Value of positron emission tomography in full-thickness chest wall resections for malignancies.

Preoperative imaging for resection of chest wall malignancies is generally performed by computed tomography (CT). We evaluated the role of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in planning full-thickness chest wall resections for malignancies. We retrospectively included 18 consecutive patients operated from 2004 to 2006 at our institution. Tumor extent was measured by CT and PET, using the two largest perpendicular tumor extensions in the chest wall plane to compute the tumor surface assuming an elliptical shape. Imaging measurements were compared to histopathology assessment of tumor borders. CT assessment consistently overestimated the tumor size as compared to PET (+64% vs. +1%, P<0.001). Moreover, PET was significantly better than CT at defining the size of lesions >24 cm(2) corresponding to a mean diameter >5.5 cm or an ellipse of >4 cm x 7.6 cm (positive predictive value 80% vs. 44% and specificity 93% vs. 64%, respectively). Metabolic PET imaging was superior to CT for defining the extent of chest wall tumors, particularly for tumors with a diameter >5.5 cm. PET can complement CT in planning full-thickness chest wall resection for malignancies, but its true value remains to be determined in larger, prospective studies.

Characteristics of 2D convective structures in Catalonia (NE Spain): an analysis using radar data and GIS

Flood simulation studies use spatial-temporal rainfall data input into distributed hydrological models. A correct description of rainfall in space and in time contributes to improvements on hydrological modelling and design. This work is focused on the analysis of 2-D convective structures (rain cells), whose contribution is especially significant in most flood events. The objective of this paper is to provide statistical descriptors and distribution functions for convective structure characteristics of precipitation systems producing floods in Catalonia (NE Spain). To achieve this purpose heavy rainfall events recorded between 1996 and 2000 have been analysed. By means of weather radar, and applying 2-D radar algorithms a distinction between convective and stratiform precipitation is made. These data are introduced and analyzed with a GIS. In a first step different groups of connected pixels with convective precipitation are identified. Only convective structures with an area greater than 32 km2 are selected. Then, geometric characteristics (area, perimeter, orientation and dimensions of the ellipse), and rainfall statistics (maximum, mean, minimum, range, standard deviation, and sum) of these structures are obtained and stored in a database. Finally, descriptive statistics for selected characteristics are calculated and statistical distributions are fitted to the observed frequency distributions. Statistical analyses reveal that the Generalized Pareto distribution for the area and the Generalized Extreme Value distribution for the perimeter, dimensions, orientation and mean areal precipitation are the statistical distributions that best fit the observed ones of these parameters. The statistical descriptors and the probability distribution functions obtained are of direct use as an input in spatial rainfall generators.

Deep radio images of the HEGRA and Whipple TeV sources in the Cygnus OB2 region.

The modern generation of Cherenkov telescopes has revealed a new population of gamma-ray sources in the Galaxy. Some of them have been identified with previously known X-ray binary systems while other remain without clear counterparts a lower energies. Our initial goal here was reporting on extensive radio observations of the first extended and yet unidentified source, namely TeV J2032+4130. This object was originally detected by the HEGRA telescope in the direction of the Cygnus OB2 region and its nature has been a matter of debate during the latest years. The situation has become more complex with the Whipple and MILAGRO telescopes new TeV detections in the same field which could be consistent with the historic HEGRA source, although a different origin cannot be ruled out. Aims.We aim to pursue our radio exploration of the TeV J2032+4130 position that we initiated in a previous paper but taking now into account the latest results from new Whipple and MILAGRO TeV telescopes. The data presented here are an extended follow up of our previous work. Methods.Our investigation is mostly based on interferometric radio observations with the Giant Metre Wave Radio Telescope (GMRT) close to Pune (India) and the Very Large Array (VLA) in New Mexico (USA). We also conducted near infrared observations with the 3.5 m telescope and the OMEGA2000 camera at the Centro Astronómico Hispano Alemán (CAHA) in Almería (Spain). Results.We present deep radio maps centered on the TeV J2032+4130 position at different wavelengths. In particular, our 49 and 20 cm maps cover a field of view larger than half a degree that fully includes the Whipple position and the peak of MILAGRO emission. Our most important result here is a catalogue of 153 radio sources detected at 49 cm within the GMRT antennae primary beam with a full width half maximum (FWHM) of 43 arc-minute. Among them, peculiar sources inside the Whipple error ellipse are discussed in detail, including a likely double-double radio galaxy and a one-sided jet source of possible blazar nature. This last object adds another alternative counterpart possibility to be considered for both the HEGRA, Whipple and MILAGRO emission. Moreover, our multi-configuration VLA images reveal the non-thermal extended emission previously reported by us with improved angular resolution. Its non-thermal spectral index is also confirmed thanks to matching beam observations at the 20 and 6 cm wavelengths.

