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WWW -- Moteurs de recherche, Une alternative aux bases de données en sciences sociales?Dans l'ère du "World Wide Web" (WWW), les utilisateurs des fournisseurs d'informations sont confrontés avec un espace de données hautement décentralisé et hétérogène venant de sources différentes et avec de différentes "valeurs ajoutées". Mais se posent à eux une question encore plus fondamentale: doivent-ils continuer à chercher, par exemple, encore de la littérature (gris) scientifique dans des bases de données spécialisées des centres d'informations tel que l'IZ à Bonn (Allemagne), ou doivent-ils n'utiliser que des moteurs de recherche généralistes comme AltaVista ou Fast? Est-ce que le WWW remplace des centres d'information et leurs bases de données de haute qualité ou ne fera-t-il que combler les lacunes d'information restantes? Que sont les résultats actuels de l'utilisation des moteurs de recherche généralistes sur le WWW? Comment fonctionnent ces derniers et comment diffèrent-ils des systèmes de navigation des bases de données spécialisées?

This paper reports on methodological considerations and the results of the Information Retrieval (IR) project PADOK I and II. PADOK has been carried out by the Linguistic Information Science Group of the University of Regensburg (LIR) since November 1984 and has been sponsored by the German Ministry for Research and Technology. The long term objective is to integrate artificial intelligence topics and the methods of information retrieval research without neglecting traditional IR methodology. In PADOK we consider a type of mass data IR system which indexes its documents rather shallowly (freetext or morphological components) and adds an intelligent information retrieval component to this kernel system. So far we have obtained, on the basis of two large-scale retrieval tests of the German Patent Information System results which show how the linguistically based functions of an indexing system contribute to its performance, and indicate what is the most reasonable basic content analysis program for a German Patent Information System. This paper focusses on the general principles and aims of PADOK I and PADOK R and on the statistical evaluation of the retrieval tests.

The paper is concerned with the question of whether and under what conditions active help systems with plan recognition components that have been developed in the environment of artificial intelligence research are able to prove their value in the real context of commercial application programs. The question is investigated using the development of the COMFOHELP intelligent help system as an example. COMFOHELP supports the COMFOTEX graphical text processing program and has been developed by the Linguistic Information Science Group at the University of Regensburg since 1988. The system recognizes erroneous and suboptimal plans pursued by the user by analyzing the dialog history and comparing them with the correct plan for achieving the user's goal.

Previous studies suggest that patients with achalasia exhibit degenerative changes of extraesophageal nerve fibers. We investigated whether these morphological alterations are associated with functional abnormalities of the gastrointestinal tract. Patients with achalasia had a normal acid secretory response (5.5±1.5 mmol/hr) to vagal stimulation when compared to controls (6.0±5.5 mmol/hr). However, the half time of gastric emptying of liquids was significantly shorter in patients with achalasia (10.4±1.8 min) than in control subjects (19.3±11.3 min) (P<0.01). Although there was a tendency towards a more rapid gastrointestinal transit in patients with achalasia, these changes failed to reach statistical significance. It is concluded that patients with achalasia have a gastric emptying disorder that could either be explained by a selective defect of extraesophageal vagal inhibitory nerve fibers or as an epiphenomenon occurring as a consequence of impaired esophageal emptying.

Objective Despite the recent advances in surgical techniques and perioperative care, liver resection (especially extended hepatectomy) is still a high-risk procedure with considerable morbidity and mortality. Experimental large animal models are the best option for studies in this regard. The present study was performed to present an easy-to-learn, fast, and multipurpose model of liver resection in a porcine model.Method Stepwise liver resections (resection of segments II/III, IVa/IVb, and VIII/IV) were performed in eight pigs with intraoperative monitoring of hemodynamic parameters. The technical aspects, tips, and tricks of this method are explained in detail.Results Based on the specific anatomical characteristics of the porcine liver, all resection types including segmental resection, hemihepatectomy, and extended hepatectomy could be performed in one animal in an easy-to-learn and fast technique. All animals were hemodynamically stable following stepwise liver resection.Conclusion Stepwise liver resection using stapler in a porcine model is a fast and easy-to-learn method with which junior staff and research fellows can perform liver resection up to extended hepatectomy under stable conditions.