The Catalonian Conflict : an Interpretive Structural Model

The methodology ISM (Interpretive Structural Modeling) is used to study the conflict in Catalonia, listing a listof factors and the influences between them, building from them the Matrix of Influences and the Matrix of Scope, fromwhich they classify the factors into levels and a flow diagram is drawn up, concluding what the possible paths of evolutionof said conflict would b

Approximate reduction of nonlinear discrete models with two time scales

The aim of this work is to present a general class of nonlinear discrete time models with two time scales whose dynamics is susceptible of being approached by means of a reduced system. The reduction process is included in the so-called approximate aggregation of variables methods which consist of describing the dynamics of a complex system involving many coupled variables through the dynamics of a reduced system formulated in terms of a few global variables. For the time unit of the discrete system we use that of the slow dynamics and assume that fast dynamics acts a large number of times during it. After introducing a general two-time scales nonlinear discrete model we present its reduced accompanying model and the relationships between them. The main result proves that certain asymptotic behaviours, hyperbolic asymptotically stable (A.S.) periodic solutions, to the aggregated system entail that to the original system

Informalidad y evasión de impuestos de los pequeños negocios del Mercado Huamantanga, Puente Piedra 2020

La presente investigación tuvo como objetivo general determinar la relación que existe entre la informalidad y evasión de impuestos, de los pequeños negocios del mercado Huamantanga, la acción ilícita de los pequeños negocios, la fiscalización y la Administración Tributaria de los pequeños negocios del mercado Huamantanga. La metodología fue de tipo aplicada, de nivel cuantitativo y diseño no experimental. La muestra de estudio consta de 40 personas que tengan actividad comercial en el Mercado Huamantanga, los resultados de acuerdo a las estadísticas realizadas, fueron que el valor de Rho de Spearman es 0.591 lo que indica una Correlación positivo Moderada y la significancia bilateral (p= 0.00<0.01) comparado con el α = 0.05 que indica que se acepta la hipótesis alterna y se rechaza la hipótesis nula. Se concluyó que la informalidad tiene relación con la evasión de impuestos de los pequeños negocios del mercado Huamantanga Puente Piedra 2020, puesto que, al examinar el resultado se estableció que la correlación entre la informalidad y la evasión de impuestos es positiva moderada, por lo que, si existe un mayor número de comercios informales, incrementará los niveles de evasión tributaria

Guideline for dialysate quality of Spanish Society of Nephrology (second edition, 2015)

A Best Practice Guideline about Dialysis fluid purity was developed under the leadership of the Spanish Society of Nephrology in 2004. The second edition revised Guideline considered new evidences and International Standard. The Guideline has established recommen- dations for standards for preparing dialysate: water, concentrates and hemodialysis proportioning systems. This Guideline is based on the ISO 13959, European Pharmacopoeia, the Real Farmacopea Española, the AAMI Standards and Recommended Practices, Euro- pean Best Practice Guidelines for Haemodialysis, literature reviews, according to their level of evidence, and the opinion of the expert Spanish group. Two levels of quality of water were defined: purified water and high purified water (ultra pure) and for dialysate: ultra pure dialysate. Regular use of ultra pure dialysate is recom- mended for all type of hemodialysis to prevent and delay the occurrence of complications: inflammation, malnutrition, anaemia and amiloidosis. Water, concentrates and dialysate quality requirements are defined as maximum allowa- ble contaminant levels: chemicals (4.1.2), conductivity, microbial and endotoxins (4.1.1): Monitoring frequency, maintenance and corrective actions were specified. Methods of sampling and analysis were described in appendix (anexos). For microbiological monitoring, R2A medium is recommended, incubated during 7-14 days at a temperature of 17-23 °C. The dialysate quality assurance process involves all dialysis staff members and requires strict protocols. The physician in charge of hemodialysis has the ultimate responsibility for dialysate quality

Reduction of Discrete Dynamical Systems with Applications to Dynamics Population Models

