698 research outputs found

    II Workshop on Modeling and Simulation for Science and Engineering

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    II Workshop on Modeling and Simulation for Science and Engineering (II WMSSE) was a conference conducted at Universidad Tecnológica de Bolívar, in the city of Cartagena de Indias, Colombia, on September 24, 25 and 26, 2019. There, works in several topics of science, technology and engineering were presented. Specially, the participants of conference wanted to bring some solutions to the actual industrial requirements such as improvement and optimization of the heat transfer equipment, electronic devices, system control by mean of computational modeling. Also, dynamic system control was widely used for the prediction of power flow market, diffusion of bacteria in coffee production, stress concentration in industrial machines, analysis of population dynamics, model of hydrological and pluviometric networks, encryption for intercommunication of substation control centers, and others

    Patient centred diagnosis: sharing diagnostic decisions with patients in clinical practice.

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    Patient centred diagnosis is best practised through shared decision making; an iterative dialogue between doctor and patient, whichrespects a patient’s needs, values, preferences, and circumstances. Shared decision making for diagnostic situations differs fundamentally from that for treatment decisions. This has important implications when considering its practical application. The nature of dialogue should be tailored to the specific diagnostic decision; scenarios with higher stakes or uncertainty usually require more detailed conversation

    Quantum hypercomputation based on the dynamical algebra su(1,1)

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    An adaptation of Kieu's hypercomputational quantum algorithm (KHQA) is presented. The method that was used was to replace the Weyl-Heisenberg algebra by other dynamical algebra of low dimension that admits infinite-dimensional irreducible representations with naturally defined generalized coherent states. We have selected the Lie algebra su(1,1)\mathfrak{su}(1,1), due to that this algebra posses the necessary characteristics for to realize the hypercomputation and also due to that such algebra has been identified as the dynamical algebra associated to many relatively simple quantum systems. In addition to an algebraic adaptation of KHQA over the algebra su(1,1)\mathfrak{su}(1,1), we presented an adaptations of KHQA over some concrete physical referents: the infinite square well, the infinite cylindrical well, the perturbed infinite cylindrical well, the P{\"o}sch-Teller potentials, the Holstein-Primakoff system, and the Laguerre oscillator. We conclude that it is possible to have many physical systems within condensed matter and quantum optics on which it is possible to consider an implementation of KHQA.Comment: 25 pages, 1 figure, conclusions rewritten, typing and language errors corrected and latex format changed minor changes elsewhere and

    The census of interstellar complex organic molecules in the Class I hot corino of SVS13-A

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    We present the first census of the interstellar Complex Organic Molecules (iCOMs) in the low-mass Class I protostar SVS13-A, obtained by analysing data from the IRAM-30m Large Project ASAI (Astrochemical Surveys At IRAM). They consist of an high-sensitivity unbiased spectral survey at the 1mm, 2mm and 3mm IRAM bands. We detected five iCOMs: acetaldehyde (CH3_3CHO), methyl formate (HCOOCH3_3), dimethyl ether (CH3_3OCH3_3), ethanol (CH3_3CH2_2OH) and formamide (NH2_2CHO). In addition we searched for other iCOMs and ketene (H2_2CCO), formic acid (HCOOH) and methoxy (CH3_3O), whose only ketene was detected. The numerous detected lines, from 5 to 37 depending on the species, cover a large upper level energy range, between 15 and 254 K. This allowed us to carry out a rotational diagram analysis and derive rotational temperatures between 35 and 110 K, and column densities between 3×10153\times 10^{15} and 1×10171\times 10^{17} cm2^{-2} on the 0."3 size previously determined by interferometric observations of glycolaldehyde. These new observations clearly demonstrate the presence of a rich chemistry in the hot corino towards SVS13-A. The measured iCOMs abundances were compared to other Class 0 and I hot corinos, as well as comets, previously published in the literature. We find evidence that (i) SVS13-A is as chemically rich as younger Class 0 protostars, and (ii) the iCOMs relative abundances do not substantially evolve during the protostellar phase.Comment: 24 pages, MNRAS in pres

    Role of the Fractalkine Receptor in CNS Autoimmune Inflammation: New Approach Utilizing a Mouse Model Expressing the Human CX3CR1

