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Description
Background: Effective glucose management using exercise modalities in older patients with type 2 diabetes and activities of daily living (ADL) disabilities are unknown.

Purpose: The study investigated the acute effects of motor-assisted cycling and functional electrical stimulation (FES) cycling on the 2-h postprandial glucose responses compared with sitting control

Background: Effective glucose management using exercise modalities in older patients with type 2 diabetes and activities of daily living (ADL) disabilities are unknown.

Purpose: The study investigated the acute effects of motor-assisted cycling and functional electrical stimulation (FES) cycling on the 2-h postprandial glucose responses compared with sitting control in older adults with type 2 diabetes and ADL disabilities.

Methods: The study used a 3×3 crossover study design. Nine participants were randomly assigned to one of the three treatment sequences: ABC, BCA, and CAB. (A, motor-assisted cycling; B, FES cycling; C, sitting control). Linear mixed models (LMM) with Bonferroni post-hoc tests were used to test the mean differences for the 2-h postprandial glucose, estimated by the area under the curve (AUC) and incremental AUC (iAUC), between intervention and control treatments after adjustment for covariates (e.g., age, sex, and race).

Results: There were significant mean differences for iAUC (p = 0.005) and AUC (p = 0.038) across motor-assisted cycling, control, and FES cycling treatments. The FES cycling had a lower mean of 2-hour postprandial iAUC as compared with sitting control (iAUC 3.98 mmol∙h/L vs 6.92 mmol∙h/L, p = 0.006, effect size [ES] = 1.72) and the motor-assisted cycling (iAUC, 3.98 mmol∙h/L vs 6.19 mmol∙h/L , p = 0.0368, ES = 1.29), respectively. The FES cycling also had a lower mean of the 2-hour postprandial AUC as compared with sitting control (AUC, 18.29 mmol∙h/L vs 20.95 mmol∙h/L, p = 0.043, ES = 0.89), but had an AUC similar to the motor-assisted cycling (18.29 mmol∙h/L vs 20.23 mmol∙h/L , p = 0.183, ES = 0.19). There were no statistical differences in iAUC (6.19 mmol∙h/L vs 6.92 mmol∙h/L) and AUC (20.23 mmol∙h/L vs 20.95 mmol∙h/L) between the motor-assisted cycling and sitting control (all p>0.05).

Conclusion: Performing 30 minutes of FES cycling on a motor-assisted bike (40 Hz, 39 rpm, 25-29 mA) significantly decreased the 2-h postprandial glucose levels in older adults with type 2 diabetes and ADL disabilities. These findings suggested that FES cycling can be a promising exercise modality for glucose management in diabetic patients with ADL disabilities.
Contributorsma, tongyu (Author) / Lee, Chong (Thesis advisor) / Hooker, Steven (Committee member) / Shaibi, Gabriel (Committee member) / Johnston, Carol (Committee member) / Ringenbach, Shannon (Committee member) / Arizona State University (Publisher)
Created2019
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Description
Understanding how microorganisms adapt and respond to the microgravity environment of spaceflight is important for the function and integrity of onboard life support systems, astronaut health and mission success. Microbial contamination of spacecraft Environmental Life Support Systems (ECLSS), including the potable water system, are well documented and have caused major

