5,066 research outputs found

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

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    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

    Unsupervised machine learning approaches to the qq-state Potts model

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    In this paper with study phase transitions of the qq-state Potts model, through a number of unsupervised machine learning techniques, namely Principal Component Analysis (PCA), kk-means clustering, Uniform Manifold Approximation and Projection (UMAP), and Topological Data Analysis (TDA). Even though in all cases we are able to retrieve the correct critical temperatures Tc(q)T_c(q), for q=3,4q = 3, 4 and 55, results show that non-linear methods as UMAP and TDA are less dependent on finite size effects, while still being able to distinguish between first and second order phase transitions. This study may be considered as a benchmark for the use of different unsupervised machine learning algorithms in the investigation of phase transitions.Comment: Added computation of critical exponents; exposition improve

    Post-Treated Prostate Cancer: Normal Findings and Signs of Local Relapse on Multiparametric Magnetic Resonance Imaging

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    The use of multiparametric magnetic resonance imaging (mp-MRI) for prostate cancer has increased over recent years, mainly for detection, staging, and active surveillance. However, suspicion of recurrence in the set of biochemical failure is becoming a significant reason for clinicians to request mp-MRI. Radiologists should be able to recognize the normal post-treatment MRI findings. Fibrosis and atrophic remnant seminal vesicles after prostatectomy are often found and must be differentiated from local relapse. Moreover, brachytherapy, external beam radiotherapy, cryosurgery, and hormonal therapy tend to diffusely decrease the signal intensity of the peripheral zone on T2-weighted images (T2WI) due to the loss of water content, consequently mimicking tumor and hemorrhage. The combination of T2WI and functional studies like diffusion-weighted imaging and dynamic contrast-enhanced improves the identification of local relapse. Tumor recurrence tends to restrict on diffusion images and avidly enhances after contrast administration either within or outside the gland. The authors provide a pictorial review of the normal findings and the signs of local tumor relapse after radical prostatectomy, external beam radiotherapy, brachytherapy, cryosurgery, and hormonal therapy

    Progressive Web Applications (PWA) e seu uso no ecossistema digital da pecuária: experiência no Cria Certo.

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    Progressive Web Applications (PWA) são aplicações web que se comportam e se parecem com aplicativos móveis e se tornaram uma alternativa ao aplicativo de código nativo por serem confiáveis, rápidas e envolventes. Com a utilização desta tecnologia, o objetivo do projeto foi desenvolver uma ferramenta que possa auxiliar a tomada de decisão no processo produtivo da pecuária de corte, mais precisamente na área de reprodução, respondendo aos seguintes questionamentos

    Cria Certo: simulador de resultados de técnicas reprodutivas na bovinocultura.

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    NPARSEC : NTT Parallaxes of Southern Extremely Cool objects. Goals, targets, procedures and first results

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    The discovery and subsequent detailed study of T dwarfs have provided many surprises and pushed the physics and modelling of cool atmospheres in unpredicted directions. Distance is a critical parameter for studies of these objects to determine intrinsic luminosities, test binarity and measure their motion in the Galaxy. We describe a new observational programme to determine distances across the full range of T-dwarf subtypes using the New Technology Telescope (NTT)/SOFI telescope/instrument combination. We present preliminary results for ten objects, five of which represent new distances.Peer reviewe
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