Assessing resilience of forests to wildfires and fuel management in northern California through forest inventory and aerial photography analyses

In California, large-scale tree mortality has occurred due to a combination of increased drought and intensified wildfires. Long-lasting fire suppression, logging, and overgrazing resulted in an increased density of trees and hazardous fuels accumulation. In combination with climate change, this has led to larger and higher intensity wildfires. I investigated how altered forest structure after optimal management improves forest resilience to wildfires and determined which factors are most important to predicting burn severity. My study area focused on the Lassen and Plumas National Forests in northern California, especially the area burned by the Chips Fire. I used Forest Inventory and Analysis (FIA) data to examine tree mortality patterns and the Forest Vegetation Simulator (FVS) to simulate how wildfires and management affects forest resilience. I used National Agriculture Imagery Program (NAIP) imagery to estimate burn severity and used regressions to determine which factors are best at predicting it. The simulation showed that heavily thinning resulted in higher forest resilience. For both California mixed conifer and Jeffrey pine forest types, tree-size-related structural diversity has a negative relationship with forest resilience because of fuel continuity, but species diversity was not related to forest resilience. Time since most recent fire, weather, and climate variables were the most important predictors of burn severity. Forest managers can use information from my burn severity models to map burn severity risk and to help determine where to apply fuel treatments. With climate change predicted to worsen droughts and increase the area burned by fires in the future, it is important for forest managers to make decisions on what the optimal levels of thinning, prescribed burning, and fuel reduction are for managing forests in California, which should be assisted by the results of my research

Warning system in smart vehicles for detection of traffic signs, lights, and obstacles

Vehicle accidents can occur due to driver negligence and failure to follow traffic rules. For safe driving, the driver needs to be aware of different situations occurring on the road while driving. To improve a driver’s ability to maintain their focus and reduce accidents, this research proposes to enhance an automated driver early warning system. Such a system would alert the driver whenever a traffic object is detected. This research specifically focuses on improving detection of traffic signs, signals, pedestrians, and obstacles. In this work, a pre-processing enhancement with ESRGAN (Enhanced Super Resolution Generative Adversarial Network) is employed for enhancing the contrast and resolution of the extracted traffic objects. Many advancements have been made in object detection and image processing, but vehicle systems identifying the traffic signs, lights, pedestrians, and obstacles still need improvement. This research also compares the accuracy of two algorithms, You Only Look Once version 3 (YOLOv3) and You Only Look Once version 4 (YOLOv4) with and without the preprocessing ESRGAN enhancement. This research would facilitate advancing automatic systems in autonomous vehicles for sensing traffic objects in real-time. The main objective of this research is to increase the performance of traffic object detection in terms of accuracy, and compare deep learning techniques to see which would result in better performance. The proposed enhancement in this research is applying preprocessing using ESRGAN to the traffic objects, which increases the accuracy of the traffic object detection in different conditions such as nighttime, rain, or extreme weather conditions. The enhanced YOLOv3 model was found to have an average accuracy of 92.83% for traffic object detection, compared to only 87.11% for the unenhanced YOLOv3 model, which is a 5.72% improvement. The enhanced YOLOv4 model was found to have an average accuracy of 94.16% for traffic object detection, compared to only 87.32% for the unenhanced YOLOv4 model, which is a 6.84% improvement

Effect of blended freshwater on growth and development of Solanum lycopersicum

A total of 175 Solanum lycopersicum plants were grown to study the physiological characteristics of the species grown with unconventional water. All plants in the five treatments were arranged in a randomized complete block design (RCBD), at the Department of Agriculture, Agribusiness, and Environmental Science (AAES) greenhouse. Each treatment had 35 plants with five replications. The treatments that were diluted from 53.065 mS/cm seawater included: 0.5%, 1%, 1.5%, and 2% and a freshwater control. Plants were treated weekly and data collection occurred within the same period. Physiological and growth medium parameters measured include height, changes in electrical conductivity of the soil and water, changes in soil pH, total chlorophyll content, transpiration rates, leaf area and fruit yield. Statistical analysis of data showed significant differences in the electrical conductivity of the growth medium with increase in seawater concentration, but no significant differences existed between the other parameters measured

