Effects of lead exposure on salivary glands of rats: insights into the oxidative biochemistry and glandular morphology

Environmental Science and Pollution Research - This study aimed to investigate the effects of lead (Pb) exposure on parotid and submandibular glands through morphological aspects as well as the...     

Aquatic ecotoxicity assessment of a new natural formicide

Background, aim and scope

Agrochemicals could reach aquatic ecosystems and damage ecosystem functionality. Natural formicide could be an alternative to use in comparison with the more toxic formicides available on the market. Thus, the objective of this study was to assess the ecotoxicity of the new natural formicide Macex? with a battery of classical aquatic ecotoxicity tests.

Material and methods

Bacteria (Aliivibrio fischeri), algae (Pseudokirchneriella subcapitata), hydra (Hydra attenuata), daphnids (Daphnia magna), and fish (Danio rerio) tests were performed in accordance with international standardized methodologies.

Results

In the range of formicide concentrations tested (0.03 to 2.0?g?L^?1) EC₅₀ values varied from 0.49 to >2.0?g?L^?1, with P. subcapitata being the most sensitive species and H. attenuata and D. rerio the most tolerant species to this product in aqueous solutions.

Conclusions

This new formicide preparation can be classed as a product of low toxicity compared to the aquatic ecotoxicity of the most common commercialized formicides.     

The ecological apparency hypothesis and the importance of useful plants in rural communities from northeastern Brazil: an assessment based on use value

The ecological apparency hypothesis in ethnobotanical studies predicts that the apparent plants (i.e., the most easily found in the vegetation) would be the most commonly collected and used by people. To test this hypothesis, it has been used the concept of use value (VU), which measures the relative importance of useful plants for a group of people. However, the use value has got some limitations, including the fact that it does not distinguish "current use" (plants which are effectively used) from "potential use" (well known plants, however not used). Therefore, this study has tested whether the obtained results through three different use value calculations could be useful in testing the ecological apparency hypothesis. These calculations have included the current use value, the potential use value, and the general use value. It has been carried out a vegetation survey and an interview for residents from the rural communities from Barrocas and Cachoeira (Soledade, Paraíba, Brazil). It has been used Spearman's coefficient to correlate phytosociological and ethnobotanical data. It has been observed that phytosociological parameters in Cachoeira were not correlated with any of the use values calculations, except the relationship between the current use value and the relative dominance (r(s)?=?0.57; p?相似文献   

Biochar: a synthesis of its agronomic impact beyond carbon sequestration

Biochar has been heralded as an amendment to revitalize degraded soils, improve soil carbon sequestration, increase agronomic productivity, and enter into future carbon trading markets. However, scientific and economic technicalties may limit the ability of biochar to consistently deliver on these expectations. Past research has demonstrated that biochar is part of the black carbon continuum with variable properties due to the net result of production (e.g., feedstock and pyrolysis conditions) and postproduction factors (storage or activation). Therefore, biochar is not a single entity but rather spans a wide range of black carbon forms. Biochar is black carbon, but not all black carbon is biochar. Agronomic benefits arising from biochar additions to degraded soils have been emphasized, but negligible and negative agronomic effects have also been reported. Fifty percent of the reviewed studies reported yield increases after black carbon or biochar additions, with the remainder of the studies reporting alarming decreases to no significant differences. Hardwood biochar (black carbon) produced by traditional methods (kilns or soil pits) possessed the most consistent yield increases when added to soils. The universality of this conclusion requires further evaluation due to the highly skewed feedstock preferences within existing studies. With global population expanding while the amount of arable land remains limited, restoring soil quality to nonproductive soils could be key to meeting future global food production, food security, and energy supplies; biochar may play a role in this endeavor. Biochar economics are often marginally viable and are tightly tied to the assumed duration of agronomic benefits. Further research is needed to determine the conditions under which biochar can provide economic and agronomic benefits and to elucidate the fundamental mechanisms responsible for these benefits.     

Integrated hydro- and wind power generation: a game changer towards environmental flow in the Sub-middle and Lower São Francisco River Basin?

Many renewable resources for the generation of electricity, such as hydropower and wind power, are dependent on climatic factors. Reservoirs have been created to overcome the stochastic nature of river flows and to make water supply more reliable. However, reservoirs are affecting the ecological status of river ecosystems, e.g., by modifying the flow regime, triggering discussions regarding the discharge of reservoirs. In Brazil’s northeast region, the installed capacity for wind power generation has increased substantially in recent years. Setting up a modeling system for simulating wind power and hydropower generation in this study, it is analyzed whether wind power generation, peaking in the dry season, can help to achieve a more environmentally oriented flow regime in the Sub-middle and Lower São Francisco River Basin. Simulated higher discharges from reservoirs during the rainy season and lower discharges during the dry season, representing a more natural flow regime, will reduce hydropower generation in the dry season. Under recent conditions, the resulting gap in electricity generation can only be partially covered by wind power. A large share needs to be generated by thermal power plants or be imported from other regions in Brazil. The planned future increase in installed wind power capacity can change this picture; the demand for electricity generated by thermal power plants and imported will decrease. Adopting an integrated approach for hydropower and wind power generation, the flow regime in the Sub-middle and Lower São Francisco River Basin can be modified to improve the ecological status of the river system.     

