Finite element analysis of a fluid-structure interaction in flexible pipe line

This paper describes the basic theory and computing method for transient flow of liquid in flexible pipe such as rubber tubing and arterial system. A mathematical model taking into account tube wall axial and radial motion (in which the dynamic fluid pressure causes circumferential and axial motion of the tube wall) is presented. The tube wall is assumed to be elastic material and the compressibility of the liquid is neglected. Circumferential and axial strain-stress relationships for the tube are considered. The obtained mathematical system is constituted of four non-linear hyperbolic partial differential equations describing the wave  propagation in both pipe wall and liquid flow. The fluid-structure interaction is found to be governed by Poisson’s ratio. In this steady finite element method based on Galerkin formulation is applied. Numerical results show a good similarity with those of the literature obtained by the characteristics method.Key words : Fluid-structure interaction, flexible pipe, rubber, finite element method

Preliminary study of haplotypes linked to the rare cystic fibrosis E1104X mutation

The analysis of some extra- and intragenic markers within or closely linked to the cystic fibrosis transmembrane regulator (CFTR) gene is useful as a molecular method in clinical linkage analysis. Indeed, knowing that the molecular basis of cystic fibrosis (CF) is highly heterogeneous in our population, the study of haplotype association with normal and CF chromosomes could be very helpful in cases where one or both mutations remain unidentified. In this study, we analysed with PCR-RFLP and capillary electrophoresis some extra (pJ3.11, KM19 and XV2C) and intragenic (IVS8CA, IVS17bTA and IVS17bCA) polymorphic markers in 50 normal and 10 Tunisian patients carrying the rare E1104X mutation in order to determine the haplotype associated with this mutation. For the extragenic markers, 8 haplotypes were identified. The most frequent of them are the 221 and 112 accounting for 80% of total haplotypes. For the intragenic markers, five haplotypes were present on the E1104X chromosomes. One of them 16-31-13 accounted for 50%. To our knowledge, this is the first work to be interested to the haplotypes linked to the E1104X mutation. This preliminary study of haplotypes could be a helpful method to determine the molecular lesions responsible of this pathology

Localisation nasosinusienne des tumeurs plasmocytaires

Introduction : Les tumeurs plasmocytaires représentent 3 à 4% des tumeurs des cavités naso-sinusiennes. Elles nécessitent un bilan diagnostique spécifique et une prise en charge adéquate. Nous nous proposons d’étudier les particularités diagnostiques et thérapeutiques des plasmocytomes naso-sinusiens. Matériel et méthodes : Notre étude est rétrospective comportant 5 cas de plasmocytomes naso-sinusiens confirmés histologiquement.Résultats : Il s’agit de 3 hommes et 2 femmes âgés de 32 à 77 ans. Le plasmocytome avait une localisation sphénoïdale dans un cas, nasale dans 2 cas, ethmoïdo-nasale dans un cas et naso-maxillaire dans le cas restant. Il s’agissait d’un myélome multiple dans un cas. Trois patients ont eu une radiothérapie. Celle-ci était associée à une chimiothérapie dans le cas du myélome multiple et à une exérèse chirurgicale dans les 2 autres cas La chirurgie a été seule dans un cas. La chimiothérapie exclusive a été proposée dans un cas de plasmocytome localement avancé mais le patient a été perdu de vue. Pour les patients suivis, une seule récidive a été notée à 18 mois.Conclusion : La présentation clinique des plasmocytomes nasosinusiens est aspécifique. Le diagnostic est confirmé par l’histologie. Le pronostic est dominé par la présence ou non d’un myélome multiple et par la taille tumorale. Un suivi prolongé est nécessaire.Mots clés : plasmocytome extramédullaire ; cavités naso-sinusiennes ; radiothérapie ; chirurgie.Introduction: Plasmocytomas represent 3-4% of tumors naso-sinus cavities. Their diagnosis requires a specific investigations and adequate management. We report 5 cases of naso-sinus plasmacytoma and we propose to study their diagnostic and therapeutic characteristics.Materials and methods: Our study is retrospective including 5 cases of naso-sinus plasmacytoma confirmed histologically.Results: There were 3 men and 2 women aged 32 to 77 years. The plasmacytoma had a sphenoidal location in one case, nasal in 2 cases, ethmoid-nasal in one case and naso-maxillary in the remaining case. Multiple myeloma was found in one case. Three patients underwent radiotherapy. This was associated with chemotherapy in multiple myeloma case and surgical resection in 2 cases. Surgery alone was performed in one case. Exclusive chemotherapy was proposed in a case of plasmacytoma locally advanced but the patient was lost sight of. For followed patients, only one recurrence was noted at 18 months.Conclusion: The clinical presentation of sinonasal plasmacytomas is aspecific. The diagnosis is confirmed by histology. The prognosis is dominated by the presence or absence of multiple myeloma and tumor size. Prolonged follow-up is necessary.Keywords : extramedullary plasmacytoma, naso-sinus cavities, radiotherapy ; surgery

