Now showing items 1483-1502 of 19641

    • "Baby Veronica" & The Indian Child Welfare Act (ICWA): A Public's Perception

      Luna Firebaugh, Eileen; Ross-Mulkey, Mikhelle Lynn; Luna Firebaugh, Eileen; Tippeconnic-Fox, Mary Jo; Oberly, Stacey (The University of Arizona., 2015)
      What has become known to the world as the Baby Veronica case (2009-2013) involves several parties including the biological father, Dusten Brown, who is a Cherokee citizen, the Non-Native adoptive parents, the Capobiancos, the Cherokee Nation, and most importantly the baby who is now a child getting ready to start school, Veronica. It is a complex child custody case, but one that is well supported in Federal Indian Law and Policy with the Indian Child Welfare Act (ICWA) of 1978 and Mississippi Band of Choctaw Indians v. Holyfields (1989). In the beginning of the Adoptive Couple v. Baby Girl et al case (or famously known simply as the Baby Veronica case), the South Carolina Family Court and Supreme Court used the legalese of the ICWA to uphold the biological father's parental right to stop the adoption of his child. However, in an interesting turn of events the case was then taken up by the United States (U.S.) Supreme Court where it was ruled that the biological father was not an Indian parent as defined by ICWA (before the child was placed with the prospective adoptive couple there was no preexisting custody of the newborn child by the father) and stating that state law applied and not ICWA in this case and since the father was not married to the birth mother and had not paid child support he was not deemed a parent by South Carolina’s definition of the word. The most recent decision came from the South Carolina court stating that Baby Veronica, after two years of living with her father, must be returned to the prospective adoptive parents. Most everyone out there felt sadness for the prospective adoptive couple who had loved and provided for this child for two years, but all adoptive/foster parents know there is always a chance for the natural parents to object to the placement (it is called legal risk in child welfare). Each state sets their own laws on how long the natural parents have to change their mind, but in this case the biological father was not even aware that the biological mother was planning on giving the child up for adoption. Once he discovered the adoption, four months after the child was born and had been living with the Capobiancos since birth, he filed a petition to stop it and regain custody. This action would lead to a four year long custody battle. While it is important to look at all the facts and the history of the ICWA (and now the future of the ICWA) this dissertation focuses mostly on the public perception of the case. This case has received a fair amount of media coverage throughout the United States including a one-hour episode on Dr. Phil which aired on CBS. It is not often that something happening in Indian County makes it to mainstream media/attention, but when it does there is usually a great deal of misunderstanding on the issue. This is also true for most of the coverage and public responses from the media. This time around it was also true of the U.S. Supreme Court who focused too much attention on Dusten Brown’s blood quantum and not his cultural upbringing. Further the majority of the Supreme Court Justices held that the problems that existed pre-ICWA are not really a problem anymore which is reverberated through the public's perception. It is the intention of this dissertation to follow and analyze the media and the public of this particular case and the ICWA in general through the theories of framing and Red Power. In the social sciences framing is the social construction of a social phenomenon (the Baby Veronica case) by mass media sources (newspapers and television shows), political or social movements, political leaders (Chief John Baker of the Cherokee Nation), or other actors and organizations (National Indian Child Welfare Association). The individual's perception of the facts and meaning attributed to words or phrases will be influenced by some or all of these entities. A frame creates rhetoric in a way that can either encourage or discourage certain interpretations. Stereotypes are one example of framing and are seen in the Baby Veronica case especially as people try to define what it means to be Cherokee. Red Power can be seen as a frame, but is also an American Indian theory that links ethnic pride and political activism to a resurgence of Indian identity. There was a lot of ethnic pride and political activism that took place in favor of Dusten Brown retaining custody of his daughter which no doubt heightened the Cherokee Indian identity, but unfortunately in this case this resurgence would not be enough to keep Veronica, now at the age of four, living with her biological father. However, this dissertation will conclude with some possible recommendations for the Indian Child Welfare Act and the future of American Indian child custody cases.
    • Bach Transcription for Marimba: Creating an Authentic Performance Edition of Johann Sebastian Bach's Sonata no. 1 for Violin Solo, BWV 1001, and Sonata no. 2: Grave, BWV 1003, Using Guitar and Lute Transcriptions as Models

