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El autor comenta sentencia de la Corte de Apelaciones de Concepción, que rechazó un recurso de amparo interpuesto en favor de adolescentes que se encontraban privados de libertad y que denunciaban un trato degradante por parte de funcionarios de Gendarmería al efectuarles allanamientos y registros corporales. En el comentario se hace una breve referencia a la protección reforzada que se debe brindar a los y las adolescentes privados de libertad conforme a la normativa internacional de los derechos humanos y en particular, al derecho a ser oídos en los procedimientos judiciales seguidos en su contra. Finaliza el comentario, haciendo especial hincapié en la obligación de los órganos del Estado de prevenir, investigar y sancionar la violencia institucional.

In this study, a modified linear technique is proposed for the controllability and observability of robotic arms, the modified linear technique consists of the following steps: a transformation is used to rewrite a nonlinear time-variant model as a quasi-linear time-variant model, this quasi-linear time-variant model is evaluated at origin to obtain a linear time-invariant model, and the rank condition tests the controllability and observability of the linear time-invariant model. The modified linear technique is better than the linearization technique because the modified linear technique does not use the Jacobian approximation, while the linearization technique needs the Jacobian approximation. The modified linear technique is better than the linear technique because the modified linear technique can be applied to robotic arms with rotational and prismatic joints, while the linear technique can only be applied to robotic arms with rotational joints.

Physical activity plays an important role in the well-being and development of adolescents. Physical activity habits expressed in terms of frequency and duration are consistently associated with sociodemographic factors such as age, gender, and socioeconomic status. However, there is less evidence of the relationship between the type and context of physical activity in adolescents. The aim of this article is to analyze physical activity habits and their relationship with sociodemographic factors in Chilean adolescents. The cross-sectional study consisted of 7,263 adolescents aged between 10 and 20 years old, students from both public and private schools in all regions of Chile. Physical activity habits were examined by means of a self-report questionnaire. The age groups were classified according to the three stages of adolescence (early: 10 to 13, middle: 14 to 16, and late: 17 to 20 years old). Socioeconomic level was established based on the school vulnerability index (SVI) of the school attended by each adolescent. In the study it was obvious to the level of physical activity for the adolescents was below the international recommendations. A statistically significant association can also be found between the sociodemographic factors studied and the physical activity habits reported by the young people. The multivariate regression analysis established that the risk of not achieving the physical activity recommendations was 2.8 times higher in females than in males, 2.4 times higher in the older age groups (14–16 and 17–20 years old) compared to the 10–13-year age range and 1.1 times in the medium and high vulnerability groups than in the low socioeconomic vulnerability group. These findings highlight the importance of considering all these factors holistically whenever designing programs or public policies that promote the development of healthy physical activity habits in adolescents.

Los humedales son ecosistemas frágiles e importantes que, a pesar de su gran biodiversidad, se conoce poco sobre la diversidad de mamíferos. Por ello, en este estudio se documenta la diversidad y abundancia de los mamíferos pequeños de cuatro humedales de la costa central peruana: Albufera de Medio Mundo, Refugio de vida silvestre Pantanos de Villa, Ensenada San Antonio y Caucato. Se realizó una evaluación convencional con trampas y redes, complementada con el método acústico. El esfuerzo de muestreo fue de 4651 trampas/noche, 145 redes/noche y 48 horas/detector. Registramos 5 especies nativas de roedores, 3 roedores introducidos, 12 murciélagos y un marsupial. El roedor Akodon mollis y los murciélagos Nyctinomops laticaudatus y N. macrotis son primeros registros para el departamento de Lima. El cuy silvestre se distribuye en el centro y sur de la costa y confirmamos la presencia del marsupial Didelphis pernigra a nivel del mar. La mayoría de los humedales están fuertemente impactados por la alta abundancia relativa de roedores introducidos, especialmente de Mus musculus y Rattus rattus. La diversidad β fue moderada a pesar de la relativa cercanía entre los humedales. Resaltamos la alta diversidad de mamíferos pequeños nativos en los humedales y alertamos sobre el impacto que los roedores introducidos pueden producir sobre la sobrevivencia de las demás especies. Además, hipotetizamos que la fauna nativa aquí reportada estuvo presente en la región de Lima al menos todo el periodo republicano. Estos humedales requieren protección continua, monitoreo e implementación de medidas de restauración para asegurar la conservación de su biota.

