published_or_final_version / abstract / toc / Mathematics / Master / Master of Philosophy

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Gaelic Language Maintenance Process(es) is a contemporary ethnographic study of seventeen isolated Gaelic language users. The seventeen individuals in the study, ages three to seventy-two, were selected from Ontario, Canada and Central Scotland to identify and illustrate the perceptions and processes involved in isolated Gaelic language maintenance. Each subject was interviewed, and subsequently shadowed, for a period of nine days. During the period of active observation, the subjects recorded their thoughts about and experiences of their Gaelic language maintenance within a personal journal. The interviews, observations, and personal diaries of the subjects' Gaelic lives were then collated by the researcher into seventeen individual narratives. Through close reading, each narrative illuminated the interwoven threads and constructs which provided additional insight into the 'quilt' of isolated Gaelic language maintenance. The seven, common-sense typologies and constructs drawn from the individuals' experience of the Gaelic language world revealed a shared, inner universe of meaning where some of the major categories in the (experience of) their social language world centred upon their recognition of Gaelic ability, maintenance, community roles, and "special" identity to form a tapestry for maintenance outside of the bloc. Peigi, Pàdruig, Catriona, Cairistiona, Chlair, Cormac, Colla, Tomasina, Tara, Teàrlag, Treasaididh, Tollaidh, Aileas, Artair, Aigneas, Anna, and Aonghas generously allow readers an opportunity to share in their thoughts and feelings and [the researcher's] observations about what it is like to maintain the Gaelic language in isolation from Cape Breton and the Western Isles.

Thesis (Master)--İzmir Institute of Technology, İzmir, 2002. / Includes bibliographical references (59-61).

Doctor of Philosophy / Department of Mathematics / Andrew G. Bennett / This dissertation investigates and compares the methods of proof validation utilized by novice and expert mathematicians within the realm of Euclidean geometry. With the use of eye tracking technology, our study presents empirical evidence supporting claims previously studied only through the use of verbal protocols. Our investigation settles a series of contentious results surrounding the practical implementation of the generalized validation strategy called zooming out (Inglis and Alcock, 2012; Weber, Mejia-Ramos, Inglis, and Alcock, 2013). This strategy analyzes the overall structure of a proof as an application of methods or logical chunks. Settling the debate through use of longer and more complicated proofs devoid of blatant errors, we found that validators do not initially skim-read proofs to gain structural insight. We did however confirm the practical implementation of zooming out strategies. The literature identifies within the proof validation process specific differences between novices and experts. We are interested in a holistic understanding of novice and expert validations. We therefore present the direct comparison of entire validation processes that assess the similarity of novice and expert overall validation attempts. We found that the validation processes of novices and experts share a certain degree of similarity. In fact novices tend to be closer to experts than to other novices. And when validations are clustered, the groups are heterogeneous with regard to mathematical maturity. Our investigation expands the proof validation literature by including diagrams in the proof validation process. We found that experts tend to spend more time proportionally on the diagram than novices and that novices spend more time on the text. Furthermore, experts tend to draw more connections within the diagram than novices as indicated by a higher proportion of attentional changes within the diagrams. Experts seem to draw on the power of visualizations within the mathematics itself, spending more time on conceptual understanding and intended connections.

Class of 2012 Abstract / Specific Aims: To evaluate surgery, infectious disease, and nephrology consult documentation of antimicrobial content in bone cement within 30 days post-surgery; evaluate documentation of antimicrobial cement content by pharmacists in pharmacokinetic drug level evaluations within 6 months post-surgery; assess frequency and severity of adverse drug events associated with antimicrobials in bone cement. Methods: Retrospective chart review, which utilized a data collection form to evaluate the dose and type of antimicrobial agents prescribed, median and range antimicrobial doses per 40 grams of cement, documentation rates of antimicrobial content in clinical notes and incidence of potential adverse drug effects. Subjects were identified based on an ICD-9 code and their electronic medical records were accessed. Main Results: The sample size was 24 patients. The surgery notes had the highest rates of documentation with 96% naming the drug and 75% included the dose. The rates were the same in the infectious diseases consults and pharmacy pharmacokinetics notes with the drug name at 27% and the dose at 9%. No nephrology consult notes mentioned antimicrobials contained in the cement. Renal dysfunction (sCr≥2) developed in 13% of patients within 30 days and 25% of patients within 100 days. Approximately 17% of patients with renal dysfunction had the antimicrobial-laden cement removed. Conclusions: A variety of antimicrobial agents were embedded in bone cement at various concentrations and documentation from multiple sources was inconsistent. Likewise, adverse events associated with antimicrobial containing bone cement are not consistent.

