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All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

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Particle Characterization And Concentration Using Aerodynamic Vectoring, Zac Humes Dec 2008

Particle Characterization And Concentration Using Aerodynamic Vectoring, Zac Humes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An experimental demonstration of a new, non-contact particle characterization technique called Aerodynamic Vectoring Particle Sorting (AVPS) is presented. AVPS uses secondary blowing and suction control flows-flows that are a fraction of the jet flow rate-to sharply change the direction of a planar, particle-laden jet. As the jet is vectored, particles present in the flow experience a resultant drag force, dependent upon their size, that balances inertia. Since this balance determines the particle's trajectory, vectoring the flow leads to a separation of particles downstream. This simple, low-pressure-drop sorting technique classifies particles with less risk of damage or contamination than currently available …


Combining Environmental History And Soil Phytolith Analysis At The City Of Rocks National Reserve: Developing New Methods In Historical Ecology, Lesley Morris Dec 2008

Combining Environmental History And Soil Phytolith Analysis At The City Of Rocks National Reserve: Developing New Methods In Historical Ecology, Lesley Morris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Historical ecology is an emerging and interdisciplinary field that seeks to explain the changes in ecosystems over time through a synthesis of information derived from human records and biological data. The methods in historical ecology cover a wide range of temporal and spatial scales. However, methods for the more recent past (about 200 years) are largely limited to the human archive and dendrochronological evidence which can be subject to human bias, limited in spatial extent or not appropriate for non-forested systems. There is a need to explore new methods by which biological data can be used to understand historic vegetation …


Dechlorinating And Iron Reducing Bacteria Distribution In A Trichloroethene Contaminated Aquifer, Carmen Lourdes Yupanqui Zaa Dec 2008

Dechlorinating And Iron Reducing Bacteria Distribution In A Trichloroethene Contaminated Aquifer, Carmen Lourdes Yupanqui Zaa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Operable Unit 5 (OU 5) area of Hill Air Force Base currently has two trichloroethene-contaminated groundwater plumes underneath residential areas in Sunset and Clinton, Utah. Bioremediation by biological reductive dechlorination can be an important mechanism for the removal of chlorinated compounds from the plumes. The presence of suitable bacteria to carry on reductive dechlorination is the key in the bioremediation process. The goal of this study was to determine the distribution and population density of the 16S rRNA genes of Bacteria, Dehalococcoides ethenogenes, Desulfuromonas michiganensis, Geobacter spp and Rhodoferax ferrireducens-like bacteria, as well as the functional genes trichloroethene reductive …


Effects Of Olfactory And Visual Predators On Nest Success And Nest-Site Selection Of Waterfowl In North Dakota., Jennifer S. Borgo Dec 2008

Effects Of Olfactory And Visual Predators On Nest Success And Nest-Site Selection Of Waterfowl In North Dakota., Jennifer S. Borgo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Selecting a nest site is an important decision for waterfowl. Because most nest failure is due to depredation, the primary selective pressure in choosing a nest site should be to reduce depredation risk. This task is difficult because predators use differing tactics to locate nests, such as olfactory or visual cues. I investigated several components of waterfowl nest-site selection and success on sites with shelterbelts (planted tree-rows) in North Dakota, during the 2006 and 2007 nesting seasons.

I found that meteorological conditions impacted nest depredation; artificial nests were more likely to be depredated when either temperature or dew point was …


Hydrogen Production Using Geothermal Energy, Theodore Wayne Hand Dec 2008

Hydrogen Production Using Geothermal Energy, Theodore Wayne Hand

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With an ever-increasing need to find alternative fuels to curb the use of oil in the world, many sources have been identified as alternative fuels. One of these sources is hydrogen. Hydrogen can be produced through an electro-chemical process. The objective of this report is to model an electrochemical process and determine gains and or losses in efficiency of the process by increasing or decreasing the temperature of the feed water. In order to make the process environmentally conscience, electricity from a geothermal plant will be used to power the electrolyzer. Using the renewable energy makes the process of producing …


