Fluorescence in situ hybridization with a synthetic (T2AG3)n polynucleotide detects several intrachromosomal telomere-like repeats on human chromosomes

The relevance of clinical signs of infant hip dysplasia and the importance of a sonographic newborn-hip screening are often discussed. Between 1984 and 1990 at our department 6532 infant hips were examined both clinically and sonographically. Sonographic hip findings were pathological in 71.7% of the hips with positive clinical Roser-Ortolani sign and in 100% of the hips with positive Hilgenreiner sign. In contrast, pathological hip types according to Graf were seen only in 18% of the hips with limitations of the abductions of the hip joint. Examining other clinical signs for infant hip dysplasia within this study, as well we can conclude, that only the Roser-Ortolani sign and that of Hilgenreiner showed a high specificity for infant hip dysplasia, while most of the clinical signs e.g. limitation of abduction in the hip joint are rather unspecific.     

Range-dependent path-loss model in residential areas for the VHFand UHF bands

Implementation digital fixed wireless systems, such as digital FM, high definition TV (HDTV) and wireless local loop (WILL), require a high level of accuracy of propagation prediction in the VHF and UHF bands. This paper presents a theoretical model that predicts the average path loss from an elevated base station to subscriber antennas at rooftop level in residential areas for frequencies in the approximate band from 30 MHz up to 3 GHz. In addition, the model gives the standard deviation of the path loss at the average rooftop level and the height gain for subscriber antennas above or below the average rooftop level. The approach used here generalizes that of Walfisch and Bertoni (1988), who developed a theoretical model of UHF propagation in urban environments. The rows of buildings in residential areas are modeled as a series of dielectric screens having random heights and uniform spacing. Propagation takes place over and through the dielectric screens, and ground reflections are included. The fields at the plane of each screen are obtained in terms of repeated numerical evaluation of the physical optics (PO) integral. Results obtained for the variation of the range dependence on frequency and row spacing are consistent with those previously found for high frequencies by assuming the screens to be totally absorbing. Using the results at different heights of receiving antenna allows computation of the height gain. The predictions are in agreement with the International Telecommunication Union Radio Communication (ITRU-R) recommendations in the VHF and UHF bands     

Tensile basic creep versus compressive basic creep at early ages: comparison between normal strength concrete and a very high strength fibre reinforced concrete

The paper presents experimental results concerning the comparison of tensile and compressive basic creep behaviours at early ages of two different concretes: a normal strength concrete (NSC) and a very high strength fibre reinforced concrete (HPFRC). This research project has been done in the context of a bilateral collaboration between Polytechnique Montreal and IFSTTAR. Observations on the HPFRC showed specific compressive creep similar to the specific tensile creep. Moreover, the specific creep curves obtained under compressive and tensile loading had always positive values, i.e. they were in same direction of the applied load on specimens. Measurements made on the NSC revealed specific compressive creep with positive values (in the loading direction). However, specific tensile creep presented negative values (opposite direction of loading) for a long period. A physical explanation based on the existence of two mechanisms with opposite effect is proposed to describe these basic creep results. The first mechanism is a coupling between the microcracking process and the water transfers that lead to additional self-drying shrinkage; the second mechanism is the self-healing of concrete induced by the microcracking.     

In Situ TEM Observation of the Behavior of an Individual Fullerene-Like MoS<Subscript>2</Subscript> Nanoparticle in a Dynamic Contact

Inorganic fullerene-(IF)-like nanoparticles made of metal dichalcogenides (IF-MoS₂, IF-WS₂) have been known to be effective as anti-wear and friction modifier additives under boundary lubrication. The lubrication mechanism of these nanoparticles has been widely investigated in the past and even if the exfoliation and third body transfer of molecular sheets onto the asperities constitute the prevalent mechanism for the improved tribological behavior of IF nanoparticles, it has also been suggested that a rolling friction process could also play a role for well crystallized and spherical particles. In this study, in situ Transmission Electron Microscopy (TEM) observations of the behavior of single IF-MoS₂ nanoparticles were conducted using a sample holder that combines TEM and Atomic Force Microscopy (AFM) which simultaneously can apply normal and shear loads. It was shown that depending on the test conditions, either a rolling process or a sliding of the fullerenes could be possible. These in situ TEM observations are the first carried out with IF nanoparticles.     

A channel differential EZW coding scheme for EEG data compression

In this paper, a method is proposed to compress multichannel electroencephalographic (EEG) signals in a scalable fashion. Correlation between EEG channels is exploited through clustering using a k-means method. Representative channels for each of the clusters are encoded individually while other channels are encoded differentially, i.e., with respect to their respective cluster representatives. The compression is performed using the embedded zero-tree wavelet encoding adapted to 1-D signals. Simulations show that the scalable features of the scheme lead to a flexible quality/rate tradeoff, without requiring detailed EEG signal modeling.     

3-D deformable image registration: a topology preservation scheme based on hierarchical deformation models and interval analysis optimization.

This paper deals with topology preservation in three-dimensional (3-D) deformable image registration. This work is a nontrivial extension of, which addresses the case of two-dimensional (2-D) topology preserving mappings. In both cases, the deformation map is modeled as a hierarchical displacement field, decomposed on a multiresolution B-spline basis. Topology preservation is enforced by controlling the Jacobian of the transformation. Finding the optimal displacement parameters amounts to solving a constrained optimization problem: The residual energy between the target image and the deformed source image is minimized under constraints on the Jacobian. Unlike the 2-D case, in which simple linear constraints are derived, the 3-D B-spline-based deformable mapping yields a difficult (until now, unsolved) optimization problem. In this paper, we tackle the problem by resorting to interval analysis optimization techniques. Care is taken to keep the computational burden as low as possible. Results on multipatient 3-D MRI registration illustrate the ability of the method to preserve topology on the continuous image domain.     

Application of a response surface method to the optimal design of the wall temperature profiles in extrusion die

A new approach to the optimal design of the die wall temperature profile in polymer extrusion processes is presented. In this approach, optimization of the design variables is conducted by a Response Surface Method (RSM) and the Sequential Quadratic Programming (SQP) algorithm. Design of experiment (DoE) needed for the construction of the response surface is used to evaluate the objective and the constraint functions on the basis of a finite element method (FEM). Two designs of experiments are used and the performances of the optimization results are compared with respect to efficiency and ability to obtain a global optimum. Typically, for extrusion die design, the objective function states that the average velocity across the die exit is uniform. Constraints are used to limit the pressure drop in the die. For this purpose, we optimize the wall temperature profile of a coat hanger die in a heterogeneous way, (i.e. the wall temperature may not be constant in the entire die). The melt temperature enables us to locally control the viscosity, which influences the flows in the various zones. The effect of the design variables in the objective and constraint functions is investigated using Taguchi method. The flow analysis results are then combined with an automatic optimization algorithm to provide a new profile of the die wall temperature distributions.