Processos de Degradação do Solo na Região Autónoma dos Açores

A RAA ou o Arquipélago dos Açores é formado por nove ilhas, distribuías por três distintos grupos: O Grupo Oriental é composto por São Miguel e Santa Maria, o grupo Central é composto pelas Ilhas da Terceira, São Jorge, Graciosa, Pico e Faial e o grupo Ocidental é composto pelas Ilhas de Flores e Corvo. A RAA possui um clima temperado marítimo, que se caracteriza por temperaturas amenas com fracas amplitudes térmicas anuais, elevada humidade relativa do ar e por uma pluviosidade distribuída ao longo do ano. O Relevo é acidentado composto por montanhas que possuem diversas caldeiras, cones vulcânicos, ravinas de grande dimensão e vales estreitos e profundos por onde correm um grande número de pequenos cursos de água, denominados por ribeiras. Os solos presentes nas nove ilhas dos Açores pertencem na sua maioria à categoria - Andossolos - estes são uma das fases de criação de um solo de origem vulcânica, surgem por norma 200 anos após uma erupção vulcânica, alcançando o topo das suas características cerca de cento e cinquenta mil anos após a erupção. As ilhas que compõem a RAA estão muito expostas a processos de degradação do solo, principalmente através da erosão hídrica e da erosão do litoral. Este facto justifica-se pelas características topográficas, litológicas e climáticas das ilhas.

Continuidade e mudança. O sistema internacional no post‐Guerra Fria

O fim da Guerra Fria é um caso inédito de mudança pacífica da estrutura internacional, em que os Estados Unidos e a União Soviética transcendem a divisão bipolar para decidir os termos da paz no quadro das instituições que definem o modelo de ordenamento multilateral, consolidando a sua legitimidade. Nesse contexto, ao contrário dos casos precedentes de reconstrução internacional no fim de uma guerra hegemónica, o novo sistema do post-Guerra Fria, caracterizado pela unipolaridade, pela regionalização e pela homogeneização, forma-se num quadro de continuidade institucional. A ordem política do post-Guerra Fria é um sistema misto em que as tensões entre a hierarquia unipolar e a anarquia multipolar, a integração global e a fragmentação regional e a homogeneidade e a heterogeneidade política, ideológica e cultural condicionam as estratégias das potências. As crises internacionais vão pôr à prova a estabilidade da nova ordem e a sua capacidade para garantir mudanças pacíficas. A primeira década do post-Guerra Fria mostra a preponderância dos Estados Unidos e a sua confiança crescente, patente nas Guerras do Golfo Pérsico e dos Balcãs, bem como na crise dos Estreitos da Formosa. A reacção aos atentados do "11 de Setembro" revela uma tentação imperial da potência unipolar, nomeadamente com a invasão do Iraque, que provoca uma crise profunda da comunidade de segurança ocidental. A vulnerabilidade do centro da ordem internacional é confirmada pela crise constitucional europeia e pela crise financeira global. Essas crises não alteram a estrutura de poder mas aceleram a erosão da ordem multilateral e criam um novo quadro de possibilidades para a evolução internacional, que inclui uma escalada dos conflitos num quadro de multipolaridade regional, uma nova polarização entre as potências democráticas conservadoras e uma coligação revisionista autoritária, bem como a restauração de um concerto entre as principais potências internacionais.

Ancient materials and techniques to improve the earthen building durability

A substantial part of the world building heritage has been performed by earthen building. The durability of this existing heritage and mainly of the new buildings built with earth is particularly conditioned by the erosion caused by water action, especially in countries with high levels of rainfall. This research aims to contribute to the increase of knowledge about the ancient building techniques that provide enhanced durability. It is possible to analyse the ancestral practices used to protect the earth material from the water action in order to understand how the old earthen buildings were preserved over the centuries, resisting to harsh weather conditions. Among these techniques are: the incorporation of biopolymers (such as oils or fats from animal or vegetable origin); the addition of some minerals; and the earth stabilization with lime. However, this knowledge seems to be forgotten, probably due to the prejudice related to earthen constructions, which several times are associated with a poor building. This research also focuses on the study of new methods of earth stabilization with lime and biopolymers, adapting the ancient knowledge to improve the durability related to the water action. Therefore, alternative solutions can be obtained to improve the performance of earthen buildings, mainly the resistance of the material in the presence of water, reducing its permeability to water. In addition, with the proposed solutions it is possible to obtain good levels of water vapour permeability, one of the major advantages of the construction with earth.

