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Title: Memory-efficient emulation of physical tabular data using quadtree decomposition
Creator: Carlson, Jared
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Computationally expensive functions are sometimes replaced in simulations with an emulator that approximates the true function (e.g., equations of state, wavelength-dependent opacity, or composition-dependent materials properties). For functions that have a constrained domain of interest, this can be done by discretizing the domain and performing a local interpolation on the tabulated function values of each local domain. For these so-called tabular data methods, the method of discretizing...
Show moreComputationally expensive functions are sometimes replaced in simulations with an emulator that approximates the true function (e.g., equations of state, wavelength-dependent opacity, or composition-dependent materials properties). For functions that have a constrained domain of interest, this can be done by discretizing the domain and performing a local interpolation on the tabulated function values of each local domain. For these so-called tabular data methods, the method of discretizing the domain and mapping the input space to each subdomain can drastically influence the memory and computational costs of the emulator. This is especially true for functions that vary drastically in different regions. We present a method for domain discretization and mapping that utilizes quadtrees, which results in significant reductions in the size of the emulator with minimal increases to computational costs or loss of global accuracy. We apply our method to the electron-positron Helmholtz free energy equation of state and show over an order of magnitude reduction in memory costs for reasonable levels of numerical accuracy.
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Title: Evaluation of potential therapeutics for non-small cell lung cancer using 3D tumor spheroid models
Creator: Stoub, Hayden Eric
Date: 2022
Collection: Electronic Theses & Dissertations
Description: The development of novel and improved therapies for cancers requires robust means of investigation that both effectively recapitulate tumor biology while also utilizing resources efficiently. 3D tissue culture methods, namely spheroids and organoids, have emerged as an effective bridge between conventional in vitro methods and in vivo animal models in cancer research. This thesis provides background into lung cancer and the current landscape of 3D in vitro models of cancer, as well as...
Show moreThe development of novel and improved therapies for cancers requires robust means of investigation that both effectively recapitulate tumor biology while also utilizing resources efficiently. 3D tissue culture methods, namely spheroids and organoids, have emerged as an effective bridge between conventional in vitro methods and in vivo animal models in cancer research. This thesis provides background into lung cancer and the current landscape of 3D in vitro models of cancer, as well as detailing two studies in which multicellular tumor spheroids were used to investigate the therapeutic potential of candidate compounds. The first study uses an NCI-H358 multicellular tumor spheroid to investigate three compounds: Apigenin, a plant derived flavonoid; MSU42011, a novel retinoid x receptor (RXR) agonist; and CEP-1347, a mixed lineage kinase (MLK) inhibitor. It was found that Apigenin alone decreased the viability of spheroids, and that the combination of Apigenin and CEP-1347 synergistically decreased viability and increased cell death within the spheroids.The second study uses a murine lung adenocarcinoma tumor spheroid model to investigate the effects of MSU-71, a novel inhibitor of the nuclear factor erythroid 2-related factor (NRF2) pathway, on macrophage-induced invasion and migration. This compound blocked both migration in conventional experiments along with spheroid invasion, indicating its potential efficacy in preventing LUAD progression. This study also adapted the spheroid invasion model for use in multiple human LUAD cell lines and THP-1 conditioned medium. The findings presented herein demonstrate the versatility and value of 3D tumor spheroid models in the cancer drug development field.
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Title: BLAME JUDGEMENTS FOR PAST ACTIONS OF GROUPS
Creator: Vallabha, Shree
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Historically, groups have committed innumerable atrocities, including genocide and slavery. I tested if people blame current groups for the actions of their past members and what underlies this blame. Current models of blame overlook the dimension of time and therefore have difficulty explaining this phenomenon. I hypothesized that perceiving higher (a) connectedness between past and present perpetrator groups, (b) unfulfilled obligations of perpetrator groups, (c) continued privilege of...
Show moreHistorically, groups have committed innumerable atrocities, including genocide and slavery. I tested if people blame current groups for the actions of their past members and what underlies this blame. Current models of blame overlook the dimension of time and therefore have difficulty explaining this phenomenon. I hypothesized that perceiving higher (a) connectedness between past and present perpetrator groups, (b) unfulfilled obligations of perpetrator groups, (c) continued privilege of perpetrator groups, and (d) continued harm of victim groups would facilitate higher blame judgements against current groups for the past. In a survey (N=518) using real events, I find results consistent with all the four hypotheses and some preliminary evidence for group differences in these relationships. I find that factors that link the present group to the past explain why groups are blamed for their past actions. These findings bring to light the deficiencies in existing theories of blame – calling into question its assumptions and incomplete criterion of judgement.
