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Soil Health and Crop Connectivity in Barley-Pulse Intercropping Systems
No full textSoil health is a necessity for a sustainable future from food security to ecosystem health. Nearly 38% of the earth’s land surface is farmed, meaning agriculture has an enormous role in maintaining the capacity of soil to sustain plants, animals, and humans. We are faced with the challenge of increasing production on this land to support current and projected population growth without jeopardizing the future by degrading our soil. This challenge is exacerbated by climate change and instability leading to changes in weather patterns, temperature, and precipitation regimes worldwide. In Idaho, producers face challenges such as drier summers, higher temperatures, and extreme precipitation, leading to increased demand for limited water resources. As such, there is a clear need to investigate growing strategies that are resilient to water stress and advantageous to soil health. The production of barley and nitrogen-fixing pulse crops such as lentils and peas, often in rotation, is already a staple of Idaho agriculture. This research investigates the effects of growing barley and pulse crops together simultaneously (intercropping) on soil health, focusing specifically on nutrient status and soil microbial communities. To understand the role water limitation will play in intercropping, soil health was measured under full irrigation and deficit irrigation conditions. We demonstrated that complementary root strategies in barley/pulse intercropping allow a more complete use of water and nitrogen in the soil profile, as barley accesses deeper resources than pulse crops. The reduced competition to barley led to improved barley yields under intercropping, while pulse crop yields were reduced. Under water stress, these yield dynamics were exacerbated, likely because reliance on the unique resource niche accessed by each crop was more apparent when water was limiting. Intercropping additionally altered the soil microbial community, overall increasing diversity as compared to barley grown alone. This shift was especially apparent for barley/lentil intercropping. The response of barley to intercropping with peas as compared to lentils was not identical. Intercropping barley with pea resulted in greater relative yields than intercropping with lentil, likely due to increased nutrient availability. Stable isotope tracing of pulse crop nutrient allocation suggests that peas release a greater proportion of fixed carbon and nitrogen to the soil than lentils, increasing access to companion crops and microbes. Further, we demonstrated the short-term connectivity of barley and pulse crops grown together, with nitrogen fixed by pulse crops detected in the roots of companion barley crops within the range of several days. Significant changes in soil health metrics observed after a single growing season are a positive indication that intercropping barley and pulse crops is a strategy that could benefit producers. Data obtained from subsequent growing seasons will further clarify the longer-term effects of intercropping and water availability on soil nutrients, microbial community, and productivity. This work can help to inform management decisions such as inputs and crop selection for producers aiming to employ diverse cropping strategies and improve soil health.masters, M.S., Environmental Science -- University of Idaho - College of Graduate Studies, 2022-0
Empirical Analysis of Molecular Modeling and Evolution of Respiratory Syncytial Virus Fusion Glycoprotein Antibody Escape Variants
No full textRespiratory syncytial virus (RSV) is an important pathogen that causes severe lower respiratory infections in young infants, the immunocompromised, and the elderly. There are no vaccines or targeted anti-viral drugs for active RSV infection and only supportive care for hospitalized patients. The only approved treatment by the FDA is the prophylactic monoclonal antibody, palivizumab, given exclusively to high-risk infants during cold and flu season. The consequence of using monoclonal antibodies to prevent or treat viral infection is that it puts selective pressure on a specific epitope, which can result in a phenomenon called antibody escape. Current identification of antibody escape variants relies on patient samples or passage experiments. In this project, we aimed to use molecular modeling to identify antibody escape variants. We used molecular modeling to predict single mutations in RSV fusion glycoprotein (F protein) that would disrupt the binding of the palivizumab derivative, motavizumab, but not disrupt the folding of the F protein monomer. We accurately predicted eight F protein variants that propagated new virus. Six of our eight mutations were identified as monoclonal antibody resistant mutants (MARMs) that had reduced neutralization and binding by motavizumab. Surface plasmon resonance revealed a reduced on-rate for motavizumab for K272E, L258K, and S275H. We then examined the evolutionary pathway of RSV F protein using passage and fitness experiments to understand the likelihood and relevance of our predicted MARMs. We directed the evolution of RSV and derived a novel escape variant from passage experiments. This study empirically tested and validated the accuracy of our molecular modeling approach. We accurately predicted viral resistance to a monoclonal antibody and established a methodology that can be used to monitor the emergence of resistant viruses.doctoral, Ph.D., Biological Sciences -- University of Idaho - College of Graduate Studies, 2022-0
