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Theses/Dissertations

2017

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Full-Text Articles in Life Sciences

Forage Selection And Habitat Architecture As Drivers Of Small Mammal Community Dynamics In An Arid, Nutrient Limited, Highly Stochastic Ecosystem, Jennifer Darby Noble Dec 2017

Forage Selection And Habitat Architecture As Drivers Of Small Mammal Community Dynamics In An Arid, Nutrient Limited, Highly Stochastic Ecosystem, Jennifer Darby Noble

Biology ETDs

In the Northern Chihuahuan desert, grassland and shrubland co-occur as separate stable states under similar climatic conditions. In this bottom up (resource driven) system, the magnitude and timing of precipitation events drives primary production which varies from year to year and season to season. Climate change is predicted to alter precipitation regimes, and increase aridity, facilitating shrub encroachment which results in increased landscape heterogeneity and a decrease in plant biodiversity. These changes will likely result in a restructuring of small mammal communities.

We used long-term data on precipitation, primary production, and abundances of small mammals in adjacent grassland and shrubland …


Prep-Hplc Method Development To Isolate Potentially-Carcinogenic, Arginine-Based Heterocyclic Amines, Victoria S. Kim Dec 2017

Prep-Hplc Method Development To Isolate Potentially-Carcinogenic, Arginine-Based Heterocyclic Amines, Victoria S. Kim

Honors Theses

Heterocyclic amines (HCAs) are carcinogenic molecules generated from the reaction of creatin(in)e and amino acids at high cooking temperatures in meat. Previous research has shown that replacing creatine with arginine leads to new, uncharacterized HCA molecules. This research entails implementing and optimizing the preparative HPLC analysis of extracts from multiple burnings of arginine with phenylalanine. Isolated fractions from the prep-HPLC analysis were further analyzed using the Ames test to identify mutagenic compounds. Prep-HPLC provides quality control to the burning process along with isolation of larger quantities of materials for further characterization and molecular structure identification.


Pros And Cons Of Marine Zoological Parks According To Marine Conservationists, Kayla L. Patama Dec 2017

Pros And Cons Of Marine Zoological Parks According To Marine Conservationists, Kayla L. Patama

HCNSO Student Capstones

Throughout history zoos and aquariums have satisfied a number of different, albeit to some, conflicting roles (Ballantyne, Packer, Hughes, & Dierking, 2007). In recent years, zoos and aquariums have shifted their focus on taking a proactive role in wildlife conservation and promoting conservation learning among their visitors. The present capstone addresses the justifications that marine conservationists see in marine zoological parks and how they believe parks can become more relevant and valuable in the future. A 65 question survey (Appendix I) was distributed to marine science professionals online through personal contact between June and September 2017 questioning participant’s personal opinions …


Nuclear Genome Size Diversity Of Marine Invertebrate Taxa Using Flow Cytometric Analysis, Kyle Roebuck Dec 2017

Nuclear Genome Size Diversity Of Marine Invertebrate Taxa Using Flow Cytometric Analysis, Kyle Roebuck

HCNSO Student Theses and Dissertations

Genomic analysis provides a substantial amount of information on evolutionary history, novel genes, transcriptomic expression and regulation in response to environmental stimuli, how efficiently organisms utilize their genome, and directional genome evolution. Genome size analysis serves as the first step in the sequencing process, because sequencing and annotation costs are directly correlated with genome size. Invertebrates represent the vast majority of faunal diversity on the planet, and, to a greater extent, the marine environment, although they are vastly understudied when compared to vertebrate genomes. Flow cytometry is a widely used, reliable, and accurate means of estimating genome sizes and has …


A Teachable Unit On Soft Corals With Instructional Method Variances, Emily Breech Dec 2017

A Teachable Unit On Soft Corals With Instructional Method Variances, Emily Breech

Honors Projects

The soft coral Sinularia flexibilis contains an aqueous alcohol extract that has shown antineoplastic activity against lymphocytic leukemia (Weinheimer and Matson, 1977). It also has other biological properties that work as antimicrobials, anti-inflammatory agents, and cytotoxicity activities (Kamel and Slattery, 2005). There is much research on the effects of flow rate on growth and morphology (Khalesi, Beeftink, & Wijffels, 2007) and the effects of light-dependency on growth rate (Khalesi, Beeftink, & Wijffels, 2009). The purpose of this student project was to further research on S. flexibilis, as well as incorporate that research into evaluating the effects of lecture-based teaching …