Elliptical machines using adjustable linkages

Elliptical machines are exercising or training machines that are used to imitate walking, jogging, running, or climbing exercises. Different from treadmill machines, elliptical machine users never leave their feet away from the pedals, which reduces the pressures to the ankle, knee, and hip joints, and significantly decreases the impact injuries of joints. The configuration of the elliptical motion commonly mimics the natural paths of the ankle, knee, and hip joints for walking, jogging or running, which further lowers the strains and stresses on the joints. In addition to the lower joint impact, a unique feature of elliptical machines is their integrated leg and arm movements that provide full-body (dual lower and upper body) exercises. Users of elliptical machines not only exercise their legs but also push and pull the handlebars to strengthen their arms. Unlike treadmills, ellipticals are usually self-powered by user-generated motion and do not need motor and belt conveyance. They have cost and maintenance advantages over treadmills. This thesis research is on analyzing and simulating elliptical machines. The closed elliptical trajectories of elliptical machines are generated through their linkages. The shapes of the closed trajectories depend on the linkage types and dimensions. The relationships between linkage dimensions and elliptical shapes and sizes are complicated and are difficult to represent using analytical expressions. The complexities and difficulties put challenges on designing elliptical machines. The elliptical trajectory including stride length of an elliptical machine needs to meet the requirements for different exercises, and various short and tall people with a wide range of arm or leg sizes. If an elliptical machine has fixed linkage dimensions, its elliptical trajectory has only one shape and size, which does not provide flexibility. For an elliptical machine to have flexibility, its linkage has to be adjustable. Adjustable linkages are more difficult to analyze and synthesize than linkages without adjustability. This thesis research is motivated to surmount the challenges facing elliptical machines. The research objective is to improve the performances of the current elliptical machines. In this thesis research, different types of elliptical machines (front, rear, and central arrangements) without and with adjustability will be analyzed. Their elliptical output motions will be simulated and compared. The research results from this thesis research will provide useful guidelines for developing and promoting elliptical machines

Effects of Citrus tree phenology on color morphology and candidatus liberibacter asiaticus acquisition potential of Diaphorina citri kuwayama (Hemiptera: Liviidae)

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae) is an economically significant pest that vectors the bacterial pathogen Candidatus Liberibacter asiaticus (CLas), associated with Huanglongbing (HLB) disease. Diaphorina citri adults exhibit three abdominal color variants of blue, grey, and yellow, which are linked to traits such as flight ability, insecticide resistance, and CLas acquisition. Color morph composition of field-collected D. citri from commercial citrus groves and residential trees in South Texas were evaluated to determine the seasonality of the three variants and assess their CLas status. D. citri samples were evaluated for their sex ratio, morphometric parameters, CLas status, and presence of endosymbionts. In both settings, the yellow color morph was dominant when young flush shoots are present, while the blue morph was the dominant color between flush cycles. Laboratory studies indicated D. citri color morphs were interchangeable depending on flush stage. On mature shoots, blue D. citri remained blue, but a significant proportion of grey and yellow also turned blue within two weeks. In contrast, on young flush shoots, yellow remained yellow while some blue and grey D. citri morphed into yellow. There was no significant effect on color morph on the percentage of CLas-positive psyllid, but there was a trend of higher bacterial titer in yellow relative to blue morphs. Multivariate analysis indicated that maximum temperature and total rainfall four and six weeks prior to D. citri collection were negatively correlated with the percentage of CLas-positive psyllids. The primary and secondary endosymbionts, Candidatus Carsonella ruddii and Candidatus Profftella armature, were present in all three D. citri color morphs. This study showed that citrus tree phenology regulated the color morph composition of D. citri, which can affect CLas transmission and dynamics in groves as well as the effectiveness of vector management

Identification of fungal plant pathogens in irrigation water in the Lower Rio Grande Valley of Texas

