Selection of AGN candidates in the GOODS-South Field through SPITZER/MIPS 24 μ\mum variability

We present a study of galaxies showing mid-infrared variability in data taken in the deepest Spitzer/MIPS 24 $\mu$m surveys in the GOODS-South field. We divide the dataset in epochs and subepochs to study the long-term (months-years) and the short-term (days) variability. We use a $\chi^2$-statistics method to select AGN candidates with a probability $\leq$ 1% that the observed variability is due to statistical errors alone. We find 39 (1.7% of the parent sample) sources that show long-term variability and 55 (2.2% of the parent sample) showing short-term variability. That is, 0.03 sources $\times$ arcmin$^{-2}$ for both, long-term and short-term variable sources. After removing the expected number of false positives inherent to the method, the estimated percentages are 1.0% and 1.4% of the parent sample for the long-term and short-term respectively. We compare our candidates with AGN selected in the X-ray and radio bands, and AGN candidates selected by their IR emission. Approximately, 50% of the MIPS 24 $\mu$m variable sources would be identified as AGN with these other methods. Therefore, MIPS 24 $\mu$m variability is a new method to identify AGN candidates, possibly dust obscured and low luminosity AGN, that might be missed by other methods. However, the contribution of the MIPS 24 $\mu$m variable identified AGN to the general AGN population is small ($\leq$ 13%) in GOODS-South.Comment: Accepted for publication in MNRA

Design and evaluation of biodegradable particulate systems with neuroprotective agents for the treatment of neurodegenerative ocular diseases

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Farmacia, Departamento de Farmacia y Tecnología Farmacéutica, leída el 15/06/2017Las enfermedades neurodegenerativas que afectan al segmento posterior del ojo se caracterizan por ser devastadoras. En su mayoría son crónicas y pueden cursar con un daño progresivo del nervio óptico y la pérdida de células ganglionares de la retina (CGR), fotorreceptores y otras células de la retina ocasionando la pérdida de visión. Una de las estrategias terapéuticas encaminadas al tratamiento de estas patologías es la neuroprotección, que se centra en prevenir, limitar, y en algunos casos revertir, la degeneración o muerte de las células neuronales. En el caso de la neuroprotección ocular, una aproximación terapéutica consiste en la administración de factores neurotróficos exógenos encargados de modular el crecimiento, la diferenciación, la reparación y la supervivencia de las neuronas gracias a su unión a receptores específicos. Estos factores engloban una amplia variedad de sustancias entre las cuales cabe destacar el Factor Neurotrófico Derivado de la Glía (GDNF), cuyo efecto neuroprotector ha sido demostrado en diversas patologías oculares. También existen otras moléculas terapéuticas que ejercen efecto neuroprotector a nivel ocular mediante mecanismos de acción diferentes a los factores neurotróficos. Un ejemplo son los antioxidantes que se destinan a paliar el daño oxidativo que acompaña a las patologías retinianas. En este sentido, la melatonina juega un papel importante ya que presenta un potente carácter antioxidante, atenuando el daño celular causado por los radicales libres tanto en las CGR como en los fotorreceptores. En esta misma línea, la administración de vitaminas antioxidantes se plantea de igual modo como una alternativa terapéutica encaminada a contrarrestar el daño oxidativo. Concretamente, la vitamina E (VitE) ha demostrado actividad en diferentes enfermedades de la retina en las que se produce, entre otros, estrés oxidativo...Neurodegenerative diseases that affect the posterior segment of the eye are characterised by being devastating in nature. The majority of them are chronic and they may involve gradual damage to the optic nerve and loss of retinal ganglion cells (RGCs), photoreceptors and other cells in the retina, thereby causing loss of vision. One therapeutic strategy intended to treat these diseases is neuroprotection, which focuses on preventing, limiting and in some cases reversing the degeneration and death of neuronal cells. In the case of ocular neuroprotection, one therapeutic approach consists of administering exogenous neurotrophic factors responsible for modulating the growth, differentiation, repair and survival of neurons through their binding to specific receptors. These factors encompass a wide variety of substances including glial cell line-derived neurotrophic factor (GDNF), whose neuroprotective effect has been demonstrated in various eye diseases. Other therapeutic molecules also exert a neuroprotective effect on the eye through different mechanisms of action than neurotrophic factors. One example is antioxidants intended to palliate the oxidative damage that accompanies retinal diseases. In this regard, melatonin plays a significant role since it has strong antioxidant properties whereby it attenuates the cell damage caused by free radicals in both RGCs and photoreceptors. Likewise, the administration of antioxidant vitamins has been proposed as a therapeutic alternative intended to counteract oxidative damage. Specifically, vitamin E (VitE) has demonstrated activity in different diseases of the retina with oxidative stress, among other features. However, as this type of disease is multifactorial, the search for new therapeutic strategies is focused on combination treatment, for which various active substances are used depending on the patient's therapeutic requirements...Depto. de Farmacia Galénica y Tecnología AlimentariaFac. de FarmaciaTRUEunpu

