Discursos e produção de sentidos: experiência da transferência da política do tratamento diretamente observado de curta duração para o controle da tuberculose em Moçambique - África

A estratégia do Tratamento Diretamente Observado de Curta Duração para o controle da tuberculose (DOTS) tem sido usada por vários países do mundo especificamente pelos 22 mais afetados pela doença, que contribuem com cerca de 80% de casos, porém, apesar da estratégia demonstrar a redução de casos e aumentar a adesão dos pacientes ao tratamento, e ter sido implementada em Moçambique desde a década de 1980, a doença continua a ser um problema grave de saúde pública no país. Este estudo tem como objetivo central: analisar a transferência da política do DOTS a partir da visão dos gestores centrais, provinciais e distritais, e profissionais de saúde da província de Nampula. Trata-se de um estudo qualitativo que usa a Análise de Discurso de matriz francesa como seu referencial teórico metodológico que busca a compreensão dos sentidos a partir das condições da produção. Participaram deste estudo 15 profissionais de saúde que ocupavam as posições de gestores, médicos e profissionais de enfermagem e/ou técnicos, e atuavam no Programa nacional de controle de Tuberculose em Moçambique com o mínimo de um ano de experiência, nos meses de maio a agosto de 2014, nos níveis central, provincial (Nampula), e distrital (em oito distritos da província de Nampula). Para a coleta de dados usou-se um roteiro de entrevista semi-estruturado que permitiu explorar os sentidos produzidos. O corpus em análise foi constituído a partir das entrevistas transcritas. Para o auxílio da organização dos dados usou-se o sofware Atlis.ti versão 6. Este estudo teve a aprovação da Comissão Nacional de Bioética e da autorização do Ministro da Saúde de Moçambique. Para a análise dos dados foram identificados quatro blocos discursivos: experiências adotadas na implementação e manutenção do DOTS; estratégias adotadas na implementação e manutenção de DOTS; potencialidades, fragilidades de DOTS no controle da tuberculose e; discursos não buscados pelo roteiro: possíveis soluções. Os sentidos produzidos enfatizam dizeres inscritos em formações discursivas que desconsideram a subjetividade do enfermo; de fragilidades do sistema de saúde, falta de recursos humanos, falta de transporte, baixos salários, insuficiência de laboratórios, distâncias longas entre a moradia do paciente e a unidade sanitária. Ainda os entrevistados entendem como potencialidade a participação dos agentes comunitários e da família no tratamento da doença. Conclui-se que para o controle da tuberculose usando a estratégia DOTS o compromisso do governo deve ser pragmático traduzindo-se em ações concretas como o aumento do financiamento das ações de controle de tuberculose, incluindo as pesquisas, formação dos recursos humanos e, sobretudo, atuar sobre os determinantes socias da saúde

Structural Polymorphism in Tau Filaments: An Implication for Neurodegenerative Diseases

Tau filaments are the pathological hallmark of >20 neurodegenerative diseases including Alzheimer's disease, Pick's disease, and progressive supranuclear palsy. In the adult human brain, six isoforms of tau are expressed that differ by presence or absence of the second of the four semiconserved repeats. As a consequence, half of the tau isoforms have three repeats (3R tau), whereas the other half has four repeats (4R tau). Site-directed spin labeling of recombinant tau in conjunction with electron paramagnetic resonance spectroscopy was used to obtain structural insights into tau filaments. The studies showed that the filaments of 4R tau and 3R tau share a highly ordered core structure in the third repeat with parallel, in-register arrangement of beta-strands. This structure in 3R and 4R is conserved regardless of whether full-length isoforms (htau40 and htau23) or truncated constructs (K18 and K19) are used. When mixed, 3R tau and 4R tau coassembled into heterogeneous filaments. Hence, these findings indicate that there are at least three compositionally distinct types of filaments: homogeneous 3R tau, homogeneous 4R tau, and heterogeneous 3R/4R tau. In vitro experiments show that the seeded filament growth, a prerequisite for tau spreading in tissue culture and brain, is crucially dependent on the isoform composition of individual seeds. Seeds of 3R tau and 3R/4R tau recruit both types of isoforms whereas seeds of 4R tau can recruit 4R tau, but not 3R tau, establishing an asymmetric barrier. Conformational templating of 4R tau onto 3R tau seeds eliminates this barrier, giving rise to a new type of tau filament. Conformational studies at the molecular level of tau filaments were done using Double electron-electron resonance spectroscopy, which allows the determination of distances between pairs of spin labels. These studies revealed structural differences between filaments of 3R tau and 4R tau. Furthermore, they indicated that 4R tau assumed the conformation of 3R tau when templated on 3R tau seeds. Our measurements have also provided insights into the heterogeneity of tau filament structure. Conformational differences due to variation in filament composition and seeding properties of tau filaments have shown that they are structurally polymorphic in nature. This structural polymorphism of tau filaments has widespread implications in understanding and treatment of neurodegenerative diseases.

