X-ray and gamma-ray orbital variability from the gamma-ray binary HESS J1832-093

Context. Gamma-ray binaries are systems composed of a massive star and a compact object whose interaction leads to particle acceleration up to relativistic energies. In the last fifteen years, a few binaries have been discovered to emit at high energies, but their number is still scarce. The TeV source HESS J1832-093 has been proposed as a binary candidate, although its nature is unclear. Neither a GeV counterpart nor a period was found for it. Aims. The purpose of this work is to search for a gamma-ray source at GeV energies to understand the origin of the TeV signal. For an unambiguous identification of its binary nature, finding an orbital modulation is crucial. Methods. We have analysed data spanning more than 10 years from the Fermi Large Area Telescope (Fermi-LAT), together with Swift archival observations taken between 2015 and 2018, using both the X-Ray Telescope (XRT) and UltraViolet and Optical Telescope (UVOT). We searched for periodicities in both X-ray and gamma-ray bands using a Lomb-Scargle periodogram. Results. We find a periodic modulation of \sim 86 days in the X-ray source XMMU J183245-0921539, together with indications of gamma-ray modulation with a compatible period in 4FGL J1832.9-0913. Neither an optical nor an UV counterpart is found at the X-ray source location. The overall spectral energy distribution strongly resembles the known gamma-ray binary HESS J0632+057. Conclusions. Both the spectrum and the discovery of an orbital period allow the identification of the TeV source HESS J1832-093 as a new member of the gamma-ray binary class.Comment: 9 pages, 9 figures. Accepted by A&

Nutrient uptake in a stream affected by hydropower plants: comparison between stream channels and diversion canals

12 páginas, 3 figuras, 4 tablas.Small hydropower plants divert part of the water from wide and physically complex stream channels with active hyporheic areas to narrow and hydraulically simple concrete canals, and thus, might affect nutrient dynamics. We compared nutrient uptake in diversion canals and in stream channels in the Leitzaran Stream (Basque Country, northern Spain). We predicted that simple morphology in diversion canals will result in lower nutrient uptake in canals than in stream channels. Periphytic chlorophyll and biomass did not differ significantly between reach types. Water was significantly deeper and faster in canals than in stream channels, but the transient storage zone did not differ significantly between reach types. There were no significant differences between uptake length for neither phosphate nor ammonium between reach types. Uptake length in both stream channels and diversion canals decreased with discharge, in a pattern similar to that previously described for pristine rivers across the world. Uptake velocity and uptake rate for phosphate did not differ signifi- cantly between reach types, but in the case of ammonium both retention metrics were significantly larger in the diversion canals. Results suggest that although hydropower schemes have minor effects on nutrient retention, these depend on the proportion of flow diverted.This research has been funded by the Spanish Department of Science and Technology, the University of the Basque Country, and the European Regional Development Fund, through projects 9/UPV00118.310-14476/ 2002 and BOS2003-04466.Peer reviewe

El desarrollo de la competencia social y ciudadana en alumnado de educación secundaria con la metodología del aprendizaje-servicio

En la experiencia de innovación docente que aquí presentamos están implicadas tres instituciones: la Universitat Jaume I de Castellón y dos centros de la localidad de Betxí: el Instituto de Educación Secundaria (IES) y la Escuela Popular de Adultos (EPA). Desde la Universitat Jaume I profesorado especializado en la metodología del Aprendizaje Servicio preparó a docentes y alumnado del instituto, concretamente al grupo que participa de un PCPI (Programa de Cualificación Profesional Inicial) para desarrollar competencias sociales y ciudadanas, al mismo tiempo que se les formaba para aprender contenidos relacionados con la asignatura de Educación Física. El elemento motivador del aprendizaje era el poder aplicar los conocimientos aprendidos prestando un servicio a las mujeres, de edad comprendida entre 70-80 años, que realizaban el segundo curso del primer nivel en la EPA. Este colectivo presenta limitaciones en la movilidad articular y la fuerza. Los jóvenes debían indagar acerca de la temática en cuestión y de los destinatarios del programa y diseñar las sesiones que sería necesario aplicar a las alumnas adultas, durante cuatro meses. La fase de análisis y diseño se llevaba a cabo en horario lectivo, mientras que la intervención se realizaba en horario libre. Presentamos aquí los resultados satisfactorios que este tipo de metodología tiene para todos los participantes.Peer Reviewe

