Avaliação morfofuncional num modelo experimental de movimentos mastigatórios parafuncionais

Introdução: O conceito de etiologia central do bruxismo tem sido reforçado por vários estudos ao longo das últimas décadas. Foi sugerido que o consumo crónico de anfetamina produz bruxismo reforçando a hipótese da etiologia central. O efeito da acupunctura no bruxismo é ainda relativamente desconhecido. Objectivos: Avaliação da atrição dentária, dos movimentos mastigatórios não funcionais (MMNF), da concentração sérica da creatina cinase (CK) e cortisol, da evolução do peso corporal e dos efeitos da acupunctura num novo modelo experimental de MMNF com d-anfetamina. Materiais e métodos: Foram utilizados 40 ratos Wistar machos com 9 semanas de idade, divididos em 4 grupos. O Grupo I (GI; de controlo) não sofreu qualquer manipulação experimental, o Grupo II (GII) foi submetido a um protocolo de indução de stresse e injecção de soro fisiológico, o Grupo III (GIII) submetido a stresse e injecção de anfetamina segundo um protocolo de doses crescentes durante 14 dias e o grupo IV (GIV) submetido ao mesmo protocolo de indução de stresse e de injecção de anfetamina e tratamento com acupunctura. Com o objectivo de avaliar a influência do stresse na atrição incisal realizaram-se marcas dentárias nos incisivos centrais inferiores dos ratos. Foram também realizadas três colheitas sanguíneas nos dias 1, 7 e 14 de modo a avaliar as variações das concentrações séricas da CK e do cortisol. O comportamento dos animais, incluindo os MMNF e o peso foram monitorizados ao longo do estudo. Resultados: A d-anfetamina potenciou o efeito do stresse no aumento do comportamento MNF, e consequentemente, da atrição: Grupo I (6,4±0.,2mm), Grupo II (6,8±0,3mm) e Grupo III (7,2±0,4mm). O protocolo de acupunctura levou a um aumento significativo de MMNF numa fase inicial do estudo e consequentemente da atrição no Grupo IV (7,84±0,62mm). Apesar de os animais do Grupo II não terem aumentado de peso, a anfetamina produziu uma diminuição do peso entre o dia 0 e o dia 14 no GrupoIII (-21,3±16,4g) e a acupunctura potenciou ainda mais esta perda de peso no Grupo IV (-49,37g±29,83g). Relativamente à concentração sérica da CK, observou-se que o stresse produziu um aumento dos teores séricos desta enzima relativamente ao Grupo I em função do tempo, atingindo o valor máximo ao 14º dia: Grupo I (1752,4 U/L), Grupo II (2573,2 U/L), Grupo III (3416,9 U/L) e Grupo IV (3315,9.U/L). Os presentes resultados demonstram ainda que a anfetamina potencia a acção do stresse no aumento da CK sérica nos dias 7 e 14 e a acupunctura parece não afectar estes valores. Os valores do cortisol para o Grupo II, Grupo III e Grupo IV são superiores ao Grupo I (p<0,0001) nos 3 tempos medidos. No entanto, não há diferenças estatisticamente significativas entre os Grupos II, III e IV. Conclusões: Em ratos, o stresse aumenta os MMNF, a atrição e a CK, sendo a anfetamina potenciadora destes factores. Uma dose crescente de d-anfetamina potencia o bruxismo induzido por stresse mas não aumenta o cortisol circulante, ao contrário do stresse, sugerindo que a expressão de MMNF atenua a activação do eixo Hipotálamo-Hipófise-Suprarrenal. Ao contrário do que se esperava, este protocolo de acupunctura não diminuiu a atrição incisal, apresentando estes animais uma perda de peso significativa. Não trouxe alterações significativas relativamente à CK, assim como aos pesos do timo, baço e supra-renais. A acupunctura aumentou o nível de cortisol na análise intermédia, para o diminuir na terceira análise. Sugere-se que a manipulação por tratamento de acupunctura poderá, por si só, ser um agente stressante, poderá necessitar de tempo para actuar ou ainda que os animais, em função do tempo, se habituam a este factor, diminuindo a intensidade de resposta.Introduction: The concept of the central etiology in bruxism has been reinforced by several studies in the last decades. It has been suggested that the chronic abuse of amphetamine produces bruxism, reinforcing its central etiology. The effects of acupuncture in bruxism are still moderately unknown. Objetive: To evaluate the impact of chronic use of amphetamine on the non-functional masticactory movements (NFMM), stresse-induced behavior and dental attrition. Serum creatinine-kinase (CK) and cortisol levels were also assessed, as well as the weight evolution and the effects of acupuncture in a new experimental model of NFMM with d-amphetamine. Materials and methods: 40 Wistar male rats (9 weeks of age) were divided as follows: Group I (control; GI) did not suffer any experimental manipulation; Group II was submitted to a stress induction protocol for 14 days including a single daily saline i.p. injection; Group III was submitted simultaneously to stress and to escalating single daily doses of amphetamine using a procedure of increasing doses and Group IV submitted to the same stress induced and amphetamine injection protocol and acupuncture treatment. Dental marks close to the gingival margin in the lower incisors were drawn to evaluate the influence of the induction protocols in the dental attrition. Blood samples were collected in days 1, 7 and 14 to evaluate the serum CK and cortisol levels. The animals’ behaviour, including NFMM, was monitored throughout the study. The animals’ behaviour, including the NFMM and their weight were monitored during the study. Results: d-Amphetamine potentiated stress-induced increase in NFMM, stress-related behavior and consequently in dental attrition (Group I: 6,4±0,2mm, Group II: 6,8±0,3mm and Group III: 7,2±0,4mm. The acupuncture protocol led to a significant gain in NFMM, in an initial phase of the study and consequently in attrition in Group IV (7,84±0,62mm). While the Group II animals didn’t gain weight, amphetamine produced a decrease in body weight between day 0 and 14 in Ggoup III (-21,3±16,4) and acupuncture potentiated this loss in Group IV (-49,37g±29,83g). The CK serum levels increased time-dependently in both GII and GIII groups (Day 14-Group I: 1752,4 U/L; Group II: 2573,2 U/L and Group III: 3416,9 U/L). The present results demonstrate that amphetamine enhances the ation of stress as suggested by higher CK serum on 7 and 14 days when compared to Group II and acupuncture seems not to affect this values. The Group II and Group III cortisol levels were higher than the Group I cortisol levels (p<0,0001) in all assessed periods. There are no statistically significant differences between GroupII, Group III e Group IV. Conclusions: In rats stress promotes behavioral changes in NFMM and an increase in attrition, in the raise of CK, being the ATS the enhancer of these factors. A sensitizing dose of d-amphetamine regimen potentiates stress-induced bruxism but does not raise cortisol levels, unlike stress, suggesting that NFMM attenuate Hypothalamus-Pituitary-Adrenal axis under this stimulant. Unlike what was expected, the acupuncture protocol did not decrease attrition and led to a significant weight decrease. It did not change CK levels, as well as thyme, spleen and adrenal glands weight. Acupuncture raised cortisol levels on the intermediate analysis, decreasing on the third analysis. We think that acupuncture manipulation may be a stressful agent, it may need longer time to produce effect or that the animals may get used to this factor, decreasing the intensity of the answer

