Discontinuous Galerkin integral equation method for light scattering from complex nanoparticle assemblies.

This paper presents a discontinuous Galerkin (DG) integral equation (IE) method for the electromagnetic analysis of arbitrarily-shaped plasmonic assemblies. The use of nonconformal meshes provides improved flexibility for CAD prototyping and tessellation of the input geometry. The formulation can readily address nonconformal multi-material junctions (where three or more material regions meet), allowing to set very different mesh sizes depending on the material properties of the different subsystems. It also enables the use of h-refinement techniques to improve accuracy without burdening the computational cost. The continuity of the equivalent electric and magnetic surface currents across the junction contours is enforced by a combination of boundary conditions and local, weakly imposed, interior penalties within the junction regions. A comprehensive study is made to compare the performance of different IE-DG alternatives applied to plasmonics. The numerical experiments conducted validate the accuracy and versatility of this formulation for the resolution of complex nanoparticle assemblies.

Brief cognitive tests as a decision-making tool in primary care. A population and validation study.

INTRODUCTION AND OBJECTIVES: Brief cognitive tests (BCT) are used in primary care (PC) for the detection of cognitive impairment (CI). Still, there are little data on their diagnostic utility (DU) in a community setting. This work evaluates the DU at the population level of Fototest, T@M, AD8 questionnaire and MMSE. It provides new cut-off points (CoP) validated in a CI early detection program. MATERIAL AND METHODS: In the population and validation samples, the evaluation was carried out in two phases, a first of screening and administration of BCT and a second of clinical diagnosis, blinded to the results of the BCT, applying the current NIA-AA criteria. The DU of BCT in the population sample was evaluated with the area under the ROC curve (aROC). Youden index and the CoP with the best specificity that ensured a sensitivity of 80% were used to decide on the most appropriate CoP. The sensitivity, specificity, and predictive values for these CoP were calculated in the validation sample. RESULTS: 260 participants (23.1% with CI) from the population sample and 177 (42.4% with CI) from the validation sample were included. The Fototest has the best UD at the population level (aROC 0.851), which improves with the combination of Fototest and AD8 (aROC 0.875). The proposed CoP are AD8 ≥ 1, Fototest ≤ 35, T@M ≤ 40, and MMSE ≤ 26. CONCLUSION: BCT are helpful in detecting CI in PC. This work supports the use of more demanding PoC.

Biomarcadores pronósticos y de seguimiento en la polineuropatía desmielinizante inflamatoria crónica / Prognostic and monitoring biomarkers in chronic inflammatory demyelinating polyneuropathy

Introducción: La polineuropatía desmielinizante inflamatoria crónica (PDIC) es una entidad clínica con una variabilidad fenotípica muy importante tanto en el inicio como en la evolución. Por lo tanto, es importante disponer de biomarcadores objetivos para monitorizar la evolución. En esta revisión presentamos los biomarcadores clínicos, neurofisiológicos, de neuroimagen, y en la sangre y el líquido cefalorraquídeo (LCR) para el seguimiento y el pronóstico de la PDIC. Desarrollo: Se han desarrollado diferentes herramientas clínicas validadas para el seguimiento de la PDIC mediante la evaluación de la fuerza y la discapacidad. No obstante, falta determinar el mejor parámetro para monitorizar la marcha. El seguimiento mediante examen neurofisiológico también está ampliamente extendido, y la amplitud del compound muscle action potential es lo más utilizado. Más recientemente, se ha desarrollado la Motor Unit Number Index sum score, que es una técnica precisa y reproducible. El papel de la ecografía de nervio se encuentra en desarrollo, y se ha descrito correlación entre la evolución clínica y los hallazgos por ecografía. Se han descrito múltiples biomarcadores en sangre y el LCR, entre los que destacan los anticuerpos antinodales/paranodales, los neurofilamentos de cadena ligera, los niveles de inmunoglobulina G en el suero y los niveles de esfingomielina en el LCR. Asimismo, se han descrito variantes genéticas y citocinas relacionadas con el pronóstico y la respuesta a los tratamientos. Conclusiones: Uno de los retos más importante en el manejo de la PDIC es la monitorización de los cambios clínicos tras el inicio del tratamiento. La combinación de biomarcadores que permitan una comprensión exacta de la enfermedad es crucial para el manejo óptimo de la PDIC.(AU)

