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Title: PROBE EFFECTS DURING CONCENTRATION DETERMINATION IN SCANNING ELECTROCHEMICAL MICROSCOPY
Creator: Mirabal, Alex
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Efficient, sustainable chemical reactions will play a large role in addressing many growing issues, including alternative energy production, greenhouse gas conversion, and pharmaceuticals. Electrochemical reactions are attractive due to their relatively mild reaction conditions and direct use of electricity. The understanding and design of the local liquid-solid interface will guide future progress in electrocatalytic reactions.Over time, nature has evolved many highly efficient reactions...
Show moreEfficient, sustainable chemical reactions will play a large role in addressing many growing issues, including alternative energy production, greenhouse gas conversion, and pharmaceuticals. Electrochemical reactions are attractive due to their relatively mild reaction conditions and direct use of electricity. The understanding and design of the local liquid-solid interface will guide future progress in electrocatalytic reactions.Over time, nature has evolved many highly efficient reactions through enzymatic reactions. These long-studied catalysts provide complex reaction environments that: 1) enhance interaction with reactants, 2) protect intermediates from side reactions, 3) increase the rates of reactions, and 4) selectively react to a specific product. The overarching lesson to be learned is that the local reaction environment plays a large role in the catalyst’s reactivity, selectivity, and efficiency. One way to characterize the local environment is through scanning electrochemical microscopy (SECM), in which a small electrochemical probe is rastered over an interface. A quantitative correlation of the probe response to concentration provides a direct measurement of the local environment. The presence of the SECM probe itself can induce changes in the local environment. Comparing the changed local environment (in situ) to what it would be without the probe present (operando), shows large differences of up to 120% under specific operating conditions. A few physical parameters such as the surface site geometry are shown to have an impact on how significant the probe effects are. Additional parameters such as the tip geometry and tip-surface separation are also to have an impact. A finite element method (FEM) simulation informed by experiments is used to examine the above-mentioned tip effects. It is found that fitting responses to other frequently used electrochemical measurements, such as approach curves and CVs, to parameterize the model appropriately describes experimental SECM results. We first apply this method to study platinum nanoparticles, where a ~50 nm resolution is the highest resolution to our knowledge for AFM-SECM. Through statistical analysis of the surface, an isolated nanoparticle SECM response is correlated with a concentration profile. It is found that the concentration profile has minimal probe effects due to the use of a conical electrode. Applying a similar approach, we also study the probe effects in pH detection during hydrogen evolution and CO2 reduction. Where we match experimental results to parameterize the system. It shown that there is a pH difference of up to ~7 pH units underneath the probe due to hindered diffusion. However, even with these large differences, the probes are still able to reflect the trends seen without the probe present. Moreover, it is shown that the physical parameters have correlated responses, indicating that hindered diffusion is controlled by the insulation radius and tip-surface separation. Finally, the importance of the analyte is discussed with regard to its interaction with the tip. In addition to the concentration impact on the response signal, the compatibility with the tip need be considered. Degradation of the tip and/or the redox couple of choice will detrimentally affect the ability to examine the local interface. We show that, of the redox couples examined, ferrocene-based compounds appear to best satisfy the most crucial factors of stability and mild redox potentials. Overall, this work studies and removes the impact of the probe for local concentration detection using SECM. This work acts as a guide to quantitatively study the local environment of electrocatalyzed reactions. This is realized through a combined experimental-FEM approach in which the simulation is informed by experiments such that it’s representative of the experimental environment.
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Title: THE ORIGINATION AND IMPLEMENTATION OF THE NATIONAL WETLANDS POLICY OF UGANDA : ENVIRONMENT, KNOWLEDGE, AND POWER FROM THE LATE NINETEENTH CENTURY TO PRESENT
Creator: Doyle-Raso, John
Date: 2022
Collection: Electronic Theses & Dissertations
Description: In the 1980s, following widespread environmental and intellectual changes associated with “swamp reclamation” that in Uganda had started in the early twentieth century, proponents of the emerging science of “wetland conservation” sought to influence the practices and thinking of people across the country. To do so, they created a national wetlands policy based on decentralized “community-based” projects. Yet, farmers’ and investors’ engagements with reclamation have continued. Meanwhile, the...
Show moreIn the 1980s, following widespread environmental and intellectual changes associated with “swamp reclamation” that in Uganda had started in the early twentieth century, proponents of the emerging science of “wetland conservation” sought to influence the practices and thinking of people across the country. To do so, they created a national wetlands policy based on decentralized “community-based” projects. Yet, farmers’ and investors’ engagements with reclamation have continued. Meanwhile, the Ugandan wetlands policy became internationally influential for its groundbreaking approach to interdisciplinary questions about governance, emphasizing economic analyses based on concepts such as “ecosystem services” and “Environmental Economic Valuation.” Ugandan wetland conservationists have had more influence abroad than domestically, as in Uganda neoliberalization and recentralization have limited the power of the community-based groups who have worked through the national policy. Using a range of sources including but not limited to archives and interviews with conservationists, this dissertation historicizes the Ugandan wetlands conservation policy. It comprises two parts addressing overlapping time periods. The first three chapters consider the origination of this policy by analyzing environmental and intellectual changes in southeastern and southwestern Uganda, leading to the creation in the late-twentieth century of environmental regulations. The latter three chapters examine how conservationists have tried implementing the policy in rural and urban places, and in relation to the national emblem of Uganda – the Grey Crowned Crane. They have focused their efforts on community-based projects outside Protected Areas promoting indigenous knowledges and practices to obtain economic benefits from wetlands that conservationists. This approach was an early manifestation of connected trends in international developmentalist networks. Furthermore, the limitations on its implementation have become pivotal in the global histories of neoliberalization, decentralization, and recentralization. Historicizing Ugandan wetland conservationism contributes to four scholarly literatures. 1) Analyzing community-based projects outside “Protected Areas” advances the historiographies of conservation and watershed management in Africa by considering the significances of neoliberalization, decentralization, and recentralization beyond extraordinary legal cases. 2) Examining intellectual changes in this history – including an emphasis on community-based projects, use of the concept of ecosystem services, and the promotion of indigenous knowledges and sciences – reveals connections between changes in environmental science and global trends in developmentalism. 3) Focusing on these changes in Uganda builds on analyses of environmental management in political power there by identifying the importance of an underexamined resource in entrenched land conflicts, and by uncovering early institutional bases of recentralization. 4) Because Ugandan wetland conservationists were global leaders in policy creation, citizen science, and more changes in scientific thinking, researching their work reveals how African scientists have navigated tensions between their local, national, and international interlocutors to become internationally influential. Studying the history of Ugandan wetland conservationism reveals how different people’s engagements with changes in environmental thinking have reshaped environments and livelihoods, as well as influenced international scientific networks.
