The cornea is the anterior most surface of the eye and plays a critical role in vision. A thin fluid layer, the tear film, coats the outer surface of the cornea and serves to protect, nourish, and lubricate the cornea. At the same time, the tear film is responsible for creating a smooth continuous surface, where the majority of refraction takes place in the eye. A significant component of vision quality is determined by the shape of the cornea and stability of the tear film. A dual interferometer system for measuring the dynamic corneal topography is designed, built, verified, and qualified by testing on human subjects. The system consists of two coaligned simultaneous phase-shifting polarization-splitting Twyman-Green interferometers. The primary interferometer measures the surface of the tear film while the secondary interferometer tracks the absolute position of the cornea, which provides enough information to reconstruct the absolute shape of the cornea. The results are high-resolution and high-accuracy surface topography measurements of the in vivo tear film and cornea that are captured at standard camera frame rates. (C) 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)

BACKGROUND: The use of three-dimensional imaging has shown to provide advantages to the clinician in assessing bone morphology. The aim of this study will be to compare the diagnostic efficacy of cone beam computed tomography (CBCT) versus diagnostic clinical measurements in patients presenting with furcation involved maxillary first molars. METHODS: The study population included 20 patients with 34 maxillary first molar teeth with furcation involvement. Clinical horizontal and vertical probing measurements were compared to CBCT measurements taken by two calibrated examiners. RESULTS: Horizontal measurements showed a significant difference between Glickman class II and class III. There were no statistical significant differences with the horizontal measurements between clinical probing, bone sounding and CBCT measurements. CBCT vertical measurements were statistically greater than clinical probing measurements. CONCLUSION: The CBCT can provide similar horizontal measurements to standard clinical horizontal probing measurements and will provide a greater vertical dimension of a furcation defect to standard vertical probing measurements.

Understanding the factors that influence regular tobacco use often involves detailed assessment of individuals' smoking behavior (i.e., puff topography), including measuring puff number, volume, duration, and inter-puff interval (IPI) via mouthpiece-based, computerized devices. For example, puff topography measurement has been used to study smoking cessation medications, as well as to demonstrate brand-induced changes in smoking behavior. However, some research suggests that the use of a mouthpiece to evaluate puff topography may alter natural smoking behavior. Thus, this study was designed to compare topography measurement using mouthpiece-based methods (i.e., desktop and portable computerized devices) to methods that do not use a mouthpiece (i.e., direct observation via video recordings).Thirty smokers of "full-flavor" or "light" cigarettes (≥15 cigarettes/day) participated in six Latin-square ordered, 2.5-hour experimental sessions. Sessions were separated by at least 48 hours, and were preceded by at least 8 hours of objectively-verified tobacco abstinence (i.e., CO level ≤10 ppm). Conditions differed by type of cigarettes smoked (own brand, Merit® Ultra-light) and by type of topography measurement method used (desktop, portable, video observation). All three measurement methods were sensitive to manipulations of cigarette brand (i.e., increased puff duration and volume for own brand relative to ultra-light; P 0.68). All methods were also reliable, as demonstrated by high correlations across cigarette bouts within each condition (most r's > 0.78). In contrast, participants perceived the use of either mouthpiece-based device to alter aspects of their smoking behavior (e.g., increased difficulty, reduced enjoyment, altered cigarette taste; P < .05) relative to direct observation alone. Although direct observational methods may be optimal for measuring certain smoking characteristics, the many logistical challenges posed by this method likely limit its usefulness in a laboratory setting. Taken together, these results suggest that mouthpiece-based devices offer a convenient and useful tool for researchers examining smoking topography.

