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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.
1

Prediction of supernumerary teeth in children

Anthonappa, Robert Prashanth. January 2011 (has links)
Supernumerary teeth are teeth in addition to the normal complement of 20 primary and 32 permanent teeth. The majority of these supernumerary teeth are conical shaped, assume an inverted orientation and remain un-erupted. Therefore, radiographic examination is considered critical for the identification of supernumerary teeth. A meta-analysis to determine the variations in the prevalence figures based on the diagnostic tools employed revealed that a clinical examination plus selected radiograph(s) are essential for determining the prevalence of supernumerary teeth; the vast disparities in the quoted prevalence of supernumerary teeth make their value questionable. Therefore, the reliability of panoramic radiographs and the influence of the level of dental training of the 18 examiners for identifying supernumerary teeth were evaluated, which demonstrated that panoramic radiographs are unreliable as a diagnostic tool, and that a high level of dental training is essential for the identification of supernumerary teeth. Based on the sensitivity figures for panoramic radiographs the prevalence of supernumerary teeth was re-analyzed and this demonstrated that the prevalence figures are higher than reported in the literature, ranging from 2.4% to 6%, or even higher; thus, indicating the need for new diagnostic tools for the identification of supernumerary teeth. Proposed hypotheses and recent molecular research, using animal models to gain new insights into the development of supernumerary teeth, have been unable to identify the etiology of supernumerary teeth. Based on the existing published reports and an additional 10 familial cases, the only definitive factors is that supernumerary teeth have a genetic component to their etiology. To identify the genetic risk factors responsible for the formation of supernumerary teeth large scale genetic epidemiological studies, with efficient and convenient methods for obtaining sufficient genomic DNA from study participants, are essential. Evaluation of the storage stability of saliva at room temperature, over an 18-month period, did not adversely influence the DNA yield and purity, or the genotyping efficacy; which clearly demonstrates that saliva is a possible alternative to blood as a source of human DNA. Supernumerary teeth are commonly associated with cleidocranial dysplasia (CCD), a genetic disorder affecting the skeletal system. Novel identical compound heterozygous mutations were identified in the RUNX2 gene of a southern Chinese family with CCD, which has been the first report of compound heterozygous mutations in CCD patients. Several mouse mutant genes have reported an association with supernumerary teeth; most of these genes have human orthologs. A case-control association study was performed to determine the role of human orthologs of the mouse mutant genes associated with supernumerary teeth in 457 southern Chinese children. DNA samples were obtained and 140 single nucleotide polymorphisms (SNPs) from 19 genes were genotyped. The findings revealed that polymorphisms on SNPs rs17619858 and rs12699798, in the sclerostin-domain containing-1 (SOSTDC1) gene on chromosome 7, were associated with the development of supernumerary teeth in the anterior region of the maxilla. This dogma of genetic risk assessment for early diagnosis facilitates the implementation of the proposal of Genetic Risk Assessment for Personalized Health and Individual Care (GRAPHIC) concept in dentistry. / published_or_final_version / Paediatric Dentistry / Doctoral / Doctor of Philosophy
2

Radiographic localization of supernumerary teeth in the maxilla

Mallineni, Sreekanth Kumar. January 2011 (has links)
published_or_final_version / Paediatric Dentistry / Master / Master of Dental Surgery
3

Epithelial cell adaptation to supernumerary centrosomes

Rhys, Alexander Daniel January 2017 (has links)
The centrosome is the main microtubule-organising centre in animal cells; important to assemble a bipolar mitotic spindle ensuring proper chromosome segregation and genomic stability. Whereas correct centrosome number (1-2) is tightly maintained in normal cells, cancer cells usually have an increased number of centrosomes (>2), termed centrosome ampli cation. Centrosome ampli cation has been correlated with aneuploidy, increased tumour grade, chemoresistance and overall poor prognosis. Cancer cells primarily adapt to supernumerary centrosomes by clustering them into two poles resulting in a `normal' pseudo-bipolar mitosis. Undermining centrosome clustering is a potential target for cancer-speci c treatment. Indeed, depleting the kinesin HSET has already been shown to speci cally kill cancer cells by impairing the centrosome clustering mechanism. However, it is unclear whether this process requires adaptation or it is inherent to all cell types. Using a panel of non-transformed cell lines, we observed that cells expressing Ecadherin have ine cient clustering mechanisms compared to cell lines without E-cadherin. Loss of E-cadherin (siRNA/CRISPR) promotes centrosome clustering and survival of epithelial cells with multiple centrosomes. In addition, loss of DDR1, involved in regulating cortical contractility downstream of E-cadherin, increases centrosome clustering in epithelial cells. Using Atomic Force Microscopy we con rmed that indeed loss of E-cadherin leads to increased cortical contractility in mitotic cells. Inhibition of actomyosin contractility prevents e cient clustering in cells that do not express E-cadherin, further suggesting that it is important for this process. Loss of E-cadherin and DDR1 is strongly correlated with high levels of centrosome ampli cation in breast cancer cell lines suggesting that these changes are an important adaptation mechanism to centrosome amplification.
4