M.A. (African Languages) / Please refer to full text to view abstract

The ability of professionals in student activities to inform students of scheduled events is a key factor in the success of their programs. While traditional forms of communication with students, such as newspaper announcements and campus flyers, have not been totally reliable, they remain among the standard forms of getting the word to students about campus activities and events. Other forms of communication with students now are available, such as web pages and electronic infolines, but student activities professionals still do not know with any degree of certainty which forms are preferred by students and which are most effective. The study was guided by the question, " What are students' preferred and actual record of use of selecting sources of information about campus activities at Virginia Tech?" and was intended to collect and analyze data about actual student use of various forms of formal communication to inform them about campus events. Descriptive statistics and chi-square analyses were used to portray actual use patterns of students and to test whether these patterns differ by class standing and gender. It is anticipated that findings from this study will be useful to all student groups who plan events for wide-spread participation by students, to advisors of student groups including the Virginia Tech Union, and to student affairs professionals who are responsible for enhancing student involvement on campus. / Master of Arts

Les objectifs de cette étude étaient de décrire l'usage des médicaments contre l'asthme et d'identifier les facteurs associés à l'usage approprié de ces derniers chez des personnes asthmatiques âgées de 12 à 45 ans. Les données sur l'usage des médicaments et sur les diverses variables indépendantes ont été recueillies par questionnaire téléphonique. Des critères permettant de définir l'usage approprié des médicaments contre l'asthme ont été développés. Au total, 43 des 349 (12,3%) personnes interrogées avaient un usage approprié de leurs médicaments contre l'asthme. Cinq facteurs sont associés à l'usage approprié des médicaments contre l'asthme : avoir de bonnes connaissances sur ses médicaments, se percevoir en bonne santé, ne pas utiliser de chambre d'espacement, avoir rencontré un médecin spécialiste et avoir manqué de médicaments à cause d'un problème d'argent. Les recommandations de la conférence canadienne de consensus sur l'asthme ne sont pas adéquatement appliquées. Des interventions visant à améliorer les connaissances sur les médicaments et les soins aux personnes asthmatiques seraient nécessaires.

