L. R. G. Fontes

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We study the threshold θ bootstrap percolation model on the homogeneous tree with degree b+ 1, 2 ≤ θ ≤ b, and initial density p. It is known that there exists a nontrivial critical value for p, which we call pf , such that a) for p > pf , the final bootstrapped configuration is fully occupied for almost every initial configuration, and b) if p < pf , then(More)
1 Laboratoire de Physique Théorique et Modélisation (CNRS-ESA8089), Université de CergyPontoise, 95031 Cergy-Pontoise, France; e-mail: dunlop@ptm.u-cergy.fr; http://www.u-cergy. fr/rech/labo/equipes/ptm/Dunlop. 2 IME–USP, Caixa Postal 66281, 05311-970 São Paulo, Brazil; e-mail: pablo@ime.usp.br, lrenato@ime.usp.br; http://www.ime.usp.br/~ pablo,(More)
A case of angiosarcoma of the right atrium in a 59-year-old woman is reported, presenting as a recurrent hematic pericardial effusion. The usefulness of echocardiography in making the diagnosis is emphasized. The tumor was already disseminated at the time of the diagnosis. The patient was on palliative therapy, dying a few months later. The histological(More)