bluuebunny/crossref_metadata_2025 huggingface dataset:
Paracompactness with respect to an ideal
Authors: Hamlett T. R. , Rose David , Janković Dragan
Published: September 2002

An ideal on a set X is a nonempty collection of subsets of X closed under the operations
of subset and finite union. Given a topological space X and an ideal ℐ of subsets of X, X is defined to be
ℐ‐paracompact if every open cover of the space admits a locally finite open refinement which is a cover
for all of X except for a set in ℐ. Basic results are investigated, particularly with regard to the ℐ‐
paracompactness of two associated topologies generated by sets of the form U − I where U is open and
I ∈ ℐ and ⋃ {U | U is open and U − A ∈ ℐ, for some open set A}. Preservation of ℐ‐paracompactness
by functions, subsets, and products is investigated. Important special cases of ℐ‐paracompact spaces are
the usual paracompact spaces and the almost paracompact spaces of Singal and Arya [“On m‐paracompact
spaces”, Math. Ann., 181 (1969), 119‐133].
A characterization of B∗‐algebras
Authors: Gaur A. K.
Published: September 2002

A characterization of B∗‐algebras amongst all Banach algebras with bounded approximate
identities is obtained.
Kostant partition functions for affine Kac‐Moody algebras
Authors: Santhanam T. S. , Chakrabarti R.
Published: September 2002

Employing the method of generating functions in conjunction with various number‐thoretic identities, we obtain recursion relations for the Kostant partition functions for the affine Kac‐Moody algebras The partition functions for the higher rank algebras are expressed in terms of
partition functions. We derive certain number‐theoretic identities using the equivalence of our result with
the expressions derived by Kac and Peterson.
A note on monotonicity property of Bessel functions
Authors: Koumandos Stamatis
Published: September 2002

A theorem of Lorch, Muldoon and Szegö states that the sequence

urn:x-wiley:01611712:media:ijmm683727:ijmm683727-math-0001

is decreasing for α > −1/2, where Jα(t) the Bessel function of the first kind order α and jα,k its kth
positive root. This monotonicity property implies Szegö′s inequality

urn:x-wiley:01611712:media:ijmm683727:ijmm683727-math-0002

,
when α ≥ α′ and α′ is the unique solution of .

We give a new and simpler proof of these classical results by expressing the above Bessel function
integral as an integral involving elementary functions.
The Fourier transforms of Lipschitz functions on certain domains
Authors: Younis M. S.
Published: September 2002

The Fourier transforms of certain Lipschitz functions are discussed and compared with
the Hankel transforms of these functions and with their Fourier transforms on the Euclidean Cartan
Motion group M(n), n ≥ 2.
On connectedness in intuitionistic fuzzy special topological spaces
Authors: Özçağ Selma , Çoker Doğan
Published: September 2002

The aim of this paper is to construct the basic concepts related to connectedness in
intuitionistic fuzzy special topological spaces. Here we introduce the concepts of C5‐connectedness,
connectedness, Cs‐connectedness, CM‐connectedness, strong connectedness, super connectedness, Ci‐connectedness
(i = 1, 2, 3, 4), and, obtain several preservation properties and some characterizations
concerning connectedness in these spaces.
On equivalence of graded rings
Authors: Refai Mashhoor , Obiedat Sofyan
Published: September 2002

Let R = ⊕g∈GRg
be a G‐graded ring. In this paper we define the “homogeneousequivalence”
concept between graded rings. We discuss some properties of the G‐graded rings and
investigate which of these are preserved under homogeneous‐equivalence maps. Furthermore, we give
some results in graded ring theory and also some applications of this concept to Z‐graded rings.
Some results on compact convergence semigroups defined by filters
Authors: Ho Phoebe , Plummer Paul , So Shing
Published: September 2002

In this paper the concept of convergence defined by filters is used and applied
in the study of semigroups. Special emphasis is placed on compact convergence semigroups and
their properties.
On strict and simple type extensions
Authors: Tikoo Mohan
Published: September 2002

Let (Y, τ) be an extension of a space (X, τ′) · p ∈ Y, let . For U ∈ τ′, let . In 1964, Banaschweski introduced the strict extension Y#, and
the simple extension Y+ of X (induced by (Y, τ)) having base {o(U) : U ∈ τ′} and
, respectively. The extensions Y# and Y+ have been extensively used since
then. In this paper, the open filters
ℒp = {W ∈ τ′ : W⫆intxclx(U) for some , and = {W ∈ τ′ : intxclx(W) ∈ ℒp} = ∩{𝒰 : 𝒰 is an open ultrafilter on
on X
are used to define some new topologies on Y. Some of these topologies produce nice
extensions of (X, τ′). We study some interrelationships of these extensions with Y#, and Y+ respectively.
Two theorems on (ϵ)‐Sasakian manifolds
Authors: Xufeng Xu , Xiaoli Chao
Published: September 2002

In this paper, We prove that every (ϵ)‐sasakian manifold is a hypersurface of
an indefinite kaehlerian manifold, and give a necessary and sufficient condition for a Riemannian
manifold to be an (ϵ)‐sasakian manifold.
On the differential system govering flows in magnetic field with data in Lp
Authors: Chen Fengxin , Wang Ping , Qu Chaoshun
Published: September 2002

In this paper we study the system governing flows in the magnetic field within the earth.
The system is similar to the magnetohydrodynamic (MHD) equations. For initial data in space Lp, we
obtained the local in time existence and uniqueness ofweak solutions of the system subject to appropriate
initial and boundary conditions.
Fractal multiwavelets related to the cantor dyadic group
Authors: Lang W. Christopher
Published: September 2002