Uptake And Release Kinetics Of Sulfolane By Cattail Plants, Tiffany Leo Dec 2008

Uptake And Release Kinetics Of Sulfolane By Cattail Plants, Tiffany Leo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sulfolane (tetrahydrothiophene 1,1-dioxide, C4H8O2S) is a highly water-soluble, non-ionizable, organic compound used along with diisopropanolamine in the Sulfinol™️ process to remove hydrogen sulfide from natural gas. Sulfolane has been identified in wetland vegetation near a sour gas processing facility in Alberta, Canada, and extensive uptake of sulfolane by cattails has also been demonstrated in a laboratory environment. Consequently, it has been suggested that plants could play an important role in the natural attenuation of sulfolane in contaminated wetlands. This assumes that the sulfolane is metabolized and/or sequestered in the plant and not released back …


Volatilization Of Trichloroethylene From Shallow Subsurface Environments: Trees And Soil, Rachel Melanie Winters Dec 2008

Volatilization Of Trichloroethylene From Shallow Subsurface Environments: Trees And Soil, Rachel Melanie Winters

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Results from two previous studies conducted at Operable Unit 2 (OU2) of Hill Air Force Base, Utah indicate that the phytovolatilization (volatilization from leaves and trunk) of TCE by indigenous trees as well as soil surface flux may play a significant role in the removal of TCE from shallow groundwater plumes around the base. Previous studies investigated late summer and early autumn TCE leaf volatilization but no attempt was made to examine potential TCE volatilization seasonal variability and the volatilization of TCE directly from tree trunks. Whole tree transpiration rates were also not directly measured. To address those limitations and …


Pulse-Laser Infrared Photothermal Spectrometry Of Condensed-Phase Aerosols Based On Photothermal Deflection Spectroscopy, Oluwatosin Olubunmi Dada Dec 2008

Pulse-Laser Infrared Photothermal Spectrometry Of Condensed-Phase Aerosols Based On Photothermal Deflection Spectroscopy, Oluwatosin Olubunmi Dada

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The research reported in this dissertation is aimed at development of photothermal deflection detector that is consistent with constraints imposed by aerosols sampling and analysis. The main objectives of this project are: 1) the design and evaluation of initial apparatus prototypes and 2) a test of the prototype apparatus with surrogate substances using conventional mid-infrared gas lasers.

Experimental evaluation of reduced size photothermal apparatus is first performed with gaseous samples. Analysis of trichlorofluoromethane (CFC-11) and ethanol vapors is performed with both conventional large apparatus and the prototype small apparatus. Comparison studies in terms of photothermal signal from both apparatuses are …


Integrating Surface And Sub Surface Flow Models Of Different Spatial And Temporal Scales Using Potential Coupling Interfaces, Alphonce Chenjerayi Guzha Dec 2008

Integrating Surface And Sub Surface Flow Models Of Different Spatial And Temporal Scales Using Potential Coupling Interfaces, Alphonce Chenjerayi Guzha

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The main objective of this research was to develop and utilize a coupled surface water groundwater model to simulate hydrological responses of watersheds. This was achieved by coupling the U.S. Geological Survey (USGS) groundwater flow model, MODFLOW, and the rainfall runoff model, TOPMODEL, in one case study and coupling MODFLOW with a networked version of TOPMODEL called TOPNET in another case study. The model coupling was achieved using the InCouple approach, which utilizes Potential Coupling Interfaces (PCIs) that are abstractions from model flow diagrams that expose only those aspects of a model relevant to coupling. Coupling the rainfall-runoff models to …


Use Of Stimulus Management Techniques To Reduce Sedentary Behaviors Of Overweight Children, Julie A. Pelletier Dec 2008

Use Of Stimulus Management Techniques To Reduce Sedentary Behaviors Of Overweight Children, Julie A. Pelletier

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An epidemic proportion of children and adolescents is currently overweight or at-risk of being overweight. This is associated with many negative outcomes, including short-term and long-term health risks, as well as increased psychosocial problems. The etiology of this problem is likely complex, though environmental factors (i.e., factors related to decreased physical activity and increased consumption of calories) have been implicated in previous research. Providing effective, easy-to-implement treatment strategies for children who are overweight or at-risk of being overweight could be helpful to reverse the current epidemic and to decrease current health care costs associated with pediatric obesity. The overall purpose …


