Parent-absent signalling of need and its consequences for sibling competition in the barn swallow

In species with parental care, competition among siblings for access to limited parental resources is common. Sibling competition can be mediated by begging behaviour, a suite of different visual and acoustic displays by which offspring solicit parental care. These are mostly addressed to the parents upon food provisioning, but can also be performed in the absence of the attending parents. This so-called parent-absent begging (PAB) may function as an intrabrood communication signal and potentially affect intrabrood competition dynamics for access to food. We investigated the role of PAB in moulding sibling interactions and its effect on food intake among altricial barn swallow (Hirundo rustica) nestlings, both under normal and experimentally reduced food intake. Frequency of PAB increased after food deprivation. Nestlings that had performed PAB increased their begging intensity upon the subsequent parental feeding visit, while siblings reduced their own begging level, but only when they had not been food-deprived. As a consequence, nestlings which had performed PAB before parental arrival had larger chances of receiving food. However, nestlings did not benefit from displaying PAB when competing with food-deprived siblings. Our findings show that PAB reliably reflects need of food, indicating that a nestling will vigorously compete for the subsequent food item. By eavesdropping siblings' PAB displays, nestlings may optimally balance the costs of scrambling competition, the direct fitness gains of being fed and the indirect fitness costs of subtracting food to needy kin. However, large asymmetries in satiation between competitors may lead individual offspring to monopolize parental resources, irrespective of PAB displays.     

The self‐built ecovillage in L'Aquila,Italy: community resilience as a grassroots response to environmental shock

The paper applies the community resilience approach to the post‐disaster case of Pescomaggiore, an Italian village affected by the L'Aquila earthquake in 2009. A group of residents refused to accept the housing recovery solutions proposed by the government, opting for autonomous recovery. They developed a housing project in the form of a self‐built ecovillage, characterised by earthquake‐proof buildings made of straw and wood. The project is a paradigmatic example of a community‐based response to an external shock. It illustrates the concept of ‘community resilience’, which is widely explored in the scientific debate but still vaguely defined. Based on qualitative methodologies, the paper seeks to understand how the community resilience process can be enacted in alternative social practices such as ecovillages. The goal is to see under which conditions natural disasters can be considered windows of opportunity for sustainability.     

Teil II: Analytik von Toxaphenrückst?nden (UWSF 2/1998)

Zusammenfassung  Die Rückstandsanalytik des Insektizides Toxaphen galt früher als problematisch wegen der gro?en Anzahl an Komponenten mit ?hnlicher Struktur und unterschiedlichem Chlorgehalt. Erschwerend kam hinzu, da? die Zusamensetzung von Toxaphenrückst?nden in Umweltproben sich von der des technischen Standards signifikant unterscheidet. Deshalb war die Quantifizierung einzelner Komponenten früher nicht m?glich. Seit jedoch eine ganze Reihe von Toxaphenkomponenten in ausreichenden Mengen isoliert wurden, von denen einige für Umweltproben repr?sentativ sind, besteht die M?glichkeit, Toxaphenrückst?nde in Umweltkompartimenten zuverl?ssig zu bestimmen. In der letzten Zeit konzentriert sich die Entwicklung vor allem auf die Trennung der chiralen Bestandteile des Gemisches, um anhand der Zusammensetzung der Rückst?nde Verteilungswege und Abbaumechanismen besser identifizieren zu k?nnen.

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Residue analysis of toxaphene has been difficult because of the complexicity of the technical mixture consisting of a high number of compounds with very similar structure and differing chloro content. Furthermore, the composition of toxaphene in environmental samples varies widely and is normally not like that of the technical mixture. Therefore, quantification of single components in environmental samples was impossible. After the isolation and identification of a great number of components during the last decade, enough standards are available for reliable quantification of toxaphene in all environmental compartments. Recently, most research has been done on the separation of chiral components of toxaphene with a view to identify degradation mechanisms and distribution pathways.

     

Impact of photocatalytic remediation of pollutants on urban air quality

In the recent years, photocatalytic self-cleaning and “depolluting” materials have been suggested as a remediation technology mainly for NO _x and aromatic VOCs in urban areas. A number of products incorporating the aforementioned technology have been made commercially available with the aim to improve urban air quality. These commercial products are based on the photocatalytic properties of a thin layer of TiO₂ at the surface of the material (such as glass, pavement, etc.) or embedded in paints or concrete. The use of TiO₂ photocatalysts as an emerging air pollution control technology has been reported in many locations worldwide. However, up to now, the effectiveness measured in situ and the expected positive impact on air quality of this relatively new technology has only been demonstrated in a limited manner. Assessing and demonstrating the effectiveness of these depolluting techniques in real scale applications aims to create a real added value, in terms of policy making (i.e., implementing air quality strategies) and economics (by providing a demonstration of the actual performance of a new technique).

