MRI semeiology of segmental contraction abnormalities in arrhythmogenic dysplasia of the right ventricle

The diagnosis of localized arrhythmogenic right ventricular dysplasia may be difficult to ascertain. Aside from electrophysiological arguments, visualization of an abnormal right ventricular contraction pattern is of crucial importance for diagnosis. Cine-MR is almost the only examination method which offers detailed informations on the right ventricular contraction pattern. Nine observations of segmental right ventricular contraction abnormalities assessed by cine-MR are described here: dyskinesia of the distal part of the anterior wall (2), of the inferior wall (2), of the right ventricular outflow tract (2); akinesia of the outflow tract (2) and of the inferior wall (1). Morphological abnormalities of the right ventricle are always associated with contraction abnormalities but seem to be less disease specific. Patients should be more readily referred for a cine-MR examination when the diagnosis of localized right ventricular dysplasia is suspected. Cine-MR sequences related to these observations may be reached via Internet at:http:@alsace.u-strasbg.fr/cardio/coeur.htm.     

Contribution of the fractal dimension to multiscale adaptive filtering of SAR imagery

Radar images can show great variability from pixel to pixel, which is an obstacle to effective processing. This variability, due to speckle created by the radar wave coherence, necessitates the use of more adapted filters. Previous studies have shown that multiresolution wavelet analysis yields better results but produces artefacts due to multiscale decomposition. This paper proposes a method that reduces these effects by introducing the fractal dimension. The resultant filter combines wavelet decomposition and variance change model based on the level of variance estimated by studying the fractal dimension of the image.     

Image Analysis of Representative Food Structures: Application of the Bootstrap Method

ABSTRACT:  Images (for example, photomicrographs) are routinely used as qualitative evidence of the microstructure of foods. In quantitative image analysis it is important to estimate the area (or volume) to be sampled, the field of view, and the resolution. The bootstrap method is proposed to estimate the size of the sampling area as a function of the coefficient of variation (CV _Bn ) and standard error (SE _Bn ) of the bootstrap taking sub-areas of different sizes. The bootstrap method was applied to simulated and real structures (apple tissue). For simulated structures, 10 computer-generated images were constructed containing 225 black circles (elements) and different coefficient of variation (CV _image ). For apple tissue, 8 images of apple tissue containing cellular cavities with different CV _image  were analyzed. Results confirmed that for simulated and real structures, increasing the size of the sampling area decreased the CV _Bn  and SE _Bn . Furthermore, there was a linear relationship between the CV _image  and CV _{Bn .} For example, to obtain a CV _Bn  = 0.10 in an image with CV _image  = 0.60, a sampling area of 400 × 400 pixels (11% of whole image) was required, whereas if CV _image  = 1.46, a sampling area of 1000 × 100 pixels (69% of whole image) became necessary. This suggests that a large-size dispersion of element sizes in an image requires increasingly larger sampling areas or a larger number of images.     

Laboratory scale electroplating and processing of long lengths of in situ Cu3Sn superconductors

The high temperature gradient solidification (HTGS) system for continuous casting of 12.7 mm diameter rods of in situ Cu-Nb is briefly reviewed. A laboratory scale continuous tin electroplating system is described and used to evaluate the effect of various parameters of the alkaline and acid baths plating process. Tin electroplating is shown to be simple and reliable. With an 8 m immersion length production speeds of ～ 1 m min^?1 are possible in an alkaline bath at 80°C. An acid bath gives satisfactory tinning deposits with a production speed of up to 3 m min^?1 at room temperature.     

H∞ control for uncertain one‐sided Lipschitz nonlinear systems in finite frequency domain

The current article discusses the H_∞ disturbance attenuation control design problem for one‐sided Lipschitz systems in finite frequency domain. Models containing norm‐bounded parameter uncertainties, disturbances, and input nonlinearities are considered. By contrast to existing full frequency methods, the H_∞ controller is computed depending on the frequency ranges of disturbances. The finite frequency disturbance attenuation index is initially defined. Thanks to Finsler's lemma, sufficient and less conservative analysis conditions are also derived for the closed‐loop system. Then, synthesis conditions in the low, middle, and high frequency ranges as well as the whole frequency range, are formulated in terms of linear matrix inequalities. At last, to prove the effectiveness and the superiority of the proposed approach, a physical example is used and a comparative study is done.     

Optimizing memory bandwidth exploitation for OpenVX applications on embedded many-core accelerators

In recent years, image processing has been a key application area for mobile and embedded computing platforms. In this context, many-core accelerators are a viable solution to efficiently execute highly parallel kernels. However, architectural constraints impose hard limits on the main memory bandwidth, and push for software techniques which optimize the memory usage of complex multi-kernel applications. In this work, we propose a set of techniques, mainly based on graph analysis and image tiling, targeted to accelerate the execution of image processing applications expressed as standard OpenVX graphs on cluster-based many-core accelerators. We have developed a run-time framework which implements these techniques using a front-end compliant to the OpenVX standard, and based on an OpenCL extension that enables more explicit control and efficient reuse of on-chip memory and greatly reduces the recourse to off-chip memory for storing intermediate results. Experiments performed on the STHORM many-core accelerator demonstrate that our approach leads to massive reduction of time and bandwidth, even when the main memory bandwidth for the accelerator is severely constrained.     

Degradation of pentachlorophenol in cyclodextrin extraction effluent using a photocatalytic process

This work evaluates a process for the elimination of pentachlorophenol (PCP) from effluents provided by a cyclodextrin-assisted flushing of contaminated soils. The effectiveness of photocatalytic degradation of PCP in several cyclodextrin (CD) solutions was evaluated using TiO2 as a photocatalyst. Effects of CD type on PCP degradation rate were studied at two pH values. A similar effect was observed for all CDs used on degradation rate of PCP and the decay of PCP was found to be less extensive at pH 11 than at pH 7. The kinetic orders of the photocatalytic reactions of PCP for all of the solutions have been determined. The first-order rate constants were found to be 0.0884, 0.0362, 0.0197 and 0.0053 min(-1) in CD solutions, respectively, at 0, 1, 2 and 5 mmol l(-1) of CD. Batch experiments were performed in order to study the CD extraction enhancement of PCP previously adsorbed on soil. The results show that the removal capacity of PCP from soil increases with CD concentration (from 0 to 5 mmol l(-1)). When the CD concentration was 5 mmol l(-1), an extraction of about 70% of PCP adsorbed on soil was observed, whereas only 37% was removed when water was used as the flushing solution. The optimal conditions for such a coupled method depend on the nature and concentration of the extracting agent and also on the photocatalytic experimental conditions. This work revealed that the coupling of cyclodextrin-enhanced solubilization and photocatalytic treatment is a promising method for contaminated soil remediation.