      Weinberg, Norman; Bastian, Darren Bruce; Weinberg, Norman; Cook, Gary; Haskell, Jeffrey; Decker, Pamela (The University of Arizona., 2009)
      Musicians have transcribed and adapted Johann Sebastian Bach's Sonatas and Partitas for Violin Solo, BWV 1001-1006, since Bach penned the works around the year 1720. Bach, himself, transcribed much of the material, adapting it for organ, harpsichord, lute, or even for his sinfonias and cantatas. It was also common for performers of the time to personalize these pieces with ornamentation, improvisation, dynamics, rhythmic interpretation, and in some cases, changes in pitch material.It is in this spirit that the author introduces marimba performance editions of Bach's Sonata no. 1 for Violin Solo, BWV 1001, and Sonata no. 2: Grave, BWV 1003, based on performances and transcriptions by guitarists and lutanists. The guitar and lute were selected as models due to their similarities to the marimba as well as the abundant resources that guitarists and lutanists have provided regarding Bach's unaccompanied string music. Their transcriptions and performances frequently include adaptations to fit their instruments' polyphonic abilities and sound characteristics. A similar approach is likewise suitable for the marimba. Thus, the present study includes an overview of Baroque performance practice as it relates to plucked-string instruments, analysis of published lute and guitar transcriptions of Bach's unaccompanied string music, and transcriptions and analysis of lute and guitar audio recordings. The plucked-string artists and scholars' approach is then assimilated into an authentic marimba performance edition of these works.
    • Backing into decisions: A study of thresholds in decision-making

      Gilliland, Stephen; Mertens, Daniel P. (The University of Arizona., 2003)
      Strategic decisions involving mergers and acquisitions often hinge on one or two critical evaluations. Similarly, when hiring a new manager, potential candidates are often rejected if they are lacking on a critical dimension. In my dissertation, I examined the way in which these critical dimensions are used to screen decision alternatives. Specifically, I am examining the nature of Image Theory's violation and rejection thresholds (the compatibility test) in the screening and elimination of undesirable decision options. In contrast to traditional decision theory, which focuses on choice (i.e., maximization of expected value), recent studies suggest that pre-choice screening of options may account for the greater part of one's decision activities and that choice serves merely to select the best of the options that survive screening. The point of the present research is to explore the variables that influence decision makers' appraisal of option compatibility. For example, I determined one such variable as the "killer variable", which is a feature of an option that is extreme in nature (wholly unacceptable or acceptable) to the decision maker. Its inclusion, regardless of the attractiveness of the rest of the option's features, counteracts usual decisions. My research also determined that individual features have the ability to effect the rejection, as well as the violation, threshold. My research tests this and similar hypotheses about screening.
    • Backside charging of CCDs

      Lesser, Michael P.; Iyer, Venkatraman, 1967- (The University of Arizona., 1997)
      Backside illuminated thinned CCDs have the highest response in the UV and blue spectral region. Their use in detectors is limited due to the instability of the CCD. A low temperature oxide nearly 30 Å thick is grown on the acid thinned backside to tie up dangling bonds. The oxide carries fixed positive charges that attract and trap photogenerated electrons. A permanent and stable backside charging procedure is necessary to create a negative bias that will drive electrons to the frontside collection wells. We have shown chemisorption charging to be a novel method to permanently charge CCDs. The catalytic nature of certain metals are exploited to chemisorb oxygen as negative atomic species at the metal/oxide interface. Charging is shown to occur by depositing a thin film 10 Å of platinum on the backside. No tunneling occurs because of the thick oxide. The Passivated Platinum Film (PPtF) which utilizes a hafnium oxide antireflection coating to passivate the platinum is an effective process, but it is sensitive to the environment and discharges quickly upon hydrogen exposure. A silver catalytic coating is shown to be far superior to other charging techniques. Silver irreversibly chemisorbs oxygen and hydrogen is not dissociatively adsorbed except at temperatures < 100°K. High quantum efficiencies have been recorded for the UV-blue ranges. A slight drop is seen at cold temperatures due to interaction of water with oxygen to form hydroxyl ions. No change in QE is seen upon exposure to hydrogen or during outgassing. Silver is also one of the most transparent metals and easily deposited by evaporation. We therefore have developed a charging process which is nearly ideal for CCD imaging.
    • Backwards and forwards: Behavioral and neurophysiological investigations into dependency processing

