Morphodynamic analysis of cerebral aneurysm pulsation from time-resolved rotational angiography

This paper presents a technique to estimate and model patient-specific pulsatility of cerebral aneurysms over onecardiac cycle, using 3D rotational X-ray angiography (3DRA) acquisitions. Aneurysm pulsation is modeled as a time varying-spline tensor field representing the deformation applied to a reference volume image, thus producing the instantaneousmorphology at each time point in the cardiac cycle. The estimated deformation is obtained by matching multiple simulated projections of the deforming volume to their corresponding original projections. A weighting scheme is introduced to account for the relevance of each original projection for the selected time point. The wide coverage of the projections, together with the weighting scheme, ensures motion consistency in all directions. The technique has been tested on digital and physical phantoms that are realistic and clinically relevant in terms of geometry, pulsation and imaging conditions. Results from digital phantomexperiments demonstrate that the proposed technique is able to recover subvoxel pulsation with an error lower than 10% of the maximum pulsation in most cases. The experiments with the physical phantom allowed demonstrating the feasibility of pulsation estimation as well as identifying different pulsation regions under clinical conditions.

The Point system of selection of immigrants in Quebec

The present paper is aimed at identifying what are the effects of the Point System of Selection of immigrants in Quebec. I defend that the distribution of points results in a different composition of immigrant stocks in terms of origin mix and not in terms of labour skills. To do so, I carry out a longitudinal descriptive analysis on the national composition of immigrants in Quebec and two other significant provinces (Ontario and British Columbia), as well as an analysis of the distribution of points in Quebec and in the rest of Canada.

Pre-procés i segmentació en imatges d’ultrasons 2D i 3D de la pròstata

Aquest projecte s'ha dut a terme amb el Grup de visió per computador del departamentd'Arquitectura i Tecnologia de Computadors (ATC) de la Universitat de Girona. Està enfocat a l'anàlisi d'imatges mèdiques, en concret s'analitzaran imatges de pròstata en relació a desenvolupaments que s'estan realitzant en el grup de visió esmentat. Els objectius fixats per aquest projecte són desenvolupar dos mòduls de processamentm d'imatges els quals afrontaran dos blocs important en el tractament d'imatges, aquests dos mòduls seran un pre-processat d'imatges, que constarà de tres filtres i un bloc de segmentació per tal de cercar la pròstata dintre de les imatges a tractar. En el projecte es treballarà amb el llenguatge de programació C++, concretament amb unes llibreries que es denominen ITK (Insight Toolkit ) i són open source enfocades al tractament d'imatges mèdiques. A part d'aquesta eina s'utilitzaran d'altres com les Qt que és una biblioteca d'eines per crear entorns gràfics

Forecasting and turning point predictions in a Bayesian panel VAR model

We provide methods for forecasting variables and predicting turning points in panel Bayesian VARs. We specify a flexible model which accounts for both interdependencies in the cross section and time variations in the parameters. Posterior distributions for the parameters are obtained for a particular type of diffuse, for Minnesota-type and for hierarchical priors. Formulas for multistep, multiunit point and average forecasts are provided. An application to the problem of forecasting the growth rate of output and of predicting turning points in the G-7 illustrates the approach. A comparison with alternative forecasting methods is also provided.

Reconstrucció 3D : comparativa d'algoritmes de correspondència

En aquest projecte s'analitzen dos algoritmes de correspondència entre imatges amb l'objectiu d'accelerar el procés de reconstrucció 3D mitjançant MVS. S'analitza tot el procés de reconstrucció i a partir d'un software existent es fa la comparació de l'algoritme SIFT i l'algoritme BRISK. A partir dels tests realitzats es conclou que el BRISK és més ràpid i millor per a una reconstrucció 3D.

Restoration of a lost geological reference point: the loggingstone of Pedralta (Girona, Spain)

The Pedralta is a loggingstone formed of monzonitic leucogranites, which has a volume of about 38 m3 and weighs 101 tons. After its fall in December 1996, a public subscription was opened to meet the expenses of the restoration work, which was completed in May 1999

Trinocular System for 3D motion and Dense Stucture Estimation

The relief of the seafloor is an important source of data for many scientists. In this paper we present an optical system to deal with underwater 3D reconstruction. This system is formed by three cameras that take images synchronously in a constant frame rate scheme. We use the images taken by these cameras to compute dense 3D reconstructions. We use Bundle Adjustment to estimate the motion ofthe trinocular rig. Given the path followed by the system, we get a dense map of the observed scene by registering the different dense local reconstructions in a unique and bigger one

Identification of geometrically consistent interest points for 3D scene reconstruction

We propose an algorithm that extracts image features that are consistent with the 3D structure of the scene. The features can be robustly tracked over multiple views and serve as vertices of planar patches that suitably represent scene surfaces, while reducing the redundancy in the description of 3D shapes. In other words, the extracted features will off er good tracking properties while providing the basis for 3D reconstruction with minimum model complexity

Inaugural adress: The concept of biostratigraphy: the view point of a stratigrapher

Colleagues, Ladies and Gentlemen. My presence here is due to accidental circumstances and I must confess that I feel a little embarassed by the fact Both your scientific quality and the worlwide acceptance of the results achieved by you in your research fields make me prudent and, to a certain extent, cautious.

