950 resultados para Primitive societies


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The development of architecture and the settlement is central to discussions concerning the Neolithic transformation asthe very visible evidence for the changes in society that run parallel to the domestication of plants and animals. Architecture hasbeen used as an important aspect of models of how the transformation occurred, and as evidence for the sharp difference betweenhunter-gatherer and farming societies. We suggest that the emerging evidence for considerable architectural complexity from theearly Neolithic indicates that some of our interpretations depend too much on a very basic understanding of structures which arenormally seen as being primarily for residential purposes and containing households, which become the organising principle for thenew communities which are often seen as fully sedentary and described as villages. Recent work in southern Jordan suggests that inthis region at least there is little evidence for a standard house, and that structures are constructed for a range of diverse primary purposes other than simple domestic shelters.

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Pseudomomentum and pseudoenergy are both measures of wave activity for disturbances in a fluid, relative to a notional background state. Together they give information on the propagation, growth, and decay of disturbances. Wave activity conservation laws are most readily derived for the primitive equations on the sphere by using isentropic coordinates. However, the intersection of isentropic surfaces with the ground (and associated potential temperature anomalies) is a crucial aspect of baroclinic wave evolution. A new expression is derived for pseudoenergy that is valid for large-amplitude disturbances spanning isentropic layers that may intersect the ground. The pseudoenergy of small-amplitude disturbances is also obtained by linearizing about a zonally symmetric background state. The new expression generalizes previous pseudoenergy results for quasigeostrophic disturbances on the β plane and complements existing large-amplitude results for pseudomomentum. The pseudomomentum and pseudoenergy diagnostics are applied to an extended winter from the European Centre for Medium-Range Weather Forecasts Interim Re-Analysis data. The time series identify distinct phenomena such as a baroclinic wave life cycle where the wave activity in boundary potential temperature saturates nonlinearly almost two days before the peak in wave activity near the tropopause. The coherent zonal propagation speed of disturbances at tropopause level, including distinct eastward, westward, and stationary phases, is shown to be dictated by the ratio of total hemispheric pseudoenergy to pseudomomentum. Variations in the lower-boundary contribution to pseudoenergy dominate changes in propagation speed; phases of westward progression are associated with stronger boundary potential temperature perturbations.

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The disadvantage of the majority of data assimilation schemes is the assumption that the conditional probability density function of the state of the system given the observations [posterior probability density function (PDF)] is distributed either locally or globally as a Gaussian. The advantage, however, is that through various different mechanisms they ensure initial conditions that are predominantly in linear balance and therefore spurious gravity wave generation is suppressed. The equivalent-weights particle filter is a data assimilation scheme that allows for a representation of a potentially multimodal posterior PDF. It does this via proposal densities that lead to extra terms being added to the model equations and means the advantage of the traditional data assimilation schemes, in generating predominantly balanced initial conditions, is no longer guaranteed. This paper looks in detail at the impact the equivalent-weights particle filter has on dynamical balance and gravity wave generation in a primitive equation model. The primary conclusions are that (i) provided the model error covariance matrix imposes geostrophic balance, then each additional term required by the equivalent-weights particle filter is also geostrophically balanced; (ii) the relaxation term required to ensure the particles are in the locality of the observations has little effect on gravity waves and actually induces a reduction in gravity wave energy if sufficiently large; and (iii) the equivalent-weights term, which leads to the particles having equivalent significance in the posterior PDF, produces a change in gravity wave energy comparable to the stochastic model error. Thus, the scheme does not produce significant spurious gravity wave energy and so has potential for application in real high-dimensional geophysical applications.

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The architecture of the amygdaloid complex of a marsupial, the opossum Didelphis aurita, was analyzed using classical stains like Nissl staining and myelin (Gallyas) staining, and enzyme histochemistry for acetylcholinesterase and NADPH-diaphorase. Most of the subdivisions of the amygdaloid complex described in eutherian mammals were identified in the opossum brain. NADPH-diaphorase revealed reactivity in the neuropil of nearly all amygdaloid subdivisions with different intensities, allowing the identification of the medial and lateral subdivisions of the cortical posterior nucleus and the lateral subdivision of the lateral nucleus. The lateral, central, basolateral and basomedial nuclei exhibited acetylcholinesterase positivity, which provided a useful chemoarchitectural criterion for the identification of the anterior basolateral nucleus. Myelin stain allowed the identification of the medial subdivision of the lateral nucleus, and resulted in intense staining of the medial subdivisions of the central nucleus. The medial, posterior, and cortical nuclei, as well as the amygdalopiriform area did not exhibit positivity for myelin staining. On the basis of cyto- and chemoarchitectural criteria, the present study highlights that the opossum amygdaloid complex shares similarities with that of other species, thus supporting the idea that the organization of the amygdala is part of a basic plan conserved through mammalian evolution. (C) 2008 Elsevier Inc. All rights reserved.

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For the most part, my project has been of an individually rewarding nature due to an extensive amount of reading and studio work. My paper functions as the major means of communication of my own experiences and findings. It is an attempt to share with others the ideas which I have found particularly stimulating and worthwhile during the course of the year. In other words, the written portion does not intend to summarize all of the phases of primitive art which I have studied during the past year; rather, it is indicative of the type of pursuit with which I became involved. It is neither a historical survey nor a specific and thorough study of one area of primitive art. Instead, my paper is a series of essays focusing upon primitive art in general, and upon some of the aspects of primitive art with which I became concerned in particular.

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Esta dissertação tem como objetivo principal elucidar as implicações de se relatar contos de fadas às crianças em idade pré-escolar, destacando-se suas origens histórico- culturais e a sua função psicopedagógica. Com subsidios obtidos em obras de alguns autores da área de história, literatura, filosofia, psicologia e pedagogia, foi feita uma análise considerando-se alguns tópicos, dentre os quais a possibilidade de serem os contos mitos transformados, cuja evolução ou construção da narrativa tem uma característica análoga aos ritos iniciáticos das sociedades consideradas "primitivas" ou pré-letradas. Neste sentido, trazem em seu bojo a nossa herança cultural. Além disso, possuem função psicopedagógica, que possibilita à criança em idade pré-escolar identificar-se com a imagem arquetípica do herói ou heroina, na medida em que estes passam por provações, e adotar uma postura positiva frente às mesmas. Argumentou-se, ainda, quanto às criticas de que estas narrativas têm sido alvo, como, por exemplo, a sua "crueldade", a visão de mundo "deturpada e irreal" que elas promoveriam de acordo com alguns autores que privilegiam o racionalismo, e o papel "degradante e passivo" destinado a algumas personagens femininas de algumas histórias. Conclui-se o trabalho avaliando-se o papel doscontos de fadas no contexto pré-escolar, e de que forma a experiência de relatá-los às crianças pode ser enriquecedora do ponto de vista pedagógico. Apoiando-se na abordagem junguiana, trata-se de um trabalho de pesquisa e análise teórica que visa ampliar, esclarecer, bem como justificar o papel dos contos de fadas na educação pré-escolar, levando-se em conta suas funções psicopedagógicas e o seu caráter socializante, na medida em que a criança tem acesso a valores sócio-culturais que predominaram e ainda repercutem nas relações sociais contemporâneas.