Sexual foraging segregation in South American sea lions increases during the pre-breeding period in the La Plata River plume

Stable carbon and nitrogen isotopes in skin and bone of South American sea lions from Brazil and Uruguay were analysed to test the hypothesis that trophic overlap between the sexes is lower during the pre-breeding season than throughout the rest of the year. The isotopic values of skin and bone were used to infer the trophic relationships between the sexes during the pre-breeding period and year round, respectively. Prey species were also analysed to establish a baseline necessary for interpreting the stable isotope ratios of skin and bone. Standard ellipse areas, estimated using Bayesian inference in the SIBER routine of the SIAR package in R, suggested that males and females used a wide diversity of foraging strategies throughout the year and that no differences existed between the sexes. However, the diversity of foraging strategies was largely reduced during the pre-breeding period, with all the individuals of each sex adopting similar strategies, but with the two sexes differing considerably in stable isotope values and the ellipse areas of males and females not overlapping at all. Nevertheless, the results revealed a general increase in the consumption of pelagic prey by both sexes during the pre-breeding period. The progressive crowding of individuals in the areas surrounding the breeding rookeries during the pre-breeding period could lead to an increase in the local population density, which could explain the above reported changes.

Development of Color Difference Equations Matching to Human Vision System

Research on color difference evaluation has been active in recent thirty years. Several color difference formulas were developed for industrial applications. The aims of this thesis are to develop the color density which is denoted by comb g and to propose the color density based chromaticity difference formulas. Color density is derived from the discrimination ellipse parameters and color positions in the xy , xyY and CIELAB color spaces, and the color based chromaticity difference formulas are compared with the line element formulas and CIE 2000 color difference formulas. As a result of the thesis, color density represents the perceived color difference accurately, and it could be used to characterize a color by the attribute of perceived color difference from this color.

Väriavaruuden rakenteen muokkaaminen yhtenäisyyden parantamiseksi

Pienien värierojen mittaamiseen käytetään CIE:n (The International Commission on Illumination) kehittämää ja standardoitua CIELAB – väriavaruutta ja sille suunniteltua CIEDE2000 – värieromittaria. CIELAB ei kuitenkaan ole täysin yhtenäinen ja siksi mittareita joudutaan virittämään sopivammiksi tähän väriavaruuteen. Työssä tutkitaan millä tavoin CIELAB - väriavaruutta voitaisiin korjata, jotta siitä saataisiin yhtenäisempi ja yksinkertainen ja virittämättömämpi värieromittari toimisi siinä paremmin. Työn tuloksena saatu muokattu väriavaruus paransi yhtenäisyyttä keskimäärin kymmenen prosenttia, mikä on liian vähän kun tavoitteena oli 30 - 50 prosenttia.

Segmentation of overlapping convex objects

This thesis presents a framework for segmentation of clustered overlapping convex objects. The proposed approach is based on a three-step framework in which the tasks of seed point extraction, contour evidence extraction, and contour estimation are addressed. The state-of-art techniques for each step were studied and evaluated using synthetic and real microscopic image data. According to obtained evaluation results, a method combining the best performers in each step was presented. In the proposed method, Fast Radial Symmetry transform, edge-to-marker association algorithm and ellipse fitting are employed for seed point extraction, contour evidence extraction and contour estimation respectively. Using synthetic and real image data, the proposed method was evaluated and compared with two competing methods and the results showed a promising improvement over the competing methods, with high segmentation and size distribution estimation accuracy.

Tasaisemmin jakaantuneen CIELAB-tyyppisen väriavaruuden määrittäminen värieroellipsien pääakselien eroja minimoimalla

Tässä työssä johdetaan lineaarimuunnoksella CIE x y z-värinsovitusfunktioista uudet värinsovitusfunktiot. Tarvittava muunnosmatriisi etsitään optimoimalla CIE ja BFD-RIT värieroellipsejä Matlab-ympäristössä. Työn tuloksena saatiin muunnosmatriisi, ja sillä muunnetut uudet värinsovitusfunktiot ja CIELAB-tyyppinen väriavaruus. Euklidisella etäisyydellä mitattuna CIE ja BFD-RIT värieroellipsien muoto ja koko paranivat noin kolmanneksen, mikä oli myös tavoitteena.

