In the current study, we consider the Bresse–Timoshenko type systems and we prove some stability results for time delay cases into setting of so called simplified Bresse–Timoshenko equations (or truncated version of Bresse–Timoshenko equations) according to contributions of Elishakoff et al. (2010, Advances in Mathematical Modeling and Experimental Methods for Materials and Structures. Solid Mechanics and Its Applications. Springer: Berlin, 249–254.; 2015, Celebrating the Centenary of Timoshenko’s study of effects of shear deformation and rotary inertia. Appl. Mech. Rev.67, 1–11.; 2017, Critical contrasting of three versions of vibrating Bresse-Timoshenko beam with a crack. Int. J. Solids Struct. 109, 143–151.). These equations are free of the so-called ‘second spectrum’ phenomenon, and they have important consequences on stabilization setting. Specifically, following Almeida Júnior and Ramos (2017, On the nature of dissipative Timoshenko systems at light of the second spectrum. Z. Angew. Math. Phys.68, 31.) in a recent contribution that shows that damping effects eliminate the consequences of this spectrum for equal wave propagation velocities, we prove that time delay effects are able of stabilizing the truncated version regardless of any relationship between coefficients of system. It is concluded that dissipative truncated versions of Bresse–Timoshenko equations are advantageous over the classical Bresse–Timoshenko equations in stabilization context.

RESUMO Introdução A avaliação do desempenho motor em escolares tem sido utilizada na identificação de talentos esportivos. Porém, existem poucos estudos, sobre esta temática, e nenhum no Sistema Colégio Militar do Brasil. Objetivo Avaliar indicadores antropométricos, fisicomotores e maturacionais; investigar a proporção de talentos motores; analisar a relação entre o diagnóstico de talento motor e o estágio maturacional; e comparar o perfil de alunos-atletas e não atletas de um colégio militar. Métodos Foram avaliados 1.490 escolares de ambos os sexos, de 11 a 17 anos. Aplicou-se uma bateria de testes multidimensional para avaliação do tamanho e da composição corporal, flexibilidade, força de preensão manual, força explosiva de membros superiores e inferiores, velocidade, resistência aeróbica e maturação somática. Os dados foram analisados por meio do teste qui-quadrado e análise de covariância. Resultados Os escolares apresentaram maior tamanho corporal, maior desempenho motor e maturação biológica discretamente avançada em relação aos dados disponíveis na literatura. Além disso, foram criados pontos de corte para oito testes relacionados com a prática esportiva, para identificar escolares com resultados muito acima da média, sendo encontrados 11% de talentos motores. Constatou-se ainda que os talentos motores foram mais frequentes nos escolares avançados biologicamente, e que os alunos-atletas apresentaram diferenças significativas em relação aos não atletas, principalmente quanto ao desempenho motor. Conclusão Os escolares do colégio militar são maiores, mais fortes, mais resistentes e mais maduros biologicamente quando comparados aos valores de referência da literatura, e tais características acentuam-se nos alunos-atletas. Além disso, aproximadamente um em cada dez escolares do colégio militar pode ser considerado um talento motor, e este diagnóstico é mais frequente nos escolares com maturação precoce. Nível de evidência II; Estudo diagnóstico.

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Cooperation plays an important role in the evolution of species and human societies. The understanding of the emergence and persistence of cooperation in those systems is a fascinating and fundamental question. Many mechanisms were extensively studied and proposed as supporting cooperation. The current work addresses the role of migration for the maintenance of cooperation in structured populations. This problem is investigated in an evolutionary perspective through the prisoner's dilemma game paradigm. It is found that migration and structure play an essential role in the evolution of the cooperative behavior. The possible outcomes of the model are extinction of the entire population, dominance of the cooperative strategy and coexistence between cooperators and defectors. The coexistence phase is obtained in the range of large migration rates. It is also verified the existence of a critical level of structuring beyond that cooperation is always likely. In resume, we conclude that the increase in the number of demes as well as in the migration rate favor the fixation of the cooperative behavior.

In this paper, we study the asymptotic behavior for a Bresse-Timoshenko type system with time-dependent delay terms. Our results follow a recent approach given by Almeida Júnior and Ramos (Zeitschrift f̈r angewandte Mathematik und Physik. 68, 1-31. 2017) where they showed that the viscous damping acting on angle rotation of the classical Bresse-Timoshenko model eliminates the damage consequences of the so called second spectrum of frequency. Moreover, for Bresse-Timoshenko type systems which are free of these consequences the assumption of equal wave speeds is not necessary anymore to get the exponential stability. Here, by introducing an appropriate Lyapunov functional we prove the exponential stability for time dependent delay cases regardless of any relationship between wave propagation velocities. K E Y W O R D SBresse-Timoshenko-type systems, exponential decay, phase velocities, second spectrum, time dependent delay 2 0 1 0 M S C 35B35,

