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Title: COLLECTIVE ACTION AND SEED PRODUCTION : A PATHWAY FOR WOMEN'S EMPOWERMENT AND COMMUNITY SEED SECURITY IN INDIA
Creator: Lewis, Arena
Date: 2022
Collection: Electronic Theses & Dissertations
Description: There exists a wide range of development interventions that aim to 1) empower women and 2) ensure food security for rural smallholder farmers. These types of interventions, implemented separately, have had varied success. The implementation of interventions to achieve both women’s empowerment and seed security simultaneously has been researched in a few studies, but the successful achievement of these goals has rarely been observed. This study investigates the impact a layered seed production...
Show moreThere exists a wide range of development interventions that aim to 1) empower women and 2) ensure food security for rural smallholder farmers. These types of interventions, implemented separately, have had varied success. The implementation of interventions to achieve both women’s empowerment and seed security simultaneously has been researched in a few studies, but the successful achievement of these goals has rarely been observed. This study investigates the impact a layered seed production/self-help group program had on women’s empowerment and seed security. The research was conducted in 2 districts in Uttar Pradesh, India using semi-structured interviews of 36 participants. The findings indicate that, through the collective power of self-help groups, women were empowered and seed security was increased for women within the group as well as the greater community through the seed production program. Further, women who participated in the seed production program in addition to their regular self-help group membership, were empowered through additional channels specific to the layered seed production systems. This research indicates that self-help groups can act as a platform for development interventions and integrate well with seed system interventions.
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Title: STREET SKATEBOARDING MITIGATION THROUGH STRATEGIC LANDSCAPE PLANTINGS
Creator: Lentz, Elijah Graham
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Bent handrails, wax covered ledges, and chipped concrete are just a few of the common damages that are far too often the consequence of street skateboarding. Too many public properties have been damaged, trespassed, and plagued by street skateboarders as they use urban architecture and amenities to perform skate tricks on. These areas are not designed for skateboarding and often suffer the consequences as street skateboarders use urban spaces for sport. The purpose of this research is to shed...
Show moreBent handrails, wax covered ledges, and chipped concrete are just a few of the common damages that are far too often the consequence of street skateboarding. Too many public properties have been damaged, trespassed, and plagued by street skateboarders as they use urban architecture and amenities to perform skate tricks on. These areas are not designed for skateboarding and often suffer the consequences as street skateboarders use urban spaces for sport. The purpose of this research is to shed light on the ongoing conflict that occurs between street skateboarders and urban public spaces and to propose design solutions utilizing strategic landscape plantings aimed to deter street skateboarding. By using a Likert-type survey with perspective design renderings used to collect and compare data from both skateboarders and non-skateboarders, as well as observing and recording evidence of street skateboarding and its damages, solutions best fit for the study’s site area of The Eli and Edythe Broad Art Museum will be determined. Ultimately, this study’s conclusions are intended to add to the knowledge of combating street skateboarding conflict. This study’s findings show that only in specific instances there are significant differences of perceptions between skateboarders and non skateboarders when determining the effectiveness of planting based street skateboarding deterrents and that a street skateboarding conflict exists at the Eli and Edythe Broad Art Museum. Having just made its debut at the Tokyo 2020 Summer Olympic Games, it is inevitable new effective street skateboarding mitigation strategies will be needed as the sport continues to grow around the world.
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Title: Fast and Memory-Efficient Subspace Embeddings for Tensor Data with Applications
Creator: Zare, Ali
Date: 2022
Collection: Electronic Theses & Dissertations
Description: The widespread use of multisensor technology and the emergence of big data sets have brought the necessity to develop more versatile tools to represent higher-order data with multiple aspects and high dimensionality. Data in the form of multidimensional arrays, also referred to as tensors, arise in a variety of applications including chemometrics, physics, hyperspectral imaging, high-resolution videos, neuroimaging, biometrics, and social network analysis. Early multiway data analysis...
Show moreThe widespread use of multisensor technology and the emergence of big data sets have brought the necessity to develop more versatile tools to represent higher-order data with multiple aspects and high dimensionality. Data in the form of multidimensional arrays, also referred to as tensors, arise in a variety of applications including chemometrics, physics, hyperspectral imaging, high-resolution videos, neuroimaging, biometrics, and social network analysis. Early multiway data analysis approaches used to reformat such tensor data as large vectors or matrices and would then resort to dimensionality reduction methods developed for low-dimensional data. However, by vectorizing tensors, the inherent multiway structure of the data and the possible correlation between different dimensions will be lost, in some cases resulting in a degradation in the performance of vector-based methods. Moreover, in many cases, vectorizing tensors leads to vectors with extremely high dimensionality that might render most existing methods computationally impractical. In the case of dimension reduction, the enormous amount of memory needed to store the embedding matrix becomes the main obstacle. This highlights the need for approaches that are applied to tensor data in their multi-dimensional form. To reduce the dimension of an $n_1 \times n_2 \times \dots \times n_d$ tensor to $m_1 \times m_2 \times \dots \times m_d$ with $m_j \leq n_j$, MPCA\footnote{Multilinear Principal Component Analysis} would change the memory requirement from $\prod_{j=1}^d m_jn_j$ for vector PCA to $\sum_{j=1}^d m_jn_j$, which can be a considerable improvement.On the other hand, tensor dimension reduction methods such as MPCA need training samples for the projection matrices to be learned. This makes such methods time consuming and computationally less efficient than oblivious approaches such as the Johnson-Lindenstrauss embedding. The term \textit{oblivious} refers to the fact that one does not need any data samples beforehand to learn the embedding that projects a new data sample onto a lower-dimensional space.\\ In this thesis, first a review of tensor concepts and algebra as well as common tensor decompositions is presented. Next, a modewise JL approach is proposed for compressing tensors without reshaping them into potentially very large vectors. Theoretical guarantees for the norm and inner product approximation errors as well as theoretical bounds on the embedding dimension are presented for data with low CP rank, and the corresponding effects of basis coherence assumptions are addressed. Experiments are performed using various choices of embedding matrices. Results verify the validity of one- and two-stage modewise JL embeddings in preserving the norm of MRI and synthesized data constructed from both coherent and incoherent bases. Two novel applications of the proposed modewise JL method are discussed. (i) Approximate solutions to least squares problems as a computationally efficient way of fitting tensor decompositions: The proposed approach is incorporated as a stage in the fitting procedure, and is tested on relatively low-rank MRI data. Results show improvement in computational complexity at a slight cost in the accuracy of the solution in the Euclidean norm. (ii) Many-Body Perturbation Theory problems involving energy calculations: In large model spaces, the dimension sizes of tensors can grow fast, rendering the direct calculation of perturbative correction terms challenging. The second-order energy correction term as well as the one-body radius correction are formulated and modeled as inner products in such a way that modewise JL can be used to reduce the computational complexity of the calculations. Experiments are performed on data from various nuclei in different model space sizes, and show that in the case of large model spaces, very good compression can be achieved at the price of small errors in the estimated energy values.