Introduction: Chronic inflammatory demyelinating polyneuropathy (CIDP) is a clinical entity with significant phenotypic variability both in its onset and in its course. Therefore, it is important to have objective biomarkers with which to monitor its evolution. In this review we present clinical, neurophysiological, neuroimaging, blood and cerebrospinal fluid (CSF) biomarkers for the monitoring and prognosis of CIDP. Development: Different clinical tools have been developed and validated to monitor CIDP by assessing strength and disability. However, the best parameter for monitoring gait remains to be determined. Monitoring by neurophysiological examination is also widespread and the amplitude of the compound muscle action potential is the most commonly used. More recently, the Motor Unit Number Index sum score has been developed, which is an accurate and reproducible technique. The role of nerve ultrasonography is under development and a correlation between clinical evolution and ultrasound findings has been described. Multiple biomarkers have been described in blood and CSF, including antinodal/paranodal antibodies, neurofilament light chain, serum immunoglobulin G levels and CSF sphingomyelin levels. Genetic variants and cytokines associated with prognosis and response to treatment have also been described. Conclusions: One of the most important challenges in the management of CIDP is the monitoring of clinical changes after treatment initiation. The combination of biomarkers that allow an accurate understanding of the disease is crucial for the optimal management of CIDP.(AU)

[Prognostic and monitoring biomarkers in chronic inflammatory demyelinating polyneuropathy]. / Biomarcadores pronósticos y de seguimiento en la polineuropatía desmielinizante inflamatoria crónica.

INTRODUCTION: Chronic inflammatory demyelinating polyneuropathy (CIDP) is a clinical entity with significant phenotypic variability both in its onset and in its course. Therefore, it is important to have objective biomarkers with which to monitor its evolution. In this review we present clinical, neurophysiological, neuroimaging, blood and cerebrospinal fluid (CSF) biomarkers for the monitoring and prognosis of CIDP. DEVELOPMENT: Different clinical tools have been developed and validated to monitor CIDP by assessing strength and disability. However, the best parameter for monitoring gait remains to be determined. Monitoring by neurophysiological examination is also widespread and the amplitude of the compound muscle action potential is the most commonly used. More recently, the Motor Unit Number Index sum score has been developed, which is an accurate and reproducible technique. The role of nerve ultrasonography is under development and a correlation between clinical evolution and ultrasound findings has been described. Multiple biomarkers have been described in blood and CSF, including antinodal/paranodal antibodies, neurofilament light chain, serum immunoglobulin G levels and CSF sphingomyelin levels. Genetic variants and cytokines associated with prognosis and response to treatment have also been described. CONCLUSIONS: One of the most important challenges in the management of CIDP is the monitoring of clinical changes after treatment initiation. The combination of biomarkers that allow an accurate understanding of the disease is crucial for the optimal management of CIDP.

TITLE: Biomarcadores pronósticos y de seguimiento en la polineuropatía desmielinizante inflamatoria crónica.Introducción. La polineuropatía desmielinizante inflamatoria crónica (PDIC) es una entidad clínica con una variabilidad fenotípica muy importante tanto en el inicio como en la evolución. Por lo tanto, es importante disponer de biomarcadores objetivos para monitorizar la evolución. En esta revisión presentamos los biomarcadores clínicos, neurofisiológicos, de neuroimagen, y en la sangre y el líquido cefalorraquídeo (LCR) para el seguimiento y el pronóstico de la PDIC. Desarrollo. Se han desarrollado diferentes herramientas clínicas validadas para el seguimiento de la PDIC mediante la evaluación de la fuerza y la discapacidad. No obstante, falta determinar el mejor parámetro para monitorizar la marcha. El seguimiento mediante examen neurofisiológico también está ampliamente extendido, y la amplitud del compound muscle action potential es lo más utilizado. Más recientemente, se ha desarrollado la Motor Unit Number Index sum score, que es una técnica precisa y reproducible. El papel de la ecografía de nervio se encuentra en desarrollo, y se ha descrito correlación entre la evolución clínica y los hallazgos por ecografía. Se han descrito múltiples biomarcadores en sangre y el LCR, entre los que destacan los anticuerpos antinodales/paranodales, los neurofilamentos de cadena ligera, los niveles de inmunoglobulina G en el suero y los niveles de esfingomielina en el LCR. Asimismo, se han descrito variantes genéticas y citocinas relacionadas con el pronóstico y la respuesta a los tratamientos. Conclusiones. Uno de los retos más importante en el manejo de la PDIC es la monitorización de los cambios clínicos tras el inicio del tratamiento. La combinación de biomarcadores que permitan una comprensión exacta de la enfermedad es crucial para el manejo óptimo de la PDIC.

