Study of Biodegradation Processes of BTEX-ethanol Mixture in Tropical Soil   总被引：1，自引：0，他引：1  

Patricia Österreicher-Cunha  Jean Rémy Davée Guimarães  Eurípedes do Amaral Vargas Jr.  Maria Isabel Pais da Silva 《Water, air, and soil pollution》2007,181(1-4):303-317

In Brazil, gasoline is currently blended with ethanol and both compounds may contaminate the environment when spills occur. Ethanol preferential biodegradation delays gasoline degradation in the aquifer, as previously observed; in unsaturated soil a delayed recovery of culturable bacteria and removal of residues in the presence of ethanol suggest a similar situation. This study monitors microbial degrading activity in unsaturated soil with BTEX and BTEX-ethanol mixtures under tropical conditions as well as the effects of bioventing on contaminants degradation. Enzymatic activity was quantified by measuring fluorescein-diacetate hydrolysis by microorganisms, which determines total degrading activity in soil. As microbial enhanced activity may alter soil electromagnetic properties, soil dielectric constant shifts were monitored using Time Domain Reflectometry (TDR), while chemical analyses evaluated contamination residues throughout the experiment. Results suggest that ethanol delays BTEX biodegradation and that bioventing may compensate for this delay by providing oxygen for the continuation of microbial activity. Contamination and bioventing stimulated soil microbiota, while culturable populations were inhibited by contamination, showing soil toxicity. The presence of ethanol caused a higher and longer-lasting boost in enzymatic activity; TDR measurements did not follow these activity shifts, proving not to be an adequate tool for evaluating microbial activity in these experimental conditions. Residual BTEX were detected only in ethanol-containing non-ventilated soils after contamination. The set of results suggests that ethanol could delay BTEX degradation because of its constitutive degradation by soil microbiota, but this effect may be bypassed by bioventing.  相似文献   

Colletotrichum gloeosporioides sensu lato associated with anthracnose in Bauhinia forficata     

de Souza Junior  Francisco Jorge Carlos  dos Santos Vieira  Willie Anderson  Veloso  Josiene Silva  Duarte  Ingrid Gomes  Amaral  Ana Gabriele Gurgel  Laranjeira  Delson  Balbino  Valdir De Queiroz  Doyle  Vinson P.  Câmara  Marcos Paz Saraiva 《European journal of plant pathology / European Foundation for Plant Pathology》2021,160(3):745-751

European Journal of Plant Pathology - Bauhinia forficata is an important plant commonly used in traditional medicine, and as an ornamental plant in parks and gardens. Its use as an ornamental plant...  相似文献   

Does resource‐mediated stress affect colony personality in leaf‐cutting ants?     

Lailla C Gandra  Karina D Amaral  Joel C Couceiro  Raul NC Guedes  Terezinha MC Della Lucia 《Pest management science》2021,77(1):96-103

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Use of satellite images for geographical localization of livestock holdings in Brazil     

Carvalho LF  de Melo CB  McManus C  Haddad JP 《Preventive veterinary medicine》2012,103(1):74-77

Google Earth^® provides free access to satellite images and has been used in several areas that require cartographic information. The present study assessed the inconsistencies between geo-referencing of livestock premises by GPS and the acquisition of geographic coordinates by remote sensing (RS) images provided by Google Earth^® in the Brazilian states of Bahia, Distrito Federal, Minas Gerais and Parana. The overall mean and standard deviation of the distances in the study were 30.98 ± 19.89 m. The mean distance differences between the two techniques were, for these states, 37.20 ± 19.75 m, 28.38 ± 17.38 m, 31.61 ± 15.72 m, 28.43 ± 24.30 m, respectively. Despite the fact that there is variation between the geo-referencing points using GPS and RS, geographical localization of health inspections should be useful as long as the errors between the results of the two methodologies are considered.  相似文献   

Analysis of variables influencing tree cork caliper in two consecutive cork extractions using cork growth index modelling   总被引：1，自引：0，他引：1  

Joana Amaral Paulo  Helena Pereira  Margarida Tomé 《Agroforestry Systems》2017,91(2):221-237

The influence of tree and stand variables, debarking intensity, and precipitation on the caliper of cork produced by a tree and on the evolution of cork caliper between consecutive cork extractions was researched. A total of 370 cork samples were collected in 23 permanent plots distributed across the cork production area in Portugal, covering a period from 1984 to 2010. Cork growth was evaluated using the cork growth index (cgi), defined as the radial width of the first eight complete years of cork growth after stripping. The differences in mean cgi at plot level between two consecutive cork growth periods (cgp) were assessed using nonparametric tests. A mixed model approach was used due to the nested structure of the data for modelling cgi value at tree level. The cgi of two consecutive cork extractions is linearly related at tree level. At plot level, the mean value of cgi decreased in 5 out of the 23 plots and increased in 2 plots for α = 0.05. The number of debarked branches and the variation of precipitation between two cgp were the variables that explained the largest part of the cgi evolution. However, significance of plot random parameters indicates that other variables are involved in the tree cgi evolution, pointing out to the need of further research. Tree size and precipitation during the cgp are related to the individual tree cgi. The effect of increasing stand density and debarking intensity on cork growth was not clear. Long term research based on permanent plot measurements and research trials is needed to clarify the impact of tree competition and debarking intensity.  相似文献   

Thymus vulgaris essential oil and thymol against Alternaria alternata (Fr.) Keissler: effects on growth,viability, early infection and cellular mode of action          下载免费PDF全文