In this work we review the aggregation of variables method for discrete dynamical systems. These methods consist of describing the asymptotic behaviour of a complex system involving many coupled variables through the asymptotic behaviour of a reduced system formulated in terms of a few global variables. We consider population dynamics models including two processes acting at different time scales. Each process has associated a map describing its effect along its specific time unit. The discrete system encompassing both processes is expressed in the slow time scale composing the map associated to the slow one and the k-th iterate of the map associated to the fast one. In the linear case a result is stated showing the relationship between the corresponding asymptotic elements of both systems, initial and reduced. In the nonlinear case, the reduction result establishes the existence, stability and basins of attraction of steady states and periodic solutions of the original system with the help of the same elements of the corresponding reduced system. Several models looking over the main applications of the method to populations dynamics are collected to illustrate the general results

Land use change in a Mediterranean metropolitan region and its periphery: Assessment of conservation policies through CORINE land cover data and Markov models

Sustainable territorial management requires reliable assessment of the impact of conservation policies on landscape structure and dynamics. Euro-Mediterranean regions present a remarkable biodiversity which is linked in part to traditional land use practices and which is currently threatened by global change. The effectiveness of one-decade conservation policies against land use changes was examined in Central Spain (Madrid Autonomous Community). A Markov model of landscape dynamics was parameterized with CORINE Land Cover information and transition matrices were obtained. The methods were applied in both protected and unprotected areas to examine whether the intensity and direction of key land use changes &mdash;urbanisation, agricultural intensification and land abandonment&mdash; differed significantly depending on the protection status of those areas. Protected areas experienced slower rates of agricultural intensification processes and faster rates of land abandonment, with respect to those which occurred in unprotected areas. It illustrates how simple mathematical tools and models &mdash;parameterized with available data&mdash; can provide to managers and policy makers useful indicators for conservation policy assessment and identification of land use transitions

An Unprecedented Aggregation of Whale Sharks, Rhincodon typus, in Mexican Coastal Waters of the Caribbean Sea

Whale sharks, Rhincodon typus, are often perceived as solitary behemoths that live and feed in the open ocean. To the contrary, evidence is accumulating that they are gregarious and form seasonal aggregations in some coastal waters. One such aggregation occurs annually north of Cabo Catoche, off Isla Holbox on the Yucatán Peninsula of Mexico. Here we report a second, much denser aggregation of whale sharks (dubbed “the Afuera”) that occurs east of the tip of the Yucatán Peninsula in the Caribbean Sea. The 2009 Afuera event comprised the largest aggregation of whale sharks ever reported, with up to 420 whale sharks observed in a single aerial survey, all gathered in an elliptical patch of ocean approximately 18 km2. Plankton studies indicated that the sharks were feeding on dense homogenous patches of fish eggs, which DNA barcoding analysis identified as belonging to little tunny, Euthynnus alletteratus. This contrasts with the annual Cabo Catoche aggregation nearby, where prey consists mostly of copepods and sergestid shrimp. Increased sightings at the Afuera coincide with decreased sightings at Cabo Catoche, and both groups have the same sex ratio, implying that the same animals are likely involved in both aggregations; tagging data support this idea. With two whale shark aggregation areas, high coastal productivity and a previously-unknown scombrid spawning ground, the northeastern Yucatán marine region is a critical habitat that deserves more concerted conservation efforts

Construyendo franklab: una plataforma web de robótica educativa

El movimiento CS for All ha logrado captar la atención durante los últimos años. En este contexto se evidencia la necesidad de desarrollar recursos didácticos específicos al campo de la Educación en Ciencias de la Computación que posibiliten una mejor aproximación de la disciplina al ámbito de la educación obligatoria. En este trabajo se presenta una plataforma Web de robótica educativa, FrankLab, diseñada para favorecer el desarrollo de los procesos de enseñanza y de aprendizaje de conceptos y prácticas en el área Algoritmos y Lenguajes de Programación durante toda la educación obligatoria. FrankLab es un entorno de programación en línea que permite a estudiantes de escuelas primarias y secundarias programar robots educativos de la familia Frankestito. Dicho ambiente está compuesto por un conjunto de herramientas de programación que soporta Programación Tangible, Programación Basada en Bloques y Programación basada en texto, como Python. Los estudiantes ejecutan sus programas desde un navegador web sobre robots físicos o sobre un ambiente simulado.VII Workshop Innovación en Educación en Informática (WIEI)Red de Universidades con Carreras en Informática (RedUNCI