Analysis Of Diagnostic, Preventive, And Disease-Modifying Therapeutic Measures Of Alzheimer’S Disease, Ghazal Habib Havoutis Dec 2017

Analysis Of Diagnostic, Preventive, And Disease-Modifying Therapeutic Measures Of Alzheimer’S Disease, Ghazal Habib Havoutis

HCNSO Student Capstones

Alzheimer’s disease (AD) is the most common late-onset neurodegenerative disorder and cause of dementia, characterized by the formation of neurofibrillary tangles and senile plaque deposits. The heterogeneous nature of the disease (both genetically and environmentally) makes it difficult to prevent or cure. Without prevention, the prevalence of AD is expected to triple by 2050. However, because the diagnosis of AD is usually preceded by years of cognitive impairment, early detection may aid in reducing prevalence. Thus, there is a need for validated diagnostic measures for early and improved diagnosis and prevention. In this review, current and ongoing classifiers of early …


The Importance Of Planning: Science Education From Many Points Of View, Kirsten Morgan Edwards Dec 2017

The Importance Of Planning: Science Education From Many Points Of View, Kirsten Morgan Edwards

Senior Theses

The purpose of this thesis project was to bridge the divide between public lands, such as parks, and the education system; national parks and monuments are great resources for education. In addition to promoting outside of the classroom education, this project explores different teaching methods and how changing pedagogical practice can help more students learn in the long term. In order to explore different methods of teaching, I created three different lesson plans that could be used, for example, in places like Congaree National Park, to bring education outside of the traditional school environment. These lesson plans are supplemental materials …


Zinc Chloride Activates Phospho-Akt And Promotes Chondrocyte Maturation In The Atdc5 Chondrogenic Cell Line, Donya T. Burgess Dec 2017

Zinc Chloride Activates Phospho-Akt And Promotes Chondrocyte Maturation In The Atdc5 Chondrogenic Cell Line, Donya T. Burgess

Seton Hall University Dissertations and Theses (ETDs)

Fracture healing is characterized by inflammation, cartilage formation, bone deposition, and remodeling. Endochondral ossification is an important part of callus formation that relies on the maturation of chondrocytes. Early in their maturation these cells express collagen type II alpha 1 chain (COL2A1) and express collagen type X alpha 1 chain (COL10A1) as they mature further and become hypertrophic chondrocytes. Activation of the insulin pathway is considered a primary factor involved in the initiation of chondrogenesis and its progression during bone healing. Insulin mimetics like zinc chloride (ZnCl2) have been shown to improve bone healing outcomes and enhance bone …


Bioinformatic And Experimental Approaches For Deeper Metaproteomic Characterization Of Complex Environmental Samples, Ramsunder Mahadevan Iyer Dec 2017

Bioinformatic And Experimental Approaches For Deeper Metaproteomic Characterization Of Complex Environmental Samples, Ramsunder Mahadevan Iyer

Doctoral Dissertations

The coupling of high performance multi-dimensional liquid chromatography and tandem mass spectrometry for characterization of microbial proteins from complex environmental samples has paved the way for a new era in scientific discovery. The field of metaproteomics, which is the study of protein suite of all the organisms in a biological system, has taken a tremendous leap with the introduction of high-throughput proteomics. However, with corresponding increase in sample complexity, novel challenges have been raised with respect to efficient peptide separation via chromatography and bioinformatic analysis of the resulting high throughput data. In this dissertation, various aspects of metaproteomic characterization, including …


Investigating The Regulation Of Indole-3-Acetic Acid Production By The Plant Associated Microbe Pantoea Sp. Yr343, Kasey Noel Estenson Dec 2017

Investigating The Regulation Of Indole-3-Acetic Acid Production By The Plant Associated Microbe Pantoea Sp. Yr343, Kasey Noel Estenson

Doctoral Dissertations

The auxin indole-3-acetic acid (IAA) plays a central role in plant growth and development and many plant-associated microbes produce IAA. Several IAA biosynthetic pathways have been identified in microbes which use the precursor tryptophan. Pantoea sp. YR343, which was isolated from the Populus deltoides rhizosphere, is a robust plant root colonizer that produces IAA. Using genomic and metabolomics analyses, we predicted that the indole-3-pyruvate (IPA) pathway is the major pathway in Pantoea sp. YR343 for IAA production. To better understand IAA biosynthesis and the effects of IAA exposure on cell physiology, we performed proteomics on Pantoea sp. YR343 grown in …