Understanding how microorganisms adapt and respond to the microgravity environment of spaceflight is important for the function and integrity of onboard life support systems, astronaut health and mission success. Microbial contamination of spacecraft Environmental Life Support Systems (ECLSS), including the potable water system, are well documented and have caused major disruption to spaceflight missions. The potable water system on the International Space Station (ISS) uses recycled wastewater purified by multiple processes so it is safe for astronaut consumption and personal hygiene. However, despite stringent antimicrobial treatments, multiple bacterial species and biofilms have been recovered from this potable water system. This finding raises concern for crew health risks, vehicle operations and ECLSS system integrity during exploration missions. These concerns are further heightened given that 1) potential pathogens have been isolated from the ISS potable water system, 2) the immune response of astronauts is blunted during spaceflight, 3) spaceflight induces unexpected alterations in microbial responses, including growth and biofilm formation, antimicrobial resistance, stress responses, and virulence, and 4) different microbial phenotypes are often observed between reductionistic pure cultures as compared to more complex multispecies co-cultures, the latter of which are more representative of natural environmental conditions. To advance the understanding of the impact of microgravity on microbial responses that could negatively impact spacecraft ECLSS systems and crew health, this study characterized a range of phenotypic profiles in both pure and co-cultures of bacterial isolates collected from the ISS potable water system between 2009 and 2014. Microbial responses profiled included population dynamics, resistance to silver, biofilm formation, and in vitro colonization of intestinal epithelial cells. Growth characteristics and antibiotic sensitivities for bacterial strains were evaluated to develop selective and/or differential media that allow for isolation of a pure culture from co-cultures, which was critical for the success of this study. Bacterial co-culture experiments were performed using dynamic Rotating Wall Vessel (RWV) bioreactors under spaceflight analogue (Low Shear Modeled Microgravity/LSMMG) and control conditions. These experiments indicated changes in fluid shear have minimal impact on strain recovery. The antimicrobial efficacy of silver on both sessile co-cultures, grown on 316L stainless steel coupons, and planktonic co-cultures showed that silver did not uniformly reduce the recovery of all strains; however, it had a stronger antimicrobial effect on biofilm cultures than planktonic cultures. The impact of silver on the ability of RWV cultured planktonic and biofilm bacterial co-cultures to colonize human intestinal epithelial cells showed that, those strains which were impacted by silver treatment, often increased adherence to the monolayer. Results from these studies provide insight into the dynamics of polymicrobial community interactions, biofilm formation and survival mechanisms of ISS potable water isolates, with potential application for future design of ECLSS systems for sustainable human space exploration.
ContributorsKing, Olivia G (Author) / Nickerson, Cheryl (Thesis advisor) / Barrila, Jennifer (Committee member) / Ott, C (Committee member) / Yang, Jiseon (Committee member) / Arizona State University (Publisher)
Created2019
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Description
This study explores the processes of designing strategies. The context of this research is scoped to the direct-marketing activities of small farm operators in eastern Iowa. The research intent is to explore and articulate trends in decision-making processes that assist small farm operators in eastern Iowa with direct marketing farm-to-table

This study explores the processes of designing strategies. The context of this research is scoped to the direct-marketing activities of small farm operators in eastern Iowa. The research intent is to explore and articulate trends in decision-making processes that assist small farm operators in eastern Iowa with direct marketing farm-to-table products, to explore and articulate how the design process creates differentiated value, and to explore and articulate the relationship between the design process and the way that small farm operators in eastern Iowa conceptualize their direct-marketing strategies.

The research design takes a post-positivist approach and uses a grounded theory methodology. The study does not have a starting hypothesis but instead starts with the research intent described previously. Convergent mixed methods and a flexible plan are used for data collection including semi-structured interviews and surveys with key concepts operationalized into Likert scales. The participants are selected from eastern Iowa farmers’ markets and Community Supported Agriculture (CSA) directories. For the qualitative data analysis, a grounded theory method is used to code interview response data, categorize the codes into related groups, and let the themes and sub-themes emerge from the data. For the quantitative data analysis, descriptive and inferential statistics are calculated on the aggregate data set.

The study finds that small farm operators are making strategic decisions about marketing mix variables such as product quality and relationship building, there are statistically significant correlations between design concepts and direct-marketing strategies, and that farmers designed their strategies by using the design process.
ContributorsLarew, Hart (Author) / Brooks, Kenneth R. (Thesis advisor) / Cheng, Chingwen (Committee member) / Mejia Ramirez, German (Committee member) / Arizona State University (Publisher)
Created2019
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Description
Research findings have shown that many computerized maintenance management systems (CMMS) are largely underutilized, often leading to the loss of efficiencies in the organization’s maintenance program. A literature review is presented of the available research in CMMS and of operations and management roles in a maintenance program. In addition, research

