Fast multipole method applied to 3D frequency domain elastodynamics

This article is concerned with the formulation and implementation of a fast multipole-accelerated BEM for 3-D elastodynamics in the frequency domain, based on the so-called diagonal form for the expansion of the elastodynamic fundamental solution, a multi-level strategy. As usual with the FM-BEM, the linear system of BEM equations is solved by GMRES, and the matrix is never explicitly formed. The truncation parameter in the multipole expansion is adjusted to the level, a feature known from recent published studies for the Maxwell equations. A preconditioning strategy based on the concept of sparse approximate inverse (SPAI) is presented and implemented. The proposed formulation is assessed on numerical examples involving $O(10^{5})$ BEM unknowns, which show in particular that, as expected, the proposed FM-BEM is much faster than the traditional BEM, and that the GMRES iteration count is significantly reduced when the SPAI preconditioner is used

Los científicos del futuro están en la escuela

El proyecto de extensión universitaria “Los Científicos del Futuro están en la Escuela” se encuentra acreditado desde el año 2004 por la Facultad de Ciencias Exactas de la UNLP. El mismo propone la divulgación, la promoción del interés por la ciencia y la tecnología, y la complementación de la enseñanza de ciencias naturales a nivel primario. Las actividades están diseñadas en formato de talleres interactivos de 50 minutos de duración que involucran una presentación breve de los contenidos teóricos básicos explicados en forma sencilla para el público infantil

More Insights into the Association between RVX-208 and Pulmonary Arterial Hypertension Reply

Therapeutic cell differentiatio

Dissecting accretion and outflows in accreting white dwarf binaries

This is a White Paper in support of the mission concept of the Large Observatory for X-ray Timing (LOFT), proposed as a medium-sized ESA mission. We discuss the potential of LOFT for the study of accreting white dwarfs. For a summary, we refer to the paper.Comment: White Paper in Support of the Mission Concept of the Large Observatory for X-ray Timin

Three-dimensional portrait through the use of low-cost digital manufacturing technologies in educational environments

The study and representation of the shapes associated with the human body and the portrait is a part of the curriculum of the subjects of plastic, visual and audiovisual education in secondary education. Currently, the exercises are performed using traditional artistic techniques and in most cases in two-dimensional supports. When it comes to creating three-dimensional models, often it is used clay or other molding elements and construction techniques. This implies the need to have the specific materials and tools to elaborate them. In this article, an activity is presented for the creation of digital and physical three-dimensional portraits, whose objective is that it can be carried out in secondary education centers. For this, low-cost 3D technologies will be used that do not require specific training, accessible for teachers and students. This activity has been carried out with two groups of teachers and students during the academic year 2015-2016. The results shows that this activity is feasible in a school environment and that 3D portraits can be obtained at low cost.</p

Diseño y fabricación digital de tarjetas pop-ups en entornos educativos mediante tecnologías de bajo coste

La implantación de tecnologías de fabricación digital en centros escolares requiere habitualmente la creación de espacios específicos (Makerspaces, Fab labs, etc.). Sin embargo resulta interesante la introducción de estas tecnologías en aulas tradicionales. En este artículo se describe una experiencia llevada a cabo en el Colegio San Isidro, Los Salesianos de la Orotava, Tenerife en 4º curso de secundaria en la asignatura de expresión plástica, visual y audiovisual, en el que se ha realizado una actividad de diseño y creación de tarjetas pop-up. La realización de esta actividad implica el corte y doblado de papel que habitualmente se realiza mediante tijeras o cutter. Sin embargo, con la aparición de técnicas de fabricación digital de bajo coste, este proceso puede ser automatizado e introducido en cualquier aula

Building a virtual world in Minecraft for learning urban sculptural heritage

En este artículo se describe una experiencia para divulgar el patrimonio escultórico a los alumnos a través de un mundo virtual inmersivo en tres dimensiones. Este mundo se ha construido con Minecraft y consiste en una simulación 3D de un espacio físico que representa parte de la ciudad de Santa Cruz de Tenerife, en concreto la Rambla que cruza toda la ciudad y el Parque García Sanabria. En esta zona de la ciudad se encuentran ubicadas 24 esculturas correspondientes a la I Exposición Internacional de Esculturas en la calle. Dichas obras se han colocado en el mundo virtual, en su ubicación real y se ha diseñado una actividad para realizar una visita virtual. En este trabajo, se detalla los pasos necesarios para crear el entorno virtual mediante programas gratuitos que se pueden manejar con conocimientos informáticos básicos. Para probar este material, se ha realizado una acción con 12 estudiantes del Máster de profesorado para validar los aspectos tecnológicos, medir el aprendizaje y al finalizar la actividad, se ha pasado un cuestionario de satisfacción.This article describes an experience to divulge the sculptural heritage to students through an immersive virtual world in three dimensions. This world has been built with Minecraft and consists of a 3D simulation of a physical space that represents part of the city of Santa Cruz de Tenerife, specifically the Rambla which crosses the entire city and the Parque García Sanabria. In this area of the city, 24 sculptures are located corresponding to the First International Street Sculpture Exhibition. These works have been placed in the virtual world in its actual location and designed an activity to make a virtual tour. This paper details the steps to create the virtual environment working with free programs that can be used with a basic computer knowledge. To test this material, an activity has been performed with 12 students belonging to the Master of Education to validate technological aspects, measure the learning improves and at the end, the students fill a satisfaction questionnaire.peerReviewe

