Now showing items 19623-19641 of 19641

    • Zapotec language shift and reversal in Juchitan, Mexico

      Hill, Jane H.; Saynes-Vazquez, Floria E. (The University of Arizona., 2002)
      This dissertation documents the process of language shift from Zapotec to Spanish in urban Juchitan, a Zapotec community in southern Mexico. The work also analyzes the current strategies Juchitecos are developing to stop the replacement of their local language. The work first provides a sociohistorical overview of the community, which helps us to understand its current sociolinguistic situation. Oral and written materials, the ways in which ethnic symbols are manipulated, and the sociopolitical dimensions of the indigenous language are analyzed in order to elucidate the tensions that define the current bilingual situation of Juchitan. The work also addresses the broader aspect of language policies in Mexico, and shows how linguistic policies in the country have promoted the loss of the Mexican languages, and the replacement of Zapotec by Spanish. After describing how these linguistic policies negatively impacted the reproduction of the Zapotec language, the study presents some of the actions Juchiteco people are currently putting into practice in order to restore mother tongue transmission and reverse the process of language shift. The salient ethnic identity of JuchitAn is explored and helps to understand the linguistic profile of the community, as well as the current actions that are being developed towards the reversal of the Zapotec language shift. This study argues, following Fishman's theory, that the reproduction of the Zapotec language and an effective reversal of the language shift depend mostly on the speakers themselves and on the resources locally developed.
    • Zen in the Art of Teaching: Contemplative/Mindfulness Practice in the Professional Development of Teachers

      Vorndran, Kenneth R.; McAllister, Ken; McAllister, Ken; Warnock, John; Miller, Thomas P. (The University of Arizona., 2009)
      This dissertation uses a Zen koan as a foundation for discussing teacher training and development. It suggests that teacher training attends to issues of theory, pedagogy, and technology, and it contends that teacher training and development does not adequately attend to the intrapersonal aspect of teaching. In spite of the use of reflective techniques in teacher education, teachers are not trained in a significant way to navigate, negotiate, or manage the issues of identity, the issues of self-belief, the patterns of thought, and/or the emotional patterns, which affect their teaching and their classrooms. This work looks at research regarding the importance of the intrapersonal aspect of teaching in relation to teacher effectiveness and classroom climate; it considers current practices in pre-service and in-service teacher training; and it reviews research related to the efficacy of mindfulness and contemplative practices, such as meditation. It argues that the intrapersonal aspect of teaching is relevant to teacher effectiveness and classroom climate; that contemplative and mindfulness practices may offer systems that support and sustain teachers as they navigate, negotiate, and manage the intrapersonal aspect of teaching; and that pre-service and in-service professional development may provide vehicles to deliver this training.
    • The zero dispersion limits of nonlinear wave equations.

      Levermore, C. David; Tso, Taicheng.; Palmer, John; Greenlee, W. Martin (The University of Arizona., 1992)
      In chapter 2 we use functional analytic methods and conservation laws to solve the initial-value problem for the Korteweg-de Vries equation, the Benjamin-Bona-Mahony equation, and the nonlinear Schrodinger equation for initial data that satisfy some suitable conditions. In chapter 3 we use the energy estimates to show that the strong convergence of the family of the solutions of the KdV equation obtained in chapter 2 in H³(R) as ε → 0; also, we show that the strong L²(R)-limit of the solutions of the BBM equation as ε → 0 before a critical time. In chapter 4 we use the Whitham modulation theory and averaging method to find the 2π-periodic solutions and the modulation equations of the KdV equation, the BBM equation, the Klein-Gordon equation, the NLS equation, the mKdV equation, and the P-system. We show that the modulation equations of the KdV equation, the K-G equation, the NLS equation, and the mKdV equation are hyperbolic but those of the BBM equation and the P-system are not hyperbolic. Also, we study the relations of the KdV equation and the mKdV equation. Finally, we study the complex mKdV equation to compare with the NLS equation, and then study the complex gKdV equation.