The perturbations are the unwanted and unknown inlets in nonlinear plants which can affect the outlets. In this article, an estimator is studied for the variables and perturbations estimation in nonlinear plants. The saturation map is used in our estimator instead of the signum map to decrease the chattering, and we ensure the estimator convergence by the Lyapunov analysis. The conditions required by our estimator gains are found to reach the variables error convergence, and these gains are used for the perturbations estimation. An algorithm is proposed to choose the gains for achieving a satisfactory performance in our estimator. The studied estimator is applied for the variables and perturbations estimation in the gas turbine and gasification plants.

In previous investigations, the nonlinear hypothesis use the linear bounded maps. Nonlinear hypothesis are described as the combination of the first order terms, and after of the mentioned combination, one bounded map is applied to alter the result. This document proposes two nonlinear hypothesis which use different structures instead of using the linear bounded maps. They are termed as novel nonlinear hypothesis and second order nonlinear hypothesis and their goal is to improve the second order processes modeling. The proposed nonlinear hypothesis are described as the combination of the first order and second order terms. Since the delta parallel robot is a second order process, it is an excellent platform to prove the effectiveness of the two proposed hypothesis.

The current agriculture is facing various challenges to produce enough food to satisfy the need of the human population consumption without having a negative impact on the environment, human health and ecosystems. The exploitation of bioinoculants has been a crucial alternative for green agriculture. Bioinoculants have two great benefits: to promote plant growth by making essential nutrients available to crops and, to increase the tolerance to biotic and abiotic stresses by inducing a long-lasting defense. Certain members of genus Trichoderma have been recognized as biocontrol agents, biofertilizers and stress alleviators for the plants. The use of Trichoderma spp. has also been extended to protect and stimulate growth of horticultural crops. Elucidating the plant signaling events triggered by Trichoderma is of high importance in order to understand the molecular basis involving plant protection against stresses. In this review, the signaling elements of the plants from Trichoderma perception through late defensive responses is discussed. Enhanced understanding how Trichoderma spp. activate defense will lead to improvement in the use of species of this genus to increase crop production with the consequent benefits for human health and care for the environment.

The objective of the study was to construct an instrument that allows measuring the perception of the communicative skills of young people with intellectual disabilities in a valid and reliable way. A descriptive study (Survey) of cross section was carried out. Sixty microentrepreneurs from the province of Talca (Chile) were studied. The work activities are for bakery, furniture and sales in grocery stores. A questionnaire was constructed to measure the perception of the communicative skills of young people with mild intellectual disability. It was validated by construct and reliability was verified by Cronbach. The validity results show values of Kaiser-Meyer-Olkin 0.78, X2 = 1031.500. Three indicators or categories were confirmed, whose saturations range from 0.52 to 0.83. The Percentage of the variance explains 65.90%. The alpha of Conbach showed a high capacity of reproducibility (r = 0.92). In conclusion, the elaborated instrument that measures communication skills is valid and reliable. The results suggest its use and application in microentrepreneurs to assess the perception of the communicative skills of young people with mild intellectual disability.

En este trabajo, se desarrolla un sistema de control automatizado para permitir que un manipulador aprenda y planifique las trayectorias a partir de las demostraciones dadas por la mano de un usuario. La entrada de datos es adquirida por un sensor, y se aprende su comportamiento a través de un algoritmo de aprendizaje automático basado en los mínimos cuadrados recursivos. Se utiliza un perfil de trayectoria de interpoladores a tramos para evitar el movimiento impulsivo del manipulador. Se realiza el análisis de las cinemáticas directa e inversa para obtener los valores de las variables articulares para el manipulador. Se crea un modelo dinámico usando la formulación de Newton-Euler. Se aplica un control proporcional derivativo al sistema. Los sistemas de monitoreo y control se implementan en una plataforma embebida para fines de prueba.