The Lower Rio Grande Valley of Texas (LRGV) is an area with high agricultural activity which uses the Rio Grande River as a primary irrigation water source. The Rio Grande River receives water from many streams that could transport pathogens, thus contaminated irrigation water with plant pathogens can be the source of inoculum for many agricultural crops in the LRGV. However, there is no data or research on the fungal plant pathogens present in the Rio Grande River. This study evaluated the water feeding the canal from the Mercedes irrigation district reservoir and the water arriving at a citrus orchard for the presence of fungal plant pathogens by Illumina sequencing. Results show that fungal communities from both sampling locations were different. A total of 994 fungal Operational Taxonomic Units (OTUs) were obtained from the six samples analyzed and 284 OTUs were detected in all samples. At the Phylum level, there was a higher relative abundance of Chytridiomycota followed by Basidiomycota and Ascomycota. However, phylogenetic analysis showed higher abundance of Ascomycetes genera identified, compared to other fungal groups. Ten OTUs were identified as fungal plant pathogens, nine were identified in the water collected at the citrus orchard, and four of those were also found at the irrigation district. The citrus orchard contained five different additional plant pathogens that were only found at this citrus orchard along with the four that were also found at the irrigation district. The irrigation district contained four plant pathogens coinciding with those of the citrus orchard, and had one additional plant pathogen found only in this location. This study indicates that fungal plant pathogens are present in irrigation water and could potentially be a source of inoculum to plant diseases. This study provides new insight to the potential risks and distribution associated with plant pathogens in irrigation water in the LRGV

Characterization of GAP43-Gfp fusion protein in PC12 and NIH3T3 stable transfectant cells

Nerve regeneration is a physiological process in which damaged axons regrow after they have been injured. In the fully grown mammalian Central Nervous System (CNS), nerve regeneration is almost nonexistent. Researchers are conducting experiments and trying to understand the mechanisms of nerve regeneration by manipulating neuronal cells at cellular and molecular levels to develop therapies for patients with nerve damage. To study the mechanism of nerve regeneration, our laboratory has been focused on studying genes and proteins that are activated and expressed during and post axonal damage. Researchers had found that GAP-43, a protein with an apparent molecular weight of 43 kilodalton (kD) by electrophoresis, is overexpressed in axonal growth cones during neuronal development and nerve regeneration. Studies led researchers to understand that GAP-43 plays a key role in axonal regeneration, particularly in neurite growth and in axonal pathfinding. Our hypothesis is that sustained high level expression of the intrinsic protein GAP-43 enhances neuritogenesis and nerve regeneration. A plasmid encoding a chimeric protein in which the GAP-43 protein is fused with a fluorescent GFP molecule was used to express a GAP43-GFP fusion protein, which allowed to detect and measure expression levels in transfected cells. The plasmid with the recombinant hGAP43-tGFP gene expressing GAP43-GFP fusion protein was transfected into PC12 cells and stable transfectant cells were selected and grown in the laboratory. Over time, the stable transfectant cells expressing GAP43-GFP showed a significant loss of expression, which was observed through fluorescent microscopy and Western blot analysis. When comparing cells expressing GFP versus GAP43-GFP, the latter showed a much lower level of expression of the fluorescent protein. To understand better the rate of loss of expression of GAP43-GFP, experiments were carried by transfecting PC12 and NIH3T3 cells and collecting cell lysates to conduct Western blot analysis of levels of expression

Faculty knowledge and preparedness with ADA compliance and the relationship to student success in higher education

Higher education instructional faculty have a multitude of job responsibilities other than classroom instruction. One of those responsibilities is the implementation of accommodations for students with disclosed disabilities. This quantitative study sought to determine if a relationship exists between faculty members’ knowledge and preparedness with ADA compliance and student success. Individuals with Disabilities Education Act of 1990 (IDEA) emphasizes preparing a transition plan for special education students in grades P-12, therefore generating research on how instructional faculty can assist students with disabilities meet their educational goals post high school. This study conducted a non-experimental survey to gather data from higher education faculty members on their knowledge regarding the requirements of the Americans with Disabilities Act and their preparedness to implement accommodations. Pearson’ Correlation was conducted to show if faculty knowledge and preparedness in ADA compliance can be associated with student success. Based on the information gathered, data informed recommendations are made on the needs of faculty members in servicing all students. The results of this study revealed that there is no statistically significant correlation between higher education instructional faculty members’ knowledge and preparedness to implement services to students with disabilities and success rates. Results will assist higher education faculty and administration with recommendations as to what may impact success of students with disabilities

English as a foreign language pre-service teachers' perceptions of task-based language teaching in Northern Mexico

