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High Sugar Diet Alters Immune Function and the Gut Microbiome in Juvenile Green Iguanas \u3ci\u3e(Iguana iguana)\u3c/i\u3e
Get PDFThe present work aimed to study whether a high sugar diet can alter immune responses and the gut microbiome in green iguanas. Thirty-six iguanas were split into four treatment groups using a 2x2 design. Iguanas received either a sugar-supplemented diet or a control diet, and either a lipopolysaccharide (LPS) injection or a phosphate-buffered saline (PBS) injection. Iguanas were given their respective diet treatment through the entire study (~3 months) and received a primary immune challenge 1 and 2 months into the experiment. Blood samples and cloacal swabs were taken at various points in the experiment and used to measure changes in the immune system (bacterial killing ability, lysis and agglutination scores, LPS-specific IgY concentrations), and alterations in the gut microbiome. We found that a sugar diet reduces bacterial killing ability following an LPS challenge, and sugar and the immune challenge temporarily alters gut microbiome composition while reducing alpha diversity. Although sugar did not directly reduce lysis and agglutination following the immune challenge, the change in these scores over a 24-h period following an immune challenge was more drastic (it decreased) relative to the control diet group. Moreover, sugar increased constitutive agglutination outside of the immune challenges (i.e. pre-challenge levels). In this study, we provide evidence that a high sugar diet affects the immune system of green iguanas (in a disruptive manner) and alters the gut microbiome
What Happened to the Geometry? Examining Spatial and Mathematical Concepts in Computational Toys and Kits for Young Children
Get PDFThis paper explores the design of computational toys and kits for young children (ages 4-7) as tools for learning integrated mathematical, spatial, and computational thinking concepts. Specifically, we examine how the design features of the toys and kits represent the concepts of rotation on a point and spatial orientation of the agent. We examine toys and kits sold commercially, developed through research, and used in early childhood classrooms. Our findings indicate that the mathematical and spatial concepts are overlooked in some designs. Prior research examined toys for their affordances related to computational thinking, the present study contributes to understanding of how these toys and kits have the potential to foster foundational mathematics and spatial skills. We discuss implications for design of toys and kits as well as recommendations for future research
Storing and Managing Water for the Environment is More Efficient Than Mimicking Natural Flows
Get PDFDams and reservoirs are often needed to provide environmental water and maintain suitable water temperatures for downstream ecosystems. Here, we evaluate if water allocated to the environment, with storage to maintain it, might allow environmental water to more reliably meet ecosystem objectives than a proportion of natural flow. We use a priority-based water balance operations model and a reservoir temperature model to evaluate 1) pass-through of a portion of reservoir inflow versus 2) allocating a portion of storage capacity and inflow for downstream flow and stream temperature objectives. We compare trade-offs to other senior and junior priority water demands. In many months, pass-through flows exceed the volumes needed to meet environmental demands. Storage provides the ability to manage release timing to use water efficiently for environmental benefit, with a co-benefit of increasing reservoir storage to protect cold-water at depth in the reservoir
Influential Individuals can Promote Prosocial Practices in Heterogeneous Societies: A Mathematical and Agent-Based Model
Get PDFIn this paper, we examine how different governance types impact prosocial behaviors in a heterogenous society. We construct a general theoretical framework to examine a game-theoretic model to assess the ease of achieving a cooperative outcome. We then build a dynamic agent-based model to examine three distinct governance types in a heterogenous population: monitoring one\u27s neighbors, despotic leadership, and influencing one\u27s neighbors to adapt strategies that lead to better fitness. In our research, we find that while despotic leadership may lead towards high prosociality and high returns it does not exceed the effects of a local individual who can exert positive influence in the community. This may suggest that greater individual gains can be had by cooperating and that global hierarchical leadership may not be essential as long as influential individuals exert their influence for public good and not for public ill
Pursuit and Escape Drive Fine-Scale Movement Variation During Migration in a Temperate Alpine Ungulate
