bluuebunny/crossref_metadata_2025 huggingface dataset:
Solvability of a nonlinear second order conjugate eigenvalue problem on a time scale
Authors: Davis John M. , Henderson Johnny , Prasad K. Rajendra , Yin William
Published: September 2002

We consider the nonlinear second order conjugate eigenvalue
problem on a time scale: y ΔΔ(t) + λa(t)f(y(σ(t))) = 0, t ∈ [0, 1], y(0) = 0 = y(σ(1))
. Values of the parameter λ (eigenvalues) are determined for which this problem has a positive solution. The methods used here extend recent results by allowing for a broader class of functions for a(t).
A Morse lemma for degenerate critical points with low differentiability
Authors: de Moura Adriano A. , de Souza Fausto M.
Published: September 2002

We prove a Morse type lemma for, possibly degenerate, critical
points of a C1 function twice strongly differentiable at those points, which allows us to recover, for Finsler metrics, the theorem of Gromoll and Meyer on the existence of infinitely many closed geodesics.
Bounded and almost periodic solutions and evolution semigroups associated with nonautonomous functional differential equations
Authors: Aulbach Bernd , Minh Nguyen Van
Published: September 2002

We study evolution semigroups associated with nonautonomous
functional differential equations. In fact, we convert a given functional differential equation to an abstract autonomous evolution equation and then derive a representation theorem for the solutions of the underlying functional differential equation. The representation theorem is then used to study the boundedness and almost periodicity of solutions of a class of nonautonomous
functional differential equations.
Factor spaces and implications on Kirchhoff equations with clamped boundary conditions
Authors: Lasiecka Irena , Triggiani Roberto
Published: September 2002

We consider mixed problems for the Kirchhoff elastic and
thermoelastic systems, subject to boundary control in the clamped
boundary conditions BC (clamped control). If w
denotes the
elastic displacement and θ
the temperature, we establish
sharp regularity of {w, wt, wtt}
in the elastic case, and
of {w, wt, wtt, θ}
in the thermoelastic case. Our
results complement those by Lagnese and Lions (1988), where sharp
(optimal) trace regularity results are obtained for the
corresponding boundary homogeneous cases. The passage from the
boundary homogeneous cases to the corresponding mixed problems
involves a duality argument. However, in the present case of
clamped BC, and only in this case, the duality argument in
question is both delicate and technical. In this respect, the
clamped BC are “exceptional” within the set of canonical
BC (hinged, clamped, free BC). Indeed, it produces new phenomena
which are accounted for by introducing new, untraditional factor
(quotient) spaces. These are critical in describing both interior
regularity and exact controllability of mixed elastic and
thermoelastic Kirchhoff problems with clamped controls.
Set quantities and Tauberian operators
Authors: Falcon Sergio , Sadarangani Kishin
Published: September 2002

The concept of convexity plays an important role in the classical
geometry of normed spaces and it is frequently used in several
branches of nonlinear analysis. In recent years some papers that
contain generalizations of the concept of convexity with the help
of the measures of noncompactness have appeared.
The Tauberian operators were introduced by Kalton and Wilansky
(1976) and they appear in the literature with the aim of
responding to some questions related with the summability and the
factorization of operators; in the preservation by isomorphisms in
Banach spaces, and so forth.
In this paper we make the study of the Tauberian operators, not
starting from the Euclidean distance, but by means of general set
quantities.
On the existence of a positive solution for a semilinear ellipticequation in the upper half space
Authors: Shaowei Chen , Yongqing Li
Published: September 2002

We show the existence of a nontrivial solution to the
semilinear elliptic equation under some suitable
conditions.
On the curvature of nonregular saddle surfaces in the hyperbolic and spherical three‐space
Authors: Kalikakis Dimitrios E.
Published: September 2002

This paper proves that any nonregular nonparametric saddle
surface in a three‐dimensional space of nonzero constant
curvature k, which is bounded by a rectifiable curve, is a
space of curvature not greater than k in the sense of
Aleksandrov. This generalizes a classical theorem by Shefel′ on
saddle surfaces in 𝔼3.
On coincidence index for multivalued perturbations of nonlinear Fredholm maps and some applications
Authors: Obukhovskii Valeri , Zecca Pietro , Zvyagin Victor
Published: September 2002

We define a nonoriented coincidence index for a compact, fundamentally restrictible, and condensing multivalued perturbations of a map
which is nonlinear Fredholm of nonnegative index on the set of coincidence points. As an application, we consider an optimal controllability problem for a system governed by a second‐order integro‐differential equation.
Generation theory for semigroups of holomorphic mappingsin Banach spaces
Authors: Reich Simeon , Shoikhet David
Published: September 2002

We study nonlinear semigroups of holomorphic mappings in Banach spaces and their infinitesimal generators. Using resolvents, we characterize, in particular, bounded holomorphic generators on bounded convex domains and obtain an analog of the Hille exponential formula. We then apply our results to the null point theory of semi‐plus complete vector fields. We study the structure of null point sets and the spectral characteristics of null points, as well as their existence and uniqueness. A global version of
the implicit function theorem and a discussion of some open problems are
also included.
The generalized Conley index and multiple solutions of semilinear elliptic problems
Authors: Dancer E. N. , Du Yihong
Published: September 2002