In this research, a proportional integral derivative regulator, a first-order sliding-mode regulator, and a second-order sliding-mode regulator are compared, for the regulation of two different types of mathematical model. A first-order sliding-mode regulator is a method where a sign-mapping checks that the error decays to zero after a convergence time; it has the problem of chattering in the output. A second-order sliding-mode regulator is a smooth method to counteract the chattering effect where the integral of the sign-mapping is used. A second-order sliding-mode regulator is presented as a new class of algorithm where the trajectory is asymptotic and stable; it is shown to greatly improve the convergence time in comparison with other regulators considered. Simulation and experimental results are described in which an electric oven is considered as a stable linear mathematical model, and an inverted pendulum is considered as an asymmetrical unstable non-linear mathematical model.

The objective of this paper is to estimate the unmeasurable variables of a multistable chaotic system using a Luenberger-like observer. First, the observability of the chaotic system is analyzed. Next, a Lipschitz constant is determined on the attractor of this system. Then, the methodology proposed by Raghavan and the result proposed by Thau are used to try to find an observer. Both attempts are unsuccessful. In spite of this, a Luenberger-like observer can still be used based on a proposed gain. The performance of this observer is tested by numerical simulation showing the convergence to zero of the estimation error. Finally, the chaotic system and its observer are implemented using 32-bit microcontrollers. The experimental results confirm good agreement between the responses of the implemented and simulated observers.

In this research, a sliding mode regulator with sine mapping is suggested for the stabilization of electricity generators being affected by magnet interaction nonlinearities and generator nonlinearities. To reach this goal, our suggested regulator has the following contributions: (a) it starts from the sliding mode regulator with the modifications that the saturation mapping is used to reach a smoother performance instead of the signum mapping, and the sine mapping is applied to reach an upper bound in the proportional gain error, (b) it is used to reach some chosen constant behaviors for the angle position, angle speed, and current in the electricity generators, and (c) its stabilization is ensured based on the Lyapunov approach. We show the simulation of the suggested regulator in two electricity generators.

System reliability is a measure of an electric grid system’s ability to deliver uninterrupted service at the proper voltage and frequency. This property of the electric system is commonly affected by critical processes, such as a total blackout. The electric system restoration is a complex process which consists of returning generators, transmission system elements, and restoring load following an outage of the electric system. However, the absence of a generator or unit of black start capabilities may worsen the duration and effects of blackouts, having severe consequences. Black start capability is important as it can reduce the interruption time, decrease the economic loss, and restart the power supply fast and efficiently. In recent years, several works have reported advances about the High Voltage Direct Current (HVDC) technology based on the Voltage-Source Converter (VSC) as an attractive and promising technology to increase black start capability. This paper is a review of the current studies of VSC-HVDC as black start power and discusses the advantages and limitations of recent methods. The major points addressed in this paper are as follows: the current theoretical approach of the black start process and the used HVDC technologies, the advantages of VSC-HVDC as black start power, a compressive review of the literature about the black start capabilities using VSC-HVDC technologies, and a description of the main methods recently used to provide an enhancement for restoration processes. Finally, this paper discusses new challenges and perspectives for VSC-HVDC links in order to provide an enhancement for restoration processes.

The perturbations are the disturbances of motion presented in the plant inputs which affect the motion of the output and states. In this paper, a sliding mode regulator is recommended for the perturbations attenuation in the plant output and states. The novelty of the advised regulator is that it does not employ an observer for the perturbations estimation; consequently, it is more compact. The asymptotic stability of the regulator is ensured via the Lyapunov approach. The mentioned regulator is employed in two tank plants prototypes.

Objectives: The goal of this study was to develop regression equations to estimate LM with anthropometric variables and to propose percentiles for evaluating by age and sex.Methods: A cross sectional study was conducted with 2,182 Chilean students (1,347 males and 835 females). Ages ranged from 5.0 to 17.9 years old. A total body scan was carried out with the double energy X-ray anthropometry (DXA) to examine and measure lean muscle mass of the entire body. Weight, height, and the circumference of the relaxed right arm were also measured.Results: Four anthropometric equations were generated to predict lean mass for both sexes (R2 = 83–88%, SEE = 3.7–5.0%, precision = 0.90–0.93, and accuracy = 0.99). The Lambda-mu-sigma method was used to obtain the sex-specific and age-specific percentile curves of lean mass (p3, p5, p10, p15, p25, p50, p75, p85, p90, p95, and p97).Conclusion: The four proposed equations were acceptable in terms of precision and accuracy to estimate lean mass in children and adolescents. The percentiles were created by means of anthropometric equations and real values for DXA. These are fundamental tools for monitoring LM in Chilean children and adolescents of both sexes.