Electronic cigarettes (ECIGs) operate by heating a nicotine-containing solution resulting in an inhalable aerosol. Nicotine delivery may be affected by users’ puffing behavior (puff topography), and little is known about the puff topography of ECIG users. The purpose of this study was to examine the extent to which a mouthpiece-based topography measurement device influences the acute effects associated with ECIG use. Twenty-nine experienced ECIG users completed two sessions differing only by the presence of a mouthpiece-based topography recording device. In both sessions, participants completed one 10 puff, 30 sec inter-puff interval (IPI) ECIG-use bout and another 90 minute ad libitum bout. Acute ECIG effects (plasma nicotine concentration, heart rate [HR], and subjective effects) were largely unaffected by the presence of the topography recording device. Evaluating ECIG puff topography through clinical laboratory methodology is necessary to understand the effects of these products (including toxicant exposure) and to inform their regulation.

Mountains are vital to ecosystems and human society given their influence on global carbon and water cycles. Yet the extent to which topography regulates montane forest carbon uptake and storage remains poorly understood. To address this knowledge gap, we compared forest aboveground carbon loading to topographic metrics describing energy balance and water availability across three headwater catchments of the Boulder Creek Watershed, Colorado, USA. The catchments range from 1800 to 3500 m above mean sea level with 46-102 cm/yr mean annual precipitation and -1.2 degrees to 12.3 degrees C mean annual temperature. In all three catchments, we found mean forest carbon loading consistently increased from ridges (27 +/- 19 Mg C ha) to valley bottoms (60 +/- 28 Mg C ha). Low topographic positions held up to 185 +/- 76 Mg C ha, more than twice the peak value of upper positions. Toe slopes fostered disproportionately high net carbon uptake relative to other topographic positions. Carbon storage was on average 20-40 Mg C ha greater on north to northeast aspects than on south to southwest aspects, a pattern most pronounced in the highest elevation, coldest and wettest catchment. Both the peak and mean aboveground carbon storage of the three catchments, crossing an 11 degrees C range in temperature and doubling of local precipitation, defied the expectation of an optimal elevation-gradient climatic zone for net primary production. These results have important implications for models of forest sensitivity to climate change, as well as to predicted estimates of continental carbon reservoirs.

Le désir de comprendre l'origine de la Terre, son évolution et sa composition, le futur de notre planète et les événements géologiques comme les séismes et les désastres qu'ils provoquent, ainsi que la curiosité de l'esprit humain font que les chercheurs étudient l'évolution tectonique et la structure actuelle de la Terre. Entre les paramètres clé pour une meilleure compréhension se trouvent la profondeur de la limite croûte-manteau (Moho) et celle de la limite entre la lithosphère et l'asthénosphère (LAB). Le but de cette thèse était de modéliser la limite lithosphère-asthénosphère (LAB) et l'épaisseur crustale sous l'Alborz central, le block sud-caspien et les régions environnantes. Dans cette étude, nous utilisions une méthode d'imagerie de la lithosphère, basée sur l'interprétation de données gravimétriques et de la topographie en équilibre isostatique local. Nous appliquons des algorithmes 1D et 2D de modélisation avant de présenter un nouvel algorithme d'inversion 3D. Nous présentons d'abord une inversion conjointe 1D de données de géoïde et de topographie. Le second pas est la modélisation 2D le long de trois profils par l'interprétation conjointe de géoïde, gravité (air libre et Bouguer), de topographie et de flux de chaleur à la surface. Finalement, nous performons une inversion 3D conjointe de données de géoïde, gravité (air libre) et de topographie. L'application des trois différentes méthodes à la région d'étude nous donne comme résultats principaux une croûte épaisse sous la chaine d'Alborz et sous l'Apsheron-Balkan Sill à la limite septentrionale du bassin sud-caspien. Des fortes variations de l'épaisseur de la lithosphère ont été obtenues, où la lithosphère la plus mince est localisée sous l'Iran central et NW, surtout dans des régions de volcanisme Cénozoïque. Les régions d'épaisseur maximale de la lithosphère se trouvent sous l'Apsheron-Balkan Sill, indiquant en combinaison avec un épaississement parallèle de la croûte une subduction de la lithosphère sud-caspienne vers le nord sous la lithosphère eurasienne. / The wish to understand the Earth's origin, evolution and composition, curiosity of the human to comprehend our planet's future evolution plus the geological needs compel researchers to investigate tectonic evolution and their present day structure and behavior. Some key parameters to better understand these subjects are depth of the Moho (the boundary between crust and mantle) and of the lithosphere-asthenosphere boundary (LAB). The targeted area of this research includes the Alborz Mountains in northern Iran and the South Caspian Basin. The Alborz Mountains separate the South Caspian Basin from Central Iran. For our research, the definition of the LAB is an isotherm and we try to calculate the temperature distribution in the lithosphere. We also consider local isostasy to be valid for our modeling. Gravity, geoid, topography and surface heat flow data are used in this research to model the Moho and LAB discontinuities. Potential field data are sensitive to the lateral density variations which happen across these two boundaries but at different depth. In this research 1D, 2D and 3D modeling has been conducted in our targeted area. In 1D modeling, our data are topography and geoid undulations. The method is a 1D inversion based on a two-layered model comprising crust and lithospheric mantle. Using gravity, geoid, topography and surface heat flow data, we have modeled 2D distributions of the density and temperature in the lithosphere along three profiles crossing Iran in SW-NE direction from the Arabian foreland in the SW to the South Caspian Basin and the Turan Platform to the NE. Finally, a 3D algorithm has been developed and tested to obtain the density structure of the lithosphere from joint inversion of free air gravity, geoid and topography data based on a Bayesian approach with Gaussian probability density function. The algorithm delivers the crustal and lithospheric thicknesses and the average crustal density. The results show crustal root under the Alborz Mountains and a thin crust under the southernmost South Caspian Basin thickening northward until the Apsheron-Balkan Sill. Regarding LAB, the results show thick lithosphere under the South Caspian Basin compared to thin lithosphere of Central Iran.

