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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.
91

Diferenciais da saúde em áreas urbanas e rurais: cárie dentária e condições gengivais em escolares no Estado de São Paulo / Health differentials in rural and urban areas: prevalence of dental caries and gingival status in the State of São Paulo

Tatiana Ribeiro de Campos Mello 29 September 2006 (has links)
Objetivos: Estudar os diferenciais entre os indicadores de cárie dentária e alterações gengivais em escolares de áreas urbanas e rurais do Estado de São Paulo. Material e Métodos. Estudo de corte transversal analítico e ecológico foram os dois delineamentos utilizados. A população de estudo foram estudantes de escolas urbanas e rurais do Estado de São Paulo de 5 a 7 e de 10 a 12 anos; a fonte de informação foi o "Levantamento das Condições de Saúde Bucal - Estado de São Paulo, 1998". Foi estimada a prevalência de cárie dentária (índice ceo-d e CPO-D), do sangramento gengival durante a sondagem e de cálculo dental (índice CPI), para o estudo de associação com características sócio-demográficas dos escolares e indicador de desenvolvimento social (IDH-M) das cidades participantes do levantamento. Foram estimadas as odds ratios ajustadas e não ajustadas, por meio de análise de regressão logística de delineamento de modelos multivariados e multiníveis. O estudo de diferenciais de prevalência entre diferentes regiões do Estado empregou uma classificação de àreas rurais homogêneas pré-existentes. Resultados: Os indicadores de saúde bucal tiveram distibuição desigual entre os estratos, indicando pior condição para a população rural. Estudar em áreas rurais, em escolas públicas, ser negro ou pardo e ser do sexo masculino associaram com a manifestação de cárie não tratada e alterações gengivais, ao nível dos indivíduos. No modelo multinível, a presença de flúor na água de abastecimento público, o Índice de Desenvolvimento Humano (IDH-M) e o Índice de Cuidado associaram com as condições de saúde bucal estudadas ao nível das cidades participantes do levantamento. Áreas rurais cujo sistema produtivo apresentava maior implementação da economia agro-industrial tiveram os melhores indicadores de saúde bucal. Conclusões: Os escolares de área rural mostraram-se mais vulneráveis para todas as condições de saúde bucal avaliadas / Objectives: To assess differentials of prevalence of dental caries and gingival status in schoolchildren from rural and urban areas of the State of São Paulo. Material and Methods: The study population comprised schoolchildren aged 5 to 7 and 10 to 12 years old; the source of information was the “Survey of Oral Health Status – State of São Paulo, 1998”. The prevalence of dental caries (dmft and DMFT indices), gingival bleeding on probing and dental calculus (CPI index) were assessed for the appraisal of association with socio-demographic characteristics of schoolchildren and indices of social development of participating towns. The estimation of adjusted and non-adjusted odds ratios used logistic regression analysis, and the fitting of multivariate multilevel models. The study of prevalence differentials among regions of the State used a previous classification of homogeneous rural areas. Results: Indices of oral health had an unequal distribution among strata, indicating a poorer profile for rural population. Studying in rural areas, in public schools, being black and being a boy associated with the odds of presenting untreated dental caries and gingival status at the individual level. Fluoride addition to tap water and the human development index associated with these outcomes at the town level. Rural areas whose productive system presented enhancements associated with the agro-industry had an improved profile of oral health. Conclusion: Schoolchildren in rural areas had a poorer profile for all outcomes of oral health. These findings should instruct health services for programming specific interventions aimed at this stratum.
92

Association between periodontal and systemic inflammation:a study of pro- and anti-inflammatory mediators

