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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Comparative assessment of conventional vs. CAD/CAM complete denture fabrication techniques on patient satisfaction, quality of life and prosthesis biofilm

Jia-mahasap, Wissanee 01 May 2017 (has links)
Objectives: The primary objective was to assess the impact of two denture fabrication techniques, conventional and CAD/CAM, on oral health-related quality of life (OHRQoL) and patient satisfaction in complete denture wearers. The secondary objective was to compare the level of microorganisms present on complete dentures from the two fabrication techniques. Methods: Twenty-eight completely edentulous subjects (16 men and 21 women, age range from 49 to 87 years old.), who had been edentulous for at least 6 months, were wearing ill-fitting complete dentures, or unsatisfied with their existing complete dentures were recruited. Subjects were randomized to conventional and computer-aided design/ computer-aided manufacturing (CAD/CAM) treatment groups. Subjects in both groups were given the OHIP-EDENT (Oral Health Impact Profile for Edentulous Patients) and patient satisfaction questionnaires to record the data at baseline and at 1 month post-delivery of the new prostheses. Plaque samples were collected from intaglio surfaces of maxillary complete dentures at 1 month post-delivery to culture for any colonization of bacteria and/or yeasts. Results: There was a significant reduction in OHIP-EDENT scores within both treatment groups at the 1 month follow-up (p < 0.05). There was also a significant reduction in almost all OHIP-EDENT domains scores at 1 month. Gender was significantly associated with OHIP-EDENT score at baseline (p = 0.0419) and at 1 month (p = 0.0152). Female subjects tend to have higher OHIP-EDENT scores than male subjects. There was no significant difference in patient satisfaction between treatment groups both at baseline and at the 1 month visit for almost all aspects of satisfaction (p> 0.05). Appearance of maxillary denture was the only significant difference in patient satisfaction across treatment groups (p = 0.0213). The comparisons of microbial counts showed no significant difference between treatment groups. Conclusions: There were no significant difference on oral health-related quality of life (OHRQoL) and patient satisfaction between two treatment groups at baseline and 1 month. There was no significant difference in microbial counts between two treatment groups.
82

Separability and complete reducibility of subgroups of the Weyl group of a simple algebraic group

Uchiyama, Tomohiro January 2012 (has links)
Let G be a reductive algebraic group defined over an algebraically closed field of characteristic p. A subgroup H of G is called G-complete reducible whenever H is contained in a parabolic subgroup P of G, it is contained in some Levi subgroup of P. In this thesis, we present a pair of reductive subgroups H and M of G of type E_7 such that H<M and H is G-completely reducible but not M-completely reducible.
83

On Reductive Subgroups of Algebraic Groups and a Question of Külshammer

Lond, Daniel January 2013 (has links)
This Thesis is motivated by two problems, each concerning representations (homomorphisms) of groups into a connected reductive algebraic group G over an algebraically closed field k. The first problem is due to B. Külshammer and is to do with representations of finite groups in G: Let Γ be a finite group and suppose k has characteristic p. Let Γp be a Sylow p-subgroup of Γ and let ρ : Γp → G be a representation. Are there only finitely many conjugacy classes of representations ρ' : Γ → G whose restriction to Γp is conjugate to ρ? The second problem follows the work of M. Liebeck and G. Seitz: describe the representations of connected reductive algebraic H in G. These two problems have been settled as long as the characteristic p is large enough but not much is known in the case where the characteristic p is a so called bad prime for G, which will be the setting for our work. At the intersection of these two problems lies another problem which we call the algebraic version of Külshammer's question where we no longer suppose Γ is finite. This new variation of Külshammer's question is interesting in its own right, and a counterexample may provide insight into Külshammer's original question. Our approach is to convert these problems into problems in the nonabelian 1-cohomology. Let K be a reductive algebraic group, P a parabolic subgroup of G with Levi subgroup L < P, V the unipotent radical of P. Let ρ₀ : K → L be a representation. Then the representations ρ : K → P that equal ρ₀ under the canonical projection P → L are in bijective correspondence with elements of the space of 1-cocycles Z¹(K,V ) where K acts on V by xv = ρ₀(x)vρ₀(x)⁻¹. We can then interpret P- and G-conjugacy classes of representations in terms of the 1-cohomology H¹(K,V ). We state and prove the conditions under which a collection of representations from K to P is a finite union of conjugacy classes in terms of the 1-cohomology in Theorem 4.22. Unlike other approaches, we work directly with the nonabelian 1-cohomology. Even so, we find that the 1-cocycles in Z¹(K,V ) often take values in an abelian subgroup of V (Lemmas 5.10 and 5.11). This is interesting, for the question "is the restriction map of 1-cohomologies H¹(H,V) → H¹(U,V) induced by the inclusion of U in K injective?" is closely linked to the question of Külshammer, and has positive answer if V is abelian and H = SL₂k) (Example 3.2). We show that for G = B4 there is a family of pairwise non-conjugate embeddings of SL₂in G, a direction provided by Stewart who proved the result for G = F4. This is important as an example like this is first needed if one hopes to find a counterexample to the algebraic version of Külshammer's question.
84

A comparative study to evaluate patient satisfaction with conventional dentures and implant retained overdentures.