Estudos cromossômicos e moleculares em Rhamdia (Pisces, Siluriformes, Heptapteridae): análise de relações evolutivas / Cromossomic and molecular studies in Rhamdia (Pisces, Siluriformes, Heptapteridae): a relationship overview

Garcia, Caroline 15 September 2009 (has links)
O gênero Rhamdia, popularmente conhecido como jundiá, pertence à família Heptapteridae, uma das maiores radiações de bagres neotropicais de água doce. Estes peixes de médio porte e hábitos oportunistas e noturnos são encontrados em pequenos rios e córregos. No passado, Rhamdia foi considerado um dos gêneros mais especiosos dentro de Siluriformes, contando com cerca de 100 espécies descritas. Entretanto, após uma revisão taxonômica recente o número de espécies desse gênero foi reduzido a 12. Dados genéticos, de natureza cromossômica e molecular, caracterizam o gênero Rhamdia como um grupo que apresenta grande diversidade, sugerindo a existência de complexos de espécies, principalmente para a espécie R. quelen, a única estudada do ponto de vista citogenético até o momento. No presente trabalho, foram utilizadas diferentes metodologias com o intuito de caracterizar cromossomicamente populações de diferentes espécies de Rhamdia, bem como estabelecer as relações evolutivas entre elas, contribuindo para o reconhecimento de padrões e processos evolutivos envolvidos em sua diferenciação. Foram analisados exemplares de R. enfurnada, R. itacaiunas, R. laukidi e R. quelen, provenientes das principais bacias hidrográficas da América do Sul, sendo somadas as análises sequências de genes mitocondriais de R. cinerascens, R. guatemalensis e R. laticauda provenientes do GenBank, totalizando sete das 12 espécies reconhecidas para o gênero. A análise de cinco regiões do genoma mitocondrial identificou a existência de 15 grupos bem definidos e com altos valores de suporte para o que hoje é reconhecido como R. quelen, confirmando a existência de um complexo de espécies. A divisão das espécies de Rhamdia em um grupo Cis-Andino e um grupo Trans-Andino, proposta anteriormente, também foi recuperada, embora o gênero não tenha sido confirmado como monofilético. Os dados citogenéticos permitiram o estabelecimento de tendências de evolução cromossômica dentro do grupo e a sugestão de um possível mecanismo de origem e diferenciação dos cromossomos supranumerários. O presente trabalho reforça a importância da utilização de diferentes abordagens na realização de estudos taxonômicos e evolutivos, sugerindo uma nova revisão do gênero Rhamdia que leve em consideração os dados genéticos obtidos. / The genus Rhamdia, popularly known as jundia, belongs to the family Heptapteridae, one of the greatest radiations within neotropical freshwater catfish. This group of middle-sized fish of opportunistic behavior is found in small rivers and streams. In the past, Rhamdia was considered one of the most specious genera of Siluriformes, comprising about 100 described species. However, after a recent taxonomic review, the number of species within this genus was reduced to 12. Genetic data, whether chromosomal or molecular, have characterized the genus Rhamdia as a high diverse group, suggesting the existence of species complexes, mainly in R. quelen, the only species where cytogenetic data are available so far. In the present work, different methodologies were used in order to characterize cytogenetically populations of distinct species of Rhamdia, as well as their evolutionary relationships, thus contributing to the recognition of evolutionary patterns and processes involved in their differentiation. Specimens of R. enfurnada, R. itacaiunas, R. laukidi and R. quelen, from the main South-American hydrographic basins were analyzed, coupled with sequence analyses of the mitochondrial genes of R. cinerascens, R. guatemalensis and R. laticauda, available in the GenBank, thereby comprising seven of the 12 valid species in the genus. The analysis of five regions of mitochondrial genome identified 15 well-defined groups with high bootstrap values within the so-called R. quelen, confirming the occurrence of a species complex. The division of Rhamdia species into a Cis-Andean group and a Trans- Andean group, as previously proposed, was also revalidated, although the genus seems not to be monophyletic. The cytogenetic data allowed establishing trends of chromosomal evolution within the group and a hypothesis for the origin and differentiation of supernumerary chromosomes could be drawn. The present work reinforces the importance of distinct approaches in taxonomic and evolutionary studies, suggesting a new revision within the genus Rhamdia that takes the present genetic data into account.
5

