegetation structure influences animal distributions; in fire-dependent ecosystems many animals rely on open-structured, fire-maintained vegetation but shrubs and trees encroach into fire-dependent ecosystems where fire has been excluded. Prescribed burning and mechanical removal are commonly used as restoration tools to control encroachment ...


Testing For Indirect Benefits Of Polyandry In The Florida Green Turtle, Christopher Long Jan 2013

Testing For Indirect Benefits Of Polyandry In The Florida Green Turtle, Christopher Long

Electronic Theses and Dissertations

Behavioral studies in the green turtle (Chelonia mydas) have indicated that promiscuous mating is commonplace. Though it has been shown that there is much variation in the rate of polyandry (females mating with multiple males), the drivers behind polyandry in this species are unknown. It has been speculated, but never demonstrated, that indirect benefits (fitness benefits resulting from offspring genetic diversity) play a role. However, previous tests of this hypothesis have limited scope of inference due to lack of environmental control. In this thesis, I attempted to study the indirect benefits of polyandry in Archie Carr National Wildlife Refuge (ACNWR ...


Estimated Diets, Diet Overlap, And Winter Habitat Associations Of Four Grassland Sparrows In Florida Dry Prairie, Marianne Korosy Jan 2013

Estimated Diets, Diet Overlap, And Winter Habitat Associations Of Four Grassland Sparrows In Florida Dry Prairie, Marianne Korosy

Electronic Theses and Dissertations

North American grassland birds show long-term population declines that generally exceed the declines of other bird groups. Efforts to conserve grassland birds require knowledge of diet and habitat requirements during both the breeding and nonbreeding periods of annual life cycles. This dissertation investigated sparrow habitat associations within two defined plant communities of the dry prairie ecosystem, the dry-mesic and wet-mesic prairie, for four prescribed fire treatments over two consecutive winters. Grasshopper and Henslow’s sparrows showed higher relative abundance in wet-mesic prairie and Bachman’s Sparrows were more abundant in dry-mesic prairie across all fire treatments. Abundances of Grasshopper and ...


The Contribution Of Visceral Fat To Positive Insulin Signaling In Ames Dwarf Mice, Vinal Menon Jan 2013

The Contribution Of Visceral Fat To Positive Insulin Signaling In Ames Dwarf Mice, Vinal Menon

Electronic Theses and Dissertations

Ames dwarf (df/df) mice are homozygous for a spontaneous mutation in the prop1 gene due to which there is no development of anterior pituitary cells – somatotrophs, lactotrophs and thyrotrophs, leading to a deficiency of growth hormone (GH), prolactin (PRL) and thyrotropin (TSH). They tend to become obese as they age, but still live longer and healthier lives compared to their wild-type littermates, being very insulin sensitive, showing no signs of diabetes and cancer. These mutant mice also have high circulating levels of anti-inflammatory and antidiabetic adiponectin. Plasma levels of this adipokine usually decrease with an increase in accumulation of ...


Immuno-Pcr Detection Of Lyme Borreliosis, Micah Halpern Jan 2013

Immuno-Pcr Detection Of Lyme Borreliosis, Micah Halpern

Electronic Theses and Dissertations

Lyme borreliosis, more commonly referred to as Lyme disease, is the fastest growing zoonotic disease in North America with approximately 30,000 confirmed cases and 300,000 estimated infections per year. In nature, the causative agent of Lyme disease, the bacterium Borrelia burgdorferi, cycles between Ixodes sp. ticks and small mammals. Humans become infected with Lyme disease after being bitten by an infected tick. The primary indicator of a Borrelia burgdorferi infection is a bull’s eye rash typically followed by flu-like symptoms with treatment consisting of a 2-4 week course of antibiotics. If not treated, later stages of the ...


