A test of the predictive validity of non-linear QALY models using time trade-off utilities

This paper presents a test of the predictive validity of various classes of QALY models (i.e., linear, power and exponential models). We first estimated TTO utilities for 43 EQ-5D chronic health states and next these states were embedded in health profiles. The chronic TTO utilities were then used to predict the responses to TTO questions with health profiles. We find that the power QALY model clearly outperforms linear and exponential QALY models. Optimal power coefficient is 0.65. Our results suggest that TTO-based QALY calculations may be biased. This bias can be avoided using a power QALY model.Cost-utility analysis, QALYs, power QALY model, predictive validity, time tradeoff, Leex

Restricted gene flow and genetic drift in recently fragmented populations of an endangered steppe bird

Identifying the genetic processes derived from habitat fragmentation is critical for the conservation of endangered species. We conducted an integrated analysis of genetic patterns in the endangered Dupont’s lark (Chersophilus duponti), a circum-Mediterranean songbird threatened by the loss and fragmentation of natural steppes in recent decades. After sampling all the remaining Spanish populations and the two clos¬est North African ones, we found that the Mediterranean Sea acts as a major barrier against gene flow and that recent habitat fragmentation is isolating Spanish populations at different spatial scales. While we found a historical signal of gene flow among Spanish regions, a coalescent model supported that the ancestral panmictic population is evolving into several different units in the absence of current gene flow, genetic drift being more intense in the smaller and more isolated populations. Moreover, small-scale spa¬tial autocorrelation analyses showed that genetic differentiation is also acting within populations. The spatial genetic structure, significant levels of inbreeding and high relatedness within patches raise con¬cerns on the viability of most of the extant populations. We highlight the urgency for steppe patches to be protected, expanded and reconnected, considering the genetic clusters identified here rather than the previously considered eco-geographic regions occupied by the species. Meanwhile, translocations could be considered as a complementary, faster management action to attenuate the crowding and genetic effects of population fragmentation and the extinction risk of small populations without compromising the current local adaptations, culture diversity and genetic clusters already known for the species.Peer Reviewe

Supporting teachers in collaborative student modeling: a framework and an implementation

Collaborative student modeling in adaptive learning environments allows the learners to inspect and modify their own student models. It is often considered as a collaboration between students and the system to promote learners’ reflection and to collaboratively assess the course. When adaptive learning environments are used in the classroom, teachers act as a guide through the learning process. Thus, they need to monitor students’ interactions in order to understand and evaluate their activities. Although, the knowledge gained through this monitorization can be extremely useful to student modeling, collaboration between teachers and the system to achieve this goal has not been considered in the literature. In this paper we present a framework to support teachers in this task. In order to prove the usefulness of this framework we have implemented and evaluated it in an adaptive web-based educational system called PDinamet.Postprint (author's final draft

El modelo turístico andaluz: una propuesta cultural

El objetivo de este trabajo es analizar las aportaciones pioneras que Andalucía tuvo en la construcción del turismo moderno. Desde las primeras décadas del siglo XIX, el negocio que comenzaba a generar la llegada de visitantes interesó a eruditos y autoridades locales, sumándose el Estado, a partir de 1905, al fomento del turismo con la creación de los primeros organismos oficiales. Durante más de cien años se mantuvo el rasgo común de la utilización de la cultura andaluza como el principal atractivo de su desarrollo turístico. Este modelo se consolidó con la Exposición Iberoamericana de 1929, con la que se terminó de dar forma a la atracción europea por una Andalucía, vista como un Oriente al sur de Europa.This paper analyzes the pioneering contributions that Andalusia had in the modern tourism’s origin. From the first decades of century XIX, the business that began to generate the arrival of visitors interested to local authorities, adding the State, as of 1905, to the promotion of the tourism with the creation of the first official organisms. For more than one hundred years the common characteristic of the use of the culture stayed main Andalusian like the attractiveness of its tourist development. This model was consolidated with the American Exhibition of 1929, where Andalusia became a tourist destiny in the south of Europe

Las ciencias sociales y la política en Puerto Rico.

The purpose of this essay is the analysis of the relationship between the development of the social sciences and the political process in Puerto Rico. This relationship has three fundamental moments. In the first moment we have the initial manifestations of nineteenth-century Puerto Rican social scientific thought in confrontation with Spanish colonial policy. We have also in this period the military conquest of Puerto Rico by the United States and the utilization of religion and the public education system as intellectual tools of Manifest Destiny ideology. In the second period Puerto Rico goes through a process of government sponsored modernization and industrialization. Operation Bootstrap brings many social scientists from the U.S to our country, whose works will have an important impact on Puerto Rican politics. The beginnings of the third period coincide with the weakening of the process of economic development in the island. This is the moment when U.S. social scientists start to be replaced by Puerto Rican professors and researchers.El propósito de este ensayo es analizar la relación entre el desarrollo de las ciencias sociales en Puerto Rico y el proceso político puertorriqueño. Esa relación pasa por tres momentos fundamentales. En la primera etapa, tienen lugar las primeras manifestaciones del pensamiento científico social decimonónico puertorriqueño frente a la política colonial española en nuestra isla. También ocurre durante ese periodo, la toma de Puerto Rico como botín de guerra por los Estados Unidos y la utilización de la religión y del sistema educativo como auxiliares intelectuales de la ideología del Destino Manifiesto. En el segundo periodo, Puerto Rico inicia el proceso de modernización e industrialización impulsado por la Operación Manos a la Obra, lo cual trae a nuestro país un número considerable de científicos sociales estadounidenses, cuyos trabajos tendrán un impacto muy importante en la política puertorriqueña. Cuando el proceso de desarrollo económico de Puerto Rico comienza a decaer se inicia el tercer y último periodo analizado, el cual es el momento en que se produce el relevo de los científicos sociales estadounidenses por profesores e investigadores puertorriqueños

Mejora de la productividad en el proceso de grasas, en fábrica Nestlé, Antigua Guatemala, Sacatepéquez

Mejorar la productividad en el proceso de grasas en la fábrica Nestlé, mediante la implementación de procedimientos y redistribución de la maquinaria utilizada, así generar un sistema que permita un ahorro considerable de agua en los lavamanos de la fábrica, como parte de protección al medio ambiente y crear un plan de capacitación que se adecúe a la capacidad del personal que labora en el área de grasas de la fábrica

Joint effects of population size and isolation on genetic erosion in fragmented populations: finding fragmentation thresholds for management

Size and isolation of local populations are main parameters of interest when assessing the genetic consequences of habitat fragmentation. However, their relative influence on the genetic erosion of local populations remains unclear. In this study, we first analysed how size and isolation of habitat patches influence the genetic variation of local populations of the Dupont's lark (Chersophilus duponti), an endangered songbird. An information-theoretic approach to model selection allowed us to address the importance of interactions between habitat variables, an aspect seldom considered in fragmentation studies, but which explained up to 65% of the variance in genetic parameters. Genetic diversity and inbreeding were influenced by the size of local populations depending on their degree of isolation, and genetic differentiation was positively related to isolation. We then identified a minimum local population of 19 male territories and a maximum distance of 30km to the nearest population as thresholds from which genetic erosion becomes apparent. Our results alert on possibly misleading conclusions and suboptimal management recommendations when only additive effects are taken into account and encourage the use of most explanatory but easy-to-measure variables for the evaluation of genetic risks in conservation programmes.Peer Reviewe