Codage entropique à base de règles de ré-écriture

Des codes de compression sans perte basés sur l'utilisation d'un ensemble de règles de ré-écriture sont introduits et leur performance théorique en compression est analysée. Le formalisme des règles de production permet d'obtenir un degré de liberté important lors de la création de codes. En particulier, il est possible de trouver des codes qui compressent sous le bit ou d'obtenir des codes dont la probabilité marginale bit est uniforme

A New Class of Codes for Robust Compression of Heterogeneous Data: Multiplexed Codes

Compression systems of real signals (images, video, audio) generate sources of information with different levels of priority which are then encoded with variable length codes (VLC). This paper addresses the issue of robust transmission of such VLC encoded heterogeneous sources over error-prone channels. VLCs are very sensitive to channel noise: when some bits are altered, synchronization losses can occur at the receiver. This paper describes a new family of codes, called multiplexed codes, that allow to confine the desynchronization phenomenon to low priority data while allowing to reach asymptotically the entropy bound for both (low and high priority) sources. The idea consists in creating Fixed length codes for high priority information and in using the inherent redundancy to describe low priority data, hence the name multiplexed codes. Theoritical and simulation results reveal a very high error resilience at almost no cost in compression efficiency

A Nanospring Named Erythrocyte. The Biomembrane Force Probe

International audienc

Contrail Virtual Execution Platform Challenges in Being Part of a Cloud Federation ⋆

Abstract. Cloud computing is quickly defining the computing paradigm in the modern networked age. Users can run their large computations online using cloud services at a fraction of the cost compared to setting their own data centers. Clearly cloud computing offers many advantages, and yet many large organizations including governments, financial sector, and health care sector are reluctant in transitioning to cloud computing. Contrail project will address the major concerns behind this reluctance namely mistrust in cloud platforms, lack of Service Level Agreements (SLAs) and Quality of Protection (QoP) of data. Contrail will provide a federation layer support for bringing a multitude of cloud providers, both private and public, together. This will allow multi-tenancy and cloudbursting capability to end user cloud applications while supporting SLAs and QoP agreements desired by several privacy aware sectors including governments, banks, health care providers to name a few. This paper describes the novel features we are building into the Contrail Virtual Execution Platform (VEP) that will be closely interfaced with the IaaS layer of cloud providers. VEP upgrades the supported cloud providers and brings trust in cloud computing by adding SLAs and QoP features missing at typical IaaS layer. Further this paper outlines challenges faced in being part of a large federation and how VEP will address some of those.

Le palmarès du Mapathon du colloque Tous (im)mobiles, tous cartographes?

La coordination du colloque Tous (im)mobiles, tous cartographes? Approches cartographiques des mobilités, des circulations, des flux et des déplacements a décidé d'ouvrir l'événement en programmant, en marge des sessions classiques de ce type de rencontre, un espace d'exposition, Images de mobilités (https://cartomob.sciencesconf.org/?resource/?page/?id/?17), et un Mapathon (https://cartomob.sciencesconf.org/?resource/?page/?id/?14), tous deux en lien avec le thème général de la cartographie des mobilités. L'article présente le palmarès des applications cartographiques

Mapping Mouse Gamete Interaction Forces Reveal Several Oocyte Membrane Regions with Different Mechanical and Adhesive Properties †

International audienc

Is melanoma survival influenced by month of diagnosis?

Background: Despite being a well-documented phenomenon, seasonal variation in the incidence of cutaneous melanoma is poorly understood, and data on the seasonality of melanoma survival are scarce. We sought to explore the seasonal variation in melanoma incidence and survival in Belgium and to assess the characteristics and outcomes of cases diagnosed during the seasonal peak. Methods: All cases of invasive cutaneous melanoma-patients over 15 years of age and registered by the Belgian Cancer Registry (BCR) from 2004 to 2009-were included (n=9782). Monthly variations in incidence were estimated by the ratio of the number of cases diagnosed each month to that diagnosed in January (Rmonth/January) using Nam's method. The observed and relative 5-year survival rates were adjusted on patient and tumour characteristics using Cox proportional hazards regression models and generalised linear models with a Poisson error structure, respectively. Results: A peak in melanoma incidence was observed in June (RJune/January=1.64, 95% confidence interval (CI)=1.54-1.73). The 5-year observed survival (OS) and relative survival (RS) rates were significantly higher for patients diagnosed in June compared with other months (OSJune=84%, 95%CI=81-86 versus OSOthermonths=79%, 95%CI=78-80; RSJune=93%, 95%CI=90-95 versus RSothermonths=87%, 95%CI=86-88). After adjustment, the 5-year OS remained significantly higher for patients diagnosed in June (hazard ratioJune=0.78, 95%CI=0.62-0.98); however, the 5-year RS was no longer significantly different for patients diagnosed in June compared with other months (relative excess riskJune=1.16, 95%CI=0.73-1.84). Conclusions: This study demonstrated a seasonal variation in melanoma incidence in Belgium with a peak in June for the period 2004-2009. When adjusted for patient and tumour characteristics, patients diagnosed in June had higher observed survival rates, but relative survival rates did not differ. Our findings do not support an influence of season of diagnosis on melanoma prognosis.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Perinatal exposure to glyphosate and a glyphosate-based herbicide affect spermatogenesis in mice

International audienceGlyphosate is the most widely used herbicide in the world. Several studies have investigated the effects of glyphosate and glyphosate-based-herbicides (GBHs) on male reproduction, but there is still little and conflicting evidence for its toxicity. In this study, we analyzed the effects of glyphosate, alone or in formula, on the male reproductive system. Pregnant mice were treated from E10.5 to 20 days postpartum (dpp) by adding glyphosate or a GBH (Roundup® 3 Plus) to their drinking water at 0.5 (the acceptable daily intake, ADI dose), 5 and 50 mg/kg/day. Male offspring derived from treated mice were sacrificed at 5, 20 and 35 days-old (d.o.) and 8 months-old (m.o.) for analysis. Our result showed that exposure to glyphosate, but not GBH, affect testis morphology in 20 d.o. and decrease serum testosterone concentrations in 35 d.o. males. We identified that the spermatozoa number decreased by 89% and 84% in 0.5 and 5 mg/kg/day of GBH and glyphosate groups, respectively. Moreover, the undifferentiated spermatogonia numbers were decreased by 60% in 5 mg/kg/day glyphosate group, which could be due to the alterations in the expression of genes involved in germ cell differentiation such as Sall4 and Nano3 and apoptosis as Bax and Bcl2. In 8 m.o. animals, a decreased testosterone level was observed in GBH groups. Our data demonstrate that glyphosate and GBHs could cause endocrine-disrupting effects on male reproduction at low doses. As glyphosate has effects at the ADI level, our data suggests that the current ADI for glyphosate could be overestimated