Environmental assessment of biodegradable multilayer film derived from carbohydrate polymers

Multilayer films exhibit excellent properties for food packaging. However, existing products are not biodegradable. Conventional plastics, manufactured from fossil fuels, not only consume non-renewable and finite resources, but also impact heavily on waste disposal. For this reason, a new multilayer film has been developed in the Multibio Project for the production of food packaging. In this paper, the environmental impacts of the new biodegradable multilayer film—based on modified starch and polylactic acid (PLA)—and those of the conventional multilayer film—based on PP and PA6—are quantified in the categories of climate change, fossil fuel depletion, acidification and eutrophication. Conventional multilayer film has a 90% higher impact than the Multibio multilayer film. The main difference between the LCA presented and the cited literature is the inventory data obtained in the phase of polymer processing to obtain multilayer film, and the assessment of the disposal phase of the multilayer film wastes.     

Who participates in conservation initiatives? Case studies in six rural communities of Mexico

Previous studies attempting to explain the factors that determine local participation in conservation initiatives have concluded that socio-political exclusion is the main barrier to being involved in such initiatives. Such studies have not differentiated between different types of conservation initiatives. In this paper, we contribute to the literature analyzing the socio-cultural correlates of participation, by differentiating between participation in three types of conservation schemes: protected areas, payment for environmental services, and community conservation. We use data obtained from six rural communities in Mexico, where different combinations of conservation schemes are found. Through linear regression analysis, we explore the relationship between participation and (1) the community of residence; (2) demographics; and (3) socioeconomic characteristics of individuals. Our results suggest that local participation in conservation strategies depends, to a large extent, on the socio-political context in which they are embedded and that the exclusion of women and young adults is clearly consistent.     

Geographic assignment of seabirds to their origin: combining morphologic, genetic, and biogeochemical analyses.

Longline fisheries, oil spills, and offshore wind farms are some of the major threats increasing seabird mortality at sea, but the impact of these threats on specific populations has been difficult to determine so far. We tested the use of molecular markers, morphometric measures, and stable isotope (delta15N and delta13C) and trace element concentrations in the first primary feather (grown at the end of the breeding period) to assign the geographic origin of Calonectris shearwaters. Overall, we sampled birds from three taxa: 13 Mediterranean Cory's Shearwater (Calonectris diomedea diomedea) breeding sites, 10 Atlantic Cory's Shearwater (Calonectris diomedea borealis) breeding sites, and one Cape Verde Shearwater (C. edwardsii) breeding site. Assignment rates were investigated at three spatial scales: breeding colony, breeding archipelago, and taxa levels. Genetic analyses based on the mitochondrial control region (198 birds from 21 breeding colonies) correctly assigned 100% of birds to the three main taxa but failed in detecting geographic structuring at lower scales. Discriminant analyses based on trace elements composition achieved the best rate of correct assignment to colony (77.5%). Body measurements or stable isotopes mainly succeeded in assigning individuals among taxa (87.9% and 89.9%, respectively) but failed at the colony level (27.1% and 38.0%, respectively). Combining all three approaches (morphometrics, isotopes, and trace elements on 186 birds from 15 breeding colonies) substantially improved correct classifications (86.0%, 90.7%, and 100% among colonies, archipelagos, and taxa, respectively). Validations using two independent data sets and jackknife cross-validation confirmed the robustness of the combined approach in the colony assignment (62.5%, 58.8%, and 69.8% for each validation test, respectively). A preliminary application of the discriminant model based on stable isotope delta15N and delta13C values and trace elements (219 birds from 17 breeding sites) showed that 41 Cory's Shearwaters caught by western Mediterranean long-liners came mainly from breeding colonies in Menorca (48.8%), Ibiza (14.6%), and Crete (31.7%). Our findings show that combining analyses of trace elements and stable isotopes on feathers can achieve high rates of correct geographic assignment of birds in the marine environment, opening new prospects for the study of seabird mortality at sea.     

Bioremediation of 3,4-dichloroaniline and 2,4,6-trinitrotoluene in soil in the presence of natural adsorbents

The use of some adsorbents may decrease the toxicity of organic pollutants to microbes and plants during soil bioremediation. Experiments were conducted with 3,4-dichloroaniline (DCA) and 2,4,6-trinitrotoluene (TNT). Here we demonstrate that activated carbon can reduce the toxicity of readily available chemicals in soil by transferring them to a less available fraction. This process results in accelerated biodegradation of dichloroaniline by the inoculated Paracoccus denitrificans st. 3XA. In the case of TNT, activated carbon promotes strong binding through accelerated microbial reduction of its nitro-groups and catalytic chemical oxidation of the methyl-group and polymerisation or binding of the products formed.     

