Dingle Marsh is a wetland complex separating the Bear River from Bear Lake. Flow direction through the marsh is controlled at four major inflow and outflow sites. These sites were chosen as monitoring sites to assess the suspended solid and nutrient transport through the marsh. High frequency turbidity measurements were collected at each site and used as a surrogate for total phosphorus (TP) and total suspended solid (TSS) concentrations. Loads of TP and TSS were calculated using flow data from the 2008 water year. Load calculations for TP and TSS were compiled at 30-minute intervals and annual mass balances were calculated for Dingle Marsh and Bear Lake. These calculations were used to identify the seasonal loading patterns within this system. This study found the majority of TSS and TP loading entered the marsh from the Bear River. As flows moved across the marsh, the loading of TSS and TP was greatly reduced. Seasonal flow patterns were analyzed to determine the loading patterns to Dingle Marsh, Bear Lake, and the Bear River. This study also identified water management strategies aimed at setting a target endpoint for TSS and TP loads.

In 1992, the Louisiana black bear (Ursus americanus luteolus) was granted threatened status under the Endangered Species Act primarily because of extensive habitat loss and fragmentation. Currently, the Louisiana black bear is restricted to 3 relatively small, disjunct breeding subpopulations located in the Tensas River Basin of northeast Louisiana, the upper Atchafalaya River Basin (ARB) of south-central Louisiana, and coastal Louisiana. The 1995 Recovery Plan mandates research to determine the viability of the remaining subpopulations. I conducted a capture-mark-recapture study during 2007–2009 to estimate population parameters for the ARB bear subpopulation by collecting hair samples (n = 2,977) from 115 barbed-wire hair traps during 8 1-week periods each summer. DNA was extracted from those hair samples and microsatellite genotypes were used to identify individuals. I analyzed encounter histories using the Huggins full heterogeneity estimator in a robust design framework in Program MARK. I compared candidate models incorporating heterogeneity, behavior, and time effects on capture using information-theoretic methods. I directly estimated apparent survival, temporary emigration, probability of capture and recapture, and probability of belonging to 1 of 2 mixtures; population abundance was a derived parameter. Apparent survival was 0.91 (SE = 0.06) and did not vary by gender or year. There was some evidence of temporary emigration for males only (0.10, 95% CI = 0.001–0.900). I modeled capture probabilities with a 2-mixture distribution for both male and females. Overall mean weekly capture probability was 0.12 (SE = 0.03) and 0.25 (SE = 0.04) for males and females, respectively. Recapture rates indicated a positive behavioral response to capture. Model-averaged mean annual abundance was 56 (SE = 4.5, 95% CI = 49–68). I calculated population density using spatially-explicit maximum-likelihood methods; model-averaged density was 0.15 bears/km2 (SE = 0.03). My results updated previous abundance estimates for the ARB bear subpopulation and will be used in a population viability analysis to determine if recovery criteria for the Louisiana black bear have been met.

Heavy metals can serve as a significant component of pollution in watersheds. In this study, ICP-MS analysis was used to determine the heavy metal content (Cd, Cr, Cu, Mn, Pb, and U) in water and sediment of three different Costa Rican watersheds: the Tarcoles River, the Terciopelo Creek, and the Cacao Creek. While the metal content of each the Terciopelo Creek and Cacao Creek was expected to be lower than that of the Tarcoles River, the results showed that this held true only for Cr and Pb. Elevated levels of the other four metals (Cd, Cu, Mn, and U) in the Terciopelo and Cacao Creeks are likely due to natural, lithogenic origin instead of anthropogenic input.

Obesity has becoming one of the nation’s largest health concerns. An individual’s physical activity, diet, sedentary behaviors, and alcohol consumption patterns all play a role in fluctuation of BMI. While it is known that all of these can affect obesity, it is less commonly known how these behaviors cluster together in emerging adulthood. Uncertainty shrouds how these characteristics cluster together in young-adults. The purpose of this study is to utilize the 2015-2016 NHANES data to explore relationships of alcohol consumption, physical activity and sedentary behaviors to ascertain how strongly these measures of health cluster, and in what demographics do they most strongly cluster. A two-step cluster analysis resulted in 4 clusters being created with physical activity being the predominate indicator for grouping. Continuing analyses regarding the association of race, sex, and BMI are being conducted.

