Performance of a narrow buffer strip in abating agricultural pollutants in the shallow subsurface water flux

The performance of a narrow buffer strip in abating dissolved P, electrical conductivity and herbicides (terbuthylazine, alachlor, nicosulfuron, pendimethalin, linuron) in subsurface water coming from cropland was tested in an experiment carried out on the low plains of the Veneto Region (NE Italy). The experiment lasted from December 1997 to June 1999, monitoring subsurface water quality entering and exiting a buffer composed of a grass strip (5 m wide) and 1 m wide row of trees. Dissolved phosphorus concentrations were reduced by almost 100% passing through the buffer and in most cases exiting water satisfied the limit for avoiding eutrophication. A positive effect was also detected on ECW (reduced by 20%), while pH was not significantly altered. Herbicide concentration abatement varied between 60 and 90%, depending on the chemical and the time elapsed since application.     

Taxing overexploited open-access fisheries: the role of demand elasticity

The paper aims at identifying the effects exerted by a tax levy on an overexploited and previously unregulated fishery. The analysis is carried out by means of a dynamic model that includes fish stock and harvesting effort as state variables. Attention is focused on the role played by demand elasticity which is shown to affect both transients and equilibria.According to the analysis, a levy induces a contraction in effort, which is sharper in the short term. As a consequence, the fish population recovers and ultimately settles at a higher equilibrium level. Therefore, a larger amount of fish is caught in the long run and sold at a lower price than in the unregulated setting. The more inelastic the demand, the smaller both the equilibrium price for fish and the tax imposed.     

Lichen biomonitoring of trace metals in the Pistoia area (central northern Italy)

The epiphytic lichen Parmelia caperata (L.) Ach. was used as bioaccumulator of the heavy metals Cd, Cr, Cu, Hg, Ni, Pb and Zn in the environs of the town of Pistoia (central northern Italy). The concentrations of Cd, Cr, Ni, Hg and Pb were comparable with those found in areas not subject to atmospheric pollution. Copper and especially Zn were found in rather high concentrations. Fertilizers and pesticides were the main source of atmospheric contamination.     

Side biases in humans (Homo sapiens): three ecological studies on hemispheric asymmetries

Hemispheric asymmetries and side biases have been studied in humans mostly in laboratory settings, and evidence obtained in naturalistic settings is scarce. We here report the results of three studies on human ear preference observed during social interactions in noisy environments, i.e., discotheques. In the first study, a spontaneous right-ear preference was observed during linguistic exchange between interacting individuals. This lateral bias was confirmed in a quasi-experimental study in which a confederate experimenter evoked an ear-orienting response in bystanders, under the pretext of approaching them with a whispered request. In the last study, subjects showed a greater proneness to meet an experimenter’s request when it was directly addressed to the right rather than the left ear. Our findings are in agreement both with laboratory studies on hemispheric lateralization for language and approach/avoidance behavior in humans and with animal research. The present work is one of the few studies demonstrating the natural expression of hemispheric asymmetries, showing their effect in everyday human behavior.     

Photochemical reaction of peroxynitrite and carbon dioxide could account for up to 15 % of carbonate radicals generation in surface waters

The carbonate radical (CO ₃ ^?· ) is a photoinduced transient species occurring in surface waters. The carbonate radical can transform both natural compounds and xenobiotics. For instance, it can react with electron-rich substrates such as anilines, phenols and organic sulfur compounds. Here we used the APEX software to assess photochemical reactions, including the formation rates of transient species, based on water chemistry and depth, under summertime irradiation conditions. We found that the reaction between peroxynitrite and carbon dioxide is a potentially significant source of CO ₃ ^?· in sunlit surface waters, and could account for up to 10–15 % of the total CO ₃ ^?· formation. The peroxynitrite pathway to CO ₃ ^?· would be most significant at pH 7–8 and would be enhanced in waters with elevated nitrate and low alkalinity. Therefore, the proposed process could add to the known photochemical sources of CO ₃ ^?· in surface-water environments.     

Age-related changes in an insect mating signal have no effect on female choice

The structure of male mating signals is often influenced by age. The causes and consequences of age-based signal variation have been much studied in visual, acoustic, and chemical signaling modalities, but are less explored in species that use vibrational signals for mate attraction. However, the complex structure of many vibrational signals makes them ideal for investigating the relationships between age, signal variation, and patterns of female choice. In the thornbug treehopper, Umbonia crassicornis, females mate more often with older males, but the mechanism underlying older male mating success is unknown. Our goals in this study were to determine whether male vibrational mate advertisement signals vary with age, and, if so, whether females prefer the signals of older males. We recorded male signals over four consecutive weeks beginning at the onset of signaling (a period spanning most of the male reproductive lifespan), and measured ten temporal, spectral, and energy-related parameters from each signal. Several features of male signals changed markedly with age. However, females responded similarly to signals representing males of different ages, indicating that they do not favor older males on the basis of long distance mate advertisement signals. Nonetheless, the results reveal that even in short-lived, determinate growth species age can have surprisingly large effects on mating signals, and we discuss some factors that may contribute to age-related signal variability in U. crassicornis.     