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Title: Single-Reference Coupled-Cluster Methods for Strongly Correlated Systems
Creator: Magoulas, Ilias
Date: 2021
Collection: Electronic Theses & Dissertations
Description: The development of computationally efficient wavefunction methods that can provide an accurate description of strongly correlated systems and materials is at the heart of electronic structure theory. In general, strong many-electron correlation effects arise from the entanglement of a large number of electrons and are characterized by the unpairing of many electron pairs and their subsequent recoupling to low-spin states, as in the case of Mott metal-insulator transitions where the system...
Show moreThe development of computationally efficient wavefunction methods that can provide an accurate description of strongly correlated systems and materials is at the heart of electronic structure theory. In general, strong many-electron correlation effects arise from the entanglement of a large number of electrons and are characterized by the unpairing of many electron pairs and their subsequent recoupling to low-spin states, as in the case of Mott metal-insulator transitions where the system traverses from a weakly correlated metallic phase to a strongly correlated insulating one. Although strong correlations have an intrinsically multi-reference nature, multi-reference approaches are not applicable due to the enormous dimensionalities of the underlying model spaces. Therefore, in this dissertation, we focus on single-reference coupled-cluster (CC) approaches, which are widely recognized as the de facto standard for high-accuracy electronic structure calculations and whose size extensivity makes them suitable for the study of extended systems and materials. However, it is well established that the traditional CC methodologies that are based on truncating the cluster operator at a given many-body rank, giving rise to the CCSD, CCSDT, CCSDTQ, etc. hierarchy, fail to provide physically meaningful solutions in the presence of strong correlations. Thus, in this dissertation, we consider unconventional single-reference CC approaches capable of providing an accurate description of the entire spectrum of many-electron correlation effects, ranging from the weakly to the strongly correlated regimes.In the first part of this dissertation, we examine the approximate coupled-pair (ACP) theories. The existing ACP methods and their various modifications retain all doubly excited cluster amplitudes, while using subsets of non-linear diagrams of the CCD/CCSD equations. This eliminates failures of conventional CC approaches, including CCSD and even CCSDT or CCSDTQ, in strongly correlated situations created by the Mott metal-insulator transitions, modeled by linear chains, rings, or cubic lattices of the equally spaced hydrogen atoms, and the π-electron networks described by the Hubbard and Pariser-Parr-Pople Hamiltonians that model one-dimensional metallic systems with periodic boundary conditions. However, typical ACP methods neglect connected triply excited T3 clusters, which are required to produce quantitative results in most chemical applications. Previous attempts to incorporate these clusters using many-body perturbation theory arguments within the ACP framework have only been partly successful. In this dissertation, we address this concern by employing the active-space ideas to incorporate the dominant T3 amplitudes in the ACP methods in a robust, yet computationally affordable, manner. Furthermore, taking into consideration that the various diagram modifications defining ACP approaches were derived using minimum-basis-set models, we introduce a novel ACP scheme utilizing basis-set-dependent scaling factors, denoted as ACCSD(1,3 × no/(no + nu) + 4 × nu/(no + nu)), to extend the ACP methodologies to larger basis sets.In the second part of this dissertation, we discuss a novel approach to extrapolating the exact energetics out of the early stages of full configuration interaction quantum Monte Carlo (FCIQMC) propagations, even in the presence of strong correlations, by merging the ACP approaches with the recently proposed cluster-analysis-driven FCIQMC (CAD-FCIQMC) methodology. In the spirit of externally corrected CC approaches, in the CAD-FCIQMC methodology, one solves CCSD-like equations for the one- and two-body clusters in the presence of their three- and four-body counterparts extracted from the FCIQMC stochastic wavefunction sampling. In this dissertation, we extend CAD-FCIQMC to the strong correlation regime by repartitioning the CC equations so that selected coupled-pair contributions are extracted from FCIQMC as well. For each new methodology described in this thesis, we discuss the relevant mathematical and computer implementation details and provide numerical examples illustrating its performance in challenging strongly correlated situations.
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Title: EFFECTS OF TEACHING ACCEPTANCE AND COMMITMENT THERAPY-BASED STRATEGIES ON IMPROVING ACADEMIC ENGAGEMENT AND PARTICIPATION FOR STUDENTS IN AN APPLIED BEHAVIOR ANALYSIS MASTER’S PROGRAM
Creator: Dunnigan, Mikeya Renee
Date: 2021
Collection: Electronic Theses & Dissertations
Description: The field of applied behavior analysis (ABA) comes with rigorous work expectations and demands. ABA practitioners who are also graduate students must balance the extensive workload of educational and work expectations. Given these demands, graduate students providing ABA services to clients with autism spectrum disorder (ASD) need strategies to maintain their own positive mental health in order to maintain high academic achievement and to prevent burnout. Using a multiple baseline design this...
Show moreThe field of applied behavior analysis (ABA) comes with rigorous work expectations and demands. ABA practitioners who are also graduate students must balance the extensive workload of educational and work expectations. Given these demands, graduate students providing ABA services to clients with autism spectrum disorder (ASD) need strategies to maintain their own positive mental health in order to maintain high academic achievement and to prevent burnout. Using a multiple baseline design this study examined whether teaching 6 graduate students enrolled in an ABA master's program who were also working as part-time practitioners providing ABA services to individuals with ASD to use Acceptance and Commitment Therapy (ACT)-based strategies impacted their engagement and active participation during an online synchronous class. Changes in psychological flexibility, stress, and values-behavior were also examined. Although there was no functional relation between the training on using ACT-based strategies and the dependent variables, the lack of effects is likely because the participants enrolled in the study did not have baseline levels that indicated a need for intervention. Additionally, it is hypothesized that competing factors and stressors related to the COVID-19 pandemic likely outweighed the impact of the training to use the ACT-based strategies. The results are discussed more in as well as implications for future research. Keywords: graduate students, behavior technician, Acceptance and Commitment Therapy, psychological flexibility, stress, value driven behavior.
