Spectroscopic and dynamical properties of comet C/2018 F4, likely a true average former member of the Oort cloud

The population of comets hosted by the Oort cloud is heterogeneous. Most studies in this area focused on highly active objects, those with small perihelion distances or examples of objects with peculiar physical properties and/or unusual chemical compositions. This may have produced a biased sample of Oort cloud comets in which the most common objects may be rare, particularly those with perihelia well beyond the orbit of the Earth. Within this context, the known Oort cloud comets may not be representative of the full sample. Here, we study the spectral properties in the visible region and the cometary activity of Comet C/2018 F4 (PANSTARRS). We also explore its orbital evolution with the aim of understanding its origin within the context of known minor bodies moving along nearly parabolic or hyperbolic paths. We present observations obtained with the 10.4 m Gran Telescopio Canarias (GTC), derive the spectral class and visible slope of C/2018 F4 and characterise its level of cometary activity. Direct N-body simulations are carried out to explore its orbital evolution. The absolute magnitude of C/2018 F4 is Hr=13.62+/-0.04. Assuming a pV=0.04 its diameter is D<10.4 km. The object presents a conspicuous coma, with a level of activity comparable to those of other comets observed at similar heliocentric distances. Comet C/2018 F4 has a visible spectrum consistent with that of an X-type asteroid, and has a spectral slope S'=4.0+/-1.0 %/1000\AA and no evidence of hydration. The spectrum matches those of well-studied primitive asteroids and comets. The analysis of its dynamical evolution prior to discovery suggests that C/2018 F4 is not of extrasolar origin. Although the present-day heliocentric orbit of C/2018 F4 is slightly hyperbolic, its observational properties and past orbital evolution are consistent with those of a dynamically old comet with an origin in the Oort cloud.Comment: 6 pages, 5 figures. In pres

Plant densities and modulation of symbiotic nitrogen fixation in soybean

Soybean nitrogen (N) demands can be supplied to a large extent via biological nitrogen fixation, but the mechanisms of source/sink regulating photosynthesis/nitrogen fixation in high yielding cultivars and current crop management arrangements need to be investigated. We investigated the modulation of symbiotic nitrogen fixation in soybean [Glycine max (L.) Merrill] at different plant densities. A field trial was performed in southern Brazil with six treatments, including non-inoculated controls without and with N-fertilizer, both at a density of 320,000 plants ha−1, and plants inoculated with Bradyrhizobium elkanii at four densities, ranging from 40,000 to 320,000 plants ha−1. Differences in nodulation, biomass production, N accumulation and partition were observed at stage R5, but not at stage V4, indicating that quantitative and qualitative factors (such as sunlight infrared/red ratio) assume increasing importance during the later stages of plant growth. Decreases in density in the inoculated treatments stimulated photosynthesis and nitrogen fixation per plant. Similar yields were obtained at the different plant densities, with decreases only at the very low density level of 40,000 plants ha−1, which was also the only treatment to show differences in seed protein and oil contents. Results confirm a fine tuning of the mechanisms of source/sink, photosynthesis/nitrogen fixation under lower plant densities. Higher photosynthesis and nitrogen fixation rates are capable of sustaining increased plant growth

La convicción en las actitudes relacionadas con el dopaje : un estudio experimental con entrenadores de fútbol

