2,331 research outputs found

    The role of the synchrotron component in the mid infrared spectrum of M 87

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    We study in detail the mid-infrared Spitzer-IRS spectrum of M 87 in the range 5 to 20 micron. Thanks to the high sensitivity of our Spitzer-IRS spectra we can disentangle the stellar and nuclear components of this active galaxy. To this end we have properly subtracted from the M 87 spectrum, the contribution of the underlying stellar continuum, derived from passive Virgo galaxies in our sample. The residual is a clear power-law, without any additional thermal component, with a zero point consistent with that obtained by high spatial resolution, ground based observations. The residual is independent of the adopted passive template. This indicates that the 10 micron silicate emission shown in spectra of M 87 can be entirely accounted for by the underlying old stellar population, leaving little room for a possible torus contribution. The MIR power-law has a slope alpha ~ 0.77-0.82 (Sννα_\nu\propto\nu^{-\alpha}), consistent with optically thin synchrotron emission.Comment: 5 pages, 4 figures, accepted for publication in ApJ main journa

    Experimental investigation of dynamical invariants in bipartite entanglement

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    The non-conservation of entanglement, when two or more particles interact, sets it apart from other dynamical quantities like energy and momentum. It does not allow the interpretation of the subtle dynamics of entanglement as a flow of this quantity between the constituents of the system. Here we show that adding a third party to a two-particle system may lead to a conservation law that relates the quantities characterizing the bipartite entanglement between each of the parties and the other two. We provide an experimental demonstration of this idea using entangled photons, and generalize it to N-partite GHZ states

    Criterion Validity of Force and Power Outputs for a Commonly Used Flywheel Resistance Training Device and Bluetooth App

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    ABSTRACT Flywheels are a resistance training device that can increase lean body mass, strength, and power. However, due to their unique design and the inertia from the concentric portion directly relating to the force that is applied during the eccentric portion, monitoring the training stimulus can be difficult. Consequently, the aim of this study was to assess the validity of the kMeter app for quantifying force and power at a range of different isoinertial loads from a flywheel training device when compared against a criterion measure. Eleven subjects volunteered to take part in this study, with subjects completing between 5-35 repetitions of the harness squat with 0.05, 0.10, 0.15 kg·m2 isoinertial load. A synchronised dual force plate and tri-camera optoelectronic setup was used as the criterion measure to calculate force and power output, while the kMeter app was used as the practical measure. Very large to nearly perfect relationships were observed between the two measures, with trivial to moderate bias reported. Additionally, typical error of the estimate (TEE) was found to be <10% at all isoinertial loads. These findings suggest that the kMeter app, when used in conjunction with the kBox flywheel device, demonstrate acceptable levels of validity. However, due to the TEE, the kMeter app may not be able to accurately detect small differences and therefore be suitable for research purposes. These findings suggest that the kMeter app is an acceptable method of monitoring flywheel resistance training. Furthermore, it is advised that practitioners utilise mean power rather than mean force. Keywords: Flywheel; Validity; kBox; kMeter; Force; Powe

