Diagnosing atmospheric motion vector observation errors for an operational high resolution data assimilation system

Atmospheric motion vectors (AMVs) are wind observations derived by tracking cloud or water vapour features in consecutive satellite images. These observations are incorporated into Numerical Weather Prediction (NWP) through data assimilation. In the assimilation algorithm, the weighting given to an observation is determined by the uncertainty associated with its measurement and representation. Previous studies assessing AMV uncertainty have used direct comparisons between AMVs with co-located radiosonde data and AMVs derived from Observing System Simulation Experiments (OSSEs). These have shown that AMV error is horizontally correlated with characteristic length scale up to 200 km. In this work, we take an alternative approach and estimate AMV error variance and horizontal error correlation using background and analysis residuals obtained from the Met Office limited area, 3 km horizontal grid length data assimilation system. The results show that the observation error variance profile ranges from 5.2 to 14.1 s m2s− 2, with the highest values occurring at high and medium heights. This is indicative that the maximum error variance occurs where wind speed and shear, in combination, are largest. With the exception of AMVs derived from the High Resolution Visible channel, the results show horizontal observation error correlations at all heights in the atmosphere, with correlation lengthscales ranging between 140 and 200 km. These horizontal lengthscales are significantly larger than current AMV observation thinning distances used in the Met Office high resolution assimilation

Las Innovaciones Educativas con TIC como generadoras de cambio en las prácticas pedagógicas de aula

In Phase 1 of the research project “Strengthening and expanding the coverage of postgraduate training in Educational Innovations with ICT through virtual education strategies in the socio-cultural context of the region”, developed by the Universidad del Cauca and in alliance with the Secretariat of Education of Popayán and of Cauca, and the Group of Creation of Companies, inquired about the meaning of Educational Innovations with ICT for teachers in south-western Colombia; global trends in the use of new technologies in education based on the Horizon project reports; and the revision of the study plans of 18 postgraduate programs in Colombia. The conclusion is that Educational Innovations with ICT, rather than the incorporation of technology in education, seeks to generate changes in the pedagogical paradigm based on the possibilities offered by these new technologies.En la Fase 1 del proyecto de investigación “Fortalecimiento y ampliación de cobertura de la formación postgradual en Innovaciones Educativas con TIC a través de estrategias de educación virtual pertinentes al contexto socio-cultural de la región”, desarrollado por la Universidad del Cauca y en alianza con la Secretaria de Educación de Popayán y del Cauca, y la Corporación Cluster CreaTIC, se indagó sobre: el sentido que tienen las Innovaciones Educativas con TIC para los docentes en el sur-occidente colombiano; las tendencias mundiales sobre el uso de las nuevas tecnologías en educación a partir de los reportes del proyecto Horizon; y la revisión de los planes de estudio de 18 programas de postgrado en Colombia. La conclusión es que las Innovaciones Educativas con TIC, más que la incorporación de tecnología en la educación, busca generar cambios en el paradigma pedagógico a partir de las posibilidades que ofrecen estas nuevas tecnologías

Brain multi-infarct and decompression sickness

Scuba diving is associated with an important risk of devel­oping decompression sickness secondary to formation of gas bubbles inside the body. The latter is formed mainly by nitrogen in the body on the diver’s way to the surface (1,2). In some cases, it might injure the central nervous system. Several decompression cases that have been asso­ciated with neurologic symptoms are described in the lit­erature; however, brain multi-infarct with lethal outcome has never been described

Brain hydatidosis: Review of the literature

Hydatidosis is a common disease worldwide. The causal agent may compromise any Organ of the body, the cerebral location is infrequent. The infection is caused by the larval form of Cestodo Echinococcus granulosus. The man is an accidental intermediary host for food consumption or water contaminated with eggs present in animal feces. We present a review of the literature. At the imaging level, the disease has a classic characteristic consisting of single, usually unilocular and less frequent multilocular, intra-axial and more frequently hemispheric cerebral lesions, compromising the vascular territory of the middle cerebral artery by the hematogenous dissemination of the parasite

