User modelling and cognitive user support: towards structured development

Model-driven engineering approaches have turned out useful when handling different perspectives on human–computer interaction, such as user profiles and problem-domain data. Their latest flavour, Model-Driven Architecture (MDA^?), targets towards platform-independent models (PIMs) and adjacent transformation mechanisms to adapt to user needs and tasks. Although in the field of user modelling and its major application domain, namely adaptive hypermedia systems (AHS), considerable effort has been spent on adaptation towards user needs, a structured development approach could not be established so far. User-oriented application designs are highly distinctive and can hardly be compared or mapped to novel or existing developments without major re-engineering effort. This paper develops an understanding of existing capabilities of already applied user-modelling techniques from a model-based perspective. Revealing the context of user models and user modelling allows determining general concepts for representing and processing knowledge for adaptation. The obtained findings show primarily technically motivated approaches, rather than designs grounded in findings from human factors. For human-centred design, a shift is suggested towards distributed cognition as a methodological and operational frame of reference for user modelling. This could help overcome existing limitations in adaptation. The corresponding research agenda requires directions on how to map psychological constructs to user-model elements and adaptable user-interface elements, such as mapping field dependence to content annotation features, in a transparent and empirically grounded way.     

Faster adjustment of O2 delivery does not affect V(O2) on-kinetics in isolated in situ canine muscle

The mechanism(s) limiting muscle O2 uptake (VO2) kinetics was investigated in isolated canine gastrocnemius muscles (n = 7) during transitions from rest to 3 min of electrically stimulated isometric tetanic contractions (200-ms trains, 50 Hz; 1 contraction/2 s; 60-70% of peak V(O2)). Two conditions were mainly compared: 1) spontaneous adjustment of blood flow (Q) [control, spontaneous Q (C Spont)]; and 2) pump-perfused Q, adjusted approximately 15 s before contractions at a constant level corresponding to the steady-state value during contractions in C Spont [faster adjustment of O2 delivery (Fast O2 Delivery)]. During Fast O2 Delivery, 1-2 ml/min of 10(-2) M adenosine were infused intra-arterially to prevent inordinate pressure increases with the elevated Q. The purpose of the study was to determine whether a faster adjustment of O2 delivery would affect V(O2) kinetics. Q was measured continuously; arterial (Ca(O2)) and popliteal venous (Cv(O2)) O2 contents were determined at rest and at 5- to 7-s intervals during contractions; O2 delivery was calculated as Q x Ca(O2), and V(O2) was calculated as Q x arteriovenous O2 content difference. Times to reach 63% of the difference between baseline and steady-state VO2 during contractions were 23.8 +/- 2.0 (SE) s in C Spont and 21.8 +/- 0.9 s in Fast O2 Delivery (not significant). In the present experimental model, elimination of any delay in O2 delivery during the rest-to-contraction transition did not affect muscle V(O2) kinetics, which suggests that this kinetics was mainly set by an intrinsic inertia of oxidative metabolism.     

Erfassung von Gehalt und chemischer Zusammensetzung der σ-Phase in austenitischen Chrom-Nickel-Stählen mit rd. 18% Cr, 8% Ni und 2 bis 10% Mo

Potentiostatische Isolierung der σ-Phase in austenitischen Chrom-Nickel-Stählen mit rd. 18% Cr, 8% Ni und 2 bis 10% Mo nach unterschiedlichen Glühbehandlungen zur Erfassung von Gehalt und chemischer Zusammensetzung der σ-Phase. Vergleich der Ergebnisse mit licht- und elektronenmikroskopischen Gefügeaufnahmen zur Beurteilung der Entstehung der σ-Phase. Prüfung der Möglichkeit einer Zuordnung von Kerbschlagzähigkeit und Gehalt an σ-Phase.     

Biochemical studies of the thermal effects on DNA modifications by the antitumor cisplatin and their repair

Using biochemical methods, we have examined the effect of two factors that might play a role in the mechanism of the biological activity of cisplatin at elevated temperatures (>37 degrees C). We show that increased temperatures result in distinct alterations in the modification of the target DNA by cisplatin, and in the repair of these modifications. Our in vitro results support the view that the enhanced DNA-cross-linking efficiency of cisplatin and the lower efficiency of native DNA repair mechanisms at higher temperature play at least a partial role in the potentiation of the antitumor effects of cisplatin under conditions of mild hyperthermia.     

The first case of leukocyte integrin deficiency syndrome in the Czech Republic and successful prenatal diagnosis in the affected family

The syndrome of leukocyte adhesion deficiency (LAD) is a rare congenital immunodeficiency which is usually manifested from birth by serious infections of the skin and mucosal membranes. The molecular basis of the disease is heterogeneous: quantitative or qualitative disorders of the beta 2 integrin sub-unit are involved which lead to the absence or substantially reduced expression of adhesive molecules of the CD11/CD18 complex on leukocytes. The authors describe the case of a boy who suffered from this syndrome. The diagnosis was established at the age of four years, based on the typical clinical picture and confirmed by examination of integrins on lymphocytes and granulocytes which were zero. During the mother's subsequent pregnancy prenatal diagnosis was made by puncture of the umbilical cord during the 22nd week of gestation. Affection of the foetus by this syndrome was ruled out by examination of integrin expression on foetal leukocytes, a normal finding was confirmed also after delivery. During delivery umbilical blood was collected which was frozen and later used for therapeutic transplantation to the sibling suffering from LAD. This is the first case of this syndrome in the Czech Republic and first prenatal diagnosis which led to aimed collection of umbilical blood used for treatment of this rare immunodeficiency.     

Landscape diversity and land use planning: a case study in Bavaria

A maximum of landscape diversity is to be regarded as a helpful target as well as an analytical tool to detect actual planning deficits. First of all, specific indicators and targets for ecosystem and landscape levels will be defined. Ecosystem types are derived from landscape ecological site conditions, and are combined with the demands of minimal areas related to present and potential ecosystem types.The suitability of management practices for the site conditions, and the requirements mentioned above, will together form the basis on which a target landscape in its pattern, and the management practices suggested can be mapped. In comparison with the present use of the landscape, measures are derived which indicate that the target of a high landscape diversity has real practical meaning: conversion of about 15% of the arable land into forests and grasslands as one result of this study fits into the political and administrative programmes already established. In addition, four modification categories of the actual usage are mapped and described in size and number in this case study. The basic assumptions of this approach will be explained, to provide further working hypotheses for an interdisciplinary and integrative research into landscape ecology in rural landscapes.