Evaluation Of Competition Between Turfgrass And Trees In The Landscape, Christopher A. Hendrickson Dec 2008

Evaluation Of Competition Between Turfgrass And Trees In The Landscape, Christopher A. Hendrickson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Population growth in regions of the Intermountain West has resulted in rapid growth of residential neighborhoods. In Utah, the landscapes associated with these expanding neighborhoods consume vast quantities of treated water. This is a concern in all states of the Intermountain West, as water becomes increasingly scarce. Traditionally used turfgrasses, trees and other plants in Intermountain West landscapes require significant amounts of supplemental water considering the intense sunlight, dry winds and sparse rainfall typical of the region. Characterizing the interactions between turfgrass and tree species in these landscapes can aid in the identification of candidate species that consume less nutritional …


Application Of Structural Control For Civil Engineering Structures, Abdollah Shafieezadeh Dec 2008

Application Of Structural Control For Civil Engineering Structures, Abdollah Shafieezadeh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study presents the application of control methods in seismic mitigation of structural responses. The study consists of two parts. In the first section, fractional order filters are utilized to enhance the performance of the conventional LQR method for optimal robust control of a simple civil structure. The introduced filters modify the state variables fed back to the constant gain controller. Four combinations of fractional order filter and LQR are considered and optimized based on a new performance criterion defined in the paper. Introducing fractional order filters is shown to improve the results considerably for both the artificially generated ground …


Synthesis And Characterization Of Lactose-Amines With Respect To Oil-In-Water Emulsion Stability, Nidhi Garg Dec 2008

Synthesis And Characterization Of Lactose-Amines With Respect To Oil-In-Water Emulsion Stability, Nidhi Garg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fatty amines (hexadecyl-amine) can be esterified to lactose via Schiff-base formation at temperatures of 60° C. Extending the time of the reaction results in a darker colored product due to the Maillard reaction. Due to the amphiphilic properties of the lactose-amines, the emulsion stabilization characteristics were investigated.

In this study, synthesis of lactose-amines was done at four different heating and cooling cycles from 4 to 24 hours. Lactose-amines processed for 24 hours and 12 hours of constant heating and cooling cycles are named as 24H and 12H, respectively. Lactose-amines 4H and 8H were processed for 4 and 8 hours of …


The Effect Of Teacher Education Level, Teaching Experience, And Teaching Behaviors On Student Science Achievement, Danhui Zhang Dec 2008

The Effect Of Teacher Education Level, Teaching Experience, And Teaching Behaviors On Student Science Achievement, Danhui Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Previous literature leaves us unanswered questions about whether teaching behaviors mediate the relationship between teacher education level and experience with student science achievement. This study examined this question with 655 students from sixth to eighth grade and their 12 science teachers. Student science achievements were measured at the beginning and end of 2006-2007 school year. Given the cluster sampling of students nested in classrooms, which are nested in teachers, a two-level multilevel model was employed to disentangle the effects from teacher-level and student-level factors. Several findings were discovered in this study. Science teachers possessing of advanced degrees in science or …


Gene Expression Analysis Of Immobilized Saccharomyces Cerevisiae, Ryan Michael Summers Dec 2008

Gene Expression Analysis Of Immobilized Saccharomyces Cerevisiae, Ryan Michael Summers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Immobilization is an effective method to increase ethanol production, as proven by previous research. Results almost exclusively demonstrate an increase in ethanol production by and decrease in reproduction rate of immobilized Saccharomyces cerevisiae cells. Recently, research has been conducted to determine the cause of this change. The extreme variance in results due to lack of technology makes it difficult to determine the cellular changes induced by immobilization. With the advent of new technology, specifically gene expression analysis, the RNA content of cells can be easily and rapidly analyzed.

