970 resultados para Defined contribution pension plans
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As a contribution to the understanding of comparative social trends within the cetacean family Delphinidae, a 22-month study was conducted on the shortfinned pilot whale, Globicephala macrorhynchus, which has been suggested to have a unique social system in which males and females in the same group are related and mating occurs outside of the group. The individual identification of 495 pilot whales, analysed in daily group association patterns, allowed identification of 46 pods. They were classified as productive or non-productive based on the presence or absence of immature animals. Productive pods were a significantly larger, although 12% of them lacked adult males. Two classes of whales (residents and visitors) were defined by patterns of occurrence,suggesting differential patterns of habitat use. Resident pods occasionally travelled together (41% of all groups) and associations between age and sex classes showed that in mixed-pod groups, the highest ranked associations of the reproductive females were with males from other pods, while within pods, adult males and females associated less. During summer, the proposed peak conception period, pilot whale groups were significantly larger and contained individuals from a significantly greater number of pods. These findings support the hypothesis that males and females mate when associating with individuals from other pods. A comparative analysis of sexual dimorphism, brain size, and testes size, habitat, prey and group size within the 17 delphinid genera identified a correlation between sexual dimorphism and body size, but relative measures of brain size and testes size did not correlate with broad ecological or social classifications. However, a comparison of three delphinid societies identified two distinct male mating systems: males of the small, mono-morphic Tursiops truncatus live in age/sex segregated groups and mate with a number of discrete female communities. Males in the large sexually dimorphic Glob icephala spp. and Orcinus orca mate with associated female pods and yet remain with their female kin. This corresponds to the avunculate social system described in some human societies. It could evolve from a promiscuous mating system where there is little guarantee of paternity and where males that live with their kin increase their inclusive fitness.
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The model dependence inherent in hadronic calculations is one of the dominant sources of uncertainty in the theoretical prediction of the anomalous magnetic moment of the muon. In this thesis, we focus on the charged pion contribution and turn a critical eye on the models employed in the few previous calculations of $a_\mu^{\pi^+\pi^-}$. Chiral perturbation theory provides a check on these models at low energies, and we therefore calculate the charged pion contribution to light-by-light (LBL) scattering to $\mathcal{O}(p^6)$. We show that the dominant corrections to the leading order (LO) result come from two low energy constants which show up in the form factors for the $\gamma\pi\pi$ and $\gamma\gamma\pi\pi$ vertices. Comparison with the existing models reveal a potentially significant omission - none include the pion polarizability corrections associated with the $\gamma\gamma\pi\pi$ vertex. We next consider alternative models where the pion polarizability is produced through exchange of the $a_1$ axial vector meson. These have poor UV behavior, however, making them unsuited for the $a_\mu^{\pi^+\pi^-}$ calculation. We turn to a simpler form factor modeling approach, generating two distinct models which reproduce the pion polarizability corrections at low energies, have the correct QCD scaling at high energies, and generate finite contributions to $a_\mu^{\pi^+\pi^-}$. With these two models, we calculate the charged pion contribution to the anomalous magnetic moment of the muon, finding values larger than those previously reported: $a_\mu^\mathrm{I} = -1.779(4)\times10^{-10}\,,\,a_\mu^\mathrm{II} = -4.892(3)\times10^{-10}$.
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Tesis leida en la Universidad de Aberdeen. 178 p.
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The contributions of hematological factors to the distribution and estimations of Eustrongylides africanus larvae densities in Clarias gariepinus and C. anguillaris of Bida floodplain of Nigeria were documented for the first time. The hematological factors making the most important contributions to the distributions of E. africanus larvae infections in clarias species are mean corpuscular haemoglobin concentration (MCHC), mean corpuscular haemoglobin (MCH), mean corpuscular volume (MCV) and neutrophils count, in descending order of magnitude; having the manifestations for the months of January, March, September, and December of the year being closely related. Five haematological factors (neutrophils, lymphocytes and eosinophils counts; MCH and MCV) having positive or negative correlation coefficient (r) between 0.50 and 0.85 contributed to the estimated of E.africanus larvae densities in the wild population of Clarias species
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Máster en Dirección Empresarial desde la Innovación y la internacionalización. Curso 2013/2014
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Aegagropila sauteri is a peculiar green algae, the branched thalli of which, according to the amount of growth, forms velvety spheres of a diameter of 3-4, sometimes to 5-6 cm. and bigger. Investigators attribute it to a special genus of green algae. The authors examine Aegagropila sauteri in Lake Markakol (Kazakhstan).
