Agroecological Practices on Private Farms in the Province of Camagüey, Cuba.

The aim of this research was to gather together the dairy farms of the José Antonio Echeverría Strengthened Coop-erative of Credits and Services (CCSF) in the province of Camaguey, Cuba, according to the frequency of application or no application of agroecological practices, and their relationship to some bioproductive variables of economic interest. Information compiled for three years was used. Three groups were made, based on hierarchical clustering analysis. The grouping system used was the link between groups. The measure criteria used was the squared Euclid-ean distance  from agroecological practices by the farmers. SPSS 21.0 was  used for statistical analysis.  The groups made were considered the factor to perform variance analysis (ANOVA) to with eight dependent variables. The Tukey´s multiple comparison test was made to the variables that showed differences for P < 0.05. A total of seven out of ten agroecological practices applied with effects  on the behavior of bioproductive indicators were identified. Group three included the farms with the best results, and the highest number of agroecological practices

Estratégia de difusão da nanotecnologia: Ensino interdisciplinar aos professores do ensino fundamental

The objective of the research was to disseminate nanotechnology concepts, applications, and benefits among educators from different Costa Rican provinces to increase their acceptance and dissemination of the subject to elementary students. Teachers from different areas of the country were called to participate.  Five training workshops were held in Turrialba, Cahuita, Alajuela, Buenos Aires, and Nicoya covering fundamental nanotechnology concepts and applications, as well as the contributions offered from an educational point of view. The workshops were held in person two full days including talks, practical activities, and discussions. In addition, educational materials were prepared, such as a poster and an information brochure, and two educational videos on nanotechnology. A total of 98 teachers, 87% men and 13% women, from different provinces were trained. Workshop evaluations were positive in terms of the knowledge acquired with an average of 57.30%, compared to 5.10% before starting the training. This project contributed to strengthen teachers’ knowledge about nanotechnology and its applications. In addition, national and international nanotechnology research projects were made known. The above will help teachers disseminate new knowledge to the student population, thus becoming knowledge multipliers.El objetivo de la investigación fue socializar los conceptos, aplicaciones y beneficios de la nanotecnología entre personal educador de las diferentes provincias de Costa Rica, para incrementar su aceptación y difusión del tema a los niños y niñas de educación primaria. Se realizó una convocatoria para seleccionar a sujetos educadores de distintas zonas del país. Se impartieron 5 talleres de capacitación en las siguientes localidades: Turrialba, Cahuita, Alajuela, Buenos Aires y Nicoya. En estos se abordaron temas fundamentales de la nanotecnología y sus aplicaciones, así como los aportes que se pueden ofrecer desde el punto de vista educativo. Los talleres se impartieron de manera presencial durante dos días completos, con exposición de charlas, actividades prácticas y discusiones. Además, se preparó material didáctico, como un afiche y un folleto informativo, y dos videos educativos alusivos a la nanotecnología. Se logró capacitar a 98 sujetos educadores, 87 % hombres y 13 % mujeres, de distintas provincias del país. Los resultados de las evaluaciones de los talleres fueron buenos, en términos del conocimiento adquirido con un promedio de calificación de un 57,30 %, comparado con un 5,10 % alcanzado antes de iniciar la capacitación. Este proyecto, contribuyó a fortalecer el conocimiento de los educadores sobre la nanotecnología y sus aplicaciones; además, se dieron a conocer proyectos de investigación nacionales e internacionales relativos a la nanotecnología. Lo anterior permitirá que los educadores sean capaces de transmitir los nuevos conocimientos a la población estudiantil, y se conviertan en multiplicadores del conocimiento.Esta pesquisa teve como objetivo socializar os conceitos, aplicações e benefícios da nanotecnologia entre os educadores dos diferentes municípios da Costa Rica, para aumentar a aceitação e difusão do tema nos estudantes do ensino fundamental. Foi realizada uma convocatória para escolher sujeitos educadores de distintas zonas do país. Foram ministradas 5 oficinas de capacitação nas seguintes localidades: Turrialba, Cahuita, Alajuela, Buenos Aires e Nicoya. Foram abordados temas fundamentais da nanotecnologia e suas aplicações, assim como as contribuições que podem ser dadas desde o ponto de vista educativo. Essas oficinas foram ministradas presencialmente durante dois dias completos, com exposição de palestras, atividades práticas e discussões. Além disso, foi preparado material didático, como um cartaz e um folheto informativo, e dois vídeos educativos alusivos à nanotecnologia. Foi possível capacitar 98 sujeitos educadores, 87 % homens e 13 % mulheres, de distintos municípios do país. Os resultados das avaliações das oficinas foram bons, em termos do conhecimento adquirido com uma média de nota de 57,30 %, comparado aos 5,10 % alcançados antes de iniciar a capacitação. Este projeto contribuiu para a consolidação do conhecimento dos educadores sobre a nanotecnologia e suas aplicações; além disso, divulgaram projetos de pesquisas nacionais e internacionais relativos à nanotecnologia. Isso permitirá que os educadores sejam capazes de transmitir os novos conhecimentos à população estudantil e de se transformar em multiplicadores do conhecimento

