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Sample records for reflexive banach space

  1. The cofinal property of the Reflexive Indecomposable Banach spaces

    OpenAIRE

    Argyros, Spiros A.; Raikoftsalis, Theocharis

    2010-01-01

    It is shown that every separable reflexive Banach space is a quotient of a reflexive Hereditarily Indecomposable space, which yields that every separable reflexive Banach is isomorphic to a subspace of a reflexive Indecomposable space. Furthermore, every separable reflexive Banach space is a quotient of a reflexive complementably $\\ell_p$ saturated space with $1

  2. Some fixed point theorems in fuzzy reflexive Banach spaces

    International Nuclear Information System (INIS)

    In this paper, we first show that there are some gaps in the fixed point theorems for fuzzy non-expansive mappings which are proved by Bag and Samanta, in [Bag T, Samanta SK. Fixed point theorems on fuzzy normed linear spaces. Inf Sci 2006;176:2910-31; Bag T, Samanta SK. Some fixed point theorems in fuzzy normed linear spaces. Inform Sci 2007;177(3):3271-89]. By introducing the notion of fuzzy and ?- fuzzy reflexive Banach spaces, we obtain some results which help us to establish the correct version of fuzzy fixed point theorems. Second, by applying Theorem 3.3 of Sadeqi and Solati kia [Sadeqi I, Solati kia F. Fuzzy normed linear space and it's topological structure. Chaos, Solitons and Fractals, in press] which says that any fuzzy normed linear space is also a topological vector space, we show that all topological version of fixed point theorems do hold in fuzzy normed linear spaces.

  3. Composite iterative schemes for maximal monotone operators in reflexive Banach spaces

    Directory of Open Access Journals (Sweden)

    Cho Yeol

    2011-01-01

    Full Text Available Abstract In this article, we introduce composite iterative schemes for finding a zero point of a finite family of maximal monotone operators in a reflexive Banach space. Then, we prove strong convergence theorems by using a shrinking projection method. Moreover, we also apply our results to a system of convex minimization problems in reflexive Banach spaces. AMS Subject Classification: 47H09, 47H10

  4. / An Immediate Derivation of Maximum Principle in Banach spaces, Assuming Reflexive Input and State Spaces

    Scientific Electronic Library Online (English)

    Paolo, d' Alessandro.

    Full Text Available Consideramos una formulacin estandar para el problema de norma optimal en espacios de Banach y mostramos que con un argumento simple que invoca algunos fuertes teoremas generales de la teora de espacios de Banach elegidos apropiadamente se deriva directamente el Principio del Maximo. [...] Abstract in english We consider a standard setting for the norm optimal problem in Banach spaces and show that with a simple argument which invokes some appropriately selected powerful general Theorems for Banach spaces a straightforward derivation of the Maximum Principle is obtained. [...

  5. Convergence theorems for common fixed points for finite families of nonexpansive mappings in reflexive Banach spaces

    International Nuclear Information System (INIS)

    Let E be a real reflexive Banach space with uniformly Gateaux differentiable norm. Let K be a nonempty closed convex subset of E. Suppose that every nonempty closed convex bounded subset of K has the fixed point property for nonexpansive mappings. Let T1, T2, ..., TN be a family of nonexpansive self-mappings of K, with F := intersectioni=1N Fix(Ti) ? 0, F = Fix(TNTN-1... T1) = Fix(T1TN ... T2) = ... Fix(TN-1TN-2... T1TN). Let { ?n} be a sequence in (0, 1) satisfying the following conditions: C1 : lim ?n 0; C2 : ? ?n = ? . For a fixed ? element of (0, 1), define Sn : K ? K by Snx := (1 - ? )x + ?Tnx for all x element of K where Tn = Tn mod N. For arbitrary fixed u, x0 element of K, let B := { x element of K : TNTN-1... T1x ?x+(1- ?)u, for some ? > 1} be bounded and let the sequence {xn} be defined iteratively by xn+1 ?n+1u + (1 - ?n+1 )Sn+1xn, for n ? 0. Assume that lim n?? vertical bar vertical bar Tnxn - Tn+1 xn vertical bar vertical bar = 0. Then, {xn} converges strongly to a common fixed point of the family T1, T2, ..., TN. Convergence theorem is also proved for non-self maps. (author)

  6. On P. Levy's Stable Laws and Reflexive Subspaces of the Banach space L of Lebesgue summable functions on [0,1

    CERN Document Server

    Tokarev, E

    2002-01-01

    To describe a set of functions, which forms a reflexive subspace B of the classical Banach space L a special function that characterizes their average integral growth is introduced. It is shown that this function essentially depends on the geometry of B. By the way, one question of la Vallee Poussin is answered. Also a short proof of the known result about the existence of an uncomplemented subspace isomorphic to the Hilbert space in every Lebesgue - Riesz space Lp (1

  7. Classical banach spaces

    CERN Document Server

    Lindenstrauss, Joram

    1977-01-01

    The appearance of Banach's book [8] in 1932 signified the beginning of a syste matic study of normed linear spaces, which have been the subject of continuous research ever since. In the sixties, and especially in the last decade, the research activity in this area grew considerably. As a result, Ban:ach space theory gained very much in depth as well as in scope: Most of its well known classical problems were solved, many interesting new directions were developed, and deep connections between Banach space theory and other areas of mathematics were established. The purpose of this book is to present the main results and current research directions in the geometry of Banach spaces, with an emphasis on the study of the structure of the classical Banach spaces, that is C(K) and Lip.) and related spaces. We did not attempt to write a comprehensive survey of Banach space theory, or even only of the theory of classical Banach spaces, since the amount of interesting results on the subject makes such a survey practic...

  8. Games in Banach spaces

    OpenAIRE

    Duda, Jakub; Tsaban, Boaz

    2006-01-01

    The notion of Aronszajn-null sets generalizes the notion of Lebesgue measure zero on the real line and the Euclidean space to infinite dimensional Banach spaces. We present a game-theoretic approach to Aronszajn-null sets, establish its basic properties, and discuss the ensuing open problems.

  9. Multipliers of Banach valued weighted function spaces

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    Serap ztop

    2000-10-01

    Full Text Available We generalize Banach valued spaces to Banach valued weighted function spaces and study the multipliers space of these spaces. We also show the relationship between multipliers and tensor product of Banach valued weighted function spaces.

  10. The Banach-Saks Property of the Banach Product Spaces

    OpenAIRE

    Jiang, Zhenglu; Fu, Xiaoyong

    2007-01-01

    In this paper we first take a detail survey of the study of the Banach-Saks property of Banach spaces and then show the Banach-Saks property of the product spaces generated by a finite number of Banach spaces having the Banach-Saks property. A more general inequality for integrals of a class of composite functions is also given by using this property.

  11. Banach spaces with projectional skeletons

    CERN Document Server

    Kubi?, Wies?aw

    2008-01-01

    A projectional skeleton in a Banach space is a sigma-directed family of projections onto separable subspaces, covering the entire space. The class of Banach spaces with projectional skeletons is strictly larger than the class of Plichko spaces (i.e. Banach spaces with a countably norming Markushevich basis). We show that every space with a projectional skeleton has a projectional resolution of the identity and has a norming space with similar properties to Sigma-spaces. We characterize the existence of a projectional skeleton in terms of elementary substructures, providing simple proofs of known results concerning weakly compactly generated spaces and Plichko spaces. We prove a preservation result for Plichko Banach spaces, involving transfinite sequences of projections. As a corollary, we show that a Banach space is Plichko if and only if it has a commutative projectional skeleton.

  12. Banach spaces with Property (w)

    OpenAIRE

    Leung, Denny H.

    1991-01-01

    A Banach space E is said to have Property (w) if every (bounded linear) operator from E into E' is weakly compact. We give some interesting examples of James type Banach spaces with Property (w). We also consider the passing of Property (w) from E to C(K,E).

  13. Universal Banach spaces

    CERN Document Server

    Dzamonja, Mirna; Shelah, Saharon

    1998-01-01

    Suppose that lambda = lambda^{ aleph_0, and we are considering a theory T. We give a criterion on T which is sufficient for the consistent existence of a universal model of T of size lambda^+ for models of T of size lambda^+. In fact, we work more generally with abstract elementary classes. We apply this criterion to show that for such lambda it is consistent to have a universal Banach space over R (or C) of density lambda^+, under isometries, while 2^{lambda}=2^{lambda^+}>> lambda^{++} . We further observe that for such lambda, for any fixed mu > lambda^+ regular with mu = mu^{lambda^+}, it is consistent that 2^lambda = mu and there is no normed vector space over Q of size < mu which is universal for normed vector spaces over Q of dimension lambda^+ under the notion of embedding h which specifies (a,b) such that | h(x) |/ | x | in (a,b) for all x . The criterion for the consistent existence of universals which is mentioned in the previous paragraph, applies to some other theories as well, like triangle-fr...

  14. Existence of zeros for operators taking their values in the dual of a Banach space

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    Ricceri Biagio

    2004-01-01

    Full Text Available Using continuous selections, we establish some existence results about the zeros of weakly continuous operators from a paracompact topological space into the dual of a reflexive real Banach space.

  15. Infimal convolution in Efimov-Ste?kin Banach spaces.

    Czech Academy of Sciences Publication Activity Database

    Fabian, Marin

    2008-01-01

    Ro?. 339, ?. 1 (2008), s. 735-739. ISSN 0022-247X R&D Projects: GA AV ?R(CZ) IAA100190610 Institutional research plan: CEZ:AV0Z10190503 Keywords : reflexive Banach space * Kadec-Klee norm * infimal convolution Subject RIV: BA - General Mathematics Impact factor: 1.046, year: 2008

  16. Smooth analysis in Banach spaces

    CERN Document Server

    Hjek, Petr

    2014-01-01

    This bookis aboutthe subject of higher smoothness in separable real Banach spaces.It brings together several angles of view on polynomials, both in finite and infinite setting.Also a rather thorough and systematic view of the more recent results, and the authors work is given. The book revolves around two main broad questions: What is the best smoothness of a given Banach space, and its structural consequences? How large is a supply of smooth functions in the sense of approximating continuous functions in the uniform topology, i.e. how does the Stone-Weierstrass theorem generalize into in

  17. Coarse embedding into uniformly convex Banach space

    OpenAIRE

    Ren, Qinggang

    2011-01-01

    In this paper, we study the coarse embedding into Banach space. We proved that under certain conditions, the property of embedding into Banach space can be preserved under taking the union the metric spaces. For a group $G$ strongly relative hyperbolic to a subgroup $H$, we proved that if $H$ admits a coarse embedding into a uniformly convex Banach space, so is $B(n)=\\{g\\in G|\\abs{g}_{S\\cup\\mathscr{H}}\\leq n\\}$.

  18. Regularization methods in Banach spaces

    CERN Document Server

    Schuster, Thomas; Hofmann, Bernd; Kazimierski, Kamil S

    2012-01-01

    Regularization methods aimed at finding stable approximate solutions are a necessary tool to tackle inverse and ill-posed problems. Usually the mathematical model of an inverse problem consists of an operator equation of the first kind and often the associated forward operator acts between Hilbert spaces. However, for numerous problems the reasons for using a Hilbert space setting seem to be based rather on conventions than on an approprimate and realistic model choice, so often a Banach space setting would be closer to reality. Furthermore, sparsity constraints using general Lp-norms or the B

  19. "The cluster value problem for Banach spaces"

    OpenAIRE

    Johnson, William B.; Castillo, Sofia Ortega

    2013-01-01

    The main result is that the cluster value problem in separable Banach spaces, for the Banach algebras $A_u$ and $H^{\\infty}$, can be reduced to the cluster value problem in those spaces which are $\\ell_1$ sums of a sequence of finite dimensional spaces.

  20. Topics in Banach space integration

    CERN Document Server

    Schwabik, tefan

    2005-01-01

    The relatively new concepts of the Henstock-Kurzweil and McShane integrals based on Riemann type sums are an interesting challenge in the study of integration of Banach space-valued functions. This timely book presents an overview of the concepts developed and results achieved during the past 15 years. The Henstock-Kurzweil and McShane integrals play the central role in the book. Various forms of the integration are introduced and compared from the viewpoint of their generality. Functional analysis is the main tool for presenting the theory of summation gauge integrals.

  1. Banach spaces of analytic functions

    CERN Document Server

    Hoffman, Kenneth

    2014-01-01

    A classic of pure mathematics, this advanced graduate-level text explores the intersection of functional analysis and analytic function theory. Close in spirit to abstract harmonic analysis, it is confined to Banach spaces of analytic functions in the unit disc.The author devotes the first four chapters to proofs of classical theorems on boundary values and boundary integral representations of analytic functions in the unit disc, including generalizations to Dirichlet algebras. The fifth chapter contains the factorization theory of Hp functions, a discussion of some partial extensions of the f

  2. Diffeomorphisms with Banach space domains

    CERN Document Server

    Zampieri, Gaetano

    2012-01-01

    Our basic element is a $C^1$ mapping $f:X\\to Y$, with $X,Y$ Banach spaces, and with derivative everywhere invertible. So $f$ is a local diffeomorphism at every point. The aim of this paper is to find a sufficient condition for $f$ to be injective, and so a global diffeomorphism $X\\to f(X)$, and a sufficient condition for $f$ to be bijective and so a global diffeomorphism onto $Y$. This last condition is also necessary in the particular case $X=Y=\\R^n$. In these theorems the key role is played by nonnegative auxiliary scalar coercive functions.

  3. On Uniformly finitely extensible Banach spaces

    OpenAIRE

    Castillo, Jesu?s M. F.; Ferenczi, Valentin; Moreno, Yolanda

    2013-01-01

    We continue the study of Uniformly Finitely Extensible Banach spaces (in short, UFO) initiated in Moreno-Plichko, \\emph{On automorphic Banach spaces}, Israel J. Math. 169 (2009) 29--45 and Castillo-Plichko, \\emph{Banach spaces in various positions.} J. Funct. Anal. 259 (2010) 2098-2138. We show that they have the Uniform Approximation Property of Pe\\l czy\\'nski and Rosenthal and are compactly extensible. We will also consider their connection with the automorphic space probl...

  4. On the equivalence of solutions for a class of stochastic evolution equations in a Banach space

    OpenAIRE

    Go?rajski, Mariusz

    2013-01-01

    We study a class of stochastic evolution equations in a Banach space $E$ driven by cylindrical Wiener process. Three different concept of solutions: generalised strong, weak and mild are defined and the conditions under which they are equivalent are given. We apply this result to prove existence, uniqueness and continuity of weak solutions to stochastic delay equation with additive noise. We also consider two examples of these equations in non-reflexive Banach spaces: a stoc...

  5. Interpolation of quasi-Banach spaces

    International Nuclear Information System (INIS)

    This dissertation presents a method of complex interpolation for familities of quasi-Banach spaces. This method generalizes the theory for families of Banach spaces, introduced by others. Intermediate spaces in several particular cases are characterized using different approaches. The situation when all the spaces have finite dimensions is studied first. The second chapter contains the definitions and main properties of the new interpolation spaces, and an example concerning the Schatten ideals associated with a separable Hilbert space. The case of L/sup P/ spaces follows from the maximal operator theory contained in Chapter III. Also introduced is a different method of interpolation for quasi-Banach lattices of functions, and conditions are given to guarantee that the two techniques yield the same result. Finally, the last chapter contains a different, and more direct, approach to the case of Hardy spaces

  6. A Gaussian Average Property for Banach Spaces

    OpenAIRE

    Casazza, Peter G.; Nielsen, Niels Jorgen

    1996-01-01

    In this paper we investigate a Gaussian average property of Banach spaces. This property is weaker than the Gordon Lewis property but closely related to this and other unconditional structures. It is also shown that this property implies that certain Hilbert space valued operators defined on subspaces of the given space can be extended.

  7. Stochastic integration in Banach spaces - a survey

    OpenAIRE

    Neerven, Jan; Veraar, Mark; Weis, Lutz

    2013-01-01

    This paper presents a brief survey of the theory of stochastic integration in Banach spaces. Expositions of the stochastic integrals in martingale type 2 spaces and UMD spaces are presented, as well as some applications of the latter to vector-valued Malliavin calculus and the stochastic maximal regularity problem. A new proof of the stochastic maximal regularity theorem is included.

  8. On Sharp Triangle Inequalities in Banach Spaces II

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    Kichi-Suke Saito

    2010-01-01

    Full Text Available Sharp triangle inequality and its reverse in Banach spaces were recently showed by Mitani et al. (2007. In this paper, we present equality attainedness for these inequalities in strictly convex Banach spaces.

  9. Banach spaces that realize minimal fillings

    International Nuclear Information System (INIS)

    It is proved that a real Banach space realizes minimal fillings for all its finite subsets (a shortest network spanning a fixed finite subset always exists and has the minimum possible length) if and only if it is a predual of L1. The spaces L1 are characterized in terms of Steiner points (medians). Bibliography: 25 titles. (paper)

  10. Strong Convergence of Viscosity Methods for Continuous Pseudocontractions in Banach Spaces

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    Filomena Cianciaruso

    2008-01-01

    Full Text Available We define a viscosity method for continuous pseudocontractive mappings defined on closed and convex subsets of reflexive Banach spaces with a uniformly Gteaux differentiable norm. We prove the convergence of these schemes improving the main theorems in the work by Y. Yao et al. (2007 and H. Zhou (2008.

  11. Special symmetries of Banach spaces isomorphic to Hilbert spaces

    OpenAIRE

    Talponen, Jarno

    2008-01-01

    In this paper Hilbert spaces are characterized among Banach spaces in terms of transitivity with respect to nicely behaved subgroups of the isometry group. For example, the following result is typical here: If X is a real Banach space isomorphic to a Hilbert space and convex-transitive with respect to the isometric finite-dimensional perturbations of the identity, then X is already isometric to a Hilbert space.

  12. Banach Spaces Which Embed into their Dual

    CERN Document Server

    Capraro, V

    2009-01-01

    We provide a nice characterization of the classical Riesz-Frechet representation theorem: if a Banach space embeds isometrically into its dual space, under some other natural assumptions, then it is a Hilbert space and the embedding is actually the canonical one (which becomes automatically surjective). We also see that requiring surjectivity a priori, one can considerably weak one of the ''other hypothesis''. Anyway, it should remains to prove that our assumptions are minimal. It seems to be a difficult problem in general, because it is already not easy at all to find non-trivial examples (Hilbert spaces!) of Banach spaces which embed isometrically into their own dual. We will discuss in some details only the fatality of the ''isometric hypothesi'' which however brought us to find an example of compact convex Hausdorff space which does not admit a Borel measure with full support.

  13. Minimization of Tikhonov Functionals in Banach Spaces

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    Thomas Schuster

    2008-03-01

    Full Text Available Tikhonov functionals are known to be well suited for obtaining regularized solutions of linear operator equations. We analyze two iterative methods for finding the minimizer of norm-based Tikhonov functionals in Banach spaces. One is the steepest descent method, whereby the iterations are directly carried out in the underlying space, and the other one performs iterations in the dual space. We prove strong convergence of both methods.

  14. Banach spaces of vector-valued functions

    CERN Document Server

    Cembranos, Pilar

    1997-01-01

    "When do the Lebesgue-Bochner function spaces contain a copy or a complemented copy of any of the classical sequence spaces?" This problem and the analogous one for vector- valued continuous function spaces have attracted quite a lot of research activity in the last twenty-five years. The aim of this monograph is to give a detailed exposition of the answers to these questions, providing a unified and self-contained treatment. It presents a great number of results, methods and techniques, which are useful for any researcher in Banach spaces and, in general, in Functional Analysis. This book is written at a graduate student level, assuming the basics in Banach space theory.

  15. An Inexact Proximal-Type Method for the Generalized Variational Inequality in Banach Spaces

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    Mastroeni G

    2007-01-01

    Full Text Available We investigate an inexact proximal-type method, applied to the generalized variational inequality problem with maximal monotone operator in reflexive Banach spaces. Solodov and Svaiter (2000 first introduced a new proximal-type method for generating a strongly convergent sequence to the zero of maximal monotone operator in Hilbert spaces, and subsequently Kamimura and Takahashi (2003 extended Solodov and Svaiter algorithm and strong convergence result to the setting of uniformly convex and uniformly smooth Banach spaces. In this paper Kamimura and Takahashi's algorithm is extended to develop a generic inexact proximal point algorithm, and their convergence analysis is extended to develop a generic convergence analysis which unifies a wide class of proximal-type methods applied to finding the zeroes of maximal monotone operators in the setting of Hilbert spaces or Banach spaces.

  16. An Inexact Proximal-Type Method for the Generalized Variational Inequality in Banach Spaces

    Directory of Open Access Journals (Sweden)

    J. C. Yao

    2008-01-01

    Full Text Available We investigate an inexact proximal-type method, applied to the generalized variational inequality problem with maximal monotone operator in reflexive Banach spaces. Solodov and Svaiter (2000 first introduced a new proximal-type method for generating a strongly convergent sequence to the zero of maximal monotone operator in Hilbert spaces, and subsequently Kamimura and Takahashi (2003 extended Solodov and Svaiter algorithm and strong convergence result to the setting of uniformly convex and uniformly smooth Banach spaces. In this paper Kamimura and Takahashi's algorithm is extended to develop a generic inexact proximal point algorithm, and their convergence analysis is extended to develop a generic convergence analysis which unifies a wide class of proximal-type methods applied to finding the zeroes of maximal monotone operators in the setting of Hilbert spaces or Banach spaces.

  17. Topological Vector-Space Valued Cone Banach Spaces

    OpenAIRE

    Nayyar Mehmood; Akbar Azam; Suzana Aleksic

    2014-01-01

    In this paper we introduce the notion of tvs-cone normed spaces, discuss related topological concepts and characterize the tvs-cone norm in various directions. We construct generalize locally convex tvs generated by a family of tvs-cone seminorms. The class of weak contractions properly includes large classes of highly applicable contractions like Banach, Kannan, Chatterjea and quasi etc. We prove fixed point results in tvs-cone Banach spaces for nonexpansive self mappings and self/non-self w...

  18. The Maslov index in symplectic Banach spaces

    DEFF Research Database (Denmark)

    Booss-Bavnbek, Bernhelm; Zhu, Chaofeng

    2015-01-01

    We consider a curve of Fredholm pairs of Lagrangian subspaces in a xed Banach space with continuously varying weak symplectic structures. Assuming vanishing index, we obtain intrinsically a continuously varying splitting of the total Banach space into pairs of symplectic subspaces. Using such decompositions we dene the Maslov index of the curve by symplectic reduction to the classical nite-dimensional case. We prove the transitivity of repeated symplectic reductions and obtain the invariance of the Maslov index under symplectic reduction, while recovering all the standard properties of the Maslov index. As an application, we consider curves of elliptic operators which have varying principal symbol, varying maximal domain and are not necessarily of Dirac type. For this class of operator curves, we derive a desuspension spectral ow formula for varying well-posed boundary conditions on manifolds with boundary and obtain the splitting of the spectral ow on partitioned manifolds.

  19. Boundedness of biorthogonal systems in Banach spaces.

    Czech Academy of Sciences Publication Activity Database

    Hjek, Petr Pavel; Montesinos, V.

    2010-01-01

    Ro?. 177, ?. 1 (2010), s. 145-154. ISSN 0021-2172 R&D Projects: GA ?R GA201/07/0394 Institutional research plan: CEZ:AV0Z10190503 Keywords : M-basis * Banach spaces Subject RIV: BA - General Mathematics Impact factor: 0.630, year: 2010 http://link.springer.com/article/10.1007%2Fs11856-010-0041-x

  20. Malliavin calculus and decoupling inequalities in Banach spaces

    OpenAIRE

    Maas, Jan

    2008-01-01

    We develop a theory of Malliavin calculus for Banach space valued random variables. Using radonifying operators instead of symmetric tensor products we extend the Wiener-Ito isometry to Banach spaces. In the white noise case we obtain two sided L^p-estimates for multiple stochastic integrals in arbitrary Banach spaces. It is shown that the Malliavin derivative is bounded on vector-valued Wiener-Ito chaoses. Our main tools are decoupling inequalities for vector-valued random ...

  1. Metrizability of Cone Metric Spaces Via Renorming the Banach Spaces

    CERN Document Server

    Asadi, Mehdi; Soleiman, Hossein

    2011-01-01

    In this paper we show that by renorming an ordered Banach space, every cone P can be converted to a normal cone with constant K = 1 and consequently due to this approach every cone metric space is really a metric one and every theorem in metric space valid for cone metric space automatically.

  2. Introduction to Banach spaces and algebras

    CERN Document Server

    Allan, Graham

    2010-01-01

    Banach spaces and algebras are a key topic of pure mathematics. Graham Allan's careful and detailed introductory account will prove essential reading for anyone wishing to specialise in functional analysis and is aimed at final year undergraduates or masters level students. Based on the author's lectures to fourth year students at Cambridge University, the book assumes knowledge typical of first degrees in mathematics, including metric spaces, analytic topology, and complexanalysis. However, readers are not expected to be familiar with the Lebesgue theory of measure and integration.The text be

  3. Discretization of variational regularization in Banach spaces

    International Nuclear Information System (INIS)

    Consider a nonlinear ill-posed operator equation F(u) = y, where F is defined on a Banach space X. In this paper we analyze finite-dimensional variational regularization, which takes into account operator approximations and noisy data. As shown in the literature, depending on the setting, convergence of the regularized solutions of the finite-dimensional problems can be with respect to the strong or just a weak topology. In this paper our contribution is twofold. First, we derive convergence rates in terms of Bregman distances in the convex regularization setting under appropriate sourcewise representation of a solution of the equation. Secondly, for particular regularization realizations in nonseparable Banach spaces, we discuss the finite-dimensional approximations of the spaces and the type of convergence, which is needed for the convergence analysis. These considerations lay the fundament for efficient numerical implementation. In particular, we emphasize on the space X of finite total variation functions and analyze in detail the cases when X is the space of the functions of finite bounded deformation and the L?-space. The latter two settings are of interest in numerous problems arising in optimal control, machine learning and engineering

  4. A Strong Convergence Theorem for a Family of Quasi-?-Nonexpansive Mappings in a Banach Space

    Directory of Open Access Journals (Sweden)

    Haiyun Zhou

    2009-01-01

    Full Text Available The purpose of this paper is to propose a modified hybrid projection algorithm and prove a strong convergence theorem for a family of quasi-?-nonexpansive mappings. The strong convergence theorem is proven in the more general reflexive, strictly convex, and smooth Banach spaces with the property (K. The results of this paper improve and extend the results of S. Matsushita and W. Takahashi (2005, X. L. Qin and Y. F. Su (2007, and others.

  5. A Strong Convergence Theorem for a Family of Quasi- -Nonexpansive Mappings in a Banach Space

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    Gao Xinghui

    2009-01-01

    Full Text Available The purpose of this paper is to propose a modified hybrid projection algorithm and prove a strong convergence theorem for a family of quasi- -nonexpansive mappings. The strong convergence theorem is proven in the more general reflexive, strictly convex, and smooth Banach spaces with the property (K. The results of this paper improve and extend the results of S. Matsushita and W. Takahashi (2005, X. L. Qin and Y. F. Su (2007, and others.

  6. Unbounded operators on Banach spaces over the quaternion field

    OpenAIRE

    Ludkovsky, S. V

    2004-01-01

    Resolvents of quasi-linear operators and operator algebras in Banach spaces over the quaternion field are investigated. Spectral theory of unbounded nonlinear operators in quaternion Banach spaces is studied. Strongly continuous semigroups of quaternion quasi-linear operators are investigated and the polar decomposition theorem for them is proved.

  7. Stochastic evolution equations in UMD Banach spaces:

    OpenAIRE

    Van Neerven, J.M.A.M.; Veraar, M.C.; Weis, L

    2008-01-01

    We discuss existence, uniqueness, and space-time H\\"older regularity for solutions of the parabolic stochastic evolution equation dU(t) = (AU(t) + F(t,U(t))) dt + B(t,U(t)) dW_H(t), t\\in [0,\\Tend], U(0) = u_0, where $A$ generates an analytic $C_0$-semigroup on a UMD Banach space $E$ and $W_H$ is a cylindrical Brownian motion with values in a Hilbert space $H$. We prove that if the mappings $F:[0,T]\\times E\\to E$ and $B:[0,T]\\times E\\to \\mathscr{L}(H,E)$ satisfy suitable Lips...

  8. On the uniqueness of minimal projections in Banach spaces

    OpenAIRE

    Ewa Szlachtowska; Dominik Mielczarek

    2012-01-01

    Let \\(X\\) be a uniformly convex Banach space with a continuous semi-inner product. We investigate the relation of orthogonality in \\(X\\) and generalized projections acting on \\(X\\). We prove uniqueness of orthogonal and co-orthogonal projections.

  9. Fractional order semilinear Volterra integrodifferential equations in Banach spaces

    OpenAIRE

    Li, Kexue

    2014-01-01

    In this paper, sufficient conditions are established for the existence results of fractional order semilinear Volterra integrodifferential equations in Banach spaces. The results are obtained by using the theory of fractional cosine families and fractional powers of operators.

  10. Asymptotically convex Banach spaces and The Index of Rotundity Problem

    Scientific Electronic Library Online (English)

    Francisco J, Garca-Pacheco.

    2012-06-01

    Full Text Available The Index of Rotundity Problem asks whether a Banach space which admits equivalent renormings with index of rotundity as small as desired also admits an equivalent rotund renorming. In this paper we continue the ongoing search for a negative answer to this question by making use of a new concept: as [...] ymptotically convex Banach spaces. Some applications to The Approximation Hyperplane Series Property are given.

  11. Asymptotically convex Banach spaces and The Index of Rotundity Problem

    Directory of Open Access Journals (Sweden)

    Francisco J Garca-Pacheco

    2012-06-01

    Full Text Available The Index of Rotundity Problem asks whether a Banach space which admits equivalent renormings with index of rotundity as small as desired also admits an equivalent rotund renorming. In this paper we continue the ongoing search for a negative answer to this question by making use of a new concept: asymptotically convex Banach spaces. Some applications to The Approximation Hyperplane Series Property are given.

  12. Stochastic evolution equations in UMD Banach spaces

    CERN Document Server

    van Neerven, J M A M; Weis, L

    2008-01-01

    We discuss existence, uniqueness, and space-time H\\"older regularity for solutions of the parabolic stochastic evolution equation dU(t) = (AU(t) + F(t,U(t))) dt + B(t,U(t)) dW_H(t), t\\in [0,\\Tend], U(0) = u_0, where $A$ generates an analytic $C_0$-semigroup on a UMD Banach space $E$ and $W_H$ is a cylindrical Brownian motion with values in a Hilbert space $H$. We prove that if the mappings $F:[0,T]\\times E\\to E$ and $B:[0,T]\\times E\\to \\mathscr{L}(H,E)$ satisfy suitable Lipschitz conditions and $u_0$ is $\\F_0$-measurable and bounded, then this problem has a unique mild solution, which has trajectories in $C^\\l([0,T];\\D((-A)^\\theta)$ provided $\\lambda\\ge 0$ and $\\theta\\ge 0$ satisfy $\\l+\\theta<\\frac12$. Various extensions of this result are given and the results are applied to parabolic stochastic partial differential equations.

  13. Iterative Approximation to Convex Feasibility Problems in Banach Space

    Directory of Open Access Journals (Sweden)

    Shih-Sen Chang

    2007-04-01

    Full Text Available The convex feasibility problem (CFP of finding a point in the nonempty intersection ∩i=1NCi is considered, where N≥1 is an integer and each Ci is assumed to be the fixed point set of a nonexpansive mapping Ti:E→E, where E is a reflexive Banach space with a weakly sequentially continuous duality mapping. By using viscosity approximation methods for a finite family of nonexpansive mappings, it is shown that for any given contractive mapping f:C→C, where C is a nonempty closed convex subset of E and for any given x0∈C the iterative scheme xn+1=P[αn+1f(xn+(1−αn+1Tn+1xn] is strongly convergent to a solution of (CFP, if and only if {αn} and {xn} satisfy certain conditions, where αn∈(0,1,Tn=Tn(modN and P is a sunny nonexpansive retraction of E onto C. The results presented in the paper extend and improve some recent results in Xu (2004, O'Hara et al. (2003, Song and Chen (2006, Bauschke (1996, Browder (1967, Halpern (1967, Jung (2005, Lions (1977, Moudafi (2000, Reich (1980, Wittmann (1992, Reich (1994.

  14. Construction of generalized atomic decompositions in Banach spaces

    Directory of Open Access Journals (Sweden)

    Raj Kumar

    2014-06-01

    Full Text Available G-atomic decompositions for Banach spaces with respect to a model space of sequences have been introduced and studied as a generalization of atomic decompositions. Examples and counter example have been provided to show its existence. It has been proved that an associated Banach space for G-atomic decomposition always has a complemented subspace. The notion of a representation system is introduced and exhibits its relation with G-atomic decomposition. Also It has been observed that G-atomic decompositions are exactly compressions of Schauder decompositions for a larger Banach space. We give a characterization for finite G-atomic decomposition in terms of finite-dimensional expansion of identity. Keywords: complemented coefficient spaces, finite-dimensional expansion of identity, G-atomic decomposition, representation system.

  15. Tauberian theorems for generalized functions with values in Banach spaces

    International Nuclear Information System (INIS)

    We state and prove Tauberian theorems of a new type. In these theorems we give sufficient conditions under which the values of a generalized function (distribution) that are assumed to lie in a locally convex topological space actually belong to some narrower (Banach) space. These conditions are stated in terms of 'general class estimates' for the standard average of this generalized function with a fixed kernel belonging to a space of test functions. The applications of these theorems are based, in particular, on the fact that asymptotical (and some other) properties of the generalized functions under investigation can be described in terms of membership of certain Banach spaces. We apply these theorems to the study of asymptotic properties of solutions of the Cauchy problem for the heat equation in the class of generalized functions of small growth (tempered distributions), and to the study of Banach spaces of Besov-Nikol'skii type

  16. Metric embeddings bilipschitz and coarse embeddings into Banach spaces

    CERN Document Server

    Ostrovskii, Mikhail I

    2013-01-01

    Embeddings of discrete metric spaces into Banach spaces recently became an important tool in computer science and topology. The book will help readers to enter and to work in this very rapidly developing area having many important connections with different parts of mathematics and computer science. The purpose of the book is to present some of the most important techniques and results, mostly on bilipschitz and coarse embeddings. The topics include embeddability of locally finite metric spaces into Banach spaces is finitely determined, constructions of embeddings, distortion in terms of Poinc

  17. Banach's space: Lviv and the Scottish cafe

    OpenAIRE

    Henderson, D

    2004-01-01

    In a sense Stefan Banach is the patron saint of this workshop. He was one of the most prominent former residents of Lviv. His ``hangout'', the Scottish Cafe, is shown in the street scene that is the cover of the book of abstracts.

  18. Banach's space: Lviv and the Scottish cafe

    Directory of Open Access Journals (Sweden)

    D.Henderson

    2004-01-01

    Full Text Available In a sense Stefan Banach is the patron saint of this workshop. He was one of the most prominent former residents of Lviv. His ``hangout'', the Scottish Cafe, is shown in the street scene that is the cover of the book of abstracts.

  19. A *-Autonomous Category of Banach Spaces--Correction

    OpenAIRE

    Day, Brian

    2009-01-01

    We describe a $\\C$-linear additive *-autonomous category of Banach spaces. Please note that a correction has been appended to the original version 1 which is maintained here for reference. Also, a proposed example of a *-autonomous category of topological $\\C$-linear spaces has been added to version 2.

  20. Phillips' Lemma for L-embedded Banach spaces

    CERN Document Server

    Pfitzner, Hermann

    2010-01-01

    In this note the following version of Phillips' lemma is proved. The L-projection of an L-embedded space - that is of a Banach space which is complemented in its bidual such that the norm between the two complementary subspaces is additive - is weak-weakly sequentially continuous.

  1. An intermediate value theorem in ordered Banach spaces

    OpenAIRE

    Kostrykin, Vadim; Oleynik, Anna

    2012-01-01

    We consider a monotone increasing operator in an ordered Banach space having $u_-$ and $u_+$ as a strong super- and subsolution, respectively. In contrast with the well studied case $u_+ < u_-$, we suppose that $u_- < u_+$. Under the assumption that the order cone is normal and minihedral, we prove the existence of a fixed point located in the ordered interval $[u_-,u_+].$

  2. Absolute continuity of stable foliations for systems on Banach spaces

    Science.gov (United States)

    Lian, Zeng; Young, Lai-Sang; Zeng, Chongchun

    We prove the absolute continuity of stable foliations for C maps of Banach spaces satisfying a globally defined infinitesimal invariant cones condition. Proofs of regularity for center and stable manifolds needed for the main theorem are included. Our results are applicable to dynamical systems generated by ordinary, partial, or functional differential equations, including non-autonomous differential equations that are periodic in time.

  3. Weak compactness and sigma-Asplund generated Banach spaces.

    Czech Academy of Sciences Publication Activity Database

    Fabian, Marin; Montesinos, V.; Zizler, Vclav

    2007-01-01

    Ro?. 181, ?. 2 (2007), s. 125-152. ISSN 0039-3223 R&D Projects: GA AV ?R IAA1019301; GA AV ?R(CZ) IAA100190610 Institutional research plan: CEZ:AV0Z10190503 Keywords : epsilon-Asplund set * epsilon-weakly compact set * weakly compactly generated Banach space Subject RIV: BA - General Mathematics Impact factor: 0.568, year: 2007

  4. On polynomial equations in Banach space, perturbation techniques and applications

    Directory of Open Access Journals (Sweden)

    Ioannis K. Argyros

    1987-03-01

    Full Text Available We use perturbation techniques to solve the polynomial equation in Banach space. Our techniques provide more accurate information on the location of solutions and yield existence and uniqueness in cases not covered before. An example is given to justify our method.

  5. On some impulsive fractional differential equations in Banach spaces

    Directory of Open Access Journals (Sweden)

    JinRong Wang

    2010-01-01

    Full Text Available This paper deals with some impulsive fractional differential equations in Banach spaces. Utilizing the Leray-Schauder fixed point theorem and the impulsive nonlinear singular version of the Gronwall inequality, the existence of \\(PC\\-mild solutions for some fractional differential equations with impulses are obtained under some easily checked conditions. At last, an example is given for demonstration.

  6. Descent methods for convex optimization problems in Banach spaces

    Directory of Open Access Journals (Sweden)

    M. S. S. Ali

    2005-09-01

    Full Text Available We consider optimization problems in Banach spaces, whose cost functions are convex and smooth, but do not possess strengthened convexity properties. We propose a general class of iterative methods, which are based on combining descent and regularization approaches and provide strong convergence of iteration sequences to a solution of the initial problem.

  7. On nonlocal problems for fractional differential equations in Banach spaces

    Directory of Open Access Journals (Sweden)

    XiWang Dong

    2011-01-01

    Full Text Available In this paper, we study the existence and uniqueness of solutions to the nonlocal problems for the fractional differential equation in Banach spaces. New sufficient conditions for the existence and uniqueness of solutions are established by means of fractional calculus and fixed point method under some suitable conditions. Two examples are given to illustrate the results.

  8. Smooth approximations of norms in separable Banach spaces.

    Czech Academy of Sciences Publication Activity Database

    Hjek, Petr Pavel; Talponen, J.

    2014-01-01

    Ro?. 65, ?. 3 (2014), s. 957-969. ISSN 0033-5606 R&D Projects: GA ?R(CZ) GAP201/11/0345 Institutional support: RVO:67985840 Keywords : Banach space * approximation Subject RIV: BA - General Mathematics Impact factor: 0.593, year: 2013 http://qjmath.oxfordjournals.org/content/65/3/957

  9. On antichains of spreading models of Banach spaces

    CERN Document Server

    Dodos, Pandelis

    2008-01-01

    We show that for every separable Banach space $X$, either $\\spw(X)$ (the set of all spreading models of $X$ generated by weakly-null sequences in $X$, modulo equivalence) is countable, or $\\spw(X)$ contains an antichain of the size of the continuum. This answers a question of S. J. Dilworth, E. Odell and B. Sari.

  10. Fast regularizing sequential subspace optimization in Banach spaces

    International Nuclear Information System (INIS)

    We are concerned with fast computations of regularized solutions of linear operator equations in Banach spaces in case only noisy data are available. To this end we modify recently developed sequential subspace optimization methods in such a way that the therein employed Bregman projections onto hyperplanes are replaced by Bregman projections onto stripes whose width is in the order of the noise level

  11. Density of asemigroup in aBanach space

    International Nuclear Information System (INIS)

    We study conditions on aset M in aBanach spaceX which are necessary or sufficient for the setR(M) of all sums x1+?+xn, xk?M, to be dense inX. We distinguish conditions under which the closure R(M)-bar is an additive subgroup ofX, and conditions under which this additive subgroup is dense inX. In particular, we prove that ifM is aclosed rectifiable curve in auniformly convex and uniformly smooth Banach spaceX, and does not lie in aclosed half-space {x?X:f(x)?0}, f?X?, and is minimal in the sense that every proper subarc ofM lies in an open half-space {x?X:f(x)>0}, then R(M)-bar =X. We apply our results to questions of approximation in various function spaces

  12. Integral operators on the section space of a Banach bundle

    Directory of Open Access Journals (Sweden)

    D. A. Robbins

    1993-09-01

    Full Text Available Let π:E→X and ρ:F→X be bundles of Banach spaces, where X is a compact Hausdorff space, and let V be a Banach space. Let Γ(π denote the space of sections of the bundle π. We obtain two representations of integral operators T:Γ(π→V in terms of measures. The first generalizes a recent result of P. Saab, the second generalizes a theorem of Grothendieck. We also study integral operators T:Γ(π→Γ(ρ which are C(X-linear.

  13. Integrals and Banach spaces for finite order distributions

    CERN Document Server

    Talvila, Erik

    2011-01-01

    Let $\\Bc$ denote the real-valued functions continuous on the extended real line and vanishing at $-\\infty$. Let $\\Br$ denote the functions that are left continuous, have a right limit at each point and vanish at $-\\infty$. Define $\\acn$ to be the space of tempered distributions that are the $n$th distributional derivative of a unique function in $\\Bc$. Similarly with $\\arn$ from $\\Br$. A type of integral is defined on distributions in $\\acn$ and $\\arn$. The multipliers are iterated integrals of functions of bounded variation. For each $n\\in\\N$, the spaces $\\acn$ and $\\arn$ are Banach spaces, Banach lattices and Banach algebras isometrically isomorphic to $\\Bc$ and $\\Br$, respectively. Under the ordering in this lattice, if a distribution is integrable then its absolute value is integrable. The dual space is isometrically isomorphic to the functions of bounded variation. The space $\\ac^1$ is the completion of the $L^1$ functions in the Alexiewicz norm. The space $\\ar^1$ contains all finite signed Borel measure...

  14. Nonlinear Operator Ideals Between Metric Spaces and Banach Spaces (PART I)

    OpenAIRE

    Saleh, Manaf Adnan Saleh

    2015-01-01

    In this paper we present part I of nonlinear operator ideals theory between metric spaces and Banach spaces. Building upon the definition of operator ideal between arbitrary Banach spaces of A. Pietsch we pose three types of nonlinear versions of operator ideals. We introduce several examples of nonlinear ideals and the relationships between them. For every space ideal $\\mathsf{A}$ can be generated by a special nonlinear ideal which consists of those Lipschitz operators admi...

  15. Strong convergence of an iterative sequence for maximal monotone operators in a Banach space

    OpenAIRE

    Wataru Takahashi; Fumiaki Kohsaka

    2004-01-01

    We first introduce a modified proximal point algorithm for maximal monotone operators in a Banach space. Next, we obtain a strong convergence theorem for resolvents of maximal monotone operators in a Banach space which generalizes the previous result by Kamimura and Takahashi in a Hilbert space. Using this result, we deal with the convex minimization problem and the variational inequality problem in a Banach space.

