Near-far resistant CML propagation delay estimation and multi-user detection for asynchronous DS-CDMA systems

Multi-user receivers in asynchronous direct sequence code division multiple access (DS-CDMA) systems require the knowledge of several parameters such as timing delay between users. The goal of this work is to present a near-far resistant joint multi-user synchronization and detection algorithm for DS-CDMA systems. The solution is based on the conditional maximum likelihood (CML) estimation method (classically used in the context of sensor array processing) that leads to a fast convergence algorithm to estimate the time delays among users. At the same time the estimator implements the decorrelating detector, identifying the transmitted symbols for the different users.Peer ReviewedPostprint (published version

Disseny del quadre de comandament d’una empresa comercial a partir de la metodologia canvas per a la definició de models de negoci

Durant els últims anys, la gran majoria d’empreses del país han fet un pas endavant alhora de controlar i gestionar el que passa a la seva organització a partir del tractament de les dades i de l’activitat de les empreses. Una de les eines més utilitzades per al control i la previsió del funcionament de les empreses és el quadre de comandament. El document que es presenta pretén ser una eina per introduir una nova manera de dissenyar un quadre de comandament a partir del trencador mètode per a la definició de models de negoci anomenat canvas. Per a procedir amb el mètode és necessari tenir molt present l’estratègia empresarial seguida en cada cas per conèixer les necessitats i els objectius marcats. Per això, es realitza una introducció a l’estratègia empresarial, els orígens, els principals desenvolupadors i les teories més esteses durant els últims anys. Un cop s’ha introduït al lector en el món de l’estratègia empresarial i en la gran importància que aquesta té, es recullen els fonaments del mètode canvas presentat l’any 2010 per Alexander Osterwalder i Yves Pigneur en el llibre Business Model Generation. El mètode canvas permet tenir una visió estructurada del funcionament de l’empresa, així com també facilita la definició i estudi dels aspectes més importants de les organitzacions. Per a totes aquestes propietats, es parteix del mètode per a definir el model de negoci d’una empresa comercial real, que serà el punt de partida per la construcció del quadre de comandament final de l’empresa. Finalment, es defineix i es dissenya el quadre de comandament per a la companyia, partint del model de negoci definit amb el canvas i amb l’ajuda de programari expert de Business Intelligence, que permet representar el quadre de comandament i els informes pertinents d’una manera molt més gràfica, visual i entenedora

Assessment of the pharmacological effects of alprazolam on electroencephalography using connectivity indexes not affected by volume conduction

Electroencephalographic analysis techniques have become a very useful tool to assess brain activity and interactions between cerebral regions, that is, the so-called cerebral connectivity analysis. The effects of some drugs have, so far, been studied using spectral analysis and, to a lesser extent, some linear and nonlinear connectivity techniques. New indexes have recently been designed based on assumptions that make them more robust against volume conduction effects that could yield to spurious connectivity results. These new indexes such as the imaginary coherence (IC) [Nolte et al., 2004], the phase-lag index (PLI) [Stam et al., 2007] and the weighted phase-lag index (WPLI) [Vinck et al., 2011] have proven very useful in several fields, for example in characterizing electroencephalographic (EEG) and magnetoencephalographic (MEG) activity of Alzheimer’s Disease patients compared to healthy controls. However, these techniques have not been applied to study the effect of drugs on the brain. The main purpose of the current work was to assess the suitability and effectiveness of these innovative indexes to study the brain connectivity under psychoactive drug treatment, and concretely, the effects of a single dose of alprazolam, a short-acting drug of the benzodiazepine family. Alprazolam is extensively prescribed for the treatment of anxiety and panic disorders, and peak plasma concentrations are obtained between 0.5 and 2 hours after intake [Greenblat and Wright, 1993]. Being a benzodiazepines, alprazolam induces an enhancement of the inhibitory pathways through their activity on the GABA A receptor complex, favouring the entrance to chloride ions into the neurons [Haefely, 1990]. Due to the enhancement of the inhibitory pathways a weakening or even an impairment of functional connectivity could be hypothesizedPostprint (author's final draft

Inhibition of alpha oscillations through serotonin-2A receptor activation underlies the visual effects of ayahuasca in humans