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Title: Evaluation of Operational Performance and Environmental Impact of a Commercial Scale Anaerobic Digester Utilizing Multiple Feedstocks
Creator: Dwilaksono, Fahmi
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Food waste and livestock manure become some of major sources that contribute to greenhouse gas (GHG) emissions in the U.S. Utilizing manure and food wastes as biogas feedstocks through anaerobic digestion (AD) process can improve renewable energy production while reducing the impact of climate change due to GHG emission from untreated organic wastes. This study evaluated the operational performance of Michigan State University’s commercial South Campus Anaerobic Digester (SCAD) as well as the...
Show moreFood waste and livestock manure become some of major sources that contribute to greenhouse gas (GHG) emissions in the U.S. Utilizing manure and food wastes as biogas feedstocks through anaerobic digestion (AD) process can improve renewable energy production while reducing the impact of climate change due to GHG emission from untreated organic wastes. This study evaluated the operational performance of Michigan State University’s commercial South Campus Anaerobic Digester (SCAD) as well as the environmental impact during its operation in 2014-2020. Evaluation of feedstock supplies quantity and output parameters of SCAD was conducted to understand the operational performance of the digester. A life cycle assessment (LCA) was done to know the environmental impact of SCAD by comparing it to the conventional waste management methods. Technoeconomic analysis was conducted to know the financial feasibility of SCAD as a commercial digester. The result shows that during its operation from 2014 to 2020, SCAD has processed 159,145 metric tons of feedstock from 18 different organic wastes to produce 15,165,156 kWh of electricity for MSU community. LCA results show that AD system possesses fewer environmental burdens in both global warming potential (GWP) and water eutrophication potential (WEP) compared to the conventional system. Technoeconomic analysis reveals that SCAD needs 21.5 years to accomplish its payback time, which is considered quite economically competitive.
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Title: INTENSITY IN TEACHING : DEVELOPING AN AFFECTIVE FRAMEWORK FOR WRITING INSTRUCTORS
Creator: Chapman Ball, Cadaxa
Date: 2022
Collection: Electronic Theses & Dissertations
Description: This qualitative research project aims to develop an affective framework for writing pedagogy through analyzing narrative data collected over the course of one semester teaching MSU’s first-year writing course, WRA 101: Writing As Inquiry. The narrative data consists of journal entries and reflections remarking on my own affective states in the writing classroom. Through analyzing these writings, this thesis reveals how and why affect theory has useful applications in writing pedagogy; namely...
Show moreThis qualitative research project aims to develop an affective framework for writing pedagogy through analyzing narrative data collected over the course of one semester teaching MSU’s first-year writing course, WRA 101: Writing As Inquiry. The narrative data consists of journal entries and reflections remarking on my own affective states in the writing classroom. Through analyzing these writings, this thesis reveals how and why affect theory has useful applications in writing pedagogy; namely, that instructors who attend to their own affective responses have the opportunity to better understand the changes they need to make to their teaching practices as well as the systems in which they teach.
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Title: PERCEPTIONS OF VOICE PRODUCTION IN HEALTHY FEMALES IN REGARDS TO AGE AND PROFESSIONALISM : AS QUANTIFIED BY ACOUSTIC AND PERCEPTUAL MEASURES
Creator: Nizami, Hafsaah Fatima
Date: 2022
Collection: Electronic Theses & Dissertations
Description: PURPOSE: This study aims to research the perception of voice as it relates to aging and professionalism in an individual. The production of voice varies in accordance with various factors. These variations often provide an insight into a listener’s perceptions of a speaker’s vocal characteristics and these perceptions may vary across settings. METHODS: This study required four components. The first component required college aged participants to rate perceptions of age and health in regards...
