Toward an ecological conception of timbre

This paper is part of a series in which we had worked in the last 6 months, and, specifically, intend to investigate the notion of timbre through the ecological perspective proposed by James Gibson in his Theory of Direct Perception. First of all, we discussed the traditional approach to timbre, mainly as developed in acoustics and psychoacoustics. Later, we proposed a new conception of timbre that was born in concepts of ecological approach. The ecological approach to perception proposed by Gibson (1966, 1979) presupposes a level of analysis of perceptual stimulated that includes, but is quite broader than the usual physical aspect. Gibson suggests as focus the relationship between the perceiver and his environment. At the core of this approach, is the notion of affordances, invariant combinations of properties at the ecological level, taken with reference to the anatomy and action systems of species or individual, and also with reference to its biological and social needs. Objects and events are understood as relates to a perceiving organism by the meaning of structured information, thus affording possibilities of action by the organism. Event perception aims at identifying properties of events to specify changes of the environment that are relevant to the organism. The perception of form is understood as a special instance of event perception, which is the identity of an object depends on the nature of the events in which is involved and what remains invariant over time. From this perspective, perception is not in any sense created by the brain, but is a part of the world where information can be found. Consequently, an ecological approach represents a form of direct realism that opposes the indirect realist based on predominant approaches to perception borrowed from psychoacoustics and computational approach

Classification of Triadic Chord Inversions Using Kohonen Self-organizing Maps

In this paper we discuss the application of the Kohonen Selforganizing Maps to the classification of triadic chords in inversions and root positions. Our motivation started in the validation of Schönberg´s hypotheses of the harmonic features of each chord inversion. We employed the Kohonen network, which has been generally known as an optimum pattern classification tool in several areas, including music, to verify that hypothesis. The outcomes of our experiment refuse the Schönberg´s assumption in two aspects: structural and perceptual/functional

Acessibilidade pedonal em espaço público exterior: requalificação do centro urbano de Guimarães

Todo o espaço urbano é fruto de uma multiplicidade de vicissitudes históricas, bem como o resultado contingencial de uma ampla variedade de circunstâncias económicas e políticas. Excetuando situações extremas, o crescimento das cidades resulta de processos de expansão relacionados com o aumento da população, bem como de novos usos do solo e dos seus edifícios. O maior interesse de uma cidade reside no seu espaço, porque é nele que se desenvolvem as diversas atividades socioeconómicas. Deste modo, para avaliar a qualidade de vida de uma cidade importa desenvolver uma análise da qualidade dos seus espaços exteriores e dos seus elementos estruturais. O objetivo deste trabalho é o de propor ações de requalificação do ambiente pedonal urbano de forma a responder às necessidades dos peões, nomeadamente das pessoas com mobilidade reduzida, com vista a aumentar os níveis de conforto e qualidade de vida dos cidadãos e visitantes da cidade de Guimarães

The Fh8 tag : a fusion partner for simple and cost-effective protein purification in Escherichia coli

Downstream processing is still a major bottleneck in recombinant protein production representing most of its costs. Hence, there is a continuing demand of novel and cost-effective purification processes aiming at the recovery of pure and active target protein. In this work, a novel purification methodology is presented, using the Fh8 solubility enhancer tag as fusion handle. The binding properties of Fh8 tag to a hydrophobic matrix were first studied via hydrophobic interaction chromatography (HIC). The Fh8 tag was then evaluated as a purification handle by its fusion to green fluorescent protein and superoxide dismutase. The purification efficiency of the Fh8-HIC strategy was compared to the immobilized metal ion affinity chromatography (IMAC) using the His6 tag. Results showed that the Fh8-HIC binding mechanism is calcium-dependent in a low salt medium, making the purification process highly selective. Both target proteins were biologically active, even when fused to Fh8, and were successfully purified by HIC, achieving efficiencies identical to those of IMAC. Thus, the Fh8 acts as an effective affinity tag that, together with its previously reported solubility enhancer capability, allows for the design of inexpensive and successful recombinant protein production processes in Escherichia coli.This work was conducted with the financial support of the Fundacao para a Ciencia e Tecnologia (FCT), Portugal, by the fellowship SFRH/BD/46482/2008 (POPH-QREN) to Sofia J. Costa. The FCT project PTDC/CVT/103081/2008 (co-funded by COMPETE) and QREN co-promotion project number 3515 are also acknowledged. The authors thank Dr. Huseyin Besir, Protein Expression and Purification Facility Core, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany, for supplying the pETM11 expression vector, and also Dr. Vitor Costa for kindly providing the SOD target gene used in this work

Effects of 3-beta-diol, an androgen metabolite with intrinsic estrogen-like effects, in modulating the aquaporin-9 expression in the rat efferent ductules

BACKGROUND: Fluid homeostasis is critical for normal function of the male reproductive tract and aquaporins (AQP) play an important role in maintenance of this water and ion balance. Several AQPs have been identified in the male, but their regulation is not fully comprehended. Hormonal regulation of AQPs appears to be dependent on the steroid in the reproductive tract region. AQP9 displays unique hormonal regulation in the efferent ductules and epididymis, as it is regulated by both estrogen and dihydrotestosterone (DHT) in the efferent ductules, but only by DHT in the initial segment epididymis. Recent data have shown that a metabolite of DHT, 5-alpha-androstane-3-beta-17-beta-diol (3-beta-diol), once considered inactive, is also present in high concentrations in the male and indeed has biological activity. 3-beta-diol does not bind to the androgen receptor, but rather to estrogen receptors ER-alpha and ER-beta, with higher affinity for ER-beta. The existence of this estrogenic DHT metabolite has raised the possibility that estradiol may not be the only estrogen to play a major role in the male reproductive system. Considering that both ER-alpha and ER-beta are highly expressed in efferent ductules, we hypothesized that the DHT regulation of AQP9 could be due to the 3-beta-diol metabolite. METHODS: To test this hypothesis, adult male rats were submitted to surgical castration followed by estradiol, DHT or 3-beta-diol replacement. Changes in AQP9 expression in the efferent ductules were investigated by using immunohistochemistry and Western blotting assay. RESULTS: Data show that, after castration, AQP9 expression was significantly reduced in the efferent ductules. 3-beta-diol injections restored AQP9 expression, similar to DHT and estradiol. The results were confirmed by Western blotting assay. CONCLUSION: This is the first evidence that 3-beta-diol has biological activity in the male reproductive tract and that this androgen metabolite has estrogen-like activity in the efferent ductules, whose major function is the reabsorption of luminal fluid