Al-Makki, Amjad January 2006 (has links)
<p><span style="font-size: 8pt / " text-align:="" font-family:="" color:="">The edentulous jaw is a common feature in elderly patients that had lost their teeth during life due to local reasons such as poor oral hygiene and dental caries as well as periodontal disease. Hence these patients are the victims of biological phenomenona that lead to difficulties in different aspects of patient comfort with dentures. Clinicians are always concerned to minimize these difficulties and increase patient comfort through manufacturing a proper prosthesis to substitute for the loss of the natural teeth as well as the surrounding structures for optimum satisfaction and improved quality of life of the patient. The aim of this study was to evaluate patient satisfaction regarding function and aesthetics with conventional mandibular dentures and implant retained mandibular overdentures in denture wearers.</span></p>
85

Functions and polynomials over finite groups from the computational perspective

Horvath, Gabor January 2008 (has links)
In the thesis we investigate the connections between arbitrary functions and their realizing polynomials over finite algebras. We study functionally complete algebras, i.e. algebras over which every function can be realized by a polynomial expression. We characterize functional completeness by the so called Stone-Weierstrass property, and we determine the functionally complete semigroups and semirings. Then we investigate the computational perspective of the function-polynomial relationships over finite groups. We consider the efficient representability, the equivalence, and the equation solvability problems. We approach the efficient representability problem from three directions. We consider the length of functions, we investigate the circuit complexity of functions, and we analyse the finite-state sequential machine representation of Boolean functions. From each of these viewpoints we give bounds on the potential efficiency of computations based on functionally complete groups compared to computations based on the two-element Boolean algebra. Neither the equivalence problem nor the equation solvability problem has been completely characterized for finite groups. The complexity of the equivalence problem was only known for nilpotent groups. In the thesis we determine the complexity of the equivalence problem for certain meta-Abelian groups and for all non-solvable groups. The complexity of the equation solvability problem is known for nilpotent groups and for non-solvable groups. There are no results about the complexity of the equation solvability problem for solvable non-nilpotent groups apart from the case of certain meta-cyclic groups that we present in the thesis. Moreover, we determine the complexity of the equation solvability problem for all functionally complete algebra. The idea of the extended equivalence problem emerges from the observation that the commutator might significantly change the length of group-polynomials. We characterize the complexity of the extended equivalence problem for finite groups. For many finite groups we determine the complexity of the equivalence problem if the commutator is considered as the basic operation of the group.
86

Numerical evidence for phase transitions of NP-complete problems for instances drawn from Lévy-stable distributions

Connelly, Abram January 2011 (has links)
Random NP-Complete problems have come under study as an important tool used in the analysis of optimization algorithms and help in our understanding of how to properly address issues of computational intractability. In this thesis, the Number Partition Problem and the Hamiltonian Cycle Problem are taken as representative NP-Complete classes. Numerical evidence is presented for a phase transition in the probability of solution when a modified Lévy-Stable distribution is used in instance creation for each. Numerical evidence is presented that show hard random instances exist near the critical threshold for the Hamiltonian Cycle problem. A choice of order parameter for the Number Partition Problem’s phase transition is also given. Finding Hamiltonian Cycles in Erdös-Rényi random graphs is well known to have almost sure polynomial time algorithms, even near the critical threshold. To the author’s knowledge, the graph ensemble presented is the first candidate, without specific graph structure built in, to generate graphs whose Hamiltonicity is intrinsically hard to determine. Random graphs are chosen via their degree sequence generated from a discretized form of Lévy-Stable distributions. Graphs chosen from this distribution still show a phase transition and appear to have a pickup in search cost for the algorithms considered. Search cost is highly dependent on the particular algorithm used and the graph ensemble is presented only as a potential graph ensemble to generate intrinsically hard graphs that are difficult to test for Hamiltonicity. Number Partition Problem instances are created by choosing each element in the list from a modified Lévy-Stable distribution. The Number Partition Problem has no known good approximation algorithms and so only numerical evidence to show the phase transition is provided without considerable focus on pickup in search cost for the solvers used. The failure of current approximation algorithms and potential candidate approximation algorithms are discussed.
87

