Reconstructing cosmic acceleration from modified and non-minimal gravity: The Yang-Mills case

A variant of the accelerating cosmology reconstruction program is developed for $f(R)$ gravity and for a modified Yang-Mills/Maxwell theory. Reconstruction schemes in terms of e-foldings and by using an auxiliary scalar field are developed and carefully compared, for the case of $f(R)$ gravity. An example of a model with a transient phantom behavior without real matter is explicitly discussed in both schemes. Further, the two reconstruction schemes are applied to the more physically interesting case of a Yang-Mills/Maxwell theory, again with explicit examples. Detailed comparison of the two schemes of reconstruction is presented also for this theory. It seems to support, as well, physical non-equivalence of the two frames.Comment: 16 pages, no figures, version to appear in Phys Rev

An efficient parametric algorithm for octree traversal

An octree is a well known hierarchical spatial structure which is widely used in Computer Graphics algorithms. One of the most frequent operations is the computation of the octree voxels intersected by a straight line. This has a number of applications, such as ray-object intersection tests speed-up and visualisation of hierarchical density models by ray-casting. Several methods have been proposed to achieve this goal, which differ in the order in which intersected voxels are visited. In this paper we introduce a new top-down parametric method. The main difference with previously proposed methods is related to descent movements, that is, the selection of a child sub-voxel from the current one. This selection, as the algorithm, is based on the parameter of the ray and comprises simple comparisons. The resulting algorithm is easy to implement, and efficient when compared to other related top-down and bottom-up algorithms for octrees. Finally, a comparison with Kelvin’s method for binary trees is presented

C-Src, ERK1/2 and Rho kinasemediate hydrogen peroxide-induced vascular contraction in hypertension: Role ofTXA2, NAD(P)H oxidase andmitochondria

AIM: : The aim of this study was to analyse the signalling pathways involved in H2O2 vascular responses in hypertension. METHODS: Vascular function, thromboxane A2 (TXA2) production, oxidative stress and protein expression were determined in mesenteric resistance arteries (MRAs) from hypertensive (spontaneously hypertensive rats, SHR) and normotensive Wistar Kyoto (WKY) rats. RESULTS: H2O2 and the TP agonist U46619 induced greater contractile responses in MRA from SHR than WKY. Moreover, H2O2 increased TXA2 production more in SHR than in WKY. The c-Src inhibitor PP1 reduced H2O2 and U46619-induced contraction and TXA2 release in both strains. The ERK1/2 inhibitor PD98059 reduced H2O2 but not U46619-induced contraction only in SHR arteries. The Rho kinase inhibitor Y26372 reduced H2O2 and U46619-induced contractions only in SHR arteries. Basal c-Src, ERK1/2 and Rho kinase expression were greater in MRA from SHR than WKY. In SHR, the combination of PD98059 with the TP antagonist SQ29548 but not with Y27632 inhibited the H2O2 contraction more than each inhibitor alone. H2O2 and U46619 increased NAD(P)H oxidase activity and O2 production and decreased mitochondrial membrane potential in vessels from SHR. The effects induced by H2O2 were abolished by inhibitors of TXA2 synthase, ERK1/2 and c-Src. The mitochondrial antioxidant mitoTEMPO reduced H2O2-induced contraction and NAD(P)H oxidase activation. CONCLUSION: In arteries from WKY, c-Src mediates H2O2 contractile responses by modulating TXA2 release and TXA2 effect. In SHR, H2O2 induces c-Src dependent TXA2 release that provokes vascular contractile responses through Rho kinase, c-Src and O2 from NAD(P)H Oxidase and mitochondria. Moreover, ERK1/2 activation contributes to H2O2 contraction in SHR through effects on mitochondria/NAD(P)H Oxidase

Toll-like receptor 4 contributes to vascular remodelling and endothelial dysfunction in angiotensin II-induced hypertension