      RASSENTI, STEPHEN. (The University of Arizona., 1982)
      Two complex resource allocation problems motivate the algorithms and applications discussed in this dissertation. The Public Broadcasting Service (PBS), a cooperative of television stations with independent budgets, must decide which programs to purchase from various producers and at what cost to its member stations. The airports of America must decide how to allocate limited takeoff and landing slots to competing airlines. Both problems are recognized as zero/one decision problems with multiple resource constraints. A computer aided allocation mechanism is proposed as an alternative to the currently practiced decision procedures. Bid information, solicited in an auction phase, provides values to parameterize a mathematical model. An optimization phase is then used to generate the best solution for the given information. The integer programming algorithms required to solve the particular models suggested are explored in detail. A best bound enumeration strategy which uses a surrogate knapsack relaxation is developd. Computer storage requirements are curtailed by using a new greedy heuristic for general integer programming problems. The PBS model has a structure closely related to certain fixed charge problems. This allows the use of necessary conditions for the existence of a solution of capacitated transportation problems to test the feasibility of candidate solution vectors. In the SLOT model feasibility testing is a trivial matter of maintaining running row sums. The bound provided by the knapsack relaxation is further enhanced with the addition of a set of generalized choice constraints. An efficient polynomial algorithm and proof of optimality are given for the linear relaxation of this problem. A procedure for generating a set of generalized choice constraints from any set of logical constraints is also given. The viability of the approach developed and the effects of parameter variation are computationally tested in both PBS and SLOT contexts. Some further computational results for project selection, set covering, and multiple knapsack problems are reported. A broad class of mixed integer linear programming problems is defined (e.g., capital expenditure and network design problems) and a suitable relaxation for a similar approach is developed. Finally, several new directions for research in algorithmic development and application are proposed.
    • Zhiyi's interpretation of the concept "dhyana" in his Shi chan boluomi tsidi famen

      Gimello, Robert M.; Wang, Huei-hsin (The University of Arizona., 2001)
      This study is an analysis of Zhiyi's interpretation of the concept of "dhyana" in his Shi chanboluomi cidi famen (An Exposition of Methods to Achieve the Stages of Meditative Perfection, hereafter, The Stages of Meditative Perfection). In the studies of Chinese Buddhism, dhyana , translated into Chinese "chan," is commonly associated with the Chan school (Chan zong ) developed in China in the seventh and the eighth century. In Zhiyi's The Stages of Meditative Perfection, however, dhyana is generally understood as the Four Dhyanas. In the "Four Dhyanas" chapter of The Stages of Meditative Perfection, Zhiyi specifically defines dhyana as "zhilin (dhyana factors)" and "gongde tsonglin (an array of meritorious qualities)." The Stages of Meditative Perfection is Zhiyi's systemization of the various dhyana methods practiced by Chinese Buddhists from the second to the sixth centuries A.D. A general sketch of The Stages of Meditative Perfection is made in the first three chapters of this study. In the first chapter I make a brief textual review and discuss some general features of this text. In chapter two, I discuss some of the important terms related to meditation practices used inThe Stages of Meditative Perfection. The third chapter is an analysis of some of Zhiyi's dhyana classification systems that appear in the first five chapters of The Stages of Meditative Perfection , which comprises Zhiyi's theoretical systemization of Dhyana-paramita . Among Zhiyi's discussion of the actual practice of the fifteen dhyana methods discussed in the sixth and seventh chapters of The Stages of Meditative Perfection, two dhyana practices, the Four Dhyanas and the Tongming guan (The Contemplation Leading to [Six] Supernormal Powers and [Three Illuminating] Insights) are the most crucial for our understanding of Zhiyi's concept of dhyana. Therefore, these two dhyana practices are selected as the subject of detailed analysis. Four aspects of Zhiyi's interpretation of dhyana will be examined in my analysis: Zhiyi's definitions of dhyana, his concepts of "Mundane Dhyana" and "Supramundane Dhyana," the role of intellect and physiology in the meditative states in Zhiyi's interpretation of dhyana, and Zhiyi's method of synthesizing practice and doctrine in his interpretation of dhyana.

      Udo, Eno Jumbo, 1937- (The University of Arizona., 1968)
    • Zinc status and functional correlates in preschool and school-aged children in Egypt.

