1,512 research outputs found

    Circular strings, wormholes and minimum size

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    The quantization of circular strings in an anti-de Sitter background spacetime is performed, obtaining a discrete spectrum for the string mass. A comparison with a four-dimensional homogeneous and isotropic spacetime coupled to a conformal scalar field shows that the string radius and the scale factor have the same classical solutions and that the quantum theories of these two models are formally equivalent. However, the physically relevant observables of these two systems have different spectra, although they are related to each other by a specific one-to-one transformation. We finally obtain a discrete spectrum for the spacetime size of both systems, which presents a nonvanishing lower bound.Comment: 11 pages, LaTeX2e, minor change

    Himno a la patrona de la infantería española [Música notada manuscrita] ]

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    Autógrafo firmado: Toledo y agosto, Madrid y noviembre 1918, Jacinto GuerreroÍncipit: Salve, salve, madre santaPapel pautado de la Sociedad de Autores Españoles-MadridCopia digital. Madrid : Fundación Jacinto e Inocencio Guerrero, 201

    Unveiling Neutrino Mixing and Leptonic CP Violation

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    We review the present understanding of neutrino masses and mixings, discussing what are the unknowns in the three family oscillation scenario. Despite the anticipated success coming from the planned long baseline neutrino experiments in unraveling the leptonic mixing sector, there are two important unknowns which may remain obscure: the mixing angle θ13\theta_{13} and the CP-phase δ\delta. The measurement of these two parameters has led us to consider the combination of superbeams and neutrino factories as the key to unveil the neutrino oscillation picture.Comment: Invited brief review, 18 pages, 6 figure

    Altered sleep and neurovascular dysfunction in alpha-synucleinopathies: the perfect storm for glymphatic failure

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    Clinical and cognitive progression in alpha-synucleinopathies is highly heterogeneous. While some patients remain stable over long periods of time, other suffer early dementia or fast motor deterioration. Sleep disturbances and nocturnal blood pressure abnormalities have been identified as independent risk factors for clinical progression but a mechanistic explanation linking both aspects is lacking. We hypothesize that impaired glymphatic system might play a key role on clinical progression. Glymphatic system clears brain waste during specific sleep stages, being blood pressure the motive force that propels the interstitial fluid through brain tissue to remove protein waste. Thus, the combination of severe sleep alterations, such as REM sleep behavioral disorder, and lack of the physiological nocturnal decrease of blood pressure due to severe dysautonomia may constitute the perfect storm for glymphatic failure, causing increased abnormal protein aggregation and spreading. In Lewy body disorders (Parkinson’s disease and dementia with Lewy bodies) the increment of intraneuronal alpha-synuclein and extracellular amyloid-β would lead to cognitive deterioration, while in multisystemic atrophy, increased pathology in oligodendroglia would relate to the faster and malignant motor progression. We present a research model that may help in developing studies aiming to elucidate the role of glymphatic function and associated factors mainly in alpha-synucleinopathies, but that could be relevant also for other protein accumulation-related neurodegenerative diseases. If the model is proven to be useful could open new lines for treatments targeting glymphatic function (for example through control of nocturnal blood pressure) with the objective to ameliorate cognitive and motor progression in alpha-synucleinopathies

    Inflammasome in als skeletal muscle: Nlrp3 as a potential biomarker

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    Since NLRP3 inflammasome plays a pivotal role in several neurodegenerative disorders, we hypothesized that levels of inflammasome components could help in diagnosis or prognosis of amyotrophic lateral sclerosis (ALS). Gene and protein expression was assayed by RT-PCR and Western blot. Spearman’s correlation coefficient was used to determine the linear correlation of transcriptional expression levels with longevity throughout disease progression in mice models. Kaplan-Meier analysis was performed to evaluate MCC950 effects (NLRP3 inhibitor) on lifespan of SOD1G93A mice. The results showed significant alterations in NLRP3 inflammasome gene and protein levels in the skeletal muscle of SOD1G93A mice. Spearman’s correlation coefficient revealed a positive association between Nlrp3 transcriptional levels in skeletal muscle and longevity of SOD1G93A mice (r = 0.506; p = 0.027). Accordingly, NLRP3 inactivation with MCC950 decreased the lifespan of mice. Furthermore, NLRP3 mRNA levels were significantly elevated in the blood of ALS patients compared to healthy controls (p = 0.03). In conclusion, NLRP3 could be involved in skeletal muscle pathogenesis of ALS, either through inflammasome or independently, and may play a dual role during disease progression. NLRP3 gene expression levels could be used as a biomarker to improve diagnosis and prognosis in skeletal muscle from animal models and also to support diagnosis in clinical practice with the blood of ALS patients

    Space-time inhomogeneity, anisotropy and gravitational collapse

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    We investigate the evolution of non-adiabatic collapse of a shear-free spherically symmetric stellar configuration with anisotropic stresses accompanied with radial heat flux. The collapse begins from a curvature singularity with infinite mass and size on an inhomogeneous space-time background. The collapse is found to proceed without formation of an even horizon to singularity when the collapsing configuration radiates all its mass energy. The impact of inhomogeneity on various parameters of the collapsing stellar configuration is examined in some specific space-time backgrounds.Comment: To appear in Gen. Relativ. Gra

