Exposing the seventeenth-century optical camera obscura

Did Vermeer van Delft create some of his paintings by means of a camera obscura? This still undecided question has stirred up heated debates. For some, the mere idea is an inexcusable insult on a great artist. All this heat has drawn attention away from a rich seam of questioning: what was the seventeenth-century camera obscura really like? And did it shape the ways in which Vermeer's contemporaries viewed, imagined, understood and, for that matter, rendered the visual world?     

Studying enzymatic bioreactions in a millisecond microfluidic flow mixer

In this study, the pre-steady state development of enzymatic bioreactions using a microfluidic mixer is presented. To follow such reactions fast mixing of reagents (enzyme and substrate) is crucial. By using a highly efficient passive micromixer based on multilaminar flow, mixing times in the low millisecond range are reached. Four lamination layers in a shallow channel reduce the diffusion lengths to a few micrometers only, enabling very fast mixing. This was proven by confocal fluorescence measurements in the channel’s cross sectional area. Adjusting the overall flow rate in the 200 μm wide and 900 μm long mixing and observation channel makes it possible to investigate enzyme reactions over several seconds. Further, the device enables changing the enzyme/substrate ratio from 1:1 up to 3:1, while still providing high mixing efficiency, as shown for the enzymatic hydrolysis using β-galactosidase. This way, the early kinetics of the enzyme reaction at multiple enzyme/substrate concentrations can be collected in a very short time (minutes). The fast and easy handling of the mixing device makes it a very powerful and convenient instrument for millisecond temporal analysis of bioreactions.     

The relation between self-regulation and the embedding of support in learning environments

The current study investigates whether embedding support may provide a solution to sub optimal use of support and whether this is related to learners’ self-regulation skills and goal orientation. Sixty students were divided in a condition where support was embedded and a condition where support was non-embedded. Results reveal that the embedded group used more and spent more time on the use of support. Quality of use differed for one support device only, with quality being higher in the non-embedded group. An interaction with self-regulation was found. High self-regulators use the support devices less optimal when support is embedded. No conclusions could be drawn with respect to goal orientation. Quality of usage and proportional time spent on support influenced learning outcomes.     

Didaktische Entwicklungsforschung als Transferförderung

“Transfer” from research into practical applications is mostly seen as an autonomous domain between research and practice. For educational research, the author develops a conception in which transfer is a part of research, especially of applied educational research with a focus on teaching activities and teaching-learning materials. The criticism of traditional teaching research is examined and a research and development approach to didactics is proposed as a chance to combine theory and practice. The article comprises considerations on the scientific nature of research and development in didactics borrowing concepts from Bunge and Stokes and R & D in the economic sciences. The last section shows two research examples and closes with considerations for process and product evaluation in didactic research and development.     

The relative contributions of vocabulary,decoding, and phonemic awareness to word reading in English versus German

Beginning readers in shallow orthographies acquire word reading skills more quickly than in deep orthographies like English. In addition to extending this evidence base by comparing reading acquisition in English with the more transparent German, we conducted a longitudinal study and investigated whether different early reading skills made different contributions to word reading as a function of orthography. Children (n = 133) were recruited from the first year of primary school in New Zealand (age 5;8) and Germany (age 7;2) and from kindergartens in Germany (age 5;0) to provide both age- and schooling-matched samples. Parallel measures of phonemic awareness, vocabulary, decoding skill, and word reading (accuracy) were administered at two time points, 1 year apart. An advantage for orthography and school attendance existed for reading development. Vocabulary made a greater contribution to word reading in English than in German as did decoding skill. Findings underscore the relative importance of vocabulary and decoding skills for early reading in English.     

Fragile knowledge and conflicting evidence: what effects do contiguity and personal characteristics of museum visitors have on their processing depth?

Until recently, museums mainly communicated well-established knowledge. Current science, however, is characterized by a rapid knowledge increase, so that we often have to deal with fragile and inconsistent knowledge. In order to develop exhibitions that encourage visitors to process information in a differentiated way, museums need to know how visitors deal with conflicting information. Furthermore, museum professionals need information on personal and situational factors that may promote the processing of such information. We tested whether conflict processing is influenced by personal characteristics such as situational interest, epistemological beliefs, tolerance of ambiguity, and self-efficacy on the one hand and by situational conditions such as the spatial arrangement of information on the other hand. In two science museums and one museum of cultural history, text pairs were displayed that described a topic from conflicting perspectives. The spatial distance between the two texts was manipulated. Semi-structured interviews and questionnaires captured the personal characteristics of 323 visitors and the way they dealt with conflicting information. The results showed that a majority of the visitors perceived a conflict, and a large proportion was willing to process the information at a deeper level. Sophisticated epistemological beliefs, a high tolerance of ambiguity, and high self-efficacy were found to promote situational interest in conflicting information. High situational interest, in turn, promoted a tendency to process deeply. Placing text pairs in close proximity had a positive effect on the processing depth in science museums but not in the museum of cultural history. A possible explanation lies in the higher density of additional and potentially interfering information in the science museums compared to the museum of cultural history.     

Using query logs of USPTO patent examiners for automatic query expansion in patent searching

In the patent domain significant efforts are invested to assist researchers in formulating better queries, preferably via automated query expansion. Currently, automatic query expansion in patent search is mostly limited to computing co-occurring terms for the searchable features of the invention. Additional query terms are extracted automatically from patent documents based on entropy measures. Learning synonyms in the patent domain for automatic query expansion has been a difficult task. No dedicated sources providing synonyms for the patent domain, such as patent domain specific lexica or thesauri, are available. In this paper we focus on the highly professional search setting of patent examiners. In particular, we use query logs to learn synonyms for the patent domain. For automatic query expansion, we create term networks based on the query logs specifically for several USPTO patent classes. Experiments show good performance in automatic query expansion using these automatically generated term networks. Specifically, with a larger number of query logs for a specific patent US class available the performance of the learned term networks increases.