Joint breeding in female burying beetles

Summary Burying beetles (Nicrophorus) exhibit advanced parental care, by feeding and guarding their offspring on buried vertebrate carrion. Till now, interactions between two conspecific females on a carcass have been thought to be mostly competitive, and parental care was thought to be provided by single females or male-female pairs exclusively. Here we demonstrate that cooperative brood care occurs in this species, and that its incidence is contingent on carcass size. Small carcasses are usually monopolized by one female; typically the larger of two female combatants secures the carcass for her offspring (Figs. 1 and 2). On large carcasses fights still occur, but in most cases both females stay on the carcass long enough to provide care for the brood. The use of genetic markers revealed that the maternity of offspring is shared evenly among joint breeders (Figs. 3, 4). We hypothesize that cooperative breeding is an adaptive response to a situation that arises partly as a consequence of a physical constraint. Correspondence to: J.K. Müller     

Economically oriented process optimization in waste management

A brief report on the development of novel apparatus is presented. It was verified in a commercial scale that a new concept of anaerobic fermentation followed by continuous pyrolysis is technically and economically feasible to manage previously enzymatically hydrolyzed waste haylage in huge volumes. The design of the concept is thoroughly described, documented in figures, and biochemically analyzed in detail. Assessment of the concept shows that subsequent pyrolysis of the anaerobically fermented residue allows among biogas to produce also high-quality biochar. This significantly improves the overall economy. In addition, it may be assumed that this applied research is consistent with previous theoretical assumptions stating that any kind of aerobic or anaerobic fermentation increases the microporosity of the biochar obtained.     

Inactivation of bacteria by sun light in a solar reactor with Immobilised TiO2

The photocatalytical inactivation of bacteria (Escherichia coli, Staphylococcus epidermidis,...) in the flow‐through plate solar reactor by sunlight was investigated. The low stability of bacteria in the reactor was attributed to bacteria sensitivity to mixing and/or gas bubbling. Sunlight inactivation proceeds with sufficient rate even under cloudy conditions.     

Levels and trends of industrial chemicals (PCBs, PFCs, PBDEs) in archived herring gull eggs from German coastal regions

Background

Polychlorinated biphenyls [PCBs], perfluorinated compounds, and polybrominated diphenyl ethers [PBDEs] were retrospectively analyzed in archived herring gull (Larus argentatus) eggs from the North and the Baltic Sea over the last 20 years. The aim was to assess temporal trends and effects of regulatory measures.

Results

PCBs (sum of 7 congeners) were highest in eggs from the North Sea island Trischen, i.e., 3,710 to 20,760 ng/g lipid weight [lw] compared to 2,530 to 11,650 ng/g lw on the North Sea island Mellum and 4,840 to 9,190 ng/g lw on the Baltic Sea island Heuwiese. During the study period, PCBs decreased significantly. Concentrations of PFOS ranged between 46 and 170 ng/g wet weight [ww] at Trischen, 39 to 99 ng/g ww at Mellum, and 20 to 159 ng/g ww at Heuwiese. Since 2000 and 2003, concentration levels decreased in eggs from Mellum and Heuwiese, respectively. Perfluorooctanoic acid was the dominant perfluorinated carboxylic acid in the North Sea eggs (Trischen 2.0 to 74 ng/g ww; Mellum 2.6 to 118 ng/g ww), whereas perfluoroundecanoate [PFUnA] and perfluorodecanoate [PFDA] (means 3.9 ± 3.6 ng/g and 2.9 ± 2.3 ng/g ww, respectively) dominated in the Baltic Sea eggs. At all three locations, longer-chained perfluorinated carboxylic acids (perfluorononanoate, PFDA, PFUnA, perfluorododecanoate) increased during the monitoring period. PBDE concentrations (sum of 35 congeners) in eggs were in the ranges of 282 to 2,059 ng/g lw (Mellum), 116 to 1,722 ng/g (Trischen), and 232 to 2,021 ng/g lw (Heuwiese). Congeners associated with commercial Penta- and Octa-BDE formulations decreased during the study period. No decrease was observed for technical Deca-BDE.

Conclusion

Effects of regulatory measures were apparent for PCBs and Penta- and Octa-BDE, while no consistent trend is noticeable for PFOS.     

Gemeinsame Kontrolle von Zellwachstum und Transportfunktionen in einer Nierenzellinie

Several protein kinases have been shown to be involved in the regulation of cell growth and differentiation. Molecules, regulating the activity of these protein kinases, also effect the activity of certain transport systems. Genetic experiments, suggesting a similar connection between the regulation of cell growth and transport functions in MDCK cells, are discussed.     

MTBE (methyl tertiary-butyl ether) in groundwaters: monitoring results from Germany

In Germany information on the occurrence of MTBE in groundwaters is scarce. In order to assess the German situation, in 1999 a monitoring programme on MTBE in groundwater was set up. Within this survey 170 wells were examined, which are used as groundwater monitoring points or which are foreseen for drinking water extraction in emergency cases or for irrigation purposes. In rural areas MTBE was found only in 9% of all samples in concentrations above the limit of determination (LOD) of 0.05 microg L(-1). In urban areas MTBE was detected in 49% of all wells under investigation and the median concentration was calculated to 0.17 microg L(-1). In one case a maximum MTBE concentration of almost 700 microg L(-1) was detected. As a first result of this survey one can conclude, that MTBE is regularly present in German groundwaters under urban areas. Although investigations about the occurrence of MTBE in German groundwaters have to be extended in future, this first snapshot can lead to the assumption, that MTBE concentrations due to diffuse sources are lower than the ones found in the USA. Nevertheless, e.g. accidental spills can lead to elevated MTBE concentrations.