Análise de ligação do gene de resistência Zym-2 com marcadores microssatélites e reação de acessos de meloeiro ao Zucchini yellow mosaic virus (ZYMV)

As viroses causam perdas significativas na cultura do melão. Dentre essas, o vírus do mosaico amarelo da abobrinha-de-moita (Zucchini yellow mosaic virus- ZYMV) possui grande importância para a cultura e é encontrado em todos os locais de plantio de cucurbitáceas. O controle desse vírus através da resistência genética é a forma mais eficiente de manejo. O acesso PI414723 é a única fonte de resistência de meloeiro ao ZYMV. Essa resistência é oligogênica e supostamente condicionada por três genes dominantes: Zym-1, Zym-2 e Zym-3. A localização cromossômica do gene Zym-1 já foi confirmada no grupo de ligação 2, próximo ao marcador CMAG36. Entretanto, a localização de Zym-2 ainda carece de confirmação experimental, muito embora existam evidências de sua localização no grupo de ligação 10 (LGX). Sendo assim, um dos objetivos do presente trabalho foi confirmar a localização do gene Zym-2 através de análises de ligação com marcadores microssatélites (SSRs). Para tanto, foi utilizada uma população F2 derivada do cruzamento PI414723 x \'Védrantais\'. As plantas foram inoculadas mecanicamente com o isolado RN6-F, patótipo 0, duas vezes em um intervalo de 24 h. A confirmação da infecção e a quantificação dos títulos virais nas plantas F2 foram realizadas através do teste PTA-ELISA. O DNA genômico das plantas foi extraído da primeira folha verdadeira e utilizado nas reações de PCR com primers específicos para SSRs selecionados pertencentes ao LGX. Observou-se uma distribuição assimétrica de classes de absorbância e maior frequência de indivíduos F2 na classe com menor valor (0,1 a 0,2), sugerindo a existência de um gene de efeito maior. O teste chi-quadrado mostrou que todos os marcadores segregaram na frequência esperada (1:2:1), exceto o marcador CMCT134b. A ligação do Zym-2 aos marcadores foi confirmada por meio de regressão linear simples. Dos marcadores analisados, a regressão linear foi significativa para MU6549 e CMBR55, com p-valores de 0,011 e 0,0054, respectivamente. As análises de ligação mostraram que as ordens e as distâncias entre os marcadores condizem com os mapas presentes na literatura. Um segundo objetivo do estudo foi o de avaliar a reação ao ZYMV de 42 acessos de meloeiro oriundos da região Nordeste do Brasil, com o intuito de explorar novas fontes de resistência. Foram realizados dois experimentos utilizando a mesma metodologia citada anteriormente. O título viral médio entre os acessos variou de 0,123 a 0,621 no experimento 1 e de 0,019 a 0,368 no experimento 2. Alguns acessos apresentaram consistentemente baixos títulos virais, próximos aos do acesso resistente PI414723 e dos controles negativos (plantas não inoculadas da cultivar \'Védrantais\'). Portanto, estes acessos mostram-se como potenciais fontes de resistência ao vírus para o emprego em programas de melhoramento.

Intra-population variation and geographic correlation in Canthon humectus hidalgoensis using FTIR-ATR spectroscopy

In some cases external morphology is not sufficient to discern between populations of a species, as occurs in the dung beetle Canthon humectus hidalgoensis Bates; and much less to determine phenotypic distances between them. FTIR-ATR spectroscopy show several advantages over other identification techniques (e.g. morphological, genetic, and cuticular hydrocarbons analysis) due to the non-invasive manner of the sample preparation, the relative speed of sample analysis and the low-cost of this technology. The infrared spectrum obtained is recognized to give a unique ‘fingerprint’ because vibrational spectra are specific and unique to the molecular nature of the sample. In our study, results showed that proteins, amino acids and aromatic ethers of insect exocuticle have promising discriminative power to discern between different populations of C. h. hidalgoensis. Furthermore, the correlation between geographic distances between populations and the chemical distances obtained by proteins + amino acids + aromatic ethers was statistically significant, showing that the spectral and spatial information available of the taxa together with appropriated chemometric methods may help to a better understanding of the identity, structure, dynamics and diversity of insect populations.

