Inhibitory effect of arachidonic acid on venom acetylcholinesterase

The venom of krait (Bungarus sindanus), an Elapidae snake, contains high level of acetylcholinesterase (AChE) activity. The effect of arachidonic acid on krait (Bungarus sindanus) venom AChE (acetylcholine hydrolase, EC 3.1.1.7) was studied using kinetic methods. This study evaluated for the first time whether arachidonic acid acts as potential AChE inhibitor of krait venom. Kinetic studies, using Line-Weaver Burk and Dixon plots, indicated that the inhibition produced by arachidonic acid was non-competitive, i.e., both k_m and V _max fell with increase in the concentration of arachidonic acid. The concentration of arachidonic acid required to inhibit 50% of enzymatic activity was found to be 1.9?µM while the inhibitory constant (K_i ) was 1.4?µM. The present results suggest that essential fatty acid (arachidonic acid) may also be used as an inhibitor of snake venom AChE.     

Sustainability indicators for environmental performance and sustainability assessment of the productions of four fine Italian wines

Increased awareness of the importance of environmental protection and the introduction of international standards like ISO 14001 stimulated development of environmental sustainability indicators as a means to measure systems environmental performance. Here, a thermodynamic approach, emergy analysis (Odum, 1988) was used to obtain sustainability indicators able to analyse and quantify the productive and ecological performance of four famous Italian wine productions: Chianti, Brunello di Montalcino, Nobile di Montepulciano, and Barbera d'hti. The application to agricultural production was motivated by the growing need for productive and environmentally sound development in modern agriculture, in which the resource base, the environment, is preserved. The choice of wines, more precisely, grape production, is due to their importance for Italian agriculture and the economy. All the wines demonstrated a good long-term environmental sustainability, especially in view of their high quality and in comparison with the average Italian wine production. Emergy analysis proved a powerful tool for assessing environmental performance of these systems, and its use could easily be extended to other wine productions to obtain a form of environmental performance classification of this product. Systematic use of emergy analysis to assess environmental performance of different processes and products, not necessarily in agriculture, could be useful for environmental certification.     

Combined effect of fire and water scarcity on vegetation patterns in arid lands

In many arid zones around the word, the vegetation spontaneously forms regular patterns to optimize the use of the scarce water resources. The patterns act as early warning signal that fragile ecosystems may suddenly undergo irreversible shifts, thus, interpreting the structural shape of vegetation patterns is crucial to deciphering the ecosystem history and its expected further development. The sudden and irreversible shift of delicate ecosystems as a consequence of minor variation of the climatic forcing has been studied extensively in the past. The attitude of the ecosystem to recover after a catastrophic event, such as fire, did not receive as much attention so far. Here we modelled fire, as a sudden shift of the ecosystem state variables and functionality and evaluated post-fire scenarios under the hypothesis that two major feedbacks shaped the vegetation patterns: a positive feedback between preferential infiltration and plant growth, and a second feedback between infiltration and vegetation burning. A simple model solving a set of partial differential equations for soil moisture, plant biomass, surface water and dead biomass balance predicted significantly diverse post-fire vegetation patterns depending on the fire severity and on the degree of soil water repellency induced by the vegetation burning.     

Production of bio-fertilizer by biotransformation of poultry waste enriched with molasses and algae

This research work consists on valorizing poultry waste by biotransformation into biofertilizers, associating this agro-industrial waste with algae (abundant natural resources) and molasses (a by-product of the sugar refining industry) ensuring a good contribution of nutritional chemical elements and obtaining a balanced formulation. A total of seven different formulations of the above three components, were examined in a simplex centroid design. A fungal inoculum of Aspergillus niger was used as a fermentation agent for better quality of biotransformation. The monitoring of this biotransformation is ensured during 15 days by following the evolution of physicochemical and microbiological parameters and, to understand the bioconversion of the simple compounds of the biofertilizer mixture such as short aliphatic chains, sugar, and amino acids into soluble mineral compounds, a Fourier transform infrared spectroscopy (FTIR) analysis was carried out before and after biotransformation. Finally, germination and fertilization tests were performed to evaluate the efficiency of the final product on a barley crop. The overall results of the present study showed that the mixture which contained 68.75% poultry waste, 12.5% molasses, and 18.75% algae presented the better microbiological and chemical safety criteria required for a good biofertilizer according to NF U44-551 standard.     

Above and below ground biomass patterns in arid lands

Regular vegetation patterns have been observed in many arid zones around the word. This particular spontaneous arrangement of the vegetation optimizes the use of the scarce water resources and could be imitated to restore vulnerable ecosystems; at the same time, the patterns of vegetation act as an early warning signal of the fact that fragile ecosystems may suddenly undergo irreversible shifts, thus, they deserve a special attention. The formation of vegetation patterns is the object of many theoretical and experimental studies, nevertheless, in previous works, the interest that is deserved to below ground biomass allocation is minor as compared to the effort that is spent to describe the organization of vegetation above ground.     

