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91.
92.
Prior to deforestation, São Paulo State had 79,000 km2 covered by Cerrado (Brazilian savanna) physiognomies, but today less than 8.5% of this biodiversity hotspot remains, mostly in private lands. The global demand for agricultural goods has imposed strong pressure on natural areas, and the economic decisions of agribusiness managers are crucial to the fate of Cerrado domain remaining areas (CDRA) in Brazil. Our aim was to investigate the effectiveness of Brazilian private protected areas policy, and to propose a feasible alternative to promote CDRA protection. This article assessed the main agribusiness opportunity costs for natural areas preservation: the land use profitability and the arable land price. The CDRA percentage and the opportunity costs were estimated for 349 municipal districts of São Paulo State through secondary spatial data and profitability values of 38 main agricultural products. We found that Brazilian private protected areas policy fails to preserve CDRA, although the values of non-compliance fines were higher than average opportunity costs. The scenario with very restrictive laws on private protected areas and historical high interest rates allowed us to conceive a feasible cross compliance proposal to improve environmental and agricultural policies.  相似文献   
93.
The São Francisco River is the largest river located entirely within Brazil, and water scarcity problems have been a major concern of Brazilian society and government. Water quality issues are also a concern and have worsened with the recent intensification of urbanization and industrialization. In this study, violations to water quality standards established by local legislation were calculated as a percentage for 26 selected parameters over a monitoring period of 14 years. The violation percentages were analyzed spatially using the Kruskal-Wallis test, followed by multiple comparison analysis. Temporal analysis was performed using the Mann-Kendall test and Spearman correlation. Some parameters could be identified as cause for concern due to high violation levels, such as the fecal coliform indicator (FCI) and phosphorus—both related to domestic and effluent disposal without treatment or with insufficient treatment—and color, turbidity, manganese, and total suspended solids—which can be affected by erosive processes of natural and anthropogenic causes. The study found that these violations are concentrated in the most urbanized and industrialized areas of the basin. Some metallic parameters, such as iron and arsenic violations, may be related to mining activities in the rich soil of the Iron Quadrangle area located within the Minas Gerais State. Trend analysis results indicated that most monitoring stations did not have significant modification (elevation or reduction) trends over time, which, together with the high violation percentages, might indicate the maintenance of a scenario of constant pressure upon water resources, in particular in those more urbanized areas.  相似文献   
94.
Abstract

This paper describes a simple, inexpensive, highly sensitive, selective, and efficient electrochemical method to determine glyphosate (GLY) in samples of milk, orange juice, and agricultural formulation. The oxidation reaction on the electrode surface was electrochemically characterised by cyclic voltammetry (CV) and square wave voltammetry (SWV). The investigation of GLY at carbon paste electrode revealed a non-reversible oxidation peak at +0.95 V versus Ag/AgCl, which was used for electrochemical detection of GLY. The operating parameters (pH, frequency, step potential, and amplitude) were optimised in relation to the peak current intensity, and a calibration curve was set up in a concentration range of 4.40?×?10?8–2.80?×?10?6 mol L?1, with a detection limit of 2?×?10?9 mol L?1. After calibration curve was plotted, the developed procedure was applied to determine GLY in previously contaminated samples: milk and orange juice, and in a commercial formulation, obtaining recovery values between 98.31% and 103.75%. These results show that the proposed method can be used for GLY quantification in different samples with high sensitivity, specificity, stability, and reproducibility.  相似文献   
95.
Detailed analyses of persistent organic pollutants (POPs) such as organochlorine pesticides (OCPs), hexachlorocyclohexane (HCH) isomers (HCHs), dichlorodiphenyltrichloro ethane (DDT) and its metabolites (DDTs) and congeners of polychlorinated biphenyls (PCBs) in soil and surface water from the northeastern São Paulo, Brazil allowed the evaluation of the contamination status, distribution and possible pollution sources. The pesticides and PCBs demonstrated markedly different distributions, reflecting different agricultural, domestic and industrial usage in each region studied. The ranges of HCH, DDT, and PCBs concentrations in the soil samples were 0.05–0.92, 0.12–11.01, 0.02–0.25 ng g−1 dry wt, respectively, and in the surface water samples were 0.02–0.6, 0.02–0.58 and 0.02–0.5 ng l−1, respectively. Overall elevated levels of DDT and PCB were recorded in region 2, a site very close to melting, automotive batteries industries, and agricultural practice regions. High ratios of metabolites of DDT to DDT isomers revealed the recent use of DDT in this environment. The sources of contamination are closely related to human activities, such as domestic and industrial discharge, street runoff, agricultural pesticides and soil erosion, due to deforestation as well as atmospheric transport.  相似文献   
96.
