Purificación y caracterización parcial de proteasas extracelulares de Pseudomonas sp. de interés biotecnológico

Publicación a texto completo no autorizada por el autorSe purifica y caracteriza proteasas extracelulares de una cepa de Pseudomonas sp. aislada de muestras de suelos de los aguajales de Tambopata en Madre de Dios. Las proteasas son purificadas mediante cromatografía de intercambio aniónico en un sistema FPLC, utilizando la columna CaptoTM Q, seguida por precipitación con sulfato de amonio al 70 %. Se purifican tres proteasas extracelulares denominadas EI, EII y EIII; siendo EI la que presenta mayor porcentaje de recuperación y factor de purificación de 80,1 % y 5,7. Los pesos moleculares de EI, EII y EIII son de 35, 40 y 55 kDa respectivamente. Las enzimas EI y EIII son clasificadas como serínmetaloproteasas, en tanto EII como metaloproteasa. El pH óptimo de EI y EII es 8, mientras que de EIII es 11. La temperatura óptima de las tres enzimas fue 60 °C. Las proteasas EI y EII incrementan su actividad en presencia de Mn+2, sin embargo, estas fueron inhibidas por Zn+2. En tanto, la proteasa EIII incrementa su actividad en presencia de Mg+2, Ca+2 y Zn+2. Según las características bioquímicas de las tres proteasas extracelulares purificadas de Pseudomonas sp. se puede indicar que son alcalinas y termoestables, principalmente la enzima EIII, por lo cual presentan gran potencial biotecnológico para su aplicación en diversos bioprocesos.Consejo Nacional de Ciencia y Tecnología (Perú). Fondo Nacional de Desarrollo Científico y Tecnológico (Fondecyt)Tesi

Novel thermophilic pectinases for recycling sustainable biomass

Large amounts of pectin-rich biomass are produced mainly from juice and sugar industries. Pectinases represent an economical and eco-friendly alternative to depolymerise it in comparison with chemical treatments, for both obtaining bio-based chemicals and improving industrial bioprocess. This thesis aimed to identify novel thermophilic pectinases, carry out their functional characterisation, and explore the synergistic activity between pectin methylesterases (PMEs) and exo-polygalacturonases (exo-PGs) for pectin bioconversion into galacturonic acid (GalA). Also, the work was focused on the co-expression of genes encoding a PME and exo-PG in a single host for a cost-effective pectin bioconversion into GalA. Finally, the synergistic activity between PMEs and pectate lyases (PGLs) for improving pectin depolymerisation, useful in several industrial processes, was also explored. A total of seven genes encoding thermophilic bacterial pectinases were successfully cloned, and the enzymes expressed included two exo-PGs (TMA01 and BLI04), two PMEs (BLI09 and SAM10) and three PGLs (TMA14, TFU19 and TFU20). Mn2+ significantly increased the exo-PGs activity (2-fold) and did not affect PMEs action allowing its inclusion in the synergistic reactions. Both exo-PGs and PMEs exhibited high activity and stability between 40 and 90 °C up to 24 h. The synergistic reactions between BLI09 PME paired either with TMA01 or BLI04 exo-PGs using apple and citrus pectin were the most successful for pectin bioconversion, releasing around 2.5 mM GalA (29% yield). GalA release by pectinases is important in industry since it is a key chemical for the synthesis of a number of valuable compounds. In addition, enzymes allow to release this compound in a sustainable biocatalytic process. Four co-expression plasmids containing a PME and exo-PG were constructed in pETDuet-1, in which the gene’s cloning order as well as the presence of a T7 terminator behind the second gene affected the pectinases expression levels. TMA01 and BLI04 exo-PGs were well expressed in all the constructs, but BLI09 PME was better expressed cloned downstream the exo-PGs in MCS-2 and with the presence of its own T7 terminator behind. Thus, the most successful co-expression plasmids were the constructs 3 and 4 (pETDuet-TMA01-BLI09 and 4 pETDuet-BLI04-BLI09, respectively) which allowed the release of around 3 mM GalA (35% yield) from apple and citrus pectin. GalA release was limited by product inhibition since this compound had an inhibitory effect on both exo-PGs from around 3 mM. Finally, the three PGLs were characterised showing Ca2+ dependant activity, while Mn2+ significantly improved the activity of TFU20 (2.5-fold). All the PGLs exhibited optimum activity and stability between 50 and 90 °C and Ca2+ improved their thermal stability. The three PGLs were able to depolymerise pectin, but the main peak of 650 kDa observed in both non-esterified and esterified substrates was depolymerised only in the non-esterified. These results evidenced the need of a synergistic action of PGLs with PMEs for improving esterified pectin depolymerisation. Thus, the smallest oligogalacturonates (oligoGalA) because of this main peak depolymerisation in apple, citrus and sugar beet pectin were obtained from synergistic reactions between SAM10 PME paired either with TMA14 (4 – 10 kDa) or TFU20 (8 – 25 kDa). Overall, this work provided optimum conditions of activity of novel thermophilic pectinases, which are fundamental to set up compatible operational conditions especially in synergistic reactions. Synergistic activity between pectinases allowed the release of GalA and co-expression systems made the pectin bioconversion process more cost-effective. Synergistic activity also improved esterified pectin depolymerisation, useful and applicable to several industries. These findings provided further insights for recycling sustainable biomass within a context of biorefineries and circular economy

