Mineral paragenesis and fluid inclusion constraints on the Torre di Rio skarn, Island of Elba

The historical iron ore deposits of eastern Elba held great importance for the region and were its primary source of iron. The Torre di Rio skarn, despite its easily accessible outcrop and vicinity to the larger Rio Marina deposit, was never properly characterized. The results of petrographic and microthermometric study presented in this work provide new constraints on the Torre di Rio skarn. Mineral assemblage of ilvaite, calcite, quartz, iron oxides and sulphides combined with textural evidence indicate that Torre di Rio skarn does not fit into classical skarn model. The complex paragenetic sequence and overlapping of skarn and ore mineralogy is result of fast formation at relatively low temperatures evidenced by the silicon enrichment and pervasive nature of limonite alteration. Hematite-magnetite textural relationship points to boundary conditions of the ore fluid in terms of oxygen fugacity. Eutectic temperatures range from -16 to -33 °C indicating complex fluids. Calculated salinities range from 1.4 to 17.4 wt% NaCleq suggesting multiple fluids of different compositions. Total homogenization temperatures vary from 330 °C to 150 °C with both homogeneously and heterogeneously trapped FIAs. Ore deposition is concentrated where skarn formation was controlled primarily by phase separation during boiling. Calculated fluid pressure at boiling suggest shallow formation depth of a few hundred meters and constrains maximum temperature of ore deposition to c. 260 °C. This work suggest that relatively low salinities of fluid inclusions could indicate dominant marine origin of the hydrothermal fluids that were activated by the Porto Azzurro pluton emplacement and that scavenged Fe from sedimentary host rocks. During boiling at shallow depths and decreasing iron solubility, these fluids started precipitating Fe-minerals at Torre di Rio mineralization. Mixing with batches of more saline fluids at around 236 °C increased salinity abruptly and marked the end of ore deposition.

Constraints on the duty cycle of the remnant radio galaxy NGC 6086 in the galaxy group Abell 2162

Galaxy clusters and groups are the most massive bounded structures and the knots of the large-scale structure of the Universe. These structures reside in dark matter haloes, hosting tens to hundreds of galaxies and they are filled with hot and rarefied gas. Radio Galaxies are a peculiar class of galaxies with a luminosity in the radio band up to 10^46 erg/s between 10 MHz and 100 GHz. These galaxies are a subclass of AGN in which there is accretion on the Super Massive Black Hole. The accretion generates jets of relativistic particles and magnetic fields which lose energy through synchrotron radiation, best observable at radio frequencies. The study of the spectral ageing of the AGN plasma is fundamental to understand its evolution, interaction with the environment and to constrain the AGN duty cycle. n this thesis, we have investigated the duty cycle of the nearby remnant radio galaxy NGC 6086, located in the centre of the galaxy group Abell 2162. We have made major steps forward thanks to the new high-sensitivity interferometers in the low-frequency radio band. We have detected for the first time three filaments of emission and a second couple of lobes. We have performed an integrated and resolved analysis on the previously known inner lobes, the new filaments and the older outer lobes. We have performed an age estimate of the two pairs of lobes to give constraints on the duty cycle of the source and an estimate of its active time.

Genetic Aspects Of Athletic Performance: The African Runners Phenomenon.

The current dominance of African runners in long-distance running is an intriguing phenomenon that highlights the close relationship between genetics and physical performance. Many factors in the interesting interaction between genotype and phenotype (eg, high cardiorespiratory fitness, higher hemoglobin concentration, good metabolic efficiency, muscle fiber composition, enzyme profile, diet, altitude training, and psychological aspects) have been proposed in the attempt to explain the extraordinary success of these runners. Increasing evidence shows that genetics may be a determining factor in physical and athletic performance. But, could this also be true for African long-distance runners? Based on this question, this brief review proposed the role of genetic factors (mitochondrial deoxyribonucleic acid, the Y chromosome, and the angiotensin-converting enzyme and the alpha-actinin-3 genes) in the amazing athletic performance observed in African runners, especially the Kenyans and Ethiopians, despite their environmental constraints.