Due to their environmental occurrence and intrinsic biological activity, human pharmaceuticals have received increasing attention from environmental and health agencies. Of particular, ecotoxicological concern are drugs that affect nervous- and endocrine-systems. Zebrafish genome-wide oligo arrays are used to collect mechanistic information on mianserin-induced changes in gene expression in zebrafish. Gene expression analysis in brain and gonad tissue clearly demonstrated the estrogenic activity of mianserin and its potency to disrupt normal endocrine (estrogenic) signaling, based on induction of molecular biomarkers of estrogenicity (e.g., vitellogenin1 and zona pellucida proteins). The possible mechanism underlying this estrogenic activity of mianserin is disturbance of the Hypothalamo-Pituitary-Gonadal (HPG) axis by direct interference of mianserin with the serotonergic and adrenergic systems in the brain of zebrafish. Taking into account the importance of the HPG-axis, and considering the concept of 'critical window of exposure', our results reveal the importance for more elaborate testing of endocrine disruptive effects of aquatic antidepressants at different lifestages and during longer exposure periods (e.g., life cycle studies). Although there is a low concordance between the gene expression results in this study and previous cDNA microarray hybridizations, the global mechanistic expression patterns are similar in both platforms. This argues in favor of pathway-driven analysis of gene expression results compared to gene-per-gene analysis.  相似文献   
97.
A brood pheromone identified in honeybee larvae has primer and releaser pheromone effects on adult bees. Using gas chromatography–mass spectrometry (GC–MS) to evaluate fatty acid esters—the pheromonal compounds—in different parts of the larvae, we have localized the source of the esters as the larval salivary glands. A histochemical study describes the glands and confirms the presence of lipids in the glands. Epithelial cells of the gland likely secrete the fatty acids into the lumen of the gland. These results demonstrate the salivary glands to be a reservoir of esters, components of brood pheromone, in honeybee larvae.  相似文献   
98.
This article compares four Dutch environmental certification schemes for agricultural food crops, analysing their methodology and the completeness of their criteria on five aspects: pesticide use, nutrient use, water management, energy and materials consumption, and habitat management. The least stringent of the labels, the MBT ('Environmentally Aware Cultivation') certificate, serves mainly to increase farmers' awareness of nutrient and pesticide use. With regard to both administrative obligations and actual management practices, the MBT label largely mirrors the terms of standing Dutch legislation. The CC ('Controlled Cultivation') and AMK ('Agro-Environmental') labels comprise more and more stringent criteria. With their restrictions on nutrient and pesticide use, these two labels serve as the two principal labels in the field of integrated agriculture. There is little difference between the two and it is recommended that they be merged, on the basis of a standardised definition of integrated agriculture. The EKO ('Organic Agriculture') label proceeds from different principles, but as a minimum should also comply with Dutch legislation without exception. For both integrated and organic agriculture, in addition to criteria on pesticide and nutrient use, criteria should also be developed for water management, energy and materials use and habitat management. The relationship between the criteria and their respective thresholds and Dutch legislation is also addressed. Existing criteria are frequently specified in such a way that the environmental benefits cannot be ascertained. This is a serious drawback for the parties further down the chain: auctioneers, retailers and consumers. It is recommended to develop qualitative guidelines for an Agricultural Stewardship Council at international level, like the Forest Stewardship Council, and a separate label for integrated agriculture per country comprising quantitative criteria for all relevant aspects of farming operations.  相似文献   
99.
This paper describes the tissue distribution of inorganic mercury, organic mercury and selenium in Dutch and British seals as well as in seals which were dosed with methylmercury under experimental conditions.In the experimental animals, a time-related increase of both mercury and selenium was found in liver and kidney after the administration of methylmercury, while in the other tissues examined, e.g. brain, thyroid, blood, only the concentrations of mercury increased.In the wild seals, it was also demonstrated that the selenium concentrations showed a positive correlation with the concentrations of mercury.Atomic ratios of mercury and selenium were close to one in the wild seals as was also found in previous studies. However, atomic ratios above one were found in seals fed additional methylmercury.In vitro studies with liver homogenates of seals did not provide evidence for the presence of a biochemical demethylation mechanism nor for any effect of selenium on the demethylation process.  相似文献   
100.
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