Sagebrush Ecosystem Characterization, Monitoring, And Forecasting With Remote Sensing: Quantifying Future Climate And Wildlife Habitat Change, Collin G. Homer Jan 2013

Sagebrush Ecosystem Characterization, Monitoring, And Forecasting With Remote Sensing: Quantifying Future Climate And Wildlife Habitat Change, Collin G. Homer

Electronic Theses and Dissertations

Sagebrush (Artemisia spp.) ecosystems constitute the largest single North American shrub ecosystem and provide vital ecological, hydrological, biological, agricultural, and recreational ecosystem services. Disturbances continue to alter this ecosystem, with climate change possibly representing the greatest future disturbance risk. Improved ways to characterize and monitor gradual change in this ecosystem are vital to its future management. A new remote sensing sagebrush characterization approach was developed in Wyoming which integrates three scales of remote sensing to derive four primary continuous field components (bare ground, herbaceousness, litter, and shrub), and four secondary components (sagebrush, big sagebrush, Wyoming sagebrush, and shrub height) using ...


Evaluating The Use Of Autonomous Recording Units To Monitor Yellow Rails, Nelson's Sparrows, And Le Conte's Sparrows, Anna Marie Sidie-Slettedahl Jan 2013

Evaluating The Use Of Autonomous Recording Units To Monitor Yellow Rails, Nelson's Sparrows, And Le Conte's Sparrows, Anna Marie Sidie-Slettedahl

Electronic Theses and Dissertations

Population status and habitat use of yellow rails (Coturnicops noveboracensis) (YERA), Nelson’s sparrows (Ammodramus nelsoni) (NESP), and Le Conte’s sparrows (Ammodramus leconteii) (LCSP) are poorly known, so systematic surveys of these elusive species are needed to inform conservation planning and guide management. A standardized protocol for monitoring secretive marsh birds exists (Conway 2009, 2011); however, these species call at night and may be missed during early-morning marsh bird surveys. I tested the effectiveness of autonomous recording units (ARUs) to survey these species by analyzing recorded vocalizations using bioacoustics software. I deployed 22 ARUs at 54 sites in northern ...


Motives For Physical Activity And Physiological Variables As Predictors Of Exercise Intentions Following A High Intensity Interval Training Protocol In College-Age Females, Sarah Joseph Jan 2013

Motives For Physical Activity And Physiological Variables As Predictors Of Exercise Intentions Following A High Intensity Interval Training Protocol In College-Age Females, Sarah Joseph

Electronic Theses and Dissertations

Recent data collected on college-aged females indicates that more females are classified as insufficiently active and may have little time for physical activity (Ligouri, et al., 2011). High intensity interval training (defined as very short intense intervals, usually above 85% maximum heart rate accompanied by alternated passive recovery periods; HIIT) has become a popular alternative to the more traditional continuous training utilized by individuals due to its time efficiency. In fact, HIIT has been shown to induce many of the same physiological changes as moderate intensity training with less training time. It is possible that college-aged females may benefit from ...


Effects Of Site Preparation, Seed Germination, And Harvest Maturity On Wiregrass Restoration Efforts At Fort Stewart, Ga, Nickey Garrett Anderson Jan 2013

Effects Of Site Preparation, Seed Germination, And Harvest Maturity On Wiregrass Restoration Efforts At Fort Stewart, Ga, Nickey Garrett Anderson

Electronic Theses and Dissertations

Wiregrass (Aristida stricta Michx.) was once the dominant ground cover species within the Atlantic Coastal Plain longleaf pine (Pinus palustris Mill.) ecosystem. Less than 1 million hectares of intact longleaf pine-wiregrass communities remain, due primarily to anthropogenic activities. Wiregrass is a keystone species in the longleaf pine ecosystem, as its presence facilitates the natural fire regime, a critical component in the perpetuation of these communities. Therefore, there is increased interest in wiregrass restoration in both existing longleaf pine communities and future longleaf pine restoration sites. Many restoration sites are on tracts that have been cleared of all vegetation. Removal of ...


Concussion Knowledge In Amateur Motocross, Kristina Miller Jan 2013

Concussion Knowledge In Amateur Motocross, Kristina Miller

Electronic Theses and Dissertations

The Center for Disease Control and Prevention estimated that there are 1.6-3.8 million sports related traumatic brain injuries in the United States annually which occur in both mainstream and extreme sports. Many of these concussions have been associated with collisional sports, like football, but high risk extreme sports, like motocross, also have many opportunities for collisions to occur. Unlike traditional varsity sports motocross races, especially at the amateur level, do not require more than advanced life support at a race in case of emergency situation leaving the amateur rider to recognize and decide on concussion management. Purpose of ...


