Air pollution from agricultural fires increases hypertension risk

In many parts of the developing world, farmers widely use deliberate fires to burn vegetation and clear land to plant crops. These agricultural fires, however, are known to be associated with health costs due to increased air pollution. We contribute to underpinning the associated health cost estimates by studying the effects of these fires on hypertension risk. Despite being one of the leading causes of mortality globally, there is little direct evidence on how hypertension risk changes with exposure to pollution from agricultural fires. To overcome common data and empirical challenges in this setting, we match blood pressure readings from nearly 784,000 individuals across India with satellite data on 1.2 million agricultural fires, wind direction realizations, and local ambient air pollution. We find that the incidence of hypertension increases by 1.8% for each standard deviation increase in the number of upwind fires observed one day before the blood pressure readings. We find that the impact is stronger among older males, smokers, individuals that were already on blood pressure medication, and individuals belonging to socially marginalized groups. Our estimates suggest that agricultural fires in India lead to hypertension-related additional mortality, associated with USD 9 billion annually in costs.Souza acknowledges generous support from the European Research Council (ERC, under the European Union’s Horizon 2020 research and innovation programme, Grant Agreement No. 772331)

Baryon Loading of AGN Jets Mediated by Neutrons

Plasmas of geometrically thick, black hole (BH) accretion flows in active galactic nuclei (AGNs) are generally collisionless for protons, and involve magnetic field turbulence. Under such conditions a fraction of protons can be accelerated stochastically and create relativistic neutrons via nuclear collisions. These neutrons can freely escape from the accretion flow and decay into protons in dilute polar region above the rotating BH to form relativistic jets. We calculate geometric efficiencies of the neutron energy and mass injections into the polar region, and show that this process can deposit luminosity as high as L_j ~ 2e-3 dot{M} c^2 and mass loading dot{M}_j ~ 6e-4 dot{M} for the case of the BH mass M ~ 1e8 M_sun, where dot{M} is mass accretion rate. The terminal Lorentz factors of the jets are Gamma ~ 3, and they may explain the AGN jets having low luminosities. For higher luminosity jets, which can be produced by additional energy inputs such as Poynting flux, the neutron decay still can be a dominant mass loading process, leading to e.g., Gamma ~ 50 for L_{j,tot} ~ 3e-2 dot{M}c^2.Comment: 7 pages, 6 figures; accepted for publication in Ap

Bacterial defenses against a natural antibiotic promote collateral resilience to clinical antibiotics

As antibiotic-resistant infections become increasingly prevalent worldwide, understanding the factors that lead to antimicrobial treatment failure is essential to optimizing the use of existing drugs. Opportunistic human pathogens in particular typically exhibit high levels of intrinsic antibiotic resistance and tolerance1, leading to chronic infections that can be nearly impossible to eradicate2. We asked whether the recalcitrance of these organisms to antibiotic treatment could be driven in part by their evolutionary history as environmental microbes, which frequently produce or encounter natural antibiotics3,4. Using the opportunistic pathogen Pseudomonas aeruginosa as a model, we demonstrate that the self-produced natural antibiotic pyocyanin (PYO) activates bacterial defenses that confer collateral tolerance to certain synthetic antibiotics, including in a clinically-relevant growth medium. Non-PYO-producing opportunistic pathogens isolated from lung infections similarly display increased antibiotic tolerance when they are co-cultured with PYO-producing P. aeruginosa. Furthermore, we show that beyond promoting bacterial survival in the presence of antibiotics, PYO can increase the apparent rate of mutation to antibiotic resistance by up to two orders of magnitude. Our work thus suggests that bacterial production of natural antibiotics in infections could play an important role in modulating not only the immediate efficacy of clinical antibiotics, but also the rate at which antibiotic resistance arises in multispecies bacterial communities

Comportamento produtivo de forrageiras cultivadas sob sombreamento no cerrado do Amapá.

O estabelecimento de pastagens na Amazônia, baseados na retirada da vegetação nativa (Cerrado e floresta), tem causado muitos prejuízos. Os sistemas silvipastoris aumentando a eficiência de utilização dos recursos naturais, surgem como alternativa, melhorando a produção de biomassa do sistema e a renda do produtor. Para o sucesso dos sistemas silvipastoris deve-se selecionar espécies forrageiras adaptadas ao sombreamento de árvores. Uma questão que chama atenção é que os programas de melhoramento das plantas forrageiras tem sido desenvolvidos em condições de plena luz e, as espécies selecionadas podem não ser tolerantes a sombra. O presente trabalho, objetivou avaliar no cerrado do Amapá, o comportamento produtivo de sete gramíneas e seis leguminosas forrageiras, sob três regimes de luminosidade em sub-bosque de taxi-branco (Slerolobium paniculatum): Pleno sol; sombreamento moderado (417 árvores/ha) e sombreamento intenso (833 árvores/ha). As espécies avaliadas, apresentaram respostas distintas e negativas às condições de sombreamento, sendo que o sombreamento intenso (833 árvores/ha) prejudicou severamente o desempenho das plantas. A gramínea B. brizantha cv. Marandú e a leguminosa S. guianensis cv. Mineirão, apresentaram os melhores desempenhos sob condição de sombreamento moderado, destacando-se como promissoras para futuros ensaios envolvendo a avaliação de sistemas silvipastoris para o cerrado do Amapá.bitstream/item/63023/1/AP-Comportamento-produtivo-forrageira.pd