Show morePURPOSE: This study aims to research the perception of voice as it relates to aging and professionalism in an individual. The production of voice varies in accordance with various factors. These variations often provide an insight into a listener’s perceptions of a speaker’s vocal characteristics and these perceptions may vary across settings. METHODS: This study required four components. The first component required college aged participants to rate perceptions of age and health in regards to young and old female vocalists. The second section required college aged participants to rate professionalism in regards to young and old female vocalists. Speech Professionals were asked to participate in the third component of this study, in which they rated listeners among the GRBAS scale. The last component required a quantification of results using a standard acoustic measure like cepstral peak prominence. RESULTS: Strong positive correlations were found between estimated age and actual age, strong negative correlations were found between older women and professionalism; moderately positive correlations were found between younger women and professionalism; moderate to strong correlation was found between age and GRBAS; and moderate negative correlations were found between age and CPPS. DISCUSSION: The following results were found: College-aged students were able to distinguish between the younger and older females. Older women were perceived as less professional. As age increases, GRBAS scores also increase. As age increases, CPPS ratings will decrease. CONCLUSION: Further research may require completion of surveys in a controlled environment, and inclusion of pitch-related measures as they relate to the workplace. Keywords: Aging voice, biological sex differences, perception of voice, professional voice, acoustic measures
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Title: PRETERM DELIVERY AND ITS ASSOCIATION WITH FALSE POSITIVE, AUDITORY BRAINSTEM RESPONSE (ABR)-BASED NEWBORN HEARING SCREENING FINDINGS
Creator: Rathore, Mandavni
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Newborn hearing screening failure can occur in infants without hearing loss; these false-positive (FP) results have been speculated to reflect neurodevelopmental disorder risk. Preterm birth (PTB), a known neurodevelopmental risk factor, has been associated with FP at initial screening. We aim to further characterize this association by stratifying PTB by gestational age and delivery circumstance. To do this, we analyzed birth certificate and Early Hearing Detection & Intervention data from...
Show moreNewborn hearing screening failure can occur in infants without hearing loss; these false-positive (FP) results have been speculated to reflect neurodevelopmental disorder risk. Preterm birth (PTB), a known neurodevelopmental risk factor, has been associated with FP at initial screening. We aim to further characterize this association by stratifying PTB by gestational age and delivery circumstance. To do this, we analyzed birth certificate and Early Hearing Detection & Intervention data from the Michigan Dept. of Health & Human Services (2007–2015; n = 919,363). We restricted our analysis to singleton live births with available ABR-based hearing screening data and obstetric estimates of gestational age (n = 655,079). We then used logistic regression to evaluate the association of PTB defined by gestational age (extreme: < 28 weeks; moderate: 28–34 weeks; late: 34–36 weeks) and delivery circumstance (spontaneous, medically indicated) with FP, using full-term birth (≥ 37 weeks) as the referent group. Approximately 4% of infants had FP findings. All gestational age categories were associated with this phenomenon (extreme: OR = 4.2, 95% CI 3.7, 4.7; moderate: OR = 1.2, 95% CI 1.1, 1.3; late: 1.6, 95% CI 1.5, 1.7). Spontaneous and medically indicated PTB were also associated with FP (OR = 1.7, 95% CI 1.6, 1.8; OR = 1.4, 95% CI 1.3, 1.5, respectively). All results persisted following adjustment for socio-demographic and antepartum factors except for moderate PTB (OR = 1.0, 95% CI 0.9, 1.1), though sensitivity analyses suggested marked heterogeneity within this group. Further research is needed to investigate factors underlying these differences and whether they correlate with neurodevelopmental disorder diagnoses.
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Title: HOW CAREGIVERS OF CHILDREN IN EARLY INTERVENTION FEEL ABOUT SIMPLIFIED LANGUAGE INPUT : A SURVEY STUDY
Creator: Nylund, Megan
Date: 2022
Collection: Electronic Theses & Dissertations
Description: There is some disagreement regarding how adults should simplify their utterances when speaking to young children with language delays. One type of simplification that has come into question is telegraphic input, a style of speaking that involves removing grammatical aspects of phrases, such as function words and grammatical markers (e.g., All done snack, Cookie yummy). In the current study, we utilized survey data collected by Andary (2020) surveying caregivers of children in early...
Show moreThere is some disagreement regarding how adults should simplify their utterances when speaking to young children with language delays. One type of simplification that has come into question is telegraphic input, a style of speaking that involves removing grammatical aspects of phrases, such as function words and grammatical markers (e.g., All done snack, Cookie yummy). In the current study, we utilized survey data collected by Andary (2020) surveying caregivers of children in early intervention about their views on different types of simplified language. Specifically, we asked: How do caregivers’ beliefs about telegraphic input relate to how comfortable they are producing different types of simplified utterances? Results were also analyzed for correlations between demographics and beliefs of simplification. Additionally, the survey provided space for caregivers to share recommendations they gained through Early On resources. Results show caregivers with a positive view of telegraphic input felt significantly less comfortable producing full, grammatical utterances than caregivers with a negative or neutral view of telegraphic input. Demographic analysis revealed caregivers with higher education levels preferred more grammatical utterances. These findings emphasize the importance of understanding caregiver perspectives in caregiver-mediated intervention approaches.
