Inhibitory effects of pharmacological doses of melatonin on aromatase activity and expression in rat glioma cells

Melatonin exerts oncostatic effects on different kinds of neoplasias, especially on oestrogen-dependent tumours. Recently, it has been described that melatonin, on the basis of its antioxidant properties, inhibits the growth of glioma cells. Glioma cells express oestrogen receptors and have the ability to synthesise oestrogens from androgens. In the present study, we demonstrate that pharmacological concentrations of melatonin decreases the growth of C6 glioma cells and reduces the local biosynthesis of oestrogens, through the inhibition of aromatase, the enzyme that catalyses the conversion of androgens into oestrogens. These results are supported by three types of evidence. Firstly, melatonin counteracts the growth stimulatory effects of testosterone on glioma cells, which is dependent on the local synthesis of oestrogens from testosterone. Secondly, we found that melatonin reduces the aromatase activity of C6 cells, measured by the tritiated water release assay. Finally, by (RT)–PCR, we found that melatonin downregulates aromatase mRNA steady-state levels in these glioma cells. We conclude that melatonin inhibits the local production of oestrogens decreasing aromatase activity and expression. By analogy to the implications of aromatase in other forms of oestrogen-sensitive tumours, it is conceivable that the modulation of the aromatase by pharmacological melatonin may play a role in the growth of glioblastomas

CARMENES input catalogue of M dwarfs IV. New rotation periods from photometric time series

Aims. The main goal of this work is to measure rotation periods of the M-type dwarf stars being observed by the CARMENES exoplanet survey to help distinguish radial-velocity signals produced by magnetic activity from those produced by exoplanets. Rotation periods are also fundamental for a detailed study of the relation between activity and rotation in late-type stars. Methods. We look for significant periodic signals in 622 photometric time series of 337 bright, nearby M dwarfs obtained by long-time baseline, automated surveys (MEarth, ASAS, SuperWASP, NSVS, Catalina, ASAS-SN, K2, and HATNet) and for 20 stars which we obtained with four 0.2-0.8 m telescopes at high geographical latitudes. Results. We present 142 rotation periods (73 new) from 0.12 d to 133 d and ten long-term activity cycles (six new) from 3.0 a to 11.5 a. We compare our determinations with those in the existing literature; we investigate the distribution of P rot in the CARMENES input catalogue,the amplitude of photometric variability, and their relation to vsin i and pEW(Halfa); and we identify three very active stars with new rotation periods between 0.34 d and 23.6 d.Comment: 34 pages, 43 figures, 2 appendix table

La reforma del sistema de defensa de la competencia en España

Artículo de revist

Time to do more

AbstractAimsClinical inertia, the tendency to maintain current treatment strategies despite results demanding escalation, is thought to substantially contribute to the disconnect between clinical aspirations for patients with diabetes and targets achieved. We wished to explore potential causes of clinical inertia among physicians and people with diabetes.MethodsA 20-min online survey of 652 adults with diabetes and 337 treating physicians in six countries explored opinions relating to clinical inertia from both perspectives, in order to correlate perceptions and expectations relating to diagnosis, treatment, diabetes complications and therapeutic escalation.ResultsPhysicians had low expectations for their patients, despite the belief that the importance of good glycaemic control through lifestyle and pharmacological interventions had been adequately conveyed. Conversely, people with diabetes had, at best, a rudimentary understanding of the risks of complications and the importance of good control; indeed, only a small proportion believed lifestyle changes were important and the majority did not intend to comply.ConclusionsThe principal findings of this survey suggest that impairments in communication are at the heart of clinical inertia. This manuscript lays out four key principles that we believe are achievable in all environments and can improve the lives of people with diabetes

Resiliencia de jóvenes deportistas en función del carácter individual o colectivo de su práctica

The objective of this study was to determine the levels of resilience with its two dimensions, “acceptance of self and life" (AUM) and "individual competence" (CP), in individual and collective sports participants. Comparisons depending on competitive level and sex, as well as, intragroup and intergroup comparisons were performed. A total of 435 athletes (300 men and 135 women) completed a socio-demographic questionnaire and the Resilience Scale (Wagnild and Young, 1993). The results indicate that those who practise individual sports obtain average values of resilience and the CP dimension higher than those obtained by athletes who do so collectively (p < 0.005). According to sex, in the AUM dimension, girls have lower averages than boys (p< 0.005). As for the competitive level, the trend is that at a higher competitive level, higher average resilience score (p < 0.05). The results draw the image of the athlete resilient as a young boy practicing sport of individual character and high level competitive.El objetivo de este estudio fue determinar los niveles de resiliencia con sus dos dimensiones, “Aceptación de uno mismo y de la vida” (AUM) y “Competencia Personal” (CP),en participantes de deportes de carácter individual y colectivo. Se realizaron comparaciones inter e intragrupo y en función del nivel competitivo y sexo. Un total de 435 deportistas (300 hombres y 135 mujeres) cumplimentaron un cuestionario socio-demográfico y La Escala de Resiliencia (Wagnild y Young, 1993). Los resultados señalan que quienes practican deportes de carácter individual obtienen valores medios de resiliencia y de la dimensión CP superiores a los obtenidos por deportistas que lo hacen de forma colectiva (p<0.005). Respecto al sexo, en la dimensión AUM, las chicas presentan medias menores que los chicos (p<0.005). En cuanto al nivel competitivo, la tendencia es que a mayor nivel competitivo, mayor puntuación media de resiliencia (p<0.05).Los resultados dibujan la imagen del deportista resiliente como un chico joven  practicante de deporte de carácter individual y de alto nivel competitivo

Reflexiones sobre ‘Occupy. The spatial dynamics of discourse in global protest movements’ de Luisa Martin Rojo

La publicación del libro Occupy. The spatial dynamics of discourse in global protest movements, editado por Luisa Martin Rojo abre un nuevo campo para los estudios del discurso en el que se otorga centralidad al espacio en un sentido dinámico. Por este motivo, como parte del foro e-conversa (promovido por la Asociación Internacional de Estudios sobre Discurso y Sociedad EDiSo; http://www.edisoportal.org/) se planteó la lectura del capítulo introductorio (cuya traducción al español se encuentra en este número de Discurso y Sociedad) y debatir sobre algunas de las cuestiones que en él se plantean. El resultado está formado por varias contribuciones que, tomando como punto de partida el texto de Martín Rojo, reflexionan, entre otros temas, sobre las prácticas espaciales, el papel de los medios de comunicación y las redes sociales, el nuevo sujeto político emergente, las formaciones contrahegemónicas, el multilingüismo, prácticas prefigurativas, etc. De este modo, este texto dialógico es una invitación a seguir pensando el análisis del discurso desde una perspectiva novedosa ligada al espacio / The publication of the volumen Occupy. The spatial dynamics of discourse in global protest movements, edited by Luisa Martín Rojo, opens up a new field of discourse studies in which the focus lies on space, in a dynamic sense. For this reason, and as part of the forum e-conversa (hosted by the International Association of Discourse Studies and Society (EDiSo); http://www.edisoportal.org/Ediso), it was suggested to read the introduction (the Spanish translation of which is included in this issue of Discurso y Sociedad) and to debate over some of the topics presented in the book. The result consists of several contributions which, by taking Martin Rojo’s text as the starting point, reflect on spatial practices, the role of mass media and social networks, the new emerging political subject, counter-hegemonic formations, multilingualism, and prefigurative practices, among other issues. Thus, this dialogic text is an invitation to continue thinking about discourse analysis from a new perspective linked to space