Literatura Nerd – #1 – Space Opera

Posted on 26 de janeiro de 2012 by okinouchi

Posted in Autocentrado, Ficção Científica, Humor | Leave a comment

Evolução da Cultura e Sociologia computacional

Posted on 21 de janeiro de 2012 by okinouchi

the physics arXiv blog

Computer Model Replays Europe’s Cultural History

Posted: 18 Jan 2012 09:10 PM PST

A simple mathematical model of the way cultures spread reproduces some aspects of European history, say complexity scientists

Some 15 years ago, the American political scientist Robert Axelrod put forward a remarkable model of the way cultural diversity persists in society. His idea was that people are more likely to interact with others like them. The more similar two people are, the more likely they are to adopt each other’s traits.

That’s how traits spread but it is also why diversity persists.

Since then, the power and simplicity of Axelrod’s approach has led complexity theorists to study numerous variations on the original theme. The model lends itself to computer simulation because people can be modelled as nodes on a grid influenced by those closest to them. Whatever the starting conditions, a computer can go through through millions of iterations to see how traits spread.

Consequently, Axelrod’s approach has been used to simulate behaviours ranging from the spread of language to voting behaviour.

Today, Bartlomiej Dybiec and pals at the Center for Models of Life in Copenhagen use an Axelrod-like model to examine the way cultures might have spread throughout Europe. They think about culture as a collective term for rumours, stories, ideas and fashions which are shared by people at the same location. Continue reading →
Posted in Cultura, Sociofísica | Leave a comment

O Meme do Meme do Meme

Posted on 20 de janeiro de 2012 by okinouchi

Quando eu li o Gene Egoísta de Richard Dawkins na década de 80, eu não imaginava que um dia o Meme estaria na Globo…

Posted in Biologia, Cultura, Evolução, Humor | Leave a comment

Como colocar papers no ArXiv?

Posted on 16 de janeiro de 2012 by okinouchi

Siga o seguinte algoritmo:

1. Faça um paper (ou pelo menos assine um).

2. No dia em que estiver submetendo o paper para a revista, entre no site do Arxiv ( a menos que você ache que seu paper é muito revolucionário – ou mal escrito – para alguma revista publicar).

3. Leia as instruções de como colocar um paper no ArXiv que estão aqui.

4. Siga as instruções e coloque seu paper ao ArXiv.

From: [email protected]
To: leonardo@****
Sent: Monday, January 16, 2012 2:10:11 AM
Subject: arXiv Replacement -> 1109.2036 in q-bio.NC from leonardo@****

Your replacement of 1109.2036 by submission submit/******* has
been published and is available at:

http://arxiv.org/abs/1109.2036

The paper password for this article is: *****
Please share this with your co-authors. They may use it to claim ownership.

Abstract will appear in today’s mailing as:

arXiv:1109.2036
From: Leonardo L. Gollo <[email protected]>
Date: Fri, 9 Sep 2011 15:03:09 GMT   (77kb)
Date (revised v2): Fri, 13 Jan 2012 20:10:34 GMT   (668kb)

Title: Statistical Physics approach to dendritic computation: The
excitable-wave mean-field approximation
Authors: Leonardo L. Gollo, Osame Kinouchi and Mauro Copelli
Categories: q-bio.NC
Comments: 30 pages, 8 figures
Journal-ref: Phys. Rev. E, 85, 011911 (2012)
DOI: 10.1103/PhysRevE.85.011911

We analytically study the input-output properties of a neuron whose active
dendritic tree, modeled as a Cayley tree of excitable elements, is subjected to
Poisson stimulus. Both single-site and two-site mean-field approximations
incorrectly predict a non-equilibrium phase transition which is not allowed in
the model. We propose an excitable-wave mean-field approximation which shows
good agreement with previously published simulation results [Gollo et al., PLoS
Comput. Biol. 5(6) e1000402 (2009)] and accounts for finite-size effects. We
also discuss the relevance of our results to experiments in neuroscience,
emphasizing the role of active dendrites in the enhancement of dynamic range
and in gain control modulation.