Variation In Population Densities Of The Florida Scrub Lizard (Sceloporus Woodi) Between Managed Sand Pine Scrub And Longleaf Pine Stands In The Ocala National Forest, Matthew D. Kaunert Jan 2013

Variation In Population Densities Of The Florida Scrub Lizard (Sceloporus Woodi) Between Managed Sand Pine Scrub And Longleaf Pine Stands In The Ocala National Forest, Matthew D. Kaunert

Electronic Theses and Dissertations

Population-level response to habitat fragmentation is central to applied species management and conservation. Managed landscapes are often subject to increased fragmentation and, consequently, may force once connected populations to function as metapopulations. Studies investigating metapopulations occurring over patchy, managed landscapes are of increasing importance as fragmentation is a known cause of biodiversity loss. In June-September 2012, populations of the rare, endemic Florida scrub lizard (Sceloporus woodi) were sampled across the Ocala National Forest (ONF) to compare abundance and density across two management types. In the ONF, sand-pine scrub is clearcut and rollerchopped whereas longleaf pine is managed via prescribed burning ...


Individual And Population Responses Of The Caribbean Sponge, Aplysina Cauliformis, To Natural And Anthropogenic Stressors, Cole Gregory Easson Jan 2013

Individual And Population Responses Of The Caribbean Sponge, Aplysina Cauliformis, To Natural And Anthropogenic Stressors, Cole Gregory Easson

Electronic Theses and Dissertations

Coral reefs are under increasing threat from a diversity of stressors. These reefs have undergone a phase shift from coral-dominated to algal-dominated ecosystems, and in many cases other functional groups such as sponges are now the predominant organisms on many reefs. This dissertation investigated the responses of a common branching sponge, Aplysina cauliformis, to algal contact, eutrophication, hurricanes, and disease. The effects of algal competition, anthropogenic nutrients and a combination of these stressors on A. cauliformis were examined using factorial designed field experiments on Bahamian reefs. These experiments demonstrated a complex interaction between sponge and alga, in which the green ...


Perspectives On Ethanol Toxicity In Medaka Embryogenesis And Possible Protection By Asian Ginseng (Panax Ginseng): Histological And Biochemical Analysis, Mona Hamdi Haron Jan 2013

Perspectives On Ethanol Toxicity In Medaka Embryogenesis And Possible Protection By Asian Ginseng (Panax Ginseng): Histological And Biochemical Analysis, Mona Hamdi Haron

Electronic Theses and Dissertations

Alcohol is recognized as a classic teratogen capable of inducing a wide range of developmental abnormalities. Alcohol consumption during pregnancy may produce permanent brain damage in the fetus and is associated with the development of a life-long behavioral, social, and cognitive disorder now known as fetal alcohol spectrum disorder (FASD). The most clinically recognizable form of FASD is fetal alcohol syndrome (FAS) which is characterized by specific features including facial dysmorphogenesis, mental dysfunction, growth retardation, and cardiovascular and limb defects. Due to ethical constraints, human studies of FASD are very limited. Therefore our current understanding of FASD is mainly based ...


Protein Kinases: Structure Modeling, Inhibition, And Protein-Protein Interactions, Khaled M. Elokely Jan 2013

Protein Kinases: Structure Modeling, Inhibition, And Protein-Protein Interactions, Khaled M. Elokely

Electronic Theses and Dissertations

Human protein kinases belong to a large and diverse enzyme family that contains more than 500 members. Deregulation of protein kinases is associated with many disorders, and this is why protein kinases are attractive targets for drug discovery. Due to the high conservation of the ATP binding pocket among this family, designing specific and/or selective inhibitors against certain member(s) is challenging. Several studies have been conducted on protein kinases to validate them as suitable drug targets. Although there are numerous target-validated protein kinases, the efforts to develop small molecule inhibitors have so far led to only a limited ...


