Variations in the Epiphytic Invertebrate Community Structure on Potamogeton Perfoliatus L. in Traunsee (Austria): Patchiness versus Impacts by Industrial Tailings

The epiphytic invertebrates found on Potamogetonperfoliatus L. in Traunsee, an oligotrophic Alpine lake inAustria, were investigated in August and October 1998 in orderto study the impact of industrial tailings discharged into thelake. 113 taxa were found, 54 could be identified to thespecies level. Their total abundance varied between ca.190,000 and 1,138,000 ind. m^-2 lake bottom area. Thisepiphytic assemblage was dominated by Dreissenapolymorpha and Sida crystallina, which resulted in avery low overall species diversity. Multivariate statisticalanalyses revealed significant differences in the communitystructure between three sites, each of them was located at adifferent distance from the site of industrial waste emission.These differences were interpreted as variations which reflectthe patchiness within highly structured habitats rather thanas being the result of the industrial pollution.     

Distribution Pattern of Benthic Invertebrate Communities in Traunsee (Austria) in Relation to Industrial Tailings and Trophy

Traunsee, an oligotrophic Alpine lake, has suffered from inputsof industrial tailings (soda- and salt-mining industries) forseveral decades. The effects of the industrial sludges on thespatial distribution of the littoral and profundal invertebratefauna was investigated along three transects at five dates. Inthe littoral zone, no negative impacts were found. A distinctgradient in faunal composition and diversity was, however,observed along a profundal transect relative to the distance fromthe waste emission. Near the industrial input, the enhanced pH,the substrate instability, and the poor sediment quality forsubstrate- and deposit-feeders were the main factors that loweror prohibit colonization of the industrial sludges. Along atransitional zone between the waste emission and the deepestbasin, recolonization was delayed, but did occur as soon aslayers of a few mm natural sediment seal the sludge. Mobile,epibenthic organisms are the first to settle these areas, whereasrecolonization by tube-building oligochaetes and chironomidsrequires thicker sealings of the industrial sludges. Differencesin the abundance of benthic invertebrates at different profundalsites were not only related to the waste emission, but also tothe influence of the main tributary, the River Traun. Theenhanced availability of allochthonous organic matter wasprobably responsible for high densities of tubificids near theinlet in the South of Traunsee. Moreover, a higher proportion oftolerant oligochaete and ostracod species in the lower profundaloutside the influence of the industrial tailings was interpretedas reflecting the increased trophy of Traunsee in the 1970s,which forced sensitive species to shift to the upper profundalwhen the oxygen climate deteriorated.     

Aktivierung,Aktivität und Inhibierung des Rindertrypsins

Trypsin is a prototype of a large group of enzymes belonging to serine proteinases. The X-ray crystal-structure analyses of its proenzyme trypsinogen, of the active trypsin and of their complexes formed with the pancreatic trypsin inhibitor (PTI) have considerably enhanced our understanding of the mechanisms of activitation, action and inhibition. The trypsinogen is an incompletely folded molecule. Its substrate-binding site becomes only completely fixed upon the enzymatic cleavage of an N-terminal peptide. The contact regions of trypsin and PTI are almost complementary. The complex formed is a (stable) intermediate in the normal tryptic substrate-cleavage reaction.     

Health Impact Evaluation of Boron in Drinking Water: A Geographical Risk Assessment in Northern France

Objective: To evaluate health impact of boron in drinking water. Methods: A regional scale geographical study in Northern France was conducted. Assessment of boron blood levels in a group of 180 healthy individuals and correlation with boron content in drinking water were followed by an assessment of health indicators such as birth rates, mortality rates, and sex ratios in zones of different boron content in drinking water. Results: After necessary adjustments, men living in municipalities with more than 0.30 mg/L of boron in drinking water had elevated but not significant boron blood levels compared with those living in municipalities with boron water levels of less than 0.30 mg/L (159.1 versus 123.0 ng/g; p > 0.05). The standardized birth ratio adjusted for the reference geographic zone and calendar time period was 1.07 and 1.28 in the low and high (>0.3 mg/L) boron content municipalities, respectively. The birth rate in municipalities with high boron content in drinking water was higher than that of the reference geographic zone and of the French general population (p < 10^-4). The standardized mortality ratio adjusted for the reference geographic zone and calendar time period was 0.94 and 0.92 in the low and high boron content municipalities, respectively. The mortality rate in municipalities with high boron content in drinking water was less than that of the reference geographic zone and of the French general population (p < 10^-3). No statistical difference was noted in the male–female sex ratios between the different municipality zones (p = 0.45). Conclusions: The results of this study do not support the idea of a deleterious effect of boron on human health, at the boron water level contents found in this specific region. In fact, there is a tendency toward a beneficial effect with low-dose environmental exposure (less than 1 mg/L of boron) in drinking water.     

Temporal trend (1988-2008) of hexabromocyclododecane enantiomers in herring gull eggs from the German coastal region

Levels of α-, β-, and γ-hexabromocyclododecane (HBCD) were determined in pooled eggs from herring gulls (Larus argentatus) sampled on three bird sanctuaries near the German North Sea coast between 1988 and 2008 (Mellum and Trischen) and the German Baltic Sea coast between 1998 and 2008 (Heuwiese) and archived by the German Environmental Specimen Bank. Pressurized fluid extraction, gel permeation chromatography, and LC-MS/MS using ¹³C₁₂-labelled isotope standards and a chiral column were applied. α-HBCD was the dominating diastereomer and ranged between 3.7 and 107 ng g⁻¹ lw while β- and γ-HBCD were throughout close to LOQ. The highest α-HBCD concentration was found in eggs from Mellum sampled in the year 2000. Interestingly, HBCD in eggs from the three islands displayed similar time courses with levels increasing to a peak contamination around 2000 and decreasing levels ever since. Chiral signatures of α-HBCD in eggs differed among the islands but indicated a preferential enrichment of the first eluting enantiomer (−)-α-HBCD.