915 research outputs found

    Modelling Taylor Rule Uncertainty

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    In recent years, one has witnessed a widespread attention on the way monetary policy is conducted and in particular on the role of the so-called monetary policy rules. The conventional approach in the literature consists in estimating reaction functions for a monetary authority (the Federal Reserve, in most cases) in which a nominal interest rate, directly or indirectly controlled by that monetary authority, is adjusted in response to deviations of inflation (current or expected) from target and of output from potential. These reaction functions, usually called Taylor rules, following John Taylor's seminal paper published in 1993, match a number of normative principles set forth in the literature for optimal monetary policy. This provides a good reason for the growing prominence of indications given by Taylor rule estimations in debates about current and prospective monetary policy stance. However, they are usually presented as point estimates for the interest rate, giving a sense of accuracy that can be misleading. Typically, no emphasis is placed on the risks of those estimates and, at least to a certain extent, the reader is encouraged to concentrate on an apparently precise central projection, ignoring the wide degree of uncertainty and operational difficulties surrounding the estimates. As in any forecasting exercise, there is uncertainty regarding both the estimated parameters and the way the explanatory variables evolve during the forecasting horizon. Our work presents a methodology to estimate a probability density function for the interest rate resulting from the application of a Taylor rule (the Taylor interest rate) which acknowledges that not only the explanatory variables but also the parameters of the rule are random variables.

    Science teaching in primary school and the importance of interdisciplinarity in knowledge construction. Case study: “Do snails prefer cabbage or lettuce?"

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    The way in which, traditionally, sciences have been taught in primary school has not allowed for the integrated use and development of the knowledge and skills acquired in the different curriculum areas. Therefore, it is necessary to promote a science teaching and learning process that encourages and enables the use of that knowledge in the context of different situations that are meaningful and relevant for children. With this goal in mind, this article seeks to illustrate, through the analysis of the process of exploration of the activity "Do snails prefer cabbage or lettuce?", which was conducted with a class of the 4th year of primary school, that research-based science activities enhance the integrated and meaningful use and development of knowledge and skills from other curricular areas, especially language and mathematics.info:eu-repo/semantics/publishedVersio

    Impact of bacterial cellulose on the physical properties and printing quality of fine papers

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    Bacterial nanocellulose (BNC), due to its inherent nanometric scale and strength properties, can be considered as a good candidate to be used in papermaking. This work explored the possibility of using it in the production of fine paper as a wet-end component and for the paper coating. Filler-containing handsheet production was performed with and without the presence of common additives typically used in the furnish of office papers. It was found that, under optimized conditions, BNC mechanically treated by high-pressure homogenization could improve all the evaluated paper properties (mechanical, optical and structural) without impairing the filler retention. However, paper strength was improved only to a small extent (increase in the tensile index of 8% for a filler content of ca. 27.5%). On the other hand, when used at the paper surface, remarkable improvements in the gamut area of >25% in comparison to the base paper and of >40% in comparison to only-starch coated papers were achieved for a formulation having 50% BNC and 50% of carboxymethylcellulose. Overall, the present results highlight the possibility of using BNC as a paper component, particularly when applied at the paper substrate as a coating agent aiming at improving printing quality.Fundacão para a Ciência e a Tecnologia (FCT), Portugal is acknowledged by SFRH/BDE/108095/2015 grant and Strategic Research Centre Project (UIDB/00102/2020). This work was also carried out under the Project Inpactus - innovative products and technologies from eucalyptus, Project N.º 21874 funded by Portugal 2020 through European Regional Development Fund (ERDF) in the frame of COMPETE 2020 nº246/AXIS II/2017info:eu-repo/semantics/publishedVersio