Competências semióticas para a alfabetização multimodal na disciplina de espanhol do ensino médio na Costa Rica

In response to the learning goals related to multimodal texts in the Costa Rican Spanish study program (MEP, 2017), and the lack of didactic proposals for its pedagogical treatment at a national level in secondary schools (Flores, 2019), this article’s purpose is to offer a series of semiotic competencies (Tobón, 2005) that will help in facilitating the multimodal teaching-learning process in the classroom. These competencies feed on the sociocognitive approach (Tobón, 2005), and the levels of creation of meaning in multimodal texts (Kress and Van Leeuwen, 2001; Kress, 2010) as well as on Bloom’s taxonomy for cognitive abilities (Talbert, 2019). As a result, they are presented as complex processes, for the approach, characterization, analysis, explanation, evaluation, and elaboration of multimodal texts, in specific sociocultural contexts and interactions. Based on the description of these competencies, the article condones the need to incorporate a semiotic dimension within the communicative competencies in the Spanish curriculum (MEP, 2017). It seeks to provide theoretical-methodological support to teachers to help them integrate the national curriculum’s objectives related to multimodal texts to the classroom. On a final note, this proposal offers a suggestion of studies regarding reading comprehension of multimodal texts, in order to update the national didactic and curricular processes, according to the development of multiple literacies at an international level (Anstey and Bull 2006; Cope and Kalantzis, 2009b; Blanchard and Farstrup 2011; Cooper et al., 2013; Reid and Comber 2004; Walsh 2010).    En respuesta a los objetivos de aprendizaje relacionados con textos multimodales, en el plan de estudios de español costarricense (MEP, 2017), y la escasez de propuestas didácticas a nivel nacional para su tratamiento pedagógico en secundaria (Flores, 2019), este artículo tiene como objetivo proponer una serie de competencias semióticas (Tobón, 2005) para facilitar los procesos de enseñanza y aprendizaje de la multimodalidad en el aula. Estas competencias se han formulado desde el enfoque sociocognitivo (Tobón, 2005), los niveles de creación de significados en textos multimodales (Kress y Van Leeuwen, 2001; Kress, 2010) y la taxonomía de Bloom para las habilidades cognitivas (Talbert, 2019). Como resultado, se plantean como procesos complejos, para la aproximación, caracterización, análisis, explicación, evaluación y producción de textos multimodales, en interacciones y contextos socioculturales específicos. Con base en la descripción de estas competencias, el artículo sostiene la necesidad de incorporar una dimensión semiótica dentro de la competencia comunicativa en el plan de estudios de español (MEP, 2017) y brindar un apoyo teórico – metodológico al profesorado para orientar la trasposición de los objetivos del currículo nacional, relacionados con textos multimodales, al salón de clases. Para concluir, sugiere vínculos entre esta propuesta y estudios sobre la comprensión lectora de textos multimodales, a fin de actualizar los procesos didácticos y curriculares nacionales, según el desarrollo de las alfabetizaciones múltiples a nivel internacional (Anstey y Bull 2006; Cope y Kalantzis, 2009b; Blanchard y Farstrup 2011; Cooper et al., 2013; Reid and Comber 2004; Walsh 2010).   Em resposta aos objetivos de aprendizagem relacionados com textos multimodais, no currículo espanhol da Costa Rica (MEP, 2017), e à escassez de propostas didáticas em nível nacional para seu tratamento pedagógico no ensino médio (Flores, 2019), este artigo visa propor uma série de competências semióticas (Tobón, 2005) para facilitar os processos de ensino e aprendizagem da multimodalidade na sala de aula. Estas competências foram formuladas a partir do enfoque sociocognitivo (Tobón, 2005), dos níveis de criação de significados em textos multimodais (Kress e Van Leeuwen, 2001; Kress, 2010) e a taxonomia de Bloom para habilidades cognitivas (Talbert, 2019). Como resultado, eles são propostos como processos complexos, para a aproximação, caracterização, análise, explicação, avaliação e produção de textos multimodais, em interações e contextos socioculturais específicos. Com base na descrição destas competências, o artigo argumenta a necessidade de incorporar uma dimensão semiótica dentro da competência comunicativa no currículo de espanhol (MEP, 2017) e fornece um apoio teórico-metodológico aos docentes para orientar a transposição dos objetivos do currículo nacional, relacionados aos textos multimodais, para a sala de aula. Em conclusão, sugere ligações entre esta proposta e estudos sobre a compreensão de leitura de textos multimodais, a fim de atualizar os processos didáticos e curriculares nacionais, de acordo com o desenvolvimento das múltiplas alfabetizações em nível internacional (Anstey e Bull 2006; Cope e Kalantzis, 2009b; Blanchard e Farstrup 2011; Cooper et al., 2013; Reid and Comber 2004; Walsh 2010).&nbsp

