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In the paper, we investigate issues of Internet-based services provisioned via low earth orbit (LEO) satellite-IP networks, which are equipped with on-board IP routers. We propose a possible network-integrating architecture for global personal communication based on IP (Internet protocol) networks. We investigate particularly challenges of handover management in LEO satellite networks, arising due, to the movement of the satellites. Handover management schemes based on mobile IPv6 are proposed for handling inter-satellite handover. Performance evaluations of the proposed schemes are carried out by means of simulation.

In this paper, a novel distributed medium access protocol for a time-slotted WDM metro ring employing all-optical packet switching and supporting QoS classes directly in the optical layer is presented and analyzed. Since we assume much more nodes than available wavelengths in the network, we obtain a scalable multi-hop WDM ring. In our architecture, each node is equipped with one tunable: transmitter and one fixed-tuned receiver. The new QoS control scheme adopts a frame-based slot reservation strategy including connection set-up and release, thus efficiently combining connection-less and connection-oriented services. Furthermore, a fairness control scheme, named M(ultiple)-ATMR, guaranteeing fairness for best-effort traffic through a credit-based mechanism is proposed.

Location management is an essential process in future mobile communication networks. An important issue is that of efficient management of the location database. The next generation mobile communication network is proposed to integrate with a TINA-compliant architecture enabling one to handle that kind of mobile-specific processes. This paper discusses the design and modeling of a distributed location management based on a TINA-compliant architecture for wireless mobile communication networks. We consider a distributed location database architecture for location management, performing two strategies: HLD (home location database) and HLD-CLD (HLD with a cache location database). The local cache CLD is used to reduce signaling traffic in the network and to accelerate database searching and updating. This paper also presents a simple methodology for evaluating some basic location management algorithms for a distributed location database based on a TINA-compliant architecture for wireless communication networks.

We propose a routing methodology for multi-hop LEO satellite networks aiming at minimising the number of link handovers per connection, while at the same time satisfying the QoS requirements. For the representation of the network topology, a graph-theoretical approach is used, where a new metric for inter-satellite links, called lifetime t/sub L/, is introduced. This metric is then considered for the minimisation of connection re-routing attempts due to the connectivity changes, for which a network graph transformation approach is proposed. In addition to this, we propose a distributed QoS routing strategy for LEO satellite networks, where the accommodation of different QoS requirements such as bandwidth or delay presume the maximisation of the lifetime of inter-satellite links (ISL), building a feasible path.

We present the effects of mobility on QoS provisioning in multi-hop low Earth orbit (LEO) satellite ATM networks and the necessity of inter-satellite handover. Based on the LEO-satellite ATM network characteristics, different feasible inter-satellite handover schemes are proposed regarding the QoS handover requirements. A combination of the schemes is suggested as an efficient handover management scheme for LEO-satellite ATM networks. In addition, handover protocols are described in terms of signaling flows and control sequences. Finally, several performance metrics are evaluated by simulation of the studied traffic and system configuration.

This paper reports the results of a general study conducted in cooperation with the Dutch ING Group to identify various fields of interaction between a financial institution and a technical university. A number of projects have been examined in terms of, amongst others, the length of the project and the possibility and term of measuring first results, in order to define the project(s) most suitable for an initial cooperation. It is found that in banking and insurance many possible fields of interaction with technology are available. Projects in these fields have a lot of potential for success, though not always fit for cooperation with technical universities, due to prioritization of issues or to a lack of of readiness for researching the possibilities of new techniques. This paper can give financial institutions as well as technical research institutes an insight into some of the possibilities of collective research.

