959 resultados para viola recital
Resumo:
Palynological investigations of sediments from northern Bavaria (Rhön, Grabfeld, Lange Berge) reveal the Late Glacial and Postglacial history of the regional vegetation. The older sedirnents were found in the Rhön (Schwarzes Moor) and date back into the Bölling Period. At the end of that period pine spread into the Grabfeld. In both areas Lacher Tuff has been found. A radiocarbon date of 10,300 BP was found for the Late Glacial - Postglacial transition and one of 9300 BP for the Preboreal - Boreal transition. Hazel reached its highest values in the Rhön around 7,400 BP. During the Atlanticum a deciduous mixed oak forest covered the Rhön and Grabfeld regions. Beech dominated since the Subatlanticum. In the Lange Berge region, however, a mixed forest with Fagus, Picea, Pinus and Abies developed. In the Rhön first anthropogenic influence was found during the Latene Period. The boundary between zone IX and X has been dated at 820 A.D., and the start of extensive forest clearances at 1000 A. D. A culmination of landuse was found for the Medieval Period. At the end of that period however the Rhön was deserted. New forest clearances started around 1500 A.D., but were interrupted by the 'Thirty Years War'. Afterwards the Rhön got its present appearance.
Resumo:
Ten algal strains from snow and permafrost substrates were tested for their ability to produce secondary carotenoids and ?-tocopherol in response to high light and decreased nitrogen levels. The Culture Collection of Cryophilic Algae at Fraunhofer IBMT in Potsdam served as the bioresource for this study. Eight of the strains belong to the Chlorophyceae and two strains are affiliated to the Trebouxiophyceae. While under low light, all 10 strains produced the normal spectrum of primary pigments known to be present in Chlorophyta, only the eight chlorophyceaen strains were able to synthesize secondary carotenoids under stress conditions, namely canthaxanthin, echinenone and astaxanthin; seven of them were also able to synthesize minor amounts of adonixanthin and an unidentified hydroxyechinenone. The two trebouxiophyceaen species of Raphidonema exhibited an unusually high pool of primary xanthophyll cycle pigments, possibly serving as a buffering reservoir against excessive irradiation. They also proved to be good alpha-tocopherol producers, which might also support the deactivation of reactive oxygen species. This study showed that some strains might be interesting novel candidates for biotechnological applications. Cold-adapted, snow and permafrost algae might serve as valuable production strains still exhibiting acceptable growth rates during the cold season in temperate regions.