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81.
Amanda F. Bontempo Gabriella D. P. Carneiro Fernanda A. R. Guimarães Marcelo R. Dos Reis Daniel V. Silva Bruno H. Rocha 《Journal of environmental science and health. Part. B》2016,51(7):465-468
Carrot (Daucus carota L.) is a vegetable crop that is grown throughout the year across various regions of Brazil in rotation or in succession to other cultures. Herbicide residual effect has emerged as a concern, because of the possibility of carryover. Thus, the objective of this study was to evaluate the effect of tembotrione and atrazine residues – in mixture and isolated – on carrot planted in succession to corn. The experiment was designed in randomized blocks with five replications. Treatments consisted of tembotrione (50.4 g ha?1), tembotrione (100.8 g ha?1), tembotrione + atrazine (50.4 g ha?1+ 2 L ha?1), tembotrione + atrazine (100.8 g ha?1+ 2 L ha?1), and atrazine (2.00 L ha?1) applied eight months before carrot seeding, plus a control treatment with no herbicide application. Investigated variables were shoot dry mass, productivity, and classification of carrot roots. The presence of atrazine and tembotrione decreased dry mass in the area, and only tembotrione reduced total root productivity. Thus, there is a carryover effect to tembotrione application that reduces the dry matter accumulation of shoot and total productivity, and an atrazine + tembotrione (100.8 g ha?1) mixture reduces the total productivity after application of these herbicides to soil. 相似文献
82.
Fernanda Freitas Caregnato Rafael Calixto Bortolin Armando Molina Divan Junior José Cláudio Fonseca Moreira 《Chemosphere》2013
Ozone (O3) has become one of the most toxic air pollutants to plants worldwide. However, investigations on O3 impacts on crops health and productivity in South America countries are still scarce. The present study analyzed the differences on the enzymatic and non-enzymatic antioxidant system in foliar tissue of two subtropical Phaseolus vulgaris varieties exposed to high O3 concentration. Both varieties were negatively impacted by the pollutant, but the responses between each variety were quite distinct. Results revealed that Irai has higher constitutive levels of reactive oxygen species (ROS) and ascorbate (AsA) concentration, but lower total thiol levels and catalase immunocontent. In this variety catalase protein concentration was increased after O3 exposure, indicating a better cellular capacity to reduce hydrogen peroxide. On the opposite, Fepagro 26-exposed plants increased ROS generation and AsA concentration, but had the levels of total thiol content and catalase protein unchanged. Furthermore, O3 treatment reduced the levels of chlorophylls a and b, and the relationship analysis between the chlorophyll ratio (a/b) and protein concentration were positively correlated indicating that photosynthetic apparatus is compromised, and thus probably is the biomass acquisition on Fepagro 26. Differently, O3 treatment of Irai did not affect chlorophylls a and b content, and loss on the protein content was lower. Altogether, these data suggest that early accumulation of ROS on Fepagro 26 are associated with an insufficient leaf antioxidant capacity, which leads to cell structure disruption and impairs the photosynthesis. Irai seems to be more tolerant to O3 toxic effects than Fepagro 26, and the observed differences on O3 sensitivity between the two varieties are apparently based on constitutive differences involved in the maintenance of intracellular redox homeostasis. 相似文献
83.
Carlos L. Negro Lidia E. Senkman Fernanda Marino Eduardo Lorenzatti Pablo Collins 《Journal of environmental science and health. Part. B》2013,48(4):261-265
The objectives of this work were to evaluate the effects of environmentally relevant chlorpyrifos and endosulfan, concentrations in the incubation period, effective hatching and survival of embryos and neonates of the freshwater burrowing crab, Zilchiopsis collastinensis (Decapoda, Trichodactylidae). Both pesticides were prepared from commercial and technical grade products. The exposure to about 100, 200, and 400 ng endosulfan L?1, and 48, 240, and 1,200 ng chlorpyrifos L?1 did not cause differences in the incubation period or in effective hatching but decreased survival of neonates, especially in the concentrations prepared from the technical grade product. Even if these concentrations are below the median lethal concentration (LC50) values for embryos, these caused a significant decrease in the survival of neonates, i.e. when crabs are outside the egg and not protected by chorion. The decrease in the neonate population caused by these concentrations, which could be found in the environment, might impact aquatic communities. 相似文献
84.
85.