Possible Unconventional Superconductivity In Substituted Bafe2as2 Revealed By Magnetic Pair-breaking Studies.

The possible existence of a sign-changing gap symmetry in BaFe2As2-derived superconductors (SC) has been an exciting topic of research in the last few years. To further investigate this subject we combine Electron Spin Resonance (ESR) and pressure-dependent transport measurements to investigate magnetic pair-breaking effects on BaFe1.9M0.1As2 (M = Mn, Co, Cu, and Ni) single crystals. An ESR signal, indicative of the presence of localized magnetic moments, is observed only for M = Cu and Mn compounds, which display very low SC transition temperature (Tc) and no SC, respectively. From the ESR analysis assuming the absence of bottleneck effects, the microscopic parameters are extracted to show that this reduction of Tc cannot be accounted by the Abrikosov-Gorkov pair-breaking expression for a sign-preserving gap function. Our results reveal an unconventional spin- and pressure-dependent pair-breaking effect and impose strong constraints on the pairing symmetry of these materials.

Convergence Of Soil Nitrogen Isotopes Across Global Climate Gradients.

Quantifying global patterns of terrestrial nitrogen (N) cycling is central to predicting future patterns of primary productivity, carbon sequestration, nutrient fluxes to aquatic systems, and climate forcing. With limited direct measures of soil N cycling at the global scale, syntheses of the (15)N:(14)N ratio of soil organic matter across climate gradients provide key insights into understanding global patterns of N cycling. In synthesizing data from over 6000 soil samples, we show strong global relationships among soil N isotopes, mean annual temperature (MAT), mean annual precipitation (MAP), and the concentrations of organic carbon and clay in soil. In both hot ecosystems and dry ecosystems, soil organic matter was more enriched in (15)N than in corresponding cold ecosystems or wet ecosystems. Below a MAT of 9.8°C, soil δ(15)N was invariant with MAT. At the global scale, soil organic C concentrations also declined with increasing MAT and decreasing MAP. After standardizing for variation among mineral soils in soil C and clay concentrations, soil δ(15)N showed no consistent trends across global climate and latitudinal gradients. Our analyses could place new constraints on interpretations of patterns of ecosystem N cycling and global budgets of gaseous N loss.

A dança na formação docente em educação física

Universidade Estadual de Campinas . Faculdade de Educação Física

Metodologia para descrição tridimensional do movimento humano a partir de cameras de video não sincronizadas

Universidade Estadual de Campinas. Faculdade de Educação Física

Habilidade motora fundamental : analise comparativa entre situação laboratorial e "natural"

Universidade Estadual de Campinas. Faculdade de Educação Física

Padrão fundamental de movimento : uma analise universal ou contextual?

Universidade Estadual de Campinas . Faculdade de Educação Física

Estabilidade motora de pessoas portadoras de Sindrome de Dawn, em tarefas de desenhar

Universidade Estadual de Campinas . Faculdade de Educação Física

Articulação Centro de Pesquisa: Escola Básica: contribuições para a alfabetização científica e tecnológica

Neste artigo são discutidos aspectos relacionados à seleção e organização dos conteúdos a serem abordados durante e após visitas a laboratórios de pesquisa em física. Utilizando como exemplo o trabalho de divulgação realizado no acelerador de partículas Pelletron (Instituto de Física da Universidade de São Paulo), com alunos do ensino médio, procuramos identificar elementos que podem orientar o desenvolvimento de propostas escolares organizadas a partir de visitas a centros de pesquisa. Nesse sentido, destaca-se o potencial dessas visitas para a realização de discussões sobre as relações entre Ciência-Tecnologia-Sociedade e a importância do estabelecimento de vínculos com o conteúdo escolar