Le IVe siècle de notre ère représente indéniablement un tournant majeur dans l’histoire de l’Europe occidentale. Le passage du christianisme du statut de culture marginale d’une communauté religieuse à celui de pôle culturel et normatif à l’échelle d’une société constitue une transition caractéristique de l’Antiquité tardive, qui s’est d’abord opérée sur le terrain des systèmes sociaux de référence que sont le temps et l’espace – lieux d’expression identitaire. La richesse documentaire de l’"Vrbs" ajoutée à sa position de capitale historique et de cité de première importance pour le christianisme en font un cadre d’étude singulier. Cette enquête sur le partage du temps et de l’espace, entre la victoire du Pont Milvius (312) et le sac d’Alaric (410), propose une reconstruction des temps de la cité et une exploration des mécanismes de développement de l’organisation calendaire de l’Église et d’insertion au sein de la trame temporelle urbaine (partie 1). Sur la base d’un catalogue qui actualise le "LTVR(S)", elle reconstitue la topographie polythéiste et examine l’inscription de l’ancrage matériel du culte chrétien au sein du territoire romain (partie 2). Au travers de ces analyses transversales et d’études de cas (partie 3), elle tente aussi de comprendre des modes d’interaction, de coexistence religieuse au sein d’une société. La recherche replace le curseur sur la continuité plutôt que la rupture. Elle révèle un modèle prioritairement intégratif et une stratégie de conformité aux dynamiques romaines dans le partage du temps et de l’espace. Elle argumente sur une cohabitation religieuse globalement pacifique portée par un investissement identitaire commun focalisé sur la "Romanitas". / The fourth century AD is admittedly a major turning point in the history of Western Europe. The evolution of Christianity from the status of a marginal culture within a religious group to that of a cultural and normative pole within society constitutes an important transition specific to Late Antiquity. This transition from margin to norm started from the social frameworks of time and space, acting as strong identity markers. The great amount of evidence from the "Vrbs", its position as historical capital, as its recognized status as important city for the development of Christianity, make it a specific research framework. This study, which focuses on the sharing of time and space between the victory of the Milvius Bridge (312) and the sack of Alaric (410), reconstructs the organization of the times in the city and explores the mechanisms behind the development of the calendar structure of the Church within this urban space (part 1). On the basis of a catalogue that brings up to date the "LTVR(S)", this study rebuilds the polytheistic topography and scrutinizes the material inscription of the Christian cult on the Roman territory (part 2). On the basis of these cross-sectional analyses and case studies (part 3), it also attempts at understanding the modes of religious co-existence and interaction within a society. The results point towards a sense of continuity rather than breaking. This dissertation reveals a model that favours integration and conformation strategies to the Roman dynamics in the sharing of time and space. It argues in favour of a religious cohabitation mostly peaceful led by a common identity investment focused on the "Romanitas".

