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Title: Development of a method for deriving the correlation between free fall and shock machine drop height based on equivalent velocity change
Creator: Li, Fanfu
Date: 1988
Collection: Electronic Theses & Dissertations

Title: Equity or equality : a question of relevant inputs and norms
Creator: Fullerton, Terrence David
Date: 1978
Collection: Electronic Theses & Dissertations

Title: Inhibition of intercellular communication in rat leydig cells in vitro by xenobiotic chemicals
Creator: Hsu, Hong
Date: 1991
Collection: Electronic Theses & Dissertations

Title: A study of the potential effectiveness of ITV at the college level
Creator: Vanoy, Gabriel Robayo
Date: 1972
Collection: Electronic Theses & Dissertations

Title: Family-community resource linkages and their relations to selected family variables
Creator: Miller, Barbara Kenrick, 1926-
Date: 1973
Collection: Electronic Theses & Dissertations

Title: Assessment of uncertainty management approaches in construction organizations
Creator: Jayaraman, Venkataramanan
Date: 2006
Collection: Electronic Theses & Dissertations

Title: Black reaction to "Bird of the Iron Feather"
Creator: Hardy, Thomas Andrew
Date: 1972
Collection: Electronic Theses & Dissertations

Title: Electrical Weed Control in Integrated Weed Management : Impacts on Vegetable Production, Weed Seed Germination, and Soil Microbial Communities
Creator: Galbraith, Christopher G.
Date: 2023
Collection: Electronic Theses & Dissertations
Description: Electrical weeding is an emerging practice for late-season weed control that is being adopted in numerous cropping systems and agricultural industries, including Michigan vegetable production. However, little scientific research has been conducted directly evaluating the performance of electrical weeding and its effects on the agroecosystem. The objectives of the research program were to investigate electrical weeding in terms of 1) weed control, 2) crop injury, 3) economic viability, as well...
Show moreElectrical weeding is an emerging practice for late-season weed control that is being adopted in numerous cropping systems and agricultural industries, including Michigan vegetable production. However, little scientific research has been conducted directly evaluating the performance of electrical weeding and its effects on the agroecosystem. The objectives of the research program were to investigate electrical weeding in terms of 1) weed control, 2) crop injury, 3) economic viability, as well as its effects on 4) weed seed germinability and 5) rhizosphere microbial communities. Field trials at Hart, MI in 2021 and 2022 investigated these research objectives in conventional carrot and organic green bean production systems. Late-season weed control methods including one hand-weeding event (HW), one electrical weeder pass (1P), two electrical weeder passes performed consecutively [2P(ST)], one pass followed by one pass after a 14-day interval [2P(14d)], two passes followed by one pass after a 14-day interval (3P), and no late-season control (NLC) were evaluated in both carrot and green beans. Early-season weed control methods [low, medium, and intensive herbicide programs, weed-free, and no early-season control (NEC)] were also included in the carrot trials in order to produce different weed densities within which to assess the performance of the late-season weed control methods. In carrot, use of the intensive herbicide program typically led to lower densities of above-canopy redroot pigweed compared to NEC or the low herbicide program. There was no difference reported in redroot pigweed control with respect to early-season weed control methods after performing the various late-season weed control methods in 2021. However, in 2022, redroot pigweed control tended to be higher for treatments that caused initially lower weed densities (weed-free and intensive herbicide program). Increasing passes above 2P(ST) did not provide any higher control of redroot pigweed in carrot, while 3P did have higher weed control in green beans. Foliar injury did not exceed 10% in carrot and 20% for green beans. Electrical weeding did not cause any internal damage to carrot root tissue or have any effect on carrot root length. Hand weeding was correlated with a yield increase in 2022, whereas none of the electrical treatments led to any difference in yield in either year that was not related to natural variation in weed pressure. For green beans, neither electrical weeding nor hand weeding led to a yield difference in both years. Hand weeding had a significantly higher cost acre-1 than all electrical treatments in both years (19.6 and 28.4 times higher than 1P in carrot and green bean, respectively) due to the greater amount of time required. The range of time and cost acre-1 observed relates to the differences in weed pressure, where fields with higher weed competition requiring longer hand and electrical weeding times. Electrical weed control was found to significantly reduce redroot pigweed seed germination in 2021 (10 to 14%) but not in 2022. However, germination did not differ between early- or late season weed control methods in either year. Electrical weeding did not generally lead to differences in NH4+ or NO3- that would indicate changes in N mineralization in the rhizosphere. Microbial biomass C was higher after 1P than NLC in 2021. Apart from this, there were no differences in microbial biomass C or N reported with respect to early-season or late-season weed control methods in either year. Informed by the experimental results, growers can make more pragmatic decisions around investing in electrical weeding equipment based on its weed control performance, risk of crop injury, and economic feasibility compared with alternative late-season control practices. As well, electrical weeding has the potential to be an effective integrated weed management solution in vegetable production for control of the weed seedbank with little to no significant impacts on rhizosphere microbial communities.
