Combinações entre cultivares, ambientes, preparo e cobertura do solo em características agronômicas de alface.

Objetivou-se identificar combinações entre cultivares, ambientes de cultivo e preparo e cobertura de solo capazes de melhorar o desempenho agronômico e aumentar a produtividade da cultura da alface em cultivo orgânico. A pesquisa foi conduzida na Universidade Federal do Acre, utilizando o delineamento experimental de blocos casualizados, com parcelas subdivididas para cada experimento (campo e casa de vegetação), com quatro repetições. Em cada experimento, três cultivares de alface (Simpson, Marisa e Vera), constituindo as sub-parcelas, foram sorteadas nas parcelas, representadas por quatro preparos e cobertura do solo (encanteiramento com cobertura de palha de arroz, polietileno prateado, solo descoberto e plantio direto). A produtividade comercial de alface foi de 12,3 t ha-1 em cultivo protegido e de 7,9 t ha-1 em campo. O cultivo protegido promoveu melhor desenvolvimento das plantas, caracterizado por maior massa da matéria fresca e seca da parte aérea, massa da matéria fresca comercial e melhor classificação comercial, além de promover bom desempenho agronômico e maior produtividade em qualquer um dos preparos de solo. As cultivares Simpson e Marisa apresentaram massa da matéria seca da parte aérea semelhante e superior à ‘Vera’, porém, o crescimento do caule da ‘Simpson’ foi elevado, caracterizando pendoamento precoce, fato que reduz sua qualidade comercial. As cultivares Marisa e Vera não alongaram o caule indicando serem tolerantes às condições ambientais de Rio Branco. A cobertura do solo com casca de arroz ou plástico prateado contribuiu para minimizar os efeitos climáticos prejudiciais ao cultivo da alface em campo. O plantio direto orgânico não diferiu do plantio em canteiro descoberto

Aspergillus fumigatus Acetate Utilization Impacts Virulence Traits and Pathogenicity

This is the final version. Available on open access from the American Society for Microbiology via the DOI in this recordData availability: The RNA-seq data set can be accessed at NCBI’s Short Read Archive under the Bioproject identifier (ID) PRJNA668271.Aspergillus fumigatus is a major opportunistic fungal pathogen of immunocompromised and immunocompetent hosts. To successfully establish an infection, A. fumigatus needs to use host carbon sources, such as acetate, present in the body fluids and peripheral tissues. However, utilization of acetate as a carbon source by fungi in the context of infection has not been investigated. This work shows that acetate is metabolized via different pathways in A. fumigatus and that acetate utilization is under the regulatory control of a transcription factor (TF), FacB. A. fumigatus acetate utilization is subject to carbon catabolite repression (CCR), although this is only partially dependent on the TF and main regulator of CCR CreA. The available extracellular carbon source, in this case glucose and acetate, significantly affected A. fumigatus virulence traits such as secondary metabolite secretion and cell wall composition, with the latter having consequences for resistance to oxidative stress, antifungal drugs, and human neutrophil-mediated killing. Furthermore, deletion of facB significantly impaired the in vivo virulence of A. fumigatus in both insect and mammalian models of invasive aspergillosis. This is the first report on acetate utilization in A. fumigatus, and this work further highlights the importance of available host-specific carbon sources in shaping fungal virulence traits and subsequent disease outcome, and a potential target for the development of antifungal strategies

BALB/c Mice Infected with Antimony Treatment Refractory Isolate of Leishmania braziliensis Present Severe Lesions due to IL-4 Production

Leishmaniasis is a neglected disease that affects more than 12 million people worldwide. In Brazil, the cutaneous disease is more prevalent with about 28,000 new cases reported each year, and L. braziliensis is the main causative agent. The interesting data about the infection with this parasite is the wide variety of clinical manifestations that ranges from single ulcerated lesions to mucocutaneous and disseminated disease. However, experimental models to study the infection with this parasite are difficult to develop due to high resistance of most mouse strains to the infection, and the mechanisms underlying the distinct manifestations remain poorly understood. Here, the authors use a mouse experimental model of infection with different L. braziliensis isolates, known to induce diseases with distinct severity in the human hosts, to elucidate immune mechanisms that may be involved in the different manifestations. They showed that distinct parasite isolates may modulate host response, and increased IL-4 production and Arg I expression was related to more severe disease, resulting in longer length of disease with larger lesions and reduced parasite clearance. These findings may be useful in the identification of immunological targets to control L. braziliensis infection and potential clinical markers of disease progression

Rhamnolipids: diversity of structures, microbial origins and roles

Rhamnolipids are glycolipidic biosurfactants produced by various bacterial species. They were initially found as exoproducts of the opportunistic pathogen Pseudomonas aeruginosa and described as a mixture of four congeners: α-L-rhamnopyranosyl-α-L-rhamnopyranosyl-β-hydroxydecanoyl-β-hydroxydecanoate (Rha-Rha-C10-C10), α-L-rhamnopyranosyl-α-L-rhamnopyranosyl-β-hydroxydecanoate (Rha-Rha-C10), as well as their mono-rhamnolipid congeners Rha-C10-C10 and Rha-C10. The development of more sensitive analytical techniques has lead to the further discovery of a wide diversity of rhamnolipid congeners and homologues (about 60) that are produced at different concentrations by various Pseudomonas species and by bacteria belonging to other families, classes, or even phyla. For example, various Burkholderia species have been shown to produce rhamnolipids that have longer alkyl chains than those produced by P. aeruginosa. In P. aeruginosa, three genes, carried on two distinct operons, code for the enzymes responsible for the final steps of rhamnolipid synthesis: one operon carries the rhlAB genes and the other rhlC. Genes highly similar to rhlA, rhlB, and rhlC have also been found in various Burkholderia species but grouped within one putative operon, and they have been shown to be required for rhamnolipid production as well. The exact physiological function of these secondary metabolites is still unclear. Most identified activities are derived from the surface activity, wetting ability, detergency, and other amphipathic-related properties of these molecules. Indeed, rhamnolipids promote the uptake and biodegradation of poorly soluble substrates, act as immune modulators and virulence factors, have antimicrobial activities, and are involved in surface motility and in bacterial biofilm development

Critérios para detecção e seleção de jovens atletas de basquetebol na cidade de São Paulo

Article in Portuguese. English title: Criterias for sport talents detection and selection for young basketball athletes in the city of Sāo Paul