Mercury toxicity in the Amazon: contrast sensitivity and color discrimination of subjects exposed to mercury

We measured visual performance in achromatic and chromatic spatial tasks of mercury-exposed subjects and compared the results with norms obtained from healthy individuals of similar age. Data were obtained for a group of 28 mercury-exposed subjects, comprising 20 Amazonian gold miners, 2 inhabitants of Amazonian riverside communities, and 6 laboratory technicians, who asked for medical care. Statistical norms were generated by testing healthy control subjects divided into three age groups. The performance of a substantial proportion of the mercury-exposed subjects was below the norms in all of these tasks. Eleven of 20 subjects (55%) performed below the norms in the achromatic contrast sensitivity task. The mercury-exposed subjects also had lower red-green contrast sensitivity deficits at all tested spatial frequencies (9/11 subjects; 81%). Three gold miners and 1 riverine (4/19 subjects, 21%) performed worse than normal subjects making more mistakes in the color arrangement test. Five of 10 subjects tested (50%), comprising 2 gold miners, 2 technicians, and 1 riverine, performed worse than normal in the color discrimination test, having areas of one or more MacAdam ellipse larger than normal subjects and high color discrimination thresholds at least in one color locus. These data indicate that psychophysical assessment can be used to quantify the degree of visual impairment of mercury-exposed subjects. They also suggest that some spatial tests such as the measurement of red-green chromatic contrast are sufficiently sensitive to detect visual dysfunction caused by mercury toxicity.

Modélisation de la diffraction des ondes de cisaillement en élastographie dynamique ultrasonore

L'élastographie ultrasonore est une technique d'imagerie émergente destinée à cartographier les paramètres mécaniques des tissus biologiques, permettant ainsi d’obtenir des informations diagnostiques additionnelles pertinentes. La méthode peut ainsi être perçue comme une extension quantitative et objective de l'examen palpatoire. Diverses techniques élastographiques ont ainsi été proposées pour l'étude d'organes tels que le foie, le sein et la prostate et. L'ensemble des méthodes proposées ont en commun une succession de trois étapes bien définies: l'excitation mécanique (statique ou dynamique) de l'organe, la mesure des déplacements induits (réponse au stimulus), puis enfin, l'étape dite d'inversion, qui permet la quantification des paramètres mécaniques, via un modèle théorique préétabli. Parallèlement à la diversification des champs d'applications accessibles à l'élastographie, de nombreux efforts sont faits afin d'améliorer la précision ainsi que la robustesse des méthodes dites d'inversion. Cette thèse regroupe un ensemble de travaux théoriques et expérimentaux destinés à la validation de nouvelles méthodes d'inversion dédiées à l'étude de milieux mécaniquement inhomogènes. Ainsi, dans le contexte du diagnostic du cancer du sein, une tumeur peut être perçue comme une hétérogénéité mécanique confinée, ou inclusion, affectant la propagation d'ondes de cisaillement (stimulus dynamique). Le premier objectif de cette thèse consiste à formuler un modèle théorique capable de prédire l'interaction des ondes de cisaillement induites avec une tumeur, dont la géométrie est modélisée par une ellipse. Après validation du modèle proposé, un problème inverse est formulé permettant la quantification des paramètres viscoélastiques de l'inclusion elliptique. Dans la continuité de cet objectif, l'approche a été étendue au cas d'une hétérogénéité mécanique tridimensionnelle et sphérique avec, comme objectifs additionnels, l'applicabilité aux mesures ultrasonores par force de radiation, mais aussi à l'estimation du comportement rhéologique de l'inclusion (i.e., la variation des paramètres mécaniques avec la fréquence d'excitation). Enfin, dans le cadre de l'étude des propriétés mécaniques du sang lors de la coagulation, une approche spécifique découlant de précédents travaux réalisés au sein de notre laboratoire est proposée. Celle-ci consiste à estimer la viscoélasticité du caillot sanguin via le phénomène de résonance mécanique, ici induit par force de radiation ultrasonore. La méthode, dénommée ARFIRE (''Acoustic Radiation Force Induced Resonance Elastography'') est appliquée à l'étude de la coagulation de sang humain complet chez des sujets sains et sa reproductibilité est évaluée.