Norppa, A. (Anna) 12 November 2012 (has links)
Abstract The principal aim of this study was to explore associations between systemic inflammatory status and periodontal inflammation and tissue destruction. The study population consisted of 61 patients with chronic periodontitis, 30 periodontally healthy control subjects, and 80 subjects with type 1 diabetes mellitus (T1DM). The T1DM subjects were periodontally treated and re-examined eight weeks after completion of the treatment. The periodontal measures included plaque, probing depth (PD), bleeding on probing (BOP) and attachment level (AL). The serum levels of interleukin (IL)-6, tumor necrosis factor (TNF)-α, and interleukin (IL)-10, as well as the gingival crevicular fluid (GCF) level of matrix metalloproteinase (MMP)-8 were analyzed using commercially available ELISA assays, and serum high density lipoprotein (HDL) level using direct enzymatic methods. Serum IL-6 level associated significantly with the extent of inflamed periodontal pockets in T1DM subjects. Moreover, serum IL-6 modulated local periodontal inflammation in T1DM patients; periodontal healing turned out to be poorer in subjects with a high level of serum IL-6 than in those with a low level. Serum TNF-α/IL-10 ratio was three times higher in chronic periodontitis patients than in periodontally healthy control subjects. In T1DM subjects a significant inverse association between serum HDL level and the extent of inflamed periodontal pockets was found; subjects with a low serum HDL level presented 50% more inflamed periodontal sites than subjects with a high serum HDL level. A significant association between GCF MMP-8 level in shallow crevices and the extent of periodontal attachment loss in chronic periodontitis patients was observed. In conclusion, we focused on analyzing associations between systemic inflammatory status and periodontal conditions. According to our results, periodontal inflammation/infection is associated with systemic inflammatory status using serum IL-6, TNF-α/IL-10 ratio and HDL as indicators. Also, a high level of MMP-8 in GCF in shallow crevices could be indicative of higher susceptibility to periodontal infection and tissue destruction. / Tiivistelmä Tutkimuksen tavoitteena oli tarkastella hampaiden kiinnityskudosten tulehduksen (pardodontiitti) ja siihen liittyvän inflammaation yhteyttä systeemiseen tulehdustilaan. Tutkimusaineistoon kuului 61 yleistervettä potilasta, joilla oli kohtalaisesti tai pitkälle edennyt parodontiitti, 30 yleistervettä yksilöä, joiden hampaiden kiinnityskudokset olivat terveet/lähes terveet (kontrolliryhmä), sekä 80 tyypin 1 diabetes mellitus (T1DM) potilasta, joilla esiintyi vaihtelevasti parodontiittia. T1DM potilaiden parodontiitti hoidettiin, ja heidät tutkittiin uudelleen kahdeksan viikon kuluttua hoidon päättymisestä. Tutkittavilta tarkastettiin plakin määrä, ientaskujen syvyys, ienverenvuoto ja hampaiden kiinnityskudoksen menetys. Systeemistä tulehdustilaa mitattiin käyttäen seerumin interleukiini (IL)-6, tuumorinekroosifaktori (TNF)-α ja interleukiini (IL)-10 tasoja. Lisäksi määritettiin ientaskunesteen matriksimetalloproteinaasi (MMP)-8 taso. Kaikki edellä mainitut tulehduksen välittäjäainetasot määritettiin käyttäen ELISA-menetelmää. T1DM potilaiden seerumin IL-6 pitoisuuden ja tulehtuneiden ientaskujen määrän välillä vallitsi positiivinen yhteys. Lisäksi havaittiin, että seerumin korkea IL-6 taso heikensi parodontiitin paranemista. T1DM potilailla havaittiin käänteinen yhteys seerumin HDL-pitoisuuden ja tulehtuneiden ientaskujen määrän välillä. Tutkittavilla, joilla seerumin HDL-taso oli matala (<1.35 mmol/l), oli 50 % enemmän tulehtuneita ientaskuja kuin niillä, joilla HDL-taso oli korkea (≥1.35). Parodontiitti-ryhmässä seerumin TNF-α/IL-10 suhde oli kolminkertainen verrattuna kontrolliryhmän vastaavaan ilmentäen voimakkaampaa matala-asteista tulehdusta parodontiitti-potilailla. Matalista (<4 mm) ientaskuista kerätyn ientasunesteen MMP-8 pitoisuuden ja parodontiitin vaikeusasteen välillä vallitsi merkittävä postiivinen yhteys parodontiitti-potilailla. Yhteenvetona, systeemisen tulehdustilan ja hampaiden kiinnityskudosten välillä vallitsee kaksisuuntainen yhteys; toisaalta parodontiitti lisää matala-asteista systeemistä tulehdustilaa ja toisaalta kohonnut systeeminen tulehdustila lisää alttiutta parodontiittiin ja siihen liittyvään inflammaatioon. Lisäksi ientaskunesteen korkea MMP-8 pitoisuus matalissa ientaskuissa voi merkitä lisääntynyttä alttiutta parodontiumin alueen tulehdukselle ja kudostuholle.
93

