Objective exposure to road traffic noise,noise annoyance and self-rated poor health – framing the relationship between noise and health as a matter of multiple stressors and resources in urban neighbourhoods

Borrowing from concepts of socio-environmental epidemiology and psychology, we conceived self-rated health as a function of multiple physical and psychosocial stressors and resources at the residential neighbourhood and individual level. In this model of multiple stressors, objective exposure to road traffic noise was specified as a physical stressor whose effect on health may be mediated and modified by residents’ subjective response to noise (serious noise annoyance). Self-reported hearing disability, recreational coping in green areas and residential neighbourhood satisfaction were examined as additional psychosocial stressors or resources, independently of socio-demographic and -economic factors. Results from our empirical analysis based on two studies and multivariable logistic regressions might support the idea that environmental planning should overcome sectoral boundaries and adopt an integrative approach including objective exposures, residents’ subjective responses, and perceived resources.     

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     

Variation in sensitivity to cadmium among genetically characterized laboratory strains of the midge Chironomus riparius

Estimating the extent of intraspecific variation in sensitivity to contaminant exposure is important in order to explain variation in the outcome of toxicity tests and to predict the effects of chemical stress on natural populations of plants and animals. However, only few studies provide evident data concerning intraspecific variation in life-history traits caused by a differential response to chemical stress. In this study, we compared the life-history response of six laboratory strains of the midge Chironomus riparius to cadmium exposure in a full life-cycle assay. In addition, the level of genetic variation in all strains was measured at five variable microsatellite loci. Several significant differences in life-history traits among the strains were observed in controls and cadmium treatments. The extent of variation among strains was largest at moderate cadmium concentration (0.42 mg Cd/kg dw). At increased Cd concentrations all strains showed similar levels of high mortality and reduced reproductive success. All strains exhibited considerable levels of genetic impoverishment compared to field populations. Strains with low genetic variation showed reduced fitness in the controls and were more susceptible to Cd exposure. For instance, no reproductive success in the lowest Cd treatment was observed for the strain with the lowest level of genetic diversity. In contrast, this Cd concentration had no negative effects on life-history traits of more variable strains. These results confirm recent findings, that inbreeding and reduced genetic variation influence the reaction of populations towards environmental stress. In addition, we show that the level of genetic variation and inbreeding directly influences the outcome of toxicity tests and contributes to the lack of reproducibility of test results among laboratories.     

Solar- und Windenergie zum Pumpen von Wasser

Water pumping by means of wind and solar energy becomes more and more attractive by reason of increasing energy prices. Water supply for remote villages especially in developing countries needs hydraulic energy of about 1 to 50 kWh per day. The use of renewable energies like solar and wind seems to be technically successfull and has a good chance to be competitive with conventional energy sources like diesel or electricity in regions with mean wind speeds above 4–5 m/s or high insolation of about 5 kWh/day annual average.     

Comparison of Extraction Methods for the Detection of Tick-Borne Encephalitis Virus RNA in Goat Raw Milk and Cream Cheese

Food and Environmental Virology - Infection with the tick-borne encephalitis virus (TBEV) can cause meningitis, meningoencephalitis and myelitis in humans. TBEV is an enveloped RNA virus of the...     

Individual protein balance strongly influences δ<Superscript>15</Superscript>N and δ<Superscript>13</Superscript>C values in Nile tilapia,<Emphasis Type="Italic"> Oreochromis niloticus</Emphasis>

Although stable isotope ratios in animals have often been used as indicators of the trophic level and for the back-calculation of diets, few experiments have been done under standardized laboratory conditions to investigate factors influencing ¹⁵N and ¹³C values. An experiment using Nile tilapia [Oreochromis niloticus (L.)] was therefore carried out to test the effect of different dietary protein contents (35.4, 42.3, and 50.9%) on ¹⁵N and ¹³C values of the whole tilapia. The fish were fed the isoenergetic and isolipidic semi-synthetic diets at a relatively low level. ¹⁵N and ¹³C values of the lipid-free body did not differ between the fish fed the diets with different protein contents, but the trophic shift for N and C isotopes decreased with increasing protein accretion in the individual fish, for N from 6.5 to 4 and for C in the lipid-free body from 4 to 2.5. This is the first study showing the strong influence of the individual protein balance to the degree to which the isotopic signature of dietary protein was modified in tissue protein of fish. The extrapolation of the trophic level or the reconstruction of the diet of an animal from stable isotope ratios without knowledge of the individual physiological condition and the feeding rate may lead to erroneous results.