Single-crossing orthogonal axial lines in orthogonal rectangles

Mengisteab, Berhane Semere 30 June 2008 (has links)
The axial map of a town is one of the key components of the space syntax method – a tool for analysing urban layout. It is derived by placing the longest and fewest lines, called axial lines, to cross the adjacencies between convex polygons in a convex map of a town. Previous research has shown that placing axial lines to cross the adjacencies between a collection of convex polygons is NP-complete, even when the convex polygons are restricted to rectangles and the axial lines to have orthogonal orientation. In this document, we show that placing orthogonal axial lines in orthogonal rectangles where the adjacencies between the rectangles are restricted to be crossed only once (ALPSC- OLOR) is NP-complete. As a result, we infer the single adjacency crossing version of the general axial line placement problem is NP-complete. The transformation of NPcompleteness of ALP-SC-OLOR is from vertex cover for biconnected planar graphs. A heuristic is then presented that gives a reasonable approximate solution to ALP-SC-OLOR based on a greedy method.
88

\"Avaliação dos efeitos da alteração dimensional de resinas para base de próteses totais submetidas a diferentes técnicas de processamento avaliados ao nível condilar\" / Evaluation of the dimensional changes of acrylic resin for complete denture submitted to different types of processing evaluated to the level of the condyle

Yamaguchi, Flavio Jun 18 September 2006 (has links)
O objetivo deste trabalho foi avaliar as alterações dimensionais de resinas acrílicas submetidas a diferentes tipos de processamento avaliados ao nível condilar. As condições experimentais foram introduzidas em três etapas. Na etapa A, as resinas acrílicas (Clássico, Ondacryl, Acron MC, Lucitone e QC-20) foram incluídas em muflas contendo muralha de gesso, prensadas na fase plástica e submetidas a cinco ciclos de acrilização. Na etapa B, as resinas acrílicas utilizadas foram a QC-20 e a Lucitone, utilizando três tipos de muralha (gesso, silicone (ZETALABOR) e filme de silicone (VIPISIL)), e duas fases de reação química da resina acrílica na prensagem (fluida e plástica). Na etapa C, foi utilizada a resina Acron MC com dois ciclos de polimerização (90W por treze minutos e 500W por três minutos) variando-se, ainda, o tipo de muralha como na etapa B. Para o estudo, foram confeccionadas 5 próteses totais para cada grupo. Ao final, obtiveram-se 23 grupos totalizando 115 próteses totais superiores. Mediu-se a variação posicional do ramo superior do articulador TT antes e após os processamentos, tendo por base a orientação oclusal da máxima intercuspidação. Tal variação foi registrada através de gesso tipo IV vertido em espaço ao redor das esferas condilares, previamente providos por meio de espaçadores utilizados antes do processamento. Foram medidas três distâncias em cada esfera condilar (superoinferior, anteroposterior e mediolateral) resultando em 690 medidas que variaram de 0 a 3 mm, com média de 0,79 mm e desvio padrão de 0,59 mm. Ocorreu alteração em 687 medidas, sendo que houve diferença entre os grupos, estatisticamente significante, principalmente para a distância anteroposterior do lado esquerdo, na variável resina. Conclui-se que, as alterações dimensionais de resinas alteraram as posições das esferas condilares. / The objective of this study is to evaluate the dimensional acrylic resin alterations submitted to different types of processing evaluated to the level of the condyle. The experimental conditions were introduced in three stages. In stage A , the acrylic resins (Classic, Ondacryl, Acron MC, Lucitone and QC-20) were enclosed in flasks contend plaster wall, pressed in the plastic phase and submitted to five cycles of acrylization. In stage B, the QC-20 and the Lucitone were used with three types of wall (plaster, silicone (ZETALABOR) and silicone film (VIPISIL)), and with two phases of chemical reaction of the acrylic resin (fluid and plastic). In stage C, the resin Acron MC with two cycles of polymerization was used (90W for thirteen minutes and 500W for three minutes) by changing the type of wall as in stage B. For the study, 5 complete dentures for each group were made. At the end of the experiment, 23 groups were obtained, totalizing 115 superior complete dentures. Positional variation of the upper member of the articulator T.T.was measured before and after the processing, based on the maximum intercuspidation orientation. Such variation was registered by using plaster type IV shed in the space around of the condyle spheres, previously provided by means of spacers used before the processing. Three distances in each condyle sphere were measured (superoinferior, anteroposterior and mediolateral) resulting in 690 measures that varied from 0 to 3 mm, with average of 0,79 mm and shunting line standard of 0,59 mm. An alteration in 687 measures occurred and there was difference between the groups statistically significant, mainly for the anteroposterior distance on the left side. The conclusion was that the dimensional resin alterations modified the positions of the condyle spheres
89

Classificação de singularidades: o método da transversal completa. / Singularities classification: the complete transversal method.