Ayahuasca is an Amazonian psychotropic plant tea typically obtained from two plants, Banisteriopsis caapi and Psychotria viridis. It contains the psychedelic 5-HT2A and sigma-1 agonist N,N-dimethyltryptamine (DMT) plus ß-carboline alkaloids with monoamine-oxidase (MAO)-inhibiting properties. Although the psychoactive effects of ayahuasca have commonly been attributed solely to agonism at the 5-HT2A receptor, the molecular target of classical psychedelics, this has not been tested experimentally. Here we wished to study the contribution of the 5-HT2A receptor to the neurophysiological and psychological effects of ayahuasca in humans. We measured drug-induced changes in spontaneous brain oscillations and subjective effects in a double-blind randomized placebo-controlled study involving the oral administration of ayahuasca (0.75 mg DMT/kg body weight) and the 5-HT2A antagonist ketanserin (40 mg). Twelve healthy, experienced psychedelic users (5 females) participated in four experimental sessions in which they received the following drug combinations: placebo+placebo, placebo+ayahuasca, ketanserin+placebo and ketanserin+ayahuasca. Ayahuasca induced EEG power decreases in the delta, theta and alpha frequency bands. Current density in alpha-band oscillations in parietal and occipital cortex was inversely correlated with the intensity of visual imagery induced by ayahuasca. Pretreatment with ketanserin inhibited neurophysiological modifications, reduced the correlation between alpha and visual effects, and attenuated the intensity of the subjective experience. These findings suggest that despite the chemical complexity of ayahuasca, 5-HT2A activation plays a key role in the neurophysiological and visual effects of ayahuasca in humans.Postprint (published version

Gestor d'incidències per a un despatx tècnic

Aplicació web que pretén donar solució a les necessitats de caràcter organitzatiu d'un despatx tècnic d'una empresa. L'objectiu principal és el de crear una eina capaç d'automatitzar el seguiment de les incidències obertes en el despatx. L'ús d'aquesta eina va dirigida a tres perfils d'usuari: Amb aquesta aplicació, l'administrador podrà efectuar tasques de manteniment de dades, donar d'alta usuaris, punts de venda o empreses externes i també podrà fer el seguiment d'incidències obertes i saber quantes se'n gestiona en cada moment. Els gestors donaran solució a les incidències utilitzant l'eina i sabran en tot moment quantes sol·licituds tenen pendents, quantes incidències hi ha registrades i en quin estat es troben. Els usuaris amb permís de sol·licitud bàsicament el que podran fer és avisar de la incidència que volen solucionar.Aplicación web que pretende dar solución a las necesidades de carácter organizativo de un despacho técnico de una empresa. El objetivo principal es crear una herramienta capaz de automatizar el seguimiento de las incidencias abiertas en el despacho. El uso de esta herramienta va dirigido a tres perfiles de usuario: con esta aplicación el administrador podrá efectuar tareas de mantenimiento de datos, dar de alta usuarios, puntos de vanta o empresas externas y también podrá hacer el seguimiento de incidencias abiertas y saber cuantas se están gestionando en cada momento. Los gestores darán solución a las incidencias utilizando la herramienta y sabrán en todo momento cuantas solicitudes tienen pendientes, cuantas incidencias hay registradas y en qué estado se encuentran. Los usuarios con permiso de solicitud podrán avisar de la incidencia que desean solucionar

ADC Quantization Requirements

In this document, we analyze the impact of the quantization at the input of the demultiplexer. The required number of bits of the Analog-to-Digital-Converter (ADC) is obtained, along with the corresponding quantization losses.Preprin

MicroRNAs and drinking: association between the Pre-miR-27a rs895819 polymorphism and alcohol consumption in a Mediterranean population

Recently, microRNAs (miRNA) have been proposed as regulators in the different processes involved in alcohol intake, and differences have been found in the miRNA expression profile in alcoholics. However, no study has focused on analyzing polymorphisms in genes encoding miRNAs and daily alcohol consumption at the population level. Our aim was to investigate the association between a functional polymorphism in the pre-miR-27a (rs895819 A>G) gene and alcohol consumption in an elderly population. We undertook a cross-sectional study of PREvención con DIeta MEDiterránea (PREDIMED)-Valencia participants (n = 1007, including men and women aged 67 ± 7 years) and measured their alcohol consumption (total and alcoholic beverages) through a validated questionnaire. We found a strong association between the pre-miR-27a polymorphism and total alcohol intake, this being higher in GG subjects (5.2 ± 0.4 in AA, 5.9 ± 0.5 in AG and 9.1 ± 1.8 g/day in GG; padjusted = 0.019). We also found a statistically-significant association of the pre-miR-27a polymorphism with the risk of having a high alcohol intake (>2 drinks/day in men and >1 in women): 5.9% in AA versus 17.5% in GG; padjusted < 0.001. In the sensitivity analysis, this association was homogeneous for sex, obesity and Mediterranean diet adherence. In conclusion, we report for the first time a significant association between a miRNA polymorphism (rs895819) and daily alcohol consumption

