512 research outputs found

    “PRESIÓN ARTERIAL SISTÉMICA EN AMBOS BRAZOS EN PACIENTES ADULTOS HIPERTENSOS NO DIABÉTICOS DE LA COMUNIDAD SANTAMARÍA, LA LOMA DE AGOSTO DE 2011 A JULIO DE 2012”

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    La hipertensión arterial es la enfermedad crónica más frecuente en nuestro medio. Tradicionalmente se ha aceptado una diferencia de hasta 10mmHg entre ambos brazos y se ha considerado como normal

    Profilometry for the measurement of 3-D object shapes based on regularized filters

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    Regularized filters RFs. are used in profilometry for the measurement of three-dimensional object shapes. A linear grating pattern projected onto an object is phase-modulated by the 3-D shape. Phase information of the pattern is obtained by a demodulation process using RFs based on Bayesian estimation theory with Markov Random Fields MRFs. as prior models. The technique is fully processed in the space domain and applied in the 2-D case to provide a better separation of the height information from noise. As shown herein, the technique is not so sensitive to the singularities in the pattern image as with common filters used in the spatial synchronous detection. The technique and experimental results of real surface profiles are presented. q1999 Published by Elsevier Science B.V. All rights reserved

    Resonant interaction between gravitational waves, electromagnetic waves and plasma flows

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    In magnetized plasmas gravitational and electromagnetic waves may interact coherently and exchange energy between themselves and with plasma flows. We derive the wave interaction equations for these processes in the case of waves propagating perpendicular or parallel to the plasma background magnetic field. In the latter case, the electromagnetic waves are taken to be circularly polarized waves of arbitrary amplitude. We allow for a background drift flow of the plasma components which increases the number of possible evolution scenarios. The interaction equations are solved analytically and the characteristic time scales for conversion between gravitational and electromagnetic waves are found. In particular, it is shown that in the presence of a drift flow there are explosive instabilities resulting in the generation of gravitational and electromagnetic waves. Conversely, we show that energetic waves can interact to accelerate particles and thereby \emph{produce} a drift flow. The relevance of these results for astrophysical and cosmological plasmas is discussed.Comment: 12 pages, 1 figure, typos corrected and numerical example adde

    Wavefront reconstruction of discontinuous phase objects from optical deflectometry

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    One of the challenges in phase measuring deflectometry is to retrieve the wavefront from objects that present discontinuities or non-differentiable gradient fields. Here, we propose the integration of such gradients fields based on an Lp-norm minimization problem. The solution of this problem results in a nonlinear partial differential equation, which can be solved with a fast and well-known numerical methods and doesn't depend on external parameters. Numerical reconstructions on both synthetic and experimental data are presented that demonstrate the capability of the proposed method

    Genome Sequence of a Novel Archaeal Fusellovirus Assembled from the Metagenome of a Mexican Hot Spring

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    The consensus genome sequence of a new member of the family Fuselloviridae designated as SMF1 (Sulfolobales Mexican fusellovirus 1) is presented. The complete circular genome was recovered from a metagenomic study of a Mexican hot spring. SMF1 exhibits an exceptional coding strand bias and a reduced set of fuselloviral core genes

    Analysis of friction coefficient for a base steel 5 % Cr, applying variable loads of 196 N, 294 N and 392 N, and speeds of 0,18 m/sec, 0,36 m/sec and 0,54 m/sec

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    The present study consists in analyzing the friction coefficient as a variable of the normal load and slip speed for 5% Cr steel, by applying the Block-on-Disk method according to ASTM D2714. The friction coefficient increases linearly 23,25 % from 0,214 to 0,266 when the load is increased from 196 N to 392 N; the same phenomenon is observed when the friction coefficient increases 47,82 % from 0,23 to 0,34 when the slip speed increases from 0,18 m/sec to 0,54 m/sec. The friction coefficient increased by 23,25 % for an increase in the load from 196 N to 392 N, which corresponds to 100 %, while an increase of the friction coefficient of 47,82 % occurred by increasing the speed from 0,18 m/sec to 0,54 m/sec which corresponds to 200 %

    Susceptibility of pepper weevil (anthonomus eugenii cano) (coleoptera: curculionidae) to seven insecticides in rural areas of Baja California Sur, MĂ©xico