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Title: CROSS-RACE FRIENDSHIPS AND ADJUSTMENT : LONGITUDINAL STUDIES OF ASIAN AMERICAN ADOLESCENTS
Creator: Liu, Shizhu
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Asian American adolescents’ cross-race friendships are poorly understood. Using data from the National Longitudinal Study for Adolescent to Adult Health, two longitudinal studies (Ns = 915 and 1,154) investigated the associations between cross-race friendships and psychosocial and academic adjustment among Asian American adolescents. Study 1 examined the influence of cross-race friendships (derived from quantity and quality measures) on trajectories of perception of peer prejudice at school....
Show moreAsian American adolescents’ cross-race friendships are poorly understood. Using data from the National Longitudinal Study for Adolescent to Adult Health, two longitudinal studies (Ns = 915 and 1,154) investigated the associations between cross-race friendships and psychosocial and academic adjustment among Asian American adolescents. Study 1 examined the influence of cross-race friendships (derived from quantity and quality measures) on trajectories of perception of peer prejudice at school. Results showed that cross-race friendships were associated with weaker perception of peer prejudice. Cross-race friendships measured as quantity had an immediate but short effect, while cross-race friendships measured as quality exerted a delayed but long-term influence over how Asian American adolescents perceive peer prejudice at school. Similar findings were observed for friendships with other non-White groups (but not with the White group and not for cross-ethnic friendships). Study 2 explored the directionality in associations between cross-race best friendships (i.e., the proportion of cross-race friends in one’s best female and male friend network) and psychological well-being and academic adjustment (school attachment and GPA). Results identified an overall linear decline in cross-race best friendships with age among Asian American adolescents. Cross-race best friendships positively influenced later self-esteem, but not the other way around. Higher levels of school attachment predicted greater decrease in cross-race best friendships, and declines in cross-race best friendships were accompanied by decreases in GPA for Asian American adolescents.
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Title: THE BANDIAGARA EMIRATE : WARFARE, SLAVERY AND COLONIZATION IN THE MIDDLE NIGER, 1863 – 1903
Creator: Bradshaw, Joseph M.
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Between 1863 and 1903, the Middle Niger, a region under the arch of the Niger River in present day Mali and Burkina Faso, was colonized by two armies. The first army was a Futanke-led army commanded by the Sufi reformer al-Hajj Umar Tal and later led by his nephew, Tijani Tal. The Futanke-led army invaded the region after their war against the Bamana Kingdom of Segu, drew the Umarian Empire into a conflict with the Caliphate of Hamdullahi. The Futanke and the Masinanke of Hamdullahi shared a...
Show moreBetween 1863 and 1903, the Middle Niger, a region under the arch of the Niger River in present day Mali and Burkina Faso, was colonized by two armies. The first army was a Futanke-led army commanded by the Sufi reformer al-Hajj Umar Tal and later led by his nephew, Tijani Tal. The Futanke-led army invaded the region after their war against the Bamana Kingdom of Segu, drew the Umarian Empire into a conflict with the Caliphate of Hamdullahi. The Futanke and the Masinanke of Hamdullahi shared a common faith, language and culture, and both had fought wars under the umbrella of ‘jihad’ against non-Muslims and Muslims whose practice they considered unorthodox. But despite the rhetoric of Futanke and Masinanke leaders, the instability of wars from 1861-90 necessitated the building of alliances that diminished the instrumental value of racial and religious exclusion. In 1893 a new French-led military regime established itself in the Middle Niger. The French, in turn, used warfare and enslavement as tools of empire, creating a military territory called the “French Sudan.” The French regime initially worked through Futanke proxies but soon demonstrated a clear preference for local chiefs and racial politics. As the French army conquered territory non-Futanke were placed directly under the administration of nearby posts. While my approach is drawn from instrumentalist theories of ethnicity, this study takes a broad view of social differentiation. Rather than centering my discussion around constructions of race, class or ethnicity, I examine how diverse categories of difference were tools of both African and European elites. I argue that military elites selectively emphasized and ignored longstanding practices of social differentiation to achieve their political and economic goals in the region. I further argue that political realism governed the strategies Futanke and French elites pursued as they conquered and ruled the diverse inhabitants of the Middle Niger in the latter half of the nineteenth century. I propose that historians of warfare in Africa should consider how elites ignored categories difference to form effective alliances, even though they may have emphasized the differences of their enemies.
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Title: DATA-INFUSED FRACTIONAL MODELING AND SPECTRAL NUMERICAL ANALYSIS FOR ANOMALOUS TRANSPORT AND TURBULENCE
Creator: Samiee, Mehdi
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Fractional calculus introduces tractable mathematical tools for accurate description of anomalous phenomena, regarded as a manifestation of self-similar structures and memory effects. Fractional approaches in modeling anomalous dynamics have been increasingly employed over the last decade in a disparate range of applications, where the standard methods have been found experimentally to be inadequate. The physical significance of employing fractional operators in such models is indicated by...
