616 research outputs found

    International Business Cycles: Background and literature review

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    El estudio de los ciclos económicos ha sido de gran interés desde su análisis formal a principios del siglo XX, no obstante no se ha producido un consenso entre los expertos en cuanto a su definición y a las técnicas de estimación de los mismos. Es por ello, que en este trabajo se presenta una revisión sobre la definición de los ciclos económicos, así como de sus características y la medición de las mismas. Por otro lado, se repasan las referencias sobre las técnicas empleadas para la extracción de los mismos, especialmente centrándonos en la estimación de los ciclos económicos internacionales en la que se emplean técnicas multivariantes complejas, sobre las cuales se ha abierto una vía de investigación con un interés cada vez mayorThe study of business cycles has been of great interest since its formal analysis in the early twentieth century; however there has been no consensus among experts about its defi nition and techniques for estimating them. Therefore, in this paper we present a review of the defi nition of business cycles and of their characteristics and approaches. On the other hand, we review the references on the techniques used to extract business cycles, especially focusing on the estimation of international business cycles employing multivariate techniques which have opened a research line with a growing interes

    (S)TEM structural and compositional nanoanalyses of chemically synthesized glutathione-shelled nanoparticles

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    This work is focused on the characterization by transmission and scanning–transmission electron microscopy-related techniques of core–shell nanoparticles synthesized via chemical methods. Diferent semiconducting, pure metallic or oxide materials have been utilized as the core (cadmium telluride, gold, magnetite, or magnetite covered with gold) of the nanoparticle, while they have been, in all cases, functionalized by a thin amorphous glutathione layer, with the goal of using the nanoparticles in biomedical applications such as biomarkers, and computerized tomography and image magnetic resonance contrast agents. The results show that it is possible to visualize the glutathione layer using spectroscopic and imaging techniques, associated with electron microscopy (such as energy-dispersive X-ray spectroscopy and high-resolution transmission electron microscopy images), that this layer is present at the surfaces of all observed nanoparticles, and that it is no thicker than a few nanometers. Electron microscopy also revealed that the nanoparticles core is crystalline and, in average, around 5-nm size.Spanish Ministry of Economy and Competitiveness MAT2015-67354-R (Program “Plan I+D+i”, subprogram “Retos”)Spanish Ministry of Education and Culture Grants ICARO-173873Spanish Ministry of Education and Culture Grants FPU16-0438

    Redacción y publicación de resultados de investigación

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    Material de formación correspondiente a los cursos sobre competencia digital y comunicación científica dentro del plan de formación de los estudiantes de doctorado de la Universidad Pablo de Olavide.Se presenta el panorama de la publicación científica actual y el de la evaluación científica, además de abordar la localización y selección de medios de difusión y el proceso de publicación.Servicio de Información Bibliográfica y Formación de UsuariosUniversidad Pablo de Olavide. Biblioteca/CRA

    Analysis of Tag Loss Ratio in dynamic RFID systems

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    Abstract. Radio Frequency Identification (RFID) systems promise a revolution in logistics and inventory applications. By means of wireless communication, a master device can detect and identify nearby electronic tags. Traditionally, the performance of RFID systems and their identification protocols has been analyzed for static configurations, that is, without considering incoming or outgoing tags, but just a fixed number of initially unidentified tags. However, many real scenarios cannot be consistently modeled that way. In this work we introduce a Markov model which allows us to study a dynamic RFID tag scenario, where a flow of tags is considered. This model can be used to compute the Tag Loss Ratio, which measures the ratio of outgoing unidentified tags to the incoming tags in the system, which is a critical metric in dynamic configurations. The analysis is carried out for two families of protocols used as medium access control in RFID, Framed Slotted Aloha and non-persistent CSMA. With the aim of validating the analysis predictions, we get simulation results, by means of a simulator. We evaluate a scenario similar to a real application, i.e. a mail control system based on RFID

    Agreement Between 18F-FDG PET/CT and Whole-Body Magnetic Resonance Compared With Skeletal Survey for Initial Staging and Response at End-of-Treatment Evaluation of Patients With Multiple Myeloma