Continental passive margins exhibit high elevation topography in many localities across the globe. The source and age of much of this topography remains a subject of great debate within the wider community, with numerous theories being presented, including significant post-rift uplift and isostatically preserved rift anks. Establishing the mechanisms that generate topography and the onshore evolution across passive margins is vital in understanding regional geological histories and their wider development. The passive margins of the NW Atlantic realm exhibit high elevation topography topped with low relief summits. The origin of this topography is debated, with both 3 km of uplift in the post-rift stage and the isostatic preservation of Cretaceous rift anks being suggested within the literature. The work of this thesis aims to resolve this debate by establishing the timing and source of uplift across the region and determining the onshore evolution prior to, during and after rifting with the application of apatite low temperature thermochronology. Contemporary analytical and modelling techniques are utilised to generate thermal histories from across both central West Greenland and SE Baffin Island, helping to de ne how the modern landscape has formed. Results from this work outline an onshore history dominated by uplift in the Cretaceous and exhumation throughout the Cenozoic. Basement samples from SW Greenland exhibit protracted cooling throughout the Mesozoic and Cenozoic, implying low rates of exhumation have been apparent throughout. Within the Nuussuaq Basin, centralWest Greenland, thermal histories display reheating i through the Late Cretaceous/Palaeogene and cooling to present, consistent with events outlined in the basin's stratigraphy and implying uplift of the topography is likely the result of extrusive volcanism and an isostatic response to the unroo ng of the lithosphere. Spatial trends in data and thermal histories across SE Ba n Island imply much of the landscape is shaped by rift ank uplift along its SE coastline, driving exhumation of the region throughout the Cenozoic. Collectively these results suggest the elevated topography of the NW Atlantic realm is the result of rift related uplift in the Cretaceous, magmatism and widespread exhumation throughout the Cenozoic, preserved by isostatic exure. This interpretation of the region's onshore history contributes greatly to our understanding of the NW Atlantic's geological evolution. The results highlight the role of extensional tectonism, exhumation and isostasy in shaping both margin's landscapes and helps to determine the principal characteristics of the wider extensional system and the evolution of the o shore domain. Moreover, these conclusions have a wider relevance to the evolution of passive margins across the North Atlantic, improving our understanding of how topography across other margins, such as of East Greenland, Norway and the UK, has formed.