Sheng, Lee Yun 20 February 2002 (has links)
Através do Método da Transversal Completa apresentamos neste trabalho a classificação dos germes simples de Rn em R, a classificação dos germes do plano no plano de corank 1 e A-codimensão no máximo 4 e uma breve classificação de bigermes de R em R2. / Applying the Complete Transversal Method we obtain, in this work, a classification of simple germs of smooth function from Rn to R, a classification of germs of maps from the plane to the plane with A-codimension up to 4 of corank 1 and an introduction to the classification of bigerms of maps from R to R2.
90

Detecção da expressão dos genes HWP1, ALS1 e ALS3 de C.albicans, por meio de RT-PCR em tempo real, após desinfecção química e por microonda, de resina acrílica para confecção de dentaduras / HWP1, ALS1 and ALS3 genes expression in Candida albicans after chemical or microwave disinfection of acrylic resin for denture prosthesis using real time PCR

Pinto, Luciana de Rezende 24 June 2010 (has links)
A desinfecção de dentaduras promove o controle do biofilme microbiano e previne doenças, como a estomatite por uso de dentadura, associada à presença de Candida albicans. A expressão dos genes HWP1, ALS1, ALS3 deste fungo está relacionada à adesão das células fúngicas às do hospedeiro. O objetivo deste estudo foi detectar e quantificar a expressão desses genes em células planctônicas e biofilme de Candida albicans, desenvolvidos sobre superfícies de resina acrílica, após tratamento com dois métodos de desinfecção. Corpos de prova de resina acrílica, previamente tratados por hipoclorito de sódio 1%, microondas, e um grupo não tratado, foram inoculados com Candida albicans para desenvolvimento de biofilme. O biofilme e as células planctônicas foram coletados em três tempos distintos, correspondentes às etapas de desenvolvimento do biofilme: inicial (6h), intermediária (12h) e madura (48h) e a expressão gênica foi quantificada pelo ensaio de RT-PCR em tempo real. Os dados obtidos foram submetidos ao teste estatístico ANOVA two-way e pós-teste de Bonferroni; valores de p<0,05, p<0,01 e p<0,001 foram considerados significantes. Os três genes avaliados foram detectados e quantificados por RT-PCR em tempo real, em biofilmes e células planctônicas, independente do grupo de tratamento ou tempo de desenvolvimento do biofilme. A expressão dos genes ALS1 e ALS3 variou de acordo com o tempo de desenvolvimento do biofilme e, e com o tratamento da superfície. Ocorreu diferença significativa (p<0,001) entre a expressão desses genes nas superfícies tratadas por hipoclorito de sódio e microondas, além de diferenças significativas (p<0,001) na expressão gênica entre células planctônicas e biofilme, para os tratamentos avaliados. Concluiu-se que os tratamentos de desinfecção alteram o padrão da expressão dos genes ALS1 e ALS3 em biofilmes desenvolvidos sobre superfície de resina acrílica e em células planctônicas e este padrão foi diferente entre os tratamentos de desinfecção. / Complete dentures disinfection promotes biofilm control and prevents diseases such as denture stomatitis associated with the presence of Candida albicans infection. The expression of the genes HWP1, ALS1, ALS3 in this fungus is related to the adhesion of fungal cells to the host tissues. Therefore, the aim of this study was to detect and quantify the expression of these genes in planktonic cells and biofilms of Candida albicans, developed on acrylic resin surfaces, after treatment with two disinfection methods. Specimens of acrylic resin, previously treated by 1% sodium hypochlorite or microwave, and an untreated group were inoculated with Candida albicans for biofilm development. Biofilm and planktonic cells were collected at three different time points corresponding to biofilm development stages: initial (6 h), intermediate (12h) and mature (48h). The total RNA of these samples was obtained and the gene expression for mRNA of HWP1, ALS1 and ALS3 were quantified by Real-Time RT-PCR assay. The data obtained were assessed throught two-way ANOVA and Bonferroni post-test. Significant levels were determined for p values at <0.05. The three genes were detected and quantified in both biofilms and planktonic cells regardless of treatment condition or time of biofilm development. ALS1 and ALS3 expression varied according to the time point, and surface treatment. Significant differences (p <0.001) were showed between gene expression on surfaces treated with sodium hypochlorite and microwave, and significant differences (p <0.001) were showed in gene expression between planktonic and biofilm cells. It can be concluded that the disinfection procedures affect the ALS1 and ALS3 expression patterns in Candida albicans denture biofilms and planktonic cells. Additionaly, differential gene expression patterns were observed among the disinfection treatments.

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