Institution
Universidade Federal de Viçosa
Education•Viçosa, Brazil•
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.
Topics: Population, Dry matter, Germination, Species richness, Soil water
Papers published on a yearly basis
Papers
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TL;DR: In this article, the effects of N and P deficiency, isolated or in combination, on leaf gas exchange and fast chlorophyll fluorescence emission were studied in common bean cv. Negrito.
Abstract: The effects of N and P deficiency, isolated or in combination, on leaf gas exchange and fast chlorophyll (Chl) fluorescence emission were studied in common bean cv. Negrito. 10-d-old plants grown in aerated nutrient solution were supplied with high N (HN, 7.5 mol m−3) or low N (LN, 0.5 mol m−3), and also with high P (HP, 0.5 mol m−3) or low P (LP, 0.005 mol m−3). Regardless of the external P supply, in LN plants the initial fluorescence (F0) increased 12 % in parallel to a quenching of about 14 % in maximum fluorescence (Fm). As a consequence, the variable to maximum fluorescence ratio (Fv/Fm) decreased by about 7 %, and the variable to initial fluorescence ratio (Fv/F0) was lowered by 25 % in relation to control plants. In LP plants, Fv/Fm remained unchanged whilst Fv/F0 decreased slightly as a result of 5 % decline in Fm. Under N deficiency, the net photosynthetic rate (PN) halved at 6 d after imposition of treatment and so remained afterwards. As compared to LN plants, PN declined in LP plants latter and to a less extent. From 12 d of P deprivation onwards. PN fell down progressively to display rates similar to those of LN plants only at the end of the experiment. The greater PN in LP plants was not reflected in larger biomass accumulation in relation to LN beans. In general, P and N limitation affected photosynthesis parameters and growth without showing any synergistic or additive effect between deficiency of both nutrients.
81 citations
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TL;DR: In this article, the authors used a phytosociological survey to determine the floristic composition of the tree stratum and make some inferences about its respective ecological groups.
Abstract: This work was carried out in a Submontane Semideciduous Forest fragment stretch on Sao Geraldo Farm, in Vicosa (20o45'23"S and 42o52'23"W), Cwa climate type, Zona da Mata, Minas Gerais, Brazil, to determine the floristic composition of the tree stratum and make some inferences about its respective ecological groups. The floristic listing was taken from a phytosociological survey in which 158 point-centered-quarters were employed. Ten surveys carried on the Zona da Mata were analysed to determine the main species of the region. A total of 632 individuals with a minimum trunk circunference of 0.15 m at 1.30m above the soil were sampled, comprising 123 species, 85 genera and 36 families. According to the ratios of the species distributed over the ecological groups, the fragment under study was classified as being at an intermediary stage of regeneration. Amongst the species observed, some are considered endangered species not only in the state of Minas Gerais but also in Brazil.
81 citations
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TL;DR: In this paper, the authors evaluated the usual gait speed of asymptomatic adult and elderly Brazilians with a 10-meter walk test and compared the results with foreign reference values.
Abstract: OBJECTIVES: To evaluate the usual gait speed of asymptomatic adult and elderly Brazilians with a 10-meter walk test and to compare the results with foreign reference values. METHODS: Seventy-nine asymptomatic volunteers >40 years old of both genders were assessed. After anamnesis, anthropometry and the application of a habitual physical activity questionnaire, the volunteers were submitted to a 10-meter walk test at usual speed by means of which gait speed, the number of steps and length of stride were calculated. RESULTS: Except for age, all study variables were significantly lower in women. Subjects >70 years old presented a significantly lower gait speed than subjects between 40 and 49 years old and between 50 and 59 in both men (1.09±0.18 m/s, 1.35±0.11 m/s and 1.34±0.22 m/s, respectively) and women (1.02±0,10 m/s, 1.27±0.20 m/s and 1.27±0,15 m/s), respectively). Gait speed showed moderate correlations with age (r=-0.41, p<0.001) and height (r=0.35, p=0.001). After multiple regression analysis, age and gender were selected as relevant attributes of gait speed in that they explained 24.6% of this variable. The gait speed values in this study were significantly lower than foreign reference values (p<0.05). CONCLUSIONS: The gait speed presented age-related decline and values significantly lower than those described for foreign populations. This finding indicates the need for comprehensive investigation of gait speed reference values for the Brazilian population.
80 citations
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TL;DR: Overall, the grains milled before processing in oven and in microwave oven retained more vitamin E and less carotenoids than those milled after these processing, and the antioxidant activity in processed flours with dry heat remained constant and decreased after processing with wet heat.
80 citations
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TL;DR: The authors combine functional genomics, phylogenetics, and metabolic modeling to describe how diatoms might have functionally integrated nitrogen metabolism during evolution and how metabolic flux is regulated across cellular compartments.
Abstract: Diatoms outcompete other phytoplankton for nitrate, yet little is known about the mechanisms underpinning this ability. Genomes and genome-enabled studies have shown that diatoms possess unique features of nitrogen metabolism however, the implications for nutrient utilization and growth are poorly understood. Using a combination of transcriptomics, proteomics, metabolomics, fluxomics, and flux balance analysis to examine short-term shifts in nitrogen utilization in the model pennate diatom in Phaeodactylum tricornutum, we obtained a systems-level understanding of assimilation and intracellular distribution of nitrogen. Chloroplasts and mitochondria are energetically integrated at the critical intersection of carbon and nitrogen metabolism in diatoms. Pathways involved in this integration are organelle-localized GS-GOGAT cycles, aspartate and alanine systems for amino moiety exchange, and a split-organelle arginine biosynthesis pathway that clarifies the role of the diatom urea cycle. This unique configuration allows diatoms to efficiently adjust to changing nitrogen status, conferring an ecological advantage over other phytoplankton taxa.
80 citations
Authors
Showing all 16194 results
Name | H-index | Papers | Citations |
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José A. Teixeira | 101 | 1414 | 47329 |
J. Alfredo Martínez | 82 | 642 | 24009 |
Andrew J. Davison | 78 | 240 | 22171 |
David H. Bromwich | 75 | 291 | 21688 |
Takeji Nishikawa | 59 | 408 | 14727 |
Thierry Candresse | 59 | 403 | 11833 |
Raul Narciso C. Guedes | 55 | 378 | 10668 |
Matthias Erb | 54 | 166 | 8599 |
Arne Janssen | 53 | 179 | 8315 |
Paulo R. Guimarães | 52 | 162 | 10206 |
Antonio Reverter | 52 | 233 | 7259 |
Adriano Nunes-Nesi | 52 | 157 | 8453 |
Fermín I. Milagro | 51 | 245 | 9281 |
Svetoslav Dimitrov Todorov | 51 | 210 | 7072 |
Marcos Heil Costa | 50 | 124 | 9660 |