bluuebunny/crossref_metadata_2025_split huggingface dataset:
Minimization properties of Hill's orbits and applications to some N -body problems
Authors: Arioli Gianni , Gazzola Filippo , Terracini Susanna 
Published: July 2002

We consider the periodic problem for a class of planar

N

-body systems in Celestial Mechanics. Our goal is to give a variational characterization of the Hill's (retrograde) orbits as minima of the action functional under some geometrical and topological constraints. The method developed here also turns out to be useful in the study of the full problem with

N

primaries each having at most two satellites.

Résumé

On considère le problème périodique pour une certaine classe de systèmes de

N

-corps en Mécanique Céleste. Notre but est de donner une caractérisation variationnelle des orbites (rétrogrades) de Hill comme minima de la fonctionnelle d’action sous certaines contraintes géométriques et topologiques. La méthode ici développée est également utile pour l’étude du problème complet avec

N

corps primaires ayant chacun au plus deux satellites.
On the minimizers of the Ginzburg–Landau energy for high kappa: the axially symmetric case
Authors: Aftalion Amandine 
Published: July 2002

The Ginzburg–Landau theory of superconductivity is examined in the case of a special geometry of the sample, the infinite cylinder. We restrict to axially symmetric solutions and consider models with and without vortices. First putting the Ginzburg–Landau parameter

κ

formally equal to infinity, the existence of a minimizer of this reduced Ginzburg–Landau energy is proved. Then asymptotic behaviour for large

κ

of minimizers of the full Ginzburg–Landau energy is analyzed and different convergence results are obtained. Our main result states that, when

κ

is large, the minimum of the energy is reached when there are about

κ

vortices at the center of the cylinder. Numerical computations illustrate the various behaviours.

Résumé

Le modèle de Ginzburg–Landau des supraconducteurs est étudié dans le cas d’une géométrie cylindrique pour des solutions radiales, avec et sans vortex. Quand le paramètre de Ginzburg–Landau est infini, on prouve l’existence d’un minimum pour une énergie réduite. Puis on étudie le comportement asymptotique des minimiseurs pour

κ

grand et on obtient différents résultats de convergence. On montre en particulier que l’énergie est minimum pour une configuration où le nombre de vortex au centre du cylindre est de l’ordre de

κ

. Des calculs numériques illustrent les divers comportements.
Limit behaviour of thin insulating layers around multiconnected domains
Authors: Boutkrida Mohamed , Grenon Nathalie , Mossino Jacqueline , Moussa Gonoko 
Published: July 2002

Let

Ω

be a bounded domain of

ℝ^{n}

, with boundary

∂Ω

. Let

Γ_0

and

Γ

be connected components of

∂Ω

. We assume that

Ω

is surrounded along

Γ_0

and

Γ

by thin insulating layers

Σ^ε_0

and

Σ^ε

of varying respective thicknesses

h^ε_0(s)

and

h^ε(s)

,

s

being the generic point of

Γ_0

and

Γ

. We denote by

Γ^ε_0

and

Γ^ε

the parts of

∂Σ^ε_0

and

∂Σ^ε

which do not meet

Ω

. We consider a class of quasilinear elliptic problems with different exponents (

p

in

Ω

,

q_0

in

Σ^ε_0

,

q

in

Σ^ε

) and with the following boundary conditions:

The restricted equations in

Σ^ε_0

and

Σ^ε

have nonconstant coefficients,

μ^ε_0

and

μ^ε

, in the form

μ^ε_0(x)=μ^ε_0(σ_0(x))

(respectively

μ^ε(x)=μ^ε(σ(x)))

,

σ_0

and

σ

being the respective projections on

Γ_0

and

Γ

. We predict the asymptotic behaviour of this problem as

h^ε_0

and

μ^ε_0

(respectively

h^ε

and

μ^ε

) tend to zero in a suitable sense, provided they are related in a convenient way.

