Rational approximations of f(R)f(R) cosmography through Pad\'e polynomials

We consider high-redshift $f(R)$ cosmography adopting the technique of polynomial reconstruction. In lieu of considering Taylor treatments, which turn out to be non-predictive as soon as $z>1$, we take into account the Pad\'e rational approximations which consist in performing expansions converging at high redshift domains. Particularly, our strategy is to reconstruct $f(z)$ functions first, assuming the Ricci scalar to be invertible with respect to the redshift $z$. Having the thus-obtained $f(z)$ functions, we invert them and we easily obtain the corresponding $f(R)$ terms. We minimize error propagation, assuming no errors upon redshift data. The treatment we follow naturally leads to evaluating curvature pressure, density and equation of state, characterizing the universe evolution at redshift much higher than standard cosmographic approaches. We therefore match these outcomes with small redshift constraints got by framing the $f(R)$ cosmology through Taylor series around $z\simeq 0$. This gives rise to a calibration procedure with small redshift that enables the definitions of polynomial approximations up to $z\simeq 10$. Last but not least, we show discrepancies with the standard cosmological model which go towards an extension of the $\Lambda$CDM paradigm, indicating an effective dark energy term evolving in time. We finally describe the evolution of our effective dark energy term by means of basic techniques of data mining.Comment: 11 pages, 14 figures, accepted for publication in JCA

Los Centros Cimarrones, estrategia pedagógica de revitalización político-identitaria del pueblo afroecuatoriano

En el texto final de la última Conferencia General del Episcopado Latinoamericano realizada en Aparecida en el 2007, se lee lo siguiente: “La historia de los afroamericanos ha sido atravesada por una exclusión social, económica, política y, sobre todo, racial, donde la identidad étnica es factor de subordinación social. Actualmente, son discriminados en la inserción laboral, en la calidad y contenido de la formación escolar, en las relaciones cotidianas y además existe un proceso de ocultamiento sistemático de sus valores, historia, cultura y expresiones religiosas...de modo que, descolonizar las mentes, el conocimiento, recuperar la memoria histórica, fortalecer espacios y relaciones interculturales, son condiciones para la afirmación de la plena ciudadanía de estos pueblos” (Aparecida, 2007: n. 96)

Conceptos y reflexiones para la conciencia cimarrona

La historia nos demuestra que los que tienen sed de conquista, al invadir un territorio y su gente, lo primero que hacen es descalificar el universo cultural del ‘otro’ para así imponer su proyecto hegemónico. En América Latina, con la conquista española primero y con la creación del Estado-nación después, se ha venido impulsando, hasta nuestros días, la construcción de un universo simbólico predominantemente blanco-mestizo, y se ha promovido un discurso homogeneizador de pertenencia nacional, obligando a todo el mundo a reconocerse parte de una misma realidad cultural

Damaging micromechanisms in an as cast ferritic and a ferritized ductile cast iron

Mechanical behavior and damaging micromechanisms in Ductile Cast Irons (DCIs) are strongly effected by matrix microstructure (e.g., phases volume fraction, grains size and grain distribution) and graphite nodules morphology peculiarities (e.g., nodularity level, nodule size, nodule count, etc.). The influence of the graphite nodules depends on both the matrix microstructure and the loading conditions (e.g., quasi-static, dynamic or cyclic loadings). According to the most recent results, these graphite nodules show a mechanical properties gradient inside the graphite nodules, with the graphite elements – matrix debonding as only one of the possible damaging micromechanisms. In this work, two different ferritic DCIs were investigated (a ferritic matrix obtained from as-cast condition and a ferritized matrix) focusing on the damaging micromechanisms in graphite nodules due to tensile stress. Specimens lateral surfaces were observed using a Scanning Electron Microscope (SEM) during the tests following a step by step procedure.Fil: D' Agostino, Laura. Università di Cassino e del Lazio Meridionale; ItaliaFil: Di Cocco, Vittorio. Università di Cassino e del Lazio Meridionale; ItaliaFil: Fernandino, Diego Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Lacoviello, Francesco. Università di Cassino e del Lazio Meridionale; Itali

