On the role of physisorption states in molecular scattering: A semi-local density-functional theory study on O2/Ag(111)

We simulate the scattering of O$_2$ from Ag(111) with classical dynamics simulations performed on a six-dimensional potential energy surface calculated within semi-local density-functional theory (DFT). The enigmatic experimental trends that originally required the conjecture of two types of repulsive walls, arising from a physisorption and chemisorption part of the interaction potential, are fully reproduced. Given the inadequate description of the physisorption properties in semi-local DFT, our work casts severe doubts on the prevalent notion to use molecular scattering data as indirect evidence for the existence of such states.Comment: 5 pages, 4 figure

Defining, quantifying, and reporting intensity, dose, and dosage of neurorehabilitative interventions focusing on motor outcomes

IntroductionDetermining the minimal amount of therapy needed for positive neurorehabilitative outcomes is important for optimizing active treatment interventions to improve motor outcomes. However, there are various challenges when quantifying these relationships: first, several consensuses on the definition and usage of the terms intensity, dose, and dosage of motor interventions have been proposed, but there seems to be no agreement, and the terms are still used inconsistently. Second, randomized controlled trials frequently underreport items relevant to determining the intensity, dose, and dosage of the interventions. Third, there is no universal measure to quantify therapy intensity accurately. This “perspectives” paper aims to increase awareness of these topics among neurorehabilitation specialists.Defining, quantifying, and reportingWe searched the literature for definitions of intensity, dose, and dosage and adapted the ones we considered the most appropriate to fit the needs of neurorehabilitative interventions. Furthermore, we suggest refining the template for intervention description and replication (TIDieR) to enhance the reporting of randomized controlled trials. Finally, we performed a systematic literature search to provide a list of intensity measures and complemented these with some novel candidate measures.DiscussionThe proposed definitions of intensity, dose, and dosage could improve the communication between neurorehabilitation specialists and the reporting of dose and dosage in interventional studies. Quantifying intensity is necessary to improve our understanding of the minimal intensity, dose, and dosage of therapy needed to improve motor outcomes in neurorehabilitation. We consider the lack of appropriate intensity measures a significant gap in knowledge requiring future research

Trasplante pulmonar

A lung transplant is usually the final therapeutic option for patients with respiratory insufficiency. In spite of the many advances in immunology and the management of complications, mortality and morbidity associated with this transplant are far higher than with others. Acute rejection is an almost universal problem in the first year, while obliterative bronchitis reduces long term survival. Respiratory infections also play a significant role in the complications associated with lung transplants due to the constant exposure of the graft to the outside. However, the success of this therapeutic option, which basically depends on a suitable selection of donor and recipient, are evident, above all with respect to quality of life

Producción de látex híbridos acrílicos/alquídicos

In this work, the production of high solids content hybrid acrylic/alkyd latexes by miniemulsion polymerization is discussed. First, the miniemulsification procedure to achieve colloidally stable hybrid nanodroplets is presented. Next, the efficient nucleation of most nanodroplets during the polymerization, avoiding other nucleation mechanisms is presented. Finally, the key aspects to control the polymer architecture as well as the particle morphology are analyzed.Fil: Goikoetxea, Monika. Universidad del País Vasco; EspañaFil: Minari, Roque Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Beristain, Itxaso. Universidad del País Vasco; EspañaFil: Paulis, María. Universidad del País Vasco; EspañaFil: Asua, José M.. Universidad del País Vasco; EspañaFil: Barandiaran, María J.. Universidad del País Vasco; Españ

Asynchronous Training of Word Embeddings for Large Text Corpora

Word embeddings are a powerful approach for analyzing language and have been widely popular in numerous tasks in information retrieval and text mining. Training embeddings over huge corpora is computationally expensive because the input is typically sequentially processed and parameters are synchronously updated. Distributed architectures for asynchronous training that have been proposed either focus on scaling vocabulary sizes and dimensionality or suffer from expensive synchronization latencies. In this paper, we propose a scalable approach to train word embeddings by partitioning the input space instead in order to scale to massive text corpora while not sacrificing the performance of the embeddings. Our training procedure does not involve any parameter synchronization except a final sub-model merge phase that typically executes in a few minutes. Our distributed training scales seamlessly to large corpus sizes and we get comparable and sometimes even up to 45% performance improvement in a variety of NLP benchmarks using models trained by our distributed procedure which requires $1/10$ of the time taken by the baseline approach. Finally we also show that we are robust to missing words in sub-models and are able to effectively reconstruct word representations.Comment: This paper contains 9 pages and has been accepted in the WSDM201

Non-adiabatic effects during the dissociative adsorption of O2 at Ag(111)? A first-principles divide and conquer study

We study the gas-surface dynamics of O2 at Ag(111) with the particular objective to unravel whether electronic non-adiabatic effects are contributing to the experimentally established inertness of the surface with respect to oxygen uptake. We employ a first-principles divide and conquer approach based on an extensive density-functional theory mapping of the adiabatic potential energy surface (PES) along the six O2 molecular degrees of freedom. Neural networks are subsequently used to interpolate this grid data to a continuous representation. The low computational cost with which forces are available from this PES representation allows then for a sufficiently large number of molecular dynamics trajectories to quantitatively determine the very low initial dissociative sticking coefficient at this surface. Already these adiabatic calculations yield dissociation probabilities close to the scattered experimental data. Our analysis shows that this low reactivity is governed by large energy barriers in excess of 1.1 eV very close to the surface. Unfortunately, these adiabatic PES characteristics render the dissociative sticking a rather insensitive quantity with respect to a potential spin or charge non-adiabaticity in the O2-Ag(111) interaction. We correspondingly attribute the remaining deviations between the computed and measured dissociation probabilities primarily to unresolved experimental issues with respect to surface imperfections.Comment: 18 pages including 6 figure

Estudio por teledetección de las entradas de polvo sahariano al océano y su posible influencia sobre la productividad marina en el área macaronésica

Ponencia presentada en: 1er Encuentro sobre Meteorología y Atmósfera de Canarias, celebrado en el Puerto de la Cruz, los días 12,13 y 14 de noviembre de 2003. El encuentro estuvo organizado por el Centro Meteorológico Territorial en Canarias Occidental, con la colaboración del Observatorio Atmosférico de Izaña y del Grupo de Física de la Atmósfera de la Facultad de Física (Universidad de La Laguna

A severe case of lipoatrophy due to human insulin and insulin analogs in a patient with diabetes: is an immunological mechanism involved?

The precipitin technique has been used in insulin resistance and immunity studies since the 1940s [7]. In the case described, the technique proved, once again, to be a valid method for choosing the most appropriate insulin. However, whether or not an immunological mechanism was involved in the lipoatrophic process remains uncertain, and further studies with adequate immunological assessment are necessary