Bears, berries, bearings on the landscape: Monitoring American black bear (Ursus americanus) populations, habitat use, and movements in Idaho
No full textBlack bears populations have historically been managed using harvest data and mark-recapture methods. New methods such as the time to event and space to event models have opted to estimate unmarked populations using trail cameras and have so far been tested on high density ungulate species and low density carnivore species. In the first chapter, we apply these two models to estimating black bear populations in several study areas across Idaho. Black bears represent an optimal species to test these models because they occur at a medium density between most carnivores and ungulates and have different movement patterns and life histories. We tested the efficacy of these models by comparing the resulting densities to comparable black bear densities found throughout similar habitats. We found that while the models did sometimes find comparable density estimates, they were often dependent upon camera placement style and the time to event model tended to overestimate populations frequently. Incorporating bootstrapping worked to bring some estimates into the comparable density range (particularly with time to event), but still resulted in high estimates. Bootstrapping the space to event model, however, often biased estimates quite low, presenting an issue where bootstrapping the models was not always the best course of action. Black bear recruitment in Idaho is strongly correlated with the late summer huckleberry crop, with low crops affecting fall black bear weights and the capability to successfully reproduce. In chapter two, we attempted to create a model predicting the huckleberry crop for the upcoming year so that managers could have a preemptive tool for managing black bear populations. Models for 2020 and 2021 found that there was some overlap in predictive covariates for huckleberry productivity, but several additional covariates were included in 2021. We also did not find a strong correlation between our 2020 model and black bear recruitment for the following year, possibly due to the short duration of our study.masters, M.S., Fish & Wildlife Sciences -- University of Idaho - College of Graduate Studies, 2022-1
Developing a System for Reliably and Predictably Generating, Recording, and Analyzing Flicker in Commercial and Residential Light Bulbs
No full textLight bulb flicker has been an issue for as long as light bulbs have existed, and many negative health effects associated with light flicker have been well established and documented. Previous research has largely focused on flicker related to incandescent bulbs and on steady-state flicker behaviors. However, the increasing adoption of light-emitting diode (LED) bulbs, coupled with a growing prevalence of non-linear noise sources—such as switch-mode power supplies and variable frequency drives—is causing an increased need to better understand flicker behavior in a variety of bulb types. This thesis documents some of the basic principles of light measurement and flicker classification while also highlighting some of the relevant research into flicker behavior and IEEE guidance related to flicker. Having established a background in flicker behavior and measurement, this research then details the development of a physical testbed and python-based toolchain for generating, recording, analyzing, and displaying flicker behavior in several different bulb types. Finally, sample outputs are provided which demonstrate the ability of the testbed and toolchain to reliably and consistently analyze flicker behavior in light bulbs.masters, M.S., Electrical and Computer Engineering -- University of Idaho - College of Graduate Studies, 2022-1
Prime Level Paramodular Hecke Algebras
No full textThis dissertation presents fundamental results on the structure of paramodular Hecke algebras for Siegel paramodular forms of prime level. We exhibit four double coset generators for the Hecke ring as well as explicit formulas for computing the coefficients and good coset representatives that appear in the multiplication of two elements of this ring. In addition, we show that there is a correspondence between the value of the coefficients appearing in a product of these Hecke operators and the number of sub-lattices of a paramodular lattice over a non-archimedean local field.doctoral, Ph.D., Mathematics & Statistical Sci -- University of Idaho - College of Graduate Studies, 2022-0