      Harrison, Gail G.; Mohs, Mary Ellen.; Berry, James W.; Ritenbaugh, Cheryl; Stini, William A.; Weber, Charles W. (The University of Arizona., 1989)
      Zinc status of Egyptian children 18-30 months and 6-10 years of age was characterized in relation to morbidity, growth, and socioeconomic variables. In a pilot study of children whose general nutrition ranged from adequately nourished to moderately malnourished, mean hair zinc was 135 ug/g (63-230 ug/g), with suboptimal zinc status suggested for 44%. Predictors of hair and serum zinc levels were explored for 23 school-aged and 40 preschool children. Included in models were weaning age for preschool children, body size (length- or height- and weight-for-age Z scores), current growth over 6 months or longer, illness experience over 10 to 12 months, demographic variables affecting food availability and distribution, sex, and season. Data were collected by Egyptian workers as part of a larger field project. Hair and serum samples were analyzed for zinc content by atomic absorption spectrophotometry. Results showed no difference in hair zinc levels by color, presence or absence of louse egg fragments and mucilage, or presence or absence of henna dye. In multiple regression models, the best predictor of hair zinc in preschool children was season of year, with zinc lower in summer. Season, negative effect of percent of weeks ill with diarrhea, and positive effects of socioeconomic status (SES) based on father's education/literacy and economic subsistence base excluding agriculture (ESB-A) predicted 23% of total hair zinc variation in preschool children. In preschool children serum zinc was lower in summer. Season, positive effect of rate of weight increase, and negative effects of rate of height increase, SES based on father's occupation(s) (SES2), and ESB-A predicted 53% of total serum zinc variation in preschool children. Serum zinc was higher in summer in school-aged children. Season, negative effect of SES2 and ESB-A, and positive effects of percent weeks ill with diarrhea and height for age Z scores predicted 60% of total serum zinc variation in school-age children. Negative effects of percent weeks ill with diarrhea and parents' age and child:adult ratio predicted 29% of hair zinc in school-aged children.

      THOMPSON, JOAN SILVERMAN. (The University of Arizona., 1983)
      The effects of 18 milligrams elemental zinc as zinc sulfate were investigated in 24 hemodialysis patients during a double blind study. The study was conducted at two different dialysis centers in Utah. Each patient was evaluated for a 12 week period. The effects of zinc supplementation were evaluated using the parameters of serum zinc, hair zinc, dialysate zinc, and objective and subjective taste evaluation procedures. To possibly clearify the above determination in zinc status, copper determination were made of the same parameters. In addition, determinations of serum ferritin, transferrin and iron levels were made. A three day diet record was used to document the dietary intakes of calories, protein, and zinc as well as indicate the balance of food groups in the diets. Patients were evaluated biweekly throughout the study period. There were a total of six evaluations made on each participant during the investigation. Complete data were collected on six patients in the treatment group, and on ten patients in the control group. Even though the sample size was small, results were very steady and values fell within narrow ranges for most parameters examined. The mean baseline serum zinc value (n = 24) was 56 micrograms per deciliter. Patients, by this value would be classified as zinc deficient. However, the hair zinc levels were within the normal range, and no other signs or symptoms of zinc deficiency were evident in any patient, other than altered taste. There were no differences between pre and post dialysis serum zinc levels, nor were there any consistent increases in zinc levels cleared from the plasma during dialysis. There were no increases seen in the serum zinc or hair levels in response to zinc supplementation. Furthermore, there was no significant improvement in the taste acuities of the treatment group patients compared to the controls. The low serum levels maintained were probably due to the redistribution of body zinc known to occur in uremia. Most patients improved their taste test scores. This displayed the learning phenomena that was inherent in the taste testing technique. Furthermore, hemodialysis patients and the failure of many subjects to identify all four tastants (sweet, sour, bitter, and salt) correctly. Daily dietary intakes of high bioglogical value protein and zinc by the patients were less than the amounts recommended by the National Dietary Counsil and the physicians. However, the daily intakes of protein (55 grams) and zinc (7.9 milligrams) were not limited to the level where deficiency signs or symptoms of either nutrient were seen. Copper serum levels were all within the normal range. The mean baseline level for all patients was 113 micrograms per deciliter. Copper status appeared unaffected by uremia or hemodialysis. Body stores of iron, determined by serum ferritin levels, ranged from possibly indicating iron deficiency to iron overload. The body iron stores did not correlate with patients’ responses to the oral zinc supplementation.
    • Zircon (U-Th)/He Dates from Radiation Damaged Crystals: A New Damage-He Diffusivity Model for the Zircon (U-Th)/He Thermochronometer

