Biofilm formation at the solid-liquid and air-liquid interfaces by Acinetobacter species

The members of the genus Acinetobacter are Gram-negative cocobacilli that are frequently found in the environment but also in the hospital setting where they have been associated with outbreaks of nosocomial infections. Among them, Acinetobacter baumannii has emerged as the most common pathogenic species involved in hospital-acquired infections. One reason for this emergence may be its persistence in the hospital wards, in particular in the intensive care unit; this persistence could be partially explained by the capacity of these microorganisms to form biofilm. Therefore, our main objective was to study the prevalence of the two main types of biofilm formed by the most relevant Acinetobacter species, comparing biofilm formation between the different species. Findings: Biofilm formation at the air-liquid and solid-liquid interfaces was investigated in different Acinetobacter spp. and it appeared to be generally more important at 25°C than at 37°C. The biofilm formation at the solid-liquid interface by the members of the ACB-complex was at least 3 times higher than the other species (80-91% versus 5-24%). In addition, only the isolates belonging to this complex were able to form biofilm at the air-liquid interface; between 9% and 36% of the tested isolates formed this type of pellicle. Finally, within the ACB-complex, the biofilm formed at the air-liquid interface was almost 4 times higher for A. baumannii and Acinetobacter G13TU than for Acinetobacter G3 (36%, 27% & 9% respectively). Conclusions: Overall, this study has shown the capacity of the Acinetobacter spp to form two different types of biofilm: solid-liquid and air-liquid interfaces. This ability was generally higher at 25°C which might contribute to their persistence in the inanimate hospital environment. Our work has also demonstrated for the first time the ability of the members of the ACB-complex to form biofilm at the air-liquid interface, a feature that was not observed in other Acinetobacter species.

Biofilm formation at the solid-liquid and air-liquid interfaces by Acinetobacter species.

BACKGROUND The members of the genus Acinetobacter are Gram-negative cocobacilli that are frequently found in the environment but also in the hospital setting where they have been associated with outbreaks of nosocomial infections. Among them, Acinetobacter baumannii has emerged as the most common pathogenic species involved in hospital-acquired infections. One reason for this emergence may be its persistence in the hospital wards, in particular in the intensive care unit; this persistence could be partially explained by the capacity of these microorganisms to form biofilm. Therefore, our main objective was to study the prevalence of the two main types of biofilm formed by the most relevant Acinetobacter species, comparing biofilm formation between the different species. FINDINGS Biofilm formation at the air-liquid and solid-liquid interfaces was investigated in different Acinetobacter spp. and it appeared to be generally more important at 25°C than at 37°C. The biofilm formation at the solid-liquid interface by the members of the ACB-complex was at least 3 times higher than the other species (80-91% versus 5-24%). In addition, only the isolates belonging to this complex were able to form biofilm at the air-liquid interface; between 9% and 36% of the tested isolates formed this type of pellicle. Finally, within the ACB-complex, the biofilm formed at the air-liquid interface was almost 4 times higher for A. baumannii and Acinetobacter G13TU than for Acinetobacter G3 (36%, 27% & 9% respectively). CONCLUSIONS Overall, this study has shown the capacity of the Acinetobacter spp to form two different types of biofilm: solid-liquid and air-liquid interfaces. This ability was generally higher at 25°C which might contribute to their persistence in the inanimate hospital environment. Our work has also demonstrated for the first time the ability of the members of the ACB-complex to form biofilm at the air-liquid interface, a feature that was not observed in other Acinetobacter species.

Bibliotecas universitarias: cabalgando la tecnología, siguiendo al usuario

Repaso de los avances tecnológicos que más han influido en la evolución de las bibliotecas universitarias, y descripción de las actuaciones realizadas para adaptarse a los mismos: repositorios y acceso abierto, renovación de espacios, servicios a los investigadores, instrumentos de descubrimiento, y libro electrónico. Se concluye que en general las bibliotecas académicas gozan de buena salud gracias a que han sabido anticiparse a los cambios, y tienen buenas perspectivas de futuro.

Detección de los movimientos de la cara de un usuario delante de la pantalla de un ordenador

Estudio de diferentes alternativas para detectar el movimiento de la cara de un usuario delante de la pantalla de un ordenador. Realización de una aplicación capaz de desplazar el mouse de forma relativa y realizar clicks de una forma sencilla mediante la cabeza del usuario con una webcam de bajo coste.

Diseño y desarrollo centrado en el usuario de un sitio web de fotografía de autor con un sistema de gestión de contenidos

El proyecto supone la puesta a punto de un sitio web cuya finalidad es mostrar y divulgar la obra de un fotógrafo. Este sitio consta de dos partes, la parte pública, visible por cualquier usuario, y una parte privada, accesible únicamente por un administrador, desde la cual se puede actualizar de forma simple la información visible en la parte pública.

Generación automàtica de formularios con asistencia al usuario para la edición de datos en la web semántica

Desarrollo de mecanismos para la edición de datos semánticos mendiante formularios generados automáticamente que asisten al usuario mediante mecanismos de auto-completado. Estos mecanismos se basarán en formularios web y se integrarán en una aplicación basada en tecnologías de web semántica. Los formularios se generarán a partir de datos basados en RDF, su estructura y semántica proporcionada por esquemas RDF. Los usuarios podrán editar los datos existentes o crear nuevas descripciones basadas en datos semánticos. En ambos casos, se recomendarán al usuario propiedades y valores conformes a los esquemas y ontologías que estructuran los datos.