  16. Strong convergence of an iterative sequence for maximal monotone operators in a Banach space

    Directory of Open Access Journals (Sweden)

    Wataru Takahashi

    2004-04-01

    Full Text Available We first introduce a modified proximal point algorithm for maximal monotone operators in a Banach space. Next, we obtain a strong convergence theorem for resolvents of maximal monotone operators in a Banach space which generalizes the previous result by Kamimura and Takahashi in a Hilbert space. Using this result, we deal with the convex minimization problem and the variational inequality problem in a Banach space.

  17. Geometric properties of Banach spaces and nonlinear iterations

    CERN Document Server

    Chidume, Charles

    2009-01-01

    Nonlinear functional analysis and applications is an area of study that has provided fascination for many mathematicians across the world. This monograph delves specifically into the topic of the geometric properties of Banach spaces and nonlinear iterations, a subject of extensive research over the past thirty years. Chapters 1 to 5 develop materials on convexity and smoothness of Banach spaces, associated moduli and connections with duality maps. Key results obtained are summarized at the end of each chapter for easy reference. Chapters 6 to 23 deal with an in-depth, comprehensive and up-to-date coverage of the main ideas, concepts and results on iterative algorithms for the approximation of fixed points of nonlinear nonexpansive and pseudo-contractive-type mappings. This includes detailed workings on solutions of variational inequality problems, solutions of Hammerstein integral equations, and common fixed points (and common zeros) of families of nonlinear mappings. Carefully referenced and full of recent,...

  18. Polynomial algebras and smooth functions in Banach spaces.

    Czech Academy of Sciences Publication Activity Database

    D'Alessandro, Stefania; Hjek, Petr Pavel

    2014-01-01

    Ro?. 266, ?. 3 (2014), s. 1627-1646. ISSN 0022-1236 R&D Projects: GA ?R(CZ) GAP201/11/0345; GA Mk(CZ) 7AMB12FR003 Institutional support: RVO:67985840 Keywords : polynomials in Banach space Subject RIV: BA - General Mathematics Impact factor: 1.152, year: 2013 http://www.sciencedirect.com/science/article/pii/S0022123613004588

  19. Approximating Fixed Points of Generalized Nonexpansive Mappings in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Bapurao C. Dhage

    2014-10-01

    Full Text Available In this paper, we prove a fixed point theorem for the selfmaps of a closed convex and bounded subset of the Banach space satisfying a generalized nonexpansive type condition. Some results concerning the approximations of fixed points with Krasnoselskii and Mann type iterations are also proved under suitable conditions. Our results include the well-known result of Kannan (1968 and Bose and Mukherjee (1981 as the special cases with a different and constructive method.

  20. Almost periodic solutions of differential equations in Banach spaces

    CERN Document Server

    Hino, Yoshiyuki; VanMinh, Nguyen; Shin, Jong Son

    2014-01-01

    This monograph presents recent developments in spectral conditions for the existence of periodic and almost periodic solutions of inhomogenous equations in Banach Spaces. Many of the results represent significant advances in this area. In particular, the authors systematically present a new approach based on the so-called evolution semigroups with an original decomposition technique. The book also extends classical techniques, such as fixed points and stability methods, to abstract functional differential equations with applications to partial functional differential equations. Almost Periodic

  1. Some problems on ordinary differential equations in Banach spaces.

    Czech Academy of Sciences Publication Activity Database

    Hjek, Petr Pavel; Vivi, P.

    2010-01-01

    Ro?. 104, ?. 2 (2010), s. 245-255. ISSN 1578-7303 R&D Projects: GA AV ?R IAA100190801; GA ?R GA201/07/0394 Institutional research plan: CEZ:AV0Z10190503 Keywords : Banach space * ODE * Peano's theorem Subject RIV: BA - General Mathematics Impact factor: 0.400, year: 2010 http://link.springer.com/article/10.5052%2FRACSAM.2010.16

  2. Geometry and Gteaux smoothness in separable Banach spaces.

    Czech Academy of Sciences Publication Activity Database

    Hjek, Petr Pavel; Montesinos, V.; Zizler, Vclav

    2012-01-01

    Ro?. 6, ?. 2 (2012), s. 201-232. ISSN 1846-3886 R&D Projects: GA ?R(CZ) GAP201/11/0345; GA AV ?R IAA100190901 Institutional research plan: CEZ:AV0Z10190503 Keywords : Gteaux differentiable norms * extreme points * Radon-Nikodm property Subject RIV: BA - General Math ematics Impact factor: 0.529, year: 2012 http://oam.ele- math .com/06-15/Geometry-and-Gateaux-smoothness-in-separable-Banach-spaces

  3. Bourgain-Delbaen $\\mathcal{L}^{\\infty}$-sums of Banach spaces

    OpenAIRE

    Zisimopoulou, Despoina

    2014-01-01

    Motivated by a problem stated by S.A.Argyros and Th. Raikoftsalis, we introduce a new class of Banach spaces. Namely, for a sequence of separable Banach spaces $(X_n,\\|\\cdot\\|_n)_{n\\in\\mathbb{N}}$, we define the Bourgain Delbaen $\\mathcal{L}^{\\infty}$-sum of the sequence $(X_n,\\|\\cdot\\|_n)_{n\\in\\mathbb{N}}$ which is a Banach space $\\mathcal{Z}$ constructed with the Bourgain-Delbaen method. In particular, for every $1\\leq p

  4. Weak polynomial topology and weak analytic topology on Banach spaces and on Freshet spaces

    OpenAIRE

    Zagorodnyuk A.V.; Mytrofanov M.A.

    2012-01-01

    We investigate under which conditions weak polynomial or weakanalytic topology ($*$-weak polynomial or $*$-weak analytictopology) coincides whith the norm topology on a real (complex)Banach or Freshet space.

  5. A proximal point method for nonsmooth convex optimization problems in Banach spaces

    Directory of Open Access Journals (Sweden)

    Y. I. Alber

    1997-01-01

    Full Text Available In this paper we show the weak convergence and stability of the proximal point method when applied to the constrained convex optimization problem in uniformly convex and uniformly smooth Banach spaces. In addition, we establish a nonasymptotic estimate of convergence rate of the sequence of functional values for the unconstrained case. This estimate depends on a geometric characteristic of the dual Banach space, namely its modulus of convexity. We apply a new technique which includes Banach space geometry, estimates of duality mappings, nonstandard Lyapunov functionals and generalized projection operators in Banach spaces.

  6. Weak and strong convergence theorems for relatively nonexpansive mappings in Banach spaces

    Directory of Open Access Journals (Sweden)

    Matsushita Shin-ya

    2004-01-01

    Full Text Available We first introduce an iterative sequence for finding fixed points of relatively nonexpansive mappings in Banach spaces, and then prove weak and strong convergence theorems by using the notion of generalized projection. We apply these results to the convex feasibility problem and a proximal-type algorithm for monotone operators in Banach spaces.

  7. Weak and strong convergence theorems for relatively nonexpansive mappings in Banach spaces

    Directory of Open Access Journals (Sweden)

    Wataru Takahashi

    2004-03-01

    Full Text Available We first introduce an iterative sequence for finding fixed points of relatively nonexpansive mappings in Banach spaces, and then prove weak and strong convergence theorems by using the notion of generalized projection. We apply these results to the convex feasibility problem and a proximal-type algorithm for monotone operators in Banach spaces.

  8. Weak and strong convergence theorems for relatively nonexpansive mappings in Banach spaces

    OpenAIRE

    Matsushita Shin-ya; Takahashi Wataru

    2004-01-01

    We first introduce an iterative sequence for finding fixed points of relatively nonexpansive mappings in Banach spaces, and then prove weak and strong convergence theorems by using the notion of generalized projection. We apply these results to the convex feasibility problem and a proximal-type algorithm for monotone operators in Banach spaces.

  9. On some existence results of mild solutions for nonlocal integrodifferential Cauchy problems in Banach spaces

    Directory of Open Access Journals (Sweden)

    YanLong Yang

    2011-01-01

    Full Text Available In this paper, we study a class of integrodifferential evolution equations with nonlocal initial conditions in Banach spaces. Existence results of mild solutions are proved for a class of integrodifferential evolution equations with nonlocal initial conditions in Banach spaces. The main results are obtained by using the Schaefer fixed point theorem and semigroup theory. Finally, an example is given for demonstration.

  10. Multiple Positive Solutions for Nonlinear Third-Order Boundary Value Problems in Banach Spaces

    OpenAIRE

    Wang, Feng

    2009-01-01

    This paper deals with the positive solutions of nonlinear boundary value problems in Banach spaces. By using fixed point index theory, some sufficient conditions for the existence of at least one or two positive solutions to boundary value problems in Banach spaces are obtained. An example illustrating the main results is given.

  11. Differentiability of quasiconvex functions on separable Banach spaces

    OpenAIRE

    Patrick J. Rabier

    2013-01-01

    We investigate the differentiability properties of real-valued quasiconvex functions f defined on a separable Banach space X. Continuity is only assumed to hold at the points of a dense subset. If so, this subset is automatically residual. Sample results that can be quoted without involving any new concept or nomenclature are as follows: (i) If f is usc or strictly quasiconvex, then f is Hadamard differentiable at the points of a dense subset of X (ii) If f is even, then f i...

  12. Generation theory for semigroups of holomorphic mappings in Banach spaces

    Directory of Open Access Journals (Sweden)

    Simeon Reich

    1996-01-01

    Full Text Available We study nonlinear semigroups of holomorphic mappings in Banach spaces and their infinitesimal generators. Using resolvents, we characterize, in particular, bounded holomorphic generators on bounded convex domains and obtain an analog of the Hille exponential formula. We then apply our results to the null point theory of semi-plus complete vector fields. We study the structure of null point sets and the spectral characteristics of null points, as well as their existence and uniqueness. A global version of the implicit function theorem and a discussion of some open problems are also included.

  13. Iterative solutions of nonlinear equations in smooth Banach spaces

    International Nuclear Information System (INIS)

    Let E be a smooth Banach space over the real field, ? not= K is contained in E closed convex and bounded, T:K ? K uniformly continuous and strongly pseudo-contractive. It is proved that the Ishikawa iteration process converges strongly to the unique fixed point of T. Applications of this result to the operator equations Au=f or u+Au=f where A is a strongly accretive mapping of E into itself and under various continuity assumptions on A are also given. (author). 41 refs

  14. p-adic Banach space operators and adelic Banach space operators

    Directory of Open Access Journals (Sweden)

    Ilwoo Cho

    2014-01-01

    Full Text Available In this paper, we study non-Archimedean Banach \\(*\\-algebras \\(\\frak{M}_{p}\\ over the \\(p\\-adic number fields \\(\\mathbb{Q}_{p}\\, and \\(\\frak{M}_{\\mathbb{Q}}\\ over the adele ring \\(\\mathbb{A}_{\\mathbb{Q}}\\. We call elements of \\(\\frak{M}_{p}\\, \\(p\\-adic operators, for all primes \\(p\\, respectively, call those of \\(\\frak{M}_{\\mathbb{Q}}\\, adelic operators. We characterize \\(\\frak{M}_{ \\mathbb{Q}}\\ in terms of \\(\\frak{M}_{p}\\'s. Based on such a structure theorem of \\(\\frak{M}_{\\mathbb{Q}}\\, we introduce some interesting \\(p\\-adic operators and adelic operators.

  15. Smoothness in Banach spaces. Selected problems.

    Czech Academy of Sciences Publication Activity Database

    Fabian, Marin; Montesinos, V.; Zizler, Vclav

    2006-01-01

    Ro?. 100, ?. 2 (2006), s. 101-125. ISSN 1578-7303 R&D Projects: GA ?R(CZ) GA201/04/0090; GA AV ?R(CZ) IAA100190610 Institutional research plan: CEZ:AV0Z10190503 Keywords : smooth norm * renorming * weakly compactly generated space Subject RIV: BA - General Mathematics

  16. Banach's and Kannan's fixed point results in fuzzy 2-metric spaces

    Scientific Electronic Library Online (English)

    Binod, Chandra Tripathy; Paul, Sudipta; Ram Das, Nanda.

    2013-12-01

    Full Text Available In this paper we establish two common fixed point theorems in fuzzy 2- metric spaces. These theorems are generalizations of the Banach Contraction mapping principle and the Kannan's fixed point theorem respectively in fuzzy 2-metric spaces. [...

  17. Weak convergence of an iterative sequence for accretive operators in Banach spaces

    OpenAIRE

    Iiduka Hideaki; Takahashi Wataru; Aoyama Koji

    2006-01-01

    Let be a nonempty closed convex subset of a smooth Banach space and let be an accretive operator of into . We first introduce the problem of finding a point such that where is the duality mapping of . Next we study a weak convergence theorem for accretive operators in Banach spaces. This theorem extends the result by Gol'shte?n and Tret'yakov in the Euclidean space to a Banach space. And using our theorem, we consider the problem of finding a fixed point of a strictly pseudocontr...

  18. Stochastic integration in Banach spaces theory and applications

    CERN Document Server

    Mandrekar, Vidyadhar

    2015-01-01

    Considering Poisson random measures as the driving sources for stochastic (partial) differential equations allows us to incorporate jumps and to model sudden, unexpected phenomena. By using such equations the present book introduces a new method for modeling the states of complex systems perturbed by random sources over time, such as interest rates in financial markets or temperature distributions in a specific region. It studies properties of the solutions of the stochastic equations, observing the long-term behavior and the sensitivity of the solutions to changes in the initial data. The authors consider an integration theory of measurable and adapted processes in appropriate Banach spaces as well as the non-Gaussian case, whereas most of the literature only focuses on predictable settings in Hilbert spaces. The book is intended for graduate students and researchers in stochastic (partial) differential equations, mathematical finance and non-linear filtering and assumes a knowledge of the required integrati...

  19. Restrictive metric regularity and generalized differential calculus in Banach spaces

    Directory of Open Access Journals (Sweden)

    Bingwu Wang

    2004-10-01

    Full Text Available We consider nonlinear mappings f:X→Y between Banach spaces and study the notion of restrictive metric regularity of f around some point x¯, that is, metric regularity of f from X into the metric space E=f(X. Some sufficient as well as necessary and sufficient conditions for restrictive metric regularity are obtained, which particularly include an extension of the classical Lyusternik-Graves theorem in the case when f is strictly differentiable at x¯ but its strict derivative ∇f(x¯ is not surjective. We develop applications of the results obtained and some other techniques in variational analysis to generalized differential calculus involving normal cones to nonsmooth and nonconvex sets, coderivatives of set-valued mappings, as well as first-order and second-order subdifferentials of extended real-valued functions.

  20. Perturbation of n dimensional AQ - mixed type functional equation via Banach spaces and Banach algebra : Hyers direct and alternative fixed point methods

    Directory of Open Access Journals (Sweden)

    M. Arunkumar

    2013-12-01

    Full Text Available In this paper, the authors obtain the general solution and generalized Ulam - Hyers stability of n dimensional additive quadratic functional equation in Banach spaces using direct and fixed point methods. We also investigate the stability of the above equation in Banach algebra using direct and fixed point approach.

  1. Porous sets for mutually nearest points in Banach spaces

    Directory of Open Access Journals (Sweden)

    Chong Li

    2008-01-01

    Full Text Available Let $B(X$ denote the family of all nonempty closed bounded subsets of a real Banach space $X$, endowed with the Hausdorff metric. For $E, F \\in B(X$ we set $\\lambda _{EF} = inf \\{\\|z - x\\| : x \\in E, z \\in F \\}$. Let $D$ denote the closure (under the maximum distance of the set of all $(E, F \\in B(X \\times B(X$ such that $\\lambda {EF} > 0$. It is proved that the set of all $(E, F \\in D $ for which the minimization problem $min_{x \\in E, z\\in F}\\|x - z\\|$ fails to be well posed in a $\\sigma$-porous subset of $D$.

  2. Multidimensional Tauberian theorems for Banach-space valued generalized functions

    International Nuclear Information System (INIS)

    Multidimensional Tauberian theorems for the standard averages of tempered Banach-space valued distributions are stated and proved. These results enable one to determine from the asymptotic behaviour of the averages the asymptotic behaviour of the generalized function itself. The role of the asymptotic scale in these results is performed by the class of regularly varying functions. Special attention is paid to averaging kernels such that several of their moments or linear combinations of moments vanish. Important in these results is the structure of the zero set of the Fourier transformations of the kernels in question. The results so established are applied to the study of the asymptotic properties of solutions of the Cauchy problem for the heat equation in the class of tempered distributions, to the problem of the diffusion of a many-component gas, and to the problem of the absence of the phenomenon of compensation of singularities for holomorphic functions in tube domains over acute cones

  3. Iterative schemes with some control conditions for a family of finite nonexpansive mappings in Banach spaces

    Directory of Open Access Journals (Sweden)

    R. P. Agarwal

    2005-06-01

    Full Text Available The iterative schemes with some control conditions for a family of finite nonexpansive mappings are established in a Banach space. The main theorem improves results of Jung and Kim (also Bauschke. Our results also improve the corresponding results of Cho et al., Shioji and Takahashi, Xu, and Zhou et al. in certain Banach spaces and of Lions, O'Hara et al., and Wittmann in a framework of a Hilbert space, respectively.

  4. Vector-valued Reproducing Kernel Banach Spaces with Applications to Multi-task Learning

    CERN Document Server

    Zhang, Haizhang

    2011-01-01

    Motivated by multi-task machine learning with Banach spaces, we propose the notion of vector-valued reproducing kernel Banach spaces (RKBS). Basic properties of the spaces and the associated reproducing kernels are investigated. We also present feature map constructions and several concrete examples of vector-valued RKBS. The theory is then applied to multi-task machine learning. Especially, the representer theorem and characterization equations for the minimizer of regularized learning schemes in vector-valued RKBS are established.

  5. Characterization of the absolutely summing operators in a Banach space using ?-approximate l_1 sequences

    Directory of Open Access Journals (Sweden)

    N. L. Braha

    2005-05-01

    Full Text Available In this paper we will give a characterization of 1-absolutely summing operators using ?-approximate l_1 sequences. Exactly if (x_n _1^? is ?-approximate l_1 , basic and normalized sequence in Banach space X then every bounded linear operator T from X into Banach space Y is 1-absolutely summing if and only if Y is isomorphic to Hilbert space.

  6. Greedy Algorithms for Reduced Bases in Banach Spaces

    CERN Document Server

    DeVore, Ronald; Wojtaszczyk, Przemyslaw

    2012-01-01

    Given a Banach space X and one of its compact sets F, we consider the problem of finding a good n dimensional space X_n \\subset X which can be used to approximate the elements of F. The best possible error we can achieve for such an approximation is given by the Kolmogorov width d_n(F)_X. However, finding the space which gives this performance is typically numerically intractable. Recently, a new greedy strategy for obtaining good spaces was given in the context of the reduced basis method for solving a parametric family of PDEs. The performance of this greedy algorithm was initially analyzed in A. Buffa, Y. Maday, A.T. Patera, C. Prud'homme, and G. Turinici, "A Priori convergence of the greedy algorithm for the parameterized reduced basis", M2AN Math. Model. Numer. Anal., 46(2012), 595-603 in the case X = H is a Hilbert space. The results there were significantly improved on in P. Binev, A. Cohen, W. Dahmen, R. DeVore, G. Petrova, and P. Wojtaszczyk, "Convergence rates for greedy algorithms in reduced bases ...

  7. Approximating zero points of accretive operators with compact domains in general Banach spaces

    Directory of Open Access Journals (Sweden)

    Miyake Hiromichi

    2005-01-01

    Full Text Available We prove strong convergence theorems of Mann's type and Halpern's type for resolvents of accretive operators with compact domains and apply these results to find fixed points of nonexpansive mappings in Banach spaces.

  8. Nonsmooth and nonlocal differential equations in lattice-ordered Banach spaces

    Directory of Open Access Journals (Sweden)

    S. Heikkil

    2005-06-01

    Full Text Available We derive existence results for initial and boundary value problems in lattice-ordered Banach spaces. The considered problems can be singular, functional, discontinuous, and nonlocal. Concrete examples are also solved.

  9. Existence of solutions for semilinear nonlocal Cauchy problems in Banach spaces

    Directory of Open Access Journals (Sweden)

    Xingmei Xue

    2005-06-01

    Full Text Available In this paper, we study a semilinear differential equations with nonlocal initial conditions in Banach spaces. We derive conditions for $f$, $T(t$, and $g$ for the existence of mild solutions.

  10. Approximating zero points of accretive operators with compact domains in general Banach spaces

    OpenAIRE

    Wataru Takahashi; Hiromichi Miyake

    2005-01-01

    We prove strong convergence theorems of Mann's type and Halpern's type for resolvents of accretive operators with compact domains and apply these results to find fixed points of nonexpansive mappings in Banach spaces.

  11. Solutions to Fractional Differential Equations with Nonlocal Initial Condition in Banach Spaces

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    Jin Liang

    2010-01-01

    Full Text Available A new existence and uniqueness theorem is given for solutions to differential equations involving the Caputo fractional derivative with nonlocal initial condition in Banach spaces. An application is also given.

  12. Existence and uniqueness of solutions for the fractional integro-differential equations in Banach spaces

    OpenAIRE

    Yicheng Liu; Jun Wu

    2009-01-01

    In this article, we established the existence and uniqueness of solutions for fractional integro-differential equations with nonlocal conditions in Banach spaces. Krasnoselskii-Krein-type conditions are used for obtaining the main result.

  13. Right-Existence and Left?Existence of Orthogonality in Quasi?Banach Spaces

    Directory of Open Access Journals (Sweden)

    XUE Jian-ming

    2012-09-01

    Full Text Available A class of new generalized orthogonality of quasi?Banach spaces is given in this paper. It is a generalization of orthogonality. First, the relation of orthogonality and linear functional are introduced. At the same time, a necessary and sufficient condition of orthogonality in quasi?Banach spaces is given. Namely, let ?X? be a quasi?Banach spaces on * is equivalent to ?x?H?. The sufficient conditions of right?existence and left?existence of orthogonality are discussed. Finally, two examples which show that right?existence of orthogonality in quasi?Banach spaces does not exist for all elements are given.(* Indicates a formula, please see the full text

  14. Controllability of impulsive neutral functional differential inclusions with infinite delay in Banach spaces

    International Nuclear Information System (INIS)

    In this work, we establish a sufficient condition for the controllability of the first-order impulsive neutral functional differential inclusions with infinite delay in Banach spaces. The results are obtained by using the Dhage's fixed point theorem.

  15. Ishikawa iterative sequence with errors for strongly pseudocontractive operators in arbitrary Banach spaces

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    Yongjin Li

    2004-07-01

    Full Text Available The Ishikawa iterative sequences with errors are studied for Lipschitzian strongly pseudocontractive operators in arbitrary real Banach spaces; some well-known results of Chidume (1998 and Zeng (2001 are generalized.

  16. Ishikawa iteration process with errors for nonexpansive mappings in uniformly convex Banach spaces

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    Li Shenghong

    2000-07-01

    Full Text Available We shall consider the behaviour of Ishikawa iteration with errors in a uniformly convex Banach space. Then we generalize the two theorems of Tan and Xu without the restrictions that C is bounded and limsupnsn<1.

  17. Ishikawa iterative sequence with errors for strongly pseudocontractive operators in arbitrary Banach spaces

    OpenAIRE

    Yongjin Li

    2004-01-01

    The Ishikawa iterative sequences with errors are studied for Lipschitzian strongly pseudocontractive operators in arbitrary real Banach spaces; some well-known results of Chidume (1998) and Zeng (2001) are generalized.

  18. Ishikawa iteration process with errors for nonexpansive mappings in uniformly convex Banach spaces

    OpenAIRE

    Li Shenghong; Deng Lei

    2000-01-01

    We shall consider the behaviour of Ishikawa iteration with errors in a uniformly convex Banach space. Then we generalize the two theorems of Tan and Xu without the restrictions that C is bounded and limsupnsn

  19. Operator self-similar processes on Banach spaces

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Operator self-similar (OSS stochastic processes on arbitrary Banach spaces are considered. If the family of expectations of such a process is a spanning subset of the space, it is proved that the scaling family of operators of the process under consideration is a uniquely determined multiplicative group of operators. If the expectation-function of the process is continuous, it is proved that the expectations of the process have power-growth with exponent greater than or equal to 0 , that is, their norm is less than a nonnegative constant times such a power-function, provided that the linear space spanned by the expectations has category 2 (in the sense of Baire in its closure. It is shown that OSS processes whose expectation-function is differentiable on an interval ( s 0 ,? , for some s 0 ?1 , have a unique scaling family of operators of the form { s H :s>0 } , if the expectations of the process span a dense linear subspace of category 2 . The existence of a scaling family of the form { s H :s>0 } is proved for proper Hilbert space OSS processes with an Abelian scaling family of positive operators.

  20. Operator self-similar processes on Banach spaces

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    Valentin Matache

    2006-05-01

    Full Text Available Operator self-similar (OSS stochastic processes on arbitrary Banach spaces are considered. If the family of expectations of such a process is a spanning subset of the space, it is proved that the scaling family of operators of the process under consideration is a uniquely determined multiplicative group of operators. If the expectation-function of the process is continuous, it is proved that the expectations of the process have power-growth with exponent greater than or equal to 0, that is, their norm is less than a nonnegative constant times such a power-function, provided that the linear space spanned by the expectations has category 2 (in the sense of Baire in its closure. It is shown that OSS processes whose expectation-function is differentiable on an interval (s0,∞, for some s0≥1, have a unique scaling family of operators of the form {sH:s>0}, if the expectations of the process span a dense linear subspace of category 2. The existence of a scaling family of the form {sH:s>0} is proved for proper Hilbert space OSS processes with an Abelian scaling family of positive operators.

  1. Estimates of disjoint sequences in Banach lattices and R.I. function spaces

    CERN Document Server

    Gonzalo, R

    2004-01-01

    We introduce UDSp-property (resp. UDTq-property) in Banach lattices as the property that every normalized disjoint sequence has a subsequence with an upper p-estimate (resp. lower q-estimate). In the case of rearrangement invariant spaces, the relationships with Boyd indices of the space are studied. Some applications of these properties are given to the high order smoothness of Banach lattices, in the sense of the existence of differentiable bump functions.

  2. Approximation of Common Fixed Points for Families of Mappings in Banach Space

    OpenAIRE

    Zhiming Cheng

    2012-01-01

    In this paper. We introduce a general iterative method for the family of mappings and prove the strong convergence of the new iterative scheme in Banach space. The new iterative method includes the iterative scheme of Khan and Domlo and Fukhar-ud-din [Common fixed points Noor iteration for a finite family of asymptotically quasi-nonexpansive mappings in Banach spaces. J. Math. Anal. Appl. 341 (2008) 111]. The results generalize the corresponding results.

  3. Stochastic Differential Equations in Banach Spaces: Decoupling, Delay Equations, and Approximations in Space and Time:

    OpenAIRE

    Cox, S.G.

    2012-01-01

    The thesis deals with various aspects of the study of stochastic partial differential equations driven by Gaussian noise. The approach taken is functional analytic rather than probabilistic: the stochastic partial differential equation is interpreted as an ordinary stochastic differential equation in a Banach space. The major part of the thesis deals with approximations of solutions to semi-linear stochastic differential equations. We consider discretizations both in time and in space. We...

  4. Space charge equation calculations for the reflex triode

    International Nuclear Information System (INIS)

    The Poisson equation solution of the space charge problem for the reflex triode is reviewed and illustrated with a number of examples. The numerical calculation technique for obtaining these results is briefly described. The results show that the characteristics of the triode are strong functions of the reflex-electron kinetic-energy spectrum, especially of the high-energy electrons

  5. Recognizing the topology of the space of closed convex subsets of a Banach space

    OpenAIRE

    Banakh, Taras; Hetman, Ivan; Sakai, Katsuro

    2011-01-01

    Let $X$ be a Banach space and $Conv_H(X)$ be the space of non-empty closed convex subsets of $X$, endowed with the Hausdorff metric $d_H$. We prove that each connected component of the space $Conv_H(X)$ is homeomorphic to one of the spaces: a singleton, the real line, a closed half-plane, the Hilbert cube multiplied by the half-line, the separable Hilbert space, or a Hilbert space of density not less than continuum.

  6. Nonlinear Integrodifferential Equations of Mixed Type in Banach Spaces

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    Grzegorz Nowak

    2007-09-01

    Full Text Available We prove two existence theorems for the integrodifferential equation of mixed type: x'(t=f(t,x(t,∫0tk1(t,sg(s,x(sds,∫0ak2(t,sh(s,x(sds, x(0=x0, where in the first part of this paper f, g, h, x are functions with values in a Banach space E and integrals are taken in the sense of Henstock-Kurzweil (HK. In the second part f, g, h, x are weakly-weakly sequentially continuous functions and integrals are taken in the sense of Henstock-Kurzweil-Pettis (HKP integral. Additionally, the functions f, g, h, x satisfy some conditions expressed in terms of the measure of noncompactness or the measure of weak noncompactness.

  7. Algorithm for Solving a Generalized Mixed Equilibrium Problem with Perturbation in a Banach Space

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    Kum Sangho

    2010-01-01

    Full Text Available Let be a real Banach space with the dual space . Let be a proper functional and let be a bifunction. In this paper, a new concept of -proximal mapping of with respect to is introduced. The existence and Lipschitz continuity of the -proximal mapping of with respect to are proved. By using properties of the -proximal mapping of with respect to , a generalized mixed equilibrium problem with perturbation (for short, GMEPP is introduced and studied in Banach space . An existence theorem of solutions of the GMEPP is established and a new iterative algorithm for computing approximate solutions of the GMEPP is suggested. The strong convergence criteria of the iterative sequence generated by the new algorithm are established in a uniformly smooth Banach space , and the weak convergence criteria of the iterative sequence generated by this new algorithm are also derived in a Hilbert space.

  8. Algorithm for Solving a Generalized Mixed Equilibrium Problem with Perturbation in a Banach Space

    Directory of Open Access Journals (Sweden)

    Jen-Chih Yao

    2010-01-01

    Full Text Available Let B be a real Banach space with the dual space B*. Let ?:B?R?{+?} be a proper functional and let ?:BB?R be a bifunction. In this paper, a new concept of ?-proximal mapping of ? with respect to ? is introduced. The existence and Lipschitz continuity of the ?-proximal mapping of ? with respect to ? are proved. By using properties of the ?-proximal mapping of ? with respect to ?, a generalized mixed equilibrium problem with perturbation (for short, GMEPP is introduced and studied in Banach space B. An existence theorem of solutions of the GMEPP is established and a new iterative algorithm for computing approximate solutions of the GMEPP is suggested. The strong convergence criteria of the iterative sequence generated by the new algorithm are established in a uniformly smooth Banach space B, and the weak convergence criteria of the iterative sequence generated by this new algorithm are also derived in B=H a Hilbert space.

  9. Accretive operators and Banach Alaoglu theorem in Linear 2-normed spaces

    Directory of Open Access Journals (Sweden)

    P. K Harikrishnan

    2011-12-01

    Full Text Available In this paper we introduce the concept of accretive operator in linear 2-normed spaces, focusing on the relationships and the various aspects of accretive, m-accretive and maximal accretive operators. We prove the analogous of Banach-Alaoglu theorem in linear 2- normed spaces, obtaining an equivalent definition for accretive operators in linear 2-normed spaces.

  10. Some results about the Schroeder-Bernstein Property for separable Banach spaces

    OpenAIRE

    Ferenczi, Valentin; Galego, Eloi Medina

    2004-01-01

    We construct a continuum of mutually non-isomorphic separable Banach spaces which are complemented in each other. Consequently, the Schroeder-Bernstein Index of any of these spaces is $2^{\\aleph_0}$. Our construction is based on a Banach space introduced by W. T. Gowers and B. Maurey in 1997. We also use classical descriptive set theory methods, as in some work of V. Ferenczi and C. Rosendal, to improve some results of P. G. Casazza and of N. J. Kalton on the Schroeder-Berns...

  11. Nonstationary iterated Tikhonov regularization for ill-posed problems in Banach spaces

    International Nuclear Information System (INIS)

    Nonstationary iterated Tikhonov regularization is an efficient method for solving ill-posed problems in Hilbert spaces. However, this method may not produce good results in some situations since it tends to oversmooth solutions and hence destroy special features such as sparsity and discontinuity. By making use of duality mappings and Bregman distance, we propose an extension of this method to the Banach space setting and establish its convergence. We also present numerical simulations which indicate that the method in Banach space setting can produce better results. (paper)

  12. Solving linear operator equations in Banach spaces non-iteratively by the method of approximate inverse

    International Nuclear Information System (INIS)

    The method of approximate inverse is a mollification method for stably solving inverse problems. In its original form it has been developed to solve operator equations in L2-spaces and general Hilbert spaces. We show that the method of approximate inverse can be extended to solve linear, ill-posed problems in Banach spaces. This paper is restricted to function spaces. The method itself consists of evaluations of dual pairings of the given data with reconstruction kernels that are associated with mollifiers and the dual of the operator. We first define what we mean by a mollifier in general Banach spaces and then investigate two settings more exactly: the case of Lp-spaces and the case of the Banach space of continuous functions on a compact set. For both settings we present the criteria turning the method of approximate inverse into a regularization method and prove convergence with rates. As an application we refer to x-ray diffractometry which is a technique of non-destructive testing that is concerned with computing the stress tensor of a specimen. Since one knows that the stress tensor is smooth, x-ray diffractometry can appropriately be modelled by a Banach space setting using continuous functions

  13. Periodic and almost periodic solutions for multi-valued differential equations in Banach spaces

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    E. Hanebaly

    2000-03-01

    Full Text Available It is known that for $omega$-periodic differential equations of monotonous type, in uniformly convex Banach spaces, the existence of a bounded solution on ${Bbb R}^+$ is equivalent to the existence of an omega-periodic solution (see Haraux [5] and Hanebaly [7, 10]. It is also known that if the Banach space is strictly convex and the equation is almost periodic and of monotonous type, then the existence of a continuous solution with a precompact range is equivalent to the existence of an almost periodic solution (see Hanebaly [8]. In this note we want to generalize the results above for multi-valued differential equations.

  14. Iterative approximation of a solution of a general variational-like inclusion in Banach spaces

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    H. Zegeye

    2004-05-01

    Full Text Available We introduce a class of η-accretive mappings in a real Banach space and show that the η-proximal point mapping for η-m-accretive mapping is Lipschitz continuous. Further, we develop an iterative algorithm for a class of general variational-like inclusions involving η-accretive mappings in real Banach space, and discuss its convergence criteria. The class of η-accretive mappings includes several important classes of operators that have been studied by various authors.

  15. Block Iterative Methods for a Finite Family of Relatively Nonexpansive Mappings in Banach Spaces

    OpenAIRE

    Fumiaki Kohsaka; Wataru Takahashi

    2007-01-01

    Using the convex combination based on Bregman distances due to Censor and Reich, we define an operator from a given family of relatively nonexpansive mappings in a Banach space. We first prove that the fixed-point set of this operator is identical to the set of all common fixed points of the mappings. Next, using this operator, we construct an iterative sequence to approximate common fixed points of the family. We finally apply our results to a convex feasibility problem in Banach spaces.

  16. Block Iterative Methods for a Finite Family of Relatively Nonexpansive Mappings in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Fumiaki Kohsaka

    2007-01-01

    Full Text Available Using the convex combination based on Bregman distances due to Censor and Reich, we define an operator from a given family of relatively nonexpansive mappings in a Banach space. We first prove that the fixed-point set of this operator is identical to the set of all common fixed points of the mappings. Next, using this operator, we construct an iterative sequence to approximate common fixed points of the family. We finally apply our results to a convex feasibility problem in Banach spaces.

  17. The approximate inverse in action: IV. Semi-discrete equations in a Banach space setting

    Science.gov (United States)

    Schuster, T.; Rieder, A.; Schpfer, F.

    2012-10-01

    This article concerns the method of approximate inverse to solve semi-discrete, linear operator equations in Banach spaces. Semi-discrete means that we search for a solution in an infinite-dimensional Banach space having only a finite number of data available. In this sense the situation is applicable to a large variety of applications where a measurement process delivers a discretization of an infinite-dimensional data space. The method of approximate inverse computes scalar products of the data with pre-computed reconstruction kernels which are associated with mollifiers and the dual of the model operator. The convergence, approximation power and regularization property of this method when applied to semi-discrete operator equations in Hilbert spaces has been investigated in three prequels to this paper. Here we extend these results to a Banach space setting. We prove convergence and stability for general Banach spaces and reproduce the results specifically for the integration operator acting on the space of continuous functions.

  18. The approximate inverse in action: IV. Semi-discrete equations in a Banach space setting

    International Nuclear Information System (INIS)

    This article concerns the method of approximate inverse to solve semi-discrete, linear operator equations in Banach spaces. Semi-discrete means that we search for a solution in an infinite-dimensional Banach space having only a finite number of data available. In this sense the situation is applicable to a large variety of applications where a measurement process delivers a discretization of an infinite-dimensional data space. The method of approximate inverse computes scalar products of the data with pre-computed reconstruction kernels which are associated with mollifiers and the dual of the model operator. The convergence, approximation power and regularization property of this method when applied to semi-discrete operator equations in Hilbert spaces has been investigated in three prequels to this paper. Here we extend these results to a Banach space setting. We prove convergence and stability for general Banach spaces and reproduce the results specifically for the integration operator acting on the space of continuous functions. (paper)

  19. ℂ-convexity in infinite-dimensional Banach spaces and applications to Kergin interpolation

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    Lars Filipsson

    2006-07-01

    Full Text Available We investigate the concepts of linear convexity and ℂ-convexity in complex Banach spaces. The main result is that any ℂ-convex domain is necessarily linearly convex. This is a complex version of the Hahn-Banach theorem, since it means the following: given a ℂ-convex domain Ω in the Banach space X and a point p∉Ω, there is a complex hyperplane through p that does not intersect Ω. We also prove that linearly convex domains are holomorphically convex, and that Kergin interpolation can be performed on holomorphic mappings defined in ℂ-convex domains.

  20. N-th order impulsive integro-differential equations in Banach spaces

    Directory of Open Access Journals (Sweden)

    Manfeng Hu

    2004-03-01

    Full Text Available We investigate the maximal and minimal solutions of initial value problem for N-th order nonlinear impulsive integro-differential equation in Banach space by establishing a comparison result and using the upper and lower solutions methods.

  1. Weak and strong convergence theorems for nonexpansive semigroups in Banach spaces

    Directory of Open Access Journals (Sweden)

    Wataru Takahashi

    2005-10-01

    Full Text Available We introduce an implicit iterative process for a nonexpansive semigroup and then we prove a weak convergence theorem for the nonexpansive semigroup in a uniformly convex Banach space which satisfies Opial's condition. Further, we discuss the strong convergence of the implicit iterative process.

  2. Weak and strong convergence theorems for nonexpansive semigroups in Banach spaces

    OpenAIRE

    Wataru Takahashi; Sachiko Atsushiba

    2005-01-01

    We introduce an implicit iterative process for a nonexpansive semigroup and then we prove a weak convergence theorem for the nonexpansive semigroup in a uniformly convex Banach space which satisfies Opial's condition. Further, we discuss the strong convergence of the implicit iterative process.

  3. Weak and strong convergence theorems for nonexpansive semigroups in Banach spaces

    Directory of Open Access Journals (Sweden)

    Takahashi Wataru

    2005-01-01

    Full Text Available We introduce an implicit iterative process for a nonexpansive semigroup and then we prove a weak convergence theorem for the nonexpansive semigroup in a uniformly convex Banach space which satisfies Opial's condition. Further, we discuss the strong convergence of the implicit iterative process.

  4. Nonuniform Exponential Stability and Instability of Evolution Operators in Banach Space

    OpenAIRE

    Mihaela Tomescu; Andrea Minda

    2006-01-01

    In this paper is presenting a parallel between nonuniform exponential stability and nonuniform exponential instability of evolution operators in Banach spaces, beginning to present the concept of the evolution operator with nonuniform exponential decay, respectively growth, next with the concept of the nonuniform stability, respectively instability, nonuniform exponential stability, respectively instability, nonuniform integrable stability, respectively instability and...

  5. Relationship between different types of stability for linear almost periodic systems in Banach spaces

    OpenAIRE

    Cheban, David N.

    1999-01-01

    For the linear equation $x'= A(t)x$ with recurrent (almost periodic) coefficients in an arbitrary Banach space, we prove that the asymptotic stability of the null solution and of all limit equations implies the uniform stability of the null solution.

  6. On a nonlinear integrodifferential evolution inclusion with nonlocal initial conditions in Banach spaces

    OpenAIRE

    Zuomao Yan

    2012-01-01

    In this paper, we discuss the existence results for a class of nnlinear integrodifferential evolution inclusions with nonlocal initial conditions in Banach spaces. Our results are based on a fixed point theorem for condensing maps due to Martelli and the resolvent operators combined with approximation techniques.

  7. Generalized Bohl-Perron principle for differential equations with delay in a Banach spaces

    OpenAIRE

    Michael Gil'

    2013-01-01

    We consider a linear homogeneous functional differential equation with delay in a Banach space. It is proved that if the corresponding non-homogeneous equation, with an arbitrary free term bounded on the positive half-line and with the zero initial condition, has a bounded solution, then the considered homogeneous equation is exponentially stable.

  8. Asymptotic behaviour of the solutions of Schroedinger equation with impulse effect in a Banach space

    International Nuclear Information System (INIS)

    The present paper studies the asymptotic behaviour of the solutions of linear homogeneous differential Schroedinger equation with impulse effect in a Banach space and finds a dependence between their asymptotic behaviour and the spectrum of the linear Hamiltonian operator. 6 refs

  9. Iterative methods for solving fixed-point problems with nonself-mappings in Banach spaces

    Directory of Open Access Journals (Sweden)

    Jen-Chih Yao

    2003-02-01

    Full Text Available We study descent-like approximation methods and proximal methods of the retraction type for solving fixed-point problems with nonself-mappings in Hilbert and Banach spaces. We prove strong and weak convergences for weakly contractive and nonexpansive maps, respectively. We also establish the stability of these methods with respect to perturbations of the operators and the constraint sets.

  10. Nonlocal Cauchy problem for time varying delay integrodifferential equations of Sobolev type in Banach spaces

    Directory of Open Access Journals (Sweden)

    K. Balachandran

    2006-09-01

    Full Text Available In this paper we prove the existence of mild and strong solutions of nonlinear time varying delay integrodifferential equations of Sobolev type with nonlocal conditions in Banach spaces. The results are obtained by using the theory of compact semigroups and Schaefer's fixed point theorem.

  11. A new composite implicit iterative process for a finite family of nonexpansive mappings in Banach spaces

    Directory of Open Access Journals (Sweden)

    Gu Feng

    2006-01-01

    Full Text Available The purpose of this paper is to study the weak and strong convergence of implicit iteration process with errors to a common fixed point for a finite family of nonexpansive mappings in Banach spaces. The results presented in this paper extend and improve the corresponding results of Chang and Cho (2003, Xu and Ori (2001, and Zhou and Chang (2002.

  12. Controllability of nonlocal impulsive quasi-linear integrodifferential systems in Banach spaces

    Science.gov (United States)

    Balachandran, K.; Park, J. Y.; Park, S. H.

    2010-04-01

    In this paper a set of sufficient conditions is established for the controllability of quasilinear integrodifferential systems with nonlocal and impulsive conditions in Banach spaces. The results are obtained by using evolution operator and semigroup theory. Examples are provided to illustrate the theory.

  13. Generalized Bohl-Perron principle for differential equations with delay in a Banach spaces

    Directory of Open Access Journals (Sweden)

    Michael Gil'

    2013-06-01

    Full Text Available We consider a linear homogeneous functional differential equation with delay in a Banach space. It is proved that if the corresponding non-homogeneous equation, with an arbitrary free term bounded on the positive half-line and with the zero initial condition, has a bounded solution, then the considered homogeneous equation is exponentially stable.