Prácticas agroecológicas en fincas privadas de Camagüey, Cuba.

El objetivo de la investigación fue agrupar a las fincas lecheras de la Cooperativa de Créditos y Servicios Fortalecida (CCSF) José Antonio Echeverría en la provincia de Camagüey, Cuba, según la frecuencia de aplicación o no de prácticas agroecológicas y su relación con algunas variables bioproductivas de interés económico. Se utilizó la información de los resultados de tres años de trabajo. Se conformaron tres grupos según el análisis de clústeres jerárquico, utilizando como método de agrupación el vínculo entre grupo y como medida la distancia euclídea al cuadrado de las prácticas agroecológicas empleada por los productores. El paquete estadístico utilizado fue SPSS versión 21.0. Los grupos formados fueron considerados como el factor para realizar un análisis de varianza (ANOVA) teniendo ocho variables dependientes. A las variables que mostraron diferencias para P < 0,05 se les aplicó la prueba de comparaciones múltiples de Tukey. Se identificaron un total de siete de las diez prácticas agroecológicas aplicadas que influyeron en el comportamiento de indicadores bioproductivos. En el grupo tres se concentraron las fincas con mejores resultados y que más prácticas agroecológicas realizaban.Agroecological Practices on Private Farms in the Province of Camagüey, CubaABSTRACTThe aim of this research was to gather together the dairy farms of the José Antonio Echeverría Strengthened Cooperative of Credit and Services (CCSF) in the province of Camaguey, Cuba, according to the frequency of application or no application of agroecological practices, and their relationship with some bioproductive variables of economic interest. The information compiled for three years was used. Three groups were arranged based on hierarchical cluster analysis. The grouping system used was the link between groups. The measure criteria used was the Euclidean Squared Distance for agroecological practices by the farmers. SPSS 21.0 was used for statistical analysis. The groups made were considering the factor to perform variance analysis (ANOVA), with eight dependent variables. The Tukey multiple comparison test was made to the variables that showed differences for P < 0.05. A total of seven out of ten agroecological practices applied that influenced on the behavior of bioproductive indicators, were identified. Group three included the farms with the best results, and the highest number of agroecological practices

Ética profesional en educación superior : finalidades, estrategias y desafíos de la formación

Todo proyecto educativo que no responde a su época se expone a problemas de legitimidad y al duro escrutinio y sanción de los usuarios. Las instituciones de educación superior no son la excepción de esta premisa clásica, incluso más validada por eldinamismos, la versatilidad y ojo crítico en el mundo contemporáneo. La ética se ha convertido en el baremo principal para someter a juicio a las instituciones y a las personas que ahí actuan, como a las finalidades que se pretenden en sus acciones. En esta perspectiva, debe examinarse la función de las instituciones de educación superior.Este libro es el esfuerzo colectivo por acercarnos a esa problemática, en especial a las finalidades, estrategias y relaciones en juego para cumplir la tarea de la formación y sus nexos inevitables con la ética profesional