Forest Resources For Bioenergy, Gerry Solano Avila Dec 2017

Forest Resources For Bioenergy, Gerry Solano Avila

Doctoral Dissertations

The overall objective of this dissertation is to evaluate forest resources biomass availability for the production of bioenergy. Chapter II provides measures of the impact that the road sustainability criteria have on the supply of feedstock for forest products and bioenergy. A linear cost minimization programming is used in estimating forest biomass supply curves. Chapter III provides estimates on the changes in US timberland acreages overtime and the ability of timberland to meet conventional timber products and woody biomass demand within the conterminous United States. Chapter IV utilizes the Biofuels Facility Location Analysis Modeling Endeavor (BioFLAME), a Geographic Information System …


Non-Canonical Signaling From The Etr1 And Etr2 Ethylene Receptors In Arabidopsis Thaliana, Arkadipta Bakshi Dec 2017

Non-Canonical Signaling From The Etr1 And Etr2 Ethylene Receptors In Arabidopsis Thaliana, Arkadipta Bakshi

Doctoral Dissertations

The gaseous phytohormone ethylene regulates several physiological and developmental processes in higher plants. There are five ethylene receptor isoforms that mediate the responses to ethylene in the model plant Arabidopsis thaliana. Prior research has shown that these five ethylene receptor isoforms in Arabidopsis have both overlapping and non-overlapping roles in regulating diverse responses such as growth in air, growth recovery after removal of ethylene, and ethylene stimulated nutational bending. Functional divergence of ETR1 has been determined in controlling some of these traits and in some of these cases, ETR1 subfunctionalization requires the receiver domain. Using homology modeling and sequence …


Morphological And Gene Expression Plasticity In Neotropical Cichlid Fishes, Sharon Fern Clemmensen Dec 2017

Morphological And Gene Expression Plasticity In Neotropical Cichlid Fishes, Sharon Fern Clemmensen

Doctoral Dissertations

Trophic divergence in cichlid fish is linked to morphological shifts in the pharyngeal jaw apparatus. For instance, in the Heroine cichlids of Central America, the ability to crush hard-shelled mollusks is a convergent phenotype with multiple evolutionary origins. These durophagous species often have very similar pharyngeal jaw morphologies associated with the pharyngeal jaw apparatus and some of these similarities could be due to phenotypically plastic responses to mechanical stress. I examined the durophagous cichlid Vieja maculicauda for differences in pharyngeal osteology, dentition, and soft tissues when exposed to different diet regimes. Here I discuss the effect on the morphology and …


Design And Synthesis Of Analogs Of Myo-Inositol, Serine, And Cysteine To Enable Chemical Biology Studies, Tanei J. Ricks Dec 2017

Design And Synthesis Of Analogs Of Myo-Inositol, Serine, And Cysteine To Enable Chemical Biology Studies, Tanei J. Ricks

Doctoral Dissertations

Phosphorylated myo-inositol compounds including inositol phosphates (InsPs) as well as the phosphatidylinositol polyphosphate lipids (PIPns) are critical biomolecules that regulate many of the most important biological processes and pathways. They are aberrant in many disease states due to their regulatory function. The same is true of the phospholipid phosphatidylserine (PS) which can serve as a marker to begin apoptosis. However, the full scope of activities of these structures is not clear, particularly since techniques that enable global detection and analysis of the production of these compounds spatially and temporally are lacking. With all of these obstacles in …


Systematics And Biogeography Of The Cortinarius Violaceus Group And Sequestrate Evolution In Cortinarius (Agaricales), Emma Harrower Dec 2017

Systematics And Biogeography Of The Cortinarius Violaceus Group And Sequestrate Evolution In Cortinarius (Agaricales), Emma Harrower

Doctoral Dissertations

Phylogenetics is a powerful tool used for illuminating the diversity of life on Earth, their evolution and their ecology. I created a multi-gene phylogenetic tree of Cortinarius section Cortinarius and uncovered five previously overlooked species, increasing the number of species in the section from seven to twelve. All members of the clade possess both cheilocystidia and pleurocystidia and possess a pigment known as (R)-39,49-dihydroxybphenylalanine. Ancestral state reconstruction estimated that the ancestral host was most likely an angiosperm, switching hosts when encountering novel host species in new lands, and only C. violaceus associating with the Pinaceae in North America. Biogeographic analysis …


Vineyard Age Effect On Juice Chemistry, Anthocyanins, And Total Phenolics, Eric L. Camera Dec 2017

