Auburn UniversityThe DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.https://etd.auburn.edu:4432024-03-28T20:44:33Z2024-03-28T20:44:33ZFood restriction during breeding and development and its implications for reproductive trade-offs in zebra finchesCoutts, Victoriahttps://etd.auburn.edu//handle/10415/91372024-03-28T19:12:59Z2024-03-28T00:00:00ZFood restriction during breeding and development and its implications for reproductive trade-offs in zebra finches
Coutts, Victoria
Breeding has a high energy requirement. Common stressors such as food restriction introduced during breeding can stimulate reproductive trade-offs by requiring more energy than the amount of energy available in the environment and further reducing that energy availability. In particular, short-lived animals may be more inclined to prioritize reproduction over self-maintenance, as they have fewer chances to breed in the future compared to long-lived animals. However, the relationship between food restriction during breeding, the outcome of reproductive trade-offs, and potential mechanisms for these trade-offs in short-lived species have proven difficult to identify, especially since directly manipulating food in the wild is nearly impossible. While there are studies that effectively restrict food and investigate reproductive trade-offs in mammals, these have rarely been identified in birds, which have higher metabolisms and generally require more daily energy than mammals. Further, if parents prioritize reproduction, they can protect their young from stressors, but this phenomenon is poorly understood. This is particularly important because developmental stressors can shape the morphology and physiology of an individual. These effects have been assumed to be permanent and consequently impact fitness. However, not all effects of developmental stressors are permanent, and repeated measures or measures of fitness are rare, thus one cannot conclude whether a stressor during development is beneficial or detrimental for the organism. Throughout my dissertation, I aimed to fill these gaps in developmental stress research and reproductive trade-offs using a model species (zebra finch, Taeniopygia castanotis) and a common stressor (food restriction). I exposed nests to either a control (ad libitum) diet or a 40% food-restricted diet when nestlings were 5 days post-hatch (dph) on average until 60 dph. To determine the effects of food restriction during breeding on the outcome and mechanisms of reproductive trade-offs, I collected samples from parents on morphology, adrenocortical and glucose responses (Chapter 2), and molecular parameters and indicators of condition (Chapter 3). To further investigate the outcomes of reproductive trade-offs and investigate the effects of chronic, developmental food restriction, I also collected samples from offspring on morphology, adrenocortical and glucose responses (Chapter 4), and development of secondary sexual characteristics and reproductive success (Chapter 5). Most of these parameters were collected at multiple time points reflecting different stages of the breeding period and development.
In parents (Chapters 2 and 3), food-restricted breeding parents had lower body mass and higher baseline corticosterone but no changes in furculum fat or glucose levels compared to controls. There was also a negative association between 1) parent body mass change and baseline corticosterone and 2) parent body mass change and offspring brood mass, but only in food-restricted birds. All effects were observed during the fledging period, which is notably the most energetically demanding period for parents. These data suggest that parents may be prioritizing their reproductive bout over somatic maintenance, and corticosterone could be a mechanism for this energy allocation. Furthermore, food-restricted breeding parents increased telomere length while controls did not alter telomere length, suggesting a robust relationship between food restriction and telomere length and an increase in cellular maintenance. I did not observe changes in DNA damage or beak coloration (an indicator of condition) during treatment. However, parents that lost more mass also had less DNA damage, suggesting that food-restricted parents may be upregulating their DNA repair mechanisms to mitigate damage to a level similar to controls.
In offspring (Chapters 4 and 5), food-restricted individuals had lower body mass only in adulthood (not during the treatment period), higher baseline corticosterone and baseline glucose, but no changes in furculum fat or growth rate. Further, there was a negative association between body mass in adulthood and baseline corticosterone in adulthood. Data from this chapter suggest that parents are buffering their offspring from the stressor, but not enough, and offspring may be utilizing corticosterone to allocate energy toward maintenance of body mass during the treatment period. Food-restricted offspring also had lower reproductive success and slower development of male cheek patches, indicating detrimental effects of chronic, developmental food restriction on fitness indices. However, there was no significant difference in beak or cheek patch color or cheek patch size in adulthood, suggesting that neither beaks nor cheek patches are honest signals of past developmental stress exposure.
