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.

Effects of Deforestation on the Onset of the Rainy Season and the Duration of Dry Spells in Southern Amazonia

Abstract: Amazonian deforestation is causing notable changes in the hydrological cycle by altering important precipitation characteristics. This study uses daily rainfall time series data from 112 rain gauges and a recent yearly 1‐km land use data set covering the period from 1974 to 2012 to evaluate the effects of the extent of deforestation at different spatial scales on the onset of the rainy season and on the duration of dry spells in southern Amazonia. Correlation analyses indicate a delay in the onset of 0.12–0.17 days per percent increase in deforestation. Analysis of cumulative probability density functions emphasizes that the likelihood of rainy season onset occurring earlier than normal decreases as the local deforestation fraction increases. In addition, the probability of occurrence of dry spells in the early and late rainy season is higher in areas with greater deforestation. The delayed onset and longer dry spell events in highly deforested areas increase the climate risk to agriculture in the region.

As espécies de ephemeroptera (insecta) registradas para o Brasil

Abstract: (As especies de Ephemeroptera (Insecta) registradas para o Brasil). Uma lista da fauna de Ephemeroptera do Brasil, com todas as especies, generos e familias registrados para o pais e apresentada, incluindo os estados para os quais as especies estao reportadas assim como a bibliografia pertinente. Comentarios acerca do estado atual do conhecimento da fauna brasileira tambem sao tecidos. Ate o presente momento 10 familias, 63 generos e 166 especies estao registrados. As familias Baetidae e Leptophlebiidae compreendem mais de 50% de todos os registros, enquanto as regioes Norte e Sudeste sao significativamente melhor estudadas que as demais.

The NAC domain-containing protein, GmNAC6, is a downstream component of the ER stress- and osmotic stress-induced NRP-mediated cell-death signaling pathway.

Abstract: The endoplasmic reticulum (ER) is a major signaling organelle, which integrates a variety of responses against physiological stresses. In plants, one such stress-integrating response is the N-rich protein (NRP)-mediated cell death signaling pathway, which is synergistically activated by combined ER stress and osmotic stress signals. Despite the potential of this integrated signaling to protect plant cells against different stress conditions, mechanistic knowledge of the pathway is lacking, and downstream components have yet to be identified. In the present investigation, we discovered an NAC domain-containing protein from soybean, GmNAC6 (Glycine max NAC6), to be a downstream component of the integrated pathway. Similar to NRP-A and NRP-B, GmNAC6 is induced by ER stress and osmotic stress individually, but requires both signals for full activation. Transient expression of GmNAC6 promoted cell death and hypersensitive-like responses in planta. GmNAC6 and NRPs also share overlapping responses to biotic signals, but the induction of NRPs peaked before the increased accumulation of GmNAC6 transcripts. Consistent with the delayed kinetics of GmNAC6 induction, increased levels of NRP-A and NRP-B transcripts induced promoter activation and the expression of the GmNAC6 gene. Collectively, our results biochemically link GmNAC6 to the ER stress- and osmotic stress-integrating cell death response and show that GmNAC6 may act downstream of the NRPs.

Metodologia de pesquisa das crenças sobre aprendizagem de línguas: estado da arte

Abstract: Language learning beliefs have been a topic in Applied Linguistics for 15 years now. Beliefs are considered as one of the individual learning differences that may influence the learning/acquisition process. Many studies have been published about language learning beliefs but few of them have examined the methodology of investigating beliefs. This paper is a state-ofart review of current research methodology on students' language learning beliefs. The author groups studies on language learning beliefs into three approaches according to their definition of beliefs, methodology, and the relationship between beliefs and actions. The main advantages and disadvantages of each approach are discussed and questions for the future research on students" language learning beliefs are offered at the end.

Blochmannia endosymbionts improve colony growth and immune defence in the ant Camponotus fellah

Abstract: Background Microorganisms are a large and diverse form of life. Many of them live in association with large multicellular organisms, developing symbiotic relations with the host and some have even evolved to form obligate endosymbiosis [1]. All Carpenter ants (genus Camponotus) studied hitherto harbour primary endosymbiotic bacteria of the Blochmannia genus. The role of these bacteria in ant nutrition has been demonstrated [2] but the omnivorous diet of these ants lead us to hypothesize that the bacteria might provide additional advantages to their host. In this study, we establish links between Blochmannia, growth of starting new colonies and the host immune response.