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1

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.

2

Mixed Variational-Like Inequality for Fuzzy Mappings in Reflexive Banach Spaces  

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Full Text Available Some existence theorems for the mixed variational-like inequality for fuzzy mappings (FMVLIP in a reflexive Banach space are established. Further, the auxiliary principle technique is used to suggest a novel and innovative iterative algorithm for computing the approximate solution. Consequently, not only the existence of solutions of the FMVLIP is shown, but also the convergence of iterative sequences generated by the algorithm is also proven. The results proved in this paper represent an improvement of previously known results.

Petrot Narin

2009-01-01

3

Symmetric polynomials on Banach spaces  

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Full Text Available A survey of general results about symmetric polynomials on Banach spaces and rearrangement-invariant function spaces and some new results in this area are given. Some applications to Banach algebras are represented.

I. V. Chernega

2009-12-01

4

Generalized uniqueness theorem for ordinary differential equations in Banach spaces.  

Science.gov (United States)

We consider nonlinear ordinary differential equations in Banach spaces. Uniqueness criterion for the Cauchy problem is given when any of the standard dissipative-type conditions does apply. A similar scalar result has been studied by Majorana (1991). Useful examples of reflexive Banach spaces whose positive cones have empty interior has been given as well. PMID:24683325

Hassan, Ezzat R; Alhuthali, M Sh; Al-Ghanmi, M M

2014-01-01

5

On unconditionally saturated Banach spaces  

CERN Document Server

We prove a structural property of the class of unconditionally saturated separable Banach spaces. We show, in particular, that for every analytic set $\\aaa$, in the Effros-Borel space of subspaces of $C[0,1]$, of unconditionally saturated separable Banach spaces, there exists an unconditionally saturated Banach space $Y$, with a Schauder basis, that contains isomorphic copies of every space $X$ in the class $\\aaa$.

Dodos, Pandelis

2008-01-01

6

Banach spaces with projectional skeletons  

CERN Document Server

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.

Kubi?, Wies?aw

2008-01-01

7

Weakly compact approximation in Banach spaces  

CERN Document Server

The Banach space $E$ has the weakly compact approximation property (W.A.P. for short) if there is a constant $C 0$ there is a weakly compact operator $V: E \\to E$ satisfying $\\sup_{x\\in D} || x - Vx || < \\epsilon$ and $|| V|| \\leq C$. We give several examples of Banach spaces both with and without this approximation property. Our main results demonstrate that the James-type spaces from a general class of quasi-reflexive spaces (which contains the classical James' space $J$) have the W.A.P, but that James' tree space $JT$ fails to have the W.A.P. It is also shown that the dual $J^*$ has the W.A.P. It follows that the Banach algebras $W(J)$ and $W(J^*)$, consisting of the weakly compact operators, have bounded left approximate identities. Among the other results we obtain a concrete Banach space $Y$ so that $Y$ fails to have the W.A.P., but $Y$ has this approximation property without the uniform bound $C$.

Odell, E; Odell, Edward; Tylli, Hans-Olav

2003-01-01

8

On separably injective Banach spaces  

CERN Document Server

In this paper we deal with two weaker forms of injectivity which turn out to have a rich structure behind: separable injectivity and universal separable injectivity. We show several structural and stability properties of these classes of Banach spaces. We provide natural examples of (universally) separably injective spaces, including $\\mathcal L_\\infty$ ultraproducts built over countably incomplete ultrafilters, in spite of the fact that these ultraproducts are never injective. We obtain two fundamental characterizations of universally separably injective spaces: a) A Banach space $E$ is universally separably injective if and only if every separable subspace is contained in a copy of $\\ell_\\infty$ inside $E$. b) A Banach space $E$ is universally separably injective if and only if for every separable space $S$ one has $\\Ext(\\ell_\\infty/S, E)=0$. The final Section of the paper focuses on special properties of 1-separably injective spaces. Lindenstrauss\\ obtained in the middle sixties a result that can be unders...

Aviles, Antonio; Castillo, Jesus M F; Gonzalez, Manuel; Moreno, Yolanda

2011-01-01

9

A pythagorean approach in Banach spaces  

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Full Text Available Let be a Banach space and let be the unit sphere of . Parameters , , , and , where and are introduced and studied. The values of these parameters in the spaces and function spaces are estimated. Among the other results, we proved that a Banach space with , or is uniform nonsquare; and a Banach space with , or has uniform normal structure.

Gao Ji

2006-01-01

10

On dual of Banach sequence spaces  

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Full Text Available J. Hagler and P. Azimi have introduced a class of Banach sequence spaces, the X?,1 spaces as a class of hereditarily $ell_1$ Banach spaces. In this paper, (i We show that X*?, 1, the dual of Banach space X?,1 contains asymptotically isometric copies of $ell_infty$. (ii With two methods, we show that X*?,1 is nonseparable although X?,1 is a separable Banach space. Also, we showX?,1 is not hereditarily indecomposable.

A. A. Ledari

2013-09-01

11

Infinitely divisible cylindrical measures on Banach spaces  

CERN Document Server

In this work infinitely divisible cylindrical probability measures on arbitrary Banach spaces are introduced. The class of infinitely divisible cylindrical probability measures is described in terms of their characteristics, a characterisation which is not known in general for infinitely divisible Radon measures on Banach spaces. Further properties of infinitely divisible cylindrical measures such as continuity are derived. Moreover, the result on the classification enables us to conclude new results on genuine Levy measures on Banach spaces.

Riedle, Markus

2011-01-01

12

Fixed Point Theorems in Cone Banach Spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this manuscript, a class of self-mappings on cone Banach spaces which have at least one fixed point is considered. More precisely, for a closed and convex subset of a cone Banach space with the norm , if there exist ,

Karap?nar Erdal

2009-01-01

13

Diffeomorphisms with Banach space domains  

CERN Document Server

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.

Zampieri, Gaetano

2012-01-01

14

Banach-Mackey spaces  

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Full Text Available In recent publications the concepts of fast completeness and local barreledness have been shown to be related to the property of all weak-* bounded subsets of the dual (of a locally convex space being strongly bounded. In this paper we clarify those relationships, as well as giving several different characterizations of this property.

Kelly McKennon

1991-06-01

15

Characterising subspaces of Banach spaces with a Schauder basis having the shift property  

CERN Document Server

We give an intrinsic characterisation of the separable reflexive Banach spaces that embed into separable reflexive spaces with an unconditional basis all of whose normalised block sequences with the same growth rate are equivalent. This uses methods of E. Odell and T. Schlumprecht.

Rosendal, Christian

2011-01-01

16

On Uniformly finitely extensible Banach spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

2013-01-01

17

Operators acting on certain Banach spaces of analytic functions  

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Full Text Available Let 𝒳 be reflexive Banach space of functions analytic plane domain Ω such that for every λ in Ω the functional of evaluation at λ is bounded. Assume further that 𝒳 contains the constants and Mz multiplication by the independent variable z, is bounded operator on 𝒳. We give sufficient conditions for Mz to be reflexive. In particular, we prove that the operators Mz on EP(Ω and certain HaP(β reflexive. We also prove that the algebra of multiplication operators on Bergman spaces is reflexive, giving simpler proof of result of Eschmeier.

B. Yousefi

1995-03-01

18

Equilateral sets in infinite dimensional Banach spaces  

CERN Document Server

We show that every Banach space $X$ containing an isomorphic copy of $c_0$ has an infinite equilateral set and also that if $X$ has a bounded biorthogonal system of size $\\alpha$ then it can be renormed so as to admit an equilateral set of equal size. If $K$ is any compact non metrizable space, then under a certain combinatorial condition on $K$ the Banach space $C(K)$ has an uncountable equilateral set.

Mercourakis, S K

2011-01-01

19

M-ideals in Banach spaces and Banach algebras  

CERN Document Server

This book provides a comprehensive exposition of M-ideal theory, a branch ofgeometric functional analysis which deals with certain subspaces of Banach spaces arising naturally in many contexts. Starting from the basic definitions the authors discuss a number of examples of M-ideals (e.g. the closed two-sided ideals of C*-algebras) and develop their general theory. Besides, applications to problems from a variety of areas including approximation theory, harmonic analysis, C*-algebra theory and Banach space geometry are presented. The book is mainly intended as a reference volume for researchers working in one of these fields, but it also addresses students at the graduate or postgraduate level. Each of its six chapters is accompanied by a Notes-and-Remarks section which explores further ramifications of the subject and gives detailed references to the literature. An extensive bibliography is included.

Harmand, Peter; Werner, Wend

1993-01-01

20

A pythagorean approach in Banach spaces  

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Full Text Available Let X be a Banach space and S ( X = { x ? X , ? x ? = 1 } be the unit sphere of X . Parameters E ( X = sup ? { ? ( x , x ? S ( X } , e ( X = inf ? { ? ( x , x ? S ( X } , F ( X = sup ? { ? ( x , x ? S ( X } , and f ( X = inf ? { ? ( x , x ? S ( X } , where ? ( x = sup ? { ? x + y ? 2 + ? x ? y ? 2 , y ? S ( X } and ? ( x = inf ? { ? x + y ? 2 + ? x ? y ? 2 , y ? S ( X } are introduced and studied. The values of these parameters in the l p spaces and function spaces L p [ 0 , 1 ] are estimated. Among the other results, we proved that a Banach space X with E ( X < 8 , or 2$"> f ( X > 2 is uniform nonsquare; and a Banach space X with E ( X < 5 , or frac{32}{9}$"> f ( X > 32 / 9 has uniform normal structure.

2006-01-01

 
 
 
 
21

A Gaussian Average Property for Banach Spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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.

Casazza, Peter G.; Nielsen, Niels Jorgen

1996-01-01

22

On Sharp Triangle Inequalities in Banach Spaces II  

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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.

Kichi-Suke Saito

2010-01-01

23

Coorbit Space Theory for Quasi-Banach Spaces  

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We generalize the classical coorbit space theory developed by Feichtinger and Gr"ochenig to quasi-Banach spaces. As a main result we provide atomic decompositions for coorbit spaces defined with respect to quasi-Banach spaces. These atomic decompositions are used to prove fast convergence rates of best $n$-term approximation schemes. We apply the abstract theory to time-frequency analysis of modulation spaces $M^{p,q}_m$, $0< p,q \\leq \\infty$.

Rauhut, Holger

2005-01-01

24

Accelerated Landweber iteration in Banach spaces  

International Nuclear Information System (INIS)

We investigate a method of accelerated Landweber type for the iterative regularization of nonlinear ill-posed operator equations in Banach spaces. Based on an auxiliary algorithm with a simplified choice of the step-size parameter we present a convergence and stability analysis of the algorithm under consideration. We will close our discussion with the presentation of a numerical example

25

On complete convergence in a Banach space  

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Full Text Available Sufficient conditions are given under which a sequence of independent random elements taking values in a Banach space satisfy the Hsu and Robbins law of large numbers. The complete convergence of random indexed sums of random elements is also considered.

Dominik Szynal

1994-03-01

26

Strong Convergence of Viscosity Methods for Continuous Pseudocontractions in Banach Spaces  

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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 Gâteaux 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.

Haiyun Zhou

2008-12-01

27

Banach spaces of vector-valued functions  

CERN Document Server

"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.

Cembranos, Pilar

1997-01-01

28

Three-space problems in Banach space theory  

CERN Document Server

This book on Banach space theory focuses on what have been called three-space problems. It contains a fairly complete description of ideas, methods, results and counterexamples. It can be considered self-contained, beyond a course in functional analysis and some familiarity with modern Banach space methods. It will be of interest to researchers for its methods and open problems, and to students for the exposition of techniques and examples.

Castillo, Jess M F

1997-01-01

29

Banach spaces with the $2$-summing property  

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A Banach space $X$ has the $2$-summing property if the norm of every linear operator from $X$ to a Hilbert space is equal to the $2$-summing norm of the operator. Up to a point, the theory of spaces which have this property is independent of the scalar field: the property is self-dual and any space with the property is a finite dimensional space of maximal distance to the Hilbert space of the same dimension. In the case of real scalars only the real line and real $\\ell_\\inft...

Arias, Alvaro; Figiel, Tadek; Johnson, William B.; Schechtman, Gideon

1994-01-01

30

Submonotone mappings in Banach spaces and applications  

International Nuclear Information System (INIS)

The notions 'submonotone' and 'strictly submonotone' mapping, introduced by J. Spingarn in Rn, are extended in a natural way to arbitrary Banach spaces. Several results about monotone operators are proved for submonotone and strictly submonotone ones: Rockafellar's result about local boundedness of monotone operators; Kenderov's result about single-valuedness and upper-semicontinuity almost everywhere of monotone operators in Asplund spaces; minimality (as w* - cusco mappings) of maximal strictly submonotone mappings, etc. It is shown that subdifferentials of various classes non-convex functions defined as pointwise suprema of quasi-differentiable functions possess submonotone properties. Results about generic differentiability of such functions are obtained (among them are new generalizations of an Ekeland and Lebourg's theorem). Applications are given to the properties of the distance function in a Banach space with uniformly Gateaux differentiable norm. (author). 29 refs

31

Malliavin calculus and decoupling inequalities in Banach spaces  

CERN Document Server

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 variables. In the opposite direction we use Meyer's inequalities to give a new proof of a decoupling result for Gaussian chaoses in UMD Banach spaces.

Maas, Jan

2008-01-01

32

Metrizability of Cone Metric Spaces Via Renorming the Banach Spaces  

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Full Text Available 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 is valid for cone metric space automatically.

Hossein Soleimani

2012-09-01

33

Banach spaces with the $2$-summing property  

CERN Document Server

A Banach space $X$ has the $2$-summing property if the norm of every linear operator from $X$ to a Hilbert space is equal to the $2$-summing norm of the operator. Up to a point, the theory of spaces which have this property is independent of the scalar field: the property is self-dual and any space with the property is a finite dimensional space of maximal distance to the Hilbert space of the same dimension. In the case of real scalars only the real line and real $\\ell_\\infty^2$ have the $2$-summing property. In the complex case there are more examples; e.g., all subspaces of complex $\\ell_\\infty^3$ and their duals.

Arias, A A; Johnson, W B; Schechtman, G; Arias, Alvaro; Figiel, Tadek; Johnson, William B.; Schechtman, Gideon

1994-01-01

34

Impulsive integral equations in Banach spaces and applications  

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Full Text Available In this paper, we first use the fixed point theory to prove two existence theorems of positive solutions for the impulsive Fredholm integral Equations in Banach spaces. And then, we offer some applications to the two-point boundary value problems for the second order impulsive differential equations in Banach spaces.

Dajun Guo

1992-01-01

35

Some results concerning frames in Banach spaces  

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Full Text Available A necessary and sufficient condition for the associated sequence of functionals to a complete minimal sequence to be a Banach frame has been given. We give the definition of a weak-exact Banach frame, and observe that an exact Banach frame is weak-exact. An example of a weak-exact Banach frame which is not exact has been given. A necessary and sufficient condition for a Banach frame to be a weak-exact Banach frame has been obtained. Finally, a necessary condition for the perturbation of a retro Banach frame by a finite number of linearly independent vectors to be a retro Banach frame has been given.

S. K. Kaushik

2007-09-01

36

Displaying Polish groups on separable Banach spaces  

CERN Document Server

A display of a topological group G on a Banach space X is a topological isomorphism of G with the isometry group Isom(X,||.||) for some equivalent norm ||.|| on X, where the latter group is equipped with the strong operator topology. Displays of Polish groups on separable real spaces are studied. It is proved that any closed subgroup of the infinite symmetric group S_\\infty containing a non-trivial central involution admits a display on any of the classical spaces c0, C([0,1]), lp and Lp for 1 <=p <\\infty. Also, for any Polsih group G, there exists a separable space X on which {-1,1} x G has a display.

Ferenczi, Valentin

2011-01-01

37

Generalized quasi-Banach sequence spaces and measures of noncompactness  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Dado 0 [...] o compacidade de Hausdorff. Como uma aplicao, conjuntos compactos nos espa, cos de interpolao s ?, de um par quase-Banach so estudados. Abstract in english Given 0 [...] As an application, compact sets in s ? -interpolation spaces of a quasi-Banach couple are studied.

EDUARDO B., SILVA; DIOCESAR L., FERNANDEZ; LUDMILA, NIKOLOVA.

2013-06-01

38

Factorization and Reflexivity on Fock spaces  

CERN Document Server

The framework of the paper is that of the full Fock space ${\\Cal F}^2({\\Cal H}_n)$ and the Banach algebra $F^\\infty$ which can be viewed as non-commutative analogues of the Hardy spaces $H^2$ and $H^\\infty$ respectively. An inner-outer factorization for any element in ${\\Cal F}^2({\\Cal H}_n)$ as well as characterization of invertible elements in $F^\\infty$ are obtained. We also give a complete characterization of invariant subspaces for the left creation operators $S_1,\\cdots, S_n$ of ${\\Cal F}^2({\\Cal H}_n)$. This enables us to show that every weakly (strongly) closed unital subalgebra of $\\{\\varphi(S_1,\\cdots,S_n):\\varphi\\in F^\\infty\\}$ is reflexive, extending in this way the classical result of Sarason [S]. Some properties of inner and outer functions and many examples are also considered.

Arias, A A; Arias, Alvaro; Popescu, Gelu

1994-01-01

39

BANACH CONTRACTION PRINCIPLE ON CONE RECTANGULAR METRIC SPACES  

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Full Text Available We introduce the notion of cone rectangular metric space and prove {sc Banach} contraction mapping principle in cone rectangular metric space setting. Our result extends recent known results.

Ismat Beg

2009-08-01

40

Generalized dissipativeness in a Banach space  

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Full Text Available Suppose X is a real or complex Banach space with dual X* and a semiscalar product [,]. For k a real number, a subset B of X×X will be called k-dissipative if for each pair of elements (x1,y1, (x2,y2 in B, there existsh∈{f∈X*:[x,f]=|x|2=|f|2}such thatRe[y1−y2,h]≤k|x1−x2|2.This definition extends a notion of dissipativeness which is equivalent to having k equal zero here. A number of definitions and theorems related to this original dissipative notion are generalized in the present paper to fit the k-dissipative situation, and proofs are given for the new theorems.

David R. Gurney

1996-03-01

 
 
 
 
41

Steinhaus' lattice-point problem for Banach spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Given a positive integer $n$, one may find a circle on the Euclidean plane surrounding exactly $n$ points of the integer lattice. This classical geometric fact due to Steinhaus has been recently extended to Hilbert spaces by Zwole\\'nski, who replaced the integer lattice by any infinite set which intersects every ball in at most finitely many points. We investigate the Banach spaces satisfying this property, which we call (S), and show that all strictly convex Banach spaces h...

Kochanek, Tomasz

2013-01-01

42

On second order impulsive functional differential equations in Banach spaces  

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Full Text Available In this paper, a fixed point theorem due to Schaefer is used to investigate the existence of solutions for second order impulsive functional differential equations in Banach spaces.

M. Benchohra

2002-01-01

43

On controllability for fractional differential inclusions in Banach spaces  

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Full Text Available In this paper, we investigate the controllability for systems governed by fractional differential inclusions in Banach spaces. The techniques rely on fractional calculus, multivalue mapping on a bounded set and Bohnenblust-Karlin's fixed point theorem

JinRong Wang

2012-01-01

44

A subsequence characterization of sequences spanning isomorphically polyhedral Banach spaces  

CERN Document Server

Let $(x_n)$ be a sequence in a Banach space $X$ which does not converge in norm, and let $E$ be an isomorphically precisely norming set for $X$ such that \\[ \\sum_n |x^*(x_{n+1}-x_n)|< \\infty, \\; \\forall x^* \\in E. \\qquad (*) \\] Then there exists a subsequence of $(x_n)$ which spans an isomorphically polyhedral Banach space. It follows immediately from results of V. Fonf that the converse is also true: If a separable Banach space $Y$ is a separable isomorphically polyhedral then there exists a non norm convergent sequence $(x_n)$ which spans $Y$ and there exists an isomorphically precisely norming set $E$ for $Y$ such that $(*)$ is satisfied. As an application of this subsequence characterization of sequences spanning isomorphically polyhedral Banach spaces we obtain a strengthening of a result of J. Elton, and an Orlicz-Pettis type result.

Androulakis, G

1996-01-01

45

Matrix transformations involving certain Banach space valued sequence spaces  

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Full Text Available In this paper for Banach spaces $X$ and $Y$ we characterize matrix classes $ (\\Gamma (X,\\lambda$, $ l_\\infty(Y,\\mu$, $ (\\Gamma(X,\\lambda,C(Y,\\mu$, $ (\\Gamma(X,\\lambda$, $ c_0(Y,\\mu$, $ (\\Gamma(X,\\lambda$, $ \\Gamma^*(Y,\\mu$, $ (l_1(X,\\lambda$, $ \\Gamma(Y,\\mu$ and $ (c_0(X,\\lambda$, $ c_0(Y,\\mu$ of bounded linear operators involving $ X$- and $ Y$-valued sequence spaces. Further as an application of the matrix class $ (c_0(X,\\lambda$, $ c_0(Y,\\mu$ we investigate the Banach space $ B(c_0(X,\\lambda$, $ c_0(Y,\\mu$ of all bounded linear mappings of $ c_0(x,\\lambda$ to $ c_0(Y,\\mu$.

J. K. Srivastava

2000-06-01

46

Stochastic evolution equations in UMD Banach spaces  

CERN Document Server

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.

van Neerven, J M A M; Weis, L

2008-01-01

47

Topological Vector-Space Valued Cone Banach Spaces  

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Full Text Available 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 weak contractive mappings. We discuss the necessary conditions for T -stability of Picard iteration. To ensure the novelty of our work we establish an application in homotopy theory without the assumption of normality on cone and many non-trivial examples.

Nayyar Mehmood

2014-10-01

48

Iterative Approximation to Convex Feasibility Problems in Banach Space  

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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.

Shih-Sen Chang

2007-04-01

49

Construction of generalized atomic decompositions in Banach spaces  

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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.

Raj Kumar

2014-06-01

50

Metric embeddings bilipschitz and coarse embeddings into Banach spaces  

CERN Document Server

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

Ostrovskii, Mikhail I

2013-01-01

51

A GLIDING HUMP PROPERTY AND BANACH-MACKEY SPACES  

Directory of Open Access Journals (Sweden)

Full Text Available We consider the Banach-Mackey property for pairs of vector spaces E and E' which are in duality. Let A be an algebra of sets and assume that P is an additive map from A into the projection operators on E. We define a continuous gliding hump property for the map P and show that pairs with this gliding hump property and anoter measure theoretic property are Banach-Mackey pairs, i. e., weakly bounded subsets of E are strongly bounded. Examples of vector valued function spaces, such as the space of Pettis integrable functions, which satisfy these conditions are given

CHARLES SWARTZ

2001-08-01

52

Banach Contraction Principle for Cyclical Mappings on Partial Metric Spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, we prove that the Banach contraction principle proved by S. G. Matthews in 1994 on 0--complete partial metric spaces can be extended to cyclical mappings. However, the generalized contraction principle proved by D. Ili\\'{c}, V. Pavlovi\\'{c} and V. Rako\\u{c}evi\\'{c} in "Some new extensions of Banach's contraction principle to partial metric spaces, Appl. Math. Lett. 24 (2011), 1326--1330" on complete partial metric spaces can not be extended to cyclical mapping...

Abdeljawad, Thabet; Alzabut, Jehad O.; Mukheimer, Aiman; Zaidan, Younes

2011-01-01

53

Banach's space: Lviv and the Scottish cafe  

Directory of Open Access Journals (Sweden)

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.

D.Henderson

2004-01-01

54

Uniform Versions of Infinitary Properties in Banach Spaces  

CERN Document Server

In functional analysis it is of interest to study the following general question: Is the uniform version of a property that holds in all Banach spaces also valid in all Banach spaces? Examples of affirmative answers to the above question are the host of proofs of almost-isometric versions of well known isometric theorems. Another example is Rosenthal's uniform version of Krivine's Theorem. Using an extended version of Henson's Compactness result for positive bounded formulas in normed structures, we show that the answer of the above question is in fact yes for every property that can be expressed in a particular infinitary language.

Ortiz, C

1999-01-01

55

Convergence to Common Fixed Point for Generalized Asymptotically Nonexpansive Semigroup in Banach Spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Let K be a nonempty closed convex subset of a reflexive and strictly convex Banach space E with a uniformly Gâteaux differentiable norm, ℱ={T(h):h≥0} a generalized asymptotically nonexpansive self-mapping semigroup of K, and f:K→K a fixed contractive mapping with contractive coefficient β∈(0,1). We prove that the following implicit and modified implicit viscosity iterative schemes {xn} defined by xn=αnf(xn)+(1−...

Lei Deng; Jianjun Liu; Yali Li

2008-01-01

56

Banach spaces and descriptive set theory selected topics  

CERN Document Server

This volume deals with problems in the structure theory of separable infinite-dimensional Banach spaces, with a central focus on universality problems. This topic goes back to the beginnings of the field and appears in Banach's classical monograph. The novelty of the approach lies in the fact that the answers to a number of basic questions are based on techniques from Descriptive Set Theory. Although the book is oriented on proofs of several structural theorems, in the main text readers will also find a detailed exposition of numerous intermediate results which are interesting in their own right and have proven to be useful in other areas of Functional Analysis. Moreover, several well-known results in the geometry of Banach spaces are presented from a modern perspective.

Dodos, Pandelis

2010-01-01

57

Improved bounds in the metric cotype inequality for Banach spaces  

CERN Document Server

It is shown that if (X, ||.||_X) is a Banach space with Rademacher cotype q then for every integer n there exists an even integer m X we have \\sum_{j=1}^n \\Avg_x [ ||f(x+ (m/2) e_j)-f(x) ||_X^q ] n^{(1/2)+(1/q)}.

Giladi, Ohad; Naor, Assaf

2010-01-01

58

On nonlocal problems for fractional differential equations in Banach spaces  

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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.

XiWang Dong

2011-01-01

59

Multivalued impulsive neutral functional differential inclusions in Banach spaces  

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Full Text Available In paper the existence of solutions for first and second order impulsive neutral functional differential inclusions in Banach spaces is investigated. The results are obtained by using a fixed point theorem for condensing multivalued maps due to Martelli and the semigroup theory.

M. Benchohra

2002-03-01

60

Coincidence and fixed point theorems in metric and Banach spaces  

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Full Text Available We prove some coincidence and fixed point theorems for generalized (ϕ,f-contractive type and f-nonexpansive type multivalued and singlevalued mappings in metric and Banach spaces, respectively. Our results extend, improve, and unify a few known results due to Browder, Browder and Petryshyn, Chang, Huang, and Cho, Husain and Latif, Husain and Tarafdar, and Karlovitz.

Mohammad S. Khan

2001-05-01

 
 
 
 
61

A characterization of Banach space with non expansive map  

International Nuclear Information System (INIS)

In this paper, we characterize a Banach space X with a certain non expansive map T: X ? X. We shall prove that T is non expansive if and only if each three dimensional subspace of X has the property that, after rotation by ?/2, its unit ball coincides with its dual unit ball. (authors). 3 refs

62

On the Fonte structure between a pair of Banach spaces  

International Nuclear Information System (INIS)

The main purpose of the present note is to establish the essential equivalence of the adjoint of a semilinear map defined through the Fonte structure between a pair of Banach spaces and the adjoint of the same map defined by Pian and the present author

63

Perturbations of isometries between Banach spaces  

CERN Document Server

We prove a very general theorem concerning the estimation of the expression $\\|T(\\frac{a+b}{2}) - \\frac{Ta+Tb}{2}\\|$ for different kinds of maps $T$ satisfying some general perurbated isometry condition. It can be seen as a quantitative generalization of the classical Mazur-Ulam theorem. The estimates improve the existing ones for bi-Lipschitz maps. As a consequence we also obtain a very simple proof of the result of Gevirtz which answers the Hyers-Ulam problem and we prove a non-linear generalization of the Banach-Stone theorem which improves the results of Jarosz and more recent results of Dutrieux and Kalton.

Gorak, Rafal

2011-01-01

64

Functional differential equations with infinite delay in Banach spaces  

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Full Text Available In this paper, a definition of the fundamental operator for the linear autonomous functional differential equation with infinite delay in a Banach space is given, and some sufficient and necessary conditions of the fundamental operator being exponentially stable in abstract phase spaces which satisfy some suitable hypotheses are obtained. Moreover, we discuss the relation between the exponential asymptotic stability of the zero solution of nonlinear functional differential equation with infinite delay in a Banach space and the exponential stability of the solution semigroup of the corresponding linear equation, and find that the exponential stability problem of the zero solution for the nonlinear equation can be discussed only in the exponentially fading memory phase space.

Tijun Xiao

1991-09-01

65

Integral operators on the section space of a Banach bundle  

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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.

D. A. Robbins

1993-09-01

66

Some remarks on controllability of evolution equations in Banach spaces  

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Full Text Available In almost all papers in the literature, the results on exact controllability hold only for finite dimensional Banach spaces, since compactness of the semigroup and the bounded invertibility of an operator implies finite dimensional. In this note we show that the existence theory on controllability in the literature, can trivially be adjusted to include the infinite dimensional space setting, if we replace the compactness of operators with the complete continuity of the nonlinearity.

Sotiris K. Ntouyas

2009-06-01

67

A GLIDING HUMP PROPERTY AND BANACH-MACKEY SPACES  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english We consider the Banach-Mackey property for pairs of vector spaces E and E' which are in duality. Let A be an algebra of sets and assume that P is an additive map from A into the projection operators on E. We define a continuous gliding hump property for the map P and show that pairs with this glidin [...] g hump property and anoter measure theoretic property are Banach-Mackey pairs, i. e., weakly bounded subsets of E are strongly bounded. Examples of vector valued function spaces, such as the space of Pettis integrable functions, which satisfy these conditions are given

CHARLES, SWARTZ.

68

Banach Contraction Principle for Cyclical Mappings on Partial Metric Spaces  

CERN Document Server

In this paper, we prove that the Banach contraction principle proved by S. G. Matthews in 1994 on 0--complete partial metric spaces can be extended to cyclical mappings. However, the generalized contraction principle proved by D. Ili\\'{c}, V. Pavlovi\\'{c} and V. Rako\\u{c}evi\\'{c} in "Some new extensions of Banach's contraction principle to partial metric spaces, Appl. Math. Lett. 24 (2011), 1326--1330" on complete partial metric spaces can not be extended to cyclical mappings. Some examples are given to illustrate the effectiveness of our results. Moreover, we generalize some of the results obtained by W. A. Kirk, P. S. Srinivasan and P. Veeramani in "Fixed points for mappings satisfying cyclical contractive conditions, Fixed Point Theory 4 (1) (2003),79--89". Finally, an Edelstein's type theorem is also extended in case one of the sets in the cyclic decomposition is 0-compact.

Abdeljawad, Thabet; Mukheimer, Aiman; Zaidan, Younes

2011-01-01

69

On best proximity points in metric and Banach spaces  

CERN Document Server

In this paper we study the existence and uniqueness of best proximity points of cyclic contractions as well as the convergence of iterates to such proximity points. We do it from two different approaches, leading each one of them to different results which complete, if not improve, other similar results in the theory. Results in this paper stand for Banach spaces, geodesic metric spaces and metric spaces. We also include an appendix on CAT(0) spaces where we study the particular behavior of these spaces regarding the problems we are concerned with.

Espinola, Rafa

2009-01-01

70

Identification for a semilinear evolution equation in a Banach space  

International Nuclear Information System (INIS)

In this paper we prove an existence result for strict solutions to an identification problem for a first-order semilinear differential equation, in a general Banach space, subjected to an overdetermination expressed by means of a Lebesgue integral. Under the additional assumption that the C0-semigroup generated by the linear part has a sufficiently fast exponential decay, we prove the uniqueness and the continuous dependence of the solution on the data

71

Elements of mathematical theory of evolutionary equations in Banach spaces  

CERN Document Server

Evolutionary equations are studied in abstract Banach spaces and in spaces of bounded number sequences. For linear and nonlinear difference equations, which are defined on finite-dimensional and infinite-dimensional tori, the problem of reducibility is solved, in particular, in neighborhoods of their invariant sets, and the basics for a theory of invariant tori and bounded semi-invariant manifolds are established. Also considered are the questions on existence and approximate construction of periodic solutions for difference equations in infinite-dimensional spaces and the problem of extendibi

Samoilenko, Anatoly M

2013-01-01

72

Optimal quantizers for Radon random vectors in a Banach space  

CERN Document Server

For every integer n and evrery positive real number r > 0 and a Radon random vector X with values in a Banach space E, let e\\_{n,r}(X,E) = inf{(E (\\min\\_{a \\in \\alpha} || X-a ||^r)^{1/r}}, where the infimum is taken over all subsets \\alpha of E with card(\\alpha) <= n (n-quantizers). We investigate the existence of optimal n-quantizers for this L^r-quantization propblem, derive their stationarity properties and establish for L^p-spaces E the pathwise regularity of stationary quantizers.

Graf, S; Gilles, P; Graf, Siegried; Luschgy, Harald; Gilles, Pag\\`{e}s

2005-01-01

73

On moduli of convexity in Banach spaces  

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Full Text Available Let be a normed linear space, an element of norm one, and and the local modulus of convexity of . We denote by the greatest such that for each closed linear subspace of the quotient mapping maps the open -neighbourhood of in onto a set containing the open -neighbourhood of in . It is known that . We prove that there is no universal constant such that , however, such a constant exists within the class of Hilbert spaces . If is a Hilbert space with , then .