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Title: The Construct Development and Measurement of Contributive Justice
Creator: Scott, William Campbell
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Organizational justice has long since been considered multi-dimensional. However, the dimensionality of organizational justice has been stagnant in recent years, consisting primarily of distributive, procedural, interpersonal, and informational justice. When further examining the meaning of justice and fairness in organizations, it becomes apparent that these organizational justice dimensions are not capturing an important element of justice, that being the equality of opportunity. This is an...
Show moreOrganizational justice has long since been considered multi-dimensional. However, the dimensionality of organizational justice has been stagnant in recent years, consisting primarily of distributive, procedural, interpersonal, and informational justice. When further examining the meaning of justice and fairness in organizations, it becomes apparent that these organizational justice dimensions are not capturing an important element of justice, that being the equality of opportunity. This is an important absence because the opportunity to contribute in organizations will likely affect both organizational outcomes and personal outcomes outside of work. Therefore, building upon previous work, the construct of contributive justice in organizations was introduced and defined as the fairness of opportunities to contribute to core work processes. Contributive justice consists of two dimensions, the equal opportunity to engage in complex labor, and the equal opportunity to participate in decision-making processes. A measure was constructed to capture these dimensions, along with specific subdimensions. In a sample of 534 full-time employees, the results suggested that the contributive justice measure was a reliable two-factor measure that was discriminable from the other organizational justice dimensions and was positively correlated with other variables such as meaningful work, instrumental voice, inclusion, empowerment, and self-esteem. Contributive justice was also found to have incremental validity over the other organizational justice dimensions. These results suggest the importance of contributive justice as an aspect of organizational fairness and employee well-being.
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Title: Depression Detection in Social Media via Differential Text Embedding
Creator: alfadhli, Norah
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Deep learning models have shown promising results for depression detection using social media data (i.e., Twitter), but the difficulties of maintaining explainability and few-shot adaptation of models for new problems remain an open challenge. Another challenging aspect of the problem of depression detection in social media is the fact that the number of instances belonging to the depressed class are in a minority when compared to the number of instances belonging to the non-depressed class....
Show moreDeep learning models have shown promising results for depression detection using social media data (i.e., Twitter), but the difficulties of maintaining explainability and few-shot adaptation of models for new problems remain an open challenge. Another challenging aspect of the problem of depression detection in social media is the fact that the number of instances belonging to the depressed class are in a minority when compared to the number of instances belonging to the non-depressed class. This, especially, makes it harder for supervised machine learning algorithms to learn and predict depressed class instances.In this study, we proposed a simple solution to this problem by generating \textit{differential embeddings} using the Sentence BERT transformer architecture. More specifically, we proposed a few-shot model that can leverage state-of-the-art (SOTA) representation learning techniques and used it in supervised and unsupervised tasks. We constructed a small set of dysfunctional thought patterns in the embedding space, i.e., a set of clinically-backed depression symptoms. We then used SBERT embedding vectors to measure the similarities between different tweets and anchor points as a distance in the vector space, or fed them directly into the machine learning model. We assessed the capability of our approach on two different datasets. We trained supervised and unsupervised models using different approaches that were derived from Sentence-BERT and the anchor points. Results show that the proposed solution improved SBERT in both supervised and unsupervised tasks.