Green Synthesis of Gold and Silver Nanoparticles from Plant Extracts and Their Possible Applications as Antimicrobial Agents in the Agricultural Area

Se seleccionó la licencia Creative Commons para este envío. El documento trae lo siguiente: © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/) (En caso de duda consultar a Meilyn Garro).Currently, metal nanoparticles have varied uses for different medical, pharmaceutical, and agricultural applications. Nanobiotechnology, combined with green chemistry, has great potential for the development of novel and necessary products that benefit human health, environment, and industries. Green chemistry has an important role due to its contribution to unconventional synthesis methods of gold and silver nanoparticles from plant extracts, which have exhibited antimicrobial potential, among other outstanding properties. Biodiversity-rich countries need to collect and convert knowledge from biological resources into processes, compounds, methods, and tools, which need to be achieved along with sustainable use and exploitation of biological diversity. Therefore, this paper describes the relevant reported green synthesis of gold and silver nanoparticles from plant extracts and their capacity as antimicrobial agents within the agricultural field for fighting against bacterial and fungal pathogens that can cause plant, waterborne, and foodborne diseases. Moreover, this work makes a brief review of nanoparticles’ contribution to water treatment and the development of “environmentally-friendly” nanofertilizers, nanopesticides, and nanoherbicides, as well as presenting the harmful effects of nanoparticles accumulation in plants and soils.Actualmente, las nanopartículas metálicas tienen usos variados para diferentes aplicaciones médicas, farmacéuticas y agrícolas. La nanobiotecnología, combinada con la química verde, tiene un gran potencial para el desarrollo de productos nuevos y necesarios que benefician la salud humana, el medio ambiente y las industrias. La química verde tiene un papel importante debido a su contribución a los métodos de síntesis no convencionales de nanopartículas de oro y plata a partir de extractos de plantas, que han exhibido potencial antimicrobiano, entre otras propiedades destacadas. Los países ricos en biodiversidad deben recopilar y convertir el conocimiento de los recursos biológicos en procesos, compuestos, métodos y herramientas, lo que debe lograrse junto con el uso y la explotación sostenibles de la diversidad biológica. Por lo tanto, este artículo describe la síntesis verde reportada relevante de nanopartículas de oro y plata a partir de extractos de plantas y su capacidad como agentes antimicrobianos dentro del campo agrícola para combatir patógenos bacterianos y fúngicos que pueden causar enfermedades transmitidas por plantas, agua y alimentos. Además, este trabajo hace una breve revisión de la contribución de las nanopartículas al tratamiento del agua y al desarrollo de nanofertilizantes, nanoplaguicidas y nanoherbicidas “amigables con el medio ambiente”, además de presentar los efectos nocivos de la acumulación de nanopartículas en plantas y suelos.Centro Nacional de Alta Tecnología, Costa RicaUniversidad Nacional, Costa RicaEscuela de Químic

Biodegradable plastics in aquatic ecosystems: Latest findings, research gaps, and recommendations

