856 resultados para continuity of generations
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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In this paper we study the continuity of invariant sets for nonautonomous infinite-dimensional dynamical systems under singular perturbations. We extend the existing results on lower-semicontinuity of attractors of autonomous and nonautonomous dynamical systems. This is accomplished through a detailed analysis of the structure of the invariant sets and its behavior under perturbation. We prove that a bounded hyperbolic global solutions persists under singular perturbations and that their nonlinear unstable manifold behave continuously. To accomplish this, we need to establish results on roughness of exponential dichotomies under these singular perturbations. Our results imply that, if the limiting pullback attractor of a nonautonomous dynamical system is the closure of a countable union of unstable manifolds of global bounded hyperbolic solutions, then it behaves continuously (upper and lower) under singular perturbations.
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The global attractor of a gradient-like semigroup has a Morse decomposition. Associated to this Morse decomposition there is a Lyapunov function (differentiable along solutions)-defined on the whole phase space- which proves relevant information on the structure of the attractor. In this paper we prove the continuity of these Lyapunov functions under perturbation. On the other hand, the attractor of a gradient-like semigroup also has an energy level decomposition which is again a Morse decomposition but with a total order between any two components. We claim that, from a dynamical point of view, this is the optimal decomposition of a global attractor; that is, if we start from the finest Morse decomposition, the energy level decomposition is the coarsest Morse decomposition that still produces a Lyapunov function which gives the same information about the structure of the attractor. We also establish sufficient conditions which ensure the stability of this kind of decomposition under perturbation. In particular, if connections between different isolated invariant sets inside the attractor remain under perturbation, we show the continuity of the energy level Morse decomposition. The class of Morse-Smale systems illustrates our results.
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Land stewardship ethics must pass from one generation to the next in order to be effective. Some examples in Connecticut are presented.
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By Walter Gardiner
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Grandparents, particularly, grandmothers in the African American community have historically provided needed care for their grandchildren (Crewe, 2003). Before there was a child welfare system that addressed the needs of African American children, there were grandmothers who served as the safety net for their biological, informally adopted grandchildren, and other minor relatives. They cared for grandchildren and others whose birth parents were unable or unwilling to care for them. For families of color, HIV/AIDS is an emerging issue that is contributing to the growing numbers of grandparent-headed households. And once again, many African American grandmothers have accepted the challenge of holding their families together. This article addresses the HIV/AIDS public health challenge in the African American community with specific focus on its impact on older grandparents responsible for raising children of infected biological parents. It advocates for a model that continues to strengthen the Children’s Bureau investment in kinship care through integrating the needs of children and their aging caregivers.
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Beginning after World War II, Argentina institutionalized a limited conservative corporatist welfare state where occupation-linked social insurance held a central position and social assistance had a residual character. This was called a limited conservative corporatist welfare state, because the huge population within the informal sector was excluded from the main system. A populist government supported by trade unions and the economic model of import-substituting industrialization were the background for the formation of this type of welfare state. During the 1990s, elements of a liberal regime were added to the Argentine welfare state under the reform carried out by the Menem Peronist government. However, social insurance reform and labor reform were not as drastic as the economic reform. They still retained a certain continuity from the traditional systems. The government intended to carry out more drastic social security and labor reform, but was unable to do so due to the legacy of corporatism of the Peronist government.
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Mode of access: Internet.
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"References and bibliography": p. [360]-391.
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Mode of access: Internet.