SIMSAFADIM-CLASTIC: A new approach to mathematical 3D forward simulation modelling for terrigenous and carbonate marine sedimentation

Most sedimentary modelling programs developed in recent years focus on either terrigenous or carbonate marine sedimentation. Nevertheless, only a few programs have attempted to consider mixed terrigenous-carbonate sedimentation, and most of these are two-dimensional, which is a major restriction since geological processes take place in 3D. This paper presents the basic concepts of a new 3D mathematical forward simulation model for clastic sediments, which was developed from SIMSAFADIM, a previous 3D carbonate sedimentation model. The new extended model, SIMSAFADIM-CLASTIC, simulates processes of autochthonous marine carbonate production and accumulation, together with clastic transport and sedimentation in three dimensions of both carbonate and terrigenous sediments. Other models and modelling strategies may also provide realistic and efficient tools for prediction of stratigraphic architecture and facies distribution of sedimentary deposits. However, SIMSAFADIM-CLASTIC becomes an innovative model that attempts to simulate different sediment types using a process-based approach, therefore being a useful tool for 3D prediction of stratigraphic architecture and facies distribution in sedimentary basins. This model is applied to the neogene Vallès-Penedès half-graben (western Mediterranean, NE Spain) to show the capacity of the program when applied to a realistic geologic situation involving interactions between terrigenous clastics and carbonate sediments.

Spanning avalanches in the three-dimensional Gaussian random-field Ising model with metastable dynamics: Field dependence and geometrical properties

Spanning avalanches in the 3D Gaussian Random Field Ising Model (3D-GRFIM) with metastable dynamics at T=0 have been studied. Statistical analysis of the field values for which avalanches occur has enabled a Finite-Size Scaling (FSS) study of the avalanche density to be performed. Furthermore, a direct measurement of the geometrical properties of the avalanches has confirmed an earlier hypothesis that several types of spanning avalanches with two different fractal dimensions coexist at the critical point. We finally compare the phase diagram of the 3D-GRFIM with metastable dynamics with the same model in equilibrium at T=0.

Hysteresis and return-point memory in deterministic cellular automata

We have investigated hysteresis and the return-point memory (RPM) property in deterministic cellular automata with avalanche dynamics. The RPM property reflects a partial ordering of metastable states, preserved by the dynamics. Recently, Sethna et al. [Phys. Rev. Lett. 70, 3347 (1993)] proved this behavior for a homogeneously driven system with static disorder. This Letter shows that the partial ordering and the RPM can be displayed as well by systems driven heterogeneously, as a result of its own evolution dynamics. In particular, we prove the RPM property for a deterministic 2D sandpile automaton driven at a central site.

Woody Allen i l'esperit de la tragèdia grega: de Crimes and Misdemeanors a Match Point

Nombrosos són ja els estudis que s'han centrat en l'anomenat "cinema seriós" de Woody Allen i, entre ells, paga la pena de mencionar el que Pau Gilabert Barberà, autor d'aquest article, va escriure (2006) sobre el que, en opinió seva, és el llegat sofístic subjacent en el guió de Crimes and Misdemeanors. En aquesta ocasió, el seu objectiu és analitzar la trajectòria fluctuant del director americà en relació a la tragèdia grega, des de la convicció que, només així, és possible revelar la seva empatia amb l'esperit tràgic dels grecs i comprendre la seva necessitat de presentar aquell gènere literari com un paradigma des del qual entendre les grandeses i misèries del món contemporani.

Woody Allen and the Spirit of the Greek Tragedy: from Crimes and Misdemeanors to Match Point

Many studies have already paid attention to what is called the "serious films" by Woody Allen and, among them, it is also worth mentioning the one written by the very Pau Gilabert Barberà (2006), which is devoted to the Sophistic legacy underlying in his opinion the screenplay of Crimes and Misdemeanors. On this occasion, his aim is to analyse the fluctuating sight of the American director with regard to the Greek tragedy. Indeed, Gilabert is convinced that, only in this way, it is possible to reveal the true Allen¿s sympathy with the tragic spirit of the Greeks, as well as to understand his urge to present that ancient literary genre as a paradigm with the help of which one can evaluate the greatness and misery of our contemporary world.