Non-invasive high-speed blinking kinematics characterization.

PURPOSE: The objective of this study was to analyze the differences in blinking kinematics of spontaneous and voluntary blinks using for the first time a self-developed, non-invasive, and image processing-based method. METHODS: The blinks of 30 subjects were recorded for 1 min with the support of an eye-tracking device based on a high-speed infrared video camera, working at 250 frames per second, under two different experimental conditions. For the first condition, subjects were ordered to look in the straightforward position at a fixation target placed 1 m in front of them, with no further instructions. For the second, subjects were additionally asked to blink only following a sound signal every 6 s. RESULTS: Mean complete blinks increased by a factor of 1.7 from the spontaneous to the voluntary condition while mean incomplete blinks reduced significantly by a factor of 0.4. In both conditions, closing mean and peak velocities were always significantly greater and durations significantly lower than opening ones. When comparing the values for each condition, velocities and amplitudes for the voluntary condition were always greater than the corresponding values for spontaneous. CONCLUSION: Voluntary blinks revealed significant kinematic differences compared to spontaneous, thus supporting a different supranuclear pathway organization. This study presents a new method, based on image analysis, for the non-invasive kinematic characterization of blinking.

There is more to accommodation of the eye than simply minimizing retinal blur.

Eyes of children and young adults change their optical power to focus nearby objects at the retina. But does accommodation function by trial and error to minimize blur and maximize contrast as is generally accepted? Three experiments in monocular and monochromatic vision were performed under two conditions while aberrations were being corrected. In the first condition, feedback was available to the eye from both optical vergence and optical blur. In the second, feedback was only available from target blur. Accommodation was less precise for the second condition, suggesting that it is more than a trial-and-error function. Optical vergence itself seems to be an important cue for accommodation.

Estimation of the mechanical properties of the eye through the study of its vibrational modes.

Measuring the eye's mechanical properties in vivo and with minimally invasive techniques can be the key for individualized solutions to a number of eye pathologies. The development of such techniques largely relies on a computational modelling of the eyeball and, it optimally requires the synergic interplay between experimentation and numerical simulation. In Astrophysics and Geophysics the remote measurement of structural properties of the systems of their realm is performed on the basis of (helio-)seismic techniques. As a biomechanical system, the eyeball possesses normal vibrational modes encompassing rich information about its structure and mechanical properties. However, the integral analysis of the eyeball vibrational modes has not been performed yet. Here we develop a new finite difference method to compute both the spheroidal and, specially, the toroidal eigenfrequencies of the human eye. Using this numerical model, we show that the vibrational eigenfrequencies of the human eye fall in the interval 100 Hz-10 MHz. We find that compressible vibrational modes may release a trace on high frequency changes of the intraocular pressure, while incompressible normal modes could be registered analyzing the scattering pattern that the motions of the vitreous humour leave on the retina. Existing contact lenses with embebed devices operating at high sampling frequency could be used to register the microfluctuations of the eyeball shape we obtain. We advance that an inverse problem to obtain the mechanical properties of a given eye (e.g., Young's modulus, Poisson ratio) measuring its normal frequencies is doable. These measurements can be done using non-invasive techniques, opening very interesting perspectives to estimate the mechanical properties of eyes in vivo. Future research might relate various ocular pathologies with anomalies in measured vibrational frequencies of the eye.

Developing a new Bayesian Risk Index for risk evaluation of soil contamination.

