Integrable systems on S3

We classify the links of basic periodic orbits of integrable vector fields on S3 generalizing results on two degree of freedom Hamiltonian systems. We also study the case of completely integrable systems and define invariants for the two classes of vector fields

Bott Integrable Hamiltonian Systems on S2 x S1

In this paper, we study the topology of Bott integrable Hamiltonian flows on S2 × S1 in terms of some types of periodic orbits, called NMS periodic orbits. The set of these periodic orbits can be identified by means of some operations applied on global and local links. These operations come from the round handle decomposition of these systems on S2 × S1. We apply the results to obtain a non-integrability criterium. 1. Introduction. Let v = sgrad (H) be a hamiltonia

Impacto en la calidad de vida en relación con la adherencia a dieta libre de gluten en pacientes con enfermedad celíaca

La enfermedad celiaca es una enfermedad autoinmune, que se caracteriza principalmente por la intolerancia a proteínas contenidas en el gluten tales como gliadina, gluteninas, principalmente, en individuos genéticamente predispuestos, y cuyo único tratamiento es la dieta libre de gluten de manera estricta y permanente. La enfermedad posee una gran variedad de características clínicas siendo las más frecuentes: diarrea, pérdida de peso, anemia, entre otros. La edad de inicio de estos síntoma s puede ser variable, siendo la adulta la más común, con inicio de ellos en un pico de 33-45 años de edad. La prevalencia de esta enfermedad a nivel mundial es de difícil estimación pero se calcula que se encuentra dentro de 1-2% de la población mundial, teniendo una relación mujer a hombre de 2:1. El único tratamiento para esta enfermedad es la dieta libre de gluten que conlleva una gran cantidad de retos para el paciente, todos ellos alterando su estilo de vida de manera positiva o negativa, por tanto en el presente trabajo se buscó identificar el impacto que tiene en la calidad de vida la adherencia a la dieta libre de gluten en los pacientes celiacos pertenecientes a la Asociación Celíacos y Sensibles al gluten de El Salvador (ACELYSES) en el periodo de mayo a septiembre de 2016. Para determinar esta relación se utilizó el cuestionario CDAT (Test de Adherencia a la Dieta libre de gluten) y el cuestionario SF36 para evaluar la calidad de vida, dividida tanto en componente físico como mental, y así identificar el impacto que tiene la adherencia a la dieta libre de gluten en la calidad de vida de los pacientes de esta investigación.Tesis presentada para optar al título de Doctorado en Medicin

Changes in guests’ hotel evaluations due to covid-19: The case of the world heritage city of Cuenca

Purpose - The COVID-19 pandemic has had an unprecedented impact on the tourism sector changing the guest satisfaction during hotel stays. In this paper, we analyse how this perception has changed considering various pandemic stages. Methodology - Using 1595 reviews for hotels in Cuenca left on the Booking platform, we analyse the changes in the ratings of the stay and identify the factors that have the greatest influence on customer satisfaction and dissatisfaction by conducting a ANOVA analysis. We also consider the urban/rural area, type of traveler, nationality, gender and room type. Findings - he main results show an improvement in guest ratings after the worst moments of the pandemic, albeit with lower scores than in 2019 and 2020, indicating that the services offered by the hotel are key elements for customer satisfaction. Therefore, hotel managers should continue on the path taken, as it seems to be producing results, and try to enhance the services offered to guests. Originality - The outbreak of the COVID -19 pandemic necessitates a detailed analysis of the changes in hotel ratings and hotel characteristics evaluated positively and negatively by guests. However, a review of the literature reveals a gap in this regard, especially when considering different points in time during the pandemic

An upper bound of the index of an equilibrium point in the plane

El títol de la versió pre-print de l'article és: On the Loewner conjectur

Liquid fuels from biomass: An energy self-sustained process integrating H2 recovery and liquid refining

