Browsing by Author "Elsner, Norbert"

To understand the functioning of brains we must bridge many levels of analysis from molecules, cells and synapses to perception and behavior. Although experimental analysis is a precondition for understanding information processing by nervous systems, it is in no way sufficient. Rather, computer simulations help to tackle problems resulting from dynamics and complexity of nervous systems. It has become common scientific practice in the neural and cognitive sciences to investigate brain function by both experiments as well as model simulations. In the higher education of the neural and cognitive sciences, however, simulations are still only applied sporadically – even though educational materials (e.g. internet applets for well-known models such as Hodgkin-Huxley, Reichardt-detector, LTP etc.) and simulation tools (e.g. MatLabTM) are readily available. Application suffers from various uncertainties of how to use simulations in higher education: Do simulations effectively complement the well established methods of "chalk and talk", laboratory practicals or paper discussions? How long will it take to prepare application? Exactly which cases have a reasonable cost-gain ratio? Should I make demonstrations or let the students make it by their own in a practical course? How can I assess success or failure of use... In sum, 'recipes' for applying simulations in education are widely missing. The monist-project has committed itself to the task of developing such recipes for simulations in higher education. The basis of the monist-project is a software package (monist-console) designed for providing compact, ready to use educational simulations. Simulations become educational as they are complemented by topical texts, instructional design, concrete tasks and an editor for individual notes and solutions. Thus, the monist-console supports self-learning but particularly aids tutors to integrate simulations in their courses. Online file-management and communication tools (via monist-server) help to organize personalized courses. The authoring mode provides means for designing or modifying educational material. Existing simulations (applets, programs etc.) can be embedded. An integrated simulation construction kit is under development. Authored educational simulations can be submitted to a central server for publication. An update routine can offer newly published simulations on the server for download to the local monist-console. Beyond software and content development, the monist-project works on several practical fields for fostering the concrete application of simulations in higher education, e.g. evaluation for best practice scenarios, studies on learning and memory and organizational networking. The demonstration of the monist-project offers applicable tools and content (work in progress). It aims at teachers wishing to apply and evaluate the monist-console, authors seeking to contribute concepts or integrate their existing simulations and developers ready to participate. The monist-project is funded in nine groups at six universities from 2001-2003 by the German Federal Ministry of Education and Research BMB+F. One group carries out evaluation (Seel, Freiburg), the others correspond to topics, as follows (alphabetically, contributing groups in brackets): Biophysics (Aertsen, Freiburg) Cognitive Neuroscience (Mallot, Tübingen) Learning and Behavior (Menzel, Berlin) Motor Systems (Cruse, Bielefeld) Neural Networks, Applied (Gross, Ilmenau) Neural Networks, Theory (Ritter, Bielefeld) Psychology (Dörner, Bamberg) Sensory Systems (Egelhaaf, Bielefeld) Further information: http://www.monist.de

Two grasshopper species Stenobothrus rubicundus and S. clavatus were previously shown to meet in a narrow hybrid zone on Mount Tomaros in northern Greece. The species are remarkable for their complex courtship songs accompanied by conspicuous movements of antennae and wings. We analyzed variations in forewing morphology, antenna shape, and courtship song across the hybrid zone using a geographic information system, and we documented three contact zones on Mount Tomaros. All male traits and female wings show abrupt transitions across the contact zones, suggesting that these traits are driven by selection rather than by drift. Male clines in antennae are displaced toward S. clavatus, whereas all clines in wings are displaced toward S. rubicundus. We explain cline discordance as depending on sexual selection via female choice. The high covariance between wings and antennae found in the centers of all contact zones results from high levels of linkage disequilibria among the underlying loci, which in turn more likely results from assortative mating than from selection against hybrids. The covariance is found to be higher in clavatus-like than rubicundus-like populations, which implies asymmetric assortative mating in parental-like sites of the hybrid zone and a movement of the hybrid zone in favor of S. clavatus.