Role of mitochondrial reverse electron transport in ROS signaling: Potential roles in health and disease

Reactive Oxygen Species (ROS) can cause oxidative damage and have been proposed to be the main cause of aging and age-related diseases including cancer, diabetes and Parkinson's disease. Accordingly, mitochondria from old individuals have higher levels of ROS. However, ROS also participate in cellular signaling, are instrumental for several physiological processes and boosting ROS levels in model organisms extends lifespan. The current consensus is that low levels of ROS are beneficial, facilitating adaptation to stress via signaling, whereas high levels of ROS are deleterious because they trigger oxidative stress. Based on this model the amount of ROS should determine the physiological effect. However, recent data suggests that the site at which ROS are generated is also instrumental in determining effects on cellular homeostasis. The best example of site-specific ROS signaling is reverse electron transport (RET). RET is produced when electrons from ubiquinol are transferred back to respiratory complex I, reducing NAD+ to NADH. This process generates a significant amount of ROS. RET has been shown to be instrumental for the activation of macrophages in response to bacterial infection, re-organization of the electron transport chain in response to changes in energy supply and adaptation of the carotid body to changes in oxygen levels. In Drosophila melanogaster, stimulating RET extends lifespan. Here, we review what is known about RET, as an example of site-specific ROS signaling, and its implications for the field of redox biology

Fuzzy entropy from weak fuzzy subsethood measures

In this paper, we propose a new construction method for fuzzy and weak fuzzy subsethood measures based on the aggregation of implication operators. We study the desired properties of the implication operators in order to construct these measures. We also show the relationship between fuzzy entropy and weak fuzzy subsethood measures constructed by our method

Applying Model-Driven Paradigm for the Improvement of Web Requirement Validation

This paper proposes an approach for Web requirements validation by applying the model-driven paradigm in classical requirements validation techniques. In particular, we present how the Navigational Development Techniques (NDT) approach exploits the model-driven paradigm to improve its requirements validation task by exploring tool cases that systematize or even automate the application of requirements validation techniques. Our solution is validated by applying it in a real industrial environment. The results and the learned lessons are presented accordingly

Multifuncionalidad y Sistemas Agroalimentarios locales: prioridades de investigación e innovación en medio ambiente, territorio y desarrollo rural en el sector español del aceite de oliva

Los sistemas agroalimentarios locales (SIAL) de aceite de oliva en España son un buen ejemplo del comportamiento multifuncional y de su contribución potencial a la gobernanza territorial. Se detectan cambios significativos en la geografía del olivar español, derivados, por una parte, de la expansión de nuevas superficies de olivar en regadío de cultivo intensivo y superintensivo y, por otra, de la creciente marginalización a la que se ve abocado el olivar español de media y alta pendiente. Por otra parte, el olivar español produce un fuerte grado de externalidades ambientales negativas, como la erosión o la contaminación difusa de suelos y acuíferos. El principal objetivo del trabajo es detectar las relaciones que se establecen entre la definición de los principales problemas que atañen a los SIAL de aceite de oliva en España y las prioridades de investigación e innovación en materia de territorio y medio ambiente, desde una óptica multidisciplinar que integre enfoques procedentes de las Ciencias Sociales y de las Ciencias Agronómicas y Ambientales. El marco teórico procede de las teorías sobre la multifuncionalidad de los espacios rurales y sobre los SIAL. La metodología utiliza información cualitativa y cuantitativa procedente de dos fuentes primarias: i) un grupo de discusión integrado en un panel presencial de expertos sobre innovación en olivicultura, sostenibilidad y aprovechamiento de residuos; ii) un análisis Delphi dirigido a un conjunto amplio de expertos sobre medio ambiente, territorio y desarrollo rural sostenible en el sector oleícola. En cuanto al análisis de resultados, el grupo de discusión ha tenido como misión categorizar las grandes tipologías de olivicultura en España y sintetizar sus respectivos problemas ambientales y territoriales. Estos resultados sirven como marco de referencia del análisis Delphi, que tiene un doble objetivo: por una parte, el análisis de los principales problemas ambientales y territoriales de los SIAL oleícolas en España; por otra, el estudio de las prioridades en materia de programas y de grupos de líneas de investigación sobre la materia, así como las relaciones entre dichas líneas de investigación y los problemas a los que se enfrentan los SIAL oleícolas.prioridades de investigación e innovación, medio ambiente y territorio, análisis Delphi., Agribusiness, Agricultural and Food Policy, Community/Rural/Urban Development, Food Consumption/Nutrition/Food Safety, Labor and Human Capital,