      Forster, Kenneth I.; Nicol, Janet L.; Witzel, Jeffrey D.; Forster, Kenneth I.; Nicol, Janet L.; Allen, John J.B.; Badecker, William; Garrett, Merrill (The University of Arizona., 2010)
      This dissertation examines the processing of sentences involving long-distance linguistic dependencies, or sentences containing elements that must be linked across intervening words and phrases. Specifically, both behavioral (self-paced reading and eye tracking) and neurophysiological (electroencephalography) methods were used (a) to evaluate the relative importance of backward- and forward-looking dependency satisfaction processes in the comprehension of sentences involving wh-dependencies and (b) to determine the extent to which common neurocognitive mechanisms are involved the processing of wh- and anaphoric dependencies. With respect to the first issue, both behavioral andneurophysiological results indicated a core role for forward-looking, expectancy-based processes in the comprehension of wh-dependency sentences. Regarding the latter issue, despite considerable overlap in the reading patterns associated with wh-dependencies and (at least some types of) anaphora, the neurophysiological responses related to these dependency types indicated that their processing draws on distinct neurocognitive mechanisms.
    • Bacterial Diversity of the Atacama Desert, Chile: The Challenges of Characterizing the Community Dynamics of Extreme Oligotrophic Ecosystems

      Maier, Raina M.; Neilson, Julia Worsley; Pepper, Ian L.; Rasmussen, Craig; Arnold, Anne Elizabeth; Maier, Raina M. (The University of Arizona., 2012)
      This dissertation examines the bacterial diversity of hyperarid and arid regions of the Atacama Desert, Chile, as a first step towards understanding the global biogeochemical significance of arid-land microbial communities. The specific objectives were to characterize bacterial diversity and infer the possible metabolic potential of these bacterial communities, and to evaluate the influence of moisture exposure on community structure. In addition, the strengths and limitations of available tools for probing microbial diversity and activity in terrestrial ecosystems were characterized for their application to extreme oligotrophic communities. Preliminary PCR-DGGE analysis of a west-east elevational transect from the Pacific Ocean near Antofagasta to the western slopes of the central Andes indicated that bacterial communities along this transect belonged to two distinct community types: 1) hyperarid (700 - 2000 m) and 2) arid (2500 - 4500 m) communities that included both vegetated and unvegetated regions. Subsequent diversity analysis of these two regions revealed novel but distinct communities in both regions. A greater diversity was observed in the unvegetated arid regions than in the unvegetated hyperarid areas. The unvegetated arid sites were characterized by a bacterial community harboring a combination of radiotolerant and halotolerant heterotrophs as wells as diverse phylotypes closely related to chemolithoautotrophs. These rare phylotypes may be uniquely adapted to arid ecosystems. Molecular tools evaluated for community diversity analysis included PCR-DGGE, Sanger-clone and 454-pyrosequencing analysis of 16S rRNA gene libraries, and the use of reverse transcriptase quantitative PCR (RT-qPCR) for quantifying the impact of environmental variables on the metabolic activity of a specific organism. These techniques were evaluated using the ecosystems of the Atacama Desert as well as model ecosystems designed to address specific questions. Molecular tools are invaluable to the study of microbial ecology because they facilitate the study of fastidious organisms that are difficult or impossible to culture, but the analysis presented in this dissertation demonstrates that each of these methods has limitations and biases which must be acknowledged to avoid inaccurate conclusions from skewed results. The most complete picture of the taxonomic and functional profile of a microbial community is obtained by employing a combination of molecular techniques.
    • Bacterial Endosymbionts of Endophytic Fungi: Diversity, Phylogenetic Structure, and Biotic Interactions

      Arnold, Anne Elizabeth; Hoffman, Michele Therese; Arnold, Anne Elizabeth; Bronstein, Judith L.; Orbach, Marc J. (The University of Arizona., 2010)
      This dissertation comprises a series of studies designed to explore the associations between plants and the endophytic fungi they harbor in their above-ground tissues. By viewing endophyte diversity in ecologically and economically important hosts through the lenses of phylogenetic biology, microbiology, and biotechnology, this body of work links plant ecology with newly discovered symbiotic units comprised of endophytic fungi and the bacteria that inhabit them.This work begins with a large-scale survey of endophytic fungi from native and non-native Cupressaceae in Arizona and North Carolina. After isolating over 400 strains of endophytes, I inferred the evolutionary relationships among these fungi using both Bayesian and parsimony analyses. In addition to showing that native and introduced plants contained different endophytes, I found that the endophytes themselves harbor additional microbial symbionts, recovering members of the beta- and gamma-proteobacterial orders Burkholderiales, Xanthomonadales, and Enterobacteriales and numerous novel, previously uncultured bacteria. This work finds that phylogenetically diverse bacterial endosymbionts occur within living hyphae of multiple major lineages of ascomycetous endophytes.A focus on 29 fungal/bacterial associations revealed that bacterial and fungal phylogenies are incongruent with each other and did not reflect the phylogenetic relationships of host plants. Instead, both endophyte and bacterial assemblages were strongly structured by geography, consistent with local horizontal transmission. Endophytes could be cured of their bacterial endosymbionts using antibiotics, providing a tractable experimental system for comparisons of growth and metabolite production under varying conditions. Studies of seven focal fungal/bacterial pairs showed that bacteria could significantly alter growth of fungi at different nutrient and temperature levels in vitro, and that different members of the same bacterial lineages interact with different fungi in different ways.Focusing on one isolate, I then describe for the first time the production of indole-3-acetic acid (IAA) by a non-pathogenic, foliar endophytic fungus (Pestalotiopsis neglecta), suggesting a potential benefit to the host plant harboring this fungus. I show that this fungus is inhabited by an endohyphal bacterium (Luteibacter sp.) and demonstrate that mycelium containing this bacterium produces significantly more IAA in vitro than the fungus alone. I predict that the general biochemical pathway used by the fungal-endohyphal complex is L-tryptophan-dependent and measure effects of IAA production in vivo, focusing on root and shoot growth in tomato seedlings.
    • Bacterial indicator organisms in various classes of cisterns in the U.S. Virgin Islands

