Metabolic regulation analysis of an ethanologenic Escherichia coli strain based on RT-PCR and enzymatic activities

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Análisis de contenido del discurso de Nayib Bukele, transmitido a través de los facebook live, durante el periodo comprendido entre el 02 de abril del año 2017 y el 03 de febrero del año 2019

En la línea de los estudios sobre los contenidos o mensajes, el trabajo ofrece un análisis ideológico del discurso de Nayib Bukele, por ser el principal exponente del proyecto político Nuevas Ideas. Mediante las figuras semánticas descripción, presuposición e implicación se interpretan categorías ideológicas y políticas para una caracterización del nuevo proyecto político y su visión del mundo o adscripción ideológica. Se presenta una reseña sobre la naturaleza política del discurso des dela Grecia antigua, se hace un recorrido sobre la trayectoria y evolución del sujeto de estudio, se aborda el caso de la campaña presidencial de Barack Obama como el principal precedente de comunicación política, y se aborda también el estado actual de las principales investigaciones acerca de los discursos y la política en el contexto de la sociedad red. La propuesta teórica está basada en el modelo del análisis ideológico del discurso propuesto por Teun A. van Dijk,y retoma postulados sociológicos sobre los nuevos movimientos sociales. Se aplica la técnica del análisis del discurso bajo los parámetros y procedimientos de la investigación cualitativa

Diseño de un sistema de envase para exportar fruta deshidratada hacia Alemania.

La distribución internacional es una fase importante de la cadena logística, los productos deben llegar al lugar de destino en condiciones óptimas, el envase cumple la función de protección para el producto en todo el proceso logístico, en cada fase de la distribución existen riesgos que afectan al producto, para evitar estos riesgos es necesario realizar un análisis y evaluación del sistema de envases que utilizan las empresas salvadoreñas que producen frutos deshidratados. El objetivo de esta investigación es diseñar un sistema de envase que cumpla con los aspectos legales, tecnológicos, logísticos y mercadológicos, mediante la creación de una guía, como solución táctica para incrementar las exportaciones de frutas deshidratadas salvadoreñas hacia Alemania. Se aplicará un tipo de investigación mixta; cualitativa y cuantitativa, en la cual se plantean problemas y se definen preguntas de investigación, aplicando un método de investigación de datos no numéricos para conocer el envase adecuado que se puede aplicar al comercio internaciona

Constitutive expression of selected genes from the pentose phosphate and aromatic pathways increases the shikimic acid yield in high-glucose batch cultures of an Escherichia coli strain lacking PTS and pykF

BACKGROUND: During the last two decades many efforts have been directed towards obtaining efficient microbial processes for the production of shikimic acid (SA); however, feeding high amounts of substrate to increase the titer of this compound has invariably rendered low conversion yields, leaving room for improvement of the producing strains. In this work we report an alternative platform to overproduce SA in a laboratory-evolved Escherichia coli strain, based on plasmid-driven constitutive expression of six genes selected from the pentose phosphate and aromatic amino acid pathways, artificially arranged as an operon. Production strains also carried inactivated genes coding for phosphotransferase system components (ptsHIcrr), shikimate kinases I and II (aroK and aroL), pyruvate kinase I (pykF) and the lactose operon repressor (lacI). RESULTS: The strong and constitutive expression of the constructed operon permitted SA production from the beginning of the cultures, as evidenced in 1 L batch-mode fermentors starting with high concentrations of glucose and yeast extract. Inactivation of the pykF gene improved SA production under the evaluated conditions by increasing the titer, yield and productivity of this metabolite compared to the isogenic pykF(+) strain. The best producing strain accumulated up to 43 g/L of SA in 30 h and relatively low concentrations of acetate and aromatic byproducts were detected, with SA accounting for 80% of the produced aromatic compounds. These results were consistent with high expression levels of the glycolytic pathway and synthetic operon genes from the beginning of fermentations, as revealed by transcriptomic analysis. Despite the consumption of 100 g/L of glucose, the yields on glucose of SA and of total aromatic compounds were about 50% and 60% of the theoretical maximum, respectively. The obtained yields and specific production and consumption rates proved to be constant with three different substrate concentrations. CONCLUSIONS: The developed production system allowed continuous SA accumulation until glucose exhaustion and eliminated the requirement for culture inducers. The obtained SA titers and yields represent the highest reported values for a high-substrate batch process, postulating the strategy described in this report as an interesting alternative to the traditionally employed fed-batch processes for SA production