Résumé

Soit

Ω

un domaine borné de

ℝ^{n}

, de frontière

∂Ω

. Soient

Γ_0

et

Γ

des composantes connexes de

∂Ω

. Nous supposons que

Ω

est entouré le long de

Γ_0

et

Γ

par de fines couches isolantes

Σ^ε_0

et

Σ^ε

d'épaisseurs variables respectives

h^ε_0(s)

et

h^ε(s)

,

s

étant le point générique de

Γ_0

ou

Γ

. Nous désignons par

Γ^ε_0

et

Γ^ε

les parties de

∂Σ^ε_0

et

∂Σ^ε

qui ne bordent pas

Ω

. Nous considérons une classe de problèmes elliptiques quasilinéaires, avec des exposants de Sobolev différents (

p

dans

Ω

,

q_0

dans

Σ^ε_0

,

q

dans

Σ^ε

) et avec les conditions au bord suivantes :

Les équations restreintes à

Σ^ε_0

et

Σ^ε

ont des coefficients non-constants,

μ^ε_0

et

μ^ε

, de la forme

μ^ε_0(x)=μ^ε_0(σ_0(x))

(resp.

μ^ε(x)=μ^ε(σ(x)))

,

σ_0

et

σ

étant les projections respectives sur

Γ_0

et

Γ

. Nous prédisons le comportement asymptotique de ce problème, lorsque

h^ε_0

et

μ^ε_0

(resp.

h^ε

et

μ^ε

) tendent vers zéro simultanément, tout en vérifiant une relation de corrélation convenable.
Relaxation of multiple integrals below the growth exponent
Authors: Fonseca Irene , Malý Jan 
Published: July 2002

The integral representation of the relaxed energies

\begin{matrix} \mathcal{F}^{q,p}\left(u,\Omega \right): =\inf_{\{u_n\}}\biggl\{\liminf_{n\to\infty}\int _{\Omega }F\left(x,u_{n},\nabla u_{n}\right)dx:u_{n} \in W^{1,q}\left(\Omega ,ℝ^{d}\right), \\ u_{n}\rightarrow u\text{ weakly in }W^{1,q}\left(\Omega ,ℝ^{d}\right) \biggr\}, \\
\mathcal{F}_{\text{loc}}^{q,p}\left(u,\Omega \right): = \inf_{\{u_n\}}\biggl\{\liminf_{n\to\infty}\int _{\Omega }F\left(x,u_{n},\nabla u_{n}\right)dx:u_{n} \in W_{\text{loc}}^{1,q}\left(\Omega ,ℝ^{d}\right), \\ u_{n}\rightarrow u\text{ weakly in }W^{1,q}\left(\Omega ,ℝ^{d}\right) \biggr\} \\
\end{matrix}

\begin{matrix} \begin{matrix} E:u\mapsto \int _{\Omega }F\left(x,u,\nabla u\right)dx, \\ \end{matrix} & u \in W^{1,q}\left(\Omega ,ℝ^{d}\right), \\ \end{matrix}

where

0 \leq F (ϰ,ζ,ξ) \leq C (1+|ζ|^r + |ξ|^q)

and

\max\left\{1,r\frac{N - 1}{N + r},q\frac{N - 1}{N}\right\} < p \leq q

, is studied. In particular,

W^{1,p}

-sequential weak lower semicontinuity of

E(\cdot)

is obtained in the case where

F = F(ξ)

is a quasiconvex function and

p > q(N − 1)/N

.

Résumé
On étudie la représentation intégrale d’énergies relaxées

\begin{matrix} \mathcal{F}^{q,p}\left(u,\Omega \right): =\inf_{\{u_n\}}\biggl\{\liminf_{n\to\infty}\int _{\Omega }F\left(x,u_{n},\nabla u_{n}\right)dx:u_{n} \in W^{1,q}\left(\Omega ,ℝ^{d}\right), \\ u_{n}\rightarrow u\text{ faible dans }W^{1,q}\left(\Omega ,ℝ^{d}\right) \biggr\}, \\ \mathcal{F}_{\text{loc}}^{q,p}\left(u,\Omega \right): = \inf_{\{u_n\}}\biggl\{\liminf_{n\to\infty}\int _{\Omega }F\left(x,u_{n},\nabla u_{n}\right)dx:u_{n} \in W_{\text{loc}}^{1,q}\left(\Omega ,ℝ^{d}\right), \\ u_{n}\rightarrow u\text{ faible dans }W^{1,q}\left(\Omega ,ℝ^{d}\right) \biggr\} \\ \end{matrix}