      Ruskin, Robert H.,1952-; Lehman, Gordon S.; Guertin, D. Phillip; Clarke, Jeanne N.; Gay, Lloyd W.; Gerba, Charles P.; Pepper, Ian L. (The University of Arizona., 1996)
      Because cisterns are exposed to the environment via their direct attachment to catchment surfaces, cistern water quality is often poor. In the U.S. Virgin Islands cisterns are involved in supplying the water needs for private homes, hotels, businesses and public housing, making them subject to the mandates of the Federal Safe Drinking Water Act. This study compares the results of the occurrence of various water quality indicators in Private Residential, Public Housing, and Hotels and Guest House cisterns in the U.S. Virgin Islands in a side-by-side analysis. Forty-seven separate independent variables were created and tested for correlation, of which only the rate at which chlorination was applied was significant. A high degree of correlation was found to exist between total and fecal coliforms. A moderate, but still significant correlation between the coliform and the heterotrophic levels in the cistern was also noted. There was no correlation between any of the bacterial indicators studied and the opportunistic pathogen Pseudomonas aeruginosa. The results show, depending upon on the type and amount of chlorination received, different bacterial indicators will predominate and that there is a logical succession from one to the next with chlorination. On the unchlorinated end of the scale, normally associated with privateresidential homes, there is a correlation between the heterotrophic bacteria and total coliform. On the other end where chlorination is constant, normally associated with public water supply systems, correlation is between total coliform and fecal coliform. The proportion at which these indicators occur is a function of the diligence at which chlorination takes place. Regression analysis showed that the heterotrophs and total coliforms were the most sensitive to chlorination while the streptococci and fecal coliform were the most resistant. Thus, what is seen is fecal coliform unmasking based upon chlorination pattern. Depending upon whether the cistern is a private or public water supply which is mandated to be treated, an appropriate indicator system based upon the likelihood of treatment can be suggested. For unchlorinated private residential home cisterns the prime indicator should be the heterotrophic plate count and for chlorinated systems the take-action organism should be the fecal coliform. P. aeruginosa should be tested for in both domestic cistern water supplies and public cistern water supply systems.
    • Bacterial Motility: From Propulsion to Collective Behavior

      Goldstein, Raymond E.; Dombrowski, Christopher Charles; Goldstein, Raymond E.; Visscher, Koen; Kessler, John O.; Manne, Srinivas; Hsieh, Ke Chiang (The University of Arizona., 2007)
      This work explores bacterial motility from the mechanisms of propulsion of an individual cell to the complex behavior of collective motility. The shear modulus of bacterial flagella was measured by stretching isolated flagella with an optical trap and by measuring force extension curves of the stretched flagella shedding light onto the me-chanics involved in the motility of single micro-organisms. Experiments in concentrated suspensions of bacteria show collective behavior with large scale mixing on a time and length scale greater than can be understood from the standard model of "run and tumble" motility of a single organism are reported. To further understand the transition from individual to collective motility a novel form of motility where an individual bacterium can reverse direction without changing cell orientation is reported here. These experiments further the understanding of bacterial motility.
    • Bacterial Symbionts at the Colony and Individual Levels: Integration through Behavior and Morphology in a Social Insect

