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Para Sandro e Ariadne estudarem (e talvez Paulo e Leonardo): American Journal of Physics, Vol. 72, No. 2, pp. 170–184, February 2004 ©2004 American Association of Physics Teachers. All rights reserved. Up: Issue Table of Contents Go to: Previous Article Next Article Other formats: HTML (smaller files) PDF (158 kB) A hint of renormalization Bertrand Delamotte Laboratoire de Physique Théorique et Hautes Energies, Universités Paris VI, Pierre et Marie Curie, Paris VII, Denis Diderot, 2 Place Jussieu, 75251 Paris Cedex 05, France Received: 28 January 2003; accepted: 15 September 2003 An elementary introduction to perturbative renormalization and renormalization group is presented. No prior knowledge of field theory is necessary because we do not refer to a particular physical theory. We are thus able to disentangle what is specific to field theory and what is intrinsic to renormalization. We link the general arguments and results to real phenomena encountered in particle physics and s...

Fig. 3. Nested θ- and β/γ-oscillations organize in the form of neuronal avalanches. ( A ) Definition of neuronal avalanches formed by the nested θ- and β/γ-oscillations. ( Top ) Threshold detection (broken line) of nLFPs (filled circles) at a single electrode. ( Middle ) Corresponding time–amplitude raster plot of nLFPs on the MEA (color: nLFP amplitude). ( Bottom ) Spatiotemporal nLFP clusters occupy successive bins of width Δ t avg (dotted rectangles). ( B ) Average cross-correlation function for nLFPs in vivo at P8 (red) and P13 (black; single experiments). ( C ) nLFP clusters from nested θ- and β/γ-oscillations organize in the form of neuronal avalanches, i.e., distribute in sizes according to a power law with slope close to α = −1.5 (broken line). Average cluster size distribution in vivo plotted in log–log coordinates for P8 (red open circles; n = 5) and P13 (black; n = 7). ( D ) Example of two simultaneous burst periods before (black) and after (red) phase-shuffling. ( E )...

Patent application title: Neuronal Avalanche Assay Inventors: Dietmar Plenz Agents: NATIONAL INSTITUTE OF HEALTH;C/O Ballard Spahr Andrews & Ingersoll, LLP Assignees: The Government of the United States of America Origin: ATLANTA, GA US IPC8 Class: AA61B50476FI USPC Class: 600544 Read more: http://www.faqs.org/patents/app/20090036791#ixzz0Zh4ZicFJ

Spontaneous cortical activity in awake monkeys composed of neuronal avalanches Thomas Petermann a , Tara C. Thiagarajan a , Mikhail A. Lebedev b , Miguel A. L. Nicolelis b , Dante R. Chialvo c and Dietmar Plenz a , 1 + Author Affiliations a Section on Critical Brain Dynamics, National Institute of Mental Health, Bethesda, MD 20892; b Department of Neurobiology, Center for Neuroengineering, Duke University, Durham, NC 27710; and c Department of Physiology, Northwestern University, Chicago, IL 60611 Edited by Eve Marder, Brandeis University, Waltham, MA, and approved July 16, 2009 (received for review April 16, 2009) Abstract Spontaneous neuronal activity is an important property of the cerebral cortex but its spatiotemporal organization and dynamical framework remain poorly understood. Studies in reduced systems—tissue cultures, acute slices, and anesthetized rats—show that spontaneous activity forms characteristic clusters in space and time, called neuronal avalanches. Modeling studie...