    Impact of the Deficiency of Micronutrients on Patients with HIV/Aids

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    Introduction: HIV-AIDS is an infectious disease that damages the immune system, putting you at risk of serious infections and certain types of cancer. Micronutrient deficiency varies widely, depending on the population and stage of the disease. It can contribute to the weakening of the immune state and the worsening of the physical condition. Objective: To identify through the collection of nutritional information the consequences produced by the lack of micronutrients in patients with HIV-AIDS. Methodology: It was carried out through bibliographic reviews, scientific articles in order to find true and proven information on the effect that micronutrient deficiency has on people with HIV/AIDS. Results: It is shown that clinical deficiencies of some nutrients occur rapidly in response to dietary deficiencies, malabsorption, or altered metabolism, while those nutrients that have reserves in the body take longer to deplete. Discussion: The acquired immunodeficiency virus that causes AIDS; is associated with weight loss due to malnutrition. There are foods that can counteract many of the symptoms of the patient with HIV/AIDS, hence the importance of their knowledge. Conclusion: Micronutrient deficiency influences the immune system, accentuating the immunodeficiency that leads to AIDS. People living with this disease should have a balanced diet with Vitamins A, B, zinc and iron to strengthen the immune system, these offer a safe and economical treatment to slow the progression of the infection. Keywords: micronutrients, HIV, AIDS. RESUMEN Introducción: El VIH-SIDA es una enfermedad infecciosa que daña el sistema inmunitario lo que pone en riesgo de contraer infecciones graves y ciertos tipos de cáncer. La deficiencia de micronutrientes varía ampliamente, según la población y el estadio de la enfermedad; puede contribuir al debilitamiento del estado inmune y al empeoramiento de la condición física. &nbsp;Objetivo: Identificar mediante la recopilación de información nutricional las consecuencias que produce la falta de micronutrientes en pacientes con VIH-SIDA. Metodología: Se realizó a través de revisiones bibliográficas, artículos científicos con el fin de encontrar información verídica y comprobada del efecto que tiene la deficiencia de micronutrientes en personas con VIH/SIDA. &nbsp;Resultados: Se demuestra que las deficiencias clínicas de algunos nutrientes ocurren rápidamente en respuesta a deficiencias dietéticas, malabsorción, o metabolismo alterado, mientras que aquellos nutrientes que tienen reservas en el cuerpo tardan más en agotarse. Discusión: El virus de la inmunodeficiencia adquirida causante del SIDA; está asociada con la pérdida de peso por malnutrición. Hay muchos alimentos del grupo de los micronutrientes que minimizan manifestaciones clínicas en los enfermos el síndrome de inmunodeficiencia adquirida, siendo necesario saber cuáles son. Conclusiones: La deficiencia de micronutrientes influye en el sistema inmune, acentuando la inmunodeficiencia que lleva al SIDA. Las personas que viven con esta enfermedad deben tener una dieta balanceada con Vitaminas A, B, zinc y hierro para fortalecer el sistema inmunológico, estas ofrecen un tratamiento seguro y económico para retardar la progresión de la infección. Palabras claves: micronutrientes, VHI, SIDA

    Colossal magnon-phonon coupling in multiferroic Eu0.75_{0.75}Y0.25_{0.25}MnO3_3

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    We report the spectra of magnetically induced electric dipole absorption in Eu0.75_{0.75}Y0.25_{0.25}MnO3_3 from temperature dependent far infrared spectroscopy (10-250 cm1^{-1}). These spectra, which occur only in the eae||a polarization, consist of two relatively narrow electromagnon features that onset at TFE=30T_{FE}=30 K and a broad absorption band that persists to temperatures well above TN=47T_N=47 K. The observed excitations account for the step up of the static dielectric constant in the ferroelectric phase. The electromagnon at 80 cm1^{-1} is observed to be strongly coupled to the nearby lowest optical phonon which transfers more than 1/2 of its spectral weight to the magnon. We attribute the origin of the broad background absorption to the two magnon emission decay process of the phonon.Comment: 4 pages, 3 figure

    Multi-modal ultrasound imaging for breast cancer detection

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    This work describes preliminary results of a two-modality imaging system aimed at the early detection of breast cancer. The first technique is based on compounding conventional echographic images taken at regular angular intervals around the imaged breast. The other modality obtains tomographic images of propagation velocity using the same circular geometry. For this study, a low-cost prototype has been built. It is based on a pair of opposed 128-element, 3.2 MHz array transducers that are mechanically moved around tissue mimicking phantoms. Compounded images around 360 degrees provide improved resolution, clutter reduction, artifact suppression and reinforce the visualization of internal structures. However, refraction at the skin interface must be corrected for an accurate image compounding process. This is achieved by estimation of the interface geometry followed by computing the internal ray paths. On the other hand, sound velocity tomographic images from time of flight projections have been also obtained. Two reconstruction methods, Filtered Back Projection (FBP) and 2D Ordered Subset Expectation Maximization (2D OSEM), were used as a first attempt towards tomographic reconstruction. These methods yield useable images in short computational times that can be considered as initial estimates in subsequent more complex methods of ultrasound image reconstruction. These images may be effective to differentiate malignant and benign masses and are very promising for breast cancer screening. (C) 2015 The Authors. Published by Elsevier B.V
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