Deciphering the iron side of stroke : Neurodegeneration at the crossroads between iron dyshomeostasis, excitotoxicity, and ferroptosis

Altres ajuts: We acknowledge the funding received from "la Caixa" Foundation CI15-00009 and from the European Institute of Innovation and Technology (EIT) PoC-2016-SPAIN-04. EIT receives support from the European Union's Horizon 2020 research and innovation program.In general, iron represents a double-edged sword in metabolism in most tissues, especially in the brain. Although the high metabolic demands of brain cells require iron as a redox-active metal for ATP-producing enzymes, the brain is highly vulnerable to the devastating consequences of excessive iron-induced oxidative stress and, as recently found, to ferroptosis as well. The blood-brain barrier (BBB) protects the brain from fluctuations in systemic iron. Under pathological conditions, especially in acute brain pathologies such as stroke, the BBB is disrupted, and iron pools from the blood gain sudden access to the brain parenchyma, which is crucial in mediating stroke-induced neurodegeneration. Each brain cell type reacts with changes in their expression of proteins involved in iron uptake, efflux, storage, and mobilization to preserve its internal iron homeostasis, with specific organelles such as mitochondria showing specialized responses. However, during ischemia, neurons are challenged with excess extracellular glutamate in the presence of high levels of extracellular iron; this causes glutamate receptor overactivation that boosts neuronal iron uptake and a subsequent overproduction of membrane peroxides. This glutamate-driven neuronal death can be attenuated by iron-chelating compounds or free radical scavenger molecules. Moreover, vascular wall rupture in hemorrhagic stroke results in the accumulation and lysis of iron-rich red blood cells at the brain parenchyma and the subsequent presence of hemoglobin and heme iron at the extracellular milieu, thereby contributing to iron-induced lipid peroxidation and cell death. This review summarizes recent progresses made in understanding the ferroptosis component underlying both ischemic and hemorrhagic stroke subtypes

Aportació a la flora micològica del Parc Nacional d'Ordesa i Monte Perdido (Prineus Centrals)

Present em un catàleg florístic de les espècies recol.lectades en el curs d'una exploració del Parc Nacional d'Ordesa i Monte Perdido (Pirineus centrals) a la tardor de 1989. en el qual comentem i il.lustrem les que considerem més interessants. com són Lentinus adhaerens (A. et S. : Fr.) Fr.. Naucoria permixta P. D. Orton, Tephrocybe baeosperma (Romagn.) Moser i Xeromphalina cornuí (Quél.) Favre

Aportació a la flora micològica del Parc Nacional d'Ordesa i Monte Perdido (Pirineus Centrals)

Presentem un catàleg florístic de les espècies recol·lectades en el curs d'una exploració de l Parc Nacional d'Ordesa i Monte Perdido (Pirineus centrals) a la tardor de 1989, en el qual comentem i Il·lust rem les que considerem més interessants, com són Lentinus adhaerens (A. et S. : Fr.) Fr., Naucoria permixta P. D. Orton, Tephrocybe baeosperma (Romagn.) Moser i Xeromphalina cornui (Quél.) Favre.Contribution to the fungus flora or the National Park or Ordesa and Monte Perdido (Central Pyrenean range, NE Spain). This work is a florístic catalogue of the fungi collected during an exploration of rhe National Park of Ordesa and Monte Perdido, in the fall of 1989. Commentaries and iconography are provided in the case or int eresting species, such as Lentinus adhaerens (A. et S. : Fr.) Fr., Naucoria permixta P. D. Orton, Tephrocybe baeosperma (Romagn.) Moser and Xeromphalina cornui (Quél.) Favre