Creation, Visualization and 3D Printing of Online Collections of Three Timensional Educative Models with Low-Cost Technologies. Practical Case of Canarian Marine Fossil Heritage

In many educational settings, the use of tangible objects is used to enhance learning (models, replicas of art works, fossils...). When knowledge is disseminated through virtual environments, sometimes, the value of these tangible objects is lost. The new low-cost technologies allow solving this problem, enabling teachers to include in their virtual classroom the access and manipulation of threedimensional objects. This article describes the process of creation and dissemination of a three-dimensional, interactive educational content for learning in a virtual environment. As a practical study, we have worked on the Canary marine fossil heritage. The fossils are used as tangible material in paleontology teaching, however they are not available for work outside the classroom. For this work, it has been digitized in 3D a selection of 18 fossils. 3D files obtained are available to students in an online environment, allowing download, multi-touch display and interaction on mobile devices. In addition, if the student prefers, they can print them using a 3D printer. Finally, there has been an experience with 70 university students who, after accessing to the online files, responded to a questionnaire to assess the made materials.El uso de objetos tangibles (maquetas, réplicas de obras artísticas, fósiles…) en entornos educativos se suele utilizar para mejorar el proceso de aprendizaje. Cuando el conocimiento se difunde a través de entornos virtuales, a veces, se pierde el valor de estos objetos tangibles. Las nuevas tecnologías de bajo coste, permiten solventar este problema, permitiendo a los profesores incluir en sus aulas virtuales el acceso y manipulación de objetos tridimensionales. En este artículo se describe el proceso de creación y divulgación de un contenido educativo tridimensional e interactivo para aprendizaje en un entorno virtual. Como caso práctico se ha trabajado sobre el patrimonio fósil marino canario. Los fósiles se usan como material tangible en la enseñanza de paleontología, sin embargo no están disponibles para el trabajo fuera del aula. En el trabajo descrito en este artículo, se han digitalizado en 3D una selección de 18 fósiles. Los archivos obtenidos están a disposición de los alumnos en un entorno online, permitiendo su descarga, visualización e interacción en dispositivos móviles multitáctiles. Además, si el alumno lo prefiere, puede imprimirlos en 3D. Para finalizar, se ha realizado una experiencia con 70 alumnos universitarios que, después de acceder al repositorio online creado, han contestado a un cuestionario para valorar los materiales diseñados

Mortality According to CD4 Count at Start of Combination Antiretroviral Therapy Among HIV-infected Patients Followed for up to 15 Years After Start of Treatment: Collaborative Cohort Study.

BACKGROUND: CD4 count at start of combination antiretroviral therapy (ART) is strongly associated with short-term survival, but its association with longer-term survival is less well characterized. METHODS: We estimated mortality rates (MRs) by time since start of ART (&lt;0.5, 0.5-0.9, 1-2.9, 3-4.9, 5-9.9, and ≥10 years) among patients from 18 European and North American cohorts who started ART during 1996-2001. Piecewise exponential models stratified by cohort were used to estimate crude and adjusted (for sex, age, transmission risk, period of starting ART [1996-1997, 1998-1999, 2000-2001], and AIDS and human immunodeficiency virus type 1 RNA at baseline) mortality rate ratios (MRRs) by CD4 count at start of ART (0-49, 50-99, 100-199, 200-349, 350-499, ≥500 cells/µL) overall and separately according to time since start of ART. RESULTS: A total of 6344 of 37 496 patients died during 359 219 years of follow-up. The MR per 1000 person-years was 32.8 (95% confidence interval [CI], 30.2-35.5) during the first 6 months, declining to 16.0 (95% CI, 15.4-16.8) during 5-9.9 years and 14.2 (95% CI, 13.3-15.1) after 10 years' duration of ART. During the first year of ART, there was a strong inverse association of CD4 count at start of ART with mortality. This diminished over the next 4 years. The adjusted MRR per CD4 group was 0.97 (95% CI, .94-1.00; P = .054) and 1.02 (95% CI, .98-1.07; P = .32) among patients followed for 5-9.9 and ≥10 years, respectively. CONCLUSIONS: After surviving 5 years of ART, the mortality of patients who started ART with low baseline CD4 count converged with mortality of patients with intermediate and high baseline CD4 counts

Allotopic expression of mitochondrial-encoded genes in mammals: achieved goal, undemonstrated mechanism or impossible task?

Mitochondrial-DNA diseases have no effective treatments. Allotopic expression—synthesis of a wild-type version of the mutated protein in the nuclear-cytosolic compartment and its importation into mitochondria—has been proposed as a gene-therapy approach. Allotopic expression has been successfully demonstrated in yeast, but in mammalian mitochondria results are contradictory. The evidence available is based on partial phenotype rescue, not on the incorporation of a functional protein into mitochondria. Here, we show that reliance on partial rescue alone can lead to a false conclusion of successful allotopic expression. We recoded mitochondrial mt-Nd6 to the universal genetic code, and added the N-terminal mitochondrial-targeting sequence of cytochrome c oxidase VIII (C8) and the HA epitope (C8Nd6HA). The protein apparently co-localized with mitochondria, but a significant part of it seemed to be located outside mitochondria. Complex I activity and assembly was restored, suggesting successful allotopic expression. However, careful examination of transfected cells showed that the allotopically-expressed protein was not internalized in mitochondria and that the selected clones were in fact revertants for the mt-Nd6 mutation. These findings demonstrate the need for extreme caution in the interpretation of functional rescue experiments and for clear-cut controls to demonstrate true rescue of mitochondrial function by allotopic expression