Now showing items 15208-15227 of 20306

    • Putting the Individualized Back into Instruction: Coaching Teachers to Implement Academically Responsive Instruction in Deaf Education Classrooms

      Antia, Shirin; Catalano, Jennifer; Umbreit, John; Liaupsin, Carl; Clift, Renee (The University of Arizona., 2018)
      The goal of this study was to examine the effects of a coaching intervention on teachers’ ability to implement academically responsive instruction through flexible instructional arrangements in self-contained classrooms for students who are Deaf and hard of hearing (DHH). A secondary goal of the study was to determine the impact of the implementation of flexible instructional arrangements on students’ academic engagement within instructional arrangements. Three teachers at a center school for the Deaf received differentiated coaching to learn how to implement the indicators of flexible instructional arrangements. Teachers were coached on 12 operationalized indicators using individual approaches that met the needs, learning styles, and preferences of each teacher. A changing criterion design replicated across teachers was used to examine the impact of the coaching intervention on teachers’ implementation of the indicators, as well as the impact of flexible instructional arrangements on students’ active engagement. Results show that coaching had an impact on all three teachers’ implementation of flexible instructional arrangements. As teachers mastered the indicators of flexible instructional arrangements requiring coaching, change occurred in their implementation of instructional arrangements. Students’ active engagement increased and passive engagement decreased when they participated in less whole class instruction and spent more time in small group and child-managed arrangements. After no longer receiving coaching, teachers maintained the implementation of flexible instructional arrangements and students continued to demonstrate higher levels of active engagement as compared to baseline. Limitations and implications for future practice and research are discussed.
    • Pyramids by day, martinis by night: The development and promotion of Mexico's tourism industry, 1928-1946

      Beezley, William H.; Berger, Dina Michele (The University of Arizona., 2002)
      This dissertation on the development and promotion of Mexico's tourism industry reconstructs the making of what is today that nation's third most profitable industry. Forged by Mexico's government in late 1928 as the cornerstone of state-led modernization programs, tourism became official business by 1929 when government officials, private investors, bankers and transportation companies agreed that it offered their nation an ideal vehicle toward progress once they began to rebuild after a long history of political violence and instability, shaky relations with the United States, economic underdevelopment and social revolution. Tourism suggests another framework for examining culture, politics and economics in Mexico following the revolution and during this period of intense nation building. More than just an economic solution, tourism fit into the state's broader cultural program to both modernize and unite Mexicans after the 1910 revolution. Tourism fostered nationalism and national unity. It encouraged the formation of tourist associations whose members pooled their resources to promote their nation's beauty and to finance infrastructure for the sake of national progress, peace and prosperity. Through tourism, government and private individuals debated and defined mexicanidad, or Mexicanness. In the end, promoters packaged a holiday in Mexico to U.S. tourists as a destination that embodied a harmonious convergence of modernity and antiquity---where one could visit the pyramids by day and drink martinis by night. By analyzing the formation, membership, activities and debates of official and private tourist groups between 1928--1946, this project reveals that to develop tourism the government relied on cooperation and capital from an elaborate network of promoters in Mexico and abroad. Moreover, Mexican financiers almost exclusively funded the construction of tourist infrastructure that visibly transformed Mexico by 1946 from a provincial, undeveloped nation to an urban, modern one. Scholars have examined these transformations as a product of President Miguel Aleman, 1946--52 whose administration was marked by corruption and U.S.-directed development. This research uncovers early origins of Mexican-led progress, and demonstrates how tourist development between 1928--1946 decidedly paved the way for Mexico's economic "miracle," and its era of political and social stability after World War II.

      Rosowski, James R. (The University of Arizona., 1969)
    • Pyrrolizidine alkaloids: Chemical basis of toxicity

