An experimental evaluation of the incidence of fitness-function/search-algorithm combinations on the classification performance of myoelectric control systems with iPCA tuning

BACKGROUND: The information of electromyographic signals can be used by Myoelectric Control Systems (MCSs) to actuate prostheses. These devices allow the performing of movements that cannot be carried out by persons with amputated limbs. The state of the art in the development of MCSs is based on the use of individual principal component analysis (iPCA) as a stage of pre-processing of the classifiers. The iPCA pre-processing implies an optimization stage which has not yet been deeply explored. METHODS: The present study considers two factors in the iPCA stage: namely A (the fitness function), and B (the search algorithm). The A factor comprises two levels, namely A(1) (the classification error) and A(2) (the correlation factor). Otherwise, the B factor has four levels, specifically B(1) (the Sequential Forward Selection, SFS), B(2) (the Sequential Floating Forward Selection, SFFS), B(3) (Artificial Bee Colony, ABC), and B(4) (Particle Swarm Optimization, PSO). This work evaluates the incidence of each one of the eight possible combinations between A and B factors over the classification error of the MCS. RESULTS: A two factor ANOVA was performed on the computed classification errors and determined that: (1) the interactive effects over the classification error are not significative (F(0.01,3,72) = 4.0659 > f( AB ) = 0.09), (2) the levels of factor A have significative effects on the classification error (F(0.02,1,72) = 5.0162 < f( A ) = 6.56), and (3) the levels of factor B over the classification error are not significative (F(0.01,3,72) = 4.0659 > f( B ) = 0.08). CONCLUSIONS: Considering the classification performance we found a superiority of using the factor A(2) in combination with any of the levels of factor B. With respect to the time performance the analysis suggests that the PSO algorithm is at least 14 percent better than its best competitor. The latter behavior has been observed for a particular configuration set of parameters in the search algorithms. Future works will investigate the effect of these parameters in the classification performance, such as length of the reduced size vector, number of particles and bees used during optimal search, the cognitive parameters in the PSO algorithm as well as the limit of cycles to improve a solution in the ABC algorithm

Computer-aided system for diagnosis of Chagas’ disease based on scalograms and self-organizing neural networks

Introdução: A Doença de Chagas é uma endemia rural, prevalente em grande parte da América Central e América do Sul e, aproximadamente, metade dos pacientes contaminados com o parasita Trypanosoma cruzi não apresentam sinais clínicos, eletrocardiográficos e radiológicos de envolvimento cardíaco. Este trabalho, entretanto, propõe uma técnica de auxílio ao diagnóstico da Doença de Chagas baseada em sinais de eletrocardiografia, que extrai informações relevantes desses sinais. Métodos: Duas abordagens são estudadas e implementadas. Ambas utilizam sinais de variabilidade da frequência cardíaca (VFC) e classificação por meio de rede neural, mais especificamente, o mapa auto-organizável de Kohonen. A VFC, que reflete a modulação neural autonômica simpática e parassimpática do coração, é avaliada com base em séries contínuas de intervalos RR do ECG convencional registradas durante 5 minutos. Na primeira abordagem, indicadores estatístico-temporais obtidos diretamente dos sinais de VFC são utilizados como entrada da rede neural para treinamento e teste do método de classificação. Na segunda proposta, são utilizados escalogramas wavelet com função de base DoG (derivative of Gaussian) para avaliação dos sinais de VFC. Indicadores obtidos dos escalogramas são utilizados como entrada da rede neural no treinamento e no teste do algoritmo. Os mapas topológicos de Kohonen são utilizados para comparar a capacidade dos indicadores calculados dos sinais de VFC em discriminar pacientes chagásicos cardiopatas, chagásicos indeterminados e indivíduos normais. Os indicadores temporais convencionais e os indicadores escalográficos são comparados. Resultados: Os resultados mostram que os indicadores escalográficos têm poder discriminatório estatisticamente superior aos indicadores temporais convencionais. Em particular, a potência média da densidade de potência do escalograma na banda de altas frequências mostrou ser estatisticamente o indicador de maior poder discriminatório (p < 0,05 para os 3 casos). Conclusão: A metodologia proposta mostrou-se capaz de distinguir entre indivíduos normais, chagásicos cardiopatas e chagásicos indeterminados. Os índices escalográficos propostos mostraram maior capacidade classificatória que os índices temporais tradicionais.Introduction: Chagas’ disease is an endemic rural disease prevalent in much of Central America and South America, and approximately half of the patients infected with the parasite Trypanosoma cruzi show no clinical, electrocardiographic and radiological cardiac involvement. This paper, however, proposes a technique for the diagnosis of Chagas’ disease based on ECG signals, which extracts relevant information from these signals. Methods: Two approaches are studied and implemented. Both approaches use heart rate variability (HRV) signals, and classification by a neural network, more specifically, the Kohonen self-organizing map. The HRV, which reflects sympathetic and parasympathetic autonomic neural modulation of the heart, is evaluated based on continuous series of RR intervals, calculated from 5-minute records of conventional ECG. In the first approach, statistical/temporal indexes obtained directly from the HRV signals are used as neural network inputs for training and testing of the classification method. In the second approach, derivative of Gaussian (DoG) wavelet scalograms are used to evaluate the HRV signals. Scalographic indexes are used as neural network inputs for training and testing of the algorithm. Kohonen topological maps are used to compare the ability of these HRV indicators of discriminating between patients with Chagas heart disease, Chagas indeterminate heart disease, and normal subjects. Conventional temporal indicators and indicators obtained from DoG scalograms are compared. Results: Results of the application of the proposed methods to HRV signal databases, and performance comparisons, are presented. The results show that scalographic indicators have superior discriminatory power than conventional time-domain indicators. Based on an analysis of statistical significance, we show that the average power of the high-frequency band of the scalogram power spectral density is the indicator with greatest discriminatory power (p < 0,05 for all 3 cases). Conclusion: The proposed method has the ability to discriminate between normal subjects, subjects with Chagas cardiomyopathy, and subjects with the indeterminate form of Chagas’ disease. It was observed that scalographic neural networks present greater discrimination ability than temporal neural networks