de la fonctionnelle

\begin{matrix} E:u\mapsto \int _{\Omega }F\left(x,u,\nabla u\right)dx, & u \in W^{1,q}\left(\Omega ,ℝ^{d}\right), \\ \end{matrix}

où

0 \leq F (ϰ,ζ,ξ) \leq C (1+|ζ|^r + |ξ|^q)

et

\max\left\{1,r\frac{N - 1}{N + r},q\frac{N - 1}{N}\right\}< p \leq q

. En particulier, la

W^{1,p}

-semicontinuité inférieure séquentielle faible de

E(\cdot)

est obtenue dans le cas où

F = F(ξ)

est une fonction quasiconvexe et

p > q(N − 1)/N

.
Solitary waves of generalized Kadomtsev–Petviashvili equations
Authors: de Bouard Anne , Saut Jean-Claude 
Published: July 2002

We classify the existence and non-existence cases for localized solitary waves of generalized Kadomtsev–Petviashvili equations according to the sign of the transverse dispersion coefficients and to the nonlinearity. We also prove regularity properties of the solitary waves.

Résumé
Nous classifions les cas d’existence et de non-existence d’ondes solitaires localisées pour les équations de Kadomtsev–Petviashvili généralisées selon le signe des coefficients de la dispersion transverse et la puissance du terme non-linéaire. Nous montrons également des propriétés de régularité de ces ondes solitaires.
Convex symmetrization and applications
Authors: Trombetti Guido , Lions Pierre-Louis , Alvino Angelo , Ferone Vincenzo 
Published: July 2002

We give a “generalized” version of the isoperimetric inequality when the perimeter is defined with respect to a convex, positively homogeneous function on

ℝ^n

. We use it to prove that, for any function

u

compactly supported in

ℝ^n

, the integral of a convex function of

Du

decreases when

u

is rearranged in the corresponding “convex” way. Similar arguments allow us, for example, to prove comparison results for solutions of the Dirichlet problem for elliptic equations when the differential operator satisfies suitable structure assumptions.

Résumé

Nous donnons une version « généralisée å de l’inégalité isopérimétrique lorsque la définition du périmètre dépend d’une fonction convexe et positivement homogène sur

ℝ^n

. Cette inégalité est employée pour démontrer que, pour toutes les fonctions

u

avec support compact dans

ℝ^n

, l’intégrale d’une fonction convexe de

Du

décroît quand

u

est rearrangée à une façon « convexe å. Avec des arguments du même type nous démontrons, par exemple, les résultats de comparaison pour les solutions du problème de Dirichlet pour des équations elliptiques quand l’opérateur différentiel satisfait des hypothèses de structure convenables.
Classification générique de synthèses temps minimales avec cible de codimension un et applications
Authors: Bonnard B. , Launay G. , Pelletier M. 
Published: July 2002

In this article we consider the problem of constructing the optimal closed loop control in the time minimal control problem, with terminal constraints belonging to a manifold of codimension one, for systems of the form

\.{\upsilon} = X + uY

,

c\in ℝ^2

,

ℝ^3

,

|u| ≤ 1

under generic assumptions. The analysis is localized near the terminal manifold and is motivated by the problem of controlling a class of chemical systems.

Résumé
Soit un système de la forme

\.{\upsilon}(t) = X(\upsilon(t)) + u(t)Y(\upsilon (t)), \qquad \upsilon \in ℝ^{n}

X, Y

sont des champs de vecteurs analytiques,

u

une application mesurable bornée à valeurs dans

[−1, + 1]

et soit

N^*

une sous-variété analytique de

ℝ^n

, de codimension 1. Dans cet article, on étudie le problème suivant : construire la loi optimale

u^*

pour le problème de contrôle en temps minimal où la variété terminale est

N

, ceci au voisinage de

N

. On se restreint à étudier toutes les situations génériques lorsque

v\in ℝ^2

ou

ℝ^3

. Cette étude est motivée par un problème de contrôle de systèmes chimiques et sera appliquée au cas

A ↦ B ↦ C

.
A kinetic formulation for multi-branch entropy solutions of scalar conservation laws
Authors: Brenier Y. , Corrias L. 
Published: July 2002

Multivalued solutions with a limited number of branches of the inviscid Burgers equation can be obtained by solving closed systems of moment equations. For this purpose, a suitable concept of
entropy
multivalued solutions with

K

branches is introduced.

