Editorial: 3D Modelling of Mammalian Embryos and Organs

The main scope of this Special issue was to gain understanding on how tissues and organs are arranged into integrative hierarchical levels of complexity, from the molecular to the morphological organization. To understand the underlying complexity of the relationships among these levels during morphogenesis or in the adult we must learn how to resolve single-cell spatial relationships in the three-dimensional (3D) organisation of tissues, organs and even of the whole organisms.Fil: Garagna, Silvia. Universita Degli Studi Di Pavia; ItaliaFil: Cebral, Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Aréchaga, Juan. Universidad del País Vasco; EspañaFil: Zuccotti, Maurizio. Universita Degli Studi Di Pavia; Itali

Hemodynamic characteristics at anterior communicating artery before aneurysm initiation using patient-specific finite element blood flow simulations

The anterior communicating artery (AComA) is a unique vascular location that receives blood from two sources of inflow and redistributes it toward the anterior part of the brain through two efferent arteries. It is widely accepted that complexity in the flow pattern is associated with the high rate of aneurysm formation in that location observed in large studies. A previous computational hemodynamic study showed a possible association between high maximum intraaneurysmal wall shear stress (WSS) at the systolic peak with rupture in a cohort of AComA aneurysms. In another study it was observed a connection between location of aneurysm blebs and regions of high WSS in models where blebs were virtually removed. The purpose of this work is to study associations between hemodynamic patterns and AComA aneurysm initiation by comparing hemodynamics between the aneurysm models and the normal model where the aneurysm was computationally removed. Vascular models of both right and left circulation were independently reconstructed from three-dimensional rotational angiography images using deformable models after image registration of both images, and later fused using a surface merging algorithm. Afterwards, the geometric models were used to generate high-quality volumetric finite element grids composed several million tetrahedral elements with an advancing front technique. For each patient the second anatomical model was created by digitally removing the aneurysm. It was iteratively achieved by applying a Laplacian smoothing filter and remeshing the surface. Finite element blood flow numerical simulations were performed for both the pathological and normal models under the same flow conditions. Personalized pulsatile flow conditions were imposed at the inlets of both models with use of the Womersley solution. The Navier-Stokes equations were numerically integrated by using a fully implicit finite-element formulation. From analysis of WSS distributions it was observed that aneurysms initiated in regions of high and moderate WSS in the counterpart normal models. Adjacent or close to those regions, low WSS portions of the arterial wall were not affected by the disease. These results are in line with previous reported observations at other vascular locations.Fil: Castro, Marcelo Adrian. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. George Mason University; Estados UnidosFil: Putman, Christopher M.. Inova Fairfax Hospital; Estados UnidosFil: Cebral, Juan Raúl. George Mason University; Estados Unido

Lapses, interruptions, babbling... Deleuze’s philosophy of language and natural language processing algorithms

La filosofía de Gilles Deleuze desarrolla la crítica nietzscheana al lenguaje y su gramática en la que el predicado depende del sujeto. En vez de ello, Deleuze propone un pensamiento basado en el “infinitivo” donde la acción queda suspendida en un eterno presente “sin espesor”. Si bien, esto ya había sido esbozado por Spinoza, el estudio deleuziano va más allá estudiando la agramaticalidad como fenómeno de desbordamiento creativo. En obras escritas junto al psicoanalista Félix Guattari, Deleuze nos presenta rasgos de esta agramaticalidad que aproximándose al fenómeno de la esquizofrenia, crea un claro más allá del lenguaje constreñido por la sintaxis. En otras obras menores Deleuze estudia casos de la literatura y el arte en los que la expresión subvierte la propia lengua y fenómenos como lapsus, interrupciones o balbuceos, no son taras psicoanalíticas, sino potencialidades creativas y deseantes. La pregunta que nos surge, ante las nuevas metodologías de procesamiento de lenguaje natural es hasta qué punto perseveran esta visión constreñida del lenguaje. Los algoritmos NLP pueden darnos una sensación técnica, computacional y constreñida del lenguaje, pero sus reglas desbordan la gramática y nos permiten analizar e incluso generar lenguaje y sentido en arreglo a su pragmática social y colectiv

La revolución cibernética desde la filosofía de Gilles Deleuze: una revisión crítica de las herramientas de minería de datos y Big Data