Orthogonal wavelets on the Cantor dyadic group are identified with multiwavelets
on the real line consisting of piecewise fractal functions. A tree algorithm for analysis using these
wavelets is described. Multiwavelet systems with algorithms of similar structure include certain
orthogonal compactly supported multiwavelets in the linear double‐knot spline space S1,2.
Stability problem of some nonlinear difference equations
Authors: Hamza Alaa E. , El-Sayed M. A.
Published: September 2002

In this paper, we investigate the asymptotic stability of the recursive sequence

urn:x-wiley:01611712:media:ijmm584819:ijmm584819-math-0001

and the existence of certain monotonic solutions of the equation

urn:x-wiley:01611712:media:ijmm584819:ijmm584819-math-0002

which includes as a special case the rational recursive sequence

urn:x-wiley:01611712:media:ijmm584819:ijmm584819-math-0003

where α ≥ 0, β > 0, γ > 0, γi ≥ 0, , p ∈ {2, 3, …}
and r ∈ {1, 2, …, p − 1}.
The case when r = 0
has been investigated by Camouzis et. al. [1], and for r = 0
and p = 2 by Camouzis et. al. [2].
α‐Derivations and their norm in projective tensor products of Γ‐Banach algebras
Authors: Dutta T. K. , Nath H. K. , Kalita R. C.
Published: September 2002

Let (V, Γ) and (V′, Γ′) be Gamma‐Banach algebras over the fields F1 and F2
isomorphic
to a field F
which possesses a real valued valuation, and (V, Γ)⊗p(V′, Γ′), their projective tensor product.
It is shown that if D1
and D2
are α ‐ derivation and α′ ‐ derivation on (V, Γ) and (V′, Γ′) respectively and
, is an arbitrary element of (V, Γ)⊗p(V′, Γ′), then there exists an α ⊗ α′‐ derivation
D on
(V, Γ)⊗p(V′, Γ′) satisfying the relation

urn:x-wiley:01611712:media:ijmm278960:ijmm278960-math-0002

and possessing many enlightening properties. The converse is also true under a certain restriction.
Furthermore, the validity of the results ‖D‖ = ‖D1‖ + ‖D2‖
and sp(D) = sp(D1) + sp(D2)
are fruitfully investigated.
Angular estimations of certain integral operators
Authors: Cho Nak Eun , Kim In Hwa , Kim Ji A
Published: September 2002

The object of the present paper is to derive some argument properties of certain integral
operators. Our results contain some interesting corollaries as the special cases.
A probablistic proof of the series representation of the MacDonald function with applications
Authors: Chaudhry M. Aslam , Ahmad Munir
Published: September 2002

A series representation of the Macdonald function is obtained using the properties of
a probability density function and its moment generating function. Some applications of the result
are discussed and an open problem is posed.
Positive solutions of an asymptotically planar system of elliptic boundary value problems
Authors: Corrêa F. J. S. A.
Published: September 2002

We will prove an existence result of positive solutions for an asymptotically planar system
of two elliptic equations. It will be used as main tools for a Maximum Principle and a result on
Bifurcation Theory.
Transient disturbances in a relaxing thermoelastic half space due to moving internal heat source
Authors: Chakravorty Sarbani , Chakravorty Amitava
Published: September 2002

This paper is concerned with the transient waves created by a line heat source that suddenly starts moving with a uniform velocity inside a thermoelastic semi‐infinite medium with thermal
relaxation of the type of Lord and Shulman. The source moves parallel to the boundary surface which is traction‐free. The problem is reduced to the solution of three differential equations, one involving the
elastic vector potential, and the other two coupled, involving the thermoelastic scalar potential and the temperature. Using Fourier and Laplace transforms, the solution for the displacements have been
obtained in the transform domain. The displacements have been calculated on the boundary surface for small time.
On inversion of H‐transform in 𝔏v,r‐space
Authors: Shlapakov Sergei A. , Saigo Megumi , Kilbas Anatoly A.
Published: September 2002

The paper is devoted to study the inversion of the integral transform

urn:x-wiley:01611712:media:ijmm417367:ijmm417367-math-0001

involving the H‐function as the kernel in the space 𝔏v,r of functions f such that

urn:x-wiley:01611712:media:ijmm417367:ijmm417367-math-0002

.
Atomoicity of mappings
Authors: Charatonik Janusz J. , Charatonik Włodzimierz J.
Published: September 2002

A mapping f : X → Y
between continua X
and Y
is said to be atomic at a
subcontinuumK
of the domain X
provided that f(K) is nondegenerate and K = f−1(f(K)). The set
of subcontinua at which a given mapping is atomic, considered as a subspace of the hyperspace of all
subcontinua of X, is studied. The introduced concept is applied to get new characterizations of atomic
and monotone mappings. Some related questions are asked.
On the existence of a periodic solution of a nonlinear ordinary differential equation
Authors: Chu Hsin , Ding Sunhong
Published: September 2002

Consider a planar forced system of the following form

urn:x-wiley:01611712:media:ijmm527812:ijmm527812-math-0001

where
h(t) and g(t) are 2π‐periodic continuous functions, t ∈ (−∞, ∞) and
μ(x, y)
and ν(x, y)
are continuous and satisfy local Lipschitz conditions. In this
paper, by using the Poincáre′s operator we show that if we assume the condltions,
(C1), (C2)
and (C3)
(see Section 2), then there is at least one 2π‐periodic
solution. In conclusion, we provide an explicit example which is not in any class
of known results.
Equilibrium points of random generalized games
Authors: Tarafdar E. , Yuan Xian-Zhi
Published: September 2002