Informative content of multiple plumage-coloured traits in female and male European Rollers

Animals may assess the quality of other individuals by using information that different ornaments may provide. The European Roller (Coracias garrulus) is a socially monogamous species in which males and females display highly conspicuous plumage colouration. According to the mutual selection hypothesis, we predicted that, in this species, plumage coloration could signal individual quality in both sexes because both female and male rollers invest a considerable amount of time caring for their offspring. We used spectrophotometric measurements to investigate the information content of multiple plumage colour traits. We found that the roller is actually a sexually dimorphic and dichromatic species. Different plumage colours from different origins were correlated within individual. Head and back brightness correlated with body condition in both sexes, and in males, head brightness correlated with the number of fledglings in successful nests, while head green-yellow saturation correlated with parental provisioning. Meanwhile, in females, back brightness was related to the number of fledglings in successful nests and to parental provisioning rate. In addition, there was a positive assortative mating in relation to weight, body condition, head green-yellow saturation and back brightness. Finally, we found a positive correlation between parent and offspring coloration. Altogether, these results suggest that multiple colour traits may act as quality indicators in the roller and that they may be used by the two sexes to assess potential mate quality.     

Unexpected toxic interactions in the freshwater amphipod Gammarus pulex (L.) exposed to binary copper and nickel mixtures

To document the toxicity of copper and nickel in binary mixtures, freshwater amphipods Gammarus pulex were exposed to the metals given independently or as mixtures. Toxicity to Cu alone was relatively high: 96-h LC₁₀ and LC₅₀ were found at 91 and 196 μg L^?1, respectively. Toxicity to Ni alone was very low, with 96-h LC₁₀ and LC₅₀ of 44,900 and 79,200 μg L^?1, respectively. Mixture toxicities were calculated from single toxicity data using conventional models. Modeled toxicity was then compared with the measured toxicity of the binary mixture. Two kinds of mixtures were tested. Type I mixtures were designed as combinations of Cu and Ni given at the same effect concentrations, when taken independently, to identify possible interactions between copper and nickel. In type II mixtures, Cu concentrations varied from 0 to 600 μg L^?1 while the nickel concentration was kept constant at 500 μg L^?1 to mimic conditions of industrial wastewater discharges. Ni and Cu showed synergic effects in type I mixtures while type II mixtures revealed antagonistic effects. Low doses of Ni reduced Cu toxicity towards G. pulex. These results show that even for simple binary mixtures of contaminants with known chemistry and toxicity, unexpected interactions between the contaminants may occur. This reduces the reliability of conventional additivity models.     

Assessing use-values and relative importance of trees for livelihood values and their potentials for environmental protection in Southern Burkina Faso

Environment, Development and Sustainability - Empirical ethnobotanical studies in Burkina Faso and the Sahel apply unmodified use-value methods, which often fail to capture uses of plants within...     

Levels of dechlorane plus and polybrominated diphenylethers in human milk in two Canadian cities

Flame retardant dechlorane plus (DP) and several polybrominated diphenylether (PBDE) congeners have been measured in 87 human milk samples collected in two Canadian cities: Kingston and Sherbrooke. The levels of PBDEs in human milk (mean (median), ng g^− 1 lipid weight = 10 (5.9), 4.1 (2.8), 3.0 (1.6), 5.12 (1.6), and 15 (ND) for BDE-47, BDE-99, BDE-100, BDE-153, and BDE-209, respectively) were comparable to those reported in Europe, U.S.A. and China. The levels of DP, with a mean value of 0.98 ng g^− 1 and a median value of 0.60 ng g^− 1 (lipid weight), were two to ten times lower than those of concurrently measured major PBDEs including BDE-209. While there is little difference in the levels of measured contaminants in milk samples collected from the two cities, the contaminants levels in human milk show, indicated by Principal Components Analysis, that DP, deca-BDE, and penta-BDE come from three distinct sources. The mean and median isomer ratio values of DP in milk were 0.67 and 0.69, respectively, very similar to that of DP commercial products.     

Ecological footprint analysis applied to a sub-national area: the case of the Province of Siena (Italy)

This work is part of a larger project, which aims at investigating the environmental sustainability of the Province of Siena and of its communes, by means of different indicators and methods of analysis. The research presented in this article uses ecological footprint and biocapacity as indicators to monitor the environmental conditions of the area of Siena, thus complementing previous studies carried out using Emergy, greenhouse gases balance and other methods. The calculations have been performed in such a way as to enable a disaggregation of the final results according to the classical categories of ecologically productive land and of consumption, but also according to citizen's and public administration's areas of influence. This information allows us to investigate in detail the socio-economic aspects of environmental resource use. Among the notable results, the Siena territory is characterized by a nearly breakeven total ecological balance, a result contrasting with the national average and most of the other Italian provinces. Furthermore, the analysis has been carried out at different spatial scales (province, districts and communes), highlighting an inhomogeneous territorial structure consisting of subareas in ecological deficit compensated by zones in ecological surplus.