      Huxtable, Ryan J.; Cooper, Roland Arthur, 1963- (The University of Arizona., 1996)
      In humans, livestock and experimental animals, pyrrolizidine alkaloids (PAs) are toxic as a consequence of their hepatic metabolism to reactive pyrrolic esters, or dehydroalkaloids (DHAs). Despite their similarity in structures, PAs often vary markedly in their lethality (LD₅₀s) and in the organs in which toxicity is expressed. We have examined whether there are differences in the physicochemical properties of certain DHAs which are associated with differences in patterns of metabolism and toxicity produced by the parent PA. Using a potentiometric method to measure hydrolysis, it was determined that the half-lives of the corresponding DHAs of retrorsine, seneciphylline, monocrotaline and trichodesmine were 1.06, 1.60, 3.39 and 5.36 sec, respectively. These values were supported by similar results from experiments measuring reactivity of DHAs toward 4-(p-nitrobenzyl)pyridine. Studies from the isolated rat liver perfused with PAs show that DHA stability is related to patterns of metabolism and toxicity. Perfusion of the primarily hepatotoxic retrorsine and seneciphylline is associated with a greater proportion of metabolite released as non-toxic 7-glutathionyl-6,7-dihydro-1-hydroxymethyl-5H-pyrrolizine (7-GSDHP), a greater proportion alkylating liver macromolecules, and a lower proportion released as DHA into the circulation. Perfusion with monocrotaline and trichodesmine, PAs producing extrahepatic toxicity, produced lower proportions of 7-GSDHP release and liver alkylation, and higher proportions of DHA released into the circulation. Other studies characterizing DHAs included the use of an in vitro enzyme assay in which DHAs were shown to inhibit the phosphotransferase activity of yeast and rat brain hexokinase. Parent PAs, and the hydrolysis product of DHAs, (±)-6,7dihydro-1-hydroxymethyl-5H-pyrrolizine (DHP) did not affect enzyme activity. In vivo studies in rats have established that glutathione and cysteine-conjugated pyrrolic metabolites of PAs likely represent detoxication pathways, providing further support for DHAs as the primary toxic metabolite. We have examined the chemical form of sulfur-bound pyrroles to establish the importance of the 7-ester position in PA toxicity. Additionally, we have developed an efficient technique for the rapid separation and purification of large quantities of PAs using high-speed counter-current chromatography.
    • Pyrrolizidine alkaloids: Hepatic metabolism and extrahepatic toxicity

      Wild, Stacie Lynn.; Huxtable, Ryan J.; Brendel, Klaus; Gandolfi, A. Jay; Halpert, James R.; Laird, Hugh E. (The University of Arizona., 1994)
      Pyrrolizidine alkaloids are proposed to be metabolized in the liver to reactive pyrrole species, or dehydroalkaloids. These reactive pyrroles are hypothesized to be responsible for pyrrolizidine alkaloid toxicity. This dissertation research has established that dehydroalkaloids are, in fact, metabolites of pyrrolizidine alkaloids. It was first determined that dehydromonocrotaline is produced during hepatic microsomal metabolism of monocrotaline and that it has the ability to bind in vitro with a synthetic thiol-containing resin, Thiopropyl Sepharose 6B. Similarly, synthetic dehydromonocrotaline binds to this resin. Dehydromonocrotaline was identified as a pyrrolizidine alkaloid metabolite based upon its resin cleavage products. When resin-bound pyrrole, synthetic or microsomally generated, was cleaved in a buffered, ethanolic silver nitrate solution, O⁷-ethyl dehydroretronecine was the major product, supporting the suggestion that the pyrrole generated by hepatic microsomes is dehydromonocrotaline. This system was then used to determine the formation of dehydroalkaloids from other pyrrolizidine alkaloids. These other alkaloids--trichodesmine, retrorsine, senecionine and heliotrine--cause toxicity to the liver as well as to extrahepatic organs. Their metabolism in this system reveals that alkaloids which produce extrahepatic toxicity have an increased percentage of reactive metabolites formed by phenobarbital-induced hepatic microsomes. Therefore, this system in vitro can be a good predictor of alkaloids which may produce extrahepatic toxicity in vivo. Trichodesmine is a pyrrolizidine alkaloid that is unique in its neurotoxicity. It is structurally similar to monocrotaline, yet it varies widely in its toxicity. It was determined that trichodesmine is more toxic in the rat than monocrotaline as indexed by LD₅₀ values. The distribution of pyrrolic metabolites reveals that trichodesmine treatment results in brain pyrrole levels 4 times higher than monocrotaline, retrorsine, or control. Histopathologic investigation of trichodesmine-treated animals reveals severe neuronal death in the cerebral cortex. These results suggest that neurotoxicity observed with trichodesmine is a result of pyrrole metabolites reaching the brain, thus providing further evidence for the involvement of pyrrole metabolites in pyrrolizidine alkaloid-induced extrahepatic toxicity.
    • Q-switched and Mode-locked Mid-IR Fiber Lasers