Caracterização Ambiental de uma Planície Aluvionar e Proposta para a sua Remediação

A ocorrência antrópica de metais em meio natural relaciona-se maioritariamente com a existência e funcionamento industrial. A actividade industrial da unidade metalúrgica de Três Marias da Votorantim Metais S.A., localizada no estado Brasileiro de Minas Gerais, tem provocado diversos impactos ambientais na sua envolvente, nomeadamente nos solos, sedimentos e na qualidade da água. A caracterização geoquímica baseada na avaliação da mobilidade dos elementos químicos através da análise da água intersticial dos sedimentos e dos ensaios de lixiviação realizados na zona revelou elevados níveis de contaminação em metaloides e metais pesados, muito acima dos níveis críticos e com elevada biodisponibilidade. O estudo teve como ponto de partida a caracterização geoquímica da zona de forma a fundamentar a escolha das técnicas de remediação ambiental mais adequada(s) para a proposta de requalificação ambiental da área em estudo

Evaluation of the Environmental Risk of Contaminated Materials in the Alluvial Plain of a Metallurgical Unit

Anthropogenic occurrence of metals in a natural environment is mainly related to the existence and functioning of industrial activities. The Três Marias metallurgical unit of Votorantim Metais S.A., located in the Brazilian state of Minas Gerais, has been producing zinc alloys since the late 1960's. Its operation has caused several environmental impacts in its surroundings, namely soils, sediments and water quality. The geochemical characterization of this area revealed a high contamination in heavy metals (cadmium, chromium, copper, manganese, nickel, lead and zinc) and arsenic, above the critical levels, most of which having high bioavailability. This study aims to evaluate and discuss the extent of contamination in the alluvial plain of Consciência waterway, a tributary of the São Francisco river, through geochemical analysis of the sediments and water column, in order to evaluate the most appropriate environmental remediation technique(s) to Implement in the are