  14. Approximating solution of nonlinear variational inclusions by Ishikawa iterative process with errors in Banach spaces

    OpenAIRE

    Yuan George Xian-Zhi; Huang Nan-Jing

    2001-01-01

    In this paper, we introduce and study the existence of solutions and convergence of Ishikawa iterative processes with errors for a class of nonlinear variational inclusions with accretive type mappings in Banach spaces. The results presented in this paper extend and improve the corresponding results of [49, 11, 1617,19].

  15. Approximating solution of nonlinear variational inclusions by Ishikawa iterative process with errors in Banach spaces

    Directory of Open Access Journals (Sweden)

    Yuan George Xian-Zhi

    2001-01-01

    Full Text Available In this paper, we introduce and study the existence of solutions and convergence of Ishikawa iterative processes with errors for a class of nonlinear variational inclusions with accretive type mappings in Banach spaces. The results presented in this paper extend and improve the corresponding results of [49, 11, 1617,19].

  16. Existence and convergence theorems for a class of multi-valued variational inclusions in Banach spaces

    International Nuclear Information System (INIS)

    An existence theorem for a new class of multi-valued variational inclusion problems is established in smooth Banach spaces. Further, it is shown that a sequence of a Mann-type iteration algorithm is strongly convergent to the solutions in this class of variational inclusion problems. (author)

  17. Convergence rates for regularization of ill-posed problems in Banach spaces by approximate source conditions

    International Nuclear Information System (INIS)

    In this paper we deal with convergence rates for regularizing ill-posed problems with operator mapping from a Hilbert space into a Banach space. Since we cannot transfer the well-established convergence rates theory in Hilbert spaces, only few convergence rates results are known in the literature for this situation. Therefore we present an alternative approach for deriving convergence rates. Hereby we deal with so-called distance functions which quantify the violation of a reference source condition. With the aid of these functions we present error bounds and convergence rates for regularized solutions of linear and nonlinear problems when the reference source condition is not satisfied. We show that the approach of applying distance functions carries over the idea of considering generalized source conditions in Hilbert spaces to inverse problems in Banach spaces in a natural way. Introducing this topic for linear ill-posed problems we additionally show that this theory can be easily extended to nonlinear problems

  18. Nonlinear semigroups, fixed points, and geometry of domains in Banach spaces

    CERN Document Server

    Reich, Simeon

    2005-01-01

    Nonlinear semigroup theory is not only of intrinsic interest, but is also important in the study of evolution problems. In the last forty years, the generation theory of flows of holomorphic mappings has been of great interest in the theory of Markov stochastic branching processes, the theory of composition operators, control theory, and optimization. It transpires that the asymptotic behavior of solutions to evolution equations is applicable to the study of the geometry of certain domains in complex spaces. Readers are provided with a systematic overview of many results concerning both nonlinear semigroups in metric and Banach spaces and the fixed point theory of mappings, which are nonexpansive with respect to hyperbolic metrics (in particular, holomorphic self-mappings of domains in Banach spaces). The exposition is organized in a readable and intuitive manner, presenting basic functional and complex analysis as well as very recent developments. Contents: Mappings in Metric and Normed Spaces; Differentiabl...

  19. From Hahn-Banach to monotonicity

    CERN Document Server

    Simons, Stephen

    2008-01-01

    In this new edition of LNM 1693 the essential idea is to reduce questions on monotone multifunctions to questions on convex functions. However, rather than using a big convexification of the graph of the multifunction and the minimax techniquefor proving the existence of linear functionals satisfying certain conditions, the Fitzpatrick function is used. The journey begins with a generalization of the Hahn-Banach theorem uniting classical functional analysis, minimax theory, Lagrange multiplier theory and convex analysis and culminates in a survey of current results on monotone multifunctions on a Banach space. The first two chapters are aimed at students interested in the development of the basic theorems of functional analysis, which leads painlessly to the theory of minimax theorems, convex Lagrange multiplier theory and convex analysis. The remaining five chapters are useful for those who wish to learn about the current research on monotone multifunctions on (possibly non reflexive) Banach spac...

  20. On LandweberKaczmarz methods for regularizing systems of ill-posed equations in Banach spaces

    International Nuclear Information System (INIS)

    In this paper, iterative regularization methods of LandweberKaczmarz type are considered for solving systems of ill-posed equations modeled (finitely many) by operators acting between Banach spaces. Using assumptions of uniform convexity and smoothness on the parameter space, we are able to prove a monotony result for the proposed method, as well as to establish convergence (for exact data) and stability results (in the noisy data case). (paper)

  1. Convergence theorems of common elements for mixed equilibrium problems, variational inequality problems and fixed point problems in Banach spaces

    Directory of Open Access Journals (Sweden)

    Kriengsak Wattanawitoon

    2011-01-01

    Full Text Available In this paper, a hybrid iterative scheme is introduced for theapproximation method for finding a common element of the set of mixed equilibrium problems, variational inequality problems and fixed point problems of two quasi-$phi$-nonexpansive mappings ina real uniformly convex and uniformly smooth Banach space. Then, we obtain a strong convergence theorem for the sequence generated by those process in Banach spaces. Moreover, we obtain new resultfor finding a zero point of maximal monotone operators in a Banach space. Our results improve and extend the corresponding results announced by Takahashi and Zembayashi [Strong and weak convergencetheorems for equilibrium problems and relatively nonexpansive mappings in Banach spaces, Nonlinear Anal. 70 (2009 45--57.] Qin, Cho and Kang [Convergence theorems of common elements forequilibrium problems and fixed point problems in Banach spaces, J. Comput. Appl. Math., 225 (2009, 20--30.] Wattanawitoon and Kumam [Strong convergence theorems by a new hybrid projection algorithmfor fixed point problems and equilibrium problems of tworelatively quasi-nonexpansive mappings, Nonlinear Anal: Hybrid Systems. 3 (2009 11--20.] Cholamjiak [A hybrid iterative scheme for equilibrium problems, variational inequality problems and fixed point problems in Banach spaces, Fixed Point Theory Appl., (2009, Article ID 719360, 18 pages] and many authors.

  2. Buried object detection by means of a Lp Banach-space inversion procedure

    Science.gov (United States)

    Estatico, Claudio; Fedeli, Alessandro; Pastorino, Matteo; Randazzo, Andrea

    2015-01-01

    Electromagnetic inspection techniques are becoming powerful tools for buried object detection and subsurface prospection in several applicative fields, such as civil engineering and archeology. However, the nonlinearity and ill-posedness of the underlying inverse problem make the development of efficient imaging techniques a very challenging task. In the present paper, an algorithm based on a regularizing approach in Lp Banach spaces is proposed for tackling such problems. The effectiveness of the approach is verified by means of numerical simulations in a noisy environment aimed at evaluating the reconstruction capabilities with respect to the choice of several model parameters. The reported results show that, for small targets, the use of Lp Banach spaces with 1 < p < 2 allows to obtain a better localization of different buried scatterers.

  3. Impulsive moving mirror model and impulsive differential equations in Banach space

    International Nuclear Information System (INIS)

    The dependence of vacuum state energy on the distance between the uniformly relatively moving mirrors is used to calculate impulsive differential equations in Banach space. We formulate the problem of moving mirrors, possibly with suddenly change of velocity v in t=tn, n=0, 1, 2, ..., upon which quantum fields satisfy Dirichlet boundary conditions, with the associated Casimir effect, in a functional Schroedinger picture. 10 refs

  4. Browder's type strong convergence theorems for infinite families of nonexpansive mappings in Banach spaces

    Directory of Open Access Journals (Sweden)

    Suzuki Tomonari

    2006-01-01

    Full Text Available We prove Browder's type strong convergence theorems for infinite families of nonexpansive mappings. One of our main results is the following: let be a bounded closed convex subset of a uniformly smooth Banach space . Let be an infinite family of commuting nonexpansive mappings on . Let and be sequences in satisfying for . Fix and define a sequence in by for . Then converges strongly to , where is the unique sunny nonexpansive retraction from onto .

  5. Frames for operators in Banach spaces via semi-inner products

    OpenAIRE

    Dastourian, Bahram; Janfada, Mohammad

    2015-01-01

    In this paper, we propose to define the concept of family of local atoms and then we generalize this concept to the atomic system for operator in Banach spaces by using semi-inner product. We also give a characterization of atomic systems leading to obtain new frames. In addition, a reconstruction formula is obtain. Next, some new results are established. The characterization of atomic systems allows us to state some results for sampling theory in semi-inner product reproduc...

  6. Iterations converging to distinct solutions of some nonlinear operator equations in Banach space

    OpenAIRE

    Argyros, Ioannis K.

    1986-01-01

    We examine the solvability of multilinear equations of the formMk(x,x,…,x)−k   times−=y,   k=2,3,…where Mk is a k-linear operator on a Banach space X and y∈X is fixed.

  7. Weak and Strong Convergence Theorems for Nonexpansive Mappings in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Jing Zhao

    2008-03-01

    Full Text Available The purpose of this paper is to introduce two implicit iteration schemes for approximating fixed points of nonexpansive mapping T and a finite family of nonexpansive mappings {Ti}i=1N, respectively, in Banach spaces and to prove weak and strong convergence theorems. The results presented in this paper improve and extend the corresponding ones of H.-K. Xu and R. Ori, 2001, Z. Opial, 1967, and others.

  8. Weak and Strong Convergence Theorems for Nonexpansive Mappings in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Su Yongfu

    2008-01-01

    Full Text Available Abstract The purpose of this paper is to introduce two implicit iteration schemes for approximating fixed points of nonexpansive mapping and a finite family of nonexpansive mappings , respectively, in Banach spaces and to prove weak and strong convergence theorems. The results presented in this paper improve and extend the corresponding ones of H.-K. Xu and R. Ori, 2001, Z. Opial, 1967, and others.

  9. Approximating fixed points of a countable family of strict pseudocontractions in Banach spaces

    Directory of Open Access Journals (Sweden)

    Prasit Cholamjiak

    2014-01-01

    Full Text Available We prove the strong convergence of the modified Mann-type iterative scheme for a countable family of strict pseudocontractions in \\(q\\-uniformly smooth Banach spaces. Our results mainly improve and extend the results announced in [Y. Yao, H. Zhou, Y.-C. Liou, Strong convergence of a modified Krasnoselski-Mann iterative algorithm for non-expansive mappings, J. Appl. Math. Comput. 29 (2009, 383-389].

  10. On the unbounded behaviour for some non-autonomous systems in Banach spaces

    International Nuclear Information System (INIS)

    By modifying our previous methods and by using the notion of integral solution introduced by Benilan, we study the asymptotic behaviour of unbounded trajectories for the quasi-autonomous dissipative system: du/dt + Au is not an element of f where X is a real Banach space, A an accretive (possibly multivalued) operator in X x X, and f - f? is an element of Lp((0, +?);X) for some f? is an element of X and 1 ? p < ?. (author). 24 refs

  11. Iterative solutions of K-positive definite operator equations in real uniformly smooth Banach spaces

    Directory of Open Access Journals (Sweden)

    Jeong Sheok Ume

    2001-10-01

    Full Text Available Let X be a real uniformly smooth Banach space and let T:D(T⫅X→X be a K-positive definite operator. Under suitable conditions we establish that the iterative method by Bai (1999 converges strongly to the unique solution of the equation Tx=f, f∈X. The results presented in this paper generalize the corresponding results of Bai (1999, Chidume and Aneke (1993, and Chidume and Osilike (1997.

  12. Fixed point iterations for strictly hemi-contractive maps in uniformly smooth Banach spaces

    International Nuclear Information System (INIS)

    It is proved that the Mann iteration process converges strongly to the fixed point of a strictly hemi-contractive map in real uniformly smooth Banach spaces. The class of strictly hemi-contractive maps includes all strictly pseudo-contractive maps with nonempty fixed point sets. A related result deals with the Ishikawa iteration scheme when the mapping is Lipschitzian and strictly hemi-contractive. Our theorems generalize important known results. (author). 29 refs

  13. Existence of weak and strong solutions of nonlinear differential equations with delay in Banach space

    International Nuclear Information System (INIS)

    Existence of weak and strong solutions of nonlinear differential equations with delay in Banach space is discussed. In the present work we give a generalization to recent results. We prove that, with certain conditions, every nonlinear differential equation with delay has at least one weak solution, furthermore, under suitable assumptions, these equations have solutions. Next under a generalization of the compactness assumptions, we show the same equations have solutions too

  14. On some Banach space constants arising in nonlinear fixed point and eigenvalue theory

    Directory of Open Access Journals (Sweden)

    Martin Vth

    2004-12-01

    Full Text Available As is well known, in any infinite-dimensional Banach space one may find fixed point free self-maps of the unit ball, retractions of the unit ball onto its boundary, contractions of the unit sphere, and nonzero maps without positive eigenvalues and normalized eigenvectors. In this paper, we give upper and lower estimates, or even explicit formulas, for the minimal Lipschitz constant and measure of noncompactness of such maps.

  15. Embedding theorems in Banach-valued -spaces and maximal -regular differential-operator equations

    Directory of Open Access Journals (Sweden)

    Shakhmurov Veli B

    2006-01-01

    Full Text Available The embedding theorems in anisotropic Besov-Lions type spaces are studied; here and are two Banach spaces. The most regular spaces are found such that the mixed differential operators are bounded from to , where are interpolation spaces between and depending on and . By using these results the separability of anisotropic differential-operator equations with dependent coefficients in principal part and the maximal -regularity of parabolic Cauchy problem are obtained. In applications, the infinite systems of the quasielliptic partial differential equations and the parabolic Cauchy problems are studied.

  16. Conical square function estimates in UMD Banach spaces and applications to H-infinity functional calculi

    OpenAIRE

    Hytonen, Tuomas; Neerven, Jan; Portal, Pierre

    2007-01-01

    We study conical square function estimates for Banach-valued functions, and introduce a vector-valued analogue of the Coifman-Meyer-Stein tent spaces. Following recent work of Auscher-McIntosh-Russ, the tent spaces in turn are used to construct a scale of vector-valued Hardy spaces associated with a given bisectorial operator (A) with certain off-diagonal bounds, such that (A) always has a bounded (H^{\\infty})-functional calculus on these spaces. This provides a new way of p...

  17. ISOMETRIC WEIGHTED COMPOSITION OPERATORS ON WEIGHTED BANACH SPACES OF HOLOMORPHIC FUNCTIONS DEFINED ON THE UNIT BALL OF A COMPLEX BANACH SPACE

    Scientific Electronic Library Online (English)

    Elke, Wolf.

    Full Text Available Sea X y Y espacios de Banach complejos, B X y B Y las bolas unitarias cerradas correspondientes. Las aplicaciones analticas : B Y [...] width=29 height=24 id="_x0000_i1044" src="http:/fbpe/img/cubo/v15n2/art04-02.jpg" alt="Descripcin: http:/fbpe/img/cubo/v15n2/art04-02.jpg">B X y: B X inducen el operador de composicin con pesos: C , : H (B Y) H (Bx), f (f o ), donde H (B Y) y H (Bx) denotan la coleccin de todas las funciones analticas f : Bx (resp. B Y) . Estudiamos cundo dichos operadores que actan entre los espacios con peso de funciones analticas son isomtricas. Abstract in english Let X and Y be complex Banach spaces and B X resp. B Y the closed unit ball. Analytic maps : B Y [...] " src="http:/fbpe/img/cubo/v15n2/art04-02.jpg" alt="Descripcin: http:/fbpe/img/cubo/v15n2/art04-02.jpg">B X and : B X induce the weighted composition operator: C , : H (B Y) H (Bx), f (f o ), where H (B Y) resp. H (Bx) denotes the collection of all analytic functions f : Bx (resp. B Y) . We study when such operators acting between weighted spaces of analytic functions are isometric.

  18. Maximal norms on Banach spaces of continuous functions. A Corrigendum to Kalton and Wood's Orthonormal systems in Banach spaces and their applications

    Science.gov (United States)

    Cabello Snchez, Alberto; Cabello Snchez, Flix

    2000-09-01

    The purpose of this short note is to reformulate theorem 93 in [5] which is not correct as stated. We note that all other results in [5] are independent of that statement.The notation is the same as [5] with the sole exception that C0(S) will always denote the space of all real-valued continuous functions on the locally compact space S vanishing at infinity. As usual, [alpha]S stands for the one-point compactification of S. Recall that a norm [Vert dbl vertical bar] [Vert dbl vertical bar] on a Banach space X is said to be maximal if there is no equivalent norm on X whose isometry group contains properly that of [Vert dbl vertical bar] [Vert dbl vertical bar].

  19. Backward Ornstein-Uhlenbeck Transition Operators and Mild Solutions of Non-Autonomous Hamilton-Jacobi Equations in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Rafael Serrano

    2014-10-01

    Full Text Available In this paper we revisit the mild-solution approach to second-order semi-linear PDEs of Hamilton-Jacobi type in infinite-dimensional spaces. We show that a well-known result on existence of mild solutions in Hilbert spaces can be easily extended to non-autonomous Hamilton-Jacobi equations in Banach spaces. The main tool is the regularizing property of Ornstein-Uhlenbeck transition evolution operators for stochastic Cauchy problems in Banach spaces with time-dependent coefficients.

  20. Backward Ornstein-Uhlenbeck transition operators and mild solutions of non-autonomous Hamilton-Jacobi equations in Banach spaces

    OpenAIRE

    Serrano, Rafael

    2014-01-01

    In this paper we revisit the mild-solution approach to second-order semi-linear PDEs of Hamilton-Jacobi type in infinite-dimensional spaces. We show that a well-known result on existence of mild solutions in Hilbert spaces can be easily extended to non-autonomous Hamilton-Jacobi equations in Banach spaces. The main tool is the regularizing property of Ornstein-Uhlenbeck transition evolution operators for stochastic Cauchy problems in Banach spaces with time-dependent coeffic...

  1. On enhanced convergence rates for Tikhonov regularization of nonlinear ill-posed problems in Banach spaces

    International Nuclear Information System (INIS)

    It is well known for the Tikhonov regularization of ill-posed problems in Hilbert spaces that the best possible convergence rate is O(?) in the noise-free case and O(? 2/3) in the noisy case if the exact solution x satisfies the source condition x is an element of R(T*T). We will show under what conditions the best possible rates with respect to ? may be obtained for nonlinear ill-posed problems in Banach spaces. Moreover, we present convergence rate results with respect to the Bregman distance and show special cases where these rates are best possible

  2. Differences of weighted composition operators between weighted Banach spaces of holomorphic functions and weighted Bloch type spaces

    Directory of Open Access Journals (Sweden)

    Elke Wolf

    2010-01-01

    Full Text Available We consider analytic self-maps ?1, ?2 of the open unit disk as well as analytic maps? 1, ?2. These maps induce differences of weighted composition operators acting between weighted Banach spaces of holomorphic functions and weighted Bloch type spaces. In this article we give necessary and sufficient conditions for such a difference to be bounded resp. compact.Nosotros consideramos auto aplicaciones ?1, ?2 del disco unitario abierto bien como aplicaciones analticas ?1, ?2. Estas aplicaciones inducen diferencias de compicin de operadores con peso actuando entre espacios de Banach pesados de funciones holomorfas y espacios de tipo Bloch con peso. En este artculo damos condiciones necesarias y suficientes para que tal diferencia sea acotada, respectivamente, compacta.

  3. Double-dual n-types over Banach spaces not containing ℓ1

    Directory of Open Access Journals (Sweden)

    Markus Pomper

    2004-07-01

    Full Text Available Let E be a Banach space. The concept of n-type overE is introduced here, generalizing the concept of type overE introduced by Krivine and Maurey. Let E″ be the second dual of E and fix g″1,…g″n∈E″. The function τ:E×ℝn→ℝ, defined by letting τ(x,a1,…,an=‖x+∑i=1naig″i‖ for all x∈E and all a1,…,an∈ℝ, defines an n-type over E. Types that can be represented in this way are called double-dual n-types; we say that (g″1,…g″n∈(E″n realizes τ. Let E be a (not necessarily separable Banach space that does not contain ℓ1. We study the set of elements of (E″n that realize a given double-dual n-type over E. We show that the set of realizations of this n-type is convex. This generalizes a result of Haydon and Maurey who showed that the set of realizations of a given 1-type over a separable Banach space E is convex. The proof makes use of Henson's language for normed space structures and uses ideas from mathematical logic, most notably the Löwenheim-Skolem theorem.

  4. Quasi-Banach spaces of almost universal disposition.

    Czech Academy of Sciences Publication Activity Database

    Snchez, C. F.; Garbuli?ska, J.; Kubi?, Wieslaw

    2014-01-01

    Ro?. 267, ?. 3 (2014), s. 744-771. ISSN 0022-1236 R&D Projects: GA ?R(CZ) GAP201/12/0290 Institutional support: RVO:67985840 Keywords : p-Gurarii space * space of universal disposition * isometry Subject RIV: BA - General Mathematics Impact factor: 1.152, year: 2013 http://www.sciencedirect.com/science/article/pii/S0022123614002043

  5. C0-semigroups of linear operators on some ultrametric Banach spaces

    Directory of Open Access Journals (Sweden)

    Toka Diagana

    2006-06-01

    Full Text Available C0-semigroups of linear operators play a crucial role in the solvability of evolution equations in the classical context. This paper is concerned with a brief conceptualization of C0-semigroups on (ultrametric free Banach spaces E. In contrast with the classical setting, the parameter of a given C0-semigroup belongs to a clopen ball Ωr of the ground field K. As an illustration, we will discuss the solvability of some homogeneous p-adic differential equations.

  6. Existence Theory for Integrodifferential Equations and Henstock-Kurzweil Integral in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Aneta Sikorska-Nowak

    2007-06-01

    Full Text Available We prove existence theorems for the integrodifferential equation x'(t=f(t,x(t,∫0tk(t,s, x(sds, x(0=x0, t∈Ia=[0,a], a>0, where f,k,x are functions with values in a Banach space E and the integral is taken in the sense of HL. Additionally, the functions f and k satisfy certain boundary conditions expressed in terms of the measure of noncompactness.

  7. Non-uniform stability for bounded semi-groups on Banach spaces

    OpenAIRE

    Batty, Cjk; Duyckaerts, T.

    2008-01-01

    Let S(t) be a bounded strongly continuous semi-group on a Banach space B and - A be its generator. We say that S(t) is semi-uniformly stable when S(t)(A + 1)-1 tends to 0 in operator norm. This notion of asymptotic stability is stronger than pointwise stability, but strictly weaker than uniform stability, and generalizes the known logarithmic, polynomial and exponential stabilities. In this note we show that if S is semi-uniformly stable then the spectrum of A does not intersect the imaginary...

  8. An analytic Koszul complex in a Banach space

    CERN Document Server

    Patyi, I

    2005-01-01

    We show that the holomorphic ideal sheaf of a linear section of a pseudoconvex open subset $\\Omega$ of, say, a Hilbert space $X=\\ell_2$ is acyclic. We also prove an analog of Hefer's lemma, i.e., if $f:\\Omega\\times\\Omega\\to\\CC$ is holomorphic and $f(x,x)=0$ for $x\\in\\Omega$, then there is a holomorphic $g:\\Omega\\times\\Omega\\to X^*$ with values in the dual space $X^*$ of $X$ such that $f(x,y)=g(x,y)(x-y)$

  9. Modification of Otolith Reflex Asymmetries Following Space Flight

    Science.gov (United States)

    Clarke, Andrew H.; Schoenfeld, Uwe; Wood, Scott J.

    2011-01-01

    We hypothesize that changes in otolith-mediated reflexes adapted for microgravity contribute to perceptual, gaze and postural disturbances upon return to Earth s gravity. Our goal was to determine pre- versus post-fight differences in unilateral otolith reflexes that reflect these adaptive changes. This study represents the first comprehensive examination of unilateral otolith function following space flight. Ten astronauts participated in unilateral otolith function tests three times pre-flight and up to four times after Shuttle flights from landing day through the subsequent 10 days. During unilateral centrifugation (UC, +/- 3.5cm at 400deg/s), utricular function was examined by the perceptual changes reflected by the subjective visual vertical (SVV) and by video-oculographic measurement of the otolith-mediated ocular counter-roll (OOR). Unilateral saccular reflexes were recorded by measurement of collic Vestibular Evoked Myogenic Potential (cVEMP). Although data from a few subjects were not obtained early post-flight, a general increase in asymmetry of otolith responses was observed on landing day relative to pre-flight baseline, with a subsequent reversal in asymmetry within 2-3 days. Recovery to baseline levels was achieved within 10 days. This fluctuation in the asymmetry measures appeared strongest for SVV, in a consistent direction for OOR, and in an opposite direction for cVEMP. These results are consistent with our hypothesis that space flight results in adaptive changes in central nervous system processing of otolith input. Adaptation to microgravity may reveal asymmetries in otolith function upon to return to Earth that were not detected prior to the flight due to compensatory mechanisms.

  10. Convergence rates and finite-dimensional approximations for nonlinear ill-posed problems involving monotone operators in Banach spaces

    International Nuclear Information System (INIS)

    The purpose of this paper is to investigate convergence rates for an operator version of Tikhonov regularization constructed by dual mapping for nonlinear ill-posed problems involving monotone operators in real reflective Banach spaces. The obtained results are considered in combination with finite-dimensional approximations for the space. An example is considered for illustration. (author). 15 refs

  11. A convergence rates result for an iteratively regularized GaussNewtonHalley method in Banach space

    International Nuclear Information System (INIS)

    The use of second order information on the forward operator often comes at a very moderate additional computational price in the context of parameter identification problems for differential equation models. On the other hand the use of general (non-Hilbert) Banach spaces has recently found much interest due to its usefulness in many applications. This motivates us to extend the second order method from Kaltenbacher (2014 Numer. Math. at press), (see also Hettlich and Rundell 2000 SIAM J. Numer. Anal. 37 587620) to a Banach space setting and analyze its convergence. We here show rates results for a particular source condition and different exponents in the formulation of Tikhonov regularization in each step. This includes a complementary result on the (first order) iteratively regularized GaussNewton method in case of a one-homogeneous data misfit term, which corresponds to exact penalization. The results clearly show the possible advantages of using second order information, which get most pronounced in this exact penalization case. Numerical simulations for an inverse source problem for a nonlinear elliptic PDE illustrate the theoretical findings. (paper)

  12. A convergence rates result for an iteratively regularized GaussNewtonHalley method in Banach space

    Science.gov (United States)

    Kaltenbacher, B.

    2015-01-01

    The use of second order information on the forward operator often comes at a very moderate additional computational price in the context of parameter identification problems for differential equation models. On the other hand the use of general (non-Hilbert) Banach spaces has recently found much interest due to its usefulness in many applications. This motivates us to extend the second order method from Kaltenbacher (2014 Numer. Math. at press), (see also Hettlich and Rundell 2000 SIAM J. Numer. Anal. 37 587620) to a Banach space setting and analyze its convergence. We here show rates results for a particular source condition and different exponents in the formulation of Tikhonov regularization in each step. This includes a complementary result on the (first order) iteratively regularized GaussNewton method in case of a one-homogeneous data misfit term, which corresponds to exact penalization. The results clearly show the possible advantages of using second order information, which get most pronounced in this exact penalization case. Numerical simulations for an inverse source problem for a nonlinear elliptic PDE illustrate the theoretical findings.

  13. Impulsive moving mirror model in a Schroedinger picture with impulse effect in a Banach space

    International Nuclear Information System (INIS)

    From a special class of systems has been used a Schroedinger equation with impulse effect in Minkowski space field theory with time dependent boundary conditions, i.e. those of moving mirrors. The field theoretical approach for studing the properties of the vacuum starts from an analysis of the behaviour of local field quantities in Minkowski space with uniformly moving mirrors. For the impulsive moving mirror model is the real process of interaction between the quantum field and the external mirror a subject to disturbances in its evolution acting in time very short compared with the entire duration of the process. So the stability of the solution of the Schroedinger evolution equation for the process is the stability of the vacuum of Casimir. The dependence of vacuum state energy on the distance between the uniformly relatively moving mirrors is used to calculate from the impulsive moving model the Schroedinger equation in a Banach space. 21 refs

  14. A perturbation result for quasi-linear stochastic differential equations in UMD Banach spaces

    CERN Document Server

    Cox, Sonja

    2012-01-01

    We consider the effect of perturbations to a quasi-linear parabolic stochastic differential equation set in a UMD Banach space $X$. To be precise, we consider perturbations of the linear part, i.e. the term concerning a linear operator $A$ generating an analytic semigroup. We provide estimates for the difference between the solution to the original equation $U$ and the solution to the perturbed equation $U_0$ in the $L^p(\\Omega;C([0,T];X))$-norm. In particular, this difference can be estimated $|| R(\\lambda:A)-R(\\lambda:A_0) ||$ for sufficiently smooth non-linear terms. The work is inspired by the desire to prove convergence of space discretization schemes for such equations. In this article we prove convergence rates for the case that $A$ is approximated by its Yosida approximation, and in a forthcoming publication we consider convergence of Galerkin and finite-element schemes in the case that $X$ is a Hilbert space.

  15. Regularization proximal point algorithm for finding a common fixed point of a finite family of nonexpansive mappings in Banach spaces

    Directory of Open Access Journals (Sweden)

    Tuyen Truong

    2011-01-01

    Full Text Available Abstract We study the strong convergence of a regularization proximal point algorithm for finding a common fixed point of a finite family of nonexpansive mappings in a uniformly convex and uniformly smooth Banach space. 2010 Mathematics Subject Classification: 47H09; 47J25; 47J30.

  16. A new theorem on exponential stability of periodic evolution families on Banach spaces

    Directory of Open Access Journals (Sweden)

    Constantin Buse

    2003-02-01

    Full Text Available We consider a mild solution $v_f(cdot, 0$ of a well-posed inhomogeneous Cauchy problem $dot v(t=A(tv(t+f(t$, $v(0=0$ on a complex Banach space $X$, where $A(cdot$ is a 1-periodic operator-valued function. We prove that if $v_f(cdot, 0$ belongs to $AP_0(mathbb{R}_+, X$ for each $fin AP_0(mathbb{R}_+, X$ then for each $xin X$ the solution of the well-posed Cauchy problem $dot u(t=A(tv(t$, $u(0=x$ is uniformly exponentially stable. The converse statement is also true. Details about the space $AP_0(mathbb{R}_+, X$ are given in the section 1, below. Our approach is based on the spectral theory of evolution semigroups.

  17. Generalized Vector Equilibrium-Like Problems without Pseudomonotonicity in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Guu Sy-Ming

    2007-01-01

    Full Text Available Let and be real Banach spaces, a nonempty closed convex subset of , and a multifunction such that for each is a proper, closed and convex cone with , where denotes the interior of . Given the mappings , , and , we study the generalized vector equilibrium-like problem: find such that for all for some . By using the KKM technique and the well-known Nadler result, we prove some existence theorems of solutions for this class of generalized vector equilibrium-like problems. Furthermore, these existence theorems can be applied to derive some existence results of solutions for the generalized vector variational-like inequalities. It is worth pointing out that there are no assumptions of pseudomonotonicity in our existence results.

  18. Hybrid methods for accretive variational inequalities involving pseudocontractions in Banach spaces

    Directory of Open Access Journals (Sweden)

    Chen Rudong

    2011-01-01

    Full Text Available Abstract We use strongly pseudocontractions to regularize a class of accretive variational inequalities in Banach spaces, where the accretive operators are complements of pseudocontractions and the solutions are sought in the set of fixed points of another pseudocontraction. In this paper, we consider an implicit scheme that can be used to find a solution of a class of accretive variational inequalities. Our results improve and generalize some recent results of Yao et al. (Fixed Point Theory Appl, doi:10.1155/2011/180534, 2011 and Lu et al. (Nonlinear Anal, 71(3-4, 1032-1041, 2009. 2000 Mathematics subject classification 47H05; 47H09; 65J15

  19. Asymptotic behaviour of solutions of nonlinear delay difference equations in Banach spaces

    Directory of Open Access Journals (Sweden)

    Anna Kisiolek

    2005-10-01

    Full Text Available We consider the second-order nonlinear difference equations of the form Δ(rn−1Δxn−1+pnf(xn−k=hn. We show that there exists a solution (xn, which possesses the asymptotic behaviour ‖xn−a∑j=0n−1(1/rj+b‖=o(1, a,b∈ℝ. In this paper, we extend the results of Agarwal (1992, Dawidowski et al. (2001, Drozdowicz and Popenda (1987, M. Migda (2001, and M. Migda and J. Migda (1988. We suppose that f has values in Banach space and satisfies some conditions with respect to the measure of noncompactness and measure of weak noncompactness.

  20. Asymptotic behaviour of solutions of nonlinear delay difference equations in Banach spaces

    OpenAIRE

    Anna Kisiolek; Ireneusz Kubiaczyk

    2005-01-01

    We consider the second-order nonlinear difference equations of the form Δ(rn−1Δxn−1)+pnf(xn−k)=hn. We show that there exists a solution (xn), which possesses the asymptotic behaviour ‖xn−a∑j=0n−1(1/rj)+b‖=o(1), a,b∈ℝ. In this paper, we extend the results of Agarwal (1992), Dawidowski et al. (2001), Drozdowicz and Popenda (1987), M. Migda (2001), and M. Migda and J. Migda (1988). We suppose that f has values in Banach space and satisfies ...

  1. An iterative regularization method for the solution of the split feasibility problem in Banach spaces

    International Nuclear Information System (INIS)

    The split feasibility problem (SFP) consists of finding a common point in the intersection of finitely many convex sets, where some of the sets arise by imposing convex constraints in the range of linear operators. We are concerned with its solution in Banach spaces. To this end we generalize the CQ algorithm of Byrne with Bregman and metric projections to obtain an iterative solution method. In case the sets projected onto are contaminated with noise we show that a discrepancy principle renders this algorithm a regularization method. We measure the distance between convex sets by local versions of the Hausdorff distance, which in contrast to the standard Hausdorff distance allow us to measure the distance between unbounded sets. Hereby we prove a uniform continuity result for both kind of projections. The performance of the algorithm is demonstrated with some numerical experiments

  2. Bourdieu's Reflexive Sociology and "Spaces of Points of View": Whose Reflexivity, Which Perspective?

    Science.gov (United States)

    Kenway, Jane; McLeod, Julie

    2004-01-01

    This paper considers Bourdieu's concepts of perspectivism and reflexivity, looking particularly at how he develops arguments about these in his recent work, The Weight of the World (1999) and Pascalian Meditations (2000b). We explicate Bourdieu's distinctive purposes and deployment of these terms and approaches, and discuss how this compares with

  3. Each Random Variable in separable Banach Space belongs to the Domain of Definition of some inverse to compact linear non-random operator

    OpenAIRE

    Ostrovsky, E.; Sirota, L.

    2014-01-01

    We give in this short report a very simple proof that arbitrary random variable with Borelian distribution in separable Banach space belongs with probability one to a pre-image of some linear compact non-random operator.

  4. The equivalence between the convergences of Mann and Ishikawa iteration methods with errors for demicontinuous φ-strongly accretive operators in uniformly smooth Banach spaces

    OpenAIRE

    Zeqing Liu; Li Wang; Jeong Sheok Ume; Shin Min Kang

    2006-01-01

    We investigate the equivalence between the convergences of the Mann iteration method and the Ishikawa iteration method with errors for demicontinuous φ-strongly accretive operators in uniformly smooth Banach spaces. A related result deals with the equivalence of the Mann iteration method and the Ishikawa iteration method for φ-pseudocontractive operators in nonempty closed convex subsets of uniformly smooth Banach spaces. The results presented in this paper extend and improve ...

  5. The equivalence between the convergences of Mann and Ishikawa iteration methods with errors for demicontinuous φ-strongly accretive operators in uniformly smooth Banach spaces

    Directory of Open Access Journals (Sweden)

    Zeqing Liu

    2006-05-01

    Full Text Available We investigate the equivalence between the convergences of the Mann iteration method and the Ishikawa iteration method with errors for demicontinuous φ-strongly accretive operators in uniformly smooth Banach spaces. A related result deals with the equivalence of the Mann iteration method and the Ishikawa iteration method for φ-pseudocontractive operators in nonempty closed convex subsets of uniformly smooth Banach spaces. The results presented in this paper extend and improve the corresponding results in the literature.

  6. A Generalized Hybrid Steepest-Descent Method for Variational Inequalities in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Wong NC

    2011-01-01

    Full Text Available Abstract The hybrid steepest-descent method introduced by Yamada (2001 is an algorithmic solution to the variational inequality problem over the fixed point set of nonlinear mapping and applicable to a broad range of convexly constrained nonlinear inverse problems in real Hilbert spaces. Lehdili and Moudafi (1996 introduced the new prox-Tikhonov regularization method for proximal point algorithm to generate a strongly convergent sequence and established a convergence property for it by using the technique of variational distance in Hilbert spaces. In this paper, motivated by Yamada's hybrid steepest-descent and Lehdili and Moudafi's algorithms, a generalized hybrid steepest-descent algorithm for computing the solutions of the variational inequality problem over the common fixed point set of sequence of nonexpansive-type mappings in the framework of Banach space is proposed. The strong convergence for the proposed algorithm to the solution is guaranteed under some assumptions. Our strong convergence theorems extend and improve certain corresponding results in the recent literature.

  7. Ishikawa Iterative Process for a Pair of Single-valued and Multivalued Nonexpansive Mappings in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Kaewkhao A

    2010-01-01

    Full Text Available Let be a nonempty compact convex subset of a uniformly convex Banach space , and let and be a single-valued nonexpansive mapping and a multivalued nonexpansive mapping, respectively. Assume in addition that and for all . We prove that the sequence of the modified Ishikawa iteration method generated from an arbitrary by , , where and , are sequences of positive numbers satisfying , , converges strongly to a common fixed point of and ; that is, there exists such that .

  8. Strong Convergence Theorems of Modified Ishikawa Iterations for Countable Hemi-Relatively Nonexpansive Mappings in a Banach Space

    OpenAIRE

    Kumam Poom; Wattanawitoon Kriengsak; Petrot Narin

    2009-01-01

    We prove some strong convergence theorems for fixed points of modified Ishikawa and Halpern iterative processes for a countable family of hemi-relatively nonexpansive mappings in a uniformly convex and uniformly smooth Banach space by using the hybrid projection methods. Moreover, we also apply our results to a class of relatively nonexpansive mappings, and hence, we immediately obtain the results announced by Qin and Su's result (2007), Nilsrakoo and Saejung's result (2008), Su et al...

  9. Comparison of fastness of the convergence among Krasnoselskij, Mann, and Ishikawa iterations in arbitrary real Banach spaces

    OpenAIRE

    Vara Prasad, K. N. V. V.; Babu, G. V. R.

    2006-01-01

    Let be an arbitrary real Banach space and a nonempty, closed, convex (not necessarily bounded) subset of . If is a member of the class of Lipschitz, strongly pseudocontractive maps with Lipschitz constant , then it is shown that to each Mann iteration there is a Krasnosleskij iteration which converges faster than the Mann iteration. It is also shown that the Mann iteration converges faster than the Ishikawa iteration to the fixed point of .

  10. Comparison of fastness of the convergence among Krasnoselskij, Mann, and Ishikawa iterations in arbitrary real Banach spaces

    Directory of Open Access Journals (Sweden)

    Vara Prasad KNVV

    2006-01-01

    Full Text Available Let be an arbitrary real Banach space and a nonempty, closed, convex (not necessarily bounded subset of . If is a member of the class of Lipschitz, strongly pseudocontractive maps with Lipschitz constant , then it is shown that to each Mann iteration there is a Krasnosleskij iteration which converges faster than the Mann iteration. It is also shown that the Mann iteration converges faster than the Ishikawa iteration to the fixed point of .

  11. Ishikawa Iterative Process for a Pair of Single-valued and Multivalued Nonexpansive Mappings in Banach Spaces

    OpenAIRE

    Sokhuma, K.; Kaewkhao, A.

    2010-01-01

    Let be a nonempty compact convex subset of a uniformly convex Banach space , and let and be a single-valued nonexpansive mapping and a multivalued nonexpansive mapping, respectively. Assume in addition that and for all . We prove that the sequence of the modified Ishikawa iteration method generated from an arbitrary by , , where and , are sequences of positive numbers satisfying , , converges strongly to a common fixed point of and ; that is, there exists such tha...

  12. Weak and strong convergence theorems for finite families of asymptotically nonexpansive mappings in Banach spaces

    International Nuclear Information System (INIS)

    Let E be a real uniformly convex Banach space whose dual space E* satisfies the Kadec- Klee property, K be a closed convex nonempty subset of E . Let T1, T2, . . . , Tm : K ? K be asymptotically nonexpansive mappings of K into E with sequences (respectively) {kin}n=1? satisfying kin ? 1 as n ? ?, i = 1, 2 , ...,m and ?n=1?(kin - 1) in}n=1? be a sequence in [?, 1 - ? ], for each i element of { 1, 2 , . . . ,m} (respectively). Let {xn} be a sequence generated for m ? 2 by, x1 element of K, xn+1 = (1 - ?1n)xn + ?1nT1nyn+m-2, yn+m-2 = (1 - ?2n)xn + ?2nT2nyn+m-3, ..., yn = (1 - ?mn)xn + ?mnTmnxn , n ? 1. Let Intersectioni=1m F (Ti) ? 0 . Then, {xn} converges weakly to a common fixed point of the family {Ti}i=1m. Under some appropriate condition on the family {Ti}i=1m, a strong convergence theorem is also roved. (author)

  13. Direct Theorems in the Theory of Approximation of the Banach Space Vectors by Entire Vectors of Exponential Type

    CERN Document Server

    Grushka, Ya

    2007-01-01

    For an arbitrary operator A on a Banach space X which is a generator of C_0-group with certain growth condition at the infinity, the direct theorems on connection between the smoothness degree of a vector $x\\in X$ with respect to the operator A, the order of convergence to zero of the best approximation of x by exponential type entire vectors for the operator A, and the k-module of continuity are given. Obtained results allows to acquire Jackson-type inequalities in many classic spaces of periodic functions and weighted $L_p$ spaces.

  14. Strong convergence and control condition of modified Halpern iterations in Banach spaces

    Directory of Open Access Journals (Sweden)

    Yonghong Yao

    2006-04-01

    Full Text Available Let C be a nonempty closed convex subset of a real Banach space X which has a uniformly Gâteaux differentiable norm. Let T∈ΓC and f∈ΠC. Assume that {xt} converges strongly to a fixed point z of T as t→0, where xt is the unique element of C which satisfies xt=tf(xt+(1−tTxt. Let {αn} and {βn} be two real sequences in (0,1 which satisfy the following conditions: (C1lim⁡n→∞αn=0;(C2∑n=0∞αn=∞;(C60

  15. Approximating common fixed points of two asymptotically quasi-nonexpansive mappings in banach spaces

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Suppose K is a nonempty closed convex subset of a real Banach space E . Let S,T:K?K be two asymptotically quasi-nonexpansive maps with sequences { u n },{ v n }?[ 0,? such that ? n=1 ? u n

  16. Quadratic equations in Banach space, perturbation techniques and applications to Chandrasekhar's and related equations

    International Nuclear Information System (INIS)

    In this dissertation perturbation techniques are developed, based on the contraction mapping principle which can be used to prove existence and uniqueness for the quadratic equation x = y + lambdaB(x,x) (1) in a Banach space X; here B: XxX?X is a bounded, symmetric bilinear operator, lambda is a positive parameter and y as a subset of X is fixed. The following is the main result. Theorem. Suppose F: XxX?X is a bounded, symmetric bilinear operator and that the equation z = y + lambdaF(z,z) has a solution z/sup */ of sufficiently small norm. Then equation (1) has a unique solution in a certain closed ball centered at z/sup */. Applications. The theorem is applied to the famous Chandrasekhar equation and to the Anselone-Moore system which are of the form (1) above and yields existence and uniqueness for a solution of (1) for larger values of lambda than previously known, as well as more accurate information on the location of solutions

  17. Microwave imaging of elliptically shaped dielectric cylinders by means of an Lp Banach-space inversion algorithm

    International Nuclear Information System (INIS)

    Microwave imaging apparatuses have become very important tools in the framework of imaging systems. However, particular care must be taken when developing the data-processing algorithm needed to solve the underlying nonlinear and ill-posed inverse problem. Usually, regularization techniques developed in the framework of Hilbert spaces are used. In this paper, a new approach based on a regularization in the framework of Lp Banach spaces is considered, and its performances are evaluated by considering a reference canonical target with elliptical cross section. (paper)

  18. Inverse theorems in the theory of approximation of vectors in a Banach space with exponential type entire vectors

    CERN Document Server

    Torba, S

    2008-01-01

    Arbitrary operator A on a Banach space X which is the generator of C_0-group with certain growth condition at infinity is considered. The relationship between its exponential type entire vectors and its spectral subspaces is found. Inverse theorems on connection between the degree of smoothness of vector $x\\in X$ with respect to operator A, the rate of convergence to zero of the best approximation of x by exponential type entire vectors for operator A, and the k-module of continuity are established. Also, a generalization of the Bernstein-type inequality is obtained. The results allow to obtain Bernstein-type inequalities in weighted L_p spaces.

