Tests for Trends in Binary Response

Tests for trend in binary response are especially important when analyzing animal experiments where the response in various dose--groups is of interest. Among the nonparametric tests the approach of Cochran and Armitage is the one which is most commonly used. This test (CA-test) is actually a test for a linear trend. The result of this test is highly dependent on the quantification of the dose. Varying score assignments can lead to totally different results. As an alternative isotonic regression is proposed. The result of this approach is independent of any monotonic transformation of the dose. The p--value related with the isotonic regression can be obtained either from considering all possible combinations of the total number of events in the dose--groups or by analyzing a random sample of all permutations. Both tests are compared within a simulation--study and on data from an experiment considering whether a certain type of fibre, para--aramid, is carcinogenic. The result of the commonly used CA--test is highly dependent on the event rate in the lowest and highest dose--group. Based on our analyses we recommend to use the isotonic regression instead of the test proposed by Cochran and Armitage

CD40, an extracellular receptor for binding and uptake of Hsp70–peptide complexes

Tumor and viral antigens elicit a potent immune response by heat shock protein–dependent uptake of antigenic peptide with subsequent presentation by MHC I. Receptors on antigen-presenting cells that specifically bind and internalize a heat shock protein–peptide complex have not yet been identified. Here, we show that cells expressing CD40, a cell surface protein crucial for B cell function and autoimmunity, specifically bind and internalize human Hsp70 with bound peptide. Binding of Hsp70–peptide complex to the exoplasmic domain of CD40 is mediated by the NH2-terminal nucleotide–binding domain of Hsp70 in its ADP state. The Hsp70 cochaperone Hip, but not the bacterial Hsp70 homologue DnaK, competes formation of the Hsp70–CD40 complex. Binding of Hsp70-ADP to CD40 is strongly increased in the presence of Hsp70 peptide substrate, and induces signaling via p38. We suggest that CD40 is a cochaperone-like receptor mediating the uptake of exogenous Hsp70–peptide complexes by macrophages and dendritic cells

Applying lessons learned from counselling : On nurturing relations in design projects

This paper elaborates on the personal relation between the facilitator and the participants in Social Practice Design. It is argued that such processes can not just be managed, but have to fostered in relatively free way, so that results can transcend expectations and more closely approach the actual possibilities. This is explained by aspects of Rogers\u27 theory on therapy. The paper aims to be an interesting and strong example of the critical need for a good relationship in facilitating design. By itself, such a conclusion would not be surprising, but some of its constituent aspects are detailed: the paper elaborates on the relevance of deploying focus and effort on personal relation, in interventions for organisational innovation. Supporting the establishment of sense making and trust with Social Practice Design (SPD) approaches is found to be of primary importance in an e-Government development project. Here regional employees user-design a computer-based aid for public tender editing – a tender configurator - with the support of facilitators. We address the structural problem with infra-structural measures including open conversations to promote shared understanding, and user design laboratories to promote concept emergence and learning, while practicing relation and trust building all along. Our constructivist approach renounces from the start to solve the governance problem within a narrow managerial perspective. The paper offers a demonstration of the mission critical relevance of the relational component in SPD, intertwined with the customary functional component, in resuming governance towards project success. This experience is far from a complete experiment. But a wealth of indications and partial results have been harvested on needs, opportunities, and practices, for promoting shared understanding and trust in the project, and letting emerge idiosyncratic solutions. We judge the quality of the SPD approach by three requirements (Baskerville and Myers 2004): a contribution to practice (the action), a contribution to research (the theory), the criteria by which to judge the research, and we show explicitly how the research in the case meets these criteria

The Concept of Creativity in the Information Systems Discipline: Past, Present, and Prospects