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Title: EXPLORING THE RELATIONSHIP BETWEEN RESILIENCE AND ADVERSE IMPACT OF STUTTERING
Creator: Grobbel, Hannah
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Children who stutter often experience adverse impact such as bullying, negative thought patterns, and reduced self-esteem that result from living with their condition. Research suggests that there are factors that may place a child who stutters at greater risk for adverse impact as well as protective factors that mitigate this risk. The aim of this study is to examine the relationship between resilience and stuttering’s adverse impact in children. Resilience reflects both internal factors...
Show moreChildren who stutter often experience adverse impact such as bullying, negative thought patterns, and reduced self-esteem that result from living with their condition. Research suggests that there are factors that may place a child who stutters at greater risk for adverse impact as well as protective factors that mitigate this risk. The aim of this study is to examine the relationship between resilience and stuttering’s adverse impact in children. Resilience reflects both internal factors such as grit and the ability to cope and external factors such as family support and access to resources. We collected data from children who stutter and their parents to assess children’s resilience and stuttering’s adverse impact using standardized assessments. We then explored the relationship between resilience and adverse impact through descriptive statistics, linear regression, and correlation analyses. Results revealed that even children in the youngest, preschool-aged group showed adverse impact due to stuttering. We also found that greater resilience predicted less adverse impact in in school-aged and adolescent children who stutter. These findings provide insight into the experience of stuttering and offer support for treatments that incorporate resilience building into therapy to help mitigate adverse impact experienced by children who stutter.
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Title: The Impact of Social Class on Students’ Pre-College Perceptions of Co-Curricular Involvement
Creator: Rossman, Danielle
Date: 2022
Collection: Electronic Theses & Dissertations
Description: This dissertation uses a cross sectional quantitative design to investigate the relationship between first-year college students’ social class and their pre-college interest in engaging in co-curricular experiences during college, their motivations for engaging in co-curricular experiences, and their perceptions of whether co-curricular activities will teach them leadership and work ethic skills. The study also investigated multiple variables to address social class- including metrics of...
Show moreThis dissertation uses a cross sectional quantitative design to investigate the relationship between first-year college students’ social class and their pre-college interest in engaging in co-curricular experiences during college, their motivations for engaging in co-curricular experiences, and their perceptions of whether co-curricular activities will teach them leadership and work ethic skills. The study also investigated multiple variables to address social class- including metrics of subjective social status and socioeconomic status. The study used data from two surveys that were administered to a sample (N = 839) of first-year, first-time college students from a regional comprehensive university prior to their matriculation. The findings of this study indicate that students’ awareness of their socioeconomic status was the only significant predictor of their interest in getting involved in co-curricular activities during college. Students’ perceived family contribution to their college education significantly predicted their interest in working during college, while social class had no impact on a student’s interest in joining fraternity and sorority life or in student government association. There was a significant relationship between a student’s race, gender, and high school extracurricular experiences and their motivation for engagement. A student’s Expected Family Contribution was not a significant predictor of the student’s interest, motivation, or perception related to involvement. Students’ awareness of their socioeconomic status also impacted their perceptions that they could learn leadership skills and work ethic from co-curricular activities, while students with higher subjective social class were more likely to believe they could learn leadership skills from being a participant or member in co-curricular experiences. Implications of these findings for research, theory and practice are offered. More research is needed that explores the impact of social class, and incorporates multiple diverse metrics of social class, on students’ college experience. Studies that investigate the ability of on-campus employment to serve as a high impact proactive for students who may not otherwise have the ability to participate in co-curricular experiences on campus are also needed.
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Title: FATE OF SILVER NANOPARTICLES DURING SIMULATED COMMERCIAL PROCESSING OF FRESH-CUT LETTUCE
Creator: Gunathilaka, Gayathri Upeksha
Date: 2022
Collection: Electronic Theses & Dissertations
Description: ABSTRACTFATE OF SILVER NANOPARTICLES DURING SIMULATED COMMERCIAL PROCESSING OF FRESH-CUT LETTUCEByGayathri Upeksha GunathilakaThe use of silver nanoparticles (Ag NPs) in pesticides could lead to residual levels in food crops, thus raising both food safety and environmental concerns. The effectiveness of typical produce processing practices to remove Ag NPs from fresh produce is poorly understood. Further, little is known about the behavior of Ag NPs in wash water during commercial production...