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Title: Detection and Characterization of Rolling Contact Fatigue types of defects using Surface Acoustic Waves
Creator: Vu, Alex Tian
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Rolling Contact Fatigue or Damage (RCF/RCD) is the surface and near-surface damage thatoccurs on the rail head and wheel treads of rail cars. The damage in the rail head due to progressive cyclic loading from the contact between the wheel and the rail head can lead to formations of small cracks that can ultimately grow and join up to form a flake that falls loose, leaving behind a cavity in the running surface of the rail or turn downward to a limited depth forming a fatigue crack commonly...
Show moreRolling Contact Fatigue or Damage (RCF/RCD) is the surface and near-surface damage thatoccurs on the rail head and wheel treads of rail cars. The damage in the rail head due to progressive cyclic loading from the contact between the wheel and the rail head can lead to formations of small cracks that can ultimately grow and join up to form a flake that falls loose, leaving behind a cavity in the running surface of the rail or turn downward to a limited depth forming a fatigue crack commonly referred to as head checks and gauge corner cracks. Quantifying RCF/RCD crack depths and density in rails is important for all the railroad authority and industries to manage their grinding programs effectively and efficiently. Detecting RCF/RCD can be challenging due to the size of the cracks, which typically starts out at 2 −10μm and progressively can grow up to depths of 3mm to 5mm. It becomes impossible to characterize these early stage RCF cracks without physically destroying the sample to get to the area of interest. To gain a better understanding, the cracks that are formed from RCF/RCD can be simplified into four different types: (I) vertical/normal, (II) oblique, (III) branched, and (IV ) clustered cracks. Methods that can accurately detect and characterize these cracks non-destructively have been of high interest for the rail community. This work focuses on utilizing Surface Acoustic Waves (SAWs) for detection and characterization of RCF/RCD defects through numerical simulations the using finite element method (FEM). A transient, elastodynamics wave propagation model was used to simulate SAW propagation. Parameters such as the transmission (Tc), reflection (Rc), scattered (Ps), and time of flight(TOF) were extracted from the model and quantified to build relationships for understanding the mode conversion and interaction phenomena. The different type of defects that were modeled in FE included vertical, oblique, and branched defects. First, SAW interaction with a set of vertical, oblique and branched RCF defects were studied by quantifying Tc. The Tc values exhibit duality at certain crack angles, which makes it challenging to accurately characterize oblique RCF/RCD type of defects. Experiments have been done to validate vertical and oblique defects: the results also exhibit a duality in Tc for the oblique defects. To understand branched crack morphology, the complex crack geometry can be simplified into a series of varying angled elastic wedges, which is part of a classical problem within elastodynamics. Finally, SAW interaction with clustered cracks for two sets of densely packed RCF/RCD type of defects: a uniform cluster and a non-uniform cluster to further develop characterization techniques using Tc/Rc relationships and through signal processing methods. The impact of this work is to provide a proof of concept that the presented numerical results can be validated through experiments and become field implemented.
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Title: Evaluation of Donor Abilities of Neutral Ligands to Vanadium(V) Nitrides
Creator: Mo, Linqing
Date: 2022
Collection: Electronic Theses & Dissertations
Description: In catalyst design, the ancillary ligands play a crucial role in tuning the steric and electronic structure of the system and catalyst performance. Among those ancillary ligands, neutral ligands like phosphines (PR3) or substituted pyridines are some of the most widely-used ligands in transition metal catalysis, making the study of the interaction between these ligands and the central metal necessary. While the interactions between phosphines and low oxidation state metals have been studied...
