Expansion of five-year-old mortars attributable to DEF: Relevance of the laboratory studies on DEF?

This paper aims to open a discussion on the relevance of the laboratory studies on heat-induced internal sulphate attack. The results presented here show that specimens of mortars conserved in frequently renewed deionised water expand after 3 years and a half. The same specimens conserved in water that is not renewed still do not expand after more than 5 years of conservation. So, it seems that the appearance of the phenomenon is linked to the experimental conditions of the test. Moreover, the period before the beginning of the expansion is very long. These results raise two important questions: may the laboratory studies be used for the prediction of the field DEF behaviour and, if so, what minimal duration should formulation qualification tests have to ensure the durability of the constructions faced with this pathology?     

FIV vaccine studies. II. Clinical findings, hematological changes and kinetics of blood lymphocyte subsets

Five groups of cats were vaccinated with different recombinant feline immunodeficiency virus (FIV) SU vaccines expressed either in Escherichia coli or in the Baculovirus system. In Part I of this series, we described the humoral immune response and outcome of intraperitoneal FIV challenge exposure. Additionally, all cats were monitored for clinical and hematological changes and the course of blood lymphocyte subsets. These results are described in this present paper. A great increase of antibodies was found after vaccination with different recombinant FIV antigens, which did not protect the cats from intraperitoneal FIV challenge infection. This observation was paralleled by an increase of eosinophils during vaccination which was even more pronounced after challenge infection. After FIV challenge, infection lymphadenopathy, gingivitis, pharyngitis, changes in total leukocytes and neutrophils and a decrease in the CD4+:CD8+ ratio were found in cats of all groups and were considered as a sign of the FIV infection taking place, independent of vaccination. The following observations suggest that in these cats a TH2-like immune response was elicited: the high counts of eosinophils, the nature of antigen and adjuvant (aluminium hydroxide) and the high amounts of antigens used for immunization. Clearly, this type of immune response did not protect the animals from intraperitoneal FIV challenge infection.     

Deterministic edge-preserving regularization in computed imaging

Many image processing problems are ill-posed and must be regularized. Usually, a roughness penalty is imposed on the solution. The difficulty is to avoid the smoothing of edges, which are very important attributes of the image. In this paper, we first give conditions for the design of such an edge-preserving regularization. Under these conditions, we show that it is possible to introduce an auxiliary variable whose role is twofold. First, it marks the discontinuities and ensures their preservation from smoothing. Second, it makes the criterion half-quadratic. The optimization is then easier. We propose a deterministic strategy, based on alternate minimizations on the image and the auxiliary variable. This leads to the definition of an original reconstruction algorithm, called ARTUR. Some theoretical properties of ARTUR are discussed. Experimental results illustrate the behavior of the algorithm. These results are shown in the field of 2D single photon emission tomography, but this method can be applied in a large number of applications in image processing.     

Realistic and efficient simulation of electro-thermal effects inVLSI circuits

Needs for electro-thermal simulation of VLSI circuits, as opposed to both the system and device levels, are analyzed. A system capable of modeling these effects in a realistic and sufficiently accurate way that uses a reasonable amount of CPU resources is presented. An innovative solver is also proposed. The system is used to study the importance of some three dimensional (3-D) effects as well as metallic connections. A complete example was treated to have an insight on the type of results to be expected and the corresponding costs in terms of CPU     

Wavelet analysis of transients in fractal superlattices

Fractal superlattices are designed by alternating dielectric layers according to an iterative fractal process. The discrete self-similarity of such stratified structures can be remotely detected from interrogation by an incident pulse. In this paper, the impulse response of one-dimensional Cantor superlattices is computed and the wavelet transform is applied to the reflected signal in order to explore its temporal distribution of singularities. For a sufficiently narrow pulse, the skeleton of the wavelet-transform modulus-maxima exhibits a hierarchical structure that makes apparent the iterative process governing the construction rule of the interrogated fractal superlattice and its geometry. In the reflected signal, such hierarchy reveals the existence of singularities that are distributed on the governing Cantor set. Finally, the similarity dimension is extracted from reflection data and a strategy for estimating the stage of growth is developed     

Hippocampal grafts of acetylcholine-producing cells are sufficient to improve behavioural performance following a unilateral fimbria-fornix lesion

Lesions of the septohippocampal pathway produce cognitive deficits that are partially attenuated by grafts of cholinergic-rich tissue into denervated target regions or by systemic administration of cholinomimetic drugs. In the present study, fibroblasts engineered to produce acetylcholine were used to test the hypothesis that restoration of hippocampal acetylcholine in rats with septohippocampal lesions is sufficient to improve cognitive processing post-damage. Rats received unilateral grafts of acetylcholine-producing or control fibroblasts into the hippocampus immediately prior to an aspirative lesion of the ipsilateral fimbria-fornix. Some rats with fimbria-fornix lesions were implanted with acetylcholine-producing or control fibroblasts into the neocortex, another major target of the basal forebrain cholinergic system, to determine if the site of acetylcholine delivery to the damaged brain is critical for functional recovery. Rats were tested in a hidden platform water maze task, a cued water maze task and activity chambers between one and three weeks post-grafting. Compared to unoperated controls, rats with fimbria fornix lesions only were significantly impaired in hidden platform water maze performance. Hippocampal grafts of acetylcholine-producing cells reduced lesion-induced deficits in the water maze, whereas hippocampal control grafts and cortical grafts of either cell type were without effect. Locomotor activity and cued water maze performance were unaffected by the lesion or the implants. Taken together, these data indicate that water maze deficits produced by fimbria fornix lesions, which disrupt a number of hippocampal neurotransmitter systems, can be attenuated by target specific replacement of acetylcholine in the hippocampus and that this recovery occurs in the absence of circuitry repair.     