Reif Ji?

2005-01-01

74

Mean convergence theorem for multidimensional arrays of random elements in Banach spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

For a d-dimensional array of random elements {Vn,n??+d} in a real separable stable type p (1?p<2) Banach space, a mean convergence theorem is established. Moreover, the conditions for the convergence in mean of order p are shown to completely characterize stable-type p Banach spaces.

Le Van Thanh

2006-01-01

75

On Asymptotic Behaviors for Linear Skew-Product Semiflows in Banach Spaces  

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Full Text Available In this paper we give several characterizations of some asymptotic behaviours: stability, instability, dichotomy and trichotomy of linear skew product semiflows in Banach spaces. The obtained results are generalizations of some well-known results on asymptotic behaviours of linear differential equations. There are also presented several examples of semiflows and linear skew-product semiflows in Banach spaces.

Andrea A. Minda

2006-10-01

76

A New Result About Uniformly Lipschitzian Mappings in Banach Space  

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Full Text Available Let E be a real Banach space, K be a nonempty closed convex subset of e,ti:K?K,i=1,2,3 be uniformly Lipschitzian mappings. Let KnC[1,?,Kn?1,{an},{8n}?[0,1],be two sequences in [0,1] atisfying the following conditions; (i8n?1(n??;(??n=0an=?,?n=0?n=?;(??n=0an2?kn?x-x ?-x(?x-x?,then {xn}converges strongly to x .The main result in the paper improes the main results in references [1,8]and references[6-7].

WANG Qi-lin

2009-06-01

77

Square variation of Brownian paths in Banach spaces  

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Full Text Available It is known that if {W(t,   0≤t≤1} is a standard Brownian motion in ℝ then limn→∞∑i=12n|W(i/2n−W((i−1/2n|2=1 almost surely. We generalize this celebrated theorem of Levy to Brownian motion in real separable Banach spaces.

Mou-Hsiung Chang

1982-09-01

78

Representations of ideals in Polish groups and in Banach spaces  

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We investigate ideals of the form $\\{A \\subseteq \\omega\\colon \\sum_{n\\in A} x_n$ is unconditionally convergent $\\}$, where $(x_n)_{n\\in\\omega}$ is a sequence in a Polish group or in a Banach space. If an ideal on $\\omega$ can be seen in this form for some sequence in $X$, then we say that it is representable in $X$. After numerous examples we show the following theorems: (1) An ideal is representable in a Polish Abelian group iff it is an analytic P-ideal. (2) An ideal ...

Borodulin-nadzieja, Piotr; Farkas, Barnabas; Plebanek, Grzegorz

2014-01-01

79

A note on nonfragmentability of Banach spaces  

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Full Text Available We use Kenderov-Moors characterization of fragmentability to show that if a compact Hausdorff space X with the tree-completeness property contains a disjoint sequences of clopen sets, then (C(X, weak is not fragmented by any metric which is stronger than weak topology. In particular, C(X does not admit any equivalent locally uniformly convex renorming.

S. Alireza Kamel Mirmostafaee

2001-07-01

80

Independent functions and the geometry of Banach spaces  

International Nuclear Information System (INIS)

The main objective of this survey is to present the 'state of the art' of those parts of the theory of independent functions which are related to the geometry of function spaces. The 'size' of a sum of independent functions is estimated in terms of classical moments and also in terms of general symmetric function norms. The exposition is centred on the Rosenthal inequalities and their various generalizations and sharp conditions under which the latter hold. The crucial tool here is the recently developed construction of the Kruglov operator. The survey also provides a number of applications to the geometry of Banach spaces. In particular, variants of the classical Khintchine-Maurey inequalities, isomorphisms between symmetric spaces on a finite interval and on the semi-axis, and a description of the class of symmetric spaces with any sequence of symmetrically and identically distributed independent random variables spanning a Hilbert subspace are considered. Bibliography: 87 titles.

 
 
 
 
81

Independent functions and the geometry of Banach spaces  

Energy Technology Data Exchange (ETDEWEB)

The main objective of this survey is to present the 'state of the art' of those parts of the theory of independent functions which are related to the geometry of function spaces. The 'size' of a sum of independent functions is estimated in terms of classical moments and also in terms of general symmetric function norms. The exposition is centred on the Rosenthal inequalities and their various generalizations and sharp conditions under which the latter hold. The crucial tool here is the recently developed construction of the Kruglov operator. The survey also provides a number of applications to the geometry of Banach spaces. In particular, variants of the classical Khintchine-Maurey inequalities, isomorphisms between symmetric spaces on a finite interval and on the semi-axis, and a description of the class of symmetric spaces with any sequence of symmetrically and identically distributed independent random variables spanning a Hilbert subspace are considered. Bibliography: 87 titles.

Astashkin, Sergey V; Sukochev, Fedor A

2010-12-31

82

Independent functions and the geometry of Banach spaces  

Science.gov (United States)

The main objective of this survey is to present the `state of the art' of those parts of the theory of independent functions which are related to the geometry of function spaces. The `size' of a sum of independent functions is estimated in terms of classical moments and also in terms of general symmetric function norms. The exposition is centred on the Rosenthal inequalities and their various generalizations and sharp conditions under which the latter hold. The crucial tool here is the recently developed construction of the Kruglov operator. The survey also provides a number of applications to the geometry of Banach spaces. In particular, variants of the classical Khintchine-Maurey inequalities, isomorphisms between symmetric spaces on a finite interval and on the semi-axis, and a description of the class of symmetric spaces with any sequence of symmetrically and identically distributed independent random variables spanning a Hilbert subspace are considered. Bibliography: 87 titles.

Astashkin, Sergey V.; Sukochev, Fedor A.

2010-12-01

83

On strictly singular operators between separable Banach spaces  

CERN Document Server

Let $X$ and $Y$ be separable Banach spaces and denote by $\\sss\\sss(X,Y)$ the subset of $\\llll(X,Y)$ consisting of all strictly singular operators. We study various ordinal ranks on the set $\\sss\\sss(X,Y)$. Our main results are summarized as follows. Firstly, we define a new rank $\\rs$ on $\\sss\\sss(X,Y)$. We show that $\\rs$ is a co-analytic rank and that dominates the rank $\\varrho$ introduced by Androulakis, Dodos, Sirotkin and Troitsky [Israel J. Math., 169 (2009), 221-250]. Secondly, for every $1\\leq p<+\\infty$ we construct a Banach space $Y_p$ with an unconditional basis such that $\\sss\\sss(\\ell_p, Y_p)$ is a co-analytic non-Borel subset of $\\llll(\\ell_p,Y_p)$ yet every strictly singular operator $T:\\ell_p\\to Y_p$ satisfies $\\varrho(T)\\leq 2$. This answers a question of Argyros.

Beanland, Kevin

2010-01-01

84

James orthogonality and orthogonal decompositions of Banach spaces  

Science.gov (United States)

We establish decompositions of a uniformly convex and uniformly smooth Banach space B and dual space B* in the form BDM[plus sign in union]J*M[perpendicular] and B*DM[perpendicular][plus sign in union]JM, where M is an arbitrary subspace in B, M[perpendicular] is its annihilator (subspace) in B*, J:B-->B* and J*:B*-->B are normalized duality mappings. The sign [plus sign in union] denotes the James orthogonal summation (in fact, it is the direct sums of the corresponding subspaces and manifolds). In a Hilbert space H, these representations coincide with the classical decomposition in a shape of direct sum of the subspace M and its orthogonal complement M[perpendicular]: HDM[circle plus operator]M[perpendicular].

Alber, Ya. I.

2005-12-01

85

Weighted Admissibility and Wellposedness of linear systems in Banach spaces  

CERN Document Server

We study linear control systems in infinite--dimensional Banach spaces governed by analytic semigroups. For $p\\in[1,\\infty]$ and $\\alpha\\in\\RR$ we introduce the notion of $L^p$--admissibility of type $\\alpha$ for unbounded observation and control operators. Generalising earlier work by Le Merdy and the first named author and Le Merdy we give conditions under which $L^p$--admissibility of type $\\alpha$ is characterised by boundedness conditions which are similar to those in the well--known Weiss conjecture. We also study $L^p$--wellposedness of type $\\alpha$ for the full system. Here we use recent ideas due to Pruess and Simonett. Our results are illustrated by a controlled heat equation with boundary control and boundary observation where we take Lebesgue and Besov spaces as state space. This extends the considerations from Byrnes, Gilliam, Shubov and Weiss to non--Hilbertian settings and to $p\

Haak, B H; Haak, Bernhard H.; Kunstmann, Peer Christian

2006-01-01

86

Existence and uniqueness of solutions of nonlinear mixed integrodifferential equations with nonlocal condition in Banach Spaces  

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Full Text Available In this article, we study the existence and uniqueness of mild and strong solutions of a nonlinear mixed Volterra-Fredholm integrodifferential equation with nonlocal condition in Banach spaces. Furthermore, we study continuous dependence of mild solutions. Our analysis is based on semigroup theory and Banach fixed point theorem.

Machindra B. Dhakne

2011-02-01

87

Generalized Browder's and Weyl's Theorems for Banach space operators  

CERN Document Server

We find necessary and sufficient conditions for a Banach space operator T to satisfy the generalized Browder's theorem, and we obtain new necessary and sufficient conditions to guarantee that the spectral mapping theorem holds for the B-Weyl spectrum and for polynomials in T. We also prove that the spectral mapping theorem holds for the B-Browder spectrum and for analytic functions on an open neighborhood of \\sigma(T). As applications, we show that if T is algebraically M-hyponormal, or if T is algebraically paranormal, then the generalized Weyl's theorem holds for f(T), where f \\in H(T), the space of functions analytic on an open neighborhood of \\sigma(T). We also show that if T is reduced by each of its eigenspaces, then the generalized Browder's theorem holds for f(T), for each f \\in H(\\sigma(T)).

Curto, R E; Curto, Raul E.; Han, Young Min

2006-01-01

88

Generalized Browder's and Weyl's theorems for Banach space operators  

Science.gov (United States)

We find necessary and sufficient conditions for a Banach space operator T to satisfy the generalized Browder's theorem. We also prove that the spectral mapping theorem holds for the Drazin spectrum and for analytic functions on an open neighborhood of [sigma](T). As applications, we show that if T is algebraically M-hyponormal, or if T is algebraically paranormal, then the generalized Weyl's theorem holds for f(T), where f[set membership, variant]H((T)), the space of functions analytic on an open neighborhood of [sigma](T). We also show that if T is reduced by each of its eigenspaces, then the generalized Browder's theorem holds for f(T), for each f[set membership, variant]H([sigma](T)).

Curto, Ral E.; Han, Young Min

2007-12-01

89

Restrictive metric regularity and generalized differential calculus in Banach spaces  

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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.

Bingwu Wang

2004-10-01

90

Factorization and Reflexivity on Fock spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The framework of the paper is that of the full Fock space ${\\Cal F}^2({\\Cal H}_n)$ and the Banach algebra $F^\\infty$ which can be viewed as non-commutative analogues of the Hardy spaces $H^2$ and $H^\\infty$ respectively. An inner-outer factorization for any element in ${\\Cal F}^2({\\Cal H}_n)$ as well as characterization of invertible elements in $F^\\infty$ are obtained. We also give a complete characterization of invariant subspaces for the left creation operators $S_1,...

Arias, Alvaro; Popescu, Gelu

1994-01-01

91

A note on local asymptotic behaviour for Brownian motion in Banach spaces  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper we obtain an integral characterization of a two-sided upper function for Brownian motion in a real separable Banach space. This characterization generalizes that of Jain and Taylor [2] where B=ℝn. The integral test obtained involves the index of a mean zero Gaussian measure on the Banach space, which is due to Kuelbs [3]. The special case that when B is itself a real separable Hilbert space is also illustrated.

Mou-Hsiung Chang

1979-12-01

92

Convergence Theorems for Asymptotically Nonexpansive Mappings in Banach Spaces  

Directory of Open Access Journals (Sweden)

Full Text Available Let E be a uniformly convex Banach space, and let K be a nonempty convex closed subset which is also a nonexpansive retract of E. Let T: K E be an asymptotically nonexpansive mapping with {kn} [1, such that ( from n=1 to (kn - 1 and let F(T be nonempty, where F(T denotes the fixed points set of T. Let{an}, {bn},{gn}, {an}, {bn}, {gn}, {an}, {bn}and {gn}be real sequences in [0, 1] such that an +bn +gn =an +bn +gn =an +bn +gn = 1 and e an,an, an 1 - e for all n N and some e > 0, starting with arbitrary x1 K,define the sequence { xn} by setting zn = P(anT(PTn-1xn+ bnxn+ gnwn, yn =P(anT(PTn-1zn+ bnxn+ gnvn, xn+1 =P(anT(PTn-1yn+ bnxn+ gnun,with the restrictions ( from n=1 to (gn ,( from n=1 to (gn and ( from n=1 to (gn where { wn} , { vn} and { un} are bounded sequences in K. (i If E is realuniformly convex Banach space satisfying Opial's condition, then weak convergence of { xn} to some p F(T is obtained; (ii If T satisfies condition (A, then { xn} convergence strongly to some p F(T.

Meijuan Shang

2008-03-01

93

Greedy Algorithms for Reduced Bases in Banach Spaces  

CERN Document Server

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 ...

DeVore, Ronald; Wojtaszczyk, Przemyslaw

2012-01-01

94

On second-order multivalued impulsive functional differential inclusions in Banach spaces  

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Full Text Available A fixed point theorem for condensing maps due to Martelli is used to investigate the existence of solutions to second-order impulsive initial value problem for functional differential inclusions in Banach spaces.

S. K. Ntouyas

2001-12-01

95

Existence of solutions for semilinear nonlocal Cauchy problems in Banach spaces  

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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.

Xingmei Xue

2005-06-01

96

Controllability of nonlinear differential evolution systems in a separable Banach space  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this article, we study the controllability of semilinear evolution differential systems with nonlocal initial conditions in a separable Banach space. The results are obtained by using Hausdorff measure of noncompactness and a new calculation method.

Bheeman Radhakrishnan; Krishnan Balachandran

2012-01-01

97

Strong convergence theorems for infinite families of nonexpansive mappings in general Banach spaces  

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Full Text Available In 1979, Ishikawa proved a strong convergence theorem for finite families of nonexpansive mappings in general Banach spaces. Motivated by Ishikawa's result, we prove strong convergence theorems for infinite families of nonexpansive mappings.

Suzuki Tomonari

2005-01-01

98

Strong convergence theorems for infinite families of nonexpansive mappings in general Banach spaces  

Directory of Open Access Journals (Sweden)

Full Text Available In 1979, Ishikawa proved a strong convergence theorem for finite families of nonexpansive mappings in general Banach spaces. Motivated by Ishikawa's result, we prove strong convergence theorems for infinite families of nonexpansive mappings.

Tomonari Suzuki

2005-04-01

99

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

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Full Text Available 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.

Yicheng Liu

2009-10-01

100

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.

 
 
 
 
101

On the complexity of the uniform homeomorphism relation between separable Banach spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We consider the problem of determining the complexity of the uniform homeomorphism relation between separable Banach spaces in the Borel reducibility hierarchy of analytic equivalence relations. We prove that the complete $K_{\\sigma}$ equivalence relation is Borel reducible to the uniform homeomorphism relation, and we also determine the possible complexities of the relation when restricted to some small classes of Banach spaces. Moreover, we determine the exact complexity o...

Gao, Su; Jackson, Steve; Sari, Bu?nyamin

2009-01-01

102

Strong convergence theorems for uniformly L-Lipschitzian mappings in Banach spaces  

International Nuclear Information System (INIS)

Let E be a real reflexive Banach space with uniform Gateaux differentiable norm, K be a nonempty bounded closed and convex subset of E , T : K ? K be a uniformly L-Lipschitzian mapping such that F (T) := {x element of K : Tx = x} ? 0, u element of K be fixed and let {?n}n?0 and {?n}n?0 subset of (0, 1) be such that limn?? ?n = 0 = limn? ? ?n and limn? ?(?n - 1)/ ?n = 0, where ?n ?j=0n ?j and ?j = 1 + ?j?jL. Let Sn := (1 - ?n?n)I + ?n?nTn. It is proved that there exists some integer N0 > 1, such that for each n ? N0, there exists unique xn element of K such that xn = ?nu+(1 -?n) 1/ (n + 1) ?j=0n Sjxn. If ? : E ? R is defined by ? (y) := LIMn vertical bar vertical bar xn -y vertical bar vertical bar2 for all y element of E here LIM denotes a Banach limit, vertical bar vertical bar xn - Txn vertical bar vertical bar ? 0 as n ? ? and Kmin intersection F (T) ? 0, where Kmin := {x element of E : ? (x) = min (u element of K) ? (u) }, then it is proved that {xn} converges strongly to a fixed point of T. As an application, it is proved that the iterative process, z0 element of K, zn+1 alpha#nu + (1 - ?n) 1/ (n + 1) ?j=0n Sjzn , n ? 0, under suitable conditions on the iteration parameters, converges strongly to a fixed point of T. (author)

103

Convergence on Composite Iterative Schemes for Nonexpansive Mappings in Banach Spaces  

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Full Text Available Let E be a reflexive Banach space with a uniformly Gâteaux differentiable norm. Suppose that every weakly compact convex subset of E has the fixed point property for nonexpansive mappings. Let C be a nonempty closed convex subset of E, f:C  →  C a contractive mapping (or a weakly contractive mapping, and T:C  →  C nonexpansive mapping with the fixed point set F(T  ≠  ∅. Let {xn} be generated by a new composite iterative scheme: yn=λnf(xn+(1−λnTxn, xn+1=(1−βnyn+βnTyn, (n≥0. It is proved that {xn} converges strongly to a point in F(T, which is a solution of certain variational inequality provided that the sequence {λn}⊂(0,1 satisfies limn→∞λn=0 and ∑n=1∞λn=∞, {βn}⊂[0,a for some 0

Jong Soo Jung

2008-05-01

104

Convergence to Common Fixed Point for Generalized Asymptotically Nonexpansive Semigroup in Banach Spaces  

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Full Text Available Let K be a nonempty closed convex subset of a reflexive and strictly convex Banach space E with a uniformly Gâteaux differentiable norm, ℱ={T(h:h≥0} a generalized asymptotically nonexpansive self-mapping semigroup of K, and f:K→K a fixed contractive mapping with contractive coefficient β∈(0,1. We prove that the following implicit and modified implicit viscosity iterative schemes {xn} defined by xn=αnf(xn+(1−αnT(tnxn and xn=αnyn+(1−αnT(tnxn, yn=βnf(xn−1+(1−βnxn−1 strongly converge to p∈F as n→∞ and p is the unique solution to the following variational inequality: 〈f(p−p,j(y−p〉≤0 for all y∈F.

Lei Deng

2008-12-01

105

\\theta-metric spaces and extension of Banach and Caristi's fixed point theorem  

CERN Document Server

In this paper, using a more generalized inequality instead of triangle inequality, the notion of \\theta-metric space is introduced. Some important properties of induced topology by such spaces are presented. Also, Banach and Caristi type fixed point in such spaces are proved.

Khojasteh, Farshid; Randenovic, Stojan

2011-01-01

106

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

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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.

P. K Harikrishnan

2011-12-01

107

Banach embedding properties of non-commutative $L^{p}$-spaces  

CERN Document Server

Let N and M be von Neumann algebras. It is proved that L^p(N) does not Banach embed in L^p(M) for N infinite, M finite, 1 < or = p < 2. The following considerably stronger result is obtained (which implies this, since the Schatten p-class C_p embeds in L^p(N) for N infinite). Theorem: Let 1 < or = p < 2 and let X be a Banach space with a spanning set (x_{ij}) so that for some C < or = 1: (i) any row or column is C-equivalent to the usual ell^2-basis; (ii) (x_{i_k,j_k}) is C-equivalent to the usual ell^p-basis, for any i_1 < i_2 < ... and j_1 < j_2 < ... . Then X is not isomorphic to a subspace of L^p(M), for M finite. Complements on the Banach space structure of non-commutative L^p-spaces are obtained, such as the p-Banach-Saks property and characterizations of subspaces of L^p(M) containing ell^p isomorphically. The spaces L^p(N) are classified up to Banach isomorphism, for N infinite-dimensional, hyperfinite and semifinite, 1 < or = p< infty, p not= 2. It is proved that ther...

Haagerup, U; Sukochev, F A

2000-01-01

108

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)

109

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english 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. [...

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

2013-12-01

110

Lower estimates of random unconditional constants of Walsh-Paley martingales with values in banach spaces  

CERN Document Server

For a Banach space X we define RUMD_n(X) to be the infimum of all c>0 such that (AVE_{\\epsilon_k =\\pm 1} || \\sum_1^n epsilon_k (M_k - M_{k-1} )||_{L_2^X}^2 )^{1/2} <= c || M_n ||_{L_2^X} holds for all Walsh-Paley martingales {M_k}_0^n subset L_2^X with M_0 =0. We relate the asymptotic behaviour of the sequence {RUMD(X)}_{n=1}^{infinity} to geometrical properties of the Banach space X such as K-convexity and superreflexivity.

Geiss, S

1992-01-01

111

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

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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.

Takahashi Wataru

2007-01-01

112

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)

113

FOREWORD: Tackling inverse problems in a Banach space environment: from theory to applications Tackling inverse problems in a Banach space environment: from theory to applications  

Science.gov (United States)

Inverse problems can usually be modelled as operator equations in infinite-dimensional spaces with a forward operator acting between Hilbert or Banach spacesa formulation which quite often also serves as the basis for defining and analyzing solution methods. The additional amount of structure and geometric interpretability provided by the concept of an inner product has rendered these methods amenable to a convergence analysis, a fact which has led to a rigorous and comprehensive study of regularization methods in Hilbert spaces over the last three decades. However, for numerous problems such as x-ray diffractometry, certain inverse scattering problems and a number of parameter identification problems in PDEs, the reasons for using a Hilbert space setting seem to be based on conventions rather than an appropriate and realistic model choice, so often a Banach space setting would be closer to reality. Furthermore, non-Hilbertian regularization and data fidelity terms incorporating a priori information on solution and noise, such as general Lp-norms, TV-type norms, or the Kullback-Leibler divergence, have recently become very popular. These facts have motivated intensive investigations on regularization methods in Banach spaces, a topic which has emerged as a highly active research field within the area of inverse problems. Meanwhile some of the most well-known regularization approaches, such as Tikhonov-type methods requiring the solution of extremal problems, and iterative ones like the Landweber method, the Gauss-Newton method, as well as the approximate inverse method, have been investigated for linear and nonlinear operator equations in Banach spaces. Convergence with rates has been proven and conditions on the solution smoothness and on the structure of nonlinearity have been formulated. Still, beyond the existing results a large number of challenging open questions have arisen, due to the more involved handling of general Banach spaces and the larger variety of concrete instances with special properties. The aim of this special section is to provide a forum for highly topical ongoing work in the area of regularization in Banach spaces, its numerics and its applications. Indeed, we have been lucky enough to obtain a number of excellent papers both from colleagues who have previously been contributing to this topic and from researchers entering the field due to its relevance in practical inverse problems. We would like to thank all contributers for enabling us to present a high quality collection of papers on topics ranging from various aspects of regularization via efficient numerical solution to applications in PDE models. We give a brief overview of the contributions included in this issue (here ordered alphabetically by first author). In their paper, Iterative regularization with general penalty termtheory and application to L1 and TV regularization, Radu Bot and Torsten Hein provide an extension of the Landweber iteration for linear operator equations in Banach space to general operators in place of the inverse duality mapping, which corresponds to the use of general regularization functionals in variational regularization. The L? topology in data space corresponds to the frequently occuring situation of uniformly distributed data noise. A numerically efficient solution of the resulting Tikhonov regularization problem via a Moreau-Yosida appriximation and a semismooth Newton method, along with a ?-free regularization parameter choice rule, is the topic of the paper L? fitting for inverse problems with uniform noise by Christian Clason. Extension of convergence rates results from classical source conditions to their generalization via variational inequalities with a priori and a posteriori stopping rules is the main contribution of the paper Regularization of linear ill-posed problems by the augmented Lagrangian method and variational inequalities by Klaus Frick and Markus Grasmair, again in the context of some iterative method. A powerful tool for proving convergence rates of Tikhonov type but also othe

Schuster, Thomas; Hofmann, Bernd; Kaltenbacher, Barbara

2012-10-01

114

On conditions for the strong law of large numbers in general Banach spaces  

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Full Text Available We give Chung-Teicher type conditions for the SLLN in general Banach spaces under the assumption that the weak law of large numbers holds. An example is provided showing that these conditions can hold when some earlier known conditions fail.

Dominik Szynal

2000-07-01

115

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

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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.

Michael Gil'

2013-06-01

116

On the rate of convergence of bootstrapped means in a Banach space  

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Full Text Available We establish the complete convergence for arrays of Banach space valued random elements. This result is applied to bootstrapped means of random elements to obtain their strong consistency and is derived in the spirit of Baum-Katz/Hsu-Robbins/Spitzer type convergence.

Andrei I. Volodin

2001-03-01

117

Fixed point iterations for quasi-contractive maps in uniformly smooth Banach spaces  

International Nuclear Information System (INIS)

Two well-known fixed point iteration methods are applied to approximate fixed points of quasi-contractive maps in real uniformly smooth Banach spaces. While our theorems generalize important known results, our method is of independent interest. (author). 25 refs

118

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

Energy Technology Data Exchange (ETDEWEB)

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.

Chang, Y.-K. [Department of Mathematics, Lanzhou Jiaotong University, Lanzhou, Gansu 730070 (China)], E-mail: lzchangyk@163.com; Anguraj, A. [Department of Mathematics, PSG College of Arts and Science, Coimbatore 641 014, Tamil Nadu (India)], E-mail: angurajpsg@yahoo.com; Mallika Arjunan, M. [Department of Mathematics, PSG College of Arts and Science, Coimbatore 641 014, Tamil Nadu (India)], E-mail: arjunphd07@yahoo.co.in

2009-02-28

119

Psi-exponential dichotomy for linear differential equations in a Banach space  

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Full Text Available In this article we extend the concept psi-exponential and psi-ordinary dichotomies for homogeneous linear differential equations in a Banach space. With these two concepts we prove the existence of psi-bounded solutions of the appropriate inhomogeneous equation. A roughness of the psi-dichotomy is also considered.

Atanaska Georgieva

2013-07-01

120

Mild Solutions for Nonlocal Impulsive Fractional Semilinear Differential Inclusions with Delay in Banach Spaces  

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Full Text Available In this paper, we give various existence results concerning the existence of mild solutions for nonlocal impulsive differential inclusions with delay and of fractional order in Caputo sense in Banach space. We consider the case when the values of the orient field are convex as well as nonconvex. Our obtained results improve and generalize many results proved in recent papers.

Ahmed Gamal Ibrahim

2013-07-01

 
 
 
 
121

Generic stability of the spectra for bounded linear operators on Banach spaces  

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Full Text Available In this paper, we study the stability of the spectra of bounded linear operators B(X in a Banach space X, and obtain that their spectra are stable on a dense residual subset of B(X.

Luo Qun

1999-01-01

122

ON EXPONENTIAL STABILITY OF VARIATIONAL NONAUTONOMOUS DIFFERENCE EQUATIONS IN BANACH SPACES  

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Full Text Available In this paper we study two concepts of exponential stability for vari-ational nonautonomous dierence equations in Banach spaces. Char-acterizations of these concepts are given. The obtained results can beconsidered as generalizations for variational nonautonomous dierenceequations of some well-known theorems due to Barbashin and Datko .

Mihail Megan

2012-07-01

123

Functional analysis an introduction to metric spaces, Hilbert spaces, and Banach algebras  

CERN Document Server

This textbook is an introduction to functional analysis suited to final year undergraduates or beginning graduates. Its various applications of Hilbert spaces, including least squares approximation, inverse problems, and Tikhonov regularization, should appeal not only to mathematicians interested in applications, but also to researchers in related fields. Functional Analysis adopts a self-contained approach to Banach spaces and operator theory that covers the main topics, based upon the classical sequence and function spaces and their operators. It assumes only a minimum of knowledge in elementary linear algebra and real analysis; the latter is redone in the light of metric spaces. It contains more than a thousand worked examples and exercises, which make up the main body of the book.

Muscat, Joseph

2014-01-01

124

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

125

Embedding operators and maximal regular differential-operator equations in Banach-valued function spaces  

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Full Text Available This study focuses on anisotropic Sobolev type spaces associated with Banach spaces , . Several conditions are found that ensure the continuity and compactness of embedding operators that are optimal regular in these spaces in terms of interpolations of and . In particular, the most regular class of interpolation spaces between , , depending of and order of spaces are found that mixed derivatives belong with values; the boundedness and compactness of differential operators from this space to -valued spaces are proved. These results are applied to partial differential-operator equations with parameters to obtain conditions that guarantee the maximal regularity uniformly with respect to these parameters.

Shakhmurov Veli B

2005-01-01

126

Domains of uniqueness for $C_0$-semigroups on the dual of a Banach space  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Let $({\\cal X},\\|\\:.\\:\\|)$ be a Banach space. In general, for a $C_0$-semigroup \\semi on $({\\cal X},\\|\\:.\\:\\|)$, its adjoint semigroup \\semia is no longer strongly continuous on the dual space $({\\cal X}^{*},\\|\\:.\\:\\|^{*})$. Consider on ${\\cal X}^{*}$ the topology of uniform convergence on compact subsets of $({\\cal X},\\|\\:.\\:\\|)$ denoted by ${\\cal C}({\\cal X}^{*},{\\cal X})$, for which the usual semigroups in literature becomes $C_0$-semigroups.\\\\ The main purpose of this paper is to prove th...

Lemle, Ludovic Dan

2008-01-01

127

A Hybrid Iterative Scheme for Equilibrium Problems, Variational Inequality Problems, and Fixed Point Problems in Banach Spaces  

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Full Text Available The purpose of this paper is to introduce a new hybrid projection algorithm for finding a common element of the set of solutions of the equilibrium problem and the set of the variational inequality for an inverse-strongly monotone operator and the set of fixed points of relatively quasi-nonexpansive mappings in a Banach space. Then we show a strong convergence theorem. Using this result, we obtain some applications in a Banach space.

Cholamjiak Prasit

2009-01-01

128

From Hahn-Banach to monotonicity  

CERN Document Server

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...

Simons, Stephen

2008-01-01

129

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

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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.

Kriengsak Wattanawitoon

2011-01-01

130

Maximal regular boundary value problems in Banach-valued weighted space  

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Full Text Available This study focuses on nonlocal boundary value problems for elliptic ordinary and partial differential-operator equations of arbitrary order, defined in Banach-valued function spaces. The region considered here has a varying bound and depends on a certain parameter. Several conditions are obtained that guarantee the maximal regularity and Fredholmness, estimates for the resolvent, and the completeness of the root elements of differential operators generated by the corresponding boundary value problems in Banach-valued weighted spaces. These results are applied to nonlocal boundary value problems for regular elliptic partial differential equations and systems of anisotropic partial differential equations on cylindrical domain to obtain the algebraic conditions that guarantee the same properties.

Bohner Martin

2005-01-01

131

Maximal regular boundary value problems in Banach-valued weighted space  

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Full Text Available This study focuses on nonlocal boundary value problems for elliptic ordinary and partial differential-operator equations of arbitrary order, defined in Banach-valued function spaces. The region considered here has a varying bound and depends on a certain parameter. Several conditions are obtained that guarantee the maximal regularity and Fredholmness, estimates for the resolvent, and the completeness of the root elements of differential operators generated by the corresponding boundary value problems in Banach-valued weighted Lp spaces. These results are applied to nonlocal boundary value problems for regular elliptic partial differential equations and systems of anisotropic partial differential equations on cylindrical domain to obtain the algebraic conditions that guarantee the same properties.

Veli B. Shakhmurov

2005-02-01

132

Inexact NewtonLandweber iteration for solving nonlinear inverse problems in Banach spaces  

International Nuclear Information System (INIS)

By making use of duality mappings, we formulate an inexact NewtonLandweber iteration method for solving nonlinear inverse problems in Banach spaces. The method consists of two components: an outer Newton iteration and an inner scheme providing the increments by applying the Landweber iteration in Banach spaces to the local linearized equations. It has the advantage of reducing computational work by computing more cheap steps in each inner scheme. We first prove a convergence result for the exact data case. When the data are given approximately, we terminate the method by a discrepancy principle and obtain a weak convergence result. Finally, we test the method by reporting some numerical simulations concerning the sparsity recovery and the noisy data containing outliers. (paper)

133

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

134

Uniform exponential stability of linear periodic systems in a Banach space  

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Full Text Available This article is devoted to the study of linear periodic dynamical systems, possessing the property of uniform exponential stability. It is proved that if the Cauchy operator of these systems possesses a certain compactness property, then the asymptotic stability implies the uniform exponential stability. We also show applications to different classes of linear evolution equations, such as ordinary linear differential equations in the space of Banach, retarded and neutral functional differential equations, some classes of evolution partial differential equations.

David N. Cheban

2001-01-01

135

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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.