Show moreIn catalyst design, the ancillary ligands play a crucial role in tuning the steric and electronic structure of the system and catalyst performance. Among those ancillary ligands, neutral ligands like phosphines (PR3) or substituted pyridines are some of the most widely-used ligands in transition metal catalysis, making the study of the interaction between these ligands and the central metal necessary. While the interactions between phosphines and low oxidation state metals have been studied for decades, there are few studies concerning the interaction of those ligands with high oxidation state metals. For anionic ligands, our group has developed a new electronic parameter (Ligand Donor Parameter, LDP) using a chromium(IV) species. However, the exploration of neutral ligands with the same chromium species is not an effective method for measuring the neutral ligand donor ability. Computational studies of how neutral ligands will interact with high oxidation state metals will be presented in Chapter 2, in which a new vanadium(V) based model has been used. In Chapter 3, reactivity studies are described where we explored methods of preparing vanadium(V) complexes for donor ability measurements. These studies can give us a better understanding of neutral ligands’ donor ability to the vanadium(V) metal center and extend our understanding of how these ligands interact to high oxidation state metals.
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Title: EVALUATION OF CHEMICAL AND BIOLOGICAL SUPPRESSION PROGRAMS FOR PYTHIUM LEAK IN MICHIGAN POTATO PRODUCTION AND SUPRESSION ASSAY OF PYTHIUM spp.
Creator: Stine, Brice Michael
Date: 2022
Collection: Electronic Theses & Dissertations
Description: AbstractMichigan leads the US in production of potatoes processed into chips. Pythium Leak is the leading cause of storage losses in US potato production. Wet and warm conditions promote germination of zoospores in the soil where after the harvesting processes cause wounds or bruises, creating entry points for P. ultimum infection post-harvest. Continued use of metalaxyl or mefenoxam against populations of Pythium spp. in potato rotations cause concern for resistant to these fungicides. Six...
Show moreAbstractMichigan leads the US in production of potatoes processed into chips. Pythium Leak is the leading cause of storage losses in US potato production. Wet and warm conditions promote germination of zoospores in the soil where after the harvesting processes cause wounds or bruises, creating entry points for P. ultimum infection post-harvest. Continued use of metalaxyl or mefenoxam against populations of Pythium spp. in potato rotations cause concern for resistant to these fungicides. Six treatments were evaluated using the cv. Silverton Russet in South-West Michigan. First year data supported statistically higher disease incidence with Tifi MaxTM, Trichoderma atroviride, compared to plots treated with Ultra FlourishTM. After plot replication, year two data were unable to show any statistical differences between treatments on agronomic attributes or disease incidence. Further in-vitro Pythium spp. sensitivity assays were conducted with these treatments. The Orondis GoldTM treatment resulted in the lowest EC50 which could not be calculated at the lowest level 0.01 ppm because it inhibited all Pythium spp. growth. Next, Ultra FlourishTM reduced half the Pythium spp. growth at 0.32ppm. The least effective treatments at reducing pathogen growth were EluminTM or Previcur FlexTM, both resulting with EC50 values of 1.9 ppm and 7.9 ppm respectively. Five days post transfer Trichoderma atroviride overtook the Pythium spp., providing support as a possible biological suppression tool.
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Title: Incorporating shelter dogs into an animal assisted therapy program : a one welfare approach
Creator: Naud, Jacqueline
Date: 2022
Collection: Electronic Theses & Dissertations
Description: The qualifications to become a therapy animal do not specify the breed or background of the dog participant, so any dog can become a therapy dog if they possess the right attributes. The question of what exactly those right attributes are is what drives research in this field. Furthermore, finding out which tools are the most valid and reliable in finding out these characteristics is just as important. If a valid and reliable tool can be used to find appropriate dogs for use in therapy from a...
