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.

Obesity and diabetes: the link between adipose tissue dysfunction and glucose homeostasis.

Abstract: Obesity and type 2 diabetes mellitus (T2DM) epidemics, which have already spread, imply the possibility of both conditions being closely related. Thus, the goal of the present review was to draw a parallel between obesity, adipose tissue (AT) changes, and T2DM development. To this end, a search was conducted in PubMed, MEDLINE and SciELO databases, using the following key words and their combinations: obesity; diabetes; insulin resistance; diet; weight loss; adipocin; inflammation markers; and interleukins. Based on a literature review, AT dysfunction observed in obesity is characterised by adipocyte hypertrophy, macrophage infiltration, impaired insulin signalling and insulin resistance. In addition, there is release of inflammatory adipokines and an excessive amount of NEFA promoting ectopic fat deposition and lipotoxicity in muscle, liver and pancreas. Recent evidence supports the hypothesis that the conception of AT as a passive energy storage organ should be replaced by a dynamic endocrine organ, which regulates metabolism through a complex adipocyte communication with the surrounding microenvironment. The present review demonstrates how glucose homeostasis is changed by AT dysfunction. A better understanding of this relationship enables performing nutritional intervention strategies with the goal of preventing T2DM.

Impactos de sistemas agroflorestais e convencional sobre a qualidade do solo no semi-árido cearense

Abstract: The environmental benefits of agroforestry system are well documented in many regions of the globe. However, works documenting the advantage of this kind of soil management system on soil quality in the cearense semi-arid region are very scarce. The aim of this work was to evaluate the impact of agroforestry and conventional systems on the physical and chemical soil characteristics, after five years of experimentation in the semi-arid region, Ceara, Brazil. The experiment consisted of seven treatments: agrosilvopasture (AGP), silvopasture (SILV), traditionally cultivated in 1998 and 1999 (TR98), traditionally cultivated in 2002 (TR02), intensive cropping (CI), and two native forests (MN-1 and MN-2). Soil samples were collected at four depths: 0-6, 6-12, 12-20 and 20-40cm. Soil quality was evaluated by the following physical and chemical characteristics analyzed: granulometry, clay dispersion, aggregate stability, exchangeable elements, soil pH and total organic carbon (COT). The treatments AGP, TR98 and CI reduced the COT content due to intensive soil management.

Social wasps (Hymenoptera: Vespidae) as indicators of conservation degree of riparian forests in Southeast Brazil.

Abstract: Social wasps present characteristics that allow their use as ecological indicators, but few studies using these insects in this context have been carried out over the past decade. Riparian Forests are important to manage runoff frequency and intensity and therefore a key ecosystem for water conservation in Minas Gerais State, Brazil. These forests play also a major role in the biodiversity conservation in the Southeast/Central regions of Brazil working as natural corridors and humidity hotspots. Here, we verify the potential use of social wasps as ecological indicators of habitat quality in riparian forests. Both margins of a 30 Km section of the “Rio das Mortes” were studied in the municipality of Barroso, Minas Gerais State, Brazil, from October 2005 to September 2007. This area was divided into 500 m sections and sampled by active search, baited traps and point-based surveys to evaluate wasp richness and habitat specificity. Land use intensity was classified in five categories, from open-disturbed to old-secondary forests. Thirty-six species of social wasps were recorded and nests for 29 of them were found. The species indicator value analysis showed that Pseudopolybia vespiceps (IndVal= 28.6; p= 0.0073) and Polybia fastidiosuscula (IndVal= 24.3; p= 0.0146) are associated positively to the high conservation degree of the riparian forest and Mischocyttarus drewseni (IndVal= 17.4; p= 0.0365) was considered an indicator of the most disturbed categories.

Genetic diversity of begomovirus infecting tomato and associated weeds in Southeastern Brazil

Abstract: *Part of the M.S. thesis of the first author. Universidade Federal de Vicosa**CNPq fellow. The genetic diversity of begomovirus isolates from tomato( Lycopersicon esculentum ) fields in the Southeastern region of Brazilwas analyzed by direct sequencing of PCR fragments amplified byusing universal oligonucleotides for the begomovirus DNA-A, andsubsequent computer-aided phylogenetic analysis. Samples of tomatoplants and associated weeds showing typical symptoms of virusinfection were collected at seven locations in the states of MinasGerais, Espirito Santo and Rio de Janeiro. A total of 137 out of 369samples were infected with a begomovirus based on PCR analysis.Phylogenetic analysis indicated a high degree of genetic diversityamong begomoviruses infecting tomatoes in the sampled area. Onespecies Tomato chlorotic mottle virus( , TCMV) occurspredominantly in Minas Gerais, whereas in Rio de Janeiro andEspirito Santo a distinct species, not yet fully characterized,predominates. Phylogenetic analysis further indicates the presenceof an additional four possible new species. This high degree ofgenetic diversity suggests a recent transfer of indigenousbegomovirus from wild hosts into tomatoes. The close phylogeneticrelationship verified between begomovirus infecting tomato andassociated weeds favors this hypothesis.

Equilibrium Data for PEG 4000 + Salt + Water Systems from (278.15 to 318.15) K

Abstract: Liquid−liquid equilibrium data of aqueous two-phase systems composed of PEG 4000 + sodium sulfate, PEG 4000 + lithium sulfate, and PEG 4000 + potassium phosphate were determined from (278.15 to 318.15) K. When the temperature was increased, the slope of the tie line (STL) tended to increase, reducing the quantity of salt necessary for phase splitting. From (308.15 to 318.15) K, for the aqueous systems PEG 4000 + lithium sulfate or potassium phosphate, a small decrease of the STL was verified. In spite of producing a phase diagram with a larger biphasic area, the sodium sulfate showed higher capability for inducing the phase splitting as compared to potassium phosphate and lithium sulfate.