Analysis of physical pore space characteristics of two pyrolytic biochars and potential as microhabitat

Background and Aims Biochar amendment to soil is a promising practice of enhancing productivity of agricultural systems. The positive effects on crop are often attributed to a promotion of beneficial soil microorganisms while suppressing pathogens e.g. This study aims to determine the influence of biochar feedstock on (i) spontaneous and fungi inoculated microbial colonisation of biochar particles and (ii) physical pore space characteristics of native and fungi colonised biochar particles which impact microbial habitat quality. Methods Pyrolytic biochars from mixed woods and Miscanthus were investigated towards spontaneous colonisation by classical microbiological isolation, phylogenetic identification of bacterial and fungal strains, and microbial respiration analysis. Physical pore space characteristics of biochar particles were determined by X-ray μ-CT. Subsequent 3D image analysis included porosity, surface area, connectivities, and pore size distribution. Results Microorganisms isolated from Wood biochar were more abundant and proliferated faster than those from the Miscanthus biochar. All isolated bacteria belonged to gram-positive bacteria and were feedstock specific. Respiration analysis revealed higher microbial activity for Wood biochar after water and substrate amendment while basal respiration was on the same low level for both biochars. Differences in porosity and physical surface area were detected only in interaction with biochar-specific colonisation. Miscanthus biochar was shown to have higher connectivity values in surface, volume and transmission than Wood biochars as well as larger pores as observed by pore size distribution. Differences in physical properties between colonised and non-colonised particles were larger in Miscanthus biochar than in Wood biochar. Conclusions Vigorous colonisation was found on Wood biochar compared to Miscanthus biochar. This is contrasted by our findings from physical pore space analysis which suggests better habitat quality in Miscanthus biochar than in Wood biochar. We conclude that (i) the selected feedstocks display large differences in microbial habitat quality as well as physical pore space characteristics and (ii) physical description of biochars alone does not suffice for the reliable prediction of microbial habitat quality and recommend that physical and surface chemical data should be linked for this purpose

Comparison of the Virulence Potential of Acinetobacter Strains from Clinical and Environmental Sources

Several Acinetobacter strains have utility for biotechnology applications, yet some are opportunistic pathogens. We compared strains of seven Acinetobacter species (baumannii, Ab; calcoaceticus, Ac; guillouiae, Ag; haemolyticus, Ah; lwoffii, Al; junii, Aj; and venetianus, Av-RAG-1) for their potential virulence attributes, including proliferation in mammalian cell conditions, haemolytic/cytolytic activity, ability to elicit inflammatory signals, and antibiotic susceptibility. Only Ah grew at 102 and 104 bacteria/well in mammalian cell culture medium at 37°C. However, co-culture with colonic epithelial cells (HT29) improved growth of all bacterial strains, except Av-RAG-1. Cytotoxicity of Ab and Ah toward HT29 was at least double that of other test bacteria. These effects included bacterial adherence, loss of metabolism, substrate detachment, and cytolysis. Only Ab and Ah exhibited resistance to killing by macrophage-like J774A.1 cells. Haemolytic activity of Ah and Av-RAG-1 was strong, but undetectable for other strains. When killed with an antibiotic, Ab, Ah, Aj and Av-RAG-1 induced 3 to 9-fold elevated HT29 interleukin (IL)-8 levels. However, none of the strains altered levels of J774A.1 pro-inflammatory cytokines (IL-1β, IL-6 and tumor necrosis factor-α). Antibiotic susceptibility profiling showed that Ab, Ag and Aj were viable at low concentrations of some antibiotics. All strains were positive for virulence factor genes ompA and epsA, and negative for mutations in gyrA and parC genes that convey fluoroquinolone resistance. The data demonstrate that Av-RAG-1, Ag and Al lack some potentially harmful characteristics compared to other Acinetobacter strains tested, but the biotechnology candidate Av-RAG-1 should be scrutinized further prior to widespread use

2 nd Brazilian Consensus on Chagas Disease, 2015

Abstract Chagas disease is a neglected chronic condition with a high burden of morbidity and mortality. It has considerable psychological, social, and economic impacts. The disease represents a significant public health issue in Brazil, with different regional patterns. This document presents the evidence that resulted in the Brazilian Consensus on Chagas Disease. The objective was to review and standardize strategies for diagnosis, treatment, prevention, and control of Chagas disease in the country, based on the available scientific evidence. The consensus is based on the articulation and strategic contribution of renowned Brazilian experts with knowledge and experience on various aspects of the disease. It is the result of a close collaboration between the Brazilian Society of Tropical Medicine and the Ministry of Health. It is hoped that this document will strengthen the development of integrated actions against Chagas disease in the country, focusing on epidemiology, management, comprehensive care (including families and communities), communication, information, education, and research

A relação entre o desenvolvimento fonológico e aprendizagem inicial da escrita em diferentes contextos socioeducacionais

Resumo:OBJETIVO: investigar a relação entre o desenvolvimento fonológico e aprendizagem inicial da escrita em diferentes contextos socioeducacionais.MÉTODOS: realizado em uma creche, uma escola municipal e escola particular, totalizando 100 crianças, entre 2:0 e 6:11 anos. Para avaliação fonológica, foi utilizado a Prova de Avaliação Fonológica. Para avaliação da leitura, foi aplicada a tarefa de Nomeação Seriada Rápida. Para avaliação da escrita, foi proposto um roteiro de atividades, como ditado de palavras e frases.RESULTADOS:foi possível observar que alguns processos fonológicos apresentaram correlação positiva com a Tarefa de Nomeação. Essa tarefa também se correlacionou positivamente com a escrita e com a idade. Ou seja, quanto melhor o desempenho na Tarefa de Nomeação, mais avançado o nível em que se encontravam na escrita e maior faixa etária. Foi observado, ainda, que as crianças de escola particular mostraram um melhor desempenho na escrita e na Tarefa de Nomeação.CONCLUSÃO:a partir desses dados, foi observado que existe uma relação entre o desenvolvimento fonológico e aprendizagem inicial da leitura e escrita, pois a superação dos processos fonológicos se relacionou com a Nomeação e a escrita em crianças na faixa etária de 2:0 a 6:11 anos. Acredita-se que estes achados podem estar relacionados a aspectos socioeducacionais

Achatina fulica infected by Angiostrongylus cantonensis on beaches, in the west zone of Rio de Janeiro, Brazil

ABSTRACT Angiostrongylus cantonensis is considered the main etiological agent of eosinophilic meningitis in humans. At present, this zoonosis is considered an emerging disease mainly in the Americas. The aim of this study was to determine the prevalence of Achatina fulica infected by Angiostrongylus cantonensis in restinga areas along beaches in the west zone of Rio de Janeiro city, Brazil. The study areas included the following beaches: Barra da Tijuca, Recreio dos Bandeirantes, Reserva, Prainha and Grumari. Ninety specimens of Achatina fulica were collected. Positive molluscs were found only in Barra da Tijuca. Infection prevalence was 5.5%. The presence of this parasite in the beachfront areas, in the west zone of Rio de Janeiro city demonstrates the potential risk of infection for visitors and the expansion of this helminth in the State of Rio de Janeiro