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Title: THE ROLE OF PREZYGOTIC SELF-COMPATIBILITY IN FACILITATING INTERSPECIFIC COMPATIBILITY IN SOLANUM SECTION PETOTA
Creator: Behling, William
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Domesticated potato (Solanum tuberosum L.) is the fourth most important food crop worldwide and critical food security crop. The high significance of this crop coupled with high production losses place potato at a high priority for genetic improvement, especially in the face of climate change. Potato breeding is undergoing a seismic shift from a tetraploid outcrossing crop towards a F1 hybrid system using diploid inbred lines as parents. This transformation has also changed how potato...
Show moreDomesticated potato (Solanum tuberosum L.) is the fourth most important food crop worldwide and critical food security crop. The high significance of this crop coupled with high production losses place potato at a high priority for genetic improvement, especially in the face of climate change. Potato breeding is undergoing a seismic shift from a tetraploid outcrossing crop towards a F1 hybrid system using diploid inbred lines as parents. This transformation has also changed how potato breeders access important traits from wild species. Pre- and post-zygotic barriers, such as self-incompatibility (SI) and endosperm failure, inhibit and complicate the use of the more valuable wild species in conventional and diploid breeding schemes. Traditionally plant breeders have employed the SC x SI rule, using self-compatibility (SC) to increase the success of interspecific crosses. In order to evaluate the potential of several different SC factors in facilitating broad interspecific compatibility: Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas9 knockout (KO) lines of S-RNase, HT-B and HT-B + S-RNase in S. tuberosum were evaluated along with the self-compatible species S. verrucosum, and S-locus inhibitor gene (Sli) from S. chacoense. Findings confirm the central role of S-RNase in interspecific pollination barriers and the inconsequential role of HT-B alone. Sli had no effect on interspecific barriers despite its prominent role as a source of SC. Finally, S. verrucosum styles displayed an absence of prezygotic barriers. Further analysis of the role of HT-A, as well as other mechanisms that potentially underlie the SC phenotype in S. verrucosum will further clarify the role of specific genetic factors that regulate interspecific compatibility in Solanum section Petota
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Title: OPPORTUNITIES AND CHALLENGES OF INTEGRATED LARGE SCALE PFAS MODELING
Creator: Raschke, Anna
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Perfluoroalkyl substances (PFAS) have been observed around the world in air, water, and soil. Recent research and monitoring studies have alluded to the widespread presence of PFAS, but most observe the impact of PFAS as a snapshot in time and space. In an effort to better understand PFAS fate and transport in the environment, computational models have been developed. For this study, we synthesized the model applications of PFAS fate and transport via water medium through surface water,...
Show morePerfluoroalkyl substances (PFAS) have been observed around the world in air, water, and soil. Recent research and monitoring studies have alluded to the widespread presence of PFAS, but most observe the impact of PFAS as a snapshot in time and space. In an effort to better understand PFAS fate and transport in the environment, computational models have been developed. For this study, we synthesized the model applications of PFAS fate and transport via water medium through surface water, vadose zone, groundwater, streamflow, as well as their uptake and accumulation in plants and aquatic organisms. In addition, the system under this study is permeable to incoming (sources) and outgoing (sinks) PFAS compounds. Ultimately, knowledge gaps in modeling PFAS for each subsystem (e.g., surface water) area were identified. From there, a case study was performed to highlight the shortcomings of widely used models for PFAS fate and transport within a large and complex watershed. With a large number of PFAS using industries, Michigan is at the forefront of PFAS sampling. Therefore, the study area chosen was the Huron River watershed, a highly PFAS impacted watershed in Southeastern Michigan. The results showed the importance of organized monitoring studies and model improvements to better understand PFAS fate and transport in a large watershed.
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Title: Improving the Efficiency of Residential Buildings in Rural Alaska : An Analysis of Existing Infrastructure and Its Importance in Creating Energy-Efficient Homes
Creator: Milan, Maria
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Rural communities in Alaska, many of which have a high Alaska Native population, currently face significant housing challenges. In a climate that can become extremely cold, houses are generally lacking in energy efficiency. Residents pay high rates for both oil and electricity to heat and operate their homes. Their homes are much smaller and with higher occupancy in comparison to typical U.S. homes. In addition, as the winter season brings sub-zero temperatures, windows remain shut with...
