The response of Populus spp. to cadmium stress: Chemical,morphological and proteomics study

Poplar (Populus) species are seen as candidates for removing heavy metal contamination from polluted soil. A bottom-up multidisciplinary approach was utilized to compare the performances of clones 58-861 and Poli (Populus nigra) and A4A, a Populus nigra × Populus deltoides hybrid to Cd toxicity. Qualitative and quantitative differences in their tolerance to Cd exposure and the uptake, accumulation and translocation of Cd were noted following the hydroponic exposure of rooted cuttings to 20 μM CdSO₄ for either 48 h or 14 d. Cadmium was less toxic for the hybrid clone A4A as compared to Poli and 58-861. Cd uptake and root to shoot translocation were determined by AAS, and its compartmentation was analyzed using SEM/EDX. A comparative proteomic approach was utilized to identify changes in proteins expression according to dose and time of exposure. Toxicity to Cd mainly influenced proteins related to general defense, stress response and carbohydrate metabolism.     

Optimal planning for the sustainable utilization of municipal solid waste

The increasing generation of municipal solid waste (MSW) is a major problem particularly for large urban areas with insufficient landfill capacities and inefficient waste management systems. Several options associated to the supply chain for implementing a MSW management system are available, however to determine the optimal solution several technical, economic, environmental and social aspects must be considered. Therefore, this paper proposes a mathematical programming model for the optimal planning of the supply chain associated to the MSW management system to maximize the economic benefit while accounting for technical and environmental issues. The optimization model simultaneously selects the processing technologies and their location, the distribution of wastes from cities as well as the distribution of products to markets. The problem was formulated as a multi-objective mixed-integer linear programing problem to maximize the profit of the supply chain and the amount of recycled wastes, where the results are showed through Pareto curves that tradeoff economic and environmental aspects. The proposed approach is applied to a case study for the west-central part of Mexico to consider the integration of MSW from several cities to yield useful products. The results show that an integrated utilization of MSW can provide economic, environmental and social benefits.     

Community-based forest management in the Yungas biosphere reserve, Northern Argentina

The purpose of this paper is to discuss a methodology for the implementation of a participative plan for forest use and management in a rural community. We present an experience carried out in an aboriginal community located in the “Yungas biosphere reserve” in Northern Argentina. We developed a methodology to work with the community to assess the quality of the forest resources and to find out the causes of degradation. We worked at three levels: the community council, the community, and the school. The community has a very short-term vision. The setup, the feasibility, and the implementation of the plan is highly dependent on the willingness of the community to participate. It is so far the first attempt, in Yungas region, to develop a multi-level methodology to work with local communities to implement a forest-management plan. Findings and recommendations could be useful for others who would like to work in similar contexts.     

Physico-chemical analysis and calorific values of poultry manure

Spain is one of the major producers of broilers and laying hens in the European Union, with an overall market share of around 12%. The poultry manure that is produced is usually employed as fertilizer on cropland, either directly or after a composting process. In some cases, however, this waste is transported over 120 km to be used as fertilizer, with the resulting high transport costs. In other countries, poultry manure is used as an alternative natural fuel source for power generation. In this study, poultry manure from all the laying hen farms in Asturias was characterized with a view to its possible use as an energy source. The Higher Heating Values on a dry basis (experimental) varies between 12,052 and 13,882 kJ/kg. Lower Heating Values (LHVs) on a wet basis range are much lower (mean values of 2664 kJ/kg) due to the high moisture content of poultry manure. Accordingly, the co-combustion of this waste with other types of waste such as forest and wood waste (LHV on a wet basis of 8044 and 15,830 kJ/kg, respectively) or municipal solid waste (LHV on a wet basis of 10,725 kJ/kg) should be considered as an alternative energy source. Chlorine and sulphur contents in dry matter vary around mean values of 0.64% and 0.11%, respectively. The waste also presents high amounts of Ca (4.84%) and K (2.38%).     

Elemental concentrations in aerosols at the Belgian coast versus seasons and air mass trajectories

Marine aerosols have extensively been monitored in the framework of a research project to investigate the inorganic and organic nutrient fluxes of the atmospheric nitrogen input into the North Sea. As a part of this project bulk analysis was also performed by energy dispersive X-ray fluorescence (EDXRF) on a total of 366 samples in order to provide detailed elemental composition. Samples have been clustered per campaign and differences were related to backward trajectories. Elements as Cl, Si, and S appeared to be the best tracers for coastal aerosols. Therefore they have been chosen to represent each campaign and to map the seasonal variations. It is clear that Cl is an excellent tracer for oceanic trajectories, while a less clear correlation between the soil dust components and the air mass trajectories is found.     