Periodontal disease during pregnancy and low birth weight of newborns at Chris Hani district of Eastern Cape

Agbeniyi, Olusola Charles 14 February 2013 (has links)
Objective: This study sought to determine the association between periodontal disease in pregnancy and the delivery of low birth weight newborns in a rural population of South African women. Methods: This case-control study involved 348 new mothers. All subjects were recruited post-delivery from three public hospitals in the rural Eastern Cape of South Africa. The cases (n=119) were mothers who delivered through normal delivery and whose babies at the time of delivery weighed <2.5 kg. Age-matched controls (n=229) were mothers who delivered ≥2.5 kg babies. Potential risk factors for periodontal disease and low birth weight were collected by means of a structured questionnaire and maternity record review. Using the WHO's community periodontal index, a trained dental clinician blinded to participants' birth-outcomes recorded the periodontal health status of each participant (intraexaminer reliability; kappa = 0.95). Mothers who presented with a probing depth ≥4 mm on more than four index teeth without the presence of gingival overgrowth were deemed to present with periodontal disease. Data analysis included conditional logistic regression analysis. Results: Periodontal disease was diagnosed in 37.9%> (n=45) of the case group and 9.2°/o (n=21) of the control group. Low birth weight was also significantly more common among those who were unemployed, those who reported fewer than three antenatal visits and drinking on five or more days per week during pregnancy. After controlling for potential confounders, mothers presenting with a probing depth ≥ 4 mm on four teeth (OR = 4.12; 95°/o Cl = 1. 78 - 9.50) or more than four teeth (OR = 4.95; 95%> Cl: 1.52 - 15.81) were found to be significantly more likely to have low birth weight babies. Conclusions: The study findings suggest that there is a significant dose-dependent positive association between periodontal disease and low birth weight, independent of other risk factors measured in this study. / Dissertation (MSc)--University of Pretoria, 2013. / Community Dentistry / unrestricted
94

Insights into Autotrophic Activities and Carbon Flow in Iron-Rich Pelagic Aggregates (Iron Snow)

Li, Qianqian, Cooper, Rebecca E., Wegner, Carl-Eric, Taubert, Martin, Jehmlich, Nico, von Bergen, Martin, Küsel, Kirsten 05 May 2023 (has links)
Pelagic aggregates function as biological carbon pumps for transporting fixed organic carbon to sediments. In iron-rich (ferruginous) lakes, photoferrotrophic and chemolithoautotrophic bacteria contribute to CO2 fixation by oxidizing reduced iron, leading to the formation of iron-rich pelagic aggregates (iron snow). The significance of iron oxidizers in carbon fixation, their general role in iron snow functioning and the flow of carbon within iron snow is still unclear. Here, we combined a two-year metatranscriptome analysis of iron snow collected from an acidic lake with protein-based stable isotope probing to determine general metabolic activities and to trace 13CO2 incorporation in iron snow over time under oxic and anoxic conditions. mRNA-derived metatranscriptome of iron snow identified four key players (Leptospirillum, Ferrovum, Acidithrix, Acidiphilium) with relative abundances (59.6–85.7%) encoding ecologically relevant pathways, including carbon fixation and polysaccharide biosynthesis. No transcriptional activity for carbon fixation from archaea or eukaryotes was detected. 13CO2 incorporation studies identified active chemolithoautotroph Ferrovum under both conditions. Only 1.0–5.3% relative 13C abundances were found in heterotrophic Acidiphilium and Acidocella under oxic conditions. These data show that iron oxidizers play an important role in CO2 fixation, but the majority of fixed C will be directly transported to the sediment without feeding heterotrophs in the water column in acidic ferruginous lakes.
95

