Pierre-and-Marie-Curie University

About: Pierre-and-Marie-Curie University is a education organization based out in Paris, France. It is known for research contribution in the topics: Population & Raman spectroscopy. The organization has 34448 authors who have published 56139 publications receiving 2392398 citations.

Proximal Alternating Minimization and Projection Methods for Nonconvex Problems: An Approach Based on the Kurdyka-Łojasiewicz Inequality

Abstract: We study the convergence properties of an alternating proximal minimization algorithm for nonconvex structured functions of the type: L(x,y)=f(x)+Q(x,y)+g(y), where f and g are proper lower semicontinuous functions, defined on Euclidean spaces, and Q is a smooth function that couples the variables x and y. The algorithm can be viewed as a proximal regularization of the usual Gauss-Seidel method to minimize L. We work in a nonconvex setting, just assuming that the function L satisfies the Kurdyka-Łojasiewicz inequality. An entire section illustrates the relevancy of such an assumption by giving examples ranging from semialgebraic geometry to “metrically regular” problems. Our main result can be stated as follows: If L has the Kurdyka-Łojasiewicz property, then each bounded sequence generated by the algorithm converges to a critical point of L. This result is completed by the study of the convergence rate of the algorithm, which depends on the geometrical properties of the function L around its critical points. When specialized to $Q(x,y)=\Vert x-y \Vert ^2$ and to f, g indicator functions, the algorithm is an alternating projection mehod (a variant of von Neumann's) that converges for a wide class of sets including semialgebraic and tame sets, transverse smooth manifolds or sets with “regular” intersection. To illustrate our results with concrete problems, we provide a convergent proximal reweighted l1 algorithm for compressive sensing and an application to rank reduction problems.

Mapping of a susceptibility locus for Crohn's disease on chromosome 16

Abstract: Crohn's disease (CD) and ulcerative colitis are the major forms of chronic inflammatory bowel diseases in the western world, and occur in young adults with an estimated prevalence of more than one per thousand inhabitants. The causes of inflammatory bowel diseases remain unknown, but genetic epidemiology studies suggest that inherited factors may contribute in part to variation in individual susceptibility to Crohn's disease. A genome-wide search performed on two consecutive and independent panels of families with multiple affected members, using a non-parametric two-point sibling-pair linkage method, identified a putative CD-susceptibility locus on chromosome 16 (P less than 0.01 for each panel). The localization was centered around loci D16S409 and D16S419 by using multipoint sibpair analysis (P less than 1.5x10(-5)). This region of the genome contains candidate genes which may be relevant to the pathogenic mechanism of inflammatory bowel diseases.

A generic architecture for on-chip packet-switched interconnections

Abstract: This paper presents an architectural study of a scalable system-level interconnection template. We explain why the shared bus, which is today's dominant template, will not meet the performance requirements of tomorrow's systems. We present an alternative interconnection in the form of switching networks. This technology originates in parallel computing, but is also well suited for heterogeneous communication between embedded processors and addresses many of the deep submicron integration issues. We discuss the necessity and the ways to provide high-level services on top of the bare network packet protocol, such as dataflow and address-space communication services. Eventually we present our first results on the cost/performance assessment of an integrated switching network.

Continuation of bevacizumab after first progression in metastatic colorectal cancer (ML18147): a randomised phase 3 trial

Abstract: Summary Background Bevacizumab plus fluoropyrimidine-based chemotherapy is standard treatment for first-line and bevacizumab-naive second-line metastatic colorectal cancer. We assessed continued use of bevacizumab plus standard second-line chemotherapy in patients with metastatic colorectal cancer progressing after standard first-line bevacizumab-based treatment. Methods In an open-label, phase 3 study in 220 centres in Austria, Belgium, Czech Republic, Denmark, Estonia, Finland, France, Germany, the Netherlands, Norway, Portugal, Saudi Arabia, Spain, Sweden, and Switzerland, patients (aged ≥18 years) with unresectable, histologically confirmed metastatic colorectal cancer progressing up to 3 months after discontinuing first-line bevacizumab plus chemotherapy were randomly assigned in a 1:1 ratio to second-line chemotherapy with or without bevacizumab 2·5 mg/kg per week equivalent (either 5 mg/kg every 2 weeks or 7·5 mg/kg every 3 weeks, intravenously). The choice between oxaliplatin-based or irinotecan-based second-line chemotherapy depended on the first-line regimen (switch of chemotherapy). A combination of a permuted block design and the Pocock and Simon minimisation algorithm was used for the randomisation. The primary endpoint was overall survival, analysed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00700102. Findings Between Feb 1, 2006, and June 9, 2010, 409 (50%) patients were assigned to bevacizumab plus chemotherapy and 411 (50%) to chemotherapy alone. Median follow-up was 11·1 months (IQR 6·4–15·6) in the bevacizumab plus chemotherapy group and 9·6 months (5·4–13·9) in the chemotherapy alone group. Median overall survival was 11·2 months (95% CI 10·4–12·2) for bevacizumab plus chemotherapy and 9·8 months (8·9–10·7) for chemotherapy alone (hazard ratio 0·81, 95% CI 0·69–0·94; unstratified log-rank test p=0·0062). Grade 3–5 bleeding or haemorrhage (eight [2%] vs one [ vs three [ vs 12 [3%]) were more common in the bevacizumab plus chemotherapy group than in the chemotherapy alone group. The most frequently reported grade 3–5 adverse events were neutropenia (65 [16%] in the bevacizumab and chemotherapy group vs 52 [13%] in the chemotherapy alone group), diarrhoea (40 [10%] vs 34 [8%], respectively), and asthenia (23 [6%] vs 17 [4%], respectively). Treatment-related deaths were reported for four patients in the bevacizumab plus chemotherapy group and three in the chemotherapy alone group. Interpretation Maintenance of VEGF inhibition with bevacizumab plus standard second-line chemotherapy beyond disease progression has clinical benefits in patients with metastatic colorectal cancer. This approach is also being investigated in other tumour types, including metastatic breast and non-small cell lung cancers. Funding F Hoffmann-La Roche.

Immune infiltration in human tumors: a prognostic factor that should not be ignored.

Abstract: The natural history of a tumor includes phases of 'in situ' growth, invasion, extravasation and metastasis. During these phases, tumor cells interact with their microenvironment and are influenced by signals coming from stromal, endothelial, inflammatory and immune cells. Indeed, tumors are often infiltrated by various numbers of lymphocytes, macrophages or mast cells. It is generally believed that the latter produce factors that maintain chronic inflammation and promote tumor growth, whereas lymphocytes may control cancer outcome, as evidenced in mouse models. In this study, we analyze data from large cohorts of human tumors, clearly establishing that infiltration of the primary tumor by memory T cells, particularly of the Th1 and cytotoxic types, is the strongest prognostic factor in terms of freedom from disease and overall survival at all stages of clinical disease. We review data suggesting that tertiary lymphoid structures adjacent to tumors and composed of mature dendritic cells (T and B cells organized as germinal centers) may be the site of an antitumor reaction. We propose an immune scoring based on the type, density and location of lymphocyte infiltrates as a novel prognostic factor for use in addition to tumor node metastasis staging to predict disease-free survival and to aid in decisions regarding adjuvant therapies in early stage human cancers.