NPOs and private governance forms for football clubs: towards a blended model

PurposeThis study explores the relationship between governance model - private organisations vs non-profit organisations (NPOs) - and performance in football clubs.Design/methodology/approachThe study is a comparative case study of two football clubs with different governance models: Malmo FF, which is an NPO, and Bologna FC, which is a privately owned club.FindingsThe results show that both football clubs focus equally on financial and non-financial performance, and in practice, both clubs use a blend of private and NPO governance models. While supporting efforts towards financial results, blending the models appears to support football clubs' management of the tension between financial and non-financial performance and the expectation that they will contribute to local development. Thus, using a blend of the two models is not only accepted but expected.Research limitations/implicationsThis study is a comparative case study of two football clubs. This study furthers our understanding of how football clubs manage the tension between financial and non-financial performance expectations. This is particularly of interest in light of the increasing professionalisation of sports, especially football, and how this might jeopardise the contributions that sport clubs make to the local community.Originality/valueBy exploring the relationship between governance model and performance, this study shows that, contrary to expectations, privately owned football clubs focus as much on non-financial performance as clubs governed as NPOs. This study contributes to the existing literature by showing how clubs use a mixture of elements from governance models to manage the tension between financial and non-financial performance that has emerged in the wake of the increasing professionalisation of football

Evidence on the Bidirectional Relationship Between Health and Life Satisfaction in Older Adults

AbstractPrevious research on health and life satisfaction in older adults has suggested a bidirectional relationship. However, most evidence either is based on cross-sectional data, being unsuitable for inferring any directionality on the results, or disregards the within-person stability of both variables over time, thus providing potentially biased results. We analysed data from 11,667 older adults interviewed between 2008 and 2016 within the English Longitudinal Study of Ageing. A health measure including self-reported and measured tests on cognitive and physical performance was computed using a Bayesian multilevel item-response theory approach. Life satisfaction was assessed with the Satisfaction with Life Scale. Cross-lagged models using a Structural Equation Modelling approach were used to analyse the longitudinal interrelation between health and life satisfaction. Models accounting and not accounting for the within-person stability in the measures were computed. Additional sensitivity models were ran using an exclusively self-reported measure of health. Health and life satisfaction were significant longitudinal predictors of one another only when the within-person stability was not considered. The effect of life satisfaction on health became negligible once that stability was modelled. The impact of not accounting for within-person stability was larger when health was measured exclusively with self-reported information. Our study suggests that health and life satisfaction are not bidirectionally related in older adults, but only health predicts a better life satisfaction over time. Thus, policies aimed at fostering older adults’ life satisfaction by focusing on health enhancement and maintenance may be fruitful, whereas the opposite may not.</jats:p

Hydrogeomorphic processes and torrent control works on a large alluvial fan in the eastern Italian Alps

Abstract. Alluvial fans are often present at the outlet of small drainage basins in alpine valleys; their formation is due to sediment transport associated with flash floods and debris flows. Alluvial fans are preferred sites for human settlements and are frequently crossed by transport routes. In order to reduce the risk for economic activities located on or near the fan and prevent loss of lives due to floods and debris flows, torrent control works have been extensively carried out on many alpine alluvial fans. Hazard management on alluvial fans in alpine regions is dependent upon reliable procedures to evaluate variations in the frequency and severity of hydrogeomorphic processes and the long-term performance of the torrent training works. An integrated approach to the analysis of hydrogeomorphic processes and their interactions with torrent control works has been applied to a large alluvial fan in the southern Carnic Alps (northeastern Italy). Study methods encompass field observations, interpretation of aerial photographs, analysis of historical documents, and numerical modelling of debris flows. The overall performance of control works implemented in the early decades of 20th century was satisfactory, and a reduction of hazardous events was recognised from features observed in the field and in aerial photographs, as well as from the analysis of historical records. The 2-D simulation of debris flows confirms these findings, indicating that debris flow deposition would not affect urban areas or main roads, even in the case of a high-magnitude event. Present issues in the management of the studied alluvial fan are representative of situations frequently found in the European Alps and deal with the need for maintenance of the control structures and the pressures for land use changes aimed at the economic exploitation of the fan surface