2,795 research outputs found
Dual-path state reconstruction scheme for propagating quantum microwaves and detector noise tomography
Quantum state reconstruction involves measurement devices that are usually
described by idealized models, but not known in full detail in experiments. For
weak propagating microwaves, the detection process requires linear amplifiers
which obscure the signal with random noise. Here, we introduce a theory which
nevertheless allows one to use these devices for measuring all quadrature
moments of propagating quantum microwaves based on cross-correlations from a
dual-path amplification setup. Simultaneously, the detector noise properties
are determined, allowing for tomography. We demonstrate the feasibility of our
novel concept by proof-of-principle experiments with classical mixtures of weak
coherent microwaves.Comment: 11 pages, 3 figure
Do stars govern our actions? astrocyte involvement in rodent behavior
Do stars govern our actions? Astrocyte involvement in rodent behaviorAstrocytes have emerged as important partners of neurons in information processing. Important progress has been made in the past two decades in understanding the role of astrocytes in the generation of neuron–astrocyte network outputs resulting in behavior. We review evidence for astrocyte involvement across four different behavioral domains: cognition, emotion, motor, and sensory processing. Accumulating evidence from animal models has provided a wealth of data that largely supports a direct involvement of astrocytes on diverse aspects of behavior. The development of tools for selectively controlling the temporal and spatial properties of astrocyte activity will help to consolidate our knowledge of the mechanisms underlying this involvement.The authors acknowledge funding from the Marie Curie Fellowship FP7-PEOPLE-2010-IEF 273936 and BIAL Foundation Grant 6112010 to J.F.O.; Foundation for Science and Technology (FCT) project grant (PTDC/SAU-NSC/118194/2010) to J.F.O., V.M.S., and S.G.G.; and fellowships (SFRH/BD/89714/2012 to V.M.S., SFRH/BPD/97281/2013 to J.F.O. and SFRH/BD/101298/2014 to S.G.G.); Human Frontier Science Program (Research Grant RGP0036/2014) to A.A.; FEDER funds through the Operational Program for Competitiveness Factors (COMPETE), and 'ON2 Programa Operacional Regional do Norte (ON.2 O Novo Norte)' QREN/FEDER to N.S
Estudio de la anisotropía de una fuente de Am-Be de 111 GBq
Se ha estudiado la anisotropía de una fuente de Am-Be de 111 GBq (3Ci) mediante el uso de un pequeño motor que permite girar paso a paso la fuente situada en su posición de irradiación habitual. Las medidas se han realizado con un contador proporcional de 3He alojado en el interior de una esfera moderadora de 8” correspondiente a un sistema de espectrometría de esferas Bonner. Se reportan los resultados obtenidos y el factor de anisotropía determinado para esta fuente
Diseño y elaboración de material docente para el seguimiento virtual de Estadística, Muestreo Estadístico e Informática en GAP
La introducción de las tecnologías de la información y la comunicación en los procesos de enseñanza permite un nuevo concepto de alumno-usuario y cambios en el modelo de enseñanza-aprendizaje que nos llevan a una educación superior más flexible. Así, el marco espaciotemporal en el que el alumno desarrolla las actividades de aprendizaje puede ser el hogar, el puesto de trabajo o un centro con recursos para el aprendizaje (como las aulas de informática de libre acceso que pone a disposición del alumno la Universidad de Jaén (UJA)).Destacar que en Gestión y Administración Pública (GAP) se encuentra un elevado número de estudiantes que trabajan para la Administración y que se matriculan con el objetivo de promocionar en su trabajo. Se trata de alumnos que, en general, no pueden asistir diariamente a las clases presenciales y a los que ciertas asignaturas como las de estadística les suponen un gran esfuerzo. Estas situaciones han llevado a la demanda generalizada por parte de los estudiantes universitarios para que se introduzcan cambios en las estrategias didácticas y en los sistemas de comunicación y distribución de los materiales de aprendizaje.El diseño e implantación de campus virtuales ha supuesto un gran reto para la mayor parte de las universidades españolas. En particular, la UJA se encuentra inmersa en este proceso, dando respuestas de diversa índole entre las que se encuentran los programas de innovación docente. Nosotros estamos iniciando a nuestros alumnos en el uso de las TICs, facilitándoles el uso de recursos y las herramientas necesarias para adquirir conocimientos y destrezas en las asignaturas de estadística, muestreo estadístico e informática
Respuesta del tomate (Lycopersicon sculentum Mill) a la fertilización con N,P,K y varios elementos menores, en suelos aluviales del Valle del Cauca (Colombia).
Se evaluó el efecto de diferentes dosis y combinaciones de varios nutrimentos y de gallinaza, en el rendimiento y calidad de los frutos de tomate. La investigación se realizó en suelos aluviales de 3 municipios del Valle del Cauca, en sitios representativos de la zona cultivada con tomate. Se estudió el efecto de distintos niveles y combinaciones de: N, P, K, S, Fe, B y Zn y materia orgánica (gallinaza). Se emplearon las variedades Chonto y Manalucie. Los resultados obtenidos indican que aún sin aplicaciones de fertilizantes en lotes previamente cultivados y abonados, se pueden obtener altos rendimientos cuando se efectúan las diferentes prácticas culturales oportuna y adecuadamente. La fertilización afecta la producción y calidad de los frutos. Al aplicar 75-150 kg/ha de N, 50 kg/ha de P2O5 y 50 kg/ha de K2O, se incrementaron los rendimientos entre 30 y 180 por ciento, en comparación con el testigo. La aplicación por separado de 60 kg/ha de sulfato de hierro, 30 kg/ha de sulfato de zinc y 15 kg/ha de bórax, tuvieron un efecto significativo en la producción y la calidad de los frutos. La materia orgánica en dosis altas tuvo efectos negativos en los rendimientos y calidad de los frutos, presentándose un mayor porcentaje de frutos rajadosTomate-Solanum lycopersicu
Therapeutic Exercise and Pain Neurophysiology Education in Female Patients with Fibromyalgia Syndrome: A Feasibility Study
Background: We compared the effects of therapeutic exercise (TE) combined with pain neurophysiology education (PNE) to those of TE in isolation on pain intensity, general fibromyalgia impact, mechanical pain sensitivity, pain catastrophizing, psychological distress and quality of life in women with fibromyalgia syndrome (FMS).