Show moreABSTRACTFATE OF SILVER NANOPARTICLES DURING SIMULATED COMMERCIAL PROCESSING OF FRESH-CUT LETTUCEByGayathri Upeksha GunathilakaThe use of silver nanoparticles (Ag NPs) in pesticides could lead to residual levels in food crops, thus raising both food safety and environmental concerns. The effectiveness of typical produce processing practices to remove Ag NPs from fresh produce is poorly understood. Further, little is known about the behavior of Ag NPs in wash water during commercial production of fresh-cut produce, which limits our ability to design effective mitigation strategies.The first study evaluated the behavior of Ag NPs over time when exposed to commercially applicable chlorine concentrations (2–100 mg chlorine/L) in simulated lettuce wash water. Aggregation and dissolution of Ag NPs (5 mg/L) were evaluated in the presence and absence of dissolved lettuce extract (DLE, 0.1%). Aggregate size of Ag NPs increased faster in the presence of chlorine (49 to 431 nm) compared to the control (P < 0.05). Lower dissolved Ag concentrations and more negative zeta potentials were found in the presence of chlorine (0.01 to 0.03 mg/L and -39 to -95 mV) and DLE (0.01 to 0.14 mg/L and -28 to -32 mV), as compared to the control (0.54 to 0.8 mg/L and -10 to -20 mV) (P < 0.05). Transmission electron microscopy with energy dispersive spectroscopy confirmed the formation of composite AgCl-Ag NPs particles in the presence of chlorine. The increased aggregate size over time likely resulted from nucleation and crystal growth of AgCl. In the presence of DLE, Ag NPs and AgCl precipitates were embedded in and bound to the DLE matrix. These observations suggest that chlorine and plant-released organic matter could substantially change the fate of Ag NPs in wash water and subsequently their environmental impact. In the second study the removal of Ag NPs from Ag NP-contaminated lettuce leaves was investigated during batch and small-scale pilot processing. First, a batch-type system (4-L carboy jar) was used to evaluate the impact of commercial produce sanitizers and simulated leafy green processing water on the removal of Ag NPs from contaminated lettuce. Peroxyacetic acid (PAA; 80 mg/L) and chlorine (100 mg/L and pH 6.5) were used with/without 2.5% (w/v) organic load as washing treatments with deionized water serving as the control treatment. Treating lettuce with the organic load alone, organic load with chlorine, chlorine alone, 0% organic load and peroxyacetic acid removed about 2.7%–6.6% of Ag from the lettuce after 5 min of washing. Thereafter, the removal of Ag NPs from contaminated lettuce was assessed using a small-scale pilot processing line during 90 seconds of flume-washing followed by centrifugal drying (a typical washing practice in commercial produce processing). The Ag removal efficiency ranged between 0.3% to 3%, probably resulting from strong binding of Ag with plant organic materials. Significantly greater Ag concentrations were found in the centrifugal water than in flume water, suggesting that centrifugation removed additional Ag from lettuce. The low Ag removal observed in both the simulated batch-type and pilot-scale produce washing systems demonstrate that typical produce processing conditions may not be effective in removing Ag NPs from contaminated produce. Thus, it is necessary to further investigate and develop effective methods for the Ag NP removal from contaminated produce.
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Title: PRODUCTIVITY IMPACTS OF STRATEGIES TO ENHANCE RUMINANT FIBER DIGESTION
Creator: Ibraheem, Muhammad
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Strategies to improve forage fiber digestibility can increase dairy sustainability. Reducing lignin content through natural breeding or genetic engineering can improve DMI, neutral detergent fiber (NDF) digestibility and feed efficiency. A 60 mid-lactating cow experiment was carried out to compare production and nutrient digestibility responses to low-lignin vs. conventional alfalfa hay. The 3 treatments provided 0% (conventional), 50% (blend) and 100% low-lignin alfalfa; all diets contained...
Show moreStrategies to improve forage fiber digestibility can increase dairy sustainability. Reducing lignin content through natural breeding or genetic engineering can improve DMI, neutral detergent fiber (NDF) digestibility and feed efficiency. A 60 mid-lactating cow experiment was carried out to compare production and nutrient digestibility responses to low-lignin vs. conventional alfalfa hay. The 3 treatments provided 0% (conventional), 50% (blend) and 100% low-lignin alfalfa; all diets contained 31.8% alfalfa on a dry matter (DM) basis. Low-lignin alfalfa decreased total-tract NDF digestibility and milk fat concentration in a dose-dependent manner. All other nutrient and production parameters were unaffected. Therefore, observed NDF digestibility and milk fat results suggest that the low-lignin alfalfa provided less physically effective fiber, failing to demonstrate obvious benefits. Another strategy for improving NDF digestibility involves use of different trace mineral supplements. In a small meta-analysis that included 8 studies and 12 comparisons in both sectors, beef and dairy, effects of hydroxy vs. sulfate trace minerals (TM) on nutrient digestibility and DM intake were investigated. Study design, sector and method of digestibility analysis were the factors included in the analysis. Hydroxy TM increased DM digestibility only in beef cattle and NDF digestibility, which was affected by digestibility analysis method. Total collection studies showed the greatest benefit, followed by use of undigested NDF as a digestibility marker, but 24-h in situ approaches did not show any significant response. In conclusion, adopting multiple strategies for optimizing fiber digestibility might help the dairy industry achieve greater feed efficiency goals.
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Title: A POTENTIAL ROLE FOR EARLY GUT MICROBIAL COLONIZATION IN INFANT BEHAVIOR AND CHILD SLEEP DISORDERS
Creator: Ma, Tengfei
Date: 2022
Collection: Electronic Theses & Dissertations
Description: There is increasing evidence from pre-clinical and human studies implicating the microbiota–gut–brain axis in behavior and sleep physiology. Infancy is a critical time period for brain development and is vulnerable to the harmful effects of gut dysbiosis. Thus, it is crucial to understand how gut microbial colonization during this period may influence behavior and sleep physiology in the later stages of life.We analyzed data from 194 mother-infant pairs from the Michigan Archive for Research...