PART I Hollow-sphere (HS) steel foam is a relatively new material whose cellular morphology and material properties qualify it as a metallic foam. This is an innovative foam-like material that exhibits high stiffness paired with low relative densities. Technological advancements in the past few decades have enabled the manufacturing of this material by a sintering process and, as a result, research has begun to accelerate as a multi-school collaboration effort for this particular work. Even though commercialization has been a challenge for metallic foams, it is imperative that researchers continue to prove and promote the advantages of metallic foams despite the current challenges posed by commercialization. One of the most promising characteristics of metallic foams is their energy absorption capacity. This work explores hollow-sphere steel foam’s ability to absorb energy at high strain rates under a dynamic impact load and builds upon an earlier work of quasi-static compression loading. Since most research in this field has been attributed to aluminum open-cell foams, the objective of this work seeks to build upon and apply existing methods to cultivate new research material for hollow-sphere steel foam. The premise of this work began with experimental research analyzing stress-strain relationships of a mass impacting samples of HS steel foam with different kinetic energies. As a result, material properties were extracted and quantified such as elastic modulus, yield stress, and energy absorption, among others. These properties set the foundation for the next set of research; finite element analysis whose objective is to develop a functional material model that could be used for a later application in structural engineering, such as a blast or crash impact. PART II The second part of this thesis applies structural engineering mechanics to a complex arboricultural project. A particular American elm (Ulmus americana L.) tree is the focus of analysis due to its usage for tree climbing competitions. Structurally, this work is relevant to structural engineering by involving finite element analysis of a branch of this American elm tree. This particular work has the objective of understanding how a particular American elm branch behaves structurally under a variety of dynamic loads with different input parameters. Before any of the analyses can be implemented, the definite geometry of the tree has to be measured and material properties have to be calculated. Field experimental data are imperative for this project so that the idealized model can represent the real system as best as possible. Following the data acquisition and modeling of the tree, loads that were either measured or calculated are applied. These loads can be idealized as an impulse load and a cyclic load, with variability imposed within each of them. It is within this variability of the parameters within the loads that the purpose of this work arises. By applying extreme loads upon this tree branch, critical points along the branch can be identified by calculating maximum bending and axial stresses. These stresses indicate not only the critical points along the primary branch but in addition, they indicate the magnitude and severity of these potential stresses, which can be compared directly with the mechanical properties of the wood in the branch. The final intent of this work is to contribute to the knowledge of how a particular branch behaves dynamically in order to better equip tree climbers, academics, and professionals by integrating structural mechanics and arboriculture.

Snow accumulation and melt characteristics were studied in Logan Canyon, Utah. Three replications of aspen, conifer, and open field types at 6300, 7100,and 8000 feet were measured for snow depth and water content during 1972. Elevation was found to have the greatest effect on snow water content. The gradient of increasing water content with rise ln elevation was found to be .51 inches/100 feet in the zone from 6300 to 7100 feet and 1.9 inches/100 feet from 7100 to 8000 feet. The cooler temperatures at higher elevations partially account for the 8000 foot zone beginning to melt 40 days after the 7100 foot zone, and the 7100 foot zone trailing the 6300 foot zone by 20 days. Although the snow at the 8000 foot elevation began melting later than the lower zones, it melted at twice the rate. Vegetation cover type has no significant effect on the amount of snow deposited. However, the conifer type protects the snowpack from solar radiation causing the snowpack to have a significantly lower density than the snowpack assocaited with either aspen or open field. The snowpack under the conifer canopy melts 30 percent slower and remains 17 days longer.

Checking stations operated during the deer hunting season serve a two-fold purpose. It has long been recognized that such inspection stations aid greatly in the enforcement of hunting laws through the detection of illegal practices, and in many cases have been set up with this as a primary purpose. A more far reaching objective, however, is the collection of information to aid in the solution of the problems of maintenance of the range and the deer herd, and determination of the quality and quantity of the deer removal.

