Use of a psychological learning technique to improve brain-computer interface (BCI) control

A Brain-Computer Interface (BCI) is a system that connects the human brain to a computer, allowing their users to communicate or control external devices using brain signals. Performance of BCI depends on the ability of subjects to control their own electroencephalographic (EEG) patterns, being necessary to provide suitable neurofeedback training techniques. The main objective of this work is to use a psychological learning technique in order to help users to acquire specific skills on the control of a BCI. The feedback provided to the subject was based on virtual reality techniques. The well-known Skinner´s shaping method (based on successive approximations) was used to reinforce two mental tasks: imagination of right hand movements and an idle state, such as mental relaxation. Two groups (5 and 4 subjects each) participated in the same number of training sessions; a control group used a standard procedure and the other group tested the shaping proposal. Both mental tasks were considered separately, so each one received different shaping levels depending on the initial control and the evolution through the training sessions. The shaping effect was implemented by modifying the feedback that users received. The study proved the effectiveness of the proposed method by enhancing the difference between the EEG responses corresponding to these two mental tasks. The use of a specific psychological learning technique in order to shape mental activity improved the training process over the control of a BCI, by adapting to the real needs of each user.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Función pulmonar y capacidad ventilatoria en pacientes hemodializados según exposición a entrenamiento físico intradiálisis

Introduction: The chronic kidney disease (CKD) is an irreversal progressive process which takes to a terminal state, where patients need permanent dialysis or even a transplant. It has been shown that the lung function and ventilatory capacity are compromised in these patients, increasing the alteration with exposure to hemodialysis and sedentarism. Objective: To compare the lung function and ventilatory capacity of hemodialysis patients, according to exposure to intradialysis physical training. Material and Methods: Study of quantitive type, not experimental, descriptive and transverse. The study population included 12 ambulatory patients between 40 and 80 years old, undergoing hemodialysis with arteriovenous fistula in the dialysis unit of Valdivia’s Central Hospital, and who obtained more than 24 points in the Minimental Test. The statistical analysis was performed with the SPSS program (version 11.5 for Windows) and the level of statistical significance through the Wilcoxon and Mann-Whitney test (p<0.05). Results: The comparison of the initial and final pimometry in patients with and without physical training did not show a statistically significant difference (p>0.05), however it was observed that the subjects exposed to physical training have higher values in the initial and final maximum inspiratory pressure compared to those who have not been trained. Conclusion: Intradialysis physical training causes a positive effect on the respiratory system. The subjects submitted to hemodialysis tend to present under predicted values in both lung function and ventilatory capacity, being mostly affected with aging and time of exposure to hemodialysis.Introducción: la enfermedad renal crónica es un proceso progresivo e irreversible; con frecuencia lleva a un estado terminal, donde los pacientes necesitan de diálisis o trasplante. Se ha demostrado que la función pulmonar y la capacidad ventilatoria se ven comprometidas en estos pacientes, y se incrementan con la exposición a hemodiálisis y el sedentarismo. Objetivo: comparar la función pulmonar y la capacidad ventilatoria de pacientes hemodializados, según exposición a entrenamiento físico intradiálisis. Materiales y métodos: estudio de tipo cuantitativo, no experimental, descriptivo y transversal; la población de estudio com-prendió 12 pacientes hemodializados mediante fístula arteriovenosa, entre 40 y 80 años de edad, en la unidad de diálisis del Hospital Base de Valdivia y que obtuvieron más de 24 puntos en el test Minimental. El análisis estadístico se realizó con el programa SPSS (versión 11.5 para Windows) y el nivel de significancia estadística a través de la prueba de Wilcoxon y Mann-Whitney (p<0,05). Resultados: la comparación de la pimometría inicial y final en los pacientes con y sin entrenamiento kinésico no mostró una diferencia estadísticamente significativa (p>0,05); sin embargo, se observó que los sujetos sometidos a entrenamiento kinésico presentan mayores valores en la presión inspiratoria máxima inicial y final en comparación con aquellos que no han sido entrenados. Conclusión: el entrenamiento físico intradiálisis provoca un efecto positivo en el sistema respiratorio. Los sujetos sometidos a hemodiálisis tienden a presentar valores bajo el predicho tanto en función pulmonar como en capacidad ventilatoria, siendo mayor mente afectados con el envejecimiento y tiempo de exposición a hemodiálisis

Efectividad de un entrenamiento cardiorrespiratorio, muscular y ventilatorio en el rendimiento aeróbico de pacientes hemodializados

