Uma técnica de projeção é usada para tratar o problema de condição inicial na teoria quântica de campos. Neste formalismo, equações de movimento do tipo cinético são deduzidas para o conjunto de variáveis dinâmicas de um corpo. Estas equações são submetidas a uma expansão não perturbativa. Tratamos esta expansão em ordem mais baixa, correspondente a aproximacão de campo médio, para um sistema uniforme de muitos fermions fora do equilíbrio descrito pelo modelo fermiônico quiral de gross-neveu. Nesta aproximação recuperamos os resultados existentes na literatura, tais como, geração dinâmica de massa, liberdade assintótica e o fenômeno de transmutação dimensional. Estudando ainda nesta aproximção o regime de pequenas oscilações em torno do equilíbrio, obtemos soluções analíticas para a evolução dinâmica de nossas variáveis. Verificamos também as condições para existencias de estados ligados neste regime. / A time-dependent projection technique is used to treat the initial value problem in Quantum Field Theory. On the basis of the general dynamics of the fields, we derive equations of kinetic type for the set of one-body dynamics variables. A non-perturbative expansion can be written for these equations. We treat this expansion in lowest order, which corresponds to the Mean-Field Approximation, for a non-equilibrium uniform many-fermions system described by Chiral Gross-Neveu Model. Several literature results are obtained such as dynamical mass generation, dimensional transmutation and asymptotic freedom. In this approximation we study the small oscillations regime obtaining analytical solution for one-body dynamical variables. We have also examined the condition for the existence of bound-state in this case.

Uma técnica de projeção é usada para tratar o problema de condição inicial na teoria quântica de campos. Neste formalismo, equações de movimento do tipo cinético são deduzidas para o conjunto de variáveis dinâmicas de um corpo. Estas equações são submetidas a uma expansão não perturbativa. Tratamos esta expansão em ordem mais baixa, correspondente a aproximacão de campo médio, para um sistema uniforme de muitos fermions fora do equilíbrio descrito pelo modelo fermiônico quiral de gross-neveu. Nesta aproximação recuperamos os resultados existentes na literatura, tais como, geração dinâmica de massa, liberdade assintótica e o fenômeno de transmutação dimensional. Estudando ainda nesta aproximção o regime de pequenas oscilações em torno do equilíbrio, obtemos soluções analíticas para a evolução dinâmica de nossas variáveis. Verificamos também as condições para existencias de estados ligados neste regime. / A time-dependent projection technique is used to treat the initial value problem in Quantum Field Theory. On the basis of the general dynamics of the fields, we derive equations of kinetic type for the set of one-body dynamics variables. A non-perturbative expansion can be written for these equations. We treat this expansion in lowest order, which corresponds to the Mean-Field Approximation, for a non-equilibrium uniform many-fermions system described by Chiral Gross-Neveu Model. Several literature results are obtained such as dynamical mass generation, dimensional transmutation and asymptotic freedom. In this approximation we study the small oscillations regime obtaining analytical solution for one-body dynamical variables. We have also examined the condition for the existence of bound-state in this case.

v anglickém jazyce: Incidence and management of muscle imbalances in physically active and inactive populations: Objective rehabilitation solutions for populations with nonspecific back pain Summary Totally 258 patients with chronic low back pain aged 51,5 +8,4 years were treated for three weeks in the Rehabilitation Centre focused on lumbar back pain. We observed incidence of muscle dysbalances and accomplished their exact objectiveness using the Tergumed system. We tried to compare and solve their mutual influence during the rehabilitation treatment. We compared differences between physically active and physically inactive population, the impact of total motivation,age and other factors on the improvement of strenght, motion, dysbalances and total pain relief.Significant improvement of movement and muscle strenght p <0,001 were documented on the Tergumed in three weeks.The physically active population and patients motivated.by using the Tergumed preferred active exercises to passive therapy. We also observed improvement in finger-floor distance and reduction of pain, documented by the visual analogue scale, decrease in body weight and cholesterol level (p <0,001). In three- week observation nor significant changes in muscle dysbalance, neither their differences according to sex,age ,chronical...

v anglickém jazyce: Incidence and management of muscle imbalances in physically active and inactive populations: Objective rehabilitation solutions for populations with nonspecific back pain Summary Totally 258 patients with chronic low back pain aged 51,5 +8,4 years were treated for three weeks in the Rehabilitation Centre focused on lumbar back pain. We observed incidence of muscle dysbalances and accomplished their exact objectiveness using the Tergumed system. We tried to compare and solve their mutual influence during the rehabilitation treatment. We compared differences between physically active and physically inactive population, the impact of total motivation,age and other factors on the improvement of strenght, motion, dysbalances and total pain relief.Significant improvement of movement and muscle strenght p <0,001 were documented on the Tergumed in three weeks.The physically active population and patients motivated.by using the Tergumed preferred active exercises to passive therapy. We also observed improvement in finger-floor distance and reduction of pain, documented by the visual analogue scale, decrease in body weight and cholesterol level (p <0,001). In three- week observation nor significant changes in muscle dysbalance, neither their differences according to sex,age ,chronical...