Égalisation itérative pour les transmissions multicodes de la liaison descendante de l'UMTS-FDD

- Cet article propose un récepteur itératif de faible complexité pour les transmissions multicodes de la liaison descendante de l'UMTS-FDD. Ce dispositif repose sur un égaliseur de canal itératif minimisant l'erreur quadratique moyenne (EQM) non biaisée en sortie du récepteur à chaque itération en fonction de la fiabilité de l'information a priori disponible. Les simulations numériques montrent que le récepteur proposé présente un compromis performances/complexité entre l'égaliseur linéaire et le récepteur de type turbo égaliseur présenté dans [1]

Characterisation of pellicles formed by acinetobacter baumannii at the air-liquidi interface

The clinical importance of Acinetobacter baumannii is partly due to its natural ability to survive in the hospital environment. This persistence may be explained by its capacity to form biofilms and, interestingly, A. baumannii can form pellicles at the air-liquid interface more readily than other less pathogenic Acinetobacter species. Pellicles from twenty-six strains were morphologically classified into three groups: I) egg-shaped (27%); II) ball-shaped (50%); and III) irregular pellicles (23%). One strain representative of each group was further analysed by Brewster's Angle Microscopy to follow pellicle development, demonstrating that their formation did not require anchoring to a solid surface. Total carbohydrate analysis of the matrix showed three main components: Glucose, GlcNAc and Kdo. Dispersin B, an enzyme that hydrolyzes poly-N-acetylglucosamine (PNAG) polysaccharide, inhibited A. baumannii pellicle formation, suggesting that this exopolysaccharide contributes to pellicle formation. Also associated with the pellicle matrix were three subunits of pili assembled by chaperon-usher systems: the major CsuA/B, A1S_1510 (presented 45% of identity with the main pilin F17-A from enterotoxigenic Escherichia coli pili) and A1S_2091. The presence of both PNAG polysaccharide and pili systems in matrix of pellicles might contribute to the virulence of this emerging pathogen

Dexamethasone in osteogenic medium strongly induces adipocyte differentiation of mouse bone marrow stromal cells and increases osteoblast differentiation

BACKGROUND: Osteoblasts and adipocytes share a common mesenchymal stem cell origin. Therefore, it has been suggested that the accumulation of marrow adipocytes observed in bone loss is caused by a shift in the commitment of mesenchymal stem cells from the osteogenic pathway to the adipogenic pathway. Supporting this hypothesis the competition between adipogenic and osteogenic lineages was widely demonstrated on partially homogeneous cell populations. However, some data from mouse models showed the existence of an independent relationship between bone mineral content and bone marrow adiposity. Therefore, the combination of adipogenesis and osteogenesis in primary culture would be helpful to determine if this competition would be observed on a whole bone marrow stromal cell population in a culture medium allowing both lineages. In this aim, mouse bone marrow stromal cells were cultured in a standard osteogenic medium added with different concentrations of Dexamethasone, known to be an important regulator of mesenchymal progenitor cell differentiation.RESULTS: Gene expression of osteoblast and adipocyte markers, biochemical and physical analyses demonstrated the presence of both cell types when Dexamethasone was used at 100 nM. Overall, our data showed that in this co-differentiation medium both differentiation lineages were enhanced compared to classical adipogenic or osteogenic culture medium. This suggests that in this model, adipocyte phenotype does not seem to increase at the expense of the osteoblast lineage.CONCLUSION: This model appears to be a promising tool to study osteoblast and adipocyte differentiation capabilities and the interactions between these two processes

Liability in Software Engineering: Overview of the LISE Approach and Illustration on a Case Study

© ACM – 2010. This is the authors' pre-version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in the Proceedings of the 32nd ACM/IEEE international Conference on Software Engineering (ICSE'10) - Volume 1 – 978-1-60558-719-6/10/05 – (May 2-8 – 2010) http://doi.acm.org/10.1145/1806799.1806823LISE is a multidisciplinary project involving lawyers and computer scientists with the aim to put forward a set of methods and tools to (1) define software liability in a precise and unambiguous way and (2) establish such liability in case of incident. This report provides an overview of the overall approach taken in the project based on a case study. The case study illustrates a situation where, in order to reduce legal uncertainties, the parties to a contract wish to include in the agreement specific clauses to define as precisely as possible the share of liabilities between them for the main types of failures of the system

Proteome Serological Determination of Tumor-Associated Antigens in Melanoma

Proteome serology may complement expression library-based approaches as strategy utilizing the patients' immune responses for the identification pathogenesis factors and potential targets for therapy and markers for diagnosis. Melanoma is a relatively immunogenic tumor and antigens recognized by melanoma-specific T cells have been extensively studied. The specificities of antibody responses to this malignancy have been analyzed to some extent by molecular genetic but not proteomics approaches. We screened sera of 94 melanoma patients for anti-melanoma reactivity and detected seropositivity in two-thirds of the patients with 2–6 antigens per case detected by 1D and an average of 2.3 per case by 2D Western blot analysis. For identification, antigen spots in Western blots were aligned with proteins in 2-DE and analyzed by mass spectrometry. 18 antigens were identified, 17 of which for the first time for melanoma. One of these antigens, galectin-3, has been related to various oncogenic processes including metastasis formation and invasiveness. Similarly, enolase has been found deregulated in different cancers. With at least 2 of 18 identified proteins implicated in oncogenic processes, the work confirms the potential of proteome-based antigen discovery to identify pathologically relevant proteins

A Chip-Interleaving Pattern Retaining Orthogonality in DS-CDMA Systems: Application to the Multicode Downlink

Abstract — Interleaving the chip-level sequence resulting from spreading before transmission in direct spread code division multiple access (DS-CDMA) systems have been reported to allow significant improvements over conventional (non chipinterleaved) DS-CDMA. This transmission scheme has been shown to be of particular interest when used in conjunction with iterative receivers, allowing performance close to the multiple access (MAI) and intersymbol (ISI) interference-free case to be reached. This paper addresses the application of chip-interleaving to existing or near-future DS-CDMA systems. An interleaving pattern is introduced that allows the orthogonality property to be retained between interleaved and non-interleaved signals. In addition, a low-complexity receiver based on iterative channel equalization is designed for the multicode downlink of chipinterleaved DS-CDMA systems. Numerical simulations show that used in conjunction with the proposed interleaving scheme, the proposed receiver allows the interference-free performance of the non-interleaved case to be attained. I

Improved bit error probability estimation for DS-CDMA downlink equalizer-based receivers with small spreading factors

International audienceThis paper provides insight INTO data_ds.tmp_pub_the statistical distribution of the interference at the output of the receivers composed of a chip-rate linear transverse equalizer followed by a despreader for the downlink of direct-sequence code-division multiple access (DS-CDMA) systems with long scrambling sequences. It is shown that for small spreading factors, the probability density function (PDF) of the interference samples can be modelled accurately as a mixture of Gaussian PDFs. Each component of the mixture is associated with a particular realization of the scrambling sequence spanning the spread symbol to be retrieved. Based on the study, an analytical method allowing the computation of the bit error probability for small spreading factors is derived. Numerical simulations show that the BEP estimation achieved by the proposed method is far more accurate than that obtained via the traditionnal Gaussian assumption on the interference statistics