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The temporoammonic (TA) pathway is the direct, monosynaptic projection from layer III of entorhinal cortex to the distal dendritic region of area CA1 of the hippo campus. Although this pathway has been implicated in various functions, such as memory encoding and retrieval, spatial navigation, generation of oscillatory activity, and control of hippocampal excitability, the details of its physiology are not well understood. In this thesis, I examine the contribution of the TA pathway to hippocampal processing. I find that, as has been previously reported, the TA pathway includes both excitatory, glutamatergic components and inhibitory, GABAergic components. Several new discoveries are reported in this thesis. I show that the TA pathway is subject to forms of short-term activity-dependent regulation, including paired-pulse and frequency dependent plasticity, similar to other hippocampal pathways such as the Schaffer collateral (SC) input from CA3 to CA1. The TA pathway provides a strongly excitatory input to stratum radiatum giant cells of CA1. The excitatory component of the TA pathway undergoes a long-lasting decrease in synaptic strength following low-frequency stimulation in a manner partially dependent on the activation of NMDA receptors. High frequency activation of the TA pathway recruits a feedforward inhibition that can prevent CA1 pyramidal cells from spiking in response to SC input; this spike-blocking effect shows that the TA pathway can act to regulate information flow through the hippocampal trisynaptic pathway.
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Glandular cells, other than the mucous cells, have been described in the skin of various groups of fish (Teleosts, Ganoids, Selachii) and they have been called 'albuminose' by various authors. The authors propose to study the albuminose cells in the skin of Torpedo ocellata Raf. from a histochemical point of view. The albuminose cells have a complex morphological structure and a correspondingly complicated histochemical make-up. One must treat them as an example of cell with secretions of a particular type, which must and will be better incorporated when more is known of characteristics existent in other species.
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During recent years in connection with the industrialisation of the Kola Peninsula, the study of this district in the botanical respect, in particular the study of the microflora of various bodies of water, began to advance markedly. This article describes the algal flora of the Kola Peninsula. Morphological descriptions are given for three Tetraspora: Tetraspora simplex, Tetraspora tenera, Tetraspora imperfecta. Chlorophysema aduata is also described, and short descriptions of further algae found in the Kola Peninsula are given.
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Planning the management of data at proposal time and throughout its lifecycle is becoming increasingly important to funding agencies and is essential to ensure its current usability and long term preservation and access. This presentation will describe the work being done at the Woods Hole Oceanographic Institution (WHOI) to assist PIs with the preparation of data management plans and the role the Library has in this process. Data management does not mean simply storing information. The emphasis is now on sharing data and making research accessible. Topics to be covered include educating staff about the NSF data policy implementation, a data management survey, resources for proposal preparation, collaborating with other librarians, and next steps.
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E2F1 and E2F2 transcription factors have an important role during the regulation of cell cycle. In experiments done with E2F1/E2F2 knockout mice, it has been described that bone-marrow-derived macrophages (BMDM) undergo an early rapid proliferation event related to DNA hyper-replication. As a consequence, DNA damage response (DDR) pathway is triggered and E2F1/E2F2 knockout macrophages enter premature senescence related to G2/M phase arrest. The exact mechanism trough which DNA hyper-replication leads to DDR in absence of E2F1 and E2F2 remains undiscovered. To determine whether the ATR/ATM pathway, the master regulator of G2/M checkpoint, might be the surveillance mechanism in order to regulate uncontrolled proliferation in the DKO model, we monitored and analysis biochemical properties of BMDM cultures in the presence of caffeine, a potent inhibitor of ATM/ATR activity. Our results show that the addition of caffeine abolishes premature senescence in DKO BMDM, stimulates γ-H2AX accumulation and decreases Mcm2 expression.
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Esta tese analisa a trajetória, os desafios e as perspectivas da regulação em saúde suplementar, contextualizados num ambiente de grandes transformações do papel dos Estados nacionais e das relações entre a Economia e a Política no âmbito mundial e no Brasil. As interrelações entre economia e política são a base para importantes mudanças no papel do Estado brasileiro, do arcabouço regulatório e da regulação da saúde suplementar em particular. A tese tem início com o desenvolvimento de uma análise sobre o panorama político e econômico mundial, de modo a identificar suas influências sobre o Brasil e o setor de saúde brasileiro. À luz deste arcabouço analítico, é desenvolvido um detalhamento retrospectivo dos principais normativos que compuseram a regulação em saúde suplementar, editados por intermédio da Agência Nacional de Saúde Suplementar ANS. Para tanto, foi construído um banco de dados que servirá não apenas para a pesquisa da tese, mas para outros trabalhos a serem desenvolvidos posteriormente. O estudo desse material permitiu identificar uma trajetória da saúde suplementar marcada por três diferentes tônicas, que tem se desdobrado a partir da cena das grandes transformações mundiais. As conclusões aqui obtidas sobre a trajetória da regulação foram ainda apreciadas, por meio de pesquisa com todos os atuais e antigos dirigentes da ANS. Adiante, foi realizada uma breve análise dos efeitos produzidos por cada uma das tônicas anteriormente descritas, bem como discutidos os principais desafios que se colocam na ordem do dia na agenda da saúde suplementar no Brasil. É interessante destacar que discussão da perspectiva futura da regulação da saúde suplementar no Brasil se dá sobre um pano de fundo de profundas transformações no plano da política e das relações de hegemonia e poder na esfera global. Por fim, o trabalho aqui apresentado tem a finalidade de contribuir para o desenvolvimento do tema e sugerir aperfeiçoamentos de modo a aprimorar o planejamento, a gestão e a regulação da saúde suplementar, buscando relações público-privadas mais harmoniosas e eficientes no tocante à assistência e promoção da saúde.
