Ostracoda: database for the Neogene of Portugal

The "Ostracoda: database for the Neogene of Portugal", prepared under the Project "POCTl/36531/PAL/2000 - Studies on Portuguese Palaeontology / Post-Paleozoic", is presented. It provides information about 158 especies that have been recognized in sections and boreholes concerning Neogene units in Portugal

Androgenic alopecia: an entity to consider in adolescence

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El plutón Precámbrico-Cámbrico Inferior de Vila Nova (Centro de Portugal)

The Vila Nova pluton is a small, Pre-Variscan granitic body that intruded rocks of the Central Iberian Zone near the contact with the Ossa Morena Zone and is affected by several shear zones and faults. Its contact metamorphic aureole is constituted by micaschist with porphyroblasts in the outer zone and hornfels in the inner zone. Small metasedimentar xenoliths are dispersed all over the body. The pluton has a great mineralogical heterogeneity with pronounced variations in muscovite/biotite and plagioclase/microcline contents and is classified as granite, granodiorite or tonalite. It is a leucogranite, highly peraluminous (A/CNK = 1.31 – 1.64), magnesian and calc-alkaline to alkaline-calcic. The variation diagrams show curvilinear trends with silica. Eu/Eu* = 0.47 – 0.77 and there is a slight enrichment in LREE relative to HREE. The normalized diagrams indicated dominantly crustal granite, related to subduction. U-Pb isotopic data of zircon and monazite gives 540-542 Ma age.El plutón de Vila Nova es un pequeño cuerpo granítico pre-varisco, que intruyó en las rocas de la Zona Centro Ibérica, cerca del contacto con la Zona de Ossa Morena, siendo afectado por varias fallas y zonas de cizalla. Su aureola de metamorfismo de contacto consiste en esquistos con porfiroblastos y corneanas. Pequeños xenolitos metasedimentarios aparecen dispersos por todo el cuerpo granítico. Presenta una gran diversidad mineralógica, con amplias variaciones en las relaciones biotita/moscovita y microclina/plagioclasa, siendo clasificado como tonalita-granodiorita-granito. Se trata de un leucogranito fuertemente peralumínico (A/CNK = 1.31 – 1.64), magnesiano y calco-alcalino a alcalino-cálcico. Los diagramas muestran variaciones curvilíneas con la variación de sílice. Eu/Eu* = 0.47 – 0.77 y hay un ligero enriquecimiento de LREE en relación con HREE. Los diagramas indican que la norma es un granito dominante de la corteza, relacionados con la subducción. El isótopo U-Pb circón y monacita indican una edad de 540-542 Ma

Predicting the critical density of topological defects in O(N) scalar field theories

O(N) symmetric $\lambda \phi^4$ field theories describe many critical phenomena in the laboratory and in the early Universe. Given N and $D\leq 3$, the dimension of space, these models exhibit topological defect classical solutions that in some cases fully determine their critical behavior. For N=2, D=3 it has been observed that the defect density is seemingly a universal quantity at T_c. We prove this conjecture and show how to predict its value based on the universal critical exponents of the field theory. Analogously, for general N and D we predict the universal critical densities of domain walls and monopoles, for which no detailed thermodynamic study exists. This procedure can also be inverted, producing an algorithm for generating typical defect networks at criticality, in contrast to the canonical procedure, which applies only in the unphysical limit of infinite temperature.Comment: 4 pages, 3 figures, uses RevTex, typos in Eq.(11) and (14) correcte

Educação e mediação intercultural: Experiências e práticas de formação e investigação

