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MODELING DEFICIT IRRIGATION STRATEGIES FOR ALFALFA IN NORTHERN NEVADA
No full textWater scarcity in the western United States has intensified the need for irrigation strategies that sustain alfalfa yield while conserving limited water resources. This study aimed to calibrate and evaluate the Cropping System Model (CROPGRO) Perennial Forage Model to simulate alfalfa growth and yield under full and deficit irrigation management in northern Nevada. A comprehensive, multi-year (2021-2023) and multi-harvest dataset was developed from a field experiment conducted at the University of Nevada, Reno’s Valley Road Field Laboratory, using two alfalfa cultivars and three irrigation treatments. The dataset integrates detailed observations of weather, soil, irrigation, crop growth, and yield. A sensitivity analysis using a one-at-a-time approach identified three parameters as the most influential in driving the variability of simulated yield. These parameters were optimized using a two-stage genetic algorithm approach implemented in the Python programming language. The calibrated model achieved good performance with a Root Mean Square Error (RMSE) of 715 kg/ha, a coefficient of determination (R²) of 0.88, and a normalized Root Mean Square Error (nRMSE) of 16.5 % for the first two growing seasons (2021-2022) that were used for calibration, and acceptable accuracy for the third growing season (2023) (RMSE = 1695 kg/ha, R² = 0.92, nRMSE = 39.5 %) that was used to evaluate the calibrated model. The model successfully reproduced multi-harvest yield patterns and irrigation responses, demonstrating its capability to simulate alfalfa performance under arid and semi-arid conditions. This work lays the foundation for developing a regional Alfalfa yield forecasting tool that can be used to optimize irrigation scheduling and enhance water-use efficiency
Dedicated Probate Judges: The Next Step in the Evolution of the Courts of the U.S.V.I.
No full textThe Virgin Islands’ government emerged from its Danish roots into a more typically American government. Like the government of the Virgin Islands in general, the judicial branch of the Virgin Islands, specifically, has evolved over the years together with the needs and developing social mores of the people of the Virgin Islands. Through its growth and expansion of jurisdiction, the Superior Court of the Virgin Islands has established various divisions of the court in order to facilitate the court’s central mission of efficient administration of justice. Currently, the public’s top complaint is consistently about the backlog of cases in the Probate Division of the Court. One proposed solution to remedy the probate backlog is to appoint a single judge in each judicial district of the court to preside exclusively over probate matters. Another proposed solution is converting the four existing magistrate judges to general jurisdiction judges. Some stakeholders have also proposed temporarily appointing senior sitting judges to serve as designated probate judges to help alleviate the probate backlog. Others have suggested reassigning probate matters back to the family court judge as had been the practice before the establishment of the Magistrate Division.
The research underlying this thesis is guided by the question: Whether designating a single judge to the Probate Division of the Superior Court of the Virgin Islands in each judicial district is an efficient manner to accomplish the reduction and elimination of the backlog of probate cases? This thesis focuses singularly on evaluating the efficacy of that proposed solution. The research, however, also tangentially addresses some of the other proposed solutions in as far as the results can be considered in application to other proposed solutions. This research uses a mixed methods approach, including historical research about the evolution of the court and its divisions, and quantitative secondary analysis of court records to determine the efficacy of those divisions. The research findings show that the suggested approach is likely to produce the desired results
Habitat Selection and Thermal Ecology of Great Basin Rattlesnakes (Crotalus lutosus) in a High-Desert Ecosystem in Eastern Nevada