This is the peer-reviewed version of the following article: "Toll-like receptor 4 contributes to vascular remodelling and endothelial dysfunction in angiotensin II-induced hypertension", British Journal of Pharmacology 172.12 (2015): 3159-76 which has been published in final form at http://dx.doi.org/10.1111/bph.13117 This article may be used for non-commercial purposes in accordance with Wiley-VCH Terms and Conditions for Self-ArchivingBackground and Purpose Toll-like receptor 4 (TLR4) signalling contributes to inflammatory cardiovascular diseases, but its role in hypertension and the associated vascular damage is not known. We investigated whether TLR4 activation contributed to angiotensin II (AngII)-induced hypertension and the associated vascular structural, mechanical and functional alterations. Experimental Approach AngII was infused (1.44 mg·kg−1·day−1, s.c.) for 2 weeks in C57BL6 mice, treated with a neutralizing anti-TLR4 antibody or IgG (1 μg·day−1); systolic BP (SBP) and aortic cytokine levels were measured. Structural, mechanical and contractile properties of aortic and mesenteric arterial segments were measured with myography and histology. RT-PCR and Western blotting were used to analyse these tissues and cultured vascular smooth muscle cells (VSMC) from hypertensive rats (SHR). Key Results Aortic TLR4 mRNA levels were raised by AngII infusion. Anti-TLR4 antibody treatment of AngII-treated mice normalised: (i) increased SBP and TNF-α, IL-6 and CCL2 levels; (ii) vascular structural and mechanical changes; (iii) altered aortic phenylephrine- and ACh-induced responses; (iv) increased NOX-1 mRNA levels, superoxide anion production and NAD(P)H oxidase activity and effects of catalase, apocynin, ML-171 and Mito-TEMPO on vascular responses; and (v) reduced NO release and effects of L-NAME on phenylephrine-induced contraction. In VSMC, the MyD88 inhibitor ST-2825 reduced AngII-induced NAD(P)H oxidase activity. The TLR4 inhibitor CLI-095 reduced AngII-induced increased phospho-JNK1/2 and p65 NF-κB subunit nuclear protein expression. Conclusions and Implications TLR4 up-regulation by AngII contributed to the inflammation, endothelial dysfunction, vascular remodelling and stiffness associated with hypertension by mechanisms involving oxidative stress. MyD88-dependent activation and JNK/NF-κB signalling pathways participated in these alterationsThis work was supported by Ministerio de Economía y Competitividad (SAF2012-36400), Instituto de Salud Carlos III (Red de Investigación Cardiovascular RD12/0042/0024 and RD12/0042/0033) and URJC (PRIN13_CS12). AMB was supported by the Ramón y Cajal Program (RYC-2010-06473)

Universal procedure to cure future singularities of dark energy models

A systematic search for different viable models of the dark energy universe, all of which give rise to finite-time, future singularities, is undertaken, with the purpose to try to find a solution to this common problem. After some work, a universal procedure to cure all future singularities is developed and carefully tested with the help of explicit examples corresponding to each one of the four different types of possible singularities, as classified in the literature. The cases of a fluid with an equation of state which depends on some parameter, of modified gravity non-minimally coupled to a matter Lagrangian, of non-local gravity, and of isotropic turbulence in a dark fluid universe theory are investigated in detail

University or labor market: preferences of young people to their future by terminating bachelor studies and professional training

La orientación socio-educativa y la elección de continuar estudiando o insertarse en el mercado laboral es un tema esencial tanto para los estudiantes como para los estamentos educativos. Objetivos: El objetivo de este estudio es describir el área vocacional de interés preferente en alumnos del último año de Bachillerato y Ciclos Formativos de Grado Superior y relacionar esto con el género y área vocacional. Método: Se desarrolla un estudio descriptivo de corte transversal sobre 1164 estudiantes, aplicándosele el CIBAP (Hernández-Franco, 2001). Resultados: Como principales resultados se obtuvo que la mayoría de los participantes procede de Bachillerato. Los participantes masculinos son mayoría en Ciclos Formativos y entre sus preferencias se hallan la investigación técnica, técnica aplicada y deportes. Por otro lado, las participantes femeninas son mayoría en bachillerato y señalan como áreas vocacionales las ciencias de la salud, la enseñanza y la orientación. Conclusiones: Las cifras obtenidas muestran la importancia de generar programas en orientación en cursos anteriores que promuevan el conocimiento de las diversas opciones educativas y laborales, y que intenten paliar en cierto modo la tendencia a seguir teniendo prototipos de índole sexista en la educación.Socio-educational orientation and the choice to continue studying or to be inserted in the labour market are subjects of interest for students and educational establishments. Aims: This study aims to determine the vocational area of preferential interest in students of last year of bachelor’s degree and superior grade of formative course from Granada, as well as to know whether there are relationships between modality of study, gender and vocational areas. Method: A descriptive and cross-sectional study was carried out on a sample of 1164 students. Results: As main results it was obtained that the majority of participants comes from bachellor’s degree. In addition, most of male respondents studied superior grades of formative course, being their preferences were technical research, applied technique and sports. On the other hand, most of female respondents studied bachelor’s degree and their preferences were health’s sciences, teaching and orientation. Conclusions: These data show the need to generate programs of orientation in previous courses in order to promote the knowledge of the various educational and labor options, as well as to mitigate the tendency to continue having sexist prototypes in education

