Characterization of the Adherence of Clostridium difficile Spores: The Integrity of the Outermost Layer Affects Adherence Properties of Spores of the Epidemic Strain R20291 to Components of the Intestinal Mucosa

Indexación: Web of Science.Clostridium difficile is the causative agent of the most frequently reported nosocomial diarrhea worldwide. The high incidence of recurrent infection is the main clinical challenge of C. difficile infections (CBI). Formation of C. difficile spores of the epidemic strain R20291 has been shown to be essential for recurrent infection and transmission of the disease in a mouse model. However, the underlying mechanisms of how these spores persist in the colonic environment remains unclear. In this work, we characterized the adherence properties of epidemic R20291 spores to components of the intestinal mucosa, and we assessed the role of the exosporium integrity in the adherence properties by using cdeC mutant spores with a defective exosporium layer. Our results showed that spores and vegetative cells of the epidemic R20291 strain adhered at high levels to monolayers of Caco-2 cells and mucin. Transmission electron micrographs of Caco-2 cells demonstrated that the hair-like projections on the surface of R20291 spores are in close proximity with the plasma membrane and microvilli of undifferentiated and differentiated monolayers of Caco-2 cells. Competitive-binding assay in differentiated Caco-2 cells suggests that spore-adherence is mediated by specific binding sites. By using spores of a cdeC mutant we demonstrated that the integrity of the exosporium layer determines the affinity of adherence of C. difficile spores to Caco-2 cells and mucin. Binding of fibronectin and vitronectin to the spore surface was concentration-dependent, and depending on the concentration, spore-adherence to Caco-2 cells was enhanced. In the presence of an aberrantly-assembled exosporium (cdeC spores), binding of fibronectin, but not vitronectin, was increased. Notably, independent of the exosporium integrity, only a fraction of the spores had fibronectin and vitronectin molecules binding to their surface. Collectively, these results demonstrate that the integrity of the exosporium layer of strain R20291 contributes to selective spore adherence to components of the intestinal mucosa.http://journal.frontiersin.org/article/10.3389/fcimb.2016.00099/ful

The relationship between truncation and phosphorylation at the C-terminus of tau protein in the paired helical filaments of Alzheimer's disease

Acknowledgements: Authors want to express their gratitude to Dr. P. Davies (Albert Einstein College of Medicine, Bronx, NY, USA) and Lester I. Binder (NorthWestern, Chicago, IL, USA) for the generous gift of mAbs (TG-3, Alz-50, and MC1), and (TauC-3), respectively, and to M. en C. Ivan J. Galván-Mendoza for his support in confocal microscopy, and Ms. Maricarmen De Lorenz for her secretarial assistance. We also want to express our gratitude to the Mexican Families who donate the brain of their loved ones affected with Alzheimer's disease, and made possible our research. This work was financially supported by CONACyT grant, No. 142293 (For R.M).Peer reviewedPublisher PD

Quadrotor modeling and a pid control approach

Since there has been an important increase in unmanned vehicles systems research such as quadrotors, a mathematical model and PID control laws are studied. Based on some dynamic variables, PID control is applied to compute a controller to be then use in autopilot simulations. As this kind of VTOL vehicle seems to be unstable, the aim of this work is to change even other flight mechanics parameters and control gains to study attitude and altitude variations. A well-known computational tool is used for simulation purposes, performance analysis and validation

Path Planning Approach for a Quadrotor Unmanned Aerial Vehicle

A path planning method for an unmanned aerial system type quadrotor is proposed in this work. It is based on Dubins curves. Therefore, different points (initial and ending) are set for generation of several paths. Additionally, to validate the proposed model a computational resource is applied. Also, some flight dynamics limits and orientation angles computations are considered to be able to determine a simplified Dubins model. Dubins paths are commonly divided into low, medium and high altitude gains. It will depend on the altitude established for the start and end points and other configurations

IDÉLU

ITESO, A.C

Bayesian Classifiers in Intrusion Detection Systems

To be able to identify computer attacks, detection systems that are based on faults are not dependent on data base upgrades unlike the ones based on misuse. The first type of systems mentioned generate a knowledge pattern from which the usual and unusual traffic is distinguished. Within computer networks, different classification traffic techniques have been implemented in intruder detection systems based on abnormalities. These try to improve the measurement that assess the performance quality of classifiers and reduce computational cost. In this research work, a comparative analysis of the obtained results is carried out after implementing different selection techniques such as Info.Gain, Gain ratio and Relief as well as Bayesian (Naïve Bayes and Bayesians Networks). Hence, 97.6% of right answers were got with 13 features. Likewise, through the implementation of both load balanced methods and attributes normalization and choice, it was also possible to diminish the number of features used in the ID classification process. Also, a reduced computational expense was achieved