We establish some framework so that the generalized Conley
index can be easily used to study the multiple solution problem of semilinear elliptic
boundary value problems. Both the parabolic flow and the gradient
flow are used. Some examples are given to compare our approach here with
other well‐known methods. Our abstract results with parabolic flows may
have applications to parabolic problems as well.
Global attractors for two‐phase stefan problems inone‐dimensional space
Authors: Aiki T.
Published: September 2002

In this paper we consider one‐dimensional two‐phase Stefan problems for a class of parabolic equations with nonlinear heat source terms
and with nonlinear flux conditions on the fixed boundary. Here, both time‐dependent and time‐independent source terms and boundary conditions are treated. We investigate the large time behavior of solutions to our problems by using the theory for dynamical systems. First, we show the existence of a global attractor 𝒜 of autonomous Stefan problem. The main purpose in the present paper is to prove that the set 𝒜 attracts all solutions of non‐autonomous Stefan problems as time tends to infinity under the assumption that time‐dependent data converge to time‐independent ones as time goes to infinity.
A result on the bifurcation from the principal eigenvalue of theAp‐Laplacian
Authors: Drábek P. , Elkhalil A. , Touzani A.
Published: September 2002

We study the following bifurcation problem in any bounded
domain Ω in ℝN:

urn:x-wiley:10853375:media:aaa468501:aaa468501-math-0001

. We prove that the principal eigenvalue λ1 of the eigenvalue problem

urn:x-wiley:10853375:media:aaa468501:aaa468501-math-0002

is a bifurcation point of the problem mentioned above.
On a problem of lower limit in the study of nonresonance
Authors: Anane A. , Chakrone O.
Published: September 2002

We prove the solvability of the Dirichlet problem

urn:x-wiley:10853375:media:aaa793549:aaa793549-math-0001

for every given h, under a condition involving only the asymptotic behaviour of the potential F of f with respect to the first
eigenvalue of the p‐Laplacian Δp. More general operators are also considered.
Existence of extremal periodic solutions for quasilinear parabolic equations
Authors: Carl Siegfried
Published: September 2002

In this paper we consider a quasilinear parabolic equation in a
bounded domain under periodic Dirichlet boundary conditions. Our main goal is to prove the existence of extremal solutions among all solutions lying in a sector formed by appropriately defined upper and lower solutions. The main tools used in the proof of our result are recently obtained abstract results on nonlinear evolution equations, comparison and truncation techniques and suitably constructed special testfunction.
Long‐time asymptotics of solutions of the second initial‐boundary valueproblem for the damped Boussinesq equation
Authors: Varlamov Vladimir V.
Published: September 2002

For the damped Boussinesq equation , the second initial‐boundary value problem is considered with small initial data. Its classical solution is constructed in the form of a series in small parameter present in the initial conditions and the uniqueness of solutions is proved. The long‐time asymptotics is obtained in the explicit form and the question of the blow up of the solution in a certain case is examined. The possibility of passing to the limit b → +0 in the constructed solution is investigated.
Positive solutions of critical quasilinear elliptic problems ingeneral domains
Authors: Gazzola Filippo
Published: September 2002

We consider a certain class of quasilinear elliptic equations with a term in the critical growth range. We prove the existence of positive solutions in bounded and unbounded domains. The proofs involve several generalizations of standard variational arguments.
Characterizations of metric projections in Banach spaces and applications
Authors: Penot Jean-Paul , Ratsimahalo Robert
Published: September 2002

This paper is devoted to the study of the metric projection onto a nonempty closed convex subset of a general Banach space. Thanks to a systematic use of semi‐inner products and duality mappings, characterizations of the metric projection are given. Applications to decompositions of Banach spaces along convex cones and variational inequalities are presented.
Analyticity of thermo‐elastic semigroups with coupled hinged/Neumann B.C.
Authors: Lasiecka Irena , Triggiani Roberto
Published: September 2002

We consider a thermo‐elastic plate system where the elastic equation does not account for rotational forces. We select the case of hinged
mechanical B.C. and Neumann thermal B.C., which are coupled on the boundary. We show that the corresponding s.c. contraction semigroup (on a natural energy space) is analytic and, hence, uniformly stable. Because of the boundary (high) coupling, this case of B.C. is not contained in, and is more challenging than, recent known cases of the
literature [L‐R.1], [L‐L.1], [L‐T.1].
Multiple solutions for a problem with resonance involving thep‐Laplacian
Authors: Alves C. O. , Carrião P. C. , Miyagaki O. H.
Published: September 2002

In this paper we will investigate the existence of multiple
solutions for the problem

urn:x-wiley:10853375:media:aaa315492:aaa315492-math-0001

where Δpu = div(|∇u|p−2∇u) is the p‐Laplacian operator, Ω⫅ℝN is a bounded domain with smooth boundary, h and g are bounded functions, N ≥ 1 and 1 < p < ∞. Using the Mountain Pass Theorem and the Ekeland Variational Principle, we will show the existence of at least three solutions for (P).
Spectral properties of operators that characterize
Authors: Chalmers B. L. , Shekhtman B.
Published: September 2002