In 1993 Couger et al. stated in an MIS Quarterly article on creativity in information systems (IS) organizations that the topic of creativity is under-researched in the IS discipline. Is the subject of creativity—despite its undisputable importance for individuals, organizations, and societies—still a neglected area in IS research? In what contexts, with what methods, and with what results have IS researchers studied the phenomenon of creativity? And what creativity-related themes warrant further investigation? In this article we analyze, based on six analytical dimensions, IS studies on creativity published in the eight top-ranked IS journals as recommended by the Association for Information Systems. The analysis provides a detailed picture of how the concept of creativity has been treated in our discipline’s arguably most influential publication outlets. It becomes apparent that IS researchers have been predominantly employing a rather limited number of research designs aiming at a rather limited number of creativity-related topics. Grounded in our analysis, we discuss the prospects of creativity research in the IS discipline and provide a future research agenda. In doing so, we propose three main research themes that can meaningfully contribute to our discipline

Zur Mechanik vibrationsgetriebener Roboter für terrestrische und aquatische Lokomotion

This thesis discusses the mechanics of mobile robots for terrestrial and aquatic locomotion. Vibration-driven locomotion systems are characterised by an internal periodic excitation, which is transformed to a directed motion due to asymmetric properties of the system. To perform a two-dimensional and controllable locomotion, mechanical properties of robots are investigated dependent on the frequency of the internal excitation. The mechanical description of the robots is done using analytical and numerical methods and supported by experimental studies. The applicability of the results in mobile robots is proved by prototypes.On the basis of mechanical fundamentals, terrestrial and aquatic locomotion principles are discussed and classified. Actuators are reviewed. The purpose is to evaluate the performance as vibration sources for terrestrial and aquatic systems. Piezoelectric bending elements are particular suitable for it. An extensive overview on the state of the art shows the great potential of vibration-driven locomotion systems for miniaturised applications in technics.Systems with bristles can perform unidirectional terrestrial locomotion. Different working principles of bristles are studied based on a rigid body model and experimental investigations. A prototype for the locomotion in tubes is presented. To perform a controllable two-dimensional locomotion with only one actuator, it is needed to overcome the limits of rigid body systems. The applied approach uses the frequency-dependent vibration behaviour of elastic systems, like beams and plates. Models of continuum mechanics and finite element methods are used and supported by experiments. Based on the investigations, a programmable and remote controlled prototype is developed. The locomotion of it can be controlled on different surfaces by a change of the excitation frequency. The velocity of the prototype is up to 100 mm/s and it can support five times its own weight.Concluding, an innovative prototype with a single piezoelectric actuator for a controllable locomotion on flat ground and floating in fluids is developed. The terrestrial and aquatic locomotion behaviour of the robot is investigated. The carrying capacity of it is calculated using a hydrostatic model.Die Mechanik von mobilen Robotern für terrestrische und aquatische Lokomotion ist der Gegenstand der Arbeit. In den untersuchten Systemen wird die periodische Erregung eines inneren Antriebs durch nicht symmetrische Systemeigenschaften in eine gerichtete Fortbewegung gewandelt. Durch die Nutzung des frequenzabhängigen Schwingungsverhaltens von elastischen Systemen, wie Balken oder Platten, werden Systeme realisiert, die durch nur einen Antrieb eine steuerbare zweidimensionale Lokomotion auf festem Untergrund und an der Oberfläche von Flüssigkeiten durchführen können. Der Schwerpunkt der Arbeit liegt auf der mathematisch-mechanischen Beschreibung der Roboter mittels analytischer und numerischer Methoden sowie ihrer experimentellen Untersuchung. Prototypen mobiler Roboter dienen dem funktionellen Nachweis.Auch im Buchhandel erhältlich: Zur Mechanik vibrationsgetriebener Roboter für terrestrische und aquatische Lokomotion / Felix Becker Ilmenau : Univ.-Verl. Ilmenau, 2015. - XIX, 149 S. ISBN 978-3-86360-124-9 URN urn:nbn:de:gbv:ilm1-2015000338 Preis (Druckausgabe): 21,30