La filosofía deleuziana (especialmente aquella parte escrita junto a Félix Guattari) es utilizada de modos opuestos a la hora de analizar la nueva revolución cibernética. Si bien hay quienes sostienen que las nuevas tecnologías realizan las propuestas de conectividad y nomadismo que Deleuze demandaba, existen también quienes acusan -mediante esta misma filosofía- nuevas situaciones de hipercontrol y vigilancia más sutil e individualizada. Debido a ello, la investigación se propone analizar los fundamentos teóricos de la cibernética, sus herramientas epistemológicas y el sentido de su aplicación social desde el punto de vista crítico de la filosofía deleuziana, propiciando una revisión de lo que esta revolución implica

Blandas maquinas de guerra: el potencial deseante de la cibernética

Cybernetics has taken over from the technical and disciplinary social technologies that characterized the social machines in the productivist capitalism until the XVIII and XIX century. Through simultaneous control of the individual and the collective, singularizing the information and redistributing ubiquitously the control points, observation and surveillance throughout the social body, the new network era facilitates behaviors and prevent any accident in the same analytical and axiomatic operation that thus always justified itself, without the possibility of being at the same time controlled, analyzed. An all-one-machine threatens to be implemented as all-one-possible against chaos; for every body, affection, folk, singularity ... The speech for the use and development of soft technologies only partly opposed to this logic; because otherwise it is also part of it. Perhaps to break this loop is necessary to clarify the issues that within the movement itself respond the problematizations already expressed in the criticism that precede us.; La cibernética ha cogido el relevo de las técnicas y tecnologías sociales disciplinarias que caracterizaron las máquinas sociales hasta el capitalismo productivista del S.XVIII y XIX. A través de un control simultáneo de lo individual y lo colectivo, singularizando la información y redistribuyendo los focos de control, observación y vigilancia ubicuamente en todo el cuerpo social, la nueva era red facilita las conductas y previene todo accidente en una misma operación analítica y axiomática que se justifica de este modo siempre a sí misma, sin posibilidad de ser a su vez controlada, analizada. Un todo-uno-máquina amenaza con implantarse como el todo-uno-posible frente al caos; para todo cuerpo, afecto, pueblo, singularidad… El discurso a favor del uso y desarrollo de tecnologías blandas sólo se opone en parte a esta lógica; pues de otro modo es también parte de la misma. Quizá, para deshacer este lazo, sea necesario precisar las cuestiones que dentro del mismo movimiento atienden a las problematizaciones ya expresadas en las críticas que nos anteceden

An automated multiscale ensemble simulation approach for vascular blood flow

Cerebrovascular diseases such as brain aneurysms are a primary cause of adult disability. The flow dynamics in brain arteries, both during periods of rest and increased activity, are known to be a major factor in the risk of aneurysm formation and rupture. The precise relation is however still an open field of investigation. We present an automated ensemble simulation method for modelling cerebrovascular blood flow under a range of flow regimes. By automatically constructing and performing an ensemble of multiscale simulations, where we unidirectionally couple a 1D solver with a 3D lattice-Boltzmann code, we are able to model the blood flow in a patient artery over a range of flow regimes. We apply the method to a model of a middle cerebral artery, and find that this approach helps us to fine-tune our modelling techniques, and opens up new ways to investigate cerebrovascular flow properties.This work has received funding from the CRESTA project within the EC-FP7 (ICT-2011.9.13) under Grant Agreements no. 287703, and from EPSRC Grants EP/I017909/1 (www.2020science.net) and EP/I034602/1

Voluntad y deseo en la filosofía moderna: un acercamiento computacional

El artículo aborda el análisis computacional de varios textos clave de la modernidad filosófica, especialmente autores que tratan la voluntad y el deseo: Spinoza, Hegel, Schopenhauer y Nietzsche. A través de un estudio comparativo de medi-das de frecuencia de términos, redes de relaciones entre palabras, modelado de tópicos y análisis de sentimientos, se visualizan afinidades y tensiones entre estos textos, explicitando la importancia que en ellos tienen los conceptos menos vinculados a la razón y al conocimiento. Al mismo tiempo, el artículo reflexiona sobre la pertinencia de los métodos computacionales y cómo pueden servir positivamente para la investigación filosófica

Parallel Advancing Front Grid Generation

A parallel advancing front scheme has been developed. The domain to be gridded is rst subdivided spatially using a relatively coarse octree. Boxes are then identiied and gridded in parallel. A scheme that resembles closely the advancing front technique on scalar machines is recovered by only considering the boxes of the active front that generate small elements. The procedure has been implemented on the SGI Origin class of machines using the shared memory paradigm. Timings for a variety of cases show speedups similar to those obtained for ow codes. The procedure has been used to generate grids in excess of a hundred million elements.&nbsp