Universidade Federal de Santa Maria

About: Universidade Federal de Santa Maria is a education organization based out in Santa Maria, Brazil. It is known for research contribution in the topics: Population & Context (language use). The organization has 21178 authors who have published 35632 publications receiving 371665 citations.

Regioselective synthesis of isochromenones by iron(III)/PhSeSePh-mediated cyclization of 2-alkynylaryl esters.

Abstract: A series of 4-Se-(Te, S)-isochromenones and 3-substituted isochromenones were synthesized in good yields via FeCl3-mediated cyclization of alkynylaryl esters with different diorganyl dichalcogenides This methodology was carried out at room temperature, using inexpensive and environmentally friendly iron salts as metallic source and under air atmosphere The reaction showed to be tolerant to a range of substituents bonded into the aromatic ring of the diorganyl dichalcogenides as well as to alkyl groups directly bonded to the chalcogen atom Alternatively, the cyclization reaction of 2-alkynylaryl esters with FeCl3, in the absence of diorganyl dichalcogenide, gave the isochromenones without the chalcogen moiety in the structure This approach proved to be highly regioselective, providing only six-membered ring products, once the possible five-membered products were not observed in any experiments

Catabolism and bioactive properties of chlorophylls

Abstract: Chlorophylls are fundamental molecules for life and probably the most important of all natural pigments. Although chlorophyll breakdown is inevitably associated with the loss of green color during ripening or senescence, the truth is that chlorophyll molecules continuously degrade through so-called chlorophyll turnover (lifetime of hours). In addition to their primary function, chlorophylls are in demand due to their bioactive properties. Recently, several chlorophyll derivatives have shown health promoting activities. This review also provides an updated outline of the most recent advances that have occurred in the deciphering mechanism of chlorophyll catabolism; it will also describe the novel biological properties associated with chlorophyll derivatives.

Análise de investimentos

Abstract: O presente trabalho objetiva evidenciar tres metodos de avaliacao de investimentos atraves das projecoes de Fluxos de Caixa Futuros, sendo estes os calculos do Valor Presente Liquido, da Taxa Interna de Retorno e o Payback Descontado. Embasado no pressuposto de que os investimentos sao realizados visando criar valor para os investidores, demonstra-se que as avaliacoes realizadas por estes metodos capacitam o investidor a visualizar se os projetos que estejam a sua disposicao sao economicamente viaveis ou nao, ou seja, se este ira agregar ou perder valor.

Incêndios florestais no parque nacional da Serra da Canastra: desafios para a conservação da biodiversidade.

Abstract: The Protected Areas in Brazil have been injured by wildfires that treathen the high biodiversity and ecological processes. The Serra da Canastra National Park (SCNP), located at south Minas Gerais State, is characterized by grasslands predominance and an ancient incorrect use of fire as a land management tool, wich cause large wildfires. The objective of this work was to analyse fire ocorrences in SCNP and to give data to reduce large wildfires as a biodiversity conservation question. The data collection was carried out with fire reports from 1987 to 2001 and local visits. The results shown that most of forest fires causes (50%) in SCNP are human originated, in spite of several forest fires caused by lightnings (44%). Among human causes the most is originated by lawbreakers (47%). There is a high number of forest fires caused by lightnings during the rainy season and transition dry-rainy season and a high number of forest fires caused by humans during the dry season. However, the forest fires caused by lightnings are often restricted to small areas (lower than 500 ha) and the forest fires caused by humans reached large areas in SCNP. Furthermore, the control of fire in SCNP should include several prevention activities, mainly environmental education and combustible isolation.