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 & Biology. The organization has 16012 authors who have published 26711 publications receiving 353416 citations.

Plant growth and solute accumulation and distribution in two sorghum genotypes, under NaCl stress

Abstract: Seedlings of two sorghum (Sorghum bicolor (L.) Moench) genotypes with differential tolerance to salinity were exposed to 0 and 100 mM NaCl, gradually added in increments of 25 mM every 12 hours, in nutrient solution. Seven days after starting the salt treatment the growth of the shoot and root system and the inorganic and organic solutes contents were determined. Salinity reduced the dry matter yield and length of the shoot and root system in both sorghum genotypes, specially in the sensitive one. In general, it was observed an increase in Na + and Cl - transfer to the shoot, in Na + and Cl - accumulation and in the Na + /Cl - ratio but a decrease in the K + and Ca 2+ transfer to shoot and in the K + and Ca 2+ contents in the shoot, always with higher intensity in sensitive genotype. Apparently, the tolerance to high saline concentrations in sorghum seems to be related to the genotype ability to avoid accumulation of harmful levels of Na + and Cl - and, or to maintain adequate levels of K + and Ca 2+ , specially in the shoot. The soluble carbohydrates and amino acids constituted together over 98% of the total organic solutes and showed the greatest absolute increase in concentration during saline stress. Probably, the soluble carbohydrates were the most important organic solutes to contribute to the osmotic adjustment in the leaves and the amino acids in the roots. Under saline stress there was an expressive increase in proline contents, specially in the oldest leaves of sensitive genotype. The proline contents, however, even under salt stress, did not reach the levels of other organic solutes. Contrary to the general acceptance, proline does not seem to have an important role in the mechanism of salt tolerance, at least for these genotypes and under the experimental conditions applied here. ADDITIONAL INDEX TERMS: Salinity, salt stress, salt accumulation, organic solutes accumulation, Sorghum bicolor.

The relationship between organizational culture and quality techniques, and its impact on operational performance

Abstract: Purpose – The purpose of this paper is to investigate if a firm’s organizational culture affects the set of quality techniques it uses, and if these quality techniques affect the relationship between organizational culture and operational performance. Design/methodology/approach – Based on data collected from 250 firms in Brazil and Denmark, structural equation modeling is used to investigate the relationship between organizational culture and the use of quality techniques, and its impact on operational performance. Four quality technique groups, four cultural profiles adopted from the Competing Values Framework and a set of operational performance indicators are used to operationalize the study. Findings – Culture does not appear to be an unequivocal predictor of the use of quality techniques. Furthermore, while most quality technique groups contribute indirectly to the total effect on operational performance in the developmental, group and hierarchical cultures, the performance effects are insignificant...

Liquid chromatography-mass spectrometry analysis of propolis.

Abstract: The composition of propolis, a resinous hive product collected by honeybees from various plant sources, depends on various factors such as season and vegetation of the area. Based on standards (either isolated from Brazilian propolis or reported from propolis) including chromane, diterpenes and phenolic compounds, different Brazilian propolis were analysed by LC-MS in order to determine their chemical constituents. Dicaffeoylquinic acids were detected in almost all water extracts of Brazilian propolis, whereas diterpenes, flavonoids and prenylated phenolic compounds were found in their methanol extracts. Based on the identified chemical constituents and their biological activities, it was determined that the quality of Brazilian propolis could be directly related to the phenolic constituents. Moreover, Baccharis dracunculifolia was concluded to be an important source of Brazilian propolis. Propolis samples from Peru, China and the Netherlands were also studied.