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The Identification of Foramsulfuron and Sulfentrazone Resistant Goosegrass (Eleusine indica) Populations
Get PDFEleusine indica, commonly known as goosegrass, is a C4 weed species infesting turfgrass, cropping systems, and home lawns. Goosegrass is well known for developing herbicide resistance to different herbicide families and modes of action. Populations collected with suspected resistance were submitted to the Herbicide Resistance Diagnostic Lab at Auburn University to evaluate for resistance to six common herbicides used in turfgrass. Research was conducted in greenhouse conditions to assess susceptible (S) goosegrass responses compared to suspected resistant (R) biotypes. Based on the postemergence screen, 30 of the 50 populations were diagnosed as resistant to one or more herbicides. In contrast, 20 populations were diagnosed as susceptible to all treatments compared to the nontreated. Seventeen populations possessed cross-resistance to two or more herbicides.
Since their discovery in 1995 and 1989, respectively, foramsulfuron and sulfentrazone have been widely utilized herbicides in turfgrass management. Despite their extensive use, limited research has been conducted on goosegrass biotypes resistant to these herbicides. Following initial postemergence screening, confirmed resistant biotypes underwent further analysis. Our research aimed to clarify the resistance level of these goosegrass biotypes by conducting dose-response assays with increasing rates of foramsulfuron (1.81 to 115.56 g ai/ha) and sulfentrazone (26.21 to 1677.78 g ai/ha). Visual injury ratings were recorded at 7, 14, 21, and 28 days after treatment (DAT), with aboveground biomass assessed at 28 DAT. Foramsulfuron-resistant populations (R-R1, R-R2, and R-R3) exhibited calculated I50 values of 0.12, 0.12, and 0.09, respectively, while the susceptible biotype displayed an I50 of 0.02. In comparison, sulfentrazone-resistant populations (D-R1 and D-R2) demonstrated I50 values of 0.11 and 0.21, respectively, whereas the susceptible biotype had an I50 of 0.03. Target-site gene sequencing of acetolactate synthase (ALS) and protoporphyrinogen IX oxidase (PPO1 and PPO2) indicated no mutation in the resistant biotypes compared to the susceptible, suggesting a potential non-target site mechanism
Effect of dehydration time on physicochemical, textural, instrumental color, and sensory characteristics of jerky-style pet treats made with swine pluck
No full textThe current growth of pet ownership, coupled with the rise of pet humanization, has driven the integration of convenient materials repurposed into pet food products, particularly pet treats. Swine pluck (SP), a combination of heart, lungs, esophagus, and trachea offers a single-removal unit that can be effectively utilized to manufacture pet treats. However, pet food manufacturers continue to seek ways to improve the product’s characteristics to satisfy both pet owners and their pets, influencing purchasing decisions. In this study, one experiment was conducted to assess the effect of dehydration time on physicochemical, textural, instrumental color changes post-production, and sensory attributes of jerky-style pet treats made with SP. Dehydration time impacted the characteristics of SP treats, with the lowest levels of moisture content and water activity observed after 7 h of dehydration. To achieve a water activity of 0.85, a minimum dehydration time of 5 h was required. Treats dehydrated for 7 h were found to be harder and stiffer, whereas those dehydrated for 3 and 4 h were the more flexible. Additionally, SP treats dehydrated for 6 and 7 h exhibited the highest firmness and toughness. Prolonged heat treatments also had a notable effect on the final color of SP treats. After 7 d of storage, SP samples dehydrated for 3 h were the lightest (L*), reddest (a*), and yellowest (b*) among treatments. Delta-E (∆E) values were the highest between d 0 and 1 post-production, indicating color changes that were perceptible to the human eye. According to pet owners’ liking scores, dehydration time impacted the color, texture, and intent of purchase. However, pet owners did not differentiate between the samples in terms of appearance and the overall liking. Variations in dehydration time impacted both instrumental and sensory characteristics. Overall, SP can be effectively used to produce jerky-style pet treats, resulting in a shelf-stable product that meets the quality standards of the pet food industry
What do Resources have to do with it? A Within-Person Examination of the Interplay Between Demands, Workaholism, and Burnout
No full textExisting research highlights associated constructs that involve sustained effort at work,
such as job demands and workaholism, and how these can lead to negative outcomes such as
burnout. Traditionally, these associations have been examined at the between-person level.
Considering the dynamic nature of these constructs, it is pertinent that these associations be
explored at the within-person level using experience sampling methodology. In my dissertation, I
employed a daily diary design to examine the association between job demands and end of
workday burnout through daily engagement in workaholic behaviors. I also explored the
conditional function of four job- and personal-related resources on this proposed indirect effect.
