Nitrogen balance in marine fish larvae: influence of developmental stage and prey density

The utilization and fate of nitrogen in larvae of plaice (Pleuronectes platessa), blenny (Blennius pavo) and herring (Clupea harengus), from the stage of first-feeding to metamorphosis, was examined under laboratory conditions. Rates of ammonia excretion, primary amine defaecation, and growth in terms of protein-nitrogen were monitored throughout larval life. Data were used to calculate daily ration, the coefficient of nitrogen utilization (absorption efficiency), and gross and net growth efficiencies. The developmental pattern of nitrogen balance was similar for plaice and blenny larvae. These species showed increasing growth efficiency (k₁: 55 to 80%) with decreasing weight-specific waste nitrogen losses with age. Absorption efficiencies. were high (83 to 98%) in plaice and blenny larvae, and tended to increase with development in the former species. Ration relative to body weight decreased with growth in both species. Herring larval development, although at a slower rate than blenny and plaice, appeared normal up to 33 d, after which high mortality occurred. Absorption efficiency in this species tended to decline (83 to 43%) with age, until metabolic costs exceeded the absorbed ration and growth ceased. Artemia sp. nauplii proved a suitable food source for the rearing of plaice and blenny larvae, but this diet may have long-term toxicity or deficiency effects on herring. Availability and density of food affected nitrogen balance in the larvae of all three species. Feeding stimulated the output of wastes in excretion and defaecation by a factor of up to ten times the 12-h non-feeding basal rates. Waste nitrogen output reached a peak some 2 to 3 h after commencement of feeding and returned slowly to the baseline in 5 to 10 h after cessation of feeding. There was an asymptotic increase in ration, ammonia output and growth of larvae as prey density increased. Ration saturated at a higher prey density (>4 prey ml^-1) than either growth or excretion rate (1 prey ml^-1). Thus the efficiency with which food is absorbed and utilized for growth must eventually decline in response to high prey density. The idea that larval fish are adapted to maximize ingestion and growth rate, rather than optimize growth efficiency and thus to respond to prey occurring in either low density or in occasional patches, is supported by these results.     

Biodegradation of aromatic compounds by white rot and ectomycorrhizal fungal species and the accumulation of chlorinated benzoic acid in ectomycorrhizal pine seedlings

The capability of different white rot (WR, Heterobasidion annosum, Phanerochaete chrysosporium, Trametes versicolor) and ectomycorrhizal (ECM, Paxillus involutus, Suillus bovinus) fungal species to degrade different aromatic compounds and the absorption of 3-chlorobenzoic acid (3-CBA) by ECM pine seedlings was examined. The effect of aromatic compounds on the fungal biomass development varied considerably and depended on (a) the compound, (b) the external concentration, and (c) the fungal species. The highest effect on the fungal biomass development was observed for 3-CBA. Generally the tolerance of WR fungi against aromatic compounds was higher than that of the biotrophic fungal species. The capability of different fungi to degrade aromatic substances varied between the species but not generally between biotrophic and saprotrophic fungi. The highest degradation capability for aromatic compounds was detected for T. versicolor and H. annosum, whereas for Phanerochaete chrysosporium and the ECM fungi lower degradation rates were found. However, Paxillus involutus and S. bovinus showed comparable degradation rates at low concentrations of benzoic acid and 4-hydroxybenzoic acid. In contrast to liquid cultures, where no biodegradation of 3-CBA by S. bovinus was observed, mycorrhizal pines inoculated with S. bovinus showed a low capability to remove 3-CBA from soil substrates. Additional X-ray microanalytical investigations showed, that 3-CBA supplied to mycorrhizal plants was accumulated in the root cell cytoplasm and is translocated across the endodermis to the shoot of mycorrhizal pine seedlings.     

