A fast version of the k-means classification algorithm for astronomical applications

Context. K-means is a clustering algorithm that has been used to classify large datasets in astronomical databases. It is an unsupervised method, able to cope very different types of problems. Aims. We check whether a variant of the algorithm called single-pass k-means can be used as a fast alternative to the traditional k-means. Methods. The execution time of the two algorithms are compared when classifying subsets drawn from the SDSS-DR7 catalog of galaxy spectra. Results. Single-pass k-means turn out to be between 20 % and 40 % faster than k-means and provide statistically equivalent classifications. This conclusion can be scaled up to other larger databases because the execution time of both algorithms increases linearly with the number of objects. Conclusions. Single-pass k-means can be safely used as a fast alternative to k-means

La Nutrigenomica en el Futuro de la Salud Humana

Discurso de agradecimiento leído por José María Ordovás con motivo de su nombramiento como Doctor Honoris Causa por la Universidad de Córdoba

A multifrequency view of active galactic nuclei

RESUMEN: En esta tesis estudiamos la relación entre la extinción en el UV/óptico (AV) y la absorción (NH) medida en rayos X de los AGN de tipo 1 usando el muestreo Bright Ultra-hard XMM-Newton Survey (BUXS). Hemos planteado dos estudios diferentes. En el primero tenemos dos AGN de tipo 1.9 (AV elevada), pero sus espectros en rayos X muestran bajo NH, por lo que estudiamos esta discrepancia. En el segundo estudio, hemos llevado a cabo un análisis estadístico de una muestra representativa de 132 AGN de tipo 1, excluyendo los AGN con L2-10 keV1. Analizamos los espectros ópticos y de rayos X para obtener AV y NH, las luminosidades intrínsecas y los flujos y anchuras de las líneas de emisión. En el primer estudio, hemos obtenido que los tipos 1.9 con bajo NH no forman una familia física de objetos, al obtener que la discordancia para cada uno es debida a diferentes factores. Con el estudio estadístico hemos comprobado que AV y NH están relacionadas con la subclasificación óptica. Si no se usan muestras con clasificación completa, los resultados están sesgados contra los AGN más oscurecidos. Hemos comprobado que el Balmer decrement no es un buen indicador de AV. Para tipos 1, obtenemos que la extinción y la absorción no están correlacionadas. Por último, usando una muestra completa, la cantidad de objetos con un cociente polvo/gas mayor que el Galáctico es mayor al reportado anteriormente.ABSTRACT: In this Thesis we study the relation between the UV/optical extinction (AV) and the X-ray absorption (NH) in type-1 AGN using the Bright Ultra-hard XMM-Newton Survey (BUXS). We have conducted two different studies. In the first one we have two type-1.9 AGN (high AV) with low NH. so we study this discordance. In the second one, we have conducted a statistical study of a representative study of 132 type-1 AGN, excluding those with L2-10 keV1. We analysed the optical and X-ray spectra to obtain AV and NH, the intrinsic luminosity and fluxes and widths of the emission lines. In the first study we obtained that low absorbed type-1 AGN do not form a physical family of objects, as the discordance in each object is caused by different factors. With the statistical study we obtained that AV and NH are related with the optical subclassification. If complete classification samples are not used, the results are biased against highly obscured sources. We checked that Balmer decrement is not a good estimator of AV. For type-1 AGN, we obtained that extinction and absorption are not correlated. Lastly, using a complete sample, the amount of AGN with higher dust-to-gas ratio than the Galactic is higher than previously reported

Social rights as the challenge for a society under sieg

La literatura sobre los derechos sociales no cesa de aumentar, claro reflejo de una importante y extendida preocupación por su presente y futuro. Tanto desde el Derecho como de la Filosofía política defensores y detractores de tales derechos los avalan o rechazan con argumentaciones opuestas pero sabedores, en todo caso, de que a día de hoy son uno de nuestros principales retos jurídicos y morales en una época en que se tiende a identificar y confundir sociedad y economía siendo casi imprescindible reinventar la idea de puebloThe literature of social rights is bigger every day. This show us an important concern for its present and future. From the Right and the political philosophy defenders and critics of these these rights approve or do not approve them. Nowadays, they know that the social rights are one of our most important legal and moral challenge at a time that going to confuse the society and the econom

La glosa que escribió en latín Gregorio Lopez

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-2010Precede al tít.: Código de las siete PartidasVól. II y III: Imprenta de F. Maroto e Hijo

Terapia con miRNAs en la enfermedad cardiovascular y envejecimiento: descubrimiento de nuevos candidatos

Cardiovascular diseases are, as of now, the main cause of death in the developed world. Aging is amain risk factor determining their development. In most of the cases, pharmacological treatments donot directly asses the problem and have only palliative effects, which decreases quality life of thepatient and increase dependence on the treatment to follow a normal lifestyle. Therefore, looking fornovel effective therapies to treat the cause of the disease will be crucial in the near future.microRNAs (miRNA) have been proved to be master regulators of many biological processes that takeplaces in the cell, since they are capable of regulating gene expression. Studies in vitro and in vivo haveassociated dysregulation of the miRNAs expression with pathology in cardiovascular disease and aging,thus postulating them as possible therapeutic targets.As result, miRNAs-mimics and anti-miRs have emerged as a new promising therapeutic approach tocorrect gene expression alterations regulated by miRNAs that have been seen in disease. Here, adetailed revision of the application of miRNA-based therapies to treat CVD is made. Although, currentlythere are only 2 studies that have reached clinical trials, many preclinical studies have publishedencouraging results.Continuing previous work of the group BSICoS, a second aim of this master’s thesis is to develop toolsfor the study of the interaction of age-related miRNAs (BIO-AGEmiRNA) with their target genes inrelation to cardiac function using human iPSC-derived cardiomyocytes. A inducible expression vectorwas created to be expressed mature miRNAs, specifically miR-4435, downstream of a fluorescentreporter gene. The vector was tested in vitro in HEK293 cells and proper expression of the reporterwas observed. However, expression of the mature miR-4435, and therefore proper processing of thepre-miRNA, could not be confirmed due to technical issues. Future work will continue to validate theremaining BIO-AGE-miRNAs in vitro, first in HEk393 and then in iPSC-derived cardiomyocytes were themolecular mechanism and functionality of the BIO-AGEmiRNAs will be investigated. The developedvector will be most certainly a useful tool to complete this future work.<br /

Subjective Well-being, Happiness, and Fairness of Marketing Systems in Brazil: Some Further Thoughts

Subjective well-being is often popularly referred to as happiness. In this dialogue commentary, we point to these additional aspects of subjective well-being or happiness: (1) Some findings from another study of this type, in another region of Brazil; (2) Several macro-level observations, drawn from Brazil as well as globally, on the complex relationships between marketing practices, public policies, consumption styles and subjective well-being