It is well known that the identity is an operator with the following property: if the operator, initially defined on an n‐dimensional Banach space V, can be extended to any Banach space with norm 1, then V is isometric to . We show that the set of all such operators consists precisely of those with spectrum lying in the unit circle. This result answers a question raised in [5] for complex spaces.
Existence and uniform boundedness of optimal solutions ofvariational problems
Authors: Zaslavski Alexander J.
Published: September 2002

Given an x0 ∈ Rn we study the infinite horizon problem of minimizing the expression as T grows to infinity where x : [0, ∞) → Rn satisfies the initial condition x(0) = x0. We analyse the existence and the properties of approximate solutions for every prescribed initial value x0. We also establish that for every bounded set E ⊂ Rn the C([0, T]) norms of approximate solutions x : [0, T] → Rn for the minimization problem on an interval [0, T] with x(0), x(T) ∈ E are bounded by some constant which does not depend on T.
Singular nonlinear elliptic equations in Rn
Authors: Alves C. O. , Goncalves J. V. , Maia L. A.
Published: September 2002

This paper deals with existence, uniqueness and regularity of positive generalized solutions of singular nonlinear equations of the form −Δu + a(x)u = h(x)u−γ in Rn where a, h are given, not necessarily continuous functions, and γ is a positive number. We explore both situations where a, h are radial functions, with a being eventually identically zero, and cases where no symmetry is required from either a or h. Schauder′s fixed point theorem, combined with penalty arguments, is exploited.
Almost periodic mild solutions of a class of partial functionaldifferential equations
Authors: Aulbach Bernd , Minh Nguyen Van
Published: September 2002

We study the existence of almost periodic mild solutions of a
class of partial functional differential equations via semilinear
almost periodic abstract functional differential equations of the form

urn:x-wiley:10853375:media:aaa915039:aaa915039-math-0001

To this end, we first associate with every almost periodic semilinear
equation

urn:x-wiley:10853375:media:aaa915039:aaa915039-math-0002

a nonlinear semigroup in the space of almost periodic functions.
We then give sufficient conditions (in terms of the accretiveness of
the generator of this semigroup) for the existence of almost periodic
mild solutions of (**) as fixed points of the semigroup.
Those results are then carried over to equation (*).
The main results are stated under accretiveness conditions of the
function f in terms of x and Lipschitz conditions with respect to xt.
Nonlocal boundary value problem for second order abstract elliptic differential equation
Authors: Denche Mohamed
Published: September 2002

We establish conditions that guarantee Fredholm solvability in
the Banach space Lp of nonlocal boundary value problems for elliptic abstract differential equations of the second order in an interval. Moreover, in the space L2 we prove in addition the coercive solvability, and the completeness of root functions (eigenfunctions and associated functions). The obtained results
are then applied to the study of a nonlocal boundary value problem for Laplace equation in a cylindrical domain.
Semilinear elliptic equations having asymptotic limits at zero and infinity
Authors: Perera Kanishka , Schechter Martin
Published: September 2002

We obtain nontrivial solutions for semilinear elliptic boundary
value problems having resonance both at zero and at infinity, when the nonlinear term has asymptotic limits.
Asymptotic properties of mild solutions of nonautonomousevolution equations with applications to retarded differential equations
Authors: Gühring Gabriele , Räbiger Frank
Published: September 2002

We investigate the asymptotic properties of the inhomogeneous
nonautonomous evolution equation (d/dt)u(t) = Au(t) + B(t)u(t) + f(t), t ∈ ℝ, where (A, D(A)) is a Hille‐Yosida operator on a Banach space X, B(t), t ∈ ℝ, is a family of operators in satisfying certain boundedness and measurability conditions and . The solutions of the corresponding homogeneous equations are represented by an evolution family . For various function spaces ℱ we show conditions on and f which ensure the existence of a unique solution contained in ℱ. In particular, if is p‐periodic there exists a unique bounded solution u subject to certain spectral assumptions on UB(p, 0), f and u. We apply the results to nonautonomous semilinear retarded differential equations. For certain p‐periodic retarded differential equations we derive a characteristic equation which is used to determine the spectrum of .
The Human Y Chromosome: The Biological Role of a “Functional Wasteland”
Authors: Quintana-Murci Lluís , Fellous Marc
Published: September 2002

“Functional wasteland,” “Nonrecombining desert” and
“Gene‐poor chromosome” are only some examples of the different
definitions given to the Y chromosome in the last decade. In
comparison to the other chromosomes, the Y is poor in genes,
being more than 50% of its sequence composed of repeated
elements. Moreover, the Y genes are in continuous decay probably
due to the lack of recombination of this chromosome. But the
human Y chromosome, at the same time, plays a central role in
human biology. The presence or absence of this chromosome
determines gonadal sex. Thus, mammalian embryos with a Y
chromosome develop testes, while those without it develop ovaries
(Polani [38]). What is responsible for the male phenotype is
the testis‐determining SRY gene (Sinclair [52]) which
remains the most distinguishing characteristic of this
chromosome. In addition to SRY, the presence of other genes with
important functions has been reported, including a region
associated to Turner estigmata, a gene related to the development
of gonadoblastoma and, most important, genes related to germ cell
development and maintenance and then, related with male fertility
(Lahn and Page [31]). This paper reviews the structure and
the biological functions of this peculiar chromosome.
Chains of KP, semi‐infinite 1‐Toda lattice hierarchy and Kontsevich integral
Authors: Dickey L. A.
Published: September 2002

