Risk Premium: Insights Over The Threshold

The aim of this paper is twofold: First to test the adequacy of Pareto distributions to describe the tail of financial returns in emerging and developed markets, and second to study the possible correlation between stock market indices observed returns and return’s extreme distributional characteristics measured by Value at Risk and Expected Shortfall. We test the empirical model using daily data from 41 countries, in the period from 1995 to 2005. The findings support the adequacy of Pareto distributions and the use of a log linear regression estimation of their parameters, as an alternative for the usually employed Hill’s estimator. We also report a significant relationship between extreme distributional characteristics and observed returns, especially for developed countries.

Myopic Loss Aversion and House-Money Effect Overseas: an experimental approach

Recent literature has found two behavioral effects - house-money and myopic loss aversion (MLA) - in several experimental designs. We show that although we can find a house-money effect using survey methods this evidence disappears when we study investment decision within a multi-period investment experiment. Loss aversion is found to govern the risk-taking behavior of subjects in dynamic settings, overcoming the house-money effect. These results are robust to experiments conducted in two different countries, Spain and Brazil.

Simple camera calibration for light measurements

The availability and decreasing prices of digital photographic cameras using megapixel sensors could point to its use as high quality light measuring devices if simple and effective calibration procedures could be put to work.This paper proposes such a system, using a common digital camera combined with low cost reference color charts. The procedure to obtain the response function of the camera, the production of the color chart and its calibration is presented.In this way, it is possible to obtain light measurements otherwise only possible with sophisticated and expensive equipments.The research work is being conducted with partial funding from FCT (Portuguese Foundation for Science and Technology)

The feasibility of wavelength dispersive X-ray fluorescence spectrometry for the assessment of lead concentration in animal bone powder

"This work demonstrates the feasibility of wavelength dispersive X-ray fluorescence for the assessment of lead in animal bone powder.

Expansion and access to high quality undergraduate courses in Brazil : other quality indicators for higher education

O artigo apresenta resultados parciais de pesquisa com foco na expansão e no acesso a cursos de graduação de alta qualidade avaliados pelo Sistema Nacional de Avaliação da Educação Superior (Sinaes). Discute aspectos que favorecem a compreensão da avaliação da qualidade da educação superior e do debate sobre o Estado avaliador e o Estado regulador. Focaliza as bases epistemológicas e a disputa pela concepção de qualidade no Sinaes capazes de provocar alterações no caráter formativo-emancipatório atribuído à avaliação. A análise de quatro cursos com maior expansão e de alta qualidade, reiterada nos três ciclos avaliativos (2004-2012), evidencia que a ampliação desses cursos não se dá no mesmo ritmo da que ocorre de forma geral. A reflexão mostra também que o Enade se consolida como métrica eficaz de qualidade, mas requer associação a outros indicadores.The article presents partial results of research focused on the expansion and access to high quality undergraduate courses according to Sinaes. It discusses aspects that favor the understanding of the evaluation of quality of higher education and the debate concerning the evaluative state and the regulatory state. It approaches the epistemological basis and the dispute for the conception of quality in the Sinaes that are able to change the formative-emancipatory evaluation of the exam. The analysis of four courses with greater expansion, and the repeated high quality in the three evaluation cycles (2004-2012) indicates that the expansion of high quality courses does not occur the rhythm of the overall expansion. The reflection also demonstrates that the Enade has consolidated itself as an efficient quality metric but its association with other indicators is required

Thermal stability and decomposition kinetics of NdNiO3− δ at 1 bar of O2

Despite the interest in rare-earth nickelates for applications, their processing under 1 bar of oxygen pressure is still challenging. In this work, we report the co-precipitation synthesis, thermal stability and thermally driven decomposition of NdNiO3 phase, in order to determine the synthesis parameters towards a pure perovskite phase. We concluded that using a 1% molar excess of Nd during preparation and posterior annealing at around 900 °C at 1 bar of O2 yields an almost pure NdNiO3−δ phase (with a hexagonal Nd2O3 phase below 0.6% molar), with an oxygen deficiency of δ = 0.082 ± 0.001. The decomposition of the NdNiO3−δ phase into Nd4Ni3O10 and NiO was found to start above 900 °C. On further heating, above 1050 °C, the Nd4Ni3O10 decomposes into Nd2NiO4 and NiO phases. Structural parameters and Raman spectra are provided for the NdNiO3, Nd4Ni3O10 and Nd2NiO4 compounds.The authors would like to acknowledge Fundacao para a Ciencia e Tecnologia (FCT) through projects NORTE/01/0145/FEDER/028538, CERN/FIS-PAR/0005/2017, CERN/FIS-TEC/0003/2019, PTDC/FIS-MAC/29454/2017 and when appropriate co-financed by FEDER under PT2020 Partnership Agreement: CQVR: UIDB/QUI/00616/2020; IFIMUP-IN: Norte-070124-FEDER-000070; NECL: NORTE-01-0145-FEDER-022096, UID/NAN/50024/2019. P. Machado and J. Oliveira acknowledge FCT through Ph.D. Grants SFRH/BD/108509/2015 and SFRH/BD/146886/2019 respectively. A special acknowledgment is made to CEMUP for XPS measurements

Movement velocity as a measure of exercise intensity in three lower limb exercises