      Peyghambarian, Nasser; Zhu, Gongwen; Peyghambarian, Nasser; Norwood, Robert A.; Zhu, Xiushan (The University of Arizona., 2015)
      Mid-infrared (IR) lasers (2-12 μm) have found tremendous applications in medical surgeries, spectroscopy, remote sensing, etc. Nowadays, mid-IR emissions are usually generated from semiconductor lasers, gas lasers, and solid-state lasers based on nonlinear wavelength conversion. However, they usually have disadvantages including poor beam quality, low efficiency, and complicated configurations. Mid-IR fiber lasers have the advantages of excellent beam quality, high efficiency, inherent simplicity, compactness, and outstanding heat-dissipating capability, and have attracted significant interest in recent years. In this dissertation, I have studied and investigated Q-switched and mode-locked fiber lasers in the mid-IR wavelength region. My dissertation includes six chapters: In Chapter 1, I review the background of mid-IR lasers and address my motivation on the research of mid-IR fiber lasers; In Chapter 2, I present the experimental results of microsecond and nanosecond Er³⁺-doped and Ho³⁺-doped fiber lasers in the 3 μm wavelength region Q-switched by Fe²⁺:ZnSe and graphene saturable absorbers. In Chapter 3, Q-switched 3 μm laser fiber amplifiers are investigated experimentally and theoretically and their power scaling are discussed. In Chapter 4, a graphene mode-locked Er³⁺-doped fiber lasers at 2.8 μm with a pulse width < 50 ps is presented. In Chapter 5, extending the spectral range of mid-IR fiber lasers by use of nonlinear wavelength conversion is addressed and discussed. I have proposed 10-watt-level 3-5 μm Raman lasers using tellurite fibers as the nonlinear gain medium and pumped by our Er³⁺-doped fiber lasers at 2.8 μm. In the last chapter, the prospect of mid-IR fiber laser is addressed and further research work is discussed.
    • QoS Improvement Schemes for Real-Time Wireless VoIP

      Rodriguez, Jeffrey J.; McNeill, Kevin M.; Liu, Mingkuan; Rodriguez, Jeffrey J.; McNeill, Kevin M.; Hariri, Salim (The University of Arizona., 2006)
      There is a tremendous demand on real-time multimedia delivery over wireless Internet due to the dramatic increase in wireless communication and the growth of the Internet. However, real-time multimedia over wireless Internet poses many challenges. First of all, the inherent best-effort characteristic of packet-switched networks makes it difficult to provide guaranteed QoS for real-time multimedia delivery. Secondly, wireless channels have much higher packet-loss rate, bit-error rate, and channel instability compared to wired channels due to noise, path loss, multi-path fading and shadowing, which result in fluctuating communication channel statistics. Thirdly, the real-time communication demands strict time limitations on the network end-to-end delay and delay jitter.In this dissertation, an intelligent application architecture and several QoS improvement mechanisms are proposed to timely estimate the current wireless network statistics and dynamically take smart actions to improve the overall performance of a real-time wireless Internet telephony system. An online network traffic modeling method based on time series analysis was used to estimate the dynamic wireless network statistics such as end-to-end packet delay and delay jitters. Using this real-time updated information, the application's sender side can take some adaptive actions such as voice codec selection and forward error-correction schemes for packet-loss concealment to improve the QoS under current available network resources. Also, a novel adaptive playout jitter buffer adjustment algorithm is proposed. The proposed algorithm achieved 11%-15% performance improvement compared to traditional adaptive playout adjustment algorithms using the ITU-E model measurement metric.
    • QoS routing in packet networks

      Krunz, Marwan; Korkmaz, Turgay (The University of Arizona., 2001)
      The current best-effort service of the Internet is not sufficient to meet the demands of emerging real-time network applications (e.g., video conferencing, Internet telephony). This has motivated the development of new networking technologies (e.g., Intserv, Diffserv, MPLS) that are geared towards providing quality-of-service (QoS) guarantees (e.g., bandwidth, delay, fitter, reliability) to prospective flows. Various aspects of these technologies are being extensively investigated in the research community. In this dissertation, we focus on the routing aspect, with the objective of providing scalable and computationally efficient solutions. The QoS routing problem involves two tasks: (a) capturing and disseminating the state information of the underlying network; and (b) using this information to compute resource-efficient constrained paths. In the presence of multiple constraints (QoS link parameters), these two tasks become notoriously challenging. We investigate several key issues in QoS routing and discuss how to integrate the provided solutions into evolving state-dependent and hierarchical routing protocols (e.g., PNNI and QoS-extended OSPF). First, we develop a hybrid mechanism based on both flooding and tree-based broadcasting for reliable and efficient dissemination of dynamic link-state parameters, such as bandwidth. Second, we present a scalable, source oriented state aggregation methodology for hierarchical networks. Third, we introduce several heuristics and approximation algorithms for path selection under multiple QoS constraints. Fourth, we consider the path selection problem under inaccurate (probabilistically modeled) state information, and provide a heuristic for a special yet important case of this problem, namely, routing under bandwidth and delay constraints. Finally, we evaluate the performance of the proposed methods through simulations.
    • QSO Pairs and the Lyman-alpha Forest: Observations, Simulations, and Cosmological Implications