Objectives: Physical growth and body adiposity patterns provide relevant information to infer the nutritional and health status of students. Our objectives were (a) to compare the variables of body adiposity and physical growth of Chilean children and adolescents with data from the CDC-2012 and international studies, and (b) to develop regional reference curves to evaluate growth and body adiposity.Methods: 8,261 children and adolescents were studied. We evaluated the weight, height, and waist circumference (WC). The Body Mass Index (BMI) was calculated. Their physical growth and body adiposity were compared with the CDC-2012 references as well as with other international references. Percentile curves for weight, height, BMI, and WC were constructed with the LMS method.Results: The Chilean students showed reduced weight and height during adolescence when compared with the CDC-2012 reference. During early ages, the BMI for the Chilean sample was lower while at advanced ages, the WC values were greater in comparison to the CDC-2012 reference. Graphic comparisons with international studies indicated that Chilean students weighed more at all ages. However, height was slightly greater until age 14 for males and age 11 for females. Body adiposity (BMI and WC) for the Chilean students was slightly higher at early ages while at later ages, adiposity values were relatively similar for both sexes.Conclusions: Discrepancies were observed between the physical growth and body adiposity trajectories and the American CDC-2012 references and the international studies. The proposed percentiles for weight, height, BMI, and WC for each age and sex may be useful for health sciences professionals and researchers.

Many investigations use a linearization method, and others use a structural properties method to determine the controllability and observability of robots. In this study, we propose a transformed structural properties method to determine the controllability and observability of robots, which is the combination of the linearization and the structural properties methods. The proposed method uses a transformation in the robot model to obtain a linear robot model with the gravity terms and uses the linearization of the gravity terms to obtain the linear robot model; this linear robot model is used to determine controllability and observability. The described combination evades the structural conditions requirement and decreases the approximation error. The proposed method is better than previous methods because the proposed method can obtain more precise controllability and observability results. The modified structural properties method is compared with the linearization method to determine the controllability and observability of three robots.

The modified backpropagation algorithm based on the backpropagation with momentum is used for the parameters updating of a radial basis mapping (RBM) network, where it requires of the best hyper-parameters for more precise modeling. Seeking of the best hyper-parameters in a model it is not an easy task. In this article, a genetic algorithm is used to seek of the best hyper-parameters in the modified backpropagation for the parameters updating of a RBM network, and this RBM network is used for more precise electricity consumption modeling in a city. The suggested approach is called genetic algorithm with a RBM network. Additionally, since the genetic algorithm with a RBM network starts from the modified backpropagation, we compare both approaches for the electricity consumption modeling in a city.

Background The norms for evaluating the maximum expiratory flow (MEF) usually are developed according to chronological age and height. However, to date, little research has been conducted using reference values that take into account the temporal changes of biological maturation. The objectives of this study were to (a) compare the MEF with those of other international studies, (b) align the MEF values with chronological and biological age, and (c) propose reference standards for children and adolescents. Methods The sample studied consisted of 3,566 students of both sexes (1,933 males and 1,633 females) ranging in age from 5.0 to 17.9 years old. Weight, standing height, and sitting height were measured. Body mass index was calculated. Biological maturation was predicted by using age of peak height velocity growth (APHV). MEF (L/min) was obtained by using a forced expiratory manoeuvre. Percentiles were calculated using the LMS method. Results and Discussion Predicted APHV was at age 14.77 ± 0.78 years for males and for females at age 12.74 ± 1.0 years. Biological age was more useful than chronological age for assessing MEF in both sexes. Based on these findings, regional percentiles were created to diagnose and monitor the risk of asthma and the general expiratory status of paediatric populations.