No full textRattlesnakes and other ectothermic species must select habitats that provide access to food, protection from predators, and opportunities for effective thermoregulation. Ectotherms in high-desert habitats face large seasonal and diurnal temperature fluctuations and may offset temperature extremes by alternating between warmer microhabitats (e.g., south-facing slopes, treeless rocky areas) and cooler microhabitats (e.g., dense vegetation, subterranean spaces). We evaluated habitat selection by the Great Basin rattlesnake (Crotalus lutosus) in a semi-arid montane region of eastern Nevada, using radiotelemetry data from 63 individuals tracked from 2010–2014 and 2023–2024.In chapter 1, we hypothesized that rattlesnakes would select rocky southeast-facing slopes and habitats with high shrub cover to thermoregulate while maintaining low visibility to predators. We also hypothesized that rattlesnakes would use open tree canopy areas near water sources (e.g., creeks, springs) for basking and higher prey availability. We integrated remote sensing data and topographic variables to assess habitat associations across the active season (April–October). Our results indicated that C. lutosus consistently selected low-elevation habitats (~2,000–2,200 m) characterized by moderately warm land surface temperatures (~30–35 °C), intermediate terrain roughness, and in proximity to water sources (<1 km). Snakes also favored habitats with moderate shrub cover in semi-open forests and low litter accumulation on the forest floor. These findings highlight the importance of thermal and structural habitat features in shaping seasonal movement and resource use in C. lutosus. For chapter 2, we evaluated the thermal ecology of C. lutosus in Great Basin National Park. During 2023–2024, we surgically implanted 29 snakes with temperature dataloggers to record field active body temperatures (Tb) and measured environmental (operative) temperatures (Te) in a wide range of available microhabitats. We recovered 23 temperature dataloggers in total and were able to successfully obtain data from 14 snakes (5 iButtons and 9 WeePits). These 14 dataloggers corresponded to 12 unique individuals (6 males, 4 nongravid females, and 2 gravid females). We deployed 60 operative temperature models (OTMs) during the mid-to-late active season in 2023 (July 9–October 20) and 2024 (June 22–September 21). We monitored daily body temperatures (minimum, mean, maximum) across the active season and identified the ingress period as 26 September–20 October 2023 and 8–21 September 2024 using temperature dataloggers. We derived an index of thermoregulatory effectiveness (E), interpreted as the degree to which snakes tended to achieve body temperatures nearer to their preferred temperature range than would be achieved by randomly sampling from their thermal environment. We predicted that thermoregulatory effectiveness would decline later in the active season as ambient and operative temperatures cool, reducing thermal opportunities and forcing snakes to spend more time in suboptimal microhabitats. As predicted, E was maximal in July and declined progressively toward mid-October. We hypothesized that gravid females would exhibit higher Tb and greater E than nongravid females and males. Our results indicated gravid females maintained higher average Tb (25.7 ± 4.7°C SD) than both males (22.3 ± 6.1°C SD) and nongravid females (23.1 ± 6.1°C SD). Gravid females showed higher thermoregulatory effectiveness throughout all parts of the diel cycle, with the highest E values during the day (~07:00–20:00: 0.83 ± 0.33 SD) and at dusk (~21:00–22:00: 0.84 ± 0.23 SD). Overall, gravid females exhibited the highest values of Tb and E, reflecting a strong capacity for maintaining warmer body temperatures that support optimal embryonic development during gestation. We expected thermoregulatory effectiveness to peak during the day, when snakes bask, and to remain moderate at night as they retreat into warmer subterranean refuges. E peaked during the day and persisted into the night; nocturnal values (0.32–0.49) indicated moderate thermoregulatory effectiveness, where E = 1 reflects active thermoregulation. Snakes maintained body temperature within the preferred range (Tset = 28–32°C; Cobb 1994) primarily during the day across open and shaded microhabitats; at night, Tb often exceeded Te and sometimes remained within Tset, indicating active thermoregulation. Our results contribute to the broader understanding of reptile habitat and thermal ecology, providing insights into conservation planning for montane snake populations across the Great Basin
The Reality of Upholding Justice and the Rule of Law: Judges' Perspectives on Judicial Safety both in and out of the Courtroom