There are well‐known constructions of integrable systems that are
chains of infinitely many copies of the equations of the KP
hierarchy “glued” together with some additional variables, for
example, the modified KP hierarchy. Another interpretation of the
latter, in terms of infinite matrices, is called the 1‐Toda
lattice hierarchy. One way infinite reduction of this hierarchy
has all the solutions in the form of sequences of expanding
Wronskians. We define another chain of the KP equations, also
with solutions of the Wronsksian type, that is characterized by
the property to stabilize with respect to a gradation. Under some
constraints imposed, the tau functions of the chain are the tau
functions associated with the Kontsevich integrals.
Quasi‐definiteness of generalized Uvarov transforms of moment functionals
Authors: Kim D. H. , Kwon K. H.
Published: September 2002

When σ
is a quasi‐definite moment functional with the
monic orthogonal polynomial system , we consider a point masses perturbation τ
of σ
given by , where λ, ulk, and cl are
constants with ci ≠ cj
for i ≠ j. That is, τ
is a generalized Uvarov transform of
σ satisfying A(x) τ = A(x) σ, where
. We find necessary and
sufficient conditions for τ
to be quasi‐definite. We also
discuss various properties of monic orthogonal polynomial system

relative to τ
including
two examples.
Radiation effect on MHD free‐convection flow of a gas at a stretching surface with a uniform free stream
Authors: Ghaly Ahmed Y. , Elbarbary Elsayed M. E.
Published: September 2002

We investigate the problem of free convection heat transfer near an isothermal stretching sheet. This has been done under the simultaneous action of buoyancy, radiation, and transverse magnetic field. The governing equations are solved by the shooting method. The velocity and temperature functions are represented graphically for various values of the flow parameters: radiation parameter F, free convection parameter Gr, magnetic parameter M, Prandtl number Pr, and the parameter of relative difference between the temperature of the sheet, and the temperature far away from the sheet r. The effects of the radiation and magnetic field parameters on the shear stress and heat flux are discussed.
A frictionless contact problem for viscoelastic materials
Authors: Barboteu Mikäel , Han Weimin , Sofonea Mircea
Published: September 2002

We consider a mathematical model which describes the contact
between a deformable body and an obstacle, the so‐called
foundation. The body is assumed to have a viscoelastic behavior
that we model with the Kelvin‐Voigt constitutive law. The contact
is frictionless and is modeled with the well‐known Signorini
condition in a form with a zero gap function. We present
two alternative yet equivalent weak formulations of the problem
and establish existence and uniqueness results for both
formulations. The proofs are based on a general result on
evolution equations with maximal monotone operators. We then
study a semi‐discrete numerical scheme for the problem, in terms
of displacements. The numerical scheme has a unique solution. We
show the convergence of the scheme under the basic solution
regularity. Under appropriate regularity assumptions on the
solution, we also provide optimal order error estimates.
Protective Function of Transcription Factor TR3 Orphan Receptor in Atherogenesis
Authors: Arkenbout E. Karin , de Waard Vivian , van Bragt Maaike , van Achterberg Tanja A.E. , Grimbergen Jos M. , Pichon Bruno , Pannekoek Hans , de Vries Carlie J.M.
Published: September 2002

Background—

Smooth muscle cells (SMCs) play a key role in intimal thickening in atherosclerosis and restenosis. The precise signaling pathways by which the proliferation of SMCs is regulated are largely unknown. The TR3 orphan receptor, the mitogen-induced nuclear orphan receptor (MINOR), and the nuclear receptor of T cells (NOT) are a subfamily of transcription factors belonging to the nuclear receptor superfamily and are induced in activated SMCs. In this study, we investigated the role of these transcription factors in SMC proliferation in atherogenesis.

Methods and Results—

Multiple human vascular specimens at distinct stages of atherosclerosis (lesion types II to V by American Heart Association classification) derived from 14 different individuals were studied for expression of these transcription factors. We observed expression of TR3, MINOR, and NOT in neointimal SMCs, whereas no expression was detected in medial SMCs. Adenovirus-mediated expression of a dominant-negative variant of TR3, which suppresses the transcriptional activity of each subfamily member, increases DNA synthesis and decreases p27
Kip1
protein expression in cultured SMCs. We generated transgenic mice that express this dominant-negative variant or full-length TR3 under control of a vascular SMC-specific promoter. Carotid artery ligation of transgenic mice that express the dominant-negative variant of TR3 in arterial SMCs, compared with lesions formed in wild-type mice, results in a 3-fold increase in neointimal formation, whereas neointimal formation is inhibited 5-fold in transgenic mice expressing full-length TR3.

Conclusions—

Our results reveal that TR3 and possibly other members of this transcription factor subfamily inhibit vascular lesion formation. These transcription factors could serve as novel targets in the treatment of vascular disease.
Survival in Primary Pulmonary Hypertension
Authors: McLaughlin Vallerie V. , Shillington Alicia , Rich Stuart
Published: September 2002

Background—

Primary pulmonary hypertension (PPH) is a severe and progressive disease. Without treatment, the median survival is 2.8 years, with survival rates of 68%, 48%, and 34% at 1, 3, and 5 years, respectively. Intravenous epoprostenol was the first Food and Drug Administration–approved therapy for PPH. The long-term impact that epoprostenol has made on PPH remains to be defined.