Responses of terrestrial arthropods to air pollution: a meta-analysis

Background, aim, and scope  

Arthropods, with over a million species described, are ubiquitous throughout different environments. Knowledge of their responses to human impact is crucial for understanding and predicting changes in ecosystem structure and functions. Our aim was to investigate the general patterns and to identify sources of variation in changes of the diversity, abundance and fitness of terrestrial arthropods (including Arachnida, Collembola and Insecta) in habitats affected by point polluters.     

Increased levels of polychlorobiphenyls in Italian women with endometriosis

Endometriosis has been hypothesised to be linked to persistent and toxic organochlorinated chemicals. Dioxins and dioxin-like compounds have in particular been associated with the disease, mainly on the basis of experimental studies. Data in women are conflicting. A case-control study on 80 Italian nulliparous women of reproductive age was carried out to assess whether there is a correlation between the presence of endometriosis and blood levels of polychlorobiphenyls (PCBs), a family of ubiquitary environmental pollutants which comprises congeners with dioxin-like activity. Higher levels of PCBs were found in women with endometriosis. A mean cumulative value of 410 ng g(-1), lipid base, was found in cases versus the value of 250 ng g(-1) observed in the control group (odds ratio for upper tertile 4.0, CI 95% 1.3-13; p = 0.0003). PCB increase involved both dioxin-like (PCBs 105, 118, 156, and 167) and non-dioxin-like congeners (PCBs 101, 138, 153, 170, 180).     

Simplified spectrophotometric method using methylene blue for determining anionic surfactants: applications to the study of primary biodegradation in aerobic screening tests

In the present work, we propose a simplified spectrophotometric method for determining anionic surfactants, based on the formation of the ionic pair anionic surfactant-methylene blue (AS-MB). This method, in relation to the conventional analytic procedure, considerably reduces not only the quantity of chloroform used in extracting the ionic pair formed, but also the time and the quantity of sample necessary to perform the assay, eliminating the filtration stage. The method has been simplified by displacing the transfer equilibrium of the ionic pair AS-MB towards the organic phase, augmenting the volumetric relationship of chloroform/sample. The method proposed has been applied in the study of primary biodegradation kinetics of linear alkylbenzenesulfonate (LAS).     

Physicochemical characterization and mercury speciation of particle-size soil fractions from an abandoned mining area in Mieres, Asturias (Spain)

Soils from old cinnabar mining areas usually exhibit high Hg contents, whose mobility depends on soil parameters and environmental conditions. This paper presents the study of the Hg speciation in soil samples from an abandoned Hg mine and metallurgical plant in Mieres (Asturias, Spain), in relation to their mineralogical and chemical composition and their particle-size distribution. A characterization of samples was made by X-Ray Diffraction Spectrometry, Scanning Electron Microscopy and Atomic Absorption and Emission Spectroscopy analyses. A sequential extraction method was applied to establish Hg mobility in the samples and their grain-size subsamples. The highest Hg mobility was found in well-developed soils, as a consequence of the adsorption processes by iron and manganese oxides, whereas in those more contaminated soils, a higher proportion of Hg was leached in the non-mobile fraction. A higher Hg mobility was found in the finest grain-size subsamples, probably due to the accumulation of clay minerals and oxides in these ranges.     

Isolation and characterization of melanopsin and pinopsin expression within photoreceptive sites of reptiles

Non-mammalian vertebrates have multiple extraocular photoreceptors, mainly localised in the pineal complex and the brain, to mediate irradiance detection. In this study, we report the full-length cDNA cloning of ruin lizard melanopsin and pinopsin. The high level of identity with opsins in both the transmembrane regions, where the chromophore binding site is located, and the intracellular loops, where the G-proteins interact, suggests that both melanopsin and pinopsin should be able to generate a stable photopigment, capable of triggering a transduction cascade mediated by G-proteins. Phylogenetic analysis showed that both opsins are located on the expected branches of the corresponding sequences of ortholog proteins. Subsequently, using RT-PCR and RPA analysis, we verified the expression of ruin lizard melanopsin and pinopsin in directly photosensitive organs, such as the lateral eye, brain, pineal gland and parietal eye. Melanopsin expression was detected in the lateral eye and all major regions of the brain. However, different from the situation in Xenopus and chicken, melanopsin is not expressed in the ruin lizard pineal. Pinopsin mRNA expression was only detected in the pineal complex. As a result of their phylogenetic position and ecology, reptiles provide the circadian field with some of the most interesting models for understanding the evolution of the vertebrate circadian timing system and its response to light. This characterization of melanopsin and pinopsin expression in the ruin lizard will be important for future studies aimed at understanding the molecular basis of circadian light detection in reptiles.