Cooperative Fusion for Multi-Obstacles Detection With Use of Stereovision and Laser Scanner

We propose a new cooperative fusion approach between stereovision and laser scanner in order to take advantage of the best features and cope with the drawbacks of these two sensors to perform robust, accurate and real time-detection of multi-obstacles in the automotive context. The proposed system is able to estimate the position and the height, width and depth of generic obstacles at video frame rate (25 frames per second). The vehicle pitch, estimated by stereovision, is used to filter laser scanner raw data. Objects out of the road are removed using road lane information computed by stereovision. Various fusion schemes are proposed and one is experimented. Results of experiments in real driving situations (multi-pedestrians and multi-vehicles detection) are presented and stress the benefits of our approach.Raphaël Labayrade was born in France, in 1976. He received the M.S. degree in 2000 from the university of Saint Etienne, and he was also graduate from the ENTPE engineer school in 2000. In 2004 he received the Ph.D. degree from the university Pierre et Marie Curie Paris VI. In his thesis he proposed a new approach for detecting road obstacles using stereovision in a generic, fast and robust manner.He is currently a researcher at INRETS since 2004 in the perception team of the LIVIC department and works on automated highway and on on-board driving assistance systems. His main work deals with obstacles detection using data fusion but he is also interested in road lane recognition. He is involved for vision tasks in various european and french projects dealing with intelligent vehicles (Carsense, Micado, Arcos). He teaches at Jussieu (Paris VI), Ecole Nationale des Ponts et Chaussées, University of Versailles.He is the author and co-author of several technical papers.Cyril Royere was born in France, in 1972. He received the M.S. degree in 1995 from the university of Reims. In 2002 he received the Ph.D. degree from the university of Technology of Compiegne. In his thesis, he describes the origins of the conflict which appears when combining of various sources of imperfect information within the framework of the belief theory. Since 2002, he is a researcher at INRETS, into the perception team of the LIVIC department (Laboratory on interactions between vehicles, Infrastructure and drivers) and works on automated highway and on on-board driving assistance systems. His main work deals with obstacles detection using data fusion. He is involved for multi-sensor fusion tasks in several European and French projects dealing with intelligent vehicles (CARSENSE, MICADO, ARCOS).He is the author and co-author of several technical papers.Dominique Gruyer was born in France, in 1969. He received the M.S. and Ph.D. degree respectively in 1995 and 1999 from the university of Technology of Compiëgne.Since 2001, he is a researcher at INRETS, into the perception team of the LIVIC department (Laboratory on interactions between vehicles, Infrastructure and drivers) and he works on the study and the development of multi-sensor/sources association, combination and fusion. His works enter into the conception of on-board driving assistance systems and more precisely on the carry out of multi-obstacle detection and tracking, extended perception, accurate localization, anti-collision system, collision mitigation. He is involved for multi-sensor fusion tasks in several European and French projects dealing with intelligent vehicles (CARSENSE, MICADO, ARCOS). He is a multi-sensor fusion expert for several companies, teaches at Orsay (Paris XI), Ecole Nationale des Ponts et Chaussées and University of Technologie of Compiëgne.He is the author and co-author of several technical papers.Didier Aubert was born in France, in 1963. He received the M.S. and Ph.D. degree respectively in 1985 and 1989 from the university of Grenoble. From 1989–1990, he worked as a research scientist on the development of an automatic road following system for the NAVLAB at Carnegie Mellon University. From 1990–1994, he worked in the research department of a private company (ITMI). During this period he was project leader of several projects dealing with computer vision (Multi-resolution, color, motion detection, 3D reconstruction, 3D location, Shape recognition, automatic shape modelling, object tracking), mobile robotic (calibration, roads following, free space computation) and manipulator robotic (calibration, automatic surface tracking). He was also working as an expert for companies on the face recognition, 3D location and roads following topics. He is currently a researcher at INRETS since 1995, manages the perception team of the LIVIC department and works on car traffic monitoring, crowd monitoring, incidents detection, automated highway and on on-board driving assistance systems. He is an image processing expert for several compagnies, teaches at Jussieu (Paris VI), Ecole Nationale des Ponts et Chaussées, Ecole Nationale Supérieure des Télécommunications, Orsay (Paris XI) and is at the editorial board of RTS (Research-Transport-Safety).He is the author and co-author of several technical papers and has participated to the redaction of the books named “Robotique mobile” and “la route automatisée.”     

Comparison and improvement of the determinations of actinide low activities using several alpha liquid scintillation spectrometers

We applied three procedures using two a liquid scintillation spectrometers (PERALS and TRI-CARB) and two scintillation cocktails (Alphaex and Ultima Gold LLT) for the determination of alpha-emitter low activities. For each procedure, the limit of detection, the resolution, the separation factor, and the Fischer coefficient were determined in order to perform 232U-234U-238U isotopic measurements. The deconvolution usually performed is clean when the PERALS spectrometer is used. This is not possible for the TRI-CARB spectrometer using the Ultima Gold LLT scintillation cocktail. This problem was solved by combining the advantages of both techniques using the Alphaex scintillation cocktail in the TRI-CARB spectrometer. Under these conditions, the limit of detection was improved, the resolution decreased from 500-800 to 420-590 keV, and the separation factor increased from 0.9 to 1.1-1.2. This third procedure was applied with success for 232U-234U-238U isotopic experiments.