Erzakova Nina A; Santana Sergio Falcon; Rgen, Appell J.; Th Martin, V.

2004-01-01

136

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

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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 .

Suzuki Tomonari

2006-01-01

137

On Exponential Stability for Skew-Evolution Semiflows on Banach Spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The paper emphasizes the property of stability for skew-evolution semiflows on Banach spaces, defined by means of evolution semiflows and evolution cocycles and which generalize the concept introduced by us in a previous paper. There are presented several general characterizations of this asymptotic property out of which can be deduced well known results of the stability theory. A unified treatment in the uniform and in the nonuniform setting is given. The main results are a...

Stoica, Codruta

2008-01-01

138

A degree theory for locally compact perturbations of Fredholm maps in Banach spaces  

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Full Text Available We present an integer valued degree theory for locally compact perturbations of Fredholm maps of index zero between (open sets in Banach spaces quasi-Fredholm maps, for short. The construction is based on the Brouwer degree theory and on the notion of orientation for nonlinear Fredholm maps given by the authors in some previous papers. The theory includes in a natural way the celebrated Leray-Schauder degree.

2006-01-01

139

Mann Type Implicit Iteration Approximation for Multivalued Mappings in Banach Spaces  

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Full Text Available Let K be a nonempty compact convex subset of a uniformly convex Banach space E and let T be a multivalued nonexpansive mapping. For the implicit iterates x0?K, xn=?nxn-1+(1-?nyn, yn?Txn, n?1. We proved that {xn} converges strongly to a fixed point of T under some suitable conditions. Our results extended corresponding ones and revised a gap in the work of Panyanak (2007.

Huimin He

2010-01-01

140

Convergence rates for the iteratively regularized GaussNewton method in Banach spaces  

International Nuclear Information System (INIS)

In this paper we consider the iteratively regularized GaussNewton method (IRGNM) in a Banach space setting and prove optimal convergence rates under approximate source conditions. These are related to the classical concept of source conditions that is available only in Hilbert space. We provide results in the framework of general index functions, which include, e.g. Hlder and logarithmic rates. Concerning the regularization parameters in each Newton step as well as the stopping index, we provide both a priori and a posteriori strategies, the latter being based on the discrepancy principle

 
 
 
 
141

On smooth extensions of vector-valued functions defined on closed subsets of Banach spaces  

CERN Document Server

Let $X$ and $Z$ be Banach spaces, $A$ a closed subset of $X$ and a mapping $f:A \\to Z$. We give necessary and sufficient conditions to obtain a $C^1$ smooth mapping $F:X \\to Z$ such that $F_{\\mid_A}=f$, when either (i) $X$ and $Z$ are Hilbert spaces and $X$ is separable, or (ii) $X^*$ is separable and $Z$ is an absolute Lipschitz retract, or (iii) $X=L_2$ and $Z=L_p$ with $1

Jimenez-Sevilla, M

2011-01-01

142

A forward-backward splitting algorithm for the minimization of non-smooth convex functionals in Banach space  

CERN Document Server

We consider the task of computing an approximate minimizer of the sum of a smooth and non-smooth convex functional, respectively, in Banach space. Motivated by the classical forward-backward splitting method for the subgradients in Hilbert space, we propose a generalization which involves the iterative solution of simpler subproblems. Descent and convergence properties of this new algorithm are studied. Furthermore, the results are applied to the minimization of Tikhonov-functionals associated with linear inverse problems and semi-norm penalization in Banach spaces. With the help of Bregman-Taylor-distance estimates, rates of convergence for the forward-backward splitting procedure are obtained. Examples which demonstrate the applicability are given, in particular, a generalization of the iterative soft-thresholding method by Daubechies, Defrise and De Mol to Banach spaces is presented.

Bredies, Kristian

2008-01-01

143

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

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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.

Elke Wolf

2010-01-01

144

Convergence theorems for a class of nonlinear maps in uniformly smooth Banach spaces  

International Nuclear Information System (INIS)

Let K be a nonempty closed and convex subset of a real uniformly smooth Banach space, E, with modulus of smoothness of power type q>1. Let T be a mapping of K into itself, T is an element of C (in the notion of Browder and Petryshyn; and Rhoades). It is proved that the Mann iteration process, under suitable conditions, converges strongly to the unique fixed point of T. If K is also bounded, then the Ishikawa iteration process converges to the fixed point of T. While our theorems generalize important known results, our method is also of independent interest. (author). 14 refs

145

Uniform exponential stability of linear almost periodic systems in Banach spaces  

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Full Text Available This article is devoted to the study linear non-autonomous dynamical systems possessing the property of uniform exponential stability. We prove that if the Cauchy operator of these systems possesses a certain compactness property, then the uniform asymptotic stability implies the uniform exponential stability. For recurrent (almost periodic systems this result is precised. We also show application for different classes of linear evolution equations: ordinary linear differential equations in a Banach space, retarded and neutral functional differential equations, and some classes of evolution partial differential equations.

David N. Cheban

2000-04-01

146

A theorem of Rolewicz's type for measurable evolution families in Banach spaces  

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Full Text Available Let $varphi$ be a positive and non-decreasing function defined on the real half-line and ${mathcal U}$ be a strongly measurable, exponentially bounded evolution family of bounded linear operators acting on a Banach space and satisfing a certain measurability condition as in Theorem 1 below. We prove that if $varphi$ and ${mathcal U}$ satisfy a certain integral condition (see the relation ef{0.1} from Theorem 1 below then ${mathcal U}$ is uniformly exponentially stable. For $varphi$ continuous and $mathcal U$ strongly continuous and exponentially bounded, this result is due to Rolewicz. The proofs uses the relatively recent techniques involving evolution semigroup theory.

Constantin Buse

2001-11-01

147

Bounded solutions of finite lifetime to differential equations in Banach spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Consider a smooth vector field $f\\colon \\mathbb{R}^n\\to\\mathbb{R}^n$ and a maximal solution $\\gamma\\colon \\,]a,b[\\,\\to \\mathbb{R}^n$ to the ordinary differential equation $x'=f(x)$. It is a well-known fact that, if $\\gamma$ is bounded, then $\\gamma$ is a global solution, i.e., $\\,]a,b[\\,=\\mathbb{R}$. We show by example that this conclusion becomes invalid if $\\mathbb{R}^n$ is replaced with an infinite-dimensional Banach space.

Dahmen, Rafael; Glockner, Helge

2014-01-01

148

Robustness of Mann Type Algorithm with Perturbed Mapping for Nonexpansive Mappings in Banach Spaces  

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Full Text Available The purpose of this paper is to study the robustness of Mann type algorithm in the sense that approximately perturbed mapping does not alter the convergence of Mann type algorithm. It is proven that Mann type algorithm with perturbed mapping xn+1=?nxn+(1??n(Txn+en??n?nF(xn remains convergent in a Banach space setting where ?n,?n?[0,1], T a nonexpansive mapping, en, n=0,1,, errors and F a strongly accretive and strictly pseudocontractive mapping.

L. C. Ceng

2010-01-01

149

A linear regularization scheme for inverse problems with unbounded linear operators on Banach spaces  

Science.gov (United States)

This paper extends the linear regularization scheme known as the approximate inverse to unbounded linear operators on Banach spaces. The principle of feature reconstruction is adapted from bounded operators to the unbounded scenario and, in addition, a new situation is examined where the data need to be pre-processed to fit into the mathematical model. In all these cases, invariance and regularization properties are surveyed and established for the example of fractional differentiation. Numerical results confirm the derived characteristics of the presented methods.

Kohr, Holger

2013-06-01

150

Approximating Common Fixed Points of Lipschitzian Semigroup in Smooth Banach Spaces  

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Full Text Available Abstract Let be a left amenable semigroup, let be a representation of as Lipschitzian mappings from a nonempty compact convex subset of a smooth Banach space into with a uniform Lipschitzian condition, let be a strongly left regular sequence of means defined on an -stable subspace of , let be a contraction on , and let , , and be sequences in (0, 1 such that , for all . Let , for all . Then, under suitable hypotheses on the constants, we show that converges strongly to some in , the set of common fixed points of , which is the unique solution of the variational inequality , for all .

Saeidi Shahram

2008-01-01

151

An analytic Koszul complex in a Banach space  

CERN Document Server

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 $f(x,y)=g(x,y)(x-y)$

Patyi, I

2005-01-01

152

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

153

On a local degree for a class of multi-valued vector fields in infinite dimensional Banach spaces  

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Full Text Available This paper is devoted to the development of a local degree for multi-valued vector fields of the form f−F. Here, f is a single-valued, proper, nonlinear, Fredholm, C1-mapping of index zero and F is a multi-valued upper semicontinuous, admissible, compact mapping with compact images. The mappings f and F are acting from a subset of a Banach space E into another Banach space E1. This local degree is used to investigate the existence of solutions of a certain class of operator inclusions.

N. M. Benkafadar

1996-01-01

154

Strong convergence theorems by a new hybrid method for equilibrium problems and relatively nonexpansive mappings in Banach spaces  

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In this paper, we introduce a new modified Ishikawa iteration for finding a common element of the set of solutions of an equilibrium problem and the set of fixed points of relatively nonexpansive mappings in a Banach space. Our results generalize, extend and enrich some existing results in the literature.

Alizadeh, Sattar; Moradlou, Fridoun

2014-01-01

155

Iterative Methods for Variational Inequalities over the Intersection of the Fixed Points Set of a Nonexpansive Semigroup in Banach Spaces  

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Full Text Available Abstract This paper presents a framework of iterative methods for finding specific common fixed points of a nonexpansive self-mappings semigroup in a Banach space. We prove, with appropriate conditions, the strong convergence to the solution of some variational inequalities.

Mohamadi Issa

2011-01-01

156

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

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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.

Constantin Buse

2003-02-01

157

Convergence rates for the iteratively regularized Gauss-Newton method in Banach spaces  

Science.gov (United States)

In this paper we consider the iteratively regularized Gauss-Newton method (IRGNM) in a Banach space setting and prove optimal convergence rates under approximate source conditions. These are related to the classical concept of source conditions that is available only in Hilbert space. We provide results in the framework of general index functions, which include, e.g. Hlder and logarithmic rates. Concerning the regularization parameters in each Newton step as well as the stopping index, we provide both a priori and a posteriori strategies, the latter being based on the discrepancy principle. Research has been partly conducted during the Mini Special Semester on Inverse Problems, 18 May-15 July 2009, organized by RICAM (Austrian Academy of Sciences), Linz, Austria, and moreover supported by Deutsche Forschungsgemeinschaft (DFG) under Grant HO1454/7-2 as well as within the Cluster of Excellence SimTech, University of Stuttgart.

Kaltenbacher, Barbara; Hofmann, Bernd

2010-03-01

158

Application of Pettis integration to differential inclusions with three-point boundary conditions in Banach spaces  

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Full Text Available This paper provide some applications of Pettis integration to differential inclusions in Banach spaces with three point boundary conditions of the form $$ ddot{u}(t in F(t,u(t,dot u(t+H(t,u(t,dot u(t,quad hbox{a.e. } t in [0,1], $$ where $F$ is a convex valued multifunction upper semicontinuous on $Eimes E$ and $H$ is a lower semicontinuous multifunction. The existence of solutions is obtained under the non convexity condition for the multifunction $H$, and the assumption that $F(t,x,ysubset Gamma_{1}(t$, $H(t,x,ysubset Gamma_{2}(t$, where the multifunctions $Gamma_{1},Gamma_{2}:[0,1] ightrightarrows E$ are uniformly Pettis integrable.

Imen Boutana

2007-12-01

159

Exponential stability of linear and almost periodic systems on Banach spaces  

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Full Text Available Let $v_f(cdot, 0$ the mild solution of the well-posed inhomogeneous Cauchy problem $$ dot v(t=A(tv(t+f(t, quad v(0=0quad tge 0 $$ on a complex Banach space $X$, where $A(cdot$ is an almost periodic (possible unbounded operator-valued function. We prove that $v_f(cdot, 0$ belongs to a suitable subspace of bounded and uniformly continuous functions if and only if for each $xin X$ the solution of the homogeneous Cauchy problem $$ dot u(t=A(tu(t, quad u(0=xquad tge 0 $$ is uniformly exponentially stable. Our approach is based on the spectral theory of evolution semigroups.

Constantin Buse

2003-12-01

160

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

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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.

Anna Kisiolek

2005-10-01

 
 
 
 
161

Improved bounds in the scaled Enflo type inequality for Banach spaces  

CERN Document Server

It is shown that if (X,||.||_X) is a Banach space with Rademacher type p \\ge 1, then for every integer n there exists an even integer m X, \\Avg_{x,\\e}[||f(x+ m\\e/2)-f(x)}||_X^p] < C(p,X) m^p\\sum_{j=1}^n\\Avg_x[||f(x+e_j)-f(x)||_X^p], where the expectation is with respect to uniformly chosen x \\in Z_m^n and \\e \\in \\{-1,1\\}^n, and C(p,X) is a constant that depends on p and the Rademacher type constant of X. This improves a bound of m < Cn^{3-2/p} that was obtained in [Mendel, Naor 2007]. The proof is based on an augmentation of the "smoothing and approximation" scheme, which was implicit in [Mendel, Naor 2007].

Giladi, Ohad

2010-01-01

162

Picard iterations for nonlinear Lipschitz strong pseudo-contractions in uniformly smooth Banach spaces  

International Nuclear Information System (INIS)

Suppose E is a real uniformly smooth Banach space and K is a nonempty closed convex and bounded subset of E, T:K ? K is a Lipschitz pseudo-contraction. It is proved that the Picard iterates of a suitably defined operator converges strongly to the unique fixed point of T. Furthermore, this result also holds for the slightly larger class of Lipschitz strong hemi-contractions. Related results deal with strong convergence of the Picard iterates to the unique solution of operator equations involving Lipschitz strongly accretive maps. Apart from establishing strong convergence, our theorems give existence, uniqueness and convergence-rate which is at least as fast as a geometric progression. (author). 51 refs

163

Convergence of hybrid steepest descent method for variational inequalities in Banach spaces  

International Nuclear Information System (INIS)

Let E be a real q-uniformly smooth Banach space with constant dq, q ? 2. Let T : E ? E and G : E ? E be a nonexpansive map and an ?-strongly accretive map which is also ? - Lipschitzian, respectively. Let {?n} be a real sequence in [0, 1] satisfying some appropriate conditions. For ? element of (0, ( q ?/dq ?q )q-1 ), define a sequence { xn} iteratively in E by x0 element of E, xn+1 = T?n+1 xn = Txn - ? ?n+1 G(Txn), n ? 0. Then, {xn} converges strongly to the unique solution x* of the variational inequality problem VI(G,K) (search for x* element of K such that q(y - x*)> ? 0 for all y element of K), where K := Fix(T) { x element of E : Tx = x} ? 0. A convergence theorem related to fi nite family of nonexpansive maps is also proved. (author)

164

Quasi-geostrophic equations with initial data in Banach spaces of local measures  

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Full Text Available This paper studies the well posedness of the initial value problem for the quasi-geostrophic type equations $$displaylines{ partial_{t}heta+u ablaheta+( -Delta ^{gamma}heta =0 quad hbox{on }mathbb{R}^{d}imes] 0,+infty[cr heta( x,0 =heta_{0}(x, quad xinmathbb{R}^{d} }$$ where 0 less than $gammaleq 1$ is a fixed parameter and the velocity field $u=(u_{1},u_{2},dots,u_{d} $ is divergence free; i.e., $ abla u=0$. The initial data $heta_{0}$ is taken in Banach spaces of local measures (see text for the definition, such as Multipliers, Lorentz and Morrey-Campanato spaces. We will focus on the subcritical case 1/2 less than $gammaleq1$ and we analyse the well-posedness of the system in three basic spaces: $L^{d/r,infty}$, $dot {X}_{r}$ and $dot {M}^{p,d/r}$, when the solution is global for sufficiently small initial data. Furtheremore, we prove that the solution is actually smooth. Mild solutions are obtained in several spaces with the right homogeneity to allow the existence of self-similar solutions.

Sadek Gala

2005-06-01

165

A maximal inequality for stochastic convolutions in 2-smooth Banach spaces  

CERN Document Server

Let (e^{tA})_{t \\geq 0} be a C_0-contraction semigroup on a 2-smooth Banach space E, let (W_t)_{t \\geq 0} be a cylindrical Brownian motion in a Hilbert space H, and let (g_t)_{t \\geq 0} be a progressively measurable process with values in the space \\gamma(H,E) of all \\gamma-radonifying operators from H to E. We prove that for all 0

van Neerven, Jan

2011-01-01

166

On the Stability of a Generalized Quadratic and Quartic Type Functional Equation in Quasi-Banach Spaces  

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Full Text Available We establish the general solution of the functional equation f(nx+y+f(nx?y=n2f(x+y+n2f(x?y+2(f(nx?n2f(x?2(n2?1f(y for fixed integers n with n?0,1 and investigate the generalized Hyers-Ulam stability of this equation in quasi-Banach spaces.

M. Eshaghi Gordji

2009-01-01

167

A Class of Semilocal E-Preinvex Maps in Banach Spaces with Applications to Nondifferentiable Vector Optimization  

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Full Text Available In this paper, a new class of semilocal E-preinvex and related maps in Banach spaces is introduced for a nondi?erentiable vector optimization problem with restrictions of inequalities and some of its basic properties are studied. Furthermore, as its applications, some optimality conditions and duality results are established for a nondi?erentiable vector optimization under the aforesaid maps assumptions.

Hehua Jiao

2014-01-01

168

Metatext Phenomenon: Mode of Irony in Reflexive-Interpretative Space  

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Full Text Available The article presents metatext and correlative interaction of irony in the reflexive-interpretative space of the literary text, clarifies the status of metatext space as linguo-cognitive activity of text producer. Irony serves as a system factor, forming metatext within the linguo-rhetoric script of text. Context plays special role in singling out of linguistic and discursive irony; multilevel character of irony is determined by context breadth, required for its decoding. The integrated nature of the information, represented in the text and metatext, actualizes implication of the literary text.

Anna V. Kuznetsova

2013-01-01

169

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

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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 C be a bounded closed convex subset of a uniformly smooth Banach space E. Let {Tn:n∈ℕ} be an infinite family of commuting nonexpansive mappings on C. Let {αn} and {tn} be sequences in (0,1/2 satisfying limntn=limnαn/tnℓ=0 for ℓ∈ℕ. Fix u∈C and define a sequence {un} in C by un=(1−αn((1−∑k=1ntnkT1un+∑k=1ntnkTk+1un+αnu for n∈ℕ. Then {un} converges strongly to Pu, where P is the unique sunny nonexpansive retraction from C onto ∩n=1∞F(Tn.

Tomonari Suzuki

2006-06-01

170

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

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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

Yonghong Yao

2006-04-01

171

Approximating fixed points of non-self asymptotically nonexpansive mappings in Banach spaces  

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Full Text Available Suppose K is a nonempty closed convex nonexpansive retract of a real uniformly convex Banach space E with P as a nonexpansive retraction. Let T:K?E be an asymptotically nonexpansive mapping with {kn}?[1,? such that ?n=1?(kn?10. Starting from arbitrary x1?K, define the sequence {xn} by x1?K, zn=P(?n''T(PTn?1xn+(1??n''xn, yn=P(?n'T(PTn?1zn+(1??n'xn, xn+1=P(?nT(PTn?1yn+(1??nxn. (i If the dual E* of E has the Kadec-Klee property, then { xn} converges weakly to a fixed point p?F(T; (ii if T satisfies condition (A, then {xn} converges strongly to a fixed point p?F(T.

Yongfu Su

2006-01-01

172

Modification of Otolith Reflex Asymmetries Following Space Flight  

Science.gov (United States)

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.

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

2011-01-01

173

Bundles of Banach algebras  

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Full Text Available We study bundles of Banach algebras π:A→X, where each fiber Ax=π−1({x} is a Banach algebra and X is a compact Hausdorff space. In the case where all fibers are commutative, we investigate how the Gelfand representation of the section space algebra Γ(π relates to the Gelfand representation of the fibers. In the general case, we investigate how adjoining an identity to the bundle π:A→X relates to the standard adjunction of identities to the fibers.

D. A. Robbins

1994-12-01

174

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

175

Some new results for Banach contractions and Edelstein contractive mappings on fuzzy metric spaces  

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The main purpose of this paper is to introduce a new class of Banach type fuzzy contractions and to present some fixed and common fixed point theorems for these mappings, as well as for the Edelstein fuzzy locally contractive mappings. Two examples are presented to show that our results are genuine generalizations of many known results.

Ciric, Ljubomir [Faculty of Mechanical Engineering, Kraljice Marije 16, 11 000 Belgrade (Serbia)], E-mail: lciric@afrodita.rcub.bg.ac.yu

2009-10-15

176

Some new results for Banach contractions and Edelstein contractive mappings on fuzzy metric spaces  

International Nuclear Information System (INIS)

The main purpose of this paper is to introduce a new class of Banach type fuzzy contractions and to present some fixed and common fixed point theorems for these mappings, as well as for the Edelstein fuzzy locally contractive mappings. Two examples are presented to show that our results are genuine generalizations of many known results.

177

Hybrid Methods for Equilibrium Problems and Fixed Points Problems of a Countable Family of Relatively Nonexpansive Mappings in Banach Spaces  

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Full Text Available The purpose of this paper is to introduce hybrid projection algorithms for finding a common element of the set of common fixed points of a countable family of relatively nonexpansive mappings and the set of solutions of an equilibrium problem in the framework of Banach spaces. Moreover, we apply our result to the problem of finding a common element of an equilibrium problem and the problem of finding a zero of a maximal monotone operator. Our result improve and extend the corresponding results announced by Takahashi and Zembayashi (2008 and 2009, and many others.

Plubtieng Somyot

2010-01-01

178

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

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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.

Narin Petrot

2009-01-01

179

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

Science.gov (United States)

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 Gauss-Newton 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.

Kaltenbacher, Barbara; Schpfer, Frank; Schuster, Thomas

2009-06-01

180

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

 
 
 
 
181

Nonlinear structure of some classical quasi-Banach spaces and -spaces  

Science.gov (United States)

We investigate the Lipschitz structure of lp and Lp for 0homeomorphic to any other Lp space, that the Lp spaces for 0spaces to their Lipschitz equivalence as metric spaces.

Albiac, F.

2008-04-01

182

Approximating common fixed points of two asymptotically quasi-nonexpansive mappings in Banach spaces  

Directory of Open Access Journals (Sweden)

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 {un},{vn}⊂[0,∞ such that ∑n=1∞un<∞ and ∑n=1∞vn<∞, and F=F(S∩F(T:={x∈K:Sx=Tx=x}≠∅. Suppose {xn} is generated iteratively by x1∈K,xn+1=(1−αnxn+αnSn[(1−βnxn+βnTnxn],n≥1 where {αn} and {βn} are real sequences in [0,1]. It is proved that (a {xn} converges strongly to some x∗∈F if and only if liminfn→∞d(xn,F=0; (b if X is uniformly convex and if either T or S is compact, then {xn} converges strongly to some x∗∈F. Furthermore, if X is uniformly convex, either T or S is compact and {xn} is generated by x1∈K,xn+1=αnxn+βnSn[α′nxn+β′nTnxn+γ′nz′n]+γnzn,n≥1, where {zn}, {z′n} are bounded, {αn},{βn},{γn},{α′n},{β′n},{γ′n} are real sequences in [0,1] such that αn+βn+γn=1=α′n+β′n+γ′n and {γn}, {γ′n} are summable; it is established that the sequence {xn} (with error member terms converges strongly to some x∗∈F.

Aniefiok Udomene

2006-02-01

183

Markov chains in smooth Banach spaces and Gromov hyperbolic metric spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A metric space $X$ has {\\em Markov type} 2, if for any reversible finite-state Markov chain $\\{Z_t\\}$ (with $Z_0$ chosen according to the stationary distribution) and any map $f$ from the state space to $X$, the distance $D_t$ from $f(Z_0)$ to $f(Z_t)$ satisfies $\\E(D_t^2) \\le K^2 t \\E(D_1^2)$ for some $K=K(X)<\\infty$. This notion is due to K. Ball (1992), who showed its importance for the Lipschitz extension problem. However until now, only Hilbert space (and its bi-Lipschi...

Naor, Assaf; Peres, Yuval; Schramm, Oded; Sheffield, Scott

2004-01-01

184

Limit theorems under the Maxwell-Woodroofe condition in Banach spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We prove that, for (adapted) stationary processes, the so-called Maxwell-Wood-roofe condition is sufficient for the law of the iterated logarithm and that it is optimal in some sense. We obtain a similar conclusion concerning the Marcinkiewicz-zygmund strong law of large numbers. Those results actually hold in the context of Banach valued stationary processes, including the case of $L^r$-valued random variables, with $1\\le r<\\infty$. In this setting we also prove the weak in...

Cuny, Christophe

2014-01-01

185

Positive solutions for Neumann boundary value problems of nonlinear second-order integro-differential equations in ordered Banach spaces  

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Full Text Available Abstract The paper deals with the existence of positive solutions for Neumann boundary value problems of nonlinear second-order integro-differential equations - u ? ( t + M u ( t = f ( t , u ( t , ( S u ( t , 0 < t < 1 , u ? ( 0 = u ? ( 1 = ? and u ? ( t + M u ( t = f ( t , u ( t , ( S u ( t , 0 < t < 1 , u ? ( 0 = u ? ( 1 = ? in an ordered Banach space E with positive cone K, where M > 0 is a constant, f : [0, 1] K K ? K is continuous, S : C([0, 1], K ? C([0, 1], K is a Fredholm integral operator with positive kernel. Under more general order conditions and measure of noncompactness conditions on the nonlinear term f, criteria on existence of positive solutions are obtained. The argument is based on the fixed point index theory of condensing mapping in cones. Mathematics Subject Classification (2000: 34B15; 34G20.

Liang Yue

2011-01-01

186

Weak and strong convergence theorems of a multistep iteration to a common fixed point of a family of nonself asymptotically nonexpansive mappings in banach spaces  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish En este artculo definimos un esquema de multi paso iterativo con errores que involucran una familia de aplicaciones no expansivas y no auto asintticamente en espacios deBanach. Una retraccin se ha usado en la construccin de la iteracin. Probamos convergencias dbiles y fuertes de las iteracione [...] s a puntos fijos clsicos de la familia de aplicaciones no expansivas no auto asintticamente. Hemos usado varios conceptos de geometra en espacios de Banach. Nuestro resultado mejora y extiende algunos resultados recientes. Abstract in english In this paper we have defined a multistep iterative scheme with errors involving a family of asymptotically nonexpansive nonself mappings in Banach spaces. A retraction has been used in the construction of theiteration. We prove here weak and strong convergences of the iteration to common fixed poin [...] ts of the family of asymptotically nonexpansive nonself mappings. We have used several concepts of Banach space geometry. Our results improve and extend some recent results.

Shrabani, Banerjee; Binayak S, Choudhury.

2012-10-01

187

Weak and strong convergence theorems of a multistep iteration to a common fixed point of a family of nonself asymptotically nonexpansive mappings in banach spaces  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish En este artculo definimos un esquema de multi paso iterativo con errores que involucran una familia de aplicaciones no expansivas y no auto asintticamente en espacios deBanach. Una retraccin se ha usado en la construccin de la iteracin. Probamos convergencias dbiles y fuertes de las iteracione [...] s a puntos fijos clsicos de la familia de aplicaciones no expansivas no auto asintticamente. Hemos usado varios conceptos de geometra en espacios de Banach. Nuestro resultado mejora y extiende algunos resultados recientes. Abstract in english In this paper we have defined a multistep iterative scheme with errors involving a family of asymptotically nonexpansive nonself mappings in Banach spaces. A retraction has been used in the construction of theiteration. We prove here weak and strong convergences of the iteration to common fixed poin [...] ts of the family of asymptotically nonexpansive nonself mappings. We have used several concepts of Banach space geometry. Our results improve and extend some recent results.

Shrabani, Banerjee; Binayak S, Choudhury.

188

Corrigendum to "Approximation by Cp-smooth, Lipschitz functions on Banach spaces" [J. Math. Anal. Appl. 315 (2006) 599-605  

Science.gov (United States)

In this erratum, we recover the results from an earlier paper of the author's which contained a gap. Specifically, we prove that if X is a Banach space with an unconditional basis and admits a C^{p}-smooth, Lipschitz bump function, and Y is a convex subset of X, then any uniformly continuous function f: Y->R can be uniformly approximated by Lipschitz, C^{p}-smooth functions K:X->R. Also, if Z is any Banach space and f:X->Z is L-Lipschitz, then the approximates K:X->Z can be chosen CL-Lipschitz and C^{p}-smooth, for some constant C depending only on X.

Fry, R.

2008-12-01

189

Corrigendum to "Approximation by C^{p}-smooth, Lipschitz functions on Banach spaces" [J. Math. Anal. Appl., 315 (2006), 599-605  

CERN Document Server

In this erratum, we recover the results from an earlier paper of the author's which contained a gap. Specifically, we prove that if X is a Banach space with an unconditional basis and admits a C^{p}-smooth, Lipschitz bump function, and Y is a convex subset of X, then any uniformly continuous function f: Y->R can be uniformly approximated by Lipschitz, C^{p}-smooth functions K:X->R. Also, if Z is any Banach space and f:X->Z is L-Lipschitz, then the approximates K:X->Z can be chosen CL-Lipschitz and C^{p}-smooth, for some constant C depending only on X.

Fry, R

2008-01-01

190

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

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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.

Raja P

2008-01-01

191

Moduli spaces of reflexive sheaves of rank 2  

CERN Document Server

Let \\sF be a coherent rank 2 sheaf on a scheme Y \\subset \\proj{n} of dimension at least two. In this paper we study the relationship between the functor which deforms a pair (\\sF,\\sigma), \\sigma \\in H^0(\\sF), and the functor which deforms the corresponding pair (X,\\xi) given as in the Serre correspondence. We prove that the scheme structure of e.g. the moduli scheme M_Y(P) of stable sheaves on a threefold Y at (\\sF), and the scheme structure at (X) of the Hilbert scheme of curves on Y are closely related. Using this relationship we get criteria for the dimension and smoothness of M_Y(P) at (\\sF), without assuming Ext^2(\\sF,\\sF) = 0. For reflexive sheaves on Y = \\proj{3} whose deficiency module M = H_{*}^1(\\sF) satisfies Ext^2(M,M) = 0 in degree zero (e.g. of diameter at most 2), we get necessary and sufficient conditions of unobstructedness which coincide in the diameter one case. The conditions are further equivalent to the vanishing of certain graded Betti numbers of the free graded minimal resolution of H_...

Kleppe, Jan O

2008-01-01

192

Frechet differential of a power series in Banach algebras  

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Full Text Available We present two new forms in which the Frechet differential of a power series in a unitary Banach algebra can be expressed in terms of absolutely convergent series involving the commutant $C(T : A \\rightarrow [A,T]$. 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.

Benedetto Silvestri

2010-01-01

193

ON OPERATOR IDEALS DEFINED BY A REFLEXIVE ORLICZ SEQUENCE SPACE  

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Full Text Available Classical theory of tensornorms and operator ideals studies mainlythose defined by means of sequence spaces ..p. Considering Orlicz sequence spaces as natural generalization of ..p spaces, in a previous paper [12] an Orlicz sequence space was used to define a tensornorm, and characterize minimal and maximal operator ideals associated, by using local techniques. Now, in this paper we give a new characterization of the maximal operator ideal to continue our analysis of some coincidences among such operator ideals. Finally we prove some new metric properties of tensornorm mentioned above

J LPEZ

2006-12-01

194

Connes amenability of the second dual of Arens regular Banach algebras  

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In this paper we study the Connes amenability of the second dual of Arens regular Banach algebras. Of course we provide a partial answer to the question posed by Volker Runde. Also we fined the necessary and sufficient conditions for the second dual of an Arens regular module extension Banach algebra to be Connes amenable when the module is reflexive.

Gordji, M. Eshaghi

2006-01-01

195

Proper Generalized Decomposition for Nonlinear Convex Problems in Tensor Banach Spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Tensor-based methods are receiving a growing interest in scientific computing for the numerical solution of problems defined in high dimensional tensor product spaces. A family of methods called Proper Generalized Decompositions methods have been recently introduced for the a priori construction of tensor approximations of the solution of such problems. In this paper, we give a mathematical analysis of a family of progressive and updated Proper Generalized Decompositions for...

Falco, Antonio; Nouy, Anthony

2011-01-01

196

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

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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.

J. M. Baker

1980-09-01

197

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

CERN Document Server

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.

Botelho, Fabio

2014-01-01

198

O Teorema de Banach- Tarski  

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Full Text Available We will present in this work the curious and provocative Banach-Tarski Theorem: subsets of the three-dimensional Euclidean space with non-empty interior is part congruent, that is, one subset can be rearranged by isometries of a ?nite number of parts of the other. The proof, here (a free translation from Karl Strombergs text, American Mathematical Monthly, 1979, is elegant and of elementary level, therefore accessible to the undergraduate student in Mathematics.