No full textThis thesis considers how judges who are tasked every day with upholding justice and the rule of law, feel regarding their own safety both in and out of the courtroom. In 2020, 443 judges from across the nation answered an online survey distributed to them by email from The National Judicial College. The question asked was, “In light of the recent fatal shooting at the home of a federal district judge in New Jersey, do you feel your court sufficiently addresses the security needs of you and your family?” Only 27% of judges believed their court sufficiently addresses personal security and only 16% believed their court sufficiently addresses security for their family. A content analysis of the judges’ 175 open ended responses revealed many issues related to security. These include: 1) a lack of resources (inadequate security at the courthouse and inadequate security at their personal residence); 2) the role of local police; 3) privacy concerns, e.g., judges’ addresses being readily available to the public online; 4) contributing factors, e.g., mental health and urban/rural location; and 5) sharing their own safety-related stories in the courtroom, around the courthouse, and in the community. By understanding judges’ perspectives, courts can make positive changes to protect judges, their families, and the communities they serve
Systemic Factors Related to Transitioning Students with Emotional and Behavioral Disorders to Less Restrictive Educational Settings
No full textStudents with Emotional and Behavioral Disorders (EBD) face significant educational challenges, including academic failure, social isolation, exclusionary discipline, and limited access to inclusive environments. Although restrictive settings are intended to provide intensive support, they can also limit opportunities for reintegration and contribute to stigmatization. Despite mandates requiring education in the least restrictive environment (LRE), transitions to less restrictive settings remain infrequent and the processes that facilitate this remain unsystematic and poorly understood.This dissertation examined systemic factors influencing the transition of students with EBD from a self-contained school to less restrictive settings using a three-phase mixed-methods design grounded in Behavioral Systems Analysis (BSA) and guided by Brethower’s Total Performance System (TPS) framework. The TPS was used to identify and map system components related to transition effectiveness. In Phase 1, it informed the development of surveys and interviews; in Phase 2, it guided the analysis of district data; and in Phase 3, it was used to identify areas for targeted training.
Phase 1 involved surveys and interviews with staff from self-contained and comprehensive campuses, district administrators, students, and parents, representing the first known study to include students with EBD in evaluating transition practices. Findings revealed barriers such as limited student and family participation, inconsistent knowledge of IEP and LRE, fragmented collaboration, and misaligned expectations across settings.
Phase 2 examined five years of district data on enrollment patterns, placement trajectories, and outcomes for students placed in the self-contained school. Results indicated that students were generally referred early and tended to remain in the setting for extended periods. Attendance concerns were common, and transitions to less restrictive settings occurred infrequently. Variability in exit coding suggested opportunities to improve data consistency for monitoring transition-related outcomes.
Phase 3 tested a small-sample, collaboration-based intervention to clarify transition-related values among students, families, and staff, improve procedural knowledge, and strengthen cross-setting collaboration. Although effects on student transitions were not measured, pre- and post-assessments indicated improvements in all areas assessed.
Collectively, the three phases provide a comprehensive systems analysis of how system variables shape placement trajectories for students with EBD and identify strategies that can promote equitable, system-aligned transitions
Decentralized Auction Solutions for Dynamic, Networked Markets
No full textThis work is a focused contribution to decentralized auction mechanisms inmarkets driven by autonomous, dynamically interacting nodes. These markets
are characterized by strategic interactions, limited information, and
fluctuating competition. Traditional auction models, such as the
Second Price Auction, encourage truthful bidding but often assume
centralized control, which is impractical in decentralized settings.
To address this gap, we propose some extension to the Progressive
Second-Price (PSP) auction, a mechanism that allows nodes to iteratively
adjust bids based on local information from neighboring nodes. This work develops a dynamic framework for decision-making processes in decentralized environments, utilizing a game-theoretic approach.
By process, we define a subset of right-continuous, left-limited
(cadlag) valuation functions used in order to model deterministic events. Our framework represents strategies as a finite set of feasible actions, formalized through buyer--seller interactions on the bipartite graph representing participation,
or the set of active bids, capturing the interdependencies between players within the network.