Military Districts, England and Wales, United Kingdom, 1804 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: A complete representation of the coast of England, together with the interior, divided into counties and military districts : also the coast of France and Holland from the Texel to Brest ... to which is annexed eighteen plans of the ports of the enemy, the principal depôts of the flotilla intended for the invasion of England, by John Luffman, Geogr. It was published by J. Luffman in 1804. Scale [ca. 1:2,500,000]. The image inside the map neatline is georeferenced to the surface of the earth and fit to the 'British National Grid' coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, administrative and military district boundaries, shoreline features including distances between selected ports, and more. Includes insets of foreign military installations and index to the military districts. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

Post Roads, Central Europe Region, 1764 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Neue und vollständige Postkarte durch ganz Deutschland und durch die angränzende Theile der benachbarten Länder = Nouvelle carte geographique des postes d'Allemagne et des provinces limitrophes, zusammen getragen und ausgefertiget von Franz Ioseph Heger. It was published by im Verlag bey denen Homaennischen Erben in 1764. Scale [ca. 1:1,500,000]. Covers the Central Europe region. Map in German. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Europe Lambert Conformal Conic coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, postal roads with distances between towns, territorial and administrative boundaries, shoreline features, and more. Relief shown pictorially.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

Massachusetts, Rhode Island, and Connecticut, Postal Statistics Map, 1876 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: The "centennial" postal statistical map of Massachusetts, Rhode Island and Connecticut : showing railroads, post routes and offices together with population and valuation of cities and towns. It compiled and published by M.G. Cook and Frank O. Ellis in 1876. Scale [ca. 1:422,400]. Covers also portions of New York, Vermont, and New Hampshire. The image inside the map neatline is georeferenced to the surface of the earth and fit to the USA Contiguous Albers Equal Area Conic projection (Meters). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, or other information associated with the principal map. This map shows features such as railroads, post routes and offices together with population and valuation of cities and towns, distances between post offices, drainage, state, county, and town boundaries, and more. Includes table of population and valuation by county and cities of Boston and vicinity, and table of distances. This layer is part of a selection of digitally scanned and georeferenced historic maps of New England from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates, scales, and purposes.

Speciation of Antechinus stuartii and A. subtropicus (Marsupialia : Dasyuridae) in eastern Australia: molecular and morphological evidence

This paper evaluates the systematic status of the Antechinus populations of northern New South Wales and southern Queensland, using a combined morphological and molecular (allozymes and mitochondrial DNA) approach. Analysis of the d-loop section of the mitochondrial DNA control region revealed two highly supported clades within A. stuartii sensu lato that were sympatric in the Border Ranges of northern New South Wales. However, genetic distances between these clades were small ( approximately 3%), indicating that time of divergence was probably relatively recent. Allozyme electrophoresis also showed very small differences between clades/ species. Analyses of cranial and dental characters showed that the members of each of these clades differed morphologically and that the clades corresponded to A. stuartii and the recently described A. subtropicus. The combined results support the species status of A. stuartii and A. subtropicus, and suggest that speciation was likely a result of a recent vicariant event.

"mind the gap": The size-distance dissociation in visual neglect is a cueing effect

There is a growing body of evidence that the processes mediating the allocation of spatial attention within objects may be separable from those governing attentional distribution between objects. In the neglect literature, a related proposal has been made regarding the perception of (within-object) sizes and (between-object) distances. This proposal follows observations that, in size-matching and bisection tasks, neglect is more strongly expressed when patients are required to attend to the sizes of discrete objects than to the (unfilled) distances between objects. These findings are consistent with a partial dissociation between size and distance processing, but a simpler alternative must also be considered. Whilst a neglect patient may fail to explore the full extent of a solid stimulus, the estimation of an unfilled distance requires that both endpoints be inspected before the task can be attempted at all. The attentional cueing implicit in distance estimation tasks might thus account for their superior performance by neglect patients. We report two bisection studies that address this issue. The first confirmed, amongst patients with left visual neglect, a reliable reduction of rightward error for unfilled gap stimuli as compared with solid lines. The second study assessed the cause of this reduction, deconfounding the effects of stimulus type (lines vs. gaps) and attentional cueing, by applying an explicit cueing manipulation to line and gap bisection tasks. Under these matched cueing conditions, all patients performed similarly on line and gap bisection tasks, suggesting that the reduction of neglect typically observed for gap stimuli may be attributable entirely to cueing effects. We found no evidence that a spatial extent, once fully attended, is judged any differently according to whether it is filled or unfilled.