Reconstruction of the equation of state for the cyclic universes in homogeneous and isotropic cosmology

We study the cosmological evolutions of the equation of state (EoS) for the universe in the homogeneous and isotropic Friedmann-Lema\^{i}tre-Robertson-Walker (FLRW) space-time. In particular, we reconstruct the cyclic universes by using the Weierstrass and Jacobian elliptic functions. It is explicitly illustrated that in several models the universe always stays in the non-phantom (quintessence) phase, whereas there also exist models in which the crossing of the phantom divide can be realized in the reconstructed cyclic universes.Comment: 29 pages, 8 figures, version accepted for publication in Central European Journal of Physic

Correlación en triatlón masculino entre fases y resultado inal en los JJOO de Pekin 2008

Introduction: Triathlon is a sport that is composed of the combination of three phases of competition. The most widespread triathlon is the Olympic, and is used in the Olympic Games, consists of swim, 1.5 km, bike 40 km and run 10 km. Aims: To determine the influence of the duration and order of the phases with the final result of the test in the male triathlon in the Olympic Games Beijing 2008. Method: We analyzed the data of 50 athletes who finished. Results and conclusions: The final result is not determined by the order of the phases, nor by the duration of these, the least influential phase has been Bike with rs = .039; p = .351; Being the one that has occupied the most time with 52.55%; The most influential phase was the Run phase with rs = .991; and p = .000; and R2 = .982 and with duration 30.21%.Introducción: El triatlón es un deporte que se compone de la combinación de tres fases de competición. La modalidad de triatlón más extendida es la olímpica, y es utilizada en los Juegos Olímpicos (JJOO), se compone de nado 1,5 km, bicicleta 40 km y carrera 10 km. Objetivos: Determinar la influencia de la duración y orden de las fases con el resultado final de la prueba en el triatlón masculino en los JJOO Pekín 2008. Método: Se analizaron los datos de 50 deportistas que finalizaron. Resultados y conclusiones: El resultado final no viene determinado ni por el orden de las fases, ni por la duración de estas, la fase menos influyente ha sido Bike con rs= 0,039; p =0,351; siendo la que más tiempo ha ocupado con un 52,55%; la fase más influyente ha sido la fase Run con rs=0,991; y p=0,000; y R2=0,982 y con duración 30,21%

Massive Consumption of Gelatinous Plankton by Mediterranean Apex Predators

Stable isotopes of carbon and nitrogen were used to test the hypothesis that stomach content analysis has systematically overlooked the consumption of gelatinous zooplankton by pelagic mesopredators and apex predators. The results strongly supported a major role of gelatinous plankton in the diet of bluefin tuna (Thunnus thynnus), little tunny (Euthynnus alletteratus), spearfish (Tetrapturus belone) and swordfish (Xiphias gladius). Loggerhead sea turtles (Caretta caretta) in the oceanic stage and ocean sunfish (Mola mola) also primarily relied on gelatinous zooplankton. In contrast, stable isotope ratios ruled out any relevant consumption of gelatinous plankton by bluefish (Pomatomus saltatrix), blue shark (Prionace glauca), leerfish (Lichia amia), bonito (Sarda sarda), striped dolphin (Stenella caerueloalba) and loggerhead sea turtles (Caretta caretta) in the neritic stage, all of which primarily relied on fish and squid. Fin whales (Balaenoptera physalus) were confirmed as crustacean consumers. The ratios of stable isotopes in albacore (Thunnus alalunga), amberjack (Seriola dumerili), blue butterfish (Stromaeus fiatola), bullet tuna (Auxis rochei), dolphinfish (Coryphaena hyppurus), horse mackerel (Trachurus trachurus), mackerel (Scomber scombrus) and pompano (Trachinotus ovatus) were consistent with mixed diets revealed by stomach content analysis, including nekton and crustaceans, but the consumption of gelatinous plankton could not be ruled out completely. In conclusion, the jellyvorous guild in the Mediterranean integrates two specialists (ocean sunfish and loggerhead sea turtles in the oceanic stage) and several opportunists (bluefin tuna, little tunny, spearfish, swordfish and, perhaps, blue butterfish), most of them with shrinking populations due to overfishing