Competências semióticas para a alfabetização multimodal na disciplina de espanhol do ensino médio na Costa Rica

In response to the learning goals related to multimodal texts in the Costa Rican Spanish study program (MEP, 2017), and the lack of didactic proposals for its pedagogical treatment at a national level in secondary schools (Flores, 2019), this article’s purpose is to offer a series of semiotic competencies (Tobón, 2005) that will help in facilitating the multimodal teaching-learning process in the classroom. These competencies feed on the sociocognitive approach (Tobón, 2005), and the levels of creation of meaning in multimodal texts (Kress and Van Leeuwen, 2001; Kress, 2010) as well as on Bloom’s taxonomy for cognitive abilities (Talbert, 2019). As a result, they are presented as complex processes, for the approach, characterization, analysis, explanation, evaluation, and elaboration of multimodal texts, in specific sociocultural contexts and interactions. Based on the description of these competencies, the article condones the need to incorporate a semiotic dimension within the communicative competencies in the Spanish curriculum (MEP, 2017). It seeks to provide theoretical-methodological support to teachers to help them integrate the national curriculum’s objectives related to multimodal texts to the classroom. On a final note, this proposal offers a suggestion of studies regarding reading comprehension of multimodal texts, in order to update the national didactic and curricular processes, according to the development of multiple literacies at an international level (Anstey and Bull 2006; Cope and Kalantzis, 2009b; Blanchard and Farstrup 2011; Cooper et al., 2013; Reid and Comber 2004; Walsh 2010).    En respuesta a los objetivos de aprendizaje relacionados con textos multimodales, en el plan de estudios de español costarricense (MEP, 2017), y la escasez de propuestas didácticas a nivel nacional para su tratamiento pedagógico en secundaria (Flores, 2019), este artículo tiene como objetivo proponer una serie de competencias semióticas (Tobón, 2005) para facilitar los procesos de enseñanza y aprendizaje de la multimodalidad en el aula. Estas competencias se han formulado desde el enfoque sociocognitivo (Tobón, 2005), los niveles de creación de significados en textos multimodales (Kress y Van Leeuwen, 2001; Kress, 2010) y la taxonomía de Bloom para las habilidades cognitivas (Talbert, 2019). Como resultado, se plantean como procesos complejos, para la aproximación, caracterización, análisis, explicación, evaluación y producción de textos multimodales, en interacciones y contextos socioculturales específicos. Con base en la descripción de estas competencias, el artículo sostiene la necesidad de incorporar una dimensión semiótica dentro de la competencia comunicativa en el plan de estudios de español (MEP, 2017) y brindar un apoyo teórico – metodológico al profesorado para orientar la trasposición de los objetivos del currículo nacional, relacionados con textos multimodales, al salón de clases. Para concluir, sugiere vínculos entre esta propuesta y estudios sobre la comprensión lectora de textos multimodales, a fin de actualizar los procesos didácticos y curriculares nacionales, según el desarrollo de las alfabetizaciones múltiples a nivel internacional (Anstey y Bull 2006; Cope y Kalantzis, 2009b; Blanchard y Farstrup 2011; Cooper et al., 2013; Reid and Comber 2004; Walsh 2010).   Em resposta aos objetivos de aprendizagem relacionados com textos multimodais, no currículo espanhol da Costa Rica (MEP, 2017), e à escassez de propostas didáticas em nível nacional para seu tratamento pedagógico no ensino médio (Flores, 2019), este artigo visa propor uma série de competências semióticas (Tobón, 2005) para facilitar os processos de ensino e aprendizagem da multimodalidade na sala de aula. Estas competências foram formuladas a partir do enfoque sociocognitivo (Tobón, 2005), dos níveis de criação de significados em textos multimodais (Kress e Van Leeuwen, 2001; Kress, 2010) e a taxonomia de Bloom para habilidades cognitivas (Talbert, 2019). Como resultado, eles são propostos como processos complexos, para a aproximação, caracterização, análise, explicação, avaliação e produção de textos multimodais, em interações e contextos socioculturais específicos. Com base na descrição destas competências, o artigo argumenta a necessidade de incorporar uma dimensão semiótica dentro da competência comunicativa no currículo de espanhol (MEP, 2017) e fornece um apoio teórico-metodológico aos docentes para orientar a transposição dos objetivos do currículo nacional, relacionados aos textos multimodais, para a sala de aula. Em conclusão, sugere ligações entre esta proposta e estudos sobre a compreensão de leitura de textos multimodais, a fim de atualizar os processos didáticos e curriculares nacionais, de acordo com o desenvolvimento das múltiplas alfabetizações em nível internacional (Anstey e Bull 2006; Cope e Kalantzis, 2009b; Blanchard e Farstrup 2011; Cooper et al., 2013; Reid and Comber 2004; Walsh 2010).&nbsp