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A afasia pode ser definida como uma alteração no conteúdo, na forma e no uso da linguagem e de seus processos cognitivos subjacentes, tais como percepção e memória adquirida por lesão neurológica. Essa alteração é caracterizada por redução e disfunção, que se manifestam tanto no aspecto expressivo quanto no receptivo da linguagem oral e escrita, embora em diferentes graus em cada uma dessas modalidades (CHAPEY 1996). A alça fonológica constitui um dos três componentes do modelo de memória de trabalho proposto por Baddeley e Hitch (1974) e sua função é armazenar temporariamente as informações verbais e retê-las por um breve período tanto para a compreensão verbal como para a repetição acústica. De acordo com Gathercole e Baddeley (1993), a tarefa de repetição de não-palavras é capaz de solicitar mais a memória fonológica, uma vez que o fato do input ser desconhecido, e não exposto às influências lexicais ou ao uso de estratégias mnemônicas, possibilita avaliar as reais condições do sistema de memória. Considerando-se que afásicos têm dificuldades para memorizar palavras, frases ou instruções e que inexistem estudos nacionais que verificassem o desempenho de afásicos em um teste de não-palavras, a presente dissertação tem como objetivo verificar a integridade da alça fonológica de seis afásicos por meio da aplicação de um teste de não-palavras elaborado para tal objetivo. Como resultado, observou-se através das análises, desempenhos variados, porém com piora significativa no desempenho influenciado pelo aumento da extensão da palavra, corroborando assim, com estudos já realizados com outras categorias de distúrbios linguísticos
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The centralized paradigm of a single controller and a single plant upon which modern control theory is built is no longer applicable to modern cyber-physical systems of interest, such as the power-grid, software defined networks or automated highways systems, as these are all large-scale and spatially distributed. Both the scale and the distributed nature of these systems has motivated the decentralization of control schemes into local sub-controllers that measure, exchange and act on locally available subsets of the globally available system information. This decentralization of control logic leads to different decision makers acting on asymmetric information sets, introduces the need for coordination between them, and perhaps not surprisingly makes the resulting optimal control problem much harder to solve. In fact, shortly after such questions were posed, it was realized that seemingly simple decentralized optimal control problems are computationally intractable to solve, with the Wistenhausen counterexample being a famous instance of this phenomenon. Spurred on by this perhaps discouraging result, a concerted 40 year effort to identify tractable classes of distributed optimal control problems culminated in the notion of quadratic invariance, which loosely states that if sub-controllers can exchange information with each other at least as quickly as the effect of their control actions propagates through the plant, then the resulting distributed optimal control problem admits a convex formulation.
The identification of quadratic invariance as an appropriate means of "convexifying" distributed optimal control problems led to a renewed enthusiasm in the controller synthesis community, resulting in a rich set of results over the past decade. The contributions of this thesis can be seen as being a part of this broader family of results, with a particular focus on closing the gap between theory and practice by relaxing or removing assumptions made in the traditional distributed optimal control framework. Our contributions are to the foundational theory of distributed optimal control, and fall under three broad categories, namely controller synthesis, architecture design and system identification.
We begin by providing two novel controller synthesis algorithms. The first is a solution to the distributed H-infinity optimal control problem subject to delay constraints, and provides the only known exact characterization of delay-constrained distributed controllers satisfying an H-infinity norm bound. The second is an explicit dynamic programming solution to a two player LQR state-feedback problem with varying delays. Accommodating varying delays represents an important first step in combining distributed optimal control theory with the area of Networked Control Systems that considers lossy channels in the feedback loop. Our next set of results are concerned with controller architecture design. When designing controllers for large-scale systems, the architectural aspects of the controller such as the placement of actuators, sensors, and the communication links between them can no longer be taken as given -- indeed the task of designing this architecture is now as important as the design of the control laws themselves. To address this task, we formulate the Regularization for Design (RFD) framework, which is a unifying computationally tractable approach, based on the model matching framework and atomic norm regularization, for the simultaneous co-design of a structured optimal controller and the architecture needed to implement it. Our final result is a contribution to distributed system identification. Traditional system identification techniques such as subspace identification are not computationally scalable, and destroy rather than leverage any a priori information about the system's interconnection structure. We argue that in the context of system identification, an essential building block of any scalable algorithm is the ability to estimate local dynamics within a large interconnected system. To that end we propose a promising heuristic for identifying the dynamics of a subsystem that is still connected to a large system. We exploit the fact that the transfer function of the local dynamics is low-order, but full-rank, while the transfer function of the global dynamics is high-order, but low-rank, to formulate this separation task as a nuclear norm minimization problem. Finally, we conclude with a brief discussion of future research directions, with a particular emphasis on how to incorporate the results of this thesis, and those of optimal control theory in general, into a broader theory of dynamics, control and optimization in layered architectures.