Cofactors and pathogens: Flavin mononucleotide and flavin adenine dinucleotide (FAD) biosynthesis by the FAD synthase from Brucella ovis

The biosynthesis of the flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), cofactors used by 2% of proteins, occurs through the sequential action of two ubiquitous activities: a riboflavinkinase (RFK) that phosphorylates the riboflavin (RF) precursor to FMN, and a FMN:adenylyltransferase (FMNAT) that transforms FMN into FAD. In most mammals two different monofunctional enzymes have each of these activities, but in prokaryotes a single bifunctional enzyme, FAD synthase (FADS), holds them. Differential structural and functional traits for RFK and FMNAT catalysis between bacteria and mammals, as well as within the few bacterial FADSs so far characterized, has envisaged the potentiality of FADSs from pathogens as targets for the development of species-specific inhibitors. Here, we particularly characterize the FADS from the ovine pathogen Brucella ovis (BoFADS), causative agent of brucellosis. We show that BoFADS has RFK activity independently of the media redox status, but its FMNAT activity (in both forward and reverse senses) only occurs under strong reducing conditions. Moreover, kinetics for flavin and adenine nucleotides binding to the RFK site show that BoFADS binds preferentially the substrates of the RFK reaction over the products and that the adenine nucleotide must bind prior to flavin entrapment. These results, together with multiple sequence alignments and phylogenetic analysis, point to variability in the less conserved regions as contributing to the species-specific features in prokaryotic FADSs, including those from pathogens, that allow them to adopt alternative strategies in FMN and FAD biosynthesis and overall flavin homeostasis

Engineering Student’s Self-Efficacy Judgment to Solve Mathematical Problems in the Classroom or Online

This study explored in a sample of 560 high level education students their judgment formation to perceived self-efficacy to solve mathematical tasks. Students had to read 36 experimental vignettes describing educative scenarios to learn mathematics. Each scenario presented four manipulated pieces of information (learning modality, task difficulty, task relevance, and structure). After reading each scenario students were required to provide judgments regarding their believed self-efficacy to solve mathematical tasks described in the vignette by using a scale. Results showed that in regard to how students perceived their self-efficacy they could be grouped in two clusters (high and moderate). Most relevant factors to their judgment formation were task difficulty, task relevance and structure. Here, both groups used the same cognitive algebra mechanism to integrate factor information. Here, students valuated academic performance and feedback (e.g. difficulty and relevance) as most relevant even when they are conscious that learning is a primordial target. These and other results are discussed in the paper

Risk factors associated with methicillin-resistant Staphylococcus aureus skin and soft tissue infections in hospitalized patients in Colombia

Q2Q160-66Pacientes hospitalizadosObjectives: Methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTIs) represent a major clinical problem in Colombia. The aim of this study was to evaluate the risk factors associated with MRSA SSTI in Colombia. Methods: A multicenter cohort study with nested case–control design was performed. Patients with an SSTI with at least 48 h of inpatient care were included. Patients with an MRSA SSTI were considered the case group and patients with either a non-MRSA SSTI or with an Methicillin-susceptible S. aureus (MSSA) SSTI were the control groups. A multivariate logistic regression approach was used to evaluate risk factors associated with MRSA SSTI with two different statistical models. Results: A total 1134 patients were included. Cultures were positive for 498 patients, of which 52% (n = 259) were Staphylococcus aureus. MRSA was confirmed in 68.3% of the S. aureus cultures. In the first model, independent risk factors for MRSA SSTI were identified as the presence of abscess (P<0.0001), cellulitis (P = 0.0007), age 18–44 years (P = 0.001), and previous outpatient treatment in the previous index visit (P = 0.003); surgical site infection was a protective factor (P = 0.008). In the second model, the main risk factor found was previous outpatient treatment in the previous index visit (P = 0.013). Conclusions: Community-acquired SSTIs in Colombia are commonly caused by MRSA. Therefore, clinicians should consider MRSA when designing the initial empirical treatment for purulent SSTI in Colombia, although there seems to be low awareness of this fact

Réquiem médico. Un pasado acabado: absurdos de la medicina actual

EL LIBRO MUESTRA EXPERIENCIAS SOBRE EL TEMA DE LA PRÁCTICA MEDICA.EL LIBRO ABORDA TEMAS RELACIONADAS CON LA PRACTICA MEDICA, Y LOS DIFERENTES OBSTÁCULOS QUE SE ENCUENTRAN A NIVEL DE LAS INSTITUCIONES PARA OFRECER UNA MEJOR ATENCIÓN A LA POBLACIÓN PARA EL TRATAMIENTO DE LA ENFERMEDAD Y LA SALUDNINGUN

Análisis y recomendaciones al sistema administrativo de la Universidad de El Salvador volumen II

La finalidad de este Informe es la de exponer, de un modo integral y objetivo, los diversos pormenores de la investigación científica efectuada en doce diferentes sistemas componentes del quehacer administrativo de la Universidad de El Salvado

Estudios de Caso sobre Ciencias Agropecuarias y Rurales en el siglo XXI.

Libro científico sobre estudios de casos en el medio agropecuario y ruralCon el advenimiento del siglo XXI y el avance de los procesos de globalización, el medio rural presenta diversos cambios económicos, sociales, políticos y culturales. Lo anterior significa que el campo es un objeto de estudio altamente dinámico, complejo e inasible. las ciencias agropecuarias y rurales, en la actualidad, requieren de un abordaje sistémico e interdisciplinario que den cuenta de la heterogeneidad de situaciones y contextos que enfrenta el campo mexicano. La presente obra agrupa 18 estudios de caso, que capturan algunas fotografías de las diversas problemáticas de la ruralidad mexicana, con lo cual se pretende dar cuenta tanto de los objetivos de estudio como de la perspectiva teórico metodológico desde que estos son abordados. lo anterior tiene que ver con el hecho de que las ciencias agropecuarias y rurales manifiestan un alto grado de observación empírica, motivo por el que los estudios de caso se convierten en la perspectiva metodológica idónea que permite ir y venir de la realidad a la teoría y viceversa para la construcción de objetos de estudio. En este volumen se aborda una gran diversidad de casos, que sintetizan la heterogeneidad de enfoques y perspectivas mediante las cuales los fenómenos agropecuarios y rurales han sido abordados en el Instituto de Ciencias Agropecuarias y Rurales de la Universidad Autónoma del Estado de México, en los últimos 30 años

Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Forward-central two-particle correlations in p-Pb collisions at root s(NN)=5.02 TeV

Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2GeV/c. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B. V.Peer reviewe