3,042 research outputs found

    RT-SLAM: A Generic and Real-Time Visual SLAM Implementation

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    This article presents a new open-source C++ implementation to solve the SLAM problem, which is focused on genericity, versatility and high execution speed. It is based on an original object oriented architecture, that allows the combination of numerous sensors and landmark types, and the integration of various approaches proposed in the literature. The system capacities are illustrated by the presentation of an inertial/vision SLAM approach, for which several improvements over existing methods have been introduced, and that copes with very high dynamic motions. Results with a hand-held camera are presented.Comment: 10 page

    Weak limits of entropy regularized Optimal Transport; potentials, plans and divergences

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    This work deals with the asymptotic distribution of both potentials and couplings of entropic regularized optimal transport for compactly supported probabilities in Rd\R^d. We first provide the central limit theorem of the Sinkhorn potentials -- the solutions of the dual problem -- as a Gaussian process in \Cs. Then we obtain the weak limits of the couplings -- the solutions of the primal problem -- evaluated on integrable functions, proving a conjecture of \cite{ChaosDecom}. In both cases, their limit is a real Gaussian random variable. Finally we consider the weak limit of the entropic Sinkhorn divergence under both assumptions H0: P=QH_0:\ {\rm P}={\rm Q} or H1: PQH_1:\ {\rm P}\neq{\rm Q}. Under H0H_0 the limit is a quadratic form applied to a Gaussian process in a Sobolev space, while under H1H_1, the limit is Gaussian. We provide also a different characterisation of the limit under H0H_0 in terms of an infinite sum of an i.i.d. sequence of standard Gaussian random variables. Such results enable statistical inference based on entropic regularized optimal transport

    Human APOBEC1 cytidine deaminase edits HBV DNA

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    Retroviruses, hepadnaviruses, and some other retroelements are vulnerable to editing by single stranded DNA cytidine deaminases. Of the eleven human genes encoding such enzymes, eight have demonstrable enzymatic activity. Six of seven human APOBEC3 are able to hyperedit HBV DNA, frequently on both strands. Although human APOBEC1 (hA1) is not generally expressed in normal liver, hA1 can edit single stranded DNA in a variety of experimental assays. The possibility of ectopic expression of hA1 in vivo cannot be ruled out and interestingly, transgenic mice with A1 expressed under a liver specific promoter develop hepatocellular carcinoma. The impact of hA1 on HBV in tissue culture is varied with reports noting either reduced DNA synthesis or not, with cytidine deamination taking a low profile. We sought to examine the hA1 editing activity on replicating HBV. Using highly sensitive 3DPCR it was possible to show that hA1 edits the HBV minus DNA strand as efficiently as hA3G, considered the reference deaminase for HIV and HBV. The dinucleotide specificity of editing was unique among human cytidine deaminases providing a hallmark of use in a posteriori analyses of in vivo edited genomes. Analysis of sequences derived from the serum of two chronic carriers, indicated that hA1 explained only a small fraction of edited HBV genomes. By contrast, several human APOBEC3 deaminases were active including hA3G

    Photodynamic drug delivery enhancement in tumours does not depend on leukocyte-endothelial interaction in a human mesothelioma xenograft model†

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    OBJECTIVES The pre-treatment of tumour neovessels by low-level photodynamic therapy (PDT) improves the distribution of concomitantly administered systemic chemotherapy. The mechanism by which PDT permeabilizes the tumour vessel wall is only partially known. We have recently shown that leukocyte-endothelial cell interaction is essential for photodynamic drug delivery to normal tissue. The present study investigates whether PDT enhances drug delivery in malignant mesothelioma and whether it involves comparable mechanisms of actions. METHODS Human mesothelioma xenografts (H-meso-1) were grown in the dorsal skinfold chambers of 28 nude mice. By intravital microscopy, the rolling and recruitment of leukocytes were assessed in tumour vessels following PDT (Visudyne® 400μg/kg, fluence rate 200mW/cm2and fluence 60J/cm2) using intravital microscopy. Likewise, the distribution of fluorescently labelled macromolecular dextran (FITC-dextran, MW 2000kDa) was determined after PDT. Study groups included no PDT, PDT, PDT plus a functionally blocking anti-pan-selectin antibody cocktail and PDT plus isotype control antibody. RESULTS PDT significantly enhanced the extravascular accumulation of FITC-dextran in mesothelioma xenografts, but not in normal tissue. PDT significantly increased leukocyte-endothelial cell interaction in tumour. While PDT-induced leukocyte recruitment was significantly blunted by the anti-pan-selectin antibodies in the tumour xenograft, this manipulation did not affect the PDT-induced extravasation of FITC-dextran. CONCLUSIONS Low-level PDT pre-treatment selectively enhances the uptake of systemically circulating macromolecular drugs in malignant mesothelioma, but not in normal tissue. Leukocyte-endothelial cell interaction is not required for PDT-induced drug delivery to malignant mesotheliom