A rain and scintillation Ka-band channel simulator

This paper describes the implementation of a Ka-band satellite channel simulator with emphasis on the synthesis of scintillation processes. The problem becomes one of generating a given probability density function, the Moulsley-Vilar distribution, with a specified power spectral density using aWiener model based on orthogonal Hermite polynomials for the nonlinearity. A numerical procedure is devised to calculate the filter and non-linearity coefficients of the Wiener model. The generation of rain processes conforms to the Maseng-Bakken model.Postprint (published version

Non-targeted metabolomic biomarkers and metabotypes of type 2 diabetes: A cross-sectional study of PREDIMED trial participants

Aim. - To characterize the urinary metabolomic fingerprint and multi-metabolite signature associated with type 2 diabetes (T2D), and to classify the population into metabotypes related to T2D. Methods. - A metabolomics analysis using the 1 H-NMR-based, non-targeted metabolomic approach was conducted to determine the urinary metabolomic fingerprint of T2D compared with non-T2D participants in the PREDIMED trial. The discriminant metabolite fingerprint was subjected to logistic regression analysis and ROC analyses to establish and to assess the multi-metabolite signature of T2D prevalence, respectively. Metabotypes associated with T2D were identified using the k-means algorithm. Results. - A total of 33 metabolites were significantly different (P < 0.05) between T2D and non-T2D participants. The multi-metabolite signature of T2D comprised high levels of methylsuccinate, alanine, dimethylglycine and guanidoacetate, and reduced levels of glutamine, methylguanidine, 3-hydroxymandelate and hippurate, and had a 96.4% AUC, which was higher than the metabolites on their own and glucose. Amino-acid and carbohydrate metabolism were the main metabolic alterations in T2D, and various metabotypes were identified in the studied population. Among T2D participants, those with a metabotype of higher levels of phenylalanine, phenylacetylglutamine, p-cresol and acetoacetate had significantly higher levels of plasma glucose. Conclusion. - The multi-metabolite signature of T2D highlights the altered metabolic fingerprint associated mainly with amino-acid, carbohydrate and microbiota metabolism. Metabotypes identified in this patient population could be related to higher risk of long-term cardiovascular events and therefore require further studies. Metabolomics is a useful tool for elucidating the metabolic complexity and interindividual variation in T2D towards the development of stratified precision nutrition and medicin

Microbial metabolites are associated with a high adherence to a Mediterranean dietary pattern using a 1h-nmr-based untargeted metabolomics approach

The study of biomarkers of dietary patterns including the Mediterranean diet (MedDiet) is scarce and could improve the assessment of these patterns. Moreover, it could provide a better understanding of health benefits of dietary patterns in nutritional epidemiology. We aimed to determine a robust and accurate biomarker associated with a high adherence to a MedDiet pattern that included dietary assessment and its biological effect. In this cross-sectional study, we included 56 and 63 individuals with high (H-MDA) and low (L-MDA) MedDiet adherence categories, respectively, all from the Prevención con Dieta Mediterránea trial. A 1H-NMR-based untargeted metabolomics approach was applied to urine samples. Multivariate statistical analyses were conducted to determine the metabolite differences between groups. A stepwise logistic regression and receiver operating characteristic curves were used to build and evaluate the prediction model for H-MDA. Thirty-four metabolites were identified as discriminant between H-MDA and L-MDA. The fingerprint associated with H-MDA included higher excretion of proline betaine and phenylacetylglutamine, among others, and decreased amounts of metabolites related to glucose metabolism. Three microbial metabolites - phenylacetylglutamine, p-cresol and 4-hydroxyphenylacetate - were included in the prediction model of H-MDA (95% specificity, 95% sensitivity and 97% area under the curve). The model composed of microbial metabolites was the biomarker that defined high adherence to a Mediterranean dietary pattern. The overall metabolite profiling identified reflects the metabolic modulation produced by H-MDA. The proposed biomarker may be a better tool for assessing and aiding nutritional epidemiology in future associations between H-MDA and the prevention or amelioration of chronic diseases