Non-normal Recurrent Neural Network (nnRNN): learning long time dependencies while improving expressivity with transient dynamics

A recent strategy to circumvent the exploding and vanishing gradient problem in RNNs, and to allow the stable propagation of signals over long time scales, is to constrain recurrent connectivity matrices to be orthogonal or unitary. This ensures eigenvalues with unit norm and thus stable dynamics and training. However this comes at the cost of reduced expressivity due to the limited variety of orthogonal transformations. We propose a novel connectivity structure based on the Schur decomposition and a splitting of the Schur form into normal and non-normal parts. This allows to parametrize matrices with unit-norm eigenspectra without orthogonality constraints on eigenbases. The resulting architecture ensures access to a larger space of spectrally constrained matrices, of which orthogonal matrices are a subset. This crucial difference retains the stability advantages and training speed of orthogonal RNNs while enhancing expressivity, especially on tasks that require computations over ongoing input sequences

La gráfica como artefacto cultural. Una aproximación semiótica al cartel social en Chile

This article presents a critical review of the contribution of semiotics to the study of image, with the aim of formulating a proposal of analysis applied to poster in Chile. It seeks to contribute to the study of image, incorporating new approaches to complement the classical perspectives of analysis. The method used keeps using semiotics categories and includes the contexts of production and decoding of messages, when analyzing them as part of a bigger symbolic context. The sample analyzed was composed of posters that addressed social issues developed between 1970 and 1973, for the government of Salvador Allende,that had a huge impact in the local public space. The results of the analysis shows an aesthetic and communicational proposal that expressed the desire to build a new kind of society and its way of being represented through functional stakeholders to the political and social project at the time and incorporating visual references from the popular world and the mass culture. This visual synthesis, gave to the Chilean poster a great communicative potential able to tune with the changing demands of a wide audience, and also to validate its own narrative as part of narrative from a larger ideological framework.Este artículo presenta una revisión crítica de la semiótica al estudio de la imagen, con el objetivo de formular una propuesta de análisis aplicada al cartel en Chile. Con esto, se busca contribuir a los estudios de la imagen, incorporando enfoques que complementen las perspectivas clásicas de análisis. El método utilizado mantiene el uso de categorías de la semiótica e incorpora los contextos de producción y decodificación de los mensajes, al analizarlos como parte de un contexto simbólico mayor. La muestra analizada estuvo compuesta por carteles que abordaron temáticas sociales entre los años 1970 y 1973, correspondientes al gobierno de Salvador Allende, y que tuvieron un gran impacto en el espacio público local. Los resultados dan cuenta de una propuesta estética y comunicacional, que expresó la voluntad de construir un nuevo tipo de sociedad, y su forma de ser representada, a través de actores sociales funcio­nales al proyecto político en marcha, incorporando referentes visuales tanto del mundo popular como de la cultura de masas. Esta síntesis visual, otorgó al cartel chileno un gran potencial comunicativo, capaz de sintonizar con las demandas de cambio y de validar, a su vez, un relato propio como correlato de un marco ideológico mayor

Retiros presuntos gravados con impuesto global complementario. Artículo 21 de la Ley de impuesto a !a renta

Una de las características más notables de la Ley de la Renta consisteen su deseo ferviente y majadero de dotar a la autoridad tributaria deatribuciones poderosas para fiscalizar la conducta económica de los contribuyentes.En la medida que la legislación le otorgue poderes amplios/casi ¡limitados, al Servicio de Impuestos Internos/ existirá un organismopúblico capaz de materializar la difícil y ardua tarea de verificar por partede los diversos actores económicos el cumplimiento estricto de las obligacionestributarias. Ello representa una tendencia natural y generalizadaen las modificaciones que permanentemente se introducen a este cuerpolegislativo/ precisamente por la finalidad recaudatoria pro fisco que ellapersigue. Recordemos que la piedra angular de sus principios y normasestá esencialmente ligado a controlar que los contribuyentes determinen,declaren y paguen, en forma íntegra y oportuna, sus impuestos por las rentasque han obtenido en un período de tiempo determinado