Evaluating Polyaluminum Chloride Coagulants for a Large Drinking Water Provider Using Benchtop and Pilot Plant Scale Analysis
No full textIn this study, polyaluminum chloride (PACl) coagulants were evaluated for use at a surface water treatment facility in that currently uses aluminum sulfate (alum). The coagulants were evaluated using a triple bottom line approach incorporating publich health, fiancial viability, and environmental impact in three phases. In phase 1, jar tests were utilized determine two high performing PACls out of 8 to move forward into phase 2 based on treatment efficiency in comparison each other and to alum. One of the top performing PACl coagulants was evaluated to determine the treatment factors that are significant to turbidity removal via jar testing utilizing a central composite design (CCD). In phase 2, the selected PACl coagulants were evaluated at the pilot plant scale. The data from phase 2 was utilized in the triple bottom line analysis. Finally, in phase 3, financial analysis and sludge production of PACls was conducted and compared with Alum to evaluate the environtmental impact and financial viability. The research concluded the PACl coagulants performed as well or better than alum at meeting clean and safe drinking water treatment criteria. Alum, PACl 1, and PACl 2 had a similar disinfeciton by product formation potential with negligable difference in THM production. Both PACls performed better in removing TOC and DOC consistently above the EPA guideline of 25% through the pilot plant runs with 28-42% and 30-40% for PACl 1 and PACl 2 respectively and 19-42% for alum. PACl coagulants displayed an increased percentage of turbidity removal per mg/L of coagulant added. During the pilot trail, alum exhibited 1.88-2.23% turbidity removal per mg/L coagulant added while PACl 1 and PACl2 exhibited 4.35-5.64% and 3.86-4.85% respectively. The PACl coagulants were not as financially feasible as alum based on the pilot plant data. PACl treatment trains in pilot runs retained alkalinity and thus reduced lime feed and had zero caustic feed. Sludge production was reduced in PACl treatment. These reductions were not enough to offset the increased chemical cost of PACl to alum with PACl 1 being 652,100 higher than alum annualized and extrapolated based on 2018 production data. The reduction of chemical additions and sludge prodcution made the PACl coagulants more environmental friendly. The CCD examination validated that raw water pH and coagulant dosages are the significant variables to both settled and filtered turbidity removal when using polyaluminum chloride coagulants on water from Beaver Lake. The study produced significant model equations to determine values for these variables to achieve optimal treatment.masters, M.S., Environmental Science -- University of Idaho - College of Graduate Studies, 2022-0
Extraterrestrial Oceanography of Titan’s Northern Seas from Cassini VIMS Sun Glitter Observations
No full textIn this thesis, I investigate the occurrence of sun glitter and waves on the sea surfacesof Titan’s northern seas, Kraken Mare and Punga Mare. These studies of various sun glitter features help to uncover unique liquid bodies, such as liquid-filled channels, better understand the dynamics behind the air-sea-land interactions during the northern summer. Some of these interactions include wind-generated capillary waves, tidal currents, and wave shoaling. In Chapter 1, I introduce the physics of sunglint and sun glitter observations in a terrestrial context and elaborate on the spacecraft geometry that necessitates a sun glitter observation on Titan. In addition, I provide an overview of prior specular observations from the seas on Titan and the geographical context for Titan’s seas. In Chapter 2, I present Cassini VIMS observations of sun glitter – wave-induced reflections from a liquid surface offset from a specular point – on Kraken Mare. Sun glitter reveals rough sea surfaces around Kraken Mare, namely the coasts and narrow straits. The sun glitter observations indicate wave activity driven by the winds and tidal currents in Kraken Mare during northern summer. T104 Cassini VIMS observations show three sun glitter features in Bayta Fretum indicative of variegated wave fields. I cannot uniquely determine one source for the coastal Bayta waves, but I lean toward the interpretation of surface winds, because tidal currents should be too weak to generate capillary-gravity waves in Bayta Fretum. T105 and T110 observations reveal wave fields in the straits of Seldon Fretum, Lulworth Sinus, and Tunu Sinus that likely originate from the constriction of tidal currents. Coastlines of Bermoothes and Hufaidh Insulae adjoin rough sea surfaces, suggesting a complex interplay of windroughened seas and localized tidal currents. Bermoothes and Hufaidh Insulae may share characteristics of either