Methods and Results—

One hundred sixty-two consecutive patients diagnosed with PPH and treated with epoprostenol were followed for a mean of 36.3 months (median, 31 months). Data including functional class, exercise tolerance, and hemodynamics were recorded in a customized database. Vital status was verified in each patient. Observed survival with epoprostenol therapy at 1, 2, and 3 years was 87.8%, 76.3%, and 62.8% and was significantly greater than the expected survival of 58.9%, 46.3%, and 35.4% based on historical data. Baseline predictors of survival included exercise tolerance, functional class, right atrial pressure, and vasodilator response to adenosine. Predictors of survival after the first year of therapy included functional class and improvement in exercise tolerance, cardiac index, and mean pulmonary artery pressure.

Conclusions—

Intravenous epoprostenol improves long-term survival in PPH.
Simvastatin Lowers C-Reactive Protein Within 14 Days
Authors: Plenge Julie K. , Hernandez Teri L. , Weil Kathleen M. , Poirier Paul , Grunwald Gary K. , Marcovina Santica M. , Eckel Robert H.
Published: September 2002

Background—

The early response of C-reactive protein to initiation of a hydroxymethylglutaryl coenzyme A reductase inhibitor (statin) is not known. The purpose of this study was to determine the rate at which highly sensitive C-reactive protein (hsCRP) levels change after initiation of simvastatin and whether this occurs independently of the change in LDL cholesterol.

Methods and Results—

The study was a crossover, double-blind design including 40 subjects with elevated LDL cholesterol. Subjects were randomly assigned to 1 of 2 groups: simvastatin 40 mg for 14 days, then placebo for 14 days, or placebo first, then simvastatin. Simvastatin decreased LDL cholesterol by 56±4 mg/dL (
P
<0.0001) at day 7 and by an additional 8±3 mg/dL (
P
=0.02) at day 14. Baseline log(hsCRP) levels were similar in the 2 groups. By day 14, log(hsCRP) was significantly lower in patients on simvastatin when compared with placebo (
P
=0.011). Although there was no significant difference in fibrinogen levels, simvastatin produced a modest increase in log[lipoprotein(a)] (
P
=0.03) at days 7 and 14. There were no relationships between the decrease in LDL cholesterol and the decrease in hsCRP.

Conclusions—

Simvastatin lowers hsCRP by 14 days, independent of its effect on LDL cholesterol. This rapid impact of a statin on hsCRP has potential implications in the management of acute coronary syndromes.
Augmented Expression of Cardiotrophin-1 in Failing Human Hearts Is Accompanied by Diminished Glycoprotein 130 Receptor Protein Abundance
Authors: Zolk Oliver , Ng Leong L. , O’Brien Russell J. , Weyand Michael , Eschenhagen Thomas
Published: September 2002

Background—

Cardiotrophin-1 (CT-1), a member of the interleukin-6 superfamily, is a potent inducer of cardiomyocyte hypertrophy that prolongs myocyte survival. Although cardiac CT-1 gene expression is known to be upregulated in some animal models of congestive heart failure, the activation state of the CT-1 system in patients with congestive heart failure is unknown.

Methods and Results—

This study was designed to determine left ventricular expression of CT-1 and its glycoprotein 130 (gp130)/leukemia inhibitory factor receptor complex in human end-stage heart failure due to ischemic and dilated cardiomyopathy. In addition, we investigated the activation state of signal transducer and activator of transcription 3 (STAT3), the downstream effector of gp130 signaling. In the failing left ventricular myocardium, expression levels of CT-1 mRNA and protein were significantly increased by 142% and 68%, respectively, compared with non-failing donor hearts. Immunohistochemistry confirmed the increased expression of CT-1 in cardiac myocytes. Although gp130 gene expression was increased by 91% (
P
<0.001), gp130 protein abundance was significantly diminished by 34% in the failing myocardium. In contrast, leukemia inhibitory factor receptor and suppressor of cytokine signaling-3 protein concentrations were not changed. In addition, the ratio of activated tyrosine phosphorylated STAT3 to total STAT3 was not significantly altered in failing hearts compared with non-failing controls.

Conclusions—

Our data suggest that gp130 receptor downregulation balances enhanced CT-1 expression in human heart failure and thereby inhibits excessive activation of the gp130 signaling pathway.
Collision risk for fixed offshore structures close to high-density shipping lanes
Authors: Pedersen P T
Published: September 2002

Fixed offshore structures in the vicinity of intense ship traffic pose a potential collision hazard such as risk of loss of life, economic loss, environmental damage and other possible unwanted events. Therefore, one of the many performance goals in the design phase of such structures is to ensure that the risk of such major accidents and service disruptions is low enough to be acceptable to users, the public and those responsible for public safety.

The present paper uses a risk analysis performed for a large suspension bridge with approach spans as an example of the key elements required in a rational risk analysis procedure for fixed offshore structures in shipping lanes with high traffic densities. It deals with the following items: the basic information and the navigational studies needed for a rational collision risk assessment, exemplification of target risk acceptance criteria for the bridge structure, an analysis procedure for ship collision frequencies as a function of the structural layout, elements in a calculation of the probabilistic distribution of collision forces on the fixed structure, given a collision has taken place, and finally it is shown how the consequences due to accidental ship collisions can be assessed, i.e. the risks that have to be compared to the target risk acceptance criteria.

