Lichen diversity in Iberian beech forests, a tool to assess environmental status

Universitat de Barcelona

Cyanobacteria in biological soil crusts, Earth´s Most Extensive Biofilms: adaptation and sensitivity to global warming

School of Life Sciences, Arizona State University, Tempe AZ, USA

The Brown algae Sargassum muticum in the Atlantic coast of Morocco: new record in Africa and risks of its potential expansion to nearby areas

Centro de Biodiversidad y Gestión Ambiental, Facultad de Ciencias del Mar, Universidad de Las Palmas de Gran Canaria, Las Palmas, Spain

CART application to image primitives tracking

[EN] [EN] In this paper we present a new method for image primitives tracking based on a CART (Classification and Regression Tree). Primitives tracking procedure uses lines and circles as primitives. We have applied the proposed method to sport event scenarios, specifically, soccer matches. We estimate CART parameters using a learning procedure based on RGB image channels. In order to illustrate its performance, it has been applied to real HD (High Definition) video sequences and some numerical experiments are shown. The quality of the primitives tracking with the decision tree is validated by the percentage error rates obtained and the comparison with other techniques as a morphological method. We also present applications of the proposed method to camera calibration and graphic object insertion in real video sequences.

A variational approach to 3D geometry reconstruction from two or multiple views

[EN] In the last years we have developed some methods for 3D reconstruction. First we began with the problem of reconstructing a 3D scene from a stereoscopic pair of images. We developed some methods based on energy functionals which produce dense disparity maps by preserving discontinuities from image boundaries. Then we passed to the problem of reconstructing a 3D scene from multiple views (more than 2). The method for multiple view reconstruction relies on the method for stereoscopic reconstruction. For every pair of consecutive images we estimate a disparity map and then we apply a robust method that searches for good correspondences through the sequence of images. Recently we have proposed several methods for 3D surface regularization. This is a postprocessing step necessary for smoothing the final surface, which could be afected by noise or mismatch correspondences. These regularization methods are interesting because they use the information from the reconstructing process and not only from the 3D surface. We have tackled all these problems from an energy minimization approach. We investigate the associated Euler-Lagrange equation of the energy functional, and we approach the solution of the underlying partial differential equation (PDE) using a gradient descent method.

Henry Melson Stommel : from pionner to clasic

[EN] Stommel has been the most important physicist oceanographer of the second half of the XX century. Builder, to a great extent, of the present Dynamical Oceanography. He contributed to the transformation of the Oceanography from a sort of appendix of the studies of the Atmosphere to a new specialty of Geophysics. After graduating in Astronomy in Yale in 1942 he started his research participating in the WWII effort, collaborating together with many other future oceanographers, in support of the USA Navy. Research that was carried out in the Woods Hole Oceanographic Institution (WHOI). Between 1959 and 1978 he was professor of oceanography in Harvard U. first, and later in the Massachusetts Institute of Technology, returning to WHOI where he stayed until his death. Stommel established important and fundamental theories on the ocean global circulation and studied many other oceanographic phenomena. This theoretical activity he combined with not a less important observational one. He received many awards and hhonors, including the Craadford prize, equivalent to the Nobel in Geosciences.

Submarine emissions on the seafloor : from cold seeps to hot vents

[EN] The main types of submarine geological emissions are classified as cold seeps (hydrocarbons and brines) and hot vents. These processes result in the emission of geological fluids: brine, gases (mainly hydro-carbons), sediments and rocks. Submarine emissions are associated with an intensive geological, geo-chemical, thermal and biological activity (Judd and Hovland, 2007), and constitute a key process in the dynamics of the global cycles of the planet Earth.