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Synaptic learning rules, cortical circuits, and visual function
 NEUROSCIENTIST
, 2005
"... Sensory experience is essential for the refinement of neuronal circuits during development and for learning and memory in the adult brain. Such experiencedependent plasticity is largely mediated by activitydependent synaptic modification. In this review, we focus on a spike timing–dependent synapti ..."
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Sensory experience is essential for the refinement of neuronal circuits during development and for learning and memory in the adult brain. Such experiencedependent plasticity is largely mediated by activitydependent synaptic modification. In this review, we focus on a spike timing–dependent synaptic learning rule, in which the direction and magnitude of synaptic modification depend on the relative spike timing of presynaptic and postsynaptic neurons. We discuss a series of recent studies exploring the functional implications of this learning rule in the visual system. These studies show that temporally patterned visual stimuli can cause rapid changes in visual circuits, neuronal receptive fields, and visual perception, with a temporal specificity of tens of milliseconds. Particularly, motion stimuli that are common in natural scenes may interact strongly with the spike timing–dependent learning rule, leaving distinct marks in the perceptual function of the mature brain.
An Implementation for Mapping SBML to BioSPI
 in Wang,L., and Jin,Y. (Eds.): FSKD 2005, LNAI 3614
, 2005
"... Abstract. The Systems Biology Markup Language(SBML) is an XMLbased format for representing models of Systems Biology. BioSPI is a formal model to simulate biological systems, which is evolved from process calculi. Based on the previous research on modeling Systems Biology using process algebra, we ..."
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Abstract. The Systems Biology Markup Language(SBML) is an XMLbased format for representing models of Systems Biology. BioSPI is a formal model to simulate biological systems, which is evolved from process calculi. Based on the previous research on modeling Systems Biology using process algebra, we propose a method to map SBML to BioSPI. The motivation of the work is to make full use of BioSPI to analyze biological systems described by SBML. In this paper, the mapping rules are presented and an example is given to show the simulation results. 1
Tau laws for pi calculus
 Theoretical Computer Science
"... The paper investigates the nonsymbolic algebraic semantics of the weak bisimulation congruences on finite pi processes. The weak bisimulation congruences are studied both in the absence and in the presence of the mismatch operator. Some interesting phenomena about the open congruences are revealed. ..."
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The paper investigates the nonsymbolic algebraic semantics of the weak bisimulation congruences on finite pi processes. The weak bisimulation congruences are studied both in the absence and in the presence of the mismatch operator. Some interesting phenomena about the open congruences are revealed. Several new tau laws are discovered and their relationship is discussed. The contributions of the paper are mainly as follows: 1. It is proved that Milner’s three tau laws fail to lift a complete system for the strong open congruence to a complete system for the weak open congruence in the absence of both the mismatch operator and the restriction operator. A fourth tau law is proposed to deal with the match operator under the prefix operation. It is shown that for this calculus a complete system for the strong open congruence extended with all the four tau laws is complete for the weak open congruence. 2. It is verified that the four tau laws are also enough for the weak open congruence of the pi calculus without the mismatch operator. Two complete systems are given, one using distinctions and the other using a schematic law for the restriction operator.
Asymmetry in Visual Cortical Circuits Underlying Motioninduced Perceptual Mislocalization
, 2004
"... Motion signals in the visual field can cause strong biases in the perceived positions of stationary objects. Local motion signal within an object induces a shift in the perceived object position in the direction of motion, whereas adaptation to motion stimuli causes a perceptual shift in the opposit ..."
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Motion signals in the visual field can cause strong biases in the perceived positions of stationary objects. Local motion signal within an object induces a shift in the perceived object position in the direction of motion, whereas adaptation to motion stimuli causes a perceptual shift in the opposite direction. The neural mechanisms underlying these illusions are poorly understood. Here we report two novel receptive field (RF) properties in cat primary visual cortex that may account for these motionposition illusions. First, motion signal in a stationary test stimulus causes a displacement of the RF in the direction opposite to motion. Second, motion adaptation induces a shift of the RF in the direction of adaptation. Comparison with human psychophysical measurements under similar conditions indicates that these RF properties can primarily account for the motionposition illusions. Importantly, both RF properties indicate a spatial asymmetry in the synaptic connections from directionselective cells, and this circuit feature can be predicted by spiketimingdependent synaptic plasticity, a widespread phenomenon in the nervous system. Thus, motioninduced perceptual mislocalization may be mediated by asymmetric cortical circuits, as a natural consequence of experiencedependent synaptic modification during circuit development.
Vessiot structure for manifolds of (p� q)hyperbolic type: Darboux integrability and symmetry, Mathematics research report No
, 1998
"... Abstract. It is well known that if a scalar second order hyperbolic partial differential equation in two independent variables is Darboux integrable, then its local Cauchy problem may be solved by ordinary differential equations. In addition, such an equation has infinitely many nontrivial conserva ..."