  19. Morse theory on banach manifolds

    International Nuclear Information System (INIS)

    The Morse Theory of critical points was extended by Palais and Smale to a certain class of functions on Hilbert manifolds. However, there are many variational problems in a nonlinear setting which for technical reasons are posed not on Hilbert but on Banach manifolds of mappings. This paper introduces a concept of a multivalued gradient vector field for a function defined on a Banach manifold. Using this concept, the Morse theory is generalized to some kind of Banach manifolds. The first chapter gives a definition of nondegeneracy of critical points for a real valued function defined on a reflexive Banach manifold, and then a handle-body decomposition theorem and Morse inequalities for this manifold are obtained. The second chapter proves the existence of solutions for a differential inclusion for a so-called accretive multi-valued mapping on a Finsler manifold. The third chapter introduces a definition of nondegeneracy of critical points for a real valued function defined on a general Banach manifold and, furthermore, generalizes the Morse handle-body decomposition theorem and the Morse inequalities to the Banach manifold

  20. An Extragradient Method and Proximal Point Algorithm for Inverse Strongly Monotone Operators and Maximal Monotone Operators in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Plubtieng Somyot

    2009-01-01

    Full Text Available Abstract We introduce an iterative scheme for finding a common element of the solution set of a maximal monotone operator and the solution set of the variational inequality problem for an inverse strongly-monotone operator in a uniformly smooth and uniformly convex Banach space, and then we prove weak and strong convergence theorems by using the notion of generalized projection. The result presented in this paper extend and improve the corresponding results of Kamimura et al. (2004, and Iiduka and Takahashi (2008. Finally, we apply our convergence theorem to the convex minimization problem, the problem of finding a zero point of a maximal monotone operator and the complementary problem.

  1. An Extragradient Method and Proximal Point Algorithm for Inverse Strongly Monotone Operators and Maximal Monotone Operators in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Somyot Plubtieng

    2009-01-01

    Full Text Available We introduce an iterative scheme for finding a common element of the solution set of a maximal monotone operator and the solution set of the variational inequality problem for an inverse strongly-monotone operator in a uniformly smooth and uniformly convex Banach space, and then we prove weak and strong convergence theorems by using the notion of generalized projection. The result presented in this paper extend and improve the corresponding results of Kamimura et al. (2004, and Iiduka and Takahashi (2008. Finally, we apply our convergence theorem to the convex minimization problem, the problem of finding a zero point of a maximal monotone operator and the complementary problem.

  2. Convergence in mean of weighted sums of {ank}-compactly uniformly integrable random elements in Banach spaces

    Directory of Open Access Journals (Sweden)

    M. Ordez Cabrera

    1997-09-01

    Full Text Available The convergence in mean of a weighted sum ∑kank(Xk−EXk of random elements in a separable Banach space is studied under a new hypothesis which relates the random elements with their respective weights in the sum: the {ank}-compactly uniform integrability of {Xn}. This condition, which is implied by the tightness of {Xn} and the {ank}-uniform integrability of {‖Xn‖}, is weaker than the compactly miform integrability of {Xn} and leads to a result of convergence in mean which is strictly stronger than a recent result of Wang, Rao and Deli.

  3. Iterative methods for nonlinear ill-posed problems in Banach spaces: convergence and applications to parameter identification problems

    International Nuclear Information System (INIS)

    In this paper, we study convergence of two different iterative regularization methods for nonlinear ill-posed problems in Banach spaces. One of them is a Landweber type iteration, the other one the iteratively regularized GaussNewton method with an a posteriori chosen regularization parameter in each step. We show that a discrepancy principle as a stopping rule renders these iteration schemes regularization methods, i.e., we prove their convergence as the noise level tends to zero. The theoretical findings are illustrated by two parameter identification problems for elliptic PDEs

  4. Strong Convergence Theorems of Modified Ishikawa Iterations for Countable Hemi-Relatively Nonexpansive Mappings in a Banach Space

    Directory of Open Access Journals (Sweden)

    Kumam Poom

    2009-01-01

    Full Text Available We prove some strong convergence theorems for fixed points of modified Ishikawa and Halpern iterative processes for a countable family of hemi-relatively nonexpansive mappings in a uniformly convex and uniformly smooth Banach space by using the hybrid projection methods. Moreover, we also apply our results to a class of relatively nonexpansive mappings, and hence, we immediately obtain the results announced by Qin and Su's result (2007, Nilsrakoo and Saejung's result (2008, Su et al.'s result (2008, and some known corresponding results in the literatures.

  5. Comparison of fastness of the convergence among Krasnoselskij, Mann, and Ishikawa iterations in arbitrary real Banach spaces

    Directory of Open Access Journals (Sweden)

    K. N. V. V. Vara Prasad

    2007-01-01

    Full Text Available Let E be an arbitrary real Banach space and K a nonempty, closed, convex (not necessarily bounded subset of E. If T is a member of the class of Lipschitz, strongly pseudocontractive maps with Lipschitz constant L≥1, then it is shown that to each Mann iteration there is a Krasnosleskij iteration which converges faster than the Mann iteration. It is also shown that the Mann iteration converges faster than the Ishikawa iteration to the fixed point of T.

  6. A Variational Principle in Reflexive Spaces with Kadec-Klee Norm.

    Czech Academy of Sciences Publication Activity Database

    Fabian, Marin; Revalski, J. P.

    2009-01-01

    Ro?. 16, ?. 1 (2009), s. 211-226. ISSN 0944-6532 R&D Projects: GA ?R GA201/04/0090 Institutional research plan: CEZ:AV0Z10190503 Keywords : reflexive space * Kadec-Klee norm * variational principle * perturbed function * well-posed infimum Subject RIV: BA - General Mathematics Impact factor: 0.813, year: 2009

  7. Two classes of spaces reflexive in the sense of Pontryagin

    International Nuclear Information System (INIS)

    The Pontryagin-van Kampen duality for locally compact Abelian groups can be generalized in two ways to wider classes of topological Abelian groups: in the first approach the dual group X. is endowed with the topology of uniform convergence on compact subsets of X and in the second, with the topology of uniform convergence on totally bounded subsets of X. The corresponding two classes of groups 'reflexive in the sense of Pontryagin-van Kampen' are very wide and are so close to each other that it was unclear until recently whether they coincide or not. A series of counterexamples constructed in this paper shows that these classes do not coincide and also answer several other questions arising in this theory. The results of the paper can be interpreted as evidence that the second approach to the generalization of the Pontryagin duality is more natural

  8. Integral mappings and the principle of local reflexivity for noncommutative L^1-spaces

    CERN Document Server

    Effros, E G; Ruan, Z J; Effros, Edward G.; Junge, Marius; Ruan, Zhong-Jin

    2000-01-01

    The operator space analogue of the {\\em strong form} of the principle of local reflexivity is shown to hold for any von Neumann algebra predual, and thus for any $C^{*}$-algebraic dual. This is in striking contrast to the situation for $C^{*}$-algebras, since, for example, $K(H)$ does not have that property. The proof uses the Kaplansky density theorem together with a careful analysis of two notions of integrality for mappings of operator spaces.

  9. Co-representations of Hopf-von Neumann algebras on operator spaces other than column Hilbert space

    OpenAIRE

    Runde, Volker

    2009-01-01

    Recently, M. Daws introduced a notion of co-representation of abelian Hopf--von Neumann algebras on general reflexive Banach spaces. In this note, we show that this notion cannot be extended beyond subhomogeneous Hopf--von Neumann algebras. The key is our observation that, for a von Neumann algebra $\\M$ and a reflexive operator space $E$, the normal spatial tensor product $\\M \\bar{\\tensor} \\CB(E)$ is a Banach algebra if and only if $\\M$ is subhomogeneous or $E$ is completely...

  10. Ring homomorphisms on real Banach algebras

    OpenAIRE

    Sin-Ei Takahasi; Takeshi Miura

    2003-01-01

    Let B be a strictly real commutative real Banach algebra with the carrier space ΦB. If A is a commutative real Banach algebra, then we give a representation of a ring homomorphism ρ:A→B, which needs not be linear nor continuous. If A is a commutative complex Banach algebra, then ρ(A) is contained in the radical of B.

  11. Ring homomorphisms on real Banach algebras

    Directory of Open Access Journals (Sweden)

    Sin-Ei Takahasi

    2003-08-01

    Full Text Available Let B be a strictly real commutative real Banach algebra with the carrier space ΦB. If A is a commutative real Banach algebra, then we give a representation of a ring homomorphism ρ:A→B, which needs not be linear nor continuous. If A is a commutative complex Banach algebra, then ρ(A is contained in the radical of B.

  12. On some strong convergence results of a new Halpern-type iterative process for quasi-nonexpansive mappings and accretive operators in Banach spaces

    OpenAIRE

    Dogan, K.; Karakaya, V.

    2015-01-01

    In this study, we introduce a new iterative processes to approximate common fixed points of an infinite family of quasi-nonexpansive mappings and obtain a strongly convergent iterative sequence to the common fixed points of these mappings in a uniformly convex Banach space. Also we prove that this process to approximate zeros of an infinite family of accretive operators and we obtain a strong convergence result for these operators. Our results improve and generalize many kno...

  13. Strong Convergence Theorems of the Ishikawa Process with Errors for Strictly Pseudocontractive Mapping of Browder-Petryshyn Type in Banach Spaces

    OpenAIRE

    Tang Yu-Chao; Cai Yong; Liu Li-Wei

    2011-01-01

    We prove several strong convergence theorems for the Ishikawa iterative sequence with errors to a fixed point of strictly pseudocontractive mapping of Browder-Petryshyn type in Banach spaces and give sufficient and necessary conditions for the convergence of the scheme to a fixed point of the mapping. The results presented in this work give an affirmative answer to the open question raised by Zeng et al. 2006, and generalize the corresponding result of Zeng et al. 2006, Osilike and Udomene 2...

  14. Positive Solutions of Singular Multipoint Boundary Value Problems for Systems of Nonlinear Second-Order Differential Equations on Infinite Intervals in Banach Spaces

    OpenAIRE

    Xingqiu Zhang

    2009-01-01

    The cone theory together with Mnch fixed point theorem and a monotone iterative technique is used to investigate the positive solutions for some boundary problems for systems of nonlinear second-order differential equations with multipoint boundary value conditions on infinite intervals in Banach spaces. The conditions for the existence of positive solutions are established. In addition, an explicit iterative approximation of the solution for the boundary value problem is also derived.

  15. On the fractional order m-point boundary value problem in reflexive Banach spaces and weak topologies

    Science.gov (United States)

    Salem, Hussein A. H.

    2009-02-01

    This paper is devoted to investigate the existence of Pseudo solutions for the nonlinear m-point boundary value problem of fractional type where 00 with . It is assumed that q is a real-valued continuous function and f is a nonlinear Pettis integrable function.

  16. Some Extensions of Banach's Contraction Principle in Complete Cone Metric Spaces

    Directory of Open Access Journals (Sweden)

    Raja P

    2008-01-01

    Full Text Available Abstract In this paper we consider complete cone metric spaces. We generalize some definitions such as -nonexpansive and -uniformly locally contractive functions -closure, -isometric in cone metric spaces, and certain fixed point theorems will be proved in those spaces. Among other results, we prove some interesting applications for the fixed point theorems in cone metric spaces.

  17. Moro reflex

    Science.gov (United States)

    Startle response; Startle reflex; Embrace reflex ... Your baby's doctor will check for this reflex right after birth and during well-child visits. To see the Moro reflex, the child will be placed face up on a soft, ...

  18. Inner characterizations of weakly compactly generated Banach spaces and their relatives.

    Czech Academy of Sciences Publication Activity Database

    Fabian, Marin; Godefroy, G.; Montesinos, V.; Zizler, V.

    2004-01-01

    Ro?. 297, - (2004), s. 419-455. ISSN 0022-247X R&D Projects: GA AV ?R IAA1019301; GA ?R GA201/01/1198 Institutional research plan: CEZ:AV0Z1019905 Keywords : weakly compactly generated space * weakly Lindel"of determined space * Hilbert generated space Subject RIV: BA - General Mathematics Impact factor: 0.490, year: 2004

  19. On some properties of Banach operators. II

    Directory of Open Access Journals (Sweden)

    A. R. Khan

    2004-09-01

    Full Text Available Using the notion of a Banach operator, wehave obtained a decompositional property of aHilbert space, and the equality of two invertible boundedlinear multiplicative operators on a normed algebra with identity.

  20. Strong Convergence Theorems of the Ishikawa Process with Errors for Strictly Pseudocontractive Mapping of Browder-Petryshyn Type in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Tang Yu-Chao

    2011-01-01

    Full Text Available We prove several strong convergence theorems for the Ishikawa iterative sequence with errors to a fixed point of strictly pseudocontractive mapping of Browder-Petryshyn type in Banach spaces and give sufficient and necessary conditions for the convergence of the scheme to a fixed point of the mapping. The results presented in this work give an affirmative answer to the open question raised by Zeng et al. 2006, and generalize the corresponding result of Zeng et al. 2006, Osilike and Udomene 2001, and others.

  1. Frchet differential of a power series in Banach algebras

    Directory of Open Access Journals (Sweden)

    Benedetto Silvestri

    2010-01-01

    Full Text Available We present two new forms in which the Frchet differential of a power series in a unitary Banach algebra can be expressed in terms of absolutely convergent series involving the commutant \\(C(T : A \\mapsto [A,T]\\. Then we apply the results to study series of vector-valued functions on domains in Banach spaces and to the analytic functional calculus in a complex Banach space.

  2. Reflexive Aero Structures for Enhanced Survivability Project

    National Aeronautics and Space Administration Cornerstone Research Group Inc. (CRG) proposes to develop an advanced reflexive structure system to increase the survivability of aerostructures. This reflexive...

  3. A note on biorthogonal systems in weakly compactly generated Banach spaces.

    Czech Academy of Sciences Publication Activity Database

    Fabian, Marin; Gonzles, A.; Montesinos, V.

    2009-01-01

    Ro?. 34, ?. 2 (2009), s. 555-564. ISSN 1239-629X R&D Projects: GA AV ?R(CZ) IAA100190610 Institutional research plan: CEZ:AV0Z10190503 Keywords : weakly compactly generated (sub)space * projectional resolution * fundamental biorthogonal system Subject RIV: BA - General Mathematics Impact factor: 0.539, year: 2009

  4. Operator representation of weakly Cauchy sequences in projective tensor products of Banach spaces

    Directory of Open Access Journals (Sweden)

    J. M. Baker

    1980-09-01

    Full Text Available It is shown that the above sequences always determine linear transformations and if the sequences are bounded under the least cross norm, that the transformations are continuous. Such operators are characterized to within algebraic isomorphism with the weak-star sequential closure of the tensor product space in its second dual, and consequently certain classes of weakly sequentially complete projective tensor products are exhibited.

  5. Differentiation and integration operators on weighted Banach spaces of holomorphic functions

    OpenAIRE

    Abanin, Alexander V.; Tien, Pham Trong

    2015-01-01

    We show that some previous results concerning the boundedness of differentiation and integration operators on weighted spaces given by radial weights in the unit disk or the complex plane might fail without some natural additional conditions. In view of this we develop a new elementary approach which is essentially different from the previous one and can be applied for weights and domains of general types. We also establish a new characterization of some popular classes of r...

  6. A hierarchy of Banach spaces with $C(K)$ Calkin Algebras

    OpenAIRE

    Motakis, Pavlos; Puglisi, Daniele; Zisimopoulou, Despoina

    2014-01-01

    For every well founded tree $\\mathcal{T}$ having a unique root such that every non-maximal node of it has countable infinitely many immediate successors, we construct a $\\mathcal{L}_\\infty$-space $X_{\\mathcal{T}}$. We prove that for each such tree $\\mathcal{T}$, the Calkin algebra of $X_{\\mathcal{T}}$ is homomorphic to $C(\\mathcal{T})$, the algebra of continuous functions defined on $\\mathcal{T}$, equipped with the usual topology. We use this fact to conclude that for every ...

  7. Functional analysis and applied optimization in Banach spaces applications to non-convex variational models

    CERN Document Server

    Botelho, Fabio

    2014-01-01

    This book introduces the basic concepts of real and functional analysis. It presents the fundamentals of the calculus of variations, convex analysis, duality, and optimization that are necessary to develop applications to physics and engineering problems. The book includes introductory and advanced concepts in measure and integration, as well as an introduction to Sobolev spaces. The problems presented are nonlinear, with non-convex variational formulation. Notably, the primal global minima may not be attained in some situations, in which cases the solution of the dual problem corresponds to an appropriate weak cluster point of minimizing sequences for the primal one. Indeed, the dual approach more readily facilitates numerical computations for some of the selected models. While intended primarily for applied mathematicians, the text will also be of interest to engineers, physicists, and other researchers in related fields.

  8. Spaces of compact operators which are M-ideals in L(X,Y)

    OpenAIRE

    Chong-Man Cho

    1992-01-01

    Suppose X and Y are reflexive Banach spaces. If K(X,Y), the space of all compact linear operaters from X to Y is an M-ideal in L(X,Y), the space of all bounded linear operators from X to Y, then the second dual space K(X,Y)** of K(X,Y) is isometrically isomorphic to L(X,Y).

  9. Knee Jerk Reflex (Patellar Reflex)

    Science.gov (United States)

    2012-06-26

    In this quick and simple activity about reflexes (third activity on the page), learners conduct a simple test to explore the knee jerk reflex, typically conducted at the doctor's office. In this version, learners work in pairs and use their hand to prompt the reflex (not a hammer!). This activity is one of several activities featured on this webpage related to human reflexes.

  10. ANALYSIS OF AN OPERATOR EQUATION WITH THE DIFFERENTIABLE IN BANACH SPACE OPERATOR AND ITS APPLICATION TO THE INVESTIGATION OF REACTOR MODEL DYNAMICS

    Directory of Open Access Journals (Sweden)

    Micha? Podowski

    1977-01-01

    Full Text Available An operator equation of the following form?x = z + F(x,where z - an element of Banach space X and F(x?X for x?D?X, is investigated. In the cas of m-order differentiable operator F (m>3, conditions of existence and uniqueness of a solution of considered equation are formulated and an estimation of the norm of this solution as a function of the norm z is obtained.The results of theoretical analysis are applied to the point reactor model with nonlinear, temperature-type reactivity feedback. The conditions of the asymptotic stability for the autonomous system as well as for the system including the external reactivity oscilations, are formulated.

  11. Q.H.I. spaces

    OpenAIRE

    Ferenczi, Valentin

    1996-01-01

    A Banach space $X$ is said to be Q.H.I. if eve\\-ry infinite dimensional quo\\-tient spa\\-ce of $X$ is H.I.: that is, a space is Q.H.I. if the H.I. property is not only stable passing to subspaces, but also passing to quotients and to the dual. We show that Gowers-Maurey's space is Q.H.I.; then we provide an example of a reflexive H.I. space ${\\cal X}$ whose dual is not H.I., from which it follows that $\\cal X$ is not Q.H.I.

  12. Modification of Otolith-Ocular Reflexes, Motion Perception and Manual Control During Variable Radius Centrifugation Following Space Flight

    Science.gov (United States)

    Wood, Scott J.; Clarke, A. H.; Rupert, A. H.; Harm, D. L.; Clement, G. R.

    2009-01-01

    Two joint ESA-NASA studies are examining changes in otolith-ocular reflexes and motion perception following short duration space flights, and the operational implications of post-flight tilt-translation ambiguity for manual control performance. Vibrotactile feedback of tilt orientation is also being evaluated as a countermeasure to improve performance during a closed-loop nulling task. Data is currently being collected on astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation is utilized to elicit otolith reflexes in the lateral plane without concordant roll canal cues. Unilateral centrifugation (400 deg/s, 3.5 cm radius) stimulates one otolith positioned off-axis while the opposite side is centered over the axis of rotation. During this paradigm, roll-tilt perception is measured using a subjective visual vertical task and ocular counter-rolling is obtained using binocular video-oculography. During a second paradigm (216 deg/s, less than 20 cm radius), the effects of stimulus frequency (0.15 - 0.6 Hz) are examined on eye movements and motion perception. A closed-loop nulling task is also performed with and without vibrotactile display feedback of chair radial position. Data collection is currently ongoing. Results to date suggest there is a trend for perceived tilt and translation amplitudes to be increased at the low and medium frequencies on landing day compared to pre-flight. Manual control performance is improved with vibrotactile feedback. One result of this study will be to characterize the variability (gain, asymmetry) in both otolith-ocular responses and motion perception during variable radius centrifugation, and measure the time course of post-flight recovery. This study will also address how adaptive changes in otolith-mediated reflexes correspond to one's ability to perform closed-loop nulling tasks following G-transitions, and whether manual control performance can be improved with vibrotactile feedback of orientation.

  13. Reduction of LieJordan Banach algebras and quantum states

    International Nuclear Information System (INIS)

    In this paper, it is shown that the concept of dynamical correspondence for Jordan Banach algebras is equivalent to a Lie structure compatible with the Jordan one. Then a theory of reduction of LieJordan Banach algebras in the presence of quantum constraints is presented and compared to the standard reduction of C*-algebras of observables of a quantum system. The space of states of the reduced LieJordan Banach algebra is characterized in terms of Dirac states on the physical algebra of observables and its GNS representations described in terms of states on the unreduced algebra. (paper)

  14. Derivations on Banach algebras

    OpenAIRE

    Talebi, S.; Hejazian, S.

    2003-01-01

    Let D be a derivation on a Banach algebra; by using the operator D2, we give necessary and sufficient conditions for the separating ideal of D to be nilpotent. We also introduce an ideal M(D) and apply it to find out more equivalent conditions for the continuity of D and for nilpotency of its separating ideal.

  15. Module amenability for Banach modules

    Scientific Electronic Library Online (English)

    D, Ebrahimi Bagha; M, Amini.

    2011-06-01

    Full Text Available Se estudia el mdulo de receptividad de los mdulos de Banach. Esta es una generalizacin natural de la receptividad de Johnson de las lgebras de Banach. Como ejemplo se muestra que para un grupo abeliano discreto G l p(G) es receptivo como un G l p(G)- mdulo, si y slo si G es receptivo, donde l [...] (G) es un lgebra de Banach con producto punto. Abstract in english We study the module amenability of Banach modules. This is a natural generalization of Johnsons amenability of Banach algebras. As an example we show that for a discrete abelian group G, l p(G) is amenable as an l(G)-module if and only if G is amenable, where l(G) is a Banach algebra with pointwi [...] se multiplication.

  16. Impulsive moving mirror model and the stability of linear homogeneous differential equations with impulse effect in a Banach space

    International Nuclear Information System (INIS)

    From a special class of systems has been used the linear homogeneous differential equations with impulse effect in Minkowski space field theory with time dependent boundary conditions, i.e. those of moving mirrors. The field theoretical approach for studing the properties of the vacuum starts from an analysis of the behaviour of local field quantities in Minkowski space with uniformly moving mirrors. For the impulsive moving mirror model is the real process of interaction between the quantum field and the external mirror a subject to disturbances in its evolution acting in time very short compared with the entire duration of the process. The stability of the process in the stability of the vacuum state energy. 7 refs

  17. Existence of positive solutions for nonlocal second-order boundary value problem with variable parameter in Banach spaces

    Directory of Open Access Journals (Sweden)

    Zhang Peiguo

    2011-01-01

    Full Text Available Abstract By obtaining intervals of the parameter ?, this article investigates the existence of a positive solution for a class of nonlinear boundary value problems of second-order differential equations with integral boundary conditions in abstract spaces. The arguments are based upon a specially constructed cone and the fixed point theory in cone for a strict set contraction operator. MSC: 34B15; 34B16.

  18. Reflexive Aero Structures for Enhanced Survivability Project

    National Aeronautics and Space Administration Cornerstone Research Group Inc. (CRG) will develop an advanced reflexive structure technology system to increase the survivability of future systems constructed of...

  19. Moduli and Characteristics of Monotonicity in Some Banach Lattices.

    Czech Academy of Sciences Publication Activity Database

    Foralewski, P.; Hudzik, H.; Kaczmarek, R.; Krbec, Miroslav

    -, - (2010), s. 852346. ISSN 1687-1812 R&D Projects: GA AV ?R IAA100190804; GA Mk LC06052 Institutional research plan: CEZ:AV0Z10190503 Keywords : Banach lattice * characteristics of monotonicity * Orlicz function space * Orlicz sequence space Subject RIV: BA - General Mathematics http://www.fixedpointtheoryandapplications.com/content/2010/1/852346

  20. ZAG-Otolith: Modification of Otolith-Ocular Reflexes, Motion Perception and Manual Control during Variable Radius Centrifugation Following Space Flight

    Science.gov (United States)

    Wood, S. J.; Clarke, A. H.; Rupert, A. H.; Harm, D. L.; Clement, G. R.

    2009-01-01

    Two joint ESA-NASA studies are examining changes in otolith-ocular reflexes and motion perception following short duration space flights, and the operational implications of post-flight tilt-translation ambiguity for manual control performance. Vibrotactile feedback of tilt orientation is also being evaluated as a countermeasure to improve performance during a closed-loop nulling task. METHODS. Data is currently being collected on astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation is utilized to elicit otolith reflexes in the lateral plane without concordant roll canal cues. Unilateral centrifugation (400 deg/s, 3.5 cm radius) stimulates one otolith positioned off-axis while the opposite side is centered over the axis of rotation. During this paradigm, roll-tilt perception is measured using a subjective visual vertical task and ocular counter-rolling is obtained using binocular video-oculography. During a second paradigm (216 deg/s, centrifugation, and measure the time course of postflight recovery. This study will also address how adaptive changes in otolith-mediated reflexes correspond to one's ability to perform closed-loop nulling tasks following G-transitions, and whether manual control performance can be improved with vibrotactile feedback of orientation.

  1. The reconstruction formula for Banach frames and duality

    CERN Document Server

    Carando, Daniel; Schmidberg, Pablo

    2011-01-01

    We study conditions on a Banach frame that ensures the validity of a reconstruction formula. In particular, we show that any Banach frames for (a subspace of) $L_p$ or $L_{p,q}$ ($1\\le p < \\infty$) with respect to a solid sequence space always satisfies an unconditional reconstruction formula. The existence of reconstruction formulae allows us to prove some James-type results for atomic decompositions: an unconditional atomic decomposition (or unconditional Schauder frame) for $X$ is shrinking (respectively, boundedly complete) if and only if $X$ does not contain an isomorphic copy of $\\ell_1$ (respectively, $c_0$).

  2. Group actions on chains of Banach manifolds and applications to fluid dynamics

    OpenAIRE

    Gay-balmaz, Franc?ois; Ratiu, Tudor S.

    2006-01-01

    This paper presents the theory of non-smooth Lie group actions on chains of Banach manifolds. The rigorous functional analytic spaces are given to deal with quotients of such actions. A hydrodynamical example is studied in detail.

  3. Vestibular-Ocular Reflex

    Science.gov (United States)

    Marlene Y. MacLeish, Ed.D.

    2013-01-30

    In this activity, learners will perform various investigations to understand the vestibular-ocular reflex and learn about the importance of visual cues in maintaining balance. During the two-part activity, learners will compare the stability of a moving image under two conditions as well as compare the effects of rotation on the sensation of spinning under varying conditions. This lesson guide includes background information, review and critical thinking questions with answers, and handouts. Educators can also use this activity to discuss how the brain functions in space and how researchers study the vestibular function in space.

  4. Baroreceptor Reflex Role Play

    Science.gov (United States)

    Marlene Y. MacLeish

    2012-06-26

    In this activity about the baroreceptor reflex (BR) arc (page 123 of the PDF), learners discover the importance of maintaining adequate arterial blood pressure through a role playing exercise. This activity will model how the brain processes information and sends out signals to the heart and arteries. Learners can also consider how this affects astronauts in the microgravity environment of space. The lesson guide, part of NASA's "The Brain in Space: A Teacher's Guide with Activities for Neuroscience," includes background information and evaluation strategies. Note: this activity requires 9 learners per group.

  5. Wireless quantified reflex device

    Science.gov (United States)

    Lemoyne, Robert Charles

    The deep tendon reflex is a fundamental aspect of a neurological examination. The two major parameters of the tendon reflex are response and latency, which are presently evaluated qualitatively during a neurological examination. The reflex loop is capable of providing insight for the status and therapy response of both upper and lower motor neuron syndromes. Attempts have been made to ascertain reflex response and latency, however these systems are relatively complex, resource intensive, with issues of consistent and reliable accuracy. The solution presented is a wireless quantified reflex device using tandem three dimensional wireless accelerometers to obtain response based on acceleration waveform amplitude and latency derived from temporal acceleration waveform disparity. Three specific aims have been established for the proposed wireless quantified reflex device: 1. Demonstrate the wireless quantified reflex device is reliably capable of ascertaining quantified reflex response and latency using a quantified input. 2. Evaluate the precision of the device using an artificial reflex system. 3.Conduct a longitudinal study respective of subjects with healthy patellar tendon reflexes, using the wireless quantified reflex evaluation device to obtain quantified reflex response and latency. Aim 1 has led to the steady evolution of the wireless quantified reflex device from a singular two dimensional wireless accelerometer capable of measuring reflex response to a tandem three dimensional wireless accelerometer capable of reliably measuring reflex response and latency. The hypothesis for aim 1 is that a reflex quantification device can be established for reliably measuring reflex response and latency for the patellar tendon reflex, comprised of an integrated system of wireless three dimensional MEMS accelerometers. Aim 2 further emphasized the reliability of the wireless quantified reflex device by evaluating an artificial reflex system. The hypothesis for aim 2 is that the wireless quantified reflex device can obtain reliable reflex parameters (response and latency) from an artificial reflex device. Aim 3 synthesizes the findings relevant to aim 1 and 2, while applying the wireless accelerometer reflex quantification device to a longitudinal study of healthy patellar tendon reflexes. The hypothesis for aim 3 is that during a longitudinal evaluation of the deep tendon reflex the parameters for reflex response and latency can be measured with a considerable degree of accuracy, reliability, and reproducibility. Enclosed is a detailed description of a wireless quantified reflex device with research findings and potential utility of the system, inclusive of a comprehensive description of tendon reflexes, prior reflex quantification systems, and correlated applications.

  6. On projection constant problems and the existence of metric projections in normed spaces

    Directory of Open Access Journals (Sweden)

    Wataru Takahashi

    2001-12-01

    Full Text Available We give the sufficient conditions for the existence of a metric projection onto convex closed subsets of normed linear spaces which are reduced conditions than that in the case of reflexive Banach spaces and we find a general formula for the projections onto the maximal proper subspaces of the classical Banach spaces l p,1≤p<∞ and c 0. We also give the sufficient and necessary conditions for an infinite matrix to represent a projection operator from l p,1≤p<∞ or c 0 onto anyone of their maximal proper subspaces.

  7. Reflexive open mapping on generalized graphs

    International Nuclear Information System (INIS)

    A locally connected and locally compact metric image of generalized graph under a reflexive open mapping is proved to be a generalized graph; further it is shown that for all acyclic generalized graphs X any locally one-to-one reflexive open mapping of X into a Hansdorff space is globally one-to-one. Several problems are posed and some examples are given

  8. Brane tilings and reflexive polygons

    International Nuclear Information System (INIS)

    Reflexive polygons have attracted great interest both in mathematics and in physics. This paper discusses a new aspect of the existing study in the context of quiver gauge theories. These theories are 4d supersymmetric worldvolume theories of D3 branes with toric Calabi-Yau moduli spaces that are conveniently described with brane tilings. We find all 30 theories corresponding to the 16 reflexive polygons, some of the theories being toric (Seiberg) dual to each other. The mesonic generators of the moduli spaces are identified through the Hilbert series. It is shown that the lattice of generators is the dual reflexive polygon of the toric diagram. Thus, the duality forms pairs of quiver gauge theories with the lattice of generators being the toric diagram of the dual and vice versa. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Stability of functional equations in Banach algebras

    CERN Document Server

    Cho, Yeol Je; Rassias, Themistocles M; Saadati, Reza

    2015-01-01

    Some of the most recent and significant results on homomorphisms and derivations in Banach algebras, quasi-Banach algebras, C*-algebras, C*-ternary algebras, non-Archimedean Banach algebras and multi-normed algebras are presented in this book. A brief introduction for functional equations and their stability is provided with historical remarks. Since the homomorphisms and derivations in Banach algebras are additive and R-linear or C-linear, the stability problems for additive functional equations and additive mappings are studied in detail. The latest results are discussed and examined in stability theory for new functional equations and functional inequalities in Banach algebras and C*-algebras, non-Archimedean Banach algebras, non-Archimedean C*-algebras, multi-Banach algebras and multi-C*-algebras. Graduate students with an understanding of operator theory, functional analysis, functional equations and analytic inequalities will find this book useful for furthering their understanding and discovering the l...

  10. Integral functionals on $L^p$-spaces: infima over sub-level sets

    OpenAIRE

    Ricceri, Biagio

    2013-01-01

    In this paper, we establish the following result: Let $(T,{\\cal F},\\mu)$ be a $\\sigma$-finite measure space, let $Y$ be a reflexive real Banach space, and let $\\varphi, \\psi:Y\\to {\\bf R}$ be two sequentially weakly lower semicontinuous functionals such that $$\\inf_{y\\in Y}{{\\min\\{\\varphi(y),\\psi(y)\\}}\\over {1+\\|y\\|^p}}>-\\infty$$ for some $p>0$. Moreover, assume that $\\varphi$ has no global minima, while $\\varphi+\\lambda\\psi$ is coercive and has a unique global minimum for ...

  11. Several complex variables and Banach algebras

    International Nuclear Information System (INIS)

    This paper aims to present certain applications of the theory of holomorphic functions of several complex variables to the study of commutative Banach algebras. The material falls into the following sections: (A) Introcution to Banach algebras (this will not presuppose any knowledge of the subject); (B) Groups of differential forms (mainly concerned with setting up a useful language); (C) Polynomially convex domains. (D) Holomorphic functional calculus for Banach algebras; (E) Some applications of the functional calculus. (author)

  12. Module Biprojective and Module Biflat Banach Algebras

    OpenAIRE

    Bodaghi, Abasalt; Amini, Massoud

    2009-01-01

    In this paper we define module biprojctivity and module biflatness for a Banach algebra which is a Banach module over another Banach algebra with compatible actions, and find their relation to classical biprojectivity and biflatness. As a typical example, We show that for an inverse semigroup $S$ with an upward directed set of idempotents $E$, the semigroup algebra $ \\ell ^{1}(S)$, as an $\\ell ^{1}(E)$-module, is module biprojective if and only if an appropriate group homomo...

  13. On Banach modules II. Pseudodeterminants and traces

    Science.gov (United States)

    Kaijser, S.

    1997-03-01

    1. In the paper [Kai] it was observed that if A is a Banach algebra (over R or C) then the dual space is not only an A-A-bimodule, but is also injective as a left (or right) A-module. Furthermore, if M is a left (or right) Banach module over the unital Banach algebra A, then there is a natural bilinear map, there denoted TrA, from M M[prime prime or minute] to A[prime prime or minute], defined byformula here(or [left angle bracket]TrA(m, m[prime prime or minute]), a[right angle bracket] = [left angle bracket]m[prime prime or minute], ma[right angle bracket]). The map TrA can be extended to the projective tensor product M[multiply sign in circle, circumflex accent]M[prime prime or minute], which is also an A-A-bimodule. It is easy to see that the map TrA is a bimodule homomorphism, so that the image is an A-A-submodule of A[prime prime or minute]. This module was denoted EA (M) in [Kai] and is in general not closed as a subspace of M[prime prime or minute]. It does, however, have a natural norm (as a quotient space of M[multiply sign in circle, circumflex accent]M[prime prime or minute]) and the unit ball can be used to define a new norm [parallel R: parallel]a[parallel R: parallel]new = sup {|[left angle bracket]e, a[right angle bracket] | e[set membership] the unit ball of EA(M)} on A, and it is easy to see that this new norm is simply the operator norm of a as an operator on M. The conclusion is that if a[prime prime or minute][set membership]A[prime prime or minute] is not only continuous with respect to the norm [parallel R: parallel]a[parallel R: parallel]L(M) (which is of course in general smaller thatn the given norm on A) but also with respect to the weak topology on A given by the set of all functionals of the form (01), then a[prime prime or minute] has a representation of the formformula here.

  14. Quasi-multipliers of Hilbert and Banach C*-bimodules

    CERN Document Server

    Pavlov, Alexander; Schick, Thomas

    2010-01-01

    Quasi-multipliers for a Hilbert C*-bimodule V were introduced by Brown, Mingo and Shen 1994 as a certain subset of the Banach bidual module V**. We give another (equivalent) definition of quasi-multipliers for Hilbert C*-bimodules using the centralizer approach and then show that quasi-multipliers are, in fact, universal (maximal) objects of a certain category. We also introduce quasi-multipliers for bimodules in Kasparov's sense and even for Banach bimodules over C*-algebras, provided these C*-algebras act non-degenerately. A topological picture of quasi-multipliers via the quasi-strict topology is given. Finally, we describe quasi-multipliers in two main situations: for the standard Hilbert bimodule l_2(A) and for bimodules of sections of Hilbert C*-bimodule bundles over locally compact spaces.

  15. Banach *-algebras, B*-seminorms, and positive functionals

    Science.gov (United States)

    Gaur, A.

    2007-07-01

    This paper concerns Banach *-algebras which are nonunital or have bounded approximate identity. A necessary and sufficient condition is given for a B*-seminorm to be regular. A one-to-one correspondence between the carrier space of a complex Banach *-algebra and the set of all regular B*-seminorms is established. Interaction between [alpha]-bounded functionals and regular B*-seminorms is examined. We prove that the carrier space of a Banach *-algebra is identical with the set of all extreme points of positive linear functionals. The main approach is via an ordering of the algebra, the positive cone being the closure of the set of certain elements in the set of self-adjoint (hermitian) elements of the algebra (but not in the algebra) where the involution on the algebra is not continuous. A characterization of the set of centralizers for algebra in terms of positive cones where the involution is not continuous is given. This result improves some previous results on this topic. In the context of approximate identity of norm less than or equal to the real number 1, we prove that a cone is closed with respect to a special product if and only if the algebra is commutative modulo its radical. An application of the Shirali-Ford theorem is also discussed. In particular, the equality between the two positive cones is established if the algebra is symmetric.

  16. Modern methods in topological vector spaces

    CERN Document Server

    Wilansky, Albert

    2013-01-01

    Designed for a one-year course in topological vector spaces, this text is geared toward advanced undergraduates and beginning graduate students of mathematics. The subjects involve properties employed by researchers in classical analysis, differential and integral equations, distributions, summability, and classical Banach and Frecht spaces. Optional problems with hints and references introduce non-locally convex spaces, Kthe-Toeplitz spaces, Banach algebra, sequentially barrelled spaces, and norming subspaces.Extensive introductory chapters cover metric ideas, Banach space, topological vect

  17. A note on Banach algebras that are not isomorphic to a group algebra / Una nota sobre lgebras de Banach no isomorfas a una lgebra de grupos

    Scientific Electronic Library Online (English)

    DIOMEDES, BARCENAS; WALTER, ESPINOZA; EDIXON, ROJAS.

    2008-06-15

    Full Text Available En este artculo se prueba que algunas lgebras de Banach clsicas no son isomorfas a un lgebra de grupo. Estas lgebras incluyen a las lgebras C(K) donde K es un espacio de Hausdorff Compacto. En el caso de las amalgamas, damos condiciones para que una amalgama sea un lgebra de grupo. [...] Abstract in english It is proved in this paper that several classical Banach algebras are not isomorphic to a group algebra. These algebras includes C(K) algebras where K is a compact Hausdorff space. In the case of amalgams, we give conditions for an amalgam to be a group algebra. [...

  18. A note on Banach algebras that are not isomorphic to a group algebra Una nota sobre lgebras de Banach no isomorfas a una lgebra de grupos

    Directory of Open Access Journals (Sweden)

    DIOMEDES BARCENAS

    Full Text Available It is proved in this paper that several classical Banach algebras are not isomorphic to a group algebra. These algebras includes C(K algebras where K is a compact Hausdorff space. In the case of amalgams, we give conditions for an amalgam to be a group algebra.En este artculo se prueba que algunas lgebras de Banach clsicas no son isomorfas a un lgebra de grupo. Estas lgebras incluyen a las lgebras C(K donde K es un espacio de Hausdorff Compacto. En el caso de las amalgamas, damos condiciones para que una amalgama sea un lgebra de grupo.

  19. Computer simulations of a reflex triode

    International Nuclear Information System (INIS)

    A reflex triode can achieve a low-impedance state with higher current and lower voltage than an ordinary diode with the same anode-cathode spacing. Because its lower impedance is the result of reflexing electrons, it is possible to switch between low and high impedance states by altering the electron population. The authors have built a special-purpose computer code to study details of the reflex triode in one-dimension. They present simulations of a reflex triode as it approaches the low-impedance conduction phase. The simulations show evidence of viractor-like oscillations as well as a Pierce-type instability in certain parameter regimes. This instability violently disrupts the current in some cases

  20. Wave-front sets of Banach function types

    OpenAIRE

    Coriasco, Sandro; Johansson, Karoline; Toft, Joachim

    2009-01-01

    Let $\\omega ,\\omega _0$ be appropriate weight functions and $\\mathscr B$ be an invariant BF-space. We introduce the wave-front set $\\WF_{\\FB(\\omega )}(f)$ with respect to weighted Fourier Banach space $\\FB(\\omega )$. We prove that usual mapping properties for pseudo-differential operators $\\op _t (a)$ with symbols $a$ in $S^{(\\omega _0)}_{\\rho ,0}$ hold for such wave-front sets. In particular we prove %% $\\displaystyle\\WF _{\\FB(\\omega /\\omega _0)}(\\op _t (a) f)\\subseteq \\WF _{\\FB(\\omega...

  1. The Grasp Reflex and Moro Reflex in Infants: Hierarchy of Primitive Reflex Responses

    OpenAIRE

    Yasuhiro Suzuki; Yasuhisa Toribe; Yasuyuki Futagi

    2012-01-01

    The plantar grasp reflex is of great clinical significance, especially in terms of the detection of spasticity. The palmar grasp reflex also has diagnostic significance. This grasp reflex of the hands and feet is mediated by a spinal reflex mechanism, which appears to be under the regulatory control of nonprimary motor areas through the spinal interneurons. This reflex in human infants can be regarded as a rudiment of phylogenetic function. The absence of the Moro reflex during the neonatal p...