Este experimento analizó el efecto que el pensamiento deliberativo involucrado en el procesamiento de información relevante produjo sobre la convicción de los participantes en sus actitudes relacionadas con el dopaje. Los participantes fueron entrenadores de fútbol que recibieron por escrito una propuesta (i.e., un mensaje persuasivo) en contra (o a favor) de la legalización de algunas sustancias y conductas consideradas como dopaje en la actualidad. A su vez, la cantidad de pensamiento deliberativo (i.e., la probabilidad de elaboración, alta vs. baja) fue manipulada entre los participanes. Finalmente, las actitudes hacia la propuesta de legalización y la convicción en esas actitudes fueron medidas como variables dependientes. Como se predijo, los resultados mostraron que las actitudes fueron significativamente influidas sólo por la dirección del mensaje persuasivo (η2 = .064); de tal forma que los entrenadores que recibieron el mensaje en contra de la legalización mostraron actitudes más desfavorables que los que recibieron el mensaje a favor. Sin embargo, como se esperaba, la convicción en las actitudes estuvo sólo en función de la elaboración (η2 = .050). Así, los entrenadores de la condición de alta probabilidad de elaboración mostraron más convicción en sus actitudes que los de la condición de baja probabilidad de elaboración. En este artículo, discutimos la importancia de esta convicción para comprender y predecir mejor el impacto que las actitudes tienen sobre los consecuentes modos de pensar y de actuar de entrenadores y deportistas respecto al dopaje.This experiment analysed the effect that deliberative thinking involved in the processing of relevant information had on the conviction of the participants in their doping-related attitudes. Participants were football coaches who received a written proposal (i.e., a persuasive message) against (or in favour of) the legalization of several banned substances and doping behaviours. Moreover, the extent of deliberative thinking (i.e., the elaboration likelihood, high vs. low) was manipulated between participants. Finally, attitudes towards legalization and conviction in those attitudes were assessed as dependent variables. As predicted, results showed attitudes were only affected by the direction of the message (η2 = .064). Therefore, coaches who received the message against legalisation showed attitudes which were less favourable than coaches who received the message in favour of legalization. However, as expected, conviction was only in relation to elaboration likelihood (η2 = .050). Thus, coaches with a high elaboration likelihood showed more conviction in their attitudes than coaches with a low elaboration likelihood. In this paper, we discuss the importance of conviction in the understanding and the prediction of the impact of attitudes on subsequent thinking and behaviour with respect to doping in coaches and athletes.Este estudo analisou o efeito que o pensamento deliberativo envolvido no processamento de informação relevante produziu sobre a convicção dos participantes nas suas atitudes relacionadas com o doping. Os participantes foram treinadores de futebol que receberam por escrito uma proposta (i.e., uma mensagem persuasiva) contra (ou a favor) da legalização de algumas substâncias e comportamentos considerados como doping na actualidade. Por seu turno, a quantidade de pensamento deliberativo (i.e., a probabilidade de elaboração, Alta vs. Baixa) foi manipulada entre os participantes. Por último, as atitudes face à proposta de legalização e a convicção nessas atitudes foram medidas como variáveis dependentes. Como foi hipotetizado, os resultados mostram que as atitudes foram significativamente influídas apenas pela direcção da mensagem persuasiva (η2 = .064); de tal forma que os treinadores que receberam a mensagem contra a legalização revelaram atitudes mais desfavoráveis que os que receberam a mensagem a favor. Contudo, como esperado, a convicção nas atitudes variaram apenas em função da elaboração (η2 = .050). Assim, os treinadores da condição de alta probabilidade de elaboração revelaram mais convicção nas suas atitudes que os da condição de baixa probabilidade de elaboração. Neste artigo, discutimos a importância desta convicção para compreender e prever melhor o impacto que as atitudes têm sobre os consequentes modos de pensar e actuar dos treinadores e atletas a respeito do doping

Enzymatically mediated fluorescent copper nanocluster generation for tyramine determination

This work details the enzymatic generation of fluorescence nanomaterials and the use of this optical signal as the analytical parameter for the quantification of the substrate. More specifically, fluorescent copper nanoclusters have been obtained during the enzymatic reaction of tyramine oxidase and tyramine in the presence of Cu(II); the fluorescence intensity being proportional to the concentration of tyramine. The nanoclusters obtained show fluorescence at 445 nm by being excited at 320 nm and have been characterized by TEM, EDX, and XPS. The formation mechanism has also been studied, suggesting that under the optimal conditions (0.1 M MES buffer and pH = 6), the formation of the nanoclusters is due to the reducing properties of the product of the enzymatic reaction (p-hydroxybenzaldehyde) in MES buffer. The method shows a linear relationship with the concentration of tyramine in the range from 1.0·10−5 to 2.5·10−4 M, a RSD of 3% (n = 5) and a LOD of 6.3·10−6 M. The method has been applied to the determination of tyramine in sausage with good results