      Impey, Chris D.; Marble, Andrew R; Impey, Chris D.; Schmidt, Gary; Dave, Romeel; Fan, Xiaohui (The University of Arizona., 2007)
      This dissertation addresses two cosmological applications of the Lyman-alpha (Ly ɑ) forest observed in QSO pairs separated by several arcminutes or less. The Ly ɑ flux autocorrelation and cross-correlation provide a measurement of cosmic geometry at z > 2, via a variant of the Alcock-Paczyński test. I present the results of an observing campaign to obtain moderate resolution spectroscopy of the Ly ɑ forest in QSO pairs with small redshift differences (Δz < 0.25) and arcminute separations (θ < 5'). This new sample includes 29 pairs and one triplet suitable for measuring the cross-correlation and 78 individual QSO spectra for determining the autocorrelation. Continuum fits are provided, as are seven revisions for previously published QSO identifications and/or redshifts. Using a suite of hydrodynamic simulations, anisotropies in the Ly ɑ flux correlation function due to redshift-space distortions and spectral smoothing are investigated for 1:8 ≤ z ≤ 3, further enabling future applications of the Alcock-Paczyński test with Ly ɑ correlation measurements. Sources of systematic error including limitations in mass-resolution and simulation volume, prescriptions for galactic outflow, and the observationally uncertain mean flux decrement are considered. The latter is found to be dominant. An approximate solution for obtaining the zero-lag cross-correlation for arbitrary spectral resolution is presented, as is a method for implementing the resulting anisotropy corrections while mitigating systematic uncertainty.
    • Qualitative assessment of successful individuals who have a learning disability

      Sales, Amos; McDonnell, Daniel Michael, 1948- (The University of Arizona., 1996)
      This study used qualitative methods to investigate successful individuals who had a learning disability. Six participants, three men and three women, along with their family members and significant others were interviewed. A participant observation was also conducted during each participant's typical day at work. Four common characteristics were found among the participants. These characteristics were organizational skills, drive, a match between strengths and career, and interpersonal competence. The characteristics identified by the study were similar to those found by Gerber and Ginsberg (1990); however, it was noted that over-reliance on one characteristic and an inability to adjust to success often created difficulties. Further, job satisfaction and eminence in one's field did not always mean self-fulfillment, happiness, and psychological maturity. A definition of success which suggests a balance between career, family, and social activities was given. The study noted that a key element in coping with a learning disability was that the individuals understood both their strengths and weakness. Family members indicated that the transition from school to adult life was critical and that the role of parent and family members' perceptions about the participants usually needed to be adjusted. Older participants indicated that having a son or a daughter who had a learning disability helped them to come to terms with their disability. They also noted the importance of having a diagnosis, so they could reframe their self-perception in terms of a condition rather than a sense of mental incompetence or laziness. Recommendations for future research in this field were presented.
    • The qualitative generation of wellness motivation theory

      Derenowski, Julie Margaret (The University of Arizona., 1990)
    • A Qualitative Inquiry: Parental Approaches and Expectations, What Role Does Disability Play?

      Shaw, Linda; Ficchi, Gabrielle; Shaw, Linda; Hartley, Michael; Kroeger, Sue (The University of Arizona., 2017)
      Parenting a child with a disability is a unique experience, and both parents and children need to find the most effective parenting strategies. The purpose of this qualitative study is to gain a better understanding of the experiences associated with raising a child who has a disability. Specifically, this study examines what factors parents feel influence them in making decisions about their child and the expectations they have for them. In addition, it assesses how parents perceive they have modified their childrearing approaches and expectations for their child with a disability. To collect qualitative data, the investigator used narrative inquiry. This methodology was appropriate as eliciting specific stories and examples from participants allowed the team to capture the authentic experience of each one. The primary investigator collected qualitative data through multiple interviews with parents who have children with disabilities. For purposes of this study, sampling methods were a mix between convenience and non-probability sampling. Parents included were those of children whose disability is primarily physical. The researcher conducted a semi-structured interview to examine the feelings, thought processes, challenges and overall life experience surrounding parenting a child who has a physical disability. Data was analyzed using a "constant comparative" method whereby the researcher constantly compares within the study the data being collected. Periodic review of the data, as well as summaries, helped identify trends warranting further analysis. Overall, the results of this study indicate that parents and families perceive that they have needs that are not being met, empowering them to make certain parenting decisions. Based upon these perceptions, it would appear that there is a need for change in the types of services and information parents are receiving. While medical support is necessary, parents are also expressing a need for more practical forms of assistance. This study explores several ways in which rehabilitation professionals might implement changes in order to accommodate these needs. Families whose children have disabilities expressed both a strong desire to provide the best possible care. What appears to be currently lacking is sufficient education and emotional support to channel their loving energy into setting higher expectations for their children, knowing how to effectively plan for and reach milestones, while being confident enough in their child’s abilities to afford them opportunities to take control of their own lives.
    • A qualitative study of the academic program at the Center for Academic Precocity, Arizona State University