Inferring the immune response from repertoire sequencing

High-throughput sequencing of B- and T-cell receptors makes it possible to track immune repertoires across time, in different tissues, and in acute and chronic diseases or in healthy individuals. However, quantitative comparison between repertoires is confounded by variability in the read count of each receptor clonotype due to sampling, library preparation, and expression noise. Here, we present a general Bayesian approach to disentangle repertoire variations from these stochastic effects. Using replicate experiments, we first show how to learn the natural variability of read counts by inferring the distributions of clone sizes as well as an explicit noise model relating true frequencies of clones to their read count. We then use that null model as a baseline to infer a model of clonal expansion from two repertoire time points taken before and after an immune challenge. Applying our approach to yellow fever vaccination as a model of acute infection in humans, we identify candidate clones participating in the response

Graphic as a cultural Artifact. A semiotic approach to social poster in Chile

This article presents a critical review of the contribution of semiotics to the study of image, with the aim of formulating a proposal of analysis applied to poster in Chile. It seeks to contribute to the study of image, incorporating new approaches to complement the classical perspectives of analysis. The method used keeps using semiotics categories and includes the contexts of production and decoding of messages, when analyzing them as part of a bigger symbolic context. The sample analyzed was composed of posters that addressed social issues developed between 1970 and 1973, for the government of Salvador Allende,that had a huge impact in the local public space. The results of the analysis shows an aesthetic and communicational proposal that expressed the desire to build a new kind of society and its way of being represented through functional stakeholders to the political and social project at the time and incorporating visual references from the popular world and the mass culture. This visual synthesis, gave to the Chilean poster a great communicative potential able to tune with the changing demands of a wide audience, and also to validate its own narrative as part of narrative from a larger ideological framework.</span

The CAMELS-CL dataset: catchment attributes and meteorology for large sample studies – Chile dataset

We introduce the first catchment dataset for large sample studies in Chile. This dataset includes 516 catchments; it covers particularly wide latitude (17.8 to 55.0∘ S) and elevation (0 to 6993 m a.s.l.) ranges, and it relies on multiple data sources (including ground data, remote-sensed products and reanalyses) to characterise the hydroclimatic conditions and landscape of a region where in situ measurements are scarce. For each catchment, the dataset provides boundaries, daily streamflow records and basin-averaged daily time series of precipitation (from one national and three global datasets), maximum, minimum and mean temperatures, potential evapotranspiration (PET; from two datasets), and snow water equivalent. We calculated hydro-climatological indices using these time series, and leveraged diverse data sources to extract topographic, geological and land cover features. Relying on publicly available reservoirs and water rights data for the country, we estimated the degree of anthropic intervention within the catchments. To facilitate the use of this dataset and promote common standards in large sample studies, we computed most catchment attributes introduced by Addor et al. (2017) in their Catchment Attributes and MEteorology for Large-sample Studies (CAMELS) dataset, and added several others. We used the dataset presented here (named CAMELS-CL) to characterise regional variations in hydroclimatic conditions over Chile and to explore how basin behaviour is influenced by catchment attributes and water extractions. Further, CAMELS-CL enabled us to analyse biases and uncertainties in basin-wide precipitation and PET. The characterisation of catchment water balances revealed large discrepancies between precipitation products in arid regions and a systematic precipitation underestimation in headwater mountain catchments (high elevations and steep slopes) over humid regions. We evaluated PET products based on ground data and found a fairly good performance of both products in humid regions (r>0.91) and lower correlation (r<0.76) in hyper-arid regions. Further, the satellite-based PET showed a consistent overestimation of observation-based PET. Finally, we explored local anomalies in catchment response by analysing the relationship between hydrological signatures and an attribute characterising the level of anthropic interventions. We showed that larger anthropic interventions are correlated with lower than normal annual flows, runoff ratios, elasticity of runoff with respect to precipitation, and flashiness of runoff, especially in arid catchments. CAMELS-CL provides unprecedented information on catchments in a region largely underrepresented in large sample studies. This effort is part of an international initiative to create multi-national large sample datasets freely available for the community. CAMELS-CL can be visualised from http://camels.cr2.cl and downloaded from https://doi.pangaea.de/10.1594/PANGAEA.894885