      Wheeler, Diana E; Rodrigues, Pedro A D P.; Wheeler, Diana E.; Bronstein, Judith L.; Davidowitz, Goggy; Anderson, Kirk E.; Powell, Scott (The University of Arizona., 2016)
      The determination of a symbiotic association as beneficial requires good assessment of the costs and benefits involved in the maintenance and transmission of these microbes across generations. In social insects, symbiotic associations are complex as they may involve a network of interactions between individual and colony that result in stable associations over evolutionary time. My goal was to investigate the roles of behavior and morphology as integrators that have enabled the benefits of harboring gut microbes to reach both adult and growing brood in a colony. To achieve this goal, I used turtle ants (Cephalotes), a group that has co-evolved with their gut microbes since the Eocene (Sanders et al. 2014) and that shows a variety of morphological and behavioral specializations likely connected to this symbiotic association. In my dissertation I present evidence that the specialized behavior and morphology of Cephalotes are indeed strongly associated with mechanisms that ensure stability of ant-gut microbe interactions over evolutionary time. In Appendix A, I show that a valve between the crop and midgut (proventriculus) of C. rohweri works as a filtration organ, capable of excluding possible pathogens from the mostly liquid diet consumed by turtle ants. In addition, the proventricular filter is also associated with the structuring of the gut microbiota, dividing it in at least two great groups: one upstream and another downstream of the proventriculus. Through behavioral observation and microscopy, we also suggest that the formation of the proventricular filter is only complete after young and sterile workers (callows) are inoculated with the core group of symbiotic bacteria. In Appendix B, I present results confirming that the compartmentalization of gut microbiota is also present in the congener C. varians. I compare these results with previously published data, defining the meta-communities of the gut microbiota, and demonstrate that the previously recognized core microbiota is composed of compartment-specific microbial communities and lineages. This compartmentalization of the gut microbiota is similar to the one found in highly specialized herbivores, both vertebrates and invertebrates. In addition, I also sampled the infrabuccal pocket, a characteristic oral cavity found in ants and that has largely been ignored in studies of gut symbiosis. Based on my results, I provide compelling evidence that hindgut microbes are inoculated into food particles trapped in the infrabuccal pocket, aiding in digestion of this substrate. Moreover, I suggest that trophallaxis olays a central role in inoculation of food and individuals, and might be responsible for the transmission of nutrients that are predicted to result from the gut bacteria metabolism. Finally, in Appendix C I characterize abdominal trophallaxis in C. rohweri to gain insight on its role in the context of symbiotic associations with gut microbes. I show that the hindgut contents, including bacteria, can be transmitted via abdominal trophallaxis. This interaction is found to occur between all combinations of major and minor workers, in addition to callows. The rate of solicitation of abdominal trophallaxis is higher when individuals are protein starved, indicating that hindgut content may also be nutritive. Using shotgun metagenomic data, we show that the microbiota present in the infrabuccal pocket (mostly hindgut bacteria) are indeed capable of re-utilizing nitrogen and synthesizing essential amino acids, in addition to breaking down plant material. We also report that oral trophallaxis is a possible route for transmission of crop-specific bacteria for callows, as this group has performed oral trophallaxis at a relatively higher rate than older workers. Put together, these results highlight the importance of nestmate interactions and gut morphology in the establishment and maintenance of symbiotic microbes in a social insect, introducing a new model for explaining the evolution and functioning of ant-gut microbe symbiosis.
    • Bacterial transport in variably saturated porous media.

      Jewett, David Gordon; Bales, Roger C.; Logan, Bruce E.; Arnold, Robert G.; Wilson, Lorne G.; Yeh, Tian-Chyi J.; Gerba, Charles P. (The University of Arizona., 1995)
      The transport of Pseudomonas fluorescens strain P17 through saturated and unsaturated porous media was investigated. Continuous-flow column experiments examined the effects of ionic strength and pH on P17 transport in saturated porous media. Bacterial penetration was measured and filtration theory was used to calculate bacterial collision efficiencies (ɑ). A decrease in ionic strength from 10⁻¹ to 10⁻⁵ M produced an approximately 90% decrease in bacterial ɑ's (from 0.12 to 0.015). This change in a is consistent with double-layer theory, but suggests that very large changes in ionic strength are necessary to influence transport. Cell transport was unaffected by pH in the range of 5.5 < pH < 7.0. Column results were compared to a screening technique using large-pore filters. Filter ɑ's followed similar trends, but were about 1.5 times that of column ɑ's, likely due to the use of an idealized model to describe different porous media geometries and system hydraulics. Column results also indicate that uncertainty in measurements of culturable bacteria can preclude reliable estimation of low ɑ values. For ɑ < 0.01, a rapid and more reliable mini-column method is suggested for measuring biocolloid attenuation in saturated porous media. Laboratory experiments also determined P17 transport as a function of water content and the influence of the gas-liquid and solid-liquid interfaces in limiting microbial transport. Cells were suspended in artificial groundwater and injected into saturated and unsaturated quartz sand columns. Total P17 retention (R(t)) was inversely proportional to water content with approximately twice the cell retention at 46% water saturation (R(t) = 0.95) compared to saturated experiments (R(t) = 0.50). Retained cells were divided into fractions attached at the gas-liquid (R(g)) and solid-liquid (R(s)) interfaces. The ratio of R(g)/R(t), increased with decreasing water content suggesting increased bacterial removal was due to cell attachment at the gas-liquid interface and was in proportion to gas-liquid interfacial area. Bacterial transport under unsaturated conditions was enhanced by decreasing the ionic strength of the carrying solution and adding non ionic surfactant. Decreased cell attachment at both the gas-liquid and solid-liquid interfaces was likely due to changes in electrostatic interactions between the interfaces and cell surfaces brought on by water chemistry modifications.
    • Bacterial transport, distribution and activity in porous media

