Visualización del proceso de enseñanza-aprendizaje, apoyado de una interfaz gráfica

186 páginas. Doctorado en DiseñoEn esta tesis se presenta un conjunto de requerimientos obtenidos a partir de un análisis metodológico, con el objetivo de conformar un sistema educativo, haciendo énfasis en el diseño de una interfaz gráfica, en lo sucesivo IG que permita el proceso de enseñanza- aprendizaje de la matemática, en el dominio de las ecuaciones de primer grado con una incógnita. Para tal propósito fue necesario que se abordarán distintos enfoques metodológicos pertenecientes al campo de: 1) Los modelos para el diseño de una interfaz gráfica, 2) Los modelos instruccionales, tomando en consideración las inteligencias múltiples de Gardner, 3) Las metodologías de desarrollo de software educativ

Diseño de un sistema tutorial inteligente

Los problemas de aprendizaje en la matemática a nivel licenciatura se reflejan en el bajo rendimiento escolar o, en el peor de los casos, en el truncamiento de una carrera, por no acreditar asignaturas relacionadas con ésta. Un alto porcentaje de alumnos no cumplen con los requerimientos mínimos en su aprendizaje y, conforme aumentan su comple - jidad, ocurre su rezago e incremento del índice de reprobación, lo que ocasiona en el alumnado angustia y frustración. La investigación se desarrolla en la Unidad Académica Profesional Nezahualcóyotl (UAP-Nezahualcóyotl) de la Universidad Autónoma del Es - tado de México (UAEM), con el objetivo de identificar los problemas en el aprendizaje de la matemática en los alumnos de nivel licenciatura y obtener, así, el modelo del sistema tutorial inteligente en matemáticas con la implementación de los diferentes estilos de aprendizaje

Identification and evaluation of fungal strains with fucoidan degradation potential

Ten fungal strains isolated of Mexican semi-desert were screened for ability to hydrolyze fucoidan in order to search microorganism capable to produce sulfated fucans-degrading enzymes. Plate assay and liquid fermentation experiments were carried out using Laminaria japonica fucoidan as only carbon source, testing three nitrogen sources. Growth was observed only in Aspergillus niger PSH, Mucor sp., and Penicillum purpurogenum GH2 in fucoidan-urea medium. The activity of fucoidanases was determined by reduced sugars. Aspergillus niger PSH showed the highest activity titles. This research indicate that filamentous fungi, using specific medium, are sources enable to induce active metabolism that act toward this class of polysaccharide

El Videojuego. Un enfoque educativo en el área de la matemática

Documento elaborado para ser utilizado como apoyo en el trabajo docente.Con el auge en las modalidades educativas en los últimos tiempos, así como en las propuestas en el modelaje de la elaboración de nuevos materiales didácticos que apoyen el proceso de enseñanza aprendizaje, además del aporte que ofrecen las Tecnologías de la Información y la Comunicación; elementos conjuntos que demandan un cambio de fondo en el diseño de herramientas lúdicas, en cuanto a las metodologías y estrategias educativas, están dando como resultado nuevas formas de enseñar y de aprender. En este sentido, se han realizado diversas acciones para proporcionar recursos educativos, derivados del juego, que apoyen la actividad diaria de docentes-discentes. Es por ello que la propuesta de investigación va encaminada a presentar un videojuego educativo y la manera en que puede estimular el proceso enseñanza-aprendizaje. Todo lo anterior desde la perspectiva de los estilos de aprendizaje de los educandos, tomando en consideración las teorías de Gardner. Para este caso de estudio, se implementó un software denominado MALV en el área de la matemática para la resolución de ecuaciones de primer grado con una incógnita, como apoyo para alumnos de una licenciatura de la UAE

Extraction of sulfated polysaccharides by autohydrolysis of brown seaweed Fucus vesiculosus

The extraction of sulfated polysaccharides (fucoidan) by autohydrolysis (AH) of brown seaweed Fucus vesiculosus was studied. Experimental assays were performed under different conditions of temperature (160 to 200°C) and reaction time (10 to 30 min) according to a 22 central composite design, and the conditions able to maximize the fucoidan yield were selected. The alga degradation and the total sugar yield in the liquor after AH were also determined to each experimental condition. The highest fucoidan yield (∼16.5% w/w) was obtained when the AH process was performed at 180°C for 20 min. This product was characterized by high-performance liquid chromatography, infrared analysis spectroscopy, and thermal gravimetric analyses, which verified the presence of fucose and galactose as main components (70:30% mol ratio, in average) and an SO3 content higher than 20%. AH process under optimum reaction conditions was an effective method to recover fucoidan from F. vesiculosus. The use of this technology brings also important advantages from economical and environmental viewpoints since it does not require the use of chemical solvent and generates less waste when compared to conventional extraction procedures.R.M. Rodriguez-Jasso would like to thank the Mexican Science and Technology Council (CONACYT, Mexico) for Ph.D. fellowship support (grant number 213592/308679). The authors also thank Professor Isabel Sousa Pinto, Rita Araujo PhD from CII-MAR, University of Porto, and Bartolomeu de Souza PhD for the collaboration during the selection and collection of the seaweed used in this study