  2. A note on the L-fuzzy Banach's contraction principle

    International Nuclear Information System (INIS)

    Recently, Alaca et al. [Alaca C, Turkoglu D, Yildiz C. Fixed points in intuitionistic fuzzy metric spaces. Chaos, Solitons and Fractals 2006;29:10738] proved fuzzy Banach fixed point theorem in intuitionistic fuzzy metric spaces and Saadati [Saadati R. Notes to the paper 'fixed points in intuitionistic fuzzy metric spaces' and its generalization to L-fuzzy metric spaces. Chaos, Solitions and Fractals 2008;35:80-176] extended it in generalized fuzzy metric spaces. The purpose of this paper is to give a correct proof of the main result in Saadati [Saadati R. Notes to the paper 'fixed points in intuitionistic fuzzy metric spaces' and its generalization to L-fuzzy metric spaces. Chaos, Solitions and Fractals 2008;35:80-176].

  3. BanachMazur Distance Between Convex Quadrangles

    Directory of Open Access Journals (Sweden)

    Lassak Marek

    2014-12-01

    Full Text Available It is proved that the Banach-Mazur distance between arbitrary two convex quadrangles is at most 2. The distance equals 2 if and only if the pair of these quadrangles is a parallelogram and a triangle.

  4. On Reflexive Data Models

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, S.

    2000-08-20

    An information system is reflexive if it stores a description of its current structure in the body of stored information and is acting on the base of this information. A data model is reflexive, if its language is meta-closed and can be used to build such a system. The need for reflexive data models in new areas of information technology applications is argued. An attempt to express basic notions related to information systems is made in the case when the system supports and uses meta-closed representation of the data.

  5. The Banach-Mazur-Schmidt game and the Banach-Mazur-McMullen game

    OpenAIRE

    Fishman, Lior; Reams, Vanessa; Simmons, David

    2015-01-01

    We introduce two new mathematical games, the Banach-Mazur-Schmidt game and the Banach-Mazur-McMullen game, merging well-known games. We investigate the properties of the games, as well as providing an application to Diophantine approximation theory, analyzing the geometric structure of certain Diophantine sets.

  6. Central Limit Theorem for truncated heavy tailed Banach valued random vectors

    OpenAIRE

    Chakrabarty, Arijit

    2010-01-01

    In this paper the question of the extent to which truncated heavy tailed random vectors, taking values in a Banach space, retain the characteristic features of heavy tailed random vectors, is answered from the point of view of the central limit theorem.

  7. Reflexivity and connectedness

    OpenAIRE

    Sather-Wagstaff, Sean

    2012-01-01

    Given a finitely generated module over a commutative noetherian ring that satisfies certain reflexivity conditions, we show how failure of the semidualizing property for the module manifests in a disconnection of the prime spectrum of the ring.

  8. Reflex sympathetic dystrophy

    International Nuclear Information System (INIS)

    Reflex sympathetic dystrophy is characterized by intense and disproportionate local pain, associated with vasomotor and trophic changes. Extremities are commonly involved, especially when a trauma or surgery, even minor, has occurred. Likewise, spontaneous or idiopathic presentation of this syndrome is much less frequent. Here we describe the clinical picture of a young woman presenting with idiopathic reflex sympathetic dystrophy. Then we present a brief review, emphasizing on diagnosis and treatment of this disease.

  9. On the Cauchy Functional Inequality in Banach Modules

    Directory of Open Access Journals (Sweden)

    Park Choonkil

    2008-01-01

    Full Text Available Abstract We investigate the following functional inequality: in Banach modules over a -algebra, and prove the generalized Hyers-Ulam stability of linear mappings in Banach modules over a -algebra.

  10. Global attractors for gradient flows in metric spaces

    CERN Document Server

    Rossi, Riccarda; Stefanelli, Ulisse

    2009-01-01

    We develop the long-time analysis for gradient flow equations in metric spaces. In particular, we consider two notions of solutions for metric gradient flows, namely energy and generalized solutions. While the former concept coincides with the notion of curves of maximal slope, we introduce the latter to include limits of time-incremental approximations constructed via the Minimizing Movements approach. For both notions of solutions we prove the existence of the global attractor. Since the evolutionary problems we consider may lack uniqueness, we rely on the theory of generalized semiflows introduced by J.M. Ball. The notions of generalized and energy solutions are quite flexible and can be used to address gradient flows in a variety of contexts, ranging from Banach spaces to Wasserstein spaces of probability measures. We present applications of our abstract results by proving the existence of the global attractor for the energy solutions both of abstract doubly nonlinear evolution equations in reflexive Bana...

  11. The closed range property Banach space operators.

    Czech Academy of Sciences Publication Activity Database

    Miller, T.L.; Mller, Vladimr

    2008-01-01

    Ro?. 50, ?. 1 (2008), s. 17-26. ISSN 0017-0895 R&D Projects: GA ?R(CZ) GA201/06/0128 Institutional research plan: CEZ:AV0Z10190503 Keywords : closed range property * local spectral theory * Kato-type operators Subject RIV: BA - General Mathematics Impact factor: 0.276, year: 2008

  12. On dominated polynomials between Banach spaces

    CERN Document Server

    Botelho, Geraldo; Rueda, Pilar

    2008-01-01

    In this paper, among other results, we prove a conjecture concerning coincidence theorems for dominated polynomials. We also obtain an abstract version of Pietsch Domination Theorem (PDT) which unifies and generalizes several different nonlinear approaches; our result recovers, as a particular case, the well-known PDT for dominated multilinear mappings.

  13. Using ESO Reflex with Web Services

    Science.gov (United States)

    Jrvelinen, P.; Savolainen, V.; Oittinen, T.; Maisala, S.; Ullgrn, M. Hook, R.

    2008-08-01

    ESO Reflex is a prototype graphical workflow system, based on Taverna, and primarily intended to be a flexible way of running ESO data reduction recipes along with other legacy applications and user-written tools. ESO Reflex can also readily use the Taverna Web Services features that are based on the Apache Axis SOAP implementation. Taverna is a general purpose Web Service client, and requires no programming to use such services. However, Taverna also has some restrictions: for example, no numerical types such integers. In addition the preferred binding style is document/literal wrapped, but most astronomical services publish the Axis default WSDL using RPC/encoded style. Despite these minor limitations we have created simple but very promising test VO workflow using the Sesame name resolver service at CDS Strasbourg, the Hubble SIAP server at the Multi-Mission Archive at Space Telescope (MAST) and the WESIX image cataloging and catalogue cross-referencing service at the University of Pittsburgh. ESO Reflex can also pass files and URIs via the PLASTIC protocol to visualisation tools and has its own viewer for VOTables. We picked these three Web Services to try to set up a realistic and useful ESO Reflex workflow. They also demonstrate ESO Reflex abilities to use many kind of Web Services because each of them requires a different interface. We describe each of these services in turn and comment on how it was used

  14. On the Classification of Reflexive Polyhedra

    Science.gov (United States)

    Kreuzer, M.; Skarke, H.

    Reflexive polyhedra encode the combinatorial data for mirror pairs of Calabi-Yau hypersurfaces in toric varieties. We investigate the geometrical structures of circumscribed polytopes with a minimal number of facets and of inscribed polytopes with a minimal number of vertices. These objects, which constrain reflexive pairs of polyhedra from the interior and the exterior, can be described in terms of certain non-negative integral matrices. A major tool in the classification of these matrices is the existence of a pair of weight systems, indicating a relation to weighted projective spaces. This is the cornerstone for an algorithm for the construction of all dual pairs of reflexive polyhedra that we expect to be efficient enough for an enumerative classification in up to 4 dimensions, which is the relevant case for Calabi-Yau compactifications in string theory.

  15. On the classification of reflexive polyhedra

    CERN Document Server

    Kreuzer, M

    1997-01-01

    Reflexive polyhedra encode the combinatorial data for mirror pairs of Calabi-Yau hypersurfaces in toric varieties. We investigate the geometrical structures of circumscribed polytopes with a minimal number of facets and of inscribed polytopes with a minimal number of vertices. These objects, which constrain reflexive pairs of polyhedra from the interior and the exterior, can be described in terms of certain non-negative integral matrices. A major tool in the classification of these matrices is the existence of a pair of weight systems, indicating a relation to weighted projective spaces. This is the corner stone for an algorithm for the construction of all dual pairs of reflexive polyhedra that we expect to be efficient enough for an enumerative classification in up to 4 dimensions, which is the relevant case for Calabi-Yau compactifications in string theory.

  16. Spectral theory of linear operators and spectral systems in Banach algebras

    CERN Document Server

    Mller, Vladimir

    2003-01-01

    This book is dedicated to the spectral theory of linear operators on Banach spaces and of elements in Banach algebras. It presents a survey of results concerning various types of spectra, both of single and n-tuples of elements. Typical examples are the one-sided spectra, the approximate point, essential, local and Taylor spectrum, and their variants. The theory is presented in a unified, axiomatic and elementary way. Many results appear here for the first time in a monograph. The material is self-contained. Only a basic knowledge of functional analysis, topology, and complex analysis is assumed. The monograph should appeal both to students who would like to learn about spectral theory and to experts in the field. It can also serve as a reference book. The present second edition contains a number of new results, in particular, concerning orbits and their relations to the invariant subspace problem. This book is dedicated to the spectral theory of linear operators on Banach spaces and of elements in Banach alg...

  17. On orbit-reflexive operators.

    Czech Academy of Sciences Publication Activity Database

    Mller, Vladimr; Vrovsk, Jan

    2009-01-01

    Ro?. 79, ?. 2 (2009), s. 497-510. ISSN 0024-6107 Institutional research plan: CEZ:AV0Z10190503 Keywords : reflexive operators * orbit-reflexivity Subject RIV: BA - General Mathematics Impact factor: 0.798, year: 2009

  18. On Reflection : Is Reflexivity Necessarily Beneficial in Intercultural Education?

    DEFF Research Database (Denmark)

    Blasco, Maribel

    2012-01-01

    This article explores how the concept of reflexivity is used in intercultural education. Reflexivity is often presented as a key learning goal in acquiring intercultural competence (ICC). Yet, reflexivity can be defined in different ways, and take different forms across time and space, depending on the concepts of selfhood that prevail and how notions of difference are constructed. First, I discuss how the dominant usages of reflexivity in intercultural education reflect and reproduce a Cartesian view of the self that shapes how ICC is conceptualized and taught. I discuss three assumptions that this view produces: that the self is accessible and transcendable, that reflexivity is universal across space and time, and that the self can act as its own remedial change agent or inner consultant. I argue that because reflexivity is understood in many different ways, attention to definition is crucial, both in designing learning objectives in intercultural education and in devising ways to attain them. Greater attention is also needed in intercultural education to the ways in which selfhood, and hence also reflexivity and constructions of difference, differ across space and time.

  19. Spaces of small metric cotype

    CERN Document Server

    Veomett, Ellen

    2010-01-01

    Naor and Mendel's metric cotype extends the notion of the Rademacher cotype of a Banach space to all metric spaces. Every Banach space has metric cotype at least 2. We show that any metric space that is bi-Lipschitz equivalent to an ultrametric space has infinimal metric cotype 1. We discuss the invariance of metric cotype inequalities under snowflaking mappings and Gromov-Hausdorff limits, and use these facts to establish a partial converse of the main result.

  20. Reflex Sympathetic Dystrophy Syndrome

    OpenAIRE

    Annil Mahajan, Pawan Suri

    2004-01-01

    Reflex Sympathetic Dystrophy (RSD) or Complex Regional Pain Syndome Type-I (CRPS-I), adisease of unknown prevalance, complicates any minor trauma, stroke, myocardial infection, collesfracture, peripheral nerve injury and in one-fourth of cases without any precipitant factor. Anawareness of RSD and the injuries, illnesses and drugs that can provoke it is the first step to learnfor an early treatment and better outcome. Here we present a neglected case of RSD followingminor trauma who presen...

  1. A high-power reflex triode

    International Nuclear Information System (INIS)

    The generation of gigahertz radiation via the reflex-mechanism in the diode of a pulsed-power generator has been investigated with particle simulations and laboratory experiments. The microwave triode was designed using the 2-1/2 D, fully electromagnetic and relativistic particle-in-cell code CCUBE. The simulations pertain to a stalk supporting a ''cup'' shaped 13-cm diameter cathode spaced 3-cm from a flat foil anode grid. Magnetic insulation produced by the 10-20 kiloampere current conducted by the stalk allows the field energy to be effectively transferred to the face of the cathode and to the subsequent electrons emitted off the surface. These field emitted electrons are accelerated through the foil and build up a space charge limited virtual cathode cloud beyond the anode, then reflex between the cathode and virtual cathode producing microwaves at a frequency of 1.6 Ghz

  2. Corporeal reflexivity and autism.

    Science.gov (United States)

    Ochs, Elinor

    2015-06-01

    Ethnographic video recordings of high functioning children with autism or Aspergers Syndrome in everyday social encounters evidence their first person perspectives. High quality visual and audio data allow detailed analysis of children's bodies and talk as loci of reflexivity. Corporeal reflexivity involves displays of awareness of one's body as an experiencing subject and a physical object accessible to the gaze of others. Gaze, demeanor, actions, and sotto voce commentaries on unfolding situations indicate a range of moment-by-moment reflexive responses to social situations. Autism is associated with neurologically based motor problems (e.g. delayed action-goal coordination, clumsiness) and highly repetitive movements to self-soothe. These behaviors can provoke derision among classmates at school. Focusing on a 9-year-old girl's encounters with peers on the playground, this study documents precisely how autistic children can become enmeshed as unwitting objects of stigma and how they reflect upon their social rejection as it transpires. Children with autism spectrum disorders in laboratory settings manifest diminished understandings of social emotions such as embarrassment, as part of a more general impairment in social perspective-taking. Video ethnography, however, takes us further, into discovering autistic children's subjective sense of vulnerability to the gaze of classmates. PMID:25939529

  3. Banach Algebras of Integral Operators, Off-Diagonal Decay, and Applications in Wireless Communications

    CERN Document Server

    Beaver, S

    2004-01-01

    In this dissertation I establish that a broad class of Banach *-algebras of infinite integral operators, defined by the property that the kernels of the elements of the algebras possess subexponential off-diagonal decay, is inverse closed in the Banach space of bounded linear operators on the Hilbert space of square-integrable functions. I also show that the algebras under consideration are symmetric. In the second part of this dissertation, I present the results of the IEEE Transactions on Communications paper written jointly by Thomas Strohmer and me. We develop a comprehensive framework for the design of orthogonal frequency-division multiplexing (OFDM) systems, using techniques from Gabor frame theory, sphere-packing theory, representation theory, and the Heisenberg group.

  4. Hereditary properties of Amenability modulo an ideal of Banach algebras

    Directory of Open Access Journals (Sweden)

    Hamidreza Rahimi

    2014-10-01

    Full Text Available In this paper we investigate some hereditary properties of amenability modulo an ideal of Banach algebras. We show thatif $(e_{\\alpha}_{\\alpha}$ is a bounded approximate identity modulo $I$ of a Banach algebra $A$ and $X$ is a neo-unital modulo $I$, then $(e_{\\alpha}_{\\alpha}$ is a bounded approximate identity for $X$. Moreover we show that amenability modulo an ideal of a Banach algebra $A$ can be only considered by the neo-unital modulo $I$ Banach algebra over $A$

  5. Reflex myoclonus in olivopontocerebellar atrophy.

    OpenAIRE

    Rodriguez, M E; Artieda, J.; Zubieta, J.L. (Jos L.); Obeso, J. A.

    1994-01-01

    The presence of reflex myoclonus in response to touching and pin-pricking the wrist or stretching the fingers and to photic stimulation was assessed in 24 patients with a presumed diagnosis of olivopontocerebellar atrophy (OPCA) and in 30 age matched control subjects. Reflex myoclonus to soma-esthetic stimulation was found in 23 patients and in none of the controls. Photic myoclonus was present in 12 patients and in none of the controls. Electrophysiological study of the reflex myoclonus show...

  6. Homotopical stable ranks for Banach algebras

    CERN Document Server

    Nica, Bogdan

    2009-01-01

    The connected stable rank and the general stable rank are homotopy invariants for Banach algebras, whereas the Bass stable rank and the topological stable rank should be thought of as dimensional invariants. This paper studies the two homotopical stable ranks, viz. their general properties as well as specific examples and computations. The picture that emerges is that of a strong affinity between the homotopical stable ranks, and a marked contrast with the dimensional ones.

  7. Left introverted subspaces of duals of Banach algebras and $WEAK^*-$continuous derivations on dual Banach algebras

    OpenAIRE

    Gordji, M Eshaghi

    2006-01-01

    Let $X$ be a left introverted subspace of dual of a Banach algebra. We study $Z_t(X^*),$ the topological center of Banach algebra $X^*$. We fined the topological center of $(X\\cA)^*$, when $\\cA$ has a bounded right approximate identity and $\\cA\\subseteq X^*.$ So we introduce a new notation of amenability for a dual Banach algebra $\\cal A$. A dual Banach algebra $\\cal A$ is weakly Connes-amenable if the first $weak^*-$continuous cohomology group of $\\cal A$ with coefficients ...

  8. Characterization of a Banach-Finsler manifold in terms of the algebras of smooth functions

    CERN Document Server

    Jaramillo, J A; Sanchez-Gonzalez, L

    2011-01-01

    In this note we give sufficient conditions to ensure that the weak Finsler structure of a complete $C^k$ Finsler manifold $M$ is determined by the normed algebra $C_b^k(M)$ of all real-valued, bounded and $C^k$ smooth functions with bounded derivative defined on $M$. As a consequence, we obtain: (i) the Finsler structure of a finite-dimensional and complete $C^k$ Finsler manifold $M$ is determined by the algebra $C_b^k(M)$; (ii) the weak Finsler structure of a separable and complete $C^k$ Finsler manifold $M$ modeled on a Banach space with a Lipschitz and $C^k$ smooth bump function is determined by the algebra $C^k_b(M)$; (iii) the weak Finsler structure of a $C^k$ uniformly bumpable and complete $C^k$ Finsler manifold $M$ modeled on a Weakly Compactly Generated (WCG) Banach space with an (equivalent) $C^k$ smooth norm is determined by the algebra $C^k_b(M)$; and (iii) the isometric structure of a WCG Banach space $X$ with an $C^1$ smooth bump function is determined by the algebra $C_b^1(X)$.

  9. On a class of translation-invariant spaces of quasianalytic ultradistributions

    OpenAIRE

    Dimovski, Pavel; Prangoski, Bojan; Vindas, Jasson

    2015-01-01

    A class of translation-invariant Banach spaces of quasianalytic ultradistributions is introduced and studied. They are Banach modules over a Beurling algebra. Based on this class of Banach spaces, we define corresponding test function spaces $\\mathcal{D}^*_E$ and their strong duals $\\mathcal{D}'^*_{E'_{\\ast}}$ of quasianalytic type, and study convolution and multiplicative products on $\\mathcal{D}'^*_{E'_{\\ast}}$. These new spaces generalize previous works about translation-...

  10. Reflex Sympathetic Dystrophy Syndrome

    Directory of Open Access Journals (Sweden)

    Annil Mahajan, Pawan Suri, Ghulam Hussain Bardi, J.B. Singh, Dheeraj Gandotra, Vijay Gupta

    2004-07-01

    Full Text Available Reflex Sympathetic Dystrophy (RSD or Complex Regional Pain Syndome Type-I (CRPS-I, adisease of unknown prevalance, complicates any minor trauma, stroke, myocardial infection, collesfracture, peripheral nerve injury and in one-fourth of cases without any precipitant factor. Anawareness of RSD and the injuries, illnesses and drugs that can provoke it is the first step to learnfor an early treatment and better outcome. Here we present a neglected case of RSD followingminor trauma who presented to us after 6-7 months of onset of disease. Delay in treatment resultedin partial recovery of the patient.

  11. On Automatic Continuity of 3-Homomorphisms on Banach Algebras

    OpenAIRE

    Bracic, Janko; Moslehian, Mohammad Sal

    2006-01-01

    A linear map $\\phi:{\\mathcal A}\\to {\\mathcal B} $ between (Banach) algebras is called 3-homomorphism if $\\phi(abc)=\\phi(a)\\phi(b)\\phi(c)$ for each $a, b, c \\in {\\mathcal A}$. We investigate 3-homomorphisms on Banach algebras with bounded approximate identities and establish in two ways that every involution preserving homomorphism between $C^*$-algebras is norm decreasing.

  12. Left introverted subspaces of duals of Banach algebras and $WEAK^*-$continuous derivations on dual Banach algebras

    CERN Document Server

    Gordji, M E

    2006-01-01

    Let $X$ be a left introverted subspace of dual of a Banach algebra. We study $Z_t(X^*),$ the topological center of Banach algebra $X^*$. We fined the topological center of $(X\\cA)^*$, when $\\cA$ has a bounded right approximate identity and $\\cA\\subseteq X^*.$ So we introduce a new notation of amenability for a dual Banach algebra $\\cal A$. A dual Banach algebra $\\cal A$ is weakly Connes-amenable if the first $weak^*-$continuous cohomology group of $\\cal A$ with coefficients in $\\cal A$ is zero; i.e., $H^1_{w^*}(\\cal A, \\cal A)=\\{o\\}$. We study the weak Connes-amenability of some dual Banach algebras.

  13. Hyers-Ulam-Rassias stability of Jordan homomorphisms on Banach algebras

    OpenAIRE

    Hirasawa Go; Miura Takeshi; Takahasi Sin-Ei

    2005-01-01

    We prove that a Jordan homomorphism from a Banach algebra into a semisimple commutative Banach algebra is a ring homomorphism. Using a signum effectively, we can give a simple proof of the Hyers-Ulam-Rassias stability of a Jordan homomorphism between Banach algebras. As a direct corollary, we show that to each approximate Jordan homomorphism from a Banach algebra into a semisimple commutative Banach algebra there corresponds a unique ring homomorphism near to .

  14. Hyers-Ulam-Rassias stability of Jordan homomorphisms on Banach algebras

    Directory of Open Access Journals (Sweden)

    Hirasawa Go

    2005-01-01

    Full Text Available We prove that a Jordan homomorphism from a Banach algebra into a semisimple commutative Banach algebra is a ring homomorphism. Using a signum effectively, we can give a simple proof of the Hyers-Ulam-Rassias stability of a Jordan homomorphism between Banach algebras. As a direct corollary, we show that to each approximate Jordan homomorphism from a Banach algebra into a semisimple commutative Banach algebra there corresponds a unique ring homomorphism near to .

  15. A new definition for variational inequalities on real normed linear spaces and the case that it is singelton for (u, v)-cocoercive mappings

    OpenAIRE

    Soori, Ebrahim

    2015-01-01

    Let C be a nonempty closed convex subset of a Banach space $E$. In this paper we introduce a new definition for variational inequality V I (C, B) on E that generalizes the analogue definition on Hilbert spaces. We generalize (u, v)-cocoercive mappings and v-strongly monotone mappings from Hilbert spaces to Banach spaces. Then we prove the generalized variational inequality V I (C, B) is singleton for (u, v)-cocoercive mappings under appropriate assumptions on Banach spaces t...

  16. Simulations of a reflex triode

    International Nuclear Information System (INIS)

    The reflex triode is an important device in pulsed-power for such applications as ion beam production and high power switching. While steady-state solutions exist, the time- dependent behavior of these devices is not well-known. The authors have designed a one-dimensional electrostatic particle-in-cell code called REFLEX or model a reflex triode. The code includes a circuit model and a Monte Carlo simulation of electron transport through a thin foil. These are integrated together with the PIC-code approach to this problem

  17. Soleus stretch reflex during cycling

    DEFF Research Database (Denmark)

    Grey, Michael James; Pierce, C. W.

    2001-01-01

    The modulation and strength of the human soleus short latency stretch reflex was investigated by mechanically perturbing the ankle during an unconstrained pedaling task. Eight subjects pedaled at 60 rpm against a preload of 10 Nm. A torque pulse was applied to the crank at various positions during the crank cycle, producing ankle dorsiflexion perturbations of similar trajectory. The stretch reflex was greatest during the power phase of the crank cycle and was decreased to the level of background EMG during recovery. Matched perturbations were induced under static conditions at the same crank angle and background soleus EMG as recorded during the power phase of active pedaling. The magnitude of the stretch reflex was not statistically different from that during the static condition throughout the power phase of the movement. The results of this study indicate that the stretch reflex is not depressed during active cycling as has been shown with the H-reflex. This lack of depression may reflect a decreased susceptibility of the stretch reflex to inhibition, possibly originating from presynaptic mechanisms.

  18. Polynomial Bridgeland Stable Objects and Reflexive Sheaves

    CERN Document Server

    Lo, Jason

    2011-01-01

    On a smooth projective threefold, we show that there are only two isomorphism types for the moduli of stable objects with respect to Bayer's standard polynomial Bridgeland stability - the moduli of Gieseker-stable sheaves and the moduli of PT-stable objects - under the following assumptions: no two of the stability vectors are collinear, and the degree and rank of the objects are relatively prime. We also describe a close relation between the intersection of the moduli spaces of PT-stable and dual-PT-stable objects, and the moduli of reflexive sheaves.

  19. Approaching Reflexivity through Reflection: Issues for Critical Management Education

    Science.gov (United States)

    Hibbert, Paul

    2013-01-01

    This conceptual article seeks to develop insights for teaching reflexivity in undergraduate management classes through developing processes of critical reflection. Theoretical inferences to support this aim are developed and organized in relation to four principles. They are as follows: first, preparing and making space for reflection in the

  20. Dentocardiac Reflex: an Allegedly New Subform of the Trigeminocardiac Reflex

    Directory of Open Access Journals (Sweden)

    Amr Abdulazim

    2011-05-01

    Full Text Available Trigeminocardiac reflex (TCR is currently defined as a sudden bradycardia and decrease in mean arterial blood pressure by 20% during the manipulation of the branches of trigeminal nerve. TCR, especially during the last decade has been mostly studied in the course of neurosurgical procedures which are supposed to elicit the central subtype of TCR. Previously the well-known oculocardiac reflex was also considered as a subtype of TCR. Recently, surgeons dealing with the other branches of the fifth cranial nerve have become more interested in this reflex. Some noteworthy points have been published discussing new aspects of the trigeminocardiac reflex (TCR in simple oral surgical procedures. Arakeri et al. have reviewed the similarities and differences between TCR, vasovagal response (VVR, and syncope. They have also explained a new possible pathway for the reflex during the simple extraction of upper first molars. The present paper aims to briefly discuss these recently presented points. Although the discussed concepts are noteworthy and consistent our preliminary results of our yet to be published studies, it seemed timely for us to discuss some possible shortcomings that may affect the results of such assessments.

  1. On the Cauchy Functional Inequality in Banach Modules

    Directory of Open Access Journals (Sweden)

    Choonkil Park

    2008-05-01

    Full Text Available We investigate the following functional inequality: ‖f(x+f(y+f(z‖≤‖f(x+y+z‖ in Banach modules over a C∗-algebra, and prove the generalized Hyers-Ulam stability of linear mappings in Banach modules over a C∗-algebra.

  2. A characterization of Hilbert spaces

    OpenAIRE

    DELBOSCO, Domenico

    2005-01-01

    The classical Jordan-Neumann paper is the first of a large literature on the subject on the characterization of the inner product space (Hilbert space) among the linear normed space X (Banach space). For each \\theta ? R/2?Z, we define an operator R_{\\theta} on space X + X. the characterization introduced in this paper has the following statement : the Banach space X is an Hilbert space if and only if R_theta turn out to be an isometry of X + X for some \\theta . We remark that when \\t...

  3. Analytic subsets of Hilbert spaces

    OpenAIRE

    Pestov, Vladimir

    1995-01-01

    We show that every complete metric space is homeomorphic to the precise locus of zeros of an entire analytic map from a Hilbert space to a Banach space. As a corollary, every complete separable metric space is homeomorphic to the precise locus of zeros of an entire analytic map between two separable complex Hilbert spaces. AmS TeX 2.1.

  4. TRANSIENT RELEASE REFLEXES IN CATONIC SCHIZOPHRENIA

    OpenAIRE

    Damodaran, Saji S.; Sinha, Vinod K.

    1994-01-01

    This case report describes the presence of grasp reflex and palmomental reflex as a state dependant phenomenon in a 23 year old patient with catatonic schizophrenia. A transitory disturbance of frontal lobe function is proposed as the probable mechanism. The need to study the release reflexes as an effort to delineate a neurological sub group of schizophrenia is suggested.

  5. Educating the Reflexive Practitioner

    Directory of Open Access Journals (Sweden)

    Marc J. Neveu

    2012-09-01

    Full Text Available I cannot teach anybody anything, I can only make them think.SocratesIntroductionStudio as a model of education is distinct from many other professionaldisciplines and although it can be quite rewarding on many levels it mayalso be an extremely unconstructive endeavor.1 The amount of time spent in studio typically far outweighs that spent for other courses and often atthe expense of such other courses. The dedication that students bring tothe studio is remarkable, yet much of the time spent in studio is not alwaysproductive. Students often complain of not knowing what is expected ofthem and as a result much of the time is spent thinking about what they think the professor wants to see as opposed to working through theirprojects. In an alternate scenario, students are crushed by the workload, tasks, demands or expectations of their instructors. In either case, the work is almost invariably driven by the students own creativity and imagination; unlike law, medicine, business, or engineering for example, where the interpretation and inquiry into case studies and cadaversis much less based on the personal introspection than established traditions. This extremely personal nature of the architectural studio canmake reviews either a devastating or extremely empowering process. As seen from the perspective of the larger university community, the studio is simply not an efficient way of education. The faculty to student ratio, for example, is not in accordance with other undergraduate disciplines. But this ratio, as we all know can also be a real strength. The often hermeticnature of the studio offers latitude for students to develop theirwork in relatively safe surroundings. This environment, however, may also foster the cult of personality that develops around certain professorsthat harkens back to the very roots of education but can also lead to anentourage of disciples who have no incentive to inform the Emperor that he or she is no longer wearing any clothes.Notwithstanding such issues, I do believe the studio holds the potentialto be an empowering learning experience. The intention of this article is to question the mode of instruction in an architectural studio. Ive structured the paper in three parts. First, I will briefly describe the findingsof the study made by the Carnegie Foundation for the Advancementof Teaching known as the Boyer Report.2 To develop and support the findings of the Boyer Report, I introduce the work of the educator Donald Schn. Though I see much merit in the Boyer Report, and Schnsproposals, I argue that a more nuanced approach is required. I will recommend, therefore, in the second section of this paper that a meansof architectural education as based on the Socratic method may be amore productive approach. My reading of the Socratic method is basedprimarily on early Socratic dialogues and I will specifically use Charmidesto illustrate the issues that I believe are relevant to studio pedagogy.3 From my analysis of Charmides I will, in the third section of the essay,describe how the Socratic method is beneficial to studio pedagogy threeways: reflexive, non-propositional, and finally how Socrates approachmay indeed be practical. This last section will be illustrated with a studentproject. It is my conjecture that the Socratic method offers insight intocurrent discussions of educational theory, namely student-centered,project-based learning.

  6. Reflexive aerostructures: increased vehicle survivability

    Science.gov (United States)

    Margraf, Thomas W.; Hemmelgarn, Christopher D.; Barnell, Thomas J.; Franklin, Mark A.

    2007-04-01

    Aerospace systems stand to benefit significantly from the advancement of reflexive aerostructure technologies for increased vehicle survivability. Cornerstone Research Group Inc. (CRG) is developing lightweight, healable composite systems for use as primary load-bearing aircraft components. The reflexive system is comprised of piezoelectric structural health monitoring systems, localized thermal activation systems, and lightweight, healable composite structures. The reflexive system is designed to mimic the involuntary human response to damage. Upon impact, the structural health monitoring system will identify the location and magnitude of the damage, sending a signal to a discrete thermal activation control system to resistively heat the shape memory polymer (SMP) matrix composite above activation temperature, resulting in localized shape recovery and healing of the damaged areas. CRG has demonstrated SMP composites that can recover 90 percent of flexural yield stress and modulus after postfailure healing. During the development, CRG has overcome issues of discrete activation, structural health monitoring integration, and healable resin systems. This paper will address the challenges associated with development of a reflexive aerostructure, including integration of structural health monitoring, discrete healing, and healable shape memory resin systems.

  7. Uniqueness of the maximal ideal of the Banach algebra of bounded operators on $C([0,\\omega_1])$

    CERN Document Server

    Kania, Tomasz

    2011-01-01

    Let $\\omega_1$ be the first uncountable ordinal. By a result of Rudin, bounded operators on the Banach space $C([0,\\omega_1])$ have a natural representation as $[0,\\omega_1]\\times 0,\\omega_1]$-matrices. Loy and Willis observed that the set of operators whose final column is continuous when viewed as a scalar-valued function on $[0,\\omega_1]$ defines a maximal ideal of codimension one in the Banach algebra $\\mathscr{B}(C([0,\\omega_1]))$ of bounded operators on $C([0,\\omega_1])$. We give a coordinate-free characterization of this ideal and deduce from it that $\\mathscr{B}(C([0,\\omega_1]))$ contains no other maximal ideals. We then obtain a list of equivalent conditions describing the strictly smaller ideal of operators with separable range, and finally we investigate the structure of the lattice of all closed ideals of $\\mathscr{B}(C([0,\\omega_1]))$.

  8. Th\\'eor\\`eme de division de Weierstrass sur un anneau de Banach. Application aux espaces de Berkovich sur Z

    CERN Document Server

    Poineau, Jrme

    2012-01-01

    Nous d\\'emontrons un th\\'eor\\`eme de division de Weierstrass pour les points rigides des fibres d'un espace de Berkovich affine X sur un anneau de Banach A et en tirons des informations sur la structure locale de X. Lorsque A est un corps valu\\'e complet, un anneau de valuation discr\\`ete ou un anneau d'entiers de corps de nombres, nous en d\\'eduisons qu'en tout point de X, la fibre du faisceau structural est un anneau local noeth\\'erien et r\\'egulier. Nous montrons \\'egalement que le faisceau structural est coh\\'erent. Nos m\\'ethodes traitent de fa\\c{c}on unifi\\'ee espaces complexes et p-adiques. Weierstrass division theorem over a Banach ring. Application to Berkovich spaces over Z. We prove a Weierstrass division theorem for the rigid points of the fibers of an affine Berkovich space X over a Banach ring A and use it to study the local structure of X. In case A is a valued field, a discrete valuation ring or the ring of integers of a number field, we deduce that the stalks of the structure sheaf of X are n...

  9. A note on mutiplication operators on Kthe-Bochner spaces

    OpenAIRE

    S. S. Khurana

    2012-01-01

    Let (?, A, ?) is a finite measure space, E an order continuous Banach function space over ?, X a Banach space and E(X) the Kthe-Bochner space. A new simple proof is given of the result that a continuous linear operator T: E(X) E(X) is a multiplication operator (by a function in L) iff T(g x) =g x for everyg L, f E(X), x X, x* X*.

  10. Integrating Reflexivity in Livelihoods Research

    DEFF Research Database (Denmark)

    Prowse, Martin

    2010-01-01

    Much poverty and development research is not explicit about its methodology or philosophical foundations. Based on the extended case method of Burawoy and the epistemological standpoint of critical realism, this paper discusses a methodological approach for reflexive inductive livelihoods research that overcomes the unproductive social science dualism of positivism and social constructivism. The approach is linked to a conceptual framework and a menu of research methods that can be sequenced and iterated in light of research questions.

  11. Integrating Reflexivity in Livelihoods Research

    OpenAIRE

    Prowse, Martin

    2010-01-01

    Much poverty and development research is not explicit about its methodology or philosophical foundations. Based on the extended case method of Burawoy and the epistemological standpoint of critical realism, this paper discusses a methodological approach for reflexive inductive livelihoods research that overcomes the unproductive social science dualism of positivism and social constructivism. The approach is linked to a conceptual framework and a menu of research methods that can be sequenced ...

  12. Representations of *-Algebras, Locally Compact Groups, and Banach *-Algebraic Bundles Banach *-Algebraic Bundles, Induced Representations, and the Generalized Mackey Analysis

    CERN Document Server

    Fell, James M G

    1988-01-01

    This is an all-encompassing and exhaustive exposition of the theory of infinite-dimensional Unitary Representations of Locally Compact Groups and its generalization to representations of Banach algebras. The presentation is detailed, accessible, and self-contained (except for some elementary knowledge in algebra, topology, and abstract measure theory). In the later chapters the reader is brought to the frontiers of present-day knowledge in the area of Mackey normal subgroup analysisand its generalization to the context of Banach *-Algebraic Bundles.

  13. Winning the pressing down game but not Banach Mazur

    OpenAIRE

    Kellner, Jakob; Pauna, Matti; Shelah, Saharon

    2006-01-01

    Let $S$ be the set of those $\\alpha\\in\\omega_2$ that have cofinality $\\omega_1$. It is consistent relative to a measurable that the nonempty player wins the pressing down game of length $\\omega_1$, but not the Banach Mazur game of length $\\omega+1$ (both games starting with $S$).

  14. Perspective on the human cough reflex

    OpenAIRE

    Brooks Stuart M

    2011-01-01

    Abstract This review dissects the complex human cough reflex and suggests hypotheses about the evolutionary basis for the reflex. A mechanosensory-induced cough reflex conveys through branches of myelinated A? nerve fibers is not chemically reactive (i.e., capsaicin, bradykinin); possibly, its evolution is to prevent the harmful effects of aspiration of gastric or particulate contents into the lungs. This became necessary as the larynx moves closer to the opening of the esophagus as human an...

  15. Reflections on Reflexivity: Sociological Issues and Perspectives

    OpenAIRE

    Charalambos Tskekeris

    2010-01-01

    This paper attempts to comprehensively concentrate and critically reflect upon the theoretical and methodological conception of sociological reflexivity. It thus concisely presents some relevant debates on reflexivitys most influential sociological and epistemological definitions, as well as on its varied and complex relationship with the contentious notions of the self and spokespersonship. The conceptual elaboration on both notions emphatically highlights the crucial importance of the re...

  16. 21 CFR 890.1450 - Powered reflex hammer.

    Science.gov (United States)

    2010-04-01

    ...2010-04-01 2010-04-01 false Powered reflex hammer. 890.1450 Section 890.1450...Diagnostic Devices 890.1450 Powered reflex hammer. (a) Identification. A powered reflex hammer is a motorized device intended...

  17. Spectral synthesis for operator space projective tensor product of $C^*$-algebras

    OpenAIRE

    Jain, Ranjana; Kumar, Ajay

    2011-01-01

    We study the spectral synthesis for the Banach *-algebra $A\\oop B$, the operator space projective tensor product of $C^*$-algebras $A$ and $B$. It is shown that if $A$ or $B$ has finitely many closed ideals, then $A\\oop B$ obeys spectral synthesis. The Banach algebra $A \\oop A$ with the reverse involution is also studied.

  18. Optimization in function spaces with stability considerations in Orlicz spaces

    CERN Document Server

    Kosmol, Peter

    2011-01-01

    This is an essentially self-contained book on the theory of convex functions and convex optimization in Banach spaces, with a special interest in Orlicz spaces. Approximate algorithms based on the stability principles and the solution of the corresponding nonlinear equationsaredeveloped in this text.A synopsis of the geometry of Banach spaces, aspects of stability and the duality of different levels of differentiability and convexity is developed. And it isprovided a novel approach to the fundamental theorems of Variational Calculus based on the principle of pointwise minimization of the Lagra

  19. Stability of stationary and periodic solutions equations in Banach space

    OpenAIRE

    Ya Dorogovtsev, A.

    1997-01-01

    Linear difference and differential equations with operator coefficients and random stationary (periodic) input are considered. Conditions are presented for the mean stability of stationary (periodic) solutions under small perturbation of the coefficients.

  20. Nonlocal Cauchy problem for quasilinear integrodifferential equations in Banach spaces

    Directory of Open Access Journals (Sweden)

    Mariappan Chandrasekaran

    2007-02-01

    Full Text Available The aim of this paper is to prove the existence of mild solutions of the nonlocal Cauchy problem for a nonlinear integrodifferential equation. The results are established by using the method of semigroup and the Schaefer theorem.

  1. Reflex sympathetic dystrophy in a child

    International Nuclear Information System (INIS)

    A case of reflex sympathetic dystrophy in 11 years old girl was described. The acute pain of the left food was preceded by loss of consciousness of unknown origin. Patchy osteopenia, very rare and non characteristic X-ray changes in children's reflex sympathetic dystrophy, was observed, mimicking osteomyelitis, bone malignant tumor or Sudeck disease. (author)

  2. Lattices generated by skeletons of reflexive polytopes

    CERN Document Server

    Haase, C; Haase, Christian; Nill, Benjamin

    2005-01-01

    Lattices generated by lattice points in skeletons of reflexive polytopes are essential in determining the fundamental group and integral cohomology of Calabi-Yau hypersurfaces. Here we prove that the lattice generated by all lattice points in a reflexive polytope is already generated by lattice points in codimension two faces. This answers a question of J. Morgan.

  3. Lectures given at the Banach Center and C.I.M.E. Joint Summer School

    CERN Document Server

    Lachowicz, Miros?aw

    2008-01-01

    The aim of this volume that presents Lectures given at a joint CIME and Banach Center Summer School, is to offer a broad presentation of a class of updated methods providing a mathematical framework for the development of a hierarchy of models of complex systems in the natural sciences, with a special attention to Biology and Medicine. Mastering complexity implies sharing different tools requiring much higher level of communication between different mathematical and scientific schools, for solving classes of problems of the same nature. Today more than ever, one of the most important challenges derives from the need to bridge parts of a system evolving at different time and space scales, especially with respect to computational affordability. As a result the content has a rather general character; the main role is played by stochastic processes, positive semigroups, asymptotic analysis, kinetic theory, continuum theory and game theory.

  4. Reflexivity and technology in adult learning

    Directory of Open Access Journals (Sweden)

    Neil Selwyn

    2005-03-01

    Full Text Available It is argued by influential commentators such as Ulrich Beck and Scott Lash that we now live in a reflexively modern' age. People are seen to now be free of the structures of modern society and driven instead by individualised opportunities to reflexively engage with their fast-changing social worlds and identities. Taking the notion of reflexive modernisation as its starting point, this paper explores the roles that information technologies (ITs may play in supporting adults' reflexive judgements about, and reflexive engagements with, education and learning. Through an analysis of interview data with 100 adults in the UK the paper finds that whilst a minority of interviewees were using ITs to support and inform reflexive engagementwith learning, the majority of individuals relayed little sign of technology-supported reflexivity when it came to their (nonengagement with education. For most people ITs were found, at best, to reinforce pre-established tendencies to drift' through the formal education system. The paper concludes by considering the implications of these findings for ongoing efforts in developed countries to establish technology-supported learning societies'.