Data was collected through 17 surveys: two for determining eligible participants and gathering
baseline data, and 15 administered over a five-day workweek. Results demonstrated that daily
demands were positively related to both daily engagement in workaholic behaviors and end of
workday burnout. However, daily engagement in workaholic behaviors did not explain this
association at the overall level. Supplemental analyses revealed that the motivational and
cognitive dimensions of workaholism explained the relationship between daily demands and end
of workday burnout. Additionally, the four cross-level resources (autonomy, direct supervisor
support, work colleague support, and core-self evaluations) did not function as the link among
the three variables of interest. This suggests the need to explore the dynamic nature of these
resources or to identify different ones that may be more theoretically and empirically related to
the variables at hand
Effect of Roundup on the Release of Reproductive Hormones in Rough Shiner (Notropis baileyi)
No full textRoundup is the most used herbicide across the world, with over a billion kgs applied in the US since its introduction in 1974. Long thought to be harmless to non-target species, recent studies have called this supposition into question. Aquatic environments are particularly susceptible, as Roundup binds to the soil and can be washed into the water spiking concentrations for several days. Our research focused on the effect of Roundup on fish reproduction, looking at three common reproductive hormones (prostaglandin-F2a, 11-ketotestosterone, and estradiol) produced by leuciscids. Our research found significant impacts to fishes’ ability to detect and react to the reproductive signal prostaglandin-F2a, which is essential for ensuring simultaneous breeding. After fish were exposed to Roundup for 3 days, they released significantly less of all three reproductive hormones studied in this experiment, with levels of prostaglandin-F2a and 11-ketotestoterone being too low to detect
Investigating the Role of Post-Learning Activities on Memory Consolidation in Scent Detection Dogs
No full textMemory consolidation is a flexible process, allowing the strength of memories to be modified by highly arousing positive or negative experiences occurring after learning. Previous studies in dogs have shown that different post-learning activities improve performance on visual discrimination tasks (Affenzeller et al., 2017; Snigdha et al., 2014). Memory consolidation has not been investigated in working dog populations. This study investigates the effect of post-learning activities (social play, individual play, or control) on memory consolidation in working dogs learning a scent detection task. Dogs were trained in one session to find an odor in a line-up, followed by a baseline test and then participated in one of the three post-learning activities for 15 min. Dog’s 24-hour and 1-week retention performance were tested. Salivary cortisol and heartrate were measured around training and interventions. Arousal during training, measured by heart rate, interacted with arousal post-training and baseline reward arousal scores, such that dogs with low baseline arousal in the social play group performed better when they reached higher training heart rates. However, high baseline arousal dogs in the social play group performed worse when reaching higher training heart rates. The results of this study emphasize the importance of selecting training methods to meet the needs of individual dogs. Understanding how arousal during and after training influence memory consolidation may shorten training timelines and improve long-term performance in working dog training
Assessing Clade Specific Putative Secreted Proteins in Fusarium oxysporum f.sp vasinfectum for their Contribution to Virulence on Cotton
No full textFusarium wilt (FW) of cotton is caused by the fungus Fusarium oxysporum f. sp. vasinfectum (Fov). Fov invades and colonizes the vascular system of cotton plants and results in browning or black discoloration of vascular bundles, wilting due to disrupted water transportation, and eventual plant death. Some of the virulence of Fov is mediated by effectors, which are usually small secreted proteins (SSPs). One of the roles of effectors is that they enable the pathogen to overcome the host defense system, e.g., pattern-triggered immunity, and to promote effector-triggered susceptibility to spread disease symptoms for the benefit of the pathogen. The main focus of this study is to evaluate clade specific secreted proteins in Fov race 4 that could be involved in virulence on cotton.
In Chapter 2, using comparative genomics between twelve Fov genomes (cotton) and ten publicly available F. oxysporum genomes, host-specific putative secreted proteins which could be contributing to virulence (fungal effectors on cotton) were identified. Among the Fov isolates, the highly virulent race 4 is of particular interest due to its ability to cause early-season severe damage, including seedling wilt and death, without any nematode requirement to initiate infection. EffectorP3 was used to identify proteins that could serve as putative effectors, which identified eleven proteins specific to Fov race 4. To narrow down unique putative effectors, we conducted RT-qPCR to assess the relative expression levels of these genes during infection, identifying five putative secreted proteins of interest. Three mutants of SSP genes, FUN_011311, FUN_014580 and FUN_002905 were chosen for gene mutation based on their upregulation and presence as a single copy in the genome. A hydroponic virulence assay was conducted with Pima cotton cultivar Rowden, to assess whether these proteins serve as a virulence factor on cotton. FUN_011311 was confirmed to contribute to virulence on cotton.