In this paper, the concepts of random maximal elements, random equilibria
and random generalized games are described. Secondly by measurable selection theorem, some
existence theorems of random maximal elements for
Lc‐majorized correspondences are obtained.
Then we prove existence theorems of random equilibria for non‐compact one‐person random
games. Finally, a random equilibrium existence theorem for non‐compact random generalized
games (resp., random abstract economics) in topological vector spaces and a random equilibrium
existence theorem of non‐compact random games in locally convex topological vector spaces
in which the constraint mappings are lower semicontinuous with countable number of players
(resp., agents) are given. Our results are stochastic versions of corresponding results in the
recent literatures.
p‐topological and p‐regular: dual notions in convergence theory
Authors: Wilde Scott A. , Kent D. C.
Published: September 2002

The natural duality between “topological” and “regular,” both considered as convergence space properties, extends
naturally to p‐regular convergence spaces, resulting in the new concept of a p‐topological convergence space. Taking advantage of this duality, the behavior of p‐topological and p‐regular convergence spaces is explored, with particular emphasis on the former, since they have not been previously studied. Their study leads to the new notion of a neighborhood operator for filters, which in turn leads to an especially simple characterization of a topology in terms of convergence criteria. Applications include the topological and regularity series of a convergence space.
Nonwandering sets of maps on the circle
Authors: Yeom Seung Wha , Min Kyung Jin , Cho Seong Hoon
Published: September 2002

Let f be a continuous map of the circle S1 into itself. And let R(f), Λ(f), Γ(f), and Ω(f) denote the set of recurrent points, ω‐limit points, γ‐limit points, and nonwandering points of f, respectively. In this paper, we show that each point of is one‐side isolated, and prove that

(1) Ω(f)\Γ(f) is countable and

(2) Λ(f)\Γ(f) and are either empty or countably infinite.
q‐series, elliptic curves, and odd values of the partition function
Authors: Eriksson Nicholas
Published: September 2002

Let p(n) be the number of partitions of an integer n. Euler proved the following recurrence for p(n):

urn:x-wiley:01611712:media:ijmm796128:ijmm796128-math-0001

where ω(k) = (3k 2 + k)/2. In view of Euler′s result, one sees that it is fairly easy to compute p(n) very quickly. However, many questions remain open even regarding the parity of p(n). In this paper, we use various facts about elliptic curves and q‐series to construct, for every i ≥ 1, finite sets Mi for which p(n) is odd for an odd number of n ∈ Mi.
Noncommutativity and noncentral zero divisors
Authors: Bell Howard E. , Klein Abraham A.
Published: September 2002

Let R be a ring, Z its center, and D the set of zero divisors. For finite noncommutative rings, it is known that D\Z ≠ ∅. We investigate the size of |D\Z| in this case and, also, in the case of infinite noncommutative rings with D\Z ≠ ∅.
Some remarks on the algebraic structure of the finite Coxeter group F4
Authors: Albar Muhammad A. , Al-Saleh Norah
Published: September 2002

We consider in this paper the algebraic structure and some properties of the finite Coxeter group F4.
Dirac structures on Hilbert spaces
Authors: Parsian A. , Deh Abad A. Shafei
Published: September 2002

For a real Hilbert space (H, 〈, 〉), a subspace L ⊂ H ⊕ H is said to be a Dirac structure on H if it is maximally isotropic with respect to the pairing . By investigating some basic properties of these structures, it is
shown that Dirac structures on H are in one‐to‐one correspondence with isometries on H, and, any two Dirac structures are isometric. It is, also, proved that any Dirac structure on a smooth manifold in the sense of [1] yields a Dirac structure on some Hilbert space. The graph of any densely defined skew symmetric linear operator on a Hilbert space is, also, shown to be a Dirac structure. For a Dirac structure L on H, every z ∈ H is uniquely decomposed as z = p1(l) + p2(l) for some l ∈ L, where p1 and p2 are projections. When p1(L) is closed, for any Hilbert subspace W ⊂ H, an induced Dirac structure on W is introduced. The latter concept has also been generalized.
Asymptotic behavior of solutions of the damped Boussinesq equation in two space dimensions
Authors: Varlamov Vladimir V.
Published: September 2002

The Cauchy problem for the damped Boussinesq equation with small initial data is considered in two space dimensions. Existence and uniqueness of its
classical solution is proved and the solution is constructed in the form of a series. The major term of its long‐time asymptotics is calculated explicitly and a uniform in space estimate of the residual term is given.
On functional representation of locally m‐pseudoconvex algebras
Authors: Arhippainen Jorma
Published: September 2002

Functional representation of a topological algebra (A, T) has been studied in many papers under various assumptions for the
topology T on A. Usually the image of the Gelfand map has been equipped with the compact‐open topology. This leads, in several cases, to such kind of difficulties as, for instance,
that the Gelfand map is not necessarily continuous or that the compact‐open topology is not of the same type as the topology T. In this paper, we study locally m‐pseudoconvex algebras and provide with such kind of topology that the above two claims are fulfilled. By using this representation the description of the closed ideals of (A, T) is studied.
On θ‐generalized closed sets
Authors: Dontchev Julian , Maki Haruo
Published: September 2002

