Visualisation and Quantification of Intracellular Interactions of Neisseria meningitidis and Human α-actinin by Confocal Imaging

The Opc protein of Neisseria meningitidis (Nm, meningococcus) is a surface-expressed integral outer membrane protein, which can act as an adhesin and an effective invasin for human epithelial and endothelial cells. We have identified endothelial surface-located integrins as major receptors for Opc, a process which requires Opc to first bind to integrin ligands such as vitronectin and via these to the cell-expressed receptors1. This process leads to bacterial invasion of endothelial cells2. More recently, we observed an interaction of Opc with a 100kDa protein found in whole cell lysates of human cells3. We initially observed this interaction when host cell proteins separated by electrophoresis and blotted on to nitrocellulose were overlaid with Opc-expressing Nm. The interaction was direct and did not involve intermediate molecules. By mass spectrometry, we established the identity of the protein as α-actinin. As no surface expressed α-actinin was found on any of the eight cell lines examined, and as Opc interactions with endothelial cells in the presence of serum lead to bacterial entry into the target cells, we examined the possibility of the two proteins interacting intracellularly. For this, cultured human brain microvascular endothelial cells (HBMECs) were infected with Opc-expressing Nm for extended periods and the locations of internalised bacteria and α-actinin were examined by confocal microscopy. We observed time-dependent increase in colocalisation of Nm with the cytoskeletal protein, which was considerable after an eight hour period of bacterial internalisation. In addition, the use of quantitative imaging software enabled us to obtain a relative measure of the colocalisation of Nm with α-actinin and other cytoskeletal proteins. Here we present a protocol for visualisation and quantification of the colocalisation of the bacterium with intracellular proteins after bacterial entry into human endothelial cells, although the procedure is also applicable to human epithelial cells

Genetic Dissection of the Signaling Cascade that Controls Activation of the <i>Shigella</i> Type III Secretion System from the Needle Tip

Many Gram-negative bacterial pathogens use type III secretion systems (T3SSs) for virulence. The Shigella T3SS consists of a hollow needle, made of MxiH and protruding from the bacterial surface, anchored in both bacterial membranes by multimeric protein rings. Atop the needle lies the tip complex (TC), formed by IpaD and IpaB. Upon physical contact with eukaryotic host cells, T3S is initiated leading to formation of a pore in the eukaryotic cell membrane, which is made of IpaB and IpaC. Through the needle and pore channels, further bacterial proteins are translocated inside the host cell to meditate its invasion. IpaD and the needle are implicated in transduction of the host cell-sensing signal to the T3S apparatus. Furthermore, the sensing-competent TC seems formed of 4 IpaDs topped by 1 IpaB. However, nothing further is known about the activation process. To investigate IpaB’s role during T3SS activation, we isolated secretion-deregulated IpaB mutants using random mutagenesis and a genetic screen. We found ipaB point mutations in leading to defects in secretion activation, which sometimes diminished pore insertion and host cell invasion. We also demonstrated IpaB communicates intramolecularly and intermolecularly with IpaD and MxiH within the TC because mutations affecting these interactions impair signal transduction

Activation energy in particle suspensions

Assuming that the molar activation energy in a fluid is interpreted as a measure of the potential energy barrier required for the molecular movement [1], the viscosity of a fluid depends on the actual size of the molecules, and the presence of solid particles in a suspension increases the dissipation of energy when the system flows, therefore it is expected that the viscosity of the suspension is higher than that of the pure solvent at a given temperature. The dependence of the viscosity of some silica/glycol suspensions with the temperature can be fitted using an empirical function analogous to the Arrhenius equation, ln⁡η=E/RT-ln⁡C, where η is the viscosity, C is a system-dependent constant, E is the molar activation energy for the viscous flow, T is the absolute temperature and R is the gas universal constant. When the temperature of the suspension decreases two effects are observed. First, larger aggregates of particles are formed due to the reduction of the thermal agitation and, second, the number of links among the molecules of the liquid phase increases. These two effects give place to a higher increase in the viscosity with the temperature compared to the pure solvent. Assuming that a higher viscosity value is due to a smaller free volume available for the molecular movement, and taking into account that the free suspension volume is limited only to the liquid fraction [2], it should be expected that the viscosity of the suspension is less sensitive to temperature than that of the pure solvent. In this work the dependence on the temperature of the viscosity values of the silica/glycol suspensions is compared to that of the liquid media. The results have shown a lower activation energy when the solid volume fraction increases, which has been explained with a scheme that assumes that the particle links are less sensitive to thermal energy absorption than the joining bonds among the solvent molecules. Our conclusion is that, for a given mechanical energy applied to the system, the thermal energy absorbed by the system is mainly used in the rupture of bonds between the solvent molecules. This study can be useful to understand the mechanisms that govern the differences in the activation energy values found between samples of foods, in which many factors are connected with sample composition [3]. [1] Briscoe B, Luckham P, Zhu S. Rheological properties of poly (ethylene oxide) aqueous solutions. J Appl Polym Sci 70 (1998) 419-429. [2] Shenoy AV. Rheology of filled polymer systems. Kluwer Acad Pub, 1999, The Netherlands. [3] Alvarez MD, Canet W. Time-independent and time-dependent rheological characterization of vegetable-based infant purees. J Food Eng 114 (2013) 449-464.Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tech

Planificación de un sistema de gestión ambiental para la empresa agropecuaria Senegal S.A.S fundamentada en la NTC ISO 14001:2015

La empresa Agropecuaria Senegal S.A.S se desempeña en la producción de cítricos, plátanos y aguacate en el municipio de Pereira. La organización expresa su deseo de certificarse en ISO 14001:2015, por lo cual surge iniciar la planificación de un Sistema de gestión Ambiental basado en la NTC ISO 14001:2015 para dar debida gestión a los aspectos e impactos ambientales en el área administrativa y centro de acopio. El presente trabajo plasma los objetivos que se desean cumplir, así como la metodología para lograrlos y la fundamentación teórico conceptual para cumplir a cabalidad con los objetivos propuestos

Evaluación y rediseño del modelo estructural, funcional y administrativo del municipio del cantón San Jacinto de Yaguachi.