The past ownership of a resource affects the agonistic behavior of hermit crabs

Resource value is often considered the most important nonstrategic variable in the fighting behavior of invertebrates. In our study, we tested whether the experience of shells of a given quality, occupied in the recent past, might affect the agonistic behavior of the hermit crab Pagurus longicarpus. We analyzed the fights battled by 84 test crabs against size-matched unknown rivals before (premanipulation phase) and after (postmanipulation phase) having modified the quality of the domicile shell of the contestants. Specifically, we compared the behavior of crabs that had been subject to either a worsening or an improvement in the quality of their shell with crabs that, although being similarly subject to a shell manipulation, occupied a shell of the same quality as in the premanipulation phase. We found that the crabs subject to a worsening in the quality of their shell were more aggressive than those subject to its improvement and that the former were even more aggressive than those that occupied a bad quality shell also in the premanipulation phase. Crabs seemed not to gather information about the opponent’s shell during fights or not to use this information, most often behaving in accordance with the quality of the domicile shell. These results are clear in showing the role played by the experience of a previously occupied shell, also confirming that the agonistic behavior of P. longicarpus is mainly based on decision rules of the type “own resource value dependency.”     

Transfer rate of pesticide residues from medicinal plants in different types of extractive solutions

Abstract

Starting from the suspicion that the medicinal herbs may contain traces of pesticides and taking into account the risks of patients being exposed to contaminated products, the aim of this research was to evaluate the pesticide residues and the degree of their transfer (%) in three types of preparations (infusion, decoctionand cold maceration), for four medicinal plant species very often used in phytotherapy (Rosmarini folium, Menthae folium, Saturejae herba and Basilica herba). For each type of plant product, four samples were purchased from different manufacturers and they have been analyzed using gas chromatography- tandem mass spectrometry. One out of four samples of the same plant species contain at least one pesticide residue above the maximum level and shows a significant transfer of these residues in aqueous extractive solutions during extraction. The highest rate of pesticide transfer from medicinal plants was identified in infusions, recommended by many manufacturers.     

Sterols in sediment samples from Venice Lagoon, Italy

Sterols of different origin were analysed in sediment samples collected in the Venice Lagoon. The purpose of the study was to investigate the degree of sewage contamination within the Lagoon using fecal sterols (coprostanol, epicoprostanol and coprostanone) and to analyse the pattern of the sterols to plot the origin of the organic matter.

Sedimentary coprostanol at Canal Grande within the city of Venice was more than one order of magnitude higher than other stations in the Lagoon and two orders higher than in a sediment sample collected in the open sea. The cholesterol/coprostanol ratio, like the percentage of coprostanol in total sterols at this sample site was very similar to values in sewage sludge. The different pattern of sterols at station 2 which had the largest amount of total sterol indicates a difference in the origin of the organic material. Nevertheless the sterols used as tracer of terrestrial vascular plants did not show any particular trend at this station, receiving fresh water inputs. (3-Sitosterol and cholestanol reached the highest levels at the station within the Chioggia basin.     

Determination of the temperature dependence of water solubilities of polycyclic aromatic hydrocarbons by a generator column-on-line solid-phase extraction-liquid chromatographic method

An improved dynamic coupled column liquid chromatographic (DCCLC) technique for determining water solubility data of hydrophobic compounds is presented. The technique is based on pumping water through a thermostated generator column in order to generate emulsion-free, saturated aqueous solutions of the compound under study. Through a switching valve system the solute in the aqueous solution is extracted and concentrated by an on-line solid-phase extraction process and subsequently eluted and analyzed by high performance liquid chromatography (fluorescence detection coupled to photodiode array detection). The improvements carried out to the original DCCLC technique have given rise to savings in time for the experimental work and increased sensitivity during the detection and quantification stage. Applicability of the method for studying highly hydrophobic substances is demonstrated by determining water solubility of anthracene and pyrene in the temperature range of 8.9-49.9 and 8.5-32.2 degrees C, respectively. The measured water solubilities are in good agreement with the best available literature data. The method has also been applied to the determination of water solubility of m-terphenyl, 9, 10-dihydrophenanthrene and guaiazulene, in the temperature range of 4.8-49.9, 4.8-25.0, and 4.5-29.9 degrees C, respectively. The uncertainty in the Sw values determined in this work ranged from 0.7% to 4.6%. The experimental water solubility data, as a function of temperature, are fitted to the equation In Sw = A + B/T; where Sw and T are given in mole fraction and Kelvin, respectively.     

Satellite image analysis of human caused changes in the tundra vegetation around the city of Vorkuta,north-European Russia

In this paper we present what kind of human impacted changes can be found in dwarf birch (Betula nana) dominated shrub tundra vegetation around the large industrial complex of Vorkuta in the north-European Russian tundra. Using fieldwork data and Landsat TM satellite image we could identify two impact zones: (1) Pollution zone (150-200 km2). In this zone most of the lichen species are absent. Changes in vegetation communities' species composition in all main plant groups are obvious. Willows especially are more dominant than in the unpolluted sites. (2) Slight pollution/disturbance zone (600-900 km2). Here vegetation changes are mainly similar but less so than the changes in the first zone. Particularly, the amount of herbs and grasses is increased when compared to unpolluted areas. The pollution zones are spatially connected to the main emission sources in the area. Zones spread furthest to the northeast, matching the prevailing winds during winter.