The aim of this paper is to study the class of θ‐generalized closed sets, which is properly placed between the classes of generalized closed and θ‐closed sets.
Furthermore, generalized Λ‐sets [16] are extended to
θ‐generalized Λ‐sets and R0‐, T1/2‐ and T1‐spaces are characterized. The relations with other notions directly or indirectly connected with generalized closed sets are investigated. The notion of TGO‐connectedness is introduced.
Two countable, biconnected, not widely connected Hausdroff spaces
Authors: Tzannes V.
Published: September 2002

We construct two countable, biconnected spaces, not widely connected, not having a dispersion point, and not being strongly connected. The first is Hausdorff and the second is Urysohn and almost regular.
Global existence and boundedness for quasi‐variational systems
Authors: Cantarelli Giancarlo
Published: September 2002

We consider quasi‐variational ordinary differential systems, which
may be considered as the motion law for holonomic mechanical systems. Even when the potential energy of the system is not bounded from below, by constructing appropriate Liapunov functions and using the comparison method, we obtain sufficient conditions for global existence of solutions in the future and for their partial boundedness.
Oscillatory and periodic solutions to a diffusion equation of neutral type
Authors: Wiener Joseph , Heller William
Published: September 2002

We examine a PDE with piecewise constant time delay. The equation
is of neutral type since it contains the derivative ut at different values of the t‐argument. Furthermore, the argument deviation changes its sign within intervals of unit length, so that the given PDE is alternately of retarded and advanced type. It is shown that the argument deviation generates, under certain conditions, oscillations of the solutions, which is an impossible phenomenon for the corresponding equation without delay. Of special interest is the appearance of periodic solutions as well as solutions asymptotically approaching closed curves which are not solutions of the equation studied.
Level crossings and turning points of random hyperbolic polynomials
Authors: Farahmand K. , Hannigan P.
Published: September 2002

In this paper, we show that the asymptotic estimate for the expected number of K‐level crossings of a random hyperbolic polynomial a1sinhx + a2sinh2x + ⋯+ansinhnx, where aj(j = 1, 2, …, n) are independent normally distributed random variables with mean zero and variance one, is (1/π)logn. This result is true for all K independent of x, provided . It is also shown that the asymptotic estimate of the expected number of turning points for the random polynomial a1coshx + a2cosh2x + ⋯+ancoshnx, with aj(j = 1, 2, …, n) as before, is also (1/π)logn.
Power of a determinant with two physical applications
Authors: Louck James D.
Published: September 2002

An expression for the kth power of an n × n determinant in n2 indeterminates (zij) is given as a sum of monomials. Two applications of this expression are given: the first is the Regge generating function for the Clebsch‐Gordan coefficients of the unitary group SU(2), noting also the relation to the  3 F2 hypergeometric series; the second is to the even powers of the Vandermonde determinant, or, equivalently, all powers of the discriminant. The second result leads to an interesting map between magic square arrays and partitions and has applications to the wave functions describing the quantum Hall effect. The generalization of this map to arbitrary square arrays of nonnegative integers, having given row and column sums, is also given.
Characterization on some absolute summability factors of infinite series
Authors: Sulaiman W. T.
Published: September 2002

A general theorem concerning some absolute summability factors of infinite series is proved. This theorem characterizes as well as generalizes our previous result [4]. Other results are also deduced.
Time averaging for random nonlinear abstract parabolic equations
Authors: Bruno G. , Pankov A. , Pankova T.
Published: September 2002

On the basis of G‐convergence we prove an averaging result for nonlinear abstract parabolic equations, the operator coefficient of which is a stationary stochastic process.
Integration with respect to a vector measure and functionapproximation
Authors: García-Raffi L. M. , Ginestar D. , Sánchez-Pérez E. A.
Published: September 2002

The integration with respect to a vector measure may be applied in order to approximate a function in a Hilbert space by means of a finite orthogonal sequence {fi} attending to two different error criterions. In particular, if Ω ∈ ℝ is a Lebesgue measurable set, f ∈ L2(Ω), and {Ai} is a finite family of disjoint subsets of Ω, we can obtain a measure μ0 and an approximation f0 satisfying the following conditions: (1) f0 is the projection of the function f in the subspace generated by {fi} in the Hilbert space f ∈ L2(Ω, μ0). (2) The integral distance between f and f0 on the sets {Ai} is small.
Periodic solutions of a class of non‐autonomous second‐order differential inclusions systems
Authors: Paşca Daniel
Published: September 2002

Using an abstract framework due to Clarke (1999), we prove the
existence of periodic solutions for second‐order differential inclusions systems.
Nonexistence theorems for weak solutions of quasilinear elliptic equations
Authors: Kartsatos A. G. , Kurta V. V.
Published: September 2002

New nonexistence results are obtained for entire bounded (either
from above or from below) weak solutions of wide classes of quasilinear elliptic equations and inequalities. It should be stressed that these solutions belong only locally to the
corresponding Sobolev spaces. Important examples of the situations
considered herein are the following: ,,, where n ≥ 1,  p > 1,  q > 0
are fixed real numbers, and a(x)
is a nonnegative measurable locally bounded function. The methods involve the use of capacity theory in connection with special types of test
functions and new integral inequalities. Various results,
involving mainly classical solutions, are improved and/or extended
to the present cases.
Obstacles to bounded recovery
Authors: Shekhtman Boris
Published: September 2002