Comparative adsorption of spherical argon and flexible n-butane in carbon slit pores - a GCMC computer simulation study

In this paper we investigate the difference between the adsorption of spherical molecule argon (at 87.3 K) and the flexible normal butane (at an equivalent temperature of 150 K) in carbon slit pores. These temperatures are equivalent in the sense that they have the same relative distances between their respective triple points and critical points. Higher equivalent temperatures are also studied (122.67 K for argon and 303 K for n-butane) to investigate the effects of temperature on the 2D-transition in adsorbed density. The Grand Canonical Monte Carlo simulation is used to study the adsorption of these two model adsorbates. Beside the longer computation times involved in the computation of n-butane adsorption, n-butane exhibits many interesting behaviors such as: (i) the onset of adsorption occurs sooner (in terms of relative pressure), (ii) the hysteresis for 2D- and 3D-transitions is larger, (iii) liquid-solid transition is not possible, (iv) 2D-transition occurs for n-butane at 150 K while it does not happen for argon except for pores that accommodate two layers of molecules, (v) the maximum pore density is about four times less than that of argon and (vi) the sieving pore width is slightly larger than that for argon. Finally another feature obtained from the Grand Canonical Monte Carlo (GCMC) simulation is the configurational arrangement of molecules in pores. For spherical argon, the arrangement is rather well structured, while for n-butane the arrangement depends very much on the pore size. (C) 2004 Elsevier B.V. All rights reserved.

Hierarchical indexing structure for efficient similarity search in video retrieval

With the rapid increase in both centralized video archives and distributed WWW video resources, content-based video retrieval is gaining its importance. To support such applications efficiently, content-based video indexing must be addressed. Typically, each video is represented by a sequence of frames. Due to the high dimensionality of frame representation and the large number of frames, video indexing introduces an additional degree of complexity. In this paper, we address the problem of content-based video indexing and propose an efficient solution, called the Ordered VA-File (OVA-File) based on the VA-file. OVA-File is a hierarchical structure and has two novel features: 1) partitioning the whole file into slices such that only a small number of slices are accessed and checked during k Nearest Neighbor (kNN) search and 2) efficient handling of insertions of new vectors into the OVA-File, such that the average distance between the new vectors and those approximations near that position is minimized. To facilitate a search, we present an efficient approximate kNN algorithm named Ordered VA-LOW (OVA-LOW) based on the proposed OVA-File. OVA-LOW first chooses possible OVA-Slices by ranking the distances between their corresponding centers and the query vector, and then visits all approximations in the selected OVA-Slices to work out approximate kNN. The number of possible OVA-Slices is controlled by a user-defined parameter delta. By adjusting delta, OVA-LOW provides a trade-off between the query cost and the result quality. Query by video clip consisting of multiple frames is also discussed. Extensive experimental studies using real video data sets were conducted and the results showed that our methods can yield a significant speed-up over an existing VA-file-based method and iDistance with high query result quality. Furthermore, by incorporating temporal correlation of video content, our methods achieved much more efficient performance.

