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Perceptual auditory filter banks such as Bark-scale filter bank are widely used as front-end processing in speech recognition systems. However, the problem of the design of optimized filter banks that provide higher accuracy in recognition tasks is still open. Owing to spectral analysis in feature extraction, an adaptive bands filter bank (ABFB) is presented. The design adopts flexible bandwidths and center frequencies for the frequency responses of the filters and utilizes genetic algorithm (GA) to optimize the design parameters. The optimization process is realized by combining the front-end filter bank with the back-end recognition network in the performance evaluation loop. The deployment of ABFB together with zero-crossing peak amplitude (ZCPA) feature as a front process for radial basis function (RBF) system shows significant improvement in robustness compared with the Bark-scale filter bank. In ABFB, several sub-bands are still more concentrated toward lower frequency but their exact locations are determined by the performance rather than the perceptual criteria. For the ease of optimization, only symmetrical bands are considered here, which still provide satisfactory results.

Polyribonucleotide phosphorilase from the psychrophilic Antarctic eubacterium Pseudoalteromonas haloplanktis (PhPNPase) has been purified. This enzyme catalyzes both the RNA polymerisation and degradation reaction, showing the highest activity at temperatures below 40°C. PhPNPase is quite sensitive to heat treatment and it is endowed with remarkable halotolerance.

A series of 47 patients undergoing abdominoperineal resection of the distal colon and anorectum and construction of a continent perineal colostomy using electrostimulated gracilis muscle is described. External and implanted pulse generators have both been used. An analysis of complications and oncological data are reported. There was no operative mortality. The incidence of complications, divided into three classes, mild (62%), moderate (27%) and severe (11%), has not significantly altered the functional results, with the exception of early ischaemia of the colonic stump in two cases. During the first 22 cases, no preoperative oncological staging was performed. In the last 23 patients endorectal ultrasonography and CT scanning were carried out. Functional results were evaluated by electromanometry, electromyostimulation and dynamic defaecography. Clinical data assessed postoperatively showed good function in 65% of cases, fair in 22.5% and poor in 12.5%. The quality of life in 15 patients with a perineal colostomy and electrostimulated gracilis was significantly better than in 15 patients having an abdomino-perineal resection without gracilis plastic reconstruction.

During open reduction of an irreducible anterior dislocation of a total hip replacement with an Oxinium femoral head, it was observed that the head had been significantly damaged. Gross and scanning electron microscopic examination revealed cracking, gouging, and delamination of the surface. Because of the risk which this poses for damaging the polyethylene acetabular liner, it is strongly recommended that patients with this type of prosthetic head be carefully monitored after a dislocation.

We review the derivation and design of digital waveguides from physical models of stiff systems, useful for the synthesis of sounds from strings, rods, and similar objects. A transform method approach is proposed to solve the classic fourth-order equations of stiff systems in order to reduce it to two second-order equations. By introducing scattering boundary matrices, the eigenfrequencies are determined and theirdependency is discussed for the clamped, hinged, and intermediate cases. On the basis of the frequency-domain physical model, the numerical discretization is carried out, showing how the insertion of an all-pass delay line generalizes the Karplus-Strong algorithm for the synthesis of ideally flexible vibrating strings. Knowing the physical parameters, the synthesis can proceed using the generalized structure. Another point of view is offered by Laguerre expansions and frequency warping, which are introduced in order to show that a stiff system can be treated as a nonstiff one, provided that the solutions are warped. A method to compute the all-pass chain coefficients and the optimum warping curves from sound samples is discussed. Once the optimum warping characteristic is found, the length of the dispersive delay line to be employed in the simulation is simply determined from the requirement of matching the desired fundamental frequency. The regularization of the dispersion curves by means of optimum unwarping is experimentally evaluated.