  5. Tone and reflex development before term.

    Science.gov (United States)

    Allen, M C; Capute, A J

    1990-03-01

    The evolution of tone and reflexes from 25 weeks postmenstrual age (gestational age plus chronologic age) to term in a population of 42 surviving infants is described. The infants were born in 1983 at the Johns Hopkins Hospital, had birth weights less than 1300 g, were examined weekly until neonatal intensive care unit discharge, and did not develop cerebral palsy. Lower-extremity flexor tone was first detectable at 29 weeks post-menstrual age by the popliteal angle and heel to ear maneuvers. Flexor tone, recoil, and hyperreflexia were all noted 2 to 3 weeks earlier in the lower extremities (33 to 35 weeks) than in the upper extremities (35 to 37 weeks). Hip tone (35 to 37 weeks) followed knee flexor tone, but preceded shoulder tone (37 to 38 weeks). Trunk tone on ventral suspension emerged closer to term (36 to 40 weeks), and more than half of infants evaluated at term continued to demonstrate head lag when pulled to sitting position. The emergence of the primitive and pathologic reflexes reflects (both in timing and pattern) the evolution of tone: development of the reflexes in the lower extremities precedes that of those in the upper extremities, and development of the distal reflexes precedes that of the proximal. Maturation of tone, deep tendon reflexes, pathologic reflexes, and primitive reflexes occurs in an orderly, sequential manner, with a well-defined pattern: caudocephalad (lower extremities to upper extremities) and centripetal (distal to proximal). PMID:2304800

  6. Astronomical Data Reduction Workflows with Reflex

    Science.gov (United States)

    Ballester, P.; Bramich, D.; Forchi, V.; Freudling, W.; Garcia-Dab, C. E.; klein Gebbinck, M.; Modigliani, A.; Moehler, S.; Romaniello, M.

    2014-05-01

    Reflex (http://www.eso.org/reflex) is an environment that provides an easy and flexible way to reduce VLT/VLTI science data using the ESO. Its top-level functionalities are: (1) Reflex allows to graphically specify the sequence in which the data reduction steps are executed, including conditional stops, loops and conditional branches, (2) Reflex makes it easy to inspect the intermediate and final data products and to repeat selected processing steps to optimize the data reduction, (3) the data organization necessary to reduce the data is built into the system and is fully automatic, (4) advanced users can plug-in their own Python or IDL modules and steps into the data reduction sequence, and (5) Reflex supports the development of data reduction workflows based on the ESO Common Pipeline Library. Reflex is based on the concept of a scientific workflow, whereby the data reduction cascade is rendered graphically and data seamlessly flow from one processing step to the next. It is distributed with a number of complete test datasets so that users can immediately start experimenting and familiarize themselves with the system (http://www.eso.org/pipelines). In this demo, we present the latest version of Reflex and its applications for astronomical data reduction processes.

  7. Computer simulations of reflex E-beam systems and plasma

    International Nuclear Information System (INIS)

    The dynamics was numerically studied of electrons and ions in systems with virtual or reflex cathodes by means of 1.5-dimensional PIC simulation model OREBIA-REX in close correlation with the experimental work on relativistic high-current electron beam and ion beam generation. The results of numerical simulation of the formation and relaxation of an oscillating electron beam are discussed. A possible explanation is given of the enhanced energy deposition observed in the REBEX experiment with short plasma columns. Planar reflex diodes and symmetrical reflex triodes, coupled to an external circuit and operated with and without ions, are investigated. In regimes with ions, besides fast oscillations of the diode (triode) voltage and current, slower oscillations due to electron-ion relaxation processes also appear, even leading to periodical collapses of the high-voltage triode. Phase-space diagrams illustrating the motion of particles and time-dependent contour maps of electric field strength and potential are presented. (J.U.)

  8. Reflex sympathetic dystrophy syndrome (RSDS)

    International Nuclear Information System (INIS)

    An attempt was made to establish Magnetic Resonance Imaging (MRI) diagnostic criteria for the study of the reflex sympathetic dystrophy syndrome (RSDS). Five patients with hip and knee pain were studied. The radiographic pattern was ''positive'' only in two patients, while radionuclide studies showed increased activity in the painful joint in all; Only in three cases Computed Tomography was performed. In all patients MRI demonstrates the lesions and defines their extension. MRI allows a differential diagnosis between RSDS and other bone lesions such as osteonecrosis and tumors. The relation between anatomopathological findings of RSDS and MRI features is discussed. MRI proved to be a reliable technique in showing and characterizing RSDS better than radiographic examination (often ''negative'' in early phases), and radionuclide study (a sensitive but not specific technique)

  9. Laryngeal and respiratory protective reflexes.

    Science.gov (United States)

    Altschuler, S M

    2001-12-01

    Swallowing is a complex motor behavior that relies on an interneuronal network of premotor neurons (PMNs) to organize the sequential activity of motor neurons that are active during the buccopharyngeal and esophageal phases. Swallowing PMNs are highly interconnected to multiple areas of the brain stem and the central nervous system and provide a potential anatomic substrate integration of swallowing activity with airway protective reflexes. Because these neurons have synaptic contact with both afferent inputs and motor neurons and exhibit a true central activity, they appear to constitute the swallowing central pattern generator. We studied the viscerotopic organization of the nucleus of the solitary tract (NTS), the nucleus ambiguus (NA), the dorsal motor nucleus (DMN), and the hypoglossal nucleus (XII) using cholera toxin horseradish peroxidase (CT-HRP), a sensitive antegrade and retrograde tracer that effectively labels afferent terminal fields within the NTS as well as swallowing motor neurons and their dendritic fields within the NA, DMN, and XII. We used CT-HRP to provide a comprehensive description of the dendritic architecture of NA motor neurons innervating swallowing muscles. We also conducted studies using pseudorabies virus (PRV), a swine alpha-herpesvirus, to map central neural circuits after injection in the peripheral or central nervous systems. One attenuated vaccine strain, Bartha PRV, has preferential affinity for sites of afferent synaptic contact on the cell body and dendrites and a reactive gliosis that effectively isolates the infected neurons and provides a barrier to the nonspecific spread to adjacent neurons. The findings provide a basis for the central integration of swallowing and respiratory protective reflexes. PMID:11749932

  10. Loading and reflexes : the influence of body weight and active movements on reflex responses in humans

    OpenAIRE

    Bastiaanse, Catharina Maria

    2003-01-01

    This thesis describes six studies on the influence of active movements and body loading on reflex responses. To measure those influences healthy subjects were asked to walk with different loadings (e.g. a backpack) or with different active movements (e.g. arm swing) while different reflex responses were measured. After a general introduction (chapter 1), the studies are described. In chapter 2 a description is given about the influence of body (un)loading on cutaneous reflex responses during ...

  11. Modular functionals and perturbations of Nakano spaces

    CERN Document Server

    Yaacov, Ita Ben

    2008-01-01

    We settle several questions regarding the model theory of Nakano spaces left open by the PhD thesis of Poitevin \\cite{Poitevin:PhD}. We start by studying isometric Banach lattice embeddings of Nakano spaces, showing that in dimension two and above such embeddings have a particularly simple and rigid form. We use this to show show that in the Banach lattice language the modular functional is definable and that complete theories of atomless Nakano spaces are model complete. We also show that up to arbitrarily small perturbations of the exponent Nakano spaces are $\\aleph_0$-categorical and $\\aleph_0$-stable. In particular they are stable.

  12. Two iterative algorithms for solving coupled matrix equations over reflexive and anti-reflexive matrices

    Scientific Electronic Library Online (English)

    Mehdi, Dehghan; Masoud, Hajarian.

    Full Text Available An n n real matrix P is said to be a generalized reflection matrix if P T = P and P = I (where P T is the transpose of P). A matrix A ? Rnn is said to be a reflexive (anti-reflexive) matrix with respect to the generalized reflection matrix P if A = P A P (A = - P A P). The reflexive and anti-ref [...] lexive matrices have wide applications in many fields. In this article, two iterative algorithms are proposed to solve the coupled matrix equations { A1 XB1 + C1X T D1 = M1. A2 XB2 + C2X T D2 = M2. over reflexive and anti-reflexive matrices, respectively. We prove that the first (second) algorithm converges to the reflexive (anti-reflexive) solution of the coupled matrix equations for any initial reflexive (anti-reflexive) matrix. Finally two numerical examples are used to illustrate the efficiency of the proposed algorithms. Mathematical subject classification: 15A06, 15A24, 65F15, 65F20.

  13. A testbed for autonomous reflexive grasping

    Science.gov (United States)

    Kemme, David A.; McDonnell, John R.

    1993-03-01

    This work describes the development of a testbed which combines a subsumption architecture approach with neural network processing of tactile information in a reflexive behavior feasibility study. An overview of the tactile sensor, the neural network processor, and subsumption architecture is provided along with a plan for integrating these components into a single system. By incorporating local (reflexive) processing capabilities within a robot gripper, an additional layer of control is attained without an increased computing burden being placed on the system controller.

  14. Visual modulation of proprioceptive reflexes during movement

    OpenAIRE

    Mutha, Pratik K.; Boulinguez, Philippe; Sainburg, Robert L.

    2008-01-01

    Previous research has demonstrated that feedback circuits such as reflexes can be tuned by setting their gains prior to movement onset during both posture and movement tasks. However, such a control strategy requires that perturbation contingencies be predicted during movement planning and that task goals remain fixed. Here we test the hypothesis that feedforward regulation of reflex circuits also occurs during the course of movement in response to changes in task goals. Participants reached ...

  15. The passive of reflexive verbs in Icelandic

    Directory of Open Access Journals (Sweden)

    Hlf rnadttir

    2011-10-01

    Full Text Available The Reflexive Passive in Icelandic is reminiscent of the so-called New Passive (or New Impersonal in that the oblique case of a passivized object NP is preserved. As is shown by recent surveys, however, speakers who accept the Reflexive Passive do not necessarily accept the New Passive, whereas conversely, speakers who accept the New Passive do also accept the Reflexive Passive. Based on these results we suggest that there is a hierarchy in the acceptance of passive sentences in Icelandic, termed the Passive Acceptability Hierarchy. The validity of this hierarchy is confirmed by our diachronic corpus study of open access digital library texts from Icelandic journals and newspapers dating from the 19th and 20th centuries (tmarit.is. Finally, we sketch an analysis of the Reflexive Passive, proposing that the different acceptability rates of the Reflexive and New Passives lie in the argument status of the object. Simplex reflexive pronouns are semantically dependent on the verbs which select them, and should therefore be analyzed as syntactic arguments only, and not as semantic arguments of these verbs.

  16. Next generation control system for reflexive aerostructures

    Science.gov (United States)

    Maddux, Michael R.; Meents, Elizabeth P.; Barnell, Thomas J.; Cable, Kristin M.; Hemmelgarn, Christopher; Margraf, Thomas W.; Havens, Ernie

    2010-04-01

    Cornerstone Research Group Inc. (CRG) has developed and demonstrated a composite structural solution called reflexive composites for aerospace applications featuring CRG's healable shape memory polymer (SMP) matrix. In reflexive composites, an integrated structural health monitoring (SHM) system autonomously monitors the structural health of composite aerospace structures, while integrated intelligent controls monitor data from the SHM system to characterize damage and initiate healing when damage is detected. Development of next generation intelligent controls for reflexive composites were initiated for the purpose of integrating prognostic health monitoring capabilities into the reflexive composite structural solution. Initial efforts involved data generation through physical inspections and mechanical testing. Compression after impact (CAI) testing was conducted on composite-reinforced shape memory polymer samples to induce damage and investigate the effectiveness of matrix healing on mechanical performance. Non-destructive evaluation (NDE) techniques were employed to observe and characterize material damage. Restoration of mechanical performance was demonstrated through healing, while NDE data showed location and size of damage and verified mitigation of damage post-healing. Data generated was used in the development of next generation reflexive controls software. Data output from the intelligent controls could serve as input to Integrated Vehicle Health Management (IVHM) systems and Integrated Resilient Aircraft Controls (IRAC). Reflexive composite technology has the ability to reduce maintenance required on composite structures through healing, offering potential to significantly extend service life of aerospace vehicles and reduce operating and lifecycle costs.

  17. Evidence for sustained cortical involvement in peripheral stretch reflex during the full long latency reflex period.

    Science.gov (United States)

    Perenboom, M J L; Van de Ruit, M; De Groot, J H; Schouten, A C; Meskers, C G M

    2015-01-01

    Adaptation of reflexes to environment and task at hand is a key mechanism in optimal motor control, possibly regulated by the cortex. In order to locate the corticospinal integration, i.e. spinal or supraspinal, and to study the critical temporal window of reflex adaptation, we combined transcranial magnetic stimulation (TMS) and upper extremity muscle stretch reflexes at high temporal precision. In twelve participants (age 49 13 years, eight male), afferent signals were evoked by 40 ms ramp and subsequent hold stretches of the m. flexor carpi radialis (FCR). Motor conduction delays (TMS time of arrival at the muscle) and TMS-motor threshold were individually assessed. Subsequently TMS pulses at 96% of active motor threshold were applied with a resolution of 5-10 ms between 10 ms before and 120 ms after onset of series of FCR stretches. Controlled for the individually assessed motor conduction delay, subthreshold TMS was found to significantly augment EMG responses between 60 and 90 ms after stretch onset. This sensitive temporal window suggests a cortical integration consistent with a long latency reflex period rather than a spinal integration consistent with a short latency reflex period. The potential cortical role in reflex adaptation extends over the full long latency reflex period, suggesting adaptive mechanisms beyond reflex onset. PMID:25449867

  18. Determining elements in Banach algebras through spectral properties

    OpenAIRE

    Bres?ar, M.; S?penko, S?

    2012-01-01

    Let $A$ be a Banach algebra. By $\\sigma(x)$ and $r(x)$ we denote the spectrum and the spectral radius of $x\\in A$, respectively. We consider the relationship between elements $a,b\\in A$ that satisfy one of the following two conditions: (1) $\\sigma(ax) = \\sigma(bx)$ for all $x\\in A$, (2) $r(ax) \\le r(bx)$ for all $x\\in A$. In particular we show that (1) implies $a=b$ if $A$ is a $C^*$-algebra, and (2) implies $a\\in \\mathbb C b$ if $A$ is a prime $C^*$-algebra. As an applicati...

  19. The effect of elbow position on biceps tendon reflex

    Directory of Open Access Journals (Sweden)

    Keles Isik

    2004-07-01

    Full Text Available Background: Testing of tendon (T reflex is the basic method used in the diagnostic procedure of clinical neurology. Measurement of T reflexes precisely can be a valuable adjunct to clinical examination. Quantification of T reflexes may provide more accurate results. Aims: To analyze the effect of elbow position on biceps T reflex. Settings and Design: A self-controlled clinical trial of biceps T reflex testing at the Electrophysiology Unit of the Department of Physical Medicine and Rehabilitation. Methods and Materials: Biceps T reflex was obtained utilizing a hand-held electronic reflex hammer in 50 extremities of 25 healthy volunteers and the effect of elbow position (at 90, 120 and 150 on reflex response was evaluated. Statistical Analysis: Repeated-measures analysis of variance by the General Linear Model and Pearson correlation test procedures. Results: Onset latency was significantly shorter at 120 of elbow position. The maximum amplitude value of biceps T reflex was obtained at 90 of elbow position. Onset latency of the reflex correlated significantly with the height and arm length but not with age. Conclusions: The electrophysiological measurement of T reflexes is an easy and useful method in the quantification of reflexes, supplying more objective data. However, when performing T reflex studies, the position of the extremity should be taken into consideration to achieve more reliable results.

  20. Pelczynski's property (V) on spaces of vector valued functions

    CERN Document Server

    Randrianantoanina, N

    1994-01-01

    Let $E$ be a separable Banach space and $\\Omega$ be a compact Hausdorff space. It is shown that the space $C(\\Omega,E)$ has property (V) if and only if $E$ does. Similar result is also given for Bochner spaces $L^p(\\mu,E)$ if $1

  1. The effect of whole body vibration on the H-reflex, the stretch reflex, and the short-latency response during hopping

    OpenAIRE

    Ritzmann, R.; Kramer, A; Gollhofer, Albert; Taube, Wolfgang

    2012-01-01

    The effect of whole body vibration (WBV) on reflex responses is controversially discussed in the literature. In this study, three different modalities of reflex activation with increased motor complexity have been selected to clarify the effects of acute WBV on reflex activation: (1) the electrically evoked H-reflex, (2) the mechanically elicited stretch reflex, and (3) the short-latency response (SLR) during hopping. WBV-induced changes of the H-reflex, the stretch reflex, and the SLR during...

  2. Principal Lyapunov exponents and principal Floquet spaces of positive random dynamical systems. I. General theory

    OpenAIRE

    Mierczyn?ski, Janusz; Shen, Wenxian

    2012-01-01

    This is the first of a series of papers concerned with principal Lyapunov exponents and principal Floquet subspaces of positive random dynamical systems in ordered Banach spaces. It focuses on the development of general theory. First, the notions of generalized principal Floquet subspaces, generalized principal Lyapunov exponents, and generalized exponential separations for general positive random dynamical systems in ordered Banach spaces are introduced, which extend the cl...

  3. Selection Principles and Baire spaces

    OpenAIRE

    Scheepers, Marion

    2007-01-01

    We prove that if X is a separable metric space with the Hurewicz covering property, then the Banach-Mazur game played on X is determined. The implication is not true when "Hurewicz covering property" is replaced with "Menger covering property".

  4. Reflexive composites: self-healing composite structures

    Science.gov (United States)

    Margraf, Thomas W., Jr.; Barnell, Thomas J.; Havens, Ernie; Hemmelgarn, Christopher D.

    2008-03-01

    Cornerstone Research Group Inc. has developed reflexive composites achieving increased vehicle survivability through integrated structural awareness and responsiveness to damage. Reflexive composites can sense damage through integrated piezoelectric sensing networks and respond to damage by heating discrete locations to activate the healable polymer matrix in areas of damage. The polymer matrix is a modified thermoset shape memory polymer that heals based on phenomena known as reptation. In theory, the reptation healing phenomena should occur in microseconds; however, during experimentation, it has been observed that to maximize healing and restore up to 85 % of mechanical properties a healing cycle of at least three minutes is required. This paper will focus on work conducted to determine the healing mechanisms at work in CRG's reflexive composites, the optimal healing cycles, and an explanation of the difference between the reptation model and actual healing times.

  5. Reflexive structures an introduction to computability theory

    CERN Document Server

    Sanchis, Luis E

    1988-01-01

    Reflexive Structures: An Introduction to Computability Theory is concerned with the foundations of the theory of recursive functions. The approach taken presents the fundamental structures in a fairly general setting, but avoiding the introduction of abstract axiomatic domains. Natural numbers and numerical functions are considered exclusively, which results in a concrete theory conceptually organized around Church's thesis. The book develops the important structures in recursive function theory: closure properties, reflexivity, enumeration, and hyperenumeration. Of particular interest is the treatment of recursion, which is considered from two different points of view: via the minimal fixed point theory of continuous transformations, and via the well known stack algorithm. Reflexive Structures is intended as an introduction to the general theory of computability. It can be used as a text or reference in senior undergraduate and first year graduate level classes in computer science or mathematics.

  6. Reflex: Graphical workflow engine for data reduction

    Science.gov (United States)

    ESO Reflex development Team

    2014-01-01

    Reflex provides an easy and flexible way to reduce VLT/VLTI science data using the ESO pipelines. It allows graphically specifying the sequence in which the data reduction steps are executed, including conditional stops, loops and conditional branches. It eases inspection of the intermediate and final data products and allows repetition of selected processing steps to optimize the data reduction. The data organization necessary to reduce the data is built into the system and is fully automatic; advanced users can plug their own modules and steps into the data reduction sequence. Reflex supports the development of data reduction workflows based on the ESO Common Pipeline Library. Reflex is based on the concept of a scientific workflow, whereby the data reduction cascade is rendered graphically and data seamlessly flow from one processing step to the next. It is distributed with a number of complete test datasets so users can immediately start experimenting and familiarize themselves with the system.

  7. The Reflexive Teacher Educator in TESOL Roots and Wings

    CERN Document Server

    Edge, Julian

    2010-01-01

    Edge explores the construct of reflexivity in teacher education, differentiating it from, while locating it in, reflective practice, and introduces a framework (Copying, Applying, Theorising, Reflecting, Acting) to help teacher educators become reflexive professionals.

  8. Reflex control for safe autonomous robot operation

    International Nuclear Information System (INIS)

    This paper describes the design of an autonomous, sonar-based world mapping system for collision prevention in robotic systems. Obstacle detection and mapping is performed as a task that competes with higher-level tasks for the robot's attention. All tasks are integrated within a hierarchy, organized and co-ordinated by schemes analogous to biological reflexes and fixed action patterns. It is illustrated how the existence of low-level reflex behaviours can enhance the survivability and autonomy of complex systems and simplify the design of complex higher-level controls like our autonomous sonar-based world mapping system

  9. Polarized neutron reflectometer 'Reflex-P'

    CERN Document Server

    Korneev, D A; Yaradajkin, S P

    2002-01-01

    About 10 years ago the idea of a new spectrometer 'Reflex' at the IBR-2 reactor was formulated. According to the initial idea, the spectrometer was projected as a combination of two reflectometers. One of them is the spectrometer with polarized neutrons and another one with nonpolarized neutrons. At present half of the project has been executed. On the 9th beam of the IBR-2 reactor the polarized branch of the spectrometer 'Reflex-P' is successfully working. This paper is devoted to the description of main parameters of this spectrometer and development perspectives.

  10. Computer modeling of a spinal reflex circuit

    Scientific Electronic Library Online (English)

    Bruno L., Dalcin; Frederico Alan, Cruz; Clia Martins, Cortez; Emmanuel P. L., Passos.

    2005-12-01

    Full Text Available We used a set of properties of the interactions among the spinal neurons in order to develop a computer model for a spinal reflex circuit. The model equations take into account the synaptic characteristics of the somatodendritic membrane of neurons in a morphofunctional unity of the spinal reflex ac [...] tivity. This model is based on the idea that the responses of spinal alpha-motoneurons to a sensorial stimulation can be modulated by the serial activation of a motor command chain. We developed a Fortran program for simulating a physiological situation. The results are discussed in terms of available experimental data for the motoneuron firing rate.

  11. Nasal Reflexes: Implications for Exercise, Breathing, and Sex

    OpenAIRE

    James N. BARANIUK; Merck, Samantha J

    2008-01-01

    Nasal patency, with both congestion and decongestion, is affected in a wide variety of reflexes. Stimuli that lead to nasal reflexes include exercise, alterations of body position, pressure, and temperature, neurological syndromes, and dentists. As anticipated, the vagal and trigeminal systems are closely integrated through nasobronchial and bronchonasal reflexes. However, perhaps of greater pathophysiological importance are the naso-hypopharyngea-laryngeal reflexes that become aggravated dur...

  12. Specificity of Reflex Adaptation for Task-Relevant Variability

    OpenAIRE

    Franklin, David W.; Wolpert, Daniel M

    2008-01-01

    The motor system responds to perturbations with reflexes, such as the vestibulo-ocular reflex or stretch reflex, whose gains adapt in response to novel and fixed changes in the environment, such as magnifying spectacles or standing on a tilting platform. Here we demonstrate a reflex response to shifts in the hands visual location during reaching, which occurs before the onset of voluntary reaction time, and investigate how its magnitude depends on statistical properties of the environment....

  13. Efficient Estimation of Time-Varying Intrinsic and Reflex Stiffness

    OpenAIRE

    Ludvig, Daniel; Perreault, Eric J; Kearney, Robert E

    2011-01-01

    Dynamic joint stiffness defines the dynamic relationship between the position of the joint and the torque acting about it; hence it is important in the control of movement and posture. Joint stiffness consists of two components: intrinsic stiffness and reflex stiffness. Measuring intrinsic and reflex torques directly is not possible, thus estimating intrinsic and reflex stiffness is challenging. A further complication is that both intrinsic and reflex stiffness vary with joint position and to...

  14. Brainstem reflexes and brainstem auditory evoked responses in Huntington's chorea.

    OpenAIRE

    Bollen, E; Arts, R J; Roos, R.A.; Van der Velde, E A; Buruma, O J

    1986-01-01

    Blink reflex, corneal reflex, jaw reflex, exteroceptive suppression in masseter muscles and brainstem auditory evoked potentials were measured in 20 patients with Huntington's chorea and 12 controls. A significantly increased latency of the second component of the homolateral and heterolateral blink reflex was found in the patient group as compared with the controls. The other investigations revealed no significant differences between patients and controls except for some facilitation of the ...

  15. Conductive Hearing Loss with Present Acoustic Reflex: A Case Report

    OpenAIRE

    Takashi Sakamoto; Shu Kikuta; Shinji Urata; Kazuo Yasuhara; Kikkawa, Yayoi S.; Tatsuya Yamasoba

    2014-01-01

    Acoustic reflex is a sensitive indicator of middle ear lesions when the tympanic membrane is in-tact and tympanometry is normal. Acoustic reflex is not usually observed in conductive hearing loss caused by disruption of the ossicular chain including ossicular discontinuity and fixation. Ossicular disruption can show at least partially intact acoustic reflex under a certain condition. Moreover, ossicular discontinuity with a nearly intact acoustic reflex is quite rare and there have been few r...

  16. Anatomy and neuro-pathophysiology of the cough reflex arc

    OpenAIRE

    Polverino Mario; Polverino Francesca; Fasolino Marco; And Filippo; Alfieri Antonio; De Blasio Francesco

    2012-01-01

    Abstract Coughing is an important defensive reflex that occurs through the stimulation of a complex reflex arc. It accounts for a significant number of consultations both at the level of general practitioner and of respiratory specialists. In this review we first analyze the cough reflex under normal conditions; then we analyze the anatomy and the neuro-pathophysiology of the cough reflex arc. The aim of this review is to provide the anatomic and pathophysiologic elements of evaluation of the...

  17. A weak Hilbert space with few symmetries

    OpenAIRE

    Argyros, Spiros A.; Beanland, Kevin; Raikoftsalis, Theocharis

    2009-01-01

    We construct a weak Hilbert Banach space such that for every block subspace $Y$ every bounded linear operator on Y is of the form D+S where S is a strictly singular operator and D is a diagonal operator. We show that this yields a weak Hilbert space whose block subspaces are not isomorphic to any of their proper subspaces.

  18. Some properties of space of compact operators

    CERN Document Server

    Randrianantoanina, N

    1994-01-01

    Let $X$ be a separable Banach space, $Y$ be a Banach space and $\\Lambda$ be a subset of the dual group of a given compact metrizable abelian group. We prove that if $X^*$ and $Y$ have the type I-$\\Lambda$-RNP (resp. type II-$\\Lambda$-RNP) then $K(X,Y)$ has the type I-$\\Lambda$-RNP (resp. type II-$\\Lambda$-RNP) provided $L(X,Y)=K(X,Y)$. Some corollaries are then presented as well as results conserning the separability assumption on $X$. Similar results for the NearRNP and the WeakRNP are also presented.

  19. Impulsive discontinuous hyperbolic partial differential equationsof fractional order on Banach algebras

    Directory of Open Access Journals (Sweden)

    Said Abbas

    2010-07-01

    Full Text Available This article studies the existence of solutions and extremal solutions to partial hyperbolic differential equations of fractional order with impulses in Banach algebras under Lipschitz and Caratheodory conditions and certain monotonicity conditions.

  20. Reflex Anuria After Renal Tumor Embolization

    International Nuclear Information System (INIS)

    We report a case of reflex anuria after transarterial embolization of a renal tumor. Anuria developed immediately after embolization and resolved 74 hr following the procedure. We postulate that reflux anuria in our case was related to mechanoreceptors, chemoreceptors, or both, as these are stimulated by the occluded blood vessels, ischemia, and edema of the normal renal tissue of an embolized kidney

  1. Human investigations into the exercise pressor reflex

    DEFF Research Database (Denmark)

    Secher, Niels H; Amann, Markus

    2012-01-01

    During exercise, neural input from skeletal muscles reflexly maintains or elevates blood pressure (BP) despite a maybe fivefold increase in vascular conductance. This exercise pressor reflex is illustrated by similar heart rate (HR) and BP responses to electrically induced and voluntary exercise. The importance of the exercise pressor reflex for tight cardiovascular regulation during dynamic exercise is supported by studies using pharmacological blockade of lower limb muscle afferent nerves. These experiments show attenuation of the increase in BP and cardiac output when exercise is performed with attenuated neural feedback. Additionally, there is no BP response to electrically induced exercise with paralysing epidural anaesthesia or when similar exercise is evoked in paraplegic patients. Furthermore, BP decreases when electrically induced exercise is carried out in tetraplegic patients. The lack of an increase in BP during exercise with paralysed legs manifests, although electrical stimulation of muscles enhances lactate release and reduces muscle glycogen. Thus, the exercise pressor reflex enhances sympathetic activity and maintains perfusion pressure by restraining abdominal blood flow, while brain, skin and muscle blood flow may also become affected because the reflex 'resets' arterial baroreceptor modulation of vascular conductance, making BP the primarily regulated cardiovascular variable during exercise.

  2. Managing Normative Criteria in Action Research : A reflexive analysis

    DEFF Research Database (Denmark)

    Boulus-Rdje, Nina

    2015-01-01

    A much revisited question within the field of Information Systems is how research- ers can intervene in the context of large-scale, complex and heterogeneous information in- frastructures, while ensuring impact on field settings. To explore this question, I draw upon my interventions and fieldwork experiences from an action research project in a healthcare infrastructural setting. I use these experiences as a basis for appraising the normative crite- ria for rigor and relevance that are enacted in IS action research literature. I argue that while these criteria originally had important contributions, there are also weaknesses with norma- tive approaches. Specifically, these norms of action research leave relatively little space for understanding and managing emerging empirical uncertainties. These norms are important because they have implications not only on how we conduct action research in practice, but also on how we share research experiences, document and report research processes, and on how we use this literature for teaching and training purposes. Therefore, we need meth- odological perspectives more adequate to the varied experiences of empirical IS research. I propose replacing the normative frameworks found in some IS action research literature with a reflexive framework that encourages researchers to investigate critically how their methods are enacted and practiced in the field. The contribution of this paper lies in pro- viding a reflexive analysis of the situated and emergent challenges encountered when han- dling action researchers dual agenda of combining academic and practical contribution.

  3. Determining elements in Banach algebras through spectral properties

    CERN Document Server

    Brear, M

    2012-01-01

    Let $A$ be a Banach algebra. By $\\sigma(x)$ and $r(x)$ we denote the spectrum and the spectral radius of $x\\in A$, respectively. We consider the relationship between elements $a,b\\in A$ that satisfy one of the following two conditions: (1) $\\sigma(ax) = \\sigma(bx)$ for all $x\\in A$, (2) $r(ax) \\le r(bx)$ for all $x\\in A$. In particular we show that (1) implies $a=b$ if $A$ is a $C^*$-algebra, and (2) implies $a\\in \\mathbb C b$ if $A$ is a prime $C^*$-algebra. As an application of the results concerning the conditions (1) and (2) we obtain some spectral characterizations of multiplicative maps.

  4. Fixed Points of Non-expansive Operators on Weakly Cauchy Normed Spaces

    OpenAIRE

    Ali, Sahar M.

    2007-01-01

    We proved the existence of fixed points of non-expansive operators defined on weakly Cauchy spaces in which parallelogram law holds, the given normed space is not necessarily be uniformly convex Banach space or Hilbert space, we reduced the completeness and the uniform convexity assumptions which imposed on the given normed space.

  5. Fixed Points of Non-expansive Operators on Weakly Cauchy Normed Spaces

    Directory of Open Access Journals (Sweden)

    Sahar M. Ali

    2007-01-01

    Full Text Available We proved the existence of fixed points of non-expansive operators defined on weakly Cauchy spaces in which parallelogram law holds, the given normed space is not necessarily be uniformly convex Banach space or Hilbert space, we reduced the completeness and the uniform convexity assumptions which imposed on the given normed space.

  6. FIXED POINTS THEOREMS IN MULTI-METRIC SPACES

    Directory of Open Access Journals (Sweden)

    Laurentiu I. Calmutchi

    2011-07-01

    Full Text Available The aim of the present article is to give some general methods inthe fixed point theory for mappings of general topological spaces. Using the notions of the multi-metric space and of the E-metric space, we proved the analogous of several classical theorems: Banach fixed point principle, Theorems of Edelstein, Meyers, Janos etc.

  7. Feminist Politics as Reflexive Citizenship

    Directory of Open Access Journals (Sweden)

    Nikos Katrivesis

    2008-11-01

    Full Text Available This article examines the potential feminist contribution to a radically renovated citizenship, according to which we all ought to undertake our responsibilities towards family, society and world. This contribution mainly consists in the critical transgression of the traditional dualism between private and public space, which arises from the politicization of everyday experience and results to the emergence of an essentially participial civil society.

  8. Newtonian Lorentz Metric Spaces

    CERN Document Server

    Costea, Serban

    2011-01-01

    This paper studies Newtonian Sobolev-Lorentz spaces. We prove that these spaces are Banach. We also study the global p,q-capacity and the p,q-modulus of families of rectifiable curves. Under some additional assumptions (that is, the space carries a doubling measure and a weak Poincare inequality) and some restrictions on q, we show that the Lipschitz functions are dense in those spaces. Moreover, in the same setting we also show that the p,q-capacity is Choquet provided that q is strictly greater than 1. We provide a counterexample for the density result of Lipschitz functions in the Euclidean setting.

  9. Stick balancing with reflex delay in case of parametric forcing

    Science.gov (United States)

    Insperger, Tamas

    2011-04-01

    The effect of parametric forcing on a PD control of an inverted pendulum is analyzed in the presence of feedback delay. The stability of the time-periodic and time-delayed system is determined numerically using the first-order semi-discretization method in the 5-dimensional parameter space of the pendulum's length, the forcing frequency, the forcing amplitude, the proportional and the differential gains. It is shown that the critical length of the pendulum (that can just be balanced against the time-delay) can significantly be decreased by parametric forcing even if the maximum forcing acceleration is limited. The numerical analysis showed that the critical stick length about 30 cm corresponding to the unforced system with reflex delay 0.1 s can be decreased to 18 cm with keeping maximum acceleration below the gravitational acceleration.

  10. Complemented copies of $\\ell_{1}$ in spaces of vector valued measures and applications

    CERN Document Server

    Randrianantoanina, N

    1995-01-01

    Let $X$ be a Banach space and $(\\Omega,\\Sigma)$ be a measure space. We provide a characterization of sequences in the space of $X$-valued countably additive measures on $\\Omega,\\Sigma)$ of bounded variation that generate complemented copies of $\\ell_1$. As application, we prove that if a dual Banach space $E^*$ has Pe\\l czy\\'nski's property (V*) then so does the space of $E^*$-valued countably additive measures with bounded variation. Another application, we show that for a Banach space $X$, the space $\\ell_\\infty(X)$ contains a complemented copy of $\\ell_1$ if and only if $X$ contains all $\\ell_1^n$ uniformly complemented.

  11. Creativity in ethnographic interviews : reflexive participatory observation

    DEFF Research Database (Denmark)

    Kauffmann, Lene Teglhus

    2014-01-01

    The article discusses interviews as participatory reflexive observation. It is based on experiences of interviewing policymakers and researchers about knowledge and evidence in health promotion. This particular group of informants challenged an approach to interviews as getting informants to describe their everyday work life. By employing a methodological framework focusing on reflexive processes, interviews became consensual interactions, and the content of the interviews turned out to be analyses, interpretations and meaning making, that is, knowledge production. Interpretation and meaning making drew on ideologies, norms and values central to the field and thereby the strategies employed by the informants as well as by the researcher could be seen as wayfaring strategies; creating the paths in the field as they go along. Such an approach to interviews opens up the creative character of knowledge production and points out the role of the researcher as an active participant in the creative process.

  12. Reflexivity and rigidity for complexes, II: Schemes

    CERN Document Server

    Avramov, Luchezar L; Lipman, Joseph

    2010-01-01

    We prove basic facts about reflexivity in derived categories over noetherian schemes; and about related notions such as semidualizing complexes, invertible complexes, and Gorenstein-perfect maps. Also, we study a notion of rigidity with respect to semidualizing complexes, in particular, relative dualizing complexes for Gorenstein-perfect maps. Our results include theorems of Yekutieli and Zhang concerning rigid dualizing complexes on schemes. This work is a continuation of part I, which dealt with commutative rings.

  13. Reflexivity and rigidity for complexes, II: Schemes

    OpenAIRE

    Avramov, Luchezar L.; Iyengar, Srikanth B.; Lipman, Joseph

    2010-01-01

    We prove basic facts about reflexivity in derived categories over noetherian schemes; and about related notions such as semidualizing complexes, invertible complexes, and Gorenstein-perfect maps. Also, we study a notion of rigidity with respect to semidualizing complexes, in particular, relative dualizing complexes for Gorenstein-perfect maps. Our results include theorems of Yekutieli and Zhang concerning rigid dualizing complexes on schemes. This work is a continuation of p...

  14. Axially evoked postural reflexes: influence of task

    OpenAIRE

    Govender, Sendhil; Dennis, Danielle L.; Colebatch, James G.

    2014-01-01

    Postural reflexes were recorded in healthy subjects (n=17) using brief axial accelerations and tap stimuli applied at the vertebra prominens (C7) and manubrium sterni. Short latency (SL) responses were recorded from the soleus, hamstrings and tibialis anterior muscles and expressed as a percentage of the background EMG prior to stimulus onset. In the majority of postural conditions tested, subjects were recorded standing erect and leaning forward with their feet together. The SL response ...

  15. Reflexivity and adjustment strategies at the interfaces

    OpenAIRE

    Ismael Teomiro

    2011-01-01

    I argue in this work that Reinhart & Reulands (1993) conditions A and B hold for Spanish. I provide evidence supporting the hypothesis that this language makes use of both SE and SELF-anaphors. Inherent reflexive verbs undergo an internal argument reduction operation in the lexicon. However, the syntax always requires two arguments. Therefore certain clitics, which are SE-anaphors, are inserted in these derivations. This is a last-resort mechanism that makes an adjustment between t...

  16. Mechanically evoked perioral reflexes in infants.

    Science.gov (United States)

    Barlow, S M; Finan, D S; Rowland, S G

    1992-12-18

    Mechanically evoked activity in the superior and inferior segments of the orbicularis oris muscle was sampled in several young infants using a specially designed position-servo linear motor and a pacifier instrumented with eight miniature EMG electrodes. Unilateral stimulation of lip vermilion resulted in short latency, bilateral activation of the upper and lower lip recording sites. The ontogenesis of facial reflex sensitivity to mechanical inputs is discussed in relation to the acquisition of motor skills, including speech and smiling. PMID:1493544

  17. Tsirelson's space

    CERN Document Server

    Casazza, Peter G

    1989-01-01

    This monograph provides a structure theory for the increasingly important Banach space discovered by B.S. Tsirelson. The basic construction should be accessible to graduate students of functional analysis with a knowledge of the theory of Schauder bases, while topics of a more advanced nature are presented for the specialist. Bounded linear operators are studied through the use of finite-dimensional decompositions, and complemented subspaces are studied at length. A myriad of variant constructions are presented and explored, while open questions are broached in almost every chapter. Two appendices are attached: one dealing with a computer program which computes norms of finitely-supported vectors, while the other surveys recent work on weak Hilbert spaces (where a Tsirelson-type space provides an example).

  18. The swallowing reflex and its significance as an airway defensive reflex

    Directory of Open Access Journals (Sweden)

    TakashiNishino

    2013-01-01

    Full Text Available Swallowing function, in humans, is very complex. Swallowing plays, not only an important role in food digestion, but also a major role in preventing the entrance of food and/or other materials into the lower respiratory tract. To achieve this, precise coordination is necessary between breathing and swallowing since the pharynx serves as a common pathway for both respiration and digestion. The swallowing reflex consists of afferent pathways, central integration, and efferent pathways. Any defect or disorder along reflex arc can cause a potential delay or impairment in swallow function. The swallowing reflex can be modulated not only by pathological factors but also by physiological factors. Among these, timing of swallows in relation to the phase of respiration may be the most important factor that determines the occurrence of pulmonary aspiration, since phases of inspiration and the expiration-inspiration transition are the most vulnerable for pulmonary aspiration.

  19. Short reflex expirations (expiration reflexes induced by mechanical stimulation of the trachea in anesthetized cats

    Directory of Open Access Journals (Sweden)

    Stransky Albert

    2008-04-01

    Full Text Available Abstract Fifty spontaneously breathing pentobarbital-anesthetized cats were used to determine the incidence rate and parameters of short reflex expirations induced by mechanical stimulation of the tracheal mucosa (ERt. The mechanical stimuli evoked coughs; in addition, 67.6% of the stimulation trials began with ERt. The expiration reflex mechanically induced from the glottis (ERg was also analyzed (99.5% incidence, p In an additional 8 cats, the effect of codeine administered via the vertebral artery was tested. Codeine, in a dose (0.03 mg/kg that markedly suppressed cough did not significantly alter either the incidence rate or magnitudes of ERt. In the anesthetized cat the ERt induced by mechanical stimulation of the trachea was similar to the ERg from the glottis. These two reflex responses differ substantially only in the frequency of occurrence in response to mechanical stimulus and in the intensity of motor output.

  20. Fixed Points and Hyers-Ulam-Rassias Stability of Cauchy-Jensen Functional Equations in Banach Algebras

    OpenAIRE

    Choonkil Park

    2007-01-01

    We prove the Hyers-Ulam-Rassias stability of homomorphisms in real Banach algebras and of generalized derivations on real Banach algebras for the following Cauchy-Jensen functional equations: , , which were introduced and investigated by Baak (2006). The concept of Hyers-Ulam-Rassias stability originated from Th. M. Rassias' stability theorem that appeared in his paper (1978).

  1. Fixed Points and Hyers-Ulam-Rassias Stability of Cauchy-Jensen Functional Equations in Banach Algebras

    Directory of Open Access Journals (Sweden)

    Park Choonkil

    2007-01-01

    Full Text Available We prove the Hyers-Ulam-Rassias stability of homomorphisms in real Banach algebras and of generalized derivations on real Banach algebras for the following Cauchy-Jensen functional equations: , , which were introduced and investigated by Baak (2006. The concept of Hyers-Ulam-Rassias stability originated from Th. M. Rassias' stability theorem that appeared in his paper (1978.

  2. Dopamine agonists suppress visual-cortical reflex myoclonus.

    OpenAIRE

    Obeso, J. A.; Artieda, J.; T. Tun; Luquin, M R; Martnez Lage, J M

    1985-01-01

    Two patients with a diagnosis of olivo-ponto-cerebellar atrophy developed cortical reflex myoclonus to visual (flash) and somaesthetic stimuli. Oral treatment with levodopacarbidopa (1000/100 mg) or subcutaneous administration of apomorphine (1 mg) abolished the visually-triggered myoclonus, without modifying reflex myoclonus to electrical or tactile stimulation. Intravenous administration of lisuride (0.1 mg) produced a marked reduction in both types of reflex myoclonus. These results indica...

  3. Automated detection of energy profiles of slow electron diffraction reflexes

    International Nuclear Information System (INIS)

    A method allowing one to automate the recording of energy profiles of slow electron diffraction reflexes carrying information about a surface atomic structure has been developed. The method is applicable in electron diffraction cameras equiped with a photometric device. It consists in the provision of diffraction reflex geometric position stabilization with subsequent self-tuning of the device to the maximum intensity of the reflex studied

  4. Cardiovascular regulation by skeletal muscle reflexes in health and disease

    OpenAIRE

    Murphy, Megan N.; Mizuno, Masaki; Mitchell, Jere H.; Smith, Scott A

    2011-01-01

    Heart rate and blood pressure are elevated at the onset and throughout the duration of dynamic or static exercise. These neurally mediated cardiovascular adjustments to physical activity are regulated, in part, by a peripheral reflex originating in contracting skeletal muscle termed the exercise pressor reflex. Mechanically sensitive and metabolically sensitive receptors activating the exercise pressor reflex are located on the unencapsulated nerve terminals of group III and group IV afferent...

  5. The Role of Transformational Leadership in Enhancing Team Reflexivity

    OpenAIRE

    Schippers, M. C.; Hartog, D. N. Den; Koopman, P. L.; Knippenberg, D. L.

    2007-01-01

    Team reflexivity, or the extent to which teams reflect upon and modify their functioning, has been identified as a key factor in the effectiveness of work teams. As yet, however, little is known about the factors that play a role in enhancing team reflexivity, and it is thus important to develop theorizing around the determinants of reflexivity. From an applied perspective, leadership is a very relevant factor. The current study is a first step in the development of such a theory, and add...