Résumé

On reconstruit les solutions multivoques de l’équation de Burgers sans viscosité, quand leur nombre de branches est connu
a priori
, en résolvant un système fermé d’équations de moments. A cet effet, on introduit un concept de solutions multivoques entropiques à

K

branches.
Blow-up results for vector-valued nonlinear heat equations with no gradient structure
Authors: Zaag Hatem 
Published: July 2002

We construct a blow-up solution for the following nonlinear complex equation:

u_{t} = \Delta u + \left(1 + i\delta \right)\left|u\right|^{p - 1}u,u \in ℂ.

We also find the asymptotic profile near the singularity, and generalize the result to other vector-valued equations.

Résumé
On construit une solution explosive de l’équation non linéaire complexe suivante:

u_{t} = \Delta u + \left(1 + i\delta \right)\left|u\right|^{p - 1}u,u \in ℂ.

On donne aussi son profil asymptotique au voisinage de la singularité, et on généralise le résultat à d’autres équations à valeurs vectorielles.
Équation de Burgers avec conditions initiales à accroissements indépendants et homogènes
Authors: Carraro Laurent , Duchon Jean 
Published: July 2002

We study here solutions of inviscid Burgers equation with a stochastic initial value with homogeneous and independent increments without positive jumps. We define the notion of intrinsic statistical solution of this evolution equation and show that a family

(X (t); t ≥ 0)

of homogeneous Lévy processes is an intrinsic statistical solution of Burgers equation if and only if the exponent functions

ψ (t, w)

satisfy the differential equation:

∂_tψ = i ψ ∂_wψ

. The existence of such solutions follows then from the examination of that last equation. The case of a brownian initial condition is made explicit.

Résumé

On s’intéresse ici aux solutions de l’équation de Burgers non visqueuse avec condition initiale à accroissements indépendants et homogènes, à sauts négatifs. On dégage la notion de solution statistique intrinsèque de cette équation d’évolution et on montre qu’une famille

(X (t); t ≥ 0)

de processus de Lévy homogènes est solution statistique intrinsèque de l’équation de Burgers si et seulement si les fonctions exposants

ψ (t, w)

satisfont l’équation:

∂_tψ = i ψ ∂_wψ

. L’étude de cette équation permet d’établir l’existence d’une telle solution. Le cas d’une condition initiale brownienne est explicité.
Comparison theorems for some quasilinear degenerate elliptic operators and applications to symmetry and monotonicity results
Authors: Damascelli Lucio 
Published: July 2002

We prove some weak and strong comparison theorems for solutions of differential inequalities involving a class of elliptic operators that includes the

p

-laplacian operator. We then use these theorems together with the method of moving planes and the sliding method to get symmetry and monotonicity properties of solutions to quasilinear elliptic equations in bounded domains.

Résumé

Nous prouvons quelques théorèmes de comparaison faible et fort pour solutions de certaines inéqualités différentielles liées à une classe d’opérateurs elliptiques qui comprend le

p

-laplacien. Ces théorèmes sont utilisés avec la méthode de « déplacement d’hyperplanes å et la méthode de « translation å pour obtenir des propriétés de symétrie et de monotonie des solutions d’équations elliptiques quasilinéaires dans des domaines bornés.
On the non-locality of quasiconvexity
Authors: Kristensen Jan 
Published: July 2002

It is shown that in the class of smooth real-valued functions on

n × m

matrices (

n ≥ 3

,

m ≥ 2

) there can be no “local condition” which is equivalent to quasiconvexity.

