A robust nonsmooth generalized-α$\alpha $ scheme for flexible systems with impacts

Multibody System Dynamics - The aim of this work is the development of a robust and accurate time integrator for the simulation of the dynamics of multibody systems composed of rigid and/or...     

Skin extracts from 2 italian table grapes (italia and palieri) inhibit tissue factor expression by human blood mononuclear cells

Grape and its products such as red wine and grape juice have well-known antithrombotic properties, which have been attributed to their high content in polyphenolic compounds. Most studies on the mechanisms underlying these beneficial effects, among which the suppression of tissue factor (TF) synthesis in blood mononuclear cells (MNC) and vascular endothelium is a prominent one, have been performed with purified polyphenols, while little is known about the effect of fresh grapes which contain a multitude of phytochemicals whose interaction may lead to different cell responses. In this study, we investigated the effect of grape skin extracts (GSEs) on TF expression in isolated blood MNC and in whole blood. Alcoholic extracts from skins of 2 grape varieties (Palieri and Italia) inhibited TF expression in lipopolysaccharide (LPS)-stimulated MNC in a concentration-dependent manner with ≥90% inhibition of TF activity and antigen at 6 μg/mL of gallic acid equivalents. Noteworthy, GSEs were also able to inhibit the appearance of TF in whole blood challenged with LPS. The 2 grape varieties displayed a fairly similar TF-inhibiting capacity despite marked differences in phenolic profile. When selected purified polyphenols were tested, their ability to inhibit TF expression was markedly lower as compared to grape extracts, whereas a mixture of some representative polyphenols was much more efficient, supporting the occurrence of a synergistic effect. Given the key role of cell TF in thrombotic diseases, the inhibition of MNC-mediated clotting activation, if confirmed by in vivo studies, might represent an important antithrombotic mechanism. Practical Application: Our data indicate that the combination of different polyphenols, as in grape extracts, is much more efficient than the single constituents, a finding that might be useful as starting point for the development of new antithrombotic nutraceutics. In addition, our study validated a simple, inexpensive, and physiologically relevant in vitro method on whole blood that allows the evaluation of one of the most important antithrombotic activities of food and food-derived products. The simplicity of the method makes it suitable also for screening purposes in large-scale studies.     

Plastein synthesis with α-chymotrypsin immobilised on chitin

Low-molecular weight peptide fractions were prepared from soya bean, lucerne (alfalfa) leaf protein, and wild grass leaf protein by enzymatic hydrolysis. The concentrated hydrolysates were used as substrates for plastein synthesis with α-chymotrypsin immobilised on chitin. When submitted to gel filtration on Sephadex G-50, the plasteins formed with the immobilised α-chymotrypsin were comparable to the plasteins formed from the soluble enzyme. Isoelectric focusing of the plasteins showed five bands each from immobilised α-chymotrypsin and from soluble chymotrypsin. However, slight differences in the isoelectric points of the comparable bands were observed.     

Pyroelectric sensor signals processing for early-warning generation in CO2 laser welding

Three different techniques were chosen for processing pyroelectric sensor signals that would provide early warnings of malfunctioning in the CO₂ laser welding. The corresponding algorithms were implemented using the mean, the root mean square and variance of a suitable number of digitized signal samples. Each pair of these algorithms was found complementary in reaching 100% success in the early individuation of the defects. The one based on the variance was more efficient than the other two in identifying the causes of malfunctioning. The processing times ranged from 20 μs to 200 ms, and the spatial resolutions varied from 18 μm to 0.5 mm.     

The File Mover: high‐performance data transfer for the grid

The exploration in many scientific disciplines (e.g. High‐Energy Physics, Climate Modeling, and Life Sciences) involves the production and the analysis of massive data collections, whose archival, retrieval, and analysis require the coordinated usage of high‐capacity computing, network, and storage resources. To obtain satisfactory performance, these applications require the availability of a high‐performance, reliable data transfer mechanisms, able to minimize the data transfer time that often dominates their execution time. In this paper we present the File Mover, an efficient data transfer system specifically tailored to the needs of data‐intensive applications, that exploits the overlay networks paradigm to provide superior performance with respect to conventional file transfer systems. An extensive experimental evaluation, carried out by means of a proof‐of‐concept implementation of the File Mover for a variety of network scenarios, shows the ability of the File Mover to outperform alternative data transfer systems. Copyright © 2007 John Wiley & Sons, Ltd.     

Dynamic Cluster Recognition with Multiple Self-Organising Maps

: A neural architecture, based on several self-organising maps, is presented which counteracts the parameter drift problem for an array of conducting polymer gas sensors when used for odour sensing. The neural architecture is named mSom, where m is the number of odours to be recognised, and is mainly constituted of m maps; each one approximates the statistical distribution of a given odour. Competition occurs both within each map and between maps for the selection of the minimum map distance in the Euclidean space. The network (mSom) is able to adapt itself to new changes of the input probability distribution by repetitive self-training processes based on its experience. This architecture has been tested and compared with other neural architectures, such as RBF and Fuzzy ARTMAP. The network shows long-term stable behaviour, and is completely autonomous during the testing phase, where re-adaptation of the neurons is needed due to the changes of the input probability distribution of the given data set. Received: 23 November 2000, Received in revised form: 01 June 2001, Accepted: 23 July 2001     

Global rainbow thermometry: improvements in the data inversion algorithm and validation technique in liquid-liquid suspension

Improvements on the validation of a nonintrusive laser-based measurement technique are presented. This new technique, called global rainbow thermometry (GRT), is capable of determining the temperature and the size distributions of liquid droplets dispersed in a liquid or gaseous bulk. We propose a new data inversion algorithm that takes into account the whole rainbow pattern. Experimental validation of the GRT technique is performed for a liquid-liquid suspension. We performed the validation by comparing the measurements obtained with the GRT technique for the mean droplet temperature and size with the results obtained with alternative techniques.