In conclusion, the Fov genomes can provide necessary resource for comparative genomic analysis to identify genes that are involved in pathogenicity on cotton and may be used to develop improved disease management strategies. Understanding the function of effectors in pathogen-plant interactions provides insight into the mechanisms of host specificity and pathogenicity, enabling the identification of genetic resistance markers and the development of resistant cotton varieties. Such foundational research is essential for devising innovative methods to combat pathogens like Fusarium, ultimately improving agricultural biosecurity and sustainability
Conservation Compliance and Public Awareness: Assessing Dolphin and Sea Turtle Interactions in Coastal Alabama
Get PDFThe Marine Mammal Protection Act (MMPA) and the Endangered Species Act (ESA) serve as critical legislation for safeguarding marine species in the United States, particularly in the Gulf of Mexico region. Despite legal protections, charismatic and ecologically important species like dolphins and sea turtles remain vulnerable to human activities along the Gulf Coast. Anthropogenic threats include habituation to human presence, habitat degradation, harassment, bycatch, and challenges in enforcing legal protections. Understanding public awareness of wildlife and compliance with conservation laws is crucial for mitigating such threats. This study addresses this gap by examining the extent of public demographics, knowledge, and behaviors regarding dolphins and sea turtles in Mobile Bay, Alabama. Analysis of survey data using generalized linear models highlights the relationship between various factors, such as gender, state residency, and ecological knowledge, on public willingness to adopt pro-conservation behaviors, specifically receptiveness to stop feeding dolphins and using sea turtle-friendly fishing gear. These findings emphasize the importance of tailored strategies and educational outreach efforts by state and federal fish and wildlife agencies, such as targeted educational campaigns and community engagement initiatives, to enhance public awareness and promote behavioral changes that align with wildlife protection laws. By addressing gaps in understanding and promoting responsible behaviors among coastal tourists, conservation efforts can effectively mitigate anthropogenic threats to dolphin and sea turtle populations in the Gulf of Mexico and beyond
Chemical Process Design Approaches Leveraging Process Modularization, Intensification, and Large Language Models
Get PDFThis dissertation investigates critical aspects of chemical engineering, including reactor intensification, process expansion, distributed natural gas desulfurization, and large language models. The key findings of this work highlight the complex interplay among reactor intensification, separation design, production costs, and environmental considerations, emphasizing the necessity for tailored approaches. Economic analysis confirmed triazine-based absorption and SourCatTM to be cost-effective desulfurization methods. Moreover, In one of our study we underscored the limitations of general-purpose language models and advocated for the use of domain-specific training data to enhance reliability in process design applications.
As a case study, the first study discusses the critical effects of reactor intensification on downstream processes and the impact of different process expansion approaches on the cost and environmental effects of ethylene oxide production. In this study, the production of ethylene oxide was simulated at a production capacity of 100 kt/yr using a conventional reactor and reaction kinetics. Subsequently, the impact of reactor intensification was investigated using microfibrous-entrapped catalysts on separation section design. Second, three expansion approaches, namely, the Brownfield, retrofitting, and Greenfield processes, were explored with an emphasis on the implications of their cost and environmental impact. Despite offering cost reduction, the limited separation capacity of the Brownfield process limits the potential increase in production achievable through reactor intensification. Although retrofitting reduces production costs, it introduces complexities at a capacity of >130 kt/yr, necessitating additional separation columns. The Greenfield process, with the lowest carbon emissions among the three investigated expansion approaches, is cost-effective only at production rates above 160 kt/yr. The retrofitted process involves a moderate increase in carbon emissions, whereas the Brownfield process leads to a substantial increase in carbon emissions with capacity expansion. These findings emphasize the complex interplay among reactor intensification, separation train design, production costs, environmental considerations, and capacity limitations in chemical processes, underscoring the importance of formulating tailored approaches to suit specific requirements and carbon emission goals.
The second section discusses natural gas as a reliable, clean, and abundant energy source for heat and electricity generation. A vital aspect of using natural gas as an energy source is the removal of water, CO2, and H2S before pipeline transmission. Desulfurization is a crucial and routinely used purification step for removing H2S from natural gas in conventional reservoirs. With increasing energy demand, stranded/distributed natural gas resources, which remain unused for economic reasons (small scale and remote from the market), are being increasingly considered at present. Investigating low-cost distributed natural gas desulfurization is essential as a preprocessing step for utilizing stranded gas. In this study, three desulfurization processes, namely, triazine-based absorption, a liquid redox system (LOCAT®), and solid-bed oxidation (SourCatTM), were analyzed to study their economics and capability to remove H2S from small-scale distributed natural gas resources. Besides considering the impact of modularizing these processes, which typically use standardized equipment sizes owing to the transmission difficulties of stranded gas resources, the economics of the modularized processes were compared with those of traditional-design processes. Each process was simulated using Aspen Plus at different sulfur concentrations (500–2500 ppm) and natural gas capacities (1–100,000 MSCFD), and the corresponding desulfurization costs were estimated. In addition, a sensitivity analysis was used to identify the parameters influencing the desulfurization cost. The results revealed that the triazine-based absorption process is economical for processing capacities lower than 500 MSCFD, whereas SourCatTM is cost-effective for processing capacities between 500 and 100,000 MSCFD. Furthermore, the raw material, pump utility, and sorbent costs substantially impact the triazine-based absorption, LOCAT®, and SourCatTM processes, respectively. An analysis of the applicability of modularized desulfurization units in gas fields is expected to provide valuable insights into the quantitative assessment of the modularization effectiveness and its potential application limitations.