S. cerevisiae cells were immobilized in 3% (w/v) calcium alginate beads and …


Rank-Data Distribution Method (R-D Method) For Daily Time-Series Bayesian Networks And Total Maximum Daily Load Estimation, Joon-Hee Lee Dec 2008

Rank-Data Distribution Method (R-D Method) For Daily Time-Series Bayesian Networks And Total Maximum Daily Load Estimation, Joon-Hee Lee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Daily time series-based models are required to estimate the higher frequency fluctuations of nutrient loads and concentrations. Some mechanistic mathematical models can provide daily time series outputs of nutrient concentrations but it is difficult to incorporate non-numerical data, such as management scenarios, to mechanistic mathematical models. Bayesian networks (BNs) were designed to accept and process inputs of varied types of both numerical and non-numerical inputs.

A Rank-Data distribution method (R-D method) was developed to provide large time series of daily predicted flows and Total Phosphorus (TP) loads to BNs driving daily time series estimates of T-P concentrations into Hyrum and …


Measuring And Modeling Of Plant Root Uptake Of Organic Chemicals, Erik Dettenmaier Dec 2008

Measuring And Modeling Of Plant Root Uptake Of Organic Chemicals, Erik Dettenmaier

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Determining the root uptake of xenobiotic organic chemicals into plants is critical for assessing the human and ecological health risks associated with the consumption of plants growing in contaminated environments. Root uptake of xenobiotic organics occurs passively in conjunction with transpiration and the transport from root to shoot is ultimately controlled by passage through one or more lipid root membranes. The transpiration stream concentration factor (TSCF), the ratio between the concentration of a chemical in the xylem to that in the solution used by the roots, is used to describe the relative ability of an organic chemical to be passively …


Student Teachers' Beliefs And Practices About Developmentally Appropriate Practice For Infants And Toddlers, Trisha Haws Dec 2008

Student Teachers' Beliefs And Practices About Developmentally Appropriate Practice For Infants And Toddlers, Trisha Haws

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to examine students’ beliefs and practices about developmentally appropriate practice with infants and toddlers. This study examined whether coursework in child development, combined with a lab experience engaging with children of the same age group, was related to developmentally appropriate beliefs and practices of student teachers. In particular, the study examined how coursework and practicum taken concurrently may have differed from taking the coursework alone. The relationships between descriptive data and student teachers’ developmentally appropriate beliefs and practices were also of interest.

A total of 390 college students participated in this study. These students …


Ecotypic Variation In Elymus Elymoides Subspecies Brevifolius Race C In The Northern Intermountain West, Matthew C. Parsons Dec 2008

Ecotypic Variation In Elymus Elymoides Subspecies Brevifolius Race C In The Northern Intermountain West, Matthew C. Parsons

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Little information is available on the extent of local adaptation for many native grass species. This is the case for squirreltail (Elymus section Sitanion), despite this group's prevalence and importance in rangeland restoration efforts. I evaluated 32 populations of E. elymoides ssp. brevifolius race C, a phylogenetic subdivision of bottlebrush squirreltail (E. elymoides) centered in the northern Intermountain West, for phenotypic variables and neutral genetic markers to measure their association with geographical origin. Phenotypic traits were measured in common field and greenhouse environments, and genetic diversity was assessed using Amplified Fragment Length Polymorphism. Three factors were extracted from the phenotypic …


Sedimentology, Stratigraphy, And Organic Geochemistry Of The Red Pine Shale, Uinta Mountains, Utah: A Prograding Deltaic System In A Mid-Neoproterozoic Interior Seaway, Caroline Amelia Myer Dec 2008

Sedimentology, Stratigraphy, And Organic Geochemistry Of The Red Pine Shale, Uinta Mountains, Utah: A Prograding Deltaic System In A Mid-Neoproterozoic Interior Seaway, Caroline Amelia Myer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Red Pine Shale (RPS; ~1120m thick), uppermost formation of the Neoproterozoic Uinta Mountain Group, Utah, is an organic-rich sedimentary succession interpreted as a marine deltaic system that delivered immature sediment from the north that mixed with mature sediment from the east. Multiple data sets suggest regional climate and sea-level changes associated with changing organic-carbon burial rates.

