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991.
The exploitation of minerals from coastal dunes in northeastern Brazil requires subsequent revegetation for ecosystem recovery. In mined dunes areas, we have compared the growth of Guazuma ulmifolia and Tabebuia roseo-alba seedlings using substrates containing 10 or 15% of cattle manure, uninoculated or inoculated with a mixture of native arbuscular mycorrhizal fungi (AMF) or exotic AMF (Acaulospora longula). The inoculated plants had a higher percentage of colonization than those that were uninoculated. Plants of G. ulmifolia had the highest growth when inoculated with native AMF and fertilized with 10% manure or inoculated with A. longula and fertilized with 15% manure. In general, fertilization with 15% manure did not produce greater seedling development and had a negative effect on the effectiveness of the symbiosis. Twenty one AMF species were recorded in the planting areas at the end of the experiments, with a predominance of species that form acaulosporoid spores in areas with T. roseo-alba and gigasporoid spores in areas with G. ulmifolia plants. The incorporation of 10% cattle manure and native AMF in the substrate of T. roseo-alba and G. ulmifolia seedlings contributes to the initial establishment of plants in the field and to the incorporation of AMF propagules in the soil of the revegetated mined dunes.  相似文献   
992.
993.
The textile industry is known to generate large quantities of effluents contaminated with dyes that are not fixed to the fibers during the dyeing process. The available technologies to remove these dyes from the wastewater are expensive and ineffective. Within this context, low-cost, easy-maintenance technologies for the removal of dyes have been studied, such as adsorption on aquatic macrophytes. Thus, the macrophyte Salvinia sp., raw or pretreated with NaOH or H3PO4, was used as biosorbent of Blue 5G reactive dye. The study showed that pH and temperature affect the dye removal capacity. The analysis of the infrared spectrum (FTIR) showed that chemical treatment of the Salvinia sp. modified the biomass surface and affected dye adsorption capacity. The pseudo-second-order kinetic model satisfactorily described the experimental data for raw and NaOH-pretreated biomass, and the pseudo-first-order model was more appropriate to describe the experimental data obtained with H3PO4-pretreated biomass. The highest capacity of Blue 5G dye removal was obtained with raw biomass, at 333?K and pH?1.0, with 98.35?% adsorption.  相似文献   
994.
The presence of some anionic species, such as nitrate, nitrite, chloride, sulfide, fluoride, and cyanide, in water supplies may represent a serious environmental problem. In this work, the main sources and harmful effects of their bioaccumulation on living organisms are reviewed, as well as the most adopted technologies for their uptake. The major advantages and disadvantages of each methodology are also listed. In general, ion-exchange has been elucidated as the most suitable removal process. In view of that the most promising materials used to remove anionic pollutants from aqueous solutions are highlighted in this review. In particular, the major efforts towards the development of low-cost and easily available effective sorbents for water decontamination are covered. For instance, natural waste solid materials and derivatives have emerged as promising low-cost exchangers for selective anions uptake. Besides, a number of structural modifications including the introduction of more suitable surface functional groups or compensation species into the sorbent matrix have been investigated in order to enhance sorbents selectivity and capacity for anionic pollutants. The influence of speciation and removal conditions is also focused.  相似文献   
995.
Illegal wildlife trade is a widespread activity with direct impacts on biodiversity and street markets are frequently pointed out as hotspots in the wildlife trade route. However, due to its illegal character, it is difficult to accurately estimate how many individuals and how much money are handled by traders. Precise data on the number of individuals and species involved, and the drivers behind the illegal wildlife trade are essential for fighting it. We use the example of the metropolitan area of Recife, in northeastern Brazil, a well-known route of illegal wildlife in the country, to access the extent and impact street markets may have on biodiversity. We present quantitative and qualitative information on the illegal trade of wild birds in eight street markets in the area, indicating which species are preferred and why, estimating the number of animals and the volume of money involved, and quantifying the impact that the removal of those animals may have. We observed a high and diversified species offer, biased towards adult male songbirds, with birds of 15 families and 55 species on sale. Birds are kept in poor conditions and some individuals are sold for as little as US$ 1.00. However, we projected that up to 50,000 wild birds may be sold annually in the markets surveyed, including possibly 16,800 individuals of Sporophila nigricollis (the yellow-bellied seedeater), the most frequently observed species. The activity is profitable and may deal with significant amounts of money (up to nearly US$ 630,000.00/year). The numbers involved indicate that street markets are significant wildlife sinks, with a large and frequently ignored impact that must be taken into account in the control and conservation of the biodiversity, not just in Brazil but elsewhere.  相似文献   
996.

Purpose  

The dynamics and availability of potassium (K) in soils depend on many factors, including the mineralogy of fractions and the soil geochemical conditions. The objective of this work is to quantify K in distinct lowland soil compartments in the south of Brazil, relating them to particle size fractions and mineralogical constitution.  相似文献   
997.
Journal of Crop Science and Biotechnology - The rhizobacteria of genus Azospirillum and Bacillus are effective at fixing atmospheric nitrogen, promote plant growth and can largely contribute to...  相似文献   
998.
N-3 polyunsaturated fatty acids (n-3 PUFAs), and especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are essential compounds for human health. They have been proven to act positively on a panel of diseases and have interesting anti-oxidative, anti-inflammatory or anti-cancer properties. For these reasons, they are receiving more and more attention in recent years, especially future food or feed development. EPA and DHA come mainly from marine sources like fish or seaweed. Unfortunately, due to global warming, these compounds are becoming scarce for humans because of overfishing and stock reduction. Although increasing in recent years, aquaculture appears insufficient to meet the increasing requirements of these healthy molecules for humans. One alternative resides in the cultivation of microalgae, the initial producers of EPA and DHA. They are also rich in biochemicals with interesting properties. After defining macro and microalgae, this review synthesizes the current knowledge on n-3 PUFAs regarding health benefits and the challenges surrounding their supply within the environmental context. Microalgae n-3 PUFA production is examined and its synthesis pathways are discussed. Finally, the use of EPA and DHA in food and feed is investigated. This work aims to define better the issues surrounding n-3 PUFA production and supply and the potential of microalgae as a sustainable source of compounds to enhance the food and feed of the future.  相似文献   
999.
Schistosomiasis is a parasitic disease that affects more than 250 million people. The treatment is limited to praziquantel and the control of the intermediate host with the highly toxic molluscicidal niclosamide. Marine algae are a poorly explored and promising alternative that can provide lead compounds, and the use of multivariate analysis could contribute to quicker discovery. As part of our search for new natural compounds with which to control schistosomiasis, we screened 45 crude extracts obtained from 37 Brazilian seaweed species for their molluscicidal activity against Biomphalaria glabrata embryos and schistosomicidal activities against Schistosoma mansoni. Two sets of extracts were taxonomically grouped for metabolomic analysis. The extracts were analyzed by GC–MS, and the data were subjected to Pattern Hunter and Pearson correlation tests. Overall, 22 species (60%) showed activity in at least one of the two models. Multivariate analysis pointed towards 3 hits against B. glabrata veliger embryos in the Laurencia/Laurenciella set, 5 hits against B. glabrata blastula embryos, and 31 against S. mansoni in the Ochrophyta set. Preliminary annotations suggested some compounds such as triquinane alcohols, prenylated guaianes, dichotomanes, and xenianes. Despite the putative identification, this work presents potential candidates and can guide future isolation and identification.  相似文献   
1000.
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