Luciano Panek

2004-11-01

199

The Automorphism Group of a Banach Principal Bundle with {1}-structure  

CERN Document Server

A {1}-structure on a Banach manifold M (with model space E) is an E-valued 1-form on M that induces on each tangent space an isomorphism onto E. Given a Banach principal bundle P with connected base space and a {1}-structure on P, we show that its automorphism group can be turned into a Banach-Lie group acting smoothly on P provided the Lie algebra of infinitesimal automorphisms consists of complete vector fields. As a consequence we show that the automorphism group of a connected geodesically complete affine Banach manifold M can be turned into a Banach-Lie group acting smoothly on M.

Klotz, Michael

2009-01-01

200

Sectional representation of Banach modules and their multipliers  

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Full Text Available Let X be a Banach module over the commutative Banach algebra A with maximal ideal space Δ. We show that there is a norm-decreasing representation of X as a space of bounded sections in a Banach bundle π:ℰ→Δ, whose fibers are quotient modules of X. There is also a representation of M(X, the space of multipliers T:A→X, as a space of sections in the same bundle, but this representation may not be continuous. These sectional representations subsume results of various authors over the past three decades.

D. A. Robbins

2003-02-01

 
 
 
 
201

Separating maps between commutative Banach algebras  

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Let $\\cal A$ and $\\cal B$ be Banach algebras. A linear map $T:{\\cal A} \\rightarrow {\\cal B}$ is called separating or disjointness preserving if $ab=0$ implies $Ta\\;Tb = 0$ for all $a,b\\in {\\cal A}$. In this paper, we study a new class of regular Tauberian algebras and prove that some well-known Banach algebras in harmonic analysis belong to this class. We show that a bijective separating map between these algebras turns out to be continuous and the maximal ideal spaces of un...

Alaghmandan, Mahmood; Nasr-isfahani, Rasoul; Nemati, Mehdi

2011-01-01

202

Lost in Transmission: Using Study Groups to Provide Space for Creativity and Reflexivity in an Instrumentalist University Environment  

Science.gov (United States)

Since independent study groups can be important in providing spaces for students in creative disciplines to develop a critically reflexive approach to their creative practice, tutors in an Australian university introduced independent group learning to students studying in creative disciplines. However, student responses to the experience of

Pearce, Jane; Crouch, Christopher

2010-01-01

203

Ultrametric Banach algebras  

CERN Document Server

In this book, ultrametric Banach algebras are studied with the help of topological considerations, properties from affinoid algebras, and circular filters which characterize absolute values on polynomials and make a nice tree structure. The Shilov boundary does exist for normed ultrametric algebras. In uniform Banach algebras, the spectral norm is equal to the supremum of all continuous multiplicative seminorms whose kernel is a maximal ideal. Two different such seminorms can have the same kernel. Krasner-Tate algebras are characterized among Krasner algebras, affinoid algebras, and ultrametri

Escassut, Alain

2003-01-01

204

On hypersurfaces in a locally affine Riemannian Banach manifold II  

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Full Text Available In our previous work (2002, we proved that an essential second-order hypersurface in an infinite-dimensional locally affine Riemannian Banach manifold is a Riemannian manifold of constant nonzero curvature. In this note, we prove the converse, in other words, we prove that a hypersurface of constant nonzero Riemannian curvature in a locally affine (flat semi-Riemannian Banach space is an essential hypersurface of second order.

Tarek F. Mersal

2004-01-01

205

Null-orbit reflexive operators  

CERN Document Server

We introduce and study the notion of null-orbit reflexivity, which is a slight perturbation of the notion of orbit-reflexivity. Positive results for orbit reflexivity and the recent notion of $\\mathbb{C}$-orbit reflexivity both extend to null-orbit reflexivity. Of the two known examples of operators that are not orbit-reflexive, one is null-orbit reflexive and the other is not. The class of null-orbit reflexive operators includes the classes of hyponormal, algebraic, compact, strictly block-upper (lower) triangular operators, and operators whose spectral radius is not 1. We also prove that every polynomially bounded operator on a Hilbert space is both orbit-reflexive and null-orbit reflexive.

Hadwin, Don; Yousefi, Hassan

2011-01-01

206

Moro reflex  

Science.gov (United States)

... of involuntary (without trying) response to stimulation. The Moro reflex is one of many reflexes that are ... and during well-child visits. To see the Moro reflex, the child will be placed face up ...

207

Module amenability for Banach modules  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish 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.

D, Ebrahimi Bagha; M, Amini.

208

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

209

Module extensions of dual Banach algebras  

CERN Document Server

In this paper we define the module extension dual Banach algebras and we use this Banach algebras to finding the relationship between $weak^*-$continuous homomorphisms of dual Banach algebras and Connes-amenability. So we study the $weak^*-$continuous derivations on module extension dual Banach algebras.

Gordji, M E; Rejali, A

2006-01-01

210

Strong convergence theorems for a common fixed point of a finite family of Bregman weak relativity nonexpansive mappings in reflexive Banach spaces.  

Science.gov (United States)

We introduce an iterative process for finding an element of a common fixed point of a finite family of Bregman weak relatively nonexpansive mappings. Our theorems improve and unify most of the results that have been proved for this important class of nonlinear operators. PMID:24757423

Zegeye, Habtu; Shahzad, Naseer

2014-01-01

211

Torsional vestibulo-ocular reflex measurements for identifying otolith asymmetries possibly related to space motion sickness susceptibility  

Science.gov (United States)

Recent studies by Diamond and Markham 1,2 have identified significant correlations between space motion sickness susceptibility and measures of disconjugate torsional eye movements recorded during parabolic flights. These results support an earlier proposal by von Baumgarten and Thmler 3 which hypothesized that an asymmetry of otolith function between the two ears is the cause of space motion sickness. It may be possible to devise experiments that can be performed in the 1 g environment on earth that could identify and quantify the presence of asymmetric otolith function. This paper summarizes the known physiological and anatomical properties of the otolith organs and the properties of the torsional vestibulo-ocular reflex which are relevant to the design of a stimulus to identify otolith asymmetries. A specific stimulus which takes advantage of these properties is proposed.

Peterka, Robert J.

212

Tensor products of abstract Besov spaces  

Directory of Open Access Journals (Sweden)

Full Text Available We prove the interpolation theorem for tensor products of abstract Besov spaces, associated with closed operators in Banach spaces and show its application to the problems of approximations of elements of tensor products of Banach spaces.

Dmytryshyn M.I.

2012-12-01

213

Additive Functional Inequalities in Banach Modules  

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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 in the spirit of the Th. M. Rassias stability approach. Moreover, these results are applied to investigate homomorphisms in complex Banach algebras and prove the generalized Hyers-Ulam stability of homomorphisms in complex Banach algebras.

An JongSu

2008-01-01

214

C-orbit reflexive operators  

CERN Document Server

We introduce the notion of C-orbit reflexivity and study its properties. An operator on a finite-dimensional space is C-orbit reflexive if and only if the two largest blocks in its Jordan form corresponding to nonzero eigenvalues with the largest modulus differ in size by at most one. Most of the proofs of our results in infinite dimensions are obtained from purely algebraic results we obtain from linear-algebraic analogs of C-orbit reflexivity.

Hadwin, Don; McHugh, Michael; Yousefi, Hassan

2010-01-01

215

Endomorphic Elements in Banach Algebras  

CERN Document Server

The use of the properties of actions on an algebra to enrich the study of the algebra is well-trodden and still fashionable. Here, the notion and study of endomorphic elements of (Banach) algebras are introduced. This study is initiated, in the hope that it will open up, further, the structure of (Banach) algebras in general, enrich the study of endomorphisms and provide examples. In particular, here, we use it to classify algebras for the convenience of our study. We also present results on the structure of some classes of endomorphic elements and bring out the contrast with idempotents.

Babalola, V A

2004-01-01

216

Splitting criterion for reflexive sheaves  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The purpose of this paper is to study the structure of reflexive sheaves over projective spaces through hyperplane sections. We give a criterion for a reflexive sheaf to split into a direct sum of line bundles. An application to the theory of free hyperplane arrangements is also given.

Abe, Takuro; Yoshinaga, Masahiko

2005-01-01

217

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)

218

Approximately -Jordan Homomorphisms on Banach Algebras  

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Full Text Available Let , and let be two rings. An additive map is called -Jordan homomorphism if for all . In this paper, we establish the Hyers-Ulam-Rassias stability of -Jordan homomorphisms on Banach algebras. Also we show that (a to each approximate 3-Jordan homomorphism from a Banach algebra into a semisimple commutative Banach algebra there corresponds a unique 3-ring homomorphism near to , (b to each approximate -Jordan homomorphism between two commutative Banach algebras there corresponds a unique -ring homomorphism near to for all .

Karimi T

2009-01-01

219

Reflex epilepsy.  

Science.gov (United States)

We report 3 cases of reflex epilepsy, 2 of them triggered by reading (reading epilepsy) and one by mathematical calculation (epilepsy arithmetics). Electroencephalographic abnormalities predominated in the dominant hemisphere. The pathophysiologic mechanisms involved in this rare form of epilepsy are commented on, particularly the role played by the association of mental concentration and emotional strain. A possible deficiency in GABA-ergic inhibitory synapses would cause a deficit in cortical inhibition. Different drugs have been used successfully in patients with reflex epilepsy. Psychotherapy relieves anxiety and has been shown to be an effective complement to medical treatment. PMID:1320525

Espadaler Medina, J M; Espadaler Gamissans, J M; Seoane, J L

1992-01-01

220

Stability of multipliers on Banach algebras  

Directory of Open Access Journals (Sweden)

Full Text Available Suppose A is a Banach algebra without order. We show that an approximate multiplier T:A→A is an exact multiplier. We also consider an approximate multiplier T on a Banach algebra which need not be without order. If, in addition, T is approximately additive, then we prove the Hyers-Ulam-Rassias stability of T.

Sin-Ei Takahasi

2004-09-01

 
 
 
 
221

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Ricceri, Biagio

2013-01-01

222

Banach-Stone Theorems for maps preserving common zeros  

CERN Document Server

Let $X$ and $Y$ be completely regular spaces and $E$ and $F$ be Hausdorff topological vector spaces. We call a linear map $T$ from a subspace of $C(X,E)$ into $C(Y,F)$ a \\emph{Banach-Stone map} if it has the form $Tf(y) = S_{y}(f(h(y))$ for a family of linear operators $S_{y} : E \\to F$, $y \\in Y$, and a function $h: Y \\to X$. In this paper, we consider maps having the property: \\cap^{k}_{i=1}Z(f_{i}) \

Leung, Denny H

2009-01-01

223

Vestibular-Ocular Reflex  

Science.gov (United States)

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.

Marlene Y. Macleish, Ed D.; Bernice R. Mclean, M. E.

2013-01-30

224

Baroreceptor Reflex Role Play  

Science.gov (United States)

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.

Macleish, Marlene Y.; Mclean, Bernice R.

2012-06-26

225

Dunford-Pettis sets in Banach lattices  

Directory of Open Access Journals (Sweden)

Full Text Available We study the class of Dunford-Pettis sets in Banach lattices. In particular, we establish some sufficient conditions for which a Dunford-Pettis set is relatively weakly compact (resp. relatively compact

B. Aqzzouz

2012-09-01

226

On the last question of Stefan Banach  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We discuss the last question of Banach, posed by him shortly before his death, about extension of a ternary operation to superposition of a binary one. We try to put things into the context of Polish mathematics of that time.

Zusmanovich, Pasha

2014-01-01

227

Tensor products of commutative Banach algebras  

Directory of Open Access Journals (Sweden)

Full Text Available Let A1, A2 be commutative semisimple Banach algebras and A1⊗∂A2 be their projective tensor product. We prove that, if A1⊗∂A2 is a group algebra (measure algebra of a locally compact abelian group, then so are A1 and A2. As a consequence, we prove that, if G is a locally compact abelian group and A is a comutative semi-simple Banach algebra, then the Banach algebra L1(G,A of A-valued Bochner integrable functions on G is a group algebra if and only if A is a group algebra. Furthermore, if A has the Radon-Nikodym property, then the Banach algebra M(G,A of A-valued regular Borel measures of bounded variation on G is a measure algebra only if A is a measure algebra.

Shobha Madan

1982-09-01

228

The forth duals of Banach algebras  

CERN Document Server

Let $\\cal A$ be a Banach algebra. Then $\\cal A^{**}$ the second dual of $\\cal A$ is a Banach algebra with first (second) Arens product. We study the Arens products of $\\cal A^{4}(=({\\cal A^{**}})^{**}).$ We fined some conditions on $\\cal A^{**}$ to be a left ideal in $\\cal A^{4}.$ We fined the biggest two sided ideal $I$ of ${\\cal A},$ in which $I$ is a left (right) ideal of ${\\cal A}^{**}$.

Gordji, M E

2006-01-01

229

An elementary approach to a lattice-valued Banach-Stone Theorem  

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Full Text Available Let $ X $ and $ Y $ be compact Hausdorff spaces, and $ E $ be a nonzero real Banach lattice. In this note, we give an elementary proof of a lattice-valued Banach-Stone theorem by Cao, Reilly and Xiong [3] which asserts that if there exists a Riesz isomorphism $ \\Phi: C(X,E\\rightarrow C(Y,\\mathbb{R} $ such that $ \\Phi(f $ has no zeros if $ f $ has none, then $ X $ is homeomorphic to $ Y $ and $ E $ is Riesz isomorphic to $ \\mathbb{R} $.

Jinxi Chen

2007-09-01

230

Isometries and Isomorphisms in quasi-Banach algebras  

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Full Text Available In this paper, we prove the Hyers-Ulam-Rassias stability of isometries and of homomorphisms for additive functional equations in quasi-Banach algebras. This is applied to investigate isomorphisms between quasi-Banach algebras.

Zhihua Wang

2011-09-01

231

On the Cauchy Functional Inequality in Banach Modules  

Directory of Open Access Journals (Sweden)

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.

Park Choonkil

2008-01-01

232

An extension of Helson-Edwards theorem to Banach Modules  

Directory of Open Access Journals (Sweden)

Full Text Available An extension of the Helson-Edwards theorem for the group algebras to Banach modules over commutative Banach algebras is given. This extension can be viewed as a generalization of Liu-Rooij-Wang's result for Banach modules over the group algebras.

Sin-Ei Takahasi

1991-06-01

233

On Reflection: Is Reflexivity Necessarily Beneficial in Intercultural Education?  

Science.gov (United States)

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

Blasco, Maribel

2012-01-01

234

The Banach algebra of continuous bounded functions with separable support  

CERN Document Server

We prove a Gelfand Representation type of theorem, by showing that the set $C_s(X)$ of continuous bounded (real or complex valued) functions with separable support on a locally separable metrizable space $X$ (provided with the supremum norm) is a Banach algebra, isometrically isomorphic to $C_0(Y)$, for some unique (up to homeomorphism) locally compact Hausdorff space $Y$. The space $Y$, which we explicitly construct as a subspace of the Stone-\\v{C}ech compactification of $X$, is countably compact, and if $X$ is non--separable, is moreover non--normal; in addition $C_0(Y)=C_{00}(Y)$. When the underlying field of scalars is the complex numbers, the space $Y$ coincides with the spectrum of the ${C}^*$--algebra $C_s(X)$. Further, we find the dimension of the algebra $C_s(X)$.

Koushesh, M R

2012-01-01

235

Regularity of difference equations on Banach spaces  

CERN Document Server

This work introduces readers to the topic of maximal regularity for difference equations. The authors systematically present the method of maximal regularity, outlining basic linear difference equations along with relevant results. They address recent advances in the field, as well as basic semigroup and cosine operator theories in the discrete setting. The authors also identify some open problems that readers may wish to take up for further research. This book is intended for graduate students and researchers in the area of difference equations, particularly those with advance knowledge of and interest in functional analysis.

Agarwal, Ravi P; Lizama, Carlos

2014-01-01

236

Banach representations and affine compactifications of dynamical systems  

CERN Document Server

To every Banach space V we associate a compact right topological affine semigroup E(V). We show that a separable Banach space V is Asplund if and only if E(V) is metrizable, and it is Rosenthal (i.e. it does not contain an isomorphic copy of $l_1$) if and only if E(V) is a Rosenthal compactum. We study representations of compact right topological semigroups in E(V). In particular, representations of tame and HNS-semigroups arise naturally as enveloping semigroups of tame and HNS (hereditarily non-sensitive) dynamical systems, respectively. As an application we obtain a generalization of a theorem of R. Ellis. A main theme of our investigation is the relationship between the enveloping semigroup of a dynamical system X and the enveloping semigroup of its various affine compactifications Q(X). When the two coincide we say that the affine compactification Q(X) is E-compatible. This is a refinement of the notion of injectivity. We show that distal non-equicontinuous systems do not admit any E-compatible compactif...

Glasner, Eli

2012-01-01

237

Derivations in the Banach ideals of $\\tau$-compact operators  

CERN Document Server

Let $\\mathcal{M}$ be a von Neumann algebra equipped with a faithful normal semi-finite trace $\\tau$ and let $S_0(\\tau)$ be the algebra of all $\\tau$-compact operators affiliated with $\\mathcal{M}$. Let $E(\\tau)\\subseteq S_0(\\tau)$ be a symmetric operator space (on $\\mathcal{M}$) and let $\\mathcal{E}$ be a symmetrically-normed Banach ideal of $\\tau$-compact operators in $\\mathcal{M}$. We study (i) derivations $\\delta$ on $\\mathcal{M}$ with the range in $E(\\tau)$ and (ii) derivations on the Banach algebra $\\mathcal{E}$. In the first case our main results assert that such derivations are continuous (with respect to the norm topologies) and also inner (under some mild assumptions on $E(\\tau)$). In the second case we show that any such derivation is necessarily inner when $\\mathcal{M}$ is a type $I$ factor. As an interesting application of our results for the case (i) we deduce that any derivation from $\\mathcal{M}$ into an $L_p$-space, $L_p(\\mathcal{M},\\tau)$, ($1

Ber, A F

2012-01-01

238

ON UNICYCLIC REFLEXIVE GRAPHS  

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Full Text Available A simple graph is said to be reflexive if the second largest eigenvalue of its (0, 1-adjacency matrix does not exceed 2. Based on some recent results on reflexive graphs with more cycles and some new observations, we construct in this paper several classes of maximal unicyclic reflexive graphs.

Zoran Radosavljevi?

2007-04-01

239

A G.N.S.-type theorem for a non-involutive Banach algebra  

International Nuclear Information System (INIS)

Given an involutive Banach algebra A with a bounded approximate identity, the elegant construction by Gelfand, Naimark and Segal, associates to each positive linear functional f on A, a triple (Hf, ?f, ?f), where Hf is a Hilbert space with scalar product denoted by: , ?f is a representation of A into L(Hf), the space of bounded linear operators on Hf, ?f is a cyclic vector in Hf, such that: f(x)=f(x)?f, ?f >, for all x is an element of A. In this result, the existence of a (multiplicative) involution on A, is central. The aim of this paper is to show that such a construction may be performed for a non-involutive Banach algebra, to obtain a similar triple (H, ?, ?) as above. Moreover, this procedure indeed enables us to associate to the topological dual of any Banach space, a liminary C*-subalgebra of L(H). A notion of compact Hilbert algebras will be introduced, together with a method of construction of a large collection of such spaces. (author). 14 refs

240

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

CERN Document Server

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.

Beaver, S

2004-01-01

 
 
 
 
241

Emotionally Colorful Reflexive Games  

CERN Document Server

This study addresses the matter of reflexive control of the emotional states by means of Reflexive Game Theory (RGT). It is shown how to build a bridge between RGT and emotions. For this purpose the Pleasure-Arousal-Dominance (PAD) model is adopted. The major advantages of RGT are its ability to predict human behavior and unfold the entire spectra of reflexion in the human mind. On the other hand, PAD provides ultimate approach to model emotions. It is illustrated that emotions are reflexive processes and, consequently, RGT fused with PAD model is natural solution to model emotional interactions between people. The fusion of RGT and PAD, called Emotional Reflexive Games (ERG), inherits the key features of both components. Using ERG, we show how reflexive control can be successfully applied to model human emotional states. Up to date, EGR is a unique methodology capable of modeling human reflexive processes and emotional aspects simultaneously.

Tarasenko, Sergey

2011-01-01

242

Approximate weak amenability of Banach algebras  

CERN Document Server

In this paper we deal with three generalized notions of amenability, approximate, approximate weak and approximate n-weak amenability. The first two were introduced and studied by Ghahramani and Loy in [5]. We introduce the third one. Then we investigate some properties of Banach algebras in each of these classes. Also we consider approximate weak amenability and approximate n-weak amenability of second duals.

Esslamzadeh, G H

2009-01-01

243

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Gordji, M. Eshaghi

2006-01-01

244

Supersets for the spectrum of elements in extended Banach algebras  

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Full Text Available If A is a Banach Algebra with or without an identity, A can be always extended to a Banach algebra A¯ with identity, where A¯ is simply the direct sum of A and C, the algebra of complex numbers. In this note we find supersets for the spectrum of elements of A¯.

Morteza Seddighin

1989-09-01

245

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

CERN Document Server

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.

Gordji, M E

2006-01-01

246

Slanted matrices, Banach frames, and sampling  

CERN Document Server

In this paper we present a rare combination of abstract results on the spectral properties of slanted matrices and some of their very specific applications to frame theory and sampling problems. We show that for a large class of slanted matrices boundedness below of the corresponding operator in $\\ell^p$ for some $p$ implies boundedness below in $\\ell^p$ for all $p$. We use the established resultto enrich our understanding of Banach frames and obtain new results for irregular sampling problems. We also present a version of a non-commutative Wiener's lemma for slanted matrices.

Aldroubi, A; Krishtal, I

2007-01-01

247

Stable reflexive sheaves and localization  

CERN Document Server

We study moduli spaces $\\N$ of rank 2 stable reflexive sheaves on $\\PP^3$. Fixing Chern classes $c_1$, $c_2$, and summing over $c_3$, we consider the generating function $G^{refl}(q)$ of Euler characteristics of such moduli spaces. The action of the dense open torus $T$ on $\\PP^3$ lifts to $\\N$ and we classify all sheaves in $\\N^T$. This leads to an explicit expression for $G^{refl}(q)$. Since $c_3$ is bounded below and above, $G^{refl}(q)$ is a polynomial. For $c_1=-1$, we show its leading term is $12c_2 q^{c_{2}^{2}}$. Next, we study moduli spaces of rank 2 stable torsion free sheaves on $\\PP^3$ and consider the generating function $G(q)$ of Euler characteristics of such moduli spaces. We give an expression for this generating function in terms of $G^{refl}(q)$ and Euler characteristics of Quot schemes of certain $T$-equivariant reflexive sheaves. These Quot schemes and their fixed point loci are studied in a sequel with B. Young. The components of these fixed point loci are products of $\\PP^1$'s and give r...

Gholampour, Amin

2013-01-01

248

R-Orbit Reflexive Operators  

CERN Document Server

We completely characterize orbit reflexivity and R-orbit reflexivity for square matrices over the real numbers. Unlike the complex case in which every matrix is orbit reflexive and C-orbit reflexivity is characterized solely in terms of the Jordan form, the orbit reflexivity and R-orbit reflexivity of a real matrix is described in terms of the linear dependence over Q of certain elements of R/Q. We also show that every n-by-n matrix over an uncountable field F is algebraically F-orbit reflexive.

Hadwin, Don; Yousefi, Hassan

2011-01-01

249

Ideal amenability of Banach algebras on locally compact groups  

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In this paper we study the ideal amenability of Banach algebras. Let $\\cal A$ be a Banach algebra and let $I$ be a closed two-sided ideal in $\\cal A$, $\\cal A$ is $I$-weakly amenable if $H^{1}({\\cal A},I^*)=\\{0\\}$. Further, $\\cal A$ is ideally amenable if $\\cal A$ is $I$-weakly amenable for every closed two-sided ideal $I$ in $\\cal A$. We know that a continuous homomorphic image of an amenable Banach algebra is again amenable. We show that for ideal amenability the homomorph...

Gordji, M. Eshaghi; Hosseiniun, S. A. R.

2005-01-01

250

A Banach algebraic Approach to the Borsuk-Ulam Theorem  

CERN Document Server

Using methods from the theory of commutative graded Banach algebras, we obtain a generalization of the two dimensional Borsuk-Ulam theorem as follows: Let $\\phi:S^{2} \\rightarrow S^{2}$ be a homeomorphism of order n and $\\lambda\

Taghavi, Ali

2011-01-01

251

Topological radicals, IV. Frattini theory for Banach Lie algebras  

CERN Document Server

The paper develops the theory of topological radicals of Banach Lie algebras and studies the structure of Banach Lie algebras with sufficiently many Lie subalgebras of finite codimensions -- the intersection of all these subalgebras is zero. It is shown that the intersections of certain families of Lie subalgebras (closed Lie subalgebras of finite codimension, closed Lie ideals of finite codimension, closed maximal Lie subalgebras of finite codimension, closed maximal Lie ideals of finite codimension) correspond to different preradicals, and that these preradicals generate the same radical, the Frattini radical. The main attention is given to structural properties of Frattini-semisimple Banach Lie algebras and, in particular, to a new infinite-dimensional phenomenon associated with the strong Frattini preradical introduced in this paper. A constructive description of Frattini-free Banach Lie algebras is obtained.

Kissin, Edward; Turovskii, Yurii

2012-01-01

252

Ideal amenability of Banach algebras on locally compact groups  

CERN Document Server

In this paper we study the ideal amenability of Banach algebras. Let $\\cal A$ be a Banach algebra and let $I$ be a closed two-sided ideal in $\\cal A$, $\\cal A$ is $I$-weakly amenable if $H^{1}({\\cal A},I^*)=\\{0\\}$. Further, $\\cal A$ is ideally amenable if $\\cal A$ is $I$-weakly amenable for every closed two-sided ideal $I$ in $\\cal A$. We know that a continuous homomorphic image of an amenable Banach algebra is again amenable. We show that for ideal amenability the homomorphism property for suitable direct summands is true similar to weak amenability and we apply this result for ideal amenability of Banach algebras on locally compact groups.

Gordji, M E

2005-01-01

253

On the Cauchy Functional Inequality in Banach Modules  

Directory of Open Access Journals (Sweden)

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.

Choonkil Park

2008-05-01

254

Riemann-Stieltjes Operators between Vector-Valued Weighted Bloch Spaces  

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Full Text Available Abstract Let be a Banach space, we study Riemann-Stieltjes operators between -valued weighted Bloch spaces. Some necessary and sufficient conditions for these operators induced by holomorphic functions to be weakly compact and weakly conditionally compact are given by certain growth properties of the inducing symbols and some structural properties of the abstract Banach space, which extend some previous results.

Wang Maofa

2008-01-01

255

Derivations into n-th duals of ideals of Banach algebras  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We introduce two notions of amenability for a Banach algebra $\\cal A$. Let $n\\in \\Bbb N$ and let $I$ be a closed two-sided ideal in $\\cal A$, $\\cal A$ is $n-I-$weakly amenable if the first cohomology group of $\\cal A$ with coefficients in the n-th dual space $I^{(n)}$ is zero; i.e., $H^1({\\cal A},I^{(n)})=\\{0\\}$. Further, $\\cal A$ is n-ideally amenable if $\\cal A$ is $n-I-$weakly amenable for every closed two-sided ideal $I$ in $\\cal A$. We find some relationships of $n-I-$ ...

Gordji, M. Eshaghi; Memarbashi, R.

2006-01-01

256

On Reflection : Is Reflexivity Necessarily Beneficial in Intercultural Education?  

DEFF Research Database (Denmark)

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.

Blasco, Maribel

2012-01-01

257

Continuous linear maps on reflexive algebras behaving like Jordan left derivations at idempotent-product elements  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Let $\\A$ be a Banach algebra with unity $\\textbf{1}$ and $ \\M $ be a unital Banach left $ \\A $-module. let $ \\delta: \\A \\rightarrow \\M$ be a continuous linear map with the property that \\[ a,b\\in \\A, \\quad ab+ba=z \\Rightarrow 2a\\delta(b)+2b\\delta(a)=\\delta(z), \\] where $z\\in \\A$. In this article, first we characterize $\\delta$ for $z=\\textbf{1}$. Then we consider the case $\\A=\\M=Alg \\mathcal{L}$, where $Alg \\mathcal{L}$ is areflexive algebra on a Hilbert space $ \\Hh $ and $z...

Fadaee, B.; Ghahramani, H.

2013-01-01

258

On Multi-Metric Spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A Smarandache multi-space is a union of n spaces with someadditional conditions holding. Combining Smarandache multi-spaces with classical metricspaces, the conception of multi-metric spaces is introduced. Some characteristics of multi- metric spaces are obtained and the Banach's fixed-point theorem is generalized in this paper.

Mao, Linfan

2006-01-01

259

Reflexive sig is an argument  

Directory of Open Access Journals (Sweden)

Full Text Available This paper argues that the simple reflexive pronoun sig is unambiguously a thematic argument in Icelandic. This is shown to be true not only of sig with naturally reflexive verbs but also of inherently reflexive sig. This view is mainly supported by two sets of facts: (i that sig is impossible with verbs that fail to theta-mark their object (middles and anticausatives, and (ii that case assignment works the same way for sig as for non- reflexive DP arguments. Potential counterarguments against my view involving focalization and reflexive passives are argued not to be valid.

Jhannes Gsli Jnsson

2011-10-01

260

Spinal reflexes in brain death.  

Science.gov (United States)

Spontaneous and reflex movements have been described in brain death and these unusual movements might cause uncertainties in diagnosis. In this study we evaluated the presence of spinal reflexes in patients who fulfilled the criteria for brain death. Thirty-two (22%) of 144 patients presented unexpected motor movements spontaneously or during examinations. These patients exhibited the following signs: undulating toe, increased deep tendon reflexes, plantar responses, Lazarus sign, flexion-withdrawal reflex, facial myokymia, neck-arm flexion, finger jerks and fasciculations. In comparison, there were no significant differences in age, sex, etiology of brain death and hemodynamic laboratory findings in patients with and without reflex motor movement. Spinal reflexes should be well recognized by physicians and it should be born in mind that brain death can be determined in the presence of spinal reflexes. PMID:24604683

Beckmann, Yesim; Cifti, Yeliz; Incesu, Tlay Kurt; Seil, Yaprak; Akhan, Galip

2014-12-01

 
 
 
 
261

A characterization of Hilbert spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Delbosco, Domenico

2005-01-01

262

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

CERN Document Server

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...

Poineau, Jrme

2012-01-01

263

Photosensitivity and Reflex Epilepsies  

Directory of Open Access Journals (Sweden)

Full Text Available Reflex epilepsies (RE objectively and consistently provoked by specific external or internal stimuli are important clues for investigating complex mechanisms of epileptogenesis. RE have many intriguing subtypes depending on the trigger. Visually-sensitive epilepsies or photosensitive epilepsies are genetically determined and constitute the major part of RE but their diversity is even huge both clinically and electrophysiologically. Reflex seizures can occur in both focal and generalized epilepsy syndromes and can also be associated with spontaneous seizures. Afferent external stimuli can be: elementary or elaborate, structured and complex. Moreover, triggering activity may also be elementary (motor movement or elaborate (reading, chess playing, or both (reading aloud. Complex forms of RE pose many different questions and there are reported cases with various symptomatic etiologies indicating some acquired factors besides genetics. This review will focus on the current understanding of RE and its pathogenetic implications.

Leyla Baysal

2014-06-01

264

Emergence and Reflexive Downward  

Directory of Open Access Journals (Sweden)

Full Text Available This paper responds to Jaegwon Kim's powerful objection to the very possibility of genuinely novel emergent properties Kim argue that the incoherence of reflexive downward causation means that the causal power of an emergent phenomenon is ultimately reducible to the causal powers of its constituents. I offer a a simple argument showing how to characterize emergent properties m terms of the effects of structural relations an the causal powers of that constituents.

John Symons

2002-06-01

265

Analytic Mappings Between LB-spaces and Applications in Infinite-Dimensional Lie Theory  

CERN Document Server

We give a sufficient criterion for complex analyticity of nonlinear maps defined on direct limits of normed spaces. This tool is then used to construct new classes of (real and complex) infinite dimensional Lie groups: (a) groups of germs of analytic diffeomorphisms around a compact set in a Banach space and (b) unions of ascending sequences of Banach Lie groups.

Dahmen, Rafael

2008-01-01

266

The Socle and finite dimensionality of some Banach algebras  

CERN Document Server

The purpose of this note is to describe some algebraic conditions on a Banach algebra which force it to be finite dimensional. One of the main results in Theorem~2 which states that for a locally compact group $G$, $G$ is compact if there exists a measure $\\mu$ in $\\hbox{Soc}(L^{1}(G))$ such that $\\mu(G) \

Ghaffari, A; Ghaffari, Ali; Medghalchi, Ali Reza

2005-01-01

267

Winning the pressing down game but not Banach Mazur  

CERN Document Server

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

Kellner, J; Shelah, S; Kellner, Jakob; Pauna, Matti; Shelah, Saharon

2006-01-01

268

Approximate Connes-amenability of dual Banach algebras  

CERN Document Server

We introduce the notions of approximate Connes-amenability and approximate strong Connes-amenability. Then we characterize these two types of dual Banach algebras in terms of approximate normal virtual diagonal and approximate $\\sigma WC-$ virtual diagonals. Some concrete cases are also discussed.

