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Emerging Diseases, Abiotic Disorders, And Macrophomina Root Rot Management Of California Strawberry
Get PDFStrawberry is an economically important crop in California, with an estimated value of $2.68 billion in 2023. In California strawberry production, mitigation of low plant health and yield often focuses on major soilborne pathogens, while the contribution of minor pathogens and abiotic disorders to production shortcomings are often overlooked. The objectives of the first project in this thesis are to determine the pathogenicity of multiple minor pathogens and quantify other biotic and abiotic factors that can reduce plant health such as viruses and soil salinity. Two pathogens of the black root rot complex, Pythium spp. and Rhizoctonia spp. as well as Neopestalotiopsis rosae are included in this study. The pathogens were identified using ITS DNA sequencing and evaluated for optimal colony growth temperatures. Over the course of two trials, Koch\u27s postulates of P. ultimum and P. irregulare isolates were confirmed for pathogenicity of strawberry roots and crowns, Rhizoctonia spp. isolates were confirmed over 2 trials for pathogenicity of strawberry roots and crowns, and Neopestalotiopsis rosae isolates were confirmed for pathogenicity of strawberry crowns, leaves, and fruit. In 2022 and 2023, 60 root zone soil samples of symptomatic plants that tested negative for major soilborne pathogens were evaluated for electrical conductivity (ECe). Average soil ECe was 1.17 dS/m ranging between 0.18 and 2.45 dS/m, categorizing all samples as non- or slightly-saline except for two which were moderately-saline. Virus testing between 2022 and 2024 diagnosed eight positive samples out of 38 total samples: three in 2022 for Beet pseudo-yellows, two samples in 2023 for Strawberry mild yellow edge and Strawberry polerovirus 1 and one for Strawberry polerovirus 1, and two samples in 2024 for Beet pseudo-yellows. The results from this study suggest that while the tested minor pathogens can infect and reduce strawberry plant health, it is unlikely they are the sole cause of the observed plant mortality from recent diagnostic samples. Additionally, the low to moderate soil salinity levels and infrequent positive virus diagnostics are also not likely the sole cause of observed plant mortality. Future research into these topics could focus on the combination of major and minor pathogens as well as abiotic disorders to decipher how each factor affects plant health.
Additionally, Macrophomina phaseolina (MP), an important soilborne pathogen in California strawberry production, was observed to cause 29.7%-52.0% of late-season strawberry mortality in major strawberry growing districts in recent surveys. The objective of the study of this thesis is to assess the efficacy of crop termination and cover cropping on MP suppression to reduce disease incidence of Macrophomina root rot and improve strawberry yield and soil health. Studies were conducted using conventional field soil as a pot trial and a field trial, as well as an organic field trial. The greenhouse pot trial utilized strawberry cultivars Albion and Royal Royce planted in soil collected from a conventional grower field in the Santa Maria district in a randomized complete block design. Treatments included untreated control soil (C), untreated control soil planted with wheat (W) \u27Summit 515’ (C+W), soil fumigated with metam potassium (crop termination) planted with wheat (CT+W), and soil fumigated with metam potassium (crop termination) and chloropicrin (flat fumigation) (CT+FF). Plant infection and soil pathogen levels were assessed via plating on semi-selective media and using a pour plate method, respectively. Two repetitions of the trial were conducted. There was no significant soil treatment × cultivar interaction or cultivar effects in trial 1 and 2 for the MP CFU/g soil, but there was a significant soil treatment effect in the MP CFU/g soil of both trials (P = 0.0001). The trial 1 CT+W treatment had the highest-level MP CFU/g soil, which descended in significance to C+W, then C, and then finally CT+FF. In trial 2 CT+W had a significantly higher MP CFU/g soil value than the other treatments, while C and C+W were comparable to each other and both higher than CT+FF. Chemical soil evaluations for mineralizable carbon (MinC) and permanganate oxidizable carbon (POXC) were also performed. Trial 1 C+W had a significantly higher MinC value than CT+FF, while C and CT+W were comparable with both treatments. In the trial 2 MinC soil test the soil treatment × cultivar interaction and the main effects were not statistically significant. In trial 1 and trial 2 POXC soil tests the soil treatment × cultivar interaction and the main effects were not statistically significant. The second year of this study took place in the field and soil samples were collected pre- and post-soil treatments of CT, CT+W, CT+Triticale ‘Pacheco’ (T), CT+W+FF, and CT+T+FF to be evaluated for MP CFU/g soil. T was added as a cover crop treatment to compare a triticale variety to wheat as well as its prevalence as a cover crop in California. There was a significant soil treatment effect (P = 0.02) with post-cover crop wheat treatment having a significantly higher MP CFU/g soil than post-cover crop triticale. The strawberry cultivar Portola was planted after fumigation across all cover crop blocks. Additionally, an organic strawberry field trial compared wheat and triticale cover crops for MP suppression with strawberry cultivars Valiant and Monterey. Soil and plants were tested in the same manner as the pot trial. MP CFU/g soil, MinC, and POXC were not significantly different between soil treatments. Preliminary results suggest single season cover cropping cannot manage high pathogen levels, while crop termination can reduce the pathogen inoculum if the application is timed correctly. The completion of this project will include plant mortality evaluations and microbiome analyses from the field trials. This research aims to help the California strawberry industry by enhancing disease management and reducing fumigant use
Smart Cushion Device for Elderly Aging in Place
Get PDFOur task at hand is to develop a consumer-focused solution for improving elder care to provide additional peace of mind for seniors and caregivers using technology to extend independent living. We intend to create a device that will improve the quality of life of elderly individuals living alone by encouraging periodical movement throughout the day, along with monitoring pressure distribution and alerting when pressure concentration is potentially harmful. It will also alert users to the presence of moisture which can arise from spills or incontinence. The key stakeholders of this project include elderly adults over the age of 65 who live alone, along with their loved ones, supporters, and Apple Health Technologies, the sponsor of this project.
