White clover clones as a cost-effective indicator of phytotoxic ozone: 10 years of experience from central Italy

Data collected at one site in central Italy using the NC-S/NC-R clover (Trifolium repens) biotype system during 1997-2007 were analysed in order to assess: (a) its performance under Mediterranean conditions; (b) variations of ozone damage linked with meteorological conditions; (c) if critical level approach is a good predictor of ozone risk on vegetation. NC-S dry biomasses were systematically lower than those of NC-R, the mean ratio being 0.7. Relevant relationship between ozone visible injury and cumulated values of AOT40 were also reported. Temperature and number of rainy days were the most important factors associated with ozone presence and, as a consequence, with leaf injury index. Photosynthetic gas exchange properties indicate that NC-S has higher values of stomatal conductance.     

Lettuce plants as bioaccumulators of trace elements in a community of central Italy

A survey, based on the use of vascular plants to describe the distribution of selected elements (21 in total) was performed in 11 sites in the area of Castelfiorentino (Tuscany, Central Italy) differing for land use, from urban to industrial and rural areas. Lettuce plants grown under standardized conditions were positively used as biodeposimeters of airborne trace elements. Washing was found to be highly significant in reducing concentrations of many elements in the samples, suggesting a general surface contamination of leaves. The typical crustal element Al showed good correlations with Co, Fe, Li and V; on the contrary, Zn and Cd were intercorrelated and showed no connection with crustal indicators. Lead was still a relevant environmental presence, as the experiments were carried out before the ban of leaded gasoline. Source apportionment by factor analysis put in evidence a major contribution of crustal materials, followed by man-related activities; a minor role was ascertained for marine aerosol. A comparison was made between analytical data of lettuce plants grown in our experimental sites and a bulk of commercial lettuce purchased at a local supermarket. It should be stressed how Cu concentrations of commercial material were significantly higher than those found in our plants; this is likely caused by phytosanitary treatments.     

A simple linear model for estimating ozone AOT40 at forest sites from raw passive sampling data

A rapid, empirical method is described for estimating weekly AOT40 from ozone concentrations measured with passive samplers at forest sites. The method is based on linear regression and was developed after three years of measurements in Trentino (northern Italy). It was tested against an independent set of data from passive sampler sites across Italy. It provides good weekly estimates compared with those measured by conventional monitors (0.85 ≤R(2)≤ 0.970; 97 ≤ RMSE ≤ 302). Estimates obtained using passive sampling at forest sites are comparable to those obtained by another estimation method based on modelling hourly concentrations (R(2) = 0.94; 131 ≤ RMSE ≤ 351). Regression coefficients of passive sampling are similar to those obtained with conventional monitors at forest sites. Testing against an independent dataset generated by passive sampling provided similar results (0.86 ≤R(2)≤ 0.99; 65 ≤ RMSE ≤ 478). Errors tend to accumulate when weekly AOT40 estimates are summed to obtain the total AOT40 over the May-July period, and the median deviation between the two estimation methods based on passive sampling is 11%. The method proposed does not require any assumptions, complex calculation or modelling technique, and can be useful when other estimation methods are not feasible, either in principle or in practice. However, the method is not useful when estimates of hourly concentrations are of interest.     

Statistical analysis of heavy metals in Cerastoderma edule glaucum and Venerupis aurea laeta from Ganzirri Lake, Messina (Italy)

Our study was carried out on two species of clams, Venerupis aurea laeta and Cerastoderma edule glaucum, from Ganzirri Lake considered as “environmental biomarkers” for their changes in physiology, morphology or distribution under the influence of substances in the environment. The aim of the present study was to conduct a statistical analysis on Venerupis and Cerastoderma to investigate the difference between the two autochthonous clams according to the presence of metals, and to link metal concentrations to the reproductive cycle of clam during 2009–2010. Metal analysis was carried out with inductively coupled plasma mass spectrometry (ICP-MS). Accuracy and precision were assessed by analyzing the certified standard matrix: mussel tissue NIST SRM 2976. The multivariate analysis was made using the SPSS 13.0 software package for Windows (SPSS Inc., Chicago, IL). In this study, the concentrations of some metals found in clam tissues showed seasonal cycles with higher values in summer than in winter. The significances of metal concentrations differences between Venerupis and Cerastoderma samples were estimated with Mann–Whitney U-test. The concentrations of Ag, As, Cd, Mn, Se and Zn show a significant p-level that suggests a difference between the two group samples. Statistical analysis showed that the link of metal concentrations to the reproductive cycles of Venerupis and Cerastoderma was not evident.     