The main objective of the procedure is to provide the designers with the maximum flexibility to develop new cost effective offshore structures based on performance standards for the structural requirements and the requirements to the navigational arrangements, instead of basing the design on the more traditional prescriptive rules or codes. For the example bridge structure it is shown that fulfilment of the established risk criteria substantially influences the geometric requirements for the navigation clearance and the needed resistance to ship, impacts. In addition it was found necessary to establish a vessel traffic system (VTS).
Development of a new efficient stiffened plate element for dynamic analysis of a three-dimensional ship structure
Authors: Kumar Y V Satish , Mukhopadhyay M , Sarkar T
Published: September 2002

The dynamic analysis of a complete ship structure is presented using a new stiffened plate element to model the hull plating, bulkheads, decks and other parts. The analysis is based on three-dimensional modelling of the complete vessel, and the hydrodynamic loads are computed using a panel method (based on linear diffraction theory). The stiffened plate element can elegantly accommodate any number of arbitrarily oriented stiffeners and obviates the use of mesh lines along the longitudinals and transverses. It enhances the flexibility in mesh generation over the hull components. Analysis is limited to zero forward speed and head sea conditions only. As an example, three-dimensional dynamic analysis of a bulk carrier with an accurate treatment of stiffeners is presented. Results in terms of stress amplitudes are presented for several wave frequencies. The present method provides a unique, elegant and economic way for three-dimensional dynamic analysis of complete ship structures.
Reduced models for statistically stationary and non-stationary flows with control applications
Authors: Tan M , Uzunogĝlu B , Price W G , Rogers E
Published: September 2002

Reduced modelling techniques, based on a proper orthogonal decomposition (POD) method, are applied to an investigation of the incompressible Navier-Stokes equations with inputs. A circular cylinder in uniform flow with and without inputs is studied. Reduced dynamic models are created by POD and by extended POD (EPOD) approaches for the forced flow which is statistically non-stationary. A direct control action is applied to the flow at particular points and this investigation provides insights into the applications of the proposed approaches coupled with a full solver.
Patterns of morphological discrimination in selected human tarsal elements
Authors: Kidd R.S. , Oxnard C.E.
Published: September 2002

A suite of measurements was collected from the talus, calcaneus, navicular, and cuboid of humans from Southern China, Victorian Britain, Roman Britain, and Zulu tribes people from the Republic of South Africa. Univariate and multivariate statistical analyses of dimensions of individual foot bones revealed subtle but distinct patterns of morphological discrimination on the basis of sex and size on the one hand, and geographical relationships on the other. These differences are largely expressed in the first three canonical variates of the multivariate analyses: the first axis expresses both sex and size differences, and the second and third, geographical group differences. Confirmation of morphological patterns obtained from individual multivariate analyses was provided by an integrated analysis of the four tarsal elements together. However, the integrated analysis also gave larger separations with discriminations along different axes. Thus the three geographical groups (Zulus, Southern Chinese, and the two British groups together) were separated by first and third variates. The discrimination of sex and size differences was found in the second axis, mirroring what was found in the first axes of the individual studies. This axis reversal implies that in examining all bones together, there is enough redundant information about sex and size in each individual bone that they are relegated to a second axis. It likewise implies that the data referring to geographic discriminations provided by each individual bone are not redundant; they sum in the integrated analysis, and therefore contribute to the overall analysis to a greater extent, with increased clarity. Am J Phys Anthropol 117:169–181, 2002. © 2002 Wiley‐Liss, Inc.
Synthesis of a new type of adsorbent containing carboxyl and amidoxime groups by preirradiation grafting and its absorption of metal ions
Authors: Zhanhai Yao , Lei Rao , Jun Xu
Published: September 2002

A new type of adsorbent containing amidoxime and carboxyl groups was synthesized by the preirradiation graft copolymerization of acrylonitrile (AN) and acrylic acid (AA) onto fibrous‐type poly(vinyl alcohol) followed by amidoximation with hydroxylamine. The radiation dose and ratio of AN and AA monomers influenced the degree of grafting, the content of the amidoxime group, and the adsorption capacity. The synthesis course, structure, and properties of the adsorbent were investigated with Fourier transform infrared, scanning electron microscopy, and thermogravimetry. The adsorption property of the adsorbent for palladium(II) ions was also studied systematically. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1986–1992, 2002
Molecular pathology parameters in human nasopharyngeal carcinoma
Authors: Shi Wei , Pataki Istvan , MacMillan Christine , Pintilie M.Sc. M. , Payne David , O'Sullivan M.B. Brian , Cummings M.B. Ch.B. Bernard J. , Warde Padraig , Liu Fei‐Fei
Published: September 2002

BACKGROUND

To derive a better understanding of the biologic behavior of nasopharyngeal carcinoma (NPC), the authors evaluated a number of molecular variables to address the hypothesis that p53 dysfunction in NPC is associated with Epstein‐Barr virus (EBV), increased tumor angiogenesis, lower likelihood of apoptosis, and poorer clinical outcome.

