Matching Items (203)
Description
Filtration for microfluidic sample-collection devices is desirable for sample selection, concentration, preprocessing, and downstream manipulation, but microfabricating the required sub-micrometer filtration structure is an elaborate process. This thesis presents a simple method to fabricate polydimethylsiloxane (PDMS) devices with an integrated membrane filter that will sample, lyse, and extract the DNA from microorganisms in aqueous environments. An off-the-shelf membrane filter disc was embedded in a PDMS layer and sequentially bound with other PDMS channel layers. No leakage was observed during filtration. This device was validated by concentrating a large amount of cyanobacterium Synechocystis in simulated sample water with consistent performance across devices. After accumulating sufficient biomass on the filter, a sequential electrochemical lysing process was performed by applying 5VDC across the filter. This device was further evaluated by delivering several samples of differing concentrations of cyanobacterium Synechocystis then quantifying the DNA using real-time PCR. Lastly, an environmental sample was run through the device and the amount of photosynthetic microorganisms present in the water was determined. The major breakthroughs in this design are low energy demand, cheap materials, simple design, straightforward fabrication, and robust performance, together enabling wide-utility of similar chip-based devices for field-deployable operations in environmental micro-biotechnology.
ContributorsLecluse, Aurelie (Author) / Meldrum, Deirdre (Thesis advisor) / Chao, Joseph (Thesis advisor) / Westerhoff, Paul (Committee member) / Arizona State University (Publisher)
Created2011
Description
Music has consistently been documented as a manner to bring people together across cultures throughout the world. In this research, we propose that people use similar musical taste as a strong sign of potential social connection. To investigate this notion, we draw on literature examining how music merges the public/private self, the link to personality, and group identity, as well as how it is linked to romantic relationships. Thus, music can be a tool when wanting to get to know someone else and/or forge a platonic relationship. To test this hypothesis, we designed an experiment comparing music relative to another commonality (sharing a sports team in common) to see which factor is stronger in triggering an online social connection. We argue that people believe they have more in common with someone who shares similar music taste compared to other commonalities. We discuss implications for marketers on music streaming platforms.
ContributorsDrambarean, Julianna Rose (Co-author) / Simmons, Logan (Co-author) / Samper, Adriana (Thesis director) / Martin, Nathan (Committee member) / Department of Marketing (Contributor) / Watts College of Public Service & Community Solut (Contributor) / Dean, W.P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Music has consistently been documented as a manner to bring people together across cultures throughout the world. In this research, we propose that people use similar musical tastes as a strong sign of potential social connection. To investigate this notion, we draw on literature examining how music merges the public/private self, the link to personality, and group identity, as well as how it is linked to romantic relationships. Thus, music can be a tool when wanting to get to know someone else and/or forge a platonic relationship. To test this hypothesis, we designed an experiment comparing music relative to another commonality (sharing a sports team in common) to see which factor is stronger in triggering an online social connection. We argue that people believe they have more in common with someone who shares similar music taste compared to other commonalities. We discuss implications for marketers on music streaming platforms.
ContributorsSimmons, Logan Patrick (Co-author) / Drambarean, Julianna (Co-author) / Samper, Adriana (Thesis director) / Martin, Nathan (Committee member) / School of International Letters and Cultures (Contributor) / Department of Marketing (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Single cell phenotypic heterogeneity studies reveal more information about the pathogenesis process than conventional bulk methods. Furthermore, investigation of the individual cellular response mechanism during rapid environmental changes can only be achieved at single cell level. By enabling the study of cellular morphology, a single cell three-dimensional (3D) imaging system can be used to diagnose fatal diseases, such as cancer, at an early stage. One proven method, CellCT, accomplishes 3D imaging by rotating a single cell around a fixed axis. However, some existing cell rotating mechanisms require either intricate microfabrication, and some fail to provide a suitable environment for living cells. This thesis develops a microvorterx chamber that allows living cells to be rotated by hydrodynamic alone while facilitating imaging access. In this thesis work, 1) the new chamber design was developed through numerical simulation. Simulations revealed that in order to form a microvortex in the side chamber, the ratio of the chamber opening to the channel width must be smaller than one. After comparing different chamber designs, the trapezoidal side chamber was selected because it demonstrated controllable circulation and met the imaging requirements. Microvortex properties were not sensitive to the chambers with interface angles ranging from 0.32 to 0.64. A similar trend was observed when chamber heights were larger than chamber opening. 2) Micro-particle image velocimetry was used to characterize microvortices and validate simulation results. Agreement between experimentation and simulation confirmed that numerical simulation was an effective method for chamber design. 3) Finally, cell rotation experiments were performed in the trapezoidal side chamber. The experimental results demonstrated cell rotational rates ranging from 12 to 29 rpm for regular cells. With a volumetric flow rate of 0.5 µL/s, an irregular cell rotated at a mean rate of 97 ± 3 rpm. Rotational rates can be changed by altering inlet flow rates.
