Age effects on EEG correlates of the Wisconsin card sorting test

Body and brain undergo several changes with aging. One of the domains in which these changes are more remarkable relates with cognitive performance. In the present work, electroencephalogram (EEG) markers (power spectral density and spectral coherence) of age-related cognitive decline were sought whilst the subjects performed the Wisconsin Card Sorting Test (WCST). Considering the expected age-related cognitive deficits, WCST was applied to young, mid-age and elderly participants, and the theta and alpha frequency bands were analyzed. From the results herein presented, higher theta and alpha power were found to be associated with a good performance in the WCST of younger subjects. Additionally, higher theta and alpha coherence were also associated with good performance and were shown to decline with age and a decrease in alpha peak frequency seems to be associated with aging. Additionally, inter-hemispheric long-range coherences and parietal theta power were identified as age-independent EEG correlates of cognitive performance. In summary, these data reveals age-dependent as well as age-independent EEG correlates of cognitive performance that contribute to the understanding of brain aging and related cognitive deficits.

Contributos do postal ilustrado para a história do Free Card

Dissertação de mestrado em Ciências da Comunicação (área de especialização em Publicidade e Relações Públicas)

UV-visible scanning spectrophotometry and chemometric analysis as tools for carotenoids analysis in cassava genotypes (Manihot esculenta Crantz)

In this study, the metabolomics characterization focusing on the carotenoid composition of ten cassava (Manihot esculenta) genotypes cultivated in southern Brazil by UV-visible scanning spectrophotometry and reverse phase-high performance liquid chromatography was performed. Cassava roots rich in -carotene are an important staple food for populations with risk of vitamin A deficiency. Cassava genotypes with high pro-vitamin A activity have been identified as a strategy to reduce the prevalence of deficiency of this vitamin. The data set was used for the construction of a descriptive model by chemometric analysis. The genotypes of yellow-fleshed roots were clustered by the higher concentrations of cis--carotene and lutein. Inversely, cream-fleshed roots genotypes were grouped precisely due to their lower concentrations of these pigments, as samples rich in lycopene (redfleshed) differed among the studied genotypes. The analytical approach (UV-Vis, HPLC, and chemometrics) used showed to be efficient for understanding the chemodiversity of cassava genotypes, allowing to classify them according to important features for human health and nutrition.

Implementação de um sistema de abastecimento logístico numa empresa de cilindros de aço

Dissertação de mestrado integrado em Engenharia e Gestão Industrial

Análise comparativa do consumo de biomassa para fins energéticos

Dissertação de mestrado integrado em Engenharia Mecânica

Introducing resistance genes against ToMV, TYLCV and TSWV infections in two tomato varieties (Muchamiel and De la Pera)

Dissertação de mestrado em Biologia Molecular, Biotecnologia e Bioempreendedorismo em Plantas

Optical properties of zirconium oxynitride films: the effect of composition, electronic and crystalline structures

tThis work is devoted to the investigation of zirconium oxynitride (ZrOxNy) films with varied opticalresponses prompted by the variations in their compositional and structural properties. The films wereprepared by dc reactive magnetron sputtering of Zr, using Ar and a reactive gas mixture of N2+ O2(17:3).The colour of the films changed from metallic-like, very bright yellow-pale and golden yellow, for low gasflows to red-brownish for intermediate gas flows. Associated to this colour change there was a significantdecrease of brightness. With further increase of the reactive gas flow, the colour of the samples changedfrom red-brownish to dark blue or even to interference colourations. The variations in composition dis-closed the existence of four different zones, which were found to be closely related with the variationsin the crystalline structure. XRD analysis revealed the change from a B1 NaCl face-centred cubic zirco-nium nitride-type phase for films prepared with low reactive gas flows, towards a poorly crystallizedover-stoichiometric nitride phase, which may be similar to that of Zr3N4with some probable oxygeninclusions within nitrogen positions, for films prepared with intermediate reactive gas flows. For highreactive gas flows, the films developed an oxynitride-type phase, similar to that of -Zr2ON2with someoxygen atoms occupying some of the nitrogen positions, evolving to a ZrO2monoclinic type structurewithin the zone where films were prepared with relatively high reactive gas flows. The analysis carriedout by reflected electron energy loss spectroscopy (REELS) revealed a continuous depopulation of thed-band and an opening of an energy gap between the valence band (2p) and the Fermi level close to 5 eV.The ZrN-based coatings (zone I and II) presented intrinsic colourations, with a decrease in brightness anda colour change from bright yellow to golden yellow, red brownish and dark blue. Associated to thesechanges, there was also a shift of the reflectivity minimum to lower energies, with the increase of thenon-metallic content. The samples lying in the two last zones (zone III, oxynitride and zone IV, oxide films)revealed a typical semi-transparent-optical behaviour showing interference-like colourations only dueto the complete depopulation of the d band at the Fermi level. The samples lying in these zones presentedalso an increase of the optical bandgap from 2 to 3.6 eV.

Tailored deposition of coloured coatings: on the widening of the available colour range

Dissertação de mestrado integrado em Engenharia de Materiais

Carbon materials as new generation of new electron shuttles for the anaerobic degradation of environmental xenobiotics

Tese de Doutoramento em Engenharia Química e Biológica

La carte postale et la représentation des espaces public et intime

La carte postale est un kaléidoscope de vues, d’ornements et de couleurs, qui consacre un tout petit espace au message. C’est à la photographie et aux procédés de reproduction photomécaniques que revient le mérite d’avoir industrialisé la production de la carte postale. Et ce sont les clichés de villes, avec leurs monuments et leurs paysages, qui confèrent à la carte postale son statut de moyen de communication de masse et qui lui concèdent une affinité avec l’industrie du tourisme. La carte postale s’est ainsi emparée de l’ambition photographique de reproduire le monde, s’alliant aux « besoins de l’exploration, des expéditions et des relevés topographiques » du médium photographique à ses débuts. Ayant comme point de départ la carte postale, notre objectif est de montrer les conséquences culturelles de la révolution optique, commencée au milieu du XIXe siècle, avec l’invention de l’appareil photo, et consumée dans la seconde moitié du XXe siècle, avec l’apparition de l’ordinateur. En effet, depuis l’apparition de l’appareil photographique et des cartes postales jusqu’au flux de pixels de Google Images et aux images satellite de Google Earth, un entrelacement de territoire, puissance et technique a été mis en oeuvre, la terre devenant, en conséquence, de plus en plus auscultée par les appareils de vision, ce qui impacte sur la perception de l’espace. Nous espérons pouvoir montrer avec cette étude que la lettre traditionnelle est à l’email ce que la carte postale est au post que l’on publie dans un blog ou dans des réseaux comme Facebook et Twitter. À notre sens, les cartes postales correspondent à l’ouverture maximale du système postal moderne, qui d’universel devient dépendant et partie intégrante des réseaux télématiques d’envoi. Par elles sont annoncés, en effet, la vitesse de transmission de l’information, la brièveté de la parole et l’hégémonie de la dimension imagétique du message, et pour finir, l’embarras provoqué par la fusion de l’espace public avec l’espace privé.