Análisis de un flujo de depósitos (debris flow) en la ladera norte del Pico de Orizaba (México)

[Resumen] Los flujos o coladas de depósitos (debris flows) son deslizamientos homogéneos de enormes masas de sedimentos originados como consecuencia de una sobresaturación de agua, pasando a transformarse en una segunda fase en un flujo turbulento, donde toda la masa transportada se mezcla, hasta alcanzar su estado de reposo debido a la pérdida de pendiente, de manera que va a constituir muros laterales (levées) y lóbulos finales (INNES, 1983; JOHNSON y RODINE, 1984). En áreas volcánicas, estos procesos inciden de manera especial en la estabilidad y evolución geomorfológica de las laderas. El lento crecimiento de la vegetación, prácticamente nulo, hace de éstas, áreas inestables con efectos morfológicos de gran magnitud (movimientos en masa).[Abstract] The volcanic areas are influenced by significant slope processes. This study analyzes a debris flow processe on the northern slope of Pico de Orizaba volcano (Mexique). The rapid retreat of the glaciers in this volcano during the past century and the absence of a land cover are suitable conditions to start debris flows processes. The conclusions indicate the importance of the glacial and periglacial activity in this geomorphologic event, the same as in the landform evolution and its activity in relation to climatic change

Postcranial elements of "Maledictosuchus riclaensis" (Thalattosuchia) from the Middle Jurassic of Spain

Maledictosuchus riclaensis is a metriorhynchid crocodylomorph from the Callovian (Middle Jurassic) of Ricla (Spain). It is the most basal member of the Rhacheosaurini Tribe; it has recently been described and defined by its cranial elements (an almost complete skull and part of the lower jaw), but there were no data on the postcranial elements. Associated with the skull three vertebrae were collected. These vertebrae were preserved in black calcite nodules, and they have recently been prepared. The postcranial elements of the metriorhynchids are poorly documented, and usually badly preserved or included in the matrix. Herein we describe the three vertebrae (part of the holotype) of M. riclaensis. These comprise one cervical, one dorsal and one caudal vertebra, which, like the skull, are well preserved and lack postmortem distortion or deformation.Maledictosuchus riclaensis es un crocodilomorfo metriorrínquido del Calloviense (Jurásico medio) de Ricla (España). Es el miembro más basal de la tribu de los raqueosaurinos, y ha sido definido a partir de sus elementos craneales (un cráneo prácticamente completo y parte de la mandíbula inferior). Sin embargo no había datos de los elementos poscraneales. Durante la campaña de prospección en la que se recuperó el holotipo, se recuperaron tres vértebras asociadas al cráneo. Las vértebras estaban preservadas en nódulos de calcita, y han sido preparadas recientemente. Los elementos poscraneales de los metriorrínquidos están poco documentados, y normalmente, mal preservados o incluidos en la matriz. En este trabajo se hace descripción de tres vértebras, cervical, dorsal y caudal, del ejemplar tipo de M. riclaensis

The Evolution of Active Droplets in Chemorobotic Platforms

There is great interest in oil-in-water droplets as simple systems that display astonishingly complex behaviours. Recently, we reported a chemorobotic platform capable of autonomously exploring and evolving the behaviours these droplets can exhibit. The platform enabled us to undertake a large number of reproducible experiments, allowing us to probe the non-linear relationship between droplet composition and behaviour. Herein we introduce this work, and also report on the recent developments we have made to this system. These include new platforms to simultaneously evolve the droplets’ physical and chemical environments and the inclusion of selfreplicating molecules in the droplets

Improved image quality with new ultrasound imaging techniques

AbstractThis work addresses three key subjects to the image quality with phased arrays: timing accuracy, beamforming strategy and post-processing for increased resolution and suppression of grating and side lobes.Timing accuracy is achieved by defining a modular and scalable architecture which guarantees timing errors of a few tens of picoseconds, whatever is the system size. The proposed beamforming methodology follows the progressive focusing correction technique, which keeps low focusing errors, provides a high information density and has a simple implementation for real-time imaging. Then, phase coherence imaging is defined to suppress grating and sidelobe indications and increasing the lateral resolution

Flow injection determination of total catechins and procyanidins in white and red wines