The negative impact of plastic accumulation in aquatic ecosystems is a known and undeniable problem. However, while many of the scientific community's countermeasures against such accumulation target the effects of the most common commodity plastics, the consequences of so-called 'biodegradable' plastics in those ecosystems are seldom discussed. After all, though their alleged biodegradability sustains the widespread belief that they are harmless to the environment, because a material's fate determines its classification as biodegradable or not, many plastics classified as biodegradable do not in fact meet the required norms and standards of biodegradability in aquatic ecosystems. Furthermore, during the past five years, the scientific community has shown that the degradation of such plastics can generate bio-microplastics that have effects similar to or worse than those of conventional microplastics (MPs). Against that background, this review details the latest findings regarding how biodegradable plastics can influence aquatic ecosystems and thus cause adverse health effects in living organisms and/or act as vectors of chemical pollutants. Beyond that, it identifies the key aspects of such trends to be investigated in greater depth, including the need to consider a wider variety of biodegradable plastics and to develop systematic methods that allow quantifying and identifying the remains of those pollutants in living species. Other aspects worth considering include the arrival and mobilisation dynamics of MPs in oceans. The ways in which small animals fed by filtering (e.g. red crabs and other zooplankton organisms) move MPs through the water column and into food webs also merit attention, for those MPs are ingested by numerous species at different trophic levels, at which point bioaccumulation in tissues has to be considered as a factor of toxicity. This review closes with a series of recommendations and perspectives for future studies on 'biodegradable plastics' in aquatic ecosystems.Fil: Ribba, Laura Gabriela. Instituto Nacional de Tecnología Industrial; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lopretti, Mary. Universidad de la República; UruguayFil: Montes de Oca Vásquez, Gabriela. Laboratorio Nacional de Nanotecnologia (lanotec) ; Centro Nacional de Alta Tecnologia;Fil: Batista, Diego. Laboratorio Nacional de Nanotecnologia (lanotec) ; Centro Nacional de Alta Tecnologia;Fil: Goyanes, Silvia Nair. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Vega Baudrit, José Roberto. Laboratorio Nacional de Nanotecnologia (lanotec) ; Centro Nacional de Alta Tecnologia

Optimization of the biosynthesis of silver nanoparticles using bacterial extracts and their antimicrobial potential

In the present study, silver nanoparticles (AgNPs) were biosynthesized using the supernatant and the intracellular extract of Cupriavidus necator, Bacillus megaterium, and Bacillus subtilis. The characterization of the AgNPs was carried out using UV–Vis spectroscopy, FTIR, DLS and TEM. Resazurin microtiter-plate assay was used to determine the antimicrobial action of AgNPs against Escherichia coli. UV–Visible spectra showed peaks between 414 and 460 nm. TEM analysis revealed that the synthesized AgNPs showed mostly spherical shapes. DLS results determined sizes from 20.8 to 118.4 nm. The highest antimicrobial activity was obtained with the AgNPs synthesized with supernatant rather than those using the intracellular extract. Therefore, it was determined that the bacterial species, temperature, pH, and type of extract (supernatant or intracellular) influence the biosynthesis. This synthesis thus offers a simple, environmentally friendly, and low-cost method for the production of AgNPs, which can be used as antibacterial agents

Microhabitat heterogeneity associated with Vanilla spp. and its influences on the microbial community of leaf litter and soil