New insights into Escherichia coli metabolism: carbon scavenging, acetate metabolism and carbon recycling responses during growth on glycerol

<p>Abstract</p> <p>Background</p> <p>Glycerol has enhanced its biotechnological importance since it is a byproduct of biodiesel synthesis. A study of <it>Escherichia coli</it> physiology during growth on glycerol was performed combining transcriptional-proteomic analysis as well as kinetic and stoichiometric evaluations in the strain JM101 and certain derivatives with important inactivated genes.</p> <p>Results</p> <p>Transcriptional and proteomic analysis of metabolic central genes of strain JM101 growing on glycerol, revealed important changes not only in the synthesis of MglB, LamB and MalE proteins, but also in the overexpression of carbon scavenging genes: <it>lamB</it>, <it>malE</it>, <it>mglB</it>, <it>mglC</it>, <it>galP</it> and <it>glk</it> and some members of the RpoS regulon (<it>pfkA</it>, <it>pfkB</it>, <it>fbaA</it>, <it>fbaB</it>, <it>pgi, poxB</it>, <it>acs</it>, <it>actP</it> and <it>acnA</it>). Inactivation of <it>rpoS</it> had an important effect on stoichiometric parameters and growth adaptation on glycerol. The observed overexpression of <it>poxB</it>, <it>pta</it>, <it>acs</it> genes, glyoxylate shunt genes (<it>aceA, aceB</it>, <it>glcB</it> and <it>glcC</it>) and <it>actP</it>, suggested a possible carbon flux deviation into the PoxB, Acs and glyoxylate shunt. In this scenario acetate synthesized from pyruvate with PoxB was apparently reutilized via Acs and the glyoxylate shunt enzymes. In agreement, no acetate was detected when growing on glycerol, this strain was also capable of glycerol and acetate coutilization when growing in mineral media and derivatives carrying inactivated <it>poxB</it> or <it>pckA</it> genes, accumulated acetate. Tryptophanase A (TnaA) was synthesized at high levels and indole was produced by this enzyme, in strain JM101 growing on glycerol. Additionally, in the isogenic derivative with the inactivated <it>tnaA</it> gene, no indole was detected and acetate and lactate were accumulated. A high efficiency aromatic compounds production capability was detected in JM101 carrying pJLB<it>aroG</it>^<it>fbr</it><it>tktA</it>, when growing on glycerol, as compared to glucose.</p> <p>Conclusions</p> <p>The overexpression of several carbon scavenging, acetate metabolism genes and the absence of acetate accumulation occurred in JM101 cultures growing on glycerol. To explain these results it is proposed that in addition to the glycolytic metabolism, a gluconeogenic carbon recycling process that involves acetate is occurring simultaneously in this strain when growing on glycerol. Carbon flux from glycerol can be efficiently redirected in JM101 strain into the aromatic pathway using appropriate tools.</p

Factorial Equivalence of the Social Skills Scale in the Lambayeque University Context According to Sex

This study aimed to show whether the theoretical model of the social skills construct, proposed by Gismero (2000), is invariant in male and female samples of Peruvian university students from Lambayeque. In order to meet the proposed objective, a non-experimental, cross-sectional, comparative psychometric design by hierarchical confirmatory procedures was chosen. Two samples of university students were used, one of 1,084 female students and the other of 1,043 male students. Both groups were applied the self-report of social skills (EHS). With the data obtained, a confirmatory factor analysis of the first-order factor structure of the social skills construct was performed in each group, based on the polychoric correlation matrix. The invariance of the scale according to sex was evaluated on the basis of the second-order factor structure, by means of multigroup confirmatory factor analysis of nested models. No significant differences in the fit to the data were found between the two-factor second-order factor structure and the alternative one-factor model. Consecutive tests of configurational invariance, disturbance, and first- and second-order metrics gave evidence, respectively, that the model structure, second-order factor errors, and first- and second-order loadings are equivalent in the two study samples. With the data from the study, it is concluded that the structure of the EHS scale is invariant to the sex variable in the Lambayeque context

Efecto de la recuperación nutricia en la concentración sérica de lipoperoxidos en niños con desnutrición proteínico-energética primaria grave.