Get PDFClimate change reduces snowpack, advances snowmelt phenology, drives summer warming, alters growing season precipitation regimes, and consequently modifies vegetation phenology in mountain systems. Elevational migrants track spatial variation in seasonal plant growth by moving between ranges at different elevations during spring, so climate-driven vegetation change may disrupt historic benefits of migration. Elevational migrants can furthermore cope with short-term environmental variability by undertaking brief vertical movements to refugia when sudden adverse conditions arise. We uncover drivers of fine-scale vertical movement variation during upland migration in an endangered alpine specialist, Sierra Nevada bighorn sheep (Ovis canadensis sierrae) using a 20-year study of GPS collar data collected from 311 unique individuals. We used integrated step-selection analysis to determine factors that promote vertical movements and drive selection of destinations following vertical movements. Our results reveal that relatively high temperatures consistently drive uphill movements, while precipitation likely drives downhill movements. Furthermore, bighorn select destinations a their peak annual biomass and maximal time since snowmelt. These results indicate that although Sierra Nevada bighorn sheep seek out foraging opportunities related to landscape phenology, they compensate for short-term environmental stressors by undertaking brief up- and downslope vertical movements. Migrants may therefore be impacted by future warming and increased storm frequency or intensity, with shifts in annual migration timing and fine-scale vertical movemen
Investigating the Biochemical Aspects of Meat Tenderness
Get PDFOf all the attributes that define beef\u27s eating quality, tenderness stands out as one of the most important. Previous studies have shown that consumers are willing to pay a premium for beef that is guaranteed to be more tender and are more likely to purchase that product repeatedly. Yet, due to the influence of numerous internal and external factors, controlling and predicting tenderness remains to be difficult. However, among these factors, meat aging is the primary contributor to end-product tenderness, as it is recognized for breaking down muscle tissue via enzymes present within the muscle. The activity of these enzymes weakens the structural integrity of muscle proteins and, consequently, results in meat that requires less force to chew (i.e., tenderness). The calpains, caspases, and cathepsins are three of the main enzyme families that participate in meat aging; however, the calpains contribute the most to this process. Despite the current understanding of meat aging and the enzymes that participate, producing consistently tender products is still an issue within the meat industry. This means that the aging process is not fully understood and there are more controlling factors that remain undiscovered.
Previous studies have found that many biochemical characteristics within meat can contribute to the aging process. These include the predominant muscle fiber type and its associated attributes within different muscles, the integrity and function of cellular machinery such as the powerhouse of the cell (mitochondria), and whether or not the meat has been previously frozen/thawed. However, the influence of these factors on the enzymes contributing to aging and the overall structural changes within the tissue could help us further understand what ultimately affects meat tenderization and end-product tenderness. Therefore, the purpose of this project is to use biochemical methods to evaluate the internal characteristics of different muscles, the abundance of mitochondria, and how freezing storage influences aging and subsequent meat quality in beef, to better understand the processes that affect meat tenderization. This is an effort to provide foundational knowledge that will enhance meat palatability and reduce variations in beef tenderness. To accomplish this, we performed four independent studies. Our first study examined the progression of protein breakdown during aging between muscles with unique muscle fiber compositions and biochemical properties. The second study evaluated how different concentrations of mitochondria alter protein breakdown along with enzyme activity, utilizing an in vitro system containing all of the chemicals needed to recreate postmortem conditions. Our third study sought to test how freezing/thawing and then aging the meat influences enzyme activity compared to only aging the meat, while our final study looked into different freezing/thawing rates and their effects on the microstructure and overall quality of large sections of meat known as primals.
Overall, our results showed that meat aging is a complicated process but is largely influenced by the fiber type composition and accompanying biochemical properties within different muscles, mitochondrial abundance, and integrity, whether the meat had been previously frozen/thawed, and the rates to which freezing/thawing occurred. Moreover, this project provides a greater understanding of the biochemical aspects of meat aging and their importance when optimizing beef tenderness. However, further research is needed to evaluate different breeds and species of meat-producing animals
Development of a Multidimensional Index of Fall Risk for Older Adults: The Cache County Study
Get PDFOne out of four adults over the age of 65 are estimated to fall each year in the U.S. alone, with that number expected to rise to 52 million falls per year by the year 2030. Improving accuracy for identification of older adults at a higher risk of falling is increasingly important and may be integral in informing the distribution of limited resources and assist in preventing falls in older adults. This project examined the relationship between previously identified risk factors and fall risk to create multidimensional fall risk indexes for older adults, specific for each sex.