Show moreThere is increasing evidence from pre-clinical and human studies implicating the microbiota–gut–brain axis in behavior and sleep physiology. Infancy is a critical time period for brain development and is vulnerable to the harmful effects of gut dysbiosis. Thus, it is crucial to understand how gut microbial colonization during this period may influence behavior and sleep physiology in the later stages of life.We analyzed data from 194 mother-infant pairs from the Michigan Archive for Research on Child Health (MARCH) cohort Study. Clinical and demographic information was obtained from the birth certificate and interview during pregnancy and childhood. Fecal samples from infants at 3-9 months of age were sequenced at the V4 region of the 16S rRNA gene. In the first study, which examined whether feeding practices may affect early gut microbial colonization, we found that the gut microbiota of infants who were exclusively breastfed displayed a significantly lower Shannon diversity (p-adjust < 0.001) and a different gut microbiota composition than infants who were not breastfed (p-value = 0.001). Among the exclusively breastfed infants, recipients of supplemental vitamin D displayed a significantly lower Shannon diversity (p-adjust = 0.007) and different gut microbiota composition structure than non-supplemented, breastfed infants (p-value = 0.02). In addition, several individual taxa were identified to be associated with different feeding practices. In the second study, we examined whether gut microbiota in early infancy was associated with temperament in the nine-month-old infants. We identified that a microbial cluster characterized by a higher abundance of Bifidobacterium, Veillonella, and Escherichia-Shigella that was associated with lower emotionality scores (coefficient = -0.58, p-value = 0.02) compared to a cluster characterized by a higher abundance of Bacteroides. This association was especially prominent among infants who were not supplemented with vitamin D (coefficient = -1.01, p-value = 0.01), while no significant association was found among infants who were supplemented (coefficient = -0.43, p-value = 0.20). In the final aim, we assessed the association between gut microbiota in early infancy and the difficulty of initiating and maintaining sleep at age of two years. The gut microbiota of children who had difficulty maintaining sleep displayed significantly higher Shannon index (OR: 2.41, 95% CI= 1.23-4.93, p-adjust < 0.04) and Chao 1 index (OR: 1.01, 95% CI= 1.0-1.03, p-adjust < 0.008) after adjustment for covariates. We also observed that gut microbiota composition was significantly different between children with difficulty initiating (p-value= 0.043) and maintaining sleep (p-value= 0.004) by PERMANOVA based on the unweighted UniFrac distance metric. In conclusion, these results from analysis in a prospective cohort study suggest that early gut microbial colonization is shaped by breastfeeding status, vitamin D supplement, and maternal characteristics including gestational age, delivery mode and education level. Our findings suggested that the infant gut microbiome clusters may be associated with the temperament characteristic of negative emotionality in 9-month-old infants. We also demonstrated a significant association between infant gut microbiome composition and sleep problems in 2-year-old children. Thus, our results add to the evidence that early gut microbial colonization may be linked with brain outcomes with potential long-term effects.
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Title: Quantitative Analysis of New Key Factors of Immune Cells in Autoimmune Diseases
Creator: Bunn, Demarcus
Date: 2022
Collection: Electronic Theses & Dissertations
Description: AbstractExplorations of New Key Factors of Immune Cells in Autoimmune Diseases By Demarcus Bunn The work presented in this dissertation demonstrates an emerging role of immune cells in type one diabetes (T1D) and multiple sclerosis (MS). The immune cells that will be presented are neutrophils and T-cells. Presented work shows an altered cell metabolism in both disease states that leads to further secondary complications. An overview of the immunology, as well as each autoimmune disease, will...
Show moreAbstractExplorations of New Key Factors of Immune Cells in Autoimmune Diseases By Demarcus Bunn The work presented in this dissertation demonstrates an emerging role of immune cells in type one diabetes (T1D) and multiple sclerosis (MS). The immune cells that will be presented are neutrophils and T-cells. Presented work shows an altered cell metabolism in both disease states that leads to further secondary complications. An overview of the immunology, as well as each autoimmune disease, will be presented. Experimental efforts to increase or decrease cell metabolism in order to alleviate secondary complications will be shown. Furthermore, the use of 3D printed devices for in vitro models mimicking these disease states properties will be presented.Individuals T1D have a history of being more susceptible to infection. This section of the dissertation will demonstrate how a once forgotten pancreatic peptide, C-peptide, has a positive effect on raising immunity through improving immune cell energetics. Previous studies in the Spence lab have shown that C-peptide only binds to red blood cells (RBC) in the presence of albumin, but for the biological changes, Zn2+ is needed. Spence lab research has shown that the combination of C-peptide/Zn2+/albumin increases the metabolism of RBCs. This work shows novel data showing that C-peptide binds specifically to other cell types. Additionally, changes in cell metabolism will be investigated. This portion of the dissertation is important for alleviating reoccurring and persistent infections.MS is characterized by the destruction of the myelin sheath around the nerves. The cell type that does the damage is T lymphocytes. However, little research has been done investigating what makes the permeability of the blood-brain barrier increase. Here, we will introduce the potential role of NETosis, a form of programmed cell death, has on blood brain barrier permeability. There have been recent reports that exogenous adenosine triphosphate (ATP) increases the rate of NETosis production in vitro. Previous work in the Spence lab has shown that RBCs from individuals with MS secrete significantly more ATP than control red blood cells. Presented work will show that ATP derived directly from RBCs causes dysregulation of NETosis. The concluding section of the dissertation will be dedicated to 3D printing. An overview of the current state and future advancements of 3D printing will be presented. Presented work will show the use of 3D printing to provide more relevant conditions for in vitro experiments. Here, 3D printed models were used to investigate immune cell behaviors and changes in cell bioenergetics.
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Title: Molecular epidemiology, pangenomic diversity, and comparative genomics of Campylobacter jejuni
Creator: Rodrigues, Jose Alexandre
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Campylobacter jejuni, the leading cause of bacterial gastroenteritis in the United States, is often resistant to commonly used antibiotics and has been classified as a serious threat to public health. Through this work, we sought to evaluate infection trends, quantify resistance frequencies, identify epidemiological factors associated with infection, and use whole-genome sequencing (WGS) as well as comparative phylogenomic and pangenomic approaches to understand circulating C. jejuni...