  6. Barycentric Metric Spaces

    Directory of Open Access Journals (Sweden)

    Mendel Manor

    2013-05-01

    Full Text Available The metric Markov cotype of barycentric metric spaces is computed, yielding the first class of metric spaces that are not Banach spaces for which this bi-Lipschitz invariant is understood. It is shown that this leads to new nonlinear spectral calculus inequalities, as well as a unified framework for Lipschitz extension, including new Lipschitz extension results for CAT (0 targets. An example that elucidates the relation between metric Markov cotype and Rademacher cotype is analyzed, showing that a classical Lipschitz extension theorem of Johnson, Lindenstrauss and Benyamini is asymptotically sharp.

  7. Completeness of regular inductive limits

    OpenAIRE

    Kelly McKennon; Jan Kucera

    1989-01-01

    Regular LB-space is fast complete but may not be quasi-complete. Regular inductive limit of a sequence of fast complete, resp. weakly quasi-complete, resp. reflexive Banach, spaces is fast complete, resp. weakly quasi-complete, resp. reflexive complete, space.

  8. Completeness of regular inductive limits

    Directory of Open Access Journals (Sweden)

    Kelly McKennon

    1989-09-01

    Full Text Available Regular LB-space is fast complete but may not be quasi-complete. Regular inductive limit of a sequence of fast complete, resp. weakly quasi-complete, resp. reflexive Banach, spaces is fast complete, resp. weakly quasi-complete, resp. reflexive complete, space.

  9. Cholesteric Liquid Crystal Based Reflex Color Reflective Displays

    Science.gov (United States)

    Khan, Asad

    2012-02-01

    Bistable color cholesteric liquid crystal displays are unique LCDs that exhibit high reflectivity, good contrast, extremely low power operation, and are amenable to versatile roll-to-roll manufacturing. The display technology, now branded as Reflex has been in commercialized products since 1996. It has been the subject of extensive research and development globally by a variety of parties in both academic and industrial settings. Today, the display technology is in volume production for applications such as dedicated eWriters (Boogie Board), full color electronic skins (eSkin), and displays for smart cards. The flexibility comes from polymerization induced phase separation using unique materials unparalleled in any other display technology. The blend of monomers, polymers, cross linkers, and other components along with nematic liquid crystals and chiral dopants is created and processed in such ways so as to enable highly efficient manufactrable displays using ultra thin plastic substrates -- often as thin as 50?m. Other significant aspects include full color by stacking or spatial separation, night vision capability, ultra high resolution, as well as active matrix capabilities. Of particular note is the stacking approach of Reflex based displays to show full color. This approach for reflective color displays is unique to this technology. Owing to high transparency in wavelength bands outside the selective reflection band, three primarily color layers can be stacked on top of each other and reflect without interfering with other layers. This highly surprising architecture enables the highest reflectivity of any other reflective electronic color display technology. The optics, architecture, electro-topics, and process techniques will be discussed. This presentation will focus on the physics of the core technology and color, it's evolution from rigid glass based displays to flexible displays, development of products from the paradigm shifting concepts to consumer products and related markets. This is a development that spans a wide space of highly technical development and fundamental science to products and commercialization to enable the entry of the technology into consumer markets.

  10. Reflex tetrode for producing an efficient unidirectional ion beam

    International Nuclear Information System (INIS)

    A reflex tetrode device for efficiently generating intense, pulsed unidirectional ion beams is disclosed. The device includes two thin, semitransparent anodes spaced from a real cathode which is maintained at ground potential. The first anode is spaced from and faces the real cathode. The second anode is spaced a short distance from the first anode and a virtual cathode is formed beyond the second anode when a sufficiently high electron current flows from the real cathode and through the anodes. The anodes are ring-like or disc-like structures secured to the edges of a support member with their planes perpendicular to the axis of the device between the real and virtual cathodes. The anode structure (i.e., the support member together with the two anodes) is connected to a pulsed high-voltage generator which is operated in positive polarity. Consequently, both anodes are at the same positive potential. The first anode, because of its material, does not readily form an ionic plasma when electrons pass through it, but the second anode does

  11. Neural reflex regulation of arterial pressure in pathophysiological conditions: interplay among the baroreflex, the cardiopulmonary reflexes and the chemoreflex

    Scientific Electronic Library Online (English)

    E.C., Vasquez; S.S., Meyrelles; H., Mauad; A.M., Cabral.

    1997-04-01

    Full Text Available The maintenance of arterial pressure at levels adequate to perfuse the tissues is a basic requirement for the constancy of the internal environment and survival. The objective of the present review was to provide information about the basic reflex mechanisms that are responsible for the moment-to-mo [...] ment regulation of the cardiovascular system. We demonstrate that this control is largely provided by the action of arterial and non-arterial reflexes that detect and correct changes in arterial pressure (baroreflex), blood volume or chemical composition (mechano- and chemosensitive cardiopulmonary reflexes), and changes in blood-gas composition (chemoreceptor reflex). The importance of the integration of these cardiovascular reflexes is well understood and it is clear that processing mainly occurs in the nucleus tractus solitarii, although the mechanism is poorly understood. There are several indications that the interactions of baroreflex, chemoreflex and Bezold-Jarisch reflex inputs, and the central nervous system control the activity of autonomic preganglionic neurons through parallel afferent and efferent pathways to achieve cardiovascular homeostasis. It is surprising that so little appears in the literature about the integration of these neural reflexes in cardiovascular function. Thus, our purpose was to review the interplay between peripheral neural reflex mechanisms of arterial blood pressure and blood volume regulation in physiological and pathophysiological states. Special emphasis is placed on the experimental model of arterial hypertension induced by N-nitro-L-arginine methyl ester (L-NAME) in which the interplay of these three reflexes is demonstrable

  12. Effects of direct current on motoneuron reflex excitability (Assessed by H-reflex amplitude) in healthy subjects

    OpenAIRE

    Olyaei G; Akbari M; Esfandiarpoor F

    2000-01-01

    The purpose of the this study was to investigate the effect of direct current on montoneuron reflex exitability. Thirty six subjects (18 males, 18 females) 19.36 years of age ( x= 24.06, SD= 3.63) participated in this study. The reflex excitability of soleus motoneruons was assessed by measuring the amount of change in the peak to peak ampitude of the H-reflex before and after direct current was applied to the skin over the sural nerve. Reflex recordings were taken before and after direct cur...

  13. Neural reflex regulation of arterial pressure in pathophysiological conditions: interplay among the baroreflex, the cardiopulmonary reflexes and the chemoreflex

    Directory of Open Access Journals (Sweden)

    E.C. Vasquez

    1997-04-01

    Full Text Available The maintenance of arterial pressure at levels adequate to perfuse the tissues is a basic requirement for the constancy of the internal environment and survival. The objective of the present review was to provide information about the basic reflex mechanisms that are responsible for the moment-to-moment regulation of the cardiovascular system. We demonstrate that this control is largely provided by the action of arterial and non-arterial reflexes that detect and correct changes in arterial pressure (baroreflex, blood volume or chemical composition (mechano- and chemosensitive cardiopulmonary reflexes, and changes in blood-gas composition (chemoreceptor reflex. The importance of the integration of these cardiovascular reflexes is well understood and it is clear that processing mainly occurs in the nucleus tractus solitarii, although the mechanism is poorly understood. There are several indications that the interactions of baroreflex, chemoreflex and Bezold-Jarisch reflex inputs, and the central nervous system control the activity of autonomic preganglionic neurons through parallel afferent and efferent pathways to achieve cardiovascular homeostasis. It is surprising that so little appears in the literature about the integration of these neural reflexes in cardiovascular function. Thus, our purpose was to review the interplay between peripheral neural reflex mechanisms of arterial blood pressure and blood volume regulation in physiological and pathophysiological states. Special emphasis is placed on the experimental model of arterial hypertension induced by N-nitro-L-arginine methyl ester (L-NAME in which the interplay of these three reflexes is demonstrable

  14. An Enabling Framework for Reflexive Learning: Experiential Learning and Reflexivity in Contemporary Modernity

    Science.gov (United States)

    Dyke, Martin

    2009-01-01

    The paper presents an enabling framework for experiential learning that connects with reflexive modernity. This framework places an emphasis on learning with others and on the role of theory, practice and reflection. A sociological argument is constructed for an alternative framework for experiential learning that derives from social theory. It is

  15. Serotonergic Modulation of the Trigeminocardiac Reflex Neurotransmission to Cardiac Vagal Neurons in the Nucleus Ambiguus

    OpenAIRE

    Gorini, C.; Jameson, H. S.; Mendelowitz, D.

    2009-01-01

    Stimulation of the trigeminal nerve evokes a dramatic decrease in heart rate and blood pressure, and this reflex has generally been termed the trigeminocardiac reflex. A subset of the trigeminocardiac reflex is the diving reflex in which the nasal mucosa is stimulated with water or air-borne chemical irritants. Activation of the diving reflex evokes a pronounced bradycardia, mediated by increased parasympathetic cardiac activity, and is the most powerful autonomic reflex. However, exaggeratio...

  16. The Validity and Reliability of Motion Analysis in Patellar Tendon Reflex Assessment

    OpenAIRE

    Lim Kheng Seang

    2013-01-01

    The deep tendon reflex assessments that are essential to the accurate diagnosis of neurological or neuromuscular disorders are conducted subjectively in clinical neurology. Our aim was to assess deep tendon reflexes objectively with a new reflex quantification method.|The present study used a motion analysis technique to collect quantitative measurements for both the input and output of normal patellar tendon reflex. Reflex responses were measured as knee angles. The patellar tendon reflexes ...

  17. Axially evoked postural reflexes: influence of task.

    Science.gov (United States)

    Govender, Sendhil; Dennis, Danielle L; Colebatch, James G

    2015-01-01

    Postural reflexes were recorded in healthy subjects (n = 17) using brief axial accelerations and tap stimuli applied at the vertebra prominens (C7) and manubrium sterni. Short latency (SL) responses were recorded from the soleus, hamstrings and tibialis anterior muscles and expressed as a percentage of the background EMG prior to stimulus onset. In the majority of postural conditions tested, subjects were recorded standing erect and leaning forward with their feet together. The SL response was larger for soleus than for the hamstrings during standing (soleus vs hamstrings; 70.4 vs 28.1%), whereas the opposite occurred during kneeling (25.3 vs 127.3%). Concordant head and trunk accelerations produced larger SL responses than discordant accelerations for soleus and hamstrings, but the evoked excitatory response was independent of head direction and as expected for the direction of truncal acceleration. Postural reflexes for soleus and tibialis anterior were strongly affected by conditions that posed a significant threat to postural stability; stimulation at C7 was associated with significant SL enhancement for soleus during anterior lean while sternal stimulation showed SL enhancement for tibialis anterior during posterior lean. Cutaneous anaesthesia applied over the C7 stimulation site had no significant effect on EMG responses, nor did vision or surface type (rigid or compliant). This study provides further evidence that postural reflexes produced by brief axial accelerations are independent of cutaneous receptors, vestibular afferents and ankle proprioceptors, and demonstrates that postural tasks and truncal orientation significantly affect the evoked response, consistent with a role in stabilising posture. PMID:25300958

  18. Formation of H- beams in reflex systems

    International Nuclear Information System (INIS)

    The formation of H- beams in reflex systems has been studied. The use of charge-exchange method and suppression of the background from protons accelerated from the anode made it possible to determine the concentration of H- ions in the plasma near the cathode at the level of 0.5--2%. The H- current density lies in the range 0.25 +- 0.15 A/cm2. A significant improvement in measurement accuracy can be achieved by using a deuterated coating on the cathode and by switching to a high accelerator current density

  19. On the L-characteristic of nonlinear superposition operators in lp-spaces

    International Nuclear Information System (INIS)

    In this paper we describe the L-characteristic of the nonlinear superposition operator F(x) f(s,x(s)) between two Banach spaces of functions x from N to R. It was shown that L-characteristic of the nonlinear superposition operator which acts between two Lebesgue spaces has so-called ?-convexity property. In this paper we show that L-characteristic of the operator F (between two Banach spaces) has the convexity property. It means that the classical interpolation theorem of Reisz-Thorin for a linear operator holds for the nonlinear operator superposition which acts between two Banach spaces of sequences. Moreover, we consider the growth function of the operator superposition in mentioned spaces and we show that one has the logarithmically convexity property. (author). 7 refs

  20. The proboscis extension reflex not elicited in Magachilid bees

    Science.gov (United States)

    Honey bees (Apis mellifera L.) will reflexively extend their proboscis in response to antennal stimulation with sucrose solution. For decades, the proboscis extension reflex (PER) of honey bees has been used as a tool to further the understanding of their cognitive processes, such as learning and m...

  1. Reflexivity of Discomfort in Insider-Outsider Educational Research

    Science.gov (United States)

    Hamdan, Amani K.

    2009-01-01

    This paper discusses my position as an Arab Muslim woman researcher who is affiliated with a Western university, researching Arab Muslim Canadian women. I discuss how reflexivity has emerged as an element of my research endeavours. Various notions of reflexivity in educational research have been expressed in the literature, yet I focus on what it

  2. Sympathetic reflex control of blood flow in human peripheral tissues.

    DEFF Research Database (Denmark)

    Henriksen, O

    1991-01-01

    Sympathetic vasoconstrictor reflexes are essential for the maintenance of arterial blood pressure in upright position. It has been generally believed that supraspinal sympathetic vasoconstrictor reflexes elicited by changes in baroreceptor activity play an important role. Recent studies on human skeletal muscle, cutaneous and subcutaneous tissues of the limbs indicate that the situation is more complex. Measurements have been carried out during acute as well as chronic sympathetic denervation. Spinal sympathetic reflex mechanisms have been evaluated in tetraplegic patients, where supraspinal sympathetic vasoconstrictor reflexes are blocked. Blood flow has been measure by the local 133Xe-technique. The results indicate the presence of spinal as well as supraspinal sympathetic vasoconstrictor reflexes to human peripheral tissues. Especially is emphasized the presence of a local sympathetic veno-arteriolar axon reflex which is elicited by increase in venous transmural pressure of more than about 25 mm Hg. Finally, centrally elicited vasoconstrictor activity is modified by simultaneously activating the local veno-arteriolar axon reflex or vice versa by means of an intraneuronal impulse inhibition due to collision of normodromically and antidromically conducted impulses in efferent sympathetic vasoconstrictor fibers. The evidence obtained suggests that sympathetic vasoconstrictor reflexes to postural changes are complex and highly differentiated.

  3. Reflex switch experiments with capacitor bank drivers

    International Nuclear Information System (INIS)

    Pulsed power systems based on power amplifications of magnetic energy stored in vacuum offer significant advantages in power scaling, compactness and cost over conventional technology. The key component of such a system is the vacuum switch, which is to stay closed for a long enough time to energize an inductor with current and then to open in a short enough time to produce a power-amplified output pulse near the final vacuum load. The reflex switch is a simple system that meets these requirements. It consists of a primary cathode, a thin anode, and an electrically floating secondary electrode that acts first as a cathode and then as the anode. The closed mode of the switch is characterized by the presence of a population of reflexing electrons (passing many times through the thin anode, depositing a fraction of their initial energy on each pass) and counterstreaming ions. The current can be orders of magnitude greater than the Langmuir bipolar current for the same geometry and voltage. Previous experiments employed high voltage, short pulse drivers. The authors report their bank drivers. They measured scaling laws and an empirical figure-of-merit that allows them to design experiments for desired results

  4. Reflexivity and adjustment strategies at the interfaces

    Directory of Open Access Journals (Sweden)

    Ismael Teomiro

    2011-10-01

    Full Text Available I argue in this work that Reinhart & Reulands (1993 conditions A and B hold for Spanish. I provide evidence supporting the hypothesis that this language makes use of both SE and SELF-anaphors. Inherent reflexive verbs undergo an internal argument reduction operation in the lexicon. However, the syntax always requires two arguments. Therefore certain clitics, which are SE-anaphors, are inserted in these derivations. This is a last-resort mechanism that makes an adjustment between the valence of the lexical entry of the verb and the requirements of the syntax in order for the derivation to converge at the C-I interface. These clitics are syntactic arguments. Nevertheless, they are not interpreted as semantic arguments since they violate the double chain condition, which forces nominal elements to share both a tense and thematic features with the verb and the tense heads. Non- inherent reflexive verbs require the presence of a SELF-anaphor, which is formed out of a SE-anaphor along with a protector SELF element. Therefore, both syntactic elements are interpreted as two distinguishable semantic elements at C-I despite the fact that there is binding between them both. The interpretation of both syntactic elements as just one semantic element is a pragmatic epiphenomenon.

  5. Does total knee arthroplasty affect the patellar tendon reflex?

    Directory of Open Access Journals (Sweden)

    Richard Jamieson

    2010-02-01

    Full Text Available BackgroundThere may be a perception in clinical practice that anydeficit in the patellar tendon reflex arc could beattributed to a total knee arthroplasty (TKA. There is noevidence in the literature to support this conclusion.MethodsSixty-six knees were examined to determine whetherTKA affects the patellar tendon reflex.ResultsThere was no difference observed between the kneeswith a history of TKA and those knees without a historyof TKA.DiscussionThere is no plausible reason that TKA should affect thepatellar tendon reflex. Despite this, in clinical practiceTKA is often thought to be responsible for absentpatellar tendon reflexes. This study supports thehypothesis that there is no effect of TKA on patellartendon reflexes.

  6. The near Radon-Nikodym property in Lebesgue-Bochner function spaces

    CERN Document Server

    Randrianantoanina, N; Randrianantoanina, Narcisse; Saab, Elias

    1997-01-01

    Let $X$ be a Banach space $E$ a K\\"othe function space that does not contain $c_0$. It is shown that the vector valued function space $E(X)$ has the Near Radon Nikodym property if and only if $X$ does.

  7. On solvability of some quadratic functional-integral equation in Banach algebra

    International Nuclear Information System (INIS)

    Using the technique of a suitable measure of non-compactness in Banach algebra, we prove an existence theorem for some functional-integral equations which contain, as particular cases, a lot of integral and functional-integral equations that arise in many branches of nonlinear analysis and its applications. Also, the famous Chandrasekhar's integral equation is considered as a special case. (author)

  8. Central limit theorem for the Banach-valued weakly dependent random variables

    International Nuclear Information System (INIS)

    The central limit theorem (CLT) for the Banach-valued weakly dependent random variables is proved. In proving CLT convergence of finite-measured (i.e. cylindrical) distributions is established. A weak compactness of the family of measures generated by a certain sequence is confirmed. The continuity of the limiting field is checked

  9. Effects of Bed Rest on Conduction Velocity of the Triceps Surae Stretch Reflex and Postural Control

    Science.gov (United States)

    Reschke, M. F.; Wood, S. J.; Cerisano, J. M.; Kofman, I. S.; Fisher, E. A.; Esteves, J. T.; Taylor, L. C.; DeDios, Y. E.; Harm, D. L.

    2011-01-01

    Despite rigorous exercise and nutritional management during space missions, astronauts returning from microgravity exhibit neuromuscular deficits and a significant loss in muscle mass in the postural muscles of the lower leg. Similar changes in the postural muscles occur in subjects participating in long-duration bed rest studies. These adaptive muscle changes manifest as a reduction in reflex conduction velocity during head-down bed rest. Because the stretch reflex encompasses both the peripheral (muscle spindle and nerve axon) and central (spinal synapse) components involved in adaptation to calf muscle unloading, it may be used to provide feedback on the general condition of neuromuscular function, and might be used to evaluate the effectiveness of countermeasures aimed at preserving muscle mass and function during periods of unloading. Stretch reflexes were measured on 18 control subjects who spent 60 to 90 days in continuous 6 deg head-down bed rest. Using a motorized system capable of rotating the foot around the ankle joint (dorsiflexion) through an angle of 10 degrees at a peak velocity of about 250 deg/sec, a stretch reflex was recorded from the subject's left triceps surae muscle group. Using surface electromyography, about 300 reflex responses were obtained and ensemble-averaged on 3 separate days before bed rest, 3 to 4 times in bed, and 3 times after bed rest. The averaged responses for each test day were examined for reflex latency and conduction velocity (CV) across gender. Computerized posturography was also conducted on these same subjects before and after bed rest as part of the standard measures. Peak-to-peak sway was measured during Sensory Organization Tests (SOTs) to evaluate changes in the ability to effectively use or suppress visual, vestibular, and proprioceptive information for postural control. Although no gender differences were found, a significant increase in reflex latency and a significant decrease in CV were observed during the bed rest period, with a return to baseline 3 to 5 days after bed rest, depending on the duration of bed rest. In addition, a relationship between CV and loss of muscle strength in the lower leg was observed post bed rest for most subjects. Immediately post-bed rest, most subjects showed decreased performance on SOTs, with the greater decrements on sway-referenced support and head movement conditions. Post-bed rest decrements were less than typically observed following spaceflight. Decrements in postural control and the stretch reflex can be primarily attributed to the unloading mechanisms this ground-based analog provides. The stretch reflex is a concise test measurement that can be obtained during the head-down phase of bed rest, as it does not interfere with the bed rest paradigm. This makes it an ideal tool that can detect, early on, whether a countermeasure is successful in preserving muscle function.

  10. Partial inner product spaces theory and applications

    CERN Document Server

    Antoine, Jean-Pierre

    2009-01-01

    Partial Inner Product (PIP) Spaces are ubiquitous, e.g. Rigged Hilbert spaces, chains of Hilbert or Banach spaces (such as the Lebesgue spaces Lp over the real line), etc. In fact, most functional spaces used in (quantum) physics and in signal processing are of this type. The book contains a systematic analysis of PIP spaces and operators defined on them. Numerous examples are described in detail and a large bibliography is provided. Finally, the last chapters cover the many applications of PIP spaces in physics and in signal/image processing, respectively. As such, the book will be useful both for researchers in mathematics and practitioners of these disciplines.

  11. [Quantitative measurement of the tendon reflexes. A study on Achilles tendon reflex (author's transl)].

    Science.gov (United States)

    Mimatsu, K

    1979-04-01

    Quantitative analyses of tendon reflexes were performed for the purpose of clinical application. Tendon tap was marked with a WNS-5D semiconductor load cell inserted in the hammer to measure tapping force. Achilles tendon reflex (ATR) was measured with a LAS-0.1 displacement transducer in kneeling position on the chair. In ATR, six factors, i.e. duration of reaction time, the height of the wave, the time from the hammer tap to the top of the wave, the maximum speed of contraction, the time from the hammer tap to the maximum speed and half relaxation time, were analyzed. Correlation between these six factors were discussed. From the analyses of these factors, half relaxation time may serve as the best indicator of clinical status among the factors obtained by analysis of ATR. PMID:490007

  12. The swallowing reflex and its significance as an airway defensive reflex

    OpenAIRE

    TakashiNishino

    2013-01-01

    Swallowing function, in humans, is very complex. Swallowing plays, not only an important role in food digestion, but also a major role in preventing the entrance of food and/or other materials into the lower respiratory tract. To achieve this, precise coordination is necessary between breathing and swallowing since the pharynx serves as a common pathway for both respiration and digestion. The swallowing reflex consists of afferent pathways, central integration, and efferent pathways. Any ...

  13. The swallowing reflex and its significance as an airway defensive reflex

    OpenAIRE

    Nishino, Takashi

    2013-01-01

    Swallowing function, in humans, is very complex. Swallowing plays, not only an important role in food digestion, but also a major role in preventing the entrance of food and/or other materials into the lower respiratory tract. To achieve this, precise coordination is necessary between breathing and swallowing since the pharynx serves as a common pathway for both respiration and digestion. The swallowing reflex consists of afferent pathways, central integration, and efferent pathways. Any defe...

  14. Topological Properties of Real Normed Space

    Directory of Open Access Journals (Sweden)

    Nakasho Kazuhisa

    2014-09-01

    Full Text Available In this article, we formalize topological properties of real normed spaces. In the first part, open and closed, density, separability and sequence and its convergence are discussed. Then we argue properties of real normed subspace. Then we discuss linear functions between real normed speces. Several kinds of subspaces induced by linear functions such as kernel, image and inverse image are considered here. The fact that Lipschitz continuity operators preserve convergence of sequences is also refered here. Then we argue the condition when real normed subspaces become Banachs spaces. We also formalize quotient vector space. In the last session, we argue the properties of the closure of real normed space. These formalizations are based on [19](p.3-41, [2] and [34](p.3-67.

  15. Avian reflex and electroencephalogram responses in different states of consciousness.

    Science.gov (United States)

    Sandercock, Dale A; Auckburally, Adam; Flaherty, Derek; Sandilands, Victoria; McKeegan, Dorothy E F

    2014-06-22

    Defining states of clinical consciousness in animals is important in veterinary anaesthesia and in studies of euthanasia and welfare assessment at slaughter. The aim of this study was to validate readily observable reflex responses in relation to different conscious states, as confirmed by EEG analysis, in two species of birds under laboratory conditions (35-week-old layer hens (n=12) and 11-week-old turkeys (n=10)). We evaluated clinical reflexes and characterised electroencephalograph (EEG) activity (as a measure of brain function) using spectral analyses in four different clinical states of consciousness: conscious (fully awake), semi-conscious (sedated), unconscious-optimal (general anaesthesia), unconscious-sub optimal (deep hypnotic state), as well as assessment immediately following euthanasia. Jaw or neck muscle tone was the most reliable reflex measure distinguishing between conscious and unconscious states. Pupillary reflex was consistently observed until respiratory arrest. Nictitating membrane reflex persisted for a short time (reflex is a conservative measure of death in poultry. Using spectral analyses of the EEG waveforms it was possible to readily distinguish between the different states of clinical consciousness. In all cases, when birds progressed from a conscious to unconscious state; total spectral power (PTOT) significantly increased, whereas median (F50) and spectral edge (F95) frequencies significantly decreased. This study demonstrates that EEG analysis can differentiate between clinical states (and loss of brain function at death) in birds and provides a unique integration of reflex responses and EEG activity. PMID:24878315

  16. Reflexivity, description and the analysis of social settings

    Directory of Open Access Journals (Sweden)

    Rodney Watson

    2005-01-01

    Full Text Available The concept of 'reflexivity' has become an often-intoned mantra in contemporary social science, particulary, perhaps, sociology. This article, however, argues that the 'blanket use' of 'reflexivity' glosses over and confuses many different actual definitions and understandings of the concept - not least because the concept operates differently as a move within each of the divergent analytic 'games' that compose the overall discipline. One (among many other crucial distinctions is that between 'stipulative' and 'essential' reflexivity - the former originating in part in G.H.Mead's notions of the 'I' and the 'Me', and extended within current theories of reflexive modernity. This concept has been wrenched by professional social scientist from its mundane moorings and has been 'elevated' into an analytic technique of self interrogation. By contrast, 'essential' reflexivity, as adduced by ethnomethodological sociologists, remains resolutely emplaced in the domain of lay society-members' ordinary sense-making practices: it here refers to the reciprocal, back-and-forth determinations of sense of members' mundane descriptions of their specific circumstances and of the circumstances they describe - description and circumstance reflect upon each other during the sense-making practices. A brief example of essential reflexivity is given- reflexive formulations in ordinary conversations.

  17. Reflex sympathetic dystrophy syndrome: MR imaging study

    International Nuclear Information System (INIS)

    Reflex sympathetic dystrophy syndrome (RSDS) is characterized by pain, swelling, and limitation of motion. The etiology and pathophysiology mechanism have not yet been identified. We considered eight patients with clinical signs of RSDS, in five cases located at the knee joint and in three cases in the hip. In all cases conventional radiography and radionuclide bone scanning were performed before MR imaging. Conventional radiography was negative in three cases while scintigraphy demonstrated the lesion in all patients. MR imaging showed an area of low intensity signal on T1-weighted scans and an increased signal intensity on T2-weighted images. This area is located at the bone marrow and its regular and homogeneous. This specific finding on MR images is due to reflect edema by hyperemia of the bone marrow. The MR imaging diagnosis was confirmed on clinical and radiological follow-up. MR imaging can have a role in the differential diagnosis when other studies are nondiagnostic or nonspecific for RSDS

  18. Leukocoria and the red reflex test

    Directory of Open Access Journals (Sweden)

    Mirna Yae Yassuda Tamura

    2009-09-01

    Full Text Available Until recently, the ophthalmologic examination of newborns in maternity hospitals was not a priority; even today, few hospitals perform this examination adequately. Consequences may be disastrous, because by the time eye alterations are found, the child may have developed permanent loss of visual acuity. The ophthalmologic examination in nurseries, carried out by neonatologists, permits an early diagnosis and referral for effective therapy and adequate development of vision. This study underlines the importance of the red reflex test in newborns and presents the main causes of leukocoria (cataract, retinoblastoma, and retinal and vitreous diseases to alert pediatricians and neonatologists about this condition. Special emphasis is given to retinoblastoma, a condition affecting 1/14,000 to 1/20,000 live newborns; genetic, clinical, diagnostic, and therapeutic aspects are presented. Early diagnosis of retinoblastoma is essential for reducing morbidity and mortality.

  19. Cultural reflexivity in health research and practice.

    Science.gov (United States)

    Aronowitz, Robert; Deener, Andrew; Keene, Danya; Schnittker, Jason; Tach, Laura

    2015-07-01

    Recent public health movements have invoked cultural change to improve health and reduce health disparities. We argue that these cultural discourses have sometimes justified and maintained health inequalities when those with power and authority designated their own social practices as legitimate and healthy while labeling the practices of marginalized groups as illegitimate or unhealthy. This "misrecognition," which creates seemingly objective knowledge without understanding historical and social conditions, sustains unequal power dynamics and obscures the fact that what is deemed legitimate and healthy can be temporally, geographically, and socially relative. We use examples from research across multiple disciplines to illustrate the potential consequences of cultural misrecognition, highlight instances in which culture was invoked in ways that overcame misrecognition, and discuss how cultural reflexivity can be used to improve health research and practice. PMID:25905833

  20. Distrofia simptico-reflexa Reflex sympathetic dystrophy

    Directory of Open Access Journals (Sweden)

    Ana P. N. Lotito

    2004-04-01

    Full Text Available OBJETIVO: Descrever as caractersticas clnicas, laboratoriais e teraputicas de oito crianas com distrofia simptico-reflexa. DESCRIO: Foram analisados retrospectivamente oito casos de distrofia simptico-reflexa. O diagnstico foi baseado na presena de dor no segmento distal de um membro, edema local, alteraes vasomotoras e de sensibilidade. Dentre os oito pacientes com distrofia simptico-reflexa, dois eram portadores de lpus eritematoso sistmico, um de artrite idioptica juvenil e um de trombastenia de Glanzmann. Quatro eram meninas, e a mdia de idade foi de 11,5 anos. Os membros inferiores foram acometidos na maioria dos pacientes (7/8, e as caractersticas clnicas mais marcantes foram dor, edema e alteraes vasomotoras da extremidade afetada (7/8, incapacitao funcional (7/8 e alteraes de sensibilidade (3/8. A velocidade de hemossedimentao esteve alterada em trs pacientes, e a cintilografia msculo-esqueltica em cinco. Todos os pacientes receberam antiinflamatrios no-hormonais e fisioterapia, com melhora clnica observada em sete pacientes em at 6 meses de tratamento. Trs pacientes foram submetidos acupuntura, com boa resposta. Um paciente teve curso de difcil controle, tendo recebido antidepressivos tricclicos e apresentando melhora aps mais de 1 ano de tratamento. COMENTRIOS: A distrofia simptico-reflexa uma doena que deve ser includa no diagnstico diferencial das dores em membros na infncia, para que se estabelea o diagnstico precocemente, evitando-se, assim, prejuzo funcional a mdio e longo prazo.OBJECTIVE: To describe eight patients with reflex sympathetic dystrophy in terms of clinical and laboratory characteristics and treatment. DESCRIPTION: Eight children (four girls with reflex sympathetic dystrophy were retrospectively analyzed. The diagnosis of reflex sympathetic dystrophy was based on the presence of pain in the distal extremities, local edema, vasomotor instability and impairment of sensibility. Two patients had associated systemic lupus erythematosus, one had juvenile idiopathic arthritis and one had Glanzmann's thrombasthenia. Mean age was 11.5 years. Most of the patients had lower extremity involvement (7/8. The most important clinical signs were pain, edema and vasomotor instability in the affected extremity (8/8, functional impairment (7/8, and impaired sensibility (3/7. The erythrocyte sedimentation rate was abnormal in three patients and the bone scans in five. All patients received non-steroidal anti-inflammatory drugs and physical therapy with improvement of the symptoms in seven patients, until six months of treatment. Three patients were submitted to acupuncture with good response. One patient had a severe disease and received tricyclic antidepressants, with improvement more than one year after. COMMENTS: Reflex sympathetic dystrophy should be included as part of the differential diagnosis of limb pains of childhood, so that physicians can make an earlier diagnosis and prevent functional impairment.

  1. Focusing experiments with an inverse reflex tetrode

    International Nuclear Information System (INIS)

    The focusing properties of an Inverse Reflex Tetrode (IRT) used for ion beam generation have been investigated experimentally. Focusing is achieved by replacing the planar (00) electrodes of a standard IRT with moderately inwardly tapered electrodes (7.5, 10, and 150). The greatest degree of focusing is obtained with the 150 electrodes as determined by beam profile measurements using streak photography and nuclear activation techniques at various axial target positions. A scissoring effect is observed, due to temporal variations in generator voltage and current, that is manifested by an axial variation in the focal point with time. Calculations of proton trajectories confirm the experimental results and demonstrate the importance of self-fields within the A-K gap in determining the characteristics of an ion beam generated by an IRT

  2. Study of the Reflex-Klystron

    International Nuclear Information System (INIS)

    The main purpose of this paper is the theoretical study and the development of a technique for designing. A low power Reflex-Klystron, in order to construct it in the graduated section laboratories of the Instituto Politecnico Nacional. It is pretended to attain a power of 15-45 m W in frequencies of 8-10 GHz with low acceleration potentials (300-400 V) and electric current of 15-25 m A; the device will be mechanically tuned and will have a fine tuning through the potential of the reflector (150-180 V negative with respect to the resonator). The International System of Units is used in this thesis. (Author)

  3. Distrofia simptico-reflexa / Reflex sympathetic dystrophy

    Scientific Electronic Library Online (English)

    Ana P. N., Lotito; Lcia M. M. A., Campos; Marialda H. P., Dias; Clovis A. A., Silva.

    2004-04-01

    Full Text Available OBJETIVO: Descrever as caractersticas clnicas, laboratoriais e teraputicas de oito crianas com distrofia simptico-reflexa. DESCRIO: Foram analisados retrospectivamente oito casos de distrofia simptico-reflexa. O diagnstico foi baseado na presena de dor no segmento distal de um membro, edem [...] a local, alteraes vasomotoras e de sensibilidade. Dentre os oito pacientes com distrofia simptico-reflexa, dois eram portadores de lpus eritematoso sistmico, um de artrite idioptica juvenil e um de trombastenia de Glanzmann. Quatro eram meninas, e a mdia de idade foi de 11,5 anos. Os membros inferiores foram acometidos na maioria dos pacientes (7/8), e as caractersticas clnicas mais marcantes foram dor, edema e alteraes vasomotoras da extremidade afetada (7/8), incapacitao funcional (7/8) e alteraes de sensibilidade (3/8). A velocidade de hemossedimentao esteve alterada em trs pacientes, e a cintilografia msculo-esqueltica em cinco. Todos os pacientes receberam antiinflamatrios no-hormonais e fisioterapia, com melhora clnica observada em sete pacientes em at 6 meses de tratamento. Trs pacientes foram submetidos acupuntura, com boa resposta. Um paciente teve curso de difcil controle, tendo recebido antidepressivos tricclicos e apresentando melhora aps mais de 1 ano de tratamento. COMENTRIOS: A distrofia simptico-reflexa uma doena que deve ser includa no diagnstico diferencial das dores em membros na infncia, para que se estabelea o diagnstico precocemente, evitando-se, assim, prejuzo funcional a mdio e longo prazo. Abstract in english OBJECTIVE: To describe eight patients with reflex sympathetic dystrophy in terms of clinical and laboratory characteristics and treatment. DESCRIPTION: Eight children (four girls) with reflex sympathetic dystrophy were retrospectively analyzed. The diagnosis of reflex sympathetic dystrophy was based [...] on the presence of pain in the distal extremities, local edema, vasomotor instability and impairment of sensibility. Two patients had associated systemic lupus erythematosus, one had juvenile idiopathic arthritis and one had Glanzmann's thrombasthenia. Mean age was 11.5 years. Most of the patients had lower extremity involvement (7/8). The most important clinical signs were pain, edema and vasomotor instability in the affected extremity (8/8), functional impairment (7/8), and impaired sensibility (3/7). The erythrocyte sedimentation rate was abnormal in three patients and the bone scans in five. All patients received non-steroidal anti-inflammatory drugs and physical therapy with improvement of the symptoms in seven patients, until six months of treatment. Three patients were submitted to acupuncture with good response. One patient had a severe disease and received tricyclic antidepressants, with improvement more than one year after. COMMENTS: Reflex sympathetic dystrophy should be included as part of the differential diagnosis of limb pains of childhood, so that physicians can make an earlier diagnosis and prevent functional impairment.

  4. Interindividual differences in H reflex modulation during normal walking

    DEFF Research Database (Denmark)

    Simonsen, Erik B; Dyhre-Poulsen, Poul

    2002-01-01

    Based on previous studies, at least two different types of soleus Hoffmann (H) reflex modulation were likely to be found during normal human walking. Accordingly, the aim of the present study was to identify different patterns of modulation of the soleus H reflex and to examine whether or not subjects with different H reflex modulation would exhibit different walking mechanics and different EMG activity. Fifteen subjects walked across two force platforms at 4.5 km/h (+/-10%) while the movements were recorded on video. The soleus H reflex and EMG activity were recorded separately during treadmill walking at 4.5 km/h. Using a two-dimensional analysis joint angles, angular velocities, accelerations, linear velocities and accelerations were calculated, and net joint moments about the ankle, knee and hip joint were computed by inverse dynamics from the video and force plate data. Six subjects (group S) showed a suppressed H reflex during the swing phase, and 9 subjects (group LS) showed increasing reflex excitability during the swing phase. The plantar flexor dominated moment about the ankle joint was greater for group LS. In contrast, the extensor dominated moment about the knee joint was greater for the S group. The hip joint moment was similar for the groups. The EMG activity in the vastus lateralis and anterior tibial muscles was greater prior to heel strike for the S group. These data indicate that human walking exhibits at least two different motor patterns as evaluated by gating of afferent input to the spinal cord, by EMG activity and by walking mechanics. Increasing H reflex excitability during the swing phase appears to protect the subject against unexpected perturbations around heel strike by a facilitated stretch reflex in the triceps surae muscle. Alternatively, in subjects with a suppressed H reflex in the swing phase the knee joint extensors seem to form the primary protection around heel strike.

  5. Recovery of the vestibulocolic reflex after aminoglycoside ototoxicity in domestic chickens.

    Science.gov (United States)

    Goode, C T; Carey, J P; Fuchs, A F; Rubel, E W

    1999-03-01

    Avian auditory and vestibular hair cells regenerate after damage by ototoxic drugs, but until recently there was little evidence that regenerated vestibular hair cells function normally. In an earlier study we showed that the vestibuloocular reflex (VOR) is eliminated with aminoglycoside antibiotic treatment and recovers as hair cells regenerate. The VOR, which stabilizes the eye in the head, is an open-loop system that is thought to depend largely on regularly firing afferents. Recovery of the VOR is highly correlated with the regeneration of type I hair cells. In contrast, the vestibulocolic reflex (VCR), which stabilizes the head in space, is a closed-loop, negative-feedback system that seems to depend more on irregularly firing afferent input and is thought to be subserved by different circuitry than the VOR. We examined whether this different reflex also of vestibular origin would show similar recovery after hair cell regeneration. Lesions of the vestibular hair cells of 10-day-old chicks were created by a 5-day course of streptomycin sulfate. One day after completion of streptomycin treatment there was no measurable VCR gain, and total hair cell density was approximately 35% of that in untreated, age-matched controls. At 2 wk postlesion there was significant recovery of the VCR; at this time two subjects showed VCR gains within the range of control chicks. At 3 wk postlesion all subjects showed VCR gains and phase shifts within the normal range. These data show that the VCR recovers before the VOR. Unlike VOR gain, recovering VCR gain correlates equally well with the density of regenerating type I and type II vestibular hair cells, except at high frequencies. Several factors other than hair cell regeneration, such as length of stereocilia, reafferentation of hair cells, and compensation involving central neural pathways, may be involved in behavioral recovery. Our data suggest that one or more of these factors differentially affect the recovery of these two vestibular reflexes. PMID:10085330

  6. Analysis of ion beam extracted from reflex tetrode

    International Nuclear Information System (INIS)

    A reflex tetrode is proposed to be made on the basis of a new idea that the plasma source is separated from the anode. It is shown that the ion beam is forced to move from the anode toward the virtual cathode in the reflex tetrode. The expressions are derived for the ion-beam current densities which are extracted from reflex tetrodes. Two types of tetrodes, one of which has the ion source and the other has the plasma source, are considered. The analyses are given for the three kinds of geometries; plane, cylindrical and spherical. (author)

  7. The functional and pragmatic features of assonance phraseological reflexes

    Directory of Open Access Journals (Sweden)

    Shkapenko T.

    2014-09-01

    Full Text Available This paper analyzes a specific group of phraseological reflexes based on an assonance rhyme with an initial interrogative utterance. Assonance phraseological reflexes cannot perform a descriptive or nominative function acting in the process of verbal interaction only as markers of pragmatic intentions. Therefore, the attempts to describe them in terms of traditional semantics prove unsuccessful. A proper study of assonance phraseological reflexes is possible only in the framework of speech act theory. From the cognitive perspective, these units of speech are an example of a language game typical of speech subcultures.

  8. Ternary numbers and algebras. Reflexive numbers and Berger graphs

    CERN Document Server

    Dubrovskiy, A

    2007-01-01

    The Calabi-Yau spaces with SU(n) holonomy can be studied by the algebraic way through the integer lattice where one can construct the Newton reflexive polyhedra or the Berger graphs. Our conjecture is that the Berger graphs can be directly related with the $n$-ary algebras. To find such algebras we study the n-ary generalization of the well-known binary norm division algebras, ${\\mathbb R}$, ${\\mathbb C}$, ${\\mathbb H}$, ${\\mathbb O}$, which helped to discover the most important "minimal" binary simple Lie groups, U(1), SU(2) and G(2). As the most important example, we consider the case $n=3$, which gives the ternary generalization of quaternions and octonions, $3^n$, $n=2,3$, respectively. The ternary generalization of quaternions is directly related to the new ternary algebra and group which are related to the natural extensions of the binary $su(3)$ algebra and SU(3) group. Using this ternary algebra we found the solution for the Berger graph: a tetrahedron.

