Can diagnostic problem-solving competences of car mechatronics be validly assessed using a paper-pencil test?

In this study, an authentic paper-based key-feature test for electrotechnical diagnostic problem-solving competence was developed, administered to car mechatronic apprentices (N = 206) and validated using diagnostic problem-solving scores. It was hypothesized that the paper-based test scores represent the same construct as the problem-solving scores. The written test turned out to have a relatively high reliability (EAP/PV = .75). Additionally, it was found that the paper-based scores and problem-solving scores were highly correlated (r = .76) but represented empirically distinct dimensions. Presumably, the written test especially covered diagnostic knowledge and failed to cover other relevant subcomponents of diagnostic problem-solving competence. It is argued that this unexpected finding might be caused by construct underrepresentation and construct-irrelevant variance of the paper-based key-feature test.Keywords: Professional competence, domain-specific problem-solving, key-feature items, construct representation, construct-irrelevant varianc

Das neue Reservierungssystem WLB-Riserva

Alle öffentlichen Einrichtungen leisten ihren Beitrag zur Eindämmung der Corona-Pandemie. Auch die Württembergische Landesbibliothek stand 2020 vor der Herausforderung, ein Konzept für die Abstandsregelungen, Besucherzahlbeschränkungen und Kontaktpersonennachverfolgung in kürzester Zeit zu entwickeln und umzusetzen. So wurde in der WLB innerhalb weniger Wochen das Online-Reservierungssystem WLB-Riserva entwickelt

Struktur und Niveaus des Fachwissens von Kfz-Mechatronikern gegen Ende der formalen Ausbildung

ZusammenfassungIn diesem Beitrag stellen wir Ergebnisse zum Fachwissen von Kfz-Mechatronikern vor, das sich als in hohem Grade prädiktiv für berufsfachliche Leistungen in den zentralen Handlungsfeldern von Kfz-Mechatronikern erweist. Die Analysen gründen auf einer Stichprobe von rund 1000 Auszubildenden. Die in früheren Modellierungen dokumentierten Strukturen des Fachwissens können weitgehend repliziert werden, die in früheren Modellierungen beobachtbaren Inkonsistenzen zur Ausdifferenzierung des Fachwissens an fachsystematischen Inhaltsbereichen einerseits und tätigkeitsbezogenem Wissen andererseits können aufgelöst werden. Die in anderen Untersuchungen identifizierten Schwierigkeits-merkmale der berufsfachlichen Aufgaben können partiell repliziert werden, einen besonders hohen Erklärungsanteil erbringen Merkmale des Aufgabenformats. Als schwierig erwies es sich, diese Aufgabenmerkmale für die Modellierung von Fachwissensniveaus zu nutzen, was abschließend eingehend diskutiert wird.Schlüsselwörter: Kfz-Mechatroniker, Fachwissen, Strukturmodellierung, schwierigkeits-bestimmende Aufgabenmerkmale, NiveaumodellierungStructure and Levels of Car Mechatronics Technicians’ Professional Knowledge towards the End of Vocational TrainingAbstractThis paper examines the results of modeling professional knowledge of car mechatronics technicians. Professional knowledge is highly predictive for explaining professional competences in key areas in the work of car mechatronics technicians. The analyses are based on a sample of 1000 trainees. The structure of the professional knowledge found in previous studies could largely be replicated. Hereby we were able to resolve the inconsistencies between content specific dimensions and activity specific dimensions that existed in previous models. The difficulty features of the profession specific tasks that were identified in previous studies could partially be replicated. Features of the item format predict the item difficulty particularly well. It turned out to be very difficult to take those features as a basis for proficiency scaling which we finally discuss in detail.Keywords: car mechatronics technicians, professional knowledge, knowledge structure, difficulty features of items, proficiency scalin

Test of Symmetries with Neutrons and Nuclei

Precision experiments at low energies probing weak interaction are a very promising and complementary tool for investigating the structure of the electro-weak sector of the standard model, and for searching for new phenomena revealing signs for an underlaying new symmetry. With the advent of new technologies in particle trapping and production of beams for exotic nuclei as well as ultracold neutrons, we expect one or two orders of magnitude gain in precision. This corresponds to the progress expected by new high luminosity B-factories or the LHC. Domains studied are $\beta$-decays where decay correlations, partial or total decay rates may reveal the nature of the left-right structure of the interaction and the investigation of discrete symmetries. Here the search for a finite electric dipole moment which, due to its CP-violating nature were sensational by itself, could shed light on the structure of the vacuum at very small distances. Last but not least ideas of a mirror world can be extended to the sector of baryons which can be studied with neutrons.Comment: 8 pages, 20 figures, PANIC 2008 conference proceedings (invited talk

