Alteration of brain electrical activity by electromagnetic field

To better understand the affect of different levels of EMF on one’s brain activity, the Hodgkin–Huxley model has been used to describe the generation of an active potential in the nerve cell membrane. The theoretical calculations have shown that by the simultaneous affect of both passing an electrical potential and external very low frequency AC, one’s excitation pulses may be suppressed beginning with a certain level of external current. The level of this current depends on the frequency. It is postulated that to eliminate this suppression, the brain increases its normal level relatively to the lower limit. It is also postulated that the brain “tunes up” in the presence of external AC, by increasing the amplitude of its own excitation signals so that suppression does not occur. It is possible that this “tuning” process lasts some time after removing the external EMF as the brain adapts. This has been observed experimentally.     

Simulation of a waste incineration process with flue-gas cleaning and heat recovery sections using Aspen Plus

In the present paper, the modeling of a dual-purpose plant for the production of electrical and thermal energy from the heat treatment of solid wastes is presented. Particularly, the process has been modeled by using the Aspen Plus Shell, with the aim of performing a study about the applicability of this software in the simulation of a solid waste incineration process, which involves complex gas-solid reactions where the solids are referred to as "non-conventional". The model is developed to analyze and quantify the expected benefits associated with refuse derived fuel (RDF) thermal utilization; thus attention is focused on the performance of the energy recovery section.     

A mild photochemical approach to the degradation of phenols from olive oil mill wastewater

Photooxidation of cathecol (1) is carried out in aqueous solution at lambda > 300 nm using different sensitizers: rose bengal (RB), 9,10-dicyanoanthracene (DCA), 2,4,6-triphenylpyrylium tetrafluoroborate (Pyryl). The highest degradation is observed in the UV/RB-sensitized reaction (66% after 15 h of irradiation), mineralization and formation of dimers are the final events. This procedure has been extended to tyrosol (2), caffeic acid (3), vanillic acid (4), 4-hydroxycinnamic acid (5) and 4-hydroxybenzoic acid (6) as well as to a mixture of all phenols. A reduced toxicity of the UV/RB-irradiated solutions of cathecol and tyrosol towards alga Ankistrodesmus braunii is also verified.     

Microscale variation in<Emphasis Type="Italic"> Aat</Emphasis> (aspartate aminotransferase) is supported by activity differences between upper and lower shore allozymes of<Emphasis Type="Italic"> Littorina saxatilis</Emphasis>

The role of natural selection in maintaining inherited variation in morphological characters is indisputable. In contrast, genetic variation in allozyme loci is mostly assumed neutral or under weak selection, although enzyme functions are critical to central metabolic processes. A locus coding for aspartate aminotransferase (AAT) is polymorphic with two alleles in the rocky shore gastropod Littorina saxatilis. One allele (Aat ¹²⁰ ) is most frequent (0.8–0.9) in upper shore subpopulations, while the other (Aat ¹⁰⁰ ) dominates (0.7–0.8) lower shore subpopulations only meters below. Earlier studies show this variation to be maintained by divergent selection, but the mechanism is unknown. We measured enzyme activities in AAT extracts from individuals of known Aat genotype in populations from two islands and at three different temperatures. In all treatments lower shore homozygotes (Aat ^100/100 ) had higher enzyme activity than upper shore homozygotes (Aat ^120/120 ), with heterozygotes having intermediate levels of activity. AAT has a central role in anaerobic energy production in marine mollusks during low-tide periods of emergence, and it might appear surprising that upper shore snails, which are most likely to be emerged, have lower enzyme activity. However, upper shore snails are forced to survive long periods of desiccation, and a low metabolic rate will help to conserve limited resources of energy and nutrients and reduce accumulation of waste products.Communicated by L. Hagerman, Helsingør     

The role the Great Barrier Reef plays in resident wellbeing and implications for its management

Improvements in human wellbeing are dependent on improving ecosystems. Such considerations are particularly pertinent for regions of high ecological, but also social and cultural importance that are facing rapid change. One such region is the Great Barrier Reef (GBR). Although the GBR has world heritage status for its ‘outstanding universal value’, little is known about resident perceptions of its values. We surveyed 1545 residents, finding that absence of visible rubbish; healthy reef fish, coral cover, and mangroves; and iconic marine species, are considered to be more important to quality of life than the jobs and incomes associated with industry (most respondents were dissatisfied with the benefits they received from industry). Highly educated females placed more importance on environmental non-use values than other respondents; less educated males and those employed in mining found non-market use-values relatively more important. Environmental non-use values emerged as the most important management priority for all.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-014-0554-3) contains supplementary material, which is available to authorized users.     