Aportació a la flora micològica del Parc Nacional d'Ordesa i Monte Perdido (Pirineus Centrals)

Presentem un catàleg florístic de les espècies recol·lectades en el curs d'una exploració de l Parc Nacional d'Ordesa i Monte Perdido (Pirineus centrals) a la tardor de 1989, en el qual comentem i Il·lust rem les que considerem més interessants, com són Lentinus adhaerens (A. et S. : Fr.) Fr., Naucoria permixta P. D. Orton, Tephrocybe baeosperma (Romagn.) Moser i Xeromphalina cornui (Quél.) Favre.Contribution to the fungus flora or the National Park or Ordesa and Monte Perdido (Central Pyrenean range, NE Spain). This work is a florístic catalogue of the fungi collected during an exploration of rhe National Park of Ordesa and Monte Perdido, in the fall of 1989. Commentaries and iconography are provided in the case or int eresting species, such as Lentinus adhaerens (A. et S. : Fr.) Fr., Naucoria permixta P. D. Orton, Tephrocybe baeosperma (Romagn.) Moser and Xeromphalina cornui (Quél.) Favre

Effects of cholesterol on the binding of the precursor neurotransmitter tryptophan to zwitterionic membranes

The characterization of the microscopical forces between the essential a-amino-acid tryptophan, precursor of the neurotransmitter serotonin and of the hormone melatonin, and the basic components of cell membranes and their environments (phospholipids, cholesterol, ionic species, and water) is of central importance to elucidate their local structure and dynamics as well as the mechanisms responsible for the access of tryptophan to the interior of the cell. We have performed nanosecond molecular dynamics simulations of tryptophan embedded in model zwitterionic bilayer membranes made by di-palmitoyl-phosphatidyl-choline and cholesterol inside aqueous sodium-chloride solution in order to systematically examine tryptophan-lipid, tryptophan-cholesterol, and tryptophan-water interactions under liquid-crystalline phase conditions. Microscopic properties such as the area per lipid, lipid thickness, radial distribution functions, hydrogen-bonding lengths, atomic spectral densities, and self-diffusion coefficients have been evaluated. Our results show that the presence of tryptophan significantly affects the structure and dynamics of the membrane. Tryptophan spends long periods of time at the water-membrane interface, and it plays a central role by bridging a few lipids and cholesterol chains by means of hydrogen-bonds. The computed spectral densities, in excellent agreement with experimental infrared and Raman data, revealed the participation of each atomic site of tryptophan to the complete spectrum of the molecule. Tryptophan self-diffusion coefficients have been found to be in between 10^(-7) and 10^(-6) cm^2/s and strongly depending of the concentration of cholesterol in the system.Postprint (published version

Physisorption of helium on a TiO2(110) surface: periodic and finite clusters approaches

Workshop CMST Action CM1200 CODECS: Holistic Computational Spectroscopy, 16-18 November 2011, Pisa, Italy. http://codecs.sns.it/index.php/Holistic_Computational_SpectroscopyAs a proto-typical case of physisorption on an extended transition-metal oxide surface, the interaction of a helium atom with a TiO2(110) surface is studied here by using finite cluster and periodic approaches and both wavefunction-based (post Hartree-Fock) quantum chemistry methods, as well as density functional theory. The finite cluster approach is applied to provide reference results at coupled-cluster and perturbative second-order Möller-Plesset levels of theory. It is shown that once the basis set is specifically tailored to minimize the basis set superposition error, periodic calculations using the Perdew Burke-Ernzerhof functional yield short and medium-range interaction potentials in very reasonable agreement with those obtained using the correlated wave-function-based methods, while small long-range dispersion corrections are necessary to reproduce the correct asymptotic behavior. This study is aimed at the simulation of helium droplet-mediated deposition of metallic clusters on oxide surfaces.Peer Reviewe