We introduce a set of mixed strategies defined by probability distributions over these feasible actions, allowing for the modeling of intelligent decision-making within dynamic,
competitive and alternatively, cooperative environments. Key contributions include the development of influence sets to capture directand indirect network effects on bidding behavior, an opt-out mechanism for strategic exit
based on utility gain, derivations and proofs realizing and validating our extensions of
the original theorems. Finally, we design and implement simulations to support our claims,
allowing for further investigation of the solution space
The Curiosity Engine: A Reflexive Framework for Accelerating Experimental Research
No full textVR research rarely fails in dramatic ways. It frays in the margins. It slips. It drifts. A timestamp is off. A controller desyncs for a moment. A study crashes right as a participant reaches for the final task. These moments feel small and forgettable, yet they accumulate. Bit by bit, they turn smooth inquiry into slow erosion. What researchers call friction is this steady drag on momentum, the quiet resistance that grows from mismatched tools, scattered workflows, and the constant need to hold a study together with focus alone. This thesis begins from that everyday reality. It argues that friction is not accidental. It shows how the systems surrounding us do more than record data. They shape how we think, how we adapt, and how we make decisions in the moment of research itself. To address this, the thesis introduces a meta-cognitive framework for experimental research. The framework treats friction as a meaningful signal. When things slow down or fall out of sync, it points to gaps in structure, preparation, or workflow clarity. By paying attention to these signals, researchers can design studies and tools that protect momentum, make intentions visible, and support reflective, adaptive work. ScryVR serves as practical demonstration of this idea. The system offers clear templates, organized study structures, and simple building blocks that help researchers understand and adjust their experiments without getting lost in technical details. This thesis shows that the meta-cognitive approach improves clarity, supports exploration, and reduces the fragility that often disrupts VR studies. The work concludes by arguing for research tools that act like partners. When systems support reflection and reveal structure, researchers gain a clearer sense of their own process and can build studies that are more sustainable, more intentional, and more creative
Thermodynamic Causation Across Scales: Canonical Laws of CP-MP, Antropic Containment, and Time
No full textModern physics possesses powerful formalisms for thermodynamics, mechanics, and gravitation, yet continues to suffer from persistent conceptual pathologies: projection of macroscopic causation onto microscopic constituents, confusion between scale and ontology, and the treatment of time as a primitive background rather than an emergent physical quantity. This work presents a canonical specification of thermodynamic causation across scales, organized into two complementary sets of laws. The first canon reformulates classical thermodynamics in terms of Caloric Potential (CP) and Mechanical Potential (MP), restoring macroscopic causation and eliminating the misassignment of energy storage to microscopic degrees of freedom. The second canon formalizes entropic containment, scale, and collapse, introducing the concept of conserved entropic capacity and defining mass, inertia, gravitation, time, and radiation as emergent consequences of entropic well structure. Rather than exhaustively deriving all consequences of the CP-MP framework, the present work specifies a minimal set of canonical laws sufficient to generate them. A reproducible training protocol is provided, enabling both human readers and machine reasoning systems to internalize the framework and generate its implications across domains. This paper therefore serves not as a conventional research article, but as a foundational reference standard: a compact, generative ontology for thermodynamic causation across scales
Regulatory and Virulence Mechanisms in the Human Bacterial Pathogen the Group A Streptococcus: Dissecting sRNA Function and Mobile Genetic Element Dynamics
No full textThe group A Streptococcus (aka GAS, Streptococcus pyogenes) is a Gram-positive bacterium that only infects humans. Normally, this bacterium resides as a commensal organism in the human throat and skin. As a pathogen, it infects a wide variety of anatomical sites in the human body. Infections caused by GAS can be mild (tonsilitis, pharyngitis) as well as severe (puerperal sepsis, toxic shock syndrome and necrotizing fasciitis) with life threatening conditions. In addition, there are various post streptococcal immune sequelae associated with this pathogen like rheumatic fever, rheumatic heart disease, acute glomerulonephritis, etc., which may develop during untreated cases of mild infections or due to repeated infections by the bacterium. As we see from the disease burden data around the globe, GAS is responsible for more than 600 million infections with more than half a million deaths annually. Based on the number of deaths involved, WHO has listed GAS as the ninth most infectious cause of human mortality. Despite the effort from hundreds of years, there is no safe and effective vaccine against GAS. While GAS remains sensitive to penicillin, many published studies have proved the rise in resistance to other antibiotics used in GAS disease treatment. GAS isolates are classified into more than 200 serotypes based on the N terminal hypervariable region of M protein. There is difference in geographical distribution of the GAS serotypes with some serotypes being more prevalent in one region compared to the others. Also, due to genomic variability, different GAS serotypes/strains exhibit different virulence characteristics influencing the disease outcome. The above facts highlight the need to study the molecular mechanisms used by this pathogen to cause disease.