Esslamzadeh, G H

2009-01-01

269

Derivations into duals of closed ideals of Banach algebras  

CERN Document Server

Let $\\cal A$ be a Banach algebra. We study those closed ideals $I$ of $\\cal A$ for which the first cohomology group of $\\cal A$ with coefficients in $I^*$ is trivial; i.e. $H^1(\\cal A,I^*)=\\{0\\}$. We investigate such closed ideals when $\\cal A$ is weakly amenable or biflat. Also we give some hereditary properties of ideal amenability.

Gordji, M E; Hosseiniun, S A R

2006-01-01

270

Decompositions of Reflexive Modules  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We continue [GbSh:568] (math.LO/0003164), proving a stronger result under the special continuum hypothesis (CH). The original question of Eklof and Mekler related to dual abelian groups. We want to find a particular example of a dual group, which will provide a negative answer to the question. In order to derive a stronger and also more general result we will concentrate on reflexive modules over countable principal ideal domains R. Following H.Bass, an R-module G is reflexi...

Goebel, Ruediger; Shelah, Saharon

2000-01-01

271

Von NeumannJordan constant for LebesgueBochner spaces  

Directory of Open Access Journals (Sweden)

Full Text Available The von NeumannJordan (NJ- constant for LebesgueBochner spaces is determined under some conditions on a Banach space . In particular the NJ-constant for as well as (the space of -Schatten class operators is determined. For a general Banach space we estimate the NJ-constant of , which may be regarded as a sharpened result of a previous one concerning the uniform non-squareness for . Similar estimates are given for Banach sequence spaces ( -sum of Banach spaces , which gives a condition by NJ-constants of 's under which is uniformly non-square. A bi-product concerning 'Clarkson's inequality' for and is also given.

Takahashi Yasuji

1998-01-01

272

Vestibulocollic reflexes in the absence of head postural control.  

Science.gov (United States)

Percutaneous electrical vestibular stimulation evokes reflexive responses in appendicular muscles that are suppressed during tasks in which the muscles are not contributing to balance control. In neck muscles, which stabilize the head on the torso and in space, it is unclear whether similar postural task dependence shapes vestibular reflexes. We investigated whether vestibulocollic reflexes are modulated during tasks in which vestibular information is not directly relevant to maintaining the head balanced on the torso. We hypothesized that vestibulocollic reflexes would be 1) evoked when neck muscles are not involved in balancing the head on the torso and 2) invariant across synergistic neck muscle contraction tasks. Muscle activity was recorded bilaterally in sternocleidomastoid and splenius capitis muscles during head-free and head-fixed conditions while subjects were exposed to stochastic electrical vestibular stimulation (5 mA, 0-75 Hz). Significant vestibular reflex responses (P muscle contractions (i.e., axial rotation/flexion/extension) provided the muscle was active. In contrast, when subjects cocontracted neck muscles, vestibular-evoked responses decreased in sternocleidomastoid by ?30-45% (P muscle contractions but remained unchanged in splenius capitis. These results indicate robust vestibulocollic reflex coupling, which we suggest functions through its closed-loop influence on head posture to ensure cervical spine stabilization. PMID:25008409

Forbes, Patrick A; Siegmund, Gunter P; Happee, Riender; Schouten, Alfred C; Blouin, Jean-Sbastien

2014-10-01

273

Fixed points of holomorphic mappings for domains in Banach spaces  

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Full Text Available We discuss the Earle-Hamilton fixed-point theorem and show how it can be applied when restrictions are known on the numerical range of a holomorphic function. In particular, we extend the Earle-Hamilton theorem to holomorphic functions with numerical range having real part strictly less than 1. We also extend the Lumer-Phillips theorem estimating resolvents to dissipative holomorphic functions.

Lawrence A. Harris

2003-03-01

274

On exponential stability of C_0-quasisemigroups in Banach spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Inthis paper we study some stability concepts for linear systems the evolution which can be described by a C_0 -quasisemigroup.The results obtained may be regarded as generalizations of well known results of Datko, Pazy, Littman and Neerven about exponential stability of C_0 -semigroups.

Mihail Megan; Vincen?iu Cuc

1999-01-01

275

Existence theorems for functional differential equations in Banach spaces  

Directory of Open Access Journals (Sweden)

Full Text Available This paper concernes with the study of existence theorems for a general class of functional differential equations of the form u'(t=f(t,u circ g(t,cdot.The obtained results generalize the retarded functional differential equations [5], [6], [8] and cover singular functional differential equations [1], [3], [4], [7], [9], [12].

A. Sghir

2009-08-01

276

Geometry of Mntz spaces and related questions  

CERN Document Server

Starting point and motivation for this volume is the classical Muentz theorem which states that the space of all polynomials on the unit interval, whose exponents have too many gaps, is no longer dense in the space of all continuous functions. The resulting spaces of Muentz polynomials are largely unexplored as far as the Banach space geometry is concerned and deserve the attention that the authors arouse. They present the known theorems and prove new results concerning, for example, the isomorphic and isometric classification and the existence of bases in these spaces. Moreover they state many open problems. Although the viewpoint is that of the geometry of Banach spaces they only assume that the reader is familiar with basic functional analysis. In the first part of the book the Banach spaces notions are systematically introduced and are later on applied for Muentz spaces. They include the opening and inclination of subspaces, bases and bounded approximation properties and versions of universality.

Gurariy, Vladimir

2005-01-01

277

Noncommutative spectral synthesis for the involutive Banach algebra associated with a topological dynamical system  

CERN Document Server

If X is a compact Hausdorff space, supplied with a homeomorphism, then a crossed product involutive Banach algebra is naturally associated with these data. If X consists of one point, then this algebra is the group algebra of the integers. In this paper, we study spectral synthesis for the closed ideals of this associated algebra in two versions, one modeled after C(X), and one modeled after the group algebra of the integers. We identify the closed ideals which are equal to (what is the analogue of) the kernel of their hull, and determine when this holds for all closed ideals, i.e., when spectral synthesis holds. In both models, this is the case precisely when the homeomorphism has no periodic points.

de Jeu, Marcel

2012-01-01

278

On the Banach $*$-algebra crossed product associated with a topological dynamical system  

CERN Document Server

Given an arbitrary topological dynamical system $\\Sigma = (X, \\sigma)$, where $X$ is a compact Hausdorff space and $\\sigma$ a homeomorphism of $X$, we introduce and analyze the associated Banach $*$-algebra crossed product $\\ell^1 (\\Sigma)$. The $C^*$-envelope of this algebra is the usual $C^*$-crossed product of $C(X)$ by the integers under the automorphism of $C(X)$ induced by $\\sigma$. While the connections between the structure of this $C^*$-algebra and the properties of $\\Sigma$ are well-studied, such considerations concerning $\\ell^1 (\\Sigma)$ are new. We derive equivalences between topological dynamical properties of $\\Sigma$ and structural properties of $\\ell^1 (\\Sigma)$ that have well-known analogues in the $C^*$-algebra context, but also obtain a result on this so-called interplay whose counterpart in the case of $C^* (\\Sigma)$ is false.

Svensson, Christian

2009-01-01

279

Derivations into n-th duals of ideals of Banach algebras  

CERN Document Server

We introduce two notions of amenability for a Banach algebra $\\cal A$. Let $n\\in \\Bbb N$ and let $I$ be a closed two-sided ideal in $\\cal A$, $\\cal A$ is $n-I-$weakly amenable if the first cohomology group of $\\cal A$ with coefficients in the n-th dual space $I^{(n)}$ is zero; i.e., $H^1({\\cal A},I^{(n)})=\\{0\\}$. Further, $\\cal A$ is n-ideally amenable if $\\cal A$ is $n-I-$weakly amenable for every closed two-sided ideal $I$ in $\\cal A$. We find some relationships of $n-I-$ weak amenability and $m-J-$ weak amenability for some different m and n or for different closed ideals $I$ and $J$ of $\\cal A$.

Gordji, M E

2006-01-01

280

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

CERN Document Server

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.

Lachowicz, Miros?aw

2008-01-01

 
 
 
 
281

Characterization of atomic decompositions, Banach frames, Xd-frames, duals and synthesis-pseudo-duals, with application to Hilbert frame theory  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper we give a characterization of atomic decompositions, Banach frames, $X_d$-Riesz bases, $X_d$-frames, $X_d$-Bessel sequences, sequences satisfying the lower $X_d$-frame condition, duals of $X_d$-frames and synthesis pseudo-duals, based on an operator acting on the canonical basis of a sequence space. We also consider necessary and sufficient conditions for operators to preserve the sequence type of the listed concepts. Further, we discuss relationships between e...

Stoeva, Diana T.

2011-01-01

282

Jaw stretch reflexes in children.  

Science.gov (United States)

The substantial morphological transformations that occur during human development present the nervous system with a considerable challenge in terms of motor control. Variability of skilled motor performance is a hallmark of a developing system. In adults, the jaw stretch reflex contributes to the functional stability of the jaw. We have investigated the response properties of the jaw stretch reflex in two groups of young children and a group of young adults. Response latencies increased with development, and all age groups produced stimulus-magnitude-dependent increases in reflex gain and resulting biting force. Reflex gain was largest for the older children (9-10 years), yet net increases in resulting biting force were comparable across age groups. These data and earlier experiments suggest that oral sensorimotor pathways mature throughout childhood in concert with the continued acquisition of complex motor skills. PMID:15981018

Finan, Donald S; Smith, Anne

2005-07-01

283

Optimization in function spaces with stability considerations in Orlicz spaces  

CERN Document Server

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

Kosmol, Peter

2011-01-01

284

Polynomial Bridgeland Stable Objects and Reflexive Sheaves  

CERN Document Server

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.

Lo, Jason

2011-01-01

285

The McShane integral in weakly compactly generated spaces  

CERN Document Server

Di Piazza and Preiss asked whether every Pettis integrable function defined on [0,1] and taking values in a weakly compactly generated Banach space is McShane integrable. In this paper we answer this question in the negative.

Avils, Antonio; Rodrguez, Jos

2010-01-01

286

Seven views on approximate convexity and the geometry of K-spaces  

CERN Document Server

As in Hokusai's series of paintings "Thirty six views of mount Fuji" in which mount Fuji's is sometimes scarcely visible, the central topic of this paper is the geometry of $K$-spaces although in some of the seven views presented $K$-spaces are not easily visible. We study the interplay between the behaviour of approximately convex (and approximately affine) functions on the unit ball of a Banach space and the geometry of Banach K-spaces.

Cabello-Snchez, F; Papini, P L; Sanchez, Felix Cabello; Castillo, Jesus M. F.; Papini, Pier Luigi

2005-01-01

287

Reflexive Dirinya: A Syntactic Analysis  

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Full Text Available This article discusses noun phrase (NP diriya which is known as reflexive in Malay language. However, this reflexive has an ambiguous reading in a sentence. This is because the NP dirinya can have a reference in a clause as well as outside a clause in the same sentence. As a result, this reflexive disobeyed Principle A. On the other hand, this type of reflexive occasionally is known as a long distance reflexive. Mashudi and Solakhiah (1997 had analysed this form of dirinya in a generative framework. They have claimed that the ambiguous reading of this reflexive dirinya was caused by the existence of [+reflexive] and [+pronominal] features which is generated by the NP dirinya at Sstructure. Even though, both of these language experts have argued very convincingly that the reason for the ambiguity of the NP dirinya was because of the different of features that existed on the NP but they didnt explain how two readings could have co-existed at the same level in the syntax. Their suggestions to have two readings to operate at the same level will not be able to reach the explanatory adequacy of a grammar. This analysis too will not be able to explain sentences like these: Sayai percaya bahawa Salimj telah menembak dirinya*i/j/k. (I believe that Salim has shot himself atau Salimj percaya bahawa sayai telah menembak dirinya*i/j/k.( Salim believe that I have shot himself/myself. Therefore, this paper will try to fill the gaps. This analysis claims that the reasons for the ambiguity is due to the features [+3] and [+pronominal] on the enclitic -nya and the feature [+reflexive] on the form diri which operates at a different syntactic level. This means that the ambiguity reading on dirinya in a sentence is because at the D-structure the native speaker will have the pronominal reading and it continues to exist until the Sstructure. At the S-structure, the speaker will have reflexive reading. The existence of two readings at different levels will cause dirinya to have an ambiguity reading. This analysis will be argued using the Binding Theory which controls the distribution of NP in a sentence.

Fazal Mohamed

2008-01-01

288

Reflexive algebras and sigma algebras  

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Full Text Available The concept of a reflexive algebra (σ-algebra β of subsets of a set X is defined in this paper. Various characterizations are given for an algebra (σ-algebra β to be reflexive. If V is a real vector lattice of functions on a set X which is closed for pointwise limits of functions and if β={A|A⫅X   and   CA(x∈V} is the σ-algebra induced by V then necessary and sufficient conditions are given for β to be reflexive (where CA(x is the indicator function.

V. K. Srinivasan

1986-12-01

289

Nonlinear dynamics in a reflex diode  

International Nuclear Information System (INIS)

Potentials in high current reflexing electron diodes such as vircators are dominated by space charge effects, and are rapidly time varying and nonlinear because of the oscillating virtual cathode and strong particle bunching. Previous experiments showed the stochastic character of the oscillating electromagnetic fields. The dynamical behavior of this type of device is studied with the 2 dimensional electromagnetic code MAGIC and with a simplified 1 dimensional nonlinear analytic model. Computed particle trajectory phase space plots show several classes of electron trajectories. The 1 dimensional nonlinear model generates a similar set. The calculations show that the stochastic behavior of the electromagnetic fields in both frequency and time are similar to the experimental observations. These models are used to investigate the dependence of spectral bandwidth and the RF fluctuations on the macroscopic system parameters

290

The history of examination of reflexes.  

Science.gov (United States)

In the late 1800s, Wilhelm Erb, Joseph Babinski, William Gowers, and others helped develop the neurologic examination as we know it today. Erb was one of the first to emphasize a detailed and systematic neurologic exam and was co-discoverer of the muscle stretch reflex, Gowers began studying the knee jerk shortly after it was described, and Babinski focused on finding reliable signs that could differentiate organic from hysterical paralysis. These physicians and others emphasized the bedside examination of reflexes, which have been an important part of the neurologic examination ever since. This review will focus on the history of the examination of the following muscle stretch and superficial/cutaneous reflexes: knee jerk, jaw jerk, deep abdominal reflexes, superficial abdominal reflexes, plantar reflex/Babinski sign, and palmomental reflex. The history of reflex grading will also be discussed. PMID:24695995

Boes, Christopher J

2014-12-01

291

Riemann-Stieltjes Operators between Vector-Valued Weighted Bloch Spaces  

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Full Text Available Let X be a Banach space, we study Riemann-Stieltjes operators between X-valued weighted Bloch spaces. Some necessary and sufficient conditions for these operators induced by holomorphic functions to be weakly compact and weakly conditionally compact are given by certain growth properties of the inducing symbols and some structural properties of the abstract Banach space, which extend some previous results.

Maofa Wang

2008-10-01

292

Tonic vibration reflexes and background force level  

Science.gov (United States)

On earth, the functional stretch reflex is an important component in the maintenance of posture and muscle tone. In parabolic flight experiments, it is evaluated whether the functional stretch reflex, as reflected in the tonic vibration reflex, adjusts appropriately for changes in background gravitoinertial force level. Virtually immediate alterations of appropriate sign occurred.

Lackner, James R.; Dizio, Paul; Fisk, John

1992-01-01

293

Intracranial causes of ophthalmoplegia: the visual reflex pathways.  

Science.gov (United States)

The gathering of visual information is a complex process that relies on concerted movements of the eyes, and cranial nerves II-VIII are at least partially involved in the visual system. The cranial nerves do not function in isolation, however, and there are multiple higher-order cortical centers that have input into the cranial nerves to coordinate eye movement. Among the functions of the cortical reflex pathways are (a) controlling vertical and horizontal gaze in response to vestibular input to keep the eyes focused on an object as the head moves through space, and (b) controlling rapid, coordinated eye movement to a new visual target (saccades). There are also reflex pathways connecting the cranial nerves involved in vision that produce consensual blinking of the eyes in response to corneal stimulation of one eye and consensual pupillary constriction in response to light input on one pupil. A variety of intracranial pathologic conditions, including benign and malignant neoplasms, infection, trauma, autoimmune diseases, vascular anomalies, degenerative diseases, and inherited-congenital disorders, can disrupt the cranial nerves and visual reflex pathways. This disruption can manifest in myriad ways-for example, as extraocular muscle paresis, afferent pupillary defect, oculosympathetic paresis (Horner syndrome), internuclear ophthalmoplegia, dorsal midbrain (Parinaud) syndrome, or loss of the corneal reflex. Knowledge of the function and anatomy of the cranial nerves and visual reflex pathways, coupled with selection of the proper magnetic resonance pulse sequence, will allow the radiologist to order appropriate imaging of the involved cranial nerve or visual reflex pathway based on the patient's symptoms and thereby play an essential role in establishing the diagnosis and planning appropriate therapy. PMID:24025940

Stalcup, Seth T; Tuan, August S; Hesselink, John R

2013-01-01

294

Superstability for Generalized Module Left Derivations and Generalized Module Derivations on a Banach Module (I  

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Full Text Available We discuss the superstability of generalized module left derivations and generalized module derivations on a Banach module. Let be a Banach algebra and a Banach -module, and . The mappings , and are defined and it is proved that if (resp., is dominated by then is a generalized (resp., linear module- left derivation and is a (resp., linear module- left derivation. It is also shown that if (resp., is dominated by then is a generalized (resp., linear module- derivation and is a (resp., linear module- derivation.

Rassias JM

2009-01-01

295

Hypercyclic operators on topological vector spaces  

CERN Document Server

Bonet, Frerick, Peris and Wengenroth constructed a hypercyclic operator on the locally convex direct sum of countably many copies of the Banach space $\\ell_1$. We extend this result. In particular, we show that there is a hypercyclic operator on the locally convex direct sum of a sequence $\\{X_n\\}_{n\\in\\N}$ of Fr\\'echet spaces if and only if each $X_n$ is separable and there are infinitely many $n\\in\\N$ for which $X_n$ is infinite dimensional. Moreover, we characterize inductive limits of sequences of separable Banach spaces which support a hypercyclic operator.

Shkarin, Stanislav

2010-01-01

296

Nuclear operators on spaces of continuous vector-valued functions  

CERN Document Server

Let $\\Omega$ be a compact Hausdorff space, let $E$ be a Banach space, and let $C(\\Omega, E)$ stand for the Banach space of all $E$-valued continuous functions on $\\Omega$ under supnorm. In this paper we study when nuclear operators on $C(\\Omega, E)$ spaces can be completely characterized in terms of properties of their representing vector measures. We also show that if $F$ is a Banach space and if $T:\\ C(\\Omega, E)\\rightarrow F$ is a nuclear operator, then $T$ induces a bounded linear operator $T^\\#$ from the space $C(\\Omega)$ of scalar valued continuous functions on $\\Omega$ into $\\slN(E,F)$ the space of nuclear operators from $E$ to $F$, in this case we show that $E^*$ has the Radon-Nikodym property if and only if $T^\\#$ is nuclear whenever $T$ is nuclear.

Saab, P; Saab, Paulette; Smith, Brenda

1992-01-01

297

Impulsive discontinuous hyperbolic partial differential equationsof fractional order on Banach algebras  

Directory of Open Access Journals (Sweden)

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.

Said Abbas

2010-07-01

298

Effects of simulated microgravity on brain plasticity: a startle reflex habituation study.  

Science.gov (United States)

There is limited but increasing evidence that space environment, namely weightless condition, may affect astronauts' cerebral neurotransmitters and cognitive performance. The present experiment hypothesized that learning and brain plasticity are affected by simulated microgravity condition. To this aim, 22 male subjects matching astronauts' characteristics were divided in two groups, Head-Down Bed Rest (HDBR) and Sitting Control. After 3-h bed rest (or sitting condition) subjects started a picture viewing task during which 30 acoustic startle probes (100 dBA loudness), divided into three consecutive blocks, were delivered through headphones while startle reflex amplitude was measured from the EMG of the orbicularis oculi muscle. Habituation analysis of the startle reflex showed a normal reflex inhibition across blocks in sitting controls and no habituation in HDBR subjects. Results point to a microgravity-induced lack of startle reflex plasticity in subjects matching astronauts, a learning deficit which may affect the success of long-term space missions. PMID:21627974

Messerotti Benvenuti, Simone; Bianchin, Marta; Angrilli, Alessandro

2011-09-01

299

Integrating Reflexivity in Livelihoods Research  

DEFF Research Database (Denmark)

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.

Prowse, Martin

2010-01-01

300

Integrating Reflexivity in Livelihoods Research  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Prowse, Martin

2010-01-01

 
 
 
 
301

Determining elements in Banach algebras through spectral properties  

CERN Document Server

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.

Brear, M

2012-01-01

302

Ionotropic glutamate receptors in the external lateral parabrachial nucleus participate in processing cardiac sympathoexcitatory reflexes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Stimulation of cardiac sympathetic afferents during myocardial ischemia with metabolites such as bradykinin (BK) evokes sympathoexcitatory reflex responses and activates neurons in the external lateral parabrachial nucleus (elPBN). The present study tested the hypothesis that this region in the pons processes sympathoexcitatory cardiac reflexes through an ionotropic glutamate receptor mechanism. The ischemic metabolite BK (0.11 ?g) was injected into the pericardial space of anesthetized a...

Fu, Liang-wu; Guo, Zhi-ling; Longhurst, John C.

2012-01-01

303

[Reflexivity: a critical issue in qualitative research].  

Science.gov (United States)

Reflexivity is an English term that Spanish speaking people have to assign a technical meaning. Reflexivity expresses the conscience of researchers conscience and refers to their connection with the study's situation. It is a process by which researchers step back to critically exam the effect they have on the study and the impact of their interactions with participants. The reflexive process is embedded in all research levels and is present in all the research phases, from the research question to fieldwork, from data analysis to writing the final report. Nevertheless, the question is not so much to engage in reflective activities but to be a reflexive researcher. Reflexivity is a human ability that is present during social interactions. For this reason it is present in qualitative research. A self inquirer can be addressed as it is constructed by the relationships and interactions that are established with study participants. Reflexivity has an educational character that continues after the study is completed. PMID:21531602

de la Cuesta-Benjumea, Carmen

2011-01-01

304

Perspective on the human cough reflex  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 a...

Brooks Stuart M

2011-01-01

305

Reflex: Scientific Workflows for the ESO Pipelines  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The recently released Reflex scientific workflow environment supports the interactive execution of ESO VLT data reduction pipelines. Reflex is based upon the Kepler workflow engine, and provides components for organising the data, executing pipeline recipes based on the ESO Common Pipeline Library, invoking Python scripts, and constructing interaction loops. Reflex will greatly enhance the quick validation and reduction of the scientific data. In this paper we summarize the ...

Ballester, Pascal; Bramich, Daniel; Forchi, Vincenzo; Freudling, Wolfram; Garcia-dabo, Cesar Enrique; Gebbinck, Maurice Klein; Modigliani, Andrea; Romaniello, Martino

2011-01-01

306

Reflexivity, social transformation, and counter culture  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper attempts to identify how reflexivity works within the local rationalities of social movement milieux that, it is argued, represent an important source of the development of reflexivity in contemporary lifeworlds. In interviews in the Dublin counter culture, reflexivity appears above all as the institutionalisation of autonomy, the creation of new social forms for self-determined purposes. A starting point is strategies of distancing from the taken-for-granted assumptions of in...

Cox, Laurence

1997-01-01

307

On Isoperimetric Inequalities in Minkowski Spaces  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of this expository paper is to collect some (mainly recent inequalities, conjectures, and open questions closely related to isoperimetric problems in real, finite-dimensional Banach spaces (= Minkowski spaces. We will also show that, in a way, Steiner symmetrization could be used as a useful tool to prove Petty's conjectured projection inequality.

Horst Martini

2010-01-01

308

Arakeris Reflex: an Alternative Pathway for Dento-Cardiac Reflex Mediated Syncope  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Introduction: Dentocardiac reflex, a variant of trigeminocardiac reflex elicited specifically during tooth extraction procedures in den-tal/maxillofacial surgery and is believed to cause syncope with an afferent link mediated by posterior superior alveolar nerve. Another variant of trigeminocardiac reflex which is also of interest to the oral and maxillofacial surgeon is oculocardiac reflex which can be triggered by direct or indirect manipulation of eye globe or muscles around it.The hypothe...

Veena Arali; Shailaja Reddy; Raghuram, C. G.; Gururaj Arakeri

2010-01-01

309

Nondiscrete P-Groups Can be Reflexive  

CERN Document Server

We present a series of examples of nondiscrete reflexive P-groups (i.e., groups in which all $G_\\delta$-sets are open) as well as noncompact reflexive $\\omega$-bounded groups (in which the closure of every countable set is compact). Our main result implies that every product of feathered (equivalently, almost metrizable) Abelian groups equipped with the P-modified topology is a reflexive group. In particular, every compact Abelian group with the P-modified topology is reflexive. This answers a question posed by S. Hern\\'andez and P. Nickolas and solves a problem raised by Ardanza-Trevijano, Chasco, Dom\\'{\\i}nguez, and Tkachenko.

Galindo, Jorge; Tkachenko, Mikhail

2010-01-01

310

On the dual space C0*(S, X  

Directory of Open Access Journals (Sweden)

Full Text Available Let S be a locally compact Hausdorff space and let us consider the space C0(S, X of continuous functions vanishing at infinity, from S into the Banach space X. A theorem of I. Singer, settled for S compact, states that the topological dual C0*(S, X is isometrically isomorphic to the Banach space r?bv(S, X* of all regular vector measures of bounded variation on S, with values in the strong dual X*. Using the Riesz-Kakutani theorem and some routine topological arguments, we propose a constructive detailed proof which is, as far as we know, different from that supplied elsewhere.

L. Meziani

2009-02-01

311

FIXED POINTS THEOREMS IN MULTI-METRIC SPACES  

Directory of Open Access Journals (Sweden)

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.

Laurentiu I. Calmutchi

2011-07-01

312

A dichotomy for the convex spaces of probability measures  

CERN Document Server

We show that every nonempty compact and convex space M of probability Radon measures either contains a measure which has `small' local character in M or else M contains a measure of `large' Maharam type. Such a dichotomy is related to several results on Radon measures on compact spaces and to some properties of Banach spaces of continuous functions.

Krupski, Miko?aj

2011-01-01

313

On the space of morphisms between \\'etale groupoids  

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Given two \\'etale groupoids $\\Cal G$ and $\\Cal G'$, we consider the set of pointed morphisms from $\\Cal G$ to $\\Cal G'$. Under suitable hypothesis we introduce on this set a structure of Banach manifold which can be considered as the space of objects of an \\'etale groupoid whose space of orbits is the space of morphisms from $\\Cal G$ to $\\Cal G'$.

Haefliger, Andre?

2007-01-01

314

On the \\text{UMD} constants for a class of iterated $L_p(L_q)$ spaces  

CERN Document Server

Let $1 1$ and $ c_2 = c_2(p, q, s) > 1$, such that the $\\text{UMD}_s$ constants of $X_n$'s satisfy $c_1^n \\leq C_s(X_n) \\leq c_2^n$ for all $1 < s < \\infty$. Similar results will be showed for the analytic $\\text{UMD}$ constants. We mention that the first super-reflexive non-$\\text{UMD}$ Banach lattices were constructed by Bourgain. Our results yield another elementary construction of super-reflexive non-$\\text{UMD}$ Banach lattices, i.e. the inductive limit of $X_n$, which can be viewed as iterating infinitely many times $L_p(L_q)$.

Qiu, Yanqi

2011-01-01

315

Newtonian Lorentz Metric Spaces  

CERN Document Server

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.

Costea, Serban

2011-01-01

316

Representation of contractively complemented Hilbertian operator spaces and the Fock space  

CERN Document Server

The operator spaces $H_n^k$ $1\\le k\\le n$, generalizing the row and column Hilbert spaces, and arising in the authors' previous study of contractively complemented subspaces of $C^*$-algebras, are shown to be homogeneous and completely isometric to a space of creation operators on a subspace of the anti-symmetric Fock space. The completely bounded Banach-Mazur distance from $H_n^k$ to row or column space is explicitly calculated.

Neal, M; Neal, Matthew; Russo, Bernard

2004-01-01

317

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.)

318

Approximately Lie ternary $(\\sigma,\\tau,\\xi)-$derivations on Banach ternary algebras  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Let $A$ be a Banach ternary algebra over a scalar field $\\Bbb R$ or $\\Bbb C$ and $X$ be a ternary Banach $A-$module. Let $\\sigma,\\tau$ and $\\xi$ be linear mappings on $A$, a linear mapping $D:(A,[]_A)\\to (X,[]_X)$ is called a Lie ternary $(\\sigma,\\tau,\\xi)-$derivation, if $$D([abc]_A)=[[D(a)bc]_X]_{(\\sigma,\\tau,\\xi)}+[[D(b)ac]_X]_{(\\sigma,\\tau,\\xi)}+[[D(c)ba]_X]_{(\\sigma,\\tau,\\xi)},$$ for all $a,b,c\\in A$, where $[abc]_{(\\sigma,\\tau,\\xi)}=a\\tau(b)\\xi(c)-\\sigma(c)\\tau(b)a.$ I...

Gordji, M. Eshaghi; Farrokhzad, R.; Hosseinioun, S. A. R.

2009-01-01

319

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

Mehdi, Dehghan; Masoud, Hajarian.

320

About Banach Fixed Point Theorem and The Scottish Caf :-Applications of Banach Fixed Point Theorem. -Culturehistorical background for The Scottish Caf  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Sammendrag I kapittel 1 gjres klart hvilke forkunnskaper som er ndvendige for kunne forst og ha utbytte av lese denne oppgaven. Det henvises ogs til litteratur som kan brukes som oppslagsverk hvis noen begreper under lesningen skulle vre ukjente. I kapittel 2 klargjres sentrale begreper som fikspunkt, kontraksjon og kompletthet. Dernest presenteres Banachs fikspunktteorem med bevis. Kapitlet peker ogs mot ulike anvendelser av teoremet. Kapittel 3 handler i sin helhet...

Nilsen, Torger Johannes

2006-01-01

 
 
 
 
321

Review Essay: Grenzgnger Seeks Reflexive Methodology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Review Essay: Mats Alvesson & Kaj Skldberg: Reflexive Methodology: New Vistas for Qualitative Research. London: Sage 2000. ISBN 0-8039-7707-7. 2. Christiane K. Alsop (Ed.): Grenzgngerin: Bridges Between Disciplines. Eine Festschrift fr Irmingard Staeuble. Heidelberg: Asanger 2001. ISBN 3-89334-363-6. Reflexive Methodology versucht, die bedeutendsten Strme wissenschaftlichen Denkens in der Epistemologie, der Philosophie und in den Sozialwissenschaften auf ihre potentielle Anwendbarkei...

Roth, Wolff-michael

2002-01-01

322

[The oculocardiac reflex during vitrectomy under neuroleptanalgesia].  

Science.gov (United States)

Oculocardiac reflex (OCR) is a frequently occurring complication in eye operations. It is a trigemino-vagal reflex characterised by the clinical occurrence of bradycardia and other cardiac rhythm disturbances following manipulations on the eye and its surroundings especially after traction of the external eye muscles. In this paper based on an analysis of 402 anaesthesia records, a bradycardia frequency (f = less than 60/min) of 31.8% was noted while other rhythm disturbances occurred in 5.7%. Predisposition facts were identified as age over 50, hypertension and cardiac diseases requiring medication with cardiac drugs. The frequency of OCR is considerably lowered by diabetes mellitus. Examination of 159 traction measurements made at the lateral rectus muscle revealed that the first manipulation made at the rectus bulbi superior muscle resulted in a statistically significantly stronger reflex activity than at the other muscles. In a further series of investigations in which rectus bulbi superior muscle was tested last, this muscle again showed the biggest frequency deviation. Only determination of the percentage heart rate decrease is suitable for characterising reflex activity. The frequency of the reflex occurring in our study was 71.7%, the result being reduced by the high proportion of diabetics, who are relatively reflex insensitive. PMID:2054038

Dornberger, I; Quast, D; Velhagen, K H; Bellach, J; Guckler, A

1991-01-01

323

Brauer-Thrall for totally reflexive modules  

CERN Document Server

Let R be a commutative noetherian local ring that is not Gorenstein. It was recently discovered that the category of totally reflexive modules over R is representation infinite, provided that it contains a non-free module. The main goal of this paper is to understand how complex the category of totally reflexive modules can be in this situation. Local rings (R,m) with m^3=0 are commonly regarded as the structurally simplest rings to admit diverse categorical and homological characteristics. For such rings we obtain conclusive results about the category of totally reflexive modules, modeled on the Brauer-Thrall conjectures. Starting from a non-free cyclic totally reflexive module, we construct a family of indecomposable totally reflexive R-modules that contains, for every n in N, a module that is minimally generated by n elements. Moreover, if the residue field R/m is algebraically closed, then we construct for every n in N an infinite family of indecomposable and pairwise non-isomorphic totally reflexive R-mo...

Christensen, Lars Winther; Rahmati, Hamidreza; Striuli, Janet; Wiegand, Roger

2010-01-01

324

The passive of reflexive verbs in Icelandic  

Directory of Open Access Journals (Sweden)

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.

Hlf rnadttir

2011-10-01

325

Next generation control system for reflexive aerostructures  

Science.gov (United States)

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.