Overall, these data suggest there could be a trade-off between current reproductive bout and self-maintenance where parents attempt to buffer their offspring from food restriction and allocate the remainder of their energy toward protecting their DNA. However, this may not be enough, as offspring still experience adverse effects of food restriction after treatment, even in adulthood. Therefore, examining the outcomes of reproductive trade-offs and long-term studies are important to determine the full effects of a stressor, and food restriction applied during development is overall detrimental in a short-lived passerine.
2024-03-28T00:00:00ZIntegration of Lean and Industry 4.0 for Smart ManufacturingHossain, Md Monirhttps://etd.auburn.edu//handle/10415/91362024-03-28T19:10:33Z2024-03-28T00:00:00ZIntegration of Lean and Industry 4.0 for Smart Manufacturing
Hossain, Md Monir
The purpose of this study was to investigate the potential of integrating Industry 4.0 (I-4.0) technology with Lean Production (LP) systems to increase manufacturing productivity. LP has been in use for over four decades and has resulted in the development of a range of Lean tools and principles that have been proven effective in improving productivity and performance in different manufacturing sectors. However, since 2011, I-4.0 has also been increasingly utilized to enhance productivity. While both paradigms share the goal of enhancing productivity, Lean is a people-centered, while I-4.0 is a technology-centered approach. As a result, some researchers have raised concerns about the integration of I-4.0 into LP systems and the potential for a synergistic relationship between the two approaches. To analyze these concerns systematically, we conducted a Systematic Literature Review (SLR) investigating the relationship between Lean and I-4.0, identifying existing frameworks for combining the two, and identifying key factors that drive the successful integration of I-4.0 into LP systems. We also explored potential challenges that may arise during the integration process. The SLR findings revealed a lack of understanding of the relationship between Lean tools and I-4.0 technologies, particularly the one-to-one relationship. In addition, there is a lack of empirical studies exploring how these two paradigms can be integrated to enhance productivity. By addressing these gaps, we were motivated to conduct this dissertation research. The entire research work is divided into three studies. In the first study, we aimed to propose a conceptual framework for the successful integration of I-4.0 into the LP system. Besides the research gaps derived from the SLR in designing the framework, we employed basic principles of system thinking. The proposed framework is designed with a clear direction of the relationship between Lean and I-4.0, while also taking into account potential key driving factors and challenges. In the second study, we attempted to implement the proposed framework in a Lean Educational Automotive Manufacturing Lab. We demonstrated it as a small manufacturing floor to delineate the different phases of the proposed framework. To measure its performance, we defined the overall equipment effectiveness (OEE) as the primary key performance indicator (KPI). To explore the synergistic impact of Lean and I-4.0, we defined four treatments, namely `Control,' `Lean,' `Industry 4.0', and `Lean \& Industry 4.0'. In this study, 48 research subjects assembled SUV model cars using Lego parts to test the framework's performance based on the research protocol. The subjects assembled the cars individually under each treatment and also in combination. After conducting a comprehensive analysis, we found that the `Industry 4.0' approach resulted in significantly higher OEE compared to the other treatments. However, the study is limited to a small sample size. To overcome the limitation of a small sample size and to evaluate the effectiveness of workflow layout followed by subject, we were motivated to conduct the third study. In the third study, we explored whether the workflow layout impacts productivity or efficiency. To conduct our investigation, we randomly selected 12 research subjects to observe their performance during the car assembly process. We analyzed their performance based on recorded videos from our second study. Next, we created a discrete event simulation (DES) model to validate the observation using the empirical data of 12 research subjects. Through the observation, we found subjects followed eight different workflow sequences. Through the DES analysis, we discovered the significant impact of workflow on productivity and efficiency. In this study, we employed Throughput (TP) and Time In System (TIS) performance metrics to test our proposed hypotheses. Overall, it is worth mentioning that the study makes three contributions. Firstly, it presents a conceptual framework for integrating I-4.0 technologies into LP systems. Secondly, the performance of the proposed framework is validated by using human subjects in a prototype environment. Finally, effective utilization of DES in determining an efficient workflow sequence for picking and placing parts during the assembly of SUV cars.