      Maier, R. M.; Jordan, Fiona Lya (The University of Arizona., 2000)
      Understanding the extent of microbial transport, distribution and activity in the subsurface is paramount for effective in-situ bioremediation. In one study, we investigated the impact a substrate pulse has on the movement of inoculated or indigenous bacteria through saturated porous media. In another study, we developed a method to visualize the distribution of bacteria on soil surfaces. The elution of either inoculated or indigenous bacteria was monitored from model (homogenous) sand or natural (heterogenous) soil column systems. Sand columns receiving salicylate resulted in enhanced elution of inoculated P. putida. However, the salicylate pulse did not result in enhanced elution of P. putida from a natural system. For natural heterogenous systems, the salicylate pulse significantly affected the elution of certain indigenous bacteria. Specifically, more heterotrophs were eluted from soil columns receiving salicylate than from those that did not for both loamy sand soils tested. On the other hand, there were consistently fewer salicylate-degrading cells eluted in the presence of salicylate from one of the two soils tested. These data suggest that bacterial transport is a function of both the porous medium and the microbial population(s) under investigation. In the second study, an agar lift-DNA/DNA hybridization technique was developed to visualize the distribution of eubacteria on soil surfaces. Briefly, a single layer of soil was lifted from the surface of soil microcosms onto agar slabs and allowed to incubate. Bacterial colonies were lifted from the agar slabs onto membranes. The location of individual colonies was detected on the membranes by hybridization with a probe complementary to a conserved region of the eubacterial genome. This method was able to detect active microorganisms on different soil surfaces. The probe signal correlated well with the number of metabolically active microorganisms found in soils amended with a carbon source. This technique also allowed for visualization of localized microbial activity. A combined approach utilizing both soil column studies and the agar-lift technique should allow researchers to better elucidate microbial transport, distribution and activity in subsurface environments.
    • Bacteriophage T5 DNA polymerase relationships of DNA polymerases.

      Ito, Junetsu; Leavitt, Markley Carl.; Bernstein, Harris; Bernstein, Carol; Spizizen, John (The University of Arizona., 1990)
      T5 DNA polymerase, a highly processive single polypeptide enzyme, and PRD1 DNA polymerase, a protein-primed DNA polymerase, have been analyzed for their primary structural features. The amino acid sequence of T5 DNA polymerase reveals a high degree of homology with DNA polymerase I (Pol I) of Escherichia coli and retains many of the amino acid residues which have been implicated in the 3'-5' exonuclease and DNA polymerase activities of that enzyme. Alignment with sequences of polymerase I and T7 DNA polymerase (family A polymerases) was used to identify regions possibly involved in the high processivity of this enzyme. Further amino acid sequence comparisons of T5 DNA polymerase with a large group of DNA polymerases (family B) previously shown to exhibit little similarity to Pol I, indicate certain sequence segments are shared among distantly related DNA polymerases. These shared regions have been implicated in the 3'-5' exonuclease function of Pol I which suggests that the proofreading domains of all these enzymes may be related. Mutations in these segments in T5 DNA polymerase (family A) and PRD1 DNA polymerase (family B) greatly decrease the exonuclease activity of these enzymes but leave the polymerase activities intact. Additionally, an exonuclease deficient T5 DNA polymerase is used in DNA sequencing reactions and yields consistent results with low background contamination on autoradiographs of polyacrylamide/urea gels. PRD1 mutants defective in 3 regions which are highly conserved among family B DNA polymerases, are deficient in DNA polymerase activity but retain exonuclease activity.
    • Bad Boys, Bad Boys, Who's Gotta Thing For You?: Examining the Sexual Appeal of the Bad Boy Archetype