Show moreFractional calculus introduces tractable mathematical tools for accurate description of anomalous phenomena, regarded as a manifestation of self-similar structures and memory effects. Fractional approaches in modeling anomalous dynamics have been increasingly employed over the last decade in a disparate range of applications, where the standard methods have been found experimentally to be inadequate. The physical significance of employing fractional operators in such models is indicated by their potentials in describing the inherent abnormal-exponential or heavy-tailed processes due to their power-law or logarithmic kernels of convolution type. However, it is also inevitably challenging to provide efficient and yet accurate numerical methods for fractional differential equations. More concretely, history-dependent and nonlocal characteristics of fractional operators impose further numerical complexities, ranging from theoretical analysis to large memory requirement. Therefore, to establish a robust framework for developing fractional models, a great deal of attention is required in theoretical and numerical studies of fractional calculus. In particular, developing a fractional model depends on some key elements, given as: stochastic interpretation, theoretical analysis, numerical methods, and optimization of model parameters. In this dissertation, we provide a robust framework for fractional modeling of anomalous features in the applied areas of research such as solute transport in underground waters and homogeneous isotropic turbulent flows. Inspired by the stochastic interpretation of fractional diffusion problems in terms of time-changed Markov processes, we develop a unified Petrov-Galerkin (PG) spectral method for a class of fractional partial differential equations (FPDEs) with two-sided derivatives and constant coefficients. We employ the eigenfunctions of the fractional Sturm-Liouville eigen-problems, called Jacobi poly-fractonomials, as temporal bases and test functions. Furthermore, we formulate a novel unified fast linear solver for the resulting high-dimensional linear system based on the solution of generalized eigenproblem of spatial mass matrices with respect to the corresponding stiffness matrices. On the theoretical side, we prove existence and uniqueness of the solution to the corresponding bilinear form of the problem and subsequently, provide the corresponding stability and error analyses. Moreover, we compare the theoretical and computational rates of spectral convergence by performing several numerical simulations. Motivated by the multifractal characteristics of anomalous phenomena, we extend the unified PG method to the generalized form of FPDEs with distributed-order two-sided derivatives and carry out the corresponding stability and error analyses. In the large-eddy simulation of homogeneous turbulence, presence of nonlocal triad interactions and intermittent structures urges developing new nonlocal closure models. Such anomalous effects become even more pronounced when the filter-width enlarges. Within the proposed framework, we start modeling of turbulent effects at the Boltzmann transport using fractional calculus. In practice, we approximate the filtered collision operator with a power-law function which contributes to the corresponding fractional subgrid-scale (SGS) model in the filtered NS equations through a meticulous derivation. Inspired by the self-similar cascading of energy from large to small scales and the exponential decay in the dissipation range, we adopt tempered \textit{L\'evy}-stable distribution as a statistically-consistent choice at the kinetic level and subsequently, we derive the corresponding operator in terms of the tempered fractional Laplacian, $(\Delta+\lambda)^{\alpha}(\cdot)$, $\alpha \in (0,1]$, $\alpha \neq \frac{1}{2}$, and $\lambda>0$ in the filtered NS equations, termed as tempered fractional SGS (TFSGS) model. The model parameters appear to be strictly depending on the filter-width and the flow Reynolds number. Such a tractable fractional operator offers a great flexibility in characterizing nonlocal structures in the turbulent inertial and dissipation ranges through fractional and tempering parameters. To infer optimum values of the model parameters, we develop a robust optimization algorithm, involving two-point structure functions and conventional correlation coefficients. In \textit{a priori} / \textit{a posteriori} statistical analyses, we evaluate capabilities of the TFSGS model in fulfilling the closed essential requirements and also study the numerical stability of LES solutions in time.
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Title: AGGREGATE PLANNING IN MANUFACTURING OF REUSABLE CONTAINERS
Creator: Tao, Jinli
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Aggregate production planning (APP) is a method to make several decisions simultaneously on production, inventory, and workforce levels over a finite time horizon, aiming to maximize the profit or minimize the cost while meeting fluctuating demands. Building mathematical models that reflect real-world problems is often difficult, as the constraints are usually intricate and may interact with each other. Decomposing the interconnected system into a number of independent phases could simplify...
Show moreAggregate production planning (APP) is a method to make several decisions simultaneously on production, inventory, and workforce levels over a finite time horizon, aiming to maximize the profit or minimize the cost while meeting fluctuating demands. Building mathematical models that reflect real-world problems is often difficult, as the constraints are usually intricate and may interact with each other. Decomposing the interconnected system into a number of independent phases could simplify the problem; however, it may not guarantee the optimality of the best solutions due to the missed constraints between stages. In this study, two mixed integer programming models for the manufacturing of reusable plastic containers are presented. One is based on the flow of the material and the other is based on the level of the workforce at each period. The proposed models are able to (i) deal with varying demand, (ii) reflect various regulations and restrictions of public and private warehouses for storing materials, and (iii) identify the importance of subcontracting when demand increases dramatically. Both mathematical models are implemented in the case of packaging manufacturing. A comprehensive sensitivity analysis has been conducted on different parameters of the problem to test the effect of parameter changes. To sum up, the general framework of the mathematical models not only can be used for reusable container manufacturing but also the manufacturing of any type of product with a similar supply chain network.
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Title: MIDWEST FARMERS’ DECISION-MAKING IN CONSERVATION AGRICULTURE ADOPTION
Creator: Tian, Qi
Date: 2021
Collection: Electronic Theses & Dissertations
Description: ABSTRACTMIDWEST FARMERS’ DECISION-MAKING IN CONSERVATION AGRICULTURE ADOPTIONByQi TianConservation Agriculture (CA) adoption can alleviate the environmental consequences of conventional agricultural production while maintaining yields. A better understanding of farmers’ decision-making in CA adoption is needed to inform policy design that encourages adoption. In the absence of the CA adoption market, experimental methods provide an essential alternative to investigate decision-makers’...
Show moreABSTRACTMIDWEST FARMERS’ DECISION-MAKING IN CONSERVATION AGRICULTURE ADOPTIONByQi TianConservation Agriculture (CA) adoption can alleviate the environmental consequences of conventional agricultural production while maintaining yields. A better understanding of farmers’ decision-making in CA adoption is needed to inform policy design that encourages adoption. In the absence of the CA adoption market, experimental methods provide an essential alternative to investigate decision-makers’ preference. Therefore, this dissertation leverages a Discrete Choice Experiment (DCE) to analyze farmers’ decision-making to shed light on policy design as well as to inform methodological issues associated with DCE approach.The first chapter evaluates farmers’ Willingness-to-Accept (WTA) CA practices and assesses the factors affecting the WTA. In addition to the payment to compensate the expenses or efforts of taking a CA practice, a substantial payment is needed to incentivize farmers leaving the status quo and committing to a CA program. Internal factors, such as farmers’ characteristics and experience with CA practices, as well as external factors, i.e., policy design in terms of information framing and the decision time window, both have impacts on the WTA. These findings provide a practical guide for cost-efficient policy design.The traditional DCE approach for stated preference evaluation builds on an essential assumption that decision-making is reference independent, i.e., independent of irrelevant alternatives. The second chapter develops a new framework to relax and test this assumption by incorporating behavioral realism into modeling. I found that decision-makers use behavioral strategies, i.e., reference dependence, in decision making, and that different sources of information are evaluated differently as reference points. These findings, on the one hand, set caveats for modeling DCE data based on independence of irrelevance assumption, and on the other hand, indicate a more cost-efficient policy design tool that nudges desired behaviors through shaping the reference point.Three decision-making strategies could describe the decision making in a DCE: reference independence, reference dependence, and attributes non-attendance. This last chapter explicitly discusses which strategy is adopted and how such strategies evolve in repeated choice tasks. I found that decision-makers use behavioral strategies to make decisions. As decision-makers collect information over the repeated choice scenarios, they are shifting from the current choice set to the path as the reference point. Failing to account for the reference dependence behavior in choice modeling could misidentify the attended attributes as non-attended. This finding suggests that the reference dependence model can be a guiding choice for DCE modeling. Again, this chapter implies that discrete choice modeling without accounting for behavioral realism will fail to reveal the true preference.