Show moreThe qualifications to become a therapy animal do not specify the breed or background of the dog participant, so any dog can become a therapy dog if they possess the right attributes. The question of what exactly those right attributes are is what drives research in this field. Furthermore, finding out which tools are the most valid and reliable in finding out these characteristics is just as important. If a valid and reliable tool can be used to find appropriate dogs for use in therapy from a shelter setting, many dogs can fill an important role in society while awaiting adoption and experience a novel form of enrichment. For this research, a literature review was conducted in order to determine how dogs are chosen for AAT and if these methods are appropriate in terms of validity and reliability. Next, the interest in involving shelter dogs in AAT was identified utilizing a survey. Finally, a test battery was developed in order to select shelter dogs appropriate for a simulated AAT session. In order to assess preferences in terms of the type of dog used in AAT, whether that be a trained therapy animal or a shelter dog, a survey was administered to assess the respondent’s trauma background, interest in AAT, and any stigmas associated with shelter dogs. It was hypothesized that individuals with a trauma history would be more likely to express interest in working with shelter dogs in AAT, due to increased empathy and prosocial behavior (Hoffman, 2008). Results from the survey indicated respondents were more likely to agree with certain questions as the number of traumas they had experienced increased. Respondents believed that AAT would benefit shelter dogs due to interaction with a person, and as traumas increased (on a continuous scale), respondents were 1.436 (CI: 1.037 – 1.988) times more likely to choose that they strongly agree with this statement. As traumas increased, respondents were 1.512 (CI: 1.016 – 2.249) times more likely to report that they strongly agree that having time out of the kennel during an AAT session would be beneficial for shelter dogs. Finally, respondents were 1.403 (CI 1.094 – 1.799) times more likely to indicate that AAT with a shelter dog would be beneficial because of possible shared trauma as traumas increased. Most notably, these questions related to the dog’s experience during AAT (i.e. respondents agreed most strongly with prompts that indicated the dog would gain enjoyment from the activity). Therefore, it is speculated based on these results that our population of respondents were more inclined to participate in AAT because of the potential benefits to the dog participants, and this may be influenced by their trauma history.The cylinder detour task (Bray & Gruen, 2020), pointing test (Hare & Tomasello; 1999), impossible test (Cavalli et al. 2020), empathy assessment (Meyers-Manor & Botten, 2020), and novel object test (Bray & Gruen, 2020) were all used in order to identify dogs in terms of their impulsivity, social cognition, help seeking behavior, empathy, and resilience, respectively. It was hypothesized that dogs that displayed low levels of impulsivity, high levels of social cognition, frequent help seeking behaviors, high levels of empathy, and high levels of resilience would be best suited for a simulated group animal-assisted therapy scenario. To evaluate this hypothesis, dogs were screened via the aforementioned behavioral assessments 24 hours prior to a simulated AAT experience. Only about half of all dog participants (24/49) performed above chance in the pointing test, that is, they correctly chose the bowl containing the treat based on following the human point indicating where the treat was located. Despite this, the analysis was still significant, with a p-value of 0.0314. Only around one-third of dog participants (17/49) displayed the help seeking behavior during the impossible task; however, analysis for this variable also proved significant, with a p-value being 0.0322. The analysis for all other variables were non-significant. Human participants were asked to evaluate their overall level of enjoyment during simulated AAT, as well as their mood (MFS) and stress level (SFS) before and after sessions. The dogs’ experiences were evaluated using the Human Animal Interaction Scale (HAIS), a validated scale, reported by the human participants. All human participants found simulated AAT enjoyable, and based on HAIS scores, the majority of dog participants had positive experiences. All human participants reported positive experiences with nearly 85% of participants reporting simulated AAT to be a very positive experience and 15% reporting it to be somewhat positive. Approximately half of all participants also experienced an improvement to their MFS and SFS scores (54.84% and 41.94%, respectively). A third of participants had no net change to MFS (32.26%) and SFS (29.03%). A few individuals reported an increase in stress and mood levels post-AAT session (9.68% and 3.23%, respectively). Out of the 47 dog participants with complete HAIS profiles, almost 90% of dogs had a net positive experience (HAIS greater than 0). The main takeaways from this research are that the population surveyed was eager to engage in AAT, regardless of the background of the dog participants. Also, human participants seem particularly motivated to participate in AAT due to the potential benefits to the dog participants, not only to themselves. During the simulated AAT session in the second research study, all human participants reported a positive experience. Dog participants also showed an overwhelming majority in terms of a net positive experience. Therefore, the One Welfare goal of the research was successful.