Show moreRural communities in Alaska, many of which have a high Alaska Native population, currently face significant housing challenges. In a climate that can become extremely cold, houses are generally lacking in energy efficiency. Residents pay high rates for both oil and electricity to heat and operate their homes. Their homes are much smaller and with higher occupancy in comparison to typical U.S. homes. In addition, as the winter season brings sub-zero temperatures, windows remain shut with limited mechanical or natural ventilation, also creating indoor air quality concerns. To date there has been limited studies of rural Alaskan communities’ housing, to better understand and quantify such housing challenges. This research focuses on a detailed study of the rural Alaskan community of Unalakleet. Located on the western shore of Alaska, this coastal community of approximately 765 people faces many housing challenges, similar to other rural Alaskan communities. Through collaboration with the housing authority in Unalakleet, this research conducted home energy assessments and resident interviews in the summer of 2021, including 27 energy assessments and 22 interviews. The purpose of the energy assessments was to collect information on typical building features and data, as well as to identify housing challenges. The interviews were generally completed for homes that also had an energy assessment and were used to better understand residents’ perspectives on energy and housing challenges beyond what was observed in the assessments. Blower door tests suggest that homes are usually small and tight, with leakiness around areas like the windows, where mold frequently was observed. Short-term indoor air quality monitoring suggests that some homes, especially those less than 46 m2 , had high CO2 concentrations, relative to others. Some homes had significant mold growth, and others had many areas of damage. Still, interviews with community members suggest that they were grateful for their housing and the ability to live in Unalakleet. The overall purpose of this research is to provide evidence to quantify the typical housing characteristics presence in rural Alaskan communities, as well as to provide results that motivate and support opportunities for new, more efficient housing. The introduction discusses major housing challenges, from high energy bills to the history of inefficient infrastructure in rural Alaska. Physical characteristics of assessed homes, followed by indoor air quality and air flow, are discussed in Chapters 2 and 3, respectively. Finally, Chapter 4 uses data collected from the 27 housing assessments to create a building energy model, where energy usage in existing housing is modeled to represent a ‘typical’ rural Alaskan home. The results of this model show where the largest improvements in efficiency can be made, especially in adding higher R-value insulation. The conclusion provides a brief overview of research contribution, limitations, and future work.
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Title: PRESCRIPTION OPIOIDS, OPIOID USE DISORDERS, AND OPIOID DEATHS ACROSS 21 OECD NATIONS
Creator: Siddiqui, Zehra Jabeen
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Since the 1990s, the United States has seen increased prescription opioid consumption (POC) and an increase in the prevalence of opioid use disorders (OUD) and the opioid disorder death (ODD) rate. This paper examines three factors that may have fueled the opioid crisis: increased supply of prescription opioids, increased demand for opioids because of pain and economic related despair. A regression analysis of twenty-one OECD nations was used to examine the determinants of and the...
Show moreSince the 1990s, the United States has seen increased prescription opioid consumption (POC) and an increase in the prevalence of opioid use disorders (OUD) and the opioid disorder death (ODD) rate. This paper examines three factors that may have fueled the opioid crisis: increased supply of prescription opioids, increased demand for opioids because of pain and economic related despair. A regression analysis of twenty-one OECD nations was used to examine the determinants of and the relationships between POC, OUDs, and ODDs. Over 1991-2019, consumption did not have a significant effect on OUDs or ODDs, but over 2003-2019 it had a positive significant effect on both. These results held if the US was removed from the sample, supporting some supply side effect across the panels after 2003. Furthermore, OUDs have a large, positive and significant effect on ODDs, indicating two possible pathways direct (straight from consumption) and indirect (through an effect on opioid use disorders) that POC relates to increased ODDs. One model estimates that 39% of the increase in US opioid fatalities is attributable to increased POC between 2003-2010.
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Title: WE DON’T NEED TO KNOW WHAT WE SEE : MODEST MEDIATION OF BISTABLE PERCEPTION BY KNOWLEDGE
Creator: Zhang, Bobicheng
Date: 2022
Collection: Electronic Theses & Dissertations
Description: When faced with ambiguous visual input, an observer may have various perceptual interpre- tations even when the input remains unchanged. Indeed, such ambiguous displays can cause the observer to experience distinct perceptual interpretations in turn, unpredictably switching between them over time. Theories of such so-called multistable perception broadly fall into two categories: top-down theories that hold that perception in these cases depends strongly on higher-level cogni- tive factors...
