A Smart Pixel Camera for future Cherenkov Telescopes

The Smart Pixel Camera is a new camera for imaging atmospheric Cherenkov telescopes, suited for a next generation of large multi-telescope ground based gamma-ray observatories. The design of the camera foresees all electronics needed to process the images to be located inside the camera body at the focal plane. The camera has a modular design and is scalable in the number of pixels. The camera electronics provides the performance needed for the next generation instruments, like short signal integration time, topological trigger and short trigger gate, and at the same time the design is optimized to minimize the cost per channel. In addition new features are implemented, like the measurement of the arrival time of light pulses in the pixels on the few hundred psec timescale. The buffered readout system of the camera allows to take images at sustained rates of O(10 kHz) with a dead-time of only about 0.8 % per kHz.Comment: 8 pages, 5 figures; to appear in the proceedings of "Towards a Network of Atmospheric Cherenkov Detectors VII", 2005, Palaiseau, Franc

Testing Drives Learning?

Der Autor setzt sich mit den Effekten des Testens für das Lernen auseinander. Er gibt einen Überblick über Befunde zur Verbesserung von Lernen durch Testen. Es werden Wirkungen von Vergleichstests, von Teaching-to-the-Test und formativen Tests beschrieben. Dabei wird unter anderem konstatiert, dass Teaching-to-the-Test nur dann ein Problem ist, wenn die Tests schlecht sind. (DIPF/Orig.

How to facilitate critical action learning

Critical Action Learning (CAL) is a well-established approach to action learning. However, it has not necessarily been clear to action learning practitioners what makes CAL ‘critical’ and what are the implications in practice. In CAL, the facilitator has a key role in helping the set to engage with underlying emotions and power relations that are inevitably embedded in learning sets, and that both promote and prevent learning. The paper explains the main ideas of critical action learning, why facilitation is important, and how to facilitate CAL. Examples are provided from the authors’ practice and eight key components are presented as a guide to facilitating CAL. The aim of the paper is to improve the action learning community’s knowledge of how to facilitate critical action learning and when it is appropriate to utilize this approach.</p

Learning through play – pedagogy and learning outcomes in early childhood mathematics

Whilst research underlines the importance of early mathematics in kindergarten, practitioners need effective and innovative approaches to pedagogy. Currently, very different approaches are deployed from an instructional, educator-led approach based on training programmes to a play-based approach. This intervention study examines the effects on the mathematical competency of these two pedagogies. Thirty-five kindergarten educators and 324 six-year-old children were randomly assigned to either a training programme, a play-based approach with card and board games or to the control group. Educators’ views on the interventions were gathered in semi-structured interviews. The results indicate higher learning gains overall for the play-based approach. Differentiated effects were found as tendencies: children with low competencies tend to gain more from training programmes compared to no intervention; children with high competencies gain more from the play-based approach than the training. Educators evaluated the play-based intervention with card and board games as better suited to children’s diverse needs

Caesium and strontium accumulation in shoots of Arabidopsis thaliana: genetic and physiological aspects

Due to the physico-chemical similarities of caesium (Cs+) to potassium (K+) on the one hand and strontium (Sr2+) to calcium (Ca2+) on the other hand, both elements can easily be taken up by plants and thus enter the food chain. This could be detrimental when radionuclides such as 137Cs and 90Sr are involved. In this study, both genetic and physiological aspects of Cs+ and Sr2+ accumulation in Arabidopsis thaliana were investigated using 86 Arabidopsis accessions and a segregating F2 population of the low Cs+ accumulating Sq-1 (Ascot, UK) crossed with the high uptaking Sorbo (Khurmatov, Tajikistan). Hydroponically grown plants were exposed to subtoxic levels of Cs+ and Sr2+ using radioactive isotopes as tracers. In the natural accessions shoot concentration of Cs+ as well as Sr2+ varied about 2-fold, whereas its heritability ranged for both ions between 0.60 and 0.73. Shoot accumulation of Cs+ and Sr2+ could be compromised by increasing concentrations of their essential analogues K+ and Ca2+, respectively, causing a reduction of up to 80%. In the case of the segregating F2/F3 population Sq-1×Sorbo, this study identified several QTL for the trait Cs+ and Sr2+ accumulation, with main QTL on chromosomes 1 and 5. According to the correlation and discrimination surveys combined with QTL-analysis Cs+ and Sr2+ uptake seemed to be mediated mostly via non-selective cation channels. A polymorphism, affecting amino acids close to the K+-pore of one candidate, CYCLIC-NUCLEOTIDE-GATED CHANNEL 1 (CNGC1), was identified in Sorbo and associated with high Cs+ concentrating accessions