Let X
be a Banach space, V ⊂ X
is its subspace and U ⊂ X*. Given x ∈ X, we are looking for v ∈ V such
that u (v) = u (x)
for all u ∈ U and ‖v‖  ≤ M‖x‖. In
this article, we study the restrictions placed on the constant M
as a function of X, V, and U.
Inertial manifolds and stabilization of nonlinear beam equationswith Balakrishnan‐Taylor damping
Authors: You Yuncheng
Published: September 2002

In this paper we study a hinged, extensible, and elastic nonlinear beam equation
with structural damping and Balakrishnan‐Taylor damping with the full exponent 2(n + β) + 1. This strongly nonlinear equation, initially proposed by Balakrishnan
and Taylor in 1989, is a very general and useful model for large aerospace
structures. In this work, the existence of global solutions and the existence
of absorbing sets in the energy space are proved. For this equation, the feature
is that the exponential rate of the absorbing property is not a global constant, but
which is uniform for the family of trajectories starting from any given bounded set in the
state space. Then it is proved that there exists an inertial manifold whose
exponentially attracting rate is accordingly non‐uniform. Finally, the spillover
problem with respect to the stabilization of this equation is solved by constructing
a linear state feedback control involving only finitely many modes. The obtained
results are robust in regard to the uncertainty of the structural parameters.
Existence of multiple critical points for an asymptoticallyquadratic functional with applications
Authors: Li Shujie , Su Jiabao
Published: September 2002

Morse theory for isolated critical points at infinity is used for
the existence of multiple critical points for an asymptotically quadratic
functional. Applications are also given for the existence of multiple
nontrivial periodic solutions of asymptotically Hamiltonian systems.
The topological degree method for equations of the Navier‐Stokes type
Authors: Dmitrienko V. T. , Zvyagin V. G.
Published: September 2002

We obtain results of existence of weak solutions in the Hopf sense
of the initial‐boundary value problem for the generalized Navier‐Stokes equations containing perturbations of retarded type. The degree theory for maps A − g, where A is invertible and g is 𝒜‐condensing, is used.
A new spectral theory for nonlinear operators and its applications
Authors: Feng W.
Published: September 2002

In this paper, by applying (p, k)‐epi mapping theory, we introduce a new definition of spectrum for nonlinear operators which contains all eigenvalues, as in the linear case. Properties of this spectrum are given and comparison is made with the other
definitions of spectra. We also give applications of the new theory.
A parabolic analogue of Finn′s maximum principle
Authors: Kurta Vasyl V.
Published: September 2002

We obtain a parabolic analogue of the well‐known maximum principle established by R. Finn for solutions of the minimal surface equation.
On the existence of classical solutions for differential‐functional IBVP
Authors: Topolski Krzysztof A.
Published: September 2002

We consider the initial‐boundary value problem for second order differential‐functional equations of parabolic type. Functional dependence in the equation is of the Hale type. By using Leray‐Schauder theorem we prove the existence of classical solutions. Our formulation and results cover a large class
of parabolic problems both with a deviated argument and integro‐differential equations.
Convergence of generic infinite products of affine operators
Authors: Reich S. , Zaslavski A. J.
Published: September 2002

We establish several results concerning the asymptotic behavior of random infinite products of generic sequences of affine uniformly continuous operators on bounded closed convex subsets of a Banach space. In addition to weak ergodic theorems we also obtain convergence to a unique common fixed point and more generally, to an affine retraction.
Cellular Senescence: Ex Vivo p53‐Dependent Asymmetric Cell Kinetics
Authors: Rambhatla Lakshmi , Bohn Shirley A. , Stadler Patrizia B. , Boyd Jonathan T. , Coss Ronald A. , Sherley James L.
Published: September 2002

Although senescence is a defining property of euploid mammalian
cells, its physiologic basis remains obscure. Previously, cell
kinetics properties of normal tissue cells have not been
considered in models for senescence. We now provide evidence that
senescence is in fact the natural consequence of normal
in vivo somatic stem cell kinetics extended in culture.
This concept of senescence is based on our discovery that cells
engineered to conditionally express the well‐recognized tumor
suppressor protein and senescence factor, p53, exhibit asymmetric
cell kinetics. In vivo, asymmetric cell kinetics are
essential for maintenance of somatic stem cells; ex
vivo, the same cell kinetics yield senescence as a simple
kinetic endpoint. This new “asymmetric cell kinetics model” for
senescence suggests novel strategies for the isolation and
propagation of somatic tissue stem cells in culture.
Quantum relativistic Toda chain
Authors: Pronko G. , Sergeev Sergei
Published: September 2002

Investigated is the quantum relativistic periodic Toda chain, to
each site of which the ultra‐local Weyl algebra is associated.
Weyl’s q
we are considering here is restricted to be inside the
unit circle. Quantum Lax operators of the model are intertwined by
six‐vertex R‐matrix. Both independent Baxter’s Q‐operators are constructed explicitly as
seria over local Weyl generators. The operator‐valued Wronskian of R‐matrix. Both independent Baxter’s Qs
is also calculated.
Explicit solutions of generalized nonlinear Boussinesq equations
Authors: Kaya Doğan
Published: September 2002

By considering the Adomian decomposition scheme, we
solve a generalized Boussinesq equation. The method does not need
linearization or weak nonlinearly assumptions. By using this
scheme, the solutions are calculated in the form of a convergent
power series with easily computable components. The decomposition
series analytic solution of the problem is quickly obtained by
observing the existence of the self‐canceling “noise” terms
where sum of components vanishes in the limit.
Intracellular Action of Matrix Metalloproteinase-2 Accounts for Acute Myocardial Ischemia and Reperfusion Injury
Authors: Wang Wenjie , Schulze Costas J. , Suarez-Pinzon Wilma L. , Dyck Jason R.B. , Sawicki Grzegorz , Schulz Richard
Published: September 2002

Background—

Matrix metalloproteinases are best recognized for their ability to degrade the extracellular matrix in both physiological and pathological conditions. However, recent findings indicate that some of them are also involved in mediating acute processes such as platelet aggregation and vascular tone. The acute contractile defect of the heart after ischemia-reperfusion may involve the proteolytic degradation of the thin filament protein troponin I; however, the protease responsible for this remains obscure.