MATERIALS

The biopsy samples from 87 NPC patients were obtained and sections were made to detect EBV, using in‐situ hybridization; the authors used immunohistochemistry to assess p53, p21WAF1/CIP1expression, and microvessel density count (MVD). In situ end labelling was used to evaluate apoptosis and necrosis. Analyses were conducted on the association between each of these variables as well as clinical outcome, including survival and local control.

RESULTS

There was a highly significant association between EBV‐encoded RNA (EBER) positivity with p53 over‐expression in that only 1 out of 32 p53 over‐expressing tumors was EBER negative, as opposed to 19 out of 48 p53 negative tumors being EBER negative (P= 0.001). In addition, EBER positivity was highly associated with World Health Organization (WHO) type 3 NPC, Asian/Chinese ethnicity, a lower apoptotic index, and p21 over‐expression. p53 over‐expression was associated with a higher MVD count. Controlling for age and nodal status, EBER positivity was associated with both improved overall survival (P= 0.02), and disease‐free survival (P= 0.04). In contrast, the presence of tumor necrosis was associated with an inferior local control (P= 0.03).

CONCLUSION

p53 protein was over‐expressed in approximately one third of NPC samples in the current study, and this correlated significantly with the presence of EBER. Epstein‐Barr virus status was also associated with WHO type 3 NPC, Asian/Chinese ethnicity, and induction of p21. The presence of EBV appeared to predict for improved survival, the mechanism of which remains to be elucidated in this biologically complex disease. Cancer 2002;94:1997–2006. © 2002 American Cancer Society.

DOI 10.1002/cncr.10440
Encouraging homework completion among older adults in therapy
Authors: Coon David W. , Gallagher‐Thompson Dolores
Published: September 2002

A growing body of research suggests that homework assignments facilitate positive outcomes in psychotherapy. We describe a cognitive behavioral outpatient therapy that stresses the important role homework plays in psychotherapy outcomes and that is found to be successful for treating emotional distress in both older adults and family caregivers. Just as a number of barriers can make it difficult for older clients to commit to regular therapy appointments, a variety of factors can also influence their completion of homework. We also address key issues frequently encountered when fostering homework compliance among older adults and utilize case vignettes to illustrate successful approaches to address these barriers. We present basic tenets for effective homework completion regardless of age group as well as several methods to address homework challenges that we find to be particularly pertinent for therapists treating today's older adults. © 2002 Wiley Periodicals, Inc. J Clin Psychol/In Session 58: 549–563, 2002.
Bracken Distribution in Great Britain: Strategies for its Control and the Sustainable Management of Marginal Land
Authors: Pakeman Robin J. , Le Duc Mike G. , Marrs Rob H.
Published: September 2002

Bracken is often perceived as a widespread and increasing land management problem. The pollen record of a wide range of sites in Great Britain suggests that the current abundance of bracken is less than or, at worst, equivalent to maximum historical levels. Recently gathered data also suggest that bracken cover is declining. Results of risk assessments of land use change, and experimental and modelling investigations into the effects of climate change are synthesized. This synthesis suggests that there is the potential for increased bracken dominance in northern Britain, spread into new areas at high altitudes, and possible spread into areas with reduced grazing. However, this must be set against any changes in the extent of other vegetation types at the expense of bracken. There is now a long history of bracken control, both in Great Britain and globally. Conventional methods of control (cutting, asulam application) are well understood, but many control attempts do not result in long-term success, as control is often not followed by aftercare. Bracken control is just one part of the process to ensure a sustainable use of resources and to maintain biodiversity. A coherent strategy for bracken control is put forward, a necessary part of which includes the restoration of vegetation and subsequent land management which takes into account an understanding of bracken ecology.
On the structure and variability of atmospheric circulation regimes in coupled climate models
Authors: Weisheimer Antje , Handorf Dörthe , Dethloff Klaus
Published: September 2002

In order to investigate whether climate models of different complexity have the potential to simulate natural atmospheric circulation regimes, 1000‐year‐long integrations with constant external forcing have been analysed. Significant non‐Gaussian uni‐, bi‐, and trimodal probability density functions have been found in 100‐year segments. Copyright © 2001 Royal Meteorological Society.
Indication of shrinking atmosphere above Tromsø (69 °N, 19 °E)
Authors: Hall C. M. , Cannon P. S.
Published: September 2002

At Tromsø (69 °N; 19 °E), ionospheric data from 1952 onwards indicate that the mean altitude of the F2 layer is dropping by 4 km per decade on average. This effect is thought to be attributable to middle atmosphere cooling due to increasing concentrations of anthropogenic carbon dioxide and methane. Copyright © 2003 Royal Meteorological Society.
Effects of different terrain on velocity standard deviations
Authors: Al‐Jiboori M. H. , Xu Yumao , Qian Yongfu
Published: September 2002

The standard deviations of wind velocity components are calculated and compared based on the measurements of turbulence fluctuations over three underlying surfaces: uniform, inhomogeneous and urban. Statistical analysis shows that there are the differences between them which prove the influences of surfaces roughness on turbulence. Copyright © 2003 Royal Meteorological Society.
Ascribing potential causes of recent trends in free atmosphere temperatures
Authors: Thorne P. W. , Jones P. D. , Tett S. F. B. , Parker D. E. , Osborn T. J. , Davies T. D.
Published: September 2002