Sustainability assessment of entire forest value chains: Integrating stakeholder perspectives and indicators in decision support tools

The optimization of value chains is an important process to promote sustainable development, since value chains are closely linked to the satisfaction of human needs and combine different driving forces for environmental change. This article presents a methodological approach for the participatory development of value-chain wide sustainability indicator sets and their integration into a decision support tool in the specific case study of the chain “construction and refurbishment with wood”. There are numerous indicator sets for sustainable development of forests and sustainable forestry available at different levels, ranging from local, regional and national to global scale assessments. Some efforts were also made to integrate later production stages of forest value chains (such as wood processing) in the assessment scope (e.g. for chain-of-custody certification). However, no indicator set has so far been available covering environmental, social and economic aspects for the entire value chain of building with timber. This gap was closed through applied sustainability research in the project “Holzwende 2020: Sustainable future markets for wood in the building sector”.     

The polymorphism of the human serum paraoxonase †

The activity of paraoxonase, the enzyme which hydrolyses paraoxon, 0,0‐diethyl‐0–4‐nitrophenylphosphate, in human serum shows a genetically determined polymorphism with strong interethnic differences. The serum paraoxonase genotype has a significant influence on the paraoxon clearance. Individuals with high serum paraoxonase activity may be better protected against the toxic effects of parathion (0,0‐diethyl‐0–4‐nitrophenylthiophosphate).

In Caucasians the polymorphism is governed by two alleles. The first allele has a gene frequency p _low of 0.67 to 0.78, and is manifested in both the form of a first homozygotic group with low activities and a second heterozygotic group with medium activities. About 50% of all Europeans belong to the low activity group. The second allele with a gene frequency q _high of 0.22 to 0.33 is manifested in the second heterozygotic and a third homozygotic group with medium resp. high activities. The Hardy‐Weinberg rule for a two allele model is valid for the distribution.

The percentage of the low activity group decreases as one moves from Europe to Africa and Asia. In most of the Mongoloids and Negroids only 5 to 20% of the population can be included in the low activity group, which is not even demonstrable in Aborigines, Maoris, Tonga and some African and Indian (Central America) tribes. The validity of the Hardy‐Weinberg rule for a two‐ or three‐allele model must be rejected in non‐Caucasians.     

'All hazards approach' to disaster management: the role of information and knowledge management, Boyd's OODA Loop, and network-centricity

The ever-increasing complexity of disasters demands utilisation of knowledge that exists outside domains traditionally drawn upon in disaster management. To be operationally useful, such knowledge must he extracted, combined with information generated by the disaster itself, and transformed into actionable knowledge. The process, though, is hampered by existing, business-oriented approaches to knowledge management, by technical issues related to access to relevant, multi-domain information/knowledge, and by executive decision-making processes based predominantly on historical knowledge. Consequently, as shown by many recent incidents, the management of large-scale (mega) disasters is often inefficient and exceedingly costly. This paper demonstrates that the integration of modified information and knowledge management into the concepts of network-centric operations and network-enabled capabilities, and the employment of Boyd's OODA (Observe, Orient, Decide, and Act) Loop-based decision-making in unpredictable and dynamically changing environments, may address some of these problems.     

Domorganus oligochaetophilus n. sp., ein endoparasitischer Vertreter der Nematoda Adenophorea im darm von oligochaeten aus dem litoral der Kieler Bucht

Domorganus oligochaetophilus n.sp., a new representative of the Cylindrolaiminae Micoletzky (1922) sensu De Coninck (1965) is described. The adults live as endo-parasites in the intestine of littoral oligochaetes (Lumbricillus lineatus O. F. Müller 1774) from the Kieler Bucht (western Baltic Sea). This is the first endo-parasitic record in marine invertebrates of the Nematoda Adenophorea. The new species is characterized morphologically by: 4 cephalic setae, a very small buccalcavity without any sclerotized structures, an esophagus, with 2 bulbs, an excretory pore located posterior to the esophagus, reflexed diorchic ovaria, outstretched diochic testes, and 1 vesicular pre-anal organ in the male. Observations on living specimens show that the parasites live free in the intestinal lumen or are fixed by their spinneret glands at the intestinal wall of their hosts. Their food consists apparently of particulate intestinal contents.