ContributorsZhang, Wenjie (Author) / Frakes, David (Thesis advisor) / Meldrum, Deirdre (Thesis advisor) / Chao, Shih-hui (Committee member) / Wang, Xiao (Committee member) / Arizona State University (Publisher)
Created2011
Description
Laboratory automation systems have seen a lot of technological advances in recent times. As a result, the software that is written for them are becoming increasingly sophisticated. Existing software architectures and standards are targeted to a wider domain of software development and need to be customized in order to use them for developing software for laboratory automation systems. This thesis proposes an architecture that is based on existing software architectural paradigms and is specifically tailored to developing software for a laboratory automation system. The architecture is based on fairly autonomous software components that can be distributed across multiple computers. The components in the architecture make use of asynchronous communication methodologies that are facilitated by passing messages between one another. The architecture can be used to develop software that is distributed, responsive and thread-safe. The thesis also proposes a framework that has been developed to implement the ideas proposed by the architecture. The framework is used to develop software that is scalable, distributed, responsive and thread-safe. The framework currently has components to control very commonly used laboratory automation devices such as mechanical stages, cameras, and also to do common laboratory automation functionalities such as imaging.
ContributorsKuppuswamy, Venkataramanan (Author) / Meldrum, Deirdre (Thesis advisor) / Collofello, James (Thesis advisor) / Sarjoughian, Hessam S. (Committee member) / Johnson, Roger (Committee member) / Arizona State University (Publisher)
Created2012
Description
Single cell analysis has become increasingly important in understanding disease onset, progression, treatment and prognosis, especially when applied to cancer where cellular responses are highly heterogeneous. Through the advent of single cell computerized tomography (Cell-CT), researchers and clinicians now have the ability to obtain high resolution three-dimensional (3D) reconstructions of single cells. Yet to date, no live-cell compatible version of the technology exists. In this thesis, a microfluidic chip with the ability to rotate live single cells in hydrodynamic microvortices about an axis parallel to the optical focal plane has been demonstrated. The chip utilizes a novel 3D microchamber design arranged beneath a main channel creating flow detachment into the chamber, producing recirculating flow conditions. Single cells are flowed through the main channel, held in the center of the microvortex by an optical trap, and rotated by the forces induced by the recirculating fluid flow. Computational fluid dynamics (CFD) was employed to optimize the geometry of the microchamber. Two methods for the fabrication of the 3D microchamber were devised: anisotropic etching of silicon and backside diffuser photolithography (BDPL). First, the optimization of the silicon etching conditions was demonstrated through design of experiment (DOE). In addition, a non-conventional method of soft-lithography was demonstrated which incorporates the use of two positive molds, one of the main channel and the other of the microchambers, compressed together during replication to produce a single ultra-thin (<200 µm) negative used for device assembly. Second, methods for using thick negative photoresists such as SU-8 with BDPL have been developed which include a new simple and effective method for promoting the adhesion of SU-8 to glass. An assembly method that bonds two individual ultra-thin (<100 µm) replications of the channel and the microfeatures has also been demonstrated. Finally, a pressure driven pumping system with nanoliter per minute flow rate regulation, sub-second response times, and < 3% flow variability has been designed and characterized. The fabrication and assembly of this device is inexpensive and utilizes simple variants of conventional microfluidic fabrication techniques, making it easily accessible to the single cell analysis community.
ContributorsMyers, Jakrey R (Author) / Meldrum, Deirdre (Thesis advisor) / Johnson, Roger (Committee member) / Frakes, David (Committee member) / Arizona State University (Publisher)
Created2012
Description
GEICO Insurance offers a wide range of insurance options to consumers nationwide. The company has experienced exponential growth over the past 15 years largely due to their low rates, ease of purchase, online business model, and their industry-revolutionizing approach to advertising these competitive advantages. Operating primarily within the enormous Property and Casualty sector of the insurance industry, GEICO faces extremely high levels of competition from many well-resourced companies. The most dangerous of which have begun to respond to GEICO's humorous, charming, and often detached advertising strategy through the employment of one of two general strategies; either imitating and attempting to improve upon GEICO's brand image and advertising practices, or else attacking it, insinuating that a company with this appeal does not truly care about its customers or its services. As GEICO has already solidified their low price point and ease of purchase in the minds of consumers, a tactical shift in response to competitive actions is now optimal. To avoid being labeled as a "cut-rate" insurance provider who cares little about the safety or well-being of their clients, and provides them with low quality insurance products and services; the following integrated marketing campaign is proposed. Spearheaded by the slogan "As long as you have GEICO, Things are looking up.", this campaign will focus on raising awareness of the plethora of customer service programs and initiatives already offered by GEICO that are unknown to the general public. The humorous, lighthearted appeal will remain, but the focus on highlighting customer service benefits and the high quality associated with GEICO's product will serve to shift the public perception of GEICO. As a result of this campaign, GEICO will appeal to a broader segment of the market, retain customers for longer period of time, raise awareness of their helpful customer service products and services, and differentiate themselves from the competition.