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Title: HOW DO MANAGEMENT DECISIONS IMPACT THE SUSTAINABILITY OF UPPER MIDWEST BEEF CATTLE GRAZING?
Creator: Thompson, Logan Riley
Date: 2021
Collection: Electronic Theses & Dissertations
Description: The conversion of grass to beef is less efficient than the process of converting feed to human-edible protein in nonruminants, although ruminal fermentation does allow for the utilization of complex carbohydrates. This has resulted in the cattle industry receiving increased attention due to its perceived high carbon (C) footprint. While ruminants have evolved to fill the niche of converting human inedible carbohydrates into usable end-products for growth, this process results in considerable...
Show moreThe conversion of grass to beef is less efficient than the process of converting feed to human-edible protein in nonruminants, although ruminal fermentation does allow for the utilization of complex carbohydrates. This has resulted in the cattle industry receiving increased attention due to its perceived high carbon (C) footprint. While ruminants have evolved to fill the niche of converting human inedible carbohydrates into usable end-products for growth, this process results in considerable greenhouse gas (GHG) emissions as byproducts of the reticulo-rumen fermentation process. Life Cycle Assessments have shown that the grazing sector of the cattle industry, cow-calf and stocker cattle, may be responsible for 70 to 80% of the industry’s total C footprint. Therefore, research is needed to explore the soil-plant-animal interrelationships and generate data to provide management recommendations to producers to improve the C footprint of their operation. As it relates to agriculture, sustainability has three legs that must be met addressed to improve its sustainability: 1) social- the strategy must maintain social license to operate, 2) environmental- the strategy must reduce negative environmental consequences, and 3) economic- producers must remain economically viable. This dissertation examines how management decisions impact grazing beef cattle through two of the three legs of sustainability: environmental and economic sustainability. The literature review focuses on the role on enteric methane on the C footprint of the beef industry, as this topic “keeps the lights on” in many laboratories due to increased consumer concern about the industry’s C footprint. However, key nutritional abatement strategies that goes beyond enteric methane are management decisions that improve the efficiency of ruminal fermentation. Matching cows to the production environment is a critical management decision, as selecting cows too small or too large would result in an inefficient utilization of the forage base. This idea is explored chapter 2, modeling the biological and economic output of a Michigan beef herd. We conducted a backwards looking enterprise budget analysis and forward-looking net present value analysis on the Lake City AgBioResearch Center Red Angus herd to determine what size cow best fits the present production environment. We found that as cow size increased, within the range of cow body weights of 430.83 to 634.92 kg, calculated net returns per unit of land decreased by $10.27/ha. The last two chapters compare environmental tradeoffs between two different forage mixtures grazed by beef cattle: a biologically diverse, mixed-specie pasture (COMP), and a simple binary mixture of alfalfa:orchardgrass (SIMP). The hypothesis was that the COMP mixture would have reduced enteric methane production, increased forage productivity due to the diversity of the mixture, and greater soil C accumulation. Both treatments performed similarly in animal performance, soil GHG fluxes, and soil organic C and total N stocks. Animals grazing COMP mixtures tended to have lower enteric CH4 emissions compared to SIMP, but there was no difference in emission intensity across three grazing seasons. This project serves to supplement the dearth of literature comparing a simple and diverse forage mixture. More research on the long-term performance of the diverse and simple forage mixtures and the utilization of new technologies such as eddy covariance flux towers will help provide a more robust examination on the environmental tradeoffs between forage mixtures than the methodologies utilized in this experiment.
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Title: CHEMOENZYMATIC SYNTHESIS OF HEPARAN SULFATE PROTEOGLYCAN AND MIMETICS
Creator: Gao, Jia
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Proteoglycans (PGs) are an important class of glycoproteins widely distributed in mammals. They are involved in numerous biological events, including tumor progression, inflammation, and cellular communication. Generally, a PG is composed of a core protein and one or more glycosaminoglycan (GAG) polysaccharide chains. The GAG chain is covalently attached to the core protein via a serine residue in the consensus sequence -Ser-Gly-X-Gly- (X being any natural amino acid residue but proline) by a...
Show moreProteoglycans (PGs) are an important class of glycoproteins widely distributed in mammals. They are involved in numerous biological events, including tumor progression, inflammation, and cellular communication. Generally, a PG is composed of a core protein and one or more glycosaminoglycan (GAG) polysaccharide chains. The GAG chain is covalently attached to the core protein via a serine residue in the consensus sequence -Ser-Gly-X-Gly- (X being any natural amino acid residue but proline) by a common tetrasaccharide linkage. Heparan sulfate proteoglycans (HSPGs), along with chondroitin sulfate proteoglycans (CSPGs) and keratan sulfate proteoglycans (KSPGs), are main subtypes of the PG family. Naturally existing HSPGs, due to complex post-translational modifications (PTMs) on the GAG chains, are highly heterogeneous. That makes direct isolation of homogeneous HSPGs from natural sources almost impossible. To date, preparing structurally defined HSPGs solely relies on formidable and tedious chemical synthesis.In this dissertation, two novel approaches have been investigated to expedite the synthesis of HSPGs. The convergent chemoenzymatic approach takes advantage of efficient enzymatic synthesis of heparan sulfate (HS) oligosaccharides and well-developed solid phase supported peptide synthesis (SPPS). By substituting the non-functional tetrasaccharide linkage, the GAG chain and peptide were conjugated through a flexible artificial linker to make a syndecan-1 mimetic, which mimics the natural structures of syndecan-1, an important member of HSPG family. The mimetic binds strongly to integrin αvβ3, a key cell-surface protein that plays an active role in tumor proliferation process. Furthermore, the mimetic compound is able to inhibit the migration of breast cancer cells MDA-MB-231. In the native form of PGs, the core protein and GAG chains are connected through a common tetrasaccharide linkage consisted of GlcA-β(1→3)-Gal-β(1→3)-Gal-β(1→4)-Xyl-β(1→O)-Ser to efficiently prepare native heparan sulfate glycopeptides and glycoproteins, enzymes involved in the PG linkage biosynthesis were investigated and developed as synthetic tools. Human β-1,4- galactosyltransferase 7 (β4GalT7) was used to catalyze the transfer of galactose units and synthesize galactose-xylose (Gal-Xyl) bearing PG glycopeptides. Human xylosyltransferase I (XT-I), the enzyme that initiates PG biosynthesis in nature, was then studied and applied towards the synthesis of PG linkage region.