Introduction: End stage kidney disease causes fatigue and progressive muscle weakness, which affects not only the muscles of extremities, but also the respiratory. There are several studies of combined training in dialysis patients, but not including respiratory work. Therefore, the present study aims to determine the effectiveness of an aerobic, lower limb resistance and inspiratory muscle resistance combined training in the generation of changes in aerobic performance of patients undergoing hemodialysis. Material and methods: Randomized controlled trial which included 11 hemodialysis patients from Valdivia’s Central Hospital. The sample was divided in two groups, the first one included: an aerobic, lower limbs and inspiratory muscle training (ARM+V) (n=6) and the second one included an aerobic and lower limbs muscle training (ARM) (n=5). The training was performed during 8 weeks and three variables were measured in both groups pre and post intervention, inspiratory muscle strength (Carefore Airlift NIF-gauge ®), aerobic endurance (6MWT) and pulmonary function (Sibelmed Datospir Micro Spirometer 120D ®). Results: ARM+V group obtained significant improvements (p<0.05) in 6MWT performance (p=0.027) and MIP (p=0,001). Likewise performance improved in 6MWT (p=0.022) and MIP (p=0.002) at ARM group, but decreased in spirometry values: FEV1 (p=0.004), FVC (p=0.005) and FEV1/FVC (p=0,038). Conclusion: Both training protocols were effective in the aerobic endurance improvement, however the patients in the ARM+V group presented better changes than the ARM group. Neither of the two training programs improved pulmonary function.Introducción: la enfermedad renal crónica terminal provoca fatiga y debilidad muscular progresiva, que afecta no solo la muscula- tura de extremidades, sino también la respiratoria. Existen diversos estudios de entrenamiento combinado en pacientes dializados, pero sin incluir trabajo respiratorio. Por esto, el presente estudio pretende determinar la efectividad de un entrenamiento combinado aeróbico, de resistencia de miembro inferior y de resistencia muscular inspiratoria, en el rendimiento aeróbico de pacientes hemodializados. Materiales y métodos: ensayo clínico aleatorizado que incluyó 11 pacientes hemodializados del Hospital Base Valdivia. Fueron divididos en dos grupos, uno sometido a un programa de entrenamiento con ejercicio aeróbico, de resistencia muscular de miembros inferiores y de musculatura inspiratoria (ARM+V) (n=6), y el otro, a un programa de entrenamiento con ejercicio aeróbico y de resistencia muscular de miembros inferiores (ARM) (n=5). La intervención fue realizada durante 8 semanas evaluando el rendimiento pre y post intervención de capacidad aeróbica (TM6M), fuerza inspiratoria máxima (Carefore Airlift NIF-gauge®) y función pulmonar (Sibelmed Datospir Micro Spirometer 120D®) en ambos grupos. Resultados: el grupo ARM+V obtuvo mejoras significativas (p<0,05) en el rendimiento del TM6M (p=0,027) y PIM (p=0,001); así mismo el grupo ARM mejoró en el TM6M (p=0,022) y PIM (p=0,002) y en la espirometría se mostró una disminución significativa en VEF1 (p=0,004), CVF (p=0,005) y VEF1/CVF (p=0,038). Conclusión: ambos entrenamientos fueron efectivos en la mejora del rendimiento aeróbico, pero el grupo ARM+V obtuvo mejoras significativamente superiores en este ítem. Ninguno de los dos entrenamientos obtuvo mejoras en los valores espirométricos. Palabras clave: diálisis renal, terapia por ejercicio, músculos respiratorios

Oxidative stress: therapeutic approaches for cervical cancer treatment

OBJECTIVES: Oxidative stress results from an imbalance between the generation and elimination of oxidant species. This condition may result in DNA, RNA and protein damage, leading to the accumulation of genetic alterations that can favor malignant transformation. Persistent infection with high-risk human papillomavirus types is associated with inflammatory responses and reactive oxygen species production. In this context, oxidative stress, chronic inflammation and high-risk human papillomavirus can act in a synergistic manner. To counteract the harmful effects of oxidant species, protective molecules, known as antioxidant defenses, are produced by cells to maintain redox homeostasis. In recent years, the use of natural antioxidants as therapeutic strategies for cancer treatment has attracted the attention of the scientific community. This review discusses specific molecules and mechanisms that can act against or together with oxidative stress, presenting alternatives for cervical cancer prevention and treatment

Efeito dos extratos de cascas dos frutos de duas espécies de Campomanesia (Myrtaceae) em Allium cepa L. (Amaryllidaceae)