    Los principales problemas de salud según la opinión de los usuarios

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    ObjetivoConocer los problemas de salud o enfermedades que los usuarios de 2 áreas básicas de salud (ABS) consideran más importantes para la población española y para sí mismos; averiguar si existe relación entre estos problemas y los que afectan a miembros de su entorno familiar y social.DiseñoEstudio observacional, transversal, descriptivo.EmplazamientoCuatro y 2 consultas de las ABS Sant Josep (L’Hospitalet de Llobregat) y San Martí (Barcelonés), respectivamente.PacientesSe incluyeron 360 pacientes mayores de 26 años que acudieron a las consultas por algún problema de salud. Los participantes fueron elegidos por muestreo aleatorio sistemático entre los meses de mayo y octubre de 2000.Mediciones y resultados principalesLos datos se obtuvieron a partir de una encuesta con 10 preguntas. En opinión de los participantes, los principales problemas de salud en la población española y para sí mismos fueron: cáncer, enfermedades cardiovasculares y sida. El cáncer (58,61%; IC del 95%, 53,53–63,69) y el sida (15,27%; IC del 95%, 11,56–18,98) fueron los problemas considerados como prioritarios para la investigación. Los problemas del aparato locomotor (22,10%; IC del 95%, 17,82–26,38), la hipertensión (14,74%; IC del 95%, 11,08–18,40) y la diabetes (13,14%, IC del 95%, 9,66–16,62) fueron los principales problemas que afirmaron tener los encuestados.ConclusionesEl cáncer y las enfermedades cardiovasculares se revelan como las que más preocupan a los encuestados y que afectan a más miembros de su entorno familiar y social. En cambio, su preocupación por el sida no refleja la realidad de dicho entorno. Con frecuencia no reconocen el problema de salud que ha motivado su visita como una verdadera enfermedad.ObjectiveTo know the health problems or diseases that patients of 2 basic health areas (BHA) assess as the most important for Spanish population and for themselves; to know if any relation exists between these problems and their existence in the family or social patients’ environment.DesignAn observational cross-sectional and descriptive studySettingFour clinics of the BHA Sant Josep (L´Hospitalet de Llobregat) and 2 clinics of the BHA Sant Martí (Barcelonés).PatientsThe sample consists of 360 patients aged above 26 years who attended clinics for some health problem. Participants were chosen by a randomised systematic sampling, from May to October 2000.Measurements and main resultsData were gathered from a questionnaire of ten items. Acording with the participants, the main problems for Spanish population and for themselves were: cancer, cardiovascular diseases and AIDS. Cancer (58,61%; 95% CI, 53,53–63,69) and AIDS (15,27%; 95% CI, 11,56–18,98) are the problems pointed out as research priorities. The aparato locomotor (22,10%; 95% CI, 17,82–26,38), hypertension (14,74%; 95% CI, 11,08–18,40) and diabetes (13,14%, 95% CI, 9,66–16,62) are the main problems suffered by the surveyed. Cancer is the disease that more participants’ relatives suffered.ConclusionsCancer and cardiovascular diseases are the pathologies that cause more concern among the surveyed and these are the diseases which mostly affect their relatives and relationships. Nevertheless their worry for the AIDS don´t show their immediate reality. Frequently, patients don´t recognize the health problem that motivated their visit as a real disease

    Situación actual y perspectivas de futuro de los productos lacteos vinculados a la raza Payoya

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    Los productos lácteos derivados de las cabras de raza Payoya, autóctona de suroeste andaluz, presentan potencialidades comerciales debido a sus características organolépticas y a otras características ligadas a su procedencia u origen y al sistema de manejo. En este estudio se analiza la situación actual de estos productos desde los puntos de vista estructural y comercial y se presentan algunos resultados empíricos que demuestran las preferencias de los consumidores andaluces por los quesos de esta raza caprina. Para la promoción de los productos, los ganaderos pueden establecer estrategias como la diferenciación de los productos en cuanto a la excelencia de calidad sensorial objetiva y la puesta en relieve de sus aspectos diferenciales intangibles

    Iron, copper, zinc and manganese determination in alcoholic beverage by electrothermal atornization-atomic absorption spectrometry

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    En el presente trabajo se ha empleado la técnica de absorción atómica con atomización electrotérmica para la determinación de hierro, cobre, zinc y manganeso en 120 muestras de bebidas alcohólicas de elevado consumo en Andalucía (vino, cerveza, sidra, cava, brandy, ron, whisky, gínebra, anis y diversos licores). Se han optimizado todos los parámetros instrumentales y analíticos que permiten el control de interferencias y la obtención de factores de exactitud y precisión apropiados. El método propuesto resulta adecuado para análisis de rutina en el control de calidad de estos productos. Los valores obtenidos oscilan entre 0.1 y 6.9 µg/L para el Fe, entre no detectables y 1.2 µg/L para el Cu, entre 0.05 y 1.06 µg/L para el Zn, y entre no detectables y 1.43 µg/L para el Mn, existiendo una amplia variabilidad entre las muestras analizadas.We used electrothermal atomization-atomic absorption spectrometry for iron, copper, zinc and manganese deterrnination in 120 samples of alcoholic beverages widely consumed in Andalusia, Spain (wine, beer, cider, champagne, brandy, rum, whiskey, gin, anisette and several liqueurs). Instrumental and analytical parameters has been optimized to avoid interferences and to obtaine accurate and precise results. The proposed method is suitable for routine analysis in quality control of these and similar products. The values obtained ranged from 0.1 to 6.9 µg/L for Fe, from not detectable to 1.2 µg/L for Cu, from 0.05 to 1.06 for Zn, and from not detectable to 1.43 for Mn; we observed a wide variability of the data in the analyzed samples
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