Understanding the need of the compression branch to characterize hyperelastic materials

[EN] Soft biological tissues are frequently modeled as hyperelastic materials. Hyperelastic behavior is typically ensured by the assumption of a stored energy function with a pre-determined shape. This function depends on some material parameters which are obtained through an optimization algorithm in order to fit experimental data from different tests. For example, when obtaining the material parameters of isotropic, incompressible models, only the extension part of a uniaxial test is frequently taken into consideration. In contrast, spline-based models do not require material parameters to exactly fit the experimental data, but need the compression branch of the curve. This is not a disadvantage because as we explain herein, to properly characterize hyperelastic materials, the compression branch of the uniaxial tests (or valid alternative tests) is also needed, in general. Then, unless we know beforehand the tendency of the compression branch, a material model should not be characterized only with tensile tests. For simplicity, here we address isotropic, incompressible materials which use the Valanis-Landel decomposition. However, the concepts are also applicable to compressible isotropic materials and are specially relevant to compressible and incompressible anisotropic materials, because in biomechanics, materials are frequently characterized only by tensile tests.Partial financial support for this work has been given by grants DPI2011-26635 and DPI2015-69801-R from the Direccion General de Proyectos de Investigacion of the Ministerio de Economia y Competitividad of Spain. Erica De Rosa acknowledges the funding for a stay at the UPM, Progetto di internazionalizzazione dei corsi di studio from COINOR-Universita Degli Studi di Napoli Federico II. F.J. Montans also acknowledges the support of the Department of Mechanical and Aerospace Engineering of University of Florida during the sabbatical period in which this paper was finished and that of Ministerio de Educacion, Cultura y Deporte of Spain for the financial support for that stay under grant PRX15/00065Latorre, M.; De Rosa, E.; Montáns, FJ. (2017). Understanding the need of the compression branch to characterize hyperelastic materials. International Journal of Non-Linear Mechanics. 89:14-24. https://doi.org/10.1016/j.ijnonlinmec.2016.11.00514248

Capturing anisotropic constitutive models with WYPiWYG hyperelasticity; and on consistency with the infinitesimal theory at all deformation levels

[EN] The elastic nonlinear behavior of fiber-reinforced materials and soft biological tissues is analyzed using anisotropic hyperelastic models. Frequently, these models are not compatible with the corresponding infinitesimal theory, but some of them may be modified to accommodate that theory in the limit. WYPiWYG hyperelasticity is compatible with the infinitesimal theory at all deformation levels and capable of capturing exactly a complete set of experimental data, which reproduces all deformation modes at every strain level, under homogeneous deformations. In this work we study the relevance of recovering the infinitesimal theory at every deformed configuration and also the performance of the WYPiWYG method in predicting the behavior of anisotropic materials at large strains under nonhomogeneous deformations.Partial financial support for this work has been given by grant DPI2015-69801-R from the Direction General de Proyectos de Investigacion of the Ministerio de Economia y Competitividad of Spain. EDR acknowledges the funding for a stay at the UPM, Progetto di internazionalizzazione dei corsi di studio from COINOR-Universita Degli Studi di Napoli Federico II. FJM also acknowledges the support of the Department of Mechanical and Aerospace Engineering of University of Florida during the sabbatical period in which part of this paper was performed, and that of Ministerio de Educacion, Cultura y Deporte of Spain for the financial support for that stay under grant PRX15/00065. The ADINA program license used for this work has been a courtesy of ADINA R&D to the UPMDe Rosa, E.; Latorre, M.; Montáns, FJ. (2017). Capturing anisotropic constitutive models with WYPiWYG hyperelasticity; and on consistency with the infinitesimal theory at all deformation levels. International Journal of Non-Linear Mechanics. 96:75-92. https://doi.org/10.1016/j.ijnonlinmec.2017.08.00575929

Análisis Dinámico Tridimensional del Sistema Catenaria-pantógrafo en Líneas Ferroviarias de Alta Velocidad (350 Km/h)

