Microstructure and Mechanical Properties of Silicon Nitride Materials Fabricated from SHS Powders

Two different silicon nitride powders, one produced by self-propagating high-temperature synthesis (SHS) and one commercial, have been equally processed to obtain dense materials. Y₂O₃ powders as a sintering aid and hot-pressing techniques were used to process the materials. The fracture toughness and strength of the materials prepared have been evaluated and the results comparatively discussed as a function of the microstructure, with special emphasis on the characteristics of the initial powders.     

Absorption and effects of 3-(N-phenylamino)-1,2-propanediol esters in relation to toxic oil syndrome

Toxic Oil Syndrome (TOS) was an epidemic disease related to the consumption of rapeseed oil denatured with aniline that made its sudden appearance in Spain in 1981. The fatty acid esters of 3-(N-phenylamino)-1,2-propanediol (PAP), which is a chemical class of by-products resulting from the reaction of aniline with oil components, have shown a strong association with TOS-related oils. These compounds also show some structural similarities to platelet-activating factor (PAF). In search of a toxic agent that could explain the widespread systemic effects observed in TOS patients, we investigated the intestinal absorption and biotransformation of the different PAP esters found in TOS-related oil samples and the possible pathophysiological effect of these mediators and their metabolic products if acting as PAF analogs. Results indicate that PAP esters are absorbed in the gastrointestinal tract and are distributed and stored in different organs, particularly in the liver and brown adipose tissue. PAP in these organs showed different patterns of fatty acids, indicating the ability of the gastrointestinal tract to modify the fatty acid composition of the parent PAP. Thus, the fatty acid profile of the PAP esters found in intestine appears to be related to the type of oil used as vehicle. Some of these PAP esters, when a long acyl chain was present in the sn-1 position of the molecule, showed an inhibitory effect on the PAF synthesis. This is an important observation in line with the systemic nature of the disease.     

Automatic correction of background phase offset in 4D-flow of great vessels and of the heart in MRI using a third-order surface model

Magnetic Resonance Materials in Physics, Biology and Medicine - To evaluate an automatic correction method for velocity offset errors in cardiac 4D-flow acquisitions. Velocity offset correction was...     

Airmed-cardio: a GSM and Internet services-based system for out-of-hospital follow-up of cardiac patients.

A platform built around three information entities (patient, health-care_agent, and central_station) was designed to enable patients with chronic heart disease (in stable condition; emergency situations were excluded deliberately) to complete specifically defined protocols for out-of-hospital follow-up and monitoring. The patients belonged to one of four specific risk groups: arterial hypertension, malignant arrhythmias, heart failure, and postinfarction rehabilitation. They were provided with portable recording equipment and a cellular phone that supported data transmission [electrocardiogram (ECG)] and wireless application protocol (WAP) (remaining parameters and ad hoc questionnaires). The central station was an automatized platform, with no human operator. The information received was organized chronologically in patient folders. The health-care_agents had continuous and secure access to the patient folders, through tools based on the world wide web and WAP, and to short messages sent by their patients. A pilot project was conducted with 89 patients (mean length of participation: 50.1 days). A total of 2168 ECGs (mean duration transmission = 2 min/30 s; network errors < 0.1%) and 4011 short messages (none lost, in 95% of cases 30 s < delay < 1 min) were transmitted; 6083 WAP sessions (mean duration = 3 min 11 s; network failures < 0.1%) were The functionality of the platform was also evaluated, analyzing the subjective component of usability, showing the evolution of patient acceptance over time.     

Device-independent Color Correction for Multimedia Applications Using Neural Networks and Abductive Modeling Approaches

Although color has appeal for developers and consumers alike, color reproduction poses a major problem in many computer based applications including multimedia and desktop publishing. The problem arises because of the device-independence of color, and the way each device processes color. Matching the appearance of monitor and print images, and achieving satisfactory results is complex. Not only are there fundamental differences between computer screen (additive) and printers (subtractive), but subtractive color is in general more prone to errors due to dye inadequacies. In order to control the error in porting color, different techniques have been applied. In this paper, the utilization of artificial neural networks as well as abductive modeling approaches to color error reduction are introduced from an RGB (Red Green Blue) color model perspective. Analysis of the results and on-going research issues are discussed.     

Heuristics for railway infrastructure saturation

This research concerns the problem of the evaluation of the railway infrastructure capacity. It is an important question when railway authorities have to choose between different infrastructure investment projects. We developped independently two heuristic approaches to solve the infrastructure saturation problem. The first is based on a constraint programming model which is solved using a greedy heuristic. The second approach identifies the saturation problem as a unicost set packing problem and its resolution is ensured by an adaption of GRASP metaheuristic. Currently, both resolution techniques are not in competition. The goal is to grasp the resolution ability of the heuristics and to analyse the kind of solutions produced. The Pierrefitte-Gonesse junction has been used as experimental support. A software environment allows to simulate several timetables involving TGV, Inter City and Freight trains.     

Physically Abusive Mothers' Responses Following Episodes of Child Noncompliance and Compliance.

The authors used sequential analysis to examine specific interaction patterns between physically abusive mothers and their children following episodes of noncompliance and compliance. Fifteen abusive and 15 nonabusive, low-risk mother-child dyads were observed, and their behaviors were coded for specific interactions. The children in the study ranged in age from 2 to 6 years. Results indicated that after noncompliance occurred, physically abusive mothers were more likely than nonabusive mothers to respond negatively and give another command. When child compliance occurred, there were no group differences in the likelihood of praising their children's prosocial behavior, but physically abusive mothers were less likely than nonabusive mothers to engage in other forms of positive behavior (e.g., positive touch) after compliance. Clinical implications are discussed in the context of working with physically abusive families. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Wireless CDN video streaming architecture for IPTV

Wireless IPTV (Internet Protocol TeleVision) aims to make the traditional IPTV and related services available to users anywhere, anytime, on any device, and through any network. Mobile streaming TV is one of the alternatives to deploy such a system; others are DVB-H or MediaFLO. In this paper we propose an alternative CDN-based architecture to distribute contents to different access networks, in order to create a triple screen platform. The core elements of the system are the video streamers, acting as surrogates of the mobile CDN-based architecture, installed in the access networks (including mobile), and the transcoding servers in the premises of the content providers. The paper focused on the wireless part of the system, analyzing the architecture and performance results related with the video coding and the efficiency obtained due to the placement of the streaming servers. The system has been deployed by a Spanish media company for its use with different Telcos, ISPs and media companies.     

Bayesian adaptation for user-dependent multimodal biometric authentication

A novel score-level fusion strategy based on Bayesian adaptation for user-dependent multimodal biometric authentication is presented. In the proposed method, the fusion function is adapted for each user based on prior information extracted from a pool of users. Experimental results are reported using on-line signature and fingerprint verification subsystems on the MCYT real bimodal database. The proposed scheme outperforms both user-independent and user-dependent standard approaches. As compared to non-adapted user-dependent fusion, relative improvements of 80% and 55% are obtained for small and large training set sizes, respectively.