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Abstract. It is well known that if a scalar second order hyperbolic partial differential equation in two independent variables is Darboux integrable, then its local Cauchy problem may be solved by ordinary differential equations. In addition, such an equation has infinitely many nontrivial conservation laws. Moreover, Darboux integrable equations have properties in common with infinite dimensional completely integrable systems. In this paper we employ a geometric object intrinsically associated with any hyperbolic partial differential equation, its hyperbolic structure, to study the Darboux integrability of the class E of semilinear second order hyperbolic partial differential equations in one dependent and two independent variables. It is shown that the problem of classifying the Darboux integrable equations in E contains, as a subproblem, that of classifying the manifolds of (p, q)hyperbolic type of rank 4 and dimension 2k +3, k ≥ 2; p =2,q ≥ 2. In turn, it is shown that the problem of classifying these manifolds in the two (lowest) cases (p, q) = (2, 2), (2, 3) contains, as a subproblem, the classification problem for Lie groups. This generalizes classical results of E. Vessiot. The main result is that if an equation in E is (2,2) or (2,3)Darboux integrable on the kjets, k ≥ 2, then its intrinsic hyperbolic structure admits a Lie group of symmetries of dimension 2k − 1or2k − 2, respectively. It follows that part of the moduli space for the Darboux integrable equations in E is determined by isomorphism classes of Lie groups. The Lie group in question is the group of automorphisms of the characteristic systems of the given equation which leaves invariant the foliation induced by the characteristic (or, Riemann) invariants of the equation, the tangential characteristic symmetries. The isomorphism class of the tangential characteristic symmetries is a contact invariant of the corresponding Darboux integrable partial differential equation. 1.
Uniformly Convergent Finite Element Methods for Singularly Perturbed Elliptic Boundary Value Problems: ConvectionDiffusion Type
, 1998
"... In this paper we consider the standard bilinear finite element method (FEM) and the corresponding streamline diffusion FEM for the singularly perturbed elliptic boundary value probleme(O2u/Ox2+ O2u/Oy 2) b(x, y).Vu + a(x, y)u =f(x, y) in the two space dimen sions. By using the asymptotic expansio ..."
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In this paper we consider the standard bilinear finite element method (FEM) and the corresponding streamline diffusion FEM for the singularly perturbed elliptic boundary value probleme(O2u/Ox2+ O2u/Oy 2) b(x, y).Vu + a(x, y)u =f(x, y) in the two space dimen sions. By using the asymptotic expansion method of ishik and Lyustemik [36] and the technique we used in [21,22], we prove that the standard bilinear FEM on a Shishkin type mesh achieves firstorder uniform convergence rate globally in L 2 norm for both the ordinary exponential boundary layer case and the parabolic boundary layer case. Extensive numerical results are carded out for both cases. The results show that our methods perform much better than either the classical standard or streamline diffusion FEM. 1998 Elsevier Science S.A. All rights reserved.
Error Estimation of Perturbations Under CRI
"... Abstract—The analysis of stability and robustness of fuzzy reasoning is an important issue in areas like intelligent systems and fuzzy control. An interesting aspect is to what extent the perturbation of input in a fuzzy reasoning scheme causes the oscillation of the output. In particular, when th ..."
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Abstract—The analysis of stability and robustness of fuzzy reasoning is an important issue in areas like intelligent systems and fuzzy control. An interesting aspect is to what extent the perturbation of input in a fuzzy reasoning scheme causes the oscillation of the output. In particular, when the error limits (restrictions) of the input values are given, what the error limits of the output values are. In this correspondence, we estimate the upper and lower bounds of the output error affected by the perturbation parameters of the input, and obtain the limits of the output values when the input values range over some interval in many fuzzy reasoning schemes under compositional rule of fuzzy inference (CRI). Index Terms—Error estimation, fuzzy reasoning, fuzzy set, interval perturbation, simple perturbation. I.
st Periodic Progress Report
"... Machine for the Calculus of Constructions : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 84 CONTENTS 2 5.11 Appendix B: Report on implementation of LiLac : : : : : : : : : : : : : 86 5.12 Report on Workshop on Evaluation Logic and Synthetic Domain Theory 88 5.13 Preliminary ..."
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Machine for the Calculus of Constructions : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 84 CONTENTS 2 5.11 Appendix B: Report on implementation of LiLac : : : : : : : : : : : : : 86 5.12 Report on Workshop on Evaluation Logic and Synthetic Domain Theory 88 5.13 Preliminary Programme of Workshop on Games, Logic and Processes : Chapter 1 Executive summary 1.1 Milestones and Deliverables The CLICS II project started on October 1st 1992. The first Milestone occurs after 12 months. The first Review meeting will take place in Marseille on October 8th 1993. As set out in Chapter II of the Technical Annex, the Workplan is structured into nine research topics, A through I. The main deliverables, as specified in Section II2.2 of the Technical Annex, comprise detailed accounts of progress on each of these topics, written by the "Topic Leader". These are contained in Chapter 5 of this report. Each Topic progress report references the relevant papers produced within...
Results 11  20
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