Tainá Elisa de Mello Lazarini Raquel Fernanda Milani 《Journal of environmental science and health. Part. B》2019,54(5):387-393
The purpose of this work was to evaluate the risk-benefit associated with canned sardine consumption, considering the selenium, the mercury and the methylmercury contents and the Se:Hg molar ratio and the Se-health benefit value (HBV) index. In this study, 63 canned sardine samples were purchased worldwide and for the determination of selenium and mercury species, the inductively coupled plasma optical emission spectrometry and thermal decomposition and amalgamation atomic absorption spectrometry were employed. The mean results obtained for the Brazilian samples varied between 12.6 and 65.5?μg kg?1 for Hg; <3.7 and 45.4?μg kg?1 for methylmercury; 310 and 1370?μg kg?1 for Se. The MeHg/Hg ratio showed that the most toxic forms of Hg (MeHg) is predominant in 52 and 39% of the Brazilian samples conserved in tomato sauce and in oil, respectively. Nevertheless, the Se-HBV index and the Hg:Se and Se:Hg molar ratios indicated that the selenium content in canned sardine samples is enough to provide a protective effect on the Hg species. 相似文献
86.
Bandala ER Domínguez Z Rivas F Gelover S 《Journal of environmental science and health. Part. B》2007,42(1):21-26
Atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) was degraded using cobalt-peroximonosulfate (Co/PMS) advanced oxidation process (AOP). Three Co concentrations (0.00, 0.25 and 0.50 mM) and five peroximonosulfate (PMS) concentrations (0, 5, 8, 16 and 32 mM) were tested. Maximum degradation reached was 88% using dark Co/PMS in 126 minutes when 0.25 mM of cobalt and 32 mM of PMS were used. Complete atrazine degradation was achieved when the samples were irradiated by the sun under the same experimental conditions described. Tests for identification of intermediate products allowed identification and quantification of deethylatrazine in both dark and radiated conditions. Kinetic data for both processes was calculated fitting a pseudo-first order reaction rate approach to the experimental data. Having kinetic parameters enabled comparison between both conditions. It was found that the kinetic approach describes data behavior appropriately (R2 > or = 0.95). Pseudo-kinetic constants determined for both Co/PMS processes, show k value of 10(-4) for Co/PMS and a k value of 10(-3) for Co/PMS/ultraviolet (UV). This means, that, with the same Co/PMS concentrations, UV light increases the reaction rate by around one order of magnitude than performing the reaction under dark conditions. 相似文献
87.
88.
Juan Fern��ndez-Tajes Fernanda Fl��rez Sandra Pereira Tamara R��bade Blanca Laffon Josefina M��ndez 《Environmental monitoring and assessment》2011,177(1-4):289-300
Estuaries are marine areas at great contamination risk due to their hydrodynamic features. PAH are wide and ubiquitous contaminants with a high presence in these marine environments. Chemical analysis of sediments can provide information, although it does not give a direct measure of the toxicological effect of such contaminants in the biota. Samples of Venerupis pullastra, Cerastoderma edule, and Mytilus galloprovincialis were collected from two locations in Corcubión estuary (Norhwest of Spain). The level of PAH in sediment and biota, and its possible origin were assessed. A moderate level of contamination was observed with a predominance of PAH of a pyrogenic origin. Genotoxic damage, measured as single-strand DNA breaks with the comet assay, was evaluated in gill tissue and in hemolymph. The values of DNA damage obtained showed a higher sensitivity of clams and cockles to the pollution load level. These differences among species make us suggest the use of some other species coupled with mussels as an optimal tool for biomonitoring estuarine environments. 相似文献
89.
Santiago Guillermo Ceballos Enrique Pablo Lessa Mariela Fernanda Victorio Daniel Alfredo Fernández 《Marine Biology》2012,159(3):499-505
Phylogeography studies add insights into the geographic and evolutionary processes that underline the genetic divergence of
populations. This work examines the geographic genetic structure of the Patagonian blennie, Eleginops maclovinus, a notothenioid (Perciformes) endemic to South American temperate and sub-Antarctic waters, using mitochondrial DNA cytochrome
b sequences. We found 58 haplotypes in the analysis of 261 individual sequences of 833 base pairs in length. Among-population
variance was very low (1.62%) and many haplotypes were shared between several populations across the species geographic range.
Genetic differentiation was not consistent with a simple model of isolation by distance, possibly suggesting a lack of equilibrium
between gene flow and local genetic drift. The analysis of mismatch distributions, neutrality tests, and the Bayesian Skyline
Plot showed a pattern consistent with a recent population expansion event that may have taken place during the Middle Pleistocene. 相似文献