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Title: THE IMPLICATIONS THAT CHANGE IN MANUFACTURING WILL HAVE ON EMPLOYMENT OF MICHIGAN WORKERS
Creator: Jackson, Gina Marcella
Date: 2021
Collection: Electronic Theses & Dissertations
Description: ABSTRACTMichigan is closely tied to its economic success as a manufacturing center and a hub for the global automotive industry. Over the years, automation and relocation has reduced the role of manufacturing as a source of employment and led to the decline of manufacturing communities in Michigan. The challenges of declining manufacturing communities and concern for access to employment by displaced workers and underrepresented groups prompts this analysis of career paths and education for...
Show moreABSTRACTMichigan is closely tied to its economic success as a manufacturing center and a hub for the global automotive industry. Over the years, automation and relocation has reduced the role of manufacturing as a source of employment and led to the decline of manufacturing communities in Michigan. The challenges of declining manufacturing communities and concern for access to employment by displaced workers and underrepresented groups prompts this analysis of career paths and education for advanced manufacturing. Research examined the potential for training and upskilling at community colleges, and the development of a labor pool equipped to serve in emerging and future manufacturing jobs in the United States and the State of Michigan.To understand the career paths available and the experience of students, three analyses were conducted of students, instructors, and employers. The student survey of 190 students across five community colleges in southeast, central, and west Michigan was conducted in the summer and fall of 2020. The study found community colleges are providing Michigan workers with the technical skills needed for advanced manufacturing jobs but more work needs to be done. There is a divide between what the businesses wish community colleges were teaching and the rate it is being taught and what the budget constraints of the community colleges allow them to teach and how fast. Policy recommendations to close the divide is to formulate government policies that assist students in paying for their education to allow more to attend a community college and provide financial support for schools to invest in the latest equipment and technologies for training that employers demand. The technician study can be utilized as Michigan sets policies to get more students to meet its Sixty by 2030 goal where 60 percent of adult workers obtain a certificate or degree by 2030.
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Title: EFFECT OF ALUMINUM OXIDE ON THE FUNCTIONAL PROPERTIES OF CHITOSAN FILMS
Creator: Konda, Akhil Sai
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Chitosan is the one of the most abundant naturally occurring polymer in the world and has applications in a lot of different fields, including flexible packaging films. Aluminum oxide in the form of nanoparticle have good mechanical strength, barrier, thermal and antimicrobial properties which, when added to a polymer, can improve its properties significantly and increase its applications considerably. This research attempts to develop a biodegradable film with chitosan added with aluminum...
Show moreChitosan is the one of the most abundant naturally occurring polymer in the world and has applications in a lot of different fields, including flexible packaging films. Aluminum oxide in the form of nanoparticle have good mechanical strength, barrier, thermal and antimicrobial properties which, when added to a polymer, can improve its properties significantly and increase its applications considerably. This research attempts to develop a biodegradable film with chitosan added with aluminum oxide and study its effect on the functional properties of the chitosan film. The functional properties taken into consideration were tensile strength, % elongation at break, water vapor permeability (WVP), oxygen permeability (OP), antimicrobial and thermal properties. There can be potential novel applications in packaging if these composite films have improved requisite properties. The oxygen permeability of the films was not affected after adding aluminum oxide and decreased only by 6% after adding 2% Al2O3. On other hand, the water vapor permeability values increased significantly (p<0.05) by around 30% after adding 2% Al2O3, which is not desired. The tensile strength decreased from 40 MPa to 36 MPa and the % elongation at break reduced significantly (p<0.05) from 98% to 83%. There was no change observed in the thermal properties of the films, and there was no inhibition zone seen when tested for its antimicrobial properties after the addition of aluminum oxide. These results suggest that the properties of this composite material formed using chitosan with aluminum oxide were not affected in some aspects such as tensile strength and oxygen barrier property; and additional work is required to conclude the hypothesis of generating a composite chitosan film with aluminum oxide as nanoparticles for improved properties.
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Title: THE VALUE OF HABITAT DATA FOR CONSERVING STREAMS WITH CHANGING CLIMATE : PROMOTING GREATER USE FOR MORE EFFECTIVE MANAGEMENT
Creator: Betances, Samantha J.
Date: 2021
Collection: Electronic Theses & Dissertations
Description: North America’s rivers and streams support a diversity of fish species that provide significant ecological, socioeconomic, cultural, and spiritual benefits, and the quality and quantity of habitat in streams directly supports fish diversity. Because rivers are products of the landscapes they drain, features of the landscape like land use, geology, and climate control habitat. Based on these relationships, it stands that anticipated changes in climate will lead to changes in stream fishes...
Show moreNorth America’s rivers and streams support a diversity of fish species that provide significant ecological, socioeconomic, cultural, and spiritual benefits, and the quality and quantity of habitat in streams directly supports fish diversity. Because rivers are products of the landscapes they drain, features of the landscape like land use, geology, and climate control habitat. Based on these relationships, it stands that anticipated changes in climate will lead to changes in stream fishes through changes in habitat. While natural resource management agencies collect habitat data to help conserve streams into the future, stream habitat data are not always used as intended, in part because some managers may have an incomplete understanding of interactions between rivers and the landscapes they drain. To fully address the impacts of climate change on stream fishes, managers must better understand how climate affects stream habitat and incorporate these concepts into management decision-making processes. This thesis addresses that need. In Chapter 1, we identify ways to increase use of stream habitat data by natural resource management agencies to better conserve fishes from current and future stressors. In Chapter 2, we investigate influences of multiple landscape factors on physical stream habitat, including climate factors. Collectively, outcomes of this research offer managers information and strategies for using stream habitat data to conserve stream habitats and the fishes they support with changing climate.