Open AccessThe impact of forest microhabitats on physiochemical properties of the soil and that of microbial communities on tropical soils remain poorly understood. To elucidate the effect of tropical forest stand on leaf litter and soil microbial communities, we studied enzyme activities, microbial biomass, and diversity in three distinct microhabitats in terms of plant richness, diameter at breast height (DBH), and physiochemical properties of soil and litter, each associated with a different Vanilla sp. In the soil, positive correlations were found between electrical conductivity (EC) and total organic carbon (TOC) with phosphatase activity, and between nitrogen (N) and water-soluble carbon (WSC) content with urease activity (UA). In the litter, the water content was positively correlated with bacterial and fungal biomass, and N and WSC contents were positively correlated with fungal biomass. Positive correlations were found between plant richness and UA in the soil, plant richness and fungal biomass in the soil and litter, and DBH and fungal biomass in the litter. Amplicon sequencing revealed differences between microhabitats in the relative abundance of some fungal and bacterial taxa and in the bacterial community composition of both litter and soil. Bacterial richness and diversity were different between microhabitats, and, in litter samples, they were negatively correlated with DBH and plant richness, respectively. By contrast, none of the soil and litter physiochemical properties were significantly correlated with microbial diversity. Our results show that significant shifts in enzyme activity, microbial biomass, and diversity in the microhabitats were driven by key abiotic and biotic factors depending on the soil or litter sample type.El impacto de los microhábitats forestales sobre las propiedades fisicoquímicas del suelo y el de las comunidades microbianas en los suelos tropicales sigue siendo poco conocido. Para dilucidar el efecto del rodal del bosque tropical sobre la hojarasca y las comunidades microbianas del suelo, estudiamos las actividades enzimáticas, la biomasa microbiana y la diversidad en tres microhábitats distintos en términos de riqueza de plantas, diámetro a la altura del pecho (DAP) y propiedades fisicoquímicas del suelo y basura, cada uno asociado con una Vanilla sp. En el suelo, se encontraron correlaciones positivas entre la conductividad eléctrica (CE) y el carbono orgánico total (TOC) con la actividad de la fosfatasa, y entre el contenido de nitrógeno (N) y carbono soluble en agua (WSC) con la actividad de la ureasa (UA). En la hojarasca, el contenido de agua se correlacionó positivamente con la biomasa bacteriana y fúngica, y los contenidos de N y WSC se correlacionaron positivamente con la biomasa fúngica. Se encontraron correlaciones positivas entre la riqueza vegetal y la AU en el suelo, la riqueza vegetal y la biomasa fúngica en el suelo y la hojarasca, y el DAP y la biomasa fúngica en la hojarasca. La secuenciación de amplicones reveló diferencias entre microhábitats en la abundancia relativa de algunos taxones de hongos y bacterias y en la composición de la comunidad bacteriana de la hojarasca y el suelo. La riqueza y diversidad de bacterias fueron diferentes entre los microhábitats y, en las muestras de hojarasca, se correlacionaron negativamente con el DAP y la riqueza de plantas, respectivamente. Por el contrario, ninguna de las propiedades fisicoquímicas del suelo y la hojarasca se correlacionó significativamente con la diversidad microbiana. Nuestros resultados muestran que los cambios significativos en la actividad enzimática, la biomasa microbiana y la diversidad en los microhábitats fueron impulsados ​​por factores abióticos y bióticos clave según el tipo de muestra de suelo o hojarasca.Centro Nacional de Alta Tecnología, Costa RicaUniversidad Nacional, Costa RicaAsociación Nacional de Vainilleros Unidos, Costa RicaUniversidad de Murcia, EspañaInstitute of Microbiology of the CAS, República ChecaEscuela de Ciencias BiológicasEscuela de Químic

Development of nanocomposite chitosan films with antimicrobial activity from agave bagasse and shrimp shells

In this study, the nanocomposite chitosan films with antimicrobial activity from agave bagasse and shrimp shells were developed. Chitosan was successfully extracted from shrimp shells waste and cellulose nanofibers were obtained from bagasse agave. To improve the antimicrobial activity, different silver nanoparticle concentrations (2.5, 5, and 10% v/v) were added in the formulation. The films were prepared using the solvent casting technique and the film samples were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. The functional properties were also evaluated, including transparency, antibacterial activity (against Escherichia coli), water-solubility, swelling, and mechanical properties. The moisture content and water solubility decreased when the silver nanoparticles and nanofiber were added to the films. An increase in strength and modulus was determined when the nanofibers were added to the film. and with the addition of silver nanoparticles a decrease of the mechanical properties proportional to the nanoparticle content was observed. Therefore, there was an increase in the mechanical properties of chitin films with the incorporation of nanofibers and the addition of 2.5% and 5% of silver nanoparticles. Chitosan/nanofiber-based films displayed a total antibacterial activity against E.coli compared to chitosan-based films, with a synergistic effect between chitosan and cellulose nanofibers. This work highlights the potential of chitosan films reinforced with nanofibers and silver nanoparticles to act as green alternative for food preservation and packaging

Organic amendments exacerbate the effects of silver nanoparticles on microbial biomass and community composition of a semiarid soil