Industrial and agricultural activities heavily constrain soil quality. Potentially Toxic Elements (PTEs) are a threat to public health and the environment alike. In this regard, the identification of areas that require remediation is crucial. In the herein research a geochemical dataset (230 samples) comprising 14 elements (Cu, Pb, Zn, Ag, Ni, Mn, Fe, As, Cd, V, Cr, Ti, Al and S) was gathered throughout eight different zones distinguished by their main activity, namely, recreational, agriculture/livestock and heavy industry in the Avilés Estuary (North of Spain). Then a stratified systematic sampling method was used at short, medium, and long distances from each zone to obtain a representative picture of the total variability of the selected attributes. The information was then combined in four risk classes (Low, Moderate, High, Remediation) following reference values from several sediment quality guidelines (SQGs). A Bayesian analysis, inferred for each zone, allowed the characterization of PTEs correlations, the unsupervised learning network technique proving to be the best fit. Based on the Bayesian network structure obtained, Pb, As and Mn were selected as key contamination parameters. For these 3 elements, the conditional probability obtained was allocated to each observed point, and a simple, direct index (Bayesian Risk Index-BRI) was constructed as a linear rating of the pre-defined risk classes weighted by the previously obtained probability. Finally, the BRI underwent geostatistical modeling. One hundred Sequential Gaussian Simulations (SGS) were computed. The Mean Image and the Standard Deviation maps were obtained, allowing the definition of High/Low risk clusters (Local G clustering) and the computation of spatial uncertainty. High-risk clusters are mainly distributed within the area with the highest altitude (agriculture/livestock) showing an associated low spatial uncertainty, clearly indicating the need for remediation. Atmospheric emissions, mainly derived from the metallurgical industry, contribute to soil contamination by PTEs.

Winter circulation weather types and hospital admissions for respiratory diseases in Galicia, Spain.

The link between various pathologies and atmospheric conditions has been a constant topic of study over recent decades in many places across the world; knowing more about it enables us to pre-empt the worsening of certain diseases, thereby optimizing medical resources. This study looked specifically at the connections in winter between respiratory diseases and types of atmospheric weather conditions (Circulation Weather Types, CWT) in Galicia, a region in the north-western corner of the Iberian Peninsula. To do this, the study used hospital admission data associated with these pathologies as well as an automatic classification of weather types. The main result obtained was that weather types giving rise to an increase in admissions due to these diseases are those associated with cold, dry weather, such as those in the east and south-east, or anticyclonic types. A second peak was associated with humid, hotter weather, generally linked to south-west weather types. In the future, this result may help to forecast the increase in respiratory pathologies in the region some days in advance.

La dificultad del diagnóstico de mareos y síncopes / The difficulty of diagnosis of dizziness and syncope

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Blastocystis hominis, un gran desconocido / Blastocystis hominis, a great unknown

Introducción: Blastocystis hominis es el protozoo que con mayor frecuencia se encuentra en las heces de las personas, tanto sintomáticas como asintomáticas. Este parásito presenta varias controversias e indefiniciones, especialmente en cuanto a su patogenicidad. El desconocimiento o la poca importancia que se le da a este microorganismo por los profesionales sanitarios es frecuente, aunque cada vez más estudios apoyan la participación del parásito en patología clínica. El objetivo del presente estudio es revisar las características epidemiológicas y clínicas de todos los niños con estudios coproparasitológicos positivos para Blastocystis hominis atendidos en los últimos cinco años en nuestro centro de salud. Material y métodos: se realizó una revisión retrospectiva y transversal de todos los coprocultivos y estudios parasitológicos realizados en los últimos cinco años a niños entre 1 y 15 años y posteriormente se revisa- ron las características epidemiológicas y clínicas de los pacientes positivos para este microorganismo. Resultados: en los últimos cinco años solicitamos 530 coprocultivos y estudios coproparasitológicos, de los cuales fueron positivos 122 (23,01%). Las bacterias más frecuentemente aisladas fueron Campylobacter jejuni, seguida de Salmonella enterica. De las muestras positivas para enteroparásitos, el Blastocystis hominis fue el que se aisló con más frecuencia (24 casos). Todos los niños eran autóctonos y no habían viajado al extranjero, excepto un niño que había sido adoptado en China. Ningún paciente presentaba alteraciones de la inmunidad o enfermedades concomitantes. Conclusiones: consideramos que el Blastocystis hominis es un microorganismo a tener en cuenta, y desde el punto de vista clínico parece razonable ofrecer tratamiento a los pacientes sintomáticos en los que una patología alternativa haya sido descartada (AU)