Generating functions and companion symmetric linear functionals

14 pages, no figures.-- MSC2000 codes: 33C45, 42C05.MR#: MR2004670 (2004i:33016)Zbl#: Zbl 1047.33004In this contribution we analyze the generating functions for polynomials orthogonal with respect to a symmetric linear functional u, i.e., a linear application in the linear space of polynomials with complex coefficients such that $$u\left({x^{2n+1}}\right)=0$$. In some cases we can deduce explicitly the expression for the generating function $${\mathcal{P}}\left({x,w}\right)=\sum\limits_{n=0}^\infty {c_n P_n \left(x \right)w^n ,}$$ where {Pn}n is the sequence of orthogonal polynomials with respect to u.Second author (S.G.M.)'s research supported by Junta de Andalucía, Grupo de Investigación FQM 0178. Third author (F.M.)'s research supported by Dirección General de Investigación (Ministerio de Ciencia y Tecnología) of Spain, Grant BFM 2000-0206-C04-01 and INTAS Project 2000-272.Publicad

Low-resolution spectroscopy and spectral energy distributions of selected sources towards sigma Orionis

Aims: We investigated in detail nine sources in the direction of the young sigma Orionis cluster, which is considered a unique site for studying stellar and substellar formation. The nine sources were selected because of some peculiar properties, such as extremely red infrared colours or too strong Halpha emission for their blue optical colours. Methods: We took high-quality, low-resolution spectroscopy (R ~ 500) of the nine targets with ALFOSC at the Nordic Optical Telescope. We also re-analyzed [24]-band photometry from MIPS/Spitzer and compiled the best photometry available at the ViJHKs passbands and the four IRAC/Spitzer channels for constructing accurate spectral energy distributions covering from 0.55 to 24 mum. Results: The nine targets were classified into: one Herbig Ae/Be star with a scatterer edge-on disc, two G-type stars, one X-ray flaring, early-M, young star with chromospheric Halpha emission, one very low-mass, accreting, young spectroscopic binary, two young objects at the brown dwarf boundary with the characteristics of classical T Tauri stars, and two emission-line galaxies, one undergoing star formation, and another one whose spectral energy distribution is dominated by an active galactic nucleus. Besides, we discover three infrared sources associated to overdensities in a cold cloud in the cluster centre. Conclusions: Low-resolution spectroscopy and spectral energy distributions are a vital tool for measuring the physical properties and the evolution of young stars and candidates in the sigma Orionis cluster.Comment: Accepted for publication in A&

Formación en sostenibilidad y su efecto en el comportamiento y la actitud de los estudiantes universitarios

El trabajo se basa en un estudio sobre la formación y el conocimiento de los alumnos universitarios acerca del concepto sostenibilidad aplicado al turismo, con el fin de analizar su efecto en el comportamiento y la actitud de los estudiantes cuando viajan. Se integra en un proyecto internacional más amplio basado en una encuesta on-line, que en este caso se ha dirigido a los alumnos de la Facultad de Turismo y Finanzas y de la Facultad de Ciencias Económicas y Empresariales de la Universidad de Sevilla. Los objetivos del trabajo son los siguientes: 1) Comparar los resultados de los alumnos de Turismo con los de Administración de Empresas, Economía y Marketing y observar si existen diferencias entre los dos grupos de estudiantes, tanto en relación con su formación sobre la materia, como con su comportamiento y actitud frente al turismo sostenible. 2) De existir diferencias, ver en qué medida pudieran derivarse de la formación recibida y asimismo del contacto con el sector económico sobre el que se analiza el concepto de sostenibilidad. Los resultados del trabajo refuerzan nuestra idea inicial de la necesidad de incorporar el concepto de sostenibilidad en programas y titulaciones universitarias y plantear no solo conocimientos disciplinares orientados al “saber” y profesionales orientados al “saber hacer”, sino también actitudes para un compromiso ético orientadas a la protección del medio ambiente y a la preservación de los pueblos y su cultura.Our paper is focused on a study about the education and knowledge of university students of the concept of sustainability as applied to tourism with the aim of analysing its effect on their behaviour and attitudes when travelling. The current study is integrated in a wider international project based on an on-line survey, that in this case has been focused on the students of the Faculty of Tourism and Finance and the Faculty of Economics and Business Studies of the University of Seville. The objectives of the paper are: 1) To compare the results of the Tourism students with those of the Business Management, Economics and Marketing students, and to observe if there are differences between the two groups of students, both in relation to their education of the material, and also to their behaviour and attitudes towards sustainable tourism. 2) On the existence of these differences, to determine in what measure they could be derived from the education received, and likewise from the contact with the economic sector about which the concept of sustainability is analysed in our study. The results of the study reinforce our initial idea of the necessity for the incorporation of the concept of sustainability into the degree syllabus, in which not only should objectives focused on "to know" and "to know how to do" be considered, but also the attitudes towards an ethic commitment for the protection of the environment and for the preservation of the people and their cultures

¿Qué conocen los alumnos universitarios sobre sostenibilidad? Un estudio comparativo en universidades de países diferentes

