Raumbezug und Repr?sentativit?t in der ?kologischen Fl?chenstichprobe

Zusammenfassung  Die Qualit?t von Raumgliederungen kann letztlich nur vor dem Hintergrund des jeweiligen Verwendungskontextes beurteilt werden. Im Bereich der Umweltbeobachtung kommt Raumgliederungen neben ihrer Nutzung zu Analysezwecken inbesondere im Hinblick auf Auswahlverfahren von Untersuchungsfl?chen gro?e Bedeutung zu. Der Beitrag erl?utert den Zusammenhang von Raumgliederung, Auswahlverfahren und Repr?sentativit?t am Beispiel der ?kologischen Fl?chenstichprobe (?FS) und stellt die Gliederung vor, die im Rahmen einer ?FS-Pilotstudie getestet wurde. Online-First: 19. Mai 2000     

Nectar dehydration by male carpenter bees as preparation for mating flights

Summary Females of all social and many solitary bees dehydrate nectar before storing it or adding it to larval provisions. Nectar dehydration by males has rarely been documented. We report on the neotropical facultatively social carpenter bee Xylocopa nigrocincta, in which the nest constant males are fed nectar by their female nestmates. Males dehydrate the nectar at the nest entrance before leaving the nest for mating territories. We show that males thereby minimize their water load, resulting in an improvement of their energy budget during hovering flights in their territories. Males can prolong the duration of territorial flights if they cany highly concentrated nectar. We assume that nectar dehydration as a pre-mating behavior is not correlated with the social organization in Xylocopa species. However, the behavior is particularly weil-developed in X. nigrocincta, where during the mating period males remain integrated in the nest society and are fed by their mothers and sisters.     

Colonial recognition of fungus in the fungus-growing ant Acromyrmex subterraneus subterraneus (Hymenoptera: Formicidae)

Summary. Leaf cutting ants live in symbiosis with a basidiomycete fungus that is exploited as a source of nutrients for the ant larvae. Tests of fungus transport demonstrated that Acromyrmex subterraneus subterraneus workers discriminate concolonial fungus from alien fungus, and rejected the latter. Larvae and pupae of the ant were used as controls. Chemical analysis of the fungus revealed a great similarity between its hydrocarbon profile and that found on the ant brood. Experiments with lures showed that chemical extracts from the fungus are responsible for this discrimination process. Moreover, the presence of brood inside the fungus seemed to be important for discrimination of the fungus by workers. Resident workers accepted concolonial broodless fungus less than concolonial fungus inoculated with brood odor. Fungus seems to acquire colonial odor passively, simply by contact with the brood. The impact of fungus volume present in the nest on closure of the colony is discussed. We show here for the first time the importance of a symbiotic vegetal organism in colonial recognition in social insects. Received 14 April 2000; accepted 29 September 2000     

Mineralölkohlenwasserstoffe im Boden bei der Sanierung von Altlasten

Various analyses and evaluative procedures are used to provide evidence of success using remediation procedures. Because of the lack of standardized procedures for soil assessment, general practice has unfortunately propagated the use of DIN standards for determining the level of similar parameters in water as well as for other heterogeneous matrices (e.g. in soil). A precise auditing of quality, however, has not been possible with this method, this procedure has even put the success of such a remediation into question. This article describes the problems of determining mineral hydrocarbon concentrations on soil as well as portraying the remediation of oil damages which has occurred on a site of a former waste oil redestillation facility [1, 2]. This procedure has been proved in practice and serves as a model because an adequately defined, standardized method (DIN standard) is lacking.     

Calcium

Calcium plays a pivotal role in cellular signal transduction. Precise control and regulation of cytoplasmic free ionic calcium concentration is a prerequisite for intracellular calcium-mediated physiology. Calmodulin is the ubiquitous calcium receptor protein which conveys the information to the calcium-dependent enzymes. Protein kinase C and receptor-stimulated phosphatidylinositol metabolisms are components of another regulatory mechanism where calcium plays an important regulatory role, too. Oncogene products have been found to possess enzymatic activities involved in phosphatidylinositol metabolism.     

Zum Stichprobenfehler im Human-Biomonitoring

Goal and Scope

Human biomonitoring determines the concentration of xenobiotics in populations by means of smaller samples, thus necessarily arising sampling errors. These are determined.

Methods

For a fictitious population of 200,000 persons, differently broad xenobiotic concentration distributions were simulated. Samples of varying size were randomly drawn and the sampling error, defined as the proportional difference between the geometric means of sample and population, was determined.

Results and Conclusions

The sampling error depends on the sample size and the width of the concentration distribution; its estimation is possible for any xenobiotic, given it has lognormal distribution, and the sample size is between 10 and 50,000. For its estimation an equation was derived.

Outlook

When presenting and interpreting results of human biomonitoring, the sampling error must be considered, together with the uncertainty of the measurement.