Solution of the 3D-Helmholtz equation in exterior domains using spherical harmonic decomposition

AbstractThis work is devoted to a finite element formulation for the Helmholtz equation in exterior domains. The proposed formulation uses a separation of variables, combining a 2D FE discretization on an intermediate spherical boundary and an ‘a priori’ analytical pattern for the radial direction. Using the analytical radial pattern and the series expansion of trial and test functions in terms of spherical harmonics, an efficient semi-analytical technique is obtained for the direct calculation of the global FE matrices. The accuracy and reliability of the formulation are illustrated through numerical examples of radiation and scattering in the exterior domain

Design and operation of a Rayleigh Ohnesorge Jetting Extensional Rheometer (ROJER) to study extensional properties of low viscosity polymer solutions

The Rayleigh Ohnesorge Jetting Extensional Rheometer (ROJER) enables measurement of very short relaxation times of low viscosity complex fluids such as those encountered in ink-jet printing and spraying applications. This paper focuses on the design and operation of the ROJER. The performance of two nozzle designs are compared using Newtonian fluids alongside a study using computational fluid dynamics (CFD). Subsequently a disposable nozzle is developed that overcomes issues of blockage and cleaning. The operability of this design is subject to a focused study where low viscosity polymer solutions are characterised. The test fluid materials are ethyl hydroxy-ethyl cellulose (EHEC) and poly ethylene oxide (PEO) mixed with water/glycerol solutions. Results obtained by the disposable nozzle are encouraging, paving the way for a more cost-efficient and robust ROJER setup

Two heads are better than one, but how much? Evidence that people's use of causal integration rules does not always conform to normative standards.

Many theories of causal learning and causal induction differ in their assumptions about how people combine the causal impact of several causes presented in compound. Some theories propose that when several causes are present, their joint causal impact is equal to the linear sum of the individual impact of each cause. However, some recent theories propose that the causal impact of several causes needs to be combined by means of a noisy-OR integration rule. In other words, the probability of the effect given several causes would be equal to the sum of the probability of the effect given each cause in isolation minus the overlap between those probabilities. In the present series of experiments, participants were given information about the causal impact of several causes and then they were asked what compounds of those causes they would prefer to use if they wanted to produce the effect. The results of these experiments suggest that participants actually use a variety of strategies, including not only the linear and the noisy-OR integration rules, but also averaging the impact of several causes

Retinoic Acid Modulates PTGDR Promoter Activity

[EN] Background and objective: Vitamin A has been linked to the development of allergic diseases although its role is not fully understood, Retinoic acid (RA), a metabolite of Vitamin A, has been previously associated with the prostaglandin pathway, and PTGDR, a receptor of PGD2, has been proposed as a candidate gene in allergy and asthma. Considering the role of PTGDR in allergy, the goal of this study was to analyze the effect of RA on the activation of the promoter region of the PTGDR gene. Methods: A549 lung epithelial cells were transfected with 4 combinations of genetic variants of the PTGDR promoter and stimulated with all-trans RA (ATRA); luciferase assays were performed using the Dual Luciferase Reporter System, and real-time quantitative polymerase chain reaction was used to measure the expression of PTGDR, CYP26A1, RARA, RARB, RARG, and RXRA in basal A549 cell cultures and after ATRA treatment. We also performed an in silico analysis. Results: After ATRA treatment increased expression of CYP26A1 (12-fold) and RARB (4-fold) was detected. ATRA activated PTGDR promoter activity in transfected cells (P<.001) and RA response element sequences were identified in silico in this promoter region. Conclusions: RA modulated PTGDR promoter activity. Differential response to RA and to new treatments based on PTGDR modulation could depend on genetic background in allergic asthmatic patients.Instituto de Salud Carlos III; European Regional Development Fund (ERDF); Junta de Castilla y León; Fundación Botín-Universidad de Salamanca; Sociedad Española de Alergología e Inmunología Clínica; Fundación Salud 200

Prototipo de Cámara Infrarroja para obtener el Índice NDVI en Agricultura de Precisión

