Influence of Transfer Entropy in the Short-Term Prediction of Financial Time Series Using an ∊-Machine.

Predicting the values of a financial time series is mainly a function of its price history, which depends on several factors, internal and external. With this history, it is possible to build an ∊-machine for predicting the financial time series. This work proposes considering the influence of a financial series through the transfer of entropy when the values of the other financial series are known. A method is proposed that considers the transfer of entropy for breaking the ties that occur when calculating the prediction with the ∊-machine. This analysis is carried out using data from six financial series: two American, the S&P 500 and the Nasdaq; two Asian, the Hang Seng and the Nikkei 225; and two European, the CAC 40 and the DAX. This work shows that it is possible to influence the prediction of the closing value of a series if the value of the influencing series is known. This work showed that the series that transfer the most information through entropy transfer are the American S&P 500 and Nasdaq, followed by the European DAX and CAC 40, and finally the Asian Nikkei 225 and Hang Seng.

Optimizing an LED array for an infrared illumination source using the near field for venous pattern detection.

Accuracy in vein detection is important for intravenous applications such as venipuncture and other medical procedures. The near-infrared (NIR) imaging technique is used to visualize veins based on the difference of absorption of the infrared light by the oxyhemoglobin present in the blood and surrounding tissue. A problem commonly found during the visualization of veins is attributed to the source of light, saturation, low contrast, and dispersion, which are causes of inhomogeneous illumination. In this work, the design and implementation of a light source with LEDs in the range of 750-860 nm are presented. To obtain the design, a numerical simulation was made using the near-field diffraction theory to obtain homogeneous illumination at 40 cm of the sample, with a radial arrangement of three concentric LED rings. With the developed light source, an experimental scheme for the acquisition of vein patterns was implemented. Using a basic algorithm for the identification of intravenous patterns, a prototype was obtained that we believe can be used in intravenous applications and other medical procedures.

Algoritmo para estimación de ángulo de rodilla en marcha normal: enfoque a trazado de trayectoria en prótesis transfemorales inteligentes / Algorithm to estimate the knee angle in normal gait: trajectory generation approach to intelligent transfemoral prosthesis

Resumen En este trabajo se presenta un algoritmo para estimar el ángulo de rodilla a partir del ángulo de cadera y parámetros de marcha, el cual sólo utiliza un sensor en el muslo para la estimación. Para el desarrollo del algoritmo fue indispensable realizar un análisis de marcha para establecer parámetros de diseño. Se utilizó la correlación natural entre cadera y rodilla para separar los movimientos de flexión-extensión de marcha en dos etapas:1) movimientos donde el pie no está en contacto total con el piso; 2) movimientos de contacto total del pie con el piso. La estimación es para movimientos de marcha, se realiza en tiempo real y la variación de velocidad en la marcha no afecta la estimación del ángulo. Se utilizaron regresores lineales para aproximar el ángulo estimado de rodilla al ángulo real. En todos los casos de estudio de marcha, los resultados mostraron una aproximación aceptable del ángulo de la rodilla; el error promedio de estimación fue de 8.25◦. El principal logro de este trabajo fue desarrollar un algoritmo para dar una posible solución al problema de coordinación entre el cuerpo humano y prótesis transfemorales inteligentes, aun ante cambios de velocidad en la marcha.

Abstract This paper presents an algorithm to estimate the knee angle from hip angle and gait parameters. This algorithm uses a single sensor on the thigh to achieve the estimation. Hip-knee natural correlations were employed in order to analyze the gait flexion-extension movements in two stages: 1) when the foot is not in full contact with the floor (swing phase and heel contact); 2) when the whole sole makes contact with the ground (stance phase). The estimation is developed in real-time for gait movements and speed fluctuations do not distort the angle estimated. In addition, the simple linear regression were used to approximate the estimated angle to actual knee angle. The experimental results obtained from the gait studies, showed an acceptable knee angle approximation; the mean error estimation was 8.25◦. The major goal of this work was the development of an algorithm that can solve the problem of human body-intelligent transfemoral prosthesis coordination, even if there are gait speed fluctuations.

A portable system with sample rate of 250 Hz for characterization of knee and hip angles in the sagittal plane during gait.

BACKGROUND: Gait analysis and research have been developed to obtain characteristics of movement patterns of people while walking. However, traditional measuring systems present different drawbacks that reduce their use and application. Among those drawbacks one can find: high price, low sampling frequency and limiting number of steps to be analyzed. Traditional measuring gait systems carry out their measurement at frequencies oscillating between 60 to 100 Hz. It can be argued about the need of higher sampling rates for gait measurements. However small displacements of the knee or hip for example, cannot be seen with low frequencies required a more detailed sampling and higher frequency sampling. Bearing this in mind, in this paper is presented a 250 Hz system based on accelerometers for gait measurement, and the particularities of knee and hip angles during gait are highlighted. METHODS: The system was designed with a PCI data acquisition card instrumented with an FPGA to achieve a rate sample of 250 Hz. The accelerometers were placed in thighs and legs to calculate the joint angles of hip and knee in the sagittal plane. The angles were estimated using the acceleration polygon method without integrating the acceleration and without filters. RESULTS: The gait of thirty healthy people of Mexican phenotype was analyzed over a flat floor free of obstacles. The results showed the gait phases and particularities associated with the walking style and people's laterality; the movement patterns were similar in the thirty persons. Based on the results, the particularities as the maximum amplitude in the angles and the shape in the movement patterns were related to the anthropometry and people phenotype. CONCLUSIONS: The sampling frequency was essential to record 340 samples in single gait cycle and so registering the gait cycle with its particularities. In this work were recorded an average of 8 to 10 gait cycles, and the results showed variation regarding works carried out in biomechanics laboratories; this variation was related to the method and reference frame used to obtain the joint angles and the accuracy of measurement system.