Methods: A feasibility study with a 3 month follow-up was designed. Thirty-two patients with FMS were randomly assigned to PNE + TE group (n = 16) or to TE group (n = 16). Both groups received 30 sessions of TE (3 per week), and the PNE + TE group received eight face-to-face educational sessions. The measuring instruments used were the visual analogue scale, a standard pressure algometer, the Revised Fibromyalgia Impact Questionnaire, the Pain Catastrophizing Scale, the Hospital Anxiety and Depression Scale and the Health Assessment Questionnaire.
Results: The PNE + TE group showed a statistically significant decrease on pain intensity compared to TE group at short term (p = 0.015). No between-groups differences were found for mechanical pain sensitivity, general fibromyalgia impact, pain catastrophizing, psychological distress or quality of life (p > 0.05).
Conclusions: The combination of PNE and TE was more effective than TE for reducing pain intensity in the short-term. No differences were found for psychological distress, pain catastrophizing and quality of life after the intervention or at 3 months of follow-up
Stroke etiologies in patients with COVID-19: the SVIN COVID-19 multinational registry
Background and purpose: Coronavirus disease 2019 (COVID-19) is associated with a small but clinically significant risk of stroke, the cause of which is frequently cryptogenic. In a large multinational cohort of consecutive COVID-19 patients with stroke, we evaluated clinical predictors of cryptogenic stroke, short-term functional outcomes and inhospital mortality among patients according to stroke etiology.
Methods: We explored clinical characteristics and short-term outcomes of consecutively evaluated patients 18 years of age or older with acute ischemic stroke (AIS) and laboratory-confirmed COVID-19 from 31 hospitals in 4 countries (3/1/20–6/16/20).
Results:Of the 14.483 laboratory-confirmed patients with COVID-19, 156 (1.1%) were diagnosed with AIS. Sixty-one (39.4%) were female, 84 (67.2%) white, and 88 (61.5%) were between 60 and 79 years of age. The most frequently reported etiology of AIS was cryptogenic (55/129, 42.6%), which was associated with significantly higher white blood cell count, c-reactive protein, and D-dimer levels than non-cryptogenic AIS patients (p
Conclusions: Our findings suggest that cryptogenic stroke among COVID-19 patients carries a significant risk of early mortality
Angular distributions in tt¯H(H→bb¯) reconstructed events at the LHC
The associated production of a Higgs boson and a top-quark pair, tt¯H, in proton-proton collisions is addressed in this paper for a center of mass energy of 13TeV at the LHC. Dileptonic final states of tt¯H events with two oppositely charged leptons and four jets from the decays t→bW+→bℓ+νℓ, t¯→b¯W−→b¯ℓ−ν¯ℓ and h→bb¯, are used. Signal events, generated with MadGraph5_aMC@NLO, are fully reconstructed by applying a kinematic fit. New angular distributions of the decay products as well as angular asymmetries are explored in order to improve discrimination of tt¯H signal events over the dominant irreducible background contribution, tt¯bb¯. Even after the full kinematic fit reconstruction of the events, the proposed angular distributions and asymmetries are still quite different in the tt¯H signal and the dominant background (tt¯bb¯).This work was partially supported by Fundação para a Ciência e Tecnologia, FCT (projects CERN/FP/123619/2011 and EXPL/FIS-NUC/1705/2013, grants SFRH/BI/52524/2014 and SFRH/BD/73438/2010, and contracts IF/00050/2013 and IF/00014/2012). The work of M.C.N. Fiolhais was supported by LIP-Laboratório de Instrumentação e Física Experimental de Partículas, Portugal (grant PestIC/FIS/LA007/2013). The work of R.S. is supported in part by FCT under contract PTDC/FIS/117951/2010. Special thanks go to Juan Antonio Aguilar-Saavedra for all the fruitful discussions and a long term collaboration
Performance of artificial neural networks and genetical evolved artificial neural networks unfolding techniques
With the Bonner spheres spectrometer neutron spectrum is obtained through an unfolding procedure. Monte Carlo methods, Regularization, Parametrization, Least-squares, and Maximum Entropy are some of the techniques utilized for unfolding. In the last decade methods based on Artificial Intelligence Technology have been used. Approaches based on Genetic Algorithms and Artificial Neural Networks have been developed in order to overcome the drawbacks of previous techniques. Nevertheless the advantages of Artificial Neural Networks still it has some drawbacks mainly in the design process of the network, vg the optimum selection of the architectural and learning ANN parameters. In recent years the use of hybrid technologies, combining Artificial Neural Networks and Genetic Algorithms, has been utilized to. In this work, several ANN topologies were trained and tested using Artificial Neural Networks and Genetically Evolved Artificial Neural Networks in the aim to unfold neutron spectra using the count rates of a Bonner sphere spectrometer. Here, a comparative study of both procedures has been carried out
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