Global properties of an age-structured virus model with saturated antibody immune response, multi-target cells and general incidence rate

Some viruses, such as human immunodeficiency virus, can infect several types of cell populations. The age of infection can also affect the dynamics of infected cells and production of viral particles. In this work, we study a virus model with infection-age and different types of target cells which takes into account the saturation effect in antibody immune response and a general non-linear infection rate. We construct suitable Lyapunov functionals to show that the global dynamics of the model is completely determined by two critical values: the basic reproduction number of virus and the reproductive number of antibody response

Multiobjective algorithms to optimize broadcasting parameters in mobile Ad-hoc networks

Congress on Evolutionary Computation. Singapore, 25-28 September 2007A mobile adhoc network (MANETs) is a self-configuring network of mobile routers (and associated hosts). The routers tend to move randomly and organize themselves arbitrarily; thus, the network's wireless topology may change fast and unpredictably. Nowadays, these networks are having a great influence due to the fact that they can create networks without a specific infrastructure. In MANETs message broadcasting is critical to network existence and organization. The broadcasting strategy in MANETs can be optimized by defining a multiobjective problem whose inputs are the broadcasting algorithm's parameters and whose objectives are: reaching as many stations as possible, minimizing the network utilization, and reducing the makespan. The network can be simulated to obtain the expected response to a given set of parameters. In this paper, we face this multiobjective problem with two algorithms: Multiobjective Particle Swarm Optimization and ESN (Evolution Strategy with NSGAII). Both algorithms are able to find an accurate approximation to the Pareto optimal front that is the solution of the problem. ESN improves the results of MOPSO in terms of the set coverage and hypervolume metrics used for comparison

ÍNDICE DE ÁREA FOLIAR, BIOMASA Y RENDIMIENTO DE GIRASOL EN FUNCIÓN DE UREA DE LENTA LIBERACIÓN

Tesis de Licenciatura sobre nutrición vegetalRESUMEN El nitrógeno es un nutrimento que incrementa el crecimiento, índice de área foliar, biomasa, y la fotosíntesis del cultivo, características que permiten al girasol aumentar el rendimiento de semilla por unidad de superficie. El objetivo de la presente investigación fue evaluar el índice de área foliar (IAF), biomasa (BIO) y algunos componentes de rendimiento de girasol en función de urea de lenta liberación (NBPT), en dos localidades del Estado de México. El diseño experimental fue bloques completos al azar con arreglo factorial. Los 16 tratamientos resultaron de las combinaciones de dos localidades, dos cultivares y cuatro niveles de nitrógeno. Los datos se analizaron con ANDEVA y las medias de los tratamientos se compararon con la prueba DSH (p≤0.05). El análisis de resultados indicó que en Chalco el girasol rindió (246.35 g m-2) más que Toluca (214.20 g m-2), debido a un mayor índice de área foliar y producción de biomasa. El cultivar Victoria, con rendimiento promedio de 243.07 g m-2 fue superior a ‘Criollo’ en 11%. La mejor dosis en este estudio fue de 120 kg ha-1 ya que su rendimiento promedio fue 329.88. Se concluye que los componentes de rendimiento fisiológicos: índice de área foliar y biomasa; y los componentes de rendimiento morfológicos: número y peso de 100 semillas explican el rendimiento de grano de girasol. Palabras clave: Helianthus annuus L., fertilización nitrogenada, urea con polímero ABSTRACT Nitrogen is a nutrient which increases growth, leaf area index and crop photosynthesis, characteristics that permit sunflower to increased seed yield per surface unit. The aim of the present study was to evaluate the leaf area index, biomass, yield and principal components as function of slow relase urea, in two localietes of the Estado de Mexico. The experimental design was complete randomized blocks with factorial arrangement. The 18 treatments resulted from the combinations of the two localities, two cultivars and the four nitrogen levels. The data were analyzed with ANOVA and treatments means, were compared with the DSH test (p≤0.05). The analysis of the results indicated that in Chalco the sunflower yielded (214.2 g m-2) more tan Toluca (214.2 g m-2) due to the higher leaf area index and biomass. ‘Victoria’, with average yield of 243.07 g m-2, was higher than ‘Criollo’ by 11%. The best dose in this study was 120 kg ha-1, since its average yield was 329.88. It is concluded that the physiological yield components: leaf area index and biomass; and morphological yield components: number and weight of 100 seeds explain the yield of sunflower grain. Kew words: Helianthus annuus L., nitrogen fertilization, polymer ure

Digital Fishes - An Interactive Virtual Aquarium

This work is supported by AUIP - Asociación Universitaria Iberoamericana de PostgradoThis work describes the creation of an interactive virtual aquarium, Digital Fishes, with a physical representation in a cubic fish tank with synchronized visual information and animated elements, such as fish and vegetation, which can be used for educational purposes. Here the solution to simulate the movement of marine flora and fauna added to our virtual Aquarium is described. An implementation of the fish behavior, to move in groups using the Boids algorithm, is created, in addition to autonomous behaviors such as chasing prey and fleeing from predators, interactive behaviors such as following the finger on the screen and going towards the food that the user may throw in the pond. The solution described in this work has managed to bring into the hands of children an interactive virtual representation of an interactive as one more learning tool at their disposal. These children who participated in the Digital Fishes Interactive Aquarium's evaluation provided positive feedback, showing great enthusiasm and positively assessed the solution

Cell-Type-Specific Profiling of the \u3ci\u3eArabidopsis thaliana\u3c/i\u3e Membrane Protein-Encoding Genes