Methods and Results—

Here we report that matrix metalloproteinase-2 is colocalized with troponin I within the thin myofilaments of cardiomyocytes in ischemic-reperfused hearts and that troponin I is a novel intracellular target for proteolytic cleavage by matrix metalloproteinase-2. Inhibition of matrix metalloproteinase-2 activity prevented ischemia-reperfusion-induced troponin I degradation and improved the recovery of mechanical function of the heart.

Conclusions—

These data reveal for the first time a novel molecular mechanism by which matrix metalloproteinase-2 causes acute myocardial dysfunction after ischemia-reperfusion-injury and that matrix metalloproteinase-2 has a biological action within the cell.
High Doses of Vitamin C Reverse
Escherichia coli
Endotoxin–Induced Hyporeactivity to Acetylcholine in the Human Forearm
Authors: Pleiner Johannes , Mittermayer Friedrich , Schaller Georg , MacAllister Raymond J. , Wolzt Michael
Published: September 2002

Background—

Acute inflammation causes endothelial vasodilator dysfunction that may be mediated by oxidative stress.

Methods and Results—

In this randomized, double-blind, crossover study, forearm blood flow responses to acetylcholine (ACh) (endothelium-dependent dilator) and glyceryl-trinitrate (GTN) (endothelium-independent dilator) were assessed before and after induction of acute systemic inflammation by low doses of
Escherichia coli
endotoxin (LPS) (20 IU/kg IV) in 8 healthy volunteers. The acute effect of intra-arterial vitamin C (24 mg/min) or placebo was studied 4 hours after LPS, respectively. Vitamin C alone was administered in control experiments. LPS administration caused systemic vasodilation, increased white blood count, elevated body temperature, and reduced vitamin C plasma concentrations. LPS decreased the responses of forearm blood flow to ACh by 30% (
P
<0.05) but not to GTN. Vitamin C completely restored the response to ACh, which was comparable with that observed under baseline conditions. Vitamin C had no effect on basal blood flow or ACh- or GTN-induced vasodilation in control subjects.

Conclusions—

Our data demonstrate that impaired endothelial vasodilation caused by
E coli
endotoxemia can be counteracted by high doses of antioxidants in vivo. Oxidative stress may play an important role in the pathogenesis of endothelial dysfunction during inflammation.
Finite element simulations on void closure behaviour inside the sheet during sheet rolling processes
Authors: Hwang Y-M , Chen D-C
Published: September 2002

The purpose of this paper is to explore the deformation mechanism of voids and stress-strain distributions around internal voids inside the sheet during sheet rolling processes. The plastic deformation and flow pattern of sheets during sheet rolling were simulated by the finite element method. The influences of various rolling conditions, such as the thickness reduction, the dimension of the internal void, friction factor, cross-sectional area of the void, etc., on the dimension of the void at the exit are discussed. The critical thickness reductions, over which the void would close completely, were also investigated. Furthermore, experiments on sheet rolling with an internal void inside the sheet were conducted. Theoretical predictions of the dimension of voids after rolling were compared with experimental results and relatively good agreement between them was found. Clearly, these analytical results can provide useful knowledge for designing the pass-schedule of sheet rolling processes for eliminating internal voids.
Power conversion mechanisms for wave energy
Authors: Salter S H , Taylor J R M , Caldwell N J
Published: September 2002

It is easy to make a device that will respond vigorously to the action of sea waves. Indeed, it is quite hard to make one that will not. However, the conversion of the slow, random, reversing energy flows with very high extreme values into phase-locked synchronous electricity with power quality acceptable to a utility network is very much harder. This paper describes a range of different control strategies of varying degrees of sophistication and then describes possible conversion equipment for high-pressure oil and water and low-pressure air. Like many renewable energy sources, waves would benefit from some form of energy storage, particularly if they are to be used in weak island networks. Flywheels, gas accumulators, submerged oil/vacuum accumulators, thermal stores and reversible fuel cells are discussed, with emphasis on the coupling hardware. This leads on to a description of a new type of hydraulic machine with digital control which has been specially designed for high efficiency and flexible control of multiple erratic sources. An explanation of the rather low performance of air turbines in the random air flows caused by sea waves suggests the need for a variable-pitch version of the Wells turbine and the design of a reciprocating-flow wind-tunnel with recirculating energy recovery in which it could be tested.
Ultimate strength of ageing ships
Authors: Paik J K , Thayamballi A K
Published: September 2002