Show moreCampylobacter jejuni, the leading cause of bacterial gastroenteritis in the United States, is often resistant to commonly used antibiotics and has been classified as a serious threat to public health. Through this work, we sought to evaluate infection trends, quantify resistance frequencies, identify epidemiological factors associated with infection, and use whole-genome sequencing (WGS) as well as comparative phylogenomic and pangenomic approaches to understand circulating C. jejuni populations in Michigan. C. jejuni isolates (n=214) were collected from patients via an active surveillance system at four metropolitan hospitals in Michigan between 2011 and 2014. Among the 214 C. jejuni isolates, 135 (63.1%) were resistant to at least one antibiotic. Resistance was observed for all nine antibiotics tested yielding 11 distinct resistance phenotypes. Tetracycline resistance predominated (n=120; 56.1%) followed by resistance to ciprofloxacin (n= 49; 22.9%), which increased from 15.6% in 2011 to 25.0% in 2014. Notably, patients with ciprofloxacin resistant infections were more likely to report traveling in the past month (Odds Ratio (OR): 3.0; 95% confidence interval (CI): 1.37, 6.68) and international travel (OR: 9.8; 95% CI: 3.69, 26.09). To further characterize these strains, we used WGS to examine the pangenome and investigate the genomic epidemiology of this set of C. jejuni strains recovered from Michigan patients. Among the 214 strains evaluated, 83 unique multilocus sequence types (STs) were identified that were classified as belonging to 19 previously defined clonal complexes (CCs). Core-gene phylogenetic reconstruction based on 615 genes identified three clades, with Clade I comprising six subclades (IA-IF) and predominating (83.2%) among the strains. Because specific cattle-associated STs, such as ST-982, predominated among strains from Michigan patients, we also examined a collection of 72 C. jejuni strains from cattle recovered during an overlapping time period by WGS. Several phylogenetic analyses demonstrated that most cattle strains clustered separately within the phylogeny, but a subset clustered together with human strains. Hence, we used high quality single nucleotide polymorphism (hqSNP) profiling to more comprehensively examine those cattle and human strains that clustered together to evaluate the likelihood of interspecies transmission. Notably, this method distinguished highly related strains and identified clusters comprising strains from both humans and cattle. For instance, 88 SNPs separated a cattle and human strain that were previously classified as ST-8, while the human and cattle derived ST-982 strains differed by >200 SNP differences. These findings demonstrate that highly similar strains were circulating among Michigan patients and cattle during the same time period and highlight the potential for interspecies transmission and diversification within each host. In all, the data presented illustrate that WGS and pangenomic analyses are important tools for enhancing our understanding of the distribution, dissemination, and evolution of specific pathogen populations. Combined with more traditional phenotypic and genotypic approaches, these tools can guide the development of public health prevention and mitigation strategies for C. jejuni and other foodborne pathogens.
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Title: DEVELOPING LIGNIN-BASED EPOXY AND POLYURETHANE RESINS
Creator: Nikafshar, Saeid
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Lignin, the most abundant natural aromatic polymer, is currently produced as by-product during biorefinery and chemical pulping processes. Lignin is rich in hydroxyl functional groups (both phenolic and aliphatic OH), making it an excellent raw material for synthesizing epoxy and polyurethane resins. However, there are several challenges in utilizing unmodified lignins as feedstock for product development, including high polydispersity/heterogeneity, low reactivity, poor accessibility of...
Show moreLignin, the most abundant natural aromatic polymer, is currently produced as by-product during biorefinery and chemical pulping processes. Lignin is rich in hydroxyl functional groups (both phenolic and aliphatic OH), making it an excellent raw material for synthesizing epoxy and polyurethane resins. However, there are several challenges in utilizing unmodified lignins as feedstock for product development, including high polydispersity/heterogeneity, low reactivity, poor accessibility of hydroxyl groups for reaction with co-monomers low solubility in common organic solvents, and dark color. There are significant variations in lignin characteristics, depending on the source of biomass and isolation methods. Therefore, in-depth lignin characterization is needed to provide the basic knowledge of the structural, chemical, and thermal properties to facilitate lignin valorization.This study was focused on lignin characterization and development of lignin-based epoxy and polyurethane resins. First, a wide range of lignin samples was fully characterized by measuring their ash contents, elemental analyses, hydroxyl contents, chemical structures, molar mass distributions, and thermal properties. Next, a novel method was developed to measure the reactivity of thirteen different unmodified lignins toward biobased epichlorohydrin (ECH). A partial least square regression (PLS-R) model (with 92 % fitting accuracy and 90 % prediction ability) was created to study the correlation between lignin properties and epoxy content. The results showed that lignins with higher phenolic hydroxyl contents and lower molecular weights were more suitable for replacing 100 % of toxic bisphenol A (BPA) in the formulation of resin precursors. Additionally, two epoxidized lignin samples (with the highest epoxy contents) were cured using a biobased hardener (Cardolite from cashew nutshell), showed comparable thermomechanical performances and thermal stabilities to a petroleum-based epoxy system. Biobased waterborne polyurethane resins (PUDs) were also developed by entirely replacing the petroleum-based polyol and the internal emulsifier with either alkaline pre-extraction lignins or enzymatic hydrolysis lignins as well as tartaric acid (a biobased diacid). The formulated resins had zero VOC (volatile organic compound), which was achieved by replacing toxic n-methyl-2-pyrrolidone (NMP) with cyrene (a biobased solvent). To further improve the mechanical properties of our biobased PUD resins, 20 wt.% of lignin was substituted with low hydroxyl value soy-polyol, which increased their tensile strength and elongation at break to 87% and 68% of a commercial PUD resin. The results of this study demonstrated that it is imperative to fully characterize lignin and choose the right lignin for each specific application. This approach enabled us to entirely replace petroleum-based raw materials (BPA and polyol) with lignin and formulate biobased epoxy and polyurethane resins.