Modeling of the human tibia bone using Bond Graph

Introdução: Procedimentos cirúrgicos ortopédicos como a osteotomia, em que se realiza o corte da tíbia, são muito comuns e devem ser muito bem executados para que sejam obtidos bons resultados. Nesse cenário, o estudo de como o osso reage ao processo de corte é um tópico relevante de estudos. O objetivo deste trabalho é apresentar um modelo matemático do processo de corte na tíbia humana por uma serra automática, usando o método de Bond Graph. Métodos: Com base em um trabalho anterior, foi desenvolvido um modelo para a força de reação ao corte da serra. Além disso, foi desenvolvido um modelo embasado no método Bond Graph para se determinar a resposta das diversas partes do osso à ação da serra. Foram também realizadas análises no domínio da frequência para se analisar a estabilidade do sistema. Resultados: Foram obtidos e apresentados os resultados das simulações descritas. Os resultados mostraram boa concordância com o comportamento esperado para a força de reação à serra e para a resposta do material ósseo ao corte. Além disso, as análises no domínio da frequência mostraram que o método de modelagem proposto tem características promissoras com relação a estabilidade do sistema. Conclusão: Os resultados sugerem que o método tem bom potencial para ser usado, no futuro próximo, para análises do processo de perfuração antes de procedimentos cirúrgicos. Entretanto, estudos adicionais sobre a estabilidade e sobre o projeto adequado de um controlador de velocidade são ainda necessários.Introduction: Orthopedic surgical procedures such as osteotomy, in which cutting of the tibia bone is performed, are very common and should be very well performed in order to yield good results. Under this scenario, the study on how the bone reacts to the cutting process is a relevant topic for studies. The goal of this work is to present a mathematical model of the cutting process in the human tibia bone using the Bond Graph method. Methods: Based on a previous work, a model for the reaction force to the cutting action of the saw has been developed. Moreover, a bond graph based model for determining the bone response to the cutting action of the saw has also been developed. Frequency domain analyses were performed for evaluating the stability of the system. Results: The results of the simulations described were obtained and presented. The results were in good agreement with the expected behavior for the reaction force to the saw, and with respect to the response of the bone material to the cutting process. Moreover, the frequency domain analyses showed that the proposed modelling method has promising characteristics regarding system stability. Conclusion: The results suggest that the method has good potential for use, in the near future, for analyses of the cutting process before the surgical procedures. However, additional studies on stability, as well as a proper project of a velocity controller, are still necessary

Resection of the liver for colorectal carcinoma metastases - A multi-institutional study of long-term survivors

