Antioxidant responses and reactive oxygen species generation in different body regions of the estuarine polychaeta Laeonereis acuta (Nereididae)

The aim of this study was to analyze the total antioxidant capacity (TOSC), generation of reactive oxygen species (ROS) and lipid peroxidation (LPO) in the different body regions of the estuarine polychaeta Laeonereis acuta (Nereididae) sampled at non-polluted (NOPOL) and polluted (POL) sites from Lagoa dos Patos (Southern Brazil). Organisms collected at POL during summer showed similar (p>0.05) TOSC values along the body, but worms collected at NOPOL presented higher (p<0.05) TOSC values in the posterior (P) region in respect of anterior (A) region and middle (M) region. TOSC in the P region at NOPOL was higher (p<0.05) compared with the same body region of worms at POL. In summer, ROS concentration was higher in A and M regions of worms at POL in respect of the organisms at NOPOL. During winter all the regions showed higher ROS in worms sampled at POL. It was registered absence of season influence on LPO content, but in the P region at NOPOL in summer there were lower LPO levels compared with the others regions (p<0.05). In vitro assays showed that P region, despite a higher basal ROS, presented a higher competence to cope with pro-oxidants compared with A and M regions (p<0.05), corroborating the field results. A lower proteic sulfhydril content was observed in P in respect of the other regions (p<0.05) supporting the idea of a highest oxidant condition in this region. The results indicate that worms collected at the POL site are confronted to higher ROS concentrations, affecting its antioxidant capacity, a result that depends of body regions.     

Indigenous people and sustainable development in Amazonas

Indigenous populations have lived for many generations in a sustainable fashion, developing knowledge about how to live in harmony with the environment. However, the sustainability of their life styles, their quality of life and the maintenance of intact ecosystems are threatened by a series of changes, including incorporation into the general fabric of society, conflict with non-indigenous migrants, expansion of indigenous populations and the globalization of national economies. This paper looks at the potential for policy to deal with these issues. In particular, it is shown that the ‘polluter pays principle’ is not appropriate for indigenous societies. The paper recommends a set of policies and shows how international cooperation in the areas of monitoring and enforcement, augmentation of demand for rain forest products and eco-certification can help indigenous groups improve their quality of life and maintain ecosystems in their current undisturbed state.     

Helmet retention system types as a risk factor to properly attach the chin strap

Objectives: This study aimed to determine the factors associated with the incorrect use of a helmet retention system (loose or open) and how often this happens.

Methods: This was an observational transversal study conducted in Curitiba, Brazil. Trained observers positioned at traffic lights collected information about the helmet fixation mode, the helmet model (full-face, open-face, modular, half), and the helmet retention system model (micrometric, double-D, fast-release). Additional data including position on the motorcycle, gender, and function of the motorcycle (as a work vehicle) were collected. The observers, collection site, and periods were randomly selected by lots.

Results: From a total of 3,050 motorcyclists, 1,807 (59.2%) had their helmets fastened correctly, 907 (29.7%) had the retention system fastened loosely, and in 336 (11.0%), the retention system was completely open. Increased odds of incorrect use were observed for the fast-release and double-D buckles compared to the micrometrics buckles, with a fixed odds ratio (OR) of 4.62 (95% confidence interval [CI], 3.89–5.51) and 3.54 (95% CI, 2.46–5.09), respectively (P <.0001). Full-face helmets had a higher chance of incorrect use (P <.0001), and passengers had a higher incidence of incorrect use of the helmet than drivers (P <.0001).

Conclusion: An important risk factor related to the incorrect use of the helmet was the type of retention system. The helmet model and being a passenger had a secondary influence on incorrect use of helmets.     

The influence of a real job on upper limb performance in motor skill tests: which abilities are transferred?

To investigate whether the specificities of real jobs create distinctions in the performance of workers in different motor tests for the upper limbs, 24 participants were divided into two groups according to their specific job: fine and repetitive tasks and general tasks. Both groups reproduced tasks related to aiming movements, handling and strength of the upper limbs. There were no significant differences between groups in the dexterity and performance of aiming movements. However, the general tasks group had higher grip strength than the repetitive tasks group, demonstrating differences according to job specificity. The results suggest that a particular motor skill in a specific job cannot improve performance in other tasks with the same motor requirements. The transfer of the fine and gross motor skills from previous experience in a job-specific task is the basis for allocating training and guidance to workers.     

Quaternized Chitosan for Ecological Treatment of Bauxite Mining Effluents

One of the major concerns of mining companies is the safety of their tailing dams. Among the cares required to operate such a dam, a proper treatment of the effluent composing its waste stands out, since that, waste must be treated before returned to the environment. In the process of bauxite beneficiation, the effluent level of turbidity is the discard parameter that deserves attention. In this work, quaternized chitosan (TMC_Cl^?) derivative with cationic charge was synthetized and investigated to be used as coagulant in bauxite treatment for tailing dam effluent. The chitosan (CHT) was quaternized by methylation reaction. The quaternized chitosan structure was characterized by the following techniques: FTIR Spectroscopy and ¹H nuclear magnetic resonance (NMR). Its thermal stability was analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis. After quaternized chitosan was obtained, analysis with aluminum sulfate, protonated and quaternized chitosan were executed in jar-test apparatus. The tests were conducted in order to find the optimum pH, velocity gradient, coagulant and alkalizer dosages, as well as coagulation, flocculation and decantation time. The studied coagulants showed good results and reduced the effluent turbidity to levels below determined by legislation. By comparing the coagulants, it was possible to state that quaternized chitosan presented higher reduction of effluent turbidity levels; the tests were performed in the same conditions.     