      Maker, C. June; Chavis, Pamela Kaye (The University of Arizona., 2000)
      The purpose of this study was to examine the ways in equity was operationalized in a supplemental academic program for gifted youth. ASU's Center for Academic Precocity in Tempe Arizona was the site of a four month study. Data was collected from documents, observation of CAP's offices, classrooms, extracurricular functions, and interviews with selected participants. In addition, selected former students were interviewed to learn about their views of their experiences in the CAP academic program and the effects their participation in CAP classes had on later academic and occupational attainment. I concluded after analysis of data that CAP administrators were creating changes to the program to acknowledge changes in scholarly knowledge about interpretations of intelligence and appropriate policies and practices. Changes for provision of students from minority backgrounds were not found. Participants were supportive of the program and former students reported that their experiences at CAP helped them adjust to college life but that their experiences did not influence their choices of majors in college or choices of occupations.
    • A Qualitative Study of the Positioning of Emergent Bilinguals during Formal and Informal School-Based Interactions

      Carter, Kathy; Sugimoto, Amanda Tori; Turner, Erin; Combs, Mary Carol; Wyman, Leisy; Carter, Kathy (The University of Arizona., 2016)
      The education of emergent bilinguals in the United States is overtly and covertly shaped by social, political, and institutional ideologies about languages and speakers of languages other than English. Using a multiple case study design, this study sought to explicate the often-complicated intersection of outsider institutional and societal ideologies with the insider lived experiences of emergent bilinguals in schools. The population of the school under study uniquely positioned emergent bilinguals as not only the linguistic minority but also the numeric minority, a population dynamic notably underrepresented in the literature. Using a positioning theory framework that focused on the normative constraints that support meaning making during social interactions, this study explored how primarily monolingual English-speaking teachers and peers interactionally positioned three fourth grade emergent bilinguals, as well as how these emergent bilinguals reflexively positioned themselves. Data collection efforts consisted of multiphase observations of classrooms including the creating of sociograms and fieldnotes, interviews with emergent bilinguals, teachers, and key peers, as well as a localized artifact analysis. Findings suggested that the emergent bilinguals unique backgrounds contributed to their variable reflexive positioning, as well as teachers' variable interactional positioning. Additionally, peer positioning and institutional norms contributed to emergent bilinguals having limited access to academic language development opportunities.
    • A Qualitative Study to Elucidate Consumer Rejection of the Practice of Coupon Use

