The Use of Additional Information in Problem-Oriented Learning Environments

Self-directed learning with authentic and complex problems (problem-oriented learning) requires that learners observe their own learning and use additional information when it is appropriate (e.g. hypertextual information in computer-supported learning environments). Research results indicate that learners in problem-oriented learning environments often have difficulties using additional information adequately, and that they should be supported. Two studies with a computer-supported problem-oriented learning environment in the domain of medicine analysed the effects of strategy instruction on the use of additional information and the quality of the problem representation. In Study 1, an expert model was used for strategy instruction. Two groups were compared: one group with strategy modelling and one group without. Strategy modelling influenced the frequency of looked-up hypertextual information, but did not influence the quality of learners' problem representations. This could be explained by difficulties in applying the general hypertext information to the problem. In Study 2, the additional information was presented in a more contextualised way as graphical representation of the case and its relevant concepts. Again, two groups were compared: one with a strategy instruction text and one without. Strategy instruction texts supported an adequate use of this graphical information by learners and had an effect on the quality of their problem representations. These findings are discussed with respect to the design of additional help systems in problem-oriented learning environments. This revised version was published online in July 2006 with corrections to the Cover Date.     

Microfluidic concentration of bacteria by on-chip electrophoresis

In this contribution, we present a system for efficient preconcentration of pathogens without affecting their viability. Development of miniaturized molecular diagnostic kits requires concentration of the sample, molecule extraction, amplification, and detection. In consequence of low analyte concentrations in real-world samples, preconcentration is a critical step within this workflow. Bacteria and viruses exhibit a negative surface charge and thus can be electrophoretically captured from a continuous flow. The concept of phaseguides was applied to define gel membranes, which enable effective and reversible collection of the target species. E. coli of the strains XL1-blue and K12 were used to evaluate the performance of the device. By suppression of the electroosmotic flow both strains were captured with efficiencies of up to 99%. At a continuous flow of 15 μl/min concentration factors of 50.17 ± 2.23 and 47.36 ± 1.72 were achieved in less than 27 min for XL1-blue and K12, respectively. These results indicate that free flow electrophoresis enables efficient concentration of bacteria and the presented device can contribute to rapid analyses of swab-derived samples.     

The English language in scientific publishing

Adapting to market changes after World War II, the German scientific publishing house Springer-Verlag decided to publish in the English language long before setting up offices in the United States. This material was adapted from Springer-Verlag: History of a Scientific Publishing House, Volume 2, 1945–1992, and appears with the permission of the publishers.     

The Technical University of Budapest/ University of Karlsruhe exchange programme

“The Technical University of Budapest and the University of Karlsruhe, guided by a common desire to promote mutual academic and cultural relations and convinced that cooperation in teaching and research will be mutually beneficial, have agreed to the following:

that both universities declare their desire to institute and promote academic and cultural cooperation; that the areas and structure and the means for cooperation shall be decided by mutual consent.”     

Cooperative Learning with Gifted and High-achieving Students: A review and meta-analyses of 12 studies

Should gifted and high-achieving students cooperate in homogeneous groups or do they learn better individually? Or should they learn together with less gifted peers in heterogeneous groups? Current empirical research is reviewed in this article and meta-analyses of available results in 12 published studies are performed. Results show that few methodologically sound studies can be found at present. In addition, researchers only considered a restricted spectrum of participants, focused on learning of relatively simple materials, measured only a restricted range of possible outcomes, and neglected processes and activities of the learners, which might determine outcomes of cooperative learning. Results therefore remain controversial even for fundamental issues like learning in homogeneous versus heterogeneous, mixed-ability groups. In spite of these limitations, analyses nevertheless show that cooperative learning offers strong potentials for further improving the quality of instruction with gifted and high-achieving students. Further empirical research is required to obtain more differentiated information on the various aspects of cooperative learning.