    La coccidiose chez les poulets domestiques : revue sur les stratégies de prévention et de contrôle

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    La coccidiose aviaire est l'un des défis les plus importants et les plus persistants auxquels est confrontée l'industrie avicole mondiale, entraînant une baisse de productivité due aux dommages intestinaux causés par le protozoaire apicomplexe intracellulaire Eimeria. Le cycle de vie d'Eimeria est complexe, caractérisé par des stades intra- et extracellulaires. Le stade intracellulaire induit une réponse inflammatoire en partie responsable de la formation de lésions tissulaires, des hémorragies diarrhéiques, une mauvaise croissance, une sensibilité accrue à d'autres agents pathogènes et, dans certains cas sévères (E. tenella et E. necatrix), une forte mortalité. Une bonne gestion sanitaire est indispensable pour prévenir la coccidiose chez les poulets. L'administration d'anticoccidiens dans les aliments peut également réduire efficacement l’intensité de l’infection par Eimeria. Cependant, leur utilisation à grande échelle et sur une longue durée a entraîné le développement de résistances à ces additifs dans le monde entier. Des vaccins vivants non atténués et atténués ont été développés mais ils présentent certaines limites. En plus des méthodes conventionnelles de prévention et de contrôle, les produits phytogéniques émergent comme alternative pour contrôler la coccidiose aviaire. Les recherches en cours sur la sélection génétique et des vaccins recombinants et sous-unitaires sont prometteuses pour la prévention, mais leur efficacité et leur adoption dans l'industrie avicole restent à démontrer. De plus, comme alternatives aux coccidiostatiques, des stratégies utilisant des extraits naturels sont plus acceptées par les consommateurs et sont de plus en plus étudiées. Cet article présente donc une vue d'ensemble de l'impact économique de la coccidiose chez les poulets sur la production et aborde les stratégies intégrées de la santé pour contrôler la coccidiose chez les poulets

    Reproductive Technologies and Genomic Selection in Cattle

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    The recent development of genomic selection induces dramatic changes in the way genetic selection schemes are to be conducted. This review describes the new context and corresponding needs for genomic based selection schemes and how reproductive technologies can be used to meet those needs. Information brought by reproductive physiology will provide new markers and new improved phenotypes that will increase the efficiency of selection schemes for reproductive traits. In this context, the value of the reproductive techniques including assisted embryo based reproductive technologies (Multiple Ovaluation Embryo Transfer and Ovum pick up associated to in vitro Fertilization) is also revisited. The interest of embryo typing is discussed. The recent results obtained with this emerging technology which are compatible with the use of the last generation of chips for genotype analysis may lead to very promising applications for the breeding industry. The combined use of several embryo based reproductive technologies will probably be more important in the near future to satisfy the needs of genomic selection for increasing the number of candidates and to preserve at the same time genetic variability

    Hemorrhagic Shock Caused by Rupture of an Intra-Abdominal Leydig Cell Tumour: Case Report

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    The rupture of an intra-abdominal testicular neoplasm is a rare cause of acute abdomen and massive intra-abdominal haemorrhage. We report the case of a 70-year-old male presenting a massive intra-abdominal bleeding caused by a Leydig cell tumour in an undescended testis. The clinical details and pathology of this rare testicular tumour are discussed
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