Résumé
On démontre qu’il n’existe pas de condition locale qui dans l’espace des fonctions regulières est equivalente à celle de quasiconvexité.
Elastic knots in Euclidean 3-space
Authors: Von Der Mosel Heiko 
Published: July 2002

This paper deals with the problem of minimizing the curvature functional

\int κ^2ds

on isotopy classes of closed knotted curves in

ℝ^3

. We show existence of minimizers under a given topological knot type and develop a regularity theory by analyzing different touching situations.

Résumé

Dans cet article nous minimisons la fonctionnelle de courbure

\int κ^2ds

dans des classes d’isotopie des courbes fermées et nouées. L’existence des courbes minimales étant donné un type de nœud topologique est démontrée et une théorie sur la régularité est développée par l’analyse de situations de touchage différentes.
Poincaré's inequality and global solutions of a nonlinear parabolic equation
Authors: Souplet Philippe , Weissler Fred B. 
Published: July 2002

We study the equation

u_t − Δu = u^p − μ|∇u|^q

,

t ≥ 0

in a general (possibly unbounded) domain

Ω ⊂ ℝ^N

. When

q ≥ p

, we show a close connection between the Poincaré inequality and the boundedness of the solutions. To be more precise, if

q > p

(or

q = p

and

μ

large enough), we prove global existence of all solutions for any domain

Ω

where the Poincaré inequality is valid. When

μ

is large enough, all solutions are bounded and decay exponentially to zero. Conversely, if

Ω

contains arbitrarily large balls (if

N < 2

and

Ω

is finitely connected, this means precisely that the Poincaré inequality does not hold), then there always exist unbounded solutions. Moreover, if

Ω = ℝ^N

, there exist global solutions which blow-up at every point in infinite time. Various qualitative properties of the solutions are also obtained.

Résumé

Nous étudions l'équation

u_t − Δu = u^p − μ|∇u|^q

,

t ≥ 0

dans un domaine

Ω ⊂ ℝ^N

général, éventuellement non borné. Lorsque

q ≥ p

, nous montrons l'existence d'un lien étroit entre l'inégalité de Poincaré et le caractère borné des solutions. Plus précisément, si

q > p

(ou si

q = p

et

μ

est assez grand), nous prouvons l'existence globale de toutes les solutions, dans tout domaine

Ω

ou l'inégalité de Poincaré est vérifiée. Lorsque

μ

est suffisamment grand, toutes les solutions sont bornées et tendent exponentiellement vers zéro. Inversement, si

Ω

contient des boules de rayon arbitrairement grand (lorsque

N < 2

et

Ω

est finiment connexe, cela signifie exactement que l'inégalité de Poincaré n'a pas lieu), alors il existe toujours des solutions non bornées. De plus, si

Ω = ℝ^N

, il existe des solutions globales qui explosent en tout point en temps infini. Diverses propriétés qualitatives des solutions globales sont également obtenues.
Cyclic tensile stretch inhibition of nitric oxide release from osteoblast‐like cells is both G protein and actin‐dependent
Authors: Hara Fumihiko , Fukuda Kanji , Asada Shigeki , Matsukawa Masataka , Hamanishi Chiaki 
Published: July 2002

AbstractRecent reports indicate the alteration of nitric oxide (NO) synthesis with mechanical stress loaded on the osteoblast and NO is considered to have a significant role in mechanotransduction. We found the involvement of guanine‐nucleotide‐binding regulatory proteins (G proteins), especially Gi, in stress‐inhibited NO release of osteoblast‐like cells (JOR:17;593–597, 1999). To determine further the mechanism involved in this process, we measured c‐Jun N‐terminal kinase/stress‐activated protein kinase (JNK/SAPK) activity under cyclic tensile stretch loaded on osteoblast‐like cells. Cyclic stretch significantly enhanced JNK/SAPK activity and pertussis toxin clearly reversed stress‐enhanced JNK/SAPK activity. Cytochalasin D, actin microfilament disrupting reagent, also abolished the stress activation of JNK/SAPK. We propose a model for signaling events induced by cyclic tensile stretch, namely a transmembrane mechanosensor which couples Gi‐protein, actin cytoskeleton and finally activates JNK/SAPK activity of osteoblasts. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Genetic factors in anorexia nervosa
Authors: Kipman A. , Gorwood P. , Mouren-Siméoni M.C. , Adès J. 
Published: July 2002