End-to-end available bandwidth estimation and its applications

Jain, Manish 09 April 2007 (has links)
As the Internet continues to evolve, without providing any performance guarantees or explicit feedback to applications, the only way to infer the state of the network and to dynamically react to congestion is through end-to-end measurements. The emph{available bandwidth} (avail-bw) is an important metric that characterizes the dynamic state of a network path. Its measurement has been the focus of significant research during the last 15 years. However, its estimation remained elusive for several reasons. The main contribution of this thesis is the development of the first estimation methodology for the avail-bw in a network path using end-to-end measurements. In more detail, our first contribution is an end-to-end methodology, called SLoPS, to determine whether the avail-bw is larger than a given rate based on the sequence of one-way delays experienced by a periodic packet stream. The second contribution is the design of two algorithms, based on SLoPS, to estimate the mean and the variation range, respectively, of the avail-bw process. These algorithms have been implemented in two measurement tools, referred to as PathLoad and PathVar. We have validated the accuracy of the tools using analysis, simulation, and extensive experimentation. Pathload has been downloaded by more than 6000 users since 2003. We have also used PathVar to study the variability of the avail-bw process as a function of various important factors, including traffic load and degree of multiplexing. Finally, we present an application of avail-bw estimation in video streaming. Specifically, we show that avail-bw measurements can be used in the dynamic selection of the best possible overlay path. The proposed scheme results in better perceived video quality than path selection algorithms that rely on jitter or loss-rate measurements.
96

TOP-K AND SKYLINE QUERY PROCESSING OVER RELATIONAL DATABASE

Samara, Rafat January 2012 (has links)
Top-k and Skyline queries are a long study topic in database and information retrieval communities and they are two popular operations for preference retrieval. Top-k query returns a subset of the most relevant answers instead of all answers. Efficient top-k processing retrieves the k objects that have the highest overall score. In this paper, some algorithms that are used as a technique for efficient top-k processing for different scenarios have been represented. A framework based on existing algorithms with considering based cost optimization that works for these scenarios has been presented. This framework will be used when the user can determine the user ranking function. A real life scenario has been applied on this framework step by step. Skyline query returns a set of points that are not dominated (a record x dominates another record y if x is as good as y in all attributes and strictly better in at least one attribute) by other points in the given datasets. In this paper, some algorithms that are used for evaluating the skyline query have been introduced. One of the problems in the skyline query which is called curse of dimensionality has been presented. A new strategy that based on the skyline existing algorithms, skyline frequency and the binary tree strategy which gives a good solution for this problem has been presented. This new strategy will be used when the user cannot determine the user ranking function. A real life scenario is presented which apply this strategy step by step. Finally, the advantages of the top-k query have been applied on the skyline query in order to have a quickly and efficient retrieving results.
97

Targeting novel soil glycosyl hydrolases by combining stable isotope probing and metagenomics

