Personalised Trachea Stent Designer: a Knowledge Feature

Modelling of anatomical parts is usually tackled through triangulated models with specialised Bio-CAD applications. If features beyond anatomy are required, geometry is usually translated into NURBS geometry for further modification in parametric feature based design CAD systems. But, they remain quite unmanageable yet. The authors present, validate and implement into a knowledge feature a methodology that generates an anatomically personalised trachea stent based a point cloud data extracted from a Computerised Axial Tomography with an open-source medical data visualisation application

Discovering frequent user-environment interactions in intelligent environments

Intelligent Environments are expected to act proactively, anticipating the user's needs and preferences. To do that, the environment must somehow obtain knowledge of those need and preferences, but unlike current computing systems, in Intelligent Environments the user ideally should be released from the burden of providing information or programming any device as much as possible. Therefore, automated learning of a user's most common behaviors becomes an important step towards allowing an environment to provide highly personalized services. In this paper we present a system that takes information collected by sensors as a starting point, and then discovers frequent relationships between actions carried out by the user. The algorithm developed to discover such patterns is supported by a language to represent those patterns and a system of interaction which provides the user the option to fine tune their preferences in a natural way, just by speaking to the system

Nutrient uptake in a stream affected by hydropower plants: comparison between stream channels and diversion canals

12 páginas, 3 figuras, 4 tablas.Small hydropower plants divert part of the water from wide and physically complex stream channels with active hyporheic areas to narrow and hydraulically simple concrete canals, and thus, might affect nutrient dynamics. We compared nutrient uptake in diversion canals and in stream channels in the Leitzaran Stream (Basque Country, northern Spain). We predicted that simple morphology in diversion canals will result in lower nutrient uptake in canals than in stream channels. Periphytic chlorophyll and biomass did not differ significantly between reach types. Water was significantly deeper and faster in canals than in stream channels, but the transient storage zone did not differ significantly between reach types. There were no significant differences between uptake length for neither phosphate nor ammonium between reach types. Uptake length in both stream channels and diversion canals decreased with discharge, in a pattern similar to that previously described for pristine rivers across the world. Uptake velocity and uptake rate for phosphate did not differ signifi- cantly between reach types, but in the case of ammonium both retention metrics were significantly larger in the diversion canals. Results suggest that although hydropower schemes have minor effects on nutrient retention, these depend on the proportion of flow diverted.This research has been funded by the Spanish Department of Science and Technology, the University of the Basque Country, and the European Regional Development Fund, through projects 9/UPV00118.310-14476/ 2002 and BOS2003-04466.Peer reviewe

To what extent do initiatives to formalize the commercial production of Astrocaryum chambira for handicrafts empower Indigenous women? A comparative analysis in communities with more and less external intervention

The management and use of the palm Astrocaryum chambira (commonly known in Peru as “chambira”) for handicrafts is a traditional activity for Indigenous women in the Amazon region. Some governmental and non-governmental initiatives have tried to formalize the production of chambira for handicrafts for commercial purposes, to promote women's empowerment and sustainable management. However, how successful these initiatives are in their efforts to empower women remains unclear. This paper aims to analyze to what extent formalizing the commercial production of chambira handicrafts empower Indigenous women in the Peruvian Amazon – specifically, in the Ampiyacu-Yahuasyacu basin, where external actors have been promoting the formal commercialization of chambira handicrafts through the last decades. Specifically, I examine (i) to what extent women can be incorporated into formal organizational systems, and why; (ii) how informal practices for the tenure and management of chambira and the production and commercialization of handicrafts interact with formal practices; and (iii) how does formalization influence women's economic, cultural, decision-making, and collective empowerment. To do so, I comparatively analyze four communities of the basin: two that have had more intervention from external actors towards formalization, and two that have had less intervention. Results show that formalization can empower Indigenous women in some ways, but empowerment continues to be limited and inequitable. First, not all women in all the communities can easily join formal systems due to a set of interrelated barriers, both external (e.g., unequal and limited institutional support, economic factors, and geographical location) and internal (e.g., limited family support, time availability, and self-confidence). Additionally, most (informal) traditional practices for the management of chambira and production of handicrafts – which go in line with the local realities, culture, and livelihoods – persist and play a key role complementing introduced formal practices. Finally, formalizing the commercial production of chambira handicrafts may empower Indigenous women – especially in terms of economic, decision-making, and inner power – but not necessarily, as the effects of formalization on culture and collective power are complex and contradictory. To empower women in a more effective, equal, and culturally sensitive manner, formalization projects need to holistically address both external and internal barriers to formalization, acknowledge the importance of traditional practices for forests and peoples, approach empowerment holistically rather than looking at economic empowerment alone, and critically recognize the complexities and paradoxes behind the impacts of formalization impact on Indigenous women’s empowerment

