Free-living marine nematode communities: In San Jorge gulf, Argentina

The aim of this study was to investigate the patterns of nematode diversity and community structure in San Jorge Gulf, Argentina, in order to improve knowledge of this key group of organisms. Free-living marine nematodes were sampled at 13 stations in February 2014 during an expedition aboard R/V Coriolis II. We found a total of 188 species (101 of which were new to science) belonging to 98 genera. The statistical results indicated the presence of three different assemblages of free-living marine nematodes distributed spatially in three distinct zones in the gulf: the central part, the outer thermal front at both sides of the entrance, and the south thermal front area. Diversity increased from the coast to the entrance of the gulf, and the highest diversity was found in areas with coarser sediment. Sediment and salinity were the environmental parameters that best matched nematode community distribution.Fil: Pastor de Ward, Catalina T.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; ArgentinaFil: Lo Russo, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; ArgentinaFil: Varisco, Martin Alejandro. Universidad Nacional de la Patagonia Austral. Centro de Investigaciones y Transferencia Golfo San Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia Golfo San Jorge. Universidad Nacional de la Patagonia "San Juan Bosco". Centro de Investigaciones y Transferencia Golfo San Jorge; Argentin

QUANTUM CORRECTIONS AND EXTREMAL BLACK HOLES

We consider static solutions of two dimensional dilaton gravity models as toy laboratories to address the question of the final fate of black holes. A non perturbative correction to the CGHS potential term is shown to lead classically to an extremal black hole geometry, thus providing a plausible solution to Hawking evaporation paradox. However, the full quantum theory does not admit an extremal solution.Comment: 12 pages, LaTex, no figures. We have improved the main argument leading to the non-existence of an extremal black hole in the quantum theor

Veamy: an extensible object-oriented C++ library for the virtual element method

This paper summarizes the development of Veamy, an object-oriented C++ library for the virtual element method (VEM) on general polygonal meshes, whose modular design is focused on its extensibility. The linear elastostatic and Poisson problems in two dimensions have been chosen as the starting stage for the development of this library. The theory of the VEM, upon which Veamy is built, is presented using a notation and a terminology that resemble the language of the finite element method (FEM) in engineering analysis. Several examples are provided to demonstrate the usage of Veamy, and in particular, one of them features the interaction between Veamy and the polygonal mesh generator PolyMesher. A computational performance comparison between VEM and FEM is also conducted. Veamy is free and open source software

Regulatory role of glycans in the control of hypoxia-driven angiogenesis and sensitivity to anti-angiogenic treatment

Abnormal glycosylation is a typical hallmark of the transition from healthy to neoplastic tissues. Although the importance of glycans and glycan-binding proteins in cancer-related processes such as tumor cell adhesion, migration, metastasis and immune escape has been largely appreciated, our awareness of the impact of lectin-glycan recognition in tumor vascularization is relatively new. Regulated glycosylation can influence vascular biology by controlling trafficking, endocytosis and signaling of endothelial cell (EC) receptors including vascular endothelial growth factor receptors, platelet EC adhesion molecule, Notch and integrins. In addition, glycans may control angiogenesis by regulating migration of endothelial tip cells and influencing EC survival and vascular permeability. Recent evidence indicated that changes in the EC surface glycome may also serve ?on-and-off? switches that control galectin binding to signaling receptors by displaying or masking-specific glycan epitopes. These glycosylation-dependent lectin-receptor interactions can link tumor hypoxia to EC signaling and control tumor sensitivity to anti-angiogenic treatment.Fil: Croci Russo, Diego Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Cerliani, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Pinto, Nicolás Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Morosi, Luciano Gastón. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Rabinovich, Gabriel Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Biológica; Argentin

Problemas de optimización combinatoria: una propuesta que combina algoritmos genéticos y metaheurísticas

Timetabling se refiere al conjunto de problemas de optimización combinatoria que intentan asignar recursos, sean aulas, docentes o intervalos de tiempo, para distintas necesidades de estudiantes, cursos y exámenes. El presente trabajo se ocupa de una de las variantes de este problema, que busca agendar exámenes a distintos intervalos de tiempo, cumpliendo con las restricciones de que ningún alumno debe asistir a más de un examen en el mismo momento y que, en la medida de lo posible, tenga el mayor tiempo libre entre las evaluaciones. Los intervalos de tiempo no tienen restricciones en cuanto a la cantidad de exámenes que puedan asignárseles. Como estrategia de resolución se utiliza un algoritmo genético, que combina diversas heurísticas para la construcción de soluciones factibles que conforman la población inicial con la que trabaja el algoritmo. Dichas heurísticas fueron seleccionadas priorizando la calidad de la solución construida. También se definieron operadores de cruzamiento y mutación particulares, con el objetivo de mejorar la calidad de la solución resultante del proceso genético o, al menos, evitar la generación de soluciones no factibles. Mediante el algoritmo propuesto se alcanzaron soluciones relativamente buenas con pocas evaluaciones de la función objetivo y en un tiempo de ejecución razonable