Six facies were identified and represent wave-, tidal-, and river-influenced parts of the distal prodelta to delta front in a marine system. These include the shale facies and associated concretion facies (distal prodelta), the shale-sandstone facies (proximal prodelta to delta front), the slump …


Hydrological Characterization Of A Riparian Vegetation Zone Using High Resolution Multi-Spectral Airborne Imagery, Osama Zaki Akasheh Dec 2008

Hydrological Characterization Of A Riparian Vegetation Zone Using High Resolution Multi-Spectral Airborne Imagery, Osama Zaki Akasheh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Middle Rio Grande River (MRGR) is the main source of fresh water for the state of New Mexico. Located in an arid area with scarce local water resources, this has led to extensive diversions of river water to supply the high demand from municipalities and irrigated agricultural activities. The extensive water diversions over the last few decades have affected the composition of the native riparian vegetation by decreasing the area of cottonwood and coyote willow and increasing the spread of invasive species such as Tamarisk and Russian Olives, harmful to the river system, due to their high transpiration rates, …


Hydrogen Production By Anaerobic Fermentation Using Agricultural And Food Processing Wastes Utilizing A Two-Stage Digestion System, Reese S. Thompson Dec 2008

Hydrogen Production By Anaerobic Fermentation Using Agricultural And Food Processing Wastes Utilizing A Two-Stage Digestion System, Reese S. Thompson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hydrogen production by means of anaerobic fermentation was researched utilizing three different substrates. Synthetic wastewater, dairy manure, and cheese whey were combined together at different concentrations under batch anaerobic conditions to determine the optimal hydrogen producing potential and waste treatment of each. Cheese whey at a concentration of 55% was combined with dairy manure at a concentration of 45% to produce 1.53 liters of hydrogen per liter of substrate. These results are significant because the control, synthetic wastewater, which was a glucose-based substrate, produced less hydrogen, 1.34 liters per liter of substrate, than the mixture of cheese whey and dairy …


Estimating Total Phosphorus And Total Suspended Solids Loads From High Frequency Data, Amber Spackman Jones Dec 2008

Estimating Total Phosphorus And Total Suspended Solids Loads From High Frequency Data, Amber Spackman Jones

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Frequently measured turbidity was examined as a surrogate for total phosphorus (TP) and total suspended solids (TSS) loads at two locations in the Little Bear River, Utah, USA. Using regression techniques, equations were developed for TP and TSS as functions of turbidity. The equations accounted for censored data, and additional explanatory variables to represent hydrological conditions were considered for inclusion in the equations. By using the resulting surrogate relationships with high frequency turbidity measurements, high frequency estimates of TP and TSS concentrations were calculated. To examine the effect of sampling frequency, reference loads were determined from the concentration records for …


Phenotypic Plasticity And The Post-Modern Synthesis: Integrating Evo-Devo And Quantitative Genetics In Theoretical And Empirical Studies, Alison G. Scoville Dec 2008

Phenotypic Plasticity And The Post-Modern Synthesis: Integrating Evo-Devo And Quantitative Genetics In Theoretical And Empirical Studies, Alison G. Scoville

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mainstream evolutionary biology lacks a mature theory of phenotype. Following from the Modern Synthesis, researchers tend to assume an unrealistically simple mapping of genotype to phenotype, or else trust that the complexities of developmental architecture can be adequately captured by measuring trait variances and covariances. In contrast, the growing field of evolutionary developmental biology (evo-devo) explicitly examines the relationship between developmental architecture and evolutionary change, but lacks a rigorous quantitative and predictive framework. In my dissertation, I strive to integrate quantitative genetics and evo-devo, using both theoretical and empirical studies of plasticity. My first paper explores the effect of realistic …


Garter Snake (Thamnophis) Natural History: Food Habits And Interspecific Aggression, Michael J. Edgehouse Dec 2008

Garter Snake (Thamnophis) Natural History: Food Habits And Interspecific Aggression, Michael J. Edgehouse

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Communication and recognition are closely intertwined and have been well documented in closely related species over the past several decades. These two types of behaviors often will aid in fostering or disrupting coexistence of similar species. Frequently, it is through different diet patterns that similar species will be able to coexist. This study uses data from 1972 through 2006 to demonstrate the diet of Thamnophis sirtalis, T. atratus, T. elegans, and T. couchii throughout their California range of sympatry with Taricha torosa. Additionally, an in depth examination of the diet of T. sirtalis, T. elegans, …