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Title: Progress toward chemical identification of the sea lamprey (Petromyzon marinus) alarm cue
Creator: Mensch, Emily Lauren
Date: 2022
Collection: Electronic Theses & Dissertations
Description: This thesis examined the chemical constituents of repellent odors in the sea lamprey (Petromyzon marinus), an invasive fish in the Great Lakes basin, for use in management and conservation. Odors are powerful tools that guide organism’s movement decisions, and repellent odors such as conspecific alarm cues are particularly potent. In chapter one, we investigated the chemistry of the alarm cue through behaviorally guided fractionation. We found substantial avoidance responses to two major...
Show moreThis thesis examined the chemical constituents of repellent odors in the sea lamprey (Petromyzon marinus), an invasive fish in the Great Lakes basin, for use in management and conservation. Odors are powerful tools that guide organism’s movement decisions, and repellent odors such as conspecific alarm cues are particularly potent. In chapter one, we investigated the chemistry of the alarm cue through behaviorally guided fractionation. We found substantial avoidance responses to two major fractions: water-soluble and chloroform soluble and a full avoidance response upon recombination of the two fractions. We found no consistent avoidance patterns to subfractions, or individual compounds identified in the water-soluble fraction, and we found no avoidance response to all 32 identified compounds from the water-soluble fraction when combined at observed ratios in the skin. In chapter two, we investigated the role of a potential repellent molecule, putrescine, on sea lamprey activity and avoidance in a small individual behavioral assay and avoidance in a large, multi-animal assay. We found a context-dependent response, where sea lamprey did not increase activity in the small assay but did show a substantial avoidance response to putrescine. No evidence of avoidance to putrescine was observed in the large assay. In sum, these results suggest the alarm cue is likely not contained in the 32 identified compounds in the water-soluble-fraction alone and that the behavioral response to putrescine is context dependent. While elucidating the chemistry of the sea lamprey alarm cue may be more difficult than through behaviorally guided fractionation alone, the continued pursuit is worthwhile because of the utility in invasive species management and conservation of native species.
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Title: Topological Data Analysis and Machine Learning Framework for Studying Time Series and Image Data
Creator: Yesilli, Melih Can
Date: 2022
Collection: Electronic Theses & Dissertations
Description: The recent advancements in signal acquisition and data mining have revealed the importance of data-driven tools for analyzing signals and images. The availability of large and complex data has also highlighted the need for investigative tools that provide autonomy, noise-robustness, and efficiently utilize data collected from different settings but pertaining to the same phenomenon. State-of-the-art approaches include using tools such as Fourier analysis, wavelets, and Empirical Mode...
Show moreThe recent advancements in signal acquisition and data mining have revealed the importance of data-driven tools for analyzing signals and images. The availability of large and complex data has also highlighted the need for investigative tools that provide autonomy, noise-robustness, and efficiently utilize data collected from different settings but pertaining to the same phenomenon. State-of-the-art approaches include using tools such as Fourier analysis, wavelets, and Empirical Mode Decomposition for extracting informative features from the data. These features can then be combined with machine learning for clustering, classification, and inference. However, these tools typically require human intervention for feature extraction, and they are sensitive to the input parameters that the user chooses during the laborious but often necessary manual data pre-processing. Therefore, this dissertation was motivated by the need for automatic, adaptive, and noise-robust methods for efficiently leveraging machine learning for studying images as well as time series of dynamical systems. Specifically, this work investigates three application areas: chatter detection in manufacturing processes, image analysis of manufactured surfaces, and tool wear detection during titanium alloys machining. This work’s novel investigations are enabled by combining machine learning with methods from Topological Data Analysis (TDA), a relatively recent field of applied topology that encompasses a variety of mature tools for quantifying the shape of data. First, this study experimentally shows for the first time that persistent homology (or persistence) from TDA can be used for chatter classification with accuracies that rival existing detection methods. Further, the efficient use of chatter data sets from different sources is formulated and studied as a transfer learning problem using experimental turning and milling vibration signals. Classification results are shown using comparisons between the TDA pipeline developed in this dissertation and prominent methods for chatter detection. Second, this work describes how to utilize TDA tools for extracting descriptive features from simulated samples generated using different Hurst roughness exponents. The efficiency of the feature extraction is tested by classifying the surfaces according to their roughness level. The resulting accuracies show that TDA can outperform several traditional feature extraction approaches in surface texture analysis. Further, as part of this work, adaptive threshold selection algorithms are developed for Discrete Cosine Transform, and Discrete Wavelet Transform to bypass the need for subjective operator input during surface roughness analysis. Both experimental and synthetic data sets are used to test the effectiveness of these two algorithms. This study also discusses a TDA-based framework that can potentially provide a feasible approach for building an automatic surface finish monitoring system.Finally, this work shows that persistence can be used for tool condition monitoring during titanium alloys machining. Since, in these processes, the cutting tools typically fracture catastrophically before the gradual tool wear reaches the maximum tool life criteria, the industry uses very conservative criteria for replacing the tools. An extensive experiment is described for relating wear markers in various sensor signals to the tool condition at different stages of the tool life. This work shows how, in this setting, TDA provides significant advantages in terms of robustness to noise and alleviating the need for an expert user to extract the informative features. The obtained TDA-based features are compared to existing state-of-the-art featurization tools using feature-level data fusion. The temporal location of the most representative tool condition features is also studied in the signals by considering a variety of window lengths preceding tool wear milestones.
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Title: Evaluating The Suitability Of Salvaged Lumber As Feedstock In Cross-Laminated Timber
Creator: Abdul Azeez, Ahamed
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Structural abandonment has been a growing concern in the United States for the past few decades. Conventional demolition procedures exercised to eliminate the abandoned structures result in wood waste that are not feasible for reuse. On the other hand, the demand for lumber has been steadily increasing. This research focuses on promoting deconstruction, obtaining the salvaged lumber from deconstructed abandoned buildings, and evaluating the possibility of reusing it to make way for a...