BACKGROUND:Hand grip strength (HGS) is associated with a number of causes resulting in cardiovascular death, in addition to bone fragility, and the presence of sarcopenia. The goal of our study was to analyze HGS of students based on chronological and biological age and propose normative standards for children and adolescents from Chile. METHODS:We studied 4604 school children of both sexes between the ages of 6.0 and 17.9 years of age. Weight, standing height, sitting height, and hand grip strength (HGS- right and left) were measured. The Body Mass Index (BMI) was calculated, and the biological age was calculated by using age at peak height velocity (APHV). RESULTS:When arranged by chronological age, no significant differences occurred in HGS between both sexes of school children from age 6 to 12 years of age. However, from ages 13 to 17, males showed greater HGS than females. Significant differences also emerged between both sexes and at all levels for biological age (APHV). For males, chronological age explained the HGS occurring between 0.74 to 0.75% and for females between 0.54 to 0.59%. For males, biological age explained the HGS for the range of 0.79 to 0.80% and 0.62 to 0.67% for females. The normative data for HGS for both sexes is expressed in percentiles. CONCLUSIONS:HGS during childhood and adolescence needs be analyzed and interpreted in terms of biological age rather than chronological age. The normative data to evaluate the HGS are a tool that can help professionals working in clinical and epidemiological contexts.

Introducción: Los objetivos del presente trabajo fueron identificar los pliegues cutáneos que predicen los indicadores de adiposidad corporal (Índice de Masa Corporal [IMC] y circunferencia de la cintura [CC]), así como analizar si los indicadores de adiposidad corporal deben ser evaluados por edad cronológica y/o biológica. Material y Métodos: Se estudió a 131 niños y adolescentes (76 hombres y 55 mujeres). El rango de edad osciló entre 6,0 hasta 14,9 años. Se evaluó el peso, estatura de pie, estatura sentada, circunferencia de la cintura. Se calculó el IMC y los años de pico de velocidad de crecimiento. Se determinaron las categorías del estado nutricional por IMC y CC de acuerdo a los puntos de corte del CDC-2012. Resultados: Los cuatro pliegues utilizados (tricipital, bicipital, suprailíaco y pantorrilla) explicaron el IMC desde 38 a 58% en hombres y en mujeres desde 38 a 72%. El poder de explicación para la CC en hombres fue de 30 a 56% y en mujeres desde 27 a 53%. La edad cronológica explicó el IMC y la CC en hombres desde 0,08 a 37% y en mujeres desde 15 a 17%. La edad biológica explicó el IMC y CC en hombres desde 11 a 44% y en mujeres desde 21 a 24%. Conclusiones: El pliegue suprailíaco se perfila como el mejor predictor del IMC y la CC en ambos sexos. El análisis de ambos indicadores debe ser efectuado por edad biológica antes que por edad cronológica.

Background The importance of assessing body fat variables and physical fitness tests plays an important role in monitoring the level of activity and physical fitness of the general population. The objective of this study was to develop reference norms to evaluate the physical fitness aptitudes of children and adolescents based on age and sex from the lake region of Itaipú, Brazil. Methods A descriptive cross-sectional study was carried out with 5,962 students (2,938 males and 3,024 females) with an age range of 6.0 and 17.9 years. Weight (kg), height (cm), and triceps (mm), and sub-scapular skinfolds (mm) were measured. Body Mass Index (BMI kg/m2) was calculated. To evaluate the four physical fitness aptitude dimensions (morphological, muscular strength, flexibility, and cardio-respiratory), the following physical education tests were given to the students: sit-and-reach (cm), push-ups (rep), standing long jump (cm), and 20-m shuttle run (m). Results and Discussion Females showed greater flexibility in the sit-and-reach test and greater body fat than the males. No differences were found in BMI. Percentiles were created for the four components for the physical fitness aptitudes, BMI, and skinfolds by using the LMS method based on age and sex. The proposed reference values may be used for detecting talents and promoting health in children and adolescents.

In previous works, a learning law with a dead zone function was developed for multilayer differential neural networks. This scheme requires strictly a priori knowledge of an upper bound for the unmodeled dynamics. In this paper, the learning law is modified in such a way that this condition is relaxed. By this modification, the tuning process is simpler and the dead-zone function is not required anymore. On the basis of this modification and by using a Lyapunov-like analysis, a stronger result is here demonstrated: the exponential convergence of the identification error to a bounded zone. Besides, a value for upper bound of such zone is provided. The workability of this approach is tested by a simulation example.