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    PURPOSE: To compare the agreement between whole-body (WB) magnetic resonance (MR) imaging, 18F-FDG PET/CT, and skeletal survey (SS) in patients with multiple myeloma (MM) for diagnosis, initial staging, response evaluation, and early detection of complications. METHODS: This is a retrospective cohort study including MM patients who were diagnosed, treated, and followed in 2 institutions. These patients were studied with SS, WB-MR, and/or 18F-FDG PET/CT. We studied bone lesions by anatomical locations and analyzed the concordance between SS and a tomographic technique (WB-MR or 18F-FDG PET/CT) and between both tomographic techniques (WB-MR and PET/CT). RESULTS: Forty-four MM patients with a mean age of 62.6 years (range, 38-85 years) were included from January 2012 to February 2016. Whole-body MR and 18F-FDG PET/CT found more lesions than SS in every location except in the skull. Concordance between WB-MR and 18F-FDG PET/CT was either good or excellent in most of the locations and in plasmacytoma studies. However, WB-MR was better than 18F-FDG PET/CT in the study of complications (medullar compression and vascular necrosis). CONCLUSIONS: Our results suggest the study of MM patients should include WB-MR and/or 18F-FDG PET/CT, whereas SS is only useful for the skull. Whole-body MR and 18F-FDG PET/CT are complementary techniques, because both of them show good concordance in almost every location. It is still necessary to individualize the indication of each technique according to patient characteristics.None declare

    Newborn screening for medium-chain acyl-CoA dehydrogenase deficiency: regional experience and high incidence of carnitine deficiency

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    Background Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is the most common inherited defect in the mitochondrial fatty acid oxidation pathway, resulting in significant morbidity and mortality in undiagnosed patients. Newborn screening (NBS) has considerably improved MCADD outcome, but the risk of complication remains in some patients. The aim of this study was to evaluate the relationship between genotype, biochemical parameters and clinical data at diagnosis and during follow-up, in order to optimize monitoring of these patients. Methods We carried out a multicenter study in southwest Europe, of MCADD patients detected by NBS. Evaluated NBS data included free carnitine (C0) and the acylcarnitines C8, C10, C10:1 together with C8/C2 and C8/C10 ratios, clinical presentation parameters and genotype, in 45 patients. Follow-up data included C0 levels, duration of carnitine supplementation and occurrence of metabolic crises. Results C8/C2 ratio and C8 were the most accurate biomarkers of MCADD in NBS. We found a high number of patients homozygous for the prevalent c.985A > G mutation (75%). Moreover, in these patients C8, C8/C10 and C8/C2 were higher than in patients with other genotypes, while median value of C0 was significantly lower (23 μmol/L vs 36 μmol/L). The average follow-up period was 43 months. To keep carnitine levels within the normal range, carnitine supplementation was required in 82% of patients, and for a longer period in patients homozygotes for the c.985A>G mutation than in patients with other genotypes (average 31 vs 18 months). Even with treatment, median C0 levels remained lower in homozygous patients than in those with other genotypes (14 μmol/L vs 22 μmol/L). Two patients died and another three suffered a metabolic crisis, all of whom were homozygous for the c.985 A>G mutation. Conclusions Our data show a direct association between homozygosity for c.985A>G and lower carnitine values at diagnosis, and a higher dose of carnitine supplementation for maintenance within the normal range. This study contributes to a better understanding of the relationship between genotype and phenotype in newborn patients with MCADD detected through screening which could be useful in improving follow-up strategies and clinical outcome

    Auxin-regulated reversible inhibition of TMK1 signaling by MAKR2 modulates the dynamics of root gravitropism

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    Plants are able to orient their growth according to gravity, which ultimately controls both shoot and root architecture.1 Gravitropism is a dynamic process whereby gravistimulation induces the asymmetric distribution of the plant hormone auxin, leading to asymmetric growth, organ bending, and subsequent reset of auxin distribution back to the original pre-gravistimulation situation.1, 2, 3 Differential auxin accumulation during the gravitropic response depends on the activity of polarly localized PIN-FORMED (PIN) auxin-efflux carriers.1, 2, 3, 4 In particular, the timing of this dynamic response is regulated by PIN2,5,6 but the underlying molecular mechanisms are poorly understood. Here, we show that MEMBRANE ASSOCIATED KINASE REGULATOR2 (MAKR2) controls the pace of the root gravitropic response. We found that MAKR2 is required for the PIN2 asymmetry during gravitropism by acting as a negative regulator of the cell-surface signaling mediated by the receptor-like kinase TRANSMEMBRANE KINASE1 (TMK1).2,7, 8, 9, 10 Furthermore, we show that the MAKR2 inhibitory effect on TMK1 signaling is antagonized by auxin itself, which triggers rapid MAKR2 membrane dissociation in a TMK1-dependent manner. Our findings suggest that the timing of the root gravitropic response is orchestrated by the reversible inhibition of the TMK1 signaling pathway at the cell surface