In this review of a collected series of patients undergoing hepatic resection for colorectal metastases, 100 patients were found to have survived greater than five years from the time of resection. Of these 100 long-term survivors, 71 remain disease-free through the last follow-up, 19 recurred prior to five years, and ten recurred after five years. Patient characteristics that may have contributed to survival were examined. Procedures performed included five trisegmentectomies, 32 lobectomies, 16 left lateral segmentectomies, and 45 wedge resections. The margin of resection was recorded in 27 patients, one of whom had a positive margin, nine of whom had a less than or equal to 1-cm margin, and 17 of whom had a greater than 1-cm margin. Eighty-one patients had a solitary metastasis to the liver, 11 patients had two metastases, one patient had three metastases, and four patients had four metastases. Thirty patients had Stage C primary carcinoma, 40 had Stage B primary carcinoma, and one had Stage A primarycarcinoma. The disease-free interval from the time of colon resection to the time of liver resection was less than one year in 65 patients, and greater than one year in 34 patients. Three patients had bilobar metastases. Four of the patients had extrahepatic disease resected simultaneously with the liver resection. Though several contraindications to hepatic resection have been proposed in the past, five-year survival has been found in patients with extrahepatic disease resected simultaneously, patients with bilobar metastases, patients with multiple metastases, and patients with positive margins. Five-year disease-free survivors are also present in each of these subsets. It is concluded that five-year survival is possible in the presence of reported contraindications to resection, and therefore that the decision to resect the liver must be individualized. © 1988 American Society of Colon and Rectal Surgeons

Fracture of the distal radius and its surgical management compared to conservative treatment: Systematic review

Introduction: distal radius fractures are one of the most common fractures in adults, with an even higher incidence in older adults. The main mechanism is the fall on the outstretched hand, followed by sports injuries and road accidents. The complications associated with the fracture can cause joint limitation or chronic pain that can limit the patient\u27s life, which represents a great challenge for its management. Material and method: this systematic review aimed to identify which approach has the best results in patients with distal radius fractures. Medline and Google Scholar were used as search bases, selecting potential works and important information. Of the 795 papers identified, 57 potential articles were selected. After applying the inclusion and exclusion criteria, 15 works were selected, dividing the patients into 2 groups: those treated surgically and those treated conservatively. Results: the results showed that surgical treatment presents a faster rate of consolidation and a potential prevention of nonunion compared to conservative treatment. However, surgical treatment also presented more complications. On the other hand, conservative treatment appears to be safer and is associated with a lower rate of complications. Conclusion: surgical treatment accelerates the return to work or previous activities earlier and to a better functional status, less pain and greater patient satisfaction compared to conservative treatment. However, conservative treatment appears to be safer and is associated with a lower complication rate. Therefore, the choice of approach to follow must be individualized for each patient, taking into account factors such as age, the severity of the fracture, and comorbidities

Käsikivi : kakskümmend pisilugu ja üks jutustus

https://www.ester.ee/record=b1239407*es

Influencia de cinco tipos de embalagens na germinaçao e no vigor de sementes de Angico - Parapiptadenia rigida (Benth)Brenan, Caixeta - Tabebuia cassinoides (Lam)Dc. e caroba-Jacaranda micrantha Cham. armazenadas em câmara fria e a temperatura ambiente

