The occurrence of a myoblastic form of muscle in the sinus venosus of the adult goldfish (Carassius auratus)

Zusammenfassung Eine licht- und elektronenmikroskopische Untersuchung von Sinus venosus des erwachsenen Goldfisches (Carassius auratus) zeigte eine myoblastische Form von spindelförmigen Zellen, welche quergestreifte Fibrillenm und ausserde eine grosse Anzahl globulärer Teilchen enthielten.     

Alterations in the levels of cAMP and cGMP after decentralization of the rat superior cervical ganglion

Summary After cutting the preganglionic nerve trunk of the rat's superior cervical ganglion, the levels of cAMP and cGMP were measured in a postoperative period of between 3 and 21 days. After 3 days, cAMP and cGMP showed a decrease by 48 and 33% respectively, followed by a partial recovery after 7 to 21 days.This work was supported by the Deutsche Forschungsgemeinschaft (SFB 70).     

A technique for sterile culture of fresh water sponges

Summary By treating the gemmules of freshwater sponges successively with hydrogen peroxide and with sodium hypochlorite in suitable concentrations, we obtained cultures that were free from any bacterial or fungal contaminant. This technique provides a useful tool for further studies on metabolic and antibiotic activities, and of the behaviour of isolated cells cultivated in artificial media.F.R. is grateful to NATO, for a grant which allowed her to stay at the Department of Cell Biology of the University of Glasgow and to all the members of this laboratory for their help.     

Modelling conservation in the Amazon basin

Expansion of the cattle and soy industries in the Amazon basin has increased deforestation rates and will soon push all-weather highways into the region's core. In the face of this growing pressure, a comprehensive conservation strategy for the Amazon basin should protect its watersheds, the full range of species and ecosystem diversity, and the stability of regional climates. Here we report that protected areas in the Amazon basin--the central feature of prevailing conservation approaches--are an important but insufficient component of this strategy, based on policy-sensitive simulations of future deforestation. By 2050, current trends in agricultural expansion will eliminate a total of 40% of Amazon forests, including at least two-thirds of the forest cover of six major watersheds and 12 ecoregions, releasing 32 +/- 8 Pg of carbon to the atmosphere. One-quarter of the 382 mammalian species examined will lose more than 40% of the forest within their Amazon ranges. Although an expanded and enforced network of protected areas could avoid as much as one-third of this projected forest loss, conservation on private lands is also essential. Expanding market pressures for sound land management and prevention of forest clearing on lands unsuitable for agriculture are critical ingredients of a strategy for comprehensive conservation.     

Reconstructing the early evolution of Fungi using a six-gene phylogeny

The ancestors of fungi are believed to be simple aquatic forms with flagellated spores, similar to members of the extant phylum Chytridiomycota (chytrids). Current classifications assume that chytrids form an early-diverging clade within the kingdom Fungi and imply a single loss of the spore flagellum, leading to the diversification of terrestrial fungi. Here we develop phylogenetic hypotheses for Fungi using data from six gene regions and nearly 200 species. Our results indicate that there may have been at least four independent losses of the flagellum in the kingdom Fungi. These losses of swimming spores coincided with the evolution of new mechanisms of spore dispersal, such as aerial dispersal in mycelial groups and polar tube eversion in the microsporidia (unicellular forms that lack mitochondria). The enigmatic microsporidia seem to be derived from an endoparasitic chytrid ancestor similar to Rozella allomycis, on the earliest diverging branch of the fungal phylogenetic tree.