September 2000, Amsterdam - Projects - Czech Republic

Jiri Hotový (19)
School: Grammar School
Hobbies: biology, reading books, sport
Career intention: Biologist

Jana Kholov (18)
School: grammar School
Hobbies: biology, reading books, gardening
Career intention: biologist

Saprobic pollution and the benthic fauna of brooks
In the period 1997-1998, the impact of saprobic pollution on the benthic fauna of brooks was investigated. Many interesting data concerning the impact of water pollution on the fauna of brooks were obtained from these investigations and we decided to summarise and evaluate these and to find out what could be done to decrease the pollution. We started with listing all deleted macro-organisms (>0,5mm), their relative abundance and saprobic value indexes due to water pollution. After this we put a sewage disposal plant into operation, in order to revitalise the benthal communities, which it did rapidly! The abundance, diversity and equitability have increased since then. The bottom silted with mud remains inhospitable, however, and the disturbance of the benthic community in such sites remains in spite of a good and effective functioning of the sewage disposal plant .

Vaclav Rehak (19)
School: Czech Technical University
Hobbies: outdoor activities (hiking, canoeing, biking), music listening, computers, linux
Career intention: computerengineer, systemadministrator

Prisoners' dilemma (Modelling of social phenomena using cellular automata)
This project deals with prisoners' dilemma (PD) as a metaphor for problems of evolution of co-operative behaviour among interacting individuals. A part of my work, describing a number of methods of modern nonequilibrium statistic physics, particularly cellular automata, has been derived from the work of M.A. Nowak and R. M. May who placed PD on a square lattice. By doing this project I was able to contribute a new feature to the model, i.e. diffusion. In the diffused situation, the lattice is not entirely filled up with players and these players are able to move. The main characteristics of this model are the dependence of concentration of co-operators on lattice occupancy and the dependance on the mobility of players. If the mobility is increased over a critical value, the frequency drops to zero. I was able to describe this behaviour with a second type phase transition, which I consider to be the most important result of this model. It can be applied in sociology for explaining high crime rates in big cities. .