Recorrência de alterações de número do incisivo lateral nas fissuras labiopalatinas unilaterais completas / Recurrence of abnormalities of number of the lateral incisor in complete cleft lip and palate

Vargas, Vivian Patricia Saldias 25 May 2012 (has links)
Alterações dentárias do incisivo lateral são bastante comuns em indivíduos com fissuras labiopalatinas. Vários estudos na literatura relatam a ocorrência frequente de hipodontia, entretanto até o momento não foi investigada a recorrência desta alteração na dentição decídua e permanente no mesmo indivíduo. Metodologia: Foi realizado um estudo piloto em 100 radiografias avaliadas duas vezes com intervalo de duas semanas, que revelou concordância substancial a quase perfeita. Foram avaliadas radiografias panorâmicas e periapicais da região da fissura dos indivíduos em diferentes momentos, disponíveis nos arquivos do HRAC/USP, para comparação da recorrência de tais alterações nas dentições decídua e permanente, até obtenção de uma amostra de 1000 indivíduos. Os resultados foram analisados por estatística descritiva e comparados pelo teste de Fisher. Resultados: 67,6% dos indivíduos apresentavam fissura do lado esquerdo, 62,9% eram do sexo masculino e 12,2% apresentavam bandeleta de Simonart. Para a dentição permanente no lado fissurado, houve diferença significativa na ocorrência de hipodontia e hiperdontia entre sexos, entretanto não houve diferença entre sexos quanto à implantação à mesial ou distal da fissura. Na dentição decídua foi observada hipodontia em 24,7% dos indivíduos com fissura do lado esquerdo e 21,91% do lado direito, sem associação com o lado da fissura (p=0,3423). Na dentição permanente houve hipodontia em 45,56% dos indivíduos com fissura do lado esquerdo e 37,65% do lado direito, com associação com o lado da fissura (p=0,02028). A prevalência de hipodontia no lado fissurado foi de 23,8% na dentição decídua e 43,0% na permanente. Quando presente, houve predominância de implantação do incisivo lateral à distal da fissura em ambas as dentições, com associação significativa entre as dentições (p=0,01231). A bandeleta de Simonart não influenciou a ocorrência de hipodontia do incisivo lateral nem o local de implantação à mesial ou distal da fissura. Conclusões: Houve associação significativa entre as dentições para a ocorrência de ambas hipodontia e hiperdontia (p<0,01 e p=0,01366, respectivamente); houve associação entre as dentições para a ocorrência de hipodontia e hiperdontia, tendo a hipodontia maior probabilidade de recorrência. Este conhecimento possibilitará melhor aconselhamento e o fornecimento de informações cientificamente embasadas para os pais, que se preocupam com a possibilidade de hipodontia do incisivo lateral permanente em idades precoces, o que frequentemente leva a exposições radiográficas desnecessárias. / Tooth abnormalities of the lateral incisor are very common in individuals with cleft lip and palate. Several studies in the literature report the frequent occurrence of hypodontia, yet the recurrence of this alteration in the deciduous and permanent dentitions in the same individual has not been analyzed so far. Methods: A pilot study was conducted on 100 radiographs evaluated twice with a two-week interval, which revealed substantial to nearly perfect agreement. Panoramic and periapical radiographs of the cleft area of individuals obtained at different moments, available in the files of HRAC/USP, were analyzed to compare the recurrence of these anomalies in the deciduous and permanent dentitions until a sample of 1,000 individuals was achieved. The results were analyzed by descriptive statistics and compared by the Fisher test. Results: 67.6% of individuals presented clefts on the left side, 62.9% were males and 12.2% had a Simonarts band. For the permanent dentition, there was significant difference in the occurrence of hypodontia and hiperdontia between genders, yet there was no difference between genders concerning tooth implantation mesial or distal to the cleft. In the deciduous dentition hypodontia was observed in 24.7% of individuals with clefts on the left side and 21.91% on the right side, without association with the cleft side (p=0.3423). In the permanent dentition there was hypodontia in 45.56% of individuals with clefts on the left side and 37.65% on the right side, with association with the cleft side (p=0.02028). The prevalence of hypodontia on the cleft side was 23.8% in the deciduous dentition and 43.0% in the permanent dentition. When present, there was predominance of implantation of the lateral incisor distal to the cleft in both dentitions, with significant association between dentitions (p=0.01231). The Simonarts band did not influence the occurrence of hypodontia of the lateral incisor nor the implantation mesial or distal to the cleft. Conclusions: There was significant association between dentitions for the occurrence of both hypodontia and hiperdontia (p<0.01 and p=0.01366, respectively); there was association between dentitions for the occurrence of hypodontia and hyperdontia, with higher probability of recurrence for hypodontia. This knowledge will allow better counseling and scientifically based information to the parents, which are often concerned about the possibility of hypodontia of the permanent lateral incisor in early ages, frequently leading to unnecessary radiographic exposure.
6

