VHE Emission from Magnetic Reconnection in the RIAF of SgrA*

The cosmic-ray (CR) accelerator at the galactic centre (GC) is not yet established by current observations. Here we investigate the radiative-inefficient accretion flow (RIAF) of Sagittarius A* (SgrA*) as a CR accelerator assuming acceleration by turbulent magnetic reconnection, and derive possible emission fluxes of CRs interacting within the RIAF (the central $\sim10^{13}$cm). The target environment of the RIAF is modelled with numerical, general relativistic magneto-hydrodynamics (GRMHD) together with leptonic radiative transfer simulations. The acceleration of the CRs is not computed here. Instead, we inject CRs constrained by the magnetic reconnection power of the accretion flow and compute the emission/absorption of $\gamma$-rays due to these CRs interacting with the RIAF, through Monte Carlo simulations employing the {\tt CRPropa 3} code. The resulting very-high-energy (VHE) fluxes are not expected to reproduce the point source HESS J1745-290 as the emission of this source is most likely produced at pc scales. The emission profiles derived here intend to trace the VHE signatures of the RIAF as a CR accelerator and provide predictions for observations of the GC with improved angular resolution and differential flux sensitivity as those of the forthcoming Cherenkov Telescope Array (CTA). Within the scenario presented here, we find that for mass accretion rates $\gtrsim 10^{-7}$M$_\odot$yr$^{-1}$, the RIAF of SgrA* produces VHE fluxes which are consistent with the H.E.S.S. upper limits for the GC and potentially observable by the future CTA. The associated neutrino fluxes are negligible compared with the diffuse neutrino emission measured by the IceCube.Comment: Accepted for publication in the Ap

Mediator assisted cooling in quantum annealing

We show a significant reduction of errors for an architecture of quantum annealers (QA) where bosonic modes mediate the interaction between qubits. These systems have a large redundancy in the subspace of solutions, supported by arbitrarily large bosonic occupations. We explain how this redundancy leads to a mitigation of errors when the bosonic modes operate in the ultrastrong coupling regime. Numerical simulations also predict a large increase of qubit coherence for a specific annealing problem with mediated interactions. We provide evidences that noise reduction occurs in more general types of quantum computers with similar architectures.Comment: 5 pages + Supplementa

Aplicación del método indirecto para la obtención de una matriz insumo-producto año 2002 para VIII Región del Bío-Bío

El objetivo de este trabajo, es presentar una serie actualizada de matrices (12*12) 1996-2002 para la VIII región del Bío Bío y el diseño de algoritmo, desarrollado mediante MATLAB, para su aplicación directa a matrices regionales implementadas en planilla electrónica EXCEL.En esta perspectiva se identifican los modelos utilizados; así como,los requerimientos de información y supuestos teóricos necesarios para estimar la matriz inversa para la economía regional, mediante la utilización de las tablas input-output (12 x 12 sectores). Las conclusiones se derivan de la propuesta metodológica Chernery Watanabe, Rasmussen y Chi-cuadrado.Finalmente, se realiza un análisis comparativo (1996 -2002) del cambio estructural acontecido en los sectores productivos, reflejado en la matriz inversa de la economía de la VIII Región

Fisiopatología de los Cuerpos Libres Intraarticulares : estudio Experimental

La cubierta cartilaginosa de los cuerpos libres intraarticulares tiene un origen no bien conocido. Se ha realizado un estudio experimental en conejos, liberando fragmentos osteocondrales en la cavidad articular de la rodilla, estudiando sus cambios histológicos desde la primera semana hasta el año. En todos los casos los fragmentos osteocondrales se observaron adheridos a la membrana sinovial. Hubo una remodelación progresiva del componente óseo y cartilaginoso, cubriéndose todo el fragmento de una cubierta fibrocartilaginosa, reabsorbiéndose el hueso central y formándose nuevo hueso en la porción periférica debajo del fibrocartí- lago. Todos los cambios tisulares dependieron de la actividad de la membrana sinovial. No pudo demostrarse crecimiento del cartílago articular.It is not well known the origin of the cartilaginous outer layer of the intrarticular loose bodies. An experimental study has been carried out on rabbits loosening out osteochondral fragments into the articular cavity of the kne e joint and studying their histological changes between the first week and the first year. The osteochondral fragments wer e found adhered to the synovial membrane in all cases. A proggressive remodeling tood place within the osseous and cartilaginous components, the whole fragment became covered by a fibrocartilaginous covering, the central bone was reabsorbed and new bone was formed at the peripheral portion unde r fibrocartilage. All tissue change s wer e dependent on synovial membrane activity. Growth of articular cartilage could not be demonstrated

Cicatrización del fibrocartílago meniscal de la Rodilla : estudio Experimental

Para estudiar la cicatrización de las lesiones meniscales se ha realizado un estudio experimental en conejos. Se han practicado tres tipos de lesiones en el menisco, transversal, longitudinal parameniscal y longitudinal interna alejeda del paramenisco. Posteriormente el defecto creado era reparado mediante puntos sueltos con material reabsorvible. Se ha estudiado el fenómeno de cicatrización desde el punto de vista histológico desde la semana a los tres meses. Los resultados muestran que la cicatrización es fundamentalmente extrínseca a partir de la capacidad plástica de la membrana sinovial. Las heridas longitudinales parameniscales cicatrizaron sin dificultad, las transversales casi en toda su anchura y las longitudinales en zona avascular cicatrizaron principalmente en su porción anterior gracias a la invasión de sinovial hiperplásica desde la inserción tibial del ligamento cruzado anterior.To study the healing of meniscal tears, the authors hav e carried out an experimental work in rabbits. They performed three types of tears in the internal menisci, radial, peripheral longitudinal (in the parameniscal zone) and longitudinal within of the parameniscus. The menisci were reparated by suture with absorbible material. The healing phenomenon has been histologically studied from the first wee k to three months after. The results showed that the cicatrization is mainly extrinsic by the plastic capacity of sinovial membrane. The longitudinal tears in the parameniscus heal without difficulty, the transversal tears almost in their whol e width and the longitudinal tears at the avascular zone healed principally in the anterior portion by the invasion of hyperplasic sinovial from the tibial insertion of the anterior cruciate ligament

Fibrocartílago meniscal como biomaterial de sustitución en los Defectos Osteocondrales. Estudio experimental en el conejo con injertos homólogos

Los autores presentan un estudio experimental en el cual han empleado homoinjertos de fibrocartílago meniscal, para reparar defectos osteocondrales localizados en zona de carga, del cóndilo medial de la rodilla del conejo. Han sido estudiados 33 animales, realizando un estudio histológico, con periodos de evolución comprendidos entre una semana y 22 meses. Los homoinjertos meniscales parecen ser capaces de restaurar una superficie articular funcional. Conservan su estructura y celularidad a lo largo de toda la experiencia consiguiendo un perfecto anclaje al lecho óseo, adaptándose a la carga y sin producir cambios en el cartílago articular vecino. No se han producido rechazos.The authors report on an experimental study, employing meniscal fibrocartilage homo grafts to repair osteochondral defects in the weightbearing area of medial condile of rabbit knee. Thirty-three animals were studied by histological means for periods of one week to 22 months. The meniscal fibrocartilage homograft appeared capable of restoring a functional articular surface, maintaining its entire histological structure and celularity throughout the experiment, obtaining a perfect union with the bone tissue, adapting to the weightbearing and not modifying the neighboring articular surface. No evidence of rejection was observed