Show moreWhen faced with ambiguous visual input, an observer may have various perceptual interpre- tations even when the input remains unchanged. Indeed, such ambiguous displays can cause the observer to experience distinct perceptual interpretations in turn, unpredictably switching between them over time. Theories of such so-called multistable perception broadly fall into two categories: top-down theories that hold that perception in these cases depends strongly on higher-level cogni- tive factors such as knowledge, and bottom-up theories which suggests more vital involvement of aspects of lower-order information processing such as local adaptation in the visual system. We evaluated whether the occurrence of perceptual reversals in the face of ambiguous input is related to the observer’s knowledge that the input is, indeed, ambiguous. We used an ambiguous animation that was designed such that subjects could report perceptual reversals without realizing the ambigu- ity. Subjects observed the animation, reported their perception, and filled out a questionnaire that assessed their knowledge of the animation’s ambiguity. We found that informed subjects reported slightly more perceptual switches than the other subjects, but that this between-group difference was very small compared to the lack of variability within each group between subjects who were aware of the ambiguity and those who were not. These findings suggests that knowledge of ambiguity can influence perception of ambiguous stimuli, but that this influence is relatively minor. This discrepancy between current findings and past work is discussed.
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Title: Environmental controls on phenoregions across an East African megatransect
Creator: Desanker, Gloria
Date: 2019
Collection: Electronic Theses & Dissertations
Description: Semi-arid and savanna-type (SAST) systems in East Africa have unique plant species compositions and characteristics that make quantifying this area's seasonality and inter-annual variability difficult. Phenoregion classification offers a way to use seasonality of vegetation growth dynamics to help understand the phenology of complex landscapes. Here, we used Normalized Difference Vegetation Index (NDVI) time series from the Landsat 8 imagery to map phenoregions in scenes centered around...
Show moreSemi-arid and savanna-type (SAST) systems in East Africa have unique plant species compositions and characteristics that make quantifying this area's seasonality and inter-annual variability difficult. Phenoregion classification offers a way to use seasonality of vegetation growth dynamics to help understand the phenology of complex landscapes. Here, we used Normalized Difference Vegetation Index (NDVI) time series from the Landsat 8 imagery to map phenoregions in scenes centered around national parks from Mt. Kenya National Park (Kenya) to Limpopo National Park (Mozambique) to assess whether landscape-scale controls on phenology are consistent across the region or if they differ on a latitudinal gradient. We used MODIS Land Cover to assess land cover composition in each phenoregion, and discriminant analysis to determine the role that elevation, slope and aspect play in driving phenological differences. There was no clear latitudinal pattern seen in land cover or geologic composition. Most of the site's phenoregions showed no unique composition of either of the variables, meaning that land cover or geology type did not help in differentiating phenoregions. The discriminant analysis showed that topography was a strong predictor of many of the phenoregions, however, these also did not reveal any clear latitudinal pattern. Using seasonality of the NDVI time series to generate phenoregions provides different and even in some cases more ecologically relevant information, compared to past studies that use only land cover to generate ecoregions. With a significant population of humans and animals that live in and depend on SAST ecosystems, it is important to better understand vegetation processes and the factors that affect them as climate change becomes an increasingly pertinent issue in dry systems.
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Title: Ruby thin film pressure sensors
Creator: Straley, Eric M.
Date: 2018
Collection: Electronic Theses & Dissertations
Description: As the population rises, it is important that society adopts a more environmentally friendly energy landscape. Currently, solid oxide fuel cells (SOFCs) are a promising technology due to high energy efficiency, power density, and fuel flexibility. However, SOFCs are held back by high costs which are due, in part, to high operating temperatures. It is the principle research goal in the SOFC community to decrease these operating temperatures and current research studies suggest that strain...
Show moreAs the population rises, it is important that society adopts a more environmentally friendly energy landscape. Currently, solid oxide fuel cells (SOFCs) are a promising technology due to high energy efficiency, power density, and fuel flexibility. However, SOFCs are held back by high costs which are due, in part, to high operating temperatures. It is the principle research goal in the SOFC community to decrease these operating temperatures and current research studies suggest that strain engineering SOFC materials can help. Current studies are hamstrung by the lack of ability to determine stress in-situ thus performance improvements due to strain cannot be isolated. A method to easily measure non-hydrostatic stress is needed to make strain engineered SOFCs a reality. Fluorescent stress sensors have been used to measure non-hydrostatic stress, but the accuracy of these measurements have never been evaluated. The work here uses ruby thin films as non-hydrostatic, fluorescent stress sensors and uses curvature-determined stress to evaluate the accuracy of these new sensors. Highly oriented ruby thin films were deposited onto single crystal sapphire and yttria-stabilized zirconia (YSZ) substrates using pulsed-laser deposition. The resulting ruby/YSZ samples achieved a fluorescence determined stress of 223C1.9 GPa while the ruby/sapphire samples achieved 223C 0.05 GPa. Stress determination from sample curvature measurements confirmed the results of the fluorescence stress measurements, indicating that the ruby piezospectroscopic tensor, which had previously been experimentally validated up to 0.9 GPa, is accurate up to nearly 2 GPa. This work concludes that ruby thin films are an effective sensor for measuring biaxial stress; thus, strain engineering a variety of thin film devices is now a possibility.