Com base na comunicação que este grupo de investigadoras realizou nas primeiras Jornadas da Rede de Ensino Superior para a Mediação Intercultural “Entre Iguais e Diferentes a Mediação Intercultural”, apresentamos, sucinta-mente, alguns projetos de investigação, formação e intervenção educativa, em que temos estado envolvidas nas nossas instituições, e nos quais a mediação constituiu uma componente relevante. Adotamos aqui um conceito abrangente de mediação, considerando dispositivos, contextos, protagonistas e interações que concorrem para o desenvolvimento de processos de comunicação e de aproximação entre pessoas, grupos e/ou comunidades, no sentido da transformação pessoal e social, da emancipação e da coesão social. É por isso que nalguns casos os projetos foram (ou são) mais focados na mediação de conflitos, noutros na mediação cultural e noutros ainda na mediação intercultural e comunitária. Também os campos de ação e investigação em que estes projetos tiveram lugar podem considerar-se diversos. Alguns deles têm o seu foco no campo da formação, por vezes em articulação com a investigação, e outros no campo da ação socioeducativa, integrando processos de investigação, designadamente de investigação-ação e de etnografia crítica. Pensamos ser esta uma oportunidade para promover a divulgação destes projetos, favorecer o reconhecimento das nossas áreas de interesse e encontrar possíveis sinergias para o desenvolvimento de projetos comuns.info:eu-repo/semantics/publishedVersio

Natural attenuation processes in AMD context by mineralogical control: iron oxyhydroxides, oxyhydroxysulfates, and efflorescent sulfates

Acid mine drainage (AMD) is a common problem associated with the weathering of metal sulfide wastes in abandoned mining areas, which can be rich in toxic metals and metalloids. Oxidative dissolution of these minerals may negatively affect the soils and water reservoirs nearby. The formation of secondary mineral phases such as iron oxyhydroxides, oxyhydroxysulfates, and efflorescent sulfates may be a natural attenuation process in these areas because these minerals can scavenge potentially toxic elements. Typically formed by the evaporation (efflorescent salts) or precipitation (ochreous iron-rich oxyhydroxides) these minerals are highly soluble and reactive. Therefore, their characterization and inventory are particularly important for predicting the cycles of retention/contamination or accumulation zones of potential toxic elements (PTE) and acidity in mining contaminated systems. The abandoned mines of Valdarcas and São Domingos were selected for the present study due to their AMD signature and occurrence of some of these secondary minerals. Valdarcas (north of Portugal) is a W-mine associated with a skarn deposit with sulfides that has already been rehabilitated. However, the AMD problems remain in the watercourse that receives leachates from the waste dumps. São Domingos is a Cu-mine composed of massive sulfide deposits that belong to the Iberian Pyrite Belt (south of Portugal). This mining area, which is presently under remediation process, is highly contaminated and AMD is a longlasting problem. The samples collected in these mining areas were characterized by their morphology, size, mineralogy, and chemical composition using different techniques: binocular microscopy, SEM-EDS, TEM, BET, DRX, FTIR, and XPS. In Valdarcas mine area, typical ochreous phases such as schwertmannite and goethite were identified as the dominant secondary phases. These brownish-yellow ferric amorphous and poorly crystalline minerals with high surface area (125 mg2 /m) can remove PTE via adsorption processes, contributing to their retention in the mining environment. In contrast, at São Domingos, efflorescent sulfate salts are more abundant. Melanterite and copiapite were the prevailing salts identified. With different morphologies, these minerals are highly soluble and therefore play a relevant key in the retention/mobilization cycles of hazardous contaminants, such as arsenic (As). This integrative methodologic approach, based on the use of several techniques, allowed a complete characterization of these minerals. In addition to composition, the surface properties that are relevant for the adsorption ability, were also obtained. Therefore, the study revealed a diversity of behaviors for the identified phases, suggesting various roles in increasing the resilience of the contaminated systems

Spatio-temporal vulnerability assessment in fractured groundwater systems

Governance reforms are required to demonstrate adaptive and resilient urban water resource management that considers complexity, uncertainty in immediate and long term change. Contamination of groundwater is a complex process and full of uncertainty at local and regional scale. The main objective of this research is the study of vulnerability to pollution in an unconfined karstic aquifer. Mainly it is addressed vulnerability integration, in relation to policy, specifically in risk evaluation and risk–benefit considerations. Development of an integrated vulnerability assessment methodology can be useful to effectively manage and protect this valuable freshwater source. The research insights suggest that the establishment of a pattern of effective governance is mandatory as the future highway, the prison and the airport are overlaying the most vulnerable areas of the aquifer and therefore provide policy makers guidance in overcoming urban water governance challenges.info:eu-repo/semantics/publishedVersio

Estratégias de comercialização do feijão no Rio Grande do Sul.

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