Estudos cromossômicos e moleculares em Rhamdia (Pisces, Siluriformes, Heptapteridae): análise de relações evolutivas / Cromossomic and molecular studies in Rhamdia (Pisces, Siluriformes, Heptapteridae): a relationship overview

Caroline Garcia 15 September 2009 (has links)
O gênero Rhamdia, popularmente conhecido como jundiá, pertence à família Heptapteridae, uma das maiores radiações de bagres neotropicais de água doce. Estes peixes de médio porte e hábitos oportunistas e noturnos são encontrados em pequenos rios e córregos. No passado, Rhamdia foi considerado um dos gêneros mais especiosos dentro de Siluriformes, contando com cerca de 100 espécies descritas. Entretanto, após uma revisão taxonômica recente o número de espécies desse gênero foi reduzido a 12. Dados genéticos, de natureza cromossômica e molecular, caracterizam o gênero Rhamdia como um grupo que apresenta grande diversidade, sugerindo a existência de complexos de espécies, principalmente para a espécie R. quelen, a única estudada do ponto de vista citogenético até o momento. No presente trabalho, foram utilizadas diferentes metodologias com o intuito de caracterizar cromossomicamente populações de diferentes espécies de Rhamdia, bem como estabelecer as relações evolutivas entre elas, contribuindo para o reconhecimento de padrões e processos evolutivos envolvidos em sua diferenciação. Foram analisados exemplares de R. enfurnada, R. itacaiunas, R. laukidi e R. quelen, provenientes das principais bacias hidrográficas da América do Sul, sendo somadas as análises sequências de genes mitocondriais de R. cinerascens, R. guatemalensis e R. laticauda provenientes do GenBank, totalizando sete das 12 espécies reconhecidas para o gênero. A análise de cinco regiões do genoma mitocondrial identificou a existência de 15 grupos bem definidos e com altos valores de suporte para o que hoje é reconhecido como R. quelen, confirmando a existência de um complexo de espécies. A divisão das espécies de Rhamdia em um grupo Cis-Andino e um grupo Trans-Andino, proposta anteriormente, também foi recuperada, embora o gênero não tenha sido confirmado como monofilético. Os dados citogenéticos permitiram o estabelecimento de tendências de evolução cromossômica dentro do grupo e a sugestão de um possível mecanismo de origem e diferenciação dos cromossomos supranumerários. O presente trabalho reforça a importância da utilização de diferentes abordagens na realização de estudos taxonômicos e evolutivos, sugerindo uma nova revisão do gênero Rhamdia que leve em consideração os dados genéticos obtidos. / The genus Rhamdia, popularly known as jundia, belongs to the family Heptapteridae, one of the greatest radiations within neotropical freshwater catfish. This group of middle-sized fish of opportunistic behavior is found in small rivers and streams. In the past, Rhamdia was considered one of the most specious genera of Siluriformes, comprising about 100 described species. However, after a recent taxonomic review, the number of species within this genus was reduced to 12. Genetic data, whether chromosomal or molecular, have characterized the genus Rhamdia as a high diverse group, suggesting the existence of species complexes, mainly in R. quelen, the only species where cytogenetic data are available so far. In the present work, different methodologies were used in order to characterize cytogenetically populations of distinct species of Rhamdia, as well as their evolutionary relationships, thus contributing to the recognition of evolutionary patterns and processes involved in their differentiation. Specimens of R. enfurnada, R. itacaiunas, R. laukidi and R. quelen, from the main South-American hydrographic basins were analyzed, coupled with sequence analyses of the mitochondrial genes of R. cinerascens, R. guatemalensis and R. laticauda, available in the GenBank, thereby comprising seven of the 12 valid species in the genus. The analysis of five regions of mitochondrial genome identified 15 well-defined groups with high bootstrap values within the so-called R. quelen, confirming the occurrence of a species complex. The division of Rhamdia species into a Cis-Andean group and a Trans- Andean group, as previously proposed, was also revalidated, although the genus seems not to be monophyletic. The cytogenetic data allowed establishing trends of chromosomal evolution within the group and a hypothesis for the origin and differentiation of supernumerary chromosomes could be drawn. The present work reinforces the importance of distinct approaches in taxonomic and evolutionary studies, suggesting a new revision within the genus Rhamdia that takes the present genetic data into account.
7

