Cross-linked enzyme aggregates (CLEAs) of the Y509E mutant of glycoside hydrolase family 52 β-xylosidase from Geobacillus stearothermophilus with dual activity of β-xylosidase and xylanase (XynB2Y509E) were prepared. Ammonium sulfate was used as the precipitant agent, and glutaraldehyde as cross-linking agent. The optimum conditions were found to be 90% ammonium sulfate, 12.5 mM glutaraldehyde, 3 h of cross-linking reaction at 25 °C, and pH 8.5. Under these (most effective) conditions, XynB2Y509E-CLEAs retained 92.3% of their original β-xylosidase activity. Biochemical characterization of both crude and immobilized enzymes demonstrated that the maximum pH and temperature after immobilization remained unchanged (pH 6.5 and 65 °C). Moreover, an improvement in pH stability and thermostability was also found after immobilization. Analysis of kinetic parameters shows that the Km value of XynB2Y509E-CLEAs obtained was slightly higher than that of free XynB2Y509E (1.2 versus 0.9 mM). Interestingly, the xylanase activity developed by the mutation was also conserved after the immobilization process.

problema de salud pública, particularmente en la población femenina; el aumento de otros padecimientos como anorexia y bulimia; y el incremento de la preocupación por el cuerpo, que lleva a transformar algunas prácticas y representaciones alimentarias no solo en población urbana, sino en mujeres de las zonas rurales. Objetivos: tener un primer acercamiento a la percepción corporal de las mujeres de las zonas rurales, conocer cómo son, cómo se perciben y cómo les gustaría ser, e identificar algunas de sus representaciones alimentarias. Material y Métodos: Se estudiaron 564 mujeres de 13 comunidades rurales, se les pesó y midió, y se les aplicó un cuestionario. Resultados: Según el IMC, 33% de las mujeres fueron clasificadas con normopeso; 9.6% con delgadez; 29.4% con sobrepeso; y 28% con obesidad. Las mujeres se percibieron más delgadas, a diferencia de otras investigaciones, y les gustaría ser más delgadas. Discusión: Se resalta la elevada prevalencia de sobrepeso y obesidad de las mujeres de estas zonas. El "desagrado hacia su cuerpo", relacionado con el aspecto estético, muestra un aumento en la preocupación por el cuerpo en mujeres de las comunidades rurales. Conclusiones: Se considera que la inclusión de temas como la percepción y el ideal corporal en los programas de alimentación y nutrición es relevante para prevenir trastornos de la alimentación. De igual manera, los significados que tienen para las mujeres el acto de comer o no comer determinados alimentos o productos "buenos para transformar el cuerpo" son centrales para la programación de las acciones o estrategias en este campo. Palabras Clave: imagen corporal; representaciones alimentarias; mujeres; comunidades rurales; México  ABSTRACT: Introduction: Nutrition studies in Mexico point in three directions: obesity as a public health problem, particularly among women; the increasing prevalence of other illnesses as anorexia and bulimia; and the concerns about the body perception, leading to transform some practices and food performances, in women who lives in rural areas. Objectives: to have a first approach to the body perception of women in rural areas, know how they are, how they perceived themselves, and how they like to be, and identifying some of their food representations. Material and Methods: We studied 564 women from 13 rural communities; they were weighed and measured, and they answered a questionnaire. Results: According to BMI, 33% of women were classified as normal weight; 9.6%, with thinness; 29.4%, overweight; and 28%, obese. Women were perceived thinner, unlike other research, and would like to be thinner. Discussion: The prevalence of overweight and obesity among women in these areas is highlighted. The "dislike to her body", related to the aesthetic aspect, shows an increase in the concern for the body in the women of the rural communities. Conclusions: It is considered that including issues, such as body perception and body ideal, in feeding and nutritional programs is relevant to prevent eating disorders. The meanings that the wo...

En el siguiente escrito compartimos algunas reflexiones en torno a la situación de las trabajadoras de casas particulares y sus relaciones laborales en el contexto del Aislamiento Social, Preventivo y Obligatorio dispuesto como respuesta al avance del Covid-19. Se abordan dos ejes íntimamente vinculados: el primero, las condiciones de inestabilidad, precariedad y pérdida de ingresos que enfrenta un alto porcentaje de trabajadoras del sector; el segundo, las relaciones laborales y, particularmente, su componente afectivo. Sostenemos que la pandemia reedita, profundiza, agudiza y, al mismo tiempo, vuelve más visibles las precariedades y desigualdades previas que caracterizan históricamente a este sector.

Ecuador is a country with a vast amount of natural and cultural heritage. The diversity of its four regions has allowed the presence of several species of flora and fauna. Most of its fauna and flora is present at 26 protected natural areas. Also, it offers historical attractions, gastronomy, and a variety of cultures and traditions. In all these aspects, Ecuador has developed several modalities of tourism, as the community based tourism, which is considered as a strategy for development. It is also considered as an object of investigation which includes three fundamental perspectives: special sensitivity to the natural environment and cultural particularities, integral sustainability (social and natural), and effective control of tourism by communities. Community tourism contributes to the country’s brand at international level, being an element of growing interest in touristic market. The Guasuntos community has natural and cultural resources, which has allowed the incursion in this tourism modality. This, however, was possible through the creation of a product according to the needs of unsatisfied demand. A survey was applied to the local tourists who visited Alausí and Chunchi cantons. Also, the market analysis of the survey was carried out, and the potential demand and competition were projected. This helps to ascertain the unsatisfied demand in order to identify the needs of the national tourists. This study was developed as a contribution to the design of a touristic product with the aim of improving the population life quality.