      Bhappu, Anita D.; Andrews, Jennifer Gloria; Helm, Sabrina; Serido, Joyce; Bhappu, Anita D. (The University of Arizona., 2016)
      Coupons are a marketing tool used to entice consumers to try a new brand or product in the hopes that they will then become loyal users after trial (Boundless, n.d.). Issuing coupons is a common practice for many businesses because it is relatively inexpensive to begin, and can be used for general advertising purposes in addition to attracting new customers. Digital coupons have been introduced in the last few years and their acceptance is growing, with redemptions in 2010 increasing by 10 times the 2009 rates and projected to increase exponentially with each year (, n.d.). Despite the higher acceptance and redemption rates for digital coupon formats over the past 5 years, the overall coupon redemption rate has remained at around 2%. Early coupon academic studies in the promotional literature examine profitability maximization through manipulating coupon characteristics or the coupon process such as the timing of release, length of expiration dates, amount of the cents-off, and other related monetary factors. Despite the ability to adjust coupon features to maximize revenue and redemption, the effect is not strong enough to generate the motivation required to elicit new use from non-users being targeted nor improve the overall low redemption rates. Basic characteristics such as demographic and socioeconomic variables as well as some predisposing motivational characteristics have also been studied to predict coupon use. While some of these characteristics demonstrate differences between consumers who do and do not use coupons, characteristics provide little insight into why non-users choose not to coupon. Furthermore, the findings cannot be generalizable to the population as a whole when the redemption rate persists at 2%. With digital coupons a rapidly growing practice, it is important to determine whether or not this new coupon format might contribute to behavior change in current non- or infrequent users of coupons. The overarching goal of this research was to better understand the motivational processes driving the decisions to not use coupons in the context of consumer packaged goods (grocery). While most previous research has concentrated on characteristics of the consumer, characteristics of the coupon, and predisposing motivational constructs, this study examined why consumers rejected coupons by examining their narratives on the various stages of the coupon process to narrow down the factors contributing the most to deterring coupon use. A two-phase qualitative approach was selected to determine how digital coupons were perceived by both frequent and infrequent users followed by a more in-depth investigation into the timing, motivation and cognitive processes occurring behind the decision not to coupon. The Phase 1 study included 58 participants, 29 frequent users and 29 infrequent users. Participants completed a set of questionnaires measuring previously identified predisposing characteristics, given guidance on the selection of digital coupons loaded onto shopper loyalty cards and were provided with Sunday circulars. Each participant had 1 week to try and redeem the digital coupons and complete follow up questionnaires to determine any changes post-trial. Participants were invited to participate in 1 of 6 focus groups to determine themes related to the digital coupon trial. The Phase 2 study included 10 individuals who participated in depth interviews focusing on the processes, motivations and decisions related to coupon use during grocery shopping. The interview was broken out into 5 stages: 1 is an ice-breaker introduction to the study; 2 involves rapport building and setting the tone; 3 is the depth interview that attempts to elicit understanding into the motivation, timing, and rationale behind rejection of coupon use; 4 presents some popular emerging technologies based on emerging applications of interest to the Association of Coupon Professional Board; and 5 includes a brief discussion of different type of coupon and verification. Overall, the consumer's perceived purpose of the coupon is to save money through item cost reduction whereas from a marketing perspective the coupon is intended to entice consumers new to the brand or to encourage trial of a new product (Boundless, n.d.). This difference in perception could be a major contributor to the valuation process and resistance/rejection themes of infrequent users. Interestingly, very few infrequent users rejected the practice of coupons outright and were far more likely to resist or postpone the practice. More research should be conducted to identify when, how and why infrequent users re-evaluate coupons or try the process again. Coupon industry members should review the coupon practice and make a decision to either abandon or overhaul the process as it currently does not provide value to either the manufacturers issuing the coupons or the consumers, even those actively using coupons. If the decision is to overhaul the practice then a decision should be made whether or not to adapt to the current perceptions that coupons are a means to reduce product price or re-educate consumers and industry members alike on the coupon as a means to solicit trial. Lastly, many of the existing apps do not address any of the coupon-related barriers, incongruities, or infrequent user needs. A disruptive technology is needed to change consumer perceptions, encourage coupon use and provide value added utility beyond just bypassing the coupon process to make the practice relevant in today's mobile culture.
    • Quality choice games in durable goods industries.

      Kim, Young Chan.; Reynolds, Stanley; Zajac, Edward; Hoffman, Elizabeth; Isaac, Mark (The University of Arizona., 1992)
      This dissertation is concerned with strategic decision processes in markets where products are both durable and differentiated in quality. Thus, a commodity is differentiated in a two dimensional space (a) its consumption time location, and (b) its quality characteristics. Consumers "self-select" a product among various differentiated products. There exists a one-to-one correspondence between a consumer group and a product with a certain quality in a certain period. A monopolist seller, a monopolist lessor, and a sequential entry duopoly seller market are studied in the framework of a two-period, two-quality model. When product diversification is feasible, the monopoly power of the seller is greatly increased. A seller adopts strategic quality introduction sequence so that the amount of competition from the second-hand market is endogenously selected by the seller. Hence, a seller is able to discriminate among consumers in both intertemporal and contemporaneous fashion. Equilibria are sensitive to the speed of technological advancement. If technology develops slowly, a seller adopts a strategic quality introduction sequence such that it introduces high quality first and low quality later, so that the creation of second-hand market is eliminated. When technology advancement is significant over time, a seller introduces low quality first and high quality later, so that a group of consumers will update the quality of the product they consume over time.
    • Quality circles and their existence in present-day high schools.