Increased utilization of silver nanoparticles (AgNPs) can result in an accumulation of these particles in the environment. The potential detrimental effects of AgNPs in soil may be associated with the low fertility of soils in semiarid regions that are usually subjected to restoration through the application of organic amendments. Microbial communities are responsible for fundamental processes related to soil fertility, yet the potential impacts of low and realistic AgNPs concentrations on soil microorganisms are still unknown. We studied the effects of realistic citrate-stabilized AgNPs concentrations (0.015 and 1.5 μg kg−1 ) at two exposure times (7 and 30 days) on a sandy clay loam Mediterranean soil unamended (SU) and amended with compost (SA). We assessed soil microbial biomass (microbial fatty acids), soil enzyme activities (urease, β-glucosidase, and alkaline phosphatase), and composition of the microbial community (bacterial 16S rRNA gene and fungal ITS2 sequencing) in a microcosm experiment. In the SA, the two concentrations of AgNPs significantly decreased the bacterial biomass after 7 days of incubation. At 30 days of incubation, only a significant decrease in the Gram+ was observed at the highest AgNPs concentration. In contrast, in the SU, there was a significant increase in bacterial biomass after 30 days of incubation at the lowest AgNPs concentration. Overall, we found that fungal biomass was more resistant to AgNPs than bacterial biomass, in both SA and SU. Further, the AgNPs changed the composition of the soil bacterial community in SA, the relative abundance of some bacterial taxa in SA and SU, and fungal richness in SU at 30 days of incubation. However, AgNPs did not affect the activity of extracellular enzymes. This study demonstrates that the exposure time and organic amendments modulate the effects of realistic concentrations of AgNPs in the biomass and composition of the microbial community of a Mediterranean soil.La mayor utilización de nanopartículas de plata (AgNP) puede resultar en una acumulación de estas partículas en el medio ambiente. Los posibles efectos perjudiciales de los AgNP en el suelo pueden estar asociados con la baja fertilidad de los suelos en las regiones semiáridas que suelen estar sometidas a restauración mediante la aplicación de enmiendas orgánicas. Las comunidades microbianas son responsables de procesos fundamentales relacionados con la fertilidad del suelo, sin embargo, aún se desconocen los impactos potenciales de concentraciones bajas y realistas de AgNPs en los microorganismos del suelo. Estudiamos los efectos de concentraciones realistas de AgNP estabilizados con citrato (0,015 y 1,5 μg kg − 1) en dos tiempos de exposición (7 y 30 días) en un suelo mediterráneo franco arcilloso arenoso sin enmendar (SU) y enmendado con compost (SA). Evaluamos la biomasa microbiana del suelo (ácidos grasos microbianos), las actividades de las enzimas del suelo (ureasa, β-glucosidasa y fosfatasa alcalina) y la composición de la comunidad microbiana (gen bacteriano del ARNr 16S y secuenciación de ITS2 fúngico) en un experimento de microcosmos. En SA, las dos concentraciones de AgNP disminuyeron significativamente la biomasa bacteriana después de 7 días de incubación. A los 30 días de incubación, solo se observó una disminución significativa en el Gram + a la concentración más alta de AgNPs. En contraste, en la UB, hubo un aumento significativo en la biomasa bacteriana después de 30 días de incubación a la concentración más baja de AgNPs. En general, encontramos que la biomasa fúngica era más resistente a los AgNP que la biomasa bacteriana, tanto en SA como en SU. Además, los AgNP cambiaron la composición de la comunidad bacteriana del suelo en SA, la abundancia relativa de algunos taxones bacterianos en SA y SU, y la riqueza fúngica en SU ​​a los 30 días de incubación. Sin embargo, los AgNP no afectaron la actividad de las enzimas extracelulares. Este estudio demuestra que el tiempo de exposición y las enmiendas orgánicas modulan los efectos de concentraciones realistas de AgNP en la biomasa y composición de la comunidad microbiana de un suelo mediterráneo.Centro Nacional de Alta Tecnología, Costa RicaUniversidad Estatal a Distancia, Costa RicaUniversidad Nacional, Costa RicaInstitute of Microbiology of the CAS, República ChecaUniversidad de Murcia, EspañaEscuela de Ciencias BiológicasEscuela de Químic