Avaliação do transporte sedimentar na bacia do rio Lima baseada em ferramentas de modelação

Dissertação de mestrado integrado em Engenharia Civil

Estudo numérico do escoamento e transporte de sedimentos em torno de pilares de pontes

Dissertação de mestrado integrado em Engenharia Civil

Estudo paleoetnobotânico do povoado da Idade do Ferro do Crastoeiro (Noroeste de Portugal)

Dissertação de mestrado em Arqueologia

Development of a poly(L-Lactic acid) based drug release system

Dissertação de mestrado em Biofísica e Bionanossistemas

A utilização dos preços de transferência pelas empresas multinacionais como mecanismo de evasão fiscal

Dissertação de mestrado em Direito Tributário e Fiscal

A comparative study of the physical, chemical and microbiological status of soils, as influenced by conventional and reduced tillage

Historically, shifts to reduced and no-tillage management for production of crops were fostered by needs to decrease soil erosion and loss of organic matter, reduce fuel and labour costs and conserve soil water, as compared with conventional fallow tillage management. Recent interest in maintaining soil quality has been stimulated by a renewed awareness of the importance of soil condition to both the sustainability of agricultural production systems and environmental quality (Doran and Parkin, 1996). The aim of this project was to determine the impact on the physical, chemical and microbiological status of the soil of conventional and reduced tillage. It has been suggested that the reduced soil disturbance associated with the tine cultivator improves soil structure, increases nutrient content in the top 10cm of soil, increases microbial activity and improves physical characteristics. From this study it was determined that the environmental benefits linked to reduced tillage in literature, did not develop in the first two years of this programmes implementation. The results of this study determined that soil nutrients did not increase in concentration in the top 10 cm of soil under reduced cultivation. The only exception was exchangeable potassium. As potassium is not a mobile nutrient its movement is dependent on soil disturbance, therefore under reduced cultivation its concentration was allowed to accumulate in the upper horizon of the soil profile. Microbial activity was greater in the conventionally tilled treatments, as determined by total aerobic bacterial numbers. This could be due to the increased rates of soil aeration in this treatment. Numbers of aerobic bacteria were greater in the conventional tillage treatments at both incubation temperatures of 22 and 32° C. The physical characteristics of the soil determined, indicate that below the depth of soil cultivation, cone penetration resistance increases. Therefore the reduced cultivation treatments would be more prone to soil compaction, higher in the soil profile.

Classical horizontal inequity and reranking: an integrated approach

The last 20 years have seen a significant evolution in the literature on horizontal inequity (HI) and have generated two major and "rival" methodological strands, namely, classical HI and reranking. We propose in this paper a class of ethically flexible tools that integrate these two strands. This is achieved using a measure of inequality that merges the well-known Gini coefficient and Atkinson indices, and that allows a decomposition of the total redistributive effect of taxes and transfers in a vertical equity effect and a loss of redistribution due to either classical HI or reranking. An inequality-change approach and a money-metric cost-of-inequality approach are developed. The latter approach makes aggregate classical HI decomposable across groups. As in recent work, equals are identified through a nonparametric estimation of the joint density of gross and net incomes. An illustration using Canadian data from 1981 to 1994 shows a substantial, and increasing, robust erosion of redistribution attributable both to classical HI and to reranking, but does not reveal which of reranking or classical HI is more important since this requires a judgement that is fundamentally normative in nature.