Superspreading event of COVID-19 in adolescents: is there a difference between the vaccinated and the unvaccinated?

Objective: The aim of this study is to estimate the incidence of COVID-19 in a vaccinated and an unvaccinated group of adolescents and describe their symptoms.   Methods: In May 2021 a private indoor event for high school adolescents took place resulting in a superspreading event. As part of the study, an anonymous questionnaire was sent to all adolescents invited to the event and details about symptoms, previous COVID-19 infection, vaccination status and behaviour during the event was assessed. Two groups were formed, one of vaccinated individuals and the other of unvaccinated individuals. A sample from a fully vaccinated symptomatic individual was sequenced. General characteristics for the studied groups are described using categorical and continuous data. The incidence of COVID-19 in each group was estimated by taking the total number of COVID-19 positive cases (numerator) divided by the total number of individuals (denominator) multiplied by 100.   Results: A total of 41 out of the 164 adolescents (incidence 25%, 95%CI 18.6- 32.4) that attended the private indoor event developed COVID-19. A sample was sequenced from one of the symptomatic and fully vaccinated individuals with BNT162b2 (Pfizer-BioNTech vaccine) finding SARS-CoV-2 Delta (B.1.617.2) variant of concern. The incidence of COVID-19 in the unvaccinated was 35.1% (95%CI 25.5-45.6), and in the vaccinated 11.4% (95%CI 5.1-21.3). There were more unvaccinated than vaccinated teenagers that developed COVID-1

Factores de riesgo psicosociales relacionados con el desempeño laboral del profesional enfermero en áreas criticas del hospital Belén de Trujillo 2022

