Una tarde con Ramón. Entrevista a Ramón Valdés

Aquesta entrevista al Catedràtic Emèrit de la UAB, Dr. Ramón Valdés del Toro, la van realitzar l'11 de juliol de 2006 un grup d'alumnes de l'assignatura Etnologia Regional que es va impartir el curs 2005-06 a la Llicenciatura d'Antropologia Social d'aquesta universitat. L'entrevista forma part d'un projecte més ampli vinculat a l'assignatura dirigit per la professora que l'imparteix, Montserrat Clua i Fainé.Esta entrevista al Catedrático Emérito de la UAB, Dr. Ramón Valdés del Toro, fue realizada el 11 de julio de 2006 por un grupo de alumnas de la asignatura Etnología Regional que se impartió el curso 2005-06 en la Licenciatura de Antropología Social de dicha universidad. La entrevista forma parte de un proyecto más amplio vinculado a la asignatura y dirigido por su profesora, Montserrat Clua i Fainé

Classification and comparison of snow fences for the protection of transport infrastructures

Blowing snow or sand transport generates serious problems such as transport infrastructures buried under snow or sand in many parts of the world. Some of the most important problems that snow and sand storms can cause include drivers getting trapped on the roads, traffic being held up indefinitely, accidents occurring and populations being isolated. Snow fences provide a solution to this problem as they can hold back the snow, preventing displacement and wind-induced drifting. In this way, they reduce these problems on transport infrastructures and improve visibility, providing safer driving conditions. In this review, a classification is proposed of snow fences based on three basic types: earth, structural and living snow fences. Among the structural ones, non-porous and porous snow fences are distinguished. The different possibilities in terms of the placement of snow fences are also analyzed. Finally, different types of snow fences have been compared under design, construction and operation criteria. This review can provide initial guidelines for technicians to choose the best snow fence for blizzard conditions

Near-Field Scanning Optical Microscope Combined with Digital Holography for Three-Dimensional Electromagnetic Field Reconstruction

International audienceNear-field scanning optical microscopy (NSOM) has proven to be a very powerful imaging technique that allows overcoming the diffraction limit and obtaining information on a scale much smaller than what can be achieved by classical optical imaging techniques. This is achieved using nanosized probes that are placed in close proximity to the sample surface, and thus allow the detection of evanescent waves that contain important information about the properties of the sample on a subwavelength scale. In particular, some aperture-based probes use a nanometer-sized hole to locally illuminate the sample. The far-field radiation of such probes is essential to their imaging properties, but cannot be easily estimated since it highly depends on the environment with which it interacts. In this chapter, we tackle this problem by introducing a microscopy method based on full-field off-axis digital holography that allows us to study in details the three-dimensional electromagnetic field scattered by a NSOM probe in different environments. We start by describing the NSOM and holography techniques independently, and continue by highlighting the advantage of combining both methods. We present a comparative study of the reconstructed light from a NSOM tip located in free space or coupled to transparent and plasmonic media. While far-field methods, such as back focal plane imaging, can be used to infer the directionality of angular radiation patterns, the advantage of our technique is that a single hologram contains information on both the amplitude and phase of the scattered light, allowing to reverse numerically the propagation of the electromagnetic field towards the source. We also present Finite Difference Time Domain (FDTD) simulations to model the radiation of the NSOM tip as a superposition of a magnetic and an electric dipole. We finally propose some promising applications that could be performed with this combined NSOM-holography technique

Adipose tissue gene expression analysis reveals changes in inflammatory, mitochondrial respiratory and lipid metabolic pathways in obese insulin-resistant subjects

<p>Abstract</p> <p>Background</p> <p>To get insight into molecular mechanisms underlying insulin resistance, we compared acute in vivo effects of insulin on adipose tissue transcriptional profiles between obese insulin-resistant and lean insulin-sensitive women.</p> <p>Methods</p> <p>Subcutaneous adipose tissue biopsies were obtained before and after 3 and 6 hours of intravenously maintained euglycemic hyperinsulinemia from 9 insulin-resistant and 11 insulin-sensitive females. Gene expression was measured using Affymetrix HG U133 Plus 2 microarrays and qRT-PCR. Microarray data and pathway analyses were performed with Chipster v1.4.2 and by using in-house developed nonparametric pathway analysis software.</p> <p>Results</p> <p>The most prominent difference in gene expression of the insulin-resistant group during hyperinsulinemia was reduced transcription of nuclear genes involved in mitochondrial respiration (mitochondrial respiratory chain, GO:0001934). Inflammatory pathways with complement components (inflammatory response, GO:0006954) and cytokines (chemotaxis, GO:0042330) were strongly up-regulated in insulin-resistant as compared to insulin-sensitive subjects both before and during hyperinsulinemia. Furthermore, differences were observed in genes contributing to fatty acid, cholesterol and triglyceride metabolism (FATP2, ELOVL6, PNPLA3, SREBF1) and in genes involved in regulating lipolysis (ANGPTL4) between the insulin-resistant and -sensitive subjects especially during hyperinsulinemia.</p> <p>Conclusions</p> <p>The major finding of this study was lower expression of mitochondrial respiratory pathway and defective induction of lipid metabolism pathways by insulin in insulin-resistant subjects. Moreover, the study reveals several novel genes whose aberrant regulation is associated with the obese insulin-resistant phenotype.</p

Aquaporins: important but elusive drug targets.

The aquaporins (AQPs) are a family of small, integral membrane proteins that facilitate water transport across the plasma membranes of cells in response to osmotic gradients. Data from knockout mice support the involvement of AQPs in epithelial fluid secretion, cell migration, brain oedema and adipocyte metabolism, which suggests that modulation of AQP function or expression could have therapeutic potential in oedema, cancer, obesity, brain injury, glaucoma and several other conditions. Moreover, loss-of-function mutations in human AQPs cause congenital cataracts (AQP0) and nephrogenic diabetes insipidus (AQP2), and autoantibodies against AQP4 cause the autoimmune demyelinating disease neuromyelitis optica. Although some potential AQP modulators have been identified, challenges associated with the development of better modulators include the druggability of the target and the suitability of the assay methods used to identify modulators

Una tarde con Ramón. Entrevista a Ramón Valdés

Aquesta entrevista al Catedràtic Emèrit de la UAB, Dr. Ramón Valdés del Toro, la van realitzar l'11 de juliol de 2006 un grup d'alumnes de l'assignatura Etnologia Regional que es va impartir el curs 2005-06 a la Llicenciatura d'Antropologia Social d'aquesta universitat. L'entrevista forma part d'un projecte més ampli vinculat a l'assignatura dirigit per la professora que l'imparteix, Montserrat Clua i Fainé.Esta entrevista al Catedrático Emérito de la UAB, Dr. Ramón Valdés del Toro, fue realizada el 11 de julio de 2006 por un grupo de alumnas de la asignatura Etnología Regional que se impartió el curso 2005-06 en la Licenciatura de Antropología Social de dicha universidad. La entrevista forma parte de un proyecto más amplio vinculado a la asignatura y dirigido por su profesora, Montserrat Clua i Fainé