453 research outputs found

    Spectra of weighted algebras of holomorphic functions

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    We consider weighted algebras of holomorphic functions on a Banach space. We determine conditions on a family of weights that assure that the corresponding weighted space is an algebra or has polynomial Schauder decompositions. We study the spectra of weighted algebras and endow them with an analytic structure. We also deal with composition operators and algebra homomorphisms, in particular to investigate how their induced mappings act on the analytic structure of the spectrum. Moreover, a Banach-Stone type question is addressed.Comment: 25 pages Corrected typo

    Life-cycle assessment of the use of peach pruning residues for electricity generation

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    Biomass residues from permanent crops might be an alternative fuel for energy generation in a local market with limited transport distances. Moreover, as activities related to CO2 reduction are of special attention in the European Union (EU), sustainable use of resources plays an important role in climate change mitigation. In this paper, a life-cycle assessment (LCA) of the integrated value chain from peach pruning residues for electricity generation is presented and compared with the common practice including the mulching process of the pruned biomass in an orchard. It was shown that biomass harvesting, chipping and its delivery to a power plant-the Pruning-to-Energy (PtE) scenario - is feasible from an environmental point of view. The total global warming potential (GWP) of this value chain was 200 kg CO2 eq.·ha-1 (or 27 kg CO2 eq.·GJ-1). In turn, the mulching and leaving of the pruned biomass in an orchard-the pruning-to-soil (PtS) scenario - is characterized by a CO2 equivalent of 2360 kg-ha-1. Other impact categories showed a lower environmental impact for the PtE scenario as well. When considering the Spanish electricity-mix instead of coal-based electricity, the PtS scenario score better in most impact categories, but the GWP for the PtE scenario remains lower

    Distribution of melanopsin positive neurons in pigmented and albino mice: evidence for melanopsin interneurons in the mouse retina.

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    Here we have studied the population of intrinsically photosensitive retinal ganglion cells (ipRGCs) in adult pigmented and albino mice. Our data show that although pigmented (C57Bl/6) and albino (Swiss) mice have a similar total number of ipRGCs, their distribution is slightly different: while in pigmented mice ipRGCs are more abundant in the temporal retina, in albinos the ipRGCs are more abundant in superior retina. In both strains, ipRGCs are located in the retinal periphery, in the areas of lower Brn3a(+)RGC density. Both strains also contain displaced ipRGCs (d-ipRGCs) in the inner nuclear layer (INL) that account for 14% of total ipRGCs in pigmented mice and 5% in albinos. Tracing from both superior colliculli shows that 98% (pigmented) and 97% (albino) of the total ipRGCs, become retrogradely labeled, while double immunodetection of melanopsin and Brn3a confirms that few ipRGCs express this transcription factor in mice. Rather surprisingly, application of a retrograde tracer to the optic nerve (ON) labels all ipRGCs, except for a sub-population of the d-ipRGCs (14% in pigmented and 28% in albino, respectively) and melanopsin positive cells residing in the ciliary marginal zone (CMZ) of the retina. In the CMZ, between 20% (pigmented) and 24% (albino) of the melanopsin positive cells are unlabeled by the tracer and we suggest that this may be because they fail to send an axon into the ON. As such, this study provides the first evidence for a population of melanopsin interneurons in the mammalian retina

    Stabilized vortex solitons in layered Kerr media

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    In this letter we demonstrate the possibility of stabilizing beams with angular momentum propagating in Kerr media. Large propagation distances without filamentation can be achieved in layered media with alternating focusing and defocusing nonlinearities. Stronger stabilization can be obtained with the addition of an incoherent beam.Comment: 4 pages, 3 figures. We have removed the sentence "Thus, they erroneously point out to the existence of fully stabilized vortex solitons" in page 2, column 2, line 7-8, because it might be confusin

    Stabilization of high-order solutions of the cubic Nonlinear Schrodinger Equation

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    In this paper we consider the stabilization of non-fundamental unstable stationary solutions of the cubic nonlinear Schrodinger equation. Specifically we study the stabilization of radially symmetric solutions with nodes and asymmetric complex stationary solutions. For the first ones we find partial stabilization similar to that recently found for vortex solutions while for the later ones stabilization does not seem possible

    Hot spring arsenic distribution in the Andes Cordillera (18-52oS)

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    1 pĂĄgina.-- Resumen presentado en el 23rd International Applied Geochemistry Symposium (IAGS), Oviedo, 14-19 Jun. 2007.-- Edited by Jorge Loredo PĂ©rez.One of the most extensive areas around the world where the low quality of groundwater due to the presence of high concentrations of arsenic of natural origin is a major concern is Argentina-Chile. The exhaustive knowledge of the geological, hydrogeological, and geochemical setting can be very effective to define an alternative strategy to mitigate the arsenic problem in water. The magnitude and extension of the arsenic affected areas is not well known. In order to understand the source of the arsenic, the development of a database of thermal waters in the Andean region is in progress. We present in this work the assessment of more than 360 hot springs and wells located in the Andes between 14 and 52oS of latitude. This information comes from projects carried out by our team in the area and from references. The hot waters with higher concentrations of arsenic (50-30,000 ÎŒg/l) are mainly located in volcanic areas with hydrothermal activity of the Andes Cordillera between 14 and 28oS.Peer reviewe

    Molecular data confirms the existence of distinct lineages within Lumbricus friendi (Cognetti 1904) and related “friends”