PhdA catalyzes the first step of phenazine-1-carboxylic acid degradation in Mycobacterium fortuitum

Phenazines are a class of bacterially produced redox-active metabolites that are found in natural, industrial, and clinical environments. In Pseudomonas spp., phenazine-1-carboxylic acid (PCA)—the precursor of all phenazine metabolites—facilitates nutrient acquisition, biofilm formation, and competition with other organisms. While the removal of phenazines negatively impacts these activities, little is known about the genes or enzymes responsible for phenazine degradation by other organisms. Here, we report that the first step of PCA degradation by Mycobacterium fortuitum is catalyzed by a phenazine-degrading decarboxylase (PhdA). PhdA is related to members of the UbiD protein family that rely on a prenylated flavin mononucleotide cofactor for activity. The gene for PhdB, the enzyme responsible for cofactor synthesis, is present in a putative operon with the gene encoding PhdA in a region of the M. fortuitum genome that is essential for PCA degradation. PhdA and PhdB are present in all known PCA-degrading organisms from the Actinobacteria. M. fortuitum can also catabolize other Pseudomonas-derived phenazines such as phenazine-1-carboxamide, 1-hydroxyphenazine, and pyocyanin. On the basis of our previous work and the current characterization of PhdA, we propose that degradation converges on a common intermediate: dihydroxyphenazine. An understanding of the genes responsible for degradation will enable targeted studies of phenazine degraders in diverse environments

The Influence of infographics in accessing information: Multidimensionality in visual representation and configuration of different media

Infographics are powerful tools for presenting information and information design has distinguished itself as a specific discipline that has efficient communication of information as main task. With new online revolu- tion, concept of infographics has evolved by combining several ways of pre- sentation in many formats and there are different denominations; simultaneously, information designers should consider some principles and differences when designing for internet or printed material. This article presents a theoretical reflection and practical examples that pretend to reflect these matters, trying to create a relationship between infographic typologies, objec- tives and how information is presented, considering final users. All types of infographics exploded in popularity a few years ago and the amount of information we must filter and understand will continue to grow; information design states itself as one of the best disciplines to share and communicate things we learn.CIAUD - Centro de Investigação em Arquitetura Urbanismo e Design, Faculdade de Arquitetura, Universidade de Lisbo

Both toxic and beneficial effects of pyocyanin contribute to the lifecycle of Pseudomonas aeruginosa

Pseudomonas aeruginosa, an opportunistic pathogen, produces redox‐active pigments called phenazines. Pyocyanin (PYO, the blue phenazine) plays an important role during biofilm development. Paradoxically, PYO auto‐poisoning can stimulate cell death and release of extracellular DNA (eDNA), yet PYO can also promote survival within biofilms when cells are oxidant‐limited. Here, we identify the environmental and physiological conditions in planktonic culture that promote PYO‐mediated cell death. We demonstrate that PYO auto‐poisoning is enhanced when cells are starved for carbon. In the presence of PYO, cells activate a set of genes involved in energy‐dependent defenses, including: (i) the oxidative stress response, (ii) RND efflux systems and (iii) iron‐sulfur cluster biogenesis factors. P. aeruginosa can avoid PYO poisoning when reduced carbon is available, but blockage of adenosine triphosphate (ATP) synthesis either through carbon limitation or direct inhibition of the F_0F_1‐ATP synthase triggers death and eDNA release. Finally, even though PYO is toxic to the majority of the population when cells are nutrient limited, a subset of cells is intrinsically PYO resistant. The effect of PYO on the producer population thus appears to be dynamic, playing dramatically different yet predictable roles throughout distinct stages of growth, helping rationalize its multifaceted contributions to biofilm development

Atividade de nucleação de gelo e densidade populacional do patógeno podem ser fatores que contribuem para o progresso da doença mancha branca do milho.

A Mancha Branca do Milho (MBM) e? uma doença foliar que tem causado perdas apreciáveis, tanto qualitativas como quantitativas para a produção de milho. Seu agente etiológico, a Pantoea ananatis, é uma bacte?ria epifi?tica, Gram-negativa formadora de colônia amarela, capaz de formar gelo, mesmo em ambiente tropical (ice nucleation activity - INA). Este estudo teve por objetivo caracterizar isolados de P. ananatis quanto à atividade INA e avaliar o efeito da densidade bacteriana na expressão do fenótipo INA e no processo de desenvolvimento da doença. O agente patogênico foi isolado de lesões iniciais da doença, as anasarcas, e avaliado quanto à expressão do fenótipo INA em diferentes concentrações bacterianas. O mesmo foi feito com isolados epifíticos obtidos da superfície foliar de plantas de milho sadias. Dos 24 isolados bacterianos estudados, apenas 13 apresentaram o fenótipo INA+. A expressão deste fenótipo foi dependente da densidade celular. Isolados INA+ e INA? foram inoculados em folhas destacadas e em plantas da cultivar HS200 a campo, em diferentes concentrações do inóculo. Nenhum isolado INA? reproduziu sintomas em laboratório. Dos cinco isolados INA+ somente um deles reproduziu sintomas em laboratório. Em campo o isolado INA+ foi capaz de promover lesões em todas as concentrações avaliadas. Conclui-se que a atividade de nucleação de gelo pela bactéria P. ananatis é dependente da linhagem e da densidade bacteriana e este fenômeno pode estar envolvido no desenvolvimento dos sintomas da MBM