      Reiners, Peter; Guenthner, William Rexford; Reiners, Peter; Ketcham, Richard; Ganguly, Jibamitra; DeCelles, Peter (The University of Arizona., 2013)
      Zircon (U-Th)/He (zircon He) dating has become a widely used thermochronologic method in the geosciences. Practitioners have traditionally interpreted (U-Th)/He dates from zircons across a broad spectrum of chemical compositions with a single set of ⁴He diffusion kinetics derived from only a handful of crystals (Reiners et al., 2004). However, it has become increasingly clear that a "one-size-fits-all" approach to these kinetics is inadequate, leading to erroneous conclusions and incongruent data. This dissertation develops a more grain-specific approach by showing the fundamental role that intracrystalline radiation damage plays in determining the He diffusivity in a given zircon. I present three appendices that seek to quantify the radiation damage effect on He diffusion in zircon, explain how this effect manifests in zircon He dates, and show how to exploit such manifestations to better constrain sample thermal histories. Of particular importance, this dissertation represents the first comprehensive study to concentrate on the entire damage spectrum found in natural zircon and also the first to show that two different mechanisms affect He diffusion in zircon in different ways across this spectrum. In the first appendix, I and my fellow co-authors describe results from a series of step-heating experiments that show how the alpha dose of a given zircon, which we interpret to be correlated with accumulated radiation damage, influences its He diffusivity. From 1.2 × 10¹⁶ α/g to 1.4 × 10¹⁸ α/g, He diffusivity at a given temperature decreases by three orders of magnitude, but as alpha dose increases from ~2 × 10¹⁸ α/g to 8.2 × 10¹⁸ α/g, He diffusivity then increases by about nine orders of magnitude. We parameterize both the initial decrease and eventual increase in diffusivity with alpha dose with a function that describes these changes in terms of increasing abundance and size of intracrystalline radiation damage zones and resulting effects on the tortuosity of He migration pathways and dual-domain behavior. This is combined with another equation that describes damage annealing in zircon. The end result is a new model that constrains the coevolution of damage, He diffusivity, and He date in zircon as a function of its actinide content and thermal history. The second and third appendices use this new model to decipher zircon He datasets comprising many single grain dates that are correlated with effective uranium (eU, a proxy for the relative degree of radiation damage among grains from the same sample). The model is critical for proper interpretation of results from igneous settings that show date-eU correlations and were once considered spurious (appendix B). When applied to partially reset sedimentary rocks, other sources of date variability, such as damage and He inheritance, have to be considered as well (appendix C).

      Newquist, David Lee, 1956- (The University of Arizona., 1976)