This report will provide information pertaining to pressure ulcer formation and the effects of sedentary lifestyles in elderly, current research, patents, and on-market devices that aim to alleviate these conditions, and requirements set by Apple. It will then detail other objectives, including indications for use, customer requirements, engineering specifications and measurement methods, including high-risk details, and a discussion of our house of quality. Next, it will cover the project timeline, key deliverables, prototyping plans, the project’s critical path, morphology, the concept evaluation process, conceptual modeling, and the failure modes and effects analysis process. After that, it will address the detailed design process and prototype manufacturing plans. Then, it will cover detailed test plans for each engineering specification, including a summary table, detailed testing protocol, personnel, and expected outcomes. Finally, it will outline the results of each test, discuss the project as a whole, and address goals moving forward and conclusions.
The device’s main functionalities are demonstrated in testing outcomes. The pressure localization test showed high accuracy in pressure recording among pixels with row and column standard deviations of 0.2 and 0.29 V respectively. It also showed short access times for data, with every row and column coming in under the 30-second threshold. The humidity test demonstrated the capability to sense moisture at multiple locations within the device, with each sensor registering an increase of at least 40% when exposed. The stationary time test showed the ability to detect high pressures, triggering every time the voltage went above the threshold value. It also showed the ability to detect extended periods of sitting, triggering within the time threshold two out of three times. The alert test demonstrated the ability to warn users with different sensory issues, with every alert scenario being recognized by the test subject
Why the Construction Industry is Falling Behind in Technology Use
Get PDFTechnology is becoming more impactful in the everyday life of almost every industry across the world. New products are being released every year to allow the mundane processes of work to be streamlined for maximum efficiency, leaving valuable time for the more pressing matters of a company. The construction industry is one of the largest and most essential industries in the world, but it has fallen behind in the use of technology. History has shown us that when new technology is introduced there is almost always some sort of pushback or buffer time for people to adopt. Just in the construction industry in the last few decades, mobile devices, iPad, and new internet software’s have taken over the old way of doing everything over the phone and on paper. Now doing everything electronically is the industry standard which has made organization and efficiency much easier on large construction projects. The purpose of this paper is to understand the reasons for this fallout. Whether it is because of stubborn employees, lack of adequate training and time resources, or the technologies are not yet practical to implement on projects today
Optimizing Medical School Enrollment
Get PDFThe increasing physician shortage, coupled with an aging population, presents significant challenges for healthcare systems. With higher education facing a projected enrollment cliff, and a decline in youth math and reading scores, identifying the most qualified medical school applicants is imperative. With thousands of applications received annually for only 300 spots at Western University of Health Sciences (WesternU), it is crucial to streamline the selection process while minimizing applicant attrition and melt.
In our research project, we develop a predictive model to identify candidates for interviews based on success data from students at WesternU. We utilized a dataset provided by WesternU of 30,000 applicant records from 2018 to 2024, encompassing various demographic, academic, and application metadata. Data preprocessing techniques included removing NaN values, checking for collinearity, applying min-max scaling, and using ADASYN oversampling.
Traditional machine learning models yielded accuracies between 35% and 45%. In our final model, our three target variables, 4th year cumulative GPA, COMLEX Level 2, and COMLEX Level 3 test scores, were categorized. For the final model, we decided to employ Linear Programming to calculate feature importances, maximizing mean differences to create a point value ranking system and to employ an ensemble approach.