the Torres Strait off Australia or the Åland region of Finland, summarized as an island-dense strait with shallow bathymetry that hosts complex surface circulation patterns. Hufaidh Insulae could host seafloor bedforms formed by tidal currents with an abundant sediment supply, similar to the Torres Strait. The coastlines of Hufaidh and Bermoothes Insulae likely host ria or flooded coastal inlets, suggesting the Insulae may be local peaks of primordial crust isolated by an episode of sea-level rise or tectonic uplift. In Chapter 3, I present new evidence for active coastal and oceanic features in Titan’s Punga Mare observed in a high-phase Cassini VIMS observation of sunglint from the T110 flyby. I observe sunglint in a river, Apanohuaya Flumen, resulting from differing pixel contributions of land adjacent to the channel and implying smooth liquid surfaces. Along the eastern coastline, I identify a 5-m-bright margin. A possible explanation for this brightening may include a coastal margin of rough seas. I find evidence of variegated sea surface roughness in Fundy Sinus and isolated sun glitter near Hawaiki Insulae that suggests seasonal interactions between surface winds and topography. RADAR observations of debouches (where rivers meet bays) within Punga Mare overlap several bright 5 m pixels that indicate rough liquid surfaces. We postulate that a change in liquid flow regimes, possibly occurring as surface streamflow, or bubble outburst events may be responsible for surface roughness near these debouches. These observations imply air-sea-land interactions and hydrological activity are present in Titan’s sea district during the northern summer. In Chapter 4, I summarize the implications of the various sun glitter observations on Titan oceanography.masters, M.S., Physics -- University of Idaho - College of Graduate Studies, 2022-1
Assessing the Performance and Stability of Intensified and Diversified Dryland Cropping Strategies in the Inland Pacific Northwest with the CropSyst Model
No full textFarmers in the Inland Pacific Northwest (IPNW) typically cultivate dryland wheat-based crop rotations, which often include spring crops and, in lower precipitation areas, fallow. As part of the Landscapes in Transition (LIT) project, the CropSyst model was employed to evaluate traditional (business-as-usual, BAU) and novel crop rotations at two locations: St. John, Washington, an annual crop-fallow transition site, and Genesee, Idaho, an annual crop site. Incremental (INC) and aspirational (ASP) crop rotations, which included winter peas and cover crops, respectively, allow farmers to intensify and diversify operations through the inclusion of winter crops and reduction in fallow. Data collected during LIT field studies, carried out during the 2018-2021 growing seasons, was used to parameterize and calibrate the CropSyst model and evaluate its ability to simulate field conditions. Subsequently, scenario testing explored the viability of the alternate crop rotations under long-term, historic climate conditions. The developed CropSyst models appeared powerful and robust, especially given the variability and range of the observed data. CropSyst achieved good agreement between predicted yield and biomass and observed values on an overall, rotational, and yearly basis (R2 greater than 0.5 and root mean square error, RMSE, less than the standard deviation, σ, of observations). Additionally, soil moisture simulated by Cropsyst exhibited greater accuracy than the precision available in the observed datasets. Crop nitrogen was also predicted well (R2>0.5 and RMSE Long-term simulations of the models, from 1980-2010, suggest opportunities exist for adoption of diversified and intensified rotations in both the annual crop and annual crop-fallow transition regions of the IPNW. In both Genesee and St. John, INC produced the greatest biomass and yield and displayed the greatest stability, based on its coefficient of variation (cv). Baling a cover crop for forage markedly increased ASP’s yield and presents an opportunity for producers to diversify. Overall, winter crops better utilized available water and reduced water loss. However, in St. John, the inclusion of fallow in the BAU rotation reduced its susceptibility to drought. Scenario testing suggested that altering management practices strategically can improve outcomes. For example, in St. John, terminating the previous cover crop earlier in the year prevented any detrimental effects on subsequent ASP winter wheat yields. Additionally, the inclusion of legume crops (winter pea, chickpea, or a nitrogen-fixing cover crop) reduced fertilization requirements. CropSyst simulations emphasize relationships and trade-offs existing between cropping choices and production outcomes and contribute to a better overall understanding of these traditional and novel crop rotations. However, consideration of factors not captured by CropSyst, such as weeds, disease, and pests would prove valuable. Additional model simulations could include future climate to explore longer-term implications of changing environmental conditions.masters, M.S., Soil & Water Systems -- University of Idaho - College of Graduate Studies, 2022-0
