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Swimming tracks



Dr. Richard Bräucker

Scientific activities

Please note: you will find more informations about the items marked green in the glossar.

I have studied Biology, Chemistry and Educational Sciences at the universities of Regensburg and Bochum. In my master thesis and my doctoral thesis I was engaged in hearing physiology of birds (Pigeons, Starlings and Quails) using a modified form of heart rate conditioning.

From 1988 to 1999 I have been a member of the Study Group Physiology of Excitable Cells. Among others this group is investigating gravitaxis and gravikinesis of ciliates. (More about ciliates) More about our hypothesis of gravikinesis in ciliates.

During the last years, ciliates have been used as model system to investigate the perception of the gravity stimulus on cellular level. The capability of orientation in their environment means a considerable benefit in evolution: Active approach to food resources and, as well, avoidance of bad areas becomes possible. Thus, even on the level of unicellular organisms, reactions to diverse physical and chemical stimuli can be found.

The gravity vector is the most reliable among these parameters, because it is virtually invariant regarding its value and direction.

The swimming behaviour of the experimental cells has been examined under normal and increased gravity and also under weightlessness (refer also, list of publications or Forschungsbericht der Universität Bochum)

The swimming behaviour of 50 to 200 cells are video-recorded simultaneously. After the experiment a sequence of video frames are superimposed creating swimming tracks .by means of a computer programme. Orientation and swimming rate of every single cell are measured using computer-aided image analysis. Finally the data are analysed statistically.

Software for digitizing, image analysis and evaluation using non parametric statistics was developed by myself.

Since 1999 I am engaged in the research project "Gravitationsbiologische Untersuchungen an Ciliaten" together with my colleagues Ruth Hemmersbach and Martin Krause at the University of Bonn and the German Aerospace Centre at Cologne.

To study the effects of long term weightlessness on ciliates e.g. in a space station it is necessary to automate the maintenance of the specimen. Development of such a computer operated culturing system (MICROPOND) is part of our research project. The system is aimed at keep a miniaturized ecosystem (ciliates and flagellates) in equilibrium for about three months.

Especially for then use in student´s courses I have done some experiments in phototaxis in ciliates. (see publications for details).

Besides implementation and evaluation of behavioural experiments I am involved in development of hard and software for specialized experimental equipment and in external scientific campaigns: examples of apparatus and some results of research under microgravity conditions.

In summer 2002 I got an employment at the German Aerospace Centre (DLR) and am now head of the DLR_School_Lab Cologne. We invite middle-class and grammar school students to visit our lab, which is located in the human centrifuge hall of the DLR institute of Aerospace Medicine. In the authentic environment we offer "hands on" experiments which are close to the current research of the DLR institutes. Our aim is to promote the interest in natural and engineering sciences and thus to encourage young people to study sciences. More on the DLR_School_Lab homepage.



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Last update: 28.12.2003