      MCCOURT, RICHARD MATTHEW.; Hendrickson, John R.; Kodric-Brown, Astrid; Brown, James H.; Hoshaw, Robert W. (The University of Arizona., 1983)
      Three species of Sargassum are the P10st abundant intertidal macroalgae at Puerto Penasco, Sonora, Mexico. Sargassum johnstonii Setchell & Gardner, S. herporhizum Setchell & Gardner, and S. sinicola Setchell & Gardner var. camouii (Dawson) Norris & Yensen are zoned on emergent reef in low intertidal areas. Sargassum johnstonii occurs in a zone above dense stands of S. herporhizum, and scattered patches of S. 8inicola occur on the lowest emergent reef. Sargassum sinicola, the most abundant species, predominates in pools throughout the intertidal zone. In mid-intertidal pools the species show the same zonation with respect to water depth that they do on emergent reef. Ecological separation is clear, the species occurring in different vertical zones or different habitats (pools or emergent reef). At some sites where S. herporhizum is rare or absent, the upper limit of emergent S. sinicola plants shifts upward probably because of a combination of physical and biological factors. The three species in this highly seasonal region reach maximum size and canopy cover in early spring. All produce fertile receptacles in the spring and shed their branches and die back in summer. Surviving S. sinicola persist through the summer at larger sizes, recommence growth and produce a second crop of receptacles in the fall; the other two species grow but are not fertile until the following spring. The species differ in allocation of biomass to vegetative and sexual reproductive structures. Sargassum herporhizum invests a high proportion of its wet and dry biomass into extensively branched, rhizoidal holdfasts. The holdfasts of the other two species are smaller relative to their upper branches, and are not rhizoidal. Experimental clearings showed that S. herporhizum was the most effective at recovering continuous space after disturbance and also after normal summer dieback. Sargassum johnstonii and S. sinicola produce large volumes of sexual receptacles on buoyant branches, which have the potential for wide dispersal, whereas S. herporhizum produces a relatively small volume. A trade-off between short-range vegetative encroachment abilities and potential for long-range dispersal of sexual propagules may have occurred in the evolution of reproductive strategies of these Sargassum species.
    • The Zone of Tolerance and its effects on the hiring of school principals.

      Grant, Robert T.; Voorhis, George William.; Sacken, Donal M.; Conley, Sharon (The University of Arizona., 1989)
      The Zone of Tolerance is a concept which describes the latitude of control that a community gives to its professional educators. Current research which attempts to delineate this zone indicates that community control of a district will vary, but is predictable when variables are arranged to meet certain criteria. Specifically, William Boyd (1976) concluded in a summary of the research that in large heterogeneous urban districts professional interests will dominate in routine internal issues such as personnel. This study used multiple qualitative methods to examine Boyd's contention by analyzing the hiring of successful principal candidates in a large heterogeneous school district. Interviews were conducted with principals selected by questionnaires and hired in the district during the period of time from 1975 to 1985. Corresponding data about school district events for the period were also collected from newspapers and other public archives. In addition, principals' perceptions of legitimacy affected by changes in influence on the hiring process were gathered. Data were then reduced, categorized and analyzed on the basis of shifting patterns of community and professional dominance. Results indicated that an increase in minority rights issues and the community's changing demographics shifted control of the hiring process from the school professionals to a newly elected school board more representative of community interests. Principals' perceptions of legitimacy affected by the changing patterns of dominance were varied and inconclusive, however the shift in control over personnel decisions regarding the hiring of principals was conclusive and contradicted Boyd's contention.

      SHETTEL-NEUBER, MARY JOYCE.; Bechtel; Ittelson; Lockard; Doxtater (The University of Arizona., 1986)
      The present study, in contrast with previous work that has isolated one or two important factors influencing the status of the zoo, considered the three important zoo reference groups--animals, visitors, and staff members--and their interrelationships within the zoo environment. Two approaches were used to investigate the system of interactions within the zoo. First, an in-depth examination of a new set of naturalistic exhibits was performed. Second, a comparison of two of these naturalistic exhibits with two older, sterile exhibits which housed the same species at the same zoo was made. Multiple methods were used in the present study and included behavior mapping of visitors, staff, and animals, timing of visitor stays at exhibits, tracking of visitors through the exhibits, a visitor questionnaire, and interviews with staff members. One major finding was the lack of correspondence among the major groups as to the acceptability of exhibits. For example, one exhibit which was considered beneficial to the enclosed animals and was well utilized and positively evaluated by visitors presented staff members with great difficulties in animal containment and exhibit maintenance. Comparisons of naturalistic enclosures and sterile cement enclosures housing the same species revealed no consistent, clear-cut differences in animal and visitor behavior, however, attitudinal differences were found for staff members and visitors. Visitors and staff members preferred the naturalistic exhibits and perceived them as more beneficial to animals and visitors. These findings were discussed in terms of theoretical and applied issues relevant to zoo design and management and to research in zoos.
    • Zooarchaeology and Chronology of Homol'ovi I and Other Pueblo IV Period Sites in the Central Little Colorado River Valley, Northern Arizona