O objetivo desse trabalho de tese foi a coleta de novas informações e a avaliação de dados disponíveis, visando a análise das melhores alternativas para a obtenção de um modelo digital de terreno (MDT) para a América do Sul. O modelo compreendeu a parte continental e oceânica, limitada pelas latitudes de 60º S a 25º N e longitudes de 100º W a 25º W. Na área continental foram usadas informações provenientes de cartas topográficas digitalizadas, do recente modelo Shuttle Radar Topography Mission (SRTM) e do modelo disponível DTM2002. Na área oceânica foram utilizadas informações de profundidade do DTM2002, de cartas náuticas em diferentes escalas, folhas de bordo e o projeto LEPLAC, para o Brasil, e de cartas náuticas na Argentina. O trabalho ensejou um processo intensivo e exaustivo de comparação dos modelos existentes (SRTM, DTM2002, GLOBE, GTOPO30, ETOPO2, JGP95E, TERRAINBASE e ETOPO5) e das novas informações disponíveis. No estudo do SRTM analisou-se 2.013 quadrículas de 1ºX1º da região continental, obtendo-se para cada quadrícula os valores máximo e mínimo da altitude com suas respectivas posições, o valor médio e o número de pontos sem informação, além da representação 3D e do histograma das altitudes. Foi também realizada a comparação das altitudes interpoladas do modelo SRTM com os pontos GPS implantados ao longo dos rios Madeira, Solimões e Amazonas e com RNs na grande São Paulo. Com os oito MDTs citados foram construídos perfis longitudinais e latitudinais de toda a área continental passando sobre a altitude máxima de cada quadrícula do SRTM. Os modelos SRTM, DTM2002, GLOBE, GTOPO30, ETOPO2 e ETOPO5 foram comparados entre si nos pontos da grade em comum. Além disso, foram realizadas comparações utilizando uma importante fonte de informação altimétrica representada pela rede de nivelamento geométrico. As análises realizadas resultaram na geração de três modelos alternativos de MDT para a América do Sul. A opção do espaçamento da malha para a construção do modelo foi proveniente da compatibilização entre a capacidade computacional e o resultado esperado nas diferentes aplicações de um MDT. Além disso, foram implementadas duas aplicações específicas importantes na área de exploração mineral e no cálculo das alturas geoidais: a correção de terreno e o efeito indireto. / The objective of this thesis has been to collect new information and to evaluate available data in order to provide arguments in the analysis for the derivation of the best DTM for South America. The continental and oceanic part of a block limited by latitudes 60º S and 25º N and longitudes 100º W and 25º W is the object of the model. In the continental area data derived from topographic maps, the recent Shuttle Radar Topography Mission (SRTM) and the available DTM2002 model were used. In the oceanic area the depth data from DTM2002, nautical maps of different scales, boarding maps and LEPLAC project were used in Brazil and nautical maps in Argentina. The activities involved an intensive process of comparison between the existing models (SRTM, DTM2002, GLOBE, GTOPO30, ETOPO2, JGP95E, TERRAINBASE e ETOPO5) and the new information. With respect to SRTM 2,013 blocks of 1º X 1º in the continental area were analysed, deriving for each block the maximum and minimum values for the height with the respective position, the mean value and the number of points without information. The 3D representation as well as the histogram of the heights for each block is also presented. The GPS points established along the Amazonas, Solimões and Madeira rivers in Amazonas on the BMs in São Paulo area were also compared with SRTM interpolated values. SRTM, DTM2002, GLOBE, GTOPO30, ETOPO2 and ETOPO5 were also compared between themselves in the common points of the grid. Besides, an important comparison were carried out with the first order levelling network. After the analysis were finished three different DTM were generated for South America. The grid spacing were select envisaged a compatibilization between computer capacity and the applications requirements. Finally, two specific applications for mineral exploration and geoid computation were implemented: the terrain correction and the indirect effect.

O objetivo deste trabalho e desenvolver um instrumento computadorizado para análise da superfície anterior da córnea humana, gerando para isto, um mapa topográfico bidimensional em código de cores. Utilizando a córnea como um espelho esférico convexo, projeta-se anéis luminosos sobre sua superfície e aquisiciona-se com uma câmera a imagem por ela refletida. Esta imagem e digitalizada e armazenada em um microcomputador para posterior processamento. Através de técnicas de computação gráfica e processamento de imagens digitais, extrai-se da imagem as informações necessárias para construção da topografia desejada. Por fim, a topografia e apresentada em forma de mapas coloridos, sendo cada cor associada a uma determinada dioptria, transmitindo ao médico oftalmologista uma noção exata da superfície da córnea do paciente em análise. / The main goal of this work is to develop a computerized instrument for the analysis of the anterior portion of the human cornea, which displays its result in topographic color maps. Approximating the cornea to a spherical convex mirror, and by projecting a known pattern over it, the reflected image is captured and stored. By means of computer graphics technology and image processing, the necessary information for mathematical calculations is extracted. The resulting maps are color-coded in accordance to the degree of power of each corneal region, that is, to the diopter value. The ophthalmologist can then make important diagnostics and surgery tactics from the analysis of these topographic maps.