Does the experience influence the efficacy of football coach? A perspective from coaches with different levels of experience as player and as coach

The experience is as an important predictor of the football coach efficacy. To study its relevance in valuation of efficacy factors we used the CESp (Duarte et al., 2010), an adapted version of the Coaching Efficacy Scale (CES), of Feltz et al. (1999), in a sample of 60 football coaches from different competitive levels working in Portugal, which were categorized according to their experience as players (professionals and non-professionals) and as coaches (high and reduced). Based on the analysis of the results it was concluded that: 1) professional experience as a player does not interfere in valuing of the efficacy factors; 2) professional experience as a coach involves a factor´s different valuation, with a significance level on character factor; 3) coaches with less experience as athletes and coaches shows less consistency in the practical application of the factors with regard to their hierarchy and frequency of its use. This is a study that allows a deeper understanding of the importance of experience in football coach performance, emphasizing the need to consider the different levels of experience in coach training, and still require subsequent studies, particulary with coaches who work in other contexts, in order to better support the applicability of the results

Avaliação da aplicabilidade de fitorremediação como complemento de técnicas de remediação in situ numa planície aluvionar contaminada por metais pesados (MG, Brasil)

A necessidade de exploração de recursos energéticos por indústrias mineiras tem vindo desde cedo a causar efeitos nefastos no ambiente, nomeadamente através da sua contaminação em metais pesados, traduzindo-se numa ameaça para os ecossistemas e, por sua vez, para o Homem. Assim, a remediação ambiental, mediante diferenciadas técnicas, tem vindo a ser cada vez mais utilizada em diferentes tipos de contaminantes e em diferentes meios. Um dos processos de remediação de materiais geológicos contaminados por metais é a fitorremediação. Este processo é definido como a utilização de vegetação in situ para remover, degradar, ou imobilizar poluentes presentes em solos, sedimentos, aluviões ou águas

A kalman filter for validate points and areas of constant depth in the acquisition of the profiles surfaces

This paper presents multisensor fusion techniques for the acquisition of the profile of surfaces with minimum error using low cost ultrasonic sensors. These surfaces are composed by areas with different depths, corners and specular surfaces. To minimize the constraints of sonar sensors, it was developed dedicated software and hardware, as well as an empirical model was obtained from real data. This model is based in two proposed concepts: Points of Constant Depth (PCD) and Areas of Constant Depth (ACD). Having this sonar model in mind, four sensor fusion techniques are used separately to validate the PCDs and decide the ACDs: average and variance, a simplified kalman filter and heuristic method based in rules. In this work a PUMA 560 manipulator was equipped with a CCD video camera and four ultrasonic sensors on the wrist, to acquire data for internally representation of the geometry of the part’s surface, exploiting the mobility of the robot. The CCD camera defines the working area while the ultrasonic sensors enable the acquisition of the surface profile

Assessment of the Environmental Risk of a Floodplain Contaminated by Metals Based on Different Indices and Environmental Classification Factors, Minas Gerais, Brazil

The geochemical characterization, of an industrial area in Minas Gerais State, Brazil, revealed presence of high levels of potentially toxic metals, higher than the values admitted. The use of three environmental classification indices enabled the comparison of data with the adopted classifications for each index, having identified cadmium, lead and zinc as the main contaminants. The construction of interpolation maps allowed the visualization of the e contaminants evolution throughout the area. It was possible to identify places where natural mitigation processes can be used end produce a comprehensive remediation proposal in places identified as requiring a more complex intervention

Acquisition the profile of surfaces with complementary sensor fusion techniques

This paper presents complementary sensor fusion techniques for the acquisition of the profile of surfaces with minimum error using low cost sensors ultrasonic sensors. These surfaces are composed by areas with different depths, corners and specular surfaces. To minimize the constraints of sonar sensors, it was developed dedicated software and hardware, as well as an empirical model was obtained from real data. This model is based in two proposed concepts: Points of Constant Depth (PCD) and Areas of Constant Depth (ACD). Having this sonar model in mind, four sensor fusion techniques are used separately to validate the PCDs and decide the ACDs: average and variance, fuzzy controller and heuristic method based in rules. In this work a PUMA 560 manipulator was equipped with a CCD video camera on the shoulder and four ultrasonic sensors on the wrist, to acquire data to model the geometry of the part’s surface, exploiting the mobility of the robot. The CCD camera view defines the working area, while the ultrasonic sensors enable the acquisition of the surface profile. For the acquisition of the profile of surfaces with a minimum error different and complementary sensor fusion techniques are implemented and applied separately, namely the average and variance, kalman filter, fuzzy controller and heuristic method based in rules