We hypothesized that during high-frequency oscillatory ventilation (HFOV), a reduction of peak-to-peak oscillatory pressure along the endotracheal tube is maximal when respiratory system compliance is maximal. We made a mathematical model of the endotracheal tube and the respiratory system of a neonate suffering from idiopathic respiratory distress syndrome (IRDS). The model consisted of linear viscous and inertive elements, a non-linear endotracheal tube resistance, and a non-linear compliance allowing for alveolar recruitment and overdistention. Respiratory compliance was maximal at the transition between maximal recruitment and minimal overdistention. A new variable, the oscillatory pressure ratio (OPR), was defined as the ratio between peak-to-peak oscillatory pressures at the distal end and the proximal opening of the endotracheal tube, respectively. The respiratory variables of four patients were fed into the model, and the relationship between respiratory system compliance and OPR was determined. OPR decreased as compliance increased, except for very low compliances below where 0.08 mL · cmH2O−1, and OPR increased with increasing compliance. The relationship between mean airway pressure Paw and OPR revealed that the minimal OPR (range, 0.37–0.78) and maximal respiratory compliance coincided at the same Paw. However, the relationship did depend on oscillation frequency, applied oscillatory pressure, and endotracheal tube resistance, parameters that may change during clinical application of HFOV. When 81 permutations of nominal and extreme respiratory variables were used in the model, the minimum OPR (0.60 ± 0.23) and maximum compliance coincided in all cases. These model experiments support our hypothesis. The results indicate that the OPR may be a useful index to optimize lung expansion, where lung recruitment is maximal and overdistention minimal. In vivo tests will be needed to reveal the feasibility and reliability of such an index for biomedical and clinical application. Pediatr Pulmonol. 2001; 31:458–463. © 2001 Wiley-Liss, Inc.

Osteoporosis is not a feature unique to primary biliary cirrhosis (PBC) but is also found in other categories of liver disease. The principles developed for monitoring and treating postmenopausal osteoporosis can also be followed for patients with PBC. Monitoring of dietary intake of calcium and vitamin D serum levels is essential, and the threshold for initiating supplementation should be low. Bisphosphonates can be considered the most rational choice when specific therapy is required.

Summary Four patients with weight loss, jaundice, a sonolucent swelling of the pancreas, and multiple bile-duct strictures are described. These cases of sclerosing pancreato-cholangitis responded to steroid therapy.

There are potential benefits to addition of visceral organ perfusion, by means of a 9-Fr. catheter system (octopus), to distal aortic perfusion during thoracoabdominal aneurysm surgery. However, in the literature there are reports of adverse effects. The authors therefore compared two groups of patients who underwent thoracoabdominal aneurysm surgery with and without visceral organ perfusion. In the group in which the visceral perfusion was applied, the use of platelets (26 versus 11 units; P

Background and Study Aims: The present study was aimed at exploring the feasibility of diagnostic laparoscopy on a day-case basis in patients with liver disease. Patients and Methods: Retrospective analysis was carried out of 85 consecutive day-case laparoscopies performed between January 1990 and January 1994. During this period, patients were observed in day-care facilities for a period of three hours. Patients' perception and acceptance of the procedure were assessed using a postal questionnaire. Results: Laparoscopy was successful in 84 of the 85 patients ; adequate liver biopsies were obtained in 83 patients. In three cases, the procedure was converted to a one-night hospital admission because of pain (1), persistent sedation (1) and collapse (1). Abdominal skin hematomas were reported by eight patients, and fever by two. Serious complications were not observed. The majority of patients experienced no complaints, or minor ones, after the procedure, and they expressed a preference for an outpatient procedure in case a renewed investigation might be indicated. Compared with in-hospital procedures, day-case laparoscopy was associated with a 33% reduction in cost. Conclusions: Diagnostic laparoscopy, with the hospital stay reduced to three hours, can be performed safely as a day-case procedure in selected patients.

In publications on language acquisition in formal and informal settings it is often assumed that utterances are addressed to one co-present other: the dyadic metaphor for communication which has 'conversation' as its paradigmatic format. Hymes (1972), Ochs (1983), and especially Goffman (1981) - among others - have emphasized that more complex participant roles are involved. In this paper structural features of the production of teacher and learner turns will be investigated. The data derive from a first English lesson, an 'action research' project and a longitudinal school diary co-authored by two teenage girls in the Netherlands. Their insider view of what happens in (language) classes corroborates the view that descriptive models of classroom talk underanalyze the notion of what are 'the' data that need to be accounted for. A more sophisticated tool is needed. It is suggested that Polanyi and Scha's Dynamic Discourse Model (Polanyi, 1988) - with modifications - could provide such a tool.

