Mycobacterium tuberculosis strains are differentially recognized by TLRs with an impact on the immune response

Tuberculosis associates with a wide spectrum of disease outcomes. The Beijing (Bj) lineage of Mycobacterium tuberculosis (Mtb) is suggested to be more virulent than other Mtb lineages and prone to elicit non-protective immune responses. However, highly heterogeneous immune responses were reported upon infection of innate immune cells with Bj strains or stimulation with their glycolipids. Using both in vitro and in vivo mouse models of infection, we here report that the molecular mechanism for this heterogeneity may be related to distinct TLR activations. Among this Mtb lineage, we found strains that preferentially activate TLR2, and others that also activate TLR4. Recognition of Mtb strains by TLR4 resulted in a distinct cytokine profile in vitro and in vivo, with specific production of type I IFN. We also uncover a novel protective role for TLR4 activation in vivo. Thus, our findings contribute to the knowledge of the molecular basis underlying how host innate immune cells handle different Mtb strains, in particular the intricate host-pathogen interaction with strains of the Mtb Bj lineage.This work has been funded by Fundacao para a Ciencia e Tecnologia, Portugal. Project grants: PTDC/SAU-MII/101977/2008 and PTDC/BIA-BCM/102776/2008. Personal grants: SFRH/BD/35981/2007 to JC; SFRH/BPD/3306/2007 to AC; SFRH/BPD/77399/2011 to LMT; SFRH/BI/33456/2008 to CS; and SFRH/BPD/33959/2009 to NSO. MS is a Ciencia 2007 fellow. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Estimativa de custo de coleta e rentabilidade para sistema extrativo de castanha-do-brasil na Amazônia.

São escassos os conhecimentos relativo ao desempenho econômico dos sistemas de produção extrativistas que podem oferecer subsídios a políticas públicas para o setor. Este trabalho teve como objetivo apresentar uma estimativa dos custos de produção para extração de castanha-do-brasil (Bertholletia excelsa H. B. K.), safra 2001/2002, no estado do Acre. A metodologia utilizada foi a análise de rentabilidade com base na propriação dos custos de oportunidade dos recursos empregados, determinando-se os custos, resultado líquido e remuneração à mão-de-obra familiar empregada pelas famílias extrativistas. Para o período analisado, o sistema apresentou rentabilidade positiva, com as receitas superando em cerca de 50% os custos totais, mesmo sendo apropriadas as despesas com a mão-de-obra familiar. No entanto, o sistema não gera renda suficiente para manter a família extrativista durante o ano

Social interaction, noise and antibiotic-mediated switches in the intestinal microbiota

The intestinal microbiota plays important roles in digestion and resistance against entero-pathogens. As with other ecosystems, its species composition is resilient against small disturbances but strong perturbations such as antibiotics can affect the consortium dramatically. Antibiotic cessation does not necessarily restore pre-treatment conditions and disturbed microbiota are often susceptible to pathogen invasion. Here we propose a mathematical model to explain how antibiotic-mediated switches in the microbiota composition can result from simple social interactions between antibiotic-tolerant and antibiotic-sensitive bacterial groups. We build a two-species (e.g. two functional-groups) model and identify regions of domination by antibiotic-sensitive or antibiotic-tolerant bacteria, as well as a region of multistability where domination by either group is possible. Using a new framework that we derived from statistical physics, we calculate the duration of each microbiota composition state. This is shown to depend on the balance between random fluctuations in the bacterial densities and the strength of microbial interactions. The singular value decomposition of recent metagenomic data confirms our assumption of grouping microbes as antibiotic-tolerant or antibiotic-sensitive in response to a single antibiotic. Our methodology can be extended to multiple bacterial groups and thus it provides an ecological formalism to help interpret the present surge in microbiome data.Comment: 20 pages, 5 figures accepted for publication in Plos Comp Bio. Supplementary video and information availabl

Agronomic, anatomic and physiological characterization of Coffea arabica L. genotypes on irrigated system in the Central Cerrado.

The objective is to verify the behavior of Coffea arabica L. genotypes in the Cerrado of the Brazilian Central Plateau through anatomical and physiological characterization and yield

Diretrizes para o monitoramento de PSA hídricos.

bitstream/item/162998/1/Manual-PSA-2017-cap-4.pd

Assessment of leaf anatomic and physiological characteristics and genetic divergence among Coffea arabica L. cultivars in the Brazilian Savanna.

The knowledge on cultivars is essential for parental choosing on breeding programs. This research aimed to study the genetic divergence of Coffea arabica L. cultivars from a germoplasm bank of the Embrapa Cerrados, Brazil, for leaf anatomic and physiological characteristics. A total of 23 cultivars were evaluated: Acaiá Cerrado MG1474, Araponga MG1, Catiguá MG1, Catiguá MG2, Catiguá MG3, Catiguá MG3 P4, Catiguá MG3 P5, Catiguá MG3 P7, Catiguá MG3 P9, Catiguá MG3 P23, Catiguá MG3 P51, Catuaí Amarelo IAC 62, Catuaí Vermelho IAC 15, Catuaí Vermelho IAC 81, Catuaí Vermelho IAC 99, Caturra Vermelho MG0187, Guatenano Colis MG0207, Mundo Novo IAC 379-19, Paraíso MG1, Pau Brasil MG1, Sacramento MG1, San Ramon MG0198 and Topázio MG1190. In addition to the genetic divergence, the broad sense heritability and coefficient of genetic and environmental variation were also evaluated. All characteristics showed high coefficients of genetic variation and heritability values greater than 70 %, indicating a predominance of genetic over environmental factors, and that these are characteristics likely to obtain genetic gain. Catiguá MG1, Catiguá MG3 P51 and Topázio MG1190 stood out, with superior gas exchange characteristics. Attributes related to gas exchange were important for cultivar differentiation, demonstrating that they can be used in the early selection of Coffea arabica L. genotypes