Show moreStructural abandonment has been a growing concern in the United States for the past few decades. Conventional demolition procedures exercised to eliminate the abandoned structures result in wood waste that are not feasible for reuse. On the other hand, the demand for lumber has been steadily increasing. This research focuses on promoting deconstruction, obtaining the salvaged lumber from deconstructed abandoned buildings, and evaluating the possibility of reusing it to make way for a secondary means of lumber production.The study evaluates the engineering properties of salvaged lumber. Furthermore, the salvaged lumber is partially used to manufacture Cross Laminated Timber (CLT) per the current standards and its properties are compared against the properties of CLT panels exclusively made of freshly sawn lumber. By developing variables for the study, the various factors affecting the properties are analyzed. The researcher believes that the intended results would inaugurate the consideration of salvaged wood usage in wood products that serve as construction material.
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Title: QUEER LESSONS IN SUBJECT FORMATION : LEARNING FROM AIDS & SEX
Creator: Travers, Jessica
Date: 2022
Collection: Electronic Theses & Dissertations
Description: My dissertation investigates the formation of the subject. The subject I refer to here is the person, the individual who is shaped by language and discourse, is hailed by interpellation, and is affected by ideological social, cultural, and political forces. I poke and prod at how and why the subject is constructed, and during my analysis of the subject and its formation, I use AIDS literature and art as a lens. While doing so, I discover there is a tight knot around how the subject can define...
Show moreMy dissertation investigates the formation of the subject. The subject I refer to here is the person, the individual who is shaped by language and discourse, is hailed by interpellation, and is affected by ideological social, cultural, and political forces. I poke and prod at how and why the subject is constructed, and during my analysis of the subject and its formation, I use AIDS literature and art as a lens. While doing so, I discover there is a tight knot around how the subject can define and experience itself; thus, I work to loosen that knot, opening more space and air for novel ways the subject is formed—ways that do not encourage conformity, ways that give the subject more agency and creativity in how they become and who they are. Through my analyses and interpretations of works from the AIDS art archive, I uncover queer lessons that confuse, interrupt, and destabilize strict notions of what the subject is, how it is constructed, and how it can express and experience itself. Furthermore, I find that queer and perverted sexualities—erotically-driven desires that exist outside of dominant cultural norms—are an extremely powerful force that destabilizes normative ways that drive and determine how the subject is formed. Ultimately, I argue for a rescripting of how the subject is constructed and offer alternative approaches to subject formations—what I refer to as queer modes of self-authorship. Each of my four chapters narrows in on a queer mode of subject construction: queer interpellation, contact relationality, bearing witness, and desire and pleasure, respectively. These modes buttress my call for a proliferation of ways the subject can be authored and be read.
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Title: Learning Fair Representations without Demographics
Creator: Wang, Xiaoxue
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Due to hard accessibility, real-world adoption of fair representation learning algorithms lacks the prior knowledge of the sensitive attributes that we wish to be fair with. To address the challenge in fairness without explicit demographics, our solution is based on the idea of maximally randomizing the representation while being as informative as possible about the target task. We operationalize this goal through the concept of maximizing the entropy of the learned representation. For this...
Show moreDue to hard accessibility, real-world adoption of fair representation learning algorithms lacks the prior knowledge of the sensitive attributes that we wish to be fair with. To address the challenge in fairness without explicit demographics, our solution is based on the idea of maximally randomizing the representation while being as informative as possible about the target task. We operationalize this goal through the concept of maximizing the entropy of the learned representation. For this purpose, we propose two new avenues for entropy maximization in the absence of demographic information: intra-class and inter-class entropy maximization. For 1) intra-class entropy maximization, it maximizes the entropy of the non-target class predictions (excluding the probability of the ground truth class label for classification problems), thus encouraging the model to discard spurious correlations between the different target classes, and for 2) inter-class entropy maximization, it maximizes the entropy of the representation conditioned on the target label, thus encouraging randomization of the samples within each target class label and minimizing the leakage of potential demographic information in the representation. Quantitative and qualitative results of our Maximum Entropy method (MaxEnt) on COMPAS and UCI Adult datasets show that 1) our method can outperform the State-of-the-art (SOTA) Adversarially Reweighted Learning (ARL) method and will enhance the difficulty of extracting sensitive demographic information in representation without prior demographic knowledge 2) our method reaches a good trade-off between utility and fairness.
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Title: THE EFFECTS OF VIDEO MODELING ON TEACHING STUDENTS WITH INTELLECTUAL AND DEVELOPMENTAL DISABILITIES HOW TO REQUEST A WORKPLACE ACCOMMODATION
Creator: Smith, Brianna
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Individuals with intellectual and developmental disabilities (IDD) may not always be proficient with self-advocacy skills or be aware of the accommodation rights afforded to them through the Americans with Disabilities Act (ADA), potentially hindering their success for maintaining employment and succeeding in individual job tasks. This study was designed to provide proper knowledge and training to teach individuals with IDD how to effectively advocate for their right to necessary...
Show moreIndividuals with intellectual and developmental disabilities (IDD) may not always be proficient with self-advocacy skills or be aware of the accommodation rights afforded to them through the Americans with Disabilities Act (ADA), potentially hindering their success for maintaining employment and succeeding in individual job tasks. This study was designed to provide proper knowledge and training to teach individuals with IDD how to effectively advocate for their right to necessary accommodations in a workplace setting. First, the effectiveness of an initial whole group PowerPoint training to teach eight individuals with IDD who attended a school-to-work transition program how to request a workplace accommodation was examined. Following the training, ability to appropriate request a workplace accommodation was assessed through role-play probes; six participants did not perform the skill accurately and required additional training. Using a multiple baseline across participants design, these six participants completed 1:1 video modeling training, involving videos and role plays depicting each participants individualized requests. All participants increased their percentage of correct responding after the introduction of video modeling training. Three of the eight participants required additional booster sessions and feedback to maintain performance once video modeling was removed. Three of the eight participants generalized the skill to their workplace setting. The implications and directions for future research are discussed.
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Title: The effect of supplementing native rumen microbes on milk production of dairy cattle
Creator: Goldsmith, Katelyn E.
