Chemical oxidation of cable insulating oil contaminated soil

Leaking cable insulating oil is a common source of soil contamination of high-voltage underground electricity cables in many European countries. In situ remediation of these contaminations is very difficult, due to the nature of the contamination and the high concentrations present. Chemical oxidation leads to partial removal of highly contaminated soil, therefore chemical oxidation was investigated and optimized aiming at a subsequent bioremediation treatment. Chemical oxidation of cable oil was studied with liquid H₂O₂ and solid CaO₂ as well as permanganate at pH 1.8, 3.0 and 7.5. Liquid H₂O₂ most effectively removed cable oil at pH 7.5 (24%). At pH 7.5 poor oil removal of below 5% was observed with solid CaO₂ and permanganate within 2 d contact time, whereas 18% and 29% was removed at pH 1.8, respectively. A prolonged contact time of 7 d showed an increased oil removal for permanganate to 19%, such improvement was not observed for CaO₂.Liquid H₂O₂ treatment at pH 7.5 was most effective with a low acid use and was best fit to a subsequent bioremediation treatment. To further optimize in situ chemical oxidation with subsequent bioremediation the effect of the addition of the iron catalyst and a stepwise liquid H₂O₂ addition was performed. Optimization led to a maximum of 46% cable oil removal with 1469 mM of H₂O₂, and 6.98 mM Fe(II) chelated with citric acid (H₂O₂:FeSO₄ = 210:1 (mol mol⁻¹). The optimum delivery method was a one step addition of the iron catalyst followed by step wise addition of H₂O₂.     

A risk framework for preventing salinity

Salinity is an insidious soil conservation issue. Its expression can be greatly removed in time and space from its causes, so a focus on prevention is preferred. To avoid over or under-investment, a communication strategy for salinity needs to be a staged approach, the risks defined and the assets at risk identified.This paper describes a risk assessment schema and associated information base designed to support community investment in preventative actions. It describes a new approach to salinity risk similar to the concepts of diagnosis and staging used by physicians for diseases such as cancer. It outlines the diagnostic tools now being developed to define the timeframes of salinity development, the biophysical features of the landscape within which salinity develops and the riskiness of current and alternative management systems and matches this with a complementary community process designed to build knowledge and intervention. A GIS/database system captures the concepts of salinity risk and a large array of diagnostic information in a form designed for the development of salinity knowledge in the community and to guide investment in salinity prevention. The communication strategy and the salinity risk system are being applied in the Fitzroy Basin, Australia, an area of approximately 150,000 km² straddling the Tropic of Capricorn.     

An absence of aggression between non-nestmates in the bull ant <Emphasis Type="Italic">Myrmecia nigriceps</Emphasis>

The ability of social insects to discriminate against non-nestmates is vital for maintaining colony integrity, and in most social insect species, individuals act aggressively towards non-nestmates that intrude into their nest. Our experimental field data revealed that intra-colony aggression in the primitive bulldog ant Myrmecia nigriceps is negligible; our series of bioassays revealed no significant difference in the occurrence of aggression in trials involving workers from the same, a close (less than 300 m) or a far (more than 1.5 km) nest. Further, non-nestmate intruders were able to enter the nest in 60% of our trials; a similar level was observed in trials involving nestmates. These results suggest that workers of M. nigriceps are either unable to recognize alien conspecifics or that the costs of ignoring workers from foreign colonies are sufficiently low to favor low levels of inter-colony aggression in this species.     

Natural History Traits Associated with Detecting Mortality Within Residential Bird Communities: Can Citizen Science Provide Insights?

Cat predation of birds in residential landscapes is ephemeral, unpredictable, and spatially dispersed, and thus requires many person-hours to observe. We sought to identify whether specific behaviors, traits, or feeding ecologies of birds contribute to their probability of cat-caused mortality around residences across temperate North America. In addressing this question, we evaluated citizen science data with respect to peer-reviewed species accounts (Birds of North America, BNA). Using information on cat predation from the BNA, we found that species that glean their prey from the ground or breed in nest boxes were three times more likely to be depredated by cats, while birds that hawk were over two times less likely to become cat prey than would be predicted by random chance. Data from citizen science sources also showed that birds using nest boxes had increased susceptibility to cat predation, as did those that use feeders and that glean from foliage. We caution that observations of predation by citizen science volunteers may be biased towards detection at feeders. Future research should focus on developing volunteer survey techniques for improving estimates of bird mortality rates and sources.     

Expression of fragile-x in a female fetus diagnosed after chorionic villus sampling

Study of different tissues of an aborted female fetus showed similar levels of fragile-X expression (6.3–9.2 per cent) and of early replication of the FRAXA-positive cells (50–66 per cent) in fetal tissues. Different culture media did not significantly affect either investigation. It is suggested that the distribution of X-inactivation in FRAXA-positive chorionic villus cells of a female fetus might indicate her future phenotype.