Sub-Finsler Structures from the Time-Optimal Control Viewpoint for some Nilpotent Distributions

In this paper, we study the sub-Finsler geometry as a time-optimal control problem. In particular, we consider non-smooth and non-strictly convex sub-Finsler structures associated with the Heisenberg, Grushin, and Martinet distributions. Motivated by problems in geometric group theory, we characterize extremal curves, discuss their optimality, and calculate the metric spheres, proving their Euclidean rectifiability. © 2016, Springer Science+Business Media New York

Aplicación de lógica difusa en la evaluación de vulnerabilidad de contaminación del agua subterránea

El objetivo del trabajo es analizar la potencialidad de la lógica difusa para evaluar la vulnerabilidad del agua subterránea a la contaminación. Se propone el uso de lógica difusa que representa el conocimiento como un predicado difuso principal compuesto por operaciones lógicas entre predicados simples, cuyo valor de verdad puede ser determinado objetivamente. Los predicados se formalizaron a partir de variables: profundidad de la capa freática, pendiente del terreno y textura del suelo. Se diseñó un software en entorno MATLAB para realizar el procesamiento difuso. Juntamente se realizó una encuesta entre profesionales vinculados a la gestión ambiental del Partido de Gral. Pueyrredón a fin de indagar acerca de la modalidad de presentación del mapa final de vulnerabilidad. El resultado final se comparó con el mapa de vulnerabilidad obtenido mediante la metodología tradicional (método DRASTIC-P), mostrando un buen ajuste espacial habiendo utilizado menos variables. El resultado de la encuesta mostró la preferencia por etiquetas con categorización cualitativa tradicional.The aim of this work is to analyze the potentiality of Fuzzy Logic to assess the groundwater pollution vulnerability. Fuzzy Logic Predicates are proposed as a natural extension of a Boolean Predicates Logic, where knowledge is represented as a Main Fuzzy Predicate that can be evaluated using numerical variables to determine a degree of groundwater pollution vulnerability. Those variables are: depth water table, land slope and soil texture. Software has been developed using MATLAB® to illustrate the fuzzy processing. The final result was compared with a vulnerability map that has been obtained with traditional methodology (DRASTIC-P Method). It was showed a good spatial adjustment having used less variables. In order to inquire about the best caption of the final vulnerability map, it was conducted a survey among professionals involved in Environmental Management at Partido General Pueyrredón. The preferred result was the traditional qualitative categorization labels.Universidad Nacional de La Plat

Kidins220/ARMS interacts with Pdzrn3, a protein containing multiple binding domains.

We report the identification of a novel partner of Kidins220/ARMS (Kinase D-interacting substrate of 220 kDa/Ankyrin Repeat-rich Membrane Spanning) an adaptor of neurotrophin receptors playing crucial roles during neurogenesis. Screening a phage display library of brain cDNA products we found that D. rerio Pdzrn3, a protein containing RING-finger and PDZ-domains, interacts with Kidins220/ARMS through its first PDZ-domain. Both zebrafish proteins share high homology with the corresponding mammalian proteins and both genes are developmentally expressed in neural districts where early neurogenesis occurs. The interaction was also confirmed by biochemical assays and by co-localization at the tips of growing neurites of PC12 cells induced with nerve growth factor

Aplicación de técnicas multicriterio en estudios de sistemas hídricos en el partido de General Pueyrredón, provincia de Buenos Aires

El agua subterránea es la única fuente de abastecimiento para la población y soporte esencial de las diversas actividades que se desarrollan en el sudeste de la provincia de Buenos Aires; constituye, además, un insumo esencial en los servicios ecológicos de los ecosistemas. El objetivo del trabajo fue generar una priorización de subcuencas hidrológicas para la gestión de los recursos hídricos subterráneos a través de un modelo multicriterio que pueda ser utilizado como herramienta de prevención y planificación del mismo. A partir del análisis de la red de drenajes en la zona mediante el modelo Soil and Water Assessment Tool (SWAT) se delimitaron siete subcuencas de interés. Dichas subcuencas se tomaron como alternativas del modelo de decisión Simple Multi-Attribute Rating Technique (SMART) utilizando el software Criterium Decision Plus (CDP). Se definieron tres criterios de decisión: ubicación de las potenciales fuentes puntuales de contaminación; ubicación de los pozos públicos de extracción de agua para consumo humano y; profundidad del agua subterránea. Los resultados obtenidos destacan dos de las subcuencas estudiadas como las de mayor prioridad, las cuales presentan numerosas fuentes puntuales de potencial contaminación y pozos de extracción de agua para consumo humano.Eje temático: Legislación del Agua, Planificación y Economía de agu