Vineyard Age Effect On Juice Chemistry, Anthocyanins, And Total Phenolics, Eric L. Camera

Wine and Viticulture

Grapevines (cv Zinfandel) planted in the same vineyard 100 years apart were analyzed for juice chemistry and phenolic content of the fruit. The vineyard was dry farmed, and vines from the original 1890 vineyard were compared to vines inter-planted in 1990. As “old vine” wines can command higher prices in the market due to a perceived difference in fruit characteristics. This study attempted to observe if there was a measurable difference in fruit characteristics, or if it is simply an effective marketing strategy. There has been little research conducted in the wine industry attempting to observe a difference of old …


Evaluating The Therapeutic Efficacy Of Restoring Wild-Type P53 Activity In P53-Mutant Tumors, Connie A. Larsson Dec 2017

Evaluating The Therapeutic Efficacy Of Restoring Wild-Type P53 Activity In P53-Mutant Tumors, Connie A. Larsson

Dissertations & Theses (Open Access)

The p53 transcription factor is the most frequently altered in human cancers usually via missense mutations that undermine its transcriptional activity. Clinically, TP53 mutations have been shown to be remarkably predictive of refractoriness to treatment, resulting in poor outcome. Consequently, the development of p53 pathway activating agents is rapidly evolving and gaining more attention in cancer therapeutics research, with several small molecule compounds currently in preclinical and clinical trials. However, it remains largely unknown what types or proportions of p53-mutant tumors will respond to p53 restoration-based therapies.

Using a mouse model of Li Fraumeni syndrome, we genetically restored wild-type …


Exercise, Cognition, And The Aging Process Among Active, Competitive, And Sedentary Middle-Aged And Older Adults, Katherine Adams Dec 2017

Exercise, Cognition, And The Aging Process Among Active, Competitive, And Sedentary Middle-Aged And Older Adults, Katherine Adams

Health, Human Performance and Recreation Undergraduate Honors Theses

Purpose This study aimed to compare the cognitive measures of reaction time and dual-task performance among recreationally active, master athletes, and sedentary older adults aged 50 years or older. Methods 59 late middle-aged and older adults between the ages of 50 to 88 years old participated in reaction time and dual-task tests of which consisted of multiple trials on the same day. Subjects were placed either into the recreationally active, masters athlete, or sedentary activity level group based on the Rapid Assessment of Physical Activity (RAPA) form. For the gait speed with associated dual-task component, subjects walked 10-meters at two …


Lake Sturgeon (Acipenser Fulvescens) Trophic Position And Movement Patterns In The Lower Niagara River, Ny, Eric Bruestle Dec 2017

Lake Sturgeon (Acipenser Fulvescens) Trophic Position And Movement Patterns In The Lower Niagara River, Ny, Eric Bruestle

Great Lakes Center Masters Theses

Lake sturgeon Acipenser fulvescens were once widely distributed throughout the Laurentian Great Lakes. However, widespread overharvest and habitat degradation has diminished their numbers. The lower Niagara River, NY contains one of the few remaining recovering populations of lake sturgeon in New York State. The goal of this study was to characterize the trophic position of lake sturgeon in the context of an invasive species dominated food web and to describe their movement patterns and residency within the lower Niagara River. Stomach content analysis and stable nitrogen (δ15N) and carbon (δ13C) isotope analysis of tissue was used …


Dopamine Levels In The Brain Of Rat Models Of Human Rheumatoid Arthritis, Amelia Stinson Dec 2017

Dopamine Levels In The Brain Of Rat Models Of Human Rheumatoid Arthritis, Amelia Stinson

Theses & Dissertations

Research Focus. Rheumatoid arthritis (RA) is a chronic, debilitating, autoimmune disease that causes the destruction of bone tissue and the articular structures of joints. At least 30% of RA patient populations have cognitive impairment. Acidic dopamine (DA) is the principal neuroimmunotransmitter that links the central nervous system and peripheral nervous system together. The aim of the present study was to determine the levels of DA and its two acidic metabolites: 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in arthritic induced rats, and whether their levels vary across four different parts of the brain: amygdala (AMG), front cerebral cortex (CX), hippocampus …


An Investigation Of The Levels Of Pro-Inflammation Cytokines In The Brain Of Autoimmune Lewis Rats, Han Yang Dec 2017

An Investigation Of The Levels Of Pro-Inflammation Cytokines In The Brain Of Autoimmune Lewis Rats, Han Yang