Research findings have shown that many computerized maintenance management systems (CMMS) are largely underutilized, often leading to the loss of efficiencies in the organization’s maintenance program. A literature review is presented of the available research in CMMS and of operations and management roles in a maintenance program. In addition, research was conducted around CMMS users to identify if any misalignments exist between management and operations. The articles selected for review offer a variety of perspectives, considerations, instructions, and noted failures involved with implementation, day to day use and reporting expectations. Through conducting a survey of both management and operations this paper will show how management and operations conceptions of CMMS vary, even greatly in some areas. The objective of this research is to gain an in-depth perspective from CMMS in all roles and analyze where utilizations vary. This information will then be utilized to understand possible misconceptions between roles, leading to inaccuracies and sub-par outcomes of proposed CMMS implementations.
ContributorsRennert, Andrew William (Author) / Sullivan, Kenneth (Thesis advisor) / Stone, Brian (Committee member) / Smithwick, Jake (Committee member) / Arizona State University (Publisher)
Created2019
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Description
For most of human history hunting has been the primary economic activity of men. Hunted animals are valued for their food energy and nutrients, however, hunting is associated with a high risk of failure. Additionally, large animals cannot be consumed entirely by the nuclear family, so much of the harvest

For most of human history hunting has been the primary economic activity of men. Hunted animals are valued for their food energy and nutrients, however, hunting is associated with a high risk of failure. Additionally, large animals cannot be consumed entirely by the nuclear family, so much of the harvest may be shared to others. This has led some researchers to ask why men hunt large and difficult game. The “costly signaling” and “show-off” hypotheses propose that large prey are hunted because the difficulty of finding and killing them is a reliable costly signal of the phenotypic quality of the hunter.

These hypotheses were tested using original interview data from Aché (hunter gatherer; n=52, age range 50-76, 46% female) and Tsimané (horticulturalist; n=40, age range 15-77, 45% female) informants. Ranking tasks and paired comparison tasks were used to determine the association between the costs of killing an animal and its value as a signal of hunter phenotypic quality for attracting mates and allies. Additional tasks compared individual large animals to groups of smaller animals to determine whether assessments of hunters’ phenotypes and preferred status were more impacted by the signal value of the species or by the weight and number of animals killed.

Aché informants perceived hunters who killed larger or harder to kill animals as having greater provisioning ability, strength, fighting ability, and disease susceptibility, and preferred them as mates and allies. Tsimané informants held a similar preference for hunters who killed large game, but not for hunters targeting hard to kill species. When total biomass harvested was controlled, both populations considered harvesting more animals in a given time period to be a better signal of preferred phenotypes than killing a single large and impressive species. Male and female informants both preferred hunters who consistently brought back small game over hunters who sometimes killed large animals and sometimes killed nothing. No evidence was found that hunters should forgo overall food return rates in order to signal phenotypic qualities by specializing on large game. Nutrient provisioning rather than costly phenotypic signaling was the strategy preferred by potential mates and allies.
ContributorsBishop, Andrew Phillip Carson (Author) / Hill, Kim (Thesis advisor) / Boyd, Robert (Committee member) / Trumble, Benjamin (Committee member) / Arizona State University (Publisher)
Created2019
Description
This study aims to address the deficiencies of the Marcus model of electron transfer

(ET) and then provide modifications to the model. A confirmation of the inverted energy

gap law, which is the cleanest verification so far, is presented for donor-acceptor complexes.

In addition to the macroscopic properties of the solvent, the physical

This study aims to address the deficiencies of the Marcus model of electron transfer

(ET) and then provide modifications to the model. A confirmation of the inverted energy

gap law, which is the cleanest verification so far, is presented for donor-acceptor complexes.

In addition to the macroscopic properties of the solvent, the physical properties of the solvent

are incorporated in the model via the microscopic solvation model. For the molecules

studied in this dissertation, the rate constant first increases with cooling, in contrast to the

prediction of the Arrhenius law, and then decreases at lower temperatures. Additionally,

the polarizability of solute, which was not considered in the original Marcus theory, is included

by the Q-model of ET. Through accounting for the polarizability of the reactants, the

Q-model offers an important design principle for achieving high performance solar energy

conversion materials. By means of the analytical Q-model of ET, it is shown that including

molecular polarizability of C60 affects the reorganization energy and the activation barrier

of ET reaction.