Factors best associated with risk of falling for females included having a history of past falling, sociodemographic information, dependence on instrumental activities of daily living, cognitive status, number of medical conditions, fall risk inducing drug (FRID) use, and being underweight. For males, the above domains, except for being underweight and use of FRIDs were associated with risk of falling.
These risk factors were used to create and validate a fall risk index, separately for each sex. The index for females predicted fall risk such that for every one-point increase on the index, there was a doubling in the hazard of experiencing a future fall, whereas for males, there was a 77% higher hazard of falling for every one-point increase on the index. With respect to the accuracy of the index, for females, the index correctly identified a future fall 69%, 74%, and 79% of the time at 1, 5, and 10 years into the study, respectively. For males, the index correctly identified a future fall 63%, 70%, and 75% of the time at each of the above time points.
The results of this study demonstrated improvement in predicting the risk of falls compared to several previously established and validated measures for evaluating fall risk and provide support to the hypothesis that fall risk is multifactorial. This project additionally highlights the role that sex plays in fall risk and is the first fall risk index developed for each sex
Mathematical and Statistical Methods to Harness Limited Data in Models for Ecological Space Use Under Global Change
Get PDFThe dynamics of how plants and animals use space in their habitats has important implications for the fields of ecology and conservation. However, understanding and responding to these spatial and temporal dynamics is often limited by data availability, financial resources and biases. As average global temperatures increase, suitable habitats shift poleward and require local populations to move with suitable habitat, adapt to the changing environment, or risk extinction. Capacity to persist without movement may be estimated by considering changes to a combination of habitat characteristics. Capacity to track suitable habitat may be modeled through synthesizing information on species demographic mechanisms and dispersal patterns. In this dissertation, I present mathematical and statistical approaches to making best use of limited data to investigate ecological space use under global change
Feature Selection in Multivariate Time Series Data for Enhanced Solar Flare Classification
Get PDFSolar flares are powerful eruptions of energy from the Sun that can cause disruptions to technology here on Earth, like communication systems, GPS, and power grids. To help manage these risks, it’s important to accurately identify and classify these solar flares before they cause problems. In our research, we focused on improving how we classify solar flares by looking at large sets of complex data collected over time. We used several techniques to find the most important factors that help us tell different types of solar flares apart. Each method has its strengths, so instead of relying on just one, we developed a new approach that combines the results from multiple methods. This combined approach, called an ensemble method, gives us a more accurate and reliable way to classify solar flares. By better understanding which factors are most important in predicting solar flares, our method can help improve the accuracy of space weather warnings and reduce the chances of unexpected disruptions to our technology. Our findings show that this new approach significantly improves the accuracy of solar flare classification, providing valuable insights that can help us better protect our technology and daily life from the impacts of solar activity
Changes in Climate and Their Implications for Cattle Nutrition and Management
Get PDFClimate change is a global challenge that impacts rangeland and pastureland landscapes by inducing shifts in temperature variability, precipitation patterns, and extreme weather events. These changes alter soil and plant conditions, reducing forage availability and chemical composition and leading to nutritional stress in cattle. This stress occurs when animals lack adequate water and feed sources or when these resources are insufficient in quantity, composition, or nutrient balance. Several strategies are essential to address these impacts. Genetic selection, epigenetic biomarkers, and exploration of epigenetic memories present promising avenues for enhancing the resilience of cattle populations and improving adaptation to environmental stresses. Remote sensing and GIS technologies assist in locating wet spots to establish islands of plant diversity and high forage quality for grazing amid ongoing climate change challenges. Establishing islands of functional plant diversity improves forage quality, reduces carbon and nitrogen footprints, and provides essential nutrients and bioactives, thus enhancing cattle health, welfare, and productivity. Real-time GPS collars coupled with accelerometers provide detailed data on cattle movement and activity, aiding livestock nutrition management while mitigating heat stress. Integrating these strategies may offer significant advantages to animals facing a changing world while securing the future of livestock production and the global food system