Verastegui Pena, Yris Milusqui 14 February 2014 (has links)
Soil represents the largest global reservoir of microbial diversity for the discovery of novel genes and enzymes. Both stable-isotope probing (SIP) and metagenomics have been used to access uncultured microbial diversity, but few studies have combined these two methods for accessing the biotechnological potential of soil genetic diversity and fewer yet have employed functional metagenomics for recovering novel genes and enzymes for bioenergy or bioproduct applications. In this research, I demonstrate the power of combining functional metagenomics and SIP using multiple plant-derived carbon substrates and diverse soils for characterizing active soil bacterial communities and recovering glycosyl hydrolases based on gene expression. Three disparate Canadian soils (tundra, temperate rainforest and agricultural) were incubated with five native carbon (12C) or stable-isotope labelled (13C) carbohydrates (glucose, cellobiose, xylose, arabinose and cellulose). Sampling at defined time intervals (one, three and six weeks) was followed by DNA extraction and cesium chloride density gradient ultracentrifugation. Denaturing gradient gel electrophoresis (DGGE) of all gradient fractions confirmed the recovery of labeled nucleic acids. Sequencing of original soil samples and labeled DNA fractions demonstrated unique heavy DNA patterns associated with all soils and substrates. Indicator species analysis revealed many uncultured and unclassified bacterial taxa in the heavy DNA for all soils and substrates. Among characterized taxa, Salinibacterium (Actinobacteria), Devosia (Alphaproteobacteria), Telmatospirillum (Alphaproteobacteria), Phenylobacterium (Alphaproteobacteria) and Asticcacaulis (Alphaproteobacteria) were the bacterial ???indicator species??? for the heavy substrates and soils tested. Both Actinomycetales and Caulobacterales (genus Phenylobacterium) were associated with metabolism of cellulose. Members of the Alphaproteobacteria were associated with the metabolism of arabinose and members of the order Rhizobiales were strongly associated with the metabolism of xylose. Annotated metagenomic data suggested diverse glycosyl hydrolase gene representation within the pooled heavy DNA. By screening only 2876 inserts derived from the 13C-cellulose heavy DNA, stable-isotope probing and functional screens enabled the recovery of six clones with activity against carboxymethylcellulose and methylumbelliferone-based substrates.
98

Remodelação alveolar e perfil bacteriano em implantes instalados em diferentes níveis relacionados à crista óssea / Bone remodeling and bacterial profile in dental implants inserted in different levels in relation to the crestal bone

Mariana Ribeiro de Moraes Rego 30 June 2014 (has links)
A substituição clínica de dentes naturais perdidos por implantes osteointegrados tem representado uma das primeiras opções terapêuticas para a reabilitação de pacientes total ou parcialmente edêntulos. Apesar dos excelentes índices de sucesso demonstrados pelas restaurações implanto-suportadas, alguns fatores permanecem não esclarecidos, principalmente no que diz respeito à remodelação óssea ao redor dos implantes osteointegrados. Desta forma, o objetivo deste estudo foi avaliar a relação do nível de instalação dos implantes dentários com os parâmetros clínicos, com a remodelação óssea peri-implantar e com a colonização bacteriana, em implantes de plataforma regular, submetidos à carga imediata. Implantes de plataforma regular foram instalados em dois diferentes níveis em relação à crista óssea ao nível ósseo e supra ósseo (1 mm). No total, trinta e cinco implantes em 9 pacientes (idade média de 62,4 11,2 anos) foram avaliados radiograficamente no momento da instalação dos implantes (T1) e 6 meses após (T2), momento no qual também foram feitas análises clínicas e coleta de amostras para o teste microbiológico. Nos exames radiográficos foram analisadas a perda óssea, a partir de mensurações lineares da distância entre um ponto fixo do componente protético e o ponto mais coronário do contato osso-implante, e a densidade óptica alveolar obtida a partir de regiões ósseas de interesse (ROIs). As análises clínicas consistiram na avaliação da profundidade de sondagem e na mensuração do volume do fluido gengival peri-implantar. O perfil bacteriano dos sítios avaliados foi caracterizado por meio do método de análise de checkerboard DNA-DNA hybridization. Os testes estatísticos realizados mostraram não haver relação entre o nível de instalação dos implantes em relação à crista óssea e a remodelação óssea alveolar, tanto com relação à perda óssea (p = 0,725), como com relação à densidade óptica alveolar (p = 0,975). Também não foi possível estabelecer uma correlação entre a remodelação óssea e parâmetros clínicos como profundidade de sondagem e volume do fluido gengival peri-implantar. Com relação ao perfil bacteriano, não foram encontradas diferenças estatisticamente significativas entre os grupos avaliados para nenhuma das 40 bactérias analisadas. / The replacement of missing teeth with osteointegrated dental implants represents one of the first therapeutic options for the rehabilitation of totally or partially edentulous patients. In spite of clinical success rates for implant-supported restorations, some factors remain nuclear, especially those related to alveolar bone remodeling around osteointegrated implants. Thus, the aim of this study was to evaluate the relation between the installation level of dental implants with bone remodeling and bacterial colonization, in regular platform implants, under an immediate loading protocol. Dental implants with regular platform were inserted in different levels related to the bone crest on the level of bone crest and above the bone crest. In total, thirty-five implants in 9 patients (mean age 62,4 11,2 years) were radiographically evaluated in the moment of implant installation (T1) and 6 months after (T2), when clinical analysis and sample collecting for microbiologic test were performed. In radiographic exams were analyzed the marginal bone loss, from linear measurements of the distance between a fixed point of prosthetic components and the most coronal point of bone-implant contact, and optical alveolar density, from bone regions of interest (ROIs). Clinical analysis consisted of probing depth evaluation and peri-implant crevicular fluid volume mensuration. The bacterial profile of selected sites was characterized by checkerboard DNA-DNA hybridization method. Statistic tests showed no relation between implant insertion levels and alveolar bone remodeling, with relation to marginal bone loss (p = 0,725) and optical alveolar density (p = 0,975). It was not also possible to establish a correlation among alveolar bone remodeling and clinical parameters as probing depth and peri-implant crevicular fluid volume. With respect to the bacterial profile, no statistically significant differences were found between the study groups, for none of the 40 bacterial specimens analyzed.
99

