Epilithic biomass in a large gravel-bed river (the Garonne, France): a manifestation of eutrophication?

In order to evaluate the impact of outputs of the city of Toulouse (740 000 inhabitants) on the epilithic communities colonizing pebble banks in the river Garonne, a large gravel-bed river (eighth order), dry mass (DM), ash-free dry mass (AFDM) and chlorophyll-a (chla) epilithic biomass per unit area were measured and autotrophic index (AI) (i.e. ratio AFDM/chla) was calculated at four stations. This river is morphologically characterized by a succession of pools and riffles and by highly fluctuating hydraulic conditions. At the four stations studied (223 km apart), the means of AFDM values varied between 17.1 and 31.1 g m−2 of colonized surface and the chla concentration varied between 112 and 254 mg m−2. However, there were no significant differences in AFDM per unit area between the parts of the river upstream and downstream of the Toulouse area (Mann–Whitney U-test statistic), nor between the four stations (Kruskal–Wallis test statistic), and the AI did not allow the description of changes in periphyton communities between sampling locations. This study showed that epilithic biomass should be considered as the typical microbial community of the river rather than as a manifestation of eutrophication

Molecular cytotaxonomy of primates by chromosomal in situ suppression hybridization

A new strategy for analyzing chromosomal evolution in primates is presented using chromosomal in situ suppression (CISS) hybridization. Biotin-labeled DNA libraries from flow-sorted human chromosomes are hybridized to chromosome preparations of catarrhines, platyrrhines, and prosimians. By this approach rearrangements of chromosomes that occurred during hominoid evolution are visualized directly at the level of DNA sequences, even in primate species with pronounced chromosomal shuffles

Endogenous and exogenous constraints in the population changes of wild boar (sus scrofa Linnaeus, 1758)

The population dynamics of wild boar (Sus scrofa) was studied in a time series over 26 years using data from the Regional Hunting Reserve of Somiedo (northern Spain). This population is controlled by a complex negative feedback system that acts with one (main) and two (secondary) years of delay (lags). The primary feedback might be explained by intraspecific competition for food resulting from fluctuations in mast production (acorns and beech), and the secondary feedback might be explained by the influence of weather conditions or the delay of a cohort to reach reproductive status. We used a stochastic model that takes environmental variability into consideration when testing the demographical analysis that’s obtains simulations from real data

CURRENT SITUATION OF FOOD SECURITY IN THE D.R. CONGO: DIAGNOSTIC AND PERSPECTIVES

Food Consumption/Nutrition/Food Safety,