Os grandes clímaces do Brasil: I - considerações sôbre os tipos vegetativos da região sul

Der Autor schlaegt eine Unterteilung der Vegetation vor, die sich auf die grossen Landschaftstypen Brasiliens bezieht. Er grenzt diese gegeneinander ab und beschreibt sie in grossen Zuegen, soweit sie bis heute bekannt sind. Er bringt einige Komentare zur Phytoklimatologie und zeigt, dass die Versuche einer floristischen Einteilung auf klimatischer Grundlage nichtbefriedigend sind; er laesst den "Klimax" nur zu als Annahme des maximalen Ausdrucks der Vegetation innerhalb eines begrenzten Gebiets. Ers bespricht kurz die regionalen geomorphologischen Studien und beschreibt zum Schluss jeden phyto-oekologischen Typ. Er beleuchtet in den Beschreibungen alle historischen Moeglichkeiten, wobei er sich auf die palaeo-Oekologie und Phylogenese stuetzt. In Suedbrasilien finden wir, abgesehen von den Waeldern der immerfeuchten Regenzonen, den Cerrado und den Campo und neben diesen den Wald der periodisch trockenen Klimate. Der Autor weist daraufhin, dass die Ausbreitung der Formationen mehr an den "Raum" als an die "Zeit" gebunden sind, dieses will besagen, dass in juengst bewachsenen Gebieten der Wald sich in jeder Richtung ausdehnt und in alt bewachsenen Regionen mit tiefen Boeden der Cerrado und in solchen mit flachen Boeden der Campo sich allseits ausbreiten. 1. Der Laubwald, der sich wahrscheinlich seit der juengeren Pluvialzeit ausbreitet, befidet sich heute noch in voller Taetigkeit: a) der Wald der Abhaenge der kristalinen Gebirge der Sued-Atlantikkueste, der schattige Haenge bedeckt und durch cyophile und phylogenetisch primitive Elemente gekennzeichnet ist, scheint die aeltere Ausbreitung darzustellen; und b) der Wald der Einzugsbecken und Kuestenebenen, der die aluvialen Gelaende einnimmt und durch heliophile und hoeher entwickelte Arten charakterisiert ist, scheint die modernere Ausbreitung zu vertreten. 2. Der Nadelwald, der dem Einzugsnetz der Hochflaech folgend sich in relativ neuer Zeit ausgebreitet hat, befindet sich ebenfalls auch heute noch in voller Taetigkeit: a) in Gebieten der Campos, neuerdings wieder bewachsen (Niederungen, Quellgruende usw), finden wir die seiner heutigen Ausbreitung; und b) die ausschliesslich erwachsenen Elemente inmitten von Laubwald zeigen sein heutigen Gebiet des Konkurrenzhampfes an. 3. Die Savannen und Campos, urspruenglich in Abhaengigkeit von ihrem geologischen Ursprung auf die sauren, armen Boeden beschraenkt, dehnen sich schnell infolge Raubbaus durch den Menschen auf neue Gebiete aus: a) zerstoerte Waldgebiete auf tiefen Sandformationen, wo der entwaldete Boden im halbfeuchten Klima der Lateritisierung beschleunigt unterliegt, sind Bildung des Cerrados ausgesetzt; b) zerstoerte Waldgebiete auf Tonformationen, wo die Erosion schnell bis zu den halbzerlegten Gesteinen fortschreitet, werden in Campo verwandelt; und c) Ackerbaugebiete und Weiden auf jedem Boden, wo periodisch gebrannt wird, sind gezwungenermassen dem "Feuer-Klimax" unterworfen. 4. Bezueglich der historischen Vergangenheit der heute von einem bestimmten Vegetationstyp bedeckten Gebiete kann nur eine Pollenanalyse der lokalen organischen Ablagerungen definitive Antwort geben.

Genome of an arbuscular mycorrhizal fungus provides insight into the oldest plant symbiosis.

The mutualistic symbiosis involving Glomeromycota, a distinctive phylum of early diverging Fungi, is widely hypothesized to have promoted the evolution of land plants during the middle Paleozoic. These arbuscular mycorrhizal fungi (AMF) perform vital functions in the phosphorus cycle that are fundamental to sustainable crop plant productivity. The unusual biological features of AMF have long fascinated evolutionary biologists. The coenocytic hyphae host a community of hundreds of nuclei and reproduce clonally through large multinucleated spores. It has been suggested that the AMF maintain a stable assemblage of several different genomes during the life cycle, but this genomic organization has been questioned. Here we introduce the 153-Mb haploid genome of Rhizophagus irregularis and its repertoire of 28,232 genes. The observed low level of genome polymorphism (0.43 SNP per kb) is not consistent with the occurrence of multiple, highly diverged genomes. The expansion of mating-related genes suggests the existence of cryptic sex-related processes. A comparison of gene categories confirms that R. irregularis is close to the Mucoromycotina. The AMF obligate biotrophy is not explained by genome erosion or any related loss of metabolic complexity in central metabolism, but is marked by a lack of genes encoding plant cell wall-degrading enzymes and of genes involved in toxin and thiamine synthesis. A battery of mycorrhiza-induced secreted proteins is expressed in symbiotic tissues. The present comprehensive repertoire of R. irregularis genes provides a basis for future research on symbiosis-related mechanisms in Glomeromycota.