An easily automatable flow-injection (FI) method for the determination of total catechins is reported. The method is based on the reaction of vanillin in acid medium to yield a coloured product with maximum absorption at 500 nm. After optimisation by the univariate and multivariate approaches as required, the linear range was established (between 10 and 90 mgL-1 and 10 and 250 mgL-1 for white and red wines, respectively). Then, the assessment of the proposed versus the reference method was studied in terms of repeatability (2.57 mgL-1), reproducibility (3.56 mgL-1) (no significant differences were found), detection and quantification limits (not far from those of the reference method and always sufficient for the determination of catechins in any type of wine), traceability (excellent correlation under all conditions) and sample throughput (23 samples h-1 for the proposed method versus 3 samples h-1 for the reference method)

The First Metriorhynchid Crocodylomorph from the Middle Jurassic of Spain, with Implications for Evolution of the Subclade Rhacheosaurini

Background: Marine deposits from the Callovian of Europe have yielded numerous species of metriorhynchid crocodylomorphs. While common in English and French Formations, metriorhynchids are poorly known from the Iberian Peninsula. Twenty years ago an incomplete, but beautifully preserved, skull was discovered from the Middle Callovian of Spain. It is currently the oldest and best preserved metriorhynchid specimen from the Iberian Peninsula. Until now it has never been properly described and its taxonomic affinities remained obscure. Methodology/Principal Findings: Here we present a comprehensive description for this specimen and in doing so we refer it to a new genus and species: Maledictosuchus riclaensis. This species is diagnosed by numerous autapomorphies, including: heterodont dentition; tightly interlocking occlusion; lachrymal anterior process excludes the jugal from the preorbital fenestra; orbits longer than supratemporal fenestrae; palatine has two non-midline and one midline anterior processes. Our phylogenetic analysis finds Maledictosuchus riclaensis to be the basal-most known member of Rhacheosaurini (the subclade of increasingly mesopelagic piscivores that includes Cricosaurus and Rhacheosaurus). Conclusions/Significance: Our description of Maledictosuchus riclaensis shows that the craniodental morphologies that underpinned the success of Rhacheosaurini in the Late Jurassic and Early Cretaceous, as a result of increasing marine specialization to adaptations for feeding on fast small-bodied prey (i.e. divided and retracted external nares; reorientation of the lateral processes of the frontal; elongate, tubular rostrum; procumbent and non-carinated dentition; high overall tooth count; and dorsolaterally inclined paroccipital processes), first appeared during the Middle Jurassic. Rhacheosaurins were curiously rare in the Middle Jurassic, as only one specimen of Maledictosuchus riclaensis is known (with no representatives discovered from the well-sampled Oxford Clay Formation of England). As such, the feeding/marine adaptations of Rhacheosaurini did not confer an immediate selective advantage upon the group, and it took until the Late Jurassic for this subclade to dominate in Western Europe

Neuroprotection: A New Therapeutic Approach of Relapsing Remitting Multiple Sclerosis

Neurodegenerative changes occurring early from primary acute immune-mediated inflammation support the hypothesis that multiple sclerosis (MS) is a complex disease. Axonal loss progresses with the disease course and represents the principal driver of disability. In this context, the pursuit of neuroprotective therapies in multiple sclerosis provides new valid alternatives that could significantly impact on disease progression and neurodegenerative changes, including the promotion of restoration of myelin sheaths through the remyelination process. This chapter reviews promising drugs with proposed neuroprotective or neuroregenerative effects that are currently approved or in clinical trials for the treatment of multiple sclerosis. Although the chapter highlights the diazoxide action on neuroinflammation and the results of a clinical trial with this drug, the review also includes other molecules with oral or parenteral administration

Mechanisms Involved in the Selective Transfer of Long Chain Polyunsaturated Fatty Acids to the Fetus