Doel: Bepalen van de atrioventriculaire (AV)-geleidingstijd bij te vroeg geboren kinderen in het kader van een vergelijkend elektrocardiologisch onderzoek naar geleidingstijden versus grootte van het hart. Opzet: Descriptief. Plaats: Afdeling Neonatologie van het Academisch Ziekenhuis van de Vrije Universiteit te Amsterdam. Methode: Bij 28 baby's, geboren na een zwangerschapsduur van 26-36 weken, werd met behulp van de gebruikelijke bewakingsapparatuur en een bipolaire precordiale afleiding zo snel mogelijk na de geboorte een ECG geregistreerd. Deze ECG's werden vervolgens handmatig geanalyseerd en de relevante geleidingstijden, zoals het PQ-interval en de QRS-duur, gemeten. De gevonden waarden werden gerelateerd aan het geboortegewicht van de kinderen. (Het hartgewicht is bij benadering 0,6% van het lichaamsgewicht.) Resultaten: Het gemiddelde geboortegewicht van de kinderen bedroeg 1374 g (SD: 491), het gemiddelde PR-interval 93 ms (9), de gemiddelde QRS-duur 40 ms (4) en de gemiddelde hartfrequentie 148/min (14). Conclusie: In hartjes met een gewicht van 6-10 g bedroeg de geleidingstijd ongeveer de helft van die van het volwassen mensenhart (350-500 g; 5O keer zo zwaar). De relatieve bijdrage van de AV-knoop aan de AV-geleidingstijd is groter naarmate het hart kleiner is.

An ethnographic document of 'objet trouvé' nature was the starting point for this study: a school diary in two volumes, co-authored by two Dutch teenage girls in the early seventies, mostly during classes-in-progress. This lively collection of fieldnotes (texts, drawings, shrieks, written conversations) constructs an insider-relevant representation of what school is like, from class-to-class, day-to-day, year-to-year. The existence of this collusive document is itself a comment on our assumptions of what goes on in classrooms, what is heard and not heard, seen and not seen. I have selected two passages from "The Writ", as the girls called these unorthodox classroom data, that illustrate how current linguistic and educational paradigms, in embracing a 'conversational' view to learning and communication in school, underanalyze the complexity of multi-party interaction in social situations, both with respect to 'the' data that have to be accounted for and the analytic tools they use to account for them (cf. 'Where is the lesson in all this talk'; Van Dam van Isselt, 1995). The relevance of what is said is constructed in highly complex floors and collusive interactional positions (cf. Goffman, 1979, 'Footing'). In the first part of the paper, a refinement of hearer roles is central. In the second part, a different type of data is used: video-recordings of lessons in 'Dutch as a second language', taught to a group of refugee children recently arrived in the Netherlands. A close examination of these data shows that 'utterance that is not talk' is relevant to contexts of early socialization and language production (cf. Palloni, 1994). The main theme of the paper is that a dynamic notion of context is needed: as produced in real time on a moment-by-moment basis by the interpretative work of co-present parties. Two discourse models that partially fulfill these requirements and that could be adapted for the purpose are discussed: the Linguistic Discourse Model by Polanyi & Scha (Polanyi, 1988) and Van Kuppevelt's proposals for tracing the structure of narrative texts through underlying questions (Van Kuppevelt, 1995).

For handling signals in optical networks transparently, two different approaches for quality-of-service routing are proposed. The features of these approaches are discussed and simulation results for an example network with various kind of services with/without wavelength shifting are given.