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    The susceptibility of the pepper weevil (Anthonomus eugenii), collected from Baja California Sur, Mexico, to seven insecticides was determined. Acontact, residual exposition method was used to obtain the lethal concentrations fifty (LC50) and the diagnostic concentration (LC95) of organophosphates (OF), carbamates (CA), pyrethroids (PIR), and organochlorine (OC) insecticides used to control pepper weevils from two agricultural areas (Los Planes and Todos Santos) in Southern Baja California Peninsula, as well as on a pepper weevil population not exposed to insecticides (PWIF) for two years. The highest LC50’s were obtained for methomyl (CA) and oxamyl (CA), followed by methamidophos (OF), endosulfan (OC), cyfluthrin (PIR) and azinphos-methyl (OF). The lowest LC50’s were observed for carbaryl (CA). The field population from Todos Santos showed lower susceptibility than the population from Los Planes to insecticides as methomyl, oxamyl, and carbaryl, while with methamidophos, azinphos-methyl, and cyfluthrin, the LC50 showed higher values. The PWIF population presented the lowest LC50 values of all three populations tested. However, in most cases, the difference was not significant in relation to the two field populations, thus the PWIF population needs to be kept free of insecticides for longer periods to establish a susceptibility baseline for Anthonomus eugenii

    Fast Magnetosonic Waves Driven by Gravitational Waves

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    The propagation of a gravitational wave (GW) through a magnetized plasma is considered. In particular, we study the excitation of fast magnetosonic waves (MSW) by a gravitational wave, using the linearized general-relativistic hydromagnetic equations. We derive the dispersion relation for the plasma, treating the gravitational wave as a perturbation in a Minkowski background space-time. We show that the presence of gravitational waves will drive magnetosonic waves in the plasma and discuss the potential astrophysical implications.Comment: 12 pages, 2 figures, Astronomy and Astrophysics in pres

    Disassembly of F-actin cytoskeleton after interaction of Bacillus cereus with fully differentiated human intestinal Caco-2 cells

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    In the present study, the role of direct procaryote-eucaryote interactions in the virulence of Bacillus cereus was investigated. As a model of human enterocytes, differentiated Caco-2 cells were used. Infection of fully differentiated Caco-2 cells with B. cereus in the exponential phase of growth, in order to minimize the concentration of spores or sporulating microorganisms, shows that a strain-dependent cytopathic effect develops. Interestingly, addition of 3-h-old cultures of some strains resulted in complete detachment of the cultured cells after a 3-h infection whereas no such effect was found after a 3-h infection with 16-h-old cultures. Infection of enterocyte-like cells with B. cereus leads to disruption of the F-actin network and necrosis. Even though the effect of secreted factors cannot be ruled out, direct eucaryote-procaryote interaction seems to be necessary. In addition, we observed that some B. cereus strains were able to be internalized in Caco-2 cells. Our findings add a new insight into the mechanisms of virulence of B. cereus in the context of intestinal infection.Facultad de Ciencias ExactasCentro de InvestigaciĂłn y Desarrollo en CriotecnologĂ­a de Alimento

    Up-Regulation of Intestinal Vascular Endothelial Growth Factor by Afa/Dr Diffusely Adhering Escherichia coli

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    BACKGROUND: Angiogenesis has been recently described as a novel component of inflammatory bowel disease pathogenesis. The level of vascular endothelial growth factor (VEGF) has been found increased in Crohn's disease and ulcerative colitis mucosa. To question whether a pro-inflammatory Escherichia coli could regulate the expression of VEGF in human intestinal epithelial cells, we examine the response of cultured human colonic T84 cells to infection by E. coli strain C1845 that belongs to the typical Afa/Dr diffusely adhering E. coli family (Afa/Dr DAEC). METHODOLOGY: VEGF mRNA expression was examined by Northern blotting and q-PCR. VEGF protein levels were assayed by ELISA and its bioactivity was analysed in endothelial cells. The bacterial factor involved in VEGF induction was identified using recombinant E. coli expressing Dr adhesin, purified Dr adhesin and lipopolysaccharide. The signaling pathway activated for the up-regulation of VEGF was identified using a blocking monoclonal anti-DAF antibody, Western blot analysis and specific pharmacological inhibitors. PRINCIPAL FINDINGS: C1845 bacteria induce the production of VEGF protein which is bioactive. VEGF is induced by adhering C1845 in both a time- and bacteria concentration-dependent manner. This phenomenon is not cell line dependent since we reproduced this observation in intestinal LS174, Caco2/TC7 and INT407 cells. Up-regulation of VEGF production requires: (1) the interaction of the bacterial F1845 adhesin with the brush border-associated decay accelerating factor (DAF, CD55) acting as a bacterial receptor, and (2) the activation of a Src protein kinase upstream of the activation of the Erk and Akt signaling pathways. CONCLUSIONS: Results demonstrate that a Afa/Dr DAEC strain induces an adhesin-dependent activation of DAF signaling that leads to the up-regulation of bioactive VEGF in cultured human intestinal cells. Thus, these results suggest a link between an entero-adherent, pro-inflammatory E. coli strain and angiogenesis which appeared recently as a novel component of IBD pathogenesis
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