Estrategia didáctica para el perfeccionamiento del proceso de enseñanza-aprendizaje desde las clases con experimentos de Ciencias Naturales en la Educación Primaria

Las Ciencias Naturales desempeñan un importante papel en la concepción científico materialista del mundo de los alumnos primarios, requiere de clases en que predominen los experimentos o demostraciones para confirmar la veracidad de lo estudiado. No todas las clases son experimentales, pero aquellas que lo son en la mayoría de los casos se realizan con insuficiencias por los maestros y el alumno es un sujeto poco protagónico en la observación de las demostraciones experimentales que se realizan. En esta propuesta el alumno es un sujeto activo y el docente un director y controlador de sus actividades garantizando su papel mediador en el proceso. Se han utilizado métodos científicos para la búsqueda y procesamiento bibliográfico, aplicación y validación, así como matemáticos para cuantificar los datos y hacer las valoraciones cualitativas de la misma. Desde el punto de vista teórico se sistematizan los referentes que sustentan el problema y se puntualizan algunos criterios del autor en correspondencia con los de la bibliografía analizad

Capacidades técnicas, legales y de gestión para equipos blueteam y redteam

Observación de la normativa y legislación referente a la seguridad de la información, código de ética, observación de un ejercicio aplicado, realización de pruebas de penetración, ataque, contención y neutralización de un ataque en un entorno controladoObserving the regulations and legislation regarding information security, code of ethics, observing an applied exercise, conducting penetration, attack, containment and neutralization tests of an attack in a controlled environmen

Paradero inteligente para mejorar el nivel de satisfacción de usuarios de la empresa de Transporte Nuevo California de Trujillo 2019

La ciudad de Trujillo hoy en día no cuenta con una red de paraderos y los pocos que hay son paraderos informales puestos provisionalmente, esto afecta cada día más a los ciudadanos puesto que el transporte urbano hace de las suyas realizando paradas en lugares prohibidos ocasionando a su vez accidentes de tránsito, esto sin tener en cuenta el aumento de la flota vehicular del sector transportes cada año que pasa. se logró implementar un paradero inteligente para mejorar el nivel de satisfacción de usuarios de la empresa de transporte nuevo california de Trujillo, se manejó el tipo de diseño experimental debido al método pre test y post test. Se tomó como muestra aleatoria a 384 usuarios de la empresa nueva california, como técnica de instrumento se realizó encuestas a los usuarios de las distintas rutas de la empresa nueva california. Se concluye que con la implementación de un paradero inteligente se mejoró el nivel de satisfacción de usuarios de la empresa de transporte nuevo california de la ciudad de Trujillo. Además, se tiene el tiempo promedio en conocer las rutas y paraderos de los buses de la empresa de transporte nuevo california actual es de 239.03 segundos (100%) y con el paradero inteligente demora 27.05 segundos (11.32%), obteniendo una reducción de 211.98 segundos representados en 88.68%. en el segundo indicador se determinó que el nivel de satisfacción de los usuarios de la empresa de transporte nuevo california de Trujillo, con el sistema actual es de 2.32 puntos (46.40) y con el paradero inteligente implementado es de 4.90 puntos representado en 98%. Obteniendo un incremento de 2.58 puntos y en un porcentaje del 51.60%. y en el último indicador la implementación del paradero inteligente, el número de papeletas de los buses de transporte de nuevo california de Trujillo con el sistema actual es de 3 papeletas (100%) y con el paradero inteligente se logró obtener 0 papeletas, logrando obtener una reducción del 100% en el número de papeletas

Optimization of a fructooligosaccharides purification method using activated charcoal

Fructooligosaccharides (FOS) have gained large commercial interest due to its beneficial properties in the human health as prebiotics. FOS are produced industrially by fermentative processes. However, the result of such fermentations is a complex mixture containing salts and approximately 50% (w/w) of low molecular weight sugars that have to be eliminated. Among other techniques that have been studied, the adsorption onto activated carbon is still the most suitable one since activated carbon is cheap, has a large surface area and pore volume conducting to a good sorption capacity. Furthermore, this sorbent can be regenerated during desorption with ethanol. Based on the above discussion, in this work the adsorption and desorption characteristics of FOS on activated carbon, using a gradient of ethanol, were optimized. Initially, the activated carbon was loaded with fermentative broth. To remove the non adsorbed sugars, a washing step with pure water was included. Afterwards, the retained sugars were recovered by elution with a gradient of ethanol increased sequentially with specific volumes from 1 to 50% (v/v). Fractions collected at different time points were evaporated and subsequently freeze‐dried. This process was found to be very efficient in the demineralization of broth, and it was possible to recover 80% of the initial FOS loaded on the column with 89% of purity. Some of the fractions were found to contain 97% of pure FOS in total sugars. In summary, purification of FOS using an activated charcoal column is a very efficient process yielding high levels of purity from a fermentative broth

Modeling and simulation of fructo-oligosaccharides production

It is foreseen that Systems Biology will have a great impact not only in Metabolic Engineering and Drug Discovery efforts, but also in Bioprocess development and optimization. In fact, the computational tools developed in this area made possible to simulate a biochemical process with a mathematical model comprising dynamical equations based on first principles as well as empirical kinetic equations and parameters that can be estimated from experimental data. Fructo-oligosaccharides (FOS) have become important as healthy food ingredients because of their beneficial characteristics to the health of human (Lee, 1999). They can be obtained biotechnologically using the enzyme Betafructofuranosidase, produced by some fungi. The main purpose of this work was to develop a mathematical model able to simulate the formation of FOS in a bioreactor, in order to perform a faster optimization of the FOS production process, allowing to identify which parameters can influence the final amount of FOS. An empirical model presented by Kow Jen Duan et al (1994) was used to obtain the first set of reactions. Several hydrolysis equations were added in order to achieve a general mathematical model of the occurring enzymatic reactions. After the reformulation of the Kow Jen Duan model, the kinetic parameters were determined from experimental data using the System Biology toolbox [2] with the Simulated Annealing method for curve fitting. Several experiments in bioreactors were performed with two different FOS producing fungi for that purpose. The time evolution of 7 state variables (Sucrose, Glucose, Fructose, 1-Kestose, Nystose, 1-Fructosyl Nystose and Biomass) was considered. After parameter fitting, several simulations were performed in MatLab and the simulation results were compared with experimental data, exhibiting a very satisfactory correlation for both fungal cultures. Correlation coefficients of 0.9980 - 0.9549 between simulated and experimental data were obtained. This model will be used to optimize the production process, using an optimization tool that has been developed in our research group

