Tätigkeitsbericht der Kaiser Wilhelm-Gesellschaft zur Förderung der Wissenschaften für das Geschäftsjahr 1939/40

Das Jahr 1939 brachte mit dem Ausbruch des großen Kampfes um Deutschlands Freiheit und Zukunft auch für die Kaiser Wilhelm-Gesellschaft die Notwendigkeit gewisser Umstellungen, jedoch wird hiervon die der Tradition der Gesellschaft entsprechende Grundlagenforschung in keiner Weise berührt. Die folgenden Ausschnitte aus der Tätigkeit der Gesellschaft und ihrer Institute beweisen, daß die ihrem Aufbau zugrunde liegenden Gedanken — die ihren ersten Vorkämpfer schon inAlexander von Humboldt gefunden haben — auch in der jetzigen Zeit ihre Gültigkeit behalten, eine Tatsache, die im Hinblick auf die 30. Wiederkehr des Gründungstages der Kaiser Wilhelm-Gesellschaft am 11. Januar 1941 von besonderer Bedeutung ist.     

Life-cycle phases of a zinc- and cadmium-resistant ecotype of Silene vulgaris in risk assessment of polymetallic mine soils

Short-term exposure of plants to heavy metals is often used for risk assessment of metal-enriched soils (OECD guideline 208) without considering the reliability of the assessment for long-term exposure, i.e. for the completion of a plant's life-cycle. In the present study with 15 orogenic soils three phases of the life-cycle of a Zn-Cd-resistant ecotype of Silene vulgaris were studied to improve risk assessment of metal-enriched soils. The first phase, i.e. emergence of seedlings was not related to the water-soluble or total metal concentration of the soils. Seedling mortality was low as long as the water-soluble metal concentration did not surpass 0.15 micromol Zn and 0.04 micromol Cu g(-1) dry soil. Curtailment of the life-cycle prior to flowering, i.e. the vegetative growth as second phase, occurred on those soils where roots and shoots were heavily enriched by Zn already in the seedling phase. In the third phase, i.e. the generative phase, time to flowering and yield differences between orogenic soils were substantial, but soil metal concentrations could not be directly related to timing of reproduction or biomass. Ranking of data showed a high inconsistency of the responses to metal exposure during the first phases of the life-cycle. It is concluded that total plant mass and seed mass are the only realistic endpoints of life-cycle bioassays in risk assessment as long as ranks are inconsistent between two successive early phases of the life-cycle.     

Chemical structure and biological activities of lipid A's from various bacterial families

The endotoxic principle of lipopolysaccharides (LPS) is localized in their lipid A component. Biological effects of LPS on, for instance, body temperature, blood pressure, and blood picture, are also induced by free lipid A. In contrast to the great variability of the 0-specific chains, the chemical structure of lipid A is much more constant. It is common for Salmonella and similar for other genera of the Enterobacteriaceae. Recently, a number of lipid A's have been recognized that exhibited distinct structural features compared with Enterobacteriaceae. These lipid A's were found to be also distinct with regard to some of their biological properties.