Die Enzymsuperfamilie der löslichen Sulfotransferasen (SULT) spielt eine wichtige Rolle in der Phase II des Fremdstoffmetabolismus. Sie katalysieren den Transfer einer Sulfonylgruppe auf nucleophile Gruppen endogener und exogener Substrate. Die Sulfokonjugation von Fremdstoffen erhöht deren Wasserlöslichkeit und behindert die passive Permeation von Zellmembranen. Dadurch wird die Ausscheidung dieser konjugierten Substanzen erleichtert. In Abhängigkeit von der Struktur des Zielmoleküls kann die Sulfokonjugation aber auch zur metabolischen Aktivierung von Fremdstoffen durch die Bildung instabiler Metabolite führen. Die SULT-vermittelte Aktivierung promutagener Substanzen ist somit von toxikologischem Interesse. Für die Detektion SULT-vermittelter Mutagenität mittels bakterieller in-vitro Testsysteme ist die heterologe Expression der fremdstoffmetabolisierenden Enzyme direkt in den Indikatorzellen notwendig. S. typhimurium exprimieren selbst keine SULT, und externe Metabolisierungssysteme sind problematisch, weil die negativ geladenen, kurzlebigen Metabolite nur schlecht die Zellmembran penetrieren können. Die Expression humaner Enyme in Bakterien ist jedoch zum Teil sehr kritisch. So zeigen z.B. sehr ähnliche Enzyme (SULT1A2*1 und *2) deutliche Unterschiede im Expressionsniveau bei exakt gleichen äußeren Bedingungen. Dies erschwert den Vergleich der enzymatischen Aktivitäten dieser Enzyme im in-vitro Testsystem. Andere Enzyme (z.B. SULT2B1b) werden unter Verwendung ihrer Wildtyp-cDNA zum Teil nicht detektierbar exprimiert. Deshalb sollte in dieser Arbeit eine Methode zur Optimierung der heterologen Expression fremdstoffmetabolisierender Enzyme für Genotoxizitätsuntersuchungen etabliert werden. <br><br> Es wurde bereits gezeigt dass synonyme Codonaustausche am 5’-Ende der humanen SULT1A2-cDNA zu einer Erhöhung der Expression des entsprechenden Enzyms in S. typhimurium führten. Dementsprechend wurden in dieser Arbeit Codonaustausche am 5’-Ende der cDNA verschiedener SULT (1A1*1, 1A2*1, 2B1b) sowie der Ratten Glutathion-S-Transferase Theta 2 (rGSTT2) und dem Reportergen Luciferase durchgeführt. Die Expression der so generierten Konstrukte wurde in verschiedenen S. typhimurium und E. coli Stämmen quantifiziert und die Aktivität der überexprimierten Enzyme im Ames-Test bzw. im Enzym-Aktivitätsassay überprüft. Durch das Einführen seltener Codons in die cDNA konnte die Proteinexpression von SULT1A1*1, SULT1A2*1 und SULT2B1b maximal 7-fach, 18-fach und 100-fach im Vergleich zur Wildtyp-cDNA gesteigert werden. Die Expression der rGSTT2 wurde ebenfalls durch das Einführen seltener Codons erhöht (maximal 5-fach). Bei dem Reportergen Luciferase jedoch führte das Austauschen häufiger Codons gegen seltene Codons zu einer Reduktion der Proteinexpression um 80 %. Die Expression von Fusionsproteinen aus 2B1b (5’-Ende) und Luciferase (3’-Ende) wurde durch das Einführen seltener Codons ebenfalls um 50 % reduziert. Die S. typhimurium Stämme mit optimierter SULT 1A1*1- bzw. 1A2*1-Expression wurden im Ames-Test eingesetzt und zeigten im Vergleich zu den geringer exprimierenden Stämmen eine höhere Sensitivität. Für SULT2B1b konnte keine Mutagenaktivierung im Ames-Test nachgewiesen werden. Allerdings zeigte ein Enzym-Aktivitätsassay mit Dehydroepiandosteron, dass das bakteriell exprimierte Enzym funktionell war. Da in der Literatur der Effekt seltener Codons auf die Expression in Bakterien bisher fast ausschließlich als inhibitorisch beschrieben wurde, sollte die Wirkungsweise der hier beobachteten Expressionserhöhung durch seltene Codons genauer untersucht werden. Dazu wurden verschiedene Konstrukte der SULT1A2*1 und der SULT2B1b, die unterschiedlich viele seltene Codons in verschiedenen Kombinationen besaßen, hergestellt. Es konnten jedoch keine einzelnen Codons, die für die Expressionssteigerung allein verantwortlich waren, identifiziert werden. Die Plasmidkopienzahl in den verschiedenen SULT2B1b-Klonen war konstant und die SULT2B1b-mRNA-Konzentration zeigte nur moderate Schwankungen, die nicht als Ursache für die dramatische Erhöhung der SULT2B1b-Expression in Frage kommen. Die berechnete Stabilität der potentiellen mRNA-Sekundärstrukturen wurde durch die seltenen Codons häufig stark gesenkt und ist als eine mögliche Ursache für die Expressionssteigerung anzusehen. Zusätzlich erhöhten die seltenen Codons den Consensus der Downstream Box zur 16S rRNA, was ebenfalls eine Ursache für die Expressionssteigerung sein kann. <br><br> In dieser Arbeit konnte somit die Expression der humanen SULT1A1*1, 1A2*1 und der 2B1b sowie der rGSTT2 erfolgreich mittels synonymer Codonaustausche erhöht werden. Die so optimierten S. typhimurium