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Dairy cows are commonly fed direct-fed microbials (DFM) to improve milk production and efficiency. Most DFM are not native to the dairy cow rumen which may limit their ability to interact with the native microbiome. We evaluated the effects of two DFM supplements containing 4 native rumen microorganisms on the production of dairy cows. Ninety Holstein cows (92 ± 23 DIM, mean ± standard deviation (SD); 45 ± 10 kg milk/d; 658 ± 86 kg BW; 40% primiparous) were fed a common diet. After 14 d, they...
Show moreDairy cows are commonly fed direct-fed microbials (DFM) to improve milk production and efficiency. Most DFM are not native to the dairy cow rumen which may limit their ability to interact with the native microbiome. We evaluated the effects of two DFM supplements containing 4 native rumen microorganisms on the production of dairy cows. Ninety Holstein cows (92 ± 23 DIM, mean ± standard deviation (SD); 45 ± 10 kg milk/d; 658 ± 86 kg BW; 40% primiparous) were fed a common diet. After 14 d, they were blocked by parity, days in milk, and energy corrected milk (ECM) per unit of metabolic body weight. Within block, cows were randomly assigned to treatments, which were top-dressed daily for the next 112 d. Treatments were 150 g of ground corn mixed with 1) no live DFM (CON), 2) 5 g of a live DFM (Galaxis 2.0; G2), and 3) 5 g of a live DFM (Galaxis 2.0 Plus; G2P). G2 and G2P were products of Native Microbials Inc. (San Diego, CA) and contained the same organisms but in different concentrations. Supplementation with DFM did not alter yield of total milk, protein, or fat, but slightly decreased body weight gain and body condition score gain with no difference between G2 and G2P. DFM tended to decrease dry matter intake (DMI) but did not significantly improve feed efficiency (ECM/DMI). DFM did not alter digestibility of fiber, starch, protein, or fat, and did not alter concentrations of glucose or non-esterified fatty acids but tended to decrease concentration of insulin in plasma. DFM decreased somatic cell counts in milk with no difference between G2 and G2P. In conclusion, supplementation with native DFM had little impact on milk production and efficiency.
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Title: ASSESSING ‘BEHAVIORAL ARTISTRY’ STAFF TRAINING ON BEHAVIOR TECHNICIANS’ USE OF BEHAVIORAL ARTISTRY TRAITS AND THE BEHAVIOR OF YOUNG CHILDREN WITH AUTISM SPECTRUM DISORDER
Creator: Notarianni, Emilia
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Training high quality practitioners continues to be a priority in the field of Applied Behavior Analysis. The concept of behavioral artistry (BA) identifies traits that may contribute to an individual’s success as a behavior analyst, including attributes such as resilience, sense of humor, and compassion. Despite BA’s potential for meaningful impact in the field, research in this area remains limited. The current study aimed to behaviorally define the BA trait “likes people” and investigated...
Show moreTraining high quality practitioners continues to be a priority in the field of Applied Behavior Analysis. The concept of behavioral artistry (BA) identifies traits that may contribute to an individual’s success as a behavior analyst, including attributes such as resilience, sense of humor, and compassion. Despite BA’s potential for meaningful impact in the field, research in this area remains limited. The current study aimed to behaviorally define the BA trait “likes people” and investigated the effects of a behavioral skills training and video self-modeling on the development of behaviors representative of that BA trait. Additionally, data were collected on client behaviors, in order to examine the effects of the BA training on client behavior. Four dyads consisting of one behavior technician and one young child diagnosed with Autism Spectrum Disorder participated in the study, which took place in an EIBI clinic affiliated with a midwestern university. Results showed an increase in the use of the BA trait “likes people” in all adult participants. However, this behavior change did not maintain over time. Child participants demonstrated very little behavior change between phases of this study. These findings indicate that BST and VSM may not be the most effective intervention for training staff on BA. Key words: behavioral artistry, behavioral skills training, staff training, video self-modeling
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Title: SYSTEMIC DELIVERY OF INSECTICIDES IN BLUEBERRIES FOR CONTROL OF BLUEBERRY STEM GALL WASP, HEMADAS NUBILIPENNIS
Creator: Bosch, Amber Kay
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Blueberry stem gall wasp (Hemadas nubilipennis) is a pest of highbush blueberry and can pose a challenge to control with foliar sprays due to adult activity during bloom and larval development within the plant tissues. In this thesis, systemic delivery of insecticides in blueberry bushes was evaluated using three application methods on potted bushes, in blueberry shoot bioassays, and on a commercial blueberry farm. Each study aimed to evaluate impact on gall and gall wasp development, along...
Show moreBlueberry stem gall wasp (Hemadas nubilipennis) is a pest of highbush blueberry and can pose a challenge to control with foliar sprays due to adult activity during bloom and larval development within the plant tissues. In this thesis, systemic delivery of insecticides in blueberry bushes was evaluated using three application methods on potted bushes, in blueberry shoot bioassays, and on a commercial blueberry farm. Each study aimed to evaluate impact on gall and gall wasp development, along with active ingredient residue delivery to plant tissues. I hypothesized that if the insecticide moved systemically within the blueberry vascular system to areas where the blueberry stem gall wasp larvae are developing, then the insecticide will kill the larvae leading to a reduction in gall formation and number of surviving adults per gall. In the potted bush study, applications were made by crown injection, soil drench and foliar sprays. Imidacloprid, flupyradifurone, and spirotetramat were recovered in shoot and leaf tissues, however there was no evidence of inhibited gall or gall wasp development. In the shoot bioassays, imidacloprid and spirotetramat were found to have the greatest potential for control of blueberry stem gall wasp. Active ingredient recovery in bioassay gall tissue revealed the concentration needed to get moribund/ lethal larval response. The on-farm study indicated there was successful movement of imidacloprid and flupyradifurone using chemigation, however, the impact on blueberry stem gall wasp was not great enough to provide control.
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