Labour flexibility and productivity in the hotel sector

In this paper, we analyze the effect of labour flexibility on productivity in the Andalusian hotel industry using raw data of our own database and applying an expanded version of the standard production function by distinguishing between part-time, temporary, and full-time labour inputs. Our results show that productivity is lower the higher the percentage of temporary and part-time workers and there are no differences between the impacts on productivity of both types of labour contract. Future studies should analyze the differential impact of all the types of contracts discussed on the mean cost per employee in this sector.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

When omnigeneity fails

A generic non-symmetric magnetic field does not confine magnetized charged particles for long times due to secular magnetic drifts. Stellarator magnetic fields should be omnigeneous (that is, designed such that the secular drifts vanish), but perfect omnigeneity is technically impossible. There always are small deviations from omnigeneity that necessarily have large gradients. The amplification of the energy flux caused by a deviation of size $\epsilon$ is calculated and it is shown that the scaling with $\epsilon$ of the amplification factor can be as large as linear. In opposition to common wisdom, most of the transport is not due to particles trapped in ripple wells, but to the perturbed motion of particles trapped in the omnigeneous magnetic wells around their bounce points.Comment: 6 pages, 2 figure

SLBN: A Scalable Max-min Fair Algorithm for Rate-Based Explicit Congestion Control

The growth of the Internet has increased the need for scalable congestion control mechanisms in high speed networks. In this context, we propose a rate-based explicit congestion control mechanism with which the sources are provided with the rate at which they can transmit. These rates are computed with a distributed max-min fair algorithm, SLBN. The novelty of SLBN is that it combines two interesting features not simultaneously present in existing proposals: scalability and fast convergence to the max-min fair rates, even under high session churn. SLBN is scalable because routers only maintain a constant amount of state information (only three integer variables per link) and only incur a constant amount of computation per protocol packet, independently of the number of sessions that cross the router. Additionally, SLBN does not require processing any data packet, and it converges independently of sessions' RTT. Finally, by design, the protocol is conservative when assigning rates, even in the presence of high churn, which helps preventing link overshoots in transient periods. We claim that, with all these features, our mechanism is a good candidate to be used in real deployments

GPU NTC Process Variation Compensation with Voltage Stacking

Near-threshold computing (NTC) has the potential to significantly improve efficiency in high throughput architectures, such as general-purpose computing on graphic processing unit (GPGPU). Nevertheless, NTC is more sensitive to process variation (PV) as it complicates power delivery. We propose GPU stacking, a novel method based on voltage stacking, to manage the effects of PV and improve the power delivery simultaneously. To evaluate our methodology, we first explore the design space of GPGPUs in the NTC to find a suitable baseline configuration and then apply GPU stacking to mitigate the effects of PV. When comparing with an equivalent NTC GPGPU without PV management, we achieve 37% more performance on average. When considering high production volume, our approach shifts all the chips closer to the nominal non-PV case, delivering on average (across chips) ˜80 % of the performance of nominal NTC GPGPU, whereas when not using our technique, chips would have ˜50 % of the nominal performance. We also show that our approach can be applied on top of multifrequency domain designs, improving the overall performance

HABLANDO DE TRABAJO COLABORATIVO CON LOS INDÍGENAS NASA

RESUMEN ANALÍTICO  Una de las metas de la educación superior es la proyección social, es decir, buscar el beneficio de la sociedad con el trabajo que se desarrolla en la academia, lamentablemente, esta premisa no se cumple muy a menudo debido al amplio trabajo que esto implica. El ámbito social es, sin embargo, una de las áreas de investigación y trabajo más interesantes de abordar, pues ofrece nuevos retos y desafíos para la aplicación de la tecnología y de la ingeniería, más aun cuando se trata de un área poco trabajada como son las comunidades indígenas. Es en este campo donde se desarrollará este artículo, la labor con las comunidades indígenas de Colombia y de forma más especifica la Comunidad Indígena Nasa, en el resguardo de Corinto López – Adentro, perteneciente al departamento del Cauca en Colombia. En este documento se pretende socializar la investigación realizada sobre los procesos de tipo colaborativo que se evidenciaron en dicha comunidad gracias a un proceso de investigación de más de un año y que sirvió de soporte al desarrollo del proyecto de pregrado “Modulo de Colaboración para la Comunidad Virtual de Apoyo a los Procesos de Etnoeducación de la Comunidad Indígena Nasa”. Se presentará así en este documento el proceso de consulta realizado tanto en la comunidad nasa como con la bibliografía existente, que contribuyó a recolectar el soporte teórico necesario para la selección de la estrategia más adecuada para la comunidad nasa y su posterior adaptación a las particularidades de dicha comunidad indígena. PALABRAS CLAVES: Comunidad, Comunidad Indígena, Comunidad Virtual, Indígenas Nasa, Colaboración,Cooperación, Etnoeducación  ANALYTICAL SUMMARY One of the main goals of college education is focused on social work, which is, always looking for the benefit of the society by means of academic works. Unfortunately, to carry out this assumption successfully is sometimes difficult due to all the hard work it implies. The social field is, however, one of the most interesting areas of doing research and work because it offers a wide variety of new challenges to implement technology and engineering applications. Even more, when referring to work with indigenous communities where little field work has been done. This article will be developed in this environment, working with the indigenous communities in Colombia, mainly with the Nasa indigenous community in the Resguardo de Corinto Lopez – Adentro, which belongs to the Department of Cauca in Colombia. The present paper focuses on the socialization of this research based on the collaborative processes that were found in the target community through a process of investigation that lasted at least more than a year and that helped as well to support the development of the project “Modulo de Colaboración para la Comunidad Virtual de Apoyo a los Procesos de Etnoeducación de la Comunidad Indígena Nasa”. This paper will also contain the reference process done in the Nasa Community as well as the one related to the existing bibliography, which helped to gather the necessary theoretical support to choose the most appropriate strategy for this community and a subsequent planning design of an strategy fitted to the indigenous community requirements. KEYWORDS: Community, Virtual community, Indigenous society, Nasa Indigenous, Collaborative, Cooperative, Ethnic Education