    Registro Español de Trasplante Cardiaco: XXXI Informe Oficial de la Asociación de Insuficiencia Cardiaca de la Sociedad Española de Cardiología

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    [Abstract] Introduction and objectives. The present report describes the clinical characteristics and outcomes of heart transplants in Spain and updates the data to 2019. Methods. We describe the clinical characteristics and outcomes of heart transplants performed in Spain in 2019, as well as trends in this procedure from 2010 to 2018. Results. In 2019, 300 transplants were performed (8794 since 1984; 2745 between 2010 and 2019). Compared with previous years, the most notable findings were the decreasing rate of urgent transplants (38%), and the consolidation of the type of circulatory support prior to transplant, with an almost complete disappearance of counterpulsation balloon (0.7%), stabilization in the use of extracorporeal membrane oxygenation (9.6%), and an increase in the use of ventricular assist devices (29.0%). Survival from 2016 to 2018 was similar to that from 2013 to 2015 (P=.34). Survival in both these periods was better than that from 2010 to 2012 (P=.002 and P=.01, respectively). Conclusions. Heart transplant activity has remained stable during the last few years, as have outcomes (in terms of survival). There has been a trend to a lower rate of urgent transplants and to a higher use of ventricular assist devices prior to transplant.[Resumen] Introducción y objetivos. Se presentan las características clínicas y los resultados de los trasplantes cardiacos realizados en España con la actualización correspondiente a 2019. Métodos. Se describen las características clínicas y los resultados de los trasplantes cardiacos realizados en 2019, así como las tendencias de estos en el periodo 2010-2018. Resultados. En 2019 se realizaron 300 trasplantes (8.794 desde 1984; 2.745 entre 2010 y 2019). Respecto a años previos, los cambios más llamativos son el descenso hasta el 38% de los trasplantes realizados en código urgente, y la consolidación en el cambio de asistencia circulatoria pretrasplante, con la práctica desaparición del balón de contrapulsación (0,7%), la estabilización del uso del oxigenador extracorpóreo de membrana (9,6%) y el aumento de los dispositivos de asistencia ventricular (29%). La supervivencia en el trienio 2016-2018 es similar a la del trienio 2013-2015 (p=0,34), y ambas mejores que la del trienio 2010-2012 (p=0,002 y p=0,01 respectivamente). Conclusiones. Se mantienen estables tanto la actividad del trasplante cardiaco en España como los resultados en supervivencia en los últimos 2 trienios. Hay una tendencia a realizar menos trasplantes urgentes, la mayoría con dispositivos de asistencia ventricular

    Television watching, videogames, and excess of body fat in Spanish adolescents: the AVENA study

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    Abstract OBJECTIVE: We assessed the individual association of sedentary behaviors with the risk of overweight and excess body fat (overfat) in adolescents. METHODS: A representative sample (1960 subjects, 1012 males, age 13-18.5 y) of Spanish adolescents was studied within the framework of the Alimentación y Valoración del Estado Nutricional de los Adolescentes (AVENA) study. Television (TV) watching, videogame and computer usage, doing homework, and the way students got to school, physical activity, and socioeconomic status were analyzed. Anthropometrics were measured to describe overweight (International Obesity Task Force cutoffs for body mass index) and overfat (body fat percentage >85th percentile). RESULTS: When all subjects were considered as an entire group, the overweight risk increased by 15.8% (P < 0.05) per increasing hour of TV watching. The overweight risks decreased by 32.5% in females, 22% per increasing year of age, and 12.5% by increasing socioeconomic status by 1 U (all Ps < 0.05). The obesity risks decreased with age by 17.8% per year in males and 27.1% in females (both Ps < 0.05). The overfat risks increased by 26.8% and 9.4% per increasing hour of TV and weekend videogame usage, respectively (both Ps < 0.05). In males, the overfat risk increased by 21.5% per increasing hour in weekend videogame usage (P < 0.05). Each hour of TV use increased the overfat risks by 22% in males and 28.3% in females (both Ps < 0.05). CONCLUSIONS: Time spent watching TV increased the risk of overweight and obesity in Spanish adolescents, but the effect was influenced by age, sex, and socioeconomic status. Moreover, an excess of body fat was more directly explained by the time spent watching TV and playing videogames during the weekend.Peer Reviewe
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