      Adams, E. Charles; Schiffer, Michael B.; LaMotta, Vincent Michael; Adams, E. Charles; Schiffer, Michael B.; Mills, Barbara J.; Stiner, Mary C. (The University of Arizona., 2006)
      This study explores aspects of the development and organization of a mid-thirteenth through fourteenth-century, ancestral Hopi settlement cluster at Homol'ovi, located in the central Little Colorado River valley in north-central Arizona. The Homol'ovi cluster has been the subject of an intensive, 20-plus year program of excavation and survey by the Arizona State Museum's Homol'ovi Research Program. Homol'ovi I, an 1100-room pueblo occupied from approximately A.D. 1290 to 1400, was excavated between 1994 and 1999 and yielded deeply stratified, intact cultural deposits. The present study develops an internal, ceramic-based chronology of deposits at Homol'ovi I; establishes temporal relationships between occupational components at Homol'ovi I and other Pueblo IV period sites in the Homol'ovi cluster; and explores spatial and temporal variation in ritual activities within the Homol'ovi cluster through the lens of zooarchaeology.The Homol'ovi I chronology developed in this study is based on frequency seriation of imported Jeddito Yellow Ware pottery; stylistic, formal, and technological analysis of Jeddito Yellow Ware; ceramic cross-dating; and high-precision AMS radiocarbon dating. These dating techniques make it possible to seriate cultural deposits at Homol'ovi I, and to tie deposits from other local sites into the Homol'ovi I sequence. Additionally, some of the techniques potentially can be applied to date sites in other regions where Jeddito Yellow Ware pottery is found. This chronological research establishes a framework for tracking behavioral and organizational changes within the village of Homol'ovi I, and for situating events and processes in the life history of this community within a broader, regional context.One potential application of this chronological framework is explored through a zooarchaeological study that addresses temporal and site-to-site variation in the use and deposition of ritually sensitive categories of fauna at Homol'ovi I and other nearby villages, including Homol'ovi II, III, and IV. The fauna of interest include birds, carnivores, artiodactyls, and certain reptiles and amphibians. This study identifies a number of temporal trends that may be related to a major, late-fourteenth century reorganization of the Homol'ovi cluster and its external relations. In doing so, it lays a foundation for further research into the ritual organization of the Homol'ovi cluster.

      BOWERS, MICHAEL WAYNE. (The University of Arizona., 1983)
      The ratification of the Bill of Rights in 1791 brought freedom of the press into the sphere of constitutional legitimacy such that it could not be nullified by the whims of elected officials. Traditionally the guarantee of a free press has been treated as an adjunct of the Speech Clause with little, if any, independent status. Recently, however, that traditional conception has come under increasing attack. Many attorneys, judges and academicians have argued for a separation of the Press and Speech Clauses. For example, former U.S. Supreme Court Justice Potter Stewart has stated his belief that the Press Clause is a structural guarantee which provides greater First Amendment protection to the press than that generally accorded the public. Therefore, the U.S. Supreme Court's decision in Zurcher v. Stanford Daily (1978) that ratified searches of non-suspect, third-party newsmen exemplified for these supporters the nadir of press freedom in recent years. In this study the importance of the Zurcher decision to public policy, public law and legal studies is examined in detail. The study utilizes the systems model popularized by David Easton to observe the events leading up to the decision and both the judicial and legislative responses to that decision. In addition, a new theory of press freedom is presented which analogizes the Press Clause to the Free Exercise of Religion Clause. This theory suggests that the Press Clause should be separated from the Speech Clause in the same way as the Free Exercise Clause has been separated. This would establish the Press Clause as an independent clause granting a special status to the press: a status which the author believes to be warranted by the language of the First Amendment and the absolute necessity for a press free of governmental intrusion and regulation.
    • The Zurna, Oboe, and Syrian Musical Practice: Authenticating a Musical Modernity