Algorithmes heuristiques et exacts pour le problème de l’ensemble dominant connexe minimum

Soualah, Sofiane 08 1900 (has links)
No description available.
100

Structural rearrangements of the HIV-1 genomic RNA during maturation of the viral particle / Etude des remaniements structuraux de l'ARN génomique du VIH-1 lors de la maturation des particules virales

Mailler, Élodie 22 September 2017 (has links)
Le VIH-1 bourgeonne sous forme immature et doit subir l’étape de maturation afin d’acquérir son caractère infectieux. La maturation protéolytique du précurseur Pr55Gag induit le réarrangement morphologique de la particule alors que le dimère d’ARNg acquiert une compaction optimale. Ces réarrangements conformationnels restent encore inconnus et sont facilités par l’activité chaperonne de la protéine NCp7. Notre but a été de déterminer les différentes étapes menant à l’obtention d’un dimère d’ARNg mature. Nous avons donc étudié la structure des 550 premiers nucléotides du génome par cartographie chimique, à la fois 1. in vitro en présence des protéines Pr55Gag, GagΔp6, intermédiaires contenant le domaine NC et NCp7 et 2. in viro par l’approche hSHAPE-Seq que nous avons développé. Les particules matures et bloquées aux différentes étapes de maturation de Pr55Gag ont été analysées ainsi que des particules matures et totalement immatures traitées avec l’éjecteur de zinc AT-2. Ce traitement permet d’identifier les sites de protection de Pr55Gag et NCp7 ainsi que leur activité déstabilisatrice. / The HIV-1 particle buds from the infected cell as an immature particle and has to undergo a maturation process to become infectious. Proteolytic processing of Pr55Gag triggers morphological rearrangements of the particle whereas the gRNA dimer becomes more stable. Genomic rearrangements remain poorly understood and are facilitated by the RNA chaperone activity of the NCp7 protein. Our goal was to determining the different steps leading to the formation of the mature dimeric gRNA. To this end, the structure of the first 550 nucleotides of the HIV-1 genome was assessed by chemical probing 1. in vitro with Pr55Gag, GagΔp6, NC-containing intermediates and NCp7 proteins and 2. in viro with the hSHAPE-Seq approach we developed. Wild type and mutant viruses mimicking the sequential processing of Pr55Gag were analysed, as well as immature PR- and mature particles treated with the AT-2 zinc ejector, in order to identify the Pr55Gag and NCp7 binding sites and their gRNA destabilising activity.

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