      Floyd, Kory; Custer, Benjamin Everett; Bonito, Joseph A.; Rains, Stephen A. (The University of Arizona., 2020)
      Mass media messages transcending genres and generations lead many of us to believe that nice guys finish behind bad boys in the mate selection process, particularly in short-term contexts. However, evidence for the validity of that claim is elusive. This dissertation takes an interdisciplinary approach to testing the enduring stereotype by mapping communication behaviors onto underlying biological and psychological mechanisms. In an experimental research design, 189 young, straight cisgender women were presented with online dating profiles manipulated by the author and asked to evaluate the depicted men on their physical attractiveness and short- and long-term mate appeal. Results failed to substantiate the bad boy stereotype, although the means for each hypothesis were in the predicted direction. Nevertheless, a significant main effect of testosterone on physical attractiveness was found, which is noteworthy because although phenotypic signs of high testosterone are not exclusive to bad boys, they represent a signature characteristic of the archetype. Interpretations and implications of the results are discussed with an emphasis on exploring explanations for their nonsignificance and avenues for future research.
    • Bahama prehistory: cultural adaptation to an island environment

      Hoffman, Charles Andrew, 1929- (The University of Arizona., 1967)
    • Bait-And-Switch: The Consequences of Financial Aid Loss in the Second Year of College

      Deil-Amen, Regina J.; Salvesen, Christine Lianna; Rhoades, Gary; Lopez, Francesca; Irwin, Mary (The University of Arizona., 2019)
      Low-income students enrolled in a four-year, public institution are three times more likely to drop out after their first year of study than their higher-income peers (Engle & Tinto, 2008, p. 11). The exorbitant price of college tuition plays a significant role in how low-income students are underserved by the current postsecondary system. Participants in this study are in large numbers also first-generation, a group that is even more at-risk for early departure from the university, especially prior to second year (Choy, 2001; Ishitani, 2003). At the research site (a southwest Research 1 university), low-income students living on-campus their first year are front-loaded with funding that then decreases in their second year. This “bait-and-switch” approach is, unfortunately, a common practice by higher education institutions (US News and World Report, 2015). The research study provides a multi-method examination to understand the university experience for low-income students that encounter this decrease in funding. The study gives a clear view of not just the challenges but successes these students experience. A significant contribution of this study is my development of the Student Management of Risk Model that represents the process students go through in identifying, interpreting, and managing risk during college. Surprisingly, my research findings show that program participants persist at a much higher rate than overall university students yet still face many obstacles on top of the traditional challenges for undergraduate students, including financial ones. I explore why and find that a feasible explanation may be a combination of the strengths students bring with them to the university combined with the proactive and comprehensive support provided by the university. First, program participants are highly motivated to complete their education for a variety of reasons, but primarily because many are first in their families to attend college. Relatedly, program participants also have a sense of individual motivation to learn, do well, and graduate to improve the likelihood of having a promising and fulfilling future (Dennis, Phinney, & Chuateco, 2005). Once accepted into the university, program participants experience wrap-around services that are put in place for them before they even arrive on campus. This research study not only suggests a new model -- a student management of risk model -- to describe key aspects of what these students face once enrolled but also identifies a powerful combination of elements that seem to provide positive results for program participants. The study shows how the university may be working at cross-purposes in removing financial support and then recouping it through wrap-around services. The study provides a variety of implications and suggestions for future research and practice that includes: 1) evaluating graduation rates not just persistence rates for program participants, 2) evaluating persistence and graduation rates of students that are qualified for the program but are non-participants, 3) research the process in which institutions formulate and execute certain policy changes or actions that can negatively affect student success, and 4) consider building on existing best practices by offering low-cost social and academic engagement opportunities for student participants.
    • Bakhtin's chronotope and the rhetoric of Hollywood film.

