30 research outputs found

    Análise multivariada de atributos pedológicos e fitossociológicos aplicada na caracterização de ambientes de cerrado no norte de Minas Gerais Multivariate analysis of pedological and phytosociogical attributes applied to characterization of cerrado environments in north of Minas Gerais State, Brazil

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    O Cerrado é uma das principais regiões de expansão agropecuária do país, entretanto a fragilidade dos seus ecossistemas restringe a capacidade de suporte a muitas das atividades agrícolas e compromete a preservação da sua biodiversidade. O objetivo deste estudo foi definir padrões locais de características edáficas e vegetacionais, em uma sub-bacia em Rio Pardo de Minas (MG), como base para o planejamento local de uso sustentável. Para tal, foram utilizadas técnicas de levantamento fitossociológico e de solos associadas à análise estatística multivariada, dendrograma e análise de componentes principais, de forma a correlacionar distribuição espacial de grupos de espécies e atributos edáficos. Os resultados indicaram a ordenação dos ambientes em dois grupos, em função da natureza dos materiais de origem: arenítico-quartzítico e sedimentos argilo-arenosos e argilosos. A seleção de variáveis pela análise multivariada foi capaz de discriminar os ambientes representados no levantamento fitossociológico. Os padrões identificados pelos agricultores corresponderam, em geral, às variações nos parâmetros florísticos e fitossociológicos e aos atributos edáficos, entre estes a densidade absoluta, a área basal e o índice de diversidade; as frações granulométricas foram determinantes na diferenciação dos ambientes.<br>The Cerrado is one of the main Brazilian expanding regions for agriculture, but the fragility of its ecosystems limits the support capacity for agriculture activities, jeopardizing the preservation of its biodiversity. The objective of this study was to define local patterns of edaphic and vegetation characteristics, of a small watershed in Rio Pardo de Minas municipality (Minas Gerais State, Brazil), as the basis for the sustainable planning for local usage. For such, techniques of phytosociological survey and soils were applied and associated to multivariate statistical procedures, dendrogram and PCA, in order to correlate the spatial distribution of groups of species with soil attributes. The results showed the classification of the environments into two groups, based on the nature of parent materials: arenitic-quartzitic and sandy-clayey and clayey sediments. The selection of variables using the multivariate analysis was able to discriminate the environments represented in the phytosociological plots. The patterns identified by the local farmers corresponded, in general, to the variations in the floristic and phytosociological parameters and edaphic attributes. The absolute density, basal area, Shannon index and the granulometric fractions were the determinant parameters in the differentiation of the environments

    The emotional feeling as a combination of two qualia: A neurophilosophical-based emotion theory

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    It is argued that the emotional feeling comprises the following two emotional qualia. (1) A nucleus feeling or primary emotional quale, which is the phenomenological counterpart of the end product of appraisal by the central nervous system. (2) The experience of being urged to emotion-related reflection or secondary emotional quale, which is the phenomenological counterpart of the brain’s decision to inhibit pre-programmed emotional behaviour, and to initiate emotion-related reflections. Different brain modules regulate these two qualia, and thus each can be experienced independently of the other. The primary emotional quale is related to activation of the amygdala, it is emotion specific, and neutral with respect to affect. The secondary emotional quale is related to activation of the orbito-prefrontal cortex (O-PFC), and includes affective aspects. It is argued that emotional behaviour is regulated by the following three neural mechanisms, two of which two are directly related to the two qualia. (1) An evolutionary ancient system (amygdala-system), which comprises the amygdalae and subcortical nuclei, and which activates pre-programmed emotional behaviour. (2) An evolutionary recent system (PFC-system), comprising the prefrontal cortex, which inhibits pre-programmed emotional behaviour, activates emotional reflection, generates and evaluates behavioural alternatives. In contrast to the preprogrammed behaviour, the behavioural alternatives are more likely to serve longterm goals. (3) A default mechanism, which gives rise to default (i.e., ‘‘just do something’’) behaviour. The first two systems are mutually competitive, while the third mechanism takes over if either the competition between the first two mechanisms, or the decision process of the PFC-system, takes too long. This default mechanism involves the function of the medial-prefrontal cortex (M-PFC)

    CVI.—Contributions towards a study of the ectoparasites of British birds and mammals.—No. 6

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