SummaryAnorexia nervosa is a severe and complex disorder with incompletely known vulnerability factors. It is generally recognized that anorexia nervosa is a familial disorder, but the majority of twin studies have shown that the concordance rate for monozygotic twins is higher (on average 44%) than for dizygotic twins (on average 12.5%). This difference in concordance rates shows that genetic factors, more than common familial environment, may explain why the `anorexia nervosa' phenotype runs in families. In order to estimate the heritability in the broad sense of anorexia nervosa according to published familial and twin studies, we first assessed the intrapair correlation between monozygotic and dizygotic twins, and secondly calculated the deviation threshold of relatives of affected probands from the relative mean. In this review, we obtained an estimation of the heritability at 0.72 according to all published controlled familial studies (six references quoted in MEDLINE®), and 0.71 for all published twin studies (59 references quoted in MEDLINE®). This estimation is close to the ones previously proposed, between 0.5 and 0.8.Familial and twin studies may also help to define the boundaries of the phenotype, shedding light on the complex relationship between anorexia nervosa on the one hand, and bulimia nervosa, mood disorders, and alcoholism on the other. Demonstrating the importance of genetic factors in anorexia nervosa, and more specifically for anorexia of the restrictive type, requires not only prospective and adoption studies (which are still lacking), but also genetic polymorphisms analyses, which began very recently.
Physical and relational aggression as predictors of children's friendship experiences: Examining the moderating role of preference norms
Authors: Correia Stephanie , Brendgen Mara , Turgeon Lyse , Vitaro Frank 
Published: April 2021

AbstractAggressive behavior is generally detrimental to children's friendships, both in terms of having friends and in terms of keeping friends. Despite this general tendency, many aggressive children have friends and some of these friendships are stable. We examined the moderating role of preference norms in the classroom and child's sex in the association between children's physical and relational aggression and their friendship experiences. A total of 1135 children (M = 10.24 years, SD = 1.01) in Grades 4 to 6 completed a peer nomination inventory in the Fall (T1) and Spring (T2) of the same school year. Norms were operationalized as the class‐ and sex‐specific correlation between physical or relational aggression and social preference. Norms moderated associations between each form of aggression and number of friends. At T1, physical and relational aggression were concurrently associated with having more friends when norms favored this behavior and with fewer friends when norms were unfavorable. The latter effect was especially pronounced in girls. Over time, youth lost friends when norms favored physical aggression and gained friends when norms favored relational aggression. T1 friends' physical and relational aggression were strong predictors of new friends' aggressive behavior, suggesting that friends provide a type of norm more significant to new friend selection than norms of the peer group and individual aggressive behavior. Overall, our results suggest that physical and relational aggression are not necessarily detrimental to children's friendship experiences and may even be beneficial in specific social contexts.
Agronomic approach to understanding climate change and food security
Authors: O'Brien Peter , Kral‐O'Brien Katherine , Hatfield Jerry L. 
Published: April 2021

AbstractClimate impacts agricultural productivity and the distribution of crops grown around the world. Because the United States is a leader in food exports, climate change impacts in the United States have the potential to disproportionately affect the global food supply. Given the change in temperature, precipitation, and carbon dioxide occurring now and expected into the future, the potential for agroecosystems to produce sufficient quantities of food to meet world demand is in question. To address this question, the concept of yield gaps, as the difference between potential yield (PY) and farm or actual yield (FY), provides a framework for the evaluation of progress in production. Across all crops, there have been increases in both PY (breeding, technological advances) and FY (implementation of improved genetic resources and management practices); however, climate change threatens to diminish those advances due to temperature stresses and more uncertain precipitation patterns. Climate change will not only directly increase the yield gap in the future but also further indirectly widen the yield gap by the degradation of the soil resource due to interactions of climate and management. Modern agricultural systems must adapt to become more resilient to climate change, and the tools to this adaptation involve genetics, environmental monitoring, and evolving management practices. However, progress can only begin once agricultural systems are managed from a more holistic view of providing both quantity and quality of a more diverse mixture of agricultural crops that will provide sustainability, equity, nutrition, and a secure food future.