Efeito do pastejo restringido em aveia preta sobre a produção de leite.

Avaliou-se o efeito do pastejo restringido em aveia sobre a produção de leite, utilizando-se vacas mestiças de Holandes-Zebu, distribuidas em blocos ao acaso

Avaliação de regimes de temperatura no desenvolvimento da ferrugem-asiática da soja.

Com o objetivo de avaliar o impacto de cinco regimes de temperatura (28oC/ 20oC, 30oC/ 22oC, 32oC/ 24oC, 34oC/ 26oC e 36oC/ 28oC) no desenvolvimento da ferrugem-asiática da soja foram realizados ensaios em condições controladas. Plantas da cultivar CD 219 RR com a quarta folha expandida foram inoculadas com esporos do fungo Phakopsora pachyrhizi e mantidas nos diferentes regimes de temperatura. A severidade da ferrugem foi avaliada aos 16 dias após a inoculação. O regime de temperatura mais favorável para o desenvolvimento da ferrugem foi 28oC/ 20oC (média 24oC). A doença não se desenvolveu nos regimes de temperatura de 34oC/ 26oC e 36oC/ 28oC, com médias 30oC e 32oC, respectivamente

The enzymes LSD1 and Set1A cooperate with the viral protein HBx to establish an active hepatitis B viral chromatin state

Indexación: Web of ScienceWith about 350 million people chronically infected around the world hepatitis B is a major health problem. Template for progeny HBV synthesis is the viral genome, organized as a minichromosome (cccDNA) inside the hepatocyte nucleus. How viral cccDNA gene expression is regulated by its chromatin structure; more importantly, how the modulation of this structure impacts on viral gene expression remains elusive. Here, we found that the enzyme SetDB1 contributes to setting up a repressed cccDNA chromatin state. This repressive state is activated by the histone lysine demethylase-1 (LSD1). Consistently, inhibiting or reducing LSD1 levels led to repression of viral gene expression. This correlates with the transcriptionally repressive mark H3K9 methylation and reduction on the activating marks H3 acetylation and H3K4 methylation on viral promoters. Investigating the importance of viral proteins we found that LSD1 recruitment to viral promoters was dependent on the viral transactivator protein HBx. Moreover, the histone methyltransferase Set1A and HBx are simultaneously bound to the core promoter, and Set1A expression correlates with cccDNA H3K4 methylation. Our results shed light on the mechanisms of HBV regulation mediated by the cccDNA chromatin structure, offering new therapeutic targets to develop drugs for the treatment of chronically infected HBV patients.http://www.nature.com/articles/srep2590

A bright impulsive solar burst detected at 30 THz

Ground- and space-based observations of solar flares from radio wavelengths to gamma-rays have produced considerable insights but raised several unsolved controversies. The last unexplored wavelength frontier for solar flares is in the range of submillimeter and infrared wavelengths. Here we report the detection of an intense impulsive burst at 30 THz using a new imaging system. The 30 THz emission exhibited remarkable time coincidence with peaks observed at microwave, mm/submm, visible, EUV and hard X-ray wavelengths. The emission location coincides with a very weak white-light feature, and is consistent with heating below the temperature minimum in the atmosphere. However, there are problems in attributing the heating to accelerated electrons. The peak 30 THz flux is several times larger than the usual microwave peak near 9 GHz, attributed to non-thermal electrons in the corona. The 30 THz emission could be consistent with an optically thick spectrum increasing from low to high frequencies. It might be part of the same spectral component found at sub-THz frequencies whose nature remains mysterious. Further observations at these wavelengths will provide a new window for flare studies.Comment: 9 pages, 11 figures, accepted by Astrophysical Journal, March 23, 201