O presente trabalho foi conduzido no Laboratório de Silvicultura do Departamento de Silvicultura e Manejo da Universidade Federal do Paraná, com o intuito de apresentar informações que permitam estudar a viabilidade de lotes de sementes de angico vermelho -Parapiptadenia rigida (Benth.) Brenan, caixeta -Tabebuia cassinoides (Lam.) DC. Caroba – Jacaranda micrantha Cham., através de um armazenamento adequado. Após uma secagem inicial, em estufa a 42ºC por períodos de 1, 2, 3, 4, 5, 6, 7 e 8 horas ficou demonstrado que sementes de angico e caixeta podem ser secadas por 3 horas até teores de umidade de 8,7%, e caroba por 2 horas até 8,0%, com pequenas perdas na porcentagem de germinação, mas sem apresentar decréscimo significativo no vigor. o restante dos lotes de sementes, das três espécies, foram submetidas ao melhor tratamento apresentado no teste de secagem, sendo em seguida embaladas e armazenadas em câmara fria (x : 4ºC e 96% UR) e à temperatura ambiente. As embalagens utilizadas foram o vidro, o saco plástico 10 mils, o saco de papel multifolhado, lata e saco de algodão. A germinação, teor de umidade e vigor das sementes foram avaliados trimestralmente. Após 12 meses as melhores condições de armazenamento para as três espécies foram: Parapiptadenia rigida: em embalagens de saco plástico e de vidro, em câmara fria e, vidro à temperatura ambiente. Tabebuia cassinoides: em embalagem de saco plástico e de vidro, em câmara fria e à temperatura ambiente. Jacaranda micranta: em embalagem de saco plástico e de vidro em câmara fria e à temperatura ambiente. Para armazenamento de sementes por períodos menores pode-se utilizar, por serem m:ris econômicos, as seguintes embalagens: Para 3 meses: saco de papel multifolhado à temperatura ambiente para sementes de angico, caixeta e caroba; saco de tela de algodão à temperatura ambiente para sementes de caroba. Para 6 meses: saco de papel multifolhado a temperatura ambiente para sementes de caroba . . Uma avaliação do vigor, através o teste de envelhecimento precoce, demonstrou ser o lote de sementes de angico vermelho m:ris vigoroso que os das outras duas espécies, após 12, 24, 36, 48, 60, 72, 84, 96, 108 e 120 horas, em câmara de envelhecimento. Para prognóstico de armazenamento foram associadas as porcentagens de germinações obtidas após os períodos de envelhecimento precoce com as conseguidas ao final de 12 meses nas cinco embalagens, concluindo-se que: Parapiptadenia rigida: 12 e 24 horas de envelhecimento precoce prognóstica a germinação em embalagens de lata, de saco plástico (10 mils) e de vidro, armazenadas em câmara fria. 36 horas de envelhecimento precoce prognostica a germinação em embalagem de vidro, à temperatura ambiente. Tabebuia cassionoides: 12 horas de envelhecimento precoce prognostica a germinação em embalagens de saco plástico (10 mils) e de vidro, em câmara fria. 24 horas de envelhecimento precoce prognostica a germinação em embalagem de lata, à temperatura ambiente. Jacaranda micrantha: 12 horas de envelhecimento precoce prognostica a germinação em saco plástico (10 mils), à temperatura ambiente

Kujundava hindamise rakendumine Eesti üldhariduskoolides

https://www.ester.ee/record=b5251827*es

Outside of Crime but Inside the ‘World of Crime’: Youth Experiences in the Midst of the War in the Peripheries of Maceió and Belo Horizonte

This article analyzes youth experiences in the face of criminal governance efforts in the peripheries of Alagoas state capital Maceió and Minas Gerais state capital Belo Horizonte. We consider the experiences of young people who are not involved in crime to demonstrate that being “outside of crime” is not the same as being outside the “world of crime,” in view of the fact that the trajectories of their lives are affected by criminal moral and legal regimes in the territories where they live and through which they pass. We argue that the instable criminal dynamics in the peripheries of Maceió and Belo Horizonte transform gang war into a form of central relationship that intersects with kinship, love, neighborhood, childhood friendship and torcidarelationships. This article analyzes youth experiences in the face of criminal governance efforts in the peripheries of Alagoas state capital Maceió and Minas Gerais state capital Belo Horizonte. We consider the experiences of young people who are not involved in crime to demonstrate that being “outside of crime” is not the same as being outside the “world of crime,” in view of the fact that the trajectories of their lives are affected by criminal moral and legal regimes in the territories where they live and through which they pass. We argue that the instable criminal dynamics in the peripheries of Maceió and Belo Horizonte transform gang war into a form of central relationship that intersects with kinship, love, neighborhood, childhood friendship and torcida relationships

Primeiro autovalor do Laplaciano: aspectos analíticos e geométricos

The notion of differentiable manifold is a concept similar to the regular surface, however, is an intrinsic notion, and therefore need not be contained in a Euclidean space. The first eigenvalue of the Laplacian, an elliptic differential operator of second order is an analytic entity that will be used to provide geometrical information about a submanifold isometrically immersed in Euclidean space. In this dissertation, will be presented the basic notions of Riemannian Geometry such as Differentiable Manifolds, Tangent Spaces, Riemannian Manifolds, Affine Connections, Curvatures and Isometric ImmersionsA noção de variedade diferenciável é um conceito análogo ao de superfície regular, porém é uma noção intrínseca, e portanto não precisa estar contida num espaço Euclidiano. O primeiro autovalor do Laplaciano, um operador diferencial elíptico de segunda ordem, é uma entidade analítica que será usado para fornecer informações geométricas sobre uma subvariedade imersa isometricamente num espaço Euclidiano. Nesta dissertação, serão apresentadas as noções básicas de Geometria Riemanniana tais como Variedades diferenciáveis, Espaços Tangentes, Variedades Riemannianas, Conexões Afins, Curvaturas e Imersões Isométricas