The Prometastatic Microenvironment of the Liver

The liver is a major metastasis-susceptible site and majority of patients with hepatic metastasis die from the disease in the absence of efficient treatments. The intrahepatic circulation and microvascular arrest of cancer cells trigger a local inflammatory reaction leading to cancer cell apoptosis and cytotoxicity via oxidative stress mediators (mainly nitric oxide and hydrogen peroxide) and hepatic natural killer cells. However, certain cancer cells that resist or even deactivate these anti-tumoral defense mechanisms still can adhere to endothelial cells of the hepatic microvasculature through proinflammatory cytokine-mediated mechanisms. During their temporary residence, some of these cancer cells ignore growth-inhibitory factors while respond to proliferation-stimulating factors released from tumor-activated hepatocytes and sinusoidal cells. This leads to avascular micrometastasis generation in periportal areas of hepatic lobules. Hepatocytes and myofibroblasts derived from portal tracts and activated hepatic stellate cells are next recruited into some of these avascular micrometastases. These create a private microenvironment that supports their development through the specific release of both proangiogenic factors and cancer cell invasion- and proliferation-stimulating factors. Moreover, both soluble factors from tumor-activated hepatocytes and myofibroblasts also contribute to the regulation of metastatic cancer cell genes. Therefore, the liver offers a prometastatic microenvironment to circulating cancer cells that supports metastasis development. The ability to resist anti-tumor hepatic defense and to take advantage of hepatic cell-derived factors are key phenotypic properties of liver-metastasizing cancer cells. Knowledge on hepatic metastasis regulation by microenvironment opens multiple opportunities for metastasis inhibition at both subclinical and advanced stages. In addition, together with metastasis-related gene profiles revealing the existence of liver metastasis potential in primary tumors, new biomarkers on the prometastatic microenvironment of the liver may be helpful for the individual assessment of hepatic metastasis risk in cancer patients

Naturaleza y cultura en Ámerica Latina

La concreción del XVIII Foro de Estudiantes Latinoamericanos de Antrología y Arqueología: Cultura y naturaleza en América Latina: escenarios para un modelo de desarrollo no civilizatorio, efectuado en Quito desde el 17 al 23 de julio del 2011, se constituyó en un acontecimiento sumamente significativo para la antropología latinoamericana debido a dos motivos. Primero porque coincidió con la emergencia del movimiento universitario estudiantil latinoamericano que expresaba sus tendencias, propuestas y exigencias de cambios tanto de las prácticas académicas como de los patrones civilizatorios que rigen las relaciones actuales. Segundo, porque se inscribía en un contexto de consolidación de las nuevas democracias de los países andinos, de carácter antineoliberal y basadas en los sujetos de derecho entre los cuales se incluye la naturaleza. Estos contextos determinaron que el Foro no ponga en escena certidumbres teóricas o metodológicas, ni se preste al exhibicionismo estéril de los avances disciplinares. Más bien, la convocatoria de la antropología y la arqueología fue apenas un pretexto para hablar, con su lenguaje, de nosotros mismos, de lo que somos, de lo que pensamos, de lo que aspiramos y sentimos sobre nuestra Latinoamérica. Lo que hemos visto, oído y compartido, en realidad, no han sido solamente ideas o conceptos sino opciones y toma de posiciones respecto a múltiples encrucijadas. Posición ante situaciones que amenazan la vida, la justicia y los derechos de todos, un desafío epistemológico todavía en ciernes y que no termina de cuajar aún en nuestras prácticas académicas

Régimen especial de pensión para jugadores de fútbol profesional en Colombia

El presente artículo tiene como principal objetivo analizar la situación en la que se encuentran los jugadores de fútbol profesional colombiano frente a las condiciones establecidas por el Sistema General de Pensiones, para obtener en virtud de sus esfuerzos laborales una pensión de vejez, invalidez o muerte, teniendo en cuenta los factores que limitan la probabilidad de los jugadores para acceder a una pensión vitalicia, la identificación de la legislación y jurisprudencia que regula a los clubes de fútbol colombiano con la finalidad de proponer un régimen especial de pensiones para los jugadores. Se parte de la contextualización e identificación del problema mencionando que, en Colombia los factores que inciden son la inexistencia de cláusula contractual, escasa educación jurídica frente a la garantía y derechos de los jugadores. Se tuvo como conclusión que, existe una regulación que reconoce a gran parte de los futbolistas, sin embargo, algunos no cuentan con los requisitos o parámetros que establece la pensión vitalicia.Universidad Libre - Facultad de Derecho - Especialización en Derecho Laboral y Seguridad SocialThe main objective of this article is to analyze the situation of Colombian professional soccer players in relation to the conditions established by the General Pension System to obtain an old age, disability or death pension by virtue of their work efforts, taking into account the factors that limit the probability of the players to access a life pension, the identification of the legislation and jurisprudence that regulates Colombian soccer clubs in order to propose a special pension system for the players. The starting point is the contextualization and identification of the problem, mentioning that in Colombia the factors that affect are the non-existence of a contractual clause, scarce legal education regarding the guarantee and rights of the players. It was concluded that there is no regulation that recognizes most of the soccer players who are not within the parameters established by the life pension

A swarm intelligence method for feature tracking in AMV derivation

Feature tracking is a key step in the derivation of Atmospheric Motion Vectors (AMV). Most operational derivation processes use some template matching technique, such as Euclidean distance or cross-correlation, for the tracking step. As this step is very expensive computationally, often shortrange forecasts generated by Numerical Weather Prediction (NWP) systems are used to reduce the search area. Alternatives, such as optical flow methods, have been explored, with the aim of improving the number and quality of the vectors generated and the computational efficiency of the process. This paper will present the research carried out to apply Stochastic Diffusion Search, a generic search technique in the Swarm Intelligence family, to feature tracking in the context of AMV derivation. The method will be described, and we will present initial results, with Euclidean distance as reference