El trabajo que presentamos se centra en un estudio comparativo sobre lo que conocen los alumnos universitarios acerca del concepto sostenibilidad. El estudio empírico, aún en curso, se basa en una encuesta on-line dirigida a alumnos de la New York University, de la Pace University y de la Universidad de Sevilla. Los resultados preliminares obtenidos nos llevan a justificar la necesaria enseñanza de dicha materia en distintos cursos y titulaciones universitarias con el fin de difundir una cultura a favor de la sostenibilidad. Y de ese modo contribuir también a garantizar el desarrollo de las generaciones futuras y a dar respuesta, asimismo, a la demanda de acciones que reclaman los organismos internacionales con objeto desarrollar el turismo de una manera sostenible.Our paper is focused on a comparative study about university’ students knowledge of sustainability. The ongoing empirical study is based on a survey that has been administered through online survey platform to a listserv of students from New York University, Pace University and Universidad de Sevilla. The preliminary results encourage us to justify the need of teaching about sustainability in different courses at university degrees in order to spread a pro-sustainability culture and contribute to guarantee the future generation development. In the same way, this project gives a response to the demanded actions that the international organizations are claiming in order to develop the tourism in a sustainable way

Software público, libre, abierto, gratuito, privativo y comercial para la innovación y mejora de la calidad en la docencia, investigación, gestión y asistencia

The public free software (now renamed as open software) is the basis of the open source software (OSS) project. This initiative promotes the use of open standards and platform-independent accessibility. Many OSS products are free or low cost, which allows their deployment even in the absence of large economic resources (developing countries, schools, etc.). Besides, their source code can be modified, adapted and optimized by anyone, since it is public. Nevertheless, the OSS may also have drawbacks. Thus, its development may not be as orderly and hierarchical as the privative software is, and may not have an appropriate funding. This may jeopardize the ease of use and coherence of the final product, increasing the transition, training and technical support costs. Besides, it must be taken into account that there is also commercial open software, as well as free privative software. In any case, the excellence of the software may be independent of such variables. Thus, the best strategy is the coexistence and free competition of all kinds of software. This will allow a quality improvement and an innovation enhancement, which will benefit the education, research, management and assistance at the university in particular and at the whole society in general.El software público libre es el fundamento del movimiento de software de fuente abierta (OSS). Éste puede facilitar el uso de estándares abiertos, con accesibilidad independiente de plataforma informática. El bajo coste o gratuidad de muchos productos OSS permite su implantación cuando los recursos económicos son escasos (países en desarrollo, escuelas, etc.). Además, su código se puede modificar, adaptar y mejorar por cualquiera, ya que es público. No obstante, el OSS también puede presentar inconvenientes. Así, su desarrollo puede no ser tan ordenado y jerárquico como el del software privativo y puede no tener una financiación apropiada. De este modo, puede verse comprometida la facilidad de uso y coherencia del producto final. Ello puede incrementar los costes de transición, entrenamiento y soporte técnico. Por otra parte, conviene recordar que existe software libre comercial y software privativo gratuito. En cualquier caso, la excelencia del software puede ser independiente de dichas variables. Por tanto, la mejor estrategia es la coexistencia y libre competencia de todo tipo de software. Así se puede conseguir una mejora de calidad y una potenciación de la innovación, que beneficie a la docencia, investigación, gestión y asistencia universitarias en particular, así como a la sociedad en general

Selection of AGN candidates in the GOODS-South Field through SPITZER/MIPS 24 μm variability

We present a study of galaxies showing mid-infrared variability in data taken in the deepest Spitzer/MIPS 24 μm surveys in the Great Observatory Origins Deep Survey South field. We divide the data set in epochs and subepochs to study the long-term (months–years) and the short-term (days) variability. We use a χ2-statistics method to select active galactic nucleus (AGN) candidates with a probability ≤1 per cent that the observed variability is due to statistical errors alone. We find 39 (1.7 per cent of the parent sample) sources that show long-term variability and 55 (2.2 per cent of the parent sample) showing short-term variability. That is, 0.03 sources × arcmin−2 for both, long-term and short-term variable sources. After removing the expected number of false positives inherent to the method, the estimated percentages are 1.0 and 1.4 per cent of the parent sample for the long term and short term, respectively. We compare our candidates with AGN selected in the X-ray and radio bands, and AGN candidates selected by their IR emission. Approximately, 50 per cent of the MIPS (Multiband Imaging Photometer for Spitzer) 24 μm variable sources would be identified as AGN with these other methods. Therefore, MIPS 24 μm variability is a new method to identify AGN candidates, possibly dust obscured and low-luminosity AGN, that might be missed by other methods. However, the contribution of the MIPS 24 μm variable identified AGN to the general AGN population is small (≤13 per cent) in GOODS-South.JG-G, AA-H, and AH-C acknowledge support from the Augusto G. Linares research programme of the Universidad de Cantabria and from the Spanish Plan Nacional through grant AYA2012-31447. PGP-G acknowledges support from MINECO grant AYA2012-31277.Peer Reviewe