Species from the genus Campomanesia have been studied due to their biological activity and low toxicity. However, studies on the fruit peel of these species are scarce. In this context, the effects of ethanol extract from the fruit peel of Campomanesia sessiliflora (O. Berg) Mattos (CS) and Campomanesia guazumifolia (Cambess) O. Berg (CG) were evaluated concerning the effect on germination and meristem cells of roots of Allium cepa. The CG ethanolic extract showed flavonoid compounds higher than CS ethanolic extract. The CS extract showed no antioxidant activity. CS showed greater antiproliferative activity with reduced root size in A. cepa seeds. The two extracts did not induce mutagenicity and cell death at the studied concentration of 1 mg mL-1. Keywords: Germination, Allelopathy, Ethanolic extract.As espécies do gênero Campomanesia têm sido estudadas devido às suas atividades biológicas e baixa toxicidade. No entanto, existem poucos estudos com as casca dos frutos dessas espécies vegetais. Nesse contexto, foram avaliados os efeitos dos extratos etanólicos das cascas dos frutos de Campomanesia sessiliflora (O. Berg) Mattos (CS) e Campomanesia guazumifolia (Cambess) O. Berg (CG) em relação ao efeito na germinação e células do meristema das raízes de Allium cepa. O extrato etanólico de CG apresentou níveis de flavonóides maiores que o extrato etanólico de CS. O extrato de CS apresentou maior atividade antiproliferativa, com redução do tamanho da raiz nas sementes de A. cepa. Os dois extratos não induziram mutagenicidade e morte celular na concentração estudada de 1 mg mL-1

Assessment of the IMERG Early-Run Precipitation Estimates over South American Country of Chile

Accurate rainfall measurement is a challenge, especially in regions with diverse climates and complex topography. Thus, knowledge of precipitation patterns requires observational networks with a very high spatial and temporal resolution, which is very difficult to construct in remote areas with complex geological features such as desert areas and mountains, particularly in countries with high topographical variability such as Chile. This study evaluated the performance of the near-real-time Integrated Multi-satellite Retrievals for GPM (IMERG) Early product throughout Chile, a country located in South America between 16°S–66°S latitude. The accuracy of the IMERG Early was assessed at different special and temporal scales from 2015 to 2020. Relative Bias (PBIAS), Mean Absolute Error (MAE), and Root-Mean-Squared Error (RMSE) were used to quantify the errors in the satellite estimates, while the Probability of Detection (POD), False Alarm Ratio (FAR), and Critical Success Index (CSI) were used to evaluate product detection accuracy. In addition, the consistency between the satellite estimates and the ground observations was assessed using the Correlation Coefficient (CC). The spatial results show that the IMERG Early had the best performance over the central zone, while the best temporal performance was detected for the yearly precipitation dataset. In addition, as latitude increases, so do errors. Also, the satellite product tends to slightly overestimate the precipitation throughout the country. The results of this study could contribute towards the improvement of the IMERG algorithms and open research opportunities in areas with high latitudes, such as Chile

Control de Sitophilus zeamais con polvos vegetales de tres especies del género Chenopodium