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Title: Importance of nutritional status of passerines to immunity and disease dynamics
Creator: Fake, Kimberly R.
Date: 2018
Collection: Electronic Theses & Dissertations
Description: Host nutritional status has been long established as a mediator of host-pathogen interactions across taxa. Nutritional status of landbirds is largely determined by environmental conditions and can vary between individuals. Many landbirds by virtue of migratory movements are exposed to a variety of pathogens. Furthermore, landbirds also face conditions of limited resources and high competition, which can impact their ability to acquire nutrients. Here I explore how the host-pathogen...
Show moreHost nutritional status has been long established as a mediator of host-pathogen interactions across taxa. Nutritional status of landbirds is largely determined by environmental conditions and can vary between individuals. Many landbirds by virtue of migratory movements are exposed to a variety of pathogens. Furthermore, landbirds also face conditions of limited resources and high competition, which can impact their ability to acquire nutrients. Here I explore how the host-pathogen interactions and subsequently disease dynamics among landbirds may be affected by host nutritional status. First, we review disease dynamics and effects of host nutrition on the host-pathogen interaction, highlighting the importance of exploring impacts of host nutritional status to disease dynamics among migratory landbirds. Second, we present a foundational study of the impact of host nutritional status, measured as energetic condition, on constitutive immune function of American robins (Turdus migratorius), a passerine which acts as a reservoir for multiple zoonotic pathogens. Together these chapters provide an ecoimmunological and conservation medicine perspective on the importance of nutritional status of passerines to immunity and disease dynamics.
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Title: The effects of supplemental fatty acids on production and nutrient digestibility responses of lactating dairy cows
Creator: Western, Marin Marie
Date: 2018
Collection: Electronic Theses & Dissertations
Description: Addition of fat supplements to dairy rations is becoming more common due to the increases in milk yield and milk fat yield that have been observed. This thesis contains two studies that evaluated the effects of palmitic (C16:0), stearic (C18:0), and oleic (C18:1) acids in the form of commercially available supplements (C16:0 and C18:0-enriched) or as custom blends (C16:0 and C18:1) on lactating dairy cows. The first experiment used two commercially-available products enriched in either C16:0 ...
Show moreAddition of fat supplements to dairy rations is becoming more common due to the increases in milk yield and milk fat yield that have been observed. This thesis contains two studies that evaluated the effects of palmitic (C16:0), stearic (C18:0), and oleic (C18:1) acids in the form of commercially available supplements (C16:0 and C18:0-enriched) or as custom blends (C16:0 and C18:1) on lactating dairy cows. The first experiment used two commercially-available products enriched in either C16:0 (PA) or C18:0 (SA) supplied at 1.5% diet dry matter (DM) and a control diet with no added fat. Fat supplementation increased milk yield, but decreased total FA digestibility when compared to control. PA increased digestibility of total, 16- and 18-carbon FA as well as NDF digestibility, energy corrected milk (ECM), and milk fat yield when compared to SA. In the second experiment, the effect of differing ratios of C16:0 and C18:1 (fed at 1.5% diet DM) was determined using blends that consisted of 80% C16:0 + 10% cis-9 C18:1 (80:10) or 60% C16:0 + 30% C18:1 (60:30) across a wide range in production level. Interactions between preliminary milk yield and treatment were observed for dry matter intake (DMI), and yields of ECM and 3.5% fat-corrected milk (3.5% FCM), indicating that higher producing cows responded better to the 60:30 and lower producing cows responded better to the 80:10. 60:30 increased digestibilities of total, 16- and 18- carbon FA compared with 80:10. Together, this work will provide information that can be used to guide feeding decisions to maximize performance and farm income while using commercial FA supplements.
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Title: AN EVOLUTIONARY MULTI-OBJECTIVE APPROACH TO SUSTAINABLE AGRICULTURAL WATER AND NUTRIENT OPTIMIZATION
Creator: Kropp, Ian Meyer
Date: 2018
Collection: Electronic Theses & Dissertations
Description: One of the main problems that society is facing in the 21st century is that agricultural production must keep pace with a rapidly increasing global population in an environmentally sustainable manner. One of the solutions to this global problem is a system approach through the application of optimization techniques to manage farm operations. However, unlike existing agricultural optimization research, this work seeks to optimize multiple agricultural objectives at once via multi-objective...
