2003
Autores
Varejao, ASP; Cabrita, AM; Geuna, S; Melo Pinto, P; Filipe, VM; Gramsbergen, A; Meek, MF;
Publicação
EXPERIMENTAL NEUROLOGY
Abstract
In experimental peripheral nerve studies, the rat sciatic nerve model is widely used to examine functional outcome following nerve injury and repair. A variety of evaluation methods exist in the literature, but an adequate selection continues to be a critical point for the researcher. Rats with sciatic nerve injury typically ambulate with an external rotation of the foot. A new functional assessment instrument, the toe out angle (TOA) is quantified using computerized gait analysis. We compared Sciatic Functional Index (SFI) with TOA parameter after peripheral nerve transection and entubulation repair. We found a good correlation between SFI and TOA measurements in terms of predicting functional recovery. Moreover, the TOA provides information on the biomechanical consequences of the external rotation of the foot in the stance phase of walking.
2003
Autores
Saraiva, J; Swierstra, D;
Publicação
GENERATIVE PROGRAMMING AND COMPONENT ENGINEERING, PROCEEDINGS
Abstract
This paper presents techniques for the formal specification and efficient incremental implementation of spreadsheet-like tools. The spreadsheets are specified by strong attribute grammars. In this style of attribute grammar programming every single inductive computation is expressed within the attribute grammar formalism. Well-known attribute grammar techniques are used to reason about such grammars. For example, ordered scheduling algorithms can be used to statically guarantee termination of the attribute grammars and to derive efficient implementations. A strong attribute grammar for a spreadsheet is defined and the first incremental results are presented.
2003
Autores
Mendonca, JT; Martins, AM; Guerreiro, A;
Publicação
PHYSICAL REVIEW A
Abstract
The effect of photon beam splitting in a time-varying medium is described by classical and quantum theoretical models. It generalizes the concept of time refraction, introduced recently by the authors as a natural extrapolation of the usual concepts of refraction and reflection into the time domain. Total time reflection is shown to exist. A sequence of time refraction processes is shown to lead to temporal interference effects. The concept of temporal beam splitter is introduced. Bogoliubov transformations for the temporal beam splitter are derived. Resonant amplification of light by change in time in the optical medium is shown to exist.
2003
Autores
Reis, JS; Lakhani, SR;
Publicação
BREAST CANCER RESEARCH
Abstract
The development of modern molecular genetic techniques has allowed breast cancer researchers to clarify the multistep model of breast carcinogenesis. Laser capture microdissection coupled with comparative genomic hybridisation and/or loss-of-heterozygosity methods have confirmed that many pre-invasive lesions of the breast harbour chromosomal abnormalities at loci known to be altered in invasive breast carcinomas. Current data do not provide strong evidence for ductal hyperplasia of usual type as a precursor lesion, although some are monoclonal proliferations; however, atypical hyperplasia and in situ carcinoma appear to be nonobligate precursors. We review current knowledge and the contribution of molecular genetics in the understanding of breast cancer precursors and pre-invasive lesions.
2003
Autores
Figueiredo, L; Machado, JAT; Ferreira, JR;
Publicação
IEEE Conference on Intelligent Transportation Systems, Proceedings, ITSC
Abstract
This paper presents the Simulator of Intelligent Transportation Systems (SITS). The SITS is based on a microscopic simulation approach to reproduce real traffic conditions in an urban or non-urban network and considers different types of vehicles, drivers and roads. A dynamical analysis of several traffic phenomena is then addressed. The results of using classical system theory tools point out that it is possible to study traffic systems, taking advantage on the knowledge gathered with automatic control algorithms. In this line of thought, it was also presented a new modelling formalism based on the embedding of statistics and Fourier transform. © 2003 IEEE.
2003
Autores
Leite, R; Brazdil, P;
Publicação
PROGRESS IN ARTIFICIAL INTELLIGENCE
Abstract
We present a method that can be seen as an improvement of standard progressive sampling method. The method exploits information concerning performance of a given algorithm on past datasets, which is used to generate predictions of the stopping point. Experimental evaluation shows that the method can lead to significant time savings without significant losses in accuracy.
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