Con el aumento de la velocidad de circulación de los ferrocarriles, el comportamiento dinámico del sistema catenaria-pantógrafo resulta cada vez más crítico debido al notable incremento en el número y duración de los despegues. Este fenómeno afecta negativamente a la correcta captación de corriente, originando a su vez perturbaciones de carácter electromagnético e incrementando el desgaste de la línea aérea. Los programas de simulación constituyen una herramienta esencial en la fase de diseño para garantizar un correcto comportamiento dinámico de estos sistemas. Además, dada la dificultad de realización de pruebas de campo en líneas electrificadas y con tráfico continuo, estas simulaciones proporcionan también una gran ayuda para mejorar líneas ya construidas, así como para la elección del pantógrafo más adecuado a cada línea

La expansión del portugués en Oriente en el siglo XVI y la documentación jesuítica

This essay is the result of the study of c. 2000 pages, a small part of the writings of the Jesuits who worked in the portuguese domains in the far East, starting from 1542. Our text reveals the great importance of the Society of Jesus's missions in the expansion of the portuguese language in those lands. Furthermore, the investigation of this documentation allows us to analyze specific features of the portuguese language in the mid 16th century. Some archaisms were preserved and certain innovations took place, not allways reflected by the writers of those days. From the point of view of the lexicon, this essay highlights the abundance of words that have cult or oriental origin. In appendix we offer a list of almost two hundred words that we consider, with the necessary caution, to be registrered for the first time in Portuguese.This essay is the result of the study of c. 2000 pages, a small part of the writings of the Jesuits who worked in the portuguese domains in the far East, starting from 1542. Our text reveals the great importance of the Society of Jesus’s missions in the expansion of the portuguese language in those lands. Furthermore, the investigation of this documentation allows us to analyze specific features of the portuguese language in the mid 16th century. Some archaisms were preserved and certain innovations took place, not allways reflected by the writers of those days. From the point of view of the lexicon, this essay highlights the abundance of words that have cult or oriental origin. In appendix we offer a list of almost two hundred words that we consider, with the necessary caution, to be registrered for the first time in Portuguese

Feasibility of lowering soybean planting density without compromising nitrogen fixation and yield

Adjusting soybean [Glycine max (L.) Merrill] density can be critical to reduce inter-plant competition for water, nutrients, and sunlight, and to increase intercepted radiation, photosynthesis, and biomass production. The objective of this study was to evaluate the effects of soybean-population density on soybean nodulation, plant nutrient status, yield, and grain quality. Three field experiments were performed in southern Brazil with soybean cultivar BRS 284, of indeterminate growth type and maturity group 6.6, at 80,000 and 320,000 plants ha–1. For N supply plants were dependent either largely on biological fixation of atmospheric N—with a naturalized population of Bradyrhizobium or inoculated with Bradyrhizobium japonicum strain CNPSo 2050—or largely on N fertilizer—200 kg N ha–1, split-applied at sowing and R1 growth stage. The lower plant density resulted in increased nodulation parameters (number and mass), but plant nutritional status—evaluated by the diagnosis and recommendation integrated system (DRIS) method—in general was not affected. Seed oil content increased by 3.4%, but protein decreased by 4.5% at the lower plant density. The N source affected nodulation, but not nutritional status or grain yield. Although plant density was reduced by 75%, yield decreased by 16% during only one of the three cropping seasons. These results indicate a high plasticity of soybean to adapt photosynthesis and N fixation to different plant densities. Furthermore, planting at the lower density has the advantages of lower input costs and less susceptibility to environmental and plant nutritional stresses.Instituto de Fisiología y Recursos Genéticos VegetalesFil: De Luca, Marcos Javier. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; Argentina. Universidade Estadual de Londrina. Departamento Microbiologia; Brasil. Embrapa Soja; BrasilFil: Nogueira, Marco Antonio. Embrapa Soja; Brasil. Universidade Estadual de Londrina. Departamento Microbiologia; BrasilFil: Hungria, Mariangela. Embrapa Soja; Brasil. Universidade Estadual de Londrina. Departamento Microbiologia; Brasi