The results show a GPA_CAT accuracy of 36%, COM2_CAT accuracy of 42%, and COM3_CAT accuracy of 55%, leading to a mean accuracy of 44%
Deep-Learning Based Microstructure Reconstruction and Generation
Get PDFCharacterizing the microstructural behavior of materials is crucial for understanding their properties and performance. Traditional imaging methods, such as optical microscopy and electron microscopy, are effective but costly and time-consuming. Computational approaches can reduce costs and time while expanding the accessibility of microstructural analysis through the generation of new microstructure images. Traditional computational approaches, namely descriptor-based approaches, are slow but effective in low-data scenarios. Modern approaches use machine learning (ML), which is faster but often requires a lot of data to approach the performance of descriptor-based methods. This research leverages a special data-efficient Generative Adversarial Network (GAN) architecture to artificially generate microstructures of strain-sensing nanomaterial networks. The nanomaterial networks consist of carbon nanotubes (CNTs) that exhibit strain sensing properties. By training the GAN on experimentally obtained microscopic images, the model can replicate complex microstructures. This ML-based approach significantly reduces the time and cost of microstructural characterization, providing an efficient method to build large databases for analyzing the electrical properties of nanomaterial networks
Design of Ballistics Armor Using Additive Manufacturing of Kevlar Composites
Get PDFThis project evaluates the effectiveness of various geometries created using advanced additive manufacturing (AM) of Kevlar fiber, chopped carbon fiber-reinforced filament for ballistic protection applications. This study expands on sandwich panel designs with woven Kevlar face sheets and investigates an optimal fiber reinforced filament core structure design. A unit cell workflow was developed in nTop to take advantage of its custom cell modeling and FEA capabilities. Unit cell types were simulated and tested from the hexagonal honeycomb, gyroid TPMS, and re-entrant auxetic cell families. Core structure thickness and cell size were additive manufacturing parameters that were varied to assess the impact absorption. Moreover, the additively manufactured cell structures were encapsulated with a damping material, particularly silica. To determine the best kind of silica for ballistic applications, 3 kinds of silica with varying tensile strengths were molded into a shape similar to the cores. The samples were then tensile tested using an INSTRON universal testing machine to determine which offered the best balance between strength and ductility. The experimental approach began by determining the material characteristics for test coupons for both continuous fiber and chopped fiber in 0- and 90-degree filament orientations
African Californios.org: Reconstructing the African Past of Spanish & Mexican California
Get PDFAfricanCalifornios.org is a research project dedicated to highlighting the significant contributions of Afro-descendants in Spanish and Mexican California. Historical colonial census records reveal that 19% of California\u27s population had African ancestry, yet many individuals concealed their identities to enhance their social standing. This project uses modern NLP and Data Science techniques to construct family trees, shedding light on their overlooked stories. The work has been published and presented at the 2024 Alliance of Digital Humanities Organizations conference
Counting Catalan: An Experimental Evaluation of the Mixing Time for the Triangulation Markov Chain
Get PDFMonte Carlo Markov chains (MCMCs) are used in many areas as a way to model a system’s behavior. By running a probabilistic simulation on a system’s state space, we can estimate properties of the system that could be untenable to directly compute. It is of interest to determine how quickly a Markov chain mixes\textemdash that is, settles into its stationary distribution. One such chain is induced by taking a binary search tree and performing a rotation or flip on one of its edges. We know that this chain eventually settles into the uniform distribution, but the time complexity bounds on the number of steps it takes to do so are not tight. We showcase an MCMC experiment suggesting that the true mixing time is likely higher than , the known lower bound. We also discuss choosing heuristics to approximate the total variation distance from the uniform distribution when a direct calculation is computationally infeasible\textemdash this calculation takes time proportional to the size of the state space, which for the binary tree chain is . Additionally, we discuss scaling the MCMC simulation as a whole to accommodate large state spaces. These findings serve to guide future studies on the direction of theoretical research on mixing times, as well as providing a framework for similar MCMC experiments
Photophoretic Optical Particle Trapping Improvements Using Beam Reflection
Get PDFCurrent research has shown that photophoretic optical trapping (POT) is a promising method for creating true three-dimensional holograms. A landmark study by Smalley et. al. at BYU was able to generate a full hologram within a 2 cm edge cube with remarkable success. However, a key drawback to this method is its poor ability to hold trapped particles within the focal point of the laser for an extended period of time. An investigation from our group presented at SPIE Photonics West 2023 sought to improve these results by varying the focal length of the trapping and the wavelength of the laser, called the one-lens control. To further extend trapping times, we take advantage of optical power lost due to scattering by reflecting it back toward the trapping site. We investigate the potential of retro-reflectors as an effective low-cost solution due to their corner- cube micro-structures which prevent interference between reflected and incident light. The reflected light is then re-focused back toward the trapping site using a Keplerian lens configuration. The resulting trapping times with retro-reflectors are measured and compared against two different control setups without reflectors, as well as a mirror setup to quantify the effects of destructive interference. Both the average and median trapping times for the retro-reflector setup showed significant improvement when compared to all three other test setups. While maximum trapping times with the retro-reflectors were comparable to those of the two-lens control setup, the new setup has higher average trapping times and shows great promise for future research. In addition we showed that at high optical laser powers the retro-reflectors showed higher average trapping times compared to the basic setup