ContributorsGood, David Gregory (Author) / Gray, Nancy (Thesis director) / Samper, Adriana (Committee member) / Barrett, The Honors College (Contributor) / Department of Marketing (Contributor) / W. P. Carey School of Business (Contributor) / Department of Management (Contributor)
Created2015-05
Description
As a self-discrepancy arises between who an individual currently is and who they aspire to become, feelings of tension arise. Reactions to this stress are based on various personal beliefs. Our feelings of our potential to reach our desired state can be affected by our orientation of locus of control, or where we believe control is derived from within our life. In the present research, we examine how a person's locus of control--whether they are internal by attributing outcomes to their own actions or external believers that fate and chance drive their life outcomes--affects their reaction to a self-discrepancy in a domain that is important to them, and how this affects valuation of the products used in that domain. We found that while internals and externals behave similarly under feelings of high competence (baseline condition) when a self-discrepancy is not evident, reactions differed under the opposing condition of feeling less competent during their goal pursuit. Externals did not significantly change their belief in the product regardless of the condition (high vs. low competence) while internals took the defeat heavily by significantly decreasing their belief that the goal-related product would help them achieve their goals and decreased their willingness to pay for it.
ContributorsSweet, Megan Ruth (Author) / Samper, Adriana (Thesis director) / Ostrom, Amy (Committee member) / Barrett, The Honors College (Contributor) / Department of Marketing (Contributor) / Department of Management (Contributor)
Created2015-05
Description
Currently, the medical industry employs an acute treatment process centered on responsiveness and restoration. This method fails those with chronic illness who require disease management and proactivity. As a solution, the medical industry has implemented programs focused on providing integrated, coordinated care. This project examines two primary models to accommodate chronically ill patients: Accountable Care Organizations (ACOs) and Patient Centered Medical Homes (PCMHs). Specifically, this paper examines the data from Pioneer and Medicare Shared Savings Program ACOs. In the aggregate, the data indicate that these programs have been unsuccessful due to several key issues: a lack of patient and physician engagement, failure to incentivize medical professionals and failed collaboration between both ACOs and PCMHs. Remedying these issues would improve the ability of both ACOs and PCMHs to provide integrated, comprehensive care to patients with chronic illnesses.
ContributorsWoods, Cassie Marie (Author) / Ketcham, Jonathan (Thesis director) / Samper, Adriana (Committee member) / Barrett, The Honors College (Contributor) / Department of Marketing (Contributor)
Created2015-05
Description
Research on teamwork has shown that teams are more productive and produce better results than individuals working on their own. Yet, research on individuals' work preferences makes it clear that not everyone prefers working in teams. In order to improve teamwork and achieve better results in both the collegiate arena and in the professional world, this study was designed to research different factors that affect a group's performance and creativity: satisfaction, familiarity, and the behavioral styles of individual team members. Additionally, this study addresses if the group's composition of Keirsey types \u2014 temperament patterns \u2014 also play a role in the group's creativity and performance. In this study, students created teams of four to seven students and completed specific in-class activities called Applied Insights. Groups composed mostly of Guardians, one of the four Keirsey temperaments, are able to adapt to the task at hand, which is demonstrated here with creativity. Further, groups who perceive themselves as sharing similar traits with many members are more satisfied and achieve a higher overall performance. Lastly, groups comprised of individuals who were least familiar with their teammates they had not previously worked with, produced more creative results in the short run. Whereas groups comprised of individuals who were least familiar with their teammates they had previously worked with, produced better overall results in short run.
ContributorsPinto, Linda (Co-author) / Hulse, Christopher (Co-author) / Vaughn, Michael (Co-author) / LePine, Marcie (Thesis director) / Samper, Adriana (Committee member) / Barrett, The Honors College (Contributor) / WPC Graduate Programs (Contributor) / School of Accountancy (Contributor) / Department of Information Systems (Contributor) / Department of Marketing (Contributor) / School of Music (Contributor)
Created2014-12