Estado del arte de los gestores de ventanas en GNU/Linux

Proyecto que recoge el estado del arte de los gestores de ventanas de GNU/Linux, incorporando un análisis y comparativa de los principales gestores de ventanas.

Desarrollo de Surrogates para la representación dinámica de la información digital

El volumen de información a la que un usuario tiene acceso en Internet esenorme. La representación de la misma ha ido evolucionando a lo largo del tiempo a lavez que se han establecido reglas, recomendaciones y directrices que conforman toda una ingeniería de diseño de interfaces con el propósito de mejorar la representación e interacción entre el usuario y el ordenador. Aún así, hay que ir evolucionando en la manera de tratar esta representación de la información ya que Internet es un espacio donde afloran, día tras día, nuevas tecnologías y servicios.De hecho, en este proyecto trataremos de mejorar la representación de lainformación mediante unos objetos que llamaremos surrogates o sustitutos. Como sunombre indica, estos sustitutos serán la representación de los elementos a reemplazar y cuya función podríamos calificar como de “puerta de enlace”. Dichos objetos estaránformados por elementos propios de la información a la que representan con el objetivo de que el usuario identifique de una manera más rápida y sencilla esta información.En definitiva, desarrollaremos unos surrogates que puedan ser usados endiferentes interfaces independientemente de la tecnología que se haya empleado para sudesarrollo y dotándolos de una serie de características y métodos con el fin de mejorar la interacción entre el usuario y la información.

Estoy sola: la experiencia de las enfermeras en el cuidado del usuario de alcohol y drogas

El propósito de este estudio es comprender cómo es ser enfermera vivenciando el cuidado de pacientes drogodependientes que ingresan al Servicio de Medicina de un hospital público de Chile. Se opta por un estudio de tipo cualitativo, de trayectoria fenomenológica, según el referencial de Martín Heidegger. La pregunta orientadora fue: ¿Cómo es cuidar a pacientes drogodependientes que ingresan en tu servicio? Los discursos de las enfermeras fueron interpretados bajo el referencial de Fenómeno Situado de Joel Martins. Después del análisis de las entrevistas, se identificó 3 temas que expresan el fenómeno: hablando del paciente drogodependiente, cuidando al paciente en un medio adverso, superando el miedo para cuidar. El estudio muestra la necesidad de capacitar al personal de salud en dependencia en alcohol y drogas para superar los preconceptos y mejorar el cuidado de estos pacientes.

Prototipação e usabilidade em interfaces para aplicações móveis

Como já é de conhecimento de todos as tecnologias móveis permitem aceder à informação em qualquer lugar e em qualquer altura. Por isso, essas tecnologias móveis podem facilitar o dia-a-dia dos utilizadores, e tornar mais eficiente e eficaz a prestação de serviços. Os profissionais da universidade necessitam de partilhar e aceder à informação adequada para auxiliar nos serviços frequentes do dia-a-dia. Assim a existência de uma interface que interage e disponibilize as diversas informações pode trazer grandes benefícios. Analisando ainda dentro desse contexto existe actualmente alguma falha no sector académico, visto que ainda existe dificuldades em aceder à informação a quem dela necessita, antes pelo contrário, originando atrasos nos afazeres do dia-a-dia. Em muitos casos a introdução de tecnologias pode evitar a ocorrência de problemas. No entanto os profissionais têm de estar preparados para a evolução dos actuais processos nos serviços académicos. Desenvolver um protótipo para aplicações móveis nesta área constitui um desafio, pois não basta somente conhecer os processos realizados pelos potenciais utilizadores, sendo igualmente necessário assegurar que funcionam do mesmo modo quando são executados através de um equipamento com características muito próprias, como os dispositivos de computação móvel.

Quantitative comparison of simulations of seismic wave propagation in heterogeneous poro-elastic media involving fluid-solid interfaces and in equivalent visco-elastic solids

There is increasing evidence to suggest that the presence of mesoscopic heterogeneities constitutes the predominant attenuation mechanism at seismic frequencies. As a consequence, centimeter-scale perturbations of the subsurface physical properties should be taken into account for seismic modeling whenever detailed and accurate responses of the target structures are desired. This is, however, computationally prohibitive since extremely small grid spacings would be necessary. A convenient way to circumvent this problem is to use an upscaling procedure to replace the heterogeneous porous media by equivalent visco-elastic solids. In this work, we solve Biot's equations of motion to perform numerical simulations of seismic wave propagation through porous media containing mesoscopic heterogeneities. We then use an upscaling procedure to replace the heterogeneous poro-elastic regions by homogeneous equivalent visco-elastic solids and repeat the simulations using visco-elastic equations of motion. We find that, despite the equivalent attenuation behavior of the heterogeneous poro-elastic medium and the equivalent visco-elastic solid, the seismograms may differ due to diverging boundary conditions at fluid-solid interfaces, where there exist additional options for the poro-elastic case. In particular, we observe that the seismograms agree for closed-pore boundary conditions, but differ significantly for open-pore boundary conditions. This is an interesting result, which has potentially important implications for wave-equation-based algorithms in exploration geophysics involving fluid-solid interfaces, such as, for example, wave field decomposition.