54 research outputs found

    APLICAÇÃO DE CONTROLADORES FUZZY E PROPORCIONAL PARA UM ROBÔ SEGUIDOR DE PAREDE AUTÔNOMO EM AMBIENTE ESTÁTICO

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    A navegação de robôs móveis apresenta uma vari- edade de problemas, como a presença de ruídos e distúrbios, necessidade de fusão sensorial e a dificuldade na obtenção do modelo matemático que representa as interações físicas do ambiente. Cabe ao sistema de controle prover comandos para a correta execução dos movimentos do robô, de forma a alcançar algum objetivo proposto mesmo diante das adversidades do ambiente. Este artigo apresenta a aplicação de diferentes tipos de sistemas de controle, como controladores fuzzy convencional, fuzzy hierárquico e proporcional, para a navegação de um robô seguidor de parede em ambiente estático, cujo objetivo é evitar colisões e manter o robô a uma distância segura da parede. Foram feitas simulações em dois ambientes 3D e um experimento real para validação da abordagem proposta. As simulações foram feitas por meio do simulador V-REP em associação com a linguagem C++, utilizando um robô diferencial autônomo munido de sensores ultrassônicos. O experimento real fez uso de sensores e da placa Arduíno acoplados ao chassi de um robô diferencial. Os resultados mostram que o objetivo é alcançado de forma satisfatória por todas as técnicas propostas

    Annona coriacea Mart. fractions promote cell cycle arrest and inhibit autophagic flux in human cervical cancer cell lines

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    Plant-based compounds are an option to explore and perhaps overcome the limitations of current antitumor treatments. Annona coriacea Mart. is a plant with a broad spectrum of biological activities, but its antitumor activity is still unclear. The purpose of our study was to determine the effects of A. coriacea fractions on a panel of cervical cancer cell lines and a normal keratinocyte cell line. The antitumor effect was investigated in vitro by viability assays, cell cycle, apoptosis, migration, and invasion assays. Intracellular signaling was assessed by Western blot, and major compounds were identified by mass spectrometry. All fractions exhibited a cytotoxic effect on cisplatin-resistant cell lines, SiHa and HeLa. C3 and C5 were significantly more cytotoxic and selective than cisplatin in SiHa and Hela cells. However, in CaSki, a cisplatin-sensitive cell line, the compounds did not demonstrate higher cytotoxicity when compared with cisplatin. Alkaloids and acetogenins were the main compounds identified in the fractions. These fractions also markedly decreased cell proliferation with p21 increase and cell cycle arrest in G2/M. These effects were accompanied by an increase of H2AX phosphorylation levels and DNA damage index. In addition, fractions C3 and C5 promoted p62 accumulation and decrease of LC3II, as well as acid vesicle levels, indicating the inhibition of autophagic flow. These findings suggest that A. coriacea fractions may become effective antineoplastic drugs and highlight the autophagy inhibition properties of these fractions in sensitizing cervical cancer cells to treatment.e FINEP (MCTI/FINEP/MS/SCTIE/DECIT-01/ 2013—FP XII-BIOPLAT), Barretos Cancer Hospital, CAPES, CNPq, FAPEMIG, UFSJ. RMR is a recipient of CNPq Productivity Gran

    CONTROLE DE ORIENTAÇÃO E VELOCIDADE DE CADEIRA DE RODAS POR VISÃO COMPUTACIONAL

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    This work proposes a computer vision system for wheelchair control based on facial coordinates and head position estimation. This work comprises the design of a low-cost motorized wheelchair, which aims to promote independence and quality of life for people who have motor difficulties to manipulate a joystick. The tests performed on the built prototype resulted in an accuracy of 87.78%, an precision of 90.00% and a sensitivity of 87.70%. Tests performed in the motorized wheelchair resulted in an average accuracy of 94.69%, average precision of 91.04% and average sensitivity of 89.38%.Este trabalho propõe um sistema de visão computacional para controle de cadeira de rodas com base em coordenadas faciais e estimativa da posição da cabeça. Este trabalho compõe o projeto de uma cadeira de rodas motorizada de baixo custo, que tem como objetivo promover independência e qualidade de vida a pessoas que possuem dificuldades motoras para manipular um joystick. Os testes realizados no protótipo construído resultaram em uma acurácia de 87,78%, a precisão de 90,00% e uma sensibilidade de 87,70%. Os testes realizados na cadeira de rodas motorizada resultaram em uma acurácia média de 94,69%, precisão média de 91,04% e sensibilidade média de 89,38%

    Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

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    Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets

    Antioxidant effects of oral Ang-(1-7) restore insulin pathway and RAS components ameliorating cardiometabolic disturbances in rats.

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    In prevention studies of metabolic syndrome (MetS), Ang-(1-7) has shown to improve the insulin signaling. We evaluated the HP?CD/Ang-(1-7) treatment on lipid metabolism, renin-angiotensin system (RAS) components, oxidative stress, and insulin pathway in the liver and gastrocnemius muscle and hepatic steatosis in rats with established MetS. After 7 weeks of high-fat (FAT) or control (CT) diets, rats were treated with cyclodextrin (HP?CD) or HP?CD/Ang-(1-7) in the last 6 weeks. FATHP?CD/ empty rats showed increased adiposity index and body mass, gene expression of ACE/ANG II/AT1R axis, and oxidative stress. These results were accompanied by imbalances in the insulin pathway, worsening of liver function, hyperglycemia, and dyslipidemia. Oral HP?CD/Ang-(1-7) treatment decreased ACE and AT1R, increased ACE2 gene expression. in the liver, and restored thiobarbituric acid reactive substances (TBARS), catalase (CAT), superoxide dismutase (SOD), insulin receptor substrate (Irs-1), glucose transporter type 4 (GLUT4), and serine/threonine kinase 2 (AKT-2) gene expression in the liver and gastrocnemius muscle improving hepatic function, cholesterol levels, and hyperglycemia in MetS rats. Overall, HP?CD/Ang-(1-7) treatment restored the RAS components, oxidative stress, and insulin signaling in the liver and gastrocnemius muscle contributing to the establishment of blood glucose and lipid homeostasis in MetS rats
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