Biomonitoramento em áreas poluídas e não poluídas do Rio Uberabinha, região de Uberlândia Minas Gerais, por meio de análise de micronúcleos e freqüência de cromossomos B em bagre (Rhamdia quelen)

Campos Júnior, Edimar Olegário de 26 July 2011 (has links)
CHAPTER 2: The aquatic environment is contaminated by toxic chemicals from industrial, agricultural and domestic activities. The environmental toxicology characterizes the effects related by chemical substances present in some species and their biological implications. The genus Rhamdia presents B chromosomes, which appear to be conserved in most species of the genus, and represents character important to the evolutionary process. The study aimed to evaluate the cytogenetic aspects of 45 copies of a population of Rhamdia quelen collected in three areas with different standards of water quality in Uberabinha River, the region of Uberlandia, Minas Gerais. The species were evaluated by the Micronucleus Test, by counting the erythrocytes. The TMN results indicate the significant genotoxic and cytotoxic potential in the points, in agreement with chemical analysis. This way the species Rhamdia quelen can be considered an efficient bioindicator. The chromosome counting showed the modal number 2n=58 with variance between none and one to seven B chromosomes. The higher frequence of B chromosomes and presence of the karyotype with seven chromosomes supernumerary occurred at Point 3, referring to the Local with the highest potentially mutagenic. There was positive correlation between the presence of B chromosomes and the interference on Environmental quality. / CAPITULO 2: O ambiente aquático está repleto de produtos químicos tóxicos oriundos de atividades industriais, agrícolas e domésticas. A toxicologia ambiental caracteriza os efeitos referentes às substâncias químicas presentes em determinada espécie biológica e suas implicações. O gênero Rhamdia apresenta cromossomos B, que parecem estar conservados em grande parte das espécies do gênero, sendo característica importante para o processo evolutivo. O trabalho objetivou avaliar os aspectos citogenéticos de 45 exemplares de uma população de Rhamdia quelen, coletados em três trechos com diferentes padrões de qualidade de água no Rio Uberabinha, região de Uberlândia, Minas Gerais. As espécies foram avaliadas pelo Teste do Micronúcleo Písceo, pela contagem de eritrócitos. Os resultados do TMN indicam significante potencial mutagênico e citotóxico nos Pontos tratados, em concordância com os parâmetros químicos analisados. Sendo assim, a espécie Rhamdia quelen pode ser considerada como bioindicador eficiente. A contagem dos cromossomos apresentou número modal 2n=58, com variação de um a sete cromossomos supranumerários. A maior frequência de cromossomos B e presença de metáfases com sete cromossomos supranumerários ocorreu no Ponto 3, referente ao Ponto de maior potencialidade mutagênica. Houve correlação positiva entre a presença de cromossomos B e a interferência da qualidade Ambiental. / Mestre em Genética e Bioquímica
8

Recorrência de alterações de número do incisivo lateral nas fissuras labiopalatinas unilaterais completas / Recurrence of abnormalities of number of the lateral incisor in complete cleft lip and palate