"El siguiente proyecto se refiere al modo de organización de les instituciones públicas en este caso nuestro objeto de estudio será si Municipio del Cantón Yaguachi, por ello se propuso inicialmente adoptar herramientas y socializares con las causas de impacto que incide en el normal desenvolvimiento de las tareas del personal administrativo: son por la falta de conocimiento de sus funciones, perfil del puesto, y de captación profesional, y por tal efecto adoptaremos la creación de la estructura organizacional. Se aplicara el Modelo de Investigación No Experimental para comprobar tas hipótesis no se afectará a ninguna variable dependiente ni independiente. En cuanto al propósito amplitud y profundidad de la investigación que se desarrollará se utilizarán la modalidad de Investigación tipo Descriptiva, Correlacional, Explicativa, y Transeccional, los métodos a utilizarse son las siguientes: Observación Inductivo, Deductivo, Síntesis, Comparativo y Estadístico. Para saber que la investigación tenga un buen resultado se utilizaran las técnicas de observación personal entrevistas y las encuestas. Las principales soluciones serian luego del rediseño darles a conocer al personal administrativo, logrando diseñar esta herramienta aportaremos a cada funcionario el modelo de eficiencia que buscamos en el quehacer diario, la planeación y control de sus actividades; además de dar una buena atención al usuario.

Volume cardiac SPECT image registration

The registration of cardiac images is relevant for the diagnosis of cardiac pathologies. In the case of SPECT (Single Photon Emission Computer Tomography) datasets, this is difficult because of the low resolution of the images. In this paper we present a new registration method for 3D images with poor resolution. Our method is based on the maximization of the mutual information (MI) using a new interpolation method which significantly improves the result of an MI-based strategy on low resolution images. We also use a different optimization strategy than other MI-based algorithms, typically achieving errors of the order of one pixel. We also discuss experimental results of our method.Postprint (published version

Mirando al mar

Acercando el concepto marítimo a la ciudad, de forma emocional, a través del arte y el diseño.Jiménez Murillo, I. (2012). Mirando al mar. http://hdl.handle.net/10251/28102.Archivo delegad

Estado del arte de la alineación de imágenes médicas e implementación del algoritmo de alineación clásico basado en la información mutua

La alineación de imágenes cardíacas procedentes de imágenes de medicina nuclear tal como la Tomografía Computerizada por Emisión Única de Positrones (SPECT) constituye un campo de investigación activo dada su importancia en el diagnóstico de cardiopatías. En este reporte presentamos el estado del arte de la alineación de imágenes médicas con énfasis en la alineación de imágenes cardíacas al igual que una aplicación del método de alineación para imágenes SPECT cardíacos usando la información mutua como medida de similitud.Cardiac images registration coming from nuclear medicine like Single Positron Emition Computer Tomography (SPECT) has become an active research field since it is an important tool for the diagnostic of cardiac pathologies. In this report we present the state of the art of medical image registration with emphasis in cardiac images, likewise it is presented an application for registration of SPECT images using mutual information like similarity measure.Postprint (published version

O mercado internacional de biocombustíveis: etanol e biodiesel.

O presente estudo tem por objetivo conhecer as caraterísticas atuais do mercado internacional dos biocombustíveis: etanol e biodiesel. Trata-se de uma pesquisa exploratória que visa determinar a importância do mercado institucional dos países envolvidos na produção, consumo e comércio dos biocombustíveis. ----------------------The objective of this article is to know the current characteristics of international market of biofuels: ethanol and biodiesel. This is an explorative research to verify the importance of the institutional markets in the countries involved with biofuels production, consumption and trade.etanol, biodiesel, mercado institucional, International Relations/Trade, Resource /Energy Economics and Policy,

Proyecto de desarrollo y posicionamiento de la imagen corporativa de la constructora thalía victoria s.a. en la ciudad de Guayaquil

La Industria de la Construcción es una de las más grandes en cualquier economía, la producción de soluciones habitacionales es una actividad económica y como tal la vivienda es un bien económico con un valor de mercado, su generación implica creación de riqueza y contribuye al crecimiento del producto interno bruto del país. Con el fin de proponer y desarrollar nuevas estrategias que favorezcan el acceso de la población a la vivienda se realizo una investigación de mercados a 800 personas (tres tipos de encuestas), para determinar las características, gustos y preferencias (a través de la elaboración de un perfil) de los clientes potenciales y actuales de la constructora Thalia Victoria, con el objetivo de saber cuales son las falencias que tiene la compañía en los actuales momentos y las estrategias a aplicar para corregirlos. Así mismo se procedió a elaborar una analisis financiero en donde se pudiera comparar la situación actual de la constructora sin las estrategias propuestas versus la situación financiera de la constructora con las estrategias propuestas, a través de un flujo de caja incremental, y el criterio del VAN y la TIR