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Levels and congener profiles of PCBs and PCDD/Fs in blue shark (Prionace glauca) liver from the South-Eastern Mediterranean Sea (Italy)

Liver of blue shark (Prionace glauca) specimens from the South-Eastern Mediterranean Sea were analyzed for the presence of polychlorinated biphenyls (PCBs), including coplanar congeners, polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). PCBs were the dominant chemicals, followed by PCDFs and PCDDs. The pattern of PCB congener concentrations in the hepatic tissue was dominated by higher chlorinated compounds. The specific profile of toxic PCDD/F congeners was characterized mainly by 2,3,7,8-TCDF and 2,3,7,8-TCDD, followed by 1,2,3,6,7,8-HxCDD and 2,3,4,6,7,8-HxCDF. The total 2,3,7,8-TCDD toxic equivalent (TEQs) was 149 pg g⁻¹ lipid wt. The profile of TEQ shows that PCDDs present the greatest risk to this species contributing to total toxicity with a percentage approximately of 60%, while the contribution of PCDFs and DL-PCBs is almost the same being 22.4% and 21.6%, respectively. Further investigations are urgently needed to characterize the PCDD/Fs contamination levels not only in elasmobranch fish but in all Mediterranean marine biota.     

Meteorological and pedological influence on the PCBs distribution in mountain soils

Polychlorinated biphenyls (PCBs) are a threat to environmental and human health due to their persistence and toxicological effects. In this paper, we analyse some meteorological and organic-matter-related effects on their distribution in the soils of an Alpine environment that is not subject to direct contamination. We collected samples and measured the contamination of 12 selected congeners from three soil layers (O, A1 and A2) and from North-, plain- and South-facing slopes on six different dates spanning the entire snowless portion of the year. We recorded the hourly air and soil temperatures, humidity and rainfall in the study period. We found evidence that PCBs contamination in soils varies significantly, depending on sampling date, layer and aspect. The observed seasonal trend shows an early summer peak and a rapid decrease during June. The layer effect demonstrates higher dry-weight-based concentrations in the O layer, whereas the differences are much smaller for SOM-based concentrations. Different factors caused significantly higher concentrations in northern soils, with a N/S enrichment factor ranging from 1.8 to 1.5 during the season. The southern site has significantly more rapid early-summer re-volatilisation kinetics (half-time of 16 d for South, 25 d for North).     

Non-parametric analysis of infrared spectra for recognition of glass and glass ceramic fragments in recycling plants

Glass ceramic detection in glass recycling plants represents a still unsolved problem, as glass ceramic material looks like normal glass and is usually detected only by specialized personnel. The presence of glass-like contaminants inside waste glass products, resulting from both industrial and differentiated urban waste collection, increases process production costs and reduces final product quality. In this paper an innovative approach for glass ceramic recognition, based on the non-parametric analysis of infrared spectra, is proposed and investigated. The work was specifically addressed to the spectral classification of glass and glass ceramic fragments collected in an actual recycling plant from three different production lines: flat glass, colored container-glass and white container-glass. The analyses, carried out in the near and mid-infrared (NIR-MIR) spectral field (1280-4480 nm), show that glass ceramic and glass fragments can be recognized by applying a wavelet transform, with a small classification error. Moreover, a method for selecting only a small subset of relevant wavelength ratios is suggested, allowing the conduct of a fast recognition of the two classes of materials. The results show how the proposed approach can be utilized to develop a classification engine to be integrated inside a hardware and software sorting architecture for fast "on-line" ceramic glass recognition and separation.     

Organic olive orchards on sloping land: More than a specialty niche production system?

Five organic Sloping and Mountainous Olive Plantation Production Systems (SMOPS) have been studied in four olive-producing areas in four European countries (Spain, Italy, Greece and Portugal). Results indicate that these SMOPS provide ecological, economic and social benefits to the regions in which they are located, although most of these benefits are not strictly limited to the organic production systems. Erosion control and organic matter balance remain significant issues in four of the SMOPS and we suggest that subsidy support should be conditional on the implementation of additional soil and water conservation measures that should be provided with specific funding. Most of the SMOPS will remain dependent on a similar level of support in order for olive production to remain economically feasible. The lower profitability compared to non-organic olive production systems suggests that there is limited scope for expansion of organic olive production, although in the study areas where there is little such production, such as Western Crete (Greece) and Basilicata-Salerno (Italy) the scope remains great. The analysis of the reasons for the beneficial effects of olive cultivation in the areas studied indicates that in most cases soil management techniques adopted in or recommended for organic production systems could provide similar benefits in other production systems as well.     

Macrobenthic invertebrates as bioindicators of trace elements in high-mountain lakes

Environmental Science and Pollution Research - Alpine lakes are extreme ecosystems located in remote areas and populated by few but well-adapted species. Because of their remote location, they are...