Vivian Patricia Saldias Vargas 25 May 2012 (has links)
Alterações dentárias do incisivo lateral são bastante comuns em indivíduos com fissuras labiopalatinas. Vários estudos na literatura relatam a ocorrência frequente de hipodontia, entretanto até o momento não foi investigada a recorrência desta alteração na dentição decídua e permanente no mesmo indivíduo. Metodologia: Foi realizado um estudo piloto em 100 radiografias avaliadas duas vezes com intervalo de duas semanas, que revelou concordância substancial a quase perfeita. Foram avaliadas radiografias panorâmicas e periapicais da região da fissura dos indivíduos em diferentes momentos, disponíveis nos arquivos do HRAC/USP, para comparação da recorrência de tais alterações nas dentições decídua e permanente, até obtenção de uma amostra de 1000 indivíduos. Os resultados foram analisados por estatística descritiva e comparados pelo teste de Fisher. Resultados: 67,6% dos indivíduos apresentavam fissura do lado esquerdo, 62,9% eram do sexo masculino e 12,2% apresentavam bandeleta de Simonart. Para a dentição permanente no lado fissurado, houve diferença significativa na ocorrência de hipodontia e hiperdontia entre sexos, entretanto não houve diferença entre sexos quanto à implantação à mesial ou distal da fissura. Na dentição decídua foi observada hipodontia em 24,7% dos indivíduos com fissura do lado esquerdo e 21,91% do lado direito, sem associação com o lado da fissura (p=0,3423). Na dentição permanente houve hipodontia em 45,56% dos indivíduos com fissura do lado esquerdo e 37,65% do lado direito, com associação com o lado da fissura (p=0,02028). A prevalência de hipodontia no lado fissurado foi de 23,8% na dentição decídua e 43,0% na permanente. Quando presente, houve predominância de implantação do incisivo lateral à distal da fissura em ambas as dentições, com associação significativa entre as dentições (p=0,01231). A bandeleta de Simonart não influenciou a ocorrência de hipodontia do incisivo lateral nem o local de implantação à mesial ou distal da fissura. Conclusões: Houve associação significativa entre as dentições para a ocorrência de ambas hipodontia e hiperdontia (p<0,01 e p=0,01366, respectivamente); houve associação entre as dentições para a ocorrência de hipodontia e hiperdontia, tendo a hipodontia maior probabilidade de recorrência. Este conhecimento possibilitará melhor aconselhamento e o fornecimento de informações cientificamente embasadas para os pais, que se preocupam com a possibilidade de hipodontia do incisivo lateral permanente em idades precoces, o que frequentemente leva a exposições radiográficas desnecessárias. / Tooth abnormalities of the lateral incisor are very common in individuals with cleft lip and palate. Several studies in the literature report the frequent occurrence of hypodontia, yet the recurrence of this alteration in the deciduous and permanent dentitions in the same individual has not been analyzed so far. Methods: A pilot study was conducted on 100 radiographs evaluated twice with a two-week interval, which revealed substantial to nearly perfect agreement. Panoramic and periapical radiographs of the cleft area of individuals obtained at different moments, available in the files of HRAC/USP, were analyzed to compare the recurrence of these anomalies in the deciduous and permanent dentitions until a sample of 1,000 individuals was achieved. The results were analyzed by descriptive statistics and compared by the Fisher test. Results: 67.6% of individuals presented clefts on the left side, 62.9% were males and 12.2% had a Simonarts band. For the permanent dentition, there was significant difference in the occurrence of hypodontia and hiperdontia between genders, yet there was no difference between genders concerning tooth implantation mesial or distal to the cleft. In the deciduous dentition hypodontia was observed in 24.7% of individuals with clefts on the left side and 21.91% on the right side, without association with the cleft side (p=0.3423). In the permanent dentition there was hypodontia in 45.56% of individuals with clefts on the left side and 37.65% on the right side, with association with the cleft side (p=0.02028). The prevalence of hypodontia on the cleft side was 23.8% in the deciduous dentition and 43.0% in the permanent dentition. When present, there was predominance of implantation of the lateral incisor distal to the cleft in both dentitions, with significant association between dentitions (p=0.01231). The Simonarts band did not influence the occurrence of hypodontia of the lateral incisor nor the implantation mesial or distal to the cleft. Conclusions: There was significant association between dentitions for the occurrence of both hypodontia and hiperdontia (p<0.01 and p=0.01366, respectively); there was association between dentitions for the occurrence of hypodontia and hyperdontia, with higher probability of recurrence for hypodontia. This knowledge will allow better counseling and scientifically based information to the parents, which are often concerned about the possibility of hypodontia of the permanent lateral incisor in early ages, frequently leading to unnecessary radiographic exposure.
9

