Quebrada San Juan, una fuente de contaminación ambiental en el Municipio de San Miguel

Actualmente, en el casco urbano de algunos municipios del departamento de San Miguel, carecen de alcantarillado sanitario y pluvial. En la colonia San Juan específicamente detrás del Centro Escolar “Niño Jesús de Praga” hasta la avenida Los Naranjos, se encuentra la “Quebrada San Juan”. Esta, representa una problemática socioambiental ya que, a raíz de una mala gestión, se utiliza para depositar basura y aguas residuales de tipo ordinario. En la presente investigación se expone la problemática ambiental que representa la “Quebrada San Juan” por falta de un saneamiento continuó. Dicho estudio, se ha desarrollado de forma bibliográfica y audiovisual para un mayor impacto en la sociedad, haciendo uso de las plataformas digitales, y que esto se utilice como herramienta para el desarrollo de nuevas investigaciones con fines de saneamiento que se puedan aplicar a: ríos, quebradas y comunidades que lo necesiten. En el video documental concluimos que se alcanzan múltiples beneficios en la comunidad cuando existe un buen saneamiento, mejorando la calidad de vida en materia de salud y recreación para los niños y adolescentes de la zona que son el grupo etario más vulnerable. Además. se recomienda que la ADESCO vele por la población y que incentiven a la alcaldía a ejercer su infrascrito de “ordenanza de protección y preservación del medio ambiente, en el municipio de San Miguel, departamento de San Miguel”, para que todas las partes desarrollen su papel adecuadamente y así esta zona salga de la contaminación y el abandono

mwr Xer site-specific recombination is hypersensitive to DNA supercoiling

The multiresistance plasmid pJHCMW1, first identified in a Klebsiella pneumoniae strain isolated from a neonate with meningitis, includes a Xer recombination site, mwr, with unique characteristics. Efficiency of resolution of mwr-containing plasmid dimers is strongly dependent on the osmotic pressure of the growth medium. An increase in supercoiling density of plasmid DNA was observed as the osmotic pressure of the growth culture decreased. Reporter plasmids containing directly repeated mwr, or the related cer sites were used to test if DNA topological changes were correlated with significant changes in efficiency of Xer recombination. Quantification of Holliday junctions showed that while recombination at cer was efficient at all levels of negative supercoiling, recombination at mwr became markedly less efficient as the level of supercoiling was reduced. These results support a model in which modifications at the level of supercoiling density caused by changes in the osmotic pressure of the culture medium affects resolution of mwr-containing plasmid dimers, a property that separates mwr from other Xer recombination target sites

Carpeta Didáctica para la enseñanza del patrimonio histórico cultural salvadoreño para estudiantes del primer año de bachillerato del Complejo Educativo Ignacio Pacheco Castro, San Marcos, San Salvador, 2021.

Este documento es el resultado del desarrollo de proyecto que tiene por objetivo principal la construcción de una carpeta didáctica, la cual incluye contenido informativo dividido en tres unidades de aprendizaje con ilustraciones que sirven de apoyo, facilitando la mejor comprensión y adquisición de los conocimientos culturales; en conjunto con actividades complementarias como un mapa interactivo, recreación de vestimentas tradicionales, elaboración de manualidades como creación de farolitos, gallardetes y máscaras. Estas actividades se lograron al estudiar la dinámica metodológica que emplea el Complejo Educativo Ignacio Pacheco Castro para contribuir al rescate del folklore salvadoreño, gracias a la cual se obtuvo una respuesta positiva de parte de los estudiantes dado que se logró un interés en la temática abordada. El proyecto se ejecutó en varias etapas dentro de las cuales está el diagnóstico donde se realizó entrevistas al director del Complejo Educativo y al maestro de Ciencias Sociales, se tramitó la gestión de recursos con diversas imprentas para materializar a bajo costo la carpeta didáctica sin perder calidad. En la etapa de conceptualización se diseñaron las piezas gráficas para el material didáctico, así mismo la ejecución de una prueba piloto contemplada en tres sesiones. El resultado final del proyecto servirá no solo a los jóvenes en bachillerato sino también será de utilidad para diferentes niveles educativos y permitiendo su fácil distribución a través de la plataforma digital Academia.edu, llegando así a más instituciones educativas salvadoreñas. Palabras Claves: Carpeta Didáctica ; Patrimonio histórico Cultural ; Rescate cultural ; Folklor

Comparison of proteomic responses as global approach to antibiotic mechanism of action elucidation