Theses & Dissertations

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease, which can cause cartilage and bone damage, as well as disability. A reported symptom of RA includes tissue inflammation disease and cognitive dysfunction. This study aimed to compare the concentration of selected cytokines in the cerebral cortex, hippocampus, hypothalamus, amygdala, and cerebellum of Lewis rats. Age and sex-matched Lewis rats were separated into two groups: control and adjuvant-induced RA. Twenty-eight days after the adjuvant injection, groups were sacrificed and brains dissected using the stereotaxic atlas of Paximos and Watson as a guide. Pro-inflammatory cytokines IL-1β, IL-6, and IL-23, plus the anti-inflammatory …


Soil-Grapevine Interactions: Insight From Verdicchio In The Marche Wine Region, Italy, Megan Luna Barlow Dec 2017

Soil-Grapevine Interactions: Insight From Verdicchio In The Marche Wine Region, Italy, Megan Luna Barlow

Theses and Dissertations

Verdicchio is a white grape varietal notably grown in the Marche wine region of east-central Italy within two Denominazione Origine Controllata (DOCs); Castelli di Jesi and Matelica, located less than 50 km apart. Jesi lies in the Apennine foothills near the coast of the Adriatic Sea and produces a smooth wine noted with apple-pear undertones and crisp, clean acidity. Conversely, Matelica is located in a synclinal valley of a fold-and-thrust belt and produces stronger wine with penetrating floral aromas and bold acidity. While macro-climatic variations do exist between DOCs, this research focuses on geological variations, specifically variations in soil composition, …


Association Of Childhood Blood Lead Levels With Firearm Violence Perpetration And Victimization, Lindsay Rae Emer Dec 2017

Association Of Childhood Blood Lead Levels With Firearm Violence Perpetration And Victimization, Lindsay Rae Emer

Theses and Dissertations

Over 10,000 Americans are killed in firearm homicides each year, and an additional 40,000 are injured in nonfatal shootings. There is a significant public health need to identify risk factors that can be modified to prevent firearm violence. Environmental lead exposure is a demonstrated neurotoxicant which causes behavior changes that are known to be criminogenic. More recent research has demonstrated that homicides and nonfatal shootings differ by the circumstances that lead to the shootings (i.e. gang, domestic violence, arguments) and aggregating them could lead to biased results. Although studies have found a relationship between childhood lead exposure and criminal behaviors, …


Comparing The Effectiveness Of Alternative And Prescription Antibiotics Against Gram-Positive Bacteria, Rachel Jenkins, Roan Dickenson, Sam Turnbull, Marcela Torres Dec 2017

Comparing The Effectiveness Of Alternative And Prescription Antibiotics Against Gram-Positive Bacteria, Rachel Jenkins, Roan Dickenson, Sam Turnbull, Marcela Torres

Senior Theses

The rapid emergence of antibiotic-resistant bacteria is a global public health concern that threatens the efficacy of antibiotic drugs. We found that natural remedies, specifically coconut oil, honey and cinnamon essential oil, have the potential to be used as a clinical alternative to treat antibiotic-resistant infections. In this experiment, we performed a disk diffusion test and measured the area of inhibition of each treatment to compare the effectiveness of natural and prescription antibiotics. Cinnamon essential oil showed significantly greater antibiotic activity compared to a prescription treatment, amoxicillin. With bacterial resistance continuously expanding, more work needs to be done to determine …


Identifying Genetic Factors Influencing Sperm Mobility Phenotype In Chicken Using Genome Wide Association Studies, Primordial Germ Cell Transplantation, And Rnaseq., Sohita Ojha Dec 2017

Identifying Genetic Factors Influencing Sperm Mobility Phenotype In Chicken Using Genome Wide Association Studies, Primordial Germ Cell Transplantation, And Rnaseq., Sohita Ojha

Graduate Theses and Dissertations

Sperm mobility is a major determinant of male fertility in chicken. In spite of low heritability of reproductive traits, sperm mobility has high heritability index which suggests presence of quantitative trait loci (QTLs) governing the trait. Our research focused on three objectives: i) to identify the QTLs affecting low mobility phenotype in chicken, ii) to understand the impact of Sertoli-cells and germ cells interactions in influencing the mobility phenotype and iii) to identify the genes and gene networks differentially expressed in male and female PGCs. To detect the QTLs, genome wide association studies (GWAS) was conducted which revealed the presence …


The Economic Benefits Of The South African Agricultural Research Council’S Wheat Breeding Program: 1992–2015, Matthew James Coale Dec 2017