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

2010-04-01

326

GENERALIZED ULAM-HYERS STABILITIES OF QUARTIC DERIVATIONS ON BANACH ALGEBRAS  

Directory of Open Access Journals (Sweden)

Full Text Available Let A , B be two rings. A mapping ? : A ? B is called quartic derivation, if ? is a quartic function satisfies ?(ab = a4?(b + ?(ab4 for all a, b ? A. The main purpose of this paper to prove the generalized Hyers-Ulam-Rassias stability of the quartic derivations on Banach algebras.

M Eshaghi Gordji

2010-12-01

327

GENERALIZED ULAM-HYERS STABILITIES OF QUARTIC DERIVATIONS ON BANACH ALGEBRAS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Let A , B be two rings. A mapping ? : A ? B is called quartic derivation, if ? is a quartic function satisfies ?(ab) = a4?(b) + ?(a)b4 for all a, b ? A. The main purpose of this paper to prove the generalized Hyers-Ulam-Rassias stability of the quartic derivations on Banach algebras.

Eshaghi Gordji, M.; Ghobadipour, N.

2010-01-01

328

Domains which are locally uniformly linearly convex in the Kobayashi distance  

Directory of Open Access Journals (Sweden)

Full Text Available We show a construction of domains in complex reflexive Banach spaces which are locally uniformly convex in linear sense in their Kobayashi distance. We also show connections between norm and Kobayashi distance properties.

Monika Budzy?ska

2003-04-01

329

Another extension of Orlicz-Sobolev spaces to metric spaces  

Directory of Open Access Journals (Sweden)

Full Text Available We propose another extension of Orlicz-Sobolev spaces to metric spaces based on the concepts of the Φ-modulus and Φ-capacity. The resulting space NΦ1 is a Banach space. The relationship between NΦ1 and MΦ1 (the first extension defined in Aïssaoui (2002 is studied. We also explore and compare different definitions of capacities and give a criterion under which NΦ1 is strictly smaller than the Orlicz space LΦ.

Noureddine Assaoui

2004-02-01

330

Evaluations of neuromuscular dynamics of hyperactive reflexes poststroke  

Directory of Open Access Journals (Sweden)

Full Text Available Tendon reflexes are widely used in clinics to conveniently evaluate various neurological disorders. This study characterized neuromuscular dynamics of tendon reflexes at the elbow with multiple quantitative measures in both patients with stroke and nondisabled controls. We employed a handheld instrumented hammer to tap the triceps muscle tendon at various elbow flexion angles and measured the tapping force, triceps electromyography, and elbow extension torque to characterize neuromuscular dynamics of tendon reflexes quantitatively in terms of the tendon reflex gain, contraction rate, half relaxation rate, reflex loop delay, and reflex threshold in tapping force. We found that the tendon reflex gain, contraction rate, and half relaxation rate were significantly higher while the reflex threshold was significantly lower across different joint angles in patients with stroke than in nondisabled controls (p < 0.05, indicating hyperactive neurological state and muscle contraction dynamics poststroke. This study presents a convenient and quantitative method to evaluate reflex excitability and muscle contraction dynamics.

Jie Liu, BS

2011-05-01

331

Stability of the Jensen--type functional equation in ternary Banach algebras: An alternative fixed point approach  

CERN Document Server

Using fixed point methods, we prove the generalized Hyers--Ulam--Rassias stability of ternary homomorphisms, and ternary multipliers in ternary Banach algebras for the Jensen--type functional equation

Gordji, M Eshaghi

2009-01-01

332

Entrepreneurship Teaching Conducted as Strategic Reflexive Conversation  

DEFF Research Database (Denmark)

The paper intends exploring and ascertaining whether the concept of strategic reflexive conversation can profitably be applied to entrepreneurship. As a start, a process of conceptualisation is undertaken, which is instrumental in placing the notion of strategic reflexive conversation into a knowledge management perspective. Strategic reflexive conversation is presented in an enhanced and updated version, which is contrasted to entrepreneurship through reflection. The findings indicate and it can be concluded that, with some important reservations, strategic reflexive conversation can advantageously, and on a pilot basis, be applied to entrepreneurship in practical environments and within the framework of entrepreneurship-centred teaching. The present theoretical investigation is solely of an introductory nature and steps are considered that can lead to the planning of additional exploratory and empirical studies. No doubt the reported study can be enhanced and refined in a theoretical sense and be empirically supported. The paper addresses a potentially significant theme and aims to stimulate discussion, which can provide input and ideas for enhancing practice-oriented entrepreneurship and be applied to entrepreneurship-centred instructional activities. The concept of strategic reflexive conversation must be regarded as relevant and are of clear pertinence to theoretical and practical entrepreneurship to entrepreneurship-oriented teaching and learning activities.

Kristiansson, Michael

333

Oculocardiac reflex in laser in situ keratomileusis  

Directory of Open Access Journals (Sweden)

Full Text Available BACKGROUND: This study was conducted to evaluate variations in heart rate and to determine the occurrence of oculocardiac reflex (OCR during laser in situ keratomileusis (LASIK. METHODS: This descriptive, prospective study was designed to observe the effect of suction ring and ablation stages during LASIK procedure on the heart rate. The ECG was taken before and during LASIK operation on the first eye in 61 patients. These patients were selected randomly among cases that presented to Al-Zahra Hospital, Isfahan, Iran for LASIK surgery in summer 2001. All patients were healthy without history of cardiovascular disease and no systemic medication. The ECG prior to the procedure was considered as baseline. Decrease in the heart rate of 10% or more of baseline was considered as oculocardiac reflex. RESULTS: In 12 patients (20% the heart rate decreased more than 10% during the suction ring stage. In 19 patients (31% the heart rate increased more than 20% of baseline. In 15 patients (25% the heart rate increased 10%-20% more than baseline during the preparation and ablation stages. In the remaining 15 patients (25% the heart rate did not change during the procedure. CONCLUSIONS: Results of this study confirm that oculocardiac reflex may occur during the LASIK procedure especially in the suction ring stage. Because the oculocardiac reflex may cause heart rate changes during LASIK, the patients should be closely monitored during the procedure. KEY WORDS: Laser in situ keratomileusis, oculocardiac reflex, suction ring.

Alireza Ashtari

2006-12-01

334

[Intragroup reflex in an experiment on pigeons].  

Science.gov (United States)

The paper presents an experimental model, used for the study of interdependent behaviour of higher vertebrates (pigeons). The techniques suggested by the author, are modifications of the already known models for the study of so called "altruism" and "cooperation" among monkeys, It is with these simple methods that the main characteristics of the intragroup food-procuring conditioned reflex were studied, the reflex, which plays the major role in the shaping of interdependent behaviour in pigeons. The results of the study confirm the idea of L. G. Voronin on the independence of the conditioning speed from the animal's phylogenetic level. PMID:7386030

Keniia, V M

1980-01-01

335

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

336

The Reflexive Teacher Educator in TESOL Roots and Wings  

CERN Document Server

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.

Edge, Julian

2010-01-01

337

Partial inner product spaces theory and applications  

CERN Document Server

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.

Antoine, Jean-Pierre

2009-01-01

338

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

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

1986-01-01

339

Completeness of regular inductive limits  

Directory of Open Access Journals (Sweden)

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.

Kelly McKennon

1989-09-01

340

Banach-Tarski paradox using pieces with the property of Baire.  

Science.gov (United States)

In 1924 Banach and Tarski, using ideas of Hausdorff, proved that there is a partition of the unit sphere S2 into sets A1,...,Ak,B1,..., Bl and a collection of isometries [sigma1,..., sigmak, rho1,..., rhol] so that [sigma1A1,..., sigmakAk] and [rho1B1,..., rholBl] both are partitions of S2. The sets in these partitions are constructed by using the axiom of choice and cannot all be Lebesgue measurable. In this note we solve a problem of Marczewski from 1930 by showing that there is a partition of S2 into sets A1,..., Ak, B1,..., Bl with a different strong regularity property, the Property of Baire. We also prove a version of the Banach-Tarski paradox that involves only open sets and does not use the axiom of choice. PMID:11607339

Dougherty, R; Foreman, M

1992-11-15

 
 
 
 
341

GENERALIZED ULAM-HYERS STABILITIES OF QUARTIC DERIVATIONS ON BANACH ALGEBRAS  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english Let A , B be two rings. A mapping ? : A ? B is called quartic derivation, if ? is a quartic function satisfies ?(ab) = a4?(b) + ?(a)b4 for all a, b ? A. The main purpose of this paper to prove the generalized Hyers-Ulam-Rassias stability of the quartic derivations on Banach algebras. [...

M, Eshaghi Gordji; N, Ghobadipour.

2010-12-01

342

Human investigations into the exercise pressor reflex  

DEFF Research Database (Denmark)

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.

Secher, Niels H; Amann, Markus

2012-01-01

343

Perspective on the human cough reflex  

Directory of Open Access Journals (Sweden)

Full Text Available 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 ancestors adapt phonation over olfaction beginning less than 10 million years ago. The second type of cough reflex, a chemosensory type, is carried by unmyelinated C fibers. Supposedly, its origin dates back when prehistoric humans began living in close proximity to each other and were at risk for infectious respiratory diseases or irritant-induced lung injury. The mechanism for the latter type of cough is analogous to induced pain after tissue injury; and, it is controlled by the identical transient receptor potential vanilloid cation channel (TRPV1. The airways do not normally manifest nociceptive pain from a stimulus but the only consistent response that capsaicin and lung inflammation provoke in healthy human airways is cough. TRPA1, another excitatory ion channel, has been referred to as the "irritant receptor" and its activation also induces cough. For both types of cough, the motor responses are identical and via coordinated, precisely-timed and sequential respiratory events orchestrated by complex neuromuscular networking of the diaphragm, chest and abdominal respiratory muscles, the glottis and parts of the brain.

Brooks Stuart M

2011-11-01

344

Dilemmas and Deliberations in Reflexive Ethnographic Research  

Science.gov (United States)

This paper traces insights into the challenges and dilemmas experienced whilst researching students' interpretations and understandings of the Behaviour Management in Schools policy in Western Australia. Journal records, supported by student transcripts, are woven together in a reflexive ethnographic journey--from the beginning phase of

Robinson, Janean Valerie

2014-01-01

345

Self hypnotherapeutic treatment of habitual reflex vomiting.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A 9 year old boy with intractable postprandial reflex vomiting was taught a self hypnotherapy technique incorporating relaxation exercises, mental imagery, and suggestions of symptom relief. The sequence was recorded on a personal stereo cassette tape. Vomiting was completely eliminated within four weeks. At 12 month review vomiting had not recurred.

Sokel, B. S.; Devane, S. P.; Bentovim, A.; Milla, P. J.

1990-01-01

346

Doing Reflexivity: Moments of Unbecoming and Becoming  

Science.gov (United States)

This paper offers an account of a reflexive "trip" undertaken by a professional doctoral student and her supervisor. It presents a series of vignettes which offer an account of unbecomings and becomings encountered by the student. Making use of a dialogic approach in which the supervisor responds to the student, we suggest this method of

Fox, Alison; Allan, Julie

2014-01-01

347

Reflectivity, Reflexivity and Situated Reflective Practice  

Science.gov (United States)

This paper describes an aspect of reflective practice referred to as situated reflective practice. The overarching theory is derived from social theories of structuration and reflexivity. In particular, from Giddens' theory of structuration, which sees social life as an interplay of agency and structure. Discussion of the research reported

Malthouse, Richard; Roffey-Barentsen, Jodi; Watts, Mike

2014-01-01

348

Centrally infused bradykinin increases baroreceptor reflex sensitivity.  

Science.gov (United States)

Kinins are present in the central nervous system, and central administration of bradykinin increases blood pressure and heart rate. In this study, we determined the effect of intracerebroventricular infusion of bradykinin on the baroreceptor reflex of conscious rats. Male Wistar rats were anesthetized with thiobarbital (40 mg/kg i.p.), and chronic intracerebroventricular cannulas (25 gauge) were implanted into the lateral ventricles. Baroreceptor control of heart rate was evaluated by recording reflex heart rate changes (beats per minute) in response to mean arterial pressure changes (mm Hg) produced by bolus injection of phenylephrine (0.5-20 micrograms/kg i.v.) or sodium nitroprusside (0.5-25 micrograms/kg i.v.). The ratio beats per minute/mm Hg or the mean slope of the individual regression lines of the relation between heart rate and mean arterial pressure changes for increases or decreases in arterial pressure was used as an index of baroreceptor reflex sensitivity. Baroreceptor control of heart rate was evaluated within 1 and 3 hours of intracerebroventricular infusion of bradykinin (7.5 micrograms/7 microliters/hr) or saline (7 microliters/hr). There was no change in basal mean arterial pressure or heart rate during central bradykinin infusion (112 +/- 2 mm Hg and 402 +/- 18 beats per minute in the control period). After 1 hour of central bradykinin infusion, there was a significant increase of baroreceptor reflex sensitivity for increments in mean arterial pressure (-2.91 +/- 0.26 versus -1.5 +/- 0.24 beats per minute/mm Hg in the control period; p less than 0.01, paired Student's t test). In contrast, no significant changes were observed for the reflex tachycardia. Similar results were obtained with 3 hours of infusion.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1735575

Gerken, V M; Santos, R A

1992-02-01

349

Feminist Politics as Reflexive Citizenship  

Directory of Open Access Journals (Sweden)

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.

Nikos Katrivesis

2008-11-01

350

Asymptotic behaviour of unbounded trajectories for some non-autonomous systems in a Hilbert space  

International Nuclear Information System (INIS)

The asymptotic behaviour of unbounded trajectories for non expansive mappings in a real Hilbert space and the extension to more general Banach spaces and to nonlinear contraction semi-group have been studied by many authors. In this paper we study the asymptotic behaviour of unbounded trajectories for a quasi non-autonomous dissipative systems. 26 refs

351

Local stability of the Pexiderized Cauchy and Jensen's equations in fuzzy spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Lex X be a normed space and Y be a Banach fuzzy space. Let D = {(x, y) ? X X : ||x|| + ||y|| ? d} where d > 0. We prove that the Pexiderized Jensen functional equation is stable in the fuzzy norm for functions defined on D and taking values in Y. We consider also the Pexiderized Cauchy functional equation. 2000 Mathematics Sub...

Kang Jung Im; Cho Yeol Je; Najati Abbas

2011-01-01

352

Stick balancing with reflex delay in case of parametric forcing  

Science.gov (United States)

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.

Insperger, Tamas

2011-04-01

353

[Nociceptive flexion reflex. Principles and applications of the threshold determination].  

Science.gov (United States)

The threshold for the pain flexion reflex in the lower limb can be used to determine the potency in man of analgesic drugs acting centrally. A new apparatus is, the "algometre", described. Bipolar electrical stimulation (5 stimuli of 1 ms over a period of 10 ms) is applied to the saphenous nerve just behind the external malleolus. An amplifier detects the muscle response (electromyogramme; EMG) at the muscle-tendon junction in the popliteal space; this occurs about 70-130 ms after the painful stimulus. The whole system is linked to a microcomputer. The EMG and EMG/intensity curves are displayed on a colour screen, and can be copied by a colour tracing table. The whole machine is mobile and can be moved from bed to bed. An increase in the threshold during inhalation of 50% nitrous oxide in oxygen was shown. However, the usefulness of the "algometre" in clinical practice remains to be assessed by further studies. PMID:2782694

Dalmas, S; Scherpereel, P

1989-01-01

354

Fixed Points of Multivalued Maps in Modular Function Spaces  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of this paper is to study the existence of fixed points for contractive-type and nonexpansive-type multivalued maps in the setting of modular function spaces. We also discuss the concept of w-modular function and prove fixed point results for weakly-modular contractive maps in modular function spaces. These results extend several similar results proved in metric and Banach spaces settings.

Marwan A. Kutbi

2009-01-01

355

Fixed Points of Multivalued Maps in Modular Function Spaces  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of this paper is to study the existence of fixed points for contractive-type and nonexpansive-type multivalued maps in the setting of modular function spaces. We also discuss the concept of -modular function and prove fixed point results for weakly-modular contractive maps in modular function spaces. These results extend several similar results proved in metric and Banach spaces settings.

Kutbi MarwanA

2009-01-01

356

Computer modeling of a spinal reflex circuit  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

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

2005-12-01

357

Effect of smoking on autonomic reflexes  

Directory of Open Access Journals (Sweden)

Full Text Available Effect of cigarette smoking on autonomic reflexes was tested in 25 male smokers and compared with 25 age, sex matched non smokers.There was insignificant difference between heart rate (HR, blood pressure (BP and other variables between non smokers andsmokers (before smoking. But in smokers after cigarette smoking, the basal HR, basal BP (< 0.001, diastolic BP (p < 0.05 withchange of posture (lying to standing, systolic BP (p < 0.01 on cold pressure test were all increased, while expiration: inspiration(E: 1 ratio (p < 0.01 and S: L ratio (p < 0.05 were reduced. These observations indicate acute rise in sympathetic traffic with someeffect on vagal activity. (Med J Indones 2001; 10: 95-7Keywords : smoking, autonomic reflexes, sympathetic, vagus

K. Singh

2001-05-01

358

Reflexivity in performative science shop projects  

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Full Text Available Science shop research projects offer possibilities for universities to engage with communities. Many science shop projects directly or indirectly intend to empower certain marginalised groups or interests within a decision-making process. In this article we argue that it is important to reflect on the role and position the researchers have in these projects. We present three science shop projects to illustrate some of the dilemmas that may arise in relation to citizen empowerment, democracy, and ethics in the field of action research and community engagement. We present reflexivity as a strategy for creating greater awareness of the power?knowledge relationship, the nature of the democratic process and the consequences of empowerment for other vulnerable groups. Keywords: Action research, community engagement, reflexivity, science shop

Raoul Beunen

2012-08-01

359

Intraoperative recording of the bulbocavernosus reflex.  

Science.gov (United States)

: The bulbocavernosus reflex (BCR) is mediated by the sacral somatic afferent/efferent periphery as well as the sacral cord. Unfortunately, the reflex has suffered from a partly deserved reputation as difficult to implement. However, recent stratagems have improved the test's reliability. Multipulse stimulation (enhanced by double trains as required) and exacting recording technique can yield positive and remarkably reproducible results in patients of all ages and either sex. In this review, we document a 94% baseline BCR acquisition rate among 100 consecutive cases in one institution. Acceptance and routine use of the BCR is needed to help assure optimal post-operative low sacral function in intradural and extradural surgeries at the level of conus medullaris, cauda equina, sacral plexus, and the pudendal nerve. Case studies within this review illustrate the power of the BCR to predict patient outcome or, much more importantly, reverse incipient patient injury in real time. PMID:25083842

Skinner, Stanley A; Voduek, David B

2014-08-01

360

Reflexivity in performative science shop projects  

Directory of Open Access Journals (Sweden)

Full Text Available Science shop research projects offer possibilities for universities to engage with communities. Many science shop projects directly or indirectly intend to empower certain marginalised groups or interests within a decision-making process. In this article we argue that it is important to reflect on the role and position the researchers have in these projects. We present three science shop projects to illustrate some of the dilemmas that may arise in relation to citizen empowerment, democracy, and ethics in the field of action research and community engagement. We present reflexivity as a strategy for creating greater awareness of the power?knowledge relationship, the nature of the democratic process and the consequences of empowerment for other vulnerable groups. Keywords: Action research, community engagement, reflexivity, science shop

Raoul Beunen

2012-08-01

 
 
 
 
361

HEIDEGGER: FROM 'REFLEXIVE' PHENOMENOLOGY TO HERMENEUTIC PHENOMENOLOGY  

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Full Text Available Martin Heidegger makes his initial thought, largely in confrontation with phenomenology of Edmund Husserl. The text aims to show how he tries to overcome the reflexive phenomenology by introducing the element of interpretation. The return to things themselves cannot be performed through suppression of the world and always significance of things, but through the consideration of radical immersion and facticity of human existence, which has always somehow understand herself and other things. In this exercise philosophy becomes original science.

Cezar Lus Seibt

2012-06-01

362

Oculocardiac reflex in laser in situ keratomileusis  

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BACKGROUND: This study was conducted to evaluate variations in heart rate and to determine the occurrence of oculocardiac reflex (OCR) during laser in situ keratomileusis (LASIK). METHODS: This descriptive, prospective study was designed to observe the effect of suction ring and ablation stages during LASIK procedure on the heart rate. The ECG was taken before and during LASIK operation on the first eye in 61 patients. These patients were selected randomly among cases that presented to A...

Alireza Ashtari; Ali Akbar Mortazavi

2006-01-01

363

Reflex anuria affecting both kidneys following hysterectomy  

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In situations when there is unilateral ureteral obstruction, the contralateral kidney retains its normal function. In rare instances however, it has been reported that unilateral ureteral obstruction can lead to reflex anuria (RA) and acute renal failure (ARF). Even more unusually, RA with ARF can occur without organic obstruction due to ureteric manipulation during pelvic surgery. We report a 78- year-old woman, who underwent hysterectomy because of endometrial carcinoma. She developed ARF e...

Gholyaf Mahmoud; Afzali Saeed; Babolhavaegi Hoshang; Rahimi Abolfazl; Wagharseyedayn Seyed

2009-01-01

364

From intensive to reflexive: the prosodic factor  

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Basing itself on a comparative study of English and French, this paper argues that prosody plays a relevant role in the semantic evolution of pronouns in natural languages. All other things being equal, the deaccenting of simplex 3rd-person personal pronouns contributes to favour their topical iterpretation, hence "disjoint reference" effects, which in turn trigger the development of marked strategies for the expression of reflexivity.

Zribi-hertz, Anne

2007-01-01

365

Reflexivity and rigidity for complexes, II: Schemes  

CERN Document Server

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.

Avramov, Luchezar L; Lipman, Joseph

2010-01-01

366

Carbamazepine, clonazepam and focal reflex proprioceptive seizures  

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We studied a 34-year-old man with focal tonic-clonic seizures sometimes elicited by some active postures of the right hand and evolving at times to secondary generalization. Treatment with carbamazepine (CBZ) in combination with parenteral diazepam induced both a dramatic increase of focal reflex proprioceptive seizures and choreoathetoid dyskinesias in the affected hand. CBZ was withdrawn and clonazepam (CZP) given 2 mg daily, with complete relief of seizures and choreoathetoid dyskinesias. ...

Sechi, Gianpietro; Corda, Davide; Deiana, Giovanni Andrea; Contu, Sabrina; Rosati, Giulio

2003-01-01

367

Central pathway of photic reflex myoclonus.  

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Direct, new evidence for the cortical origin of photic reflex myoclonus in a patient with "posterior cortical atrophy" is provided. Photic stimulation elicited myoclonic jerks in the right upper limb muscles. An H2(15)O-PET activation study with photic stimulation showed increased regional cerebral blood flow not only in both striate cortices but in the left premotor and primary motor areas as well. Transcranial magnetic stimulation over the area of the left occipital cortex elicited motor ev...

Kanouchi, T.; Yokota, T.; Kamata, T.; Ishii, K.; Senda, M.

1997-01-01

368

Arakeris Reflex: an Alternative Pathway for Dento-Cardiac Reflex Mediated Syncope  

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Full Text Available Introduction: Dentocardiac reflex, a variant of trigeminocardiac reflex elicited specifically during tooth extraction procedures in den-tal/maxillofacial surgery and is believed to cause syncope with an afferent link mediated by posterior superior alveolar nerve. Another variant of trigeminocardiac reflex which is also of interest to the oral and maxillofacial surgeon is oculocardiac reflex which can be triggered by direct or indirect manipulation of eye globe or muscles around it.The hypothesis: Excessive or injudicious pressure or manipulations around the maxillary first molars during extraction procedure are as-sociated with maximum incidence of bradycardia and hypotension than around incisor/ canine/ third molars. This is because; the pressure on eye globe and ophthalmic rectus muscle is maximum during extraction of first molar than incisor/canine and third molars. This observation led us to postulate an alternative pathway for dentocardiac reflex mediated syncope which may possibly justify the maxillary first molar region as a prone factor for the trigger. Evaluation of the hypothesis: Present hypothesis may not confer the specific factor responsible for switch in autonomic response in syncope origin during the tooth extraction procedure, but may provide a clue to where we should be looking.

Veena Arali

2010-03-01

369

Newborn neurologic screening using NBAS reflexes.  

Science.gov (United States)

The neurologic examination of the newborn infant is not easy. The nurse or physician must have technical skill in handling infants and be familiar with eliciting, scoring, and interpreting reflexes. Because it is too costly to conduct full neurologic exams on all newborns, a screening can be performed to help select infants for whom detailed examination is indicated. Given the trend to discharge term newborns within 12 to 24 hours following delivery and the importance of being sure that abnormalities have not been overlooked prior to discharge, completing a neurologic screen during this early time period is warranted. Although professionals have been trained and certified to conduct Neonatal Behavioral Assessment Scale (NBAS) exams for more than 20 years at NBAS Training Centers, the NBAS text does not adequately explain how to perform reflex assessments so they can be administered reliably across multiple examiners. This article describes how to perform these reflex assessments so they can be used consistently by nurses and physicians as a neurologic screen in a variety of settings. PMID:9325877

Pressler, J L; Hepworth, J T

1997-09-01

370

The swallowing reflex and its significance as an airway defensive reflex  

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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.

TakashiNishino

2013-01-01

371

The role of the superior laryngeal nerve in esophageal reflexes  

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The aim of this study was to determine the role of the superior laryngeal nerve (SLN) in the following esophageal reflexes: esophago-upper esophageal sphincter (UES) contractile reflex (EUCR), esophago-lower esophageal sphincter (LES) relaxation reflex (ELIR), secondary peristalsis, pharyngeal swallowing, and belch. Cats (N = 43) were decerebrated and instrumented to record EMG of the cricopharyngeus, thyrohyoideus, geniohyoideus, and cricothyroideus; esophageal pressure; and motility of LES....

Lang, I. M.; Medda, B. K.; Jadcherla, S.; Shaker, R.

2012-01-01

372

Vestibular control of the head: possible functions of the vestibulocollic reflex  

Science.gov (United States)

Here, we review the angular vestibulocollic reflex (VCR) focusing on its function during unexpected and voluntary head movements. Theoretically, the VCR could (1) stabilize the head in space during body movements and/or (2) dampen head oscillations that could occur as a result of the heads underdamped mechanics. The reflex appears unaffected when the simplest, trisynaptic VCR pathways are severed. The VCRs efficacy varies across species; in humans and monkeys, head stabilization is ineffective during low-frequency body movements in the yaw plan. While the appearance of head oscillations after the attenuation of semicircular canal function suggests a role in damping, this interpretation is complicated by defects in the vestibular input to other descending motor pathways such as gaze premotor circuits. Since the VCR should oppose head movements, it has been proposed that the reflex is suppressed during voluntary head motion. Consistent with this idea, vestibular-only (VO) neurons, which are possible vestibulocollic neurons, respond vigorously to passive, but not active, head rotations. Although VO neurons project to the spinal cord, their contribution to the VCR remains to be established. VCR cancelation during active head movements could be accomplished by an efference copy signal negating afferent activity related to active motion. Oscillations occurring during active motion could be eliminated by some combination of reflex actions and voluntary motor commands that take into account the heads biomechanics. A direct demonstration of the status of the VCR during active head movements is required to clarify the function of the reflex. PMID:21442224

Cullen, Kathleen E.

2013-01-01

373

Middle ear reflex activity in the startle reaction.  

Science.gov (United States)

By means of extratympanic phonometry, the middle ear muscular reflex activity in the startle reaction was measured in a control series, in patients with otosclerosis and in patients with operation cavaties without a functioning tensor tympani muscle. In comparison with the stapedius reflex, the startle reflex was found to be much more variable regarding latency, amplitude, and configuration. It was characterized by pronounced fatigue and a high alertness dependence. The period of latency was about 60 msec. It was possible to elicit a distinct startle reflex in operation cavities without a functioning tensor tympani muscle, probably because of contraction of the Eustachian tube muscles. PMID:1131100

Greisen, O; Neergaard, E B

1975-06-01

374

Cholesteric Liquid Crystal Based Reflex Color Reflective Displays  

Science.gov (United States)

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.

Khan, Asad

2012-02-01

375

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

Science.gov (United States)

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

Dyke, Martin

2009-01-01

376

Lower esophageal sphincter relaxation reflex kinetics: effects of peristaltic reflexes and maturation in human premature neonates.  

Science.gov (United States)

We defined the sensory-motor characteristics of the lower esophageal sphincter relaxation (LESR) (stimulus threshold volume, response onset, and relaxation period, relaxation magnitude, nadir) during maturation in human neonates. We hypothesized that LESR kinetics differs during maturation and with peristaltic reflex type. Basal and adaptive esophageal motility testing was performed (N = 20 premature neonates) at 34.7 and 39.1 wk (time 1 and time 2). Effects of midesophageal provocation with graded stimuli (N = 1,267 stimuli, air and liquids) on LESR kinetics during esophagodeglutition response (EDR) and secondary peristalsis (SP) were analyzed by mixed models. Frequency of LESR with basal primary peristalsis were different during maturation (P = 0.03). During adaptive responses with maturation, 1) the frequencies of peristaltic reflexes and LESR were similar; 2) liquid stimuli resulted in a shorter LESR response latency and LESR nadir and greater LESR magnitude (all P frequency of LESR was greater during peristaltic reflexes at both times (vs. none, P < 0.0001); 2) LESR response latency, duration, and time to complete LESR were longer with EDR (all P < 0.05, vs. SP at time 2); and 3) graded stimulus volume LESR were different for air and liquids (P < 0.01). In conclusion, sensory-motor characteristics of LESR depend on the mechanosensitive properties of the stimulus (media, volume, flow), type of peristaltic reflex, and postnatal maturation. Maturation modulates an increased recruitment of inhibitory pathways that favor LESR. PMID:20864655

Pena, Eneysis M; Parks, Vanessa N; Peng, Juan; Fernandez, Soledad A; Di Lorenzo, Carlo; Shaker, Reza; Jadcherla, Sudarshan R

2010-12-01

377

The Comparison of the Convergence Speed between Picard, Mann, Krasnoselskij and Ishikawa Iterations in Banach Spaces  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of this paper is to compare convergence speed of the Picard and Mann iterations on one hand, Krasnoselskij and Ishikawa iterations on the other hand, for the class of Zamfirescu operators. The results improve corresponding results of (Berinde 2004 and (Babu and Vara Prasad 2006.

Xue Zhiqun

2008-01-01

378

The Comparison of the Convergence Speed between Picard, Mann, Krasnoselskij and Ishikawa Iterations in Banach Spaces  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of this paper is to compare convergence speed of the Picard and Mann iterations on one hand, Krasnoselskij and Ishikawa iterations on the other hand, for the class of Zamfirescu operators. The results improve corresponding results of (Berinde 2004 and (Babu and Vara Prasad 2006.

Zhiqun Xue

2008-03-01

379

On the mild solutions of higher-order differential equations in Banach spaces  

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Full Text Available For the higher-order abstract differential equation u(n(t=Au(t+f(t, t∈ℝ, we give a new definition of mild solutions. We then characterize the regular admissibility of a translation-invariant subspace ℳ of BUC(ℝ,E with respect to the above-mentioned equation in terms of solvability of the operator equation AX−X𝒟n=C. As applications, periodicity and almost periodicity of mild solutions are also proved.

Nguyen Thanh Lan

2003-08-01

380

WEAK SOLUTIONS OF FRACTIONAL ORDER PETTIS INTEGRAL INCLUSIONS WITH MULTIPLE TIME DELAY IN BANACH SPACES  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish Estudiamos la existencia de soluciones dbiles de la inclusin integral no lineal con retardos temporales mltiples. El resultado principal del artculo se basa en el Teorema de Punto Fijo de tipo Mnch y la tcnica de medida de la no-compacidad dbil. [...] Abstract in english We study the existence of weak solutions for nonlinear integral inclusion with multiple time delay. The main result of the paper is based on the fixed point theorem of Mnch type and the technique of measure of weak noncompactness. [...

Mouffak, Benchohra; Fatima-Zohra, Mostefai.

2013-03-01

 
 
 
 
381

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Anna Kisiolek; Ireneusz Kubiaczyk

2005-01-01

382

Integral Boundary Value Problems for Fractional Impulsive Integro Differential Equations in Banach Spaces  

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Full Text Available We study in this paper,the existence of solutions for fractional integro differential equations with impulsive and integral conditions by using fixed point method. We establish the Sufficient conditions and unique solution for given problem. An Example is also explained to the main results.

A. Anguraj

2014-02-01

383

Existence and analyticity of a parabolic evolution operator for nonautonomous linear equations in Banach spaces  

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Full Text Available We give conditions for the parabolic evolution operator to be analytic with respect to a coefficient operator. We also show that the solution of a homogeneous parabolic evolution equation is analytic with respect to the coefficient operator and to the initial data. We apply our results to example that can not be studied by the standard methods.

2009-02-01

384

CONCEPTS OF DICHOTOMY FOR SKEW-EVOLUTION SEMIFLOWS IN BANACH SPACES  

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Full Text Available In this paper we investigate some dichotomy concepts for skew-evolution semiflows in Banachspaces.Our main objective is to estab-lish relations between these concepts.We motivate our approach byillustrative examples.