Handling of Astyanax sp. for biomonitoring in Cangüiri Farm within a fountainhead (Iraí River Environment Preservation Area) through the use of genetic biomarkers

Aquatic environmental pollution may cause biodiversity loss. Thus, monitoring studies are very important because fish health reflects both quality and sustainability of the environment, as well as of the individuals that live there. In the present report, genetic biomarkers (piscine micronucleus test; comet assay with blood, liver, and kidney cells) were used in specimens of Astyanax sp. to analyze the contamination level of the Cangüiri Farm through biomonitoring. The Cangüiri Farm, the old school farm of the Federal University of Paraná, is inside the Iraí River Environment Preservation Area, created in 1996 to preserve the sources of public water supply in Curitiba and metropolitan area. We verified that the fishes collected within the Cangüiri Farm area presented high damage levels, showing more environment contamination when compared to the specimens collected in the Costa Ecologic Park, used as reference in the present report. The results indicate that the Cangüiri Farm, which is inside an environment protection area, created especially for the protection of the fountainhead for water supply, may be contaminated. These toxic residues, which were remarkably persistent in the environment, are possibly derived from agricultural activities in the wider area. Thus, we suggest the analysis of the area with other biomarkers and for a longer time period.     

Polar organic chemical integrative sampler (POCIS): application for monitoring organic micropollutants in wastewater effluent and surface water

In this paper, we discuss the advantages and drawbacks of POCIS (Polar Organic Chemical Integrative Sampler) for the evaluation of river water quality downstream of wastewater treatment plants. POCIS proved well adapted to sampling alkylphenols and several pharmaceuticals. Concentration factors and the decrease in limits of quantification, compared to grab water sample analyses, were significant except for hormones, β-blockers and bronchodilators. Promising preliminary results obtained in situ on deuterated atenolol used as a performance reference compound need to be confirmed in-lab. This work confirms that POCIS is a valuable tool for monitoring hydrophilic organic molecules in river and wastewaters.     

Heavy metal and trace elements in riparian vegetation and macrophytes associated with lacustrine systems in Northern Patagonia Andean Range

Vegetation associated with lacustrine systems in Northern Patagonia was studied for heavy metal and trace element contents, regarding their elemental contribution to these aquatic ecosystems. The research focused on native species and exotic vascular plant Salix spp. potential for absorbing heavy metals and trace elements. The native species studied were riparian Amomyrtus luma, Austrocedrus chilensis, Chusquea culeou, Desfontainia fulgens, Escallonia rubra, Gaultheria mucronata, Lomatia hirsuta, Luma apiculata, Maytenus boaria, Myrceugenia exsucca, Nothofagus antarctica, Nothofagus dombeyi, Schinus patagonicus, and Weinmannia trichosperma, and macrophytes Hydrocotyle chamaemorus, Isöetes chubutiana, Galium sp., Myriophyllum quitense, Nitella sp. (algae), Potamogeton linguatus, Ranunculus sp., and Schoenoplectus californicus. Fresh leaves were analyzed as well as leaves decomposing within the aquatic bodies, collected from lakes Futalaufquen and Rivadavia (Los Alerces National Park), and lakes Moreno and Nahuel Huapi (Nahuel Huapi National Park). The elements studied were heavy metals Ag, As, Cd, Hg, and U, major elements Ca, K, and Fe, and trace elements Ba, Br, Co, Cr, Cs, Hf, Na, Rb, Se, Sr, and Zn. Geochemical tracers La and Sm were also determined to evaluate contamination of the biological tissues by geological particulate (sediment, soil, dust) and to implement concentration corrections.     

Photochemical degradation of nonylphenol in aqueous solution：The impact of pH and hydroxyl radical promoters

The degradation of nonylphenol (NP) in aqueous solution with UV, H₂O₂/UV, and Fenton/photo-Fenton processes was studied. The efficacy of direct and hydrogen peroxide photolysis proved to be dependent on the pH value. The addition of H₂O₂ to UV treatment improved NP degradation. The application of UV photolysis and the H₂O₂/UV system at pH 7 resulted in low pseudo first-order rate constants at 10^-4 sec^-1. In the experiments at elevated pH values the pseudo-first order rate constants increased to 10^-3 sec^-1. The efficacy of the Fenton process was lower in comparison with UV and hydrogen peroxide photolysis. The addition of UV irradiation to the H₂O₂/Fe²⁺ system substantially improved NP degradation efficacy. In terms of performance, the photo-Fenton process was similar to the H₂O₂/UV process. The most favourable process for complete nonylphenol degradation considering both operational cost and treatment efficacy was H₂O₂/UV at pH 11 and 250 mol/L H₂O₂.