Stämme zeigten im Ames-Test eine erhöhte Sensitivität gegenüber SULT aktivierten Promutagenen bzw. erhöhte Aktivität in spezifischen Enymaktivitätsassays. / The enzyme super familiy of human sulfotransferases (SULT) plays an important role in phase II metabolism of xenobiotics. They catalyze the transfer of a sulfonyl moiety to nucleophilic groups of endogenous and exogenous substrates. Sulfoconjugation of xenobiotics facilitates their excretion by increasing the water solubility and inhibiting passive permeation of cell membranes. Depending on the molecular structure of the substance, sulfonation can also lead to metabolic activation. Highly reactive resonance-stabilized carbenium- and nitrenium-ions that are able to covalently bind to cellular nucleophiles, e.g. DNA, can be formed. Thus, SULT-mediated activation of promutagenic compounds is of toxicological interest. The detection of SULT-mediated mutagenicity in bacterial in-vitro testsystems (e.g. S. typhimurium) requires the heterologous expression of xenobiotic-metabolizing enzymes directly in these indicator cells. S. typhimurium do not express endogenous SULT and external metabolic systems are problematic as penetration of cell membranes is hampered for charged and short-lived metabolites. But the expression of human enzymes in bacteria can be problematic too. SULT1A2*1 and *2 for instance are allelic variants that differ only in two amino acids. However, using the same experimental conditions strong differences in their expression level have been observed. This complicates the comparison of the mutagenic activities of the polymorphic enzymes in the in-vitro test system. Other enzymes (e.g. SULT2B1b) show no detectable expression in bacteria when their genuine cDNA obtained from human tissues is used. Therefore, the aim of this study was to to optimize protein levels of heterologously expressed xenobiotic-metabolizing enzymes in indicator cells for mutagenicity testing. <br><br> So far it has been shown that synonymous codon-exchanges at the 5’end of human SULT1A2-cDNA led to an enhanced expression of the corresponding enzyme in S. typhimurium. Accordingly, codon-exchanges at the 5’end of SULT1A1*1, -1A2*1, -2B1b, rat glutathione-S-transferase theta 2 (rGSTT2) and the reportergene luciferase were conducted. The expression of the resulting constructs was quantified in S. typhimurium and E. coli using specific antibodies and activity of the overexpressed enzymes was proved by Ames test and enzyme activity assays. The introduction of low-usage codons at the 5’end of SULT1A1*1, -1A2*1 and -2B1b cDNA led to a 7-, 18- and 100-fold increase of expression level, respectively. Expression of rGSTT2 was 5-fold enhanced after the introduction of low-usage codons. In contrast, the introduction of low-usage codons into the luciferase cDNA resulted in a decrease of protein expression up to 80 %. Fusionproteins of SULT2B1b (5’end) and luciferase (3’end) showed a reduction of protein expression about 50 % after the introduction of low-usage codons. S. typhimurium strains with optimized SULT1A1*1 and -1A2*1 expression were used in the Ames test and showed a higher sensitivity compared to the lower expressing strains. For SULT2B1b no mutagen-activation could be detected in the Ames test, but enzyme activity was proved through Dehydroepiandosterone sulfation in vitro. <br><br> Since an inhibitory effect of low-usage codons on expression in bacteria was described in literature, the enhancement of expression after the introduction of low-usage codons observed in this study was analyzed more in detail. Various constructs of SULT1A2*1 and -2B1b cDNAs containing different numbers and combinations of synonymous low-usage codons were generated. No single codon that was responsible for the enhanced expression could be identified. Plasmid copy number of different SULT2B1b constructs was unchanged and SULT2B1b-mRNA showed only moderate variations that could not explain the strong enhancement of SULT2B1b expression. Calculations suggested that the stability of potential mRNA secondary structures was reduced due to the introduction of low-usage codons. Moreover, the consensus of the downstream box and the 16S rRNA was increased. Both effects probably improved the efficiency of translation and thereby increased the yield of protein expression. <br><br> In this study the heterologous expression of SULT1A1*1, -1A2*1, -2B1b and rGSTT2 could be enhanced by the introduction of synonymous low-usage codons. The optimized S. typhimurium strains showed higher activities in enzyme assays with specific substrates and an increased sensitivity towards SULT-activated promutagens.