Drugs from marine organisms

A modern approach to the search for biologically active substances of potential therapeutic use isolated from marine organisms is illustrated by a presentation of the multidisciplinary project pursued by the Roche Research Institute of Marine Pharmacology near Sydney, Australia. This specialized insitute is part of the world-wide research endeavour of our company and has now been in operation for five years. Following a brief outline of the technical functions the main scientific achievements published by the scientists of the institute are reviewed. This institute is, to our knowledge, the only one of its kind in private industry and we have attempted to demonstrate how its activities should be viewed in the overall context of today's drug or product development.     

Variationen der Nährstoff-und Schwermetallgehalte in Böden

This article investigates the variations of nutrient (phosphorus (P) and potassium (K)) and heavy metal contents in soils. Therefore, selected regions in Eifel and Hunsrueck (region around Trier) were examined. The data base consists of more than 100.000 existing measurements plus own investigations on the main land use classes —field, grassland, vinicultural areas and forest—with regard to their intensities (conventional und biological). The evaluation of the nutrient contents for P and K was made using the manual adequate fertilization for field and grassland. The creation of heavy metal distribution maps is based on the Kriging method. In the past, soils in the region of Trier received a too large amount of P and K—especially in vinicultural areas. Mineral and organic fertilization has a great influence on the heavy metal contents on farmland. The immission of dust contaminated with heavy met|als is important on forest and grassland locations. On vineyards the use of cupreous plant protection agents is critical. The land use classes have had a substantial influence on the nutrient and heavy metal contents of the soil. In contrast to this, the intensities showed less differences. In order to reduce the anthropogenic impact on heavy metals in soils, it is necessary to create specific reduction strategies for each land use class. For example the fertilization has to be limited to the need of the plant, contaminated secondary raw material fertilizer has to be avoid the comparability of analytical methods has to be ensured.     

Chemische Reaktionen von Phenylarsinverbindungen

In an equilibrium reaction, phenylarsine dichloride (PFIFFIKUS) reacts rapidly with alcohols at room temperature to yield phenylarsine bisether and phenylarsine chloride ether. The reactions, however, are not quantitative. The derivatives were identified using mass spectrometry.     

Determinants of brood defence in the great tit Parus major L.

Summary Great tits (Parus major) tending nestlings reacted defensively to a live predator (Glaucidium perlatum; domestic cat) and the playback of a mixed species mobbing chorus, or to the latter alone. Defensive behaviour, mainly mobbing, reflected the risk taken and is assessed by five measures. Multivariate and contingency analyses revealed that at least 11 of 16 contextual independent variables affected the risk taken. Incremental effects are due to: Age of young, sex of the defending bird, the expected number of neighbouring mobbers, low temperature, wet canopy, the raptor's distance from cover, coniferous forest, advancing season. A decremental effect is exerted by a large brood that is older. Annual differences in defence arise probably from demographic factors such as fecundity, which in turn affect the parent's benefit-cost ratio (number of young of the same sex as the parent/residual reproductive value of the parent).While the effects of annual fecundity, age of young and season were predicted on the basis of this benefit-cost ratio, the failure to verify an incremental effect of brood size runs counter to established theory. We conclude that parents gear their defence efforts to energy investment, past or future, and are mal-adapted to brood size as a promotor of risk taken. The influence of the habitat is poorly understood. At least three factors (age and number of young, parent's sex) act additively on part of the response. Despite the large number of variables examined, about 43% of the total response variance remains unexplained.While four defence measures are determined by at least 10 contextual factors, a fifth measure, the male's minimum distance from the raptor, is determined by one other factor, the appearance of the male. The latter leads us to assume an additional, social rôle of brood defence.Risk-assessment by great tits leading to risk-aversive defence behaviour is governed by evolved restraints rather than by momentary constraints. Examples are provided by the effects of weather and cover.     

III. Ökotoxikologische Charakterisierung der Schwermetall-Immissionsmuster

The spatial variation of the immission patterns of Cr, Fe, Pb and V in the region Leipzig-Halle is dicussed in terms of similarities as well as dissimilarities. The representation by isopleths enables the identification of areas with high and low air pollution. The immission patterns can be used as criteria to select areas suitable for in-field testing so that possible effects on fauna und flora and xenobiotic fluxes can be studied at representative sites. The comparison with literature data yields a first characterization of the ecotoxic potential of the heavy-metal immission for the region. By the principal component analysis a comparative evaluation of the spatial structure of all element contents is performed, which leads to conclusions about emission sources and the physicochemical behaviour of the elements.     

Not Only Single Mating in Stingless Bees

Queens of the large, pantropical and fully eusocial taxon Meliponinae (stingless bees) are generally considered to be singly mated. We indirectly estimated queen mating frequency in two meliponids, Melipona beecheii and Scaptotrigona postica, by examining genotypes of workers at microsatellite DNA loci. Microsatellites were highly variable, providing suitable markers with which to assign patrilinial origin of workers within colonies headed by single queens. Queen mating frequency varied between 1 and 3 (M. beecheii) and 1 and 6 (S. postica), representing the first clear documentation of polyandry in the Meliponinae. Effective paternity frequency, m _e , was lower, although above 2 for S. postica. Stingless bees may provide suitable subjects for the testing of recent inclusive fitness arguments describing intracolony kin conflict in social Hymenoptera. Received: 26 August 1998 / Accepted in revised form: 18 November 1998