RESUMEN
Variation in esterase expression (EST) has been investigated in 360 specimens of the periwinkle Littorina littorea collected at nine sites along the polluted western Scheldt and the relatively clean eastern Scheldt estuary. Mean number of EST bands differed among the sites, while a Dice similarity based multi-dimensional scaling along with a minimum spanning tree procedure, revealed an estuary based structuring, clustering the most polluted and least saline like sites together. The underlying factors and mechanisms (i.e. selection, regulation) which are responsible for this structuring remain to be determined.
Asunto(s)
Esterasas/metabolismo , Caracoles/enzimología , Contaminantes del Agua/efectos adversos , Animales , Exposición a Riesgos Ambientales , Regulación de la Expresión GénicaRESUMEN
This paper gives an overview of a number of advanced techniques for image compression, which are under investigation in the Signal Processing Laboratory at the Swiss Federal Institute of Technology of Lausanne. Various applications ranging from High definition television (HDTV) to multimedia will be discussed. In particular, systems based on subband decomposition, edge based representation, as well as symmetries will be presented.