Effects of cation substitutions on the physical properties of M2M1T2O6 pyroxenes

In this PhD study, the effects of the cation substitutions on the physical properties of pyroxenes have been discussed. The results of this work extend the knowledge on pyroxenes with different chemical compositions. These properties might be used in the development of ceramic pigments, advanced materials and for the mineralogical phase identification. First of all, the crystallographic differences between Ge and Si pyroxenes have been examined. The structure of C2/c Ca rich Ge clinopyroxenes is very close to the low pressure C2/c structural configuration found in Ca-rich Si-pyroxenes. The shear of the unit cell is very similar, and the difference between a Ge end member and the corresponding Si-rich one is less than 1°. Instead, a remarkable difference exists between Ca-poor Si and Ge clinopyroxenes. First, Ca-poor Ge pyroxenes do not display a P21/c symmetry, but retain the C2/c symmetry; second, the observed C2/c structure shows, at room pressure, the configuration with highly kinked tetrahedral chains characteristic of the high pressure C2/c symmetry of Si Ca-poor pyroxenes. In orthopyroxenes, with Pbca symmetry, Ge-pyroxenes have volume larger than Si-pyroxenes. Samples along the system CaCoGe2O6 - CoCoGe2O6 have been synthesized at three different temperatures: 1050 °C, 1200 °C and 1250 °C. The aim of these solid state syntheses was to obtain a solid solution at ambient pressure, since the analogues Si-system needs high pressure. Unfortunately, very limited solution occurs because the structure forms of the two end member (high temperature for CaCoGe2O6 and high pressure CoCoGe2O6) are incompatible. The phase diagram of this system has been sketched and compared to that of Si. The cobalt end member (CoCoGe2O6) is stable at ambient pressure in two symmetries: at 1050 °C C2/c and 1200 °C Pbca. The impurity phase formed during these experiments is cobalt spinel. Raman spectroscopy has been used to investigate the vibrational properties of Ca-pyroxenes CaCoGe2O6, CaMgGe2O6, CaMgSi2O6 and CaCoSi2O6. A comparison between silicate and germanate pyroxenes shows significant changes in peak positions of the corresponding modes caused mainly by the difference of the Ge-Si atomic weight along with the distortion and compression of the coordination polyhedra. Red shift in Raman spectra of germanates has been calculated by a rough scale factor calculated by a simple harmonic oscillator model, considering the different bond lengths for 4-coordinated Si ~ 1.60- 1.65 Å vs Ge–O distance ~1.70 - 1.80 Å. The Raman spectra of CaMgGe2O6 and CaCoGe2O6 have been classified, in analogy with silicate (Wang et al., 2001) counterparts, in different ranges: - R1 (880-640 cm-1): strong T-O stretching modes of Ge and non-bridging O1 and O2 atoms within the GeO4 tetrahedron; - R2 (640-480 cm-1): stretching/bending modes of Ge-Obr-Ge bonds (chain stretching and chain bending); - R4 (480-360 cm-1): O-Ge-O vibrations; - R3 (360-240 cm-1): motions of the cations in M2 and M1 sites correlated with tetrahedral chain motion and tilting tetrahedra; - R5 (below 240 cm-1): lattice modes. The largest shift with respect to CaMgSi2O6 - CaCoSi2O6 is shown by the T-O stretching and chain modes. High-pressure Raman spectroscopy (up to about 8 GPa) on the same samples of Ca-pyroxenes using an ETH-type diamond anvil cell shows no phase transition within the P-ranges investigated, as all the peak positions vary linearly as a function of pressure. Our data confirm previous experimental findings on Si-diopside (Chopelas and Serghiou, 2000). In the investigated samples, all the Raman peaks shift upon compression, but the major changes in wavenumber with pressure are attributed to the chain bending (Ge-Obr-Ge bonds) and tetrahedra stretching modes (Ge-Onbr). Upon compression, the kinking angle, the bond lengths and T-T distances between tetrahedra decrease and consequently the wavenumber of the bending chain mode and tetrahedra stretching mode increases. Ge-pyroxenes show the higher P-induced peak-position shifts, being more compressible than corresponding silicates. The vibrational properties of CaM2+Ge2O6 (M2+ =Mg, Mn, Fe, Co, Ni, Zn) are reported for the first time. The wavenumber of Ge-Obr-Ge bending modes decreases linearly with increasing ionic radius of the M1 cation. No simple correlation has been found with M1 atomic mass or size or crystallographic parameters for the peak at ~850 cm-1 and in the low wavenumber regions. The magnetic properties of the system CaCoSi2O6 - CoCoSi2O6 have been investigated by magnetometry. The join is always characterized by 1 a.p.f.u. of cobalt in M1 site and this causes a pure collinear antiferromagnetic behaviour of the intra-chain superexchange interaction involving Co ions detected in all the measurements, while the magnetic order developed by the cobalt ions in M2 site (intra-chain) is affected by weak ferromagnetism, due to the non-collinearity of their antiferromagnetic interaction. In magnetically ordered systems, this non-collinearity effect promotes a spin canting of anti-parallel aligned magnetic moments and thus is a source of weak ferromagnetic behaviour in an antiferromagnetic. The weak ferromagnetism can be observed only for the samples with Co content higher than 0.5 a.p.f.u. in M2, when the concentration is sufficiently high to create a long range order along the M2 chain which is magnetically independent of M1 chain. The ferromagnetism was detected both in the M(T) at 10 Oe and M(H).