Show moreOne of the main problems that society is facing in the 21st century is that agricultural production must keep pace with a rapidly increasing global population in an environmentally sustainable manner. One of the solutions to this global problem is a system approach through the application of optimization techniques to manage farm operations. However, unlike existing agricultural optimization research, this work seeks to optimize multiple agricultural objectives at once via multi-objective optimization techniques. Specifically, the algorithm Unified Non-dominated Sorting Genetic Algorithm-III (U-NSGA-III) searched for irrigation and nutrient management practices that minimized combinations of environmental objectives (e.g., total irrigation applied, total nitrogen leached) while maximizing crop yield for maize. During optimization, the crop model named the Decision Support System for Agrotechnology Transfer (DSSAT) calculated the yield and nitrogen leaching for each given management practices. This study also developed a novel bi-level optimization framework to improve the performance of the optimization algorithm, employing U-NSGA-III on the upper level and Monte Carlo optimization on the lower level. The multi-objective optimization framework resulted in groups of equally optimal solutions that each offered a unique trade-off among the objectives. As a result, producers can choose the one that best addresses their needs among these groups of solutions, known as Pareto fronts. In addition, the bi-level optimization framework further improved the number, performance, and diversity of solutions within the Pareto fronts.
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Title: Identifcation, characterization, and management of Fusarium root rot pathogens of dry beans in Michigan
Creator: Oudman, Kirsten A.
Date: 2018
Collection: Electronic Theses & Dissertations
Description: Michigan is the second-largest producer of dry beans in the United States. Among the yield-limiting diseases dry bean production faces is Fusarium root rot, which can lead to decreased nutrient and water uptake, plant stress, and even plant death. Cultural control can manage root rot, however tolerant cultivars or seed treatments may be more effective, especially if common casual agents are known. To understand which species of clade 2 of the Fusarium solani species complex (FSSC) were...
Show moreMichigan is the second-largest producer of dry beans in the United States. Among the yield-limiting diseases dry bean production faces is Fusarium root rot, which can lead to decreased nutrient and water uptake, plant stress, and even plant death. Cultural control can manage root rot, however tolerant cultivars or seed treatments may be more effective, especially if common casual agents are known. To understand which species of clade 2 of the Fusarium solani species complex (FSSC) were causing Fusarium root rot in Michigan, a survey was conducted revealing 50% of samples collected to be F. cuneirostrum, 37% F. brasiliense, and 13% as F. phaseoli. Isolates collected were moderately to highly pathogenic on two cultivars of dry beans. Isolates representative of both MAT idiomorphs were detected. An inoculated field trial was conducted to determine pathogenicity of F. brasiliense and F. virguliforme on two dry bean cultivars in the field. F. brasiliense decreased stand and dry plant mass while both pathogens increased root rot. Using two qPCR assays revealed the colonization potential of F. brasiliense in taproots to be greater than that of F. virguliforme. Two seed treatments were also examined as means of F. brasiliense management on dry beans. A seed treatment containing fluopyram reduced the quantity of F. brasiliense in the taproots of both cultivars though neither seed treatment influenced yield. Greater understanding of the Fusarium root rot pathogens present in Michigan and the efficacy of seed treatments can improve dry bean production.
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Title: Production potential of chitosan as a value added coproduct for sugar beet processing facilities
Creator: Sheridan, Patrick M. (Patrick Micheal)
Date: 2019
Collection: Electronic Theses & Dissertations
Description: "Sugar beet pulp residues (SBP) were used as a feedstock for Rhizopus oryzae fermentation to produce a value added product -- chitosan. Enzymatic conditions for effective liberation of fermentable sugars from SBP were identified. Nitrogen sources, nutritional salts, and plant hormones were investigated as a means to improve the chitosan yield. Optimum conditions identified were applied to a large-scale flask culture. Fungal glucosamine yields reached 3.6% (per gram of SBP input, glucosamine...
Show more"Sugar beet pulp residues (SBP) were used as a feedstock for Rhizopus oryzae fermentation to produce a value added product -- chitosan. Enzymatic conditions for effective liberation of fermentable sugars from SBP were identified. Nitrogen sources, nutritional salts, and plant hormones were investigated as a means to improve the chitosan yield. Optimum conditions identified were applied to a large-scale flask culture. Fungal glucosamine yields reached 3.6% (per gram of SBP input, glucosamine is the monomer unit of chitosan). The economics of a fungal fermentation system for a SBP production of 2,000 metric tons per year was analyzed based on the results achieved in 2L flask culture. Compared to the current application of SBP as animal feed, the high value of the chitosan significantly enhanced the economic performance. A payback period of slightly over 7 months was correspondingly achieved for the studied fungal chitosan production."--Page ii.
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