NGC 1068: No change in the mid-IR torus structure despite X-ray variability

Context. Recent NuSTAR observations revealed a somewhat unexpected increase in the X-ray flux of the nucleus of NGC 1068. We expect the infrared emission of the dusty torus to react on the intrinsic changes of the accretion disk. Aims. We aim to investigate the origin of the X-ray variation by investigating the response of the mid-infrared environment. Methods. We obtained single-aperture and interferometric mid-infrared measurements and directly compared the measurements observed before and immediately after the X-ray variations. The average correlated and single-aperture fluxes as well as the differential phases were directly compared to detect a possible change in the structure of the nuclear emission on scales of $\sim$ 2 pc. Results. The flux densities and differential phases of the observations before and during the X-ray variation show no significant change over a period of ten years. Possible minor variations in the infrared emission are $\lesssim$ 8 %. Conclusions. Our results suggest that the mid-infrared environment of NGC 1068 has remained unchanged for a decade. The recent transient change in the X-rays did not cause a significant variation in the infrared emission. This independent study supports previous conclusions that stated that the X-ray variation detected by NuSTAR observations is due to X-ray emission piercing through a patchy section of the dusty region.Comment: 6 pages, 5 figures, 3 tables. Accepted for publication on A&

Estrutura fitossociológica de um área de cerrado sensu stricto em Sete Lagoas, MG.

Este trabalho teve como objetivo avaliar a composição, estrutura e diversidade da flora arbustivo arbórea em uma área de Cerrado sensu stricto em Sete Lagoas, MG, visando verificar sua similaridade com outras áreas de Cerrado em Minas Gerais. Foram estabelecidas 12 parcelas de 0,1 ha (20×50 m), totalizando 1,2 ha amostrados, sendo inclusas no estudo todas as árvores vivas com circunferência ?15 cm a 0.30 m do solo. Foram registrados 1.689 indivíduos. Os valores de riqueza (48 espécies e 29 famílias), de diversidade de Shannon (3,09) e de uniformidade de Pielou (0,8) evidenciaram grande heterogeneidade e baixa dominância ecológica. Plathymenia reticulata (Fabaceae) apresentou 203 indivíduos, sendo a espécie mais abundante. Fabaceae (10) Bignoniaceae (5), e Vochysiaceae (4) foram as famílias mais ricas em espécie. Os índices qualitativos de similaridade apontaram baixa diversidade entre os ambientes

The heme-based oxygen sensor Rhizobium etli FixL: influence of auxiliary ligands on heme redox potential and implications on the enzyme activity

Conformational changes associated to sensing mechanisms of heme-based protein sensors are a key molecular event that seems to modulate not only the protein activity but also the potential of the Fe redox couple of the heme domain. In this work, midpoint potentials (E) assigned to the Fe redox couple of the heme domain of FixL from Rhizobium etli (ReFixL) in the unliganded and liganded states were determined by spectroelectrochemistry in the presence of inorganic mediators. In comparison to the unliganded ReFixL protein (+ 19 mV), the binding to ligands that switch off the kinase activity induces a negative shift, i. e. E = − 51, − 57 and − 156 mV for O, imidazole and CN, respectively. Upon binding to CO, which does not affect the kinase active, E was observed at + 21 mV. The potential values observed for Fe of the heme domain of ReFixL upon binding to CO and O do not follow the expected trend based on thermodynamics, assuming that positive potential shift would be expected for ligands that bind to and therefore stabilize the Fe state. Our results suggest that the conformational changes that switch off kinase activity upon O binding have knock-on effects to the local environment of the heme, such as solvent rearrangement, destabilize the Fe state and counterbalances the Fe-stabilizing influence of the O ligand

Geléia de cupuaçu.