DETERMINAÇÃO DAS FORMAS DO ARCO DENTÁRIO INFERIOR NA OCLUSÃO NORMAL NATURAL

Com a finalidade de determinar as formas do arco dentário inferior de maior incidência na oclusão normal natural, utilizou-se um método matemático associado ao emprego de uma função polinomial, o qual foi aplicado a 63 modelos de arcadas inferiores selecionados a partir de 6118 adolescentes. Todos os indivíduos eram portadores de dentição permanente, incluindo os segundos molares, e oclusão normal natural. Em cada dente foi fixada uma esfera de vidro, que teve a função de simular o acessório do aparelho ortodôntico, sendo utilizada na medição das distâncias entre o centro da imagem dessas esferas aos eixos x e y. Após a digitalização dos modelos de gesso, as imagens foram plotadas em um programa de computador, a fim de se obterem a função polinomial de sexto grau e o gráfico dessa função para os 126 segmentos de curva, originados das secções das imagens em lado direito e esquerdo. A seguir organizaram-se esses segmentos, de acordo com as características da curvatura anterior dos arcos dentários, em oito grupos diferentes de formas, que receberam as denominações de Forma A, Forma B, Forma C, Forma D, Forma E, Forma F, Forma G, Forma H. Cada grupo foi, então, dividido em três subgrupos, conforme os tamanhos pequeno, médio e grande. Os resultados indicaram 23 formas representativas do arco dentário inferior e uma forma média para a oclusão normal natural.

AVALIAÇÃO POR MEIO DE MODELOS VIRTUAIS TRIDIMENSIONAIS DAS DISTÂNCIAS INTERCANINOS E INTERMOLARES INFERIORES EM TRÊS MOMENTOS

O propósito desse estudo foi de avaliar a estabilidade do tratamento ortodôntico em três momentos distintos, por meio de mensuração das distâncias intercaninos e intermolares inferiores, utilizando, como ferramenta, modelos virtuais tridimensionais. Foram selecionados modelos de gesso da arcada inferior de 19 pacientes em três fases distintas: pré-tratamento (T1), pós-tratamento (T2) e mínimo de 5 anos pós-contenção (T3), totalizando 57 modelos, os quais foram digitalizados por meio do Scanner 3D SCANTEH ST500 (SCAN technology A/S, Dinamarca), para obtenção dos modelos virtuais tridimensionais. Nesses modelos virtuais tridimensionais foram selecionadas e mensuradas as distâncias entre as pontas de cúspide dos caninos, denominada distância intercaninos e pontas de cúspide mesiovestibulares dos primeiros molares, denominada distância intermolares, com o auxílio do programa Rapidform ( Inus Technology Inc,). Para a análise estatística, foi realizada a análise de variância de medidas repetidas, e realizadas comparações múltiplas de Bonferroni ao nível de significância de 5%. As distâncias intercaninos e intermolares, em média, diminuíram entre T1-T2 e continuaram diminuindo entre T2- T3. Após 4 semanas, 20% da amostra foi novamente mensurada para avaliação do erro do método, onde foram encontrados valores médios semelhantes aos encontrados na primeira mensuração. Nesse trabalho, utilizando-se modelos virtuais tridimensionais, nota-se que não há estabilidade durante e após o tratamento ortodôntico, no tocante às distâncias intercaninos e intermolares.

GTM: the generative topographic mapping

This thesis describes the Generative Topographic Mapping (GTM) --- a non-linear latent variable model, intended for modelling continuous, intrinsically low-dimensional probability distributions, embedded in high-dimensional spaces. It can be seen as a non-linear form of principal component analysis or factor analysis. It also provides a principled alternative to the self-organizing map --- a widely established neural network model for unsupervised learning --- resolving many of its associated theoretical problems. An important, potential application of the GTM is visualization of high-dimensional data. Since the GTM is non-linear, the relationship between data and its visual representation may be far from trivial, but a better understanding of this relationship can be gained by computing the so-called magnification factor. In essence, the magnification factor relates the distances between data points, as they appear when visualized, to the actual distances between those data points. There are two principal limitations of the basic GTM model. The computational effort required will grow exponentially with the intrinsic dimensionality of the density model. However, if the intended application is visualization, this will typically not be a problem. The other limitation is the inherent structure of the GTM, which makes it most suitable for modelling moderately curved probability distributions of approximately rectangular shape. When the target distribution is very different to that, theaim of maintaining an `interpretable' structure, suitable for visualizing data, may come in conflict with the aim of providing a good density model. The fact that the GTM is a probabilistic model means that results from probability theory and statistics can be used to address problems such as model complexity. Furthermore, this framework provides solid ground for extending the GTM to wider contexts than that of this thesis.