Phys. Rev. E 85, 011911 (2012) [13 pages]

Statistical physics approach to dendritic computation: The excitable-wave mean-field approximation

Abstract
Download: PDF (859 kB) Buy this article Export: BibTeX or EndNote (RIS)

 Leonardo L. Gollo*
IFISC (CSIC – UIB), Instituto de Física Interdisciplinar y Sistemas Complejos, Campus Universitat Illes Balears, E-07122 Palma de Mallorca, Spain

Osame Kinouchi†
Laboratório de Física Estatística e Biologia Computacional, Departamento de Física, FFCLRP, Universidade de São Paulo, Avenida dos Bandeirantes 3900, 14040-901 Ribeirão Preto, São Paulo, Brazil

Mauro Copelli‡
Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, Pernambuco, Brazil

Received 12 September 2011; revised 23 November 2011; published 12 January 2012

We analytically study the input-output properties of a neuron whose active dendritic tree, modeled as a Cayley tree of excitable elements, is subjected to Poisson stimulus. Both single-site and two-site mean-field approximations incorrectly predict a nonequilibrium phase transition which is not allowed in the model. We propose an excitable-wave mean-field approximation which shows good agreement with previously published simulation results [ Gollo et al. PLoS Comput. Biol. 5 e1000402 (2009)] and accounts for finite-size effects. We also discuss the relevance of our results to experiments in neuroscience, emphasizing the role of active dendrites in the enhancement of dynamic range and in gain control modulation.

©2012 American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevE.85.011911
DOI:
10.1103/PhysRevE.85.011911

PACS:

87.19.ll, 05.10.-a, 87.19.lq, 87.19.ls

Posted in Autocentrado, Meus papers, Neurociência Computacional, Neurociências, Vida científica | Leave a comment

Religião Para Ateus

Posted on 13 de janeiro de 2012 by okinouchi

Home » Livros » Descrição » RELIGIAO PARA ATEUS

RELIGIAO PARA ATEUS

Formato: Livro

Autor: BOTTON, ALAIN DE

Tradutor: PAOLOZZI, VITOR

Editora: INTRINSECA

Assunto: FILOSOFIA

R$19,90
+cultura R$16,90

ou até 6x R$ 2,82 sem juros com cartão
Livraria Cultura Itaucard e ainda
ganhe 169 pontos no programa +cultura.

Clique para Comprar

Disponibilidade

Como funciona nossa entrega

Produto disponível. Veja as localidades e condições da Entrega Foguete.
Disponibilidade de acordo com a quantidade de produtos em estoque.

Entrega Foguete

Agora você pode participar do nosso site inserindo seus vídeos, suas imagens e links para seu blog ou website. Clique nos ícones ao lado e participe!

Especificações Tecnicas

ISBN: 858057093x

ISBN-13: 9788580570939

Idioma: Livro em português

Encadernação: Brochura

Dimensão: 21 x 14 cm

Edição: 1ª

Ano de Lançamento: 2011

Número de páginas: 272

Sinopse

‘Religião para ateus’ parte da premissa de que, com ou sem fé, é possível encontrar aspectos úteis, interessantes e consoladores nas religiões. E examina as possibilidades de transferir algumas dessas ideias e práticas para a vida secular. Nesse livro, Alain de Botton defende que a sociedade tem muito a aprender com as religiões ao tratar de questões como vida em comunidade, moralidade, educação e arte.

Opinião do Leitor

  • 2 Opiniões:

    Opine

  • 26/11/2011

    ALEX BONIFACIO

    O autor está de parabéns por mais essa lindíssima obra editada no Brasil, a imprensa deveria expor com maior intensidade esta referência bibliográfica.Apesar de vivermos numa nação dita religiosa, a laicidade é soberana.

  • 14/11/2011

    HELOISA EMILIA BONFIM

    Alain de Botton é um filósofo que deveria ser mais divulgado pela mídia, aqui no Brasil.
    O livro é ótimo, ideias simples e ao mesmo tempo geniais, o texto é leve – como a vida deveria ser, ou pelo menos como almejamos que seja.
    Este livro será mais um dos meus livros, do autor, que eu gosto…+ ver mais

Posted in Ateísmo, Filosofia, Livros, Neuroteologia, Religião, Teologia | Leave a comment

Computação dendrítica analógica

Posted on 12 de janeiro de 2012 by okinouchi

Finalmente saiu o Gollo, Kinoouchi and Copelli – PRE 2012

From: “American Physical Society”
To: leonardo@
Sent: Thursday, January 12, 2012 4:48:08 PM
Subject: Notification of Online Publication of Your Article in Phys. Rev. E [EJ10756]

Dear Dr. Gollo,

We are pleased to inform you that your article, “Statistical physics approach to dendritic computation: The excitable-wave mean-field approximation” has been published online today, 12 January 2012, in the January 2012 issue of Physical Review E (Vol.85, No.1):

URL: http://link.aps.org/doi/10.1103/PhysRevE.85.011911
DOI: 10.1103/PhysRevE.85.011911

Thank you for choosing to publish with the American Physical Society.

Respectfully yours,
Physical Review E
American Physical Society

Posted in Autocentrado, Meus papers, Neurociências | Leave a comment

Quotes

Posted on 10 de janeiro de 2012 by okinouchi
A man must learn to understand the motives of human beings, their illusions, and their sufferings.