Multiwavelength optical observations of chromospherically active binary systems. III. High resolution echelle spectra from Ca II H&K to Ca II IRT

This is the third paper of a series aimed at studying the chromosphere of active binary systems using the information provided for several optical spectroscopic features. High resolution echelle spectra including all the optical chromospheric activity indicators from the Ca II H & K to Ca II IRT lines are analysed here for 16 systems. The chromospheric contribution in these lines has been determined using the spectral subtraction technique. Very broad wings have been found in the subtracted H_alpha profile of the very active star HU Vir. These profiles are well matched using a two-component Gaussian fit (narrow and broad) and the broad component can be interpreted as arising from microflaring. Red-shifted absorption features in the H_alpha line have been detected in several systems and excess emission in the blue wing of FG UMa was also detected. These features indicate that several dynamical processes, or a combination of them, may be involved. Using the E(H_alpha)/E(H_beta) ratio as a diagnostic we have detected prominence-like extended material viewed off the limb in many stars of the sample, and prominences viewed against the disk at some orbital phases in the dwarfs OU Gem and BF Lyn. The He I D_3 line has been detected as an absorption feature in mainly all the giants of the sample. Total filling-in of the He I D_3, probably due to microflaring activity, is observed in HU Vir. Self-absorption with red asymmetry is detected in the Ca II H & K lines of the giants 12 Cam, FG UMa and BM CVn. All the stars analysed show clear filled-in Ca II IRT lines or even notable emission reversal. The small values of the E(8542)/E(8498) ratio we have found indicate Ca II IRT emission arises from plage-like regions.Comment: Latex file with 38 pages, 25 figures. Full postscript (text and figures) available at http://www.ucm.es/info/Astrof/pub_dmg.html To be published in Astronomy & Astrophysics Supp.

Transcriptional activation of the proapoptotic bik gene by E2F proteins in cancer cells

AbstractBH3-only proteins are required for execution of apoptotic cell death. We have found that one of these proteins, Bik, is strongly induced in cancer cells treated with chemotherapeutic agents. Furthermore, we showed that chemotherapy-induced expression of bik is independent of p53. Consistent with its pro-apoptotic activity, blockade of bik expression reduces the adriamycin-mediated apoptotic cell death. We also found that the bik gene is transcriptionally activated by E2F proteins. Consistently, adriamycin induces the E2F-bik pathway. In addition, E2Fs transactivate bik by a p53-independent mechanism. Thus, our data indicate that transcriptional regulation of bik contributes to the efficient apoptotic response to chemotherapeutic agents

Visible light-driven H2 production over highly dispersed Ruthenia on Rutile TiO2 nanorods

The immobilization of miniscule quantities of RuO2 (~0.1%) onto one-dimensional (1D) TiO2 nanorods (NRs) allows H2 evolution from water under visible light irradiation. Rod-like rutile TiO2 structures, exposing preferentially (110) surfaces, are shown to be critical for the deposition of RuO2 to enable photocatalytic activity in the visible region. The superior performance is rationalized on the basis of fundamental experimental studies and theoretical calculations, demonstrating that RuO2(110) grown as 1D nanowires on rutile TiO2(110), which occurs only at extremely low loads of RuO2, leads to the formation of a heterointerface that efficiently adsorbs visible light. The surface defects, band gap narrowing, visible photoresponse, and favorable upward band bending at the heterointerface drastically facilitate the transfer and separation of photogenerated charge carriers.Peer ReviewedPostprint (published version