Effects of Diverse Cropping Systems on Arthropod Communities and Weed Seed Predation
No full textProjected and ongoing climate change presents challenges and opportunities for wheat-based cropping systems throughout the inland Pacific Northwest (iPNW). Producers are interested in reducing the amount of land in fallow to increase overall crop production, as well as create more sustainable cropping systems that are resilient to a projected variable climate. Examples of crop rotation diversification and intensification for wheat systems include the addition of pulse crops such as dry pea and chickpea, and multi-species cover crops into rotations. Monitoring arthropod community responses to diversification and intensification can inform producers on which alternative crops are also associated with increased biodiversity and arthropod-mediated ecosystem services, such as pollination and biological control. Biological control of weedy pests in fields is a key ecosystem service provided predominately by epigeic arthropods and small mammals. The work presented here examines epigeal arthropod community structure and weed seed predation under three diversified and intensified wheat-based cropping systems at two trial locations. Results show that epigeal activity-density and diversity were greatest in winter pea plots compared to the other crops tested. Granivore community metrics were not affected by crop or sampling date at the St. John, Washington site but at the Genesee, Idaho site, winter pea consistently had greater diversity and activity-density compared to winter wheat. Generally, activity-density and diversity were greater in the crops unique to diversified rotations, though evenness was greater in winter wheat plots than in winter pea or cover crop plots. Weed seed removal was greater in fallow plots than in plots planted to any crop. Removal rates differed among four sample dates but there was no seasonal trend or interaction between sample date and crop. In weed seed preference trials, Anthemis cotula was consumed at significantly lower rates than Bromus tectorum or Chenopodium album, but when physical defenses (seed coverings) were artificially breached, A. cotula was consumed at higher rates than B. tectorum. Diversified wheat cropping systems in the iPNW either reduce or remove fallow from rotation, which could lead to increased weed abundance in seed banks, exacerbating weed management problems in these systems.masters, M.S., Entomology, Plant Path & Nematology -- University of Idaho - College of Graduate Studies, 2022-0
IoT Smart Home Device’s Security, Privacy, and Firmware Labeling System
No full textA smart home is one of the most popular Internet of Things (IoT) implementations. It is widely used because of the autonomous functions it provides to homeowners. It is equipped with smart IoT devices designed to automatically perform unique and specific functions. The IoT smart home network has different types of connections based on the application’s requirements. Any attacks or unauthorized access to IoT smart home systems or connected devices could harm the system and lead to unauthorized access to the homeowner’s information. Therefore, IoT smart home devices' security, privacy, and firmware vulnerabilities are getting more attention from researchers because of the danger that comes from attacking such devices that collect personal information about an individual’s lifestyle and behavior. This research aims to provide an IoT labeling system that covers the IoT smart home devices' security, privacy, and firmware factors. This label will target the Saudi Arabian market. The label will help IoT smart home device consumers make better decisions on which device to purchase and increase their awareness of the attacks and, therefore, use the devices more safely. Based on a review of the literature on IoT smart home devices’ security, privacy, and firmware aspects, a data collection and analysis process are used to demonstrate the importance of the factors on the label. A scoring system is designed to provide a weight for all chosen factors. An online survey is conducted and distributed among computer science and security experts, regular IoT consumers, risk management and communication, and label designers across Saudi Arabia and the United States to develop a better labeling system for the devices. This survey produces the best quality of the IoT smart home device’s security, privacy, and firmware label. The proposed label is expected to help the IoT smart home device’s consumers be educated and aware of the potential issues associated with the smart home devices, hence protecting them from being a victim of many problems and attacks when using the devices.doctoral, Ph.D., Computer Science -- University of Idaho - College of Graduate Studies, 2022-0