El diseño instruccional y la tecnología informática como herramienta para mejorar la enseñanza en la ingeniería

[SPA]El avance de la humanidad ha sido constante a través de la historia. La rapidez con la que se desarrollan nuevos hallazgos en ciencia y tecnología es vertiginosa debido a la globalización, convirtiendo la evolución y continua mejora de todos los aspectos de nuestra vida en algo fundamental para el desarrollo de los seres humanos. De esta forma, los sistemas educativos de todo el mundo se han dado a la tarea de actualizarse y reformarse, buscando un nuevo modelo de enseñanza-aprendizaje que mejore la calidad de la educación, a la vez que propicie la integración del estudiante con su entorno. En la Universidad Veracruzana, la actualización de los métodos de enseñanza se está llevando a cabo mediante la tecnología informática con la implementación del Proyecto Aula y su herramienta principal, el Diseño Instruccional. En este artículo se presentan los fundamentos y aplicación del Diseño Instruccional derivado del “Proyecto Aula” implementado en la Facultad de Ingeniería de la Universidad Veracruzana, Región Veracruz; así como el análisis de los datos disponibles tras la evaluación de este caso, el cual permitirá determinar el grado de preferencia del modelo propuesto, para la enseñanza en la Ingeniería. [ENG]Mankind advance has been constant throughout history. The fast pace at which new findings in science and technology develop is vertiginous due to globalization, turning evolution and constant improvement of every aspect of our lives into something basic for human development. Due to this, educational systems worldwide have been committed to update and reform themselves, seeking for a new teaching/learning model capable of improving education quality as propitiates student integration with the environment. At Universidad Veracruzana, the bringing up to date of teaching methodologies has been carried out by means of Informatics Technology and the implementation of “Proyecto Aula” through its main tool, the Instructional Design. This paper provides with the fundamentals and application of the Instructional Design derived from “Proyecto Aula” which has been implemented at the Engineering Faculty of the Universidad Veracruzana, in Veracruz Region; as well as the analysis of available data resulting of this case evaluation, which will allow to determine the degree of preference of the proposed model for Engineering teaching.Campus Mare Nostrum, Universidad Politécnica de Cartagena, Universidad de Murcia, Región de Murci

OpenFOAM Numerical Simulations with Different Lid Driven Cavity Shapes

The finite volume method have been developed to solve the Navier-Stokes equations with primitive variables and non dimensional form. This work examine the classical benchmark problem of the lid-driven cavity at a different Reynolds range (Re = 10,100,400, 1000, 2000, 3200) and several cavity geometries. The cavity configurations include square cavity, skewed cavity, trapezoidal cavity and arcshaped cavity. The flow is assumed laminar and solved in a uniform mesh. A CFD tool with its solvers (icoFoam) will be used for this study

Mathematical Modelling and Identification of a Quadrotor

Motivated by the important growth of VTOL vehicles research such as quadrotors and to a small extent autonomous flight, a quadrotor dynamical model is presented in this work. The purpose of this study is to get a better understanding of its flight dynamics. It is an underactuated system. So, a simplified and clear model is needed to implement controllers on these kind of unmanned aerial systems. In addition, a computational tool is used for validation purposes. For future works embedded or intelligent control systems can be developed to control them. Gyroscopic and some aerodynamics effects are neglected

Risk Association of TOX3 and MMP7 Gene Polymorphisms with Sporadic Breast Cancer in Mexican Women

Breast cancer (BC) has one of the highest incidences and mortality worldwide. Single nucleotide polymorphisms (SNPs) in TOX3 rs3803662 and MMP7 rs1943779 have been associated with susceptibility to BC. In this case-control study, we evaluated the association of rs3803662 (TOX3)/rs1943779 (MMP7) SNPs with clinical features, immunohistochemical reactivity, and risk association with BC in women from northeastern Mexico. We compared 212 BC cases and 212 controls. DNA was isolated from peripheral blood to perform the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. We calculated genotype frequencies, odds ratios, and 95% confidence intervals. We found that CT (Cytocine-Thymine) and TT (Thymine -Thymine) genotypes, and T alleles of TOX3 rs3803662, were associated with BC risk (p = 0.034, p = 0.011, respectively). SNP TOX3 rs3803662 was associated with positive progesterone receptors (PR) and triple-negative BC (TNBC) but not with estrogen receptor (ER) or HER2 reactivity. CT and TT genotypes (p = 0.006) and T alleles (p = 0.002) of SNP MMP7 rs1943779 were associated with risk of BC. We found that T alleles of TOX3 rs3803662 and MMP7 rs1943779 SNPs are associated with BC risk. These findings contribute to personalized medicine in Mexican women