3,267 research outputs found

    On the global well-posedness for the Boussinesq system with horizontal dissipation

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    In this paper, we investigate the Cauchy problem for the tridimensional Boussinesq equations with horizontal dissipation. Under the assumption that the initial data is an axisymmetric without swirl, we prove the global well-posedness for this system. In the absence of vertical dissipation, there is no smoothing effect on the vertical derivatives. To make up this shortcoming, we first establish a magic relationship between urr\frac{u^{r}}{r} and ωθr\frac{\omega_\theta}{r} by taking full advantage of the structure of the axisymmetric fluid without swirl and some tricks in harmonic analysis. This together with the structure of the coupling of \eqref{eq1.1} entails the desired regularity.Comment: 32page

    Golabi-Ito-Hall syndrome results from a missense mutation in the WW domain of the PQBP1 gene

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    Background: Golabi, Ito, and Hall reported a family with X linked mental retardation (XLMR), microcephaly, postnatal growth deficiency, and other anomalies, including atrial septal defect, in 1984.Methods: This family was restudied as part of our ongoing study of XLMR, but significant linkage to X chromosome markers could not be found. Extreme short stature and microcephaly as well as other new clinical findings were observed. Mutations in the polyglutamine tract binding protein 1 gene (PQBP1) have recently been reported in four XLMR disorders (Renpenning, Hamel cerebro-palato-cardiac, Sutherland-Haan, and Porteous syndromes) as well as in several other families. The clinical similarity of our family to these patients with mutations in PQBP1, particularly the presence of microcephaly, short stature, and atrial septal defect, prompted examination of this gene.Results: A missense mutation in PQBP1 was identified which changed the conserved tyrosine residue in the WW domain at position 65 to a cysteine (p.Y65C).Conclusions: This is the first missense mutation identified in PQBP1 and the first mutation in the WW domain of the gene. The WW domain has been shown to play an important role in the regulation of transcription by interacting with the PPxY motif found in transcription factors. The p.Y65C mutation may affect the proper functioning of the PQBP1 protein as a transcriptional co-activator

    Estudio de la dinámica sedimentaria de la Laguna costera del Sur de Túnez (Túnez, Mar Mediterráneo)

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    The South lagoon of Tunis, a shallow Mediterranean lagoon, had undergone an important restoration management (during the period 1998-2001), leading to structural and functional changes of this coastal ecosystem. In this work, a comprehensive study of sedimentary dynamic based on hydrodynamic data, granulometric analysis, mineralogy and impact evaluation is presented. Restoration project, especially the establishment of two groups of inlets gates of the channel of Rades and Tunis (recalibrated during the restoration management), imposed an east-west water flow direction, created from high tide submersion, with an average flow exchanged with the sea about 80 m3s-1. This current control local sediment sorting. The grain sizes analysis of superficial sediment shows that the lagoon bottom characterized by fine sediments ( < 63 μm, 50-90%). The sediment dynamic is controlled by the lagoon water currents inducing an east-west grain-size sorting. The extreme eastern side of the lagoon, close to the inlet gate, is lined by medium sand, moderately sorted and transported by saltation. The central and western sides of the lagoon are covered by fine sand, poorly sorted, and deposed in relatively calm hydrodynamic conditions. Mineralogical results reveal the following association: quartz (13 to 69%), biogenic calcite, (15 to 81%), aragonite (0 to 8%), pyrite (0 to 1,75%) and accessory magnetite, smectite, illite and kaolinite. The lagoon seems to be a protected zone as a result of restoration project that forms a physical barrier for sedimentary materials amount from Gulf of Tunis.La laguna sur de Túnez, una laguna costera mediterránea poco profunda, se sometió a importantes trabajos de restauración durante el período 1998-2001, lo que ha llevado a cambios estructurales y funcionales de este ecosistema costero. En este trabajo se presenta un estudio integral de dinámica sedimentaria basado en datos hidrodinámicos, análisis granulométrico, mineralogía y evaluación de impacto. El proyecto de restauración, especialmente el establecimiento de la puerta de entrada de los canales de Rades y Túnez, impuso una dirección de flujo de agua este-oeste controlando la clasificación local de sedimentos. El análisis de tamaño de grano del sedimento superficial muestra que el fondo de la laguna está revestido por sedimentos finos

    Fibrosarcome du larynx - A propos d'un cas

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    Le fibrosarcome du larynx est une entité histologique rare, qui représente moins de 10% de tous les sarcomes des tissus mous, moins de 2 % des cancers laryngés. Cette localisation pose des problèmes diagnostique, thérapeutique et pronostique. Nous présentons un cas de fibrosarcome laryngé chez un patient de 54 ans. La confirmation histologique etimmunohistologique a été faite sur la pièce d’exérèse chirurgicale et surtout sur une confrontation anatomoclinique. La prise en charge thérapeutique est multidisciplinaire, associant la chirurgie qui doit être la plus complète sans curage ganglionnaire et la radiothérapie. Le pronostic est généralement sévère, dépend essentiellement de degré de différenciation histologique.Mots clés : fibrosarcome ; larynx ; chirurgie ; radiothérapie

    ADMI: A Multi-Agent Architecture To Autonomously Generate Data Mining Servrces.

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    This paper presents a case for an intelligent agent based framework for knowledge discovery in a distributed environment comprising multiple heterogeneous data repositories

    Drug resistance profile and biofilm forming potential of Pseudomonas aeruginosa isolated from contact lenses in Karachi-Pakistan

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    BACKGROUND: The contaminated contact lens provides Pseudomonas aeruginosa an ideal site for attachment and biofilm production. Continuous contact of the eye to the biofilm-infested lens can lead to serious ocular diseases, such as keratitis (corneal ulcers). The biofilms also prevent effective penetration of the antibiotics, which increase the chances of antibiotic resistance. METHODS: For this study, 22 Pseudomonas aeruginosa isolates were obtained from 36 contact lenses and 14 contact lens protective fluid samples. These isolates were tested against eight commonly used antibiotics using Kirby-Bauer disk diffusion method. The biofilm forming potential of these isolates was also evaluated using various qualitative and quantitative techniques. Finally, a relationship between biofilm formation and antibiotic resistance was also examined. RESULTS: The isolates of Pseudomonas aeruginosa tested were found resistant to most of the antibiotics tested. Qualitative and quantitative biofilm analysis revealed that most of the isolates exhibited strong biofilm production. The biofilm production was significantly higher in isolates that were multi-drug resistant (p < 0.0001). CONCLUSION: Our study indicates that multi-drug resistant, biofilm forming Pseudomonas aeruginosa isolates are mainly involved in contact lens associated infections. This appears to be the first report from Pakistan, which analyzes both antibiotic resistance profile and biofilm forming potential of Pseudomonas aeruginosa isolates from contact lens of the patients with contact lens associated infections

    On the global well-posedness of a class of Boussinesq- Navier-Stokes systems

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    In this paper we consider the following 2D Boussinesq-Navier-Stokes systems \partial_{t}u+u\cdot\nabla u+\nabla p+ |D|^{\alpha}u &= \theta e_{2} \partial_{t}\theta+u\cdot\nabla \theta+ |D|^{\beta}\theta &=0 \quad with divu=0\textrm{div} u=0 and 0<β<α<10<\beta<\alpha<1. When 664<α<1\frac{6-\sqrt{6}}{4}<\alpha< 1, 1α<βf(α)1-\alpha<\beta\leq f(\alpha) , where f(α)f(\alpha) is an explicit function as a technical bound, we prove global well-posedness results for rough initial data.Comment: 23page
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