The Economic Benefits Of The South African Agricultural Research Council’S Wheat Breeding Program: 1992–2015, Matthew James Coale

Graduate Theses and Dissertations

Although classified as an upper middle-income country by the World Bank, food insecurity is still a concern throughout South Africa, as was evident in 2014–2015 when a drought left 22% of households food insecure. As such, agricultural research in South Africa is needed specifically in plant breeding to increase yields and help mitigate future food insecurity. To fill this need, the South African government funds the Agricultural Research Council (ARC), which conducts holistic research on wheat and other crops. Wheat is important to South African food security; due to the significant drop in wheat area planted since the abolishment of …


Surveying The Circular Rep Encoding Single Stranded (Cress) Dna Viral Consortium Found In Invasive Quagga Mussels (Dreissena Rostriformis Bugensis) And Sediments Of The Central Lake Michigan Benthos, Nicholas Gezon Dec 2017

Surveying The Circular Rep Encoding Single Stranded (Cress) Dna Viral Consortium Found In Invasive Quagga Mussels (Dreissena Rostriformis Bugensis) And Sediments Of The Central Lake Michigan Benthos, Nicholas Gezon

Masters Theses

Globalization and resulting increases in international trade has allowed for the movement of species between almost all ecosystems on Earth. The Great Lakes in particular has seen a number of high impact invasive species that have moved in following the opening of the lakes to intercontinental shipping trade. This research specifically focuses on the benthic community of Lake Michigan which has seen significant community shifts including declines of the amphipods Diporeia spp. and the expansion of invasive quagga mussels (Dreissena rostriformis bugensis). Little is known about the viral community in the benthos of Lake Michigan and how …


Evaluation Of A Direct Pcr Method And The Qiagen Investigator 24plex Go! Kit For Typing Blood, Saliva And Touch Dna On Multiple Substrates, Angelita Pierre-Noel Dec 2017

Evaluation Of A Direct Pcr Method And The Qiagen Investigator 24plex Go! Kit For Typing Blood, Saliva And Touch Dna On Multiple Substrates, Angelita Pierre-Noel

Student Theses

In forensic DNA typing, omitting the DNA extraction procedure and adding the sample directly to the polymerase chain reaction (direct PCR) mixture has several advantages. Without extraction and purification, there is less of a risk of sample loss, sample mix up, or contamination. This study tested the feasibility of direct PCR using the Qiagen® Investigator® 24plex GO! Kit, a megaplex kit that amplifies 22 polymorphic STR markers and the Amelogenin sex determination alleles. Test samples included blood, saliva and skin cells on porous substrates, specifically denim, white cotton, polyester fabric, and paper tissue. Glass slides were used to represent non-porous …


Effects Of Nicotine Exposure On Methamphetamine Oral Self-Administration, Extinction, And Reinstatement In Adolescent Rats, Zachary Robert Harmony Dec 2017

Effects Of Nicotine Exposure On Methamphetamine Oral Self-Administration, Extinction, And Reinstatement In Adolescent Rats, Zachary Robert Harmony

Electronic Theses, Projects, and Dissertations

Adolescence is a vulnerable developmental period in regards to drug initiation and use. The gateway hypothesis suggests that adolescent cigarette smoking may result in a heightened risk for methamphetamine use. However, little is understood about the role of nicotine on adolescent methamphetamine addiction. The aim of the present study was to determine whether early, late, or continuous adolescent nicotine exposure would alter oral methamphetamine self-administration, extinction, or reinstatement. A total of 164 male and female Sprague-Dawley rats were pretreated with saline or nicotine (0.16, or 0.64 mg/kg, sc) beginning on postnatal day (PD) 25 for 10 consecutive days. On PD …


Profitability Analysis Of Varying Herd Sizes Based On Price Signals In Cow-Calf Operations, Colson Tester Dec 2017

Profitability Analysis Of Varying Herd Sizes Based On Price Signals In Cow-Calf Operations, Colson Tester

Agricultural Economics and Agribusiness Undergraduate Honors Theses

The third most consumed meat around the world is beef. Despite global growth in demand, cattle markets experience price cycles related to biological production lags causing variability in cash flow and profitability for producers. Price-driven herd size management strategies thus have received attention. This study adds to that literature by analyzing both price and production risk using three herd size management strategies: i) steady state – holding herd size constant; ii) dollar cost averaging – keeping reinvestment constant by varying the number of replacement heifers retained at a constant long run average dollar total; and iii) moving average – using …