      Aleamoni, Lawrence M.; Padro, Fernando Francisco; Allen, Paul M.; Ames, Wilbur S. (The University of Arizona., 1988)
      Circles exploit teamwork by emphasizing on the techne of each individual member of an organization. In particular, Q-Cs rely on self-actualization on the part of each participant to want to do their best for the group. The literature on Quality Circle in education is scarce, but there have been attempts to define these in terms of administrative and classroom activities. If one takes the notion of the teacher as the center of attention and the focus of activity, Circles help in allowing for students to interact more fully with a specific task. And if notion of teamwork is taken, Quality Circles become a mechanism whereby the teachers can add their expertise and different scanning perspective to help the school improve its performance and its product. In Southern and Central Arizona, school districts are not using Q-Cs in name or in fact. Although there are some trends which can allow these to be formed, once a decision is made to include teachers in making decisions for the more substantive issues, for the most part what exists is the traditional approach to management.
    • Quality Control and Waste Reduction in Ultra-High-Purity Gas Delivery Systems

      Shadman, Farhang; Wu, Junsheng; Guzman, Roberto; Gervasio, Dominic (The University of Arizona., 2019)
      Today is the data age; tremendous amount of data is generated, stored, transferred, and computed every second. As the consequence of the rapidly growing data age, the semiconductor industry continues advancing, marching at the pace of Moore’s law. The number of transistors doubling every two years on a chip indicates the unique feature of semiconductor industry. It makes great challenges for the semiconductor devices and the associated production processes as the scaling-down continues. In order to meet the stringent processes requirements, the demands for UHP (ultra-high-purity) gases also increase. Ultra-high-purity (UHP) gases are widely used in semiconductor industry. They are also known as electronic specialty gases (ESGs) or electronic bulk gases when used in the processing of electronic materials. The ultra-high-purity is often defined in terms of impurity level or concentration less than 100 ppb for any volatile molecules, like moisture, which is almost the most common impurity and particulate concentration of size lager than 0.3 micrometer at less than 1 part per liter of gas under normal conditions. Most semiconductor processes are very sensitive to impurities in UHP bulk and processes gases, and a stable and well-controlled purity level is usually required at the POU (point of use) tools. Moisture, which is selected as the key impurity compound in our research, is one of the most common and difficult-to-handle impurities, due to its strong adsorption on various kinds of surfaces. It is very difficult to control moisture level variations at the POU because of two major factors: 1) Drift due to moisture preferential accumulation in the liquid phase in the source tank; 2) Changes due to adsorption / desorption on pipes and flow control devices, as well as variations in flow rate and pipes surrounding temperature. To resolve these two major issues, mathematical process models for cryogenic tanks and gas delivery pipes were developed. Thermodynamic behaviors for vapor and liquid phase impurity in the tank were studied in the tank model to predict the concentration of impurity coming out of the cryogenic tank. Traditional dispersion model was applied to simulate the impurity behaviors in the gas delivery pipes, and to predict the impurity concentration at the pipe outlet (or the POU). Tank-in-series model was introduced to represent the pipe and to mitigate impurity level variations at the POU. Two-tank system was used in the point of source instead of conventional single tank system, of which one was the fully new tank, the other was the partially used tank. By changing the mixing function, which is defined as the ratio of flow rate from the partially used tank to the overall flow rate coming from the two tanks, the mixed concentration as well as the concentration at the POU can be stabilized and well-controlled. Besides, two-tanks system brings in a lot of savings in liquid content in the cryogenic tanks. An associate control system was also designed. This system consists of two cryogenic tanks, two mass flow controllers (MFC), a gas delivery system, a real-time sensor for on-line measurement of impurities, and the auxiliary electronics for running the process simulator, data acquisition, and MFCs programing and control. The flow streams from the two tanks are controlled by two MFCs, then mixed and transported to the POU through a transport pipeline. The impurity level at the POU is monitored by an online sensor. The process simulator provides input to the MFC controller unit that adjusts the flow out of each MFC. Overall, the set-up provides a dynamic flow-mixing scheme run by the output from the process simulator. The system properties, operating conditions and purity requirements are all inputs to the process simulator. By controlling the mixing function, the concentration at the POU can be well controlled. In this dissertation, Chapter 1 is the introduction to the UHP gases and the semiconductor development trends. The experimental instruments as well as the technology used in the project are also included. Their operation principles are described in detail in Chapter 2. Chapter 3 analyzes the impurity drift and variations in UHP gas delivery systems. Chapter 4 provides the solution to the impurity level variations issue at the POU. Chapter 5 is the recommendations and future work.
    • A Quality Improvement Project Designed to Increase Diabetes Quality Indicators at a Primary Care Community Health Center