Powders of Chenopodium ambrosioides L., Chenopodium album L. and Chenopodium quinoa Willd. were evaluated under laboratory conditions for Sitophilus zeamais Motschulsky control. Evaluated parameters were insect mortality and adult emergence, grain weight loss, grain germination and the following effects of powders: ovicide and larvicide, fumigant, repellent and residual. A completely randomized experimental design with factorial arrangement and three replicates was used. The highest levels of insect mortality were obtained with the powders of Chenopodium ambrosioides L. inflorescence and the mixture of leaves and stems at 2% (w/w), with values of 69.4% and 67.9% respectively. Best emergence reductions were obtained with the same treatments. In all treatments with powders of C. ambrosioides seeds weight were reduced in less than 3%. The residual effect lasted for 15 days, obtaining a mortality of 98.3% of adult insects, when powders of C. ambrosioides inflorescence were used at 2% (w/w) concentration. Powders of C. ambrosioides showed a mortality of 100% of eggs and larvae, and a fumigation effect against adult insects with a mortality of 100% in all treatments was evaluated. Powders of C. ambrosioides have a repellent effect for S. zeamais.Powders of Chenopodium ambrosioides L., Chenopodium album L. and Chenopodium quinoa Willd. were evaluated under laboratory conditions for Sitophilus zeamais Motschulsky control. Evaluated parameters were insect mortality and adult emergence, grain weight loss, grain germination and the following effects of powders: ovicide and larvicide, fumigant, repellent and residual. A completely randomized experimental design with factorial arrangement and three replicates was used. The highest levels of insect mortality were obtained with the powders of Chenopodium ambrosioides L. inflorescence and the mixture of leaves and stems at 2% (w/w), with values of 69.4% and 67.9% respectively. Best emergence reductions were obtained with the same treatments. In all treatments with powders of C. ambrosioides seeds weight were reduced in less than 3%. The residual effect lasted for 15 days, obtaining a mortality of 98.3% of adult insects, when powders of C. ambrosioides inflorescence were used at 2% (w/w) concentration. Powders of C. ambrosioides showed a mortality of 100% of eggs and larvae, and a fumigation effect against adult insects with a mortality of 100% in all treatments was evaluated. Powders of C. ambrosioides have a repellent effect for S. zeamais.Se evaluaron polvos vegetales de Chenopodium ambrosioides L., Chenopodium album L. y Chenopodium quinoa Willd. para el control de Sitophilus zeamais Motschulsky, bajo condiciones de laboratorio. Los parámetros evaluados fueron mortalidad y emergencia de insectos adultos, pérdida de peso y germinación de los granos, efecto ovicida y larvicida, fumigación, repelencia y residualidad de los polvos. El diseño experimental fue completamente al azar, con un arreglo factorial y tres repeticiones. La mayor mortalidad de insectos se obtuvo con los polvos de la inflorescencia y la mezcla de hojas y tallos de Chenopodium ambrosioides L., al 2% (p/p) con valores de 69,4% y 67,9% respectivamente. La menor emergencia de adultos se obtuvo con los mismos tratamientos. La pérdida de peso de granos, en todos los tratamientos de C. ambrosioides, no superó el 3%. Para el tratamiento inflorescencia de C. ambrosioides al 2% (p/p), la residualidad de los polvos se mantuvo hasta los 15 días, con una mortalidad de 98,3%. Esta misma especie presentó una mortalidad de huevos y larvas de 100%, además de presentar un efecto fumigante con una mortalidad de adultos de 100%, en todos los tratamientos evaluados. El polvo de C. ambrosioides es repelente para S. zeamais

Respuesta bajo condiciones controladas del pulgón verde del duraznero (Myzus persicae S.) proveniente de distintas siembras de remolacha (Beta vulgaris var sachariffera) a la accion de insecticidas organofosforados y carbamatos

Resumen (Spanish, English)122 p.Los primeros antecedentes de resistencia a insecticidas del pulgón verde del duraznero (Myzus persicae S.) datan del año 1965 (Hocland y colaboradores, 1992, Furk, 1976) en Inglaterra aunque otros autores señalan que fue en 1955 (Rusell, 1965, Baker, 1978; Mª Clanahan y Founk, 19839 y solamente comprobado diez años después. En Chile existen muy pocos antecedentes debidamente comprobados sobre el tema, por lo que se decidió realizar una metodología de hoja inmersa (IRAC Nº1) para medir la susceptibilidad de este áfido, asociado a remolacha en San Fernando, Talca y Chillán, a los productos usados comúnmente en su control. Los bioensayos realizados mostraron elevados niveles de tolerancia a Dimetoato (Dimetoato 40EC) y fosfamidón (Dimecron 100SCW), resistencia mediana a Oxydemeton-metil (Metasystox 250EC) y casi competa susceptibilidad a Triazamate (Aztec 140 EW). Se observaron además efectos marcados de regionalidad por lo que se puede inferir la existencia de una heterogeneidad genética de las distintas poblaciones muestreadas

El trabajo infantil: La relación de los factores sociodemográficos, adaptación académica y la actividad laboral con la repitencia en niños y adolescentes de 10-17 años en los departamentos de Lima y Huánuco

Este artículo aborda la problemática del trabajo infantil y los factores que están relacionados con la repitencia de los adolescentes que trabajan dentro de la realidad peruana, por tal razón, la investigación tiene como objetivo relacionar la repitencia con los factores sociodemográficos y la actividad laboral en adolescentes de 10-17 años en los departamentos de Lima y Huánuco. La muestra está compuesta por 423 niños y adolescentes (en adelante nos referiremos como solo adolescentes) dentro de las edades de 10 y 17 años, de los departamentos de Lima y Huánuco, obtenidos de la base de datos de la encuesta nacional especializada del trabajo infantil (ETI) de la INEI 2015. Lo que concierne a los resultados, en primer lugar, se buscó una asociación entre las variables, se halló asociación de la repitencia con el departamento, el área, percepción del desempeño, por otro lado, no se halló una asociación de la repitencia con el sexo, la edad y la relación con sus compañeros, trabajo peligroso. En segundo lugar, se propone un modelo con el predictor no lineal (Logit) a través de la regresión logística