Objective. The purpose is to show lipid peroxide’s serum concentration trend during a four-week nutritional recovery period in children with primary and severe protein energy malnutrition (PEM). Methods. In a clinical intervention 12 primarily and severely malnourished children (three to 48 months of age) were included. Dependent variable: Serum lipid peroxide (LPO) concentration (nmol/mL). Independent variables: non lactose starting infant formula (200 kcal/kg/d and proteins 4 g/kg/d). Age, sex, nutritional recovery, weight/age, length/age and weight/length indices calculated and expressed as Z scores were included. For statistical analysis a repeated measure ANOVA model was applied. A non-parametric Mann Whitney U-Test was used to compare groups. Null hypothesis was rejected with a p value 0.05. Results. Throughout the study the LPO concentration was higher in subjects with PEM than in the control group (p< 0.001). There was a decrease in the LPO concentration (nmol/mL) between basal vs. two weeks (12.9 vs. 7.3, p = 0.06) and basal vs. four weeks (12.9 vs. 8.16, p = 0.08). Conclusion. LPO concentrations were significantly higher in children with severe PEM at the beginning and end of the four-week nutritional recovery period. This finding was probably associated with increased metabolism of the cellular tissue and/or the high consumption of energy and nutrients compared to a control group. The null hypothesis of basal-end differences in LPO serum concentrations could not be rejected due to the great variability in serum lipoperoxides in these children with severe primary proteinenergy malnutrition

MEIS1, PREP1, and PBX4 Are Differentially Expressed in Acute Lymphoblastic Leukemia: Association of MEIS1 Expression with Higher Proliferation and Chemotherapy Resistance

<p>Abstract</p> <p>Background</p> <p>The Three-amino acid-loop-extension (<it>TALE</it>) superfamily of homeodomain-containing transcription factors have been implicated in normal hematopoiesis and in leukemogenesis and are important survival, differentiation, and apoptosis pathway modulators. In this work, we determined the expression levels of <it>TALE </it>genes in leukemic-derived cell lines, in blood samples of patients with Acute lymphoblastic leukemia (ALL), and in the blood samples of healthy donors.</p> <p>Results</p> <p>Here we show increased expression of <it>MEIS1, MEIS2, </it>and <it>PREP1 </it>genes in leukemia-derived cell lines compared with blood normal cells. High levels of <it>MEIS1 </it>and <it>PREP1</it>, and low levels of <it>PBX4 </it>expression were also founded in samples of patients with ALL. Importantly, silencing of <it>MEIS1 </it>decreases the proliferation of leukemia-derived cells but increases their survival after etoposide treatment. Etoposide-induced apoptosis induces down-regulation of MEIS1 expression or <it>PREP1 </it>up-regulation in chemotherapy-resistant cells.</p> <p>Conclusions</p> <p>Our results indicate that up-regulation of <it>MEIS1 </it>is important for sustaining proliferation of leukemic cells and that down-regulation of <it>MEIS1 </it>or up-regulation of <it>PREP1 </it>and <it>PBX </it>genes could be implicated in the modulation of the cellular response to chemotherapeutic-induced apoptosis.</p

Observatorio Geográfico: Salud y Riesgos en México

En el año 2017, a vísperas de su culminación se publica el presente libro, en donde se abordan algunos de los temas del observatorio geográfico, cuya base teórica se centra en la Geografía de la salud, que nunca fue tan amplia y diversa en su objetivo como lo es hoy en día, además es un área científica que ha ido prosperando ampliamente en los últimos años y cuyos resultados en la actualidad son cada vez más visibles. Además de ello, el estudio sobre la salud humana ofrece al analista del territorio la oportunidad de aportar conocimiento sobre la distribución espacial de enfermedades importantes que aquejan la sociedad, presentando directamente las desigualdades ante la muerte, la enfermedad y la salud, articulando hechos naturales y sociale