      Tatman, Neil; Shaheen, Andrea Lynn; Sturman, Janet; Dietz, William; Kirkbride, Jerry; Tatman, Neil (The University of Arizona., 2012)
      In contemporary Damascus, the modern oboe and an instrument known as its predecessor, the zurna, are heard on a daily basis as they continue to be employed in Syrian popular and folk music practices. After observing the pervasiveness of the sounds of these instruments in Syria, I proceeded to investigate the socio-cultural processes surrounding their usage. This study provides a history of the zurna, traces its development in Europe into the modern oboe, and explores the oboe's re-entry into musical practices in the Middle East. Through empirical fieldwork, I collected data that allowed me to observe the social significance of the sounds of these instruments for musicians and listeners alike in the Greater Damascus area. Using Jonathan Shannon's modernity improvisation model (Shannon 2006) as a departure point, I analyze the way Syrians use instruments such as the zurna and oboe in seemingly diverging ways to create their own "modern" subjectivities. Additionally, I demonstrate how these sounds reflect what Clifford Geertz refers to as the inevitable struggle between essentialism and epochalism in post-colonial nations such as Syria (Geertz 1971) through the analyzation of discourse surrounding instruments so deemed "modern" or "authentic" (such as the oboe and zurna, respectively) in contemporary Syrian society. Musical examples are included in order to demonstrate performance practice and provide perspective on the music theory behind the ways composers and musicians include the sounds of the oboe and zurna in particular works and genres.
    • α-Alkoxyacrylic acids from α-ketoacids.

      Samaraweera, Jesmine Sriyani.; Bates, Robert B.; O'Brien, David; Mash, Eugene A., Jr.; Wigley, David; Walker, F. Ann (The University of Arizona., 1994)
      Dianions were made for the first time from α-ketoacids, using n-BuLi/t-BuOK (Lochmann's base), and alkylated on oxygen with dialkyl sulfates, alkyl sulfonates (triflates, tosylates), or alkyl halides to produce α-alkoxyacrylic acids. This is a more direct and efficient route to these acids than those used earlier. The α -ketoacids used were pyruvic acid, 2-oxobutanoic acid, and 3-methyl-2-oxobutanoic acid. 2-Oxobutanoic acid gave (Z)-2-alkoxy-2-butenoic acids with very high stereoselectivity. 3-Methyl-2-oxobutanoic acid gave 3-methyl-2-alkoxy-2-butenoic acids in low yields, but this is the only route to these acids to date.
    • δ¹³C and stomatal density variability in modern and fossil leaves of key plants in the western United States

      Leavitt, Steven W.; Van de Water, Peter Kent (The University of Arizona., 1999)
      During the last deglaciation, 15,000 to 12,000 calendar years ago, global warming and wholesale shifts in regional precipitation patterns produced dramatic changes in vegetation worldwide. Paleobotanical records, namely pollen and macrofossils, have been used not only to reconstruct shifts in plant distributions and abundances, but also to quantify changes in temperature and precipitation amounts or seasonality. In addition to climatic change, during the full glacial period atmospheric CO₂ values had dropped 30% to 200 ppmv compared to the Holocene, preindustrial value of 280 ppmv. Hypothetically, variations in atmospheric CO₂ affect plant water-use efficiency (carbon gained to plant-water transpired) and thus may have modulated vegetation response as climates change. The studies incorporated in this dissertation focused upon carbon isotope and morphological changes in leaves of key functional groups. The studies concentrated on plant species that are abundant in the fossil record and comprise major floral components of past and present vegetation. Key findings include: (1) that shifts in δ¹³C in modern populations along steep environmental gradients seldom exceeds inter-plant variability at a given site, (2) inter-plant and intra-site variability in modern and historic herbarium collections of the C₄ halophytes Altriplex canescens and A. confertilfolia and packrat midden macrofossils of A. canescens excludes their use as a reliable proxy for atmospheric δ¹³C, (3) calcium-oxalate crystals are common component in plant tissue and can have a significantly different δ¹³C value that increases inter-plant variability, especially in C₄ plants such as Atriplex canescens and A. confertifolia, (4) carbon isotope and stomatal density/index measurements of macrofossils from packrat middens show species specific adaptation in ecophysiological processes as atmospheric CO₂ rose from the full glacial, and (5) the greatest adaptation to low atmospheric CO₂ during the last ice age was in the C₃ species and that C₄ and CAM plants showed few changes in their discrimination against ¹³C or in the number of stomata on their leaf surfaces.

      Bowen, Theodore; Dawes, William R. (The University of Arizona., 1968)