Fertilisation with compost: effects on soil phosphorus sorption and on phosphorus availability in acid soils.

Phosphate mineral fertilisers are manufactured from non-renewable resources.Soil fertilisation with composts is considered a good source of reuse nutrients such as phosphorus (P). The aim of this work was to evaluate the effect of compost fertilisation on soil P sorption and consequently on P availability. It was done an incubation experiment followed by a sorption experiment in a low-P acid soil fertilised with compost (CP) or single superphosphate (SSP). The P application rates were: 0, 6.5, 13, 26 and 52 (kg∙P∙ha−1). In CP treatments, the rates 26 and 52 kg∙P∙ha−1 were achieved by adding SSP to CP since it was not allowed to incorporate into soil more than 170 kg∙N∙ha−1 from organic amendments. Although SSP has a higher proportion of easily available P than CP (86% vs 50%), the results showed that after 140 days of soil incubation, the available P was higher in CP treatments compared with SSP at the same rate of P application. The sorption experiment showed that after incubation of the fertilised soils, the P sorption maximum had lower values in treatments with CP in combination with SSP compared with only SSP fertilisation and the bonding energy had a deeper decrease in the same treatments. Also, the Standard Phosphate Requirement decreased in the CP in combination with SSP treatments. The reduction of soil P sorption capacity after compost addition to soil highlights the need of reducing P fertilisation rates to achieve similar levels of available P compared with only SSP fertilisation.info:eu-repo/semantics/publishedVersio

Reflections on digital innovation

The paper by Henfridsson et al. opens up a new agenda for IS research on the content and process of digital innovation. The crucial element in their perspective is the role of recombination in innovation. They supplement an emphasis on design recombination with a symmetrical emphasis on use recombination. While supporting Henfridsson et al.s overall argument, I point out how central parts overlap with and are extended in disciplines outside IS research

Breaking the core-envelope symmetry in p-mode pulsating stars

It has been shown that there is a potential ambiguity in the asteroseismic determination of the location of internal structures in a pulsating star. We show how, in the case of high-order non-radial acoustic modes, it is possible to remove this ambiguity by considering modes of different degree. To support our conclusions we have investigated the seismic signatures of sharp density variations in the structure of quasi-homogeneous models.Comment: 3 pages, 3 figures, accepted for publication in Astronomy and Astrophysic

Porto Oscillation Code (POSC)

The Porto Oscillation Code (POSC) has been developed in 1995 and improved over the years, with the main goal of calculating linear adiabatic oscillations for models of solar-type stars. It has also been used to estimate the frequencies and eigenfunctions of stars from the pre-main sequence up to the sub-giant phase, having a mass between 0.8 and 4 solar masses. The code solves the linearised perturbation equations of adiabatic pulsations for an equilibrium model using a second order numerical integration method. The possibility of using Richardson extrapolation is implemented. Several options for the surface boundary condition can be used. In this work we briefly review the key ingredients of the calculations, namely the equations, the numerical scheme and the output.Comment: Accepted for publication in Astrophysics and Space Science

Regulation of T cell responses by Heme Oxygenase-1

Tese de mestrado, Biologia (Biologia Molecular e Genética), 2008, Universidade de Lisboa, Faculdade de CiênciasMultiple sclerosis (MS) is a chronic inflammatory disease that affects the central nervous system (CNS). It is estimated that over 2.5 million people, mainly young adults between 25 and 40 years old, suffer from this disease. MS pathology is characterized by multifocal CNS inflammation, degeneration of the myelin sheath, surrounding the axons of neurons, and formation of sclerotic plaques that leads to axonal damage. The etiology of the disease remains unknown with genetic and environmental factors being important for its development. Mechanisms that lead to CNS degeneration result from a local inflammatory response characterized by the recruitment of T cells that recognize myelin peptides against which they mount an effector response. Heme Oxygenase-1 (HO-1) is a ubiquitously expressed stress-induced enzyme, responsible for the degradation of free heme into iron (Fe), biliverdin (BV) and carbon monoxide (CO). HO-1 controls inflammatory processes such as the ones associated with the development of MS. It is expressed in the CNS during MS as well as in experimental autoimmune encephalomyelitis (EAE), a murine model of MS. Deletion of HO-1 is associated with increased susceptibility to EAE, while pharmacological induction of its expression arrests EAE progression. The protective effect of HO-1 is associated with inhibition of expression of histocompatibility complex class II (MHC class II) on antigen presenting cells (APC), including dendritic cells (DCs). The main hypothesis tested in this project was that expression of HO-1 in DCs might modulate T cell responses in a manner that prevents the progression of EAE. We found that absence of HO-1 in DCs does not affect significantly its maturation by modulating the expression of surface activation markers. However, we failed to demonstrate whether this absence could afford any effect on the disease, when DCs are adoptively transferred into naïve mice, leading to a more severe outcome when compared to Hmox1+/+ DCsResumo alargado em português disponível no document

Aeronautical imagination and the figure of the French aviator in the Azorean press (1935/1949)

In the aftermath of “Atlantic Fever”, several test crews from the most advanced nations in aviation came to the Azores, fighting for the establishment of commercial routes between the Old and the New World. This context explains the 1935 aeronautical mission of the French aviator, Henry Nomy. The analysis of articles in the Azorean newspapers of this period shows the emphasis on the heroic figure of the aviator. In this article, we contrast this aeronautical imaginary with the one prevailing in the Azorean press’ coverage of the accident of the Constellation of Air France, which flew from Paris to New York with a stopover in Santa Maria (Azores) and crashed on the island of São Miguel on October 28, 1949. Studying the articles in these newspapers allows us to grasp a change in the aeronautical imaginary (this time associated with civil aviation): the admiration previously focused on the aviator was now focused on the aircraft itself.RÉSUMÉ: À la suite de la « fièvre de l’Atlantique », plusieurs équipages de test provenant des nations d’avant-garde dans le domaine de l’aviation arrivent aux Açores, se battant pour l’établissement de routes commerciales entre le Vieux et le Nouveau Monde. C’est ce contexte qui explique la mission aéronautique de 1935 de l’aviateur français Henry Nomy. L’analyse des articles des journaux açoréens de cette époque montre que l’accent y est mis sur la figure héroïque de l’aviateur. Dans cet article, nous faisons contraster cet imaginaire de l’aviation avec celui qui prévaut dans la couverture faite par la presse açoréenne de l’accident du Constellation d’Air France qui assurait la liaison Paris-New York avec escale à Santa Maria (Açores) et s’est écrasé sur l’île de São Miguel, le 28 octobre 1949. L’analyse des articles de ces journaux permet de saisir une modification dans l’imaginaire aéronautique (associé cette fois-ci à l’aviation commerciale) : l’admiration auparavant suscitée par l’aviateur est maintenant provoquée par l’appareil proprement dit.info:eu-repo/semantics/publishedVersio