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Title: "I Filled a Lot of Gaps" : How and Why Early Career Teachers Expand Induction Support Systems with Social Media
Creator: Staudt Willet, Kenneth Bret
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Early career teachers face numerous challenges during their transition from teacher preparation programs into professional employment contexts. With many more opportunities for professional learning available today, early career teachers must navigate an increased number of potentially conflicting messages about what and how to teach. This study explores the support systems that early career teachers construct during induction and how they use social media for this purpose. These systems can...
Show moreEarly career teachers face numerous challenges during their transition from teacher preparation programs into professional employment contexts. With many more opportunities for professional learning available today, early career teachers must navigate an increased number of potentially conflicting messages about what and how to teach. This study explores the support systems that early career teachers construct during induction and how they use social media for this purpose. These systems can be understood as professional learning networks (PLNs) consisting of tools, people, and spaces and useful for improving teaching and learning. Interviews with early career teachers provide evidence of reasons why they develop PLNs as well as what tools, people, and spaces they include in these support systems. Findings demonstrate that early career teachers construct induction support systems to navigate change, scarcity of resources, and conflicting teaching beliefs. Early career teachers look for tools for planning, enacting practice in the classroom, and connecting socially. People in early career teachers’ support systems included both in-school and out-of-school connections. Interviewees described how they use various social media platforms in their induction support systems as well as boundaries they maintain around social media use. Finally, early career teachers described their engagement on social media in terms of browsing, asking, and exchanging. Implications of these findings are discussed for early career teachers, teacher educators, and education leaders—especially regarding how stakeholders can help alleviate induction pressures on early career teachers. This study contributes insight into the convergence of tensions experienced by early career teachers as they consider whether and how to construct support systems during induction, including if and how to look for help on social media.
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Title: PRECISION DIAGNOSTICS AND INNOVATIONS FOR PLANT BREEDING RESEARCH
Creator: Hugghis, Eli
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Major technological advances are necessary to reach the goal of feeding our world’s growing population. To do this, there is an increasing demand within the agricultural field for rapid diagnostic tools to improve the efficiency of current methods in plant disease and DNA identification. The use of gold nanoparticles has emerged as a promising technology for a range of applications from smart agrochemical delivery systems to pathogen detection. In addition to this, advances in image...
Show moreMajor technological advances are necessary to reach the goal of feeding our world’s growing population. To do this, there is an increasing demand within the agricultural field for rapid diagnostic tools to improve the efficiency of current methods in plant disease and DNA identification. The use of gold nanoparticles has emerged as a promising technology for a range of applications from smart agrochemical delivery systems to pathogen detection. In addition to this, advances in image classification analyses have allowed machine learning approaches to become more accessible to the agricultural field. Here we present the use of gold nanoparticles (AuNPs) for the detection of transgenic gene sequences in maize and the use of machine learning algorithms for the identification and classification of Fusarium spp. infected wheat seed. AuNPs show promise in their ability to diagnose the presence of transgenic insertions in DNA samples within 10 minutes through colorimetric response. Image-based analysis with the utilization of logistic regression, support vector machines, and k-nearest neighbors were able to accurately identify and differentiate healthy and diseased wheat kernels within the testing set at an accuracy of 95-98.8%. These technologies act as rapid tools to be used by plant breeders and pathologists to improve their ability to make selection decisions efficiently and objectively.
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Title: Method development for capillary electrophoresis mass spectrometry (CE-MS)-based proteomics and application to uncovering proteome dynamics of zebrafish embryos during early embryogenesis
Creator: Chen, Daoyang
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Reversed-phase liquid chromatography (RPLC) coupling with tandem MS (MS/MS) is often the method of choice in both peptide-centric bottom-up proteomics (BUP) and proteoform-centric top-down proteomics (TDP) studies. In recent years, capillary zone electrophoresis (CZE)-MS has attracted attention as another platform in proteomics due to high separation efficiency, high sensitivity, and complementarity to LC-MS. This work is dedicated to developing novel CE-MS-based methods for large-scale...
Show moreReversed-phase liquid chromatography (RPLC) coupling with tandem MS (MS/MS) is often the method of choice in both peptide-centric bottom-up proteomics (BUP) and proteoform-centric top-down proteomics (TDP) studies. In recent years, capillary zone electrophoresis (CZE)-MS has attracted attention as another platform in proteomics due to high separation efficiency, high sensitivity, and complementarity to LC-MS. This work is dedicated to developing novel CE-MS-based methods for large-scale proteomics and applies them to study the proteome dynamics of zebrafish embryos during early embryogenesis.In Chapter 2, a sample stacking method, dynamic pH junction, was systematically investigated and employed to improve CZE’s sample loading capacity for large-scale BUP. The results of the optimized system represent the highest loading capacity, the highest peak capacity, and the widest separation window of CZE for peptide separation to date. The automated CZE-MS system opened the door to using CZE-MS for large-scale BUP. In Chapter 3, for the first time, a strong cation exchange (SCX)-RPLC-CZE-MS/MS platform was established for deep BUP and phosphoproteomics. The platform approached comparable performance to the modern 2D-LC-MS/MS for deep proteomic sequencing evident by identifying 8200 protein groups and 65,000 unique peptides from a mouse brain proteome digest, 11,555 phosphopeptides from the HCT116 cell line. SCX-RPLC-CZE-MS/MS and 2D-LC-MS/MS showed good complementarity in protein, peptide, and phosphopeptide IDs. In Chapter 4, a quantitative BUP study was performed on zebrafish embryos across four developmental stages during the maternal-to-zygotic transition (MZT) via coupling isobaric tag for relative and absolute quantitation (iTRAQ) chemistry with both RPLC-MS/MS and CZE-MS/MS. Expression kinetics of nearly 5000 proteins including over 100 transcription factors (TFs) across four early embryonic stages were determined. The protein expression profiles fall into several different clusters and accurately reflect the important events during early embryogenesis. Further studies of the expression profiles of TFs revealed that the differentially expressed TFs during the MZT show wave-like expression patterns. Top-down proteomics (TDP) aims to directly characterize proteoforms in cells. CZE-MS/MS has been demonstrated as a useful tool for TDP. In Chapter 5, for the first time, we evaluated various semiempirical models for predicting proteoforms’ electrophoretic mobility using large-scale TDP data sets from earlier CZE–MS/MS studies. Linear correlations were achieved between the experimental and predicted μef of E. coli proteoforms and histone proteoforms (R2 = 0.98), demonstrating that the μef of proteoforms in CZE-MS can be predicted accurately, which could be useful for validating the confidence of proteoform IDs from a database search. In Chapter 6, we concluded the results of this dissertation and provided our expectations for future studies.