2024-03-28T00:00:00ZEvaluating Cookery Characteristics, Consumer Acceptability, and Electronic Assessment of Attributes in Ground Beef PattiesDouglas, Savannahhttps://etd.auburn.edu//handle/10415/91352024-03-22T14:16:53Z2024-03-22T00:00:00ZEvaluating Cookery Characteristics, Consumer Acceptability, and Electronic Assessment of Attributes in Ground Beef Patties
Douglas, Savannah
With consumers driving beef demand, attributes such as flavor, wholesome, safe, and affordability remain at the forefront of the meat industry. Three unique studies were created and conducted to evaluate quality attributes of ground beef and are presented throughout this thesis. Consumer friendly technology such as sous vide is growing in popularity and the industry application to use across the foodservice sector is eminent. Additionally, technologies such as electronic nose and electronic tongue provide researchers the ability to analyze sensory components of a meat product without the use of human subjects. The current studies will highlight fresh and cooked characteristics of ground beef patties, explore the impact of adding alternative proteins and cooking method on sensory attributes. Sous vide cookery has gained popularity among in-home and fine dining consumers, yet its application in quick-service settings remains limited. To address this gap, ground beef patties were produced to assess how sous vide cooking time affects moisture, color, and objective tenderness. Patties cooked for 30 minutes exhibited significantly greater cook loss, Allo–Kramer Shear Force (AKSF), and darker color (L*) compared to those cooked for 60 or 90 minutes (p < 0.05). However, internal redness, chroma, hue angle, and red-to-brown values did not vary significantly across cooking times (p > 0.05). This indicates that sous vide cooking duration affects moisture, color, and texture characteristics of ground beef patties prior to grilling. In the second study, ground beef patties were cooked from frozen using various cooking methods. Evaluation of cooked patties show patties cooked on the griddle (GRID) exhibited significantly longer cooking times (p < 0.0001) compared to those cooked in the oven (OVEN) and clam shell (GARL). Additionally, GRID-cooked patties showed the highest percentage of cook loss compared to OVEN (p < 0.0001) and GARL (p = 0.0223). GRID-cooked patties required more Allo-Kramer shear force (p < 0.0001), indicating less objective tenderness compared to OVEN (p < 0.0001) and GARL (p = 0.0988). These findings highlight that the choice of cooking method significantly impacts the cooked characteristics of frozen patties. The final study aimed to evaluate the textural, color, and flavor characteristics, along with volatile compounds, of ground beef patties formulated with varying levels of beef heart inclusion. Patties were prepared with 0%, 6%, 12%, or 18% beef heart, with the remaining meat derived from shoulder clod. Overall, patties with beef heart did not require additional cooking time (p = 0.1325) nor exhibited higher cook loss (p = 0.0803). However, higher beef heart inclusion led to increased hardness (p = 0.0030) and chewiness values (p = 0.0316), deeper internal redness (p = 0.0001), and decreased consumer preference (p = 0.0367). These findings indicate that the inclusion of beef heart alters both the quality characteristics of ground beef and its consumer acceptability. Overall, results from these studies provide new foundational knowledge to an extremely popular consumer meat protein in ground beef that may elicit alternative processing and manufacturing techniques to consider throughout the meat and food industry.
2024-03-22T00:00:00ZThere’s no place like home: University campus-student interaction to promote sense of belonging among first year international studentsRakestraw, Sarahhttps://etd.auburn.edu//handle/10415/91342024-03-20T14:05:09Z2024-03-20T00:00:00ZThere’s no place like home: University campus-student interaction to promote sense of belonging among first year international students
Rakestraw, Sarah
Acclimating to a new environment can take a mental and emotional toll on anybody; compounding that change in an environment with a cultural change can intensify the toll. This study explores the initial perceptions and experiences of international students during their first semester on an American college campus. Specifically, this study explores the importance of spaces designed for social engagement and the impact of the design of those spaces on international student’s transition to the college campus. The purpose of this study is to gain understanding of firsthand experiences within these spaces on a Southeastern college campus, with regards to social connectedness, sense of community, and place attachment. Increasing the knowledge of how the design of campus influences these culturally diverse students can lead to more inclusive and well-planned design for all students. Findings from this research support thoughtful and purposeful design practices to facilitate quality connection and engagement among students on college campus. Understanding of the ways in which a space communicates with an occupant to inform perceptions of belonging and inclusion can lead to high quality experiences, and increased place attachment.
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