Este estudio fue de tipo cuantitativo correlacional, cuyo objetivo fue determinar la relación entre los factores de riesgo psicosociales y desempeño laboral del profesional enfermero en áreas críticas del Hospital Belén de Trujillo, 2022. La muestra estuvo constituida por 91 profesionales enfermeros a quienes se aplicaron dos encuestas para la recolección de datos, uno para determinar los factores de riesgo psicosociales y otro para determinar el desempeño laboral. Los resultados indicaron que el profesional enfermero percibe los factores psicosociales en su mayoría en nivel saludable y excelente representado por un 63% y un 38 % en nivel de emergencia y alerta, En cuanto al desempeño laboral, el 10% se encuentra en nivel bajo, el 5% en nivel medio y un 85% nivel alto. Al realizar la prueba chi cuadrado, se obtuvo un nivel de significancia menor a 5%, lo que indica que existe relación entre los factores de riesgo psicosociales con el desempeño laboral del profesional enfermero. Asimismo, se obtuvo el coeficiente de V de Cramer obteniéndose un resultado de 0.854, lo que significa que la relación es positiva muy fuerte.This study was of a quantitatively correlational type, whose objective was to determine the relationship between psychosocial risk factors and the work performance of the nursing professional in critical areas of the Hospital Belén de Trujillo, 2022. The sample consisted of 91 nurse professionals to whom were applied two surveys for data collection, one to determine psychosocial risk factors and another to determine job performance. The results indicated that the nursing professional perceived the psychosocial factors mostly at a healthy and excellent level represented by 63% and 38% at an emergency and alert level. Regarding work performance, 10% are at a low level, 5% at medium level and 85% at high level. When performing the Chi-square test, a significance level of less than 5% was obtained, which indicates that there is a relationship between the psychosocial risk factors with the work performance of the sick professional. Likewise, Cramer's V coefficient was obtained, obtaining a result of 0.854, which means that the relationship is very strong positive.Tesi

DNA methylases for site-selective inhibition of type IIS restriction enzyme activity

DNA methylases of the restriction-modifications (R-M) systems are promising enzymes for the development of novel molecular and synthetic biology tools. Their use in vitro enables the deployment of independent and controlled catalytic reactions. This work aimed to produce recombinant DNA methylases belonging to the R-M systems, capable of in vitro inhibition of the type IIS restriction enzymes BsaI, BpiI, or LguI. Non-switchable methylases are those whose recognition sequences fully overlap the recognition sequences of their associated endonuclease. In switch methylases, the methylase and endonuclease recognition sequences only partially overlap, allowing sequence engineering to alter methylation without altering restriction. In this work, ten methylases from type I and II R-M systems were selected for cloning and expression in E. coli strains tolerant to methylation. Isopropyl β-D-1-thiogalactopyranoside (IPTG) concentrations and post-induction temperatures were tested to optimize the soluble methylases expression, which was achieved with 0.5 mM IPTG at 20 °C. The C-terminal His6-Tag versions showed better expression than the N-terminal tagged versions. DNA methylation was analyzed using purified methylases and custom test plasmids which, after the methylation reactions, were digested using the corresponding associated type IIS endonuclease. The non-switchable methylases M2.Eco31I, M2.BsaI, M2.HpyAII, and M1.MboII along with the switch methylases M.Osp807II and M2.NmeMC58II showed the best activity for site-selective inhibition of type IIS restriction enzyme activity. This work demonstrates that our recombinant methylases were able to block the activity of type IIS endonucleases in vitro, allowing them to be developed as valuable tools in synthetic biology and DNA assembly techniques

Fortalezas y Debilidades Financieras de las Pymes de Servicios de Santa Cruz, Bolivia

The objective of this study focused on identifying the financial strengths and weaknesses of SMEs in the service sector of Santa Cruz, Bolivia, which would serve as a basis for decision making and proposing strategies and the development of effective financial planning. To this end, a quantitative research of descriptive scope was carried out in which financial managers of 38 companies were surveyed based on two dimensions: the presence of financial planning and the functional analysis of the financial area. The findings obtained showed that, for the first dimension, companies do prepare cash flow on a monthly and annual basis, but they did not have internal or external personnel to prepare these financial statements on a recurring basis. Regarding the second dimension, financial strength is specified in the analysis of the trends of the financial statements. Regarding the financial weakness, it is shown that they do not analyze the costs of sales with the expenses and sales made.El objetivo del presente estudio se centró en identificar las fortalezas y debilidades financieras de las pymes del sector de servicios de Santa Cruz, Bolivia, que sirviera de base para la toma de decisiones y proponer estrategias y la elaboración de una planificación financiera efectiva.  Para ello, se realizó una investigación cuantitativa de alcance descriptivo en la que se encuestó a gerentes financieros de 38 empresas con base en dos dimensiones: la presencia de planificación financiera y el análisis funcional del área financiera.  Los hallazgos obtenidos mostraron que, para la primera dimensión, las empresas sí elaboran el flujo de efectivo de forma mensual y anual, pero no contaban con personal interno ni externo que elabore esos estados financieros de forma recurrente. En cuanto a la segunda dimensión, la fortaleza financiera se concreta en el análisis de las tendencias de los estados financieros. Respecto de la debilidad financiera se muestra que no analizan los costos en las ventas con los gastos y ventas realizadas