Paleoceanographic proxies provide infonnation for reconstructions of the past, including climate changes, global and regional oceanography, and the cycles of biochemical components in the ocean. These prox- ies are measurable descriptors for desired but unobservable environmental variables such as tempera- ture, salinity, primary productivity, nutrient content, or surface-water carbon dioxide concentrations. The proxies are employed in a manner analogous to oceanographic methods. The water masses are first characterized according to their specific physical and chemical properties, and then...

Es ist eine der schlimmsten Seiten un serer gegenwartigen Entwickelungsperlode in der Medi dn, dass die historische Kenntniss der Dinge mit jeder Generation VOD Studirenden abnimmt. Sogal' von den selbstthatigen jiingeren Arbeitern Imnn man in der Regel annehmen. dass ihr Wissen im hochsten Falle nur bis auf 3-5 Jahre riickwiirts leicht. Was vor [) Jahren publicirt ist, existirt nicht mehr. Virchow 1&7U. Je weiter von Jahr zu Jahr die Grenzsteine der medicinischen Naturwissenschaften aus einander geriickt werden, urn so berechtigter wird die Frage: ist es dem praktischen Arzte moglich den...

Until some years ago serum or crude tissue extracts were used pre dominantly or exclusively as media supplements for the cultivation of cells. However, during this time evidence accumulated that these sup plements could not provide in an optimal way most of the cultivated cells with all factors necessary for their survival, their prolifer ation and/or differentiation. Moreover, a variety of cells could not be cultivated at all under these conditions and often the composition of the cultures changed within rather short periods of time by overgrowth of initially present subpopulations of those...