This paper is a summary of recent research and development in areas related to the ultimate strength of ageing ship hulls, undertaken by the authors. Some relevant methodologies for modelling the two age-related structural degradation factors, namely corrosion and fatigue cracking damages, are proposed and studied. The effects of corrosion and fatigue cracking damages on the ultimate strength of ship panels are investigated by non-linear finite element analyses and mechanical tests. The variations of ship hull ultimate strength as a function of age-related structural degradation are investigated by progressive collapse analyses using the idealized structural unit method (ISUM). Important insights and findings obtained by the research are noted and recommendations are made regarding future development work where appropriate. The development of procedures and criteria for the damage-tolerant design of ship structures is an eventual goal, and the overall outlook in this regard is promising.
Expression and prognostic significance of PTEN product protein in patients with esophageal squamous cell carcinoma
Authors: Tachibana Mitsuo , Shibakita Muneaki , Ohno Satoshi , Kinugasa Shoichi , Yoshimura Hiroshi , Ueda Shuhei , Fujii Toshiyuki , Rahman Mohammad A. , Dhar Dipok K. , Nagasue Naofumi
Published: September 2002

BACKGROUND

PTEN is a candidate tumor‐suppressor gene in a variety of malignant tumors. The prognostic importance of PTEN product protein (PTEN) and its correlation with clinicopathologic characteristics have yet to be delineated in patients with esophageal carcinoma.

METHODS

Specimens from 97 patients with esophageal squamous cell carcinoma were used for the immunohistochemical evaluation of PTEN expression.

RESULTS

PTEN expression was detected in the nucleus in 48 specimens (49.5%). There were statistically significant correlations between nuclear PTEN expression and macroscopic tumor classification, T stage, and American Joint Committee on Cancer (AJCC) stage (P < 0.01), indicating that PTEN expression was down‐regulated by advancement of the disease process. There were no statistically significant correlations between nuclear PTEN expression and the intensity and extent of cytoplasmic PTEN expression. The 10‐year overall survival rate was significantly better in patients with positive nuclear PTEN expression (n = 48 patients) compared with the rate in patients with negative nuclear PTEN expression (n = 49 patients; P < 0.01). The results of a multivariate analysis of factors that were prognostic for survival showed that AJCC stage (P < 0.05; relative risk, 2.038) and negative nuclear PTEN expression (P < 0.05; relative risk, 1.825) were significant factors indicative of poor survival.

CONCLUSIONS

Nuclear PTEN expression may be a favorable biologic marker and a useful prognostic indicator in patients with esophageal squamous cell carcinoma. Cancer 2002;94:1955–60. © 2002 American Cancer Society.

DOI 10.1002/cncr.10410
Editorial
Authors: Jackson Michael B.
Published: September 2002

No abstract
Native or Exotic? Double or Single? Evaluating Plants for Pollinator-friendly Gardens
Authors: Corbet Sarah A. , Bee Jennie , Dasmahapatra Kanchon , Gale Stephan , Gorringe Elizabeth , La Ferla Beverly , Moorhouse Tom , Trevail Andrea , Van Bergen Yfke , Vorontsova Maria
Published: September 2002

In a series of dawn-to-dusk studies, we examined the nature and accessibility of nectar rewards for pollinating insects by monitoring insect visits and the secretion rate and standing crop of nectar in the British native plant species Salvia pratensis , Stachys palustris , S. officinalis , Lythrum salicaria , Linaria vulgaris , the non-native Calendula officinalis , Petunia  ×  hybrida , Salvia splendens , and the possibly introduced Saponaria officinalis . We also compared single with double variants of Lotus corniculatus , Saponaria officinalis , Petunia  ×  hybrida and Calendula officinalis . All the British species studied are nectar-rich and are recommended for pollinator-friendly gardens. They showed maximal secretion rates of about 10–90 μg sugar per flower h −1 , and most had mean standing crops of about 5–60 μg sugar per flower. In all British species studied, the corolla was deep enough for the relatively long-tongued bumblebee Bombus pascuorum , but the shallower flowers of Lythrum salicaria were also much visited by shorter-tongued bees and hoverflies, as well as by butterflies. The exotic Salvia splendens , presumably coevolved with hummingbirds in the Neotropics, has such deep flowers that British bees cannot reach the nectar except by crawling down the corolla. With a secretion rate approaching 300 μg sugar per flower h −1 and little depletion by insects, S. splendens accumulated high standing crops of nectar. S. splendens , and single and double flowers of the two probably moth-pollinated species Petunia  ×  hybrida and Saponaria officinalis , received few daytime visits despite abundant nectar but Calendula was well visited by hoverflies and bees. We compared single and double variants of Lotus corniculatus , Petunia  ×  hybrida and Calendula officinalis , and also Saponaria officinalis , the last being probably introduced in Britain (Stace, 1997 New flora of the British Isles. 2nd edn. Cambridge: Cambridge University Press). In Petunia , Saponaria and Lotus , double flowers secreted little or no nectar. In Calendula , where doubling involved a change in the proportion of disc and ray florets rather than modification of individual flower structure, double and single capitula had similar standing crops of nectar. Except in Calendula , exotic or double flowers were little exploited by insect visitors. In the exotics, this was probably due to the absence or scarcity of coevolved pollinators, coupled, in double flowers, with the absence of nectar. Copyright 2001 Annals of Botany Company
Interannual variability of the extratropical northern hemisphere and the potential vorticity wave guide
Authors: Massacand Alexia C. , Davies Huw C.
Published: September 2002

Interrannual flow variations in the extratropics are reappraised from a potential vorticity (PV) perspective. A statistical study of the patterns of PV variability on a tropopause‐transecting isentropic surface provides a compact description of, and dynamical insight into, the Pacific‐North American teleconnection and the North Atlantic Oscillation. Copyright © 2003 Royal Meteorological Society.
Localisation of EGF‐Receptor mRNA in the nucleus of A431 cells by light microscopy.
Authors: Sibon Ody C. M. , Cremers Fons F. M. , Boonstra Johannes , Humbel Bruno M. , Verkleij Arie J.
Published: September 2002