Prótesis endovascualres (Stent Grafts) en el tratamiento de los aneurismas de aorta abdominal

Los objetivos del informe son producir una síntesis ordenada acerca del conocimiento existente sobre la seguridad y eficacia de las prótesis endovasculares con injerto (PEVIs) en el tratamiento de los AAA de naturaleza arterioesclerótica. Establecer una serie de recomendaciones respecto del uso apropiado de esta tecnología en el contexto español.Introducción, Objetivos del informe, Método de elaboración Definición y contexto, Clínica e historia natural de la enfermedad, Diagnóstico, Epidemiología e importancia sanitaria de los AAA, Tratamiento quirúrgico de los AAA, Tratamiento endovascular de los AAA, Resultados de la experiencia clinica disponibles, Síntesis global de resultados, Comparación de resultados del tratamiento endovascular con el, Conclusiones, Recomendaciones, Bibliografía, Tablas

Alimentos funcionales para cerdos al destete

A functional food is a compound that, being or not a nutrient, has a positive effect on one or several functions in the organism, producing well-being in the animal. The following compounds are considered functional foods: prebiotics, probiotics, symbiotics, antioxidants, secondary products of plant metabolism, structural lipids, polyunsaturated fatty acids, fat metabolism byproducts, bioactive peptides, fi ber, vitamins and minerals. Prebiotics, probiotics and symbiotics are modifi ers of the intestinal microfl ora increasing mainly lactobacilli and bifi dobacteria populations and reducing pathogenic bacteria. Lactobacilli and bifi - dobacteria use oligosaccharides and fructo-oligosaccharides arriving at the colon, producing fatty acids and freeing minerals to be absorbed and utilized by the host. Prebiotics are partially-digestible oligosaccharides; probiotics are microorganisms (mainly lactobacilli and bifi dobacteria); and symbiotics are a mixture of probiotics and prebiotics. During the weaning period, piglets face dramatic changes in feeding management and environment, affecting feed intake and, at the same time, affecting digestive functions resulting in lower growth and higher incidence of disease, mainly diarrhea. Functional food may be an alternative to reduce the effects of weaning on growth performance and health of piglets, to diminish or to avoid gastrointestinal problems during weaning, preventing the proliferation of pathogenic bacteria, and improving digestive functions. All these may help to withdraw antibiotics from piglet feed

Contribution of the single photon emission computed tomography with 99mTc red blood cells in splenosis

The term splenosis refers to the presence of auto-transplanted splenic tissue in a heterotopic location. These foci can be localized to the liver simulating a malignant lesion. Sometimes these lesions are difficult to identify using conventional imaging techniques (ultrasound, CT and MR). Then, a scan with denatured erythrocytes marked with 99mTc has proven to be an effective technique to confirm the diagnosis of splenosis and to establish its extension. The incorporation of hybrid imaging techniques (SPECT-CT) into usual clinical practice has increased the precision of the localization of these foci of splenosis. We hereby report the cases of two patients diagnosed with splenosis, the first by laparotomy and the second after performing scintigraphy with red blood cells labeled with 99mTc. In the first case, the laparotomy revealed numerous reticulated nodules on the diaphragmatic peritoneal surface, the transverse colon and the right kidney. Finally, the anatomopathological diagnosis confirmed a case of splenosis. In the second case, the results of the 99mTc marked red blood cell gammagraphy and SPECT-CT were consistent with the diagnosis of splenosis in the patient. To obtain correct information in cases of lesions highly suspicious of splenosis, 99mTc marked red blood cell gammagraphy should be performed due to the high sensitivity and specificity of the test. Combined diagnostic imaging (SPECT-CT), have increased the specificity of this test due to improvements in the characterization of lesions. We believe that the use of this technique will help avoid unnecessary surgical procedures

Direct and correlated responses to artificial selection for growth and water-use efficiency in a Mediterranean pine

Premise: Persistence of tree populations in the face of global change relies on their capacity to respond to biotic and abiotic stressors through plastic or adaptive changes. Genetic adaptation will depend on the additive genetic variation within populations and the heritability of traits related to stress tolerance. Because traits can be genetically linked, selective pressure acting on one trait may lead to correlated responses in other traits. Methods: To test direct and correlated responses to selection for growth and drought tolerance in Pinus halepensis, we selected trees in a parental population for higher growth and greater water-use efficiency (WUE) and compared their offspring with the offspring of random trees from the parental population in two contrasting common gardens. We estimated direct responses to selection for growth and WUE and correlated responses for growth and tolerance to abiotic and biotic stressors. Results: We found a strong response to selection and high realized heritability for WUE, but no response to selection for growth. Correlated responses to selection in other life-history traits were not significant, except for concentration of some chemical defenses, which was greater in the offspring of mother trees selected for growth than in the offspring of unselected control trees. Conclusions: The empirical evidence of direct responses to selection for high WUE suggests that P. halepensis has the potential to evolve in response to increasing drought stress. Contrary to expectations, the results are not conclusive of a potential negative impact of WUE and growth selection on other key life-history traits.This research was supported by grants AGL2015-68274-C03 (“Futurpine”, MINECO / FEDER / UE, subprojects 01R, 02R and 03R) and RTI2018-094691-B-C33 (“Resilpine”, MCIU / AEI / UE, subprojects C31, C32 and C33). E.S.V. received financial assistance from the FPU grant program (Ministerio de Educación, Cultura y Deporte, Gobierno de España)