Microwave-assisted extraction of sulfated fucans from brown seaweed and evaluation of fungal strains for enzymesactive production toward this class of polysaccharide

Sulphated polysaccharides from brown seaweedss comprise a complex group of macromolecules with a wide range of important biological properties such as anticoagulant, antioxidant, antiproliferative, antitumoral, anticomplementary, anti-inflammatory, antiviral, antipeptic and antiadhesive activities. Fucoidan is one of the main sulphated fucan, mostly interesting for their biological activities specially the potential to inhibit HIV reverse transcriptase and the possible application as active compound in antiretroviral drugs. However, algae remain largely unexploited and seaweeds can be found in sufficient amount for the commercial exploitation. Usually, most of the processes to recover sulfated polysaccharides from natural sources consist in acid extractions during long reaction times. Specific enzymes able to degrade fucoidan matrix (fucoidanases) are important tools to establish structural characteristics and biological functions of this polysaccharide. Such enzymes, have been only isolated from marine organisms. Reports of fungal microorganisms with enzymatic activity over this sulfated-polysaccharide are scarce. The aims of the present work were: 1) to recovery of sulphated polysaccharides (fucoidan) by microwave-assisted extraction under different operational conditions and 2) the identification of fungal strains able to growth over fucoidan-based media and to produce active fucoidanases

Kinetic and morphometric evaluation of fucoidan‐degrading fungal strains

Fucoidan is a sulfated fucose hetero‐polysaccharide found in brown algae. This compound has a wide variety of biological activities including anticoagulant, antithrombotic, antitumoral and antiviral (Alexeeva et al. 2002; Ellouali et al. 1993; McClure et al. 1992). Specific enzymes able to degrade fucoidan matrix are important tools to establish structural characteristics and biological functions of this polysaccharide. Such enzymes, called fucoidanases, have been only isolated from marine organisms (Sakai et al. 2004; Giordano et al. 2006). Reports of fungal microorganisms with enzymatic activity over this sulfated‐polysaccharide are scarce. Mycelial growth and morphology of filamentous fungi can be mathematically described by kinetic models, through the estimation of specific growth rate of molds on plates containing target polysaccharide as sole carbon source, using image processing techniques (Loera and Viniegra 1998). In this sense, the aim of this work was to identify fungal strains able to growth over fucoidan media as sources of active fucoidanases, by quantification of kinetic and morphology features, to establish the influence of media composition on growth patterns. Aspergillus niger PSH, Penicillium purpurogenum GH2 and Mucor sp. 3P were the screened strains. Different culture media with and without mineral salts were tested for microbial growth. Fucoidan of Laminaria japonica and urea were used as carbon and nitrogen source. Radial growth rate (Ur) was kinetically monitored measuring colony diameters. Hyphal length (Lav) and diameter (Dh) were quantified by image analyses measurements. All the evaluated strains were able to growth on different fucoidan‐urea media, and their plate invasion capacity and radial growth rate were directly proportional to measured morphometric parameters. The three fungi strains synthesize acting metabolites toward fucoidan matrix, and are important tools for the synthesis of sulfated fucan‐degrading enzymes. These results are, until now, the first report of enzymes able to growth and degrade fucoidan obtained by terrestrial fungus

Microwave-assisted extraction of sulfated polysaccharides(fucoidan)from brown seaweed

Sulfated polysaccharides (fucoidan) were recovered from brown seaweed Fucus vesiculosus by microwave-assisted extraction (MAE). Different conditions of pressure (30 to 120 psi), extraction time (1 to 31 min), and alga/water ratio (1/25 to 5/25 g ml-1) were evaluated during this process aiming to establish a condition to maximize the extraction results. The alga degradation (%), total sugar yield (%), and SO3 content (%) were also determined to each experimental condition. All the studied variables presented significant (p<0.05) influence on fucoidan yield. MAE at 120 psi, 1 min, using 1 g alga/25 ml water was the best condition for the fucoidan recovery. L-fucose was the main constituent of this polysaccharide, which also contained xylose and galactose. MAE under optimum reaction conditions was an effective method to recover fucoidan from Fucus vesiculosus. This method required short extraction times, and non corrosive solvents, resulting in reduced costs and being an environmentally friend technique.The financial support from Mexican Science and Technology Council (CONACYT, grant number: 2066071230415) and the Portuguese Foundation for Science and Technology (FCT) are gratefully acknowledged. The authors also thank Bruna Fonseca and Professor Teresa Tavares for the accessibility to the microwave assisted equipment; and Professor Isabel Sousa Pinto and Rita Araujo from CIIMAR - Interdisciplinary Centre of Marine and Environmental Research for facilitate the algae selection