Mate fidelity of renesting pied flycatchers Ficedula hypoleuca in relation to characteristics of the pair mates

Summary After a nesting failure, individual pied flycatchers may renest with the same or a new partner. In a 2-year study, carried out in a homogeneous habitat, we removed the clutches of a total of 124 monogamous pairs to study mate fidelity. The chance of a male obtaining a new partner if the pair bond had been broken was very low, so it would be in a male's interest to retain his original mate. Females in good condition showed a greater tendency to break the pair bond, and moved longer distances for renesting, than females in poor condition. Females that had nested in the area in a previous year were more site-tenacious, though not significantly more faithful to their mates, than those that were nesting in the area for the first time. Males that succeeded in retaining their mate were characterized primarily by having black plumage, and males from which certain feathers had been removed (=handicapped) tended to lose their mates. Females preferred the same male characteristics when they chose their mates in early spring. Hence, the decision about mate fidelity is influenced by the condition of the female and the attractiveness of her mate. Some evidence was found that male parental quality was correlated with male attractiveness.     

Guidelines for Nordic building regulations regarding indoor air quality

A subcommittee of the Nordic Committee for Building Codes has released guidelines for building regulations regarding indoor air quality, especially concerning ventilation. The main features of the guidelines, such as acceptable outdoor air quality for ventilation and minimum outdoor air flows for dwellings and offices, are presented and discussed. Mechanical ventilation is, in principle, required in all buildings including dwellings, due to the requirement of a minimum outdoor air change of 0.5 h⁻¹ and the normal highly airtight nature of new buildings. The guidelines are a basis for designing energy-efficient buildings while maintaining an indoor air quality which provides acceptable comfort and does not impair health.     

Application of the EPR spin-trapping technique for the investigation of the reactions of carbonate, bicarbonate, and phosphate anions with hydroxyl radicals generated by the photolysis of H2O2

The spin trapping technique with electron paramagnetic resonance (EPR) detection of spin adducts was applied for the investigation of the reaction of hydroxyl radicals, generated by the photolysis of hydrogen peroxide, with bicarbonate and carbonate anions. The results have been compared with those obtained for aqueous solutions of hydrogen peroxide as well as solutions containing phosphate buffers at pH values identical with those of the carbonate, and bicarbonate solutions. Both the carbonate, and bicarbonate anions quenched the hydroxyl radicals more efficiently than phosphate buffers. The effect depended on the anion concentrations, and it was most pronounced in the presence of carbonate. Rate constants for the reaction of OH with the investigated anions have been calculated. They are very close to values reported in the literature, obtained using optical detection of the carbonate and phosphate radicals.     

A multi-objective optimization framework for surfactant-enhanced remediation of DNAPL contaminations

The occurrence of Dense Non-Aqueous Phase Liquid (DNAPL) contaminations in the subsurface is a threat for drinkwater resources in the western world. Surfactant-Enhanced Aquifer Remediation (SEAR) is widely considered as one of the most promising techniques to remediate DNAPL contaminations in-situ, be it with considerable additional costs compared to classical pump-and-treat remediations. A cost-effective design of the remediation set-up is therefore essential. In this work, a pilot SEAR test is executed at a DNAPL contaminated site in Belgium in order to collect data for the calibration of a multi-phase multi-component model. The calibrated model is used to assess a series of scenario-analyses for the full-scale remediation of the site. The remediation variables that were varied were the injection and extraction rate, the injection and extraction duration, and the surfactant injection concentrations. A constrained multi-objective optimization of the model was applied to obtain a Pareto set of optimal remediation strategies with different weights for the two objectives of the remediation: (i) the maximal removal of DNAPL and (ii) a total minimal cost. These Pareto curves can help decision makers to select an optimal remediation strategy in terms of cost and remediation efficiency. The Pareto front shows a considerable trade-off between the total remediation cost and the removed DNAPL mass.     

Non-destructive pollution exposure assessment in the European hedgehog (Erinaceus europaeus): II. Hair and spines as indicators of endogenous metal and As concentrations

The role of hair and spines of the European hedgehog as non-destructive monitoring tools of metal (Ag, Al, Cd, Co, Cr, Cu, Fe, Ni, Pb, Zn) and As pollution in terrestrial ecosystems was investigated. Our results showed that mean pollution levels of a random sample of hedgehogs in Flanders are low to moderate. Yet, individual hedgehogs may be at risk for metal toxicity. Tissue distribution analyses (hair, spines, liver, kidney, muscle and fat tissue) indicated that metals and As may reach considerable concentrations in external tissues, such as hair and spines. Positive relationships were observed between concentrations in hair and those in liver, kidney and muscle for Al, Co, Cr, Cu, and Pb (0.43 < r < 0.85). Spine concentrations were positively related to liver, kidney and muscle concentrations for Cd, Co, Cr, Cu and Pb (0.37 < r < 0.62). Hair Ag, As, Fe and Zn and spine Ag, Al, As and Fe were related to metal concentrations in one or two of the investigated internal tissues (0.31 < r < 0.45). The regression models presented here may be used to predict metal and As concentrations in internal tissues of hedgehogs when concentrations in hair or spines are available. The present study demonstrated the possibility of using hair and spines for non-destructive monitoring of metal and As pollution in hedgehogs.     

Towards the improvement of UN N.5 test method for the characterization of substances which in contact with water emit flammable gases

This paper deals with a sensitivity analysis of main parameters affecting the measurement of the gas flowrate emitted during testing substances for their potential to emit flammables gases in dangerous quantities where in contact with water, according to the UN N.5 test procedure. UN N.5 is described in the Manual of Tests and Criteria of United Nations (part of the Orange Book) (ONU Manual of Test and Criteria, 2008), serving both applications of international transport regulations as well as classifications of dangerous substances according to Globally the Harmonized System (GHS) and the derived regulation applying in the EU known as “CLP” Regulation (Regulation (EC) No 1271/2008). The main reason that justifies the present research is that the measurement of emitted gases is highly critical in the final classification resulting from the interpretation of the test results. Moreover, that idea has been raised to adapt the UN N.5 test protocol for classifying, in the future, substances that by contact with water would emit dangerous quantities of toxic gases.Experiments have been carried out to cover the analysis of the influence of ambient temperature, overall volume of glassware, nature of aqueous media, mass sample and sample-to-liquid mass ratio, since such parameters are not fixed within any defined range in the UN N.5 test procedure. The influence of the flow rate measuring device was also considered. Results confirm that the above mentioned parameters may play a significant role to such an extent as to finally alter the final classification resulting from the testing. Guiding principles have also been derived from our measurements and observations towards an improved and more robust UN test protocol in the future.