Fabiano J Perina  Douglas C Amaral  Rafael S Fernandes  Claudia RG Labory  Glauco A Teixeira  Eduardo Alves 《Pest management science》2015,71(10):1371-1378

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Performance of nitrification inhibitors with different nitrogen fertilizers and soil textures     

Gabriel Barth  Sabine von Tucher  Urs Schmidhalter  Rafael Otto  Peter Motavalli  Risely Ferraz-Almeida  Thales Meinl Schmiedt Sattolo  Heitor Cantarella  Godofredo Cesar Vitti 《植物养料与土壤学杂志》2019,182(5):694-700

Nitrification inhibitors (NIs), DCD (dicyandiamide), and DMPP (3,4‐dimethylpyrazole phosphate), in combination with urea (UR) and ammonium sulfate nitrate (ASN) fertilizers were studied under contrasting soil textures (sand, loam, and clay) from cultivated soils collected in Brazil and Germany. Soil samples were incubated over 50 days and the content of ammonium ( ), nitrate ( ), and soil pH were measured periodically. Applied NIs delayed the nitrification process across all soil textures. Correlation analysis indicated that combining ASN with NIs resulted in higher content and efficiency in delaying the nitrification process with high N‐conversion rate (r = –0.82). The combination of ASN+ DMPP increased the efficiency of the N‐conversion rate (r = –0.86) due to H⁺ release in soil, while UR+DCD (r = –0.50) had an efficiency of the N‐conversion rate similar to UR (r = –0.42). All the NIs had a better performance in reducing formation in sandy soils as compared to the loam and clay textured soils. Use of DMPP with an N fertilizer results in a soil pH decrease and can be an option to increase the efficiency of the N‐conversion rate, reducing N losses in soil. Overall, our results suggest that NIs have a better performance in reducing formation in sandy soils as compared to that of the loam and clay textured soils. Use of DMPP with ASN results in a soil pH decrease and can be an option to reduce N losses in soil.  相似文献   

Dietary Protein Requirement of Juvenile Cachara Catfish,Pseudoplatystoma reticulatum     

Fernando Henrique Gomes Cornlio  Douglas Amaral da Cunha  Jennifer Silveira  Daniel Alexandre  Carlos Peres Silva  Dbora Machado Fracalossi 《Journal of the World Aquaculture Society》2014,45(1):45-54

Cachara, Pseudoplatystoma reticulatum, is a high commercial value carnivorous catfish in Brazil, but whose dietary protein requirement is still unknown. Aiming to determine this requirement, groups of 15 juveniles (16.08 ± 1.13 g) were fed isoenergetic diets (4600 kcal/kg gross energy) with increasing levels of crude protein (30, 35, 40, 45, 50, and 55%). After 60 d, regression analysis revealed a quadratic effect (P < 0.05) of increasing dietary crude protein concentration on growth variables. The highest weight gain and specific growth rate as well as the best feed conversion were shown by fish fed the 50% crude‐protein diet. Similarly, protease activities were significantly higher (P < 0.05) in fish fed 50% crude protein. However, the highest protein retention was observed in fish fed the 45% crude‐protein diet. Protein and dry matter digestibilities did not differ (P > 0.05) for diets containing 40, 45, or 50% crude protein. Therefore, based on weight gain and at a dietary energy concentration of 4600 kcal/kg, the estimated protein requirement for juvenile cachara between 16 and 85 g is 49.25% crude protein. This is equivalent to 44.79% digestible protein and a gross energy to digestible protein ratio of 10.27 kcal/g.  相似文献   

The involvement of gonadotropins and gonadal steroids in the ovulatory dysfunction of the potamodromous Salminus hilarii (Teleostei: Characidae) in captivity     

Renata Guimarães Moreira  Renato Massaaki Honji  Renato Garcia Melo  Amanda de Moraes Narcizo  Juliane Suzuki Amaral  Ronaldo de Carvalho Araújo  Alexandre Wagner Silva Hilsdorf 《Fish physiology and biochemistry》2015,41(6):1435-1447

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SOIL LOSS FROM EROSION IN THE NEXT 50 YEARS IN KARST REGIONS OF MAYABEQUE PROVINCE,CUBA     

J. M. Febles‐Gonzlez  M. B. Vega‐Carreo  N. M. B. Amaral‐Sobrinho  A. Toln‐Becerra  X. B. Lastra‐Bravo 《Land Degradation \u0026amp; Development》2014,25(6):573-580

To date, neither the method nor diagnostic indices employed in Cuba to evaluate erosion of Red Ferralitic or Ferrasol Rhodic soil in karstic regions has taken into consideration morphogenesis in such geo‐ecosystems or their relationship with erosion, which has led to sequential degradation of the most productive soils in Cuba. We explore the case for considering A + B horizon depth as one of the basic indices for evaluating the severity of erosion. There is no methodology available for estimating the volume of soil lost through karstic absorption forms (dolines). This article forecasts loss of soil cover using a model which estimates losses of 268·52 to 450·52 mm y⁻¹ for future scenarios (periods of 25 and 50 years). A mean loss rate of 1·07 mm y⁻¹ was found in areas cultivated as pastureland during the period from 1986 to 2009, which exceeds the tolerance thresholds proposed by the Universal Soil Loss Equation and the soil formation rates estimated for limestone in Cuba and it is likely there is with a marked tendency for this to increase. These results should be interpreted as a first estimate for setting loss tolerances as there is no similar experience with own data for a more precise definition of the erosion of soil in karstic regions. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献