TRASPLANTE SIMULTÿNEO DE PANCREAS-RIÿÿN. CONCEPTOS ACTUALES Y EXPERIENCIA EN CLÿNICA LAS CONDES

RESUMENEl trasplante de páncreas-riñón (TPR) para pacientes portadores de diabetes mellitus tipo 1 (DM1) con insuficiencia renal crónica terminal, ha demostrado ser una terapia eficaz para alcanzar el estado de normoglicemia de manera estable, con la consecuente disminución de las complicaciones crónicas de la DM y mejoría de la expectativa y calidad de vida. Actualmente, en casos seleccionados, se ha planteado el trasplante de páncreas (TP) como una alternativa para los pacientes con diabetes mellitus tipo 2 (DM2) considerando la diferencia entre los pacientes del tipo 1 y 2. Si bien es menos frecuente en la experiencia mundial, trasplantar pacientes con DM2 demuestra cifras alentadoras y comparables con el TP en enfermos portadores de DM1. En general, pacientes que desarrollan enfermedad renal terminal secundaria a diabetes 1 o 2 que requieren insulina, no obesos, deben ser considerados para el trasplante de páncreas con riñón simultáneo o secuencial. Clínica Las Condes es la de mayor experiencia en Chile, con resultados muy comparables a centros de gran importancia a nivel internacional.ObjetivoDar a conocer la situación actual del trasplante de páncreas y sus modalidades en el mundo y mostrar la experiencia en TPR en Clínica Las Condes en la sobrevida de los pacientes, de injerto de páncreas e injerto de riñón en 10 años y sus complicaciones, además de las técnicas quirúrgicas realizadas.MétodoSe recolectó la información de 16 pacientes sometidos a trasplante páncreas-riñón en Clínica Las Condes entre 1994-2014, analizando las variables con estadística descriptiva.ResultadosDe los 16 enfermos, 9 de ellos fueron hombres, la edad promedio fue 38,7 años al momento del trasplante, el tiempo promedio de diabetes fue 23,5+/-7.3 años. Todos los injertos pancreáticos fueron anastomosados a los vasos ilíacos comunes derechos en forma término-terminal y el duodeno fue anastomosado en 8 casos a la vejiga y en los últimos 8 al íleon. La sobrevida de los pacientes a 10 años fue del 81%, del injerto de páncreas el 82% y del injerto renal el 65%. La complicación post operatoria más importante fue sepsis, causando la muerte en 2 pacientes. Y entre las complicaciones de tipo inmunológico, 8 pacientes presentaron rechazo agudo, siendo manejados con terapia esteroidal de rescate o timo globulina.SUMMARYCombined kidney pancreas trasplant (PKT) in diabetes mellitus type 1 (DM1) patients with end stage renal disease, has proven to be an effective therapy to reach normoglicemia stability, with the consequent reduction of diabetes chronic complications an improvement in life expectancy and Quality of Life. Currently in selected cases of type 2 diabetes mellitus (DM2) patients with terminal nephropathy it has been proposed pancreas transplantation (PT) as an effective alternative. The results have been comparable between DM1 and DM2 patients. Patients who develop end stage renal disease secondary to type 1 or 2 DM, insulin dependent, non obese, should be considered for PKT. Clínica Las Condes has one of the mayor experience in Chile, in PKT, with comparable results to centers of great importance of International Level.ObjectiveTo show the situation of Pancreas Transplantation and its different modalities in the world. Also to show the experience in PKT at Clinica Las Condes, in 10 years patient's survival, in pancreas and kidney graft survival and complications and the surgical techniques.MethodInformation collected from 16 patients undergoing PKT at Clinica Las Condes between 1994-2014, analyzing the variables with descriptive statistics.ResultsOf the 16 patients, 9 were men, average age 38.7 years at transplant time; the average time of diabetes was 23.5+/-7.3 years. All pancreatic grafts were term-terminal to anastomosed the right iliac common vessels and duodenum was anastomosed is 8 cases to the bladder and in the last 8 to the ileum. Patient survival at 10 years was 81%, pancreatic graft 82% and 65% renal graft. The most relevant postoperative complication was sepsis, killing two patients. The immune complications were presented in eight patients. It was acute rejection, being managed with steroid therapy or thymoglobuline