This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license. New antibiotics are urgently needed to address the mounting resistance challenge. In early drug discovery, one of the bottlenecks is the elucidation of targets and mechanisms. To accelerate antibiotic research, we provide a proteomic approach for the rapid classification of compounds into those with precedented and unprecedented modes of action. We established a proteomic response library of Bacillus subtilis covering 91 antibiotics and comparator compounds, and a mathematical approach was developed to aid data analysis. Comparison of proteomic responses (CoPR) allows the rapid identification of antibiotics with dual mechanisms of action as shown for atypical tetracyclines. It also aids in generating hypotheses on mechanisms of action as presented for salvarsan (arsphenamine) and the antirheumatic agent auranofin, which is under consideration for repurposing. Proteomic profiling also provides insights into the impact of antibiotics on bacterial physiology through analysis of marker proteins indicative of the impairment of cellular processes and structures. As demonstrated for trans-translation, a promising target not yet exploited clinically, proteomic profiling supports chemical biology approaches to investigating bacterial physiology

Sublethal Concentrations of the Aminoglycoside Amikacin Interfere with Cell Division without Affecting Chromosome Dynamics

Aminoglycosides bind to the 16S rRNA at the tRNA acceptor site (A site) and disturb protein synthesis by inducing codon misreading. We investigated Escherichia coli cell elongation and division, as well as the dynamics of chromosome replication and segregation, in the presence of sublethal concentrations of amikacin (AMK). The fates of the chromosome ori and ter loci were monitored by visualization by using derivatives of LacI and TetR fused to fluorescent proteins in E. coli strains that carry operator arrays at the appropriate locations. The results showed that cultures containing sublethal concentrations of AMK contained abnormally elongated cells. The chromosomes in these cells were properly located, suggesting that the dynamics of replication and segregation were normal. FtsZ, an essential protein in the process of cell division, was studied by using an ectopic FtsZ-cyan fluorescent protein fusion. Consistent with a defect in cell division, we revealed that the Z ring failed to properly assemble in these elongated cells

Failsafe mechanisms couple division and DNA replication in bacteria.

The past 20 years have seen tremendous advances in our understanding of the mechanisms underlying bacterial cytokinesis, particularly the composition of the division machinery and the factors controlling its assembly [1]. At the same time, we understand very little about the relationship between cell division and other cell-cycle events in bacteria. Here we report that inhibiting division in Bacillus subtilis and Staphylococcus aureus quickly leads to an arrest in the initiation of new rounds of DNA replication, followed by a complete arrest in cell growth. Arrested cells are metabolically active but are unable to initiate new rounds of either DNA replication or division when shifted to permissive conditions. Inhibiting DNA replication results in entry into a similar quiescent state in which cells are unable to resume growth or division when returned to permissive conditions. Our data suggest the presence of two failsafe mechanisms: one linking division to the initiation of DNA replication and another linking the initiation of DNA replication to division. These findings contradict the prevailing view of the bacterial cell cycle as a series of coordinated but uncoupled events. Importantly, the terminal nature of the cell-cycle arrest validates the bacterial cell-cycle machinery as an effective target for antimicrobial development

Failsafe mechanisms couple division and DNA replication in bacteria.

The past 20 years have seen tremendous advances in our understanding of the mechanisms underlying bacterial cytokinesis, particularly the composition of the division machinery and the factors controlling its assembly [1]. At the same time, we understand very little about the relationship between cell division and other cell-cycle events in bacteria. Here we report that inhibiting division in Bacillus subtilis and Staphylococcus aureus quickly leads to an arrest in the initiation of new rounds of DNA replication, followed by a complete arrest in cell growth. Arrested cells are metabolically active but are unable to initiate new rounds of either DNA replication or division when shifted to permissive conditions. Inhibiting DNA replication results in entry into a similar quiescent state in which cells are unable to resume growth or division when returned to permissive conditions. Our data suggest the presence of two failsafe mechanisms: one linking division to the initiation of DNA replication and another linking the initiation of DNA replication to division. These findings contradict the prevailing view of the bacterial cell cycle as a series of coordinated but uncoupled events. Importantly, the terminal nature of the cell-cycle arrest validates the bacterial cell-cycle machinery as an effective target for antimicrobial development

Diastereoselective synthesis of γ- and δ-lactams from imines and sulfone-substituted anhydrides.

Sulfone-substituted γ- and δ-lactams have been prepared in a single step with high diastereoselectivity. Sulfonylglutaric anhydrides produce intermediates that readily decarboxylate to provide δ-lactams with high diastereoselectivity. Substituents at the 3- or 4-position of the glutaric anhydride induce high levels of stereocontrol. Sulfonylsuccinic anhydrides produce intermediate carboxylic acids that can be trapped as methyl esters or allowed to decarboxylate under mild conditions. This method has been applied to a short synthesis of the pyrrolizidine alkaloid (±)-isoretronecanol