We use globally gridded radiosonde temperature datasets in a simple climate change study. Two climate models, when run with historical and, particularly, anthropogenic forcings, exhibit a degree of agreement with radiosonde temperature observations for 1958–1998. Copyright © 2002 British Crown Copyright.
Failure of centromere separation leads to formation of diplochromosomes in next mitosis in okadaic acid treated HeLa cells.
Authors: Ghosh Sibdas , Paweletz Neidhard , Schroeter Dieter
Published: September 2002

High concentrations of okadaic acid, sufficient to inhibit phosphatase 1 and 2A activities, induces formation of diplochromosomes in HeLa cells. It has been shown that this is due to a failure of sister chromatid separation in earlier mitosis in the presence of okadaic acid in the medium and not due to bypassing of mitosis (endoreduplication). Moreover, it has been demonstrated that the sister chromatid adherence does not depend on any under‐replicated chromatin segment shared by the sister chromatids which might happen in okadaic acid induced premature mitosis, but due to the failure of the centromeres to separate at metaphase ‐ anaphase transition. The role of phophatase 1 in sister chromatid separation has been discussed
Microtubules in dividing root cells of the conifer pinus radiata and the cycad zamia furfuracea
Authors: Fowke Larry C.
Published: September 2002

Microtubules in dividing root cells of the gymnosperms Pinus radiata (conifer) and Zamia furfuracea (cycad) were examined using immunofluorescence techniques. Root tip squashes were prepared to visualize the 3‐dimensional organization of microtubules in intact cells while sections of methacrylate embedded roots revealed microtubules in situ. Both species were characterized by well developed preprophase bands (PPB) of microtubules and highly focused spindle poles at prophase and anaphase. The metaphase spindle and telophase phragmoplast appeared typical of flowering plants.
Effect of TGF‐Alpha on growth of normal human breast epithelial cells in serum‐free primary culture using 3‐dimensional collagen gels.
Authors: Sakthivel Ramasamy , Hamdan Maha , Yang Jason , Guzman Raphael C. , Nandi Satyabrata
Published: September 2002

The mitogenic effect of TGF‐alpha, acidic‐FGF, basic‐FGF and lithium on normal human breast epithelial cells was studied in a collagen gel culture system using a serum‐free 1:1 mixture of Ham's F12 and DME medium containing insulin, cholera toxin and bovine serum albumin. TGF‐alpha elicited a strong mitogenic response in a dose dependent manner. Addition of cortisol to TGF‐alpha stimulated growth over and above that achieved with TGF‐alpha alone. A consistent observation has been the effect of a combination of TGF‐alpha and cortisol on growth stimulation of normal human breast epithelial cells resulting in 3‐12 fold growth after 11‐13 days in culture. Acidic‐FGF, basic‐FGF and lithium were not growth promoting.
Developmental regulation of insulin like growth factor II expression in the horse.
Authors: Joujou‐Sisic Karina , Granérus Marika , Wetterling Hanna , Wikström Katarina , Engström Wilhelm , Jeffcott Leo , Schofield Paul N. , Welin Amanda
Published: September 2002

The expression of the insulin like growth factor (IGF) II gene has been examined in the developing equine fetus. It was found that IGF II transcripts were present in abundant quantities in third trimester embryonic and extraembryonic tissues as for example the placenta. The expression of the IGF II gene was high in the fetal liver where two prominent transcripts — 4.6 and 4.1 — kB were produced. However, these transcripts could not be traced in the adult liver. Instead we found two different transcripts with the sizes of 4.0 and 2.9 kB in the adult liver. These findings taken together with the demonstration of heterologous IGF II cDNA hybridizing to equine DNA‐digests suggests that the IGF II gene is under developmental control in the horse, with the possible existence of different promoters.
Changes in erythrocyte membranes after fractioned hyperthermia
Authors: Koter Maria
Published: September 2002

The structural changes in erythrocytes membranes were examined before and after the second heat shock of erythrocytes. Electrophoretic separation of protein erythrocyte membranes for cells incubated at 48.5°C was different from control i.e. from erythrocytes incubated at 37°C. No quantitative or qualitative changes were spotted in comparison with protein membranes isolated from the erythrocytes following single or double heat shock.

Fluidity of erythrocytes membranes was determined by using spin labels, 5‐doxylstearic acid and 16‐doxylstearic acid. The membranes were more rigid in their hydrophobic regions after incubation of cells at 44°C. It can be suggested that erythrocyte membranes play some role in thermotolerance and heat damage of enuclate cells.
Hypothermic preservation of hepatocytes on gelatin gels
Authors: Evans Peter J.
Published: September 2002

Hypothermic preservation of hepatocytes on gelatin gels allows hepatocytes to be stored for at least 9 days. The procedure is easy, inexpensive and does not require specialised equipment. The cells retain their morphology and are released as separate spherical entities by dissolving the gelatin layer at 37°. The recovered cells have an intact plasma membrane as judged by lactate dehydrogenase activity, attachment efficiency and subsequent monolayer formation in culture. Functional tests show that the cells recover quickly from the storage conditions. Rates of protein synthesis are maintained over a 6 day period and remain at 62% of the initial level on day 9. The liver specific, hormonal induction of the enzyme tyrosine aminotransferase is apparent throughout the culture period. In addition a phenotypic marker enzyme, γ‐glutamyl transpeptidase, remained at basal levels.