The concentration of long chain polyunsaturated fatty acid (LCPUFA) in the fetal brain increases dramatically from the third trimester until 18 months of life. Several studies have shown an association between the percentage of maternal plasma docosahexaenoic acid (DHA) during gestation and development of cognitive functions in the neonate. Since only very low levels of LCPUFA are synthesized in the fetus and placenta, their primary source for the fetus is the maternal circulation. Both in vitro and human in vivo studies using labeled fatty acids have shown preferential transfer of LCPUFA from the placenta to the fetus compared with other fatty acids, although the mechanisms involved are still uncertain. The placenta takes up circulating maternal non-esterified fatty acids (NEFA) and fatty acids released mainly by maternal lipoprotein lipase and endothelial lipase. These NEFA may enter the cell by passive diffusion or by means of membrane carrier proteins. Once in the cytosol, NEFA bind to cytosolic fatty acid-binding proteins for transfer to the fetal circulation or can be oxidized within the trophoblasts, and even re-esterified and stored in lipid droplets. Although trophoblast cells are not specialized for lipid storage, LCPUFA may up-regulate peroxisome proliferator activated receptor-γ (PPARγ) and hence the gene expression of fatty acid transport carriers, fatty acid acyl-CoA-synthetases and adipophilin or other enzymes involved in lipolysis, modifying the rate of placental transfer, and metabolism. The placental transfer of LCPUFA during pregnancy seems to be a key factor in the neurological development of the fetus. Increased knowledge of the factors that modify placental transfer of fatty acids would contribute to our understanding of this complex process

Clinical approach and treatment of benign and malignant parotid masses, personal experience

Parotid gland tumours account for 80% of all salivary gland neoplasms, 20% of these are malignant, but in daily clinical practice most parotid masses are operated on before obtaining the final histological diagnosis. This clinical setting further complicates the critical point of parotid surgery, which is the management of the facial nerve. In the present study, data were evaluated referring to 540 patients who underwent parotidectomy for a mass which was discovered to be a benign (470 cases) or a malignant (70 cases) neoplasm, between November 1994 and December 2007, at our Institution. The most significant single parameter in this series of malignancies regarding disease specific survival was the clinical involvement of the facial nerve at diagnosis (p = 0.006). Also for this reason, as there is no evidence that liberal VIIth nerve sacrifice improves prognosis, when it is not clinically involved, every attempt is made to dissect and preserve it. At present, the most complicated situation concerning nerve preservation may be, on the other hand, recurrence of a benign tumour, in particular pleomorphic adenoma, which, in our series, has a higher incidence (8.3%) of permanent facial dysfunction, than surgery with nerve preservation for malignancy (3.7%)

PERCEPCIÓN DE LOS ALUMNOS DE ENFERMERÍA SOBRE LA FUNCIÓN TUTORIAL EN LAS PRÁCTICAS

Nursing students perceived dichotomies/contradictions between the perspectives of male and female nurses while on internship. This is why we have decided to analyze nursing students’ perceptions of the tutorial function of internship. In this investigation we have opted for the descriptive method, which has as a primary objective to systematically describe facts and characteristics of a given population or area of interest in an objective and verifiable way. The study population consists of nursing students of the University School of Health Sciences, University of Seville. Based on the results obtained in this investigation, we believe it useful to provide the information necessary for the tutorial function, with the idea that tutors are aware of the same objectives. Also, they need to be sure that students are aware of the objectives of the internship and help them to understand the importance of caring for patients, and the use of a conceptual model for guidance during the internship and the use of the process of nursing care, as a method of problem solving.Los alumnos de enfermería perciben dicotomías, contradicciones, entre la perspectiva enfermera con que ellos realizan las prácticas y la perspectiva con la que la realizan las enfermeras. Es por lo que nos hemos planteado analizar la percepción de los alumnos de la diplomatura de enfermería sobre la función tutorial en las prácticas. En esta investigación nos hemos decantado por el método descriptivo, que tiene como principal objetivo describir sistemáticamente hechos y características de una población dada o área de interés de forma objetiva y comprobable. La población de estudio la componen los alumnos de enfermería de la Escuela Universitaria Ciencias de la Salud, de la Universidad de Sevilla. En base a los resultados obtenidos en esta investigación, creemos conveniente facilitar la información necesaria para la función tutorial, con la idea de que los tutores conozcan los objetivos de las mismas; que tengan constancia de que los alumnos conocen los objetivos de las prácticas y ayudarles para que comprendan la importancia que tiene para el cuidado de los pacientes la utilización de un modelo conceptual que guíe la práctica y del uso del proceso de cuidados enfermeros, como método de resolución de problemas