Estudi pilot del progrés de la restauració a les activitats extractives de Catalunya

L’objecte d’aquest estudi és determinar el ritme restaurador i caracteritzar la tipologia de les restauracions d’algunes activitats extractives de Catalunya. S’ha analitzat l’evolució dels treballs de restauració en una selecció d’activitats extractives de Catalunya i s’ha estimat la qualitat de les restauracions efectuades en base a la observació de la vegetació desenvolupada, el control de l’erosió i la integració paisatgística. Per dur a terme aquest estudi s’ha creat una base de dades en format de qüestionari, combinada amb un sistema d’informació geogràfica, que s’ha assajat en un treball de camp amb una mostra limitada d’activitats extractives. A partir de la interpretació dels resultats, es determina que actualment la gestió incorpora la necessitat de restaurar, però com a element subordinat a la producció. Això produeix una manca de planificació que incideix directament en la qualitat de les restauracions dutes a terme. La gestió de les pedreres encara ha de situar el concepte de restauració integrada com a eix central del desenvolupament i planificació de l’activitat extractiva.

The Corrosion of Career? - Occupational Trajectories of Business Economists and Engineers in Switzerland

Achievement careers are regarded as a distinctive element of the post-war period in occidental societies. Such a career was at once a modal trajectory of the modern parts of middleclass men and a social emblem for progress and success. However, if the achievement career came to be a biographical pattern with great normative power, its precise sequential course remained vague. Theories of the 1960s and 1970s described it as an orderly advancement within large firms. By the 1990s, scholars postulated an erosion of the organizational structures that once contributed to the institutionalization of careers, accompanied by a weakening of the normative weight of the achievement career by management discourse. We question the thesis of the corrosion of achievement career by analysing the trajectories of 442 engineers and business economists in Switzerland in regard to their orderliness, loyalty, and temporal rhythm. An inspection of types of careers and cohorts reveals that even if we face a decline of loyalty over time, hierarchical orderliness is not touched by those changes. Foremost, technical-industrial careers fit the loyal and regular pattern. Hence, this trajectory-type represents only a minority and is by far the slowest and least successful in terms of hierarchical ascension.

Response of photosynthetic organisms to global change: an approach based on marker pigments

Report for the scientific sojourn carried out at the Department of Freshwater Ecology, National Environmetal Research Institute, Denmark, from 2006 to 2008. The main objective of the project was to reconstruct photosynthetic organism community composition using pigmentbased methods and to study their response to natural (e.g. climate) or anthropogenic (e.g. eutrophication) perturbations that took place in the system over time. We performed a study in different locations and at different temporal scales. We analysed the pigment composition in a short sediment record (46 cm sediment depth) of a volcanic lake (Lake Furnas) in the Azores Archipelago (Portugal). The lake has been affected during the last century by successive fish introductions. The specific objective was to reconstruct the lake’s trophic state history and to assess the role of land-use, climate and fish introductions in structuring the lake community. Results obtained suggested that whereas trophic cascade and changes in nutrient concentrations have some clear effects on algal and microbial assemblages, interpreting the effects of changes in climate are not straightforward. This is probably related with the rather constant precipitation in the Azores Islands during the studied period. We also analysed the pigment composition in a long sediment record (1800 cm sediment depth) of Lake Aborre (Denmark) covering ca. 8kyr of lake history. The specific objective was to describe changes in lake primary production and lake trophic state over the Holocene and to determine the photosynthetic organisms involved. Results suggested that external forcing (i.e. land use changes) was responsible of erosion and nutrient run off to the lake that contributed to the reported changes in lake primary production along most of the Holocene.