Feeding current characteristics of three morphologically different bivalve suspension feeders, Crassostrea gigas, Mytilus edulis and Cerastoderma edule, in relation to food competition

Introduced Pacific oysters (Crassostrea gigas) have shown rapid expansion in the Oosterschelde estuary, while stocks of native bivalves declined slightly or remained stable. This indicates that they might have an advantage over native bivalve filter feeders. Hence, at the scale of individual bivalves, we studied whether this advantage occurs in optimizing food intake over native bivalves. We investigated feeding current characteristics, in which potential differences may ultimately lead to a differential food intake. We compared feeding currents of the invasive epibenthic non-siphonate Pacific oyster to those of two native bivalve suspension feeders: the epibenthic siphonate blue mussel Mytilus edulis and the endobenthic siphonate common cockle Cerastoderma edule. Inhalant flow fields were studied empirically using digital particle image velocimetry and particle tracking velocimetry. Exhalant jet speeds were modelled for a range of exhalant-aperture cross-sectional areas as determined in the laboratory and a range of filtration rates derived from literature. Significant differences were found in inhalant and exhalant current velocities and properties of the inhalant flow field (acceleration and distance of influence). At comparable body weight, inhalant current velocities were lower in C. gigas than in the other species. Modelled exhalant jets were higher in C. gigas, but oriented horizontally instead of vertically as in the other species. Despite these significant differences and apparent morphological differences between the three species, absolute differences in feeding current characteristics were small and are not expected to lead to significant differences in feeding efficiency.     

Study of fluxing in Al refining process by rotary and crucible furnaces

The process used to obtain recycled Al alloys depends on the scrap quality. Rotary furnaces are normally used in Europe as they allow a great productivity and they can process low quality scrap using a salt flux to protect the molten metal from oxidation. In this article, the effect of the quantity of salt on the metal recovery has been experimentally investigated by melting several types of scrap under a mixture of NaCl–KCl–Na₃AlF₆ salts. The quantity of salt has been related to the salt factor (SF), which is the ratio between the non-metallic content in the scrap and the quantity of salt required. The same levels of salt factor have been tested by melting the scrap in rotary and crucible furnaces. The metal recovery increases with the salt content for both furnaces. The results obtained with the different melting processes are comparable because the yield difference is similar considering different salt factors. Crucible furnace gives greater metal recovery but it cannot replace rotary furnace in Al refining industry due to lower melting capacity. However, the results highlight that the optimisation of the Al refining process can be supported by preliminary tests through crucible furnaces reducing the time and material consumptions.     

Environmental photochemistry of fluoroquinolones in soil and in aqueous soil suspensions under solar light

The photodegradation fate of widely used fluoroquinolone (FQ) drugs has been studied both at the water–soil interface and in soil at actual concentrations (500 ng g^?1) under natural solar light. Both human and veterinary drugs have been examined, namely ciprofloxacin, danofloxacin, enrofloxacin, levofloxacin, marbofloxacin and moxifloxacin. After spiking and irradiation, samples were submitted to microwave-assisted extraction and analyzed by high-performance liquid chromatography coupled to fluorescence detection (HPLC–FD). FQs degradation was faster in aqueous soil suspension than in neat soil (but lower than in “clean” water). A number of byproducts were identified by HPLC electrospray ionization tandem mass spectrometry after a post-extraction cleanup based on a molecularly imprinted polymer phase, for a more accurate detection. The distribution in the suspension was intermediate between those observed in soils and in aqueous solutions.     

Combining Environmental Factors and Agriculturalists’ Observations of Environmental Changes in the Traditional Terrace System of the Amalfi Coast (Southern Italy)

Terraces are traditional engineered ecosystems that affect the hydro-geological equilibrium, slope stability, and local communities. The aims of this paper are (i) identifying environmental factors that affect terrace stability in the Amalfi Coast, (ii) defining agriculturalists’ observations on environmental changes within that system and (iii) exploring potentiality of these observations to better define conservation strategies. All available data on physical and ecological factors recognized to affect the terrace system were collected and analyzed. Interviews were conducted with agriculturalists to obtain long-term observations on environmental factors that interact with this system. Landslides are more frequent where rainfall is high and during winter. Fires have an uneven annual distribution, with higher frequency during summers. Agriculturalists detailed complex interactions among environmental factors, economic elements, and terraces. These observations represent a valuable resource for defining causes and effects of abandonment and for better addressing conservation strategies.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-013-0433-3) contains supplementary material, which is available to authorized users.