Este manual tem como objetivo fornecer orientações básicas aos produtores rurais que queiram agregar valor ao seu produto agrícola com a diversificação do uso da polpa de cupuaçu na obtenção de geléia, reduzindo perdas de matéria-prima, aumentando a renda e permitindo a estocagem do produto por um tempo maior.bitstream/item/11875/2/00081290.pd

NGC 1068: No change in the mid-infrared torus structure despite X-ray variability

Context. Recent NuSTAR observations revealed a somewhat unexpected increase in the X-ray flux of the nucleus of NGC 1068. We expect the infrared emission of the dusty torus to react on the intrinsic changes of the accretion disk. Aims. We aim to investigate the origin of the X-ray variation by investigating the response of the mid-infrared environment. Methods. We obtained single-aperture and interferometric mid-infrared measurements and directly compared the measurements observed before and immediately after the X-ray variations. The average correlated and single-aperture fluxes as well as the differential phases were directly compared to detect a possible change in the structure of the nuclear emission on scales of ~2 pc. Results. The flux densities and differential phases of the observations before and during the X-ray variation show no significant change over a period of ten years. Possible minor variations in the infrared emission are ≲6%. Conclusions. Our results suggest that the mid-infrared environment of NGC 1068 has remained unchanged for a decade. The recent transient change in the X-rays did not cause a significant variation in the infrared emission. This independent study supports previous conclusions that stated that the X-ray variation detected by NuSTAR observations is due to X-ray emission piercing through a patchy section of the dusty region

Caracterização de uma amostra de consumidores de carne ovina.

A ovinocultura é uma atividade com grande importância econômica no Brasil com um rebanho estimado em 17,6 milhões de cabeças, sendo mais expressivo nas regiões Nordeste e Sul (IBGE, 2014), porém seu consumo per capita ainda é pouco representativo quando comparado as demais carnes com cerca de 0,7 quilograma por habitante/anoJAI

Agrotóxicos e saúde: realidade e desafios para mudança de práticas na agricultura.

Este artigo apresenta os resultados de uma pesquisa que teve como objetivo principal caracterizar o contexto e as práticas relacionadas ao uso de agrotóxicos entre agricultores residentes na Serrinha do Mendanha, comunidade agrícola situada em Campo Grande, município do Rio de Janeiro. A proposta metodológica teve uma abordagem qualitativa, sendo a principal fonte de dados a aplicação de questionário semiestruturado. Participaram da pesquisa 38 agricultores familiares. O perfil socioeconômico mostra uma realidade de idosos no trabalho agrícola, percentuais expressivos de analfabetismo e baixa renda. O uso de agrotóxicos é uma rotina para essas famílias. Apesar de existir uma naturalização do uso, a maioria dos informantes acredita que agrotóxicos podem afetar sua saúde, apresenta preocupação com o consumidor e gostaria de conhecer formas alternativas de cultivo. Tais achados apontam para a possibilidade de busca de mudança de práticas. Não se trata de repasse de conhecimento, pois este tipo de informação de alguma forma eles já possuem. Trata–se de desenvolver estratégias objetivando a minimização dos riscos ou mesmo o desuso de agrotóxicos na lavoura

Antimicrobial susceptibility and genetic profile of Mycoplasma hyopneumoniae isolates from Brazil

Mycoplasma hyopneumoniae is the etiologic agent of porcine enzootic pneumonia, responsible for major production losses worldwide. The bacteria have a limited metabolism and need to obtain molecules from the growth environment, which causes multiple difficulties for in vitro culture. These limitations have a negative influence on the ability to carry out research for the development of the rational use of antimicrobials and vaccines. The objective of this investigation was to evaluate the genetic profile and in vitro susceptibility of field isolates of M. hyopneumoniae to different antimicrobials. All 16 isolates obtained from the samples presented 100% of identity in the partial sequence of 16S rRNA gene when compared to M. hyopneumoniae. A dendrogram was created using the PCR results of the genes related to pathogenicity, and the isolates were distributed into four clusters, suggesting genetic variability among four different isolates circulating on the same farm. The minimum inhibitory concentration of the isolates was higher for the antimicrobials tylosin (< 0.001–16 mg/L) and spiramycin (< 0.001–16 mg/L) than for enrofloxacin (< 0.001–0.125 mg/L) and tiamulin (< 0.001–0.125 mg/L). Our results demonstrate the genetic variability among M. hyopneumoniae isolates from pigs of the same farm, with differences in their susceptibility to antimicrobial agents