[EN] In the last years the research activities on biomass valorisation (mainly residues from urban and agricultural activities) have been intensified. Biomass is an abundant resource for energy generation and its extensive utilization may make possible to fulfil the goals determined by the national and international regulations about renewable sources and greenhouse gas emissions. In this work, simulations are carried out using ASPEN PLUS for an integrated process to produce liquid fuels from biomass in a self-sustainable energetic regime (thermal and electric) and several process factors have been considered. The process initially combines a primary pyrolysis reactor associated to a (char + gases) gasification unit in order to optimize the biomass use, followed by downstream processes to enhance the quality of final liquid fuel. The factors studied were the composition of the biomass, the primary (or pyrolytic) liquid yield, the composition of the liquid fuel, as well as the amount of the oxidant and steam used in the primary char-gasifier reactor. The use of a simplified model for liquid fuel composition let us to stablish a range of operational conditions in which both thermal and electric balance of the process are favourable. In this sense, the maximum extraction of liquid fuel was found around 20-25% by working at 10-25% of O-2 (as pure oxygen or air) and 15-45% of steam in the gasifier and fulfilling self-sustainable process condition, while biomass should possess C/O weight ratios >= 1.Financial support by the Spanish Government (ENE2014-57651, CTQ2015-67592, and SEV-2016-0683 grants) is gratefully acknowledged.D. Catalán-Martínez; Domine ., ME.; Serra Alfaro, JM. (2018). Liquid fuels from biomass: An energy self-sustained process integrating H2 recovery and liquid refining. Fuel. 212:353-363. https://doi.org/10.1016/j.fuel.2017.10.014S35336321

The evolution of agrarian prices received and paid by the farmers in Spain (2000-2009)

La evolución de los precios de los alimentos en años recientes se ha evaluado en numerosos estudios considerando: el análisis de los márgenes comerciales y la evolución temporal de los precios, si bien, la mayoría de ellos centrados en la óptica del consumidor. En este artículo se analizó la evolución temporal de los precios de los alimentos en España en el período 2000-2009 desde el punto de vista del agricultor y ganadero. Concretamente se utilizó información relacionada con los precios percibidos, precios pagados y el índice de precios de consumo (IPC), y con técnicas de análisis de series temporales se analizó la existencia de relaciones de equilibrio a largo plazo entre las series. Los resultados reflejan una relación de equilibrio a largo plazo entre: los precios percibidos y pagados; el IPC y los precios percibidos. Las principales conclusiones muestran que, a pesar de los desequilibrios existentes a corto plazo, a largo plazo los precios percibidos y pagados tienden a una situación de equilibrio. Un elemento importante en la evolución del IPC lo constituyen los precios percibidos por los productos en el sector primario. Sin embargo, la fijación de los precios de los insumos (pagados) en el sector primario; lejos de regirse en el largo plazo por la evolución del IPC; no muestra una relación significativa con dicho indicador.The recent evolution of the foods prices has been evaluated in several studies considering: the commercial margins analysis and the prices temporal evolution although more of them have been developed using the consumer optics. In this paper, the temporal evolution of the foods prices in Spain has been analysed in the period 2000-2009 considering the farmer optics. Concretely, information in relation with the prices received by the farmers, the prices paid by them and the consumer price index (CPI) has been used. Then, using a time series analysis, the long run relationships between series have been analysed. The results show a long run balance between the prices received and paid by the farmer and between the CPI and the received prices. The main conclusions show that, in spite of the existing imbalances in the short term, in the long term the received and paid prices tend to a balance situation. An important element in the evolution of the CPI is the prices received by the products in the primary sector. Nevertheless, the inputs price fixation in the primary sector in the long term does not show a significant relationship with the CPI.Fil: Andrés Martínez, María Encarnación. Universidad de Castilla-La Mancha. Facultad de Ciencias Económicas y Empresariales de Albacete.Fil: Alfaro Navarro, José Luis. Universidad de Castilla-La Mancha. Facultad de Ciencias Económicas y Empresariales de Albacete.Fil: López Ruiz, Víctor Raúl. Universidad de Castilla-La Mancha. Facultad de Ciencias Económicas y Empresariales de Albacete