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Title: SELF-RATED HEALTH, HAPPINESS, & DEPRESSION : THE ROLE OF EXPERIENCING FINANCIAL HARDSHIP ON PARENT’S WELL-BEING
Creator: Morales, Ereisa G.
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Studies about child outcomes tend to look at parents as a primary variable of interest. Partially influenced by Conger’s Family Stress Model (FSM), the present study examines the relationship between experiencing financial hardship and parent’s well-being (i.e., physical health, happiness, and depression). FSM suggests that negative financial events will increase economic pressure which will have a negative effect on parents’ well-being (i.e., depression) and their relationships with their...
Show moreStudies about child outcomes tend to look at parents as a primary variable of interest. Partially influenced by Conger’s Family Stress Model (FSM), the present study examines the relationship between experiencing financial hardship and parent’s well-being (i.e., physical health, happiness, and depression). FSM suggests that negative financial events will increase economic pressure which will have a negative effect on parents’ well-being (i.e., depression) and their relationships with their children and partner. Therefore, this paper explores (1) whether the relationship between financial hardship and parent’s depression could be moderated by public assistance services ;(2) whether experiencing financial hardship would have a negative effect on parent’s self-rated (physical health) and happiness. Utilizing waves 1,3,4, and 5 of The National Longitudinal Study of Adolescent to Adult Health, the results indicated that financial hardship impacted parent’s physical health, happiness, and depression differently.
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Title: A COMPREHENSIVE STUDY OF PREDATOR DIETS IN LAKE HURON
Creator: Kierczynski, Katie Elline
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Lake Huron has a history of overfishing, habitat degradation, and introductions of non-native species that have resulted in a dynamic ecosystem with a prey base of primarily non-native species. In the mid-2000s, a massive shift in the ecosystem occurred when Alewife and Chinook Salmon populations collapsed. This led to an increase in native Lake Trout and Walleye populations, despite the continued low prey biomass. Alternative prey such as non-native Round Goby and Rainbow Smelt have...
Show moreLake Huron has a history of overfishing, habitat degradation, and introductions of non-native species that have resulted in a dynamic ecosystem with a prey base of primarily non-native species. In the mid-2000s, a massive shift in the ecosystem occurred when Alewife and Chinook Salmon populations collapsed. This led to an increase in native Lake Trout and Walleye populations, despite the continued low prey biomass. Alternative prey such as non-native Round Goby and Rainbow Smelt have supported predator foraging, but it is unclear if current prey biomass levels can support the continued expansion of Lake Trout and Walleye populations. I conducted a comprehensive diet study of angler-caught predators in 2017 and 2018 to evaluate current spatial and temporal trends in the diets of the major predators of Lake Huron within the context of historical foraging conditions. I observed several prominent spatiotemporal trends for the majority of Lake Huron predator diets, including a shift in consumption from Round Goby to Rainbow Smelt between spring and summer, and an overall reduced consumption of Round Goby in Saginaw Bay compared to the main basin. I also found an increased reliance on Round Goby by native Walleye and Lake Trout compared to previous studies while Chinook Salmon continued to rely upon Rainbow Smelt and Alewife. Evidence from gut fullness indices and size distributions of consumed prey indicate that forage conditions in Lake Huron continue to decline. Overall, the predator community continues to be reliant on non-native prey, and forage conditions may be indicative of prey limitation for the foreseeable future.
