Regulación de la presión de aire en procesos de producción de películas plásticas

Este artículo presenta el modelado y la simulación de un sistema de regulación de presión aplicado al control de espesor de películas plásticas. El sistema físico es descrito y modelado usando Transformada de Laplace. Se identifican los parámetros de operación del sistema y se lleva a cabo la simulación en Matlab. Se implementan acondicionadores para controlar la presión y, por consiguiente, el espesor de la película

Regulación de la presión de aire en procesos de producción de películas plásticas

Este artículo presenta el modelado y la simulación de un sistema de regulación de presión aplicado al control de espesor de películas plásticas. El sistema físico es descrito y modelado usando Transformada de Laplace. Se identifican los parámetros de operación del sistema y se lleva a cabo la simulación en Matlab. Se implementan acondicionadores para controlar la presión y, por consiguiente, el espesor de la película

International Nosocomial Infection Control Consortium (INICC) report, data summary for 2003-2008, issued June 2009

Q3Artículo original95-106We report the results of the International Infection Control Consortium (INICC) surveillance study from January 2003 throughDecember 2008 in 173 intensive care units (ICUs) in Latin America, Asia, Africa, and Europe. During the 6-year study, using Centersfor Disease Control and Prevention (CDC) US National Healthcare Safety Network (NHSN; formerly the National Nosocomial Infec-tion Surveillance system [NNIS]) definitions for device-associated health care-associated infection, we collected prospective datafrom 155,358 patients hospitalized in the consortium’s hospital ICUs for an aggregate of 923,624 days. Although device utilizationin the developing countries’ ICUs was remarkably similar to that reported from US ICUs in the CDC’s NHSN, rates of device-asso-ciated nosocomial infection were markedly higher in the ICUs of the INICC hospitals: the pooled rate of central venous catheter(CVC)-associated bloodstream infections (BSI) in the INICC ICUs, 7.6 per 1000 CVC-days, is nearly 3-fold higher than the 2.0 per1000 CVC-days reported from comparable US ICUs, and the overall rate of ventilator-associated pneumonia (VAP) was also farhigher, 13.6 versus 3.3 per 1000 ventilator-days, respectively, as was the rate of catheter-associated urinary tract infection (CAUTI),6.3 versus 3.3 per 1000 catheter-days, respectively. Most strikingly, the frequencies of resistance ofStaphylococcus aureusisolatesto methicillin (MRSA) (84.1% vs 56.8%, respectively),Klebsiella pneumoniaeto ceftazidime or ceftriaxone (76.1% vs 27.1%, respec-tively),Acinetobacter baumanniito imipenem (46.3% vs 29.2%, respectively), andPseudomonas aeruginosato piperacillin (78.0%vs 20.2%, respectively) were also far higher in the consortium’s ICUs, and the crude unadjusted excess mortalities of device-relatedinfections ranged from 23.6% (CVC-associated bloodstream infections) to 29.3% (VAP)

Problemas de entendimiento conceptual con las operaciones entre vectores

Some students from the introductory physics courses do not develop a functional understanding through a traditional instruction. Many of them do not start these courses with the necessary cognitive abilities to succeed to learn physics concepts. Some of these difficulties disturb students during the possible vector operation understanding process. Two questions related to vector operations were designed and implemented. Results show several understanding vector addition and subtraction difficulties. For instance, of these difficulties is closing the loop. In addition, despite students show a correct reasoning, some of them do not answer question properly.La mayoría de los estudiantes de los cursos introductorios de física no desarrollan un entrendieminto funcional a través de una enseñanza tradicional. Algunos de ellos no comienzan estos cursos con las herramientas conceptuales necesarias para tener éxito en el aprendizaje de conceptos físicos. Algunas de estas deficiencias se presentan cuando estos estudiantes se exponen al proceso de un posible aprendizaje de las operaciones entre vectores, en especial la suma y la resta. Este artículo muestra resultados relacionados con estas dificultades conceptuales. Se diseñó e implementó un instrumento de dos preguntas de operaciones entre vectores. Se encontraron diversas dificultades para sumar y restar vectores. Una de ellas es la llamada Cerrando el Polígono. Aquí los estudiantes obtienen le dirección del vector sume en dirección opuesta a la correcta. También se encontró que a pesar de que estos estudiantes muestran un razonamiento correcto, no responden las preguntas de manera satisfactoria

Insights into plant interactions and the biogeochemical role of the globally widespread Acidobacteriota phylum

The prevalence and abundance of Acidobacteriota raise concerns about their ecological function and metabolic activity in the environment. Studies have reported the potential of some members of Acidobacteriota to interact with plants and play a significant role in biogeochemical cycles. However, their role in this context has not been extensively studied. Here, we performed a comprehensive genomic analysis of 758 metagenome-assembled genomes (MAGs). Our analysis revealed a high frequency of plant growth-promoting traits (PGPTs) genes in the Acidobacteriaceae, Bryobacteraceae, Koribacteraceae, and Pyrinomonadaceae families. The colonization and competitive exclusion classes of PGPTs were found to be present in numerous Acidobacteriota members. In addition, these PGPTs also include genes involved in nitrogen fixation, phosphorus solubilization, exopolysaccharide production, siderophore production, and plant growth hormone production. Expression of such genes was found to be transcriptionally active in different environments. In addition, we identified numerous carbohydrate-active enzymes and peptidases involved in plant polymer degradation. By applying an in-depth insight into the diversity of the phylum, we expand the understanding of the role played by Acidobacteriota in the cycling of carbon, nitrogen, sulfur, and trace metals. Together, this study underscores the distinct potential ecological roles of each of these taxonomic groups, providing valuable insights for future research.</p