Neue Wege in die Ökotoxikologie: Quantitative Verhaltensmessungen an Fischen als Toxizitätsendpunkt

New Ways to Ecotoxicology: Quantitative Recording of Behaviour of Fish as Toxicity Endpoint The BehavioQuant system will be introduced which uses the integrative whole-organism response by automatized recording and quantifying the spontaneous behaviour of fish and other test organisms. While moving unrestricted within the test chamber, the movements of each single fish are recorded by video imaging, and their traces are digitized numerically by x-/y-coordinates. From the object traces several test parameters are calculated which give information about behavioural changes of the observed fishes. These various parameters are: the average swimming velocity (motility), the average swimming depth below surface, the inconstancy of motility, the frequency of turns, the standard frequency distributions of vertical and horizontal positions (can be used for quantification of a preference for dark or light habitats), and the distance behaviour. A continuously monitoring of up to 16 aquaria is possible. The statistic comparison between treated groups and control groups is done for each test parameter separately. The automatical evaluation of the continuous observation of surface waters results from a comparison of the actual behaviour data to the data of a reference period. Some examples for the applications of the BehavioQuant system will be demonstrated (effects of atrazine), and their results will be discussed. Behavioural changes of a single species can finally cause changes in biocenotic structures and functions. Therefore, it is necessary to include the results of quantitative behaviour measurements in ecotoxicological hazard assessment.     

Étude géochronologique du gisement polymétallique de Kowary (Pologne)

Résumé Le gisement polymétallique de Kowary (Pologne) est formé de deux types de minéralisations: 1. des lentilles de magnétites formées pendant l'orogenèse calédonienne, 2. des minéralisations polymétalliques plus jeunes avec uranium. L'étude géochronologique des pechblendes par la méthode Uranium — Plomb montre que le gisement uranifère a été formé à l'époque permienne de l'orogenèse hercynienne, il y a environ 265 M. A., qu'il a été remanié au cours de l'époque laramienne, il y a 70 M. A. L'âge de formation du gisement de Kowary correspond très exactement à l'âge des gisements français (Limousin et Vendée).

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The poly-metallic deposit of Kowary (Poland) is formed by two types of mineralizations: 1. lenses of magnetite formed during the Caledonian orogeny, 2. more recent polymetallic mineralizations with Uranium. The geochronological study of the pitchblende by Uranium — Lead method shows that the Uranium deposit was formed at the Permian epoch of the Hercynian orogeny about 265 M. Y. ago and it has been modified during the Laramide epoch, about 70 M. Y. ago. The formation age of the Kowary deposits corresponds exactly to that of the French deposits (Limousin and Vendée).

     

Non-linear optimization for seismic traveltime tomography

This paper presents a non-linear algorithmic approach for seismic traveltime. It is based on large-scale optimization using non-linear least-squares and trust-region methods. These methods provide a natural way to stabilize algorithms based on Newton's iteration for non-linear minimization. They also correspond to an alternative (and often more efficient) view of the Levenberg-Marquardt method. Numerical experience on synthetic data and on real borehole-to-borehole problems are presented. In particular, results produced by the new algorithm are compared with those of Ivansson (1985) for the Kråkemåla experiment.     

Enhancement techniques for landuse analysis

In image interpretation, to make maximum use of the available information, some sort of enhancement is usually needed. In image enhancement, the aim is to manipulate the image to improve its quality. Image enhancement techniques emphasize upon the viewing of the image for extraction of information that may not have been so readily apparent in the original. Hera the software package for various enhancement techniques that has been developed at National bemote Sensing Agency (NRSA) is described. In order to illustrate the utility of the techniques, the enhanced imagery have been analysed for land use categories and linear features, and the corresponding thematic maps have also been shown in the results.     

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