RCeveierwamide and ceramide 1-phosphate in health and disease

Sphingolipids are essential components of cell membranes, and many of them regulate vital cell functions. In particular, ceramide plays crucial roles in cell signaling processes. Two major actions of ceramides are the promotion of cell cycle arrest and the induction of apoptosis. Phosphorylation of ceramide produces ceramide 1-phosphate (C1P), which has opposite effects to ceramide. C1P is mitogenic and has prosurvival properties. In addition, C1P is an important mediator of inflammatory responses, an action that takes place through stimulation of cytosolic phospholipase A2, and the subsequent release of arachidonic acid and prostaglandin formation. All of the former actions are thought to be mediated by intracellularly generated C1P. However, the recent observation that C1P stimulates macrophage chemotaxis implicates specific plasma membrane receptors that are coupled to Gi proteins. Hence, it can be concluded that C1P has dual actions in cells, as it can act as an intracellular second messenger to promote cell survival, or as an extracellular receptor agonist to stimulate cell migration.

特大口径高功率脉冲氙灯的研制取得重大进展

由中国科学院上海光学精密机械研究所激光光源研究发展中心承担的国家863—804项目创新研究课题“特大口径高功率脉冲氙灯的研制”取得重大进展，

Synthesis of Titania in Ethanol/Acetic Acid Mixture Solvents: Phase and Morphology Variations

The phase and morphology variations of titania prepared in ethanol/acetic acid mixture solvents have been systematically investigated. X-ray diffraction results and microscopy observations reveal that pure anatase aggregates consisted of small nanoparticles, pure rutile microspheres comprised of nanofibers, and their mixtures could be obtained by varying ratios of ethanol to acetic acid under solvothermal conditions. The contents of anatase and rutile in the mixed phases also vary with the ratios of ethanol to acetic acid. Field emission scanning electron microscopy and high resolution transmission electron microscopy results show that the two phases are separated from each other in final products and form aggregates with morphologies resembling to their pure phase products obtained under favorable conditions. The as-produced rutile nanofibers, either in pure phase or in mixed phases, tend to grow into hollow microspheres.

Molecular dynamics simulation of ionic liquids: The effect of electronic polarizability

An electronically polarizable model has been developed for the ionic liquid 1-ethyl-3-methylimidazolium nitrate (EMIM+/NO3-), Molecular dynamics simulation studies were then performed on both the polarizable and nonpolarizable versions of the model. Comparisons of shear viscosity and diffusion constants at 400 K show that the effects of polarizability are quite substantial and the polarizable model results are in better agreement with the experimental values.

L'Écho de Paris

1917/02/25 (Numéro 11881).

Informe leido por el Sr. Vicerrector Canónigo D. Nicolás L. Gavilán en la solemne distribución de premios a los alumnos del Seminario Conciliar de esta ciudad en la noche del 27 de agosto de 1895 y programa de estudios para el año escolar que comenzará el día 18 del próximo octubre

UANL

Cartes conceptuelles du Glossaire

Ce guide pédagogique fait suite au Glossaire du DESS en administration de l'éducation. Il explique comment les mots du vocabulaire relié au travail des directions d'établissement scolaire et à leur formation peuvent être regroupés dans des cartes conceptuelles pour mieux en saisir la portée. Il explicite aussi la conception et la construction de cartes conceptuelles et présente des exemples issus de la concertation entre les formateurs.

Per què és com és? : diversitat de formes i colors a la natura. '¿Por qué es como es? : diversidad de formas y colores en la naturaleza'.

Resumen de la revista en catalán

Deserción estudiantil: las universidades pasan al tablero

Este reportaje multimedia muestra la realidad de la deserción universitaria en Colombia, involucrando las perspectivas de los principales actores en esta problemática nacional. Se estudiaron los discursos y los programas del Ministerio de Educación y múltiples universidades, y se compararon con los análisis de expertos en el tema, docentes y psicólogos. Estas reflexiones fueron comparadas con historias de desertores, para contrastar los conceptos académicos con la realidad.

Motion cue analysis for parkinsonian gait recognition

This paper presents a computer-vision based marker-free method for gait-impairment detection in Patients with Parkinson's disease (PWP). The system is based upon the idea that a normal human body attains equilibrium during the gait by aligning the body posture with Axis-of-Gravity (AOG) using feet as the base of support. In contrast, PWP appear to be falling forward as they are less-able to align their body with AOG due to rigid muscular tone. A normal gait exhibits periodic stride-cycles with stride-angle around 45o between the legs, whereas PWP walk with shortened stride-angle with high variability between the stride-cycles. In order to analyze Parkinsonian-gait (PG), subjects were videotaped with several gait-cycles. The subject's body was segmented using a color-segmentation method to form a silhouette. The silhouette was skeletonized for motion cues extraction. The motion cues analyzed were stride-cycles (based on the cyclic leg motion of skeleton) and posture lean (based on the angle between leaned torso of skeleton and AOG). Cosine similarity between an imaginary perfect gait pattern and the subject gait patterns produced 100% recognition rate of PG for 4 normal-controls and 3 PWP. Results suggested that the method is a promising tool to be used for PG assessment in home-environment.