Design, Modeling, and Evaluation of Soft Poly-Limbs: Toward a New Paradigm of Wearable Continuum Robotic Manipulation for Daily Living Tasks

January 2020 (has links)
abstract: The term Poly-Limb stems from the rare birth defect syndrome, called Polymelia. Although Poly-Limbs in nature have often been nonfunctional, humans have had the fascination of functional Poly-Limbs. Science fiction has led us to believe that having Poly-Limbs leads to augmented manipulation abilities and higher work efficiency. To bring this to life however, requires a synergistic combination between robot manipulation and wearable robotics. Where traditional robots feature precision and speed in constrained environments, the emerging field of soft robotics feature robots that are inherently compliant, lightweight, and cost effective. These features highlight the applicability of soft robotic systems to design personal, collaborative, and wearable systems such as the Soft Poly-Limb. This dissertation presents the design and development of three actuator classes, made from various soft materials, such as elastomers and fabrics. These materials are initially studied and characterized, leading to actuators capable of various motion capabilities, like bending, twisting, extending, and contracting. These actuators are modeled and optimized, using computational models, in order to achieve the desired articulation and payload capabilities. Using these soft actuators, modular integrated designs are created for functional tasks that require larger degrees of freedom. This work focuses on the development, modeling, and evaluation of these soft robot prototypes. In the first steps to understand whether humans have the capability of collaborating with a wearable Soft Poly-Limb, multiple versions of the Soft Poly-Limb are developed for assisting daily living tasks. The system is evaluated not only for performance, but also for safety, customizability, and modularity. Efforts were also made to monitor the position and orientation of the Soft Poly-Limbs components through embedded soft sensors and first steps were taken in developing self-powered compo-nents to bring the system out into the world. This work has pushed the boundaries of developing high powered-to-weight soft manipulators that can interact side-by-side with a human user and builds the foundation upon which researchers can investigate whether the brain can support additional limbs and whether these systems can truly allow users to augment their manipulation capabilities to improve their daily lives. / Dissertation/Thesis / Doctoral Dissertation Systems Engineering 2020
10

Studies of the assembly pathway of human ATP synthase

Douglas, Corsten Perrie Louise Claire January 2017 (has links)
Human mitochondrial ATP synthase is an enzyme containing 18 unlike subunits located in the inner mitochondrial membrane (IMM), where the catalytic F1 domain extends into the mitochondrial matrix and the FO domain, which contains the c8-ring rotor, the a-subunit and the supernumerary subunits, is anchored in the IMM. All the subunits, apart from the a- and A6L-subunits, are encoded in the nucleus and require transport into the mitochondria before being assembled. The a- and A6L-subunits are encoded on the mitochondrial genome. The respiratory complexes generate the proton motive force (PMF), which ATP synthase uses to generate ATP from ADP and Pi. Rotation of the α- and β-subunits with the central stalk γ-, δ- and ε-subunits is prevented by coupling the F1 domain to the FO domain via the peripheral stalk (the OSCP-, F6-, d- and b-subunits). ATP hydrolysis is prevented by the natural inhibitor of the enzyme, IF1, binding to the F1 domain. In addition to the aand, b-subunits, the FO domain contains the c8-ring and six supernumerary subunits not involved in the catalytic activity of ATP synthase. The roles of five of these subunits in the assembly of ATP synthase, the e-, f-, g-, DAPIT- and 6.8 kDa proteolipid-subunits, were investigated by suppressing or disrupting their expression individually. The e-subunit is the first of the supernumerary subunits to assemble, then the g-subunit followed by the f-, 6.8 kDa proteolipid- and DAPIT-subunits. All five supernumerary subunits investigated were required to facilitate the dimerisation and oligomerisation of ATP synthase. The e-, f- and g-subunits were found to be important for maintaining mitochondrial respiratory capacity.

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