Existence of attractor for the quasi-geostrophic approximation of the Navier-Stokes equations and estimate of its dimension

In this paper, we study the quasi-geostrophic approximation of the Navier-Stokes equations. This approximation is usually used in modelisation of oceanic circulations. First, we consider the barotropic modelisation, and in a second part, we supposed that the ocean is divided in N layers. For the both modelisations, we prove the existence and uniqueness of the solution, and then the existence of a maximal attractor which describes the long time behaviour of the solutions and we derive estimates of its Hausdorff and fractal dimensions in terms of the data

Recherche contemporaine sur le conditionnement du langage des enfants autistiques

Québec Université Laval, Bibliothèque 201

Les revues d’histoire de l’art au Canada

Il est possible d’identifier plusieurs découpages dans le paysage des revues d’histoire de l’art au Canada, mais deux, en particulier, méritent notre attention. Le premier, institutionnel, provient d’un fonctionnement distinct entre les revues universitaires, dites « revues savantes », et les autres revues d’art, désignées comme « revues spécialisées ». Le Canada anglophone dispose d’une terminologie qui permet d’éviter toute ambiguïté dans ce découpage : la revue savante se désigne comme « t..

The role of paternal mind‐mindedness in preschoolers' self‐regulated conduct

This study examined the prospective links between paternal mind‐mindedness (MM) and 2 indices of preschoolers' self‐regulated con-duct, namely, inhibitory control and rule‐compatible conduct.Ninety‐two families (47 boys) participated in 2 assessments. PaternalMM was assessed with a 10‐min father–child free‐play session whenchildren were aged 18 months. Children's rule‐compatible conductwas reported by mothers when children reached 3 years of age,and inhibitory control was measured with a Snack Delay task, alsoadministered at 3 years. The results suggested that after accountingfor the contribution of child temperament (social fearfulness),paternal MM was positively related to children's inhibitory control.In contrast, the relation between paternal MM and mother‐reportedrule‐compatible conduct was not significant. The results areinterpreted in light of the mechanisms that may account for the linksbetween paternal MM and preschoolers' emerging capacity tovoluntarily control their behaviour

The Finiteness of Determining Degrees of Freedom for the Quasi-Geostrophic Multi-Layer Ocean Model

In this paper, we consider a multi-layer quasi-geostrophic model of the ocean dynamics and we prove that the long-time behaviour of its solutions can be described by a finite number of determining parameters. Under some additional condition we also show that the dynamics of the bottom layer is completely determined by parameters connected with upper layers only. It means that the information about the bottom layer is not essential for a description of the long-time behaviour of the system under consideration

An Algebraic Design for the Simultaneous Stabilization of Two Systems

In this report we present a unified description for studying the problem of the simultaneous stabilization of two plants. Three approaches for the simultaneous stabilizability are defined. The first one corresponds to the definition commonly used in the literature. For the third one, we show that, like for the first one, the design of a simultaneous compensator leads to a divisibility condition in the ring of $RH_\infty$. A simple formulation of the existence condition for simultaneous stabilization is proposed. Moreover, the equivalence between the existence conditions for the first and third approaches is shown. Finally an explicit method is given to compute simultaneous compensators

On the simultaneous stabilization of three or more plants

International audienceIn this paper, the problem of the simultaneous stabilization of three multivariable plants is addressed. We consider the general case where the existence of a unit controller cannot be used as a sufficient condition to guarantee the existence of a simultaneous controller for three multivariable plants. The sufficient conditions given in this paper lead to a constructive controller design to stabilize simultaneously three multivariable plants. A generalization is proposed for stabilizing simultaneously n multivariable plants

The Phosphate Transporter PiT1 (Slc20a1) Revealed As a New Essential Gene for Mouse Liver Development

BACKGROUND: PiT1 (or SLC20a1) encodes a widely expressed plasma membrane protein functioning as a high-affinity Na(+)-phosphate (Pi) cotransporter. As such, PiT1 is often considered as a ubiquitous supplier of Pi for cellular needs regardless of the lack of experimental data. Although the importance of PiT1 in mineralizing processes have been demonstrated in vitro in osteoblasts, chondrocytes and vascular smooth muscle cells, in vivo evidence is missing. METHODOLOGY/PRINCIPAL FINDINGS: To determine the in vivo function of PiT1, we generated an allelic series of PiT1 mutations in mice by combination of wild-type, hypomorphic and null PiT1 alleles expressing from 100% to 0% of PiT1. In this report we show that complete deletion of PiT1 results in embryonic lethality at E12.5. PiT1-deficient embryos display severely hypoplastic fetal livers and subsequent reduced hematopoiesis resulting in embryonic death from anemia. We show that the anemia is not due to placental, yolk sac or vascular defects and that hematopoietic progenitors have no cell-autonomous defects in proliferation and differentiation. In contrast, mutant fetal livers display decreased proliferation and massive apoptosis. Animals carrying two copies of hypomorphic PiT1 alleles (resulting in 15% PiT1 expression comparing to wild-type animals) survive at birth but are growth-retarded and anemic. The combination of both hypomorphic and null alleles in heterozygous compounds results in late embryonic lethality (E14.5-E16.5) with phenotypic features intermediate between null and hypomorphic mice. In the three mouse lines generated we could not evidence defects in early skeleton formation. CONCLUSION/SIGNIFICANCE: This work is the first to illustrate a specific in vivo role for PiT1 by uncovering it as being a critical gene for normal developmental liver growth

Syntheses and characterization of three-and five-coordinate copper(II) complexes based on SNS pincer ligand precursors

A series of tridentate pincer ligands, each possessing two sulfur- and one nitrogen-donor functionalities (SNS), based on a bis-imidazolyl precursor were metallated with CuCl2 to give new tridentate SNS pincer copper(II) complexes [(SNS)CuCl2]. These purple complexes exhibit a five-coordinate pseudo-square pyramidal geometry at the copper center. The [(SNS)CuCl2] complexes were characterized with single crystal X-ray diffraction, electrospray mass spectrometry, EPR spectroscopy, attenuated total reflectance infrared spectroscopy, UV–Vis spectroscopy, cyclic voltammetry, and elemental analysis. The EPR spectra are consistent with typical anisotropic Cu(II) signals with four hyperfine splittings in the lower-field region (g||). Various electronic transitions are apparent in the UV–Vis spectra of the complexes and originate from d-to-d transitions or various charge transfer transitions. We preformed computational studies to understand the influence that structural constraints internal to our tridentate SNS ligand precursors have on the oxidation state of the resulting bound copper complex. We have determined that a d9 copper(II) metal center is better situated than a d10 copper(I) center to bind our tridentate SNS ligand set when it does not contain an internal CH2 group. Without this methylene linker, the SNS ligand forces the N and S atoms into a T-shaped arrangement about the metal center