The effects of the Fukushima disaster on nuclear energy debates and policies: a two-step comparative examination

Under what conditions do critical events trigger large-scale public discussion and mobilisation, and can these lead to policy change? In a comparative study of nuclear energy policy after the Japanese Fukushima disaster in March 2011, a theory-development approach is adopted, mobilising data collected from national news agencies’ newswires, public surveys, legislation and parliamentary databases, and newspaper editorials in 12 established democracies between March 2011 and March 2013. The analysis suggests two main hypotheses that can guide future research: critical events are more likely to trigger policy change when intense (contentious) mobilisation from policy challengers aligns with the views of the general public, and is backed by major political allies; and critical events are more likely to trigger intense (contentious) mobilisation when policy challengers articulate their opposition around pre-existing policy debates on the issue and resort to pre-existing organisational and mobilisation resources.     

Fire as a Soil-Forming Factor

In the span of a human generation, fire can, in theory, impact all the land covered by vegetation. Its occurrence has many important direct and indirect effects on soil, some of which are long-lasting or even permanent. As a consequence, fire must be considered a soil-forming factor, on par with the others traditionally recognized, namely: parent material, topography, time, climate, living beings not endowed with the power of reason, and humans.     

Sex-specific predation on two lizard species by kestrels

Sex-biased predation is thought to have important implications for sexual selection, sex allocation, and population dynamics (Magnhagen, 1991; Le-Galliard et al., 2005 for an example in lizards). Most studies found that males are subjected to higher predation pressure than females during the reproductive season (Korpimäki, 1985; Lodé et al., 2004; Christe et al., 2006; Costantini et al., 2007). In that period, males are very mobile, emit acoustic signals and exhibit brilliant colourations, which are needed to attract females but may make them more visible to predators. With regard to lizards, a recent study provided the first evidence that males of a lizard species may be preyed on more than females (Costantini et al., 2007). In the present study, we investigated whether there is sex-biased predation on two small lacertid species, the common wall lizard Podarcis muralis (Laurenti, 1768) and the Italian wall lizard Podarcis sicula (Rafinesque-Schmaltz, 1810), by Eurasian kestrels (Falco tinnunculus) during the reproductive season. We also examined whether (1) the rate of predation differed between species and (2) the rate of predation differed across years or among hunting habitats for each species.     

Energy efficacy used to score organic refuse pretreatment processes for hydrogen anaerobic production

The production of hydrogen through Anaerobic Digestion (AD) has been investigated to verify the efficacy of several pretreatment processes. Three types of waste with different carbon structures have been tested to obtain an extensive representation of the behavior of the materials present in Organic Waste (OW). The following types of waste were selected: Sweet Product Residue (SPR), i.e., confectionary residue removed from the market after the expiration date, Organic Waste Market (OWM) refuse from a local fruit and vegetable market, and Coffee Seed Skin (CSS) waste from a coffee production plant. Several pretreatment processes have been applied, including physical, chemical, thermal, and ultrasonic processes and a combination of these processes. Two methods have been used for the SPR to remove the packaging, manual (SPR) and mechanical (SPRex). A pilot plant that is able to extrude the refuse to 200 atm was utilized. Two parameters have been used to score the different pretreatment processes: efficiency (ξ), which takes into account the amount of energy produced in the form of hydrogen compared with the available energy embedded in the refuse, and efficacy (η), which compares the efficiency obtained using the pretreated refuse with that obtained using the untreated refuse. The best result obtained for the SPR was the basic pretreatment, with η = 6.4, whereas the thermal basic pretreatment gave the highest value, η = 17.0 for SPRex. The best result for the OWM was obtained through a combination of basic/thermal pretreatments with η = 9.9; lastly, the CSS residue with ultrasonic pretreatment produced the highest quantity of hydrogen, η = 5.2.     

Validation of a dynamic model of hydrogen permeation through Pd-based membranes

Pd-based membranes have been studied for pure hydrogen separation from syngas: in particular, a mathematical model of a Pd membrane for hydrogen separation has been developed.This model can be used in process and assessment studies of the parameters which characterize the mass transfer phenomena (such as: hydrogen permeability, surface coverage and limiting step). By coupling the permeation and water gas shift reaction kinetics, it can also be used to evaluate the performances of the membrane reactor. Further, it can be helpful to evaluate the best assembly and sizing of a H₂/CO₂ separation system.The model takes into account the kinetics of H₂ adsorption/desorption on Pd surface, the H₂ permeation into the palladium bulk and in the porous layer, and the kinetics of CO, CO₂, H₂O, O₂, H₂S competitive adsorption/desorption on Pd surface. It is also comprehensive of flux equations and bulk mass, momentum and energy balance.The results released by the model were compared to the experimental data during both the transient phase and the steady state conditions. A satisfactory agreement between model and experimental data was found.