Introduction: Blastocystis hominis is a protozoan that is most often found in the feces of people, both symptomatic and asymptomatic. This parasite has several controversies and uncertainties, especially in their pathogenicity. The ignorance or lack of importance given to this organism by health professionals is common but more and more studies support the involvement of the parasite in clinical pathology. The aim of this study is to review the epidemiological and clinical characteristics of all children with positive parasitological studies to Blastocystis hominis attended in the last five years in our health center. Material and methods: a retrospective and cross-check of all stool cultures and parasitological studies in the past five years to children between 1 and 15 years old was performed and the epidemiological and clinical characteristics of patients positive for this organism were subsequently revised. Results: in the past five years 530 parasitological and stool cultures were performed, 122 were positive (23.01%). The bacteria most frequently isolated were Campylobacter jejuni, followed by Salmonella enterica. Of enteroparasite positive samples, Blastocystis hominis was the most frequently isolated (24 cases). All children were native and had not traveled abroad, except a child who had been adopted in China. No patient had impaired immunity or comorbidities. Conclusions: Blastocystis hominis is a microorganism to consider, and from the clinical point of view it seems reasonable to offer treatment to symptomatic patients in whom an alternative pathology was discarded (AU)

Analysis and detection of functional outliers in water quality parameters from different automated monitoring stations in the Nalón river basin (Northern Spain).

The purposes and intent of the authorities in establishing water quality standards are to provide enhancement of water quality and prevention of pollution to protect the public health or welfare in accordance with the public interest for drinking water supplies, conservation of fish, wildlife and other beneficial aquatic life, and agricultural, industrial, recreational, and other reasonable and necessary uses as well as to maintain and improve the biological integrity of the waters. In this way, water quality controls involve a large number of variables and observations, often subject to some outliers. An outlier is an observation that is numerically distant from the rest of the data or that appears to deviate markedly from other members of the sample in which it occurs. An interesting analysis is to find those observations that produce measurements that are different from the pattern established in the sample. Therefore, identification of atypical observations is an important concern in water quality monitoring and a difficult task because of the multivariate nature of water quality data. Our study provides a new method for detecting outliers in water quality monitoring parameters, using turbidity, conductivity and ammonium ion as indicator variables. Until now, methods were based on considering the different parameters as a vector whose components were their concentration values. This innovative approach lies in considering water quality monitoring over time as continuous curves instead of discrete points, that is to say, the dataset of the problem are considered as a time-dependent function and not as a set of discrete values in different time instants. This new methodology, which is based on the concept of functional depth, was applied to the detection of outliers in water quality monitoring samples in the Nalón river basin with success. Results of this study were discussed here in terms of origin, causes, etc. Finally, the conclusions as well as advantages of the functional method are exposed.

Directive antenna nanocoupler to plasmonic gap waveguides.

Optical nanocouplers matching a fiber microwaveguide to a plasmonic nanowaveguide are essential components for practical applications of nanophotonic systems. In this Letter we design an efficient nanocoupler using a directive nanoantenna in the visible range λ0=0.65 µm. The antenna has been optimized both in the configuration and in the matching element in order to achieve the maximum coupling efficiency (CE). In spite of the reduced size of the nanoantenna in comparison with the impinging fiber spot size (due to the localized plasmonic resonance at such high frequency), we have shown that a good efficiency can be achieved, improving the CE by a factor of 10 with respect to the nondirective antenna nanocouplers.

Synoptic patterns and air mass transport during ozone episodes in northwestern Iberia.