Toxicity assessment of textile effluents treated by advanced oxidative process (UV/TiO2 and UV/TiO2/H2O2) in the species Artemia salina L.

Textile industry wastes raise a great concern due to their strong coloration and toxicity. The objective of the present work was to characterize the degradation and mineralization of textile effluents by advanced oxidative processes using either TiO₂ or TiO₂/H₂O₂ and to monitor the toxicity of the products formed during 6-h irradiation in relation to that of the in natura effluent. The results demonstrated that the TiO₂/H₂O₂ association was more efficient in the mineralization of textile effluents than TiO₂, with high mineralized ion concentrations (NH ₄ ⁺ , NO ₃ ^? , and SO ₄ ^2? ) and significantly decreased organic matter ratios (represented by the chemical oxygen demand and total organic carbon). The toxicity of the degradation products after 4-h irradiation to Artemia salina L. was not significant (below 10 %). However, the TiO₂/H₂O₂ association produced more toxicity under irradiation than the TiO₂ system, which was attributed to the increased presence of oxidants in the first group. Comparatively, the photogenerated products of both TiO₂ and the TiO₂/H₂O₂ association were less toxic than the in natura effluent.     

Copper, nickel and lead in lichen and tree bark transplants over different periods of time

This work aimed at comparing the dynamics of atmospheric metal accumulation by the lichen Flavoparmelia caperata and bark of Platanus hybrida over different periods of time. Transplants were exposed in three Portuguese coastal cities. Samples were retrieved (1) every 2 months (discontinuous exposure), or (2) after 2-, 4-, 6-, 8- and 10-month periods (continuous exposure), and analysed for Cu, Ni and Pb. Airborne accumulation of metals was essentially independent of climatic factors. For both biomonitors [Pb]>[Ni]>[Cu] but Pb was the only element for which a consistent pattern of accumulation was observed, with the bark outperforming the lichen. The longest exposure periods hardly ever corresponded to the highest accumulation. This might have been partly because the biomonitors bound and released metals throughout the exposure, each with its own dynamics of accumulation, but both according to the environmental metal availability.     

Evaluation of chelating and cytoprotective activity of vanillin against the toxic action of mercuric chloride as an alternative for phytoremediation

Environmental Geochemistry and Health - Mercury is widely found in nature, however, in low concentrations, but anthropological activities have increased its concentration considerably. This causes...     

Two case studies of sulfate scavenging processes in the Amazon region (Rondônia)

The scavenging processes of chemical species have been previously studied with numerical modeling, in order to understand the gas and particulate matter intra-reservoir transferences. In this study, the atmospheric (RAMS) and scavenging (B.V.2) models were used, in order to simulate sulfate concentrations in rainwater using scavenging processes as well as the local atmospheric conditions obtained within the LBA Project in the State of Rondonia, during a dry-to-wet transition season. Two case studies were conducted. The RAMS atmospheric simulation of these events presented satisfactory results, showing the detailed microphysical processes of clouds in the Amazonian region. On the other hand, with cloud entrainments, observed values have been overestimated. Modeled sulfate rainwater concentration, using exponential decay and cloud heights of 16 km and no entrainments, presented the best results, reaching 97% of the observed value. The results, using shape parameter 5, are the best, improving the overall result.     

Estimating trace gas and aerosol emissions over South America: Relationship between fire radiative energy released and aerosol optical depth observations

Contemporary human activities such as tropical deforestation, land clearing for agriculture, pest control and grassland management lead to biomass burning, which in turn leads to land-cover changes. However, biomass burning emissions are not correctly measured and the methods to assess these emissions form a part of current research area. The traditional methods for estimating aerosols and trace gases released into the atmosphere generally use emission factors associated with fuel loading and moisture characteristics and other parameters that are hard to estimate in near real-time applications. In this paper, fire radiative power (FRP) products were extracted from Moderate Resolution Imaging Spectroradiometer (MODIS) and from the Geostationary Operational Environmental Satellites (GOES) fire products and new South America generic biomes FRE-based smoke aerosol emission coefficients were derived and applied in 2002 South America fire season. The inventory estimated by MODIS and GOES FRP measurements were included in Coupled Aerosol-Tracer Transport model coupled to the Brazilian developments on the Regional Atmospheric Modeling System (CATT-BRAMS) and evaluated with ground truth collected in Large Scale Biosphere–Atmosphere Smoke, Aerosols, Clouds, rainfall, and Climate (SMOCC) and Radiation, Cloud, and Climate Interactions (RaCCI). Although the linear regression showed that GOES FRP overestimates MODIS FRP observations, the use of a common external parameter such as MODIS aerosol optical depth product could minimize the difference between sensors. The relationship between the PM_2.5μm (Particulate Matter with diameter less than 2.5 μm) and CO (Carbon Monoxide) model shows a good agreement with SMOCC/RaCCI data in the general pattern of temporal evolution. The results showed high correlations, with values between 0.80 and 0.95 (significant at 0.5 level by student t test), for the CATT-BRAMS simulations with PM_2.5μm and CO.