941 ALKALINE PHOSPHATASE VALUES ARE A SURROGATE MARKER IN PREDICTION OF TRANSPLANT FREE SURVIVAL IN PATIENTS WITH PRIMARY BILIARY CIRRHOSIS – AN INTERNATIONAL, COLLABORATIVE ANALYSIS W.J. Lammers, H.R. van Buuren, G.M. Hirschfield, A. Pares, T. Kumagi, L. Caballeria, P. Invernizzi, A. Lleo, P.M. Battezzati, C. Corpechot, A. Floreani, N. Cazzagon, M.J. Mayo, J.A. Talwalkar, M. Imam, A.K. Burroughs, G. Pieri, F. Nevens, A.L. Mason, R. Poupon, H.L.A. Janssen, K.D. Lindor, B.E. Hansen, Global PBC Study Group. Gastroenterology and Hepatology, Erasmus MC University Medical Center, Rotterdam, The Netherlands; Liver Centre, Toronto Western Hospital, Toronto, ON, Canada; Centre for Liver Research and NIHR Institute of Biomedical Research, University of Birmingham, Birmingham, UK; Liver Unit, Hospital Cĺinic, CIBERehd, IDIBAPS, Barcelona, Spain; Center for Autoimmune Liver Diseases, Humanitas Clinical and Research Center, Rozzano, Italy; Dept of Medicine, Surgery and Dentistry, Universita degli Studi di Milano, Milan, Italy; Service d’Hepatologie, Hopital Saint-Antoine, APHP, UPMC, Paris, France; Department of Surgical, Oncological and Gastroenterological, University of Padova, Padova, Italy; Digestive and Liver disease, UT Southwestern Medical Centre, Dallas, TX, Gastroenterology and Hepatology, Mayo Clinic, Rochester, MA, USA; The Sheila Sherlock Liver Centre, The Royal Free Hospital, London, UK; Hepatology, University Hospitals Leuven, UKLeuven, Leuven, Belgium; Divison of Gastroenterology and Hepatology, University of Alberta, Edmonton, AB, Canada; Health Solutions, Arizona State University, Phoenix, AZ, USA E-mail: w.lammers@erasmusmc.nl

Summary Background A favourable benefit/risk ratio for treatment of rheumatoid arthritis (RA) with second-line drugs has been established only in short-term studies. The present investigation addresses the question of whether RA patients with a good response to long-term treatment with second-line drugs benefit from continuation of such treatment. Methods A 52-week randomised double-blind placebo-controlled multicentre study was conducted to assess the effect of stopping second-line therapy in 285 RA patients with a good long-term therapeutic response. The patients either continued the second-line drug (n=142) or received a placebo (n=143). The endpoint was a flare, defined as recurrence of synovitis. Findings At entry into the study median duration of second-line drug therapy was 5 years (range 2-33). At 52 weeks the cumulative incidence of a flare was 38% for the placebo group and 22% for the continued therapy group (p=0·002). The risk of a flare was 2·0 times higher for patients receiving placebo than for those continuing the second-line drug (95% Cl 1·27 to 3·17). The same trend was found for each second-line drug separately, with the exception of d-penicillamine. Side-effects that necessitated dose reduction or discontinuation occurred in 2 patients in each group. Interpretation Second-line drugs continue to be effective in RA patients who have responded well to initial treatment.

Procedures for the determination of vinblastine (VBL), 4-O-deacetylvinblastine (DVBL) and 4-O-deacetylvinblastine-3-oic acid (DVBLA) in biological samples using high-performance liquid chromatography (HPLC) combined with selective sample clean-up are presented. VBL and DVBL were determined in plasma and urine using ion-exchange normal-phase HPLC with fluorescence detection. The limit of detection was 1 microgram/l for both compounds using a 500-microliter sample. Successful chromatographic analyses of DVBLA were achieved by using a glass column packed with 5-microns Hypersil ODS and acetonitrile-0.05 M phosphate buffer (pH 2.7) (23:77, v/v). Positive identification was supported by the use of diode-array detection. The limit of detection (at 270 nm) was 10 micrograms/l using 1-ml samples.

Een 20-jarige vrouw meldt zich op de afdeling Spoedeisende Hulp met een pijnlijke en scheefstaande duim met slotklachten na deze te hebben overstrekt. Bij lichamelijk onderzoek blijkt er een niet-anatomische stand van het metacarpofalangeale gewricht van digitorum 1. Er wordt een poging ondernomen het gewricht te reponeren. Rontgenopnamen tonen een asymmetrische verwijding in het metacarpofalangeale gewricht met het beeld van een os sesamoideum in het gewricht