A Systematic Framework for the Design and Implementation of a Quality Management Practice: The Case of a Consulting Engineering Company

Company productivity and competitiveness in today's marketplace requires creative design, innovation, and the reduction of nonconformances, which require costly rework and can damage a firm's reputation with its customers and potential customers. Using the International Organisation of Standardization's (ISO) 9000 and 14000 series of standards, the authors of this article walk readers through the rigorous process of obtaining upper management buy‐in and sponsorship and engaging workers in a bottom‐up approach to establish the procedures necessary to perform world‐class engineering services.     

A correlation study between multiple sclerosis and type 1 diabetes incidences and geochemical data in Europe

Complex multifactorial disorders usually arise in individuals genetically at risk in the presence of permissive environmental factors. For many of these diseases, predisposing gene variants are partly known while the identification of the environmental component is much more difficult. This study aims to investigate whether there are correlations between the incidence of two complex traits, multiple sclerosis and type 1 diabetes, and some chemical elements and compounds present in soils and stream sediments in Europe. Data were obtained from the published literature and analyzed by calculating the mean values of each element and of disease incidence for each Country, respectively, 17 for multiple sclerosis and 21 for type 1 diabetes. Correlation matrices and regression analyses were used in order to compare incidence data and geochemical data. R correlation index and significance were evaluated. The analyses performed in this study have revealed significant positive correlations between barium and sodium oxide on one hand and multiple sclerosis and diabetes incidences on the other hand that may suggest interactions to be evaluated between silicon-rich lithologies and/or marine environments. The negative correlations shown by cobalt, chromium and nickel (typical of silicon-poor environment), which in this case can be interpreted as protective effects against the two diseases onset, make the split between favorable and protective environments even more obvious. In conclusion, if other studies will confirm the involvement of the above elements and compounds in the etiology of these pathologies, then it will be possible to plan strategies to reduce the spread of these serious pandemics.     

Adaptive threat management framework: integrating people and turtles

In the 35 years since its inception, the Brazilian National Program for the Conservation of Marine Turtles (TAMAR) has had great success in protecting the five species of sea turtles that occur in Brazil. It has also contributed significantly to worldwide scientific data and knowledge about these species’ biology, such as life cycles and migration patterns. TAMAR’s conservation strategies have always relied on a variety of environmental education and social inclusion (EESI) activities highly adapted to the socio-environmental evolving contexts of its 25 locations distributed across nine states. Diversity and flexibility are critical to enable timely and effective local responses to existing or potential threats to sea turtles. The intuitive, locally adapted, decentralized, and independent way EESI activities have been carried out have generated positive results in the resolution of specific and evolving local problems through the course of the project. This article brings EESI under the same conceptual framework that underlies its conservation approach by adopting an adaptive threat management framework to organize and qualify its educational and social inclusion interventions according to the main categories of threat addressed by TAMAR.     

Soil heavy metal content on the hillslope region of Rio de Janeiro,Brazil: reference values

The increasing concern regarding the preservation of soil quality suggests the adoption of quality reference values as a first step in environmental monitoring actions. In this context, the objective of this study was to establish soil quality reference values for Al, Zn, Mn, Cd, Fe, Pb, Ni, Cr, and Cu and to correlate several soil properties with the occurrence of these elements in the hillslope region of Rio de Janeiro State. Sixty-two samples were collected at depths of 0–20 and 20–40 cm and analyzed using the USEPA method 3051A. After clustering analysis, the samples were separated into three groups. Classification functions were obtained based on the variables pH - Mg - Fe - Mn, i.e., the variables that were best related to heavy metal content. We determined to establish the quality reference values for the 75th percentile of the three groups. The relief forms of the area, which facilitate the transport of soil fine-particle fractions and accumulation in lowlands, were revealed to be one of most important factors in understanding the distribution of soil heavy metals.     

Evaluation of the effectiveness of red mud-supported catalysts in combination with ozone and TiO<Subscript>2</Subscript> in the treatment of solution containing benzene,toluene, and xylene

Ozone and a Fe²⁺/TiO₂-based catalyst were examined in the degradation of a synthetic solution of benzene toluene and xylene (BTX) in an advanced oxidation process (AOP). The catalyst beads were made from the slurry waste of aluminum production process, by inserting the TiO₂ content and subsequent calcination. The reduction of the BTX concentration load was monitored by the reduction of chemical oxygen demand (COD) and BTX concentration. Different levels were used on factors: pH, time of treatment, initial concentration of BTX, and percentage of TiO₂. The process was conducted in a bubble column reactor with the insertion of catalyst beads. A response surface methodology technique (CCD) was used to build a model based on COD reduction results. The model was optimized using the normal-boundary intersection (NBI) algorithm to maximize COD reduction and minimize the variance attributed to the process. Optimization led to COD reductions of 80% in 2 h of experiment. Correlation analysis of coefficient models from experimental data R²_adj was 0.9966, showing a good fit of model data. In the optimized conditions, the possible increase of the biodegradability ratio of the BTX solution, through the biochemical oxygen demand (BOD) and COD, was also analyzed. Under pre-treatment conditions, the BOD/COD ratio was 0.13. After the treatment, it increased to 0.56.

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