100039 research outputs found
Sort by
Selecting Irrigated Alfalfa Varieties
No full textSelecting an alfalfa variety is one of the most important decisions an alfalfa producer can make and is the cornerstone of successful alfalfa production. Variety selection directly impacts yield potential, forage quality, stand persistence, pest and disease resistance, and environmental adaptation—all factors that can have a major economic impact. Informed decisions can be made by carefully considering the goals of your operation and adhering to the criteria outlined in this fact sheet
Data accompanying Landscape composition surrounding restoration projects modulates use by wildlife: a case study of mule deer in Utah
No full textWith mule deer (Odocoileus hemionus), hereafter, deer, populations in decline, wildlife managers have increased their efforts to improve factors that limit population growth. In the State of Utah (hereafter, Utah), these efforts have included habitat restoration which is expected to improve environmental conditions for deer. Some of these efforts include pinon-juniper removal, prescribed burning, and spraying of invasive plant species. Although previous work has demonstrated the local impacts of restoration on deer populations, it is unknown how the environmental conditions in the landscape surrounding restoration treatments may modify local restoration impacts. Identifying how both local and landscape-scale conditions influence deer response to habitat restoration would ensure valid inference, and enable spatially-precise management recommendations. Our objective was to identify the scale-specific environmental drivers that influence mule deer seasonal use of 8 types of restoration projects using data from 1,936 GPS-collared deer from 2015-2021, and 813 treatment sites. Our findings showed that the abundance of collared deer on restoration sites is related to both the type of restoration treatment examined, and patterns of landcover composition surrounding restoration sites at 1, 5, 10, and 20km spatial scales. While High Elevation Fire Rehabilitation and Sagebrush Restoration treatments, and Pinyon-juniper Removal treatments had the highest relative use during summer, and winter, respectively, use of treatments during winter was greater in landscapes containing additional treatment sites. We found that during winter, relative use across all treatment types was higher when restoration projects were sited within 10-20km of Pinyon-Juniper Removal treatments with and without seeding. Restoration projects that were not sited in proximity of Aspen restoration or Low Elevation Fire Rehabilitation sites also had higher estimated use during winter. Together, our analyses can provide decision support for determining the optimal locations for future restoration treatments to strategically design landscapes expected to support the highest relative use by focal wildlife
The Impact of Transmission Thresholds Across Multiple Scales on the Spread of Chronic Wasting Disease in Wisconsin
No full textWildlife diseases can be difficult to control once they are established. This is especially true when they spread through contact with infectious material left in the environment. One such disease is chronic wasting disease (CWD), a fatal illness affecting deer and related species in North America and other regions. CWD is caused by prions, misfolded proteins that can remain infectious for years after shedding by infected hosts.
Recent research shows that CWD infection does not always follow from the gradual accumulation of prions through small contact events. Rather, an individual may need to encounter a certain prion dose all at once to become infected. This thesis explores what happens when this threshold dosage phenomenon is treated as a core feature in disease models.
Using mathematical tools that model animals across space and time at the population scale, I show how infection thresholds can change the way CWD spreads through a population. One mode of spread is a pulled front, in which an infected animal passes CWD directly to more than one healthy individual on average. This may be likened to a fire spreading through dry brush; even a single ember moving to unspent fuel is enough to carry the blaze ahead. Thresholds, conversely, may lead to pushed fronts, in which enough infected animals must arrive together to overcome the threshold. This is more like fire moving through damp material, where enough burning material must accumulate to dry the wood before it can ignite. The front types behave differently across highly variable landscapes, and are affected in complex ways by the frequency and distance of juvenile dispersal.
To understand how these findings play out in the real world, I build a model of CWD in Wisconsin white-tailed deer, based on years of disease sampling data from deer taken by hunters. The findings offer a realistic ballpark estimate for how threshold-based infection may shape the geographic spread of outbreaks. These insights could inform future efforts in surveillance and control
Curriculum Subcommittee Minutes November 6, 2025
No full textApproval of Minutes - October 2, 2025 Program Proposals Semester Course Approval Reviews Other Business Adjourn: 3:00 p
High Altitude Labyrinth Design and Construction
No full textGEI worked with a Colorado district to design and construct a labyrinth spillway at a high-altitude reservoir west of Denver. The labyrinth spillway increased the reservoir normal water surface elevation 10 feet, increasing reservoir storage capacity by 120 acre-feet. This additional storage was achieved with the labyrinth with minimal modification to the existing embankment dam. The site presented challenges including significant ice loading on the weir structure, complex rock conditions requiring seepage control measures, and unique construction techniques.