      Roen, Duane H.; Montgomery, Michael Vincent.; Willard, Thomas A.; Miller, Thomas P. (The University of Arizona., 1992)
      This dissertation considers Hollywood film locales rhetorically, as the site of many different kinds of community activities and perspectives. In particular, my focus will be on locales and mise-en-scene elements that replicate certain "chronotopic" patterns of time and space organized by our culture in its literature. These special patterns, along with their signifying functions, were first outlined by Mikhail Bakhtin during the period 1937-1938. As a first step, I begin with a broad survey, outlining the salient features of Bakhtin's individual chronotopes ancient and modern, and considering fundamental connections between these chronotopes and classical Hollywood genres of the 1940s. I devote my second chapter to the exploration of other important theoretical bases of Bakhtin's work; in particular, to the belief in the rejuvenating power of folk language and the carnivalesque. My argument is that the "idyllic chronotope" is given the same position of centrality in Bakhtin's discussions of space and time as carnivalesque speech genres are in his discussions of language. The appearance of an "idyllic interlude" in a work of literature or in a film can suddenly throw the rest of the represented world into moralizing "perspective" just as a carnivalesque insult or quip can "degrade" a high-sounding speech. My third theoretical problem will be the reception and processing of the film text. How does the audience of a film apply their socially-formed schema and knowledge of the characters' "situations" to a film text in order to construct meaning? Here I demonstrate how the "high-lighting" of a film text with recognizable chronotopes can help an audience to form judgments about characters and to construct analogies between character situations and situations arising in their own communities. In my fourth and final chapter, I branch out from Bakhtin's models to consider new chronotopes as they may develop during a particular historical decade. Specifically, I examine the representation of the "shopping mall" as it appears throughout a dozen or so 1980s films in order to show how the spatiotemporal worlds suggested by these films can be "opened out" into a study of teen culture and social mores across the decade as a whole.
    • The balance model: Neuropsychological treatment of dyslexia

      Obrzut, John E.; Goldstein, Bram Harold, 1969- (The University of Arizona., 1998)
      This study examined whether an intervention program based on a neuropsychological approach to specific reading disability subtypes would improve overall reading ability, Subjects were middle school righthanded boys and girls who were low achieving readers. The readers were initially subtyped according to Bakker's clinical-inferential approach used with clinic children and classified as L-type dyslexic (substantive errors and excessively fast reading), P-type dyslexic (slow and laborious reading), or M-type dyslexic (a combination of both L-type and P-type dyslexia). The method of assessment was used as a pre-posttest group design. The dependent variables included a reading decoding measure, oral reading errors, and comprehension scores from the Multilevel Academic Skills Inventory (MASI), which is a reading and language battery. All three groups were receiving additional reading instruction from their school reading program. Experimental treatment occurred in two parts: Hemispheric Specific Stimulation (HSS) and Hemispheric Alluding Stimuli (HAS). When the study was concluded, a fused dichotic listening task was administered once to discern a potential relationship between the subtypes of the groups and their particular hemispheric processing capacity for language. The results revealed that the neuropsychological treatment was effective at improving reading comprehension and accuracy. Although there were perceived benefits in comprehension, no direct comprehension exercises were used in this study so the gains could have been attributed to the school reading program. There were no changes in word recognition between the pretest and the posttest. The results from the fused dichotic words task were not significant.
    • Balancing Act: Negotiations of the Athletic and Academic Role Amongst Division I-Football Bowl Subdivision Student-Athletes

      Bell, Lydia Foster; Ruiz, Richard; Lee, Jenny J.; Cammarota, Julio; Watson, Scott B. (The University of Arizona., 2009)
      Informed by the words and experiences of 41 Division I-Football Bowl Subdivision (FBS) student-athletes, this qualitative study reveals the complexities of the student-athlete academic experience shaped by the expectations of their athletic role, the campus climate, and the NCAA Academic Reform Package. Using role-identity as a theoretical framework, it examines how, over time, these student-athletes have shaped their athletic and academic role-identities, and the roles played in such shaping by those in their academic and athletic role-sets. The study critically examines the academic decisions made by these student-athletes, questions the isomorphic academic and athletic rubric, and proposes suggestions for the enhancement of the student-athlete experience within the confines of the academic reform policies.
    • Balkan Ecumene and Synthesis in Selected Compositions for Classical Guitar by Dusan Bogdanovic, Nikos Mamangakis and Ian Krouse.

      Curry, Jane; Patterson, Thomas R.; McLaughlin, Carol; Neher, Patrick (The University of Arizona., 2010)
      Ecumene is a word describing the collective traditions and influence of a geographically and historically recognizable culture; in this study, the inhabitants of the Balkan region. In compositions by Dusan Bogdanovic (b.1955), Nikos Mamangakis (b. 1929) and Ian Krouse (b.1956), Balkan ecumene can be heard shaping modern repertoire for the classical guitar. In this study, relevant geography is first outlined, followed by a detailed investigation of how specific Balkan rhythms, melodies, and harmonies are used in selected works by these composers. The works are: Six Balkan Miniatures by Bogdanovic;, Hassapiko and Tsifteteli from Folk Dance Suite by Mamangakis, and Variations on a Moldavian Hora by Krouse. An exploration of other academic study into musical synthesis gives context to the blending of Eastern European folk music and Western classical art music found here.