Role Of The Endocannabinoid System In Cardiac Remodeling, Monica Gole Jan 2013

Role Of The Endocannabinoid System In Cardiac Remodeling, Monica Gole

Electronic Theses and Dissertations

The endocannabinoid system and CB1 and CB2 cannabinoid receptors have been implicated in cardiac remodeling with CB1 inhibition and CB2 activation reported to be beneficial. However, the role of these receptors in cardiac remodeling secondary to hypertension is not known. Moreover, the functions of the CB1 and CB2 cannabinoid receptors in cardiac ventricular fibroblasts and their downstream fibrotic pathways has not yet been elucidated. This study was designed to determine the temporal myocardial expression pattern of CB1 and CB2 receptors in cardiac remodeling secondary to pressure overload (PO) induced hypertension at 3, 5, 14 and 28 days. The expression of ...


Linking The Functional Diversity Of Ectomycorrhizal Fungal Species To Soil Carbon And The Genetics Of A Foundational Tree Species, Nicole Marie Hergott Jan 2013

Linking The Functional Diversity Of Ectomycorrhizal Fungal Species To Soil Carbon And The Genetics Of A Foundational Tree Species, Nicole Marie Hergott

Electronic Theses and Dissertations

Carbon dioxide in the atmosphere continues to increase, leading to an enhanced interest in the potential for ecosystems to sequester carbon. Soil could have a high potential to store carbon in these forests, but there is still a great deal to learn about how carbon storage in soils is influenced by ectomycorrhizal fungi. In this symbiosis, the plant host provides the vast majority of C for fungal growth. As a consequence, ECM fungi may provide one of the major pathways for C from trees to soils. Ectomycorrhizal fungal species produce extracellular enzymes that may degrade soil carbon and may differ ...


Male Reproductive Strategies And Mating Displays In The Ocellated Turkey (Meleagris Ocellata), Edward Merrill Hanlon Jan 2013

Male Reproductive Strategies And Mating Displays In The Ocellated Turkey (Meleagris Ocellata), Edward Merrill Hanlon

Electronic Theses and Dissertations

Animal mating systems are often characterized by intense competition for mates and resources. Despite how common this conflict is, mating systems exist in which some adult males of breeding age seem to not participate. These apathetic males may be exhibiting alternative reproductive strategies, or simply delaying maturation to conserve resources for future breeding attempts. In populations of the poorly studied, near-threatened Ocellated Turkey (Meleagris ocellata), males have been reported to be either "breeding" or "non-breeding," apparently irrespective of age, although empirical data are scarce. This thesis has three main objectives for establishing a better understanding of the Ocellated Turkey's ...


Molecular Considerations In The Design Of Novel Alpha/Beta Hydrolase Inhibitors, Shana Victoria Stoddard Jan 2013

Molecular Considerations In The Design Of Novel Alpha/Beta Hydrolase Inhibitors, Shana Victoria Stoddard

Electronic Theses and Dissertations

Alpha/beta hydrolases (ABHs) are a superfamily of hydrolytic enzymes that process a wide variety of substrates. A subfamily of ABHs called carboxylesterases (CEs) are important enzymes that catalyze biological detoxification, hydrolysis of certain pesticides, and metabolism of many esterified drugs. The chemotherapy drug irinotecan used for treatment of colorectal cancer is metabolized to SN-38, the active drug metabolite, by two CE isozymes CES1 (localized in the liver) and CES2 (localized in the small intestines). CES2's ability to activate irinotecan at a faster rate than CES1 creates a localization of activated SN-38 in the gut epithelium, resulting in the ...


Bacterial Assemblages And Microbial Enzyme Activity In The Major Tributaries Of The Lower Mississippi River, Justin Millar Jan 2013

Bacterial Assemblages And Microbial Enzyme Activity In The Major Tributaries Of The Lower Mississippi River, Justin Millar

Electronic Theses and Dissertations

Spatial variation in the structure and function of bacterial communities is far more complex than previously believed. High throughput sequencing techniques have begun to elucidate the dynamic worldwide patterns of bacterial biogeography; however, there are still many ecosystems for which there is little to no representative data. Currently there are no high throughput-based analyses of bacterial assemblages in large rivers. Rivers form important connections between terrestrial land use and marine biogeochemistry and act as conduits for organisms and allochthonous nutrients. Bacteria dominate carbon cycling and nutrient processing in rivers, and therefore can influence regional and global elemental cycles. This study ...