Purification of fructo-oligosaccharides by adsorption onto charcoal filters

Production of fructo-oligosaccharides has received particular attention recently due to its beneficial effects as prebiotics. Fermentative processes appear to be a good technique for large scale production of FOS. However, the result of such fermentations is a complex mixture containing salts and low molecular weight sugars that do not contribute to the beneficial properties of the higher molecular weight oligosaccharides, and so have to be eliminated. Among the several strategies being studied to solve this problem, the adorption onto activated carbon is a promising technique that still requires further development. Thus, the aim of this work was the purification of FOS from a fermentation broth using charcoal filters. Microfiltration membranes (0,20 micrometers) were successfully used to separate the biomass; nevertheless salts and other small sugars had to be eliminated using a charcoal filter. Hence, 200 mL of fermentative broth (without cells) was passed through the filter. Subsequently, the filter was washed with water removing the salts and small sugars present in the mixture. The oligosaccharides adsorbed onto the charcoal filter were recovered using a 44% ethanol solution. An increased purity, from 30% to 97% (w/w) in total sugars, was achieved using this downstream process, as compared to the initial mixture. The results gathered in this work suggest that charcoal filters are a promising technology for the purification of FOS from fermentation mixtures at an industrial scale, making clear the need for further work in order to optimize this process

Determination of frutooligosaccharides adsorption parameters using ion-exchange resins

Fructooligosaccharides (FOS) are non-digestible sugars that beneficially affect the host by stimulating the growth of specific bacteria in the colon. In large scale, FOS can be produced from sucrose by fermentation. The fermentative broth obtained from this process is a complex mixture of salts and sugars. These sugar mixtures include FOS, namely kestose (GF2), nystose (GF3) and fructo-furanosylnystose (GF4), but also fructose, glucose and sucrose that must be separated. The major challenge when designing the downstream separation process is the choice of an efficient ion-exchange resin. Therefore, adsorption isotherms of the different compounds on a mixture are an important parameter to consider when selecting the resin. Moreover, salts and other sugars present in the mixture will influence the adsorption. In view of this, in the present work adsorption isotherms of FOS, both from fermentative broths and pure mixtures, were determined for several poly(styrene-co-divinylbenzene) commercial resins in the sodium and calcium forms. A static adsorption-desorption method was used to determine the equilibrium adsorptions. The adsorption isotherms for FOS were appropriately fitted using linear regression models. Since FOS separation is mainly based on size exclusion, GF2 was found to be the most adsorbed sugar in all resins, followed by GF3 and finally GF4. Results demonstrated that there are no significant differences between the adsorption of a pure mixture of FOS and a fermentative broth using the studied commercial calcium resins. However, this was not observed for the sodium form resin. In this later case, the sugars from the fermentative broths were found to be more adsorbed than from the pure mixtures. Results gathered in this study clearly demonstrated the importance of determining the adsorption parameters using real fermentative broths instead of pure mixtures, as the presence of other sugars and salts can influence in the adsorption

Equilibrium properties of a Josephson junction ladder with screening effects

In this paper we calculate the ground state phase diagram of a Josephson Junction ladder when screening field effects are taken into account. We study the ground state configuration as a function of the external field, the penetration depth and the anisotropy of the ladder, using different approximations to the calculation of the induced fields. A series of tongues, characterized by the vortex density $\omega$, is obtained. The vortex density of the ground state, as a function of the external field, is a Devil's staircase, with a plateau for every rational value of $\omega$. The width of each of these steps depends strongly on the approximation made when calculating the inductance effect: if the self-inductance matrix is considered, the $\omega=0$ phase tends to occupy all the diagram as the penetration depth decreases. If, instead, the whole inductance matrix is considered, the width of any step tends to a non-zero value in the limit of very low penetration depth. We have also analyzed the stability of some simple metastable phases: screening fields are shown to enlarge their stability range.Comment: 16 pp, RevTex. Figures available upon request at [email protected] To be published in Physical Review B (01-Dec-96

A dynamical model for the fermentative production of fructooligosaccharides

In this paper a detailed mathematical model is presented for the fermentative production of fructo-oligosaccharides with Aspergillus sp. The model accounts for hydrolysis and transfructolization reactions, as well as biomass formation and it contains 27 parameters that were determined from experimental data using a System Biology toolbox with the Simulated Annealing method for curve fitting. Several additional experiments were performed in bioreactors where the time variation of 7 state variables (Sucrose, Glucose, Fructose, 1-Kestose, Nystose, 1-fructosyl nystose and Biomass) was measured. Experimental data were compared with results from simulations using the estimated parameters and it was verified that the model can predict the FOS production profile. The good agreement between simulated and experimental data was verified by calculating the relative percentage deviation modulus, which was lower than 10% for all cases except one. The derived and validated model can be used for process optimization, for example for indicating which fed-batch strategy could be used to improve the production of FOS while minimizing glucose concentration