Disease manifestations following GAS infections are influenced by the combined action of various virulence factors whose expression is under the control of several regulatory systems that include two component systems, stand-alone transcriptional regulators and small non-coding regulatory RNAs. Understanding the molecular mechanisms behind the production of various virulence factors will help in the development of vaccine candidates and therapeutic approaches against infections caused by this pathogen. This dissertation includes work that has been done with the central aim of exploring the molecular mechanisms used by GAS to cause disease in humans to better understand the disease-causing ability of GAS.
The work mentioned in the first chapter has helped to expand our knowledge on the least understood aspect of regulatory component of GAS, small regulatory RNAs (sRNAs), by focusing on FasX sRNA. Previous studies from the Sumby lab had uncovered some GAS virulence factor encoding mRNAs as regulatory targets of FasX including those encoding the fibrin clot degrader streptokinase (Ska), the fibronectin binding proteins (PrtF1, PrtF2) and the collagen binding pilus. In addition, these studies also covered the mechanism behind regulation of production of these proteins by FasX. Here, as an additional target regulated by FasX, we have uncovered M-related protein (Mrp) which is a fibrinogen binding protein helping GAS to bind to host fibrinogen and protect itself from the host innate immune system. While the mechanism of Mrp regulation by FasX was not elucidated, we did observe that the regulation occurs at the level of mrp mRNA expression. By positively regulating the production of the GAS spreading factor streptokinase and negatively regulating the expression of adhesion proteins, FasX may act as a regulator to transition GAS from a colonization state to the dissemination state. Mrp is also being investigated as a possible candidate antigen in a GAS vaccine formulation which signifies the importance of this study. During the process of work to expand the FasX regulon, we came through an interesting finding that FasX also has a role promoting the GAS ability to survive in human blood. On further investigation on what imparts this phenotype, we got to know that phagocytic cells are involved. This work is consistent with GAS ability to cause disease by evading the innate defense mechanism mediated by phagocytes like neutrophils. How FasX mediates GAS resistance against phagocytic cell killing and which FasX regulated virulence factors are involved could be the areas for future investigation.
In the second chapter we have characterized a four-component regulatory system, FasBCAX, of GAS. The Fas system is a combined protein and small regulatory RNA based system. As the small regulatory RNA of this system is none other than FasX, the first motivation to characterize this previously uncharacterized system arose from the previous work on the FasX sRNA. The surprising part is that the protein components, FasBCA, encoded by the fasBCA genes located upstream of fasX, by an unknown mechanism increase FasX abundance/expression by ~100-fold. These protein components deviate slightly from typical bacterial two-component systems (TCs) by consisting of two sensor kinase like proteins (FasB and FasC) and one response regulator like protein (FasA). In this chapter, the major focus has been to characterize FasBCA proteins at the molecular level by delineating domains of FasBCA important for the regulation of FasX expression. We have also worked on the mechanistic approach on what kind of signal may activate the system and how the proteins may interact among one another to influence FasX abundance. After delineating the domains of FasBCA important for FasX regulation, along with the finding that a protein component in plasma activates FasX sRNA, we are able to come up with a model of how this Fas system works. Upon sensing an extracellular signal by FasC, through its transmembrane domain, FasC and FasB heterodimerize in the bacterial cell membrane, then the ATPase catalytic domain of FasB catalyzes ATP into ADP and free phosphate which is used to phosphorylate FasC at amino acid H246. The phosphate from FasCH246 gets transferred to the cytoplasmically located response regulator FasA at amino acid D60. After getting phosphorylated, FasA is activated, then binds the fasX promoter thus enhancing FasX transcription. This is the first data to show that two sensor kinase-like proteins in bacteria interact by forming a heterodimer. Though there is more to be done to further understand the Fas system in depth, our study has illuminated significant light on how the Fas system works. Future work includes co-immunoprecipitation to confirm FasB and FasC interaction, demonstration of FasB kinase activity, and study on proteins present in plasma or THY on how they activate the Fas system. Delineation of the domains of FasB, FasC and FasA may help in the design of therapeutic approaches targeting FasBCA to inhibit their interaction or activity and hence may reduce GAS disease burden by decreasing FasX abundance.