Méthodes rapides et efficaces pour la résolution numérique d'équations de type Hamilton-Jacobi avec application à la simulation de feux de forêt

Cette thèse est divisée en trois chapitres. Le premier explique comment utiliser la méthode «level-set» de manière rigoureuse pour faire la simulation de feux de forêt en utilisant comme modèle physique pour la propagation le modèle de l'ellipse de Richards. Le second présente un nouveau schéma semi-implicite avec une preuve de convergence pour la solution d'une équation de type Hamilton-Jacobi anisotrope. L'avantage principal de cette méthode est qu'elle permet de réutiliser des solutions à des problèmes «proches» pour accélérer le calcul. Une autre application de ce schéma est l'homogénéisation. Le troisième chapitre montre comment utiliser les méthodes numériques des deux premiers chapitres pour étudier l'influence de variations à petites échelles dans la vitesse du vent sur la propagation d'un feu de forêt à l'aide de la théorie de l'homogénéisation.

Face Recognition using Probabilistic Neural Networks

In this paper we address the problem of face detection and recognition of grey scale frontal view images. We propose a face recognition system based on probabilistic neural networks (PNN) architecture. The system is implemented using voronoi/ delaunay tessellations and template matching. Images are segmented successfully into homogeneous regions by virtue of voronoi diagram properties. Face verification is achieved using matching scores computed by correlating edge gradients of reference images. The advantage of classification using PNN models is its short training time. The correlation based template matching guarantees good classification results

Face Recognition using Probabilistic Neural Networks

n this paper we address the problem of face detection and recognition of grey scale frontal view images. We propose a face recognition system based on probabilistic neural networks (PNN) architecture. The system is implemented using voronoi/ delaunay tessellations and template matching. Images are segmented successfully into homogeneous regions by virtue of voronoi diagram properties. Face verification is achieved using matching scores computed by correlating edge gradients of reference images. The advantage of classification using PNN models is its short training time. The correlation based template matching guarantees good classification results.

3D Simultaneous Inversion for Seismic Structure and Local Hypocenters in Germany under Consideration of Seismic Anisotropy in the Upper Mantel

The main task of this work has been to investigate the effects of anisotropy onto the propagation of seismic waves along the Upper Mantle below Germany and adjacent areas. Refraction- and reflexion seismic experiments proved the existence of Upper Mantle anisotropy and its influence onto the propagation of Pn-waves. By the 3D tomographic investigations that have been done here for the crust and the upper mantle, considering the influence of anisotropy, a gap for the investigations in Europe has been closed. These investigations have been done with the SSH-Inversionprogram of Prof. Dr. M. Koch, which is able to compute simultaneously the seismic structure and hypocenters. For the investigation, a dataset has been available with recordings between the years 1975 to 2003 with a total of 60249 P- and 54212 S-phase records of 10028 seismic events. At the beginning, a precise analysis of the residuals (RES, the difference between calculated and observed arrivaltime) has been done which confirmed the existence of anisotropy for Pn-phases. The recognized sinusoidal distribution has been compensated by an extension of the SSH-program by an ellipse with a slow and rectangular fast axis with azimuth to correct the Pn-velocities. The azimuth of the fast axis has been fixed by the application of the simultaneous inversion at 25° - 27° with a variation of the velocities at +- 2.5 about an average value at 8 km/s. This new value differs from the old one at 35°, recognized in the initial residual analysis. This depends on the new computed hypocenters together with the structure. The application of the elliptical correction has resulted in a better fit of the vertical layered 1D-Model, compared to the results of preceding seismological experiments and 1D and 2D investigations. The optimal result of the 1D-inversion has been used as initial starting model for the 3D-inversions to compute the three dimensional picture of the seismic structure of the Crust and Upper Mantle. The simultaneous inversion has showed an optimization of the relocalization of the hypocenters and the reconstruction of the seismic structure in comparison to the geology and tectonic, as described by other investigations. The investigations for the seismic structure and the relocalization have been confirmed by several different tests. First, synthetic traveltime data are computed with an anisotropic variation and inverted with and without anisotropic correction. Further, tests with randomly disturbed hypocenters and traveltime data have been proceeded to verify the influence of the initial values onto the relocalization accuracy and onto the seismic structure and to test for a further improvement by the application of the anisotropic correction. Finally, the results of the work have been applied onto the Waldkirch earthquake in 2004 to compare the isotropic and the anisotropic relocalization with the initial optimal one to verify whether there is some improvement.

Traduire l’ironie : un point de vue pragmatique et textuel sur la traduction

Dans cette communication, nous nous proposons d’examiner la traduction de Candide de Voltaire en hongrois afin de démontrer l’effet modificateur des procédés utilisés au cours de la traduction de l’ironie. Nous allons montrer que les signaux textuels de l’ironie (alliance des termes paradoxaux, système binaire, rythme accéléré ou ellipse des causes) sont adaptés aux particularités de la langue cible par le moyen des procédés tels que complémentation, remplacement et ajout des morphèmes.