Phylogeography Of The Malagasy Ant Species Odontomachus Coquereli, Jason Jackson Jan 2013

Phylogeography Of The Malagasy Ant Species Odontomachus Coquereli, Jason Jackson

Electronic Theses and Dissertations

Madagascar is an extremely diverse and geographically complex area boasting levels of endemism that blatantly raise questions about their origins. There is evidence that these endemics arose via insitu diversification during Madagascar's ~88 million year isolation, even though it was essentially in the middle of Gondwana with ample opportunity to acquire inhabitants. Madagascar's high levels of diversity and endemism make it an ideal location to study speciation, especially considering the evidence that such high levels speciation occurred in Madagascar itself. Several hypotheses have been formulated to relate the complex geography to genetic divergence, and thereby speciation. I explore ...


Benzo[A]Pyrene Effects On Fundulus Heteroclitus Reproductive Endpoints, Frank Booc Jan 2013

Benzo[A]Pyrene Effects On Fundulus Heteroclitus Reproductive Endpoints, Frank Booc

Electronic Theses and Dissertations

Benzo[a]pyrene (BaP) is a polycyclic aromatic hydrocarbon (PAH) that modulates aromatase enzyme function and, thus, potentially interrupts normal reproductive function. The aim of this study was to use a fish model, Fundulus heteroclitus, to assess whether BaP exposure adversely impacted reproduction. Adult fish were exposed to waterborne BaP concentrations of (0, 1 or 10 μg/L) for 28 days. Males and females were combined for the second half of the exposure (days 14-28) in order to quantitate egg production and fertilization success. Egg fertilization and subsequent hatching success of F1 embryos was significantly decreased by 10 μg/L ...


Child Friendliness Of Restaurants: A Pilot Study, Amy Mccluskey Bardwell Jan 2013

Child Friendliness Of Restaurants: A Pilot Study, Amy Mccluskey Bardwell

Electronic Theses and Dissertations

The objective of this study was to develop an instrument to measure the child friendliness of restaurants using a combination of previous literature and focus groups. The pilot study consisted of a thirty-six item survey instrument that was distributed to forty individuals. Among the forty individuals who received the survey instrument, thirty-three of them completed the survey. A panel of experts reviewed the survey results using cognitive factor analysis. The experts were asked to place each item of the survey instrument into categories. From this, five factors emerged. These included: facilities, service, atmosphere, activities, and menu. Six items from the ...


An Evaluation Of The Opinions Of School Nutrition Professionals On The New Meal Pattern Being Implemented Through The National School Lunch Program (Nslp) With A Focus On The Fruit And Vegetable Components, Sowjanya Chowdary Chilaka Jan 2013

An Evaluation Of The Opinions Of School Nutrition Professionals On The New Meal Pattern Being Implemented Through The National School Lunch Program (Nslp) With A Focus On The Fruit And Vegetable Components, Sowjanya Chowdary Chilaka

Electronic Theses and Dissertations

The National School Lunch Program (NSLP) is a federally supported school meal program. The Healthy Hunger Free Kids Act (HHFKA), 2010 based on the recommendations by Institute of Medicine (IOM) introduced new meal pattern that comply with the Dietary Guidelines for Americans, 2010 and these are the major changes made in the past 15 years to school meal programs. The objective of the study was to evaluate the opinions of school nutrition professionals on the new meal pattern being implemented through the NSLP with a focus on fruit and vegetable components. A questionnaire was developed and distributed at strategic locations ...