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Title: CHARACTERIZING FONIO PRODUCTION ACROSS SCALES : INTERDISCIPLINARY INSIGHTS FROM A LOCAL FIELD TRIAL AND A SCOPING REVIEW
Creator: Dingus, Abigail
Date: 2022
Collection: Electronic Theses & Dissertations
Description: As the changing climate places new stressors on agricultural production, novel and adaptive management practices that provide resistance or resilience are needed to overcome these challenges. Increased biodiversity can improve resilience and ecosystem function, allowing agroecosystems to continue production after temporal or extreme climate events. One way to increase both local and regional diversity is by broadening the number of crops produced. Minor crops which suffer from lack of...
Show moreAs the changing climate places new stressors on agricultural production, novel and adaptive management practices that provide resistance or resilience are needed to overcome these challenges. Increased biodiversity can improve resilience and ecosystem function, allowing agroecosystems to continue production after temporal or extreme climate events. One way to increase both local and regional diversity is by broadening the number of crops produced. Minor crops which suffer from lack of formalized research and are grown for cultural value or local adaptations, may fill niches in agroecosystems outside their traditional production systems. One of these minor crops is a small grain from West Africa called fonio (Digitaria exilis). Fonio is extremely valuable in West Africa for food security, nutrition, and cultural practices, but its value has not yet been recognized globally. Increasing our understanding of this crop may provide a pathway for improving fonio for its native habitat and new environments. While there are ample uses of fonio and opportunities to improve production, there is limited research on fonio in most disciplines. This research sought to fill knowledge gaps and inform future research on fonio through two studies: a scoping review and a field study. A scoping literature review was completed where research across disciplines was summarized and analyzed for gaps in knowledge. The review found novel uses for fonio including building materials, pharmaceutical uses, industrial uses, and feed for animals. Further use of fonio is limited by knowledge gaps in the optimization of management for different environments, mechanization for production and processing, and a lack of breeding efforts. To better understand the production and uses of fonio more documentation is needed in field management, economics, seed systems, and producer/consumer preferences. A major gap identified was the viability of fonio outside its native habitat and the effect of fertilizer and seeding rate on fonio growth and forage quality. A two-year (2021-22) field study conducted in Western Michigan tested fonio production in a new environment, assessed forage quality, and determined the effect of seeding and fertilizer rate on biomass and grain yields. Results indicated that low planting densities (4 kg/ha) improved grain yields but reduced biomass. Fertilization greater than 19.5 kg N/ha increased biomass but had no effect on grain yield. Grown in Michigan, fonio forage quality was high (RFQ=131-150) when cut at booting stage but biomass yield was low compared to other summer annuals. From these studies, we determined that fonio may be a useful crop in the US as a forage or cover crop, filling a niche in perennial pastures during dry summer months. More research is needed to further understand fonio management and global uses while ensuring West African producers maintain sovereignty as the crop stewards of fonio.
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Title: EVALUATING NITROGEN AND PHOSPHORUS IMPACTS WITHIN WATERSHEDS OF THE GREAT LAKES BASIN
Creator: Hannah, Bailey A.
Date: 2022
Collection: Electronic Theses & Dissertations
Description: The Great Lakes and the streams draining to them provide an abundance of ecosystem services, including habitat, water resources, and recreational opportunities. The success and wellbeing of these water bodies are impacted by a variety of factors, including invasive species and septic systems. Along the shoreline of the Great Lakes, invasive species, such as Phragmites and Typha, are a major concern to the coastal wetlands. Within the inland river systems, near-shore septic systems can create...
Show moreThe Great Lakes and the streams draining to them provide an abundance of ecosystem services, including habitat, water resources, and recreational opportunities. The success and wellbeing of these water bodies are impacted by a variety of factors, including invasive species and septic systems. Along the shoreline of the Great Lakes, invasive species, such as Phragmites and Typha, are a major concern to the coastal wetlands. Within the inland river systems, near-shore septic systems can create elevated levels of nutrients that can have a collection of negative impacts. Both of these threats ultimately relate back to the presence and application of nutrients such as nitrogen and phosphorus. We first address the landscape conditions that allow for coastal wetland invasion. Using machine learning algorithms, we were able to quantify relationships between the presence of invasive species in coastland wetlands, and a variety of landscape scale variables – primarily the nutrient loads of nitrogen and phosphorus. We determined that high invasion is most strongly associated with nitrogen loading above 118 kg/ha/yr within the watersheds derived from the invaded wetlands. We then address how septic systems could be contributing to nutrient loads within the Manistee and Au Sable Rivers of Michigan. We modeled groundwater flow and the transport of nutrients to assess how competently septic systems are retaining nutrients. On average, septic systems allow 88% of introduced nitrogen, and 49% of phosphorus, to enter groundwater. These findings will inform watershed management and provide a better understanding of the effectiveness of septic systems.