A labyrinth weir configuration was chosen to increase discharge capacity with minimal adjustment to the existing spillway footprint and to pass the Inflow Design Flood with the higher water surface. Empirical design methods were used to develop the labyrinth weir geometry. The spillway has 3 cycles and is 92 feet wide and 111 feet long. This paper presents a comparison of the recent computational fluid dynamics modeling and the spreadsheet-based results
Empower Yourself Through Self-Defense: Enhancing Personal Safety Through Self-Defense Education
No full textThe Empower Yourself Through Self-Defense program, developed by Utah State University faculty in 2024, builds participants’ confidence by equipping them with self-defense knowledge and skills. Participants reported reduced fear, increased preparedness, and strong interest in continued training. The program enhances personal safety by empowering individuals with practical skills for self-protection
Diverse Dust Sources and Warming Trigger Cyanobacteria Abundance in Freshwater Ecosystems in the Western United States
No full textThe rise in global temperature and the increase in atmospheric transport and deposition of dust linked to greater aridity, land abandonment, and wildfires, are placing significant stress on freshwater microbial communities. Temperature increases and the nutrients contained in the dust may independently and together alter the metabolism and structure of these communities. However, dust chemistry is widely variable, and pre-existing lake conditions will likely influence the response of the algal and microbial communities to added nutrients and temperature stress. To fill this gap of knowledge, we tested the metabolic and structural response of phytoplankton in two aquatic ecosystems in the Western United States (Half-Moon Lake and Jordanelle Reservoir), which have similar trophic status but different biogeochemical properties, in response to two types of atmospheric dust from the region. The results show that the Temperature × Dust interaction led to greater cyanobacteria growth in Half-Moon compared to Jordanelle. The effect on metabolism also differed, with Half-Moon showing a tendency toward heterotrophy, while Jordanelle trended toward autotrophy. Interestingly, our study reveals that the direction of the response was mainly regulated by each ecosystem\u27s properties, while the magnitude of the response was controlled by the type of dust. Through this work, we demonstrate that oligotrophic freshwater ecosystems are sensitive to dust-nutrient additions leading to cyanobacterial blooms and highlight the importance of considering watershed biogeochemical properties and exposure to different types of dust in lake and reservoir management strategies
Combining Submicron Spectroscopy Techniques (AFM-IR and O-PTIR) to Detect and Quantify Nanoplastics in Snow From a Utah Ski Resort
No full textAtomic force microscopy-based infrared spectroscopy (AFM-IR) and optical photothermal infrared (O-PTIR) spectroscopy are cutting-edge techniques used for precise nanoscale chemical analysis, capable of detecting and characterizing particles smaller than 1 μm. In this study, we applied both techniques to analyze snow subsamples collected from Beaver Mountain, Utah. Quantification by AFM-IR identified a concentration of 1.50 × 10–1 μg/mL of poly(3-hydroxybutyrate-co-4-hydroxybutyrate), a copolyester known for its biodegradability and biocompatibility and that was the only polymer detected. Notably, 96% of particles had thicknesses below 1 μm, with the smallest particle recorded at 14 nm in height, demonstrating the advantage of the paired AFM-IR and O-PTIR techniques to detect and identify the chemical composition of a single nanoparticle. By integrating AFM-IR and O-PTIR, we combined the spatial resolution of AFM with the chemical specificity of O-PTIR, overcoming the limitations of each technique. This dual approach enabled high-sensitivity detection of nanoplastics in complex environmental samples with no preprocessing required. This approach provides valuable insights into the dimensions and concentrations of nanoplastics in environmental samples, with broader implications for understanding their prevalence and impact
Strategies for Increasing Methane Removal in Methanotroph Stirred-Tank Reactors for the Production of Ectoine
No full textMethane is a potent greenhouse gas that requires its emissions to be mitigated. A significant source for methane emissions is in the form of the biogas that is produced from anaerobic digestion in wastewater reclamation and landfill facilities. Biogas has a high valorization potential in the form of its bioconversion into ectoines, an active ingredient in skin care products, by halotolerant alkaliphilic methanotrophs. Cultures of Methylotuvimicrobium alcaliphilum 20Z were grown in bench scale stirred-tank reactors to determine factors to improve methane uptake and removal. Tangential flow filtration was also implemented for a bio-milking method to recover ectoine from culture media. Methane uptake and reactor productivity increased, with a temperature of 28 ◦C compared with 21 ◦C. Decreasing the methane gas bubble diameter by decreasing the sparger pore size from 1 mm to 0.5 µm significantly improved methane removal and reactor productivity by increasing mass transfer. Premixing methane and air before sparging into the reactor saw a higher removal of methane, while sparging methane and air separately created an increase in reactor productivity. Maximum methane removal efficiency was observed to be 70.56% ± 0.54 which translated to a CH4-EC of 93.82 ± 3.36 g CH4 m−3 h −1 . Maximum ectoine yields was observed to be 0.579 mg ectoine L−1 h −1
Intergenerational Transfers in a Tractable Overlapping-Generations Setting
No full textMotivated by the Generation-Skipping Transfer Tax (GSTT) in the United States, we examine how varying estate tax rates by the heir’s age affects welfare. Methodologically, we introduce a parsimonious constant elasticity of substitution (CES) bequest utility that is markedly more tractable than the altruistic specifications commonly used in the literature, delivering closed-form optimal rules and transparent parameterization. Using this new framework, we provide a proof of concept showing how transfers from older to younger generations can enhance equilibrium welfare in a dynamically efficient economy à la Samuelson (1975). We embed the tractable bequest utility in a two-period overlapping-generations model with age-dependent estate tax schedules. Numerical exercises—parameterized to the fact that estate tax revenue is small relative to labor income taxation—indicate that lowering the tax rate on bequests to younger heirs (grandchildren) relative to older heirs (adult children) raises the present value of lifetime resources and overall welfare, effectively reversing the logic of the current GSTT. The findings highlight a practical avenue for implementing a “reverse social security” transfer from old to young that can improve welfare in dynamically efficient economies