    Processo de sobremoldação de vedante numa tampa plástica

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    O objeto da presente patente é o processo de sobremoldação de uma tampa Plástica com vedante incorporado, na qual é injetado o material de maior dureza sobre o De menor dureza. Este processo de sobremoldação é aplicado somente em bi-injecção (utilização de dois materiais ou mais), em tampas plásticas rígidas para embalagens de Forma redonda ou outras. A solução adotada passou por proteger o vedante (3) do fluxo (9) do material da tampa (2) de modo a evitar que este cause deformações no vedante (3) Durante o processo de enchimento. A forma de orientação precisa do fluxo (9) do sobre o Material de menor dureza (3) evita a deformação deste ultimo recorrendo aos diferenciais De pressão conjugados com a velocidade. Desta forma é possível injetar sobre um Material de menor dureza (3), um material de maior dureza (2)

    Anatomic Aspects of Inguinal Lymph Nodes Applied to Lymphadenectomy in Penile Cancer

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    Objectives. To provide a better understanding of the distribution of inguinal nodes in order to prevent the complications of unnecessary and extended dissections in penile cancer. Methods. The bilateral inguinal regions of 19 male cadavers were dissected. Nodal distribution was noted and quantified based on anatomical location. The superficial nodes were subdivided into quarters as follows: superomedial, superolateral, inferomedial, and inferolateral. Statistical analysis was performed comparing node distribution between quarters using one-way analysis of variance (ANOVA), and the unpaired T-test was used between superficial and deep nodes. Results. Superficial nodes were found in all inguinal regions studied (mean = 13.60), and their distribution was more prominent in the superomedial quarter (mean = 3.94) and less in the inferolateral quarter (mean = 2.73). There was statistical significance between quarters when comparing the upper group with the lower one (P = 0.02). Nodes were widely distributed in the superficial region compared with deep lymph nodes (mean = 13.60 versus 1.71, P < 0.001). Conclusions. A great number of inguinal lymph nodes are distributed near the classical anatomical landmarks for inguinal lymphadenectomy, more prominent in upper quadrants

    Influence of corrosion on the electrical and mechanical performance of hybrid busbars

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    This paper is focused on the electrical and mechanical performance of aluminum-copper hybrid busbars subjected to corrosion over time. Two different types of hybrid busbars with joints produced by conventional fastening with M8 hexagonal socket head bolt-nut pairs made from medium carbon steel and by a new injection lap riveting process with semi-tubular rivets made from the material of the softer conductor are used and subjected to salt spray and electrochemical tests. Electrical resistance measurements performed on hybrid busbars taken from the corrosion testing cabinet at the end of each exposure period allow concluding that the new injection lap riveted hybrid busbars have a better electrical performance over time due to the elimination of fasteners with a higher electrical resistivity than aluminum and copper and to the elimination of the aluminum-steel and copper-steel galvanic pairs. The capability of the injection lap riveted hybrid busbars to withstand shear forces after corrosion testing also revealed to be adequate and like those of the original (uncorroded) hybrid busbars.info:eu-repo/semantics/publishedVersio

    Genetic improvement of Stylosanthes guianensis populations

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    Este trabalho foi desenvolvido visando a obtenção de informações à respeito do adequado número de populações, número de repetições e número de plantas por parcela, informações essas a serem adotadas em programas de melhoramento que envolvam experimentos com a espécie Stylosanthes guianensis (AubI.) Sw. Visou-se, também, a obtenção das correlações genéticas e fenotípicas existentes entre os caracteres diâmetro médio, área basal, hábito de crescimento, quantidade de folhas, peso da matéria verde e peso da matéria seca. Em geral, observou-se que médias mais precisas foram obtidas em experimentos de maior tamanho. A precisão experimental foi influenciada principalmente pelo número de populações e pelo número de repetições; relativamente inferior foi a influência do número de plantas por parcela. Os resultados obtidos para as correlações fenotípicas indicaram que todas as correlações ao nível de plantas dentro de parcelas, para os caracteres diâmetro médio, área basal, peso verde e peso seco, foram significativas e positivas. As correlações genéticas foram significativas e positivas para dez de um total de quinze combinações entre os seis caracteres estudados, tomados dois a dois. Conclui-se que a produção de matéria seca poderá ser indiretamente aumentada, por seleção para maior diâmetro, área basal e peso verde.This research was carried out to obtain information about the adequate number of populations, replications, and plants per lot, to be adopted in genetic improvement programs for Stylosanthes guianensis, and to obtain the genetic and phenotypic correlations between the characters mean diameter, basal area, growth habit, foliage, green weight and dry weight. It was observed that more precise means were obtained in large experiments. The experimental precision was influenced mainly by the number of populations and number of replications, and the influence of number of plants per plot was minor. All phenotypic correlations within plots, involving mean diameter, basal area, green weight and dry weight were significant and positive. The genetic correlations were significant and positive for 10 out of 15 combinations among the six characteres analysed. Therefore, dry weight can be indirectly increased through selection for large diameter, basal area and green weight