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    Lumbricus friendi is a lumbricid earthworm mainly found in western Europe, considerably less well studied than its close relative L. terrestris and until now, has not been a subject of taxonomical debate. However, its disjointed geographical distribution suggesting striking similarities to the Celtic fringes and of the so-called “Lusitanian” species merits further investigation. Our aim was to examine the genetic variation of this species and other related taxa within the genus (L. terrestris, L. rubellus, L. rubellus friendoides and L. friendi bouchei) to test for the existence of cryptic lineages that might explain its current distribution. Using mitochondrial (16S and COI) and nuclear (Amplified Fragment Length Polymorphism, AFLP) markers, we provide the first genetic basis not only to support the recent claim that L. friendi bouchei should be elevated to species rank (L. bouchei Zicsi and Csuzdi 1999), but also to conclude that L. rubellus friendoides is a valid species too, deserving a new name (L. heracleus stat. nov.). In addition, the AFLP results indicated the existence of a high cryptic diversity within L. friendi populations, which lacked geographic structure, resulting in the French samples being genetically closer to those from Ireland and Wales than to the Spanish ones. Our findings further highlight the likelihood that L. friendi and L. bouchei might have been overlooked or confounded with L. terrestris/L. herculeus and question the reliability of L. friendi records reported in the literature and those deposited in museums and sequence libraries (we provide evidence that this seem to be the case with two examples). We therefore advocate for a better link between morphological diagnostic characters and molecular sequences and the taxonomical validation of museums’ collections and sequence repositories

    Real time approach to tunneling in open quantum systems: decoherence and anomalous diffusion

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    Macroscopic quantum tunneling is described using the master equation for the reduced Wigner function of an open quantum system at zero temperature. Our model consists of a particle trapped in a cubic potential interacting with an environment characterized by dissipative and normal and anomalous diffusion coefficients. A representation based on the energy eigenfunctions of the isolated system, i.e. the system uncoupled to the environment, is used to write the reduced Wigner function, and the master equation becomes simpler in that representation. The energy eigenfunctions computed in a WKB approximation incorporate the tunneling effect of the isolated system and the effect of the environment is described by an equation that it is in many ways similar to a Fokker-Planck equation. Decoherence is easily identified from the master equation and we find that when the decoherence time is much shorter than the tunneling time the master equation can be approximated by a Kramers like equation describing thermal activation due to the zero point fluctuations of the quantum environment. The effect of anomalous diffusion can be dealt with perturbatively and its overall effect is to inhibit tunneling.Comment: 25 pages, 1 figur

    Hif-1α knockdown reduces glycolytic metabolism and induces cell death of human synovial fibroblasts under normoxic conditions

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    [Abstract] Increased glycolysis and HIF-1α activity are characteristics of cells under hypoxic or inflammatory conditions. Besides, in normal O2 environments, elevated rates of glycolysis support critical cellular mechanisms such as cell survival. The purpose of this study was to analyze the contribution of HIF-1α to the energy metabolism and survival of human synovial fibroblasts (SF) under normoxic conditions. HIF-1α was silenced using lentiviral vectors or small-interfering RNA (siRNA) duplexes. Expression analysis by qRT-PCR and western blot of known HIF-1α target genes in hypoxia demonstrated the presence of functional HIF-1α in normoxic SF and confirmed the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a HIF-1α target even in normoxia. HIF-1α silencing induced apoptotic cell death in cultured SF and, similarly, treatment with glycolytic, but not with OXPHOS inhibitors, induced SF death. Finally, in vivo HIF-1α targeting by siRNA showed a significant reduction in the viability of human SF engrafted into a murine air pouch. Our results demonstrate that SF are highly dependent on glycolytic metabolism and that HIF-1α plays a regulatory role in glycolysis even under aerobic conditions. Local targeting of HIF-1α provides a feasible strategy to reduce SF hyperplasia in chronic arthritic diseases.Instituto de Salud Carlos III; FIS 12/439Instituto de Salud Carlos III; RETICS RD12/009Instituto de Salud Carlos III; CP13/00014Comunidad de Madrid; RAPHYME-CM S2010/BMD235

    Eficacia y eficiencia de Leader 11 en AndalucĂ­a. AproximaciĂłn a un Ă­ndice-resultado en materia de turismo rural

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    The evaluation has turned into a strategic element of differentiation, into the measurement into that allows to demonstrate his own beneficiaries, that the application of the public or private resources, it is as suitable as possible. To evaluate is necessary a system of indicators, which answer to five big types of which we will centre on two: efficiency (the effort inverted in terms of plysical, human or financial resources and the obtained results) and effectiveness (the impacts or results of the program with regard to his aims). In this article we try to put of manifest as the evaluation of the measurement B.3 (tourist activities) it allows across the analysis of the efficiency (projects) and the effectiveness (investment) in LEADER 11, one approximation in the construction of a proved index.La evaluación se ha convertido en un elemento estratégico de diferenciación, en la medida en que permite demostrar a sus propios beneficiarios, que la aplicación de los recursos públicos o privados, es la más adecuada posible. Para evaluar los programas de desarrollo rural es necesario un sistema de indicadores, que responden a cinco grandes tipos de los que nos centraremos en dos: eficiencia (el esfuerzo invertido en términos de recursos físicos, humanos o financieros y los resultados obtenidos) y eficacia (los impactos o resultados del programa respecto a sus objetivos). En este articulo tratamos de poner de manifiesto como la evaluación de la medida B.3 (actividades turísticas) permite, a través del análisis de la eficacia (proyectos) y la eficiencia (inversión) en LEADER 11, una primera aproximación en la construcción de un índice resultado
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