Evaluation of the minimum number of markers for individual ancestry estimation in an Argentinean population sample

La estimación de ancestría individual posee gran relevancia en el estudio de la composición poblacional en regiones como Sudamérica, que han atravesado intensos procesos de mestizaje, lo que también tiene implicancia en ciencias de la salud. Debido a esto, es importante conocer los factores que influyen en la confiabilidad de los resultados obtenidos. En este trabajo se evalúa el número mínimo de marcadores informativos de ancestría (AIMs) a partir del cual las estimaciones resultarían aceptables. Se toma como ejemplo el cálculo en individuos provenientes de una muestra poblacional de diferentes regiones de Argentina. Considerando un modelo de tres componentes (nativo americano, euroasiático y subsahariano), se calculó la ancestría de 441 individuos utilizando 10, 20, 30 y 50 AIMs. Los resultados indican que el número de marcadores influye sobre la estimación de ancestría y su precisión aumenta al incrementarse la cantidad de AIMs. Al comparar con las estimaciones obtenidas en un trabajo previo a partir de 99 AIMs, se observó que para el componente minoritario (en este caso subsahariano) se obtiene una buena correlación utilizando al menos 30 marcadores. Se concluye que es necesario considerar en los estudios de ancestría individual el número de marcadores, su capacidad informativa y las características de la población bajo estudio.Estimation of individual ancestry has great relevance when studying population composition in regions like South America, where intensive admixture processes have occurred, being also important in biomedical sciences. For that reason, it is important to assess the factors that may affect the reliability of results. In this work, we investigate the minimum number of ancestry informative markers (AIMs) for obtaining acceptable estimations of ancestry. As an example, we take individuals from a population sample of different Argentinean regions. Considering a three component model (Native American, Eurasian and Sub-Saharan), we calculated ancestry of 441 individuals using 10, 20, 30 and 50 AIMs. The results indicate that the number of markers affects ancestry estimation and its accuracy increases with AIMs number. When compared to previous estimations obtained from 99 AIMs, the result shows that at least 30 markers are needed to achieve good correlation values for the minority component (Sub-Saharan in this case). For individual ancestry studies, we suggest to take into account not only the number of markers, but also its informativeness and the background of the studied population.Fil: Russo, Maria Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Maimónides; ArgentinaFil: Di Fabio Rocca, Francisco. Universidad Maimónides; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Doldán, Patricio. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; ArgentinaFil: Cardozo, Dario Gonzalo. Universidad Maimónides; Argentina. Universidad de Buenos Aires. Facultad de Filosofía y Letras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Dejean, Cristina Beatriz. Universidad de Buenos Aires. Facultad de Filosofía y Letras; Argentina. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; ArgentinaFil: Seldes, Verónica. Universidad de Buenos Aires. Facultad de Filosofía y Letras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Avena, Sergio Alejandro. Universidad Maimónides; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Cryptographically Secure Information Flow Control on Key-Value Stores

We present Clio, an information flow control (IFC) system that transparently incorporates cryptography to enforce confidentiality and integrity policies on untrusted storage. Clio insulates developers from explicitly manipulating keys and cryptographic primitives by leveraging the policy language of the IFC system to automatically use the appropriate keys and correct cryptographic operations. We prove that Clio is secure with a novel proof technique that is based on a proof style from cryptography together with standard programming languages results. We present a prototype Clio implementation and a case study that demonstrates Clio's practicality.Comment: Full version of conference paper appearing in CCS 201

Practical Normalization by Evaluation for EDSLs

Embedded domain-specific languages (eDSLs) are typically implemented in a rich host language, such as Haskell, using a combination of deep and shallow embedding techniques. While such a combination enables programmers to exploit the execution mechanism of Haskell to build and specialize eDSL programs, it blurs the distinction between the host language and the eDSL. As a consequence, extension with features such as sums and effects requires a significant amount of ingenuity from the eDSL designer. In this paper, we demonstrate that Normalization by Evaluation (NbE) provides a principled framework for building, extending, and customizing eDSLs. We present a comprehensive treatment of NbE for deeply embedded eDSLs in Haskell that involves a rich set of features such as sums, arrays, exceptions and state, while addressing practical concerns about normalization such as code expansion and the addition of domain-specific features