Kindergarten teachers’ beliefs concerning early mathematics education: Comparing Switzerland, Germany and Austria

Die Kontextbedingungen vorschulischer Bildung in der Schweiz, in Deutschland und in Österreich unterscheiden sich in verschiedenen Aspekten. Im Beitrag wird über eine Untersuchung berichtet, die vor diesem Hintergrund der Frage nachgeht, welche Gemeinsamkeiten und Unterschiede in den Überzeugungen zur mathematischen Frühförderung pädagogische Fachkräfte aus den drei genannten Ländern zeigen. Während im Bereich der Überzeugungen zum Fach «Mathematik» und zum Lehren und Lernen von Mathematik nur wenige Unterschiede festgestellt werden konnten, zeigen sich in Überzeugungen, die sich konkreter auf die Gestaltung mathematischer Förderung im Kindergarten beziehen, deutliche Unterschiede: Schweizer Kindergartenlehrpersonen zeigen eine «intentionalere» Haltung gegenüber mathematischer Förderung im Kindergarten als ihre Kolleginnen und Kollegen aus Deutschland und Österreich. Die Ergebnisse werden in Bezug auf kulturelle Prägungen durch länder- und stufenübergreifende Bildungskonzepte und Bildungsvorstellungen und insbesondere vor dem Hintergrund der in der Schweiz vollzogenen Integration der vorschulischen Bildung in das Regelschulsystem diskutiert. (DIPF/Orig.)The structural context of early childhood education differs in Switzerland, Germany, and Austria in several aspects. This article reports findings from a research project that examines the differences and similarities between educators’ beliefs concerning early mathematics education in the German-speaking parts of the three countries. The results indicate that there are only few differences in the beliefs concerning mathematics as a subject and teaching and learning of mathematics in general. However, significant differences were found in relation to beliefs concerning specific teaching and learning approaches to fostering mathematical skills in kindergarten: Swiss kindergarten teachers express a more intentional stance on mathematics education in kindergarten than German and Austrian kindergarten educators. These results are discussed in terms of cultural influences on the understanding of education across countries and levels of education. The integration of kindergarten as a compulsory part of the Swiss education system is discussed as a crucial aspect for interpreting the differences between the three countries

Successful remission of extensive liver metastases in a breast cancer patient with acute liver failure using a combined chemotherapy regimen with mitomycin, folinate, and 5-fluorouracil (Mi/Fo/FU)

Liver failure due to disseminated hepatic secondaries represents a therapeutic dilemma in patients with metastatic breast cancer (MBC). Reduced liver function and non-assessable toxicity are limiting factors in the selection of chemotherapeutic agents. Currently, there is no standard treatment after failure of anthracycline-and taxane-based first-line therapies, although there is a variety of well evaluated drugs such as capecitabine

Interactive Visual Analysis of Heterogeneous Cohort Study Data

Cohort studies in medicine are conducted to enable the study of medical hypotheses in large samples. Often, a large amount of heterogeneous data is acquired from many subjects. The analysis is usually hypothesis-driven, i.e., a specific subset of such data is studied to confirm or reject specific hypotheses. In this paper, we demonstrate how we enable the interactive visual exploration and analysis of such data, helping with the generation of new hypotheses and contributing to the process of validating them. We propose a data-cube based model which handles partially overlapping data subsets during the interactive visualization. This model enables seamless integration of the heterogeneous data, as well as linking spatial and non-spatial views on these data. We implemented this model in an application prototype, and used it to analyze data acquired in the context of a cohort study on cognitive aging. We present case-study analyses of selected aspects of brain connectivity by using the prototype implementation of the presented model, to demonstrate its potential and flexibility