Membrane proteins work in large complexes to perceive and transduce external signals and to trigger a cellular response leading to the adaptation of the cells to their environment. Biochemical assays have been extensively used to reveal the interaction between membrane proteins. However, such analyses do not reveal the unique and complex composition of the membrane proteins of the different plant cell types. Here, we conducted a comprehensive analysis of the expression of Arabidopsis membrane proteins in the different cell types composing the root. Specifically, we analyzed the expression of genes encoding membrane proteins interacting in large complexes. We found that the transcriptional profiles of membrane protein-encoding genes differ between Arabidopsis root cell types. This result suggests that different cell types are characterized by specific sets of plasma membrane proteins, which are likely a reflection of their unique biological functions and interactions. To further explore the complexity of the Arabidopsis root cell membrane proteomes, we conducted a co-expression analysis of genes encoding interacting membrane proteins. This study confirmed previously reported interactions between membrane proteins, suggesting that the co-expression of genes at the single cell-type level can be used to support protein network predictions

Short-run market access and the construction of better transportation infrastructure in Mexico

We calculate the short-run effect that the construction of the Durango-Mazatlán highway in late 2013 and the Mexico City-Tuxpan highway in early 2014 produced on welfare in every municipality and on market access in every location of Mexico. Our estimates suggest that the former highway produced benefits not only in the region where the new highway is located, but in vast areas in the north of the country. Analogous estimates show that the latter highway mostly benefited regions near Tuxpan, but these focalized benefits were larger than any of the benefits derived from the construction of the Durango-Mazatlán highway. The municipalities in the south of the country have net short-run losses from the infrastructure construction due to losses in competitiveness. Our model is consistent with the observed sectoral growth in Sinaloa, Durango, and Veracruz in 2014. Qualitatively, market access and welfare change in the same direction and magnitudes. We thus recommend using the market access approach for shortrun analysis of infrastructure, because it is much less computationally intensive

Cell-Type-Specific Profiling of the \u3ci\u3eArabidopsis thaliana\u3c/i\u3e Membrane Protein-Encoding Genes

Membrane proteins work in large complexes to perceive and transduce external signals and to trigger a cellular response leading to the adaptation of the cells to their environment. Biochemical assays have been extensively used to reveal the interaction between membrane proteins. However, such analyses do not reveal the unique and complex composition of the membrane proteins of the different plant cell types. Here, we conducted a comprehensive analysis of the expression of Arabidopsis membrane proteins in the different cell types composing the root. Specifically, we analyzed the expression of genes encoding membrane proteins interacting in large complexes. We found that the transcriptional profiles of membrane protein-encoding genes differ between Arabidopsis root cell types. This result suggests that different cell types are characterized by specific sets of plasma membrane proteins, which are likely a reflection of their unique biological functions and interactions. To further explore the complexity of the Arabidopsis root cell membrane proteomes, we conducted a co-expression analysis of genes encoding interacting membrane proteins. This study confirmed previously reported interactions between membrane proteins, suggesting that the co-expression of genes at the single cell-type level can be used to support protein network predictions

Importancia del uso de las plataformas virtuales en la formación superior para favorecer el cambio de actitud hacia las TIC: estudio de caso. Universidad del Magdalena, Colombia

El propósito de la investigación fue analizar el cambio actitudinal en los estudiantes de pregrado acerca del uso de la plataforma virtual como apoyo al desarrollo de un curso de formación disciplinar impartido en la modalidad presencial, considerando los aportes de Vygotsky (1988), Ausubel (1983), Pozo (2001), Coll (2007), Marqués (2001; 2003), Prensky (2001), Vilaseca y Meseguer (2000), entre otros. El estudio corresponde a un estudio de caso, enmarcado en el paradigma cualitativo, que utilizó como técnicas el grupo focal y dos encuestas que permitieron apreciar la opinión de los estudiantes del dominio las TIC y la actitud por el uso de la plataforma virtual como apoyo a la clase presencial o Aprendizaje Semipresencial. Contó con la participación de 35 estudiantes de Licenciatura en Preescolar en la Universidad del Magdalena en Santa Marta (Colombia) en el periodo académico 2012-I. Se evidenció que la interacción presencial no es el único canal comunicativo que garantiza aprendizajes efectivos y más allá del incremento de la habilidad tecnológica en los estudiantes, se contribuyó a elevar la autoestima, a mejorar el tiempo de dedicación en la realización de actividades complementarias a los encuentros presenciales. A los docentes les permite establecer las pautas para participar tanto en el entorno presencial como el virtual, la asignación de ejercicios y trabajos para presentar en cada espacio, los plazos de publicación de actividades y los criterios de evaluación.The purpose of this research was to analyze the attitudinal change in undergraduate students about their use of the virtual platform to support the development of a training course in the classroom, considering the contributions of Vygotsky (1988), Ausubel (1983), Pozo (2001), Coll (2007), Marqués (2001; 2003), Prensky (2001), Vilaseca y Meseguer (2000). Is a case study, framed within the qualitative paradigm, which used as techniques a focus group and two surveys designed to appreciate the opinions and attitudes from the students on the TIC’s in the use of a virtual platform to support the Blended Learning. The research involved 35 undergraduate students of Preschool education in the Universidad del Magdalena in Santa Marta (Colombia) on the first academic period of 2012. It was evident that the clasroom interaction is not the only way of communication that ensures an effective learning and increase the students abilities beyond the tecnological system, improving time commitment in the follow-up activities to face meetings. The research also allowed teachers to establish guidelines to participate not only in the classroom, but on a virtual environment, assignig exercises and assignments to be presented in each space, the due dates of every activity and the evaluation criteria