Introdução: Nas últimas décadas aumentou o número de pessoas acima do peso, incluindo crianças e adolescentes, fato que é considerado preocupante, pois pode acarretar diversas doenças crônicas, em longo prazo.Objetivo: Avaliar a prevalência de sobrepeso e obesidade em escolares de um colégio militar, investigando possíveis diferenças entre os sexos e as faixas etárias.Métodos: Estudo quantitativo, transversal, do qual participaram 381 escolares de um colégio militar de Minas Gerais, de 11 a 17 anos, sendo 213 meninos e 168 meninas. Calculou-se o índice de massa corporal (IMC) que foi classificado segundo o PROESP-BR. Para testar diferenças entre os sexos, utilizou-se o teste do Qui-Quadrado (X2) e para testar a relação entre idade e IMC, utilizou-se a correlação de Pearson. Significância estatística: p < 0,05.Resultados: Foi observado sobrepeso em 17,8% (n = 68) e de obesidade em 5,8% (n = 22) dos escolares. Houve correlação positiva entre a idade cronológica e o IMC (r = 0,32; p < 0,0001). Não houve correlação entre estado nutricional e faixa etária. Não foram observadas diferenças significativas entre os sexos, em relação ao sobrepeso e à obesidade (16,9% e 6,6% nos meninos vs. 19,0% e 4,8% nas meninas, respectivamente).Conclusão: A prevalência sobrepeso e obesidade nos escolares do colégio militar, em conjunto, foi de 23,6%, tanto nos meninos quanto nas meninas, sem diferença significativa entre as faixas etárias. Essa prevalência foi similar à média de escolares brasileiros.Prevalence of Overweight and Obesity in Students of a Military SchoolIntroduction: Over the past few decades, the number of overweight people, including children and adolescents has increased significantly, a fact that is considered worrying, as it can lead to several chronic diseases in the long term.Objective: To evaluate the prevalence of overweight and obesity in schoolchildren of a military college, investigating possible differences between sexes and age groups.Methods: A quantitative, cross-sectional study was carried out in which 381 students from a military school in Minas Gerais, aged 11 to 17 years, were 213 boys and 168 girls. The body mass index (BMI) was calculated according to the PROESP-BR. To test for gender differences, the Chi-square test (X2) was used and Pearson's correlation was used to test the relationship between age and BMI. Statistical significance: p <0.05.Results: Overweight was observed in 17.8% (n = 68) and obesity in 5.8% (n = 22) of the students. There was a positive correlation between chronological age and BMI (r = 0.32; p <0.0001). There was no correlation between nutritional status and age range. No significant differences were observed between genders regarding overweight and obesity (16.9% and 6.6% in boys vs. 19.0% and 4.8% in girls, respectively).Conclusion: The prevalence of overweight and obesity in the students of the military college, together, was 23.6% in both boys and girls, with no significant difference between age groups. This prevalence was similar to the average of Brazilian schoolchildren.

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Introduction: Talent detection is a dynamic and multifactorial process that must start at school. Objective: Create a mathematical model for evaluating the sporting potential of schoolchildren for athletics in speed, throwing, and endurance events and to test its psychometric properties. Methods: 2871 schoolchildren of both sexes, from 11 to 17 years old, from a military school participated. Between 2015 and 2019, students were submitted to a multidimensional battery of tests containing anthropometric, physical-motor, psychological, socio-environmental, maturational, and performance indicators. In addition, ten teachers evaluated the students regarding the intangibles aspects of their sporting potential and the expectation of future success during this period. Adopting analytical and heuristic procedures, the Gold Score Athletics was created – linear, hybrid (tests + coaches´ eye), and weighted index, according to each indicator's importance, depending on the event type. Results: In the model validation sample (n = 1384), 13.9%, 16.6%, and 11.7% of boys and 10.9%, 10.1%, and 9.1% of girls were classified as high potential (Gold Score ≥ 60) for speed, throwing and endurance events, respectively. Internal consistency (r = 0.76 to 0.82) and diagnostic stability were high (r = 0.72 to 0.81). The Gold Score Athletics for sprinters, throwers, and long-distance runners, both for boys and girls, was higher in students selected for a national competition when compared to those not selected (p < 0.001; d: 0.95 a 1.44) – construct validity – and higher in medalists in an athletics competition, held two years after diagnosis, when compared to non-medalists (p < 0.05; d: 0.62 a 1.87) – predictive validity. Conclusion: The Gold Score Athletics is a valid and reliable scientific model for evaluating the sport's potential of schoolchildren, being useful in the talents detection for Athletics. Level of Evidence II; Diagnostic study.