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Title: Using Eventual Consistency to Improve the Performance of Distributed Graph Computation In Key-Value Stores
Creator: Nguyen, Duong Ngoc
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Key-value stores have gained increasing popularity due to their fast performance and simple data model. A key-value store usually consists of multiple replicas located in different geographical regions to provide higher availability and fault tolerance. Consequently, a protocol is employed to ensure that data are consistent across the replicas.The CAP theorem states the impossibility of simultaneously achieving three desirable properties in a distributed system, namely consistency,...
Show moreKey-value stores have gained increasing popularity due to their fast performance and simple data model. A key-value store usually consists of multiple replicas located in different geographical regions to provide higher availability and fault tolerance. Consequently, a protocol is employed to ensure that data are consistent across the replicas.The CAP theorem states the impossibility of simultaneously achieving three desirable properties in a distributed system, namely consistency, availability, and network partition tolerance. Since failures are a norm in distributed systems and the capability to maintain the service at an acceptable level in the presence of failures is a critical dependability and business requirement of any system, the partition tolerance property is a necessity. Consequently, the trade-off between consistency and availability (performance) is inevitable. Strong consistency is attained at the cost of slow performance and fast performance is attained at the cost of weak consistency, resulting in a spectrum of consistency models suitable for different needs. Among the consistency models, sequential consistency and eventual consistency are two common ones. The former is easier to program with but suffers from poor performance whereas the latter suffers from potential data anomalies while providing higher performance.In this dissertation, we focus on the problem of what a designer should do if he/she is asked to solve a problem on a key-value store that provides eventual consistency. Specifically, we are interested in the approaches that allow the designer to run his/her applications on an eventually consistent key-value store and handle data anomalies if they occur during the computation. To that end, we investigate two options: (1) Using detect-rollback approach, and (2) Using stabilization approach. In the first option, the designer identifies a correctness predicate, say $\Phi$, and continues to run the application as if it was running on sequential consistency, as our system monitors $\Phi$. If $\Phi$ is violated (because the underlying key-value store provides eventual consistency), the system rolls back to a state where $\Phi$ holds and the computation is resumed from there. In the second option, the data anomalies are treated as state perturbations and handled by the convergence property of stabilizing algorithms.We choose LinkedIn's Voldemort key-value store as the example key-value store for our study. We run experiments with several graph-based applications on Amazon AWS platform to evaluate the benefits of the two approaches. From the experiment results, we observe that overall, both approaches provide benefits to the applications when compared to running the applications on sequential consistency. However, stabilization provides higher benefits, especially in the aggressive stabilization mode which trades more perturbations for no locking overhead.The results suggest that while there is some cost associated with making an algorithm stabilizing, there may be a substantial benefit in revising an existing algorithm for the problem at hand to make it stabilizing and reduce the overall runtime under eventual consistency.There are several directions of extension. For the detect-rollback approach, we are working to develop a more general rollback mechanism for the applications and improve the efficiency and accuracy of the monitors. For the stabilization approach, we are working to develop an analytical model for the benefits of eventual consistency in stabilizing programs. Our current work focuses on silent stabilization and we plan to extend our approach to other variations of stabilization.
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Title: TEACHING STAFF TO IMPLEMENT MAND TRAINING WITH CHILDREN WITH ASD THROUGH TELEHEALTH
Creator: Rosalik, Shelby R.
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Telehealth services have increased substantially in the field of applied behavior analysis (ABA) since the start of the COVID-19 pandemic, though little research exists to empirically evaluate the efficacy of direct ABA telehealth treatment or more specifically, how behavior technicians can be trained to implement such treatment. The present investigation utilized a nonconcurrent multiple baseline design across participants to evaluate the use of an online behavioral skills training (BST)...
Show moreTelehealth services have increased substantially in the field of applied behavior analysis (ABA) since the start of the COVID-19 pandemic, though little research exists to empirically evaluate the efficacy of direct ABA telehealth treatment or more specifically, how behavior technicians can be trained to implement such treatment. The present investigation utilized a nonconcurrent multiple baseline design across participants to evaluate the use of an online behavioral skills training (BST) approach to teach behavior technicians to implement 20-min mand training sessions via telehealth with children diagnosed with autism spectrum disorder (ASD). The training phase of the study consisted of both role-play with feedback as well as feedback during sessions with the child participant. Results showed increases in behavior technician’s percentage of accurate implementation and rate of fully correct trials implemented following the training. Child participants also showed increased rates of independent mands following the BST implementation. Thus, BST may be an effective approach to teach behavior technicians to deliver mand training via telehealth.
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Title: Searches for Beyond the Standard Model Phenomena with the HAWC Detector
Creator: Lundeen II, Joseph Andrew
Date: 2021
Collection: Electronic Theses & Dissertations
Description: The universe is known to be dominated by a class of matter known as dark matter. No known particles possess the necessary characteristics to make up this dark sector. Possible extensions to the Standard Model produce promising candidates, in particular Weakly Interacting Massing Particles (WIMPs). Under this hypothesis, it may be possible to probe dark matter with high-energy gamma-rays. The High Altitude Water Cherenkov (HAWC) detector is a contemporary experiment sensitive to multi-TeV...
Show moreThe universe is known to be dominated by a class of matter known as dark matter. No known particles possess the necessary characteristics to make up this dark sector. Possible extensions to the Standard Model produce promising candidates, in particular Weakly Interacting Massing Particles (WIMPs). Under this hypothesis, it may be possible to probe dark matter with high-energy gamma-rays. The High Altitude Water Cherenkov (HAWC) detector is a contemporary experiment sensitive to multi-TeV cosmic gamma rays and able to observe approximately two thirds of the sky in any given day. With these properties, HAWC is able to search for high-mass classes of WIMPs from the dark matter halo surrounding the Milky Way galaxy and set strong constraints on dark matter annihilation and decay into gamma rays.
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