Exploiting trends in the foreign exchange markets

We offer further evidence on the relevance of technical trading in exchangerate markets using daily data for 95 currencies against the US dollar. To that end, we investigate the profitability of a simple technical trading rule based on Taylor’s (1980) price trend model, generating optimal one-stepahead forecasts of returns using genetic algorithms. These trading rules, that bear similarity to the popular trading rules based on moving averages, overcome the buy-and-hold strategy in 25 of 39 cases where trends are detected, even in the presence of transaction costs

Genetic Algorithm for Arbitrage with More than Three Currencies

We develop a genetic algorithm that is able to find the optimal sequence of exchange rates that maximizes arbitrage profits with more than three currencies, being both the triangular arbitrage and the direct exchange rate two special cases of the proposed algorithm. Applying the algorithm to the most traded currencies, we find average profits ranking from 4.5083% to 0.3162% for changing 1 USD for EUR with respect to the direct exchange rate, for different transaction costs, during the period October 2000-April 2012. Our results also suggest that the arbitrage profits increased just after the subprime crisis in summer of 2007 and that they are higher when the market is less liquid

Detecting trends in the foreign exchange markets

We test for the existence of trends in exchange-rate series for 95 currencies against the US dollar. To that end, we make use of Taylor’s (1980) price trend model that, instead of focusing on the mean reverting behaviour of exchange rates measured over a long horizon, concentrates on the shortterm pattern of the price trend. Employing a maximum likelihood method and a genetic algorithm to estimate the model parameters, in 39 of the 95 cases considered we find evidence in favour of the presence of trends, the trends being more frequent in intermediate exchange-rate regimes

Shadow-band radiometer measurement of diffuse solar irradiance: Calculation of geometrical and total correction factors

Among the various methods of measuring diffuse solar irradiance, shadowing devices are ones of the most commonly used in solar research all over the world. These instruments work with a basic pyranometer, properly calibrated for the measurement of solar irradiance, with a shadowing element, which can be a disk or a band (Drummond’s shadow-band), that prevents the direct incidence of solar beam irradiance on the sensor. This method is capable of precise measurements, but sensor outputs have to be corrected, so as to quantify the amount of diffuse irradiance that the band blocks from reaching the sensor. Several authors have advanced different expressions for this correction factor, most of which only apply to horizontal and equator-oriented tilting pyranometers. In this work, we present a general approach to calculate the geometrical correction factor for a tilted sensor, oriented towards all possible azimuth and zenith angles, which permits the measurement of solar diffuse irradiance on any tilted and oriented surfaces. Furthermore, five total correction models are adapted for measurement in any given direction and evaluated on vertical walls pointing the four cardinal directions. Our results show that geometrical correction improves the Mean Bias Difference (MBD), the Root Mean Squared Difference (RMSD) and the l0:99 statistics by 60%, 62% and 56%, respectively, in contrast with the raw data. The LeBaron et al. model gives the most accurate figure for total correction according to MBD, RMSD and l0:99 statistics, with promising average performances of 97%, 91%, and 96%, respectivelySpanish Government (grant ENE2011-27511

Efecto de una guía de intervención clínica basada en la Terapia de Aceptación y Compromiso, sobre la flexibilidad psicológica en excombatientes colombianos

Trabajo de investigaciónEl objetivo de esta investigación fue determinar el efecto de la guía de intervención clínica basada en la Terapia de Aceptación y Compromiso ACT) en el aumento de los procesos de aceptación experiencial, defusión cognitiva, atención plena y acción comprometida asociados a la flexibilidad psicológica en tres participantes excombatientes del conflicto armado en Colombia.RESUMEN JUSTIFICACIÓN Y PLANTEAMIENTO DEL PROBLEMA 1. ANTECEDENTES TEÓRICOS Y EMPÍRICOS 2. OBJETIVOS 3. MÉTODO 4. RESULTADOS 5. DISCUSIÓN REFERENCIAS APÉNDICESMaestríaMagister en Psicologí

Left Ventricular Dysfunction and Plasmatic NT-proBNP Are Associated with Adverse Evolution in Respiratory Syncytial Virus Bronchiolitis

Aim: To investigate whether the presence of left ventricular myocardial dysfunction (LVMD) assessed by Tei index (LVTX) impacts the outcomes of healthy infants with Respiratory Syncytial Virus Bronchiolitis (RSVB). To explore whether N-terminal pro-B-type natriuretic peptide (NT-proBNP) increases the accuracy of traditional clinical markers in predicting the outcomes. Methods: A single-centre, prospective, cohort study including healthy infants aged 1–12 months old admitted for RSVB between 1 October 2016 and 1 April 2017. All patients underwent clinical, laboratory and echocardiographic evaluation within 24 h of admission. Paediatric intensive care unit (PICU) admission was defined as severe disease. Results: We enrolled 50 cases of RSVB (median age of 2 (1–6.5) months; 40% female) and 50 age-matched controls. We observed higher values of LVTX in infants with RSVB than in controls (0.42 vs. 0.36; p = 0.008). Up to nine (18%) children presented with LVMD (LVTX > 0.5), with a higher incidence of PICU admission (89% vs. 5%; p < 0.001). The diagnostic performance of NT-proBNP in predicting LVMD was high (area under the receiver operator characteristic curve (AUC) 0.95, CI 95% 0.90–1). The diagnostic yield of the predictive model for PICU admission that included NT-proBNP was excellent (AUC 0.945, CI 95% 0.880–1), and significantly higher than the model without NT-proBNP (p = 0.026). Conclusions: LVMD could be present in healthy infants with RSVB who develop severe disease. NT-proBNP seems to improve traditional clinical markers for outcomes

A broadened scope for the use of hydrazones as neutral nucleophiles in the presence of H-bonding organocatalysts

Using thioureas as H-bonding organocatalysts, nitroalkenes can be activated for the conjugate addition of hydrazones as neutral nucleophiles. Formaldehyde derivatives react at the azomethine carbon as expected, whereas hydrazones from enolizable aldehydes behave as ene-hydrazines and react at the α-carbon instead. Ionic liquids were found to decrease the reaction times considerably compared to commonly used solvents, whereas alternative activation by Lewis acids resulted in decomposition of reactants