In our third study explored the usefulness of the large language models (LLMs)in process design context-based evaluation of, specialized metrics to assess chemical process design-specific query evaluation, problem-solving abilities, and correct terminology usage. This work highlights the general-purpose language model limitations of using general training sets to convey process engineering concepts, emphasizing the need for training on design diagrams such as process flow diagrams. The general-purpose model hallucinates in a specific process design task by either over- or under-assuming. This research reiterates the age-old phenomenon of "garbage in, garbage out” in system modeling, demonstrating that models trained on general language data exhibit lower accuracy in specialized contexts. Each engineering term was heavily contextualized to address the issues of ambiguity and polysemy in process design terminology to reduce model hallucinations. Subsequently, words and phrases were transformed into vector representations using techniques like word-to-vector. By calculating the Euclidean distances between these word vectors, terms that were close in meaning were identified within the process design context. Clustering algorithms, such as k-means, group these vectors into clusters of contextually similar terms, effectively disambiguating polysemous words based on their usage in process design documents. Graphs were then used to find relationships and contextualize technical understanding using process design diagrams such as flowsheets, flow diagrams, and graphs. Furthermore, maintaining consistent distances and clustering while training the language model ensured that the language model learned specifically in the specific flowsheet context and provided consistent answers to specific questions, thereby enhancing proficiency and maintaining consistency for each query. By analyzing the impact of training data quality on LLM performance, the integration of domain-specific texts was found to enhance model reliability. These findings suggest that targeted training approaches, such as the strategy described in this work, for different types of training data other than text are essential for developing LLMs capable of effectively operating within technical fields, such as process design engineering
The Effect of Moisture Content and Temperature on Mechanical Properties of Clear Wood Samples Cut from Southern-Pine Lumber
No full textSouthern yellow pine is a softwood species group abundantly found in the Southeast United States. With the increasing trend towards promoting sustainable construction, mass timber members such as cross-laminated timber and glulam members made from southern pine wood are becoming more widely used. Despite the widespread use of southern pine wood in construction, there are limited studies investigating the fundamental mechanical properties (strength and stiffness) of southern pine wood at the material level under different environmental conditions. This thesis presents a research study focused on characterizing generic southern yellow pine by testing clear wood samples under various load and sample conditions according to ASTM D143-22 (2022), with slight deviations when necessary. The
objective was to experimentally evaluate the effects of temperature and moisture content on the wood’s mechanical properties.
The loading conditions included compression both parallel and perpendicular to the grain, bending, shear parallel to the grain, and tension both parallel and perpendicular to the grain. The sample conditioning groups encompassed five temperature and moisture content
combinations, with three temperature conditions (-22°F, 70°F, and 150°F) and three moisture content levels (4%, 12%, and 25%). The sample conditioning combinations were designed to vary a single parameter between the conditioning groups to clearly observe the effects on strength and stiffness properties. The test results were mostly consistent with prior studies indicating that mechanical properties mostly decreased at high moisture content and increased at low moisture content. The impact of temperature on high-temperature properties was more marginal. Overall, the study contributes valuable insights into the behavior of southern yellow pine under different environmental conditions
Mind over Muscles: Testing the Impacts of Psychological Avoidance on Changes in Muscle Dysmorphia Symptoms over Time for Men Enrolled in a Body Acceptance Program
No full textMen with muscle dysmorphia (MD) engage in harmful behaviors to conform to a muscular ideal, often driven by psychological avoidance of body-related distress. While dissonance-based (DB) interventions effectively reduce MD symptoms, the impact of psychological avoidance on intervention effects remains unexplored. This study examined whether baseline psychological avoidance moderates MD symptom changes in a body acceptance program. Participants (N=200) were randomized to a DB intervention or active control condition, completing the Muscle Dysmorphic Disorder Inventory (MMDI) and Acceptance and Action Questionnaire (AAQ-II) at four timepoints (baseline, post-intervention, one-month, six-month follow-ups). AAQ-II scores were associated with MMDI subscales across time, with small to moderate effects. Multilevel modeling revealed significant symptom reductions over time but no significant interaction effects between psychological avoidance, condition, and time. Results suggest DB interventions effectively reduce MD symptoms, irrespective of psychological avoidance, although avoidance may coincide with impairment in daily functioning