We have localized the mRNA of the epidermal growth factor receptor (EGF‐receptor) in nuclei of A431 cells by non‐radioactive in situ hybridization at the light microscopical level using digoxigenin‐labelled DNA probes. Both formaldehyde and glutaraldehyde fixations were tested before the hybridization was performed. Glutaraldehyde, compared with formaldehyde fixation, gives a less diffuse hybridization signal, which is easier to localize. Therefore, glutaraldehyde was used as a fixative in the hybridization experiments. It is demonstrated that the mRNA of the EGF‐receptor is present in restricted domains mainly located around the nucleolus. This location of the EGF‐receptor mRNA was unaltered after extraction of chromatin. Therefore it is concluded that the messenger RNA of the EGF‐receptor is attached to the nuclear matrix. A possible biological role for the location of mRNA of the EGF‐receptor around the nucleolus is discussed.
Cell death in the salivary glands of metamorphosing calliphora vomitoria
Authors: Bowen I. D. , Morgan S. M. , Mullarkey K.
Published: September 2002

The salivary gland cells of Calliphora vomitoria larvae initiate and complete their own destruction in a programmed manner at the onset of metamorphosis.

On entering the post‐feeding period the larvae come to rest and the polytene salivary gland cells show a significant increase in DNA synthesis followed closely by a surge of mRNA synthesis accompanied by increasing protein production. During this prelude to cell death the new mRNA gives rise to at least 10 new proteins. The first new proteins having a MWt between 30 and 100kD appear by day 8 of the life‐cycle and a number persist until the advent of cell death on day 9. Other new proteins appear in a cascade of production during day 8 and in vitro translation of mRNA produced at this time shows a new 55kD protein appearing before cell destruction.

Significantly no evidence of DNA degeneration or laddering associated with classical apoptosis was observed, on the contrary considerable DNA synthesis in the form of chromosomal endoduplication or "genomic amplification" was seen; selective gene expression being apparently controlled at translational level. Overall the results strongly suggest a synthetically mediated programmed cell death in the metamorphosing salivary glands of the blow‐fly which is distinct from apoptosis.
A methacrylate embedding procedure developed for immunolocalization on plant tissues is also compatible with in situ hybridization.
Authors: Kronenberger J. , Desprez T. , Höfte H. , Caboche M. , Traas J.
Published: September 2002

A recently described method that uses methacrylate embedding of aldehyde fixed plant tissues allows the immunolabelling of a range of antigens (Baskin et al. 1992). We have tested whether the same embedding procedure is also compatible with in situ hybridization. For this purpose we have used 2‐ 5 μm sections of methacrylate embedded plantlets of Arabidopsis thaliana. After removal of the resin the sections were prepared for in situ hybridization following standard procedures. Three different digoxygenin (dig)‐labelled probes were used, recognizing RNAs coding for the chlorophyll a/b binding protein cab‐140, the β‐tubulin tub5 and meri a member of the meri‐5 family. Each of the probes shows the labelling pattern expected from the literature. Moreover, the method allows a good structural preservation of very fragile tissues, in contrast to paraffin embedding. We conclude that methacrylate embedding, allowing both immunolabelling and in situ hybridization with high resolution and structural preservation, offers a high potential for the functional analysis of genes and proteins in plant development. This is especially true for Arabidopsis thaliana, a widely used model species where it seems to be the method of choice.
Initiation of DNA synthesis in a high molecular weight fraction of Xenopus egg extract.
Authors: Okuhara Koji , Shioda Masaki , Shiokawa Koichiro , Murakami‐Murofushi Kimiko , Seyama Yousuke , Murofushi Hiromu
Published: September 2002

Xenopus egg extract was fractionated by gel‐filtration column chromatography and DNA synthetic activity was examined using double‐stranded DNA as a template. The major activity eluted had an apparent molecular mass of about 300 kDa. Product analyses showed that de novo DNA synthesis occurs with formation of replication bubbles, thereby suggesting that this fraction catalyzes the initiation of DNA replication. Activities of DNA polymerase α‐primase and DNA helicase overlapped with the DNA synthetic activity, but the elution profiles of the enzymes differed from that of the DNA synthetic activity. Therefore, this 300‐kDa fraction may contain a component which differs from the above enzymes yet is essential for initiation of DNA replication.
Breaking the adhesions of a cell with its substratum
Authors: Simpson Kaetrin , McGrath Michael , Curtis Adam
Published: September 2002

Investigation of the relative slowness with which trypsin detaches epithelial cells from their adhesions with a substratum suggests that the adherent surface of the cells is normally rather inaccessible to the enzyme. Trypsinisation of cells through a porous filter allowing access of the enzyme to the underside of the cells greatly accelerated detachment: a result consistent with this explanation.
Movement of cell‐associated matrix during contact competition of cells in mixed cultures.
Authors: Domnina L. V. , Fetisova E. K. , Vasiliev J. M.
Published: September 2002

Co‐cultured contacting heterotypic cell groups compete with one another for the attachment to the substratum. In the course of this competition one cell group can progressively push another from the substratum. Alterations to the distribution of cell‐associated matrix structures in the course of contact competition were examined by immunomorphological methods in the paired cultures of two epithelial lines and those of fibroblasts and epithelia. It was found that matrix structures formed by the retreating cells withdrew from the substratum simultaneously with the cells. These results show that two forms of matrix structures should be distinguished: the usually immovable matrix upon which the cells crawl and the movable matrix that the cells carry with them when they move.