He who believes in freedom of the will has never loved and never hated.
Marie von Ebner-Eschenbach

Posted in Autocentrado, Mulheres, Rita Cristina, Sem categoria | Leave a comment

LASCoN 4 – Latin American School of Computational Neuroscience

Posted on 5 de janeiro de 2012 by okinouchi

EVENTOS / LASCON 2012 – IV Latin American School on Computational Neuroscience
Descrição

Entre 15 de janeiro a 10 de fevereiro de 2012 será realizada, no Departamento de Física da FFCLRP, sob organização do Prof. Dr. Antônio Carlos Roque da Silva Filho, a 4ª Edição da Escola Latino-Americana de Neurociência Computacional – LASCON IV.

 

A escola terá a duração de quatro semanas e serão abordadas questões como: biofísico detalhados modelos único neurônio; modelos simplificados neurônio; modelos de rede neural; plasticidade sináptica e modelos de memória; modelos em nível de sistema cerebral; teoria da informação e análise de pico de trem, e neurociência cognitiva computacional. Estes modelos serão ilustrados com o uso de programas como neurónio, neuroConstruct, XPP-AUTO, NEST e Matlab.

 

O corpo docente é composto por uma equipe internacional de pesquisadores de renome mundial no campo da neurociência computacional. O evento será realizado em período integral (manhãs, tardes e noites) no bloco 1 das exatas (prédio do Departamento de Computação e Matemática).
 
 
 
Maiores informações:
Prof Dr. Antonio C. Roque
Departamento de Física da FFCLRP/USP
Tel: +55 16 3602-3768
Fax: +55 16 3602-4887
E-mail: [email protected]
URL: http://sisne.org/LASCON

Posted in Neurociência Computacional, Neurociências | Leave a comment

Emaranhados no tempo

Posted on 29 de dezembro de 2011 by okinouchi

New Type Of Entanglement Allows ‘Teleportation in Time,’ Say Physicists

Conventional entanglement links particles across space. Now physicists say a similar effect links particles through time.

KFC 01/17/2011

  • 29 COMMENTS

Entanglement is the strange quantum phenomenon in which two or more particles become so deeply linked that they share the same existence.

That leads to some counterintuitive effects, in particular, when two entangled particles become widely separated. When that happens, a measurement on one immediately influences the other, regardless of the distance between them. This “spooky-action-at-a-distance” has profound implications about the nature of reality but a clear understanding of it still eludes physicists.

Today, they have something else to puzzle over. Jay Olson and Timothy Ralph at the University of Queensland in Australia say they’ve discovered a new type of entanglement that extends, not through space, but through time. Continue reading →

Posted in Epistemologia, Ficção Científica, Filosofia, Física, Física de Partículas | Leave a comment

Mais um paper (nosso) em Avalanches Neuronais

Posted on 28 de dezembro de 2011 by okinouchi

O interessante desse trabalho é que as redes são de neurônios inibitórios… Lembrar de falar para o Maurício enfatizar isso na dissertação!

This article is part of the supplement: Twentieth Annual Computational Neuroscience Meeting: CNS*2011

Open AccessPoster presentation

 

Signal propagation and neuronal avalanches analysis in networks of formal neurons

Mauricio Girardi-Schappo1*, Marcelo HR Tragtenberg1 and Osame Kinouchi2

Author Affiliations

1 Departamento de Física, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-970, Brazil

2 Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil

For all author emails, please log on.

 
 
 
 

BMC Neuroscience 2011, 12(Suppl 1):P172 doi:10.1186/1471-2202-12-S1-P172

The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1471-2202/12/S1/P172

Published: 18 July 2011

© 2011 Girardi-Schappo et al; licensee BioMed Central Ltd.

Poster presentation

To study neurons with computational tools, one may call upon, at least, two different approaches: (i) Hodgkin-Huxley like neurons [1] (i.e. biological neurons) and (ii) formal neurons (e.g. Hindmarsh-Rose (HR) model [2], Kinouchi-Tragtenberg (KT) model [3], etc). Formal neurons may be represented by ordinary differential equations (e.g. HR), or by maps, which are dynamical systems with continuous state variables and discrete time dynamics (e.g. KT). A few maps had been proposed to describe neurons [3-10]. Such maps provide one with a number of computational advantages [10], since there is no need to set any precision on the integration variable, which leads to better performance in the calculations.

An extended KT neuron model, here called KTz model, has been studied in [4] and [5], may be supplied with a Chemical Synapse Map (CSM) in order to study interacting neurons in a lattice, in the framework of coupled map lattices. KTz model presents most of the standard behavior of excitable cells like fast spiking, regular spiking, bursting, plateau action potentials and adaptation phenomena, and the CSM is in good agreement with some standard functions used to model post-synaptic currents, like the alpha function or the double-exponential function [4]. Preliminary results indicate antiferromagnetic oscillatory behavior or plane wave behavior in KTz neurons coupled with inhibitory CSM on a square lattice.

