Universidade Federal de Viçosa

About: Universidade Federal de Viçosa is a education organization based out in Viçosa, Brazil. It is known for research contribution in the topics: Population & Dry matter. The organization has 16012 authors who have published 26711 publications receiving 353416 citations.

Characterization of biochars from different sources and evaluation of release of nutrients and contaminants

Abstract: The biochar, product of pyrolysis of organic waste, has been used as a soil conditioner and alternative on solid waste management. However, the raw material and pyrolysis temperature used influence the quantity and dynamics of release of nutrients and contaminants from the biochar. The objective wasto evaluate the use of waste sugarcane bagasse, eucalyptus and sewage sludge for production of biochar and determine the chemical, physical, mineralogical properties and acid extraction of these materials produced at 350 °C and 500 °C. Were evaluated the proportion of C, H, N, O; ashes; macro and micronutrients, plus some contaminants; characterization of mineral phases by diffractometry of X- rays; functional groups by infrared absorption spectroscopy (FTIR). Moreover, it was determined the release of nutrients and contaminants for the extraction in increasing concentration of HNO3 (0,01 - 2,0 mol L-1). The O/C and H/C relations decreased with increasing temperature of pyrolysis, which define a greater stability of the C of biochars. Sewage sludge biochar (BC-L) had the highest nutrient release rates and contaminant metals (Cd, Cr, Ni and Pb). Acid extraction of other biocarvoes was very low (<20% of the total content). The results indicate that the carbon fraction of biochar contributes to the low rateof release of the elements in acid place.

Association between dietary pattern and cardiometabolic risk in children and adolescents: a systematic review

Abstract: Objective To evaluate the association between dietary patterns and cardiometabolic risk factors in children and adolescents. Data source This article followed the recommendations of PRISMA, which aims to guide review publications in the health area. The article search strategy included searches in the electronic databases MEDLINE via PubMed, Scopus, and LILACS. There was no date limitation for publications. The descriptors were used in English according to MeSH and in Portuguese according to DeCS. Only articles on dietary patterns extracted by the a posteriori methodology were included. The question to be answered was: how much can an “unhealthy” dietary pattern influence biochemical and inflammatory markers in this population? Data synthesis The studies showed an association between dietary patterns and cardiometabolic alterations. The patterns were characterized as unhealthy when associated to the consumption of ultraprocessed products, poor in fiber and rich in sodium, fat, and refined carbohydrates. Despite the associations, in several studies, the strength of this association for some risk markers was reduced or lost after adjusting for confounding variables. Conclusion There was a positive association between “unhealthy” dietary patterns and cardiometabolic alterations in children and adolescents. Some unconfirmed associations may be related to the difficulty of assessing food consumption. Nevertheless, studies involving dietary patterns and their association with risk factors should be performed in children and adolescents, aiming at interventions and early changes in dietary habits considered to be inadequate.

Gap-phase regeneration in a semideciduous mesophytic forest, south–eastern Brazil

Abstract: The study was carried out in ten natural canopy gaps in the Santa Genebra County Reserve (22°4945S, 47°0633W) in the county of Campinas, Sao Paulo State, Brazil. The size and canopy openness of the gaps were studied using hemispherical photographs. The vegetation survey included all shrubs and trees with height 0.50 m in the gaps interiors and all the individuals with PBH (perimeter at breast height) 15 cm in a3m surrounding border of the gaps. The similarity among the gaps and among their surrounding areas was assessed by the Jaccard similarity index and by cluster analyzes. The gap size varied from 20.09 to 468 m 2 , with a predominance of small gaps. The families with the greatest species richness in the gaps were Rutaceae, Rubiaceae and Euphorbiaceae. The species with the greatest number of individuals in the gaps were Coffea arabica L., Hybanthus atropurpureus (St. Hil.) Taub. and Actinostemon klotschii (Muell. Arg.) Pax, all widely distributed in the understorey. Shade-tolerant species (late secondary species) predominated in function of the predominance of small gaps. The high number of species found in the gaps reflects the importance of these disturbances in the maintenance of species diversity in the studied forest.