Orthoptera, especially the family Locustidae, is one of the most important and most interesting orders of insects in the state of Utah. It includes a polyphagus group of great economic importance in the state. The topography and climate of Utah varies from forested alpine slopes to hot arid desert wastes, several life zones being represented. This great variation from desert to alpine in Utah presents a rather unique region for taxonomic and ecological studies of the Orthoptera. The most familiar representatives of the insect order Orthoptera are the long-horned grasshoppers, locusts, crickets, katydids, and cockroaches. Orthoptera are characterized by Comstock as those insects having mouth parts fitted for chewing, gradual metamorphosis, nymphal development terrestrial, with 2 pairs of wings or with wings bestigial or wanting. In winged forms the fore wings are more or less thickened, but have distinct venation; the hing wings, when at rest, are folded in plaits like a fan. The family Locustidae, called Acrididae by many authors, includes the locusts or short-horned grasshoppers, which are characterized by having short antennae, 3-jointed tarsi, and a short ovipositor in the female. The ovipositor has 4 separate spines and an egg guide for ovipositing. The 4 separate spines are used to penetrate the ground to a depth corresponding to the length of the abdomen. The eggs are then placed 1 at a time in regular order by the egg guide. During the process of egg-laying a fluid is secreted which hardens and binds the eggs together into a definite mass. The organs of hearing are situated on the first abdominal segment. There are 4 subfamilies of Locustidae. The Acrydiinae, commonly called pigmy locusts, have the pronotum extending over the entire dorsum of the abdomen; the claws of the tarsi have no arolium between them. The other 3 subfamilies have the pronotum extending, at most, only over the base of the abdomen, and the claws of the tarsi have an arolium between them. The Cyrtacanthacrinae (Locustinae), or spur-throated locusts, have the prosternum armed with a distinct conical tuberole. The Oedipodinae, or banded-winged locusts, lack the prosternal tubercle and have the head rounded at the union of the vertex and front. The Acridinae, commonly called slant-faced locusts, is the subfamily under consideration in this paper. The slant-faced locusts have a low median pronotal carina which is cut by one transverse sulcus; the front and vertex usually meet in an acute angle.

The habitat requirements of western freshwater mussels, Anodonta, Gonidea, and Margaritifera, remain unclear despite their imperiled status. Freshwater mussels provide a series of ecosystem services including habitat enhancement, substratum stabilization, nutrient cycling, and water clarification, which makes their loss from aquatic ecosystems particularly detrimental. To improve the efficacy of restoration actions targeting these organisms, I used random forest modeling to investigate the biotic and abiotic factors influencing mussel density and distribution throughout a 55-kilometer (km) segment of the Middle Fork John Day River (MFJDR), in northeastern Oregon. Data was collected to characterize the occurrence of mussels with respect to the hierarchical, hydrogeomorphic structure of habitat within reaches of varying valley confinement and channel units nested within these reaches. Data regarding functional habitat features were also included to ensure that models included the wide range of characteristics that mussels need from their environment. By collecting data at both the reach and channel unit scale, I was able to investigate how mussel densities and distributions vary with spatial scale and other biophysical parameters. Throughout the study area, Margaritifera density exhibited a unimodal distribution with respect to river km, while Anodonta and Gonidea density showed a negative relationship with river km and exhibited higher densities downstream. The large scale, longitudinal trends of Margaritifera were related to hydrogeomorphic characteristics at the reach scale, while less than half of the longitudinal variation in Anodonta and Gonidea were explained by hydrogeomorphic and water quality parameters. At the channel unit scale, all mussel genera responded to the patchy variation in physical habitat characteristics, particularly habitat factors that indicated more stable parts of the channel. Overall, physical habitat characteristics such as woody debris, emergent aquatic vegetation, coarse substratum, and channel morphology were more important than hydraulic, biotic, and chemical variables. These results suggest that at both the reach and channel unit scales, mussel density and distribution are influenced by high flow refugia and the hierarchical structuring of hydrogeomorphic habitat characteristics. These results will assist mussel restoration efforts by providing specific guidance about the types of physical habitat conditions that are suitable for mussels.

This thesis reports the results of a project which identified differences in characteristics of Grand Staircase-Escalante National Monument user groups as they related to their perceptions of how they experience the Monument as recreationists. It explored opinions of four groups: hikers vs. hunters and pre-designation users vs. post-designation users. Responses of these groups were compared for attribution of perceived resource damage, feelings of crowding, acceptability of management action, and importance of identified monument values to their visit. In addition, characteristics of the users were examined to determine if demographic characteristics accounted for differences in perception toward the resources. Finally, how these groups perceived grazing livestock and multiple uses on the monument was examined. Significant differences were found between most categories in hunters and hikers. Predesignation visitors and post-designation visitors differed only in a few categories.