  9. Reflex and mechanical contributions to head stabilization in alert cats.

    Science.gov (United States)

    Goldberg, J; Peterson, B W

    1986-09-01

    Five alert cats were tested for their responses to rotation in a device that allowed rotation of the head on the trunk about a vertical axis passing through the C1-C2 vertebral joint. Electrodes were implanted to record the horizontal and vertical electrooculogram and electromyographic (EMG) activity of the dorsal neck muscles splenius, biventer cervicus, and complexus. Head rotation and torque acting on the head were recorded in the horizontal plane during rotations in the 0.05-5.0 Hz frequency range. Responses were interpreted with reference to a closed-loop dynamic model of the head-neck system. Whole-body rotation (WBR) with no neck movement elicited a vestibulocollic reflex (VCR). Neck muscle EMG lagged the sinusoidal platform rotation by approximately 120 degrees at low frequencies, which represents a 60 degrees lead relative to a perfectly compensatory 180 degrees lag. This phase lead was related to the cumulative eye position of the accompanying horizontal vestibular nystagmus as reported by Vidal et al. Horizontal head torque exhibited a similar low-frequency behavior. At high frequencies, EMG exhibited a progressively increasing phase lead and gain increase typical of a second-order lead system as described in decerebrate cats. Torque, however, showed much less lead and gain increase, presumably because of the low-pass filter properties of the process coupling muscle excitation to torque. Head torque did exhibit a steep increase in gain with frequency and a phase approaching that of platform acceleration at high frequencies when weights were attached to the head to increase its moment of inertia. The same +40 dB/decade gain slope and phase approaching 0 degree was observed during WBR rotation of the anesthetized cat in which head inertia is the only factor contributing to the torque. This dynamic behavior was predicted by the inertial component of the model. In the alert unweighted cat, the inertial torque was smaller than VCR-generated torque at frequencies below 4 Hz. Rotation of the neck with the head held fixed in space (HFS rotation) elicited a cervicocollic reflex (CCR). Neck EMG response was very similar to that observed during WBR, both in dynamic behavior and overall gain. Torque, however, was consistently greater than that generated by WBR and showed a steady increase of 8 dB/decade as frequency rose. The added torque can be attributed to the viscoelastic properties of neck muscles. Driven rotation of the head on the fixed body elicited torques that could be closely approximated by a vector sum of torques observed during WBR and HFS rotations.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3491185

  10. Reflex conditioning: A new strategy for improving motor function after spinal cord injury

    OpenAIRE

    Chen, Xiang Yang; Chen, Yi; Wang, Yu; Thompson, Aiko; Carp, Jonathan S.; Segal, Richard L.; Wolpaw, Jonathan R

    2010-01-01

    Spinal reflex conditioning changes reflex size, induces spinal cord plasticity, and modifies locomotion. Appropriate reflex conditioning can improve walking in rats after spinal cord injury (SCI). Reflex conditioning offers a new therapeutic strategy for restoring function in people with SCI. This approach can address the specific deficits of individuals with SCI by targeting specific reflex pathways for increased or decreased responsiveness. In addition, once clinically significant regenerat...

  11. Non-reflexive Logical Foundation for Quantum Mechanics

    Science.gov (United States)

    da Costa, N. C. A.; de Ronde, C.

    2014-12-01

    On the one hand, non-reflexive logics are logics in which the principle of identity does not hold in general. On the other hand, quantum mechanics has difficulties regarding the interpretation of `particles' and their identity, also known in the literature as `the problem of indistinguishable particles'. In this article, we will argue that non-reflexive logics can be a useful tool to account for such quantum indistinguishability. In particular, we will provide a particular non-reflexive logic that can help us to analyze and discuss this problem. From a more general physical perspective, we will also analyze the limits imposed by the orthodox quantum formalism to consider the existence of indistinguishable particles in the first place, and argue that non-reflexive logics can also help us to think beyond the limits of classical identity.

  12. REFLEX MODIFICATION AND THE ASSESSMENT OF SENSORY DYSFUNCTION

    Science.gov (United States)

    In summary, reflex modification of the startle response is a technique that can provide rapid, objective, and quantitative assessments of sensorimotor function. dvantages of this technique involve the ability to test animals rapidly, test without prior training, test without util...

  13. Quasicontraction Mappings in Modular Spaces without ?2-Condition

    Directory of Open Access Journals (Sweden)

    Khamsi MA

    2008-01-01

    Full Text Available Abstract As a generalization to Banach contraction principle, ?iri? introduced the concept of quasi-contraction mappings. In this paper, we investigate these kinds of mappings in modular function spaces without the -condition. In particular, we prove the existence of fixed points and discuss their uniqueness.

  14. Fixed point theorems in a space with two metrics

    Directory of Open Access Journals (Sweden)

    El-Miloudi Marhrani

    2015-01-01

    Full Text Available In this paper, we prove a generalization of the Banach contraction fixed point theorem in a space with two metrics. The results presented in this paper improve the corresponding results announced by many authors. As an application, we study the existence of the solution for a functional equation arising in dynamic programming.

  15. Soleus H-reflex excitability during pedaling post-stroke

    DEFF Research Database (Denmark)

    Schindler-Ivens, Sheila; Brown, David A.

    2008-01-01

    A major contributor to impaired locomotion post-stroke is abnormal phasing of paretic muscle activity, but the mechanisms remain unclear. Previous studies have shown that, in the paretic limb of people post-stroke, Group Ia reflexes are abnormally elevated and fail to decrease in amplitude during locomotion. Hence, we hypothesized that inappropriate muscle phasing may be associated with enhanced transmission in the monosynaptic Group Ia afferent pathway. Soleus (SO) H-reflexes were used to examine transmission in the Group Ia afferent pathway to SO motor neurons during pedaling, a locomotor task in which abnormal muscle phasing is evident. Our hypothesis predicted that H-reflexes would be elevated during the flexion phase of pedaling where inappropriate SO activity occurs. H-reflexes were elicited in paretic (n = 13) and neurologically intact (NI, n = 26) individuals at 11 different positions in the pedaling cycle and during tonic plantar flexion at comparable limb positions and levels of SO EMG. In both groups, SO H-reflexes were smaller during pedaling as compared to matched tonic plantar flexion. In the NI group, but not the paretic group, SO H-reflex amplitude was significantly modulated across the pedaling cycle. H-reflexes were large during extension and small during flexion. Reduced H-reflex modulation post-stroke was associated with the level of neuromuscular impairment as indicated by Fugl-Meyer score. However, regardless of impairment level, stroke subjects displayed H-reflex suppression during the flexion phase of pedaling. After correcting for the level of background muscle activity, H-reflexes were found to be larger in paretic as compared to NI individuals, regardless of the phase of the pedaling cycle. We conclude that Group Ia afferent transmission is enhanced in the paretic SO of people post-stroke as compared to NI individuals. However, contrary to our hypothesis, enhanced transmission in the Group Ia monosynaptic spinal pathway is not specifically associated with extraneous extensor muscle activity during the flexion phase of pedaling and is unlikely to account for abnormal locomotor muscle phasing post-stroke. This result is important because it suggests that, despite the presence of hyperactive monosynaptic reflexes post-stroke, this impairment may not make an important contribution to abnormal locomotor muscle activity.

  16. Language trends: Reflexivity in commercial language policies and practices

    OpenAIRE

    Kelly-holmes, Helen

    2010-01-01

    Financier, philanthropist and economist George Soros is not the first to have used or derived the notion of reflexivity (for example, Anthony Giddens, Ulrich Beck and others have found it useful in their work).What is different about the approach of Soros is that he has used the concept of reflexivity to explain the workings of global markets, and for this reason his work seems to me to have particular potential for explaining language trends in the linguistic policies and p...

  17. Trigeminocardiac Reflex during Maxillary Reconstruction Surgery: A Case Report

    OpenAIRE

    Mayank Kulshrestha; Sahil Kapur; Col. M Kapadia

    2014-01-01

    Systemic hypotension, cardiac dysrhythmia especially bradycardia, apnoea, and gastric hypermotility occurring presumably after stimulation of any of the sensory branches of trigeminal nerve is coined as trigeminocardiac reflex (TCR). It has been described to occur in various surgeries like cerebello-pontine angle and pituitary fossa surgeries. Such bradycardic reflex responses have also been observed during maxillofacial surgeries. The TCR presents as a challenge to both the Anaesthesiologis...

  18. Early and late components in the human anal reflex.

    OpenAIRE

    Swash, M

    1982-01-01

    Perianal electrical stimulation induces reflex activity in the superficial part of the external anal sphincter muscle. Several components of differing latency can be recognised. It is suggested that these correspond with the ripples of contraction observed clinically after perianal scratch stimuli. Some of our earlier studies suggested an erroneously short latency for the first component of this cutaneously-elicited reflex. The reasons for this are discussed.

  19. Intranasal Midazolam May Prevent Gagging Reflex: a Case Report

    OpenAIRE

    Meral Arslan Malkoc; Necla Demir; Zehra Ileri; Aybuke Erdur; Seza Apiliogullari

    2013-01-01

    Background: Gagging can become a conditioned response that makes dental treatment difficult or impossible for both the individual and the dentist. The aim of this study is to report a 50 year old female and two children (15 and 11 years old) with exaggerated gag reflex referred to Faculty of Dentistry of Seluk University.Methods: During obtaining records, taking impression procedure was elicited the patients hypersensitive gagging reflex. Therefore, it was decided to administer intranasa...

  20. Lateral asymmetry of the Hoffmann reflex: relation to cortical laterality.

    OpenAIRE

    Goode, D. J.; Glenn, S.; Manning, A. A.; Middleton, J. F.

    1980-01-01

    Lateral asymmetry of the Hoffmann reflex (H-reflex) recovery curve was found in seven subjects with no personal or family history of neurological or psychiatric disorder. Differences between recovery curves from the right and left leg were larger than differences in the same leg on two successive test days. In a group of 27 psychiatric inpatients, lateral asymmetry of the later portion of the recovery curve was correlated with cortical laterality, as measured by selective identification of di...

  1. Muscle reflex in heart failure: the role of exercise training

    OpenAIRE

    HanjunWang

    2012-01-01

    Exercise evokes sympathetic activation and increases blood pressure and heart rate (HR). Two neural mechanisms that cause the exercise-induced increase in sympathetic discharge are central command and the exercise pressor reflex (EPR). The former suggests that a volitional signal emanating from central motor areas leads to increased sympathetic activation during exercise. The latter is a reflex originating in skeletal muscle which contributes significantly to the regulation of the cardiovascu...

  2. Nearest Neighbor Methods for Testing Reflexivity and Species-Correspondence

    OpenAIRE

    Ceyhan, Elvan

    2014-01-01

    Nearest neighbor (NN) methods are employed for drawing inferences about spatial patterns of points from two or more classes. We consider Pielou's test of niche specificity which is defined using a contingency table based on the NN relationships between the data points. We demonstrate that Pielou's contingency table for niche specificity is actually more appropriate for testing reflexivity in NN structure, hence we call this table as NN reflexivity contingency table (NN-RCT) ...

  3. Reflex movements for a virtual human: a biology inspired approach

    OpenAIRE

    Gutierrez, M.; Vexo, F; Thalmann, D

    2004-01-01

    This paper presents the results of a method to produce autonomous animation of virtual humans. In particular, the proposed methodology is focused on the autonomous synthesis of nonvoluntary gestures such as reflexes and subtle movements which provide a noticeable impression of realism and naturalness. The final goal of this technique is to produce virtual humans with a more spontaneous, non preprogrammed behaviour. For the moment, the technique is applied to the synthesis of reflex movements ...

  4. HPLC analysis of closed, open, and reflex eye tear proteins

    Directory of Open Access Journals (Sweden)

    Sitaramamma T

    1998-01-01

    Full Text Available Changes in the closed, open and reflex eye tear proteins of normal subjects were compared and analysed. Tear proteins were resolved by high-performance liquid chromatography (HPLC utilising both gel filtration (P-300 SW and reverse-phase (C-18 columns and the HPLC fractions were further analysed by sodium dodecyl sulphate - polyacrylamide gel electrophoresis (SDS-PAGE under reducing and non-reducing conditions. The protein composition of the closed-eye tear was significantly different from that of the open and reflex-eye tear. Secretory IgA (sIgA was the predominant protein in closed eye tears constituting 49% of the total protein compared to 11% in reflex tears, whereas lysozyme was the predominant protein (53% in reflex tears. Levels of lactoferrin, lipocalin and lysozyme were relatively constant in both open and reflex tears. HPLC profiles of the closed-eye tears, upon continuous stimulation of lacrimal glands indicated that sIgA was significantly reduced whereas lactoferrin, lipocalin, and lysozyme were significantly increased. These results indicate that the tear composition upon waking attains that of the open eye within 4 to 5 minutes, and upon continuous stimulation this reflects the reflex-eye tear composition. It also indicates that mechanisms responsible for changes in concentration of constitutive and regulated tear protein with stimulus can be studied successfully using non-invasive methods to collect human tears.

  5. Fixed Point Results for Multivalued Maps in Metric Spaces with Generalized Inwardness Conditions

    Directory of Open Access Journals (Sweden)

    Frigon M

    2010-01-01

    Full Text Available We establish fixed point theorems for multivalued mappings defined on a closed subset of a complete metric space. We generalize Lim's result on weakly inward contractions in a Banach space. We also generalize recent results of Az and Corvellec, Maciejewski, and Uderzo for contractions and directional contractions. Finally, we present local fixed point theorems and continuation principles for generalized inward contractions.

  6. Neural reflex regulation of arterial pressure in pathophysiological conditions: interplay among the baroreflex, the cardiopulmonary reflexes and the chemoreflex

    OpenAIRE

    E.C. Vasquez; S.S. Meyrelles; Mauad, H; Cabral, A.M

    1997-01-01

    The maintenance of arterial pressure at levels adequate to perfuse the tissues is a basic requirement for the constancy of the internal environment and survival. The objective of the present review was to provide information about the basic reflex mechanisms that are responsible for the moment-to-moment regulation of the cardiovascular system. We demonstrate that this control is largely provided by the action of arterial and non-arterial reflexes that detect and correct changes in arterial pr...

  7. On the Banach algebra ℬ(lp(α

    Directory of Open Access Journals (Sweden)

    Bruno de Malafosse

    2004-11-01

    Full Text Available We give some properties of the Banach algebra of bounded operators ℬ(lp(α for 1≤p≤∞, where lp(α=(1/α−1∗lp. Then we deal with the continued fractions and give some properties of the operator Δh for h>0 or integer greater than or equal to one mapping lp(α into itself for p≥1 real. These results extend, among other things, those concerning the Banach algebra Sα and some results on the continued fractions.

  8. Aging attenuates the vestibulosympathetic reflex in humans

    Science.gov (United States)

    Ray, Chester A.; Monahan, Kevin D.

    2002-01-01

    BACKGROUND: The vestibular system contributes to sympathetic activation by engagement of the otolith organs. However, there is a significant loss of vestibular function with aging. Therefore, the purpose of the present study was to determine if young and older individuals differ in their cardiovascular and sympathetic responses to otolithic stimulation (ie, head-down rotation, HDR). We hypothesized that responses to otolithic stimulation would be attenuated in older adults because of morphological and physiological alterations that occur in the vestibular system with aging. METHODS AND RESULTS: Arterial blood pressure, heart rate, muscle sympathetic nerve activity (MSNA), and head rotation were measured during HDR in 11 young (26 +/- 1 years) and 11 older (64 +/- 1 years) subjects in the prone posture. Five older subjects performed head rotation (chin to chest) in the lateral decubitus position, which simulates HDR but does not alter afferent inputs from the vestibular system. MSNA responses to HDR were significantly attenuated in older as compared with young subjects (Pcold pressor test were not different between the age groups. CONCLUSIONS: These data indicate that aging attenuates the vestibulosympathetic reflex in humans and may contribute to the increased prevalence of orthostatic hypotension with age.

  9. Bone mineral density in reflex sympathetic dystrophy

    International Nuclear Information System (INIS)

    Objectives: Reflex Sympathetic Dystrophy (RSD) is a complex of symptoms that produce pain burning sensation, swelling, tenderness, autonomic and physical dysfunction in joint areas, particularly distal of a limb. Osteopenia or osteoporosis is an important finding that is produced gradually in involved limb. Three phase bone can scan help to diagnosis of RSD. The disease may be bilateral but is mostly unilateral. As it is believed that bone densitometry will show osteopenia more accurate than plain comparative radiographs of the involved limbs, we investigated in patients with RSD. Methods: During last three years, 8 patients with RSD were admitted. Bone mineral density was measured for 5 patients by DEXA method. The patients were 3 males and 2 females with age range of 20 to 48 years (mean 32 years). The involved areas were ankle and foot in 4, and wrist and hand in one patient. Results: Mean Bone Mineral Content (BMC) of 4 involved lower limbs were 475 +-73 grams comparing with 516+-72 grams of uninvolved limbs (pth patient was not significant. conclusion: comparative bone mineral density in patients with RSD of the lower limbs contributes to more accurate diagnosis than plain radiographs

  10. Management of reflex anoxic seizures in children.

    Science.gov (United States)

    Iyer, Anand; Appleton, Richard

    2013-09-01

    Reflex anoxic seizures (RAS) are important in the differential diagnosis of non-epileptic paroxysmal events in infants and preschool-aged children. They are classically provoked by a sudden distressing stimulus, which causes loss of consciousness followed by stiffening and brief clonic movements affecting some or all limbs, often misinterpreted as an epileptic seizure. The underlying pathophysiology is a vagal-induced brief cardiac asystole with resultant transient cerebral hypoperfusion. Parents and carers who witness the event are understandably anxious, and the mainstay of management are ensuring the appropriate timely diagnosis of RAS and excluding cardiac arrhythmia. A detailed history from a witness is all that is needed to diagnose this condition and investigations like EEG or neuroimaging should be avoided. Education and reassurance remain the mainstay in the management. Some children benefit from medical treatment with atropine or fluoxetine; however, there is a lack of evidence for pharmacological treatment. Cardiac pacing is the only definitive treatment, and is reserved for frequent, severe cases in joint consultation with the cardiologist. PMID:23814085

  11. A method of reflexive balancing in a pragmatic, interdisciplinary and reflexive bioethics.

    Science.gov (United States)

    Ives, Jonathan

    2014-07-01

    In recent years there has been a wealth of literature arguing the need for empirical and interdisciplinary approaches to bioethics, based on the premise that an empirically informed ethical analysis is more grounded, contextually sensitive and therefore more relevant to clinical practice than an 'abstract' philosophical analysis. Bioethics has (arguably) always been an interdisciplinary field, and the rise of 'empirical' (bio)ethics need not be seen as an attempt to give a new name to the longstanding practice of interdisciplinary collaboration, but can perhaps best be understood as a substantive attempt to engage with the nature of that interdisciplinarity and to articulate the relationship between the many different disciplines (some of them empirical) that contribute to the field. It can also be described as an endeavour to explain how different disciplinary approaches can be integrated to effectively answer normative questions in bioethics, and fundamental to that endeavour is the need to think about how a robust methodology can be articulated that successfully marries apparently divergent epistemological and metaethical perspectives with method. This paper proposes 'Reflexive Bioethics' (RB) as a methodology for interdisciplinary and empirical bioethics, which utilizes a method of 'Reflexive Balancing' (RBL). RBL has been developed in response to criticisms of various forms of reflective equilibrium, and is built upon a pragmatic characterization of Bioethics and a 'quasi-moral foundationalism', which allows RBL to avoid some of the difficulties associated with RE and yet retain the flexible egalitarianism that makes it intuitively appealing to many. PMID:23444909

  12. ESO Reflex: a graphical workflow engine for data reduction

    Science.gov (United States)

    Hook, Richard; Ullgrn, Marko; Romaniello, Martino; Maisala, Sami; Oittinen, Tero; Solin, Otto; Savolainen, Ville; Jrvelinen, Pekka; Tyynel, Jani; Pron, Michle; Ballester, Pascal; Gabasch, Armin; Izzo, Carlo

    ESO Reflex is a prototype software tool that provides a novel approach to astronomical data reduction by integrating a modern graphical workflow system (Taverna) with existing legacy data reduction algorithms. Most of the raw data produced by instruments at the ESO Very Large Telescope (VLT) in Chile are reduced using recipes. These are compiled C applications following an ESO standard and utilising routines provided by the Common Pipeline Library (CPL). Currently these are run in batch mode as part of the data flow system to generate the input to the ESO/VLT quality control process and are also exported for use offline. ESO Reflex can invoke CPL-based recipes in a flexible way through a general purpose graphical interface. ESO Reflex is based on the Taverna system that was originally developed within the UK life-sciences community. Workflows have been created so far for three VLT/VLTI instruments, and the GUI allows the user to make changes to these or create workflows of their own. Python scripts or IDL procedures can be easily brought into workflows and a variety of visualisation and display options, including custom product inspection and validation steps, are available. Taverna is intended for use with web services and experiments using ESO Reflex to access Virtual Observatory web services have been successfully performed. ESO Reflex is the main product developed by Sampo, a project led by ESO and conducted by a software development team from Finland as an in-kind contribution to joining ESO. The goal was to look into the needs of the ESO community in the area of data reduction environments and to create pilot software products that illustrate critical steps along the road to a new system. Sampo concluded early in 2008. This contribution will describe ESO Reflex and show several examples of its use both locally and using Virtual Observatory remote web services. ESO Reflex is expected to be released to the community in early 2009.

  13. Space

    CERN Document Server

    Sylvester, Doug

    2014-01-01

    Students explore the exciting and intriguing world of space. The first section includes lecture style content combined with interesting assignments and activities to build up an information base about galaxies, solar system, planets and gravity. The second section centers around fun activities devoted to space exploration, space menu, parachute making, egg splat competition and how a rocket works. Included is an extensive reproducible student Activity Handbook that contains related assignments that will guarantee that your students get a ""blast"" out of. This Earth Science lesson provides a

  14. Space

    Science.gov (United States)

    Integrated Teaching and Learning Program,

    This unit begins by introducing students to the historical motivation for space exploration. They learn about the International Space Station, including current and futuristic ideas that engineers are designing to propel space research. Then they learn about the physical properties of the Moon, and think about what types of products engineers would need to design in order for humans to live on the Moon. Lastly, students learn some descriptive facts about asteroids, such as their sizes and how that relates to the potential danger of an asteroid colliding with the Earth.

  15. Measurement of the Achilles tendon reflex for the diagnosis of lumbosacral root compression syndromes.

    OpenAIRE

    Rico, R E; Jonkman, E J

    1982-01-01

    The Hoffmann reflex and the Achilles tendon reflex were measured in a group of 194 subjects suspected of having a lumbosacral root compression syndrome. The Achilles tendon reflex was elicited manually with a metal hammer. There was a high correlation between the H-M interval and the Achilles tendon reflex-M interval. The usefulness of the Achilles tendon reflex was evaluated in a selected sub-group of 61 patients with proven L5 or S1 root compression. Neither the H-reflex nor the Achilles te...

  16. Gravity and Development of Cardiopulmonary Reflex

    Science.gov (United States)

    Nagaoka, Shunji; Eno, Yuko; Ohira, Yoshinobu

    Cardio-pulmonary reflex, which our cardiac activity is synchronized to the respiration by autonomic nervous system regulation, is called as "respiratory sinus arrhythmia" and commonly found in adult. The physiological function of the espiratory sinus arrhythmia is considered to maximize the gas exchange during respiration cycle. This respiration induced heart rate variability (RHRV) is only found in mammals and avian showing a remarkable postnatal development, whereas no RHRV in aquatic species such as fish or amphibian. To elucidate our hypothesis that gravity exposure may plays a key role in the postnatal development of RHRV as well as its evolutional origin in these ground animals, we have studied effects of hypergravity (2G) on the postnatal development of RHRV using rat. Pregnant Wister rats were kept in centrifugal cages system for 38 days from 6th days of pregnant mother to have neonates until 23 days old. Electrocardiograph was recorded from the neonates in 2 to 23 days old in 2G group with simultaneous control (1G) group. The RHRV analysis was performed by calculating a component of Fourier power spectral coincide with the respiration frequency. In both groups, averaged resting heart rate gradually increase from 2 to 23 days old. When comparing the heart rate between the two groups, the 2G group indicated significantly lower (240 8 bpm) than 1G control (32621 bpm, p0.001) in 2 days old, where as no significance in 23 days old. The RHRV of 2 days old neonates in both groups indicated very small magnitude but significantly lower in 2G group than 1G control (p0.01). The RHRV gradually increase during the first 2 weeks and then rapid increased to reached 45 fold of magnitude in 1G control, whereas 69 fold in 2G group. The results strongly suggested that the postnatal innervation from respiration to cardiovascular centers was gravity dependent.

  17. A new martensite 15R1-structure in Co-Nb alloys and apparent ''cleavage'' of hexagonal reflexes due to this structure

    International Nuclear Information System (INIS)

    For the purpose of discovering new multilayer phases and elucidating the ''cleavage'' nature of hexagonal reflexes the Co-Nb aloys have been investigated. The study of the reciprocal lattice and X-ray photograph has shown that between neighbouring spots of the f.c.c. structure there are 5 reflexes of the ?1 phase, the spots of equal intensity on neighbouring diffusion bands being located at different Bragg reflection angles. The elementary ?1 phase cell contains 15 close-packed planes and has parameters ?=2.506 A, c=20, 60 A in hexagonal axes and ?=10, 29 A, ?=13 deg 57' in rhombohedral axes. It is obtained that the ?1-phase has 15 R1-lattice space group Dsub(3d)sup(5). It is concluded that the apparent ''bifurcation'' of hexagonal reflexes on the diffraction picture occurs not of the ''distorted'' h.c.p. structure but of the multilayer structure of rhombohedral symmetry

  18. Prevalence of family history in patients with reflex syncope

    DEFF Research Database (Denmark)

    Holmegard, Haya N; Benn, Marianne

    2013-01-01

    Reflex syncope is defined by a rapid transient loss of consciousness caused by global cerebral hypoperfusion resulting from vasodilatation and/or bradycardia attributable to inappropriate cardiovascular reflexes. A hereditary component has been suggested, but prevalence of family history may differ among subtypes of reflex syncope, as these have different autonomic responses and pathogeneses may be diverse. The present study aimed to assess the prevalence of a positive family history of syncope and cardiovascular characteristics in patients with cardioinhibitory and vasodepressor reflex syncope. Patients (n=74) were classified into subtypes of reflex syncope - cardioinhibition/asystole (Vasovagal Syncope International Study subtypes II-B [VASIS II-B], n=38) or vasodepressor (VASIS III, n=36) - using the head-up tilt test. Family history was obtained by questionnaires supplemented by interview. Patients with cardioinhibitory syncope had a mean onset of disease 8 years earlier than vasodepressor patients (mean standard deviation 14.5 years 12.6 for cardioinhibitory patients compared to 22.4 years 11.9 for vasodepressor patients, p

  19. Plasticity of the human otolith-ocular reflex

    Science.gov (United States)

    Wall, C. 3rd; Smith, T. R.; Furman, J. M.

    1992-01-01

    The eye movement response to earth vertical axis rotation in the dark, a semicircular canal stimulus, can be altered by prior exposure to combined visual-vestibular stimuli. Such plasticity of the vestibulo-ocular reflex has not been described for earth horizontal axis rotation, a dynamic otolith stimulus. Twenty normal human subjects underwent one of two types of adaptation paradigms designed either to attenuate or enhance the gain of the semicircular canal-ocular reflex prior to undergoing otolith-ocular reflex testing with horizontal axis rotation. The adaptation paradigm paired a 0.2 Hz sinusoidal rotation about a vertical axis with a 0.2 Hz optokinetic stripe pattern that was deliberately mismatched in peak velocity. Pre- and post-adaptation horizontal axis rotations were at 60 degrees/s in the dark and produced a modulation in the slow component velocity of nystagmus having a frequency of 0.17 Hz due to putative stimulation of the otolith organs. Results showed that the magnitude of this modulation component response was altered in a manner similar to the alteration in semicircular canal-ocular responses. These results suggest that physiologic alteration of the vestibulo-ocular reflex using deliberately mismatched visual and semicircular canal stimuli induces changes in both canal-ocular and otolith-ocular responses. We postulate, therefore, that central nervous system pathways responsible for controlling the gains of canal-ocular and otolith-ocular reflexes are shared.

  20. Intranasal Midazolam May Prevent Gagging Reflex: a Case Report

    Directory of Open Access Journals (Sweden)

    Meral Arslan Malkoc

    2013-10-01

    Full Text Available Background: Gagging can become a conditioned response that makes dental treatment difficult or impossible for both the individual and the dentist. The aim of this study is to report a 50 year old female and two children (15 and 11 years old with exaggerated gag reflex referred to Faculty of Dentistry of Seluk University.Methods: During obtaining records, taking impression procedure was elicited the patients hypersensitive gagging reflex. Therefore, it was decided to administer intranasal midazolam to facilitate the taking of accurate dental impressions. After given verbal information about the procedure, 2.5 mg intranasal midazolam (Demizolam, Dem Medikal, Istanbul were applied incrementally in both nostrils.Results: Five minutes later; patients had no gagging reflex and allowed the clinician to take satisfying impressions. No serious adverse effects were observed and the patients remained cooperative during the entire procedure which was completed to the full satisfaction of all involved. The short absorption time and the fast relief process of anaesthetics transferred to the systemic circulatory system are important advantages of nasal application.Conclusions: Intranasal midazolam may be very useful for the treatment of gag reflex probably effecting on the depression of upper airway reflex sensitivity.

  1. Intraoperative neurophysiologic monitoring with Hoffmann reflex during thoracic spine surgery.

    Science.gov (United States)

    Feyissa, Anteneh M; Tummala, Sudhakar

    2015-06-01

    The aim of this study was examine the role of Hoffmann reflex (H-reflex) monitoring in identifying intraoperative spinal cord injury and predicting postoperative neurological outcome in patients undergoing thoracic spine surgery. Despite the physiologic basis for the use of H-reflex to monitor spinal motor pathways, there are only a few reports highlighting its application as an intraoperative neuromonitoring tool. We retrospectively reviewed the electronic medical records of 19 consecutive patients who underwent thoracic spine surgery for metastatic thoracic spinal tumors between 2011 and 2013 at the MD Anderson Cancer Center. H-waves and somatosensory evoked potentials (SSEP) were simultaneously monitored in our series consisting of four female and 15 male patients aged 10-71years. In 10 of 19 patients, bilateral H-waves and SSEP were stable throughout the monitoring. Five of 19 patients had a neurological deficits. Stable intraoperative H-waves are suggestive of preserved postoperative neurologic outcomes. Intraoperative H-reflex monitoring could be a reasonable alternative especially when motor evoked potentials are unattainable. Given its greater sensitivity to spinal cord ischemia, relatively low cost and ease of acquisition, H-reflex monitoring could be a useful adjunct in during thoracic spine surgeries. PMID:25769258

  2. Measure, integration and function spaces

    CERN Document Server

    Swartz, Charles

    1994-01-01

    This text contains a basic introduction to the abstract measure theory and the Lebesgue integral. Most of the standard topics in the measure and integration theory are discussed. In addition, topics on the Hewitt-Yosida decomposition, the Nikodym and Vitali-Hahn-Saks theorems and material on finitely additive set functions not contained in standard texts are explored. There is an introductory section on functional analysis, including the three basic principles, which is used to discuss many of the classic Banach spaces of functions and their duals. There is also a chapter on Hilbert space and

  3. Faroese long-distance reflexives face off against Icelandic long-distance reflexives

    Directory of Open Access Journals (Sweden)

    Tania E. Strahan

    2009-01-01

    Full Text Available Long-distance reflexives (LDRs in Faroese are often compared to those in Icelandic, and are even considered to have the same distribution (Thrinsson et al., 2004. In this paper I evaluate the extent to which this is true. The results from recent fieldwork show that there are clear differences between the LDR in the two closely related languages, in particular that Faroese speakers often reject LDR sentences that contain a non-third person, and that Faroese LDR is often completely acceptable out of a non-complement clause. In addition, initial findings suggest that there may be dialectal variation with respect to at least these two aspects of LDR in Faroese.

  4. Intuitionistic fuzzy {\\psi}-{\\phi}-contractive mappings and fixed point theorems in non-Archimedean intuitionistic fuzzy metric spaces

    OpenAIRE

    Dinda, Bivas; Samanta, T. K.; Jebril, Iqbal H.

    2011-01-01

    In this paper intuitionistic fuzzy {\\psi}-{\\phi}-contractive mappings are introduced. Intuitionistic fuzzy Banach contraction theorem for M-complete non-Archimedean intuitionistic fuzzy metric spaces and intuitionistic fuzzy Elelstein contraction theorem for non-Archimedean intuitionistic fuzzy metric spaces by intuitionistic fuzzy {\\psi}-{\\phi}-contractive mappings are proved.

  5. Results on the Existence and Convergence of Best Proximity Points

    Directory of Open Access Journals (Sweden)

    Abkar Ali

    2010-01-01

    Full Text Available We first consider a cyclic -contraction map on a reflexive Banach space and provide a positive answer to a question raised by Al-Thagafi and Shahzad on the existence of best proximity points for cyclic -contraction maps in reflexive Banach spaces in one of their works (2009. In the second part of the paper, we will discuss the existence of best proximity points in the framework of more general metric spaces. We obtain some new results on the existence of best proximity points in hyperconvex metric spaces as well as in ultrametric spaces.

  6. Romantic Relationships and their Transformation in the Reflexive Society. Themes and Methods in Jean-Claude Kaufmanns Surveys

    Directory of Open Access Journals (Sweden)

    Lavinia Alexe

    2010-03-01

    Full Text Available The process of individualization, associated with reflexive modernity, which assumes that individualactions are legitimized as a result of increased reflexivity, produces major changes in the universe oflove action. Following Anthony Giddens (1992, who observed that increased autonomy andreflexivity were both elements that have shaken the romantic love, Jean-Claude Kaufmann noticesthe deep changes occurring in the way in which romantic relations are experienced - while this typeof transformation happens slower in respect to love imagery. The space, a world increasingly strayedfrom traditions, opens up glorious new opportunities for individual autonomy and self-realization(Mottier, 2007, creating, at the same time, unprecedented pressures on long-term relationships, asmore and more women and men choose to live alone.

  7. Generalization of Banach Contraction Principle in Two Directions

    OpenAIRE

    E. El-Shobaky; Sahar M. Ali; Montaser S. Ali

    2007-01-01

    We showed that the generalized contraction mapping defined on a closed convex subset of a weakly Cauchy normed space has a unique fixed point. Moreover, the sequence of iterates of any element in the domain of the given mapping is converging strongly to the fixed point of such a mapping.

  8. Automated data reduction workflows for astronomy. The ESO Reflex environment

    Science.gov (United States)

    Freudling, W.; Romaniello, M.; Bramich, D. M.; Ballester, P.; Forchi, V.; Garca-Dabl, C. E.; Moehler, S.; Neeser, M. J.

    2013-11-01

    Context. Data from complex modern astronomical instruments often consist of a large number of different science and calibration files, and their reduction requires a variety of software tools. The execution chain of the tools represents a complex workflow that needs to be tuned and supervised, often by individual researchers that are not necessarily experts for any specific instrument. Aims: The efficiency of data reduction can be improved by using automatic workflows to organise data and execute a sequence of data reduction steps. To realize such efficiency gains, we designed a system that allows intuitive representation, execution and modification of the data reduction workflow, and has facilities for inspection and interaction with the data. Methods: The European Southern Observatory (ESO) has developed Reflex, an environment to automate data reduction workflows. Reflex is implemented as a package of customized components for the Kepler workflow engine. Kepler provides the graphical user interface to create an executable flowchart-like representation of the data reduction process. Key features of Reflex are a rule-based data organiser, infrastructure to re-use results, thorough book-keeping, data progeny tracking, interactive user interfaces, and a novel concept to exploit information created during data organisation for the workflow execution. Results: Automated workflows can greatly increase the efficiency of astronomical data reduction. In Reflex, workflows can be run non-interactively as a first step. Subsequent optimization can then be carried out while transparently re-using all unchanged intermediate products. We found that such workflows enable the reduction of complex data by non-expert users and minimizes mistakes due to book-keeping errors. Conclusions: Reflex includes novel concepts to increase the efficiency of astronomical data processing. While Reflex is a specific implementation of astronomical scientific workflows within the Kepler workflow engine, the overall design choices and methods can also be applied to other environments for running automated science workflows.

  9. Kinematical grouping of reflexes of parametric X-ray radiation

    International Nuclear Information System (INIS)

    The model of parametric X-ray radiation (PXR) from moderately relativistic particles in the kinematic theory taking into account radiation absorption was developed. The model allows to calculate radiation intensity of the PXR reflex in the set direction taking into account diffraction of virtual photons on the set of incidental crystallographic planes. It was shown when the charged particle moved along the determined crystallographic direction the effect of kinematic grouping of reflexes (when the lines of parametric radiation from various planes practically coincided) was realized

  10. Standardisation of the electrical elicitation of the human flexor reflex.

    OpenAIRE

    Torring, J; Pedersen, E.; Klemar, B

    1981-01-01

    The threshold and latency of the human flexor reflex were recorded by different kinds of electrical stimuli in order to find the optimal stimulus, defined as the lowest amount of currency and the shortest possible duration. Stimulation was given over the posterior tibial nerve of the foot. The reflex response was recorded from the tibialis anterior muscle and the number and duration of the pulses and the inter-phase interval were varied. A train of five square wave pulses with a duration of 0...

  11. Does total knee arthroplasty affect the patellar tendon reflex?

    OpenAIRE

    Richard Jamieson; Jennifer Flynn; David Love

    2010-01-01

    BackgroundThere may be a perception in clinical practice that anydeficit in the patellar tendon reflex arc could beattributed to a total knee arthroplasty (TKA). There is noevidence in the literature to support this conclusion.MethodsSixty-six knees were examined to determine whetherTKA affects the patellar tendon reflex.ResultsThere was no difference observed between the kneeswith a history of TKA and those knees without a historyof TKA.DiscussionThere is no plausible reason that TKA should ...

  12. Effect of intrathecal baclofen on the monosynaptic reflex in humans: evidence for a postsynaptic action.

    OpenAIRE

    Azouvi, P; Roby-Brami, A; Biraben, A; Thiebaut, J B; Thurel, C; van Bussel, B

    1993-01-01

    Intrathecal baclofen is a very powerful antispastic agent. Its mechanism of action on the monosynaptic H-reflex in spinal patients was investigated. It could inhibit rapidly and profoundly monosynaptic reflexes in lower limbs, but did not modify Ia vibratory inhibition of the soleus H-reflex. To assess more precisely its effect on Ia afferents, an experimental paradigm using Ia heteronymous facilitation of the soleus H-reflex was used. Intrathecal baclofen did not modify the amount of monosyn...

  13. Interactions With Compliant Loads Alter Stretch Reflex Gains But Not Intermuscular Coordination

    OpenAIRE

    Perreault, Eric J; Chen, Kuifu; Trumbower, Randy D.; Lewis, Gwyn

    2008-01-01

    The human motor system regulates arm mechanics to produce stable postures during interactions with different physical environments. This occurs partly via involuntary mechanisms, including stretch reflexes. Previous single-joint studies demonstrated enhanced reflex sensitivity during interactions with compliant environments, suggesting reflex gain increases to enhance limb stability when that stability is not provided by the environment. This study examined whether similar changes in reflex g...

  14. A case of postanoxic encephalopathy with cortical action and brainstem reticular reflex myoclonus.

    OpenAIRE

    P Brown; Thompson, Pd; Rothwell, Jc; Day, BL; Marsden, CD

    1991-01-01

    A patient with postanoxic encephalopathy, with both action- and stimulus-sensitive reflex myoclonus, is described. The action myoclonus was multifocal and cortical in origin. In contrast, reflex myoclonus elicited by somaesthetic and auditory stimulation was generalised. The earliest reflex electromyograph activity was recorded in the sternocleidomastoid; myoclonic activity then spread up the brainstem and down the spinal cord, suggesting that this reflex myoclonus had its origin in the cauda...

  15. Modulation of reflex responses in activated ankle dorsiflexors differs in healthy young and elderly subjects

    OpenAIRE

    Klass, Malgorzata; Baudry, Stphane; Duchateau, Jacques

    2011-01-01

    During voluntary contractions, motor neurone activity is modulated by descending input and sensory feedback. Impaired excitatory afferent feedback with ageing may, therefore, alter motor control. This study investigated the age-related changes in afferent feedback through the recording of reflex responses during voluntary muscle activation. Short- and long-latency components of the stretch reflex and Hoffmann reflex (H-reflex) were recorded during voluntary contractions (10% of maximal volunt...

  16. Modulation of flexion reflex induced by hip angle changes in human spinal cord injury

    OpenAIRE

    Knikou, Maria; Kay, Elizabeth; Rymer, William Zev

    2005-01-01

    The flexion reflex can be elicited via stimulation of skin, muscle, and high-threshold afferents inducing a generalized flexion of the limb. In spinalized animal models this reflex is quite prominent and is strongly modulated by actions of hip proprioceptors. However, analogous actions on the flexion reflex in spinal cord injured (SCI) humans have not yet been examined. In this study, we investigated the effects of imposed static hip angle changes on the flexion reflex in ten motor incomplete...

  17. REVIEW PAPERTrigemino-cardiac reflex: A recently discovered oxygen-conserving response? The potential therapeutic role of a physiological reflex

    Directory of Open Access Journals (Sweden)

    Bernhard J. Schaller

    2006-03-01

    Full Text Available The trigemino-cardiac reflex (TCR is defined as a sudden onset of parasympathetic dysrhythmia, sympathetic hypotension, apnea or gastric hypermotility during the stimulation of any of the sensory branches of the trigeminal nerve. The sensory nerve endings of the trigeminal nerve send neuronal signals via the Gasserian ganglion to the sensory nucleus of the trigeminal nerve, forming the afferent pathway of the reflex arc. By this physiological response, adjustments of the systemic and cerebral circulations are initiated to change the cerebral blood flow in a manner that is not yet understood. It appears that the cerebrovascular response to hypoxemia is, to a large extent, due to this reflex and is generated by the activation of neurons of the rostral ventrolateral reticular nucleus; the existence of such endogenous neuroprotective strategies may extend beyond the actually known clinical appearance of the TCR and include the prevention of other potential brain injury states as well.

  18. Evaluation of relationship between feeding reflexes and articulation in spastic cerebral palsy

    Directory of Open Access Journals (Sweden)

    M.R. Hadian

    2006-07-01

    Full Text Available Background: Cerebral palsy is the term used to describe a movement disorder though to be the result of nonprogressive brain damage. Due to damage to CNS, it is associated with articulation disorder and abnormal feeding reflex. Lack of oral function control and coordination following feeding reflex disorders. Articulation disorders are seen in most of the cerebral palsied patients.This research aimed to determine the relationship between feeding reflexes and articulation in cerebral palsy (spasticchildren. Methods: This study was cross sectionally carried out on 52 children with cerebral palsy, 5 to 10 yrs old, in rehabilitation centers and private clinics. The information related to feeding reflexes was collected through direct observation of patient and evaluation of sound articulation through phonetic information test. Results: Statistical analysis carried out by SPSS and chi-square and fisher exact tests. Abnomal chewing and tongue reflex are more prevalent than other feeding reflexes.The relationship between lip reflex and articulation of p/m/r/y/f/? and chewing reflex with articulation of/z// is meaningful. The relationship between biting reflex with articulation of /z/j/l// is meaningful. The relationship between tongue reflex and rooting reflex with articulation of sound is not meaningful. Conclusion: With regard to the result of this research, it can be suggested that in children with cerebral palsy following feeding reflex disorders, abnormal posture during speech occurs that could have effect on articulation.

  19. Viscero-somatic and viscero-visceral reflexes in brain death.

    OpenAIRE

    Conci, F.; Procaccio, F; Arosio, M.; Boselli, L

    1986-01-01

    Little is known about spinal visceral reflexes in brain-dead man, although they have been described in experimental animals. In 1983, 25 brain-dead individuals were observed during donor nephrectomy. It was confirmed that some of these donors, without higher centre modulation and not under significant pharmacological influence, had viscero-somatic motor reflexes and viscero-visceral cardiovascular reflexes.

  20. On Presic Type Generalization of the Banach Contraction Mapping Principle

    Directory of Open Access Journals (Sweden)

    S. Presic

    2007-10-01

    Full Text Available Let (X, d be a metric space, k a positive integer and T a mapping of Xk into X. In this paper we proved that if T satisfies conditions (2.1 and (2.2 below, then there exists a unique x in X such that T(x, x,, x = x, This result generalizes the corresponding theorems of the second author [4], [5] and the theorem of Dhage [3].