Establishment of a coastal fish in the Azores : recent colonisation or suddenexpansion of an ancient relict population?

The processes and time scales associated with ocean-wide changes in the distribution of marinespecies have intrigued biologists since Darwin’s earliest insights into biogeography. The Azores, amid-Atlantic volcanic archipelago located more than 1000 km off the European continental shelf,offers ideal opportunities to investigate phylogeographic colonization scenarios. The benthopelagicsparid fish known as the common two-banded seabream (Diplodus vulgaris) is now relativelycommon along the coastline of the Azores archipelago, but was virtually absent prior to the 1990s.We employed a multiple genetic marker approach to test whether the successful establishment of theAzorean population derives from a recent colonization from western continental/island populationsor from the demographic explosion of an ancient relict population.Results from nuclear and mtDNA sequences show that all Atlantic and Mediterranean populationsbelong to the same phylogroup, though microsatellite data indicate significant genetic divergencebetween the Azorean sample and all other locations, as well as among Macaronesian, westernIberian and Mediterranean regions. The results from Approximate Bayesian Computation indicatethat D. vulgaris has likely inhabited the Azores for approximately 40 (95% C.I.: 5.5─83.6) to 52(95% C.I.; 6.32─89.0) generations, corresponding to roughly 80-150 years, which suggests nearcontemporary colonisation, followed by a more recent demographic expansion which could havebeen facilitated by changing climate conditions. Moreover, the lack of previous records of thisspecies over the past century, together with the absence of lineage separation and the presence ofrelatively few private alleles, do not exclude the possibility of an even more recent colonisationevent

Visualizing Readable Instance Graphs of Ontology with Memo Graph

International audienceIn the context of the Captain Memo memory prosthesis for Alzheimer’s patients, we want to generate the family/entourage tree of the user from data structured based on the PersonLink ontology. This graph ought to be accessible and readable to this particular user. In our previous work, we proposed an ontology visualization tool called Memo Graph. It aims to offer an accessible visualization to Alzheimer’s patients. In this paper, we extend it to address the readability requirement based on the IKIEV approach. It extracts the most important instances (key-instances) from ontology and generates a “summary instance graph” (middle-out browsing method). The extraction and visualization processes are undertaken incrementally. First, an “initial summary instance graph” is generated, then permitting iteratively the visualization of supplementary key-instances as required. Key-instances’ extraction is based on measures that take into account the semantic similarity between the ontological elements and the user’s navigation history

Management of albinism: French guidelines for diagnosis and care

Albinism is a worldwide genetic disorder caused by mutations in at least 20 genes, identified to date, that affect melanin production or transport in the skin, hair and eyes. Patients present with variable degrees of diffuse muco-cutaneous and adnexal hypopigmentation, as well as ocular features including nystagmus, misrouting of optic nerves and foveal hypoplasia. Less often, albinism is associated with blood, immunological, pulmonary, digestive and/or neurological anomalies. Clinical and molecular characterizations are essential in preventing potential complications. Disease-causing mutations remain unknown for about 25% of patients with albinism. These guidelines have been developed for the diagnosis and management of syndromic and non-syndromic forms of albinism, based on a systematic review of the scientific literature. These guidelines comprise clinical and molecular characterization, diagnosis, therapeutic approach and management