Besides, many systems in nature are characterized by complex behavior where large cascades of events, named avalanches, unpredictably alternate with periods of little activity (e.g. snow avalanches, earthquakes, etc). Avalanches are described by power law distributions and when the branching parameter equals to unity, the system is said to be a self-organized critical (SOC) system [13]. These have been observed for neuronal activity in vitro [11,12]. And since both SOC systems and neuronal activity show large variability, long-term stability and memory capabilities, networks of neurons have been proposed to be SOC systems. This hypothesis was tested in [13], where they made comparisons among in vivo recordings using Local Field Potentials in three macaque monkeys performing a short term memory task and three different well-established subsampled SOC models (e.g. Sandpile model, Random Neighbour Sandpile model and Forest Fire model). Some similar comparison has been done in [14] with in vivo data from fourteen rats and a cellular automaton developed by the authors.

We claim that still no simulation has been made to detect whether formal or realistic neuron models can evolve naturally to a SOC state, in a full or subsampled network. Our simulations are made with KTz model, which is a formal neuron, but keeps the usual behaviors of living cells, connected through CSM on a square lattice. We divided the work into two parts: (i) the analysis of network itself and how it evolves with time from a given initial state, varying its parameters and (ii) the analysis of the data generated by a network of silent cells, stimulated at random sites, trying to resemble the SOC models above. We compare these second part results with the experimental ones presented in [11-13].

References

  1. Hodgkin A, Huxley A: A quantitative description of membrane current.

    J Physiol 1952, 117(4):500-544. PubMed Abstract | Publisher Full Text | PubMed Central Full Text OpenURL

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  2. Hindmarsh JL, Rose RM: A model of neuronal bursting.

    Proc R Soc Lond B Biol Sci 1984, 221:87-102. PubMed Abstract | Publisher Full Text OpenURL

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  3. Kinouchi O, Tragtenberg MHR: Modeling neurons by simple maps.

    Int J Bifurcat Chaos 1996, 6:2343-2360. Publisher Full Text OpenURL

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  4. Kuva SM, Lima GF, Kinouchi O, Tragtenberg MHR, Roque AC: A minimal model for excitable and bursting elements.

    Neurocomputing 2001, 38-40:255-261. Publisher Full Text OpenURL

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  5. Copelli M, Tragtenberg MHR, Kinouchi O: Stability diagrams for bursting neurons.

    Physica A 2004, 342:263-269. Publisher Full Text OpenURL

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  6. Chialvo DR: Generic excitable dynamics on a two-dimensional map.

    Chaos Solit Fract 1995, 5:461-479. Publisher Full Text OpenURL

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  7. Rulkov NF: Modeling of spiking-bursting neuronal behavior using two-dimensional map.

    Phys Rev E 2002, 65:041922. Publisher Full Text OpenURL

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  8. Cazelles B, Courbage M, Rabinovich M: Anti-phase regularization.

    Europhys Lett 2001, 56:504-509. Publisher Full Text OpenURL

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  9. Laing CR, Longtin A: A two variable model of somaticdendritic interactions.

    Bull Math Biol 2002, 64:829-860. PubMed Abstract | Publisher Full Text OpenURL

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  10. Izhikevich EM, Hoppensteadt F: Classification of bursting mappings.

    Int J Bifurcat Chaos 2004, 14(11):3847-3854. Publisher Full Text OpenURL

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  11. Beggs JM, Plenz D: Neuronal avalanches in neocortical circuits.

    J Neurosci 2003, 23(35):11167-11177. PubMed Abstract | Publisher Full Text OpenURL

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  12. Beggs JM, Plenz D: Neuronal avalanches are diverse and precise activity patterns that are stable for many hours in cortical slice cultures.

    J Neurosci 2004, 24(22):5216-5229. PubMed Abstract | Publisher Full Text OpenURL

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  13. Priesemann V, Munk MHJ, Wibral M: Subsampling effects in neuronal avalanche.

    BMC Neurosci 2009, 10:40. PubMed Abstract | BioMed Central Full Text | PubMed Central Full Text OpenURL

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  14. Ribeiro TL, Copelli M, Caixeta F, Belchior H, Chialvo DR, Nicolelis MAL, Ribeiro S: Spike avalanches exhibit universal dynamics across the sleep-wake cycle.

    PLoS One 2010, 5(11):e14129. PubMed Abstract | Publisher Full Text | PubMed Central Full Text OpenURL

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Posted in Autocentrado, Meus papers, Neurociência Computacional, Processo de ramificação | Leave a comment