The theory and Electrochemistry of Ferredoxin and Cytochrome c are also investigated.

By providing a new formulation for reaction reorganization energy, a long-standing disconnect

between the results of atomistic simulations and cyclic voltametery experiments is

resolved. The significant role of polarizability of enzymes in reducing the activation energy

of ET is discussed. The binding/unbinding of waters to the active site of Ferredoxin leads

to non-Gaussian statistics of energy gap and result in a smaller activation energy of ET.

Furthermore, the dielectric constant of water at the interface of neutral and charged

C60 is studied. The dielectric constant is found to be in the range of 10 to 22 which is

remarkably smaller compared to bulk water( 80). Moreover, the interfacial structural

crossover and hydration thermodynamic of charged C60 in water is studied. Increasing the

charge of the C60 molecule result in a dramatic structural transition in the hydration shell,

which lead to increase in the population of dangling O-H bonds at the interface.
ContributorsWaskasi, Morteza M (Author) / Matyushov, Dmitry (Thesis advisor) / Richert, Ranko (Committee member) / Heyden, Matthias (Committee member) / Beckstein, Oliver (Committee member) / Arizona State University (Publisher)
Created2019
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Description
Calcium imaging is a well-established, non-invasive or minimally technique designed to study the electrical signaling neurons. Calcium regulates the release of gliotransmitters in astrocytes. Analyzing astrocytic calcium transients can provide significant insights into mechanisms such as neuroplasticity and neural signal modulation.

In the past decade, numerous methods have been developed

Calcium imaging is a well-established, non-invasive or minimally technique designed to study the electrical signaling neurons. Calcium regulates the release of gliotransmitters in astrocytes. Analyzing astrocytic calcium transients can provide significant insights into mechanisms such as neuroplasticity and neural signal modulation.

In the past decade, numerous methods have been developed to analyze in-vivo calcium imaging data that involves complex techniques such as overlapping signals segregation and motion artifact correction. The hypothesis used to detect calcium signal is the spatiotemporal sparsity of calcium signal, and these methods are unable to identify the passive cells that are not actively firing during the time frame in the video. Statistics regarding the percentage of cells in each frame of view can be critical for the analysis of calcium imaging data for human induced pluripotent stem cells derived neurons and astrocytes.

The objective of this research is to develop a simple and efficient semi-automated pipeline for analysis of in-vitro calcium imaging data. The region of interest (ROI) based image segmentation is used to extract the data regarding intensity fluctuation caused by calcium concentration changes in each cell. It is achieved by using two approaches: basic image segmentation approach and a machine learning approach. The intensity data is evaluated using a custom-made MATLAB that generates statistical information and graphical representation of the number of spiking cells in each field of view, the number of spikes per cell and spike height.
ContributorsBhandarkar, Siddhi Umesh (Author) / Brafman, David (Thesis advisor) / Stabenfeldt, Sarah (Committee member) / Tian, Xiaojun (Committee member) / Arizona State University (Publisher)
Created2019
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Description
In 2016, the United Nations reported a historical high of 65.6 million globally displaced people. Within the current protectionist and isolationist climate, the U.S is accepting a fewer number of refugees for resettlement than ever before and less governmental funding is being allocated to resettlement organizations, which provide support services

In 2016, the United Nations reported a historical high of 65.6 million globally displaced people. Within the current protectionist and isolationist climate, the U.S is accepting a fewer number of refugees for resettlement than ever before and less governmental funding is being allocated to resettlement organizations, which provide support services for refugee resettlement and integration.

Increased migration and the advancement of communication technologies with affordable access to these technologies have produced extensive communication networks and complex relational ties across the globe. While this is certainly true of all migrants, building and maintaining relational ties has added complexity for refugees whose journey to resettlement, economic insecurity, political disenfranchisement, and vulnerability impact the motivating factors for digital engagement.