The Puzzle of Neutron Lifetime

In this paper we review the role of the neutron lifetime and discuss the present status of measurements. In view of the large discrepancy observed by the two most precise individual measurements so far we describe the different techniques and point out principle strengths and weaknesses. In particular we discuss the estimation of systematic uncertainties and its correlation to the statistical ones. In order to solve the present puzzle, many new experiments are either ongoing or being proposed. An overview on their possible contribution to this field will be given.Comment: 10 pages, 19 figures, Proceedings of the International Workshop on Particle Physics with Slow Neutron

Comparative analysis of the lambda-interferons IL-28A and IL-29 regarding their transcriptome and their antiviral properties against hepatitis C virus.

Specific differences in signaling and antiviral properties between the different Lambda-interferons, a novel group of interferons composed of IL-28A, IL-28B and IL-29, are currently unknown. This is the first study comparatively investigating the transcriptome and the antiviral properties of the Lambda-interferons IL-28A and IL-29. Expression studies were performed by microarray analysis, quantitative PCR (qPCR), reporter gene assays and immunoluminometric assays. Signaling was analyzed by Western blot. HCV replication was measured in Huh-7 cells expressing subgenomic HCV replicon. All hepatic cell lines investigated as well as primary hepatocytes expressed both IFN-λ receptor subunits IL-10R2 and IFN-λR1. Both, IL-28A and IL-29 activated STAT1 signaling. As revealed by microarray analysis, similar genes were induced by both cytokines in Huh-7 cells (IL-28A: 117 genes; IL-29: 111 genes), many of them playing a role in antiviral immunity. However, only IL-28A was able to significantly down-regulate gene expression (n = 272 down-regulated genes). Both cytokines significantly decreased HCV replication in Huh-7 cells. In comparison to liver biopsies of patients with non-viral liver disease, liver biopsies of patients with HCV showed significantly increased mRNA expression of IL-28A and IL-29. Moreover, IL-28A serum protein levels were elevated in HCV patients. In a murine model of viral hepatitis, IL-28 expression was significantly increased. IL-28A and IL-29 are up-regulated in HCV patients and are similarly effective in inducing antiviral genes and inhibiting HCV replication. In contrast to IL-29, IL-28A is a potent gene repressor. Both IFN-λs may have therapeutic potential in the treatment of chronic HCV

The neutron and its role in cosmology and particle physics

Experiments with cold and ultracold neutrons have reached a level of precision such that problems far beyond the scale of the present Standard Model of particle physics become accessible to experimental investigation. Due to the close links between particle physics and cosmology, these studies also permit a deep look into the very first instances of our universe. First addressed in this article, both in theory and experiment, is the problem of baryogenesis ... The question how baryogenesis could have happened is open to experimental tests, and it turns out that this problem can be curbed by the very stringent limits on an electric dipole moment of the neutron, a quantity that also has deep implications for particle physics. Then we discuss the recent spectacular observation of neutron quantization in the earth's gravitational field and of resonance transitions between such gravitational energy states. These measurements, together with new evaluations of neutron scattering data, set new constraints on deviations from Newton's gravitational law at the picometer scale. Such deviations are predicted in modern theories with extra-dimensions that propose unification of the Planck scale with the scale of the Standard Model ... Another main topic is the weak-interaction parameters in various fields of physics and astrophysics that must all be derived from measured neutron decay data. Up to now, about 10 different neutron decay observables have been measured, much more than needed in the electroweak Standard Model. This allows various precise tests for new physics beyond the Standard Model, competing with or surpassing similar tests at high-energy. The review ends with a discussion of neutron and nuclear data required in the synthesis of the elements during the "first three minutes" and later on in stellar nucleosynthesis.Comment: 91 pages, 30 figures, accepted by Reviews of Modern Physic