The Tick Genus Amblyomma In Africa: Phylogeny And Mutilocus Dna Barcoding, Omobolanle Kushimo Jan 2013

The Tick Genus Amblyomma In Africa: Phylogeny And Mutilocus Dna Barcoding, Omobolanle Kushimo

Electronic Theses and Dissertations

The tick genus Amblyomma includes approximately 130 species, 28 of which are found on the African continent and/ or in Madagascar. In order to understand the evolutionary phylogeography of the genus, it is necessary to gain a better understanding of the relationships between African taxa. Therefore, the main goals of this work were to, (1) reconstruct the phylogenetic relationships of the African Amblyomma available to us and (2) test markers for their usefulness as barcoding tools to link unknown immature specimens to their corresponding adults. The mitochondrial gene markers used in this study (12SrDNA and COI) did not resolve the ...


Impacts Of Spring-Interseeded Cover Crops On Late-Emerging Weed Suppression And Ground Cover In Corn (Zea Mays L.) Production Systems, Alex D. Bich Jan 2013

Impacts Of Spring-Interseeded Cover Crops On Late-Emerging Weed Suppression And Ground Cover In Corn (Zea Mays L.) Production Systems, Alex D. Bich

Electronic Theses and Dissertations

Any alternative crop management strategy will only be adopted by growers if yield is not negatively impacted, fits within a current management practice, is easily implementable with minimal cost, or provides other beneficial features such as weed control or suppression. Corn production that incorporates a cover crop as an alternative weed control strategy and ground cover may support a sustainable system that is less dependent on herbicidal weed control. In addition, the cover crop may be used as a fall forage, act as a slow release fertilizer source the following year, and provide ground cover to reduce soil erosion. In ...


Choice Response Time Differences Between Recently Recovered Concussed And Healthy Student-Athletes, Tiffen Tapia-Lovler Jan 2013

Choice Response Time Differences Between Recently Recovered Concussed And Healthy Student-Athletes, Tiffen Tapia-Lovler

Electronic Theses and Dissertations

Some 1.6 to 3.8 million sports-related concussions occur annually in the United States. Utilization of test batteries and exercise protocols are recommended to ensure athletes recover completely. Many batteries involve response time (RT) tests, which show response time increases post concussion. A major limitation of RT tests is that all are done in static position. Additionally, many studies show a lingering effect on RT. The addition of RT tests to check for lingering symptoms could be beneficial. The purpose of this study was to see if significant differences could be found in RT tests involving dynamic movement between ...


Effectiveness Of A Training Program Using An Alter-G Treadmill To Improve Physiological And Psychosocial Measures In Female Breast Cancer Survivors, Ciaran Fairman Jan 2013

Effectiveness Of A Training Program Using An Alter-G Treadmill To Improve Physiological And Psychosocial Measures In Female Breast Cancer Survivors, Ciaran Fairman

Electronic Theses and Dissertations

Breast survivors often experience lower bone mineral density following treatment, and may be at a higher risk for osteoporosis and consequent falls and injuries. This study aimed to build on previous research using lower impact exercise programs by using an anti-gravity (Alter-G®) treadmill to administer cardiovascular training. PURPOSE: The purpose of this study was to determine the effectiveness a physical activity program, including an anti-gravity (Alter-G) treadmill at improving physiological and psychosocial measures in female breast cancer survivors. METHODS: Five female breast cancer survivors were recruited to participate in the study. A 14-week intervention using an AB-AB study design was ...


Energy In The Corn Belt: Is Maize Production Sustainable?, Matthew Bernau Jan 2013

Energy In The Corn Belt: Is Maize Production Sustainable?, Matthew Bernau

Electronic Theses and Dissertations

Technological and scientific innovation has transformed agricultural production. Corn production methods changed from a sustainable, nutrient recycling production system to one reliant on imported fossil energy inputs. Located in the Western Corn Belt, Union County, South Dakota was chosen as the study area. Changes in production methods are represented by four technological epochs: 1) The Draft Horse Epoch, 1890-1920; 2) The Tractor Epoch, 1920-1950; 3) The Fertilizer Epoch, 1950-1980; and 4) The Biotechnology and Precision Agriculture Epoch, 1980-2010. The energy budget method was used to measure the energy sustainability of corn production. The findings show that the volume of corn ...