This dissertation seeks to understand to what extent Diminescu’s (2008) concept of the connected migrant addresses the lived experience of resettled refugees in Phoenix, Arizona. The connected migrant through Information Communication Technology (ICT) use maintains transnational and local networks that produce mobility and belonging. Connected migrants are able to produce and maintain socio-technical sociality abroad and in the country of settlement to create and access social capital and resources. Using a grounded theory approach and qualitative methods, this research project explores concepts of mobility, connectivity, and belonging in relation to resettled refugees. The research indicates that age, imagined affordances, digital literacy, language, and time moderate connectivity, belonging, and mobility for resettled refugees. Finally, I offer the concept of transnational contextual relationality to understand refugee communication strategies with the transnational and local network.
ContributorsSabnis, Nandita Nishant (Author) / Cheong, Pauline (Thesis advisor) / Adame, Elissa (Committee member) / Tsuda, Takeyuki 'Gaku' (Committee member) / Arizona State University (Publisher)
Created2019
Description
There is an ongoing debate around the extent that anthropogenic processes influence both plant species distribution dynamics and plant biodiversity patterns. Past human food use may leave a strong legacy on not only the extent that food plants are dispersed and fill their potential geographic ranges, but also on food

There is an ongoing debate around the extent that anthropogenic processes influence both plant species distribution dynamics and plant biodiversity patterns. Past human food use may leave a strong legacy on not only the extent that food plants are dispersed and fill their potential geographic ranges, but also on food plant species richness in areas that have been densely populated by humans through time. The persistent legacy of plant domestication on contemporary species composition has been suggested to be significant in some regions. However, little is known about the effects that past human food use has had on the biogeography of the Sonoran Desert despite its rich cultural diversity and species richness. I used a combination of ecoinformatics, ethnobotanical, and archaeological data sources to quantitatively assess the impacts of pre-Columbian, and in some cases, more recent, human-mediated dispersal of food plants on the Sonoran Desert landscape. I found that (i) food plants do fill more of their potential geographic ranges than their un-used congeners, and that polyploidy, growth form, and life form are correlated with range filling and past food usage. I also found that (ii) both pre-Columbian and contemporary human population presence are correlated with relative food plant species richness. Thus, both past human food use and contemporary human activities may have influenced the geographic distribution of food plants at regional scales as well as species richness patterns. My research emphasizes that there is an interplay between ecological and anthropogenic processes, and that, therefore, humans must be considered as part of the landscape and included in ecological models.
ContributorsFlower, Carolyn (Author) / Blonder, Benjamin (Thesis advisor) / Hodgson, Wendy (Committee member) / Peeples, Matthew (Committee member) / Salywon, Andrew (Committee member) / Arizona State University (Publisher)
Created2019
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Description
This thesis explores the possibility of fabricating superconducting tunnel junctions (STJ) using double angle evaporation using an E-beam system. The traditional method of making STJs use a shadow mask to deposit two films requires the breaking of the vacuum of the main chamber. This technique has given bad results and

This thesis explores the possibility of fabricating superconducting tunnel junctions (STJ) using double angle evaporation using an E-beam system. The traditional method of making STJs use a shadow mask to deposit two films requires the breaking of the vacuum of the main chamber. This technique has given bad results and proven to be a tedious process. To improve on this technique, the E-beam system was modified by adding a load lock and transfer line to perform the multi-angle deposition and in situ oxidation in the load lock without breaking the vacuum of the main chamber. Bilayer photolithography process was used to prepare a pattern for double angle deposition for the STJ. The overlap length could be easily controlled by varying the deposition angles. The low-temperature resistivity measurement and scanning electron microscope (SEM) characterization showed that the deposited films were good. However, I-V measurement for tunnel junction did not give expected results for the quality of the fabricated STJs. The main objective of modifying the E-beam system for multiple angle deposition was achieved. It can be used for any application that requires angular deposition. The motivation for the project was to set up a system that can fabricate a device that can be used as a phonon spectrometer for phononic crystals. Future work will include improving the quality of the STJ and fabricating an STJs on both sides of a silicon substrate using a 4-angle deposition.
ContributorsRana, Ashish (Author) / Wang, Robert Y (Thesis advisor) / Newman, Nathan (Committee member) / Wang, Liping (Committee member) / Arizona State University (Publisher)
Created2019