This quantitative case study research explored English as a foreign language (EFL) pre-service teachers’ perceptions of the Task-Based Language Teaching (TBLT) for facilitating written language competency for learners of English in northern Mexico. EFL pre-service teachers are trained to serve in basic education secondary school, teaching English. The participants in the study (n = 193) were from two locations: Universidad Autónoma de Nuevo León (UANL) with 112 EFL Pre-service teachers (Location A) and The Normal Superior School with 81 EFL pre-service teachers (Location B). All participants took part in the study voluntarily and responded to a survey via email. The study included a survey developed for this study with a five-point scale (1. Strongly disagree, 2. Disagree, 3. Neutral, 4. Agree, 5. Strongly agree). The survey contained a demographic section followed by three subscales with a total of 35 items: Subscale one, The Teaching Process (items 1-10); Subscale two, The Role of the Task (items 11-18), and Subscale 3, The Teaching of Language Competencies (items 19-35). The last five items of the survey (31-35) asked participants about the facilitation of written expression competency through TBLT. The items of the survey responded to the three research questions (RQ) of the study, regarding perceptions about TBLT approach to the teaching of English; the role of task in English language learning; and the contribution of TBLT for teaching of the written expression competency in Mexico. The construction of the survey was informed by contributions of Prabhu (1987), Nunan (2004), Swan (2005), Ellis (2009), Long (2015), Jeon and Hahn (2006), and SEP (2011). The survey was administered using the SurveyMonkey platform. Findings showed that the majority of participants (n = 152, 79%) responding with the two highest points of the Likert scale (4. Agree and 5 Strongly agree), perceived that the TBLT approach facilitated EFL teaching process, specifically competency in the written expression of learners of English. However, there were 29 (15%) participants who provided a neutral response and 12 (6%), who by indicating the two lowest points of the Likert scale (1 Strongly disagree and 2 Disagree), had a negative response that TBLT facilitates the teaching of the writing skills

Aspects of hunting of Northern bobwhite populations: temporal and spatial analysis

Northern bobwhites (Colinus virginianus) have been studied intensively now for more than a century. Despite the attention, widespread declines have occurred across their geographic ranges. These declines raise concerns regarding the long-term sustainability of populations exposed to hunting. However, population trends of northern bobwhites in South Texas seem to lack the long-term declines occurring across much of the state and elsewhere. Research has attributed this to favorable range management practices, large property sizes, and economic incentives derived from hunting lease fees in the region. The recommended harvest rate for South Texas is 20% of the fall abundance, including factoring for crippled individuals. This harvest rate is based on simulations of empirical data but still requires thorough evaluations in the field. We assessed the 20% recommendation during the 2018–2019, 2019–2020, and 2020–2021 hunting seasons on East Foundation properties in Jim Hogg County, Texas, using designated hunted (15,030 acres) and non-hunted sites (10,813 acres). We estimated multi-temporal bobwhite densities (e.g., 4 per hunting season × 3 seasons) using line-transect distance sampling from a helicopter platform and recorded bobwhite hunting details using Garmin GPS units (i.e., trucks and pointing dogs) and detailed hunting logs. Our specific objectives were to (1) evaluate the harvest rate recommendation for northern bobwhite populations in South Texas by comparing temporal trends between hunted and non-hunted sites (Chapter 2), (2) analyze the temporal and spatial dynamics of quail hunts in South Texas (Chapter 3), and (3) evaluate the spatial effects of harvest-related hunting pressure on local distributions of northern bobwhites (Chapter 4). According to our bobwhite density estimates, spring densities on both sites (e.g., hunted vs. non-hunted) were similar through the first two years but diverged in 2020–2021, with bobwhite densities 129% higher on the non-hunted site (Chapter 2). Hunting parties effectively covered 23.8 ± 0.3 hectares per hour, with hunts lasting 3.5 ± 0.1 hours in the morning and 1.7 ± 0.1 hours in the evening (Chapter 3). We also found that hunting pressure associated with a 20% harvest (i.e., low hunting pressure; 5.3–8.3-gun hours/100 ha) has a minimal influence on the change in bobwhite density at 16 ha resolution, with the year (i.e., starting or peak density per year) as the primarily influence (Chapter 4). Our results will assist managers in making decisions regarding sustainable harvest practices and aid with the strategical distributions of hunting pressure across properties and hunting seasons