Theoretical Analysis of SPH in Simulating Free-surface Viscous flows

A theoretical analysis on the performance, close to a free surface, of the most used SPH formulations for Newtonian viscous terms is carried out in this paper. After an introduction of the SPH formalism, the SPH expressions for the viscous term in the momentum equation are analyzed in their continuous form. Using a Taylor expansion, a reformulation of those expressions is undertaken which allows to characterize the behavior of the viscous term close to the free surface. Under specific flow conditions, we show that the viscous term close to the free surface is singular when the spatial resolution is increased. This problem is in essence related to the incompleteness of the kernel function close to the free surface and appears for all the formulations considered. In order to assess the impact of such singular behavior, an analysis of the global energy dissipation is carried out, which shows that such a free-surface singularity vanishes when the integral quantities are considered. Not with standing that, not all the SPH viscous formulas allow the correct evaluation of the energy dissipation rate and, consequently, they may lead to an inaccurate modelling of viscous free-surface flows

Effective dynamics using conditional expectations

The question of coarse-graining is ubiquitous in molecular dynamics. In this article, we are interested in deriving effective properties for the dynamics of a coarse-grained variable $\xi(x)$, where $x$ describes the configuration of the system in a high-dimensional space $\R^n$, and $\xi$ is a smooth function with value in $\R$ (typically a reaction coordinate). It is well known that, given a Boltzmann-Gibbs distribution on $x \in \R^n$, the equilibrium properties on $\xi(x)$ are completely determined by the free energy. On the other hand, the question of the effective dynamics on $\xi(x)$ is much more difficult to address. Starting from an overdamped Langevin equation on $x \in \R^n$, we propose an effective dynamics for $\xi(x) \in \R$ using conditional expectations. Using entropy methods, we give sufficient conditions for the time marginals of the effective dynamics to be close to the original ones. We check numerically on some toy examples that these sufficient conditions yield an effective dynamics which accurately reproduces the residence times in the potential energy wells. We also discuss the accuracy of the effective dynamics in a pathwise sense, and the relevance of the free energy to build a coarse-grained dynamics

Preparación para el ingreso a la carrera de medicina: satisfacción de los estudiantes

Objective. To determine the satisfaction of first-level students with their preparation prior to entering the Medicine career at the Technical University of Manabí. Materials and methods. A cross-sectional descriptive study was carried out. A questionnaire validated by expert criteria, with options questions and an open question, was applied to 111 students who were studying the first level of the Medicine career during the period October 2017 to February 2018 and thus know how they valued their previous preparation. at the beginning of their university studies and the leveling semester. In addition, the route of entry and the behavior of failure in that period in the different subjects were analyzed, data that were summarized by using absolute numbers and percentages. Results. 44.1% of the students were male and 62 (55.9%) female, of which the average age was 18 years, 84.8% took entrance exams to access the race. Most of the students evaluated their previous preparation as satisfactory, and more than half said they were partially satisfied with their expectations in the preparation during the leveling semester. The contents of Anatomy were the ones that the students expressed the most should have been reinforced in the leveling. Conclusion. The preparation received by the students, prior to admission, according to the criteria of a majority, turned out to be satisfactory. The leveling semester partially met the expectations of the students.Objetivo. Determinar la satisfacción de los estudiantes de primer nivel con su preparación previa al ingreso a la carrera de Medicina de la Universidad Técnica de Manabí. Materiales y métodos. Se realizó un estudio descriptivo transversal. Se aplicó un cuestionario validado por criterio de expertos, con preguntas de opciones y una pregunta abierta, a 111 estudiantes que durante el periodo octubre 2017 a febrero 2018 estaban cursando el primer nivel de la carrera de Medicina y así conocer cómo valoraron ellos su preparación previa al inicio de sus estudios universitarios y del semestre de nivelación. Se analizó además la vía de ingreso y el comportamiento de la reprobación en ese periodo en las diferentes las materias, datos que se resumieron mediante la utilización de números absolutos y porcentajes. Resultados. Resultó un predominio de los estudiantes del sexo femenino con 62(55,9 %), de los cuales la edad promedio fue de 18 años, un 84,8% rindieron pruebas de ingreso para acceder a la carrera. La mayoría de los estudiantes evaluaron como satisfactoria su preparación previa, y más de la mitad dijo estar parcialmente satisfecho respecto a sus expectativas en la preparación durante el semestre de nivelación. Los contenidos de Anatomía resultaron los que más manifestaron los estudiantes debían haberse reforzado en la nivelación. Conclusión. La preparación recibida por los estudiantes, previo al ingreso, según el criterio de una mayoría resultó ser satisfactoria. El semestre de nivelación cumplió parcialmente las expectativas de los estudiantes