Uma aplicação do teste adaptativo computadorizado via Filtro de Kalman não-linear

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Estatística, 2019.Computarized Adaptive Test (CAT) é um tipo de teste baseado em recursos computacionais que se adapta ao nível de habilidade dos examinandos. Essencialmente, uma implementação do CAT requer dois elementos fundamentais: um banco de itens calibrado e um algoritmo para seleção adaptativa dos itens. Este trabalho tem foco no segundo elemento, para o qual apresentamos uma adaptação à formulação não linear dos filtros de Kalman, prescrita por Harvey (1989), combinada com o conhecido princípio da máxima entropia (Kullback, 1997). Neste trabalho, estudos de simulação avaliam a acurácia da estimação de proficiências em aplicações CAT, desenvolvendo duas classes de estimadores utilizando a metodologia da Teoria da Resposta ao Item para construção dos modelos probabilísticos, e suavizações recursivas ancoradas nos modelos dinâmicos, para a formulação dos modelos de Filtro de Kalman (Harvey, 1989) e Power Steady (Smith, 1979). Como resultado são apresentados sete novos estimadores da proficiência, sendo o primeiro baseado no Filtro de Kalman e os demais no Power Steady, a saber: FK_EAP, PS_EAP, PS_MAP, PS_EAP_AVG, PS_EAP_MEDIAN, PS_MAP_AVG, PS_MAP_MEDIAN. Os quatro últimos são suavizações baseadas na média e na mediana das estimativas correntes de . Com as simulações, observou-se que os estimadores PS_EAP e PS_MAP geram estimativas cíclicas, sendo corrigidas com a suavização proporcionada pelo estimador PS_EAP_AVG. Portanto, com o estudo realizado nesta dissertação conclui-se que, dentre os sete estimadores avaliados, o PS_EAP_AVG e o FK_EAP geram as melhores alternativas às estimativas de proficiência ao CAT tradicional.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) e Centro Brasileiro de Pesquisa em Avaliação e Seleção e de Promoção de Eventos (Cebraspe).Computarized Adaptive Test (CAT) is a type of test based on computational resources that adapts to the level of ability of the examinees. Essentially, an implementation of CAT requires two fundamental elements: a calibrated item bank and a algorithm for adaptive selection of items. This work focuses on the second element, for which we present an adaptation to the nonlinear formulation of the Kalman filters, prescribed by Harvey (1989), combined with the known principle of maximum entropy (Kullback, 1997). In this work, simulation studies evaluate the accuracy of proficiency estimation in CAT applications, developing two classes of estimators using Item Response Theory methodology to construct the probabilistic models, and recursive smoothing anchored in the dynamic models, for the formulation of the models of Kalman Filter (Harvey, 1989) and Power Steady (Smith, 1979). As a result, seven new proficiency estimators are presented, the first one being based on the Kalman Filter and the others in Power Steady, namely: FK_EAP, PS_EAP, PS_MAP, PS_EAP_AVG, PS_EAP_MEDIAN, PS_MAP_AVG, PS_MAP_MEDIAN. The last four are smoothing based on the mean and median. With the simulations, it was observed that the estimators PS_EAP and PS_MAP generate cyclic estimates, being corrected with the smoothing provided by the estimator PS_EAP_AVG. Therefore, the study concluded that among the seven estimators evaluated, PS_EAP_AVG and FK_EAP generate the best alternatives to traditional CAT proficiency estimates

Effects of soil drying and subsequent re-watering on the activity of nitrate reductase in roots and leaves of Helianthus annuus

The effects of drought on the activity of nitrate reductase (NR) were studied in Helianthus annuus L. plants subjected to soil drying and subsequent rewatering. Drought did not negatively affect the activation state of NR, but resulted in linearly correlated decreases in the activity of the unphosphorilated active form and the total activity of NR, both in roots and leaves. The concentration of nitrate in roots, xylem and leaves also decreased in waterstressed plants, whereas the concentration of total amino acids was only transiently depressed at the leaf level. In contrast, soluble sugars accumulated both in roots and leaves of waterstressed plants. Drought-induced decrease in root NR activity was correlated with the observed changes in root nitrate concentration. A higher percentage of the decrease in foliar NR activity could be explained by the decline in nitrate flux to the leaves than by leaf nitrate content. Following rewatering, the extent of recovery of NR activity was higher in roots than in leaves. The delay in the recovery of foliar NR activity did not result from the persistence of reduced flux of nitrate through the xylem. Several hypotheses to explain the after-effect of soil drying on foliar NR activity are discussed