Mihail Megan

2011-01-01

385

Effect of smoking on autonomic reflexes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Effect of cigarette smoking on autonomic reflexes was tested in 25 male smokers and compared with 25 age, sex matched non smokers.There was insignificant difference between heart rate (HR), blood pressure (BP) and other variables between non smokers andsmokers (before smoking). But in smokers after cigarette smoking, the basal HR, basal BP (< 0.001), diastolic BP (p < 0.05) withchange of posture (lying to standing), systolic BP (p < 0.01) on cold pressure test were all incre...

Singh, K.; Sood, S.

2001-01-01

386

Common fixed points in best approximation for Banach operator pairs with Ciric type I-contractions  

Science.gov (United States)

The common fixed point theorems, similar to those of Ciric [Lj.B. Ciric, On a common fixed point theorem of a Gregus type, Publ. Inst. Math. (Beograd) (N.S.) 49 (1991) 174-178; Lj.B. Ciric, On Diviccaro, Fisher and Sessa open questions, Arch. Math. (Brno) 29 (1993) 145-152; Lj.B. Ciric, On a generalization of Gregus fixed point theorem, Czechoslovak Math. J. 50 (2000) 449-458], Fisher and Sessa [B. Fisher, S. Sessa, On a fixed point theorem of Gregus, Internat. J. Math. Math. Sci. 9 (1986) 23-28], Jungck [G. Jungck, On a fixed point theorem of Fisher and Sessa, Internat. J. Math. Math. Sci. 13 (1990) 497-500] and Mukherjee and Verma [R.N. Mukherjee, V. Verma, A note on fixed point theorem of Gregus, Math. Japon. 33 (1988) 745-749], are proved for a Banach operator pair. As applications, common fixed point and approximation results for Banach operator pair satisfying Ciric type contractive conditions are obtained without the assumption of linearity or affinity of either T or I. Our results unify and generalize various known results to a more general class of noncommuting mappings.

Hussain, N.

2008-02-01

387

Una nota sobre el teorema de punto fijo de Banach en la solucion de sistemas de ecuaciones lineales algebraicas  

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Full Text Available En el presente artculo se muestra una nota sobre el teorema de punto fijo de Banach en la solucin de sistemas de ecuaciones lineales algebraicas y las condiciones que debe cumplir un operador asociado a dichos sistemas para que sea una contraccin en y por tanto tenga solucin nica.

PEDRO PABLO C\\u00C1RDENAS A.

2008-01-01

388

The Locally Uniform Nonsquare in Generalized Cesro Sequence Spaces  

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Full Text Available Abstract We show that the generalized Cesro sequence spaces possess the locally uniform nonsquare and have the fixed point property, but they are not uniformly nonsquare. This result is related to the result of the paper by J. Falset et al. (2006 by giving the examples and the motivation to find the geometric properties that are weaker than uniformly nonsquare but still possess the fixed point property in any Banach spaces.

Petrot Narin

2008-01-01

389

Fixed Points, Inner Product Spaces, and Functional Equations  

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Full Text Available Rassias introduced the following equality , , for a fixed integer . Let be real vector spaces. It is shown that, if a mapping satisfies the following functional equation for all with , which is defined by the above equality, then the mapping is realized as the sum of an additive mapping and a quadratic mapping. Using the fixed point method, we prove the generalized Hyers-Ulam stability of the above functional equation in real Banach spaces.

Park Choonkil

2010-01-01

390

Reflexivity of Discomfort in Insider-Outsider Educational Research  

Science.gov (United States)

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

Hamdan, Amani K.

2009-01-01

391

Does total knee arthroplasty affect the patellar tendon reflex?  

Directory of Open Access Journals (Sweden)

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.

Richard Jamieson

2010-02-01

392

Space  

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Full Text Available Two issues are explored in this article: the way in which "space" has been theorized in relation to the "sacred", and the use of contemporary cultural and social theories of space in the development of a methodology for locating religion in places, objects, bodies and groups open to investigation. After a brief recollection of the spatial contributions of van der Leeuw and Eliade, attention is given to the theoretical and methodological insights of Jonathan Z. Smith, Veikko Anttonen, and Kim Knott.

Kim Knott

2005-12-01

393

Vibration paradox and H-reflex suppression: is H-reflex suppression results from distorting effect of vibration?  

Science.gov (United States)

Vibration paradox is that an increase in muscles activity coexists with the inhibition of H-reflex during vibration. The H-reflex suppression may be due to the movement of stimulating electrode during vibration. The aim of this study was to test this hypothesis. Fifteen healthy young adult males participated in this study. The soleus myoelectrical activities were evaluated by surface electromyography (SEMG). The vibration was applied only to the left leg and the H-reflex of soleus muscle was measured in the right leg to prevent the probable measurement errors caused by the movement of stimulating electrode. The Hmax/Mmax ratio of the right soleus isolated from vibration effects significantly decreased during the left leg vibration. As a result, this study shows that the H-reflex is suppressed during the vibration and the movement of the stimulating electrode has no role on the suppression of H-reflex. PMID:25198227

Cakar, H I; Cidem, M; Kara, S; Karacan, I

2014-09-01

394

Leukocoria and the red reflex test  

Directory of Open Access Journals (Sweden)

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.

Mirna Yae Yassuda Tamura

2009-09-01

395

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

396

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)

397

Distrofia simptico-reflexa / Reflex sympathetic dystrophy  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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.

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

398

Aerial righting reflexes in flightless animals.  

Science.gov (United States)

Animals that fall upside down typically engage in an aerial righting response so as to reorient dorsoventrally. This behavior can be preparatory to gliding or other controlled aerial behaviors and is ultimately necessary for a successful landing. Aerial righting reflexes have been described historically in various mammals such as cats, guinea pigs, rabbits, rats, and primates. The mechanisms whereby such righting can be accomplished depend on the size of the animal and on anatomical features associated with motion of the limbs and body. Here we apply a comparative approach to the study of aerial righting to explore the diverse strategies used for reorientation in midair. We discuss data for two species of lizards, the gecko Hemidactylus platyurus and the anole Anolis carolinensis, as well as for the first instar of the stick insect Extatosoma tiaratum, to illustrate size-dependence of this phenomenon and its relevance to subsequent aerial performance in parachuting and gliding animals. Geckos can use rotation of their large tails to reorient their bodies via conservation of angular momentum. Lizards with tails well exceeding snout-vent length, and correspondingly large tail inertia to body inertia ratios, are more effective at creating midair reorientation maneuvers. Moreover, experiments with stick insects, weighing an order of magnitude less than the lizards, suggest that aerodynamic torques acting on the limbs and body may play a dominant role in the righting process for small invertebrates. Both inertial and aerodynamic effects, therefore, can play a role in the control of aerial righting. We propose that aerial righting reflexes are widespread among arboreal vertebrates and arthropods and that they represent an important initial adaptation in the evolution of controlled aerial behavior. PMID:21930662

Jusufi, Ardian; Zeng, Yu; Full, Robert J; Dudley, Robert

2011-12-01

399

The oculocardiac reflex in aponeurotic blepharoptosis surgery.  

Science.gov (United States)

The purpose of this study was to investigate the correlation between the oculocardiac reflex (OCR) and blepharoptosis surgery for safe eyelid surgery. Fifty-four consecutive patients with bilateral aponeurotic blepharoptosis were enrolled in this study. Changes in electrocardiography (ECG) monitoring were recorded during surgery. Preoperative pressing on the globe and intraoperative stretching of the levator aponeurosis were also carried out and the occurrence rate of the OCR was recorded. A positive OCR was observed in 12 patients (22.2%) in the preoperative globe-pressing test, whereas a positive OCR was observed in 22 patients (40.7%) in the levator-stretching test. The levator-stretching test did not indicate a significant difference in the rate of heart rate decrease with respect to laterality. No correlation was observed between age and the occurrence of OCR. On the other hand, there was a significant difference in the percentage of heart rate decrease between patients with positive OCR and negative OCR as determined in the globe-pressing test (mean = 13.1% vs. 5.4%). During the practical operative manoeuvre, no bradycardia was observed in any case. This study confirmed that a rapid and strong traction of levator aponeurosis induces the OCR regardless of laterality and age. Atraumatic and gentle handling are essential to prevent OCR. The preoperative globe-pressing test may be an index of the OCR in reflex-prone patients. Intraoperative ECG monitoring will be useful for early onset detection, although positive OCR was not observed in any patient during the practical surgical manoeuvre. PMID:24828860

Uda, Hirokazu; Sugawara, Yasusih; Sarukawa, Syunji; Sunaga, Ataru

2014-06-01

400

Is Palmomental Reflex Actually A Part of Feeding Behavior?  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose and hypothesis: Palmomental reflex is considered to be a primitive reflex and related to pathologic processes. The reflex can be obtained from every individual by electrophysiologic measures. There have been no reports concerning submental, orbicularis oris and masseter muscle reflex responses provoked by median nerve stimulation in healthy elderly individuals and patients with dementia up to now.Method: In the present study the median nerve was stimulated below the pain threshold and activities obtained from mental, submental, orbicularis oris and masseter muscles were recorded simultaneously in patients with dementia (n = 18 and in healthy elderly individuals (n = 18.Result: Latencies obtained from mental, submental, orbicularis oris and masseter muscles were approximately recorded within 80 100 milliseconds and the differences between the latencies were not statistically significant.Conclusion: The palmomental reflex seems to be an activity co-occurring with functions like mouth opening and swallowing, and reflecting hand mouth reaction, rather than being only a primitive reflex involving mental muscle. We believe close temporal relationship among the activities of mental, submental, orbicularis oris and masetter muscles after hand stimulation requires these reflexes to be investigated in the physiology of hand and mouth coordination in further studies.

Burcu UGUREL

2009-06-01

 
 
 
 
401

Voluntary, non-visual control of the human vestibulo-ocular reflex.  

Science.gov (United States)

Voluntary control of the human vestibulo-ocular reflex with and without visual targets was investigated. Subjects were rotated sinusoidally from 0.1 to 1.0 Hz using d.c. electro-oculography to record eye position. The ratio of eye to head movement, or gain, of the vestibulo-ocular reflex was measured. When subjects were rotated in the dark at 0.3 Hz whilst performing mental arithmetic the gain was 0.65. When subjects were asked to fixate imaginary targets in the dark that were stationary in space, the gain rose to 0.95. When they imagined targets rotating with them on the chair, the gain dropped to 0.35. Our results indicate that the ability to modulate the gain of the vestibulo-ocular reflex does not depend entirely on the smooth pursuit system. Higher centers must modulate eye velocity so that it is appropriate to the subject's choice of a frame of reference, whether or not vision is available. PMID:1274550

Barr, C C; Schultheis, L W; Robinson, D A

1976-01-01

402

Interindividual differences in H reflex modulation during normal walking  

DEFF Research Database (Denmark)

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.

Simonsen, Erik B; Dyhre-Poulsen, Poul

2002-01-01

403

The functional and pragmatic features of assonance phraseological reflexes  

Directory of Open Access Journals (Sweden)

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.

Shkapenko T.

2014-09-01

404

ARENS REGULARITY OF SOME BILINEAR MAPS  

Directory of Open Access Journals (Sweden)

Full Text Available Let H be a Hilbert space. we show that the following statements are equivalent: (a B(H is finite dimension, (b every left Banach module action l : B(HH ? H, is Arens regular (c every bilinear map f : B(H*? B(H is Arens regular. Indeed we show that a Banach space X is reflexive if and only if every bilinear map f : X* X ? X* is Arens regular.

M. ESHAGHI GORDJI

2009-05-01

405

ARENS REGULARITY OF SOME BILINEAR MAPS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Let H be a Hilbert space. we show that the following statements are equivalent: (a) B(H) is finite dimension, (b) every left Banach module action l : B(H)H ? H, is Arens regular (c) every bilinear map f : B(H)*? B(H) is Arens regular. Indeed we show that a Banach space X is reflexive if and only if every bilinear map f : X* X ? X* is Arens regular.

Eshaghi Gordji, M.

2009-01-01

406

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 current was applied. Direct current was administered for 5 minutes at an intensity no greater than 4 m A.A complete randomized block with one sample in each block was used. Paired t-test with Scheffe correction for multiple comparisons were used.A significant in H-refelx amplitude was demonstrated for 5 minutes at an intensity no greate than 4 m A. a complete randomized block with one sample in each block was used. Paired t-test with Scheffe correction for multiple comparisons were use.A significant in H-reflex amplitude was demonstrated for all post baseline measurements when compared to baseline. These results suggest that direct current has a facilitatory effect on motoneuron reflex excitability. In addition, motoneuron reflex excitability remained increased for 10 minutes after stimulus had been turned off

Olyaei G

2000-08-01

407

Tonic adrenergic and serotonergic inhibition of a withdrawal reflex in rabbits subjected to different levels of surgical preparation.  

Science.gov (United States)

The excitability of the heel-gastrocnemius withdrawal reflex pathway has been monitored in rabbits undergoing surgical preparation for electrophysiological experimentation under Saffan anaesthesia. Reflexes were evoked by percutaneous electrodes inserted at the heel and recorded as electromyograph signals from the ipsilateral medial gastrocnemius muscle. Two levels of surgery were carried out. The "full surgical" preparation was performed under deep Saffan anaesthesia. The trachea, carotid artery, jugular vein and intrathecal space (via a small laminectomy at L1) were cannulated, the animals were decerebrated by suction, and the left hindlimb was immobilized by screw clamps applied to the tibia and the femur. The sciatic nerve and its branches were exposed by bisection of the posterior biceps muscle and the anaesthetic was withdrawn. In the "reduced surgery" preparation, procedures were carried out with a lighter level of Saffan anaesthesia and operated tissues were infiltrated with local anaesthetic. Only the cannulations were performed in these animals. The excitability of the heel-gastrocnemius reflex declined throughout the full surgical preparation, with the median threshold increasing from 0.8 to 4.2 mA (n=19) and responses to suprathreshold stimuli reducing in size. Most of this effect was reversed after surgery was complete and anaesthesia withdrawn subsequent to decerebration. There were no significant changes in reflex excitability during the reduced surgery preparation (n = 15). Animals prepared by each of these protocols were given increasing intrathecal doses of either the selective alpha2-adrenoceptor antagonist RX 821002 (0.3 to 300 microg) or the serotonin/5-hydroxytryptamine (5-HT)1A-receptor antagonist WAY-100635 (0.01 to 30 microg). Both drugs caused significant, dose-dependent increases in reflex responses, to four to six times pre-drug control in both groups of animals. There were no differences in the effects on reflexes of either drug between the preparations. Thus, surgical preparation of decerebrated rabbits for electrophysiological recording results in depression of hindlimb withdrawal reflexes, although much of this effect did not persist beyond the completion of surgery. Tonic monoaminergic inhibition of reflexes was present to the same extent in both preparations investigated and is not therefore an epiphenomenon of the way in which the animals were prepared. PMID:10362312

Ogilvie, J; Simpson, D A; Clarke, R W

1999-01-01

408

Fixed point theory in distance spaces  

CERN Document Server

This is a monograph on fixed point theory, covering the purely metric aspects of the theoryparticularly results that do not depend on any algebraic structure of the underlying space. Traditionally, a large body of metric fixed point theory has been couched in a functional analytic framework. This aspect of the theory has been written about extensively. There are four classical fixed point theorems against which metric extensions are usually checked. These are, respectively, the Banach contraction mapping principal, Nadlers well known set-valued extension of that theorem, the extension of Banachs theorem to nonexpansive mappings, and Caristis theorem. These comparisons form a significant component of this book. This book is divided into three parts. Part I contains some aspects of the purely metric theory, especially Caristis theorem and a few of its many extensions. There is also a discussion of nonexpansive mappings, viewed in the context of logical foundations. Part I also contains certain re...

Kirk, William

2014-01-01

409

Sustainable Development: Representing a Reflexive Modernity Inside the United Nations  

Directory of Open Access Journals (Sweden)

Full Text Available This paper suggests that the discourse of sustainable development (SD within the United Nations (UN represents a paradigm shift from first/industrial modernity to a reflexive modernity. Reflexive modernity is defined by the changing nature of political structures in the face of globalised environmental risk, as well as a questioning of the hegemony of the scientific process as a basis for the development of humanity and the planet. SD is a concept that innately reflects these concerns, questioning normative assumptions. This paper will argue that the rise of SD in governance discourse is not only a catalyst for a reflexive modernity, but also is representative of a modernity that is already in a state of reflexivity. This proposition is examined by exploring the various ways that SD is utilised in the governance structure of the United Nations (UN.

Dr. Gregory Borne

2010-01-01

410

[A method for recording the human periodontal muscular reflex].  

Science.gov (United States)

Principal block-diagram and characteristics of devices recording the parameters of periodontal muscular reflex in humans are presented. Twenty healthy volunteers aged 20 to 30 years with full dentition and normal occlusion and temporomandibular articulations unchanged were studied. Parameters of periodontal muscular reflex showed no bilateral asymmetry. Temporal muscles displayed 15 +/- 0.87 s latencies, masseters 13 +/- 0.8 latencies. Silent periods in temporal muscles were 22 +/- 0.89 ms and in masseters 24 +/- 0.75 ms. In patients with mandibular fractures the time of periodontal muscular reflex was increased up to 3-4-fold as compared to that in normal subjects. The indices of the reflex are clearly different in normal and pathological conditions. This technique is useful both in scientific and diagnostic purposes. PMID:2749808

Malevich, O E; Zhitni?, N I; Chirkin, V I; Ivashenko, M V

1989-01-01

411

Soleus H-reflex excitability during pedaling post-stroke  

DEFF Research Database (Denmark)

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.

Schindler-Ivens, Sheila; Brown, David A.

2008-01-01

412

Prophylaxis of an acute vomiting reflex using orthopedic methods  

Directory of Open Access Journals (Sweden)

Full Text Available With increased gag reflex to eliminate the irritant prosthesis is crucial is not the length of the base and close fitting and uniformity of immersion in a tissue prosthesis prosthetic bed. Based on our observations, we recommend that you use before removing the impressions of patients with an increased gag reflex nasal vasoconstrictor medications that have a positive impact on reducing the sensitivity of emetic receptors throat

Dmitrieva N.V.

2011-03-01

413

Reflex control of ipsilateral and contralateral paraspinal muscles  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Homonymous and heteronymous reflex connections of the paraspinal muscles were investigated by the application of a tap to the muscle bellies of the lumbar multifidus and iliocostalis lumborum muscles and observation of surface electromyographic responses in the same muscles on both sides of the trunk. Reflexes were evoked in each of the homonymous muscles with latencies and estimated conduction velocities compatible with being evoked by Ia muscle afferents and having a monosynaptic component....

Beith, Iain D.

2012-01-01

414

Functional principal component analysis of H-reflex recruitment curves  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The primary purpose of this study was to use Functional Principal Component Analysis (FPCA) to analyze Hoffman-reflex (H-Reflex) recruitment curves. Smoothed and interpolated recruitment curves from 38 participants were used for analysis. Standard methods were used to calculate three discrete variables (i.e, Hmax/Mmax ratio, Hth, Hslp). FPCA was then used to extract principal component functions (PCFs) from the processed recruitment curves. PCF scores were calculated to determine how much ...

Kipp, Kristof; Johnson, Samuel T.; Hoffman, Mark A.

2011-01-01

415

Reversible abnormalities of the Hering Breuer reflex in acrylamide neuropathy.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The sensitivity of the Hering Breuer reflex was compared in anaesthetised rabbits before, during and after the induction of acrylamide neuropathy, and was measured as the tracheal pressure which produced 30 seconds of apnoea. After four weeks of acrylamide (400 mg/kg total dose) there was ataxia and the conduction velocity of hindlimb motor nerves was significantly reduced. At this time there was a marked and reproducible reduction in the sensitivity of the Hering Breuer reflex. The ataxia re...

Satchell, P.

1985-01-01

416

Prophylaxis of an acute vomiting reflex using orthopedic methods  

Digital Repository Infrastructure Vision for European Research (DRIVER)

With increased gag reflex to eliminate the irritant prosthesis is crucial is not the length of the base and close fitting and uniformity of immersion in a tissue prosthesis prosthetic bed. Based on our observations, we recommend that you use before removing the impressions of patients with an increased gag reflex nasal vasoconstrictor medications that have a positive impact on reducing the sensitivity of emetic receptors throat

Dmitrieva N.V.; Salnikov V.N.; Konnov V.V.; Salnikova S.N.

2011-01-01

417

Muscle reflex in heart failure: the role of exercise training  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Wang, Han-jun; Zucker, Irving H.; Wang, Wei

2012-01-01

418

Mechanical Characteristics of Reflex Durign Upright Posture in Paralyzed Subjects  

Science.gov (United States)

The characteristics of flexor reflexes have been investigated in the previous studies with human subjects who were seated or supine position. However, researchers did not describe how the spinal circuits are used in different hip angles for paralyzed subjects, such as the standing position with walker or cane. In upright posture the compatibility between a flexor reflex of leg and body balance is a special problem for lower limb injured subjects. Therefore, the purpose of this study was to investigate the effects of hip angle change on the flexor reflex evoked in standing paralyzed subjects supported by walker. In this study, six spinal cord injured and four stroke subjects were recruited through the inpatient physical therapy clinics of Korea national rehabilitation hospital. A single axis electronic goniometer was mounted on the lateral side of the hip joint of the impaired limb to record movements in the sagittal plane at this joint. The electronic goniometer was connected to a data acquisition system, through amplifiers to a computer. Since subject' posture influenced characteristics of the flexion reflex response, the subjects were supported in an upright posture by the help of parallelogram walder. Two series of tests were performed on each leg. The first series of the tests investigated the influence of hip angle during stationary standing posture on flexion reflex response. The hip angle was adjusted by the foot plate. The second examined the effect of the voluntary action of subject on swing motion during the gait. The electrically induced flexion reflex simultaneously produced the flexion of the hip, knee and dorsiflexion of the ankle enabling the swing phase of walking. Form the experimental results we observed that the reflex response of hip joint was largerwith the hip in the extended position than in the flexed position during standing posture. Under voluntary movement on flexion reflex during gaint, the peak hip angle induced by stimulation was increased in spinal cord injury and stroke patients by subject' voluntary movement.

Kim, Yongchul; Youm, Youngil; Lee, Bumsuk; Kim, Youngho; Choi, Hyeonki

419

A Noncommutative Wiener Lemma and A Faithful Tracial State on Banach Algebras of Time-Frequency Shift Operators  

CERN Document Server

In this paper we analyze the Banach *-algebra of time-frequency shifts with absolutely summable coefficients. We prove a noncommutative version of the Wiener lemma. We also construct a faithful tracial state on this algebra which implies the algebra contains no compact operators. As a corollary we obtain a special case of the Heil-Ramanathan-Topiwala conjecture regarding linear independence of finitely many time-frequency shifts of one $L^2$ function.

Balan, R

2005-01-01

420

Cortical control of hering-breuer reflexes in anesthetized rats  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract It had been hypothesized that the regions of prefrontal cortex which are involved in respiratory control can modulate Hering-Breuer reflexes evoked by vagal input from pulmonary stretch receptors. In the present study, experiments were performed on urethane anesthetized spontaneously breathing Wistar rats. The expiratory-promoting reflex was evaluated from changes in expiratory time immediately after airway occlusion at the end of inspiration. The inspiratory-inhibitory reflex was estimated from changes in inspiratory time provoked by airway occlusion at the end of expiration. The results indicate that electrical microstimulation of the responsive sites within the insular cortex significantly weakened both expiratory-promoting and inspiratory-inhibitory reflex. Activation of the infralimbic cortex depressed expiratory-promoting reflex, but inspiratory-inhibitory reflex was enhanced. These results suggest that stimulation of the prefrontal cortex influences vagally mediated control of the respiratory phases timing and several regions of the prefrontal cortex modulate distinct sets of neurons in the network controlling inspiratory and expiratory phases of a breath cycle.

Aleksandrov VG

2009-12-01

 
 
 
 
421

Faroese long-distance reflexives face off against Icelandic long-distance reflexives  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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)

Strahan, Tania E.

2009-01-01

422

Contractive projections and operator spaces  

CERN Document Server

Parallel to the study of finite dimensional Banach spaces, there is a growing interest in the corresponding local theory of operator spaces. We define a family of Hilbertian operator spaces H_n^k,0< k < n+1, generalizing the row and column Hilbert spaces R_n,C_n and show that an atomic subspace X of B(H) which is the range of a contractive projection on B(H) is isometrically completely contractive to a direct sum of the H_n^k and Cartan factors of types 1 to 4. In particular, for finite dimensional X, this answers a question posed by Oikhberg and Rosenthal. Explicit in the proof is a classification up to complete isometry of atomic w*-closed JW*-triples without an infinite dimensional rank 1 w^*-closed ideal

Neal, M; Neal, Matthew; Russo, Bernard

2002-01-01

423

Aging attenuates the vestibulosympathetic reflex in humans  

Science.gov (United States)

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 (Pdecubitus position did not elicit hypotension. MSNA responses to baroreceptor unloading and the cold 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.

Ray, Chester A.; Monahan, Kevin D.

2002-01-01

424

Reflex anuria affecting both kidneys following hysterectomy  

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Full Text Available In situations when there is unilateral ureteral obstruction, the contralateral kidney retains its normal function. In rare instances however, it has been reported that unilateral ureteral obstruction can lead to reflex anuria (RA and acute renal failure (ARF. Even more unusually, RA with ARF can occur without organic obstruction due to ureteric manipulation during pelvic surgery. We report a 78- year-old woman, who underwent hysterectomy because of endometrial carcinoma. She developed ARF evidenced by anuria of 120-hours duration, and gradual rise of serum creatinine levels to 11.8 mg/dL on the fifth day after hysterectomy. Ultrasound study of the urinary tract revealed bilateral moderate hydronephrosis. Detailed evaluation did not reveal any organic obstruc-tion. She was managed with hemodialysis, control of hypertension and correction of fluid and elec-trolyte imbalances. By the sixth day, diuresis was established, and the blood urea and serum crea-tinine levels decreased to normal by the sixteenth day. The patient was finally discharged on the eighteenth day. Our case suggests that urologists and nephrologists should consider RA as one of the causes of anuria and ARF.

Gholyaf Mahmoud

2009-01-01

425

Interoception and autonomic nervous system reflexes thermoregulation.  

Science.gov (United States)

Important conceptual changes concerning human thermoregulation have occurred in the last decade. While the hypothalamus maintains its central role in sensing core temperature and providing connectivity to orchestrate heat loss and cold defense autonomic neuronal mechanisms, it is now regarded as one of multiple, independent thermoeffector pathways that control core body temperature. Recent research in primate central and peripheral thermosensitivity has emphasized the importance of temperature-activated transient receptor potential (TRP) channels and afferent neuronal pathways from peripheral thermosensors that are activated by unique combinations of core and shell temperature. The interoceptive aspects of behavioral thermoregulation have been emphasized including the primary importance of shell (skin) temperature, the concept of thermal discomfort and the important contribution of orbitofrontal, insular, somatosensory, and amygdala cortical regions deployed to anticipate and avoid thermal stress. Clinical testing of human thermoregulation requires afferent stimuli to activate the independent thermoeffector loops while monitoring an efferent response. Patterns of sweat gland activation, amount of sweat produced, and areas of anhidrosis demonstrated by the thermoregulatory and axon reflex sweat testing provide diagnostic information about neurological and medical disorders of the autonomic nervous system. PMID:24095117

Fealey, Robert D

2013-01-01

426

Impaired Sacculocollic Reflex in Lateral Medullary Infarction  

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Full Text Available Objective: The aim of this study was to determine saccular dysfunction by measuring cervical vestibular-evoked myogenic potentials (cVEMP and to correlate abnormality of cVEMP with results of other vestibular function tests in lateral medullary infarction (LMI. Methods: We recorded cVEMP in 21 patients with LMI documented on MRI. cVEMP was induced by a short tone burst and was recorded in contracting sternocleidomastoid muscle while patients turned their heads forcefully to the contralateral side against resistance. Patients also underwent video-oculographic recording of spontaneous, gaze-evoked and head-shaking (HSN nystagmus, evaluation of ocular tilt reaction (OTR, measurement of the subjective visual vertical (SVV tilt, bithermal caloric tests and audiometry. Results: Nine patients (43% showed abnormal cVEMP, unilateral in seven and bilateral in two. The cVEMP abnormalities included decreased p13-n23 amplitude in four, delayed p13/n23 responses in five, and both decreased and delayed responses in two. The abnormal cVEMP was ipsilesional in five, contralesional in two, and bilateral in two. The prevalence of OTR/SVV tilt, spontaneous nystagmus, and HSN did not differ between the patients with normal and abnormal cVEMP. Conclusion: cVEMP was abnormal in approximately half of the patients with LMI. The abnormal cVEMP indicates damage to the descending sacculocollic reflex pathway or disruption of commissural modulation between the vestibular nuclei.

SeonhyeKim

2011-02-01

427

Impaired Sacculocollic Reflex in Lateral Medullary Infarction  

Science.gov (United States)

Objective: The aim of this study was to determine saccular dysfunction by measuring cervical vestibular-evoked myogenic potentials (cVEMP) and to correlate abnormality of cVEMP with results of other vestibular function tests in lateral medullary infarction (LMI). Methods: We recorded cVEMP in 21 patients with LMI documented on MRI. cVEMP was induced by a short tone burst and was recorded in contracting sternocleidomastoid muscle while patients turned their heads forcefully to the contralateral side against resistance. Patients also underwent video-oculographic recording of spontaneous, gaze-evoked and head shaking nystagmus (HSN), evaluation of ocular tilt reaction (OTR), measurement of the subjective visual vertical (SVV) tilt, bithermal caloric tests, and audiometry. Results: Nine patients (43%) showed abnormal cVEMP, unilateral in seven and bilateral in two. The cVEMP abnormalities included decreased p13n23 amplitude in four, delayed p13/n23 responses in five, and both decreased and delayed responses in two. The abnormal cVEMP was ipsilesional in five, contralesional in two, and bilateral in two. The prevalence of OTR/SVV tilt, spontaneous nystagmus, and HSN did not differ between the patients with normal and abnormal cVEMP. Conclusion: cVEMP was abnormal in approximately half of the patients with LMI. The abnormal cVEMP indicates damage to the descending sacculocollic reflex pathway or disruption of commissural modulation between the vestibular nuclei. PMID:21415908

Kim, Seonhye; Kim, Hyo-Jung; Kim, Ji Soo

2011-01-01

428

Minimum Cost Homomorphisms to Reflexive Digraphs  

CERN Document Server

For digraphs $G$ and $H$, a homomorphism of $G$ to $H$ is a mapping $f:\\ V(G)\\dom V(H)$ such that $uv\\in A(G)$ implies $f(u)f(v)\\in A(H)$. If moreover each vertex $u \\in V(G)$ is associated with costs $c_i(u), i \\in V(H)$, then the cost of a homomorphism $f$ is $\\sum_{u\\in V(G)}c_{f(u)}(u)$. For each fixed digraph $H$, the {\\em minimum cost homomorphism problem} for $H$, denoted MinHOM($H$), is the following problem. Given an input digraph $G$, together with costs $c_i(u)$, $u\\in V(G)$, $i\\in V(H)$, and an integer $k$, decide if $G$ admits a homomorphism to $H$ of cost not exceeding $k$. We focus on the minimum cost homomorphism problem for {\\em reflexive} digraphs $H$ (every vertex of $H$ has a loop). It is known that the problem MinHOM($H$) is polynomial time solvable if the digraph $H$ has a {\\em Min-Max ordering}, i.e., if its vertices can be linearly ordered by $<$ so that $i

Gupta, Arvind; Karimi, Mehdi; Rafiey, Arash

2007-01-01

429

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

Science.gov (United States)

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 hopping were recorded in the soleus and gastrocnemius muscles and were analyzed before, during (only the H-reflex), immediately after, 5 min and 10 min after WBV. The main findings were that (1) the H-reflexes were significantly reduced during and at least up to 5 min after WBV, (2) the stretch reflex amplitudes were also significantly reduced immediately after WBV but recovered to their initial amplitudes within 5 min, and (3) the SLR during hopping showed no vibration-induced modulation. With regard to the modalities with low motor complexities, the decreased H- and stretch reflex responses are assumed to point toward a reduced Ia afferent transmission during and after WBV. However, it is assumed that during hopping, the suppression of reflex sensitivity is compensated by facilitatory mechanisms in this complex motor task. PMID:23802287

Ritzmann, R; Kramer, A; Gollhofer, A; Taube, W

2013-06-01

430

A method of reflexive balancing in a pragmatic, interdisciplinary and reflexive bioethics.  

Science.gov (United States)

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

Ives, Jonathan

2014-07-01

431

Variable Lebesgue spaces and hyperbolic systems  

CERN Document Server

This book targets graduate students and researchers who want to learn about Lebesgue spaces and solutions to hyperbolic equations. It is divided into two parts. Part 1 provides an introduction to the theory of variable Lebesgue spaces: Banach function spaces like the classical Lebesgue spaces but with the constant exponent replaced by an exponent function. These spaces arise naturally from the study of partial differential equations and variational integrals with non-standard growth conditions. They have applications to electrorheological fluids in physics and to image reconstruction. After an introduction that sketches history and motivation, the authors develop the function space properties of variable Lebesgue spaces; proofs are modeled on the classical theory. Subsequently, the Hardy-Littlewood maximal operator is discussed. In the last chapter, other operators from harmonic analysis are considered, such as convolution operators and singular integrals. The text is mostly self-contained, with only some mor...