Consumo de alimentos, factores socioeconómicos y anemia en mujeres gestantes / Food intake, socioeconomic factors and anemia in pregnant women

Se analizó la prevalencia de anemia en mujeres embarazadas y su asociación con el consumo de alimentos, estado nutricional y variables socioeconómicas. La muestra fue de 299 mujeres que asistieron a la consulta prenatal en los ambulatorios del Municipio Libertador Estado Mérida año 2009, en edades de 13 y 45 años. Los datos recolectados fueron, hemoglobina y hematocrito de los tres trimestres de embarazo, paridad, nivel de instrucción, ocupación, ingresos económicos y gastos en alimentación. Se aplicó encuesta de frecuencia de consumo de alimentos, se determinó el Riesgo de Inseguridad Alimentaria (RIA) y el IMC para conocer el estado nutricional. El 25,75 % de las mujeres son anémicas con valores de Hb< de 10.9 mg/dL, con predominio en edades de 13 a 30 años (21,07%), con una significancia estadística entre la paridad y la presencia de anemia, un alto riesgo de inseguridad alimentaria (RIA) y un predominio de sobrepeso en todo el grupo estudiado (IMC: anémicas 27,44 ± 4,57 y no anémicas 28,25 ± 6,25). Las anémicas consumieron leche, queso y pollo, frutas como la lechosa y la naranja, arepa de maíz, café, té y bebidas gaseosas. No estuvo presente el consumo de hortalizas como el brócoli, coliflor y acelgas. Las no anémicas consumieron yogurt, pescado, hígado de res, pan de trigo, no hubo consumo de café, té y bebidas gaseosas. Se encontró, significancia estadística entre el consumo de coliflor y acelgas, en las no anémicas y la naranja, lechosa y el té en las anémicas (p < 0,05)(AU)

The prevalence of anemia in pregnant women and his association with foods intake, nutritional state and socio-economic variables has been analyzed. The sample was about 299 women that assist to a prenatal consultation in the health center Libertador Municipality, State of Merida 2009, in ages between 13 and 45 years. The obtained data was: haemoglobin and haematocrit of the three pregnancy quarters, parity, instruction level, occupation, incomes and foods expenditure. It was applyed a survey of "foods intake frequency" and it was determined Alimentary Insecurity Risk (RIA) and the IMC to the knowledge their nutritional state. 25, 75% of the women are anemics with values of HB< of 10.9 mg/dL, predominant in the ages of 13 and 30 years (21,07%), with an statistic significance between the parity and the anemia presence, a high Risk of Alimentari Insecurity (RIA) and a predominance of overweight in all the studied group (IMC: With anemia 27,44 ± 4,57 and with no presence of anemia 28,25 ± 6,25). The anaemic women consumed milk, cheese and chicken, fruits like papaya and orange, corn arepas, coffee, tea and sodas; It wasn´t present consume of vegetables like broccoli, cauliflower and chard. The no-anemic women consumed yogurt, fish, liver, wheat bread; it wasn´t consume of coffee, tea and sodas. It was found an statistic significance between the consume of cauliflower and chard in the no-anemic women and orange, milk and tea in the anemic ones (p < 0,05)(AU)

A Morlet wavelet signal analysis with a Daubechies filter for the wear assessment of hip prostheses coated with diamond-like carbon by triboadhesion.

In the present work, based on high frequency wavelet analysis of dynamic signals of mechanical systems, a multiple-resolution wavelet analysis is carried out, to the signal obtained from an accelerometer mounted on the structure of a hip prosthesis wearing test device. The prostheses employed had a femoral head made of aluminum oxide and the acetabular cup of ultra-high-molecular-weight polyethylene. The first two aluminum oxide femoral heads were coated with diamond-like carbon and a third one was tested without coating and used as a reference. The coating was carried out by triboadhesion. Tests results showed that maximum vibration amplitude reached after 32 hr for the coated prostheses was 0.2 g. The noncoated prosthesis amplitude presented was 0.75 g in the same time interval. These values were attributed to wear damage on the surface of the prostheses, indicating that thin film DLC coating caused an increase of stiffness on the surface and therefore an increase in wear resistance approximately of 314%.

Translating findings from basic fear research to clinical psychiatry in Puerto Rico.

Recent advances in the neuroscience of classical fear conditioning from both rodent and human studies are beginning to be translated to the psychiatry clinic. In particular, our understanding of fear extinction as a form of "safety learning" holds promise for the treatment of anxiety disorders in which extinction learning is thought to be compromised. The Department of Psychiatry at the UPR, School of Medicine promotes the development of innovative strategies for treating mental health problems. Given the burden resulting from anxiety disorders in Puerto Rico, and the lack of evidence-based treatment practices, there is a pressing need for a future center specializing in the treatment of anxiety related disorders. This center would also serve research and training functions, with the ultimate goal of translating extinction research into clinical practice. This review presents the current developments in extinction research and its relationship to anxiety disorders and treatment. We also analyze the available literature on the epidemiology of anxiety disorders and the existing evidence-based treatments for these conditions.