    Mitochondrial apoptosis-inducing factor is involved in doxorubicin-induced toxicity on H9c2 cardiomyoblasts

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    AbstractThe cardiotoxicity induced by the anti-cancer doxorubicin involves increased oxidative stress, disruption of calcium homeostasis and activation of cardiomyocyte death. Nevertheless, antioxidants and caspase inhibitors often show little efficacy in preventing cell death. We hypothesize that a caspase-independent cell death mechanism with the release of the apoptosis-inducing factor from mitochondria is involved in doxorubicin toxicity. To test the hypothesis, H9c2 cardiomyoblasts were used as model for cardiac cells. Our results demonstrate that z-VAD-fmk, a pan-caspase inhibitor, does not prevent doxorubicin toxicity in this cell line. Doxorubicin treatment results in AIF translocation to the nuclei, as confirmed by Western Blotting of cell fractions and confocal microscopy. Also, doxorubicin treatment of H9c2 cardiomyoblasts resulted in the appearance of 50kbp DNA fragments, a hallmark of apoptosis-inducing factor nuclear effects. Apoptosis-inducing factor knockdown using a small-interfering RNA approach in H9c2 cells resulted in a reduction of doxorubicin toxicity, including decreased p53 activation and poly-ADP-ribose-polymerase cleavage. Among the proteases that could be responsible for apoptosis-inducing factor cleavage, doxorubicin decreased calpain activity but increased cathepsin B activation, with inhibition of the latter partly decreasing doxorubicin toxicity. Altogether, the results support that apoptosis-inducing factor release is involved in doxorubicin-induced H9c2 cell death, which explains the limited ability of caspase inhibitors to prevent toxicity

    Metagenómica en la identificación de microorganismos que producen biodeterioro: patrimonio edificado con arquitectura en tierra, Vale Histórico Paulista (São Paulo, Brasil)

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    El objetivo de este trabajo es presentar resultados obtenidos mediante análisis por metagenómica como herramienta novedosa para la identificación taxonómica de hongos y bacterias a partir de biofilms en paredes de arquitectura en tierra (“pau-a-pique”, “taipa de pilão” y adobe), de edificaciones históricas del Vale Histórico Paulista, representativas del período colonial brasileño, Se extrajo el DNA total de los biofilms, que fue amplificado mediante primers específicos para regiones variables de los genes 16S y 18S ribosomal, y luego secuenciado obteniéndose bibliotecas del amplificado. El programa QIIME reveló la diversidad taxonómica en los distintos sustratos. Los géneros más abundantes de bacterias fueron: Aciditerrimonas, Blastococcus, Geodermatophilus, Arthrobacter, Micromonospora, Nocardioides, Propionibacterium, Pseudonocardia, Rubrobacter, Solirubrobacter, Thermoleophilum, Sphingobacterium, Sphaerobacter, Streptococcus, Gemmatimonas, Methylobacterium, Microvirga, Sphingomonas, Massilia, Klebsiella, Acinetobacter, Los géneros más abundantes de hongos: Passalora, Lacazia, Anisomeridium, Poliblastia, Hypocrea, Verrucaria, Caloplaca, Chaetomella, Meyerozima, Humicola, Oxyporus, Coriolopsis, Rhodotorula, Sporidiobolus, Trichosporon, Mucor, Syncephalastrum. Este trabajo es el primer reporte de comunidades microbianas a partir de paredes hechas con técnicas de arquitectura en tierra con el uso de metagenómica
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