      McEwen, Marylyn M.; Davila, Claudia Jazmin; McEwen, Marylyn M.; Carrington, Jane M.; McArthur, Donna B. (The University of Arizona., 2016)
      ABSTRACT Background: Diabetes has become an epidemic in the United States, affecting nearly 30 million people per year (National Center for Chronic Disease Prevention and Health Promotion [NCCDPHP], 2014). Type 2 Diabetes Mellitus (T2DM) disproportionately affects Hispanics. The American Diabetes Association (ADA) has established diabetes care guidelines that focus on improving diabetes care and patient outcomes. Quality improvement (QI) efforts have been developed and proven effective at targeting specific diabetes care indicators. Problem: Wesley Health Center (WHC) has identified deficiencies in select ADA diabetes quality care indicators of ophthalmologist referral, annual foot exam, smoking cessation counseling and pneumococcal vaccines for all patients with T2DM (ADA,2015). Design: A QI project applying the Plan-Do-Study-Act (PDSA) cycle was implemented to improve the select diabetes quality care indicators of ophthalmologist referral, annual foot exam, smoking cessation counseling and pneumococcal vaccines for all patients with T2DM. Setting: WHC, a community health center located in Phoenix, Arizona, services mostly uninsured and underinsured Hispanic patients. Intervention: One PDSA cycle was carried out utilizing the fishbone diagram in an effort to identify root cause of the stated problem. The team of stakeholders identified modifications of the current electronic adult template as a key contributing factor. Workflow process changes that complemented the new modifications to the template were also made. The intervention was carried out for six (6) weeks with weekly stakeholder meetings. Expected Outcome: To improve select ADA diabetes quality care indicators for adult patients with T2DM within six (6) weeks of implementation by at least 10% from baseline. Results: Errors in data querying parameters limited data accuracy and interpretation thus the impact of the intervention was not able to be evaluated. Significance: QI interventions are important to nursing practice because they emphasize the importance of a doctorally prepared Advanced Practice Nurse (APRN) to be able to identify a problem in clinical practice and carry out a QI intervention in an effort to improve patient care and outcomes. A QI intervention provides the DNP prepared APRN an opportunity to synthesize into one project the skills and knowledge learned throughout their DNP program.
    • A Quality Improvement Project to Increase Utilization of Interpretive Services for Limited English Proficiency Patients Seeking Care at an Emergency Room

      McEwen, Marilyn M.; Lozoya, Evelyn; McEwen, Marilyn M.; Daly, Patricia; Doyle, Mary (The University of Arizona., 2016)
      In the United States, approximately 59 million people speak another language other than English at home, 37 million of non-English speaking (NES) patients identified Spanish as their primary language (Flores, Abreu, Barone, Bachur & Lin, 2012; Ryan, 2013). An estimated 25.2 million have Limited English Proficiency (LEP) (Flores, Abreu, Barone, Bachur & Lin, 2012; Ryan, 2013). LEP patients are a vulnerable population with greater risk for poor health outcomes due to inappropriate provider-to-patient communication barriers (Diamond, Schenker, Curry, Bradley & Fernandez, 2009). The DNP student and a Quality Improvement (QI) team collaborated to implement a QI project using the QI Plan Do Study Act (PDSA) cycles model. The aim of this QI project was to increase implementation rates of interpretive resources including in-person professional interpreters or use of technological interpreter ad-hoc tools for LEP patients by 10% from baseline measure within four weeks of implementation at the UNMH- ED. The QI team applied the Vocera technical intervention ad-hoc tool to facilitate access for communication between Interpreter Language Services (ILS) and staff who are caring for LEP patient(s).The ILS dashboard results showed use of ILS in the pre-intervention month totaled 82% of ILS ED need met. In contrast, post-intervention use of ILS demonstrated an increase of 89% of ILS ED met. Thus, representing a 7% difference in ILS percent need met demonstrating to be statistically significant with a Chi-Square of 7.898 and p-value of .005. Correspondingly, a 6- month ILS need met was determined when considering the 6-month pre-intervention baseline of 76.8%. Consequently, demonstrating that the projected 10% increase of ILS ED need percent was met, the findings revealed an increase compared to baseline percent. These findings represent a 12% improvement from the pre-intervention baseline ILS ED need met. However, the analysis and results only demonstrate statistical significance but lack to indicate to be clinical significance. This QI project confirmed the intervention was effective in increasing and facilitating ILS access. Time restriction and limited time period for data collection were identified as the main limitations. The project discusses the DNP role in executing opportunity to employ systematic change models driven by QI evidence-based research for improvement in an emergency department setting.