A Three-Dimensional, Time-Dependent Circulation Model Of Utah Lake, Eric V. Callister Dec 2008

A Three-Dimensional, Time-Dependent Circulation Model Of Utah Lake, Eric V. Callister

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spatial and temporal variations of Utah Lake’s flow field were modeled using the Estuary Lake and Computer Model from the Centre for Water Research (CWR-ELCOM) at the University of Western Australia as part of an effort to increase understanding of the lake’s natural processes in order to restore the lake to its pristine, clear-water state and preserve the habitat of the June sucker, an endangered species. The model was validated using temperature measurements taken by sensors in 2007. The water temperature was a strong function of air temperature and incident short wave radiation, and was influenced to a lesser degree …


Mountain Pine Beetle Fecundity And Offspring Size Differ Among Lodgepole Pine And Whitebark Pine Hosts, Donovan Gross Dec 2008

Mountain Pine Beetle Fecundity And Offspring Size Differ Among Lodgepole Pine And Whitebark Pine Hosts, Donovan Gross

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Whitebark pine (Pinus albicaulis Engelmann) is a treeline species in the central Rocky Mountains. Its occupation of high elevations previously protected whitebark pine from long-term mountain pine beetle outbreaks. The mountain pine beetle, however, is currently reaching outbreaks of record magnitude in high-elevation whitebark pine. We used a factorial laboratory experiment to compare mountain pine beetle (Dendroctonus ponderosae Hopkins) life history characteristics between a typical host, lodgepole pine (Pinus contorta Engelmann), and whitebark pine. We tested the effects of natal host and brood host on beetle fecundity, offspring size, and brood sex-ratio. We reared mountain pine beetles …


Growing Wild: Crested Wheatgrass And The Landscape Of Belonging, Lafe Gerald Conner Dec 2008

Growing Wild: Crested Wheatgrass And The Landscape Of Belonging, Lafe Gerald Conner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Crested wheatgrass arrived in North America at the turn of the twentieth century through the foreign plant exploration missions sponsored by the United States Department of Agriculture. During the first two decades of the new century, scientists tested the grass at agricultural experiment stations. They determined it was useful for grazing and particularly valuable because it could grow in drought conditions with little or no care and would continue to produce high quality feed even after several years of heavy use. Beginning in the 1930s federally sponsored land utilization and agricultural adjustment programs sponsored the use of crested wheatgrass for …


Enhancing The Proportions Of Healthy Fatty Acids In Milk From Dairy Cows, Korie A.S. Nelson Dec 2008

Enhancing The Proportions Of Healthy Fatty Acids In Milk From Dairy Cows, Korie A.S. Nelson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Twenty cows were used in a repeated measures, block design experiment for 9 wk to determine the effects of feeding partially ruminally inert calcium salts (Ca-salts) of fish oil (FO) and a general fatty acid (FA) supplement (EnerGII) at varying levels. The effects on cow health, milk components, composition of milk FA, and sensory evaluation of milk were evaluated. Cows in the 4 treatments were fed either a control diet of 57% forage and 43% concentrate mix with EnerGII fat supplement at 1.65% of diet DM (CTL) or EnerGII in basal diet was partially replaced with (a) 0.21% …


Male Out-Migration And The Women Left Behind: A Case Study Of A Small Farming Community In Southeastern Mexico, Jamie P. Mcevoy Aug 2008

Male Out-Migration And The Women Left Behind: A Case Study Of A Small Farming Community In Southeastern Mexico, Jamie P. Mcevoy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Until recently, rural households in southeastern Mexico have survived on subsistence and chili farming. But over the last decade, male out-migration to the United States has also become a popular livelihood strategy. This case study used data from semi-structured qualitative interviews to assess the effects of male out-migration on women's lives in three areas: households' financial and material situation, issues of infidelity and women's vulnerability to abandonment, and the gendered division of labor.

Overall, this study found that male out-migration had both positive and negative effects on the women left behind. First, the financial outcomes of migration were mixed. A …