Las Tecnologías de la Información y Comunicación (TICs) y el uso de dispositivos móviles han revolucionado prácticamente todas las áreas del quehacer humano, dando a los usuarios de estos dispositivos las habilidades para realizar tareas que antes solo eran posibles a través de equipos de escritorio. Una de las áreas que han sido beneficiadas por estas tecnologías es la agricultura creando el término “Agricultura de Precisión (AP)”. En este artículo se presenta un prototipo de cámara infrarroja de bajo costo para obtener el Índice Diferencial de Vegetación Normalizado (NDVI: Normalized Difference Vegetation Index) el cual es usado para estimar la cantidad, calidad y desarrollo de la vegetación con base a la medición (por medio de sensores remotos) de la intensidad de la radiación de ciertas bandas del espectro electromagnético que la vegetación refleja. Este prototipo se basa en imágenes tomadas a cultivos en ambientes controlados, se realizan dos tomas del mismo objetivo (una imagen en el espectro de colores normal y una segunda foto en el espectro infrarrojo, procesando ambas imágenes es como se obtiene el índice NDVI. Asimismo, se presenta un caso de estudio con aplicabilidad para la agronomía donde usuarios sin experiencia en TICs puedan hacer uso de estas tecnologías en cualquier tipo de dispositivo (en especial los teléfonos inteligentes) para determinar los niveles de salud de plantas en el mismo lugar sin tener que esperar para su procesamiento o tener que llevar las imágenes a un centro de procesamiento especializado

Air pollution, inflammation and preterm birth in Mexico City: Study design and methods

Preterm birth is one of the leading causes of perinatal mortality and is associated with long-term adverse health consequences for surviving infants. Preterm birth rates are rising worldwide, and no effective means for prevention currently exists. Air pollution exposure may be a significant cause of prematurity, but many published studies lack the individual, clinical data needed to elucidate possible biological mechanisms mediating these epidemiological associations. This paper presents the design of a prospective study now underway to evaluate those mechanisms in a cohort of pregnant women residing in Mexico City. We address how air quality may act together with other factors to induce systemic inflammation and influence the duration of pregnancy. Data collection includes: biomarkers relevant to inflammation in cervico-vaginal exudate and peripheral blood, along with full clinical information, pro-inflammatory cytokine gene polymorphisms and air pollution data to evaluate spatial and temporal variability in air pollution exposure. Samples are collected on a monthly basis and participants are followed for the duration of pregnancy. The data will be used to evaluate whether ambient air pollution is associated with preterm birth, controlling for other risk factors. We will evaluate which time windows during pregnancy are most influential in the air pollution and preterm birth association. In addition, the epidemiological study will be complemented with a parallel toxicology invitro study, in which monocytic cells will be exposed to air particle samples to evaluate the expression of biomarkers of inflammation

The Bitter Truth About Sugar and Willpower: The Limited Evidential Value of the Glucose Model of Ego Depletion

This work was supported by European Research Council Grant 283849 (to N. Gold) under the European Union’s Seventh Framework Programme (FP/2007–2013)

On the analysis of the contact angle for impacting droplets using a polynomial fitting approach

ractical considerations on the measurement of the dynamic contact angle and the spreading diameter of impacting droplets are discussed in this paper. The contact angle of a liquid is commonly obtained either by a polynomial or a linear fitting to the droplet profile around the triple phase point. Previous works have focused on quasi-static or sessile droplets, or in cases where inertia does not play a major role on the contact angle dynamics. Here, we study the effect of droplet shape, the order of the fitting polynomial, and the fitting domain, on the measurement of the contact angle on various stages following droplet impact where the contact line is moving. Our results, presented in terms of the optical resolution and the droplet size, show that a quadratic fitting provides the most consistent results for a range of various droplet shapes. As expected, our results show that contact angle values are less sensitive to the fitting conditions for the cases where the droplet can be approximated to a spherical cap. Our experimental conditions include impact events with liquid droplets of different sizes and viscosities on various substrates. In addition, validating past works, our results show that the maximum spreading diameter can be parameterised by the Weber number and the rapidly advancing contact angle

Combined Boyden-Flow Cytometry Assay Improves Quantification and Provides Phenotypification of Leukocyte Chemotaxis

Chemotaxis has been studied by classical methods that measure chemotactic and random motility responses in vitro, but these methods do not evaluate the total number and phenotype of migrating leukocytes simultaneously. Our objective was to develop and validate a novel assay, combined Boyden-flow cytometry chemotaxis assay (CBFCA), for simultaneous quantification and phenotypification of migrating leukocytes. CBFCA exhibited several important advantages in comparison to the classic Boyden chemotaxis assay (CBCA): 1) improved precision (intra-assay coefficients of variation (CVs): CBFCA-4.7 and 4.8% vs. CBCA-30.1 and 17.3%; inter-observer CVs: CBFCA-3.6% vs. CBCA 30.1%); 2) increased recovery of cells, which increased assay to provide increased sensitivity; 3) high specificity for determining the phenotype of migrating/attracted leukocytes; and 4) reduced performance time (CBFCA 120 min vs. CBCA 265 min). Other advantages of CBFCA are: 5) robustness, 6) linearity, 7) eliminated requirement for albumin and, importantly, 8) enabled recovery of migrating leukocytes for subsequent studies. This latter feature is of great benefit in the study of migrating leukocyte subsets. We conclude that the CBFCA is a novel and improved technique for experiments focused on understanding leukocyte trafficking during the inflammatory response