High levels of ozone are frequently measured at the Galicia (NW Iberian Peninsula) air quality monitoring stations from March to October. However, there have been very few studies on surface ozone in the northwestern Iberian Peninsula, most likely because the climate of this region is not favourable to photochemical ozone generation. The occurrence of these episodes may be related to either local-scale photochemical pollution or regional-scale transport from other polluted regions. In addition, high ozone episodes usually are developed under specific synoptic conditions. The main purposes of this study are to characterise the atmospheric conditions that lead to the ozone episodes in this region and to identify possible advection paths of ozone and precursors. A surface hourly ozone dataset (2002-2007) measured at rural sites in Galicia was analysed to identify high ozone episodes together with their associated synoptic patterns using a subjective classification with 23 different synoptic types. The synoptic weather patterns revealed that most of the episodes occur with high surface pressures centred over the British Isles and/or Central Europe while a high-altitude anticyclonic ridge crosses the Peninsula from North Africa, causing easterly or southeasterly winds. This analysis was completed with 3-day backward air mass trajectories obtained with HYSPLIT to assess the contribution of long-range transport, resulting in the following main routes: Mediterranean-Peninsular, South Atlantic-Portuguese, local and French-Cantabric.

Detection of outliers in water quality monitoring samples using functional data analysis in San Esteban estuary (Northern Spain).

Water quality controls involve large number of variables and observations, often subject to some outliers. An outlier is an observation that is numerically distant from the rest of the data or that appears to deviate markedly from other members of the sample in which it occurs. An interesting analysis is to find those observations that produce measurements that are different from the pattern established in the sample. Therefore, identification of atypical observations is an important concern in water quality monitoring and a difficult task because of the multivariate nature of water quality data. Our study provides a new method for detecting outliers in water quality monitoring parameters, using oxygen and turbidity as indicator variables. Until now, methods were based on considering the different parameters as a vector whose components were their concentration values. Our approach lies in considering water quality monitoring through time as curves instead of vectors, that is to say, the data set of the problem is considered as a time-dependent function and not as a set of discrete values in different time instants. The methodology, which is based on the concept of functional depth, was applied to the detection of outliers in water quality monitoring samples in San Esteban estuary. Results were discussed in terms of origin, causes, etc., and compared with those obtained using the conventional method based on vector comparison. Finally, the advantages of the functional method are exposed.

Comparison of surface integral equation formulations for electromagnetic analysis of plasmonic nanoscatterers.

The performance of most widespread surface integral equation (SIE) formulations with the method of moments (MoM) are studied in the context of plasmonic materials. Although not yet widespread in optics, SIE-MoM approaches bring important advantages for the rigorous analysis of penetrable plasmonic bodies. Criteria such as accuracy in near and far field calculations, iterative convergence and reliability are addressed to assess the suitability of these formulations in the field of plasmonics.

Nutritive value of diets containing fish silage for juvenile Litopenaeus vannamei (Bonne, 1931).

BACKGROUND: Fish wastes has been used for many years as an alternative in feeds for aquaculture. In the present study weight gain of juvenile white shrimp Litopenaeus vannamei fed diets including fish waste silage (WS), fish waste silage with soybean meal SBM (WS + S) or fish waste meal (WM) was compared. A conventional acidic silage process was applied to obtain from wastes (skin, heads, bones and viscera) of snapper (Lutjanus spp.), grunt (Haemulon plumieri), and grouper (Epinephelus spp.) an ingredient rich in protein. RESULTS: After 3 days ensilage more than 90% protein was hydrolysed. Waste material processed at pH 3.8 lost about 24% tryptophan. Butylated hydroxytoluene (BHT) prevented lipid oxidation, as shown after 45 days with malonaldehyde production. Shrimp fed WS + S diet gained 0.7 g per week higher than those fed WS and WM diets with 0.3 g per week (P < 0.05). CONCLUSION: WS processed with formic acid under conditions of low pH is beneficial for the white shrimp L. vannamei. It sustained reasonable weight gain combined with soybean meal in practical diets. On the other hand, BHT addition was beneficial in preventing oxidative action during silage preparation.

Solution of large-scale plasmonic problems with the multilevel fast multipole algorithm.

A surface integral equation together with the multilevel fast multipole algorithm is successfully applied to fast and accurate resolution of plasmonic problems involving a large number of unknowns. The absorption, scattering, and extinction efficiencies of several plasmonic gold spheres of increasing size are efficiently obtained solving the electric and magnetic current combined-field integral equation. The numerical predictions are compared with reference analytic results to demonstrate the accuracy, suitability, and capabilities of this approach when dealing with large-scale plasmonic problems.