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    Multiple sclerosis (MS), an inflammatory demyelinating disease of the central nervous system (CNS) is the leading cause of non-traumatic neurological disability in young adults. Immune mediated destruction of myelin and oligodendrocytes is considered the primary pathology of MS, but progressive axonal loss is the major cause of neurological disability. In an effort to understand microglia function during CNS inflammation, our laboratory focuses on the fractalkine/CX3CR1 signaling as a regulator of microglia neurotoxicity in various models of neurodegeneration. Fractalkine (FKN) is a transmembrane chemokine expressed in the CNS by neurons and signals through its unique receptor CX3CR1 present in microglia. During experimental autoimmune encephalomyelitis (EAE), CX3CR1 deficiency confers exacerbated disease defined by severe inflammation and neuronal loss. The CX3CR1 human polymorphism I249/M280 present in ∼20% of the population exhibits reduced adhesion for FKN conferring defective signaling whose role in microglia function and influence on neurons during MS remains unsolved. The aim of this study is to assess the effect of weaker signaling through hCX3CR1I249/M280 during EAE. We hypothesize that dysregulated microglial responses due to impaired CX3CR1 signaling enhance neuronal/axonal damage. We generated an animal model replacing the mouse CX3CR1 locus for the hCX3CR1I249/M280 variant. Upon EAE induction, these mice exhibited exacerbated EAE correlating with severe inflammation and neuronal loss. We also observed that mice with aberrant CX3CR1 signaling are unable to produce FKN and ciliary neurotrophic factor during EAE in contrast to wild type mice. Our results provide validation of defective function of the hCX3CR1I249/M280 variant and the foundation to broaden the understanding of microglia dysfunction during neuroinflammation. © 2018 Cardona et al

    Determining science teachers’ ideas about the science process skills: a case study

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    AbstractThe aim of this study is to investigate science teachers’ ideas about the science process skills (SPS) using qualitative analysis. This study was carried out at the first term of 2008- 2009 academic year. A case study research methodology was used. The sample of this study consisted of 10 science teachers (ST), who has been working at Giresun center elementary schools in Turkey. A semi-structured interview procedure was used to collect data. The collected data were analyzed with Nvivo 8 program. The results indicate that the majority of sample have not had widespread theoretical knowledge on SPS

    Time evolution of stimulated Raman scattering and two-plasmon decay at laser intensities relevant for shock ignition in a hot plasma

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    Laser–plasma interaction (LPI) at intensities 1015–1016 W cm2 is dominated by parametric instabilities which can be responsible for a significant amount of non-collisional absorption and generate large fluxes of high-energy nonthermal electrons. Such a regime is of paramount importance for inertial confinement fusion (ICF) and in particular for the shock ignition scheme. In this paper we report on an experiment carried out at the Prague Asterix Laser System (PALS) facility to investigate the extent and time history of stimulated Raman scattering (SRS) and two-plasmon decay (TPD) instabilities, driven by the interaction of an infrared laser pulse at an intensity 1:2 1016 W cm2 with a 100 mm scalelength plasma produced from irradiation of a flat plastic target. The laser pulse duration (300 ps) and the high value of plasma temperature (4 keV) expected from hydrodynamic simulations make these results interesting for a deeper understanding of LPI in shock ignition conditions. Experimental results show that absolute TPD/SRS, driven at a quarter of the critical density, and convective SRS, driven at lower plasma densities, are well separated in time, with absolute instabilities driven at early times of interaction and convective backward SRS emerging at the laser peak and persisting all over the tail of the pulse. Side-scattering SRS, driven at low plasma densities, is also clearly observed. Experimental results are compared to fully kinetic large-scale, two-dimensional simulations. Particle-in-cell results, beyond reproducing the framework delineated by the experimental measurements, reveal the importance of filamentation instability in ruling the onset of SRS and stimulated Brillouin scattering instabilities and confirm the crucial role of collisionless absorption in the LPI energy balance

    Los buitres, aves carroñeras del Viejo Mundo y Nuevo Mundo

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    This paper reviews the existing information on the group of birds known as vultures, birds specialized in ingesting carrion, distributed in almost all continents and with similar physical characteristics and behaviors. The objective of the review is to present the global problems and threats to which this group of birds is subjected, mainly due to the anthropic effect, loss of their natural habitat, lead poisoning, and provoked or accidental poisoning, among other factors, that have caused their disappearance in various countries and have placed them on the brink of extinction. The current state of conservation and main threats of the two large groups, vultures of the Old and New World, are reviewed.El presente artículo revisa la información existente sobre el grupo de aves denominado buitres, aves especializadas en la ingestión de carroña, distribuidas en casi todos los continentes y que tienen características físicas y comportamientos similares. El objetivo de la revisión es dar a conocer la problemática mundial y amenazas a las que es sometido este grupo de aves, principalmente por el efecto antrópico, pérdida de su hábitat natural, intoxicación por plomo, y envenenamiento provocado o accidental, entre otros factores, que han causado su desaparición en diversos países y los han colocado al borde de la extinción. Se revisa el estado actual de conservación y principales amenazas de los dos grandes grupos, buitres del Viejo y del Nuevo Mundo
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