2014-01-01

432

Linear time delay methods and stability analyses of the human spine. Effects of neuromuscular reflex response.  

Science.gov (United States)

Linear stability methods were applied to a biomechanical model of the human musculoskeletal spine to investigate effects of reflex gain and reflex delay on stability. Equations of motion represented a dynamic 18 degrees-of-freedom rigid-body model with time-delayed reflexes. Optimal muscle activation levels were identified by minimizing metabolic power with the constraints of equilibrium and stability with zero reflex time delay. Muscle activation levels and associated muscle forces were used to find the delay margin, i.e., the maximum reflex delay for which the system was stable. Results demonstrated that stiffness due to antagonistic co-contraction necessary for stability declined with increased proportional reflex gain. Reflex delay limited the maximum acceptable proportional reflex gain, i.e., long reflex delay required smaller maximum reflex gain to avoid instability. As differential reflex gain increased, there was a small increase in acceptable reflex delay. However, differential reflex gain with values near intrinsic damping caused the delay margin to approach zero. Forward-dynamic simulations of the fully nonlinear time-delayed system verified the linear results. The linear methods accurately found the delay margin below which the nonlinear system was asymptotically stable. These methods may aid future investigations in the role of reflexes in musculoskeletal stability. PMID:18701383

Franklin, Timothy C; Granata, Kevin P; Madigan, Michael L; Hendricks, Scott L

2008-08-01

433

ESO Reflex: a graphical workflow engine for data reduction  

Science.gov (United States)

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.

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

434

The role of the superior laryngeal nerve in esophageal reflexes.  

Science.gov (United States)

The aim of this study was to determine the role of the superior laryngeal nerve (SLN) in the following esophageal reflexes: esophago-upper esophageal sphincter (UES) contractile reflex (EUCR), esophago-lower esophageal sphincter (LES) relaxation reflex (ELIR), secondary peristalsis, pharyngeal swallowing, and belch. Cats (N = 43) were decerebrated and instrumented to record EMG of the cricopharyngeus, thyrohyoideus, geniohyoideus, and cricothyroideus; esophageal pressure; and motility of LES. Reflexes were activated by stimulation of the esophagus via slow balloon or rapid air distension at 1 to 16 cm distal to the UES. Slow balloon distension consistently activated EUCR and ELIR from all areas of the esophagus, but the distal esophagus was more sensitive than the proximal esophagus. Transection of SLN or proximal recurrent laryngeal nerves (RLN) blocked EUCR and ELIR generated from the cervical esophagus. Distal RLN transection blocked EUCR from the distal cervical esophagus. Slow distension of all areas of the esophagus except the most proximal few centimeters activated secondary peristalsis, and SLN transection had no effect on secondary peristalsis. Slow distension of all areas of the esophagus inconsistently activated pharyngeal swallows, and SLN transection blocked generation of pharyngeal swallows from all levels of the esophagus. Slow distension of the esophagus inconsistently activated belching, but rapid air distension consistently activated belching from all areas of the esophagus. SLN transection did not block initiation of belch but blocked one aspect of belch, i.e., inhibition of cricopharyngeus EMG. Vagotomy blocked all aspects of belch generated from all areas of esophagus and blocked all responses of all reflexes not blocked by SLN or RLN transection. In conclusion, the SLN mediates all aspects of the pharyngeal swallow, no portion of the secondary peristalsis, and the EUCR and ELIR generated from the proximal esophagus. Considering that SLN is not a motor nerve for any of these reflexes, the role of the SLN in control of these reflexes is sensory in nature only. PMID:22403790

Lang, I M; Medda, B K; Jadcherla, S; Shaker, R

2012-06-15

435

Gravity and Development of Cardiopulmonary Reflex  

Science.gov (United States)

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.

Nagaoka, Shunji; Eno, Yuko; Ohira, Yoshinobu

436

The Locally Uniform Nonsquare in Generalized Cesàro Sequence Spaces  

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Full Text Available We show that the generalized Cesàro sequence spaces possess the locally uniform nonsquare and have the fixed point property, but they are not uniformly nonsquare. This result is related to the result of the paper by J. Falset et al. (2006 by giving the examples and the motivation to find the geometric properties that are weaker than uniformly nonsquare but still possess the fixed point property in any Banach spaces.

Narin Petrot

2008-12-01

437

Early Modern ET, Reflexive Telescopics, and Their Relevance Today  

Science.gov (United States)

The period from the discovery of Tycho's New Star in 1572 to Galileo's "geometrization of astronomical space" in 1610 (and the years following) saw the disintegration of the boundary between the sublunary and superlunary spheresbetween the "lower storey" and "upper storey" of the Aristotelian Universe. This establishment of a strong physical affinity between the universe "up there" and the earthly realm "down here" was also complemented by the rise of Copernicanism: for once the Earth was seen as a planet, the other planets could readily be imagined as other Earths. This analogy suggested not only physical but also biological affinities and supported the plausibility of humans' capacity to travel to the Moon and beyond. Robert Burtongiven the demise of Aristotle's physicsdeclared in 1621 that "If the heavens be penetrable it were not amiss in this aerial progress to make wings and fly up." John Wilkins and Francis Godwin in the 1630s actively imagined creatures in the Moon and human journeys thither. The epic poet John Milton in 1667 hinted that "every star [is] perhaps a world / Of destined habitation." Moreover, space travel was no one-way street: Thomas Traherne in the 1670s imagined a dweller among the stars visiting Earth and remarking on what must be the condition of its inhabitants. In these and other ways, seventeenth-century writers offered serious and impressive speculation about extraterrestrial life and its possible perceptions of Earth. Such speculations remain pertinent to astrobiological theory today. What Hans Blumenberg in the 1970s called "reflexive telescopics"the examination of Earth from an imagined extraterrestrial viewpointis an important counterpart to the search for life "out there." It serves as a reminder of the obvious but profound premise that Earth is part of the cosmos. At a popular level we often continue to speak of "outer space" as if the old "two-storey" picture of the universe still had some residual legitimacy. However, if Galileo, Wilkins, and other devotees of the New Astronomy were right about Earth's being a full participant in "the dance of the stars," then "outer" is a merely relative and parochial term, not a scientific or qualitative one. And it is no trivial claim to assert that the search for intelligent life in the universe has already identified its first specimens.

Danielson, Dennis

438

Intranasal Midazolam May Prevent Gagging Reflex: a Case Report  

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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.

Meral Arslan Malkoc

2013-10-01

439

Faroese long-distance reflexives face off against Icelandic long-distance reflexives  

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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.

Tania E. Strahan

2009-01-01

440

On a family of Wiener type spaces  

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Full Text Available Research on Wiener type spaces was initiated by N.Wiener in [15]. A number of authors worked on these spaces or some special cases of these spaces. A kind of generalization of the Wiener's definition was given by H.Feichtinger in [2] as a Banach spaces of functions (or measures, distributions on locally compact groups that are defined by means of the global behaviour of certain local properties of their elements. In the present paper we discussed Wiener type spaces using the spaces Aw,ωp,q(G and Fw,ωp,q(G (c. f. [8] as a local component, and Lνr(G as a global component, where w and ν are Beurling weights on G and ω is a Beurling weight on Gˆ (c. f. [13].

T. S. Liu

1996-03-01

 
 
 
 
441

Direct and consensual murine pupillary reflex metrics: establishing normative values.  

Science.gov (United States)

Pupillometry is a non-invasive technique, based on well-established neurophysiologic principles, that can be utilized to objectively characterize pathophysiologic demyelinating and neurodegenerative changes involving the pupillary reflex pathway. In animal models of human disorders, pupillometry derived reflex metrics could potentially be used to longitudinally monitor disease activity and responses to pharmacotherapies. These investigations would have important implications for translational initiatives focused on the identification and application of novel neuroprotective and restorative treatments for human diseases such as multiple sclerosis. Here, we have established normal reference values for various pupillary reflex metrics across different mouse strains. Ultimately, we anticipate that this new data will help to catalyze unique lines of inquiry using pupillometry methods. PMID:19683968

Hussain, Rehana Z; Hopkins, Steven C; Frohman, Elliot M; Eagar, Todd N; Cravens, Petra C; Greenberg, Benjamin M; Vernino, Steven; Stve, Olaf

2009-12-01

442

Reflex anuria: a rare cause of acute kidney injury  

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Full Text Available Background: Acute Kidney Injury results from pre renal, post renal or intrinsic renal causes. Reflex anuria is a very rare cause of renal impairment which happens due to irritation or trauma to one kidney or ureter, or severely painful stimuli to other nearby organs. Case Presentation: Here we present a case of acute kidney injury secondary to reflex anuria in a patient who underwent extensive gynecological surgery along with ureteral manipulation which recovered spontaneously. Conclusion: Reflex Anuria is a rare and often not considered as cause of acute kidney injury. This case illustrates that this should be kept as a differential in potential cause of acute kidney injury in patient undergoing urogenital or gynecological surgeries.

Samuel Adediran

2014-04-01

443

ESO Reflex: A Graphical Workflow Engine for Astronomical Data Reduction  

Science.gov (United States)

ESO Reflex is a software tool that provides a novel approach to astronomical data reduction. The reduction sequence is rendered and controlled as a graphical workflow. Users can follow and interact with the processing in an intuitive manner, without the need for complex scripting. The graphical interface also allows the modification of existing workflows and the creation of new ones. ESO Reflex can invoke standard ESO data reduction recipes in a flexible way. Python scripts, IDL procedures and shell commands can also be easily brought into workflows and a variety of visualisation and display options, including custom product inspection and validation steps, are available. ESO Reflex was developed in the context of the Sampo project, a three-year effort led by ESO and conducted by a software development team from Finland as an in-kind contribution to joining ESO. It is planned that the software will be released to the community in late 2008.

Hook, Richard; Romaniello, Martino; Ullgrn, Marko; Maisala, Sami; Solin, Otto; Oittinen, Tero; Savolainen, Villa; Jrvelinen, Pekka; Tyynel, Jani; Pron, Michle; Izzo, Carlo; Ballester, Pascal; Gabasch, Armin

2008-03-01

444

Field trials with low power lasers concerning the blink reflex.  

Science.gov (United States)

Laser belonging to class 2 emit in the visible part of the spectrum. The power is limited to 1 mW in the CW mode. Up to now the protection of the eyes has been supposed to be given by the blink reflex for incidentally intrabeam viewing in many regulations. In 3 field trials with 519 test persons we have shown that only 15.9% at 670 nm, 17.2% at 635 nm, and 20.3% at 532 nm had a blink reflex under laser irradiation. An analysis of the results showed neither significant differences concerning the age and the gender of the test persons nor whether they were wearer of glasses or right sighted. The frequent lack of the blink reflex demands organizational measures like instruction using laser class 2 in medical and other applications. PMID:12465249

Reidenbach, H D; Dollinger, K; Hofmann, J

2002-01-01

445

Romantic Relationships and their Transformation in the Reflexive Society. Themes and Methods in Jean-Claude Kaufmanns Surveys  

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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.

Lavinia Alexe

2010-03-01

446

Automated data reduction workflows for astronomy. The ESO Reflex environment  

Science.gov (United States)

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.

Freudling, W.; Romaniello, M.; Bramich, D. M.; Ballester, P.; Forchi, V.; Garca-Dabl, C. E.; Moehler, S.; Neeser, M. J.

2013-11-01

447

A MULTIPLIER GLIDING HUMP PROPERTY FOR SEQUENCE SPACES  

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Full Text Available We consider the Banach-Mackey property for pairs of vector spaces E and E' which ar in duality. Le A be and algebra of sets and assume that P is an additive map from A into the projection operators on E. We define a continuous gliding hump property for the map P and show that pairs with this gliding hump property and another measure theoretic property are Banch-Mackey pairs, i.e., weakly bounded subsets of E are strongly bounded. Examples of vector valued function spaces, such as the space of Pettis integrable functions, which satisfy these conditions are given

CHARLES SWARTZ

2001-05-01

448

Neurophysiology and Clinical Implications of the Laryngeal Adductor Reflex  

Science.gov (United States)

The laryngeal adductor reflex (LAR) is an involuntary protective response to stimuli in the larynx. The superior laryngeal nerve (SLN) acts as the afferent limb and the recurrent laryngeal nerve (RLN) as the efferent limb of this reflex, which is modulated by the central nervous system. Perhaps the most clinically significant application of the LAR is its use in laryngopharyngeal (LP) sensory discrimination testing. Importantly, aberrations in the LAR may predict dysphagia or portend clinical phenotypes of chronic cough, vocal cord dysfunction or pediatric apneas. LP sensation is a potential target for interventions addressing the aforementioned conditions though currently remains an area of active investigation.

Domer, Amanda S.; Kuhn, Maggie A.

2014-01-01

449

Analysis of ion beam extracted from reflex tetrode  

International Nuclear Information System (INIS)

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

450

Mirroring Meetings, Mirroring Media: The Microphysics of Reflexivity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

There is today a growing reflexivity in individual and collective identity constructions. Identities are always formed in relation to others and through symbolic structures, but this process has been more mobilized, differentiated, focused and problematized in late modernity the most recent phase of the process of modernization.[i] This is true for daily life as well as for research. Reflexivity has in various ways been an important theme within psychoanaly...

Forna?s, Johan

1994-01-01

451

REVIEW PAPERTrigemino-cardiac reflex: A recently discovered oxygen-conserving response? The potential therapeutic role of a physiological reflex  

Directory of Open Access Journals (Sweden)

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.

Bernhard J. Schaller

2006-03-01

452

Contribution of tonic vibration reflex to the evaluation and diagnosis of cerebellar disorders.  

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Biceps brachii tonic vibration reflexes were elicited in patients with either focal or diffuse cerebellar damage and spino-cerebellar degenerations. As compared to normal controls, tonic vibration reflex amplitude was reduced in cerebellar patients, particularly in cases with unilateral hemispheric lesion, who exhibited a clear cut tonic vibration reflex asymmetry even when clinical symptoms were mild. These reflexes were absent or very weak in patients with spino-cerebellar degenerations. Mu...

Abbruzzese, G.; Abbruzzese, M.; Ratto, S.; Favale, E.

1982-01-01

453

Proximunalty in Orlicz-bochner Function Spaces  

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Full Text Available A (closed subspace $ Y$ of a Banach space $ X$ is called proximinal if for every $ x\\in X$ there exists some $ y\\in Y$ such that $ \\|x-y\\|\\le\\|x-z\\|$ for $ z\\in Y$. It is the object of this paper is to study the proximinality of $ L^\\Phi(I,Y$ in $ L^\\Phi(I,X$ for some class of Young's functions $ \\Phi$, where $ I$ is the unit interval. We prove (among other results that if $ Y$ is a separable proximinal subspace of $ X$, then $ L^\\Phi(I,Y$ is proximinal in $ L^\\Phi(I,X$.

M. Khandaqji

2003-03-01

454

Evaluation of relationship between feeding reflexes and articulation in spastic cerebral palsy  

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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.

M.R. Hadian

2006-07-01

455

On stringy cohomology spaces  

CERN Document Server

We modify the definition of the families of $A$ and $B$ stringy cohomology spaces associated to a pair of dual reflexive Gorenstein cones. The new spaces have the same dimension as the ones defined in the joint paper with Mavlyutov \\cite{BM}, but they admit natural flat connections with respect to the appropriate parameters. This solves a longstanding question of relating GKZ hypergeometric system to stringy cohomology. We construct products on these spaces by vertex algebra techniques. In the process, we fix a minor gap in \\cite{BM} and prove a statement on intersection cohomology of dual cones that may be of independent interest.

Borisov, Lev A

2012-01-01

456

On the fine spectrum of the second order difference operator over the sequence spaces \\ell_p and bv_p, (1 < p < \\infty)  

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In general, it is well known the behaviors of the symmetric tri-band matrices on the Hilbert spaces. But the symmetric tri-band matrices have different the behavior on the Banach spaces. The main purpose of this work is to determine the fine spectra of the operator U(s, r, s) defined by symmetric tri-band matrix over the sequence spaces {\\ell}_p and bvp.

Karakaya, Vatan; Manafov, Manaf Dzh; Simsek, Necip

2011-01-01

457

Avaliao dos reflexos espinhais em cordeiros da raa Suffolk / Evaluation of spinal reflexes in Suffolk lambs  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Fez-se a avaliao qualitativa e semiquantitativa dos reflexos espinhais em ovinos, utilizando-se 51 animais da raa Suffolk, machos e fmeas, entre quatro e cinco meses de idade. Usaram-se os reflexos bilaterais dos membros torcicos, extensor carpo-radial, bicipital, tricipital e flexor, e plvico [...] s, isquitico, gastrocnmio, patelar, tibial cranial e flexor, sendo zero indicativo de ausncia de reflexo, 1= reflexo discreto e 2= reflexo evidente. Nos membros torcicos, as melhores respostas foram obtidas no flexor (99,0%) e no extensor carpo-radial (87,3%), seguidos de valores menos expressivos no bicipital (11,8%) e no tricipital (2,0%), com grau 2 de avaliao. Nos membros plvicos, todos os ovinos produziram respostas em grau 2 para o reflexo flexor. Verificam-se tambm respostas evidentes nos reflexos patelar (98,0%) e isquitico (81,4%). Apenas 20,6% dos animais apresentaram resposta evidente ao reflexo tibial cranial, e nenhum ovino respondeu ao reflexo gastrocnmio de forma satisfatria. Abstract in english This study was carried out to determine a qualitative and semiquantitative evaluation of the spinal reflexes in 51 both sexes, 4 to 5 months of age Suffolk lambs. Spinal reflexes were evaluated in the thoracic (extensor carpi reflex, biceps reflex, triceps reflex and flexor reflex) and pelvic (ischi [...] atic reflex, gastrocnemius reflex, patellar reflex, cranial tibial reflex and flexor reflex) limbs, bilaterally. Reflexes were standardized, using a 2-point grading scale (0= absense, 1= mild reflex, 2= evident). Flexor reflex (99.0%) and extensor carpi reflex (87.3%) were the best reflexes elicited in thoracic limbs, while the least evident scores were found in biceps (11.8%) and triceps reflexes (2.0%) with grade 2. In pelvic limbs, all of the ovines showed a grade-2 flexor reflex. A high percentage of evident response in patellar (98.0%) and ischiatic (81.4%) reflexes were also observed. Only 20.6% of the animals showed evident response to the cranial tibial reflex but none had a satisfactory response to the gastrocnemius reflex.

L.C.N., Mendes; G.M., Nogueira; A.S., Borges; J.R., Peir; F.L.F., Feitosa.

458

An Approximate Version of the Jordan von Neumann Theorem for Finite Dimensional Real Normed Spaces  

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It is known that any normed vector space which satisfies the parallelogram law is actually an inner product space. For finite dimensional normed vector spaces over R, we formulate an approximate version of this theorem: if a space approximately satisfies the parallelogram law, then it has a near isometry with Euclidean space. In other words, a small von Neumann Jordan constant E + 1 for X yields a small Banach-Mazur distance with R^n, d(X, R^n) < 1 + B_n E + O(E^2). Finally,...

Passer, Benjamin

2013-01-01

459

Practicing Reflexivity in the Study of Italian Migrants in London  

Science.gov (United States)

This article discusses the centrality of reflexivity in qualitative research through examples from my study on the role new media play in the lives of Italians in London. My hypothesis was that Italians were "in transit" in London and they were using new media to build "temporary" communities. I conducted in-depth interviews with members of the

Seganti, Francesca Romana

2010-01-01

460

Hindlimb venous distention evokes a pressor reflex in decerebrated rats  

Science.gov (United States)

Abstract The distention of small vessels caused by an increase in blood flow to dynamically exercising muscles has been proposed as a stimulus that activates the thin fiber (groups III and IV) afferents evoking the exercise pressor reflex. This theory has been supported by evidence obtained from both humans and animals. In decerebrated unanesthetized rats with either freely perfused femoral arteries or arteries that were ligated 3 days before the experiment, we attempted to provide evidence in support of this theory by measuring arterial pressure, heart rate, and renal sympathetic nerve discharge while retrogradely injecting Ringer's solution in increasing volumes into the femoral vein just as it excited the triceps surae muscles. We found that the pressor response to injection was directly proportional to the volume injected. Retrograde injection of volumes up to and including 1 mL had no significant effect on either heart rate or renal sympathetic nerve activity. Cyclooxygenase blockade with indomethacin attenuated the reflex pressor response to retrograde injection in both groups of rats. In contrast, gadolinium, which blocks mechanogated channels, attenuated the reflex pressor response to retrograde injection in the ligated rats, but had no effect on the response in freely perfused rats. Our findings are consistent with the possibility that distension of small vessels within exercising skeletal muscle can serve as a stimulus to the thin fiber afferents evoking the exercise pressor reflex. PMID:24907299

Yamauchi, Katsuya; Stone, Audrey J.; Kaufman, Marc P.

2014-01-01

 
 
 
 
461

A reflexing electron microwave amplifier for rf particle accelerator applications  

International Nuclear Information System (INIS)

The evolution of rf-accelerator technology toward high-power, high-current, low-emittance beams produces an ever-increasing demand for efficient, very high power microwave power sources. The present klystron technology has performed very well but is not expected to produce reliable gigawatt peak-power units in the 1- to 10-GHz regime. Further major advancements must involve other types of sources. The reflexing-electron class of sources can produce microwave powers at the gigawatt level and has demonstrated operation from 800-MHz to 40-GHz. The pulse length appears to be limited by diode closure, and reflexing-electron devices have been operated in a repetitively pulsed mode. A design is presented for a reflexing electron microwave amplifier that is frequency and phase locked. In this design, the generated microwave power can be efficiently coupled to one or several accelerator loads. Frequency and phase-locking capability may permit parallel-source operation for higher power. The low-frequency (500-MHz to 10-GHz) operation at very high power required by present and proposed microwave particle accelerators makes an amplifier, based on reflexing electron phenomena, a candidate for the development of new accelerator power sources. (author)

462

Associative Mechanosensory Conditioning of the Proboscis Extension Reflex in Honeybees  

Science.gov (United States)

The present work introduces a form of associative mechanosensory conditioning of the proboscis extension reflex (PER) in honeybees. In our paradigm, harnessed honeybees learn the elemental association between mechanosensory, antennal stimulation and a reward of sucrose solution delivered to the proboscis. Thereafter, bees extend their proboscis to

Giurfa, Martin; Malun, Dagmar

2004-01-01

463

Positioning Resumes and Cover Letters as Reflective-Reflexive Process  

Science.gov (United States)

Although the resume and cover letter genre is widely discussed in both popular and scholarly publications, discussion thus far has failed to acknowledge that the process of creating a resume and cover letter has the potential for encouraging students' reflective and reflexive capacities. This article suggests that business communication educators

Randazzo, Chalice

2012-01-01

464

How to test for the red reflex in a child  

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Full Text Available Examination of pupil reflections, also known as the red reflex text, can reveal problems in the cornea, lens and sometimes the vitreous, and is particularly useful in young children. These photographs show what can occur in the case of certain major eye conditions, the most serious of which is retinoblastoma.

Adapted from the poster: See RED produced by JR Ainsworth, UK National Retinoblastoma Service, Birmingham, UK and the Childhood Eye Cancer Trust. www.chect.org.uk.

2014-07-01

465

Power from Switching across Netdoms through Reflexive and Indexical Language.  

Directory of Open Access Journals (Sweden)

Full Text Available In differentiated societies with far-reaching yet fragmented social networks, the ability to manage pervasive ambiguity is crucial to navigate domination orders. In this paper we contend that identities, to enhance their control through switchings across networks and domains (netdoms, manage growing ambiguity via languages reflexive and indexical features. We elaborate on several featuresmetapragmatics, heteroglossia, and poeticsand assert that they are seldom innocent performances to build consensus in the reproduction of social orders. On the contrary, language is inherently implicated in relations of domination. We then argue that metapragmatic control of stories acquired in countless netdom switchings leads to strong footings that secure resources and opportunity; that rhetorics that include rich heteroglossic voicing via structural holes generate stories that can be reflexively transposed to other institutional arenas; and that poetic control of speech styles may transform identities into power-law constellations with robust footing that decouple into prisms to preserve quality. Our goal is to twofold: First, to show that the reflexivity and indexicality of language emerges from myriad switchings across netdoms; and second, to demonstrate that reflexive and indexical language is critical to identities struggles for controlof footing and dominationvia their switchings across rapidly polymerizing netdoms.

Fontdevila, Jorge

2010-06-01

466

Pure nuclear reflexes and combined hyperfine interactions in YIG  

International Nuclear Information System (INIS)

Moessbauer spectra of oriented YIG single crystals were taken and the numerical analysis using the transmission integral yielded a consistent set of hyperfine interaction parameters. They are in good agreement with theoretical values obtained by MO-calculations which included clusters up to 62 ions. Finally pure nuclear reflexes are predicted for single crystals and two theoretical spectra are given. (orig.)

467

A reflexive neural network for dynamic biped walking control.  

Science.gov (United States)

Biped walking remains a difficult problem, and robot models can greatly facilitate our understanding of the underlying biomechanical principles as well as their neuronal control. The goal of this study is to specifically demonstrate that stable biped walking can be achieved by combining the physical properties of the walking robot with a small, reflex-based neuronal network governed mainly by local sensor signals. Building on earlier work (Taga, 1995; Cruse, Kindermann, Schumm, Dean, & Schmitz, 1998), this study shows that human-like gaits emerge without specific position or trajectory control and that the walker is able to compensate small disturbances through its own dynamical properties. The reflexive controller used here has the following characteristics, which are different from earlier approaches: (1) Control is mainly local. Hence, it uses only two signals (anterior extreme angle and ground contact), which operate at the interjoint level. All other signals operate only at single joints. (2) Neither position control nor trajectory tracking control is used. Instead, the approximate nature of the local reflexes on each joint allows the robot mechanics itself (e.g., its passive dynamics) to contribute substantially to the overall gait trajectory computation. (3) The motor control scheme used in the local reflexes of our robot is more straightforward and has more biological plausibility than that of other robots, because the outputs of the motor neurons in our reflexive controller are directly driving the motors of the joints rather than working as references for position or velocity control. As a consequence, the neural controller and the robot mechanics are closely coupled as a neuromechanical system, and this study emphasizes that dynamically stable biped walking gaits emerge from the coupling between neural computation and physical computation. This is demonstrated by different walking experiments using a real robot as well as by a Poincar map analysis applied on a model of the robot in order to assess its stability. PMID:16595061

Geng, Tao; Porr, Bernd; Wrgtter, Florentin

2006-05-01

468

The Corona Theorem for the Drury-Arveson Hardy space and other holomorphic Besov-Sobolev spaces on the unit ball in $\\mathbb{C}^{n}$  

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We prove that the multiplier algebra of the Drury-Arveson Hardy space $H_{n}^{2}$ on the unit ball in $\\mathbb{C}^{n}$ has no corona in its maximal ideal space, thus generalizing the famous Corona Theorem of L. Carleson to higher dimensions. This result is obtained as a corollary of the Toeplitz corona theorem and a new Banach space result: the Besov-Sobolev space $B_{p}^{\\sigma}$ has the "baby corona property" for all $\\sigma \\geq 0$ and $1

Costea, Serban; Sawyer, Eric T.; Wick, Brett D.

2008-01-01

469

The Corona Theorem for the Drury-Arveson Hardy space and other holomorphic Besov-Sobolev spaces on the unit ball in $\\mathbb{C}^{n}$  

CERN Document Server

We prove that the multiplier algebra of the Drury-Arveson Hardy space $H_{n}^{2}$ on the unit ball in $\\mathbb{C}^{n}$ has no corona in its maximal ideal space, thus generalizing the famous Corona Theorem of L. Carleson in the unit disk. This result is obtained as a corollary of the Toeplitz Corona Theorem and a new Banach space result: the Besov-Sobolev space $B_{p}^{\\sigma}$ has the "Baby Corona Property" for all $0\\leq\\sigma<\\frac{n}{p}+1$ and $1

Costea, Serban; Wick, Brett D

2008-01-01

470

Kinematic and electromyographic study of the nociceptive withdrawal reflex in the upper limbs during rest and movement.  

Science.gov (United States)

This study set out to evaluate nociceptive withdrawal reflex (NWR) excitability and the corresponding mechanical response in the upper limbs during rest and movement. We used a three-dimensional motion analysis system and a surface EMG system to record, in 10 healthy subjects, the NWR in eight upper limb muscles and the corresponding mechanical response in two experimental conditions: rest and movement (reaching for, picking up, and moving a cylinder). The NWR was elicited through stimulation of the index finger with trains of pulses delivered at multiples of the pain threshold (PT). We correlated movement types (reach-to-grasp, grasp-and-lift), movement phases (acceleration, deceleration), and muscle activity types (shortening, lengthening, isometric) with the presence/absence of the NWR (reflex-muscle pattern), with NWR size values, and with the mechanical responses. At rest, when the stimulus was delivered at 4x PT, the NWR was present, in all muscles, in >90% of trials, and the mechanical response consisted of wrist adduction, elbow flexion, and shoulder anteflexion. At this stimulus intensity, during movement, the reflex-muscle pattern, reflex size, and mechanical responses were closely modulated by movement type and phase and by muscle activity type. We did not find, during movement, significant correlations with the level of EMG background activity. Our findings suggest that a complex functional adaptation of the spinal cord plays a role in modulating the NWR in the transition from rest to movement and during voluntary arm movement freely performed in three-dimensional space. Study of the upper limb NWR may provide a window onto the spinal neural control mechanisms operating during movement. PMID:16571758

Serrao, Mariano; Pierelli, Francesco; Don, Romildo; Ranavolo, Alberto; Cacchio, Angelo; Curr, Antonio; Sandrini, Giorgio; Frascarelli, Massimo; Santilli, Valter

2006-03-29

471

Rhythmic arm cycling differentially modulates stretch and H-reflex amplitudes in soleus muscle.  

Science.gov (United States)

During rhythmic arm cycling, soleus H-reflex amplitudes are reduced by modulation of group Ia presynaptic inhibition. This suppression of reflex amplitude is graded to the frequency of arm cycling with a threshold of 0.8Hz. Despite the data on modulation of the soleus H-reflex amplitude induced by rhythmic arm cycling, comparatively little is known about the modulation of stretch reflexes due to remote limb movement. Therefore, the present study was intended to explore the effect of arm cycling on stretch and H-reflex amplitudes in the soleus muscle. In so doing, additional information on the mechanism of action during rhythmic arm cycling would be revealed. Although both reflexes share the same afferent pathway, we hypothesized that stretch reflex amplitudes would be less suppressed by arm cycling because they are less inhibited by presynaptic inhibition. Failure to reject this hypothesis would add additional strength to the argument that Ia presynaptic inhibition is the mechanism modulating soleus H-reflex amplitude during rhythmic arm cycling. Participants were seated in a customized chair with feet strapped to footplates. Three motor tasks were performed: static control trials and arm cycling at 1 and 2Hz. Soleus H-reflexes were evoked using single 1ms pulses of electrical stimulation delivered to the tibial nerve at the popliteal fossa. A constant M-wave and ~6% MVC activation of soleus were maintained across conditions. Stretch reflexes were evoked using a single sinusoidal pulse at 100Hz given by a vibratory shaker placed over the triceps surae tendon and controlled by a custom-written LabView program. Results demonstrated that rhythmic arm cycling that was effective for conditioning soleus H-reflexes did not show a suppressive effect on the amplitude of the soleus stretch reflex. We suggest this indicates that stretch reflexes are less sensitive to conditioning by rhythmic arm movement, as compared to H-reflexes, due to the relative insensitivity to Ia presynaptic inhibition. PMID:21901451

Palomino, Andres F; Hundza, Sandra R; Zehr, E Paul

2011-10-01

472

Post-activation depression of Soleus stretch reflexes in healthy and spastic humans.  

DEFF Research Database (Denmark)

Reduced depression of transmitter release from Ia afferents following previous activation (post-activation depression) has been suggested to be involved in the pathophysiology of spasticity. However, the effect of this mechanism on the myotatic reflex and its possible contribution to increased reflex excitability in spastic participants has not been tested. To investigate these effects, we examined post-activation depression in Soleus H-reflex responses and in mechanically evoked Soleus stretch reflex responses. Stretch reflex responses were evoked with consecutive dorsiflexion perturbations delivered at different intervals. The magnitude of the stretch reflex and ankle torque response was assessed as a function of the time between perturbations. Soleus stretch reflexes were evoked with constant velocity (175 degrees /s) and amplitude (6 degrees ) plantar flexion perturbations. Soleus H-reflexes were evoked by electrical stimulation of the tibial nerve in the popliteal fossa. The stretch reflex and H-reflex responses of 30 spastic participants (with multiple sclerosis or spinal cord injury) were compared with those of 15 healthy participants. In the healthy participants, the magnitude of the soleus stretch reflex and H-reflex decreased as the interval between the stimulus/perturbation was decreased. Similarly, the stretch-evoked torque decreased. In the spastic participants, the post-activation depression of both reflexes and the stretch-evoked torque was significantly smaller than in healthy participants. These findings demonstrate that post-activation depression is an important factor in the evaluation of stretch reflex excitability and muscle stiffness in spasticity, and they strengthen the