Viatge al Marroc de la Secció de Geografia de la Universitat de Girona, 24-30 d'abril de 2000

A group of teachers and students of the Geography Unit of the University of Girona conducted a field trip in a part of Northern Morocco, which once belonged to the Spanish Protectorate. The visit took place between 24th and 30th April 2000. Some teachers of the University of Tetouan accompanied the group and offered comprehensive geographical explanations of the area, including physical, social and economic aspects

Catalase in fluvial biofilms: a comparison between different extraction methods and example of application in a metal-polluted river

Antioxidant enzymes are involved in important processes of cell detoxification during oxidative stress and have, therefore, been used as biomarkers in algae. Nevertheless, their limited use in fluvial biofilms may be due to the complexity of such communities. Here, a comparison between different extraction methods was performed to obtain a reliable method for catalase extraction from fluvial biofilms. Homogenization followed by glass bead disruption appeared to be the best compromise for catalase extraction. This method was then applied to a field study in a metal-polluted stream (Riou Mort, France). The most polluted sites were characterized by a catalase activity 4–6 times lower than in the low-polluted site. Results of the comparison process and its application are promising for the use of catalase activity as an early warning biomarker of toxicity using biofilms in the laboratory and in the field