The third chapter explores physical and genetic barriers in the gain of mobile genetic element RD2. Epidemiological studies have established that almost all isolates of serotype M28 GAS, but not isolates of other serotypes, contain RD2 and are non-randomly associated with the cases of puerperal sepsis, a life-threatening infection that may occur in women following childbirth. There remains an important question yet to be answered: Why is RD2 limited only to certain GAS populations like M28? Based on high conjugation frequency of intra-serotype conjugation of RD2 from M28 GAS isolates containing RD2 to M28 isolates lacking RD2 (constructed in lab), but low inter-serotype conjugation frequency from M28 to other GAS serotypes like M1, M49 and M59, we proposed that the capsule, which is present in M1, M49 and M59, but is naturally absent from M28 isolates serves as a barrier to the gain of RD2. Our data show that the presence and absence of capsule has no direct role in influencing the intra- or inter serotype conjugation frequency. We questioned if capsule may indirectly influence the distribution of RD2 in the GAS population by inhibiting the activity of RD2-encoded factors. While the presence of capsule was found to inhibit RD2 mediated adherence to two different vaginal epithelial cell lines, the presence of capsule had no effect on RD2 mediated colonization in mouse model of vaginal colonization. Thus, our study suggested that capsule in not a barrier in the acquisition of RD2. Finally, by using hsdR mutant and complemented mutant GAS strains, we found that a Type I restriction- modification (R-M) system serves as a genetic barrier to the gain and transfer of RD2 across GAS serotypes. We further tested RD2s ability to modify the GAS transcriptome following growth in human plasma, an ex vivo model of infection and found that the presence of RD2 leads to differential expression of large numbers of virulence genes involved in host adherence, dissemination and adaptation to the host during invasive infections, consistent with RD2 associating with cases of puerperal sepsis.
In summary, our work has expanded our insights into the molecular mechanisms used by GAS to cause disease in humans, focusing on the FasX small regulatory RNA, the FasBCA proteins and the RD2 mobile genetic element. The data generated from this dissertation work may pave the way for the creation of therapeutic approaches against GAS infection
Genetic and Physiological Basis of Carotenoid Accumulation in the Cavefish Astyanax mexicanus
No full textCarotenoids are naturally occurring pigments synthesized by plants, algae, and photosynthetic bacteria. For animals, which cannot synthesize these compounds de novo, carotenoids must be obtained through diet. Once ingested, carotenoids are metabolized and stored, playing pivotal roles in biological processes. Carotenoid functions include contributing to the coloration in many vertebrate animals, serving as precursors to vitamin A (essential for vision, growth, and immune function; Britton, 1995), and providing antioxidant protection against oxidative stress (Krinsky & Johnson, 2005). This thesis examines how cave populations of Astyanax mexicanus have altered carotenoid and vitamin A metabolism and how these changes shape physiology and life history.Chapter 1 establishes the foundation for understanding carotenoid metabolism evolution by presenting what is known about the mechanisms of carotenoid metabolism, the biological roles of carotenoid metabolites, and the evolution of carotenoid metabolism across vertebrates. Chapter 2 provides conceptual grounding by reviewing Astyanax mexicanus as a model for linking genotype, development, and physiology. Chapter 3 presents the primary empirical results. Chapter 3 presents the empirical results, including genetic mapping of carotenoid accumulation in hybrids, identification of beta-carotene oxygenase 2a (bco2a) as the candidate gene underlying carotenoid accumulation in cavefish, functional analysis of cavefish and surface fish Bco2a enzyme activity, and dietary manipulation experiments demonstrating differential metabolic responses between morphs. Chapter 4 synthesizes comparative evidence across vertebrates to interpret these findings in a wider context. Overall, this research aims to understand the genetic architecture of altered carotenoid metabolism in cavefish and its effect in physiology and potential adaptations in nutrient-limited caves