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Title: DIRECTED IRIDIUM C(sp3)–H BORYLATION CATALYSIS WITH HIGH N-ADJACENT SELECTIVITY
Creator: Yadav, Anshu
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Modern approaches for the conversion of C–H bonds to C–B bonds involve transition metal catalysts that have various advantages over traditional methods by using cheap and abundant hydrocarbon starting materials, reducing toxic by-products and streamlining the synthesis of biologically important molecules. Metal-catalyzed C–H borylation reactions that produce organoboronic esters are mostly focused on the functionalization of sp2 C–H bonds of heteroarenes and aromatic hydrocarbons. However, in...
Show moreModern approaches for the conversion of C–H bonds to C–B bonds involve transition metal catalysts that have various advantages over traditional methods by using cheap and abundant hydrocarbon starting materials, reducing toxic by-products and streamlining the synthesis of biologically important molecules. Metal-catalyzed C–H borylation reactions that produce organoboronic esters are mostly focused on the functionalization of sp2 C–H bonds of heteroarenes and aromatic hydrocarbons. However, in this work the functionalization of sp3 C–H bonds is being explored. Borylation involving sp3 C–H bonds have been shown by Sawamura and co-workers with solid silica supported phosphine ligands offering a directing strategy where a metal center can accept donor directing groups. While this ligand generates highly active borylation catalysts, it requires a lot of steps in the synthesis of the ligand. In this work, easily synthesized homogeneous bidentate monoanionic ligands were tested for the borylation of sp3 C–H bonds. Herein is reported borylation of sp3 C–H bonds of N-methyl amide groups using [Ir(OMe)(cod)]2 as a precatalyst and B2pin2 as a commercially available boron source. Following the borylation of amide as a directing group, amidine molecules are being investigated.
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Title: BEHAVIOR OF ENTERIC PATHOGENS ON WHEAT GRAINS DURING TEMPERING AND EVALUATION OF INACTIVATION METHODS PRIOR TO MILLING
Creator: Lin, Yawei
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Outbreaks linked to Salmonella and Shiga toxin-producing E. coli (STEC) in wheat flour led to increased interest in characterizing the fate of these pathogens on wheat grains during processing and exploring potential inactivation methods. Despite the increase in water activity of wheat grains to ~0.85, the changes in the pathogen populations on inoculated soft wheat grains remained relatively stable during tempering. Using confocal microscopy, no significant redistribution of pathogen was...
Show moreOutbreaks linked to Salmonella and Shiga toxin-producing E. coli (STEC) in wheat flour led to increased interest in characterizing the fate of these pathogens on wheat grains during processing and exploring potential inactivation methods. Despite the increase in water activity of wheat grains to ~0.85, the changes in the pathogen populations on inoculated soft wheat grains remained relatively stable during tempering. Using confocal microscopy, no significant redistribution of pathogen was found based on the fluorescent intensity measurement. Chlorinated water had been used in the tempering solution in mills to control mold and yeast growth. When hard wheat grains were treated with 800ppm chlorinated water as a tempering over 18 hours, pathogen population changed from -2.35 to -0.30 log CFU/g, without negatively impacting the flour quality or functionality. Treating soft wheat at 75 ̊C using vacuum steam pasteurization, resulted in D75°C of Salmonella strains of 2.8 and 3.2 min of STEC ranges from 3.1 to 4.6 min, and of E. faecium was 3.3 min.
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