The purpose of this study was to investigate the relationship between movement velocity and relative load in three lower limbs exercises commonly used to develop strength: Leg Press, Full Squat, and Half Squat. The percentage of one Repetition Maximum (%1RM) has typically been used as the main parameter to control resistance training, however more recent research has proposed movement velocity as an alternative. Fifteen participants performed a load progression with a range of loads until they reached their one repetition maximum (1RM). Maximum instantaneous velocity V max) and mean propulsive velocity (MPV) of the knee extension phase of each exercise were assessed. For all exercises, a strong relationship between V max and the %1RM was found: Leg Press (r2adj=0.96; 95% CI for slope is [-0.0244,-0.0258], p<0.0001), Full Squat (r2adj=0.94; 95% CI for slope is [-0.0144, -0.0139], p<0.0001), and Half Squat (r2adj=0.97; 95% CI for slope is [-0.0135, -0.00143], p<0.0001), and for MPV, Leg Press (r2adj=0.96; 95% CI for slope is [- 0.0169, -0.0175], p<0.0001, Full Squat (r2adj=0.95; 95% CI for slope is [-0.0136, -0.0128], p<0.0001), and Half Squat (r2adj=0.96; 95% CI for slope is [-0.0116, 0.0124], p<0.0001). The 1RM was attained with a MPV and Vmax of 0.21±0.06 ms-1 and 0.63±0.15 ms-1, 0.29±0.05 ms-1 and 0.89±0.17 ms-1, 0.33±0.05 ms-1, and 0.95±0.13 ms-1 for Leg Press, Full Squat and Half Squat respectively. Results indicate that it is possible to determine an exercise-specific %1RM by measuring movement velocity for that exercise

Micorrizas vesicular-arbusculares em mudas de cafeeiro produzidas no sul do estado de Minas Gerais

A survey was conducted to assess the mycorrhizal status of coffee (Coffea arabica L) seedlings produced in the southern part of Minas Gerais State, Brazil. The survey showed that most seedlings were poorly colonized and had a very low spore density in the rhizosphere. From the 72 samples studied, 79% had colonization percentages below 20% with a mean of 13.8%, and 65% of the 72 had less than 20 spores/100 ml of substrate with a mean of 16.3. Ten species of VAM fungi were found with Acaulospora scrobiculata, A. morrowae and A. spinosa being the most common. Correlation analyses between soil and plant variables and fungal root colonization and spore density were of little value in explaining variations in mycorrhizal development. However, natural low infectivity of the substrate and the systematic use of pesticides and fertilizers are suggested as factors responsible for the low mycorrhizal development and spore density in the rhizosphere of these seedlings. Implications of the poor mycorrhizal development to seedling growth are discussed. Levantamento da ocorrência de micorrizas vesicular-arbusculares (MVA) em mudas de cafeeiro (Coffea arabica L.),produzidas na região sul do estado de Minas Gerais, demonstrou que a maioria destas mudas estavam subcolonizadas e com baixa densidade de esporos na rizosfera. Das 72 amostras estudadas, 79% apresentaram taxa de colonização inferior a 20%, com média de 13,8% e 65% das 72 tinham menos que 20 esporos/100 ml de substrato, com média de 16,3. Foram encontradas dez espécies de fungos MVA, sendo A. scrobiculata, A. morrowae e A. spinosa as espécies predominantes. Análises de correlação entre características de solo e planta, com colonização e número de esporos não explicaram as variações na colonização e densidade de esporos. Entretanto os dados indicam que a baixa infectividade do substrato e o uso sistemático de pesticidas e fertilizantes são os fatores responsáveis pela baixa colonização micorrízica destas mudas. As implicações da baixa colonização micorrízica para o desenvolvimento das mudas são também discutidas.

An integrated analysis of the eutrophication process in the Enxoé reservoir within the DPSIR framework

The Enxoé reservoir in southern Portugal has been exhibiting the highest trophic state in the country since its early years of operation. The problem has attracted water managers’ and researchers’ attention as the reservoir is the water supply for two municipalities. Extensive research was thus conducted over the last few years, including field monitoring and modelling at the plot, catchment, and reservoir scales. This study now frames all partial findings within the Driver-Pressure-State-Impact-Response (DPSIR) framework to better understand the eutrophication process in the Enxoé reservoir. Agriculture and grazing were found to have a reduced role in the eutrophication of the reservoir, with annual sediment and nutrient loads being comparably smaller or similar to those reported for other Mediterranean catchments. Flash floods were the main mechanism for transporting particle elements to the reservoir, being in some cases able to carry up three times the average annual load. However, the main eutrophication mechanisms in the reservoir were P release from deposited sediment under anoxic conditions and the process of internal recycling of organic matter and nutrients. Reducing the P load from the catchment and deposited sediment could lead to a mesotrophic state level in the reservoir. However, this level would only be sustainable by limiting the P internal load ability to reach the photic zoneinfo:eu-repo/semantics/publishedVersio

Coeval perpendicular shortenings in the Brasilia belt : collision of irregular plate margins leading to oroclinal bending in the Neoproterozoic of central Brazil

The three belts which form the Tocantins province (central Brazil) records Neoproterozoic-EoPaleozoic collisions involving the Amazon and São Francisco paleocontinents and the Paraná continental block. The Brasília belt is a typical orocline bended around the WNW—ESE striking Pirineus Zone of High Strain (PZHS) and is comprised of the NE-trending (northern) and SE-trending (southern) segments. The Brasília dome is an N—S elliptical structural window situated in the center of the belt, at the eastern end of the PZHS. It evidences Di— D₂ and D₃ɴ shortenings (~ 750—590 Ma) due to ocean closure and Amazon- São Francisco collision following a WNW—ESE path, and demonstrates similar evolution for both segments of the belt. However, in the southern segment, D₁—D₂ structures are deformed by shortening in the SW-NE direction (D₃S). New data demonstrating D₁—D₂ and D₃ɴ tectonites deformed by D₃S struc- tures in the area close to the dome's SW margin and SE of the PZHS support understanding the Brasília belt and oroclinal bending as a consequence of the collision of two (Amazon and São Francisco) irregular continental margins leading to separation-rotation of the Paraná block from the Amazon paleocontinent and the Paraná-São Francisco collision