Variability in the analysis of a single neuroimaging dataset by many teams

Data analysis workflows in many scientific domains have become increasingly complex and flexible. To assess the impact of this flexibility on functional magnetic resonance imaging (fMRI) results, the same dataset was independently analyzed by 70 teams, testing nine ex-ante hypotheses. The flexibility of analytic approaches is exemplified by the fact that no two teams chose identical workflows to analyze the data. This flexibility resulted in sizeable variation in hypothesis test results, even for teams whose statistical maps were highly correlated at intermediate stages of their analysis pipeline. Variation in reported results was related to several aspects of analysis methodology. Importantly, meta-analytic approaches that aggregated information across teams yielded significant consensus in activated regions across teams. Furthermore, prediction markets of researchers in the field revealed an overestimation of the likelihood of significant findings, even by researchers with direct knowledge of the dataset. Our findings show that analytic flexibility can have substantial effects on scientific conclusions, and demonstrate factors related to variability in fMRI. The results emphasize the importance of validating and sharing complex analysis workflows, and demonstrate the need for multiple analyses of the same data. Potential approaches to mitigate issues related to analytical variability are discussed

Variability in the analysis of a single neuroimaging dataset by many teams

Data analysis workflows in many scientific domains have become increasingly complex and flexible. To assess the impact of this flexibility on functional magnetic resonance imaging (fMRI) results, the same dataset was independently analyzed by 70 teams, testing nine ex-ante hypotheses. The flexibility of analytic approaches is exemplified by the fact that no two teams chose identical workflows to analyze the data. This flexibility resulted in sizeable variation in hypothesis test results, even for teams whose statistical maps were highly correlated at intermediate stages of their analysis pipeline. Variation in reported results was related to several aspects of analysis methodology. Importantly, meta-analytic approaches that aggregated information across teams yielded significant consensus in activated regions across teams. Furthermore, prediction markets of researchers in the field revealed an overestimation of the likelihood of significant findings, even by researchers with direct knowledge of the dataset. Our findings show that analytic flexibility can have substantial effects on scientific conclusions, and demonstrate factors related to variability in fMRI. The results emphasize the importance of validating and sharing complex analysis workflows, and demonstrate the need for multiple analyses of the same data. Potential approaches to mitigate issues related to analytical variability are discussed

The neuronal proteins CIPP, Cypin and IRSp53 form a tripartite complex mediated by PDZ and SH3 domains

Here we report the dissection of a tripartite complex formed by CIPP (channel-interacting PDZ protein), IRSp53 (insulin receptor tyrosine kinase substrate protein) and Cypin (cytosolic PSD-95 interactor) in cultured cells. The three proteins are expressed in similar neuronal districts, where CIPP binds to different membrane channels and receptors, IRSp53 regulates the morphogenesis of actin-rich dendritic spines, and Cypin promotes dendrite branching and patterning by binding to tubulin heterodimers. We observed that the interaction among the three proteins is mediated by small binding domains: CIPP works as a bridge, linking the carboxy-termini of IRSp53 and Cypin with its PDZ domains; IRSp53 connects Cypin, through an unusual SH3-mediated association, which can be impaired by substituting two crucial positively charged residues of Cypin. The observation that the three engineered proteins co-localize in the cytoplasm, and at the tip of induced neurites in neuronal cells, raises the interesting possibility that they work together in the formation of neuronal protrusions

Antagonistic modulation of gliomagenesis by <em>Pax6</em> and <em>Olig2</em> in PDGF-induced oligodendroglioma.

Gliomas are aggressive tumors of the central nervous system originating from proliferating neural cells. Regulators of neural stem or progenitor cells biology may thus influence aspects of brain tumorigenesis, such as the maintenance of tumor-propagating potential. We investigated the role of Pax6, a neurogenic transcription factor already suggested as a positive prognostic marker for human gliomas, in a well-characterized in vivo model of PDGF-B-driven oligodendroglioma. In this system, the expression of Pax6 severely impairs tumor propagation by inducing a reduction of cell proliferation and the acquisition of differentiation traits in tumor-initiating cells. The overexpression of Pax6 correlates with a downregulation of Olig2, a bHLH transcription factor that normally antagonizes Pax6 in adult neurogenic niches and that plays a key role in the maintenance of neural stem and progenitor cells. Furthermore, we found that Olig2 is strictly required to maintain the malignancy of oligodendroglioma cells, since its silencing by interfering RNA abrogates tumor propagation. We finally show evidence that this function depends, at least in part, on the silencing of ID4, a dominant negative bHLH protein, whose upregulation follows Olig2 loss. In our model, the upregulation of ID4 mimics the loss of Olig2 in impairing the tumor-propagating potential of glioma cells. Our data, therefore, establish the relevance of physiological regulators of neural stem cell biology in regulating glial tumor malignancy and provide support for their functional interactions in this context