Equity in five Mediterranean countries

Public education systems ought to be equitable, ensuring equal opportunities to all students, irrespective of the socioeconomic status of their families. This political desideratum is based upon, not only on ethical considerations, but also – and mainly – by the need of fostering economic development and progress. To develop, at maximum, the potential of each and every individual in a community, it is imperative to reduce human resource lost and, consequently, to improve wealth creation. However, there exists the belief that the more equitable an education system is, the poorer it behaves in terms of learning standards. In fact, relevant empirical evidence points on the opposite direction: according to PISA – Programme for International Student Assessment, countries like Korea, Finland, Canada and Japan, “combine high average performance with equity and have a large proportion of top-performing students, which demonstrates that excellence and equity can go together”. According to OECD, “Equity in education has two dimensions. The first is fairness, which implies ensuring that personal and social circumstances – for example gender, socioeconomic status or ethnic origin – should not be an obstacle to achieving educational potential. The second is inclusion, which implies ensuring a basic minimum standard of education for all – for example that everyone should be able to read, write and do simple arithmetic.”. The present research lies on the utilization of a set of indicators to encompass different factors and sources of inequity. To understand these factors, four groups of students were identified, considering the economic, social and cultural status of their families (low or high) and the performance (low or high) they exhibit in the PISA mathematics tests (in 2003 and 2012), Taking into consideration the percentage of each one of these groups it is possible to perform a risk analysis (calculating relative risks, attributable risks, and odds ratio). This research aims at improving the understanding of the factors which affect the performance of education systems, in particular, those related with (i) unequal distribution of school resources, (ii) differences between public and private schools, and (iii) dissimilar conditions between rural and urban schools. In this research a set of variables were selected and analysed in order to study three different levels of analysis: individual (gender, grade repetition, and immigrant status), family (economic, social and cultural status), and school (public/private, location, class size, and resources), for five Mediterranean countries.info:eu-repo/semantics/publishedVersio

Cell surface engineering to control cellular interactions

Cell surface composition determines all interactions of the cell with its environment, thus cell functions such as adhesion, migration and cell–cell interactions can potentially be controlled by engineering and manipulating the cell membrane. Cell membranes present a rich repertoire of molecules, therefore a versatile ground for modification. However the complex and dynamic nature of the cell surface is also a major challenge for cell surface engineering that should also involve strategies compatible with cell viability. Cell surface engineering by selective chemical reactions or by the introduction of exogenous targeting ligands can be a powerful tool for engineering novel interactions and controlling cell function. In addition to chemical conjugation and modification of functional groups, ligands of interest to modify the surface of cells include recombinant proteins, liposomes or nanoparticles. Here, we review recent efforts to perform changes to cell surface composition. We focus on the engineering of the cell surface with biological, chemical or physical methods to modulate cell functions and control cell–cell and cell–microenvironment interactions. Potential applications of cell surface engineering are also discussed

Filling holes under non-linear constraints

Publisher Copyright: © 2023, The Author(s).In this paper we handle the problem of filling the hole in the graphic of a surface by means of a patch that joins the original surface with C1-smoothness and fulfills an additional non-linear geometrical constraint regarding its area or its mean curvature at some points. Furthermore, we develop a technique to estimate the optimum area that the filling patch is expected to have that will allow us to determine optimum filling patches by means of a system of linear and quadratic equations. We present several numerical and graphical examples showing the effectiveness of the proposed method.publishersversionpublishe

Cash holdings and business conditions

We investigate the relation between business conditions and corporate liquidity decisions by US firms. We find strong evidence that financially constrained firms hold more cash during recessions and that business conditions are significant to constrained firms’ cash decisions. In contrast, we find weak evidence that financially unconstrained firms adjust cash holdings according to the business cycle. This asymmetric behavior is more pronounced for changes in the short-term interest rate. Moreover, we find that firms increase the level of liquidity during periods of tighter credit conditions. Our findings support both the precautionary motive for holding cash and the pecking order theoryinfo:eu-repo/semantics/publishedVersio

Holographic Principle bounds on Primordial Black Hole abundances

The generalized Second Law of thermodynamics and the Holographic Principle are combined to obtain the maximum mass of black holes formed inside a static spherical box of size $R$ filled with radiation at initial temperature $T_{i}$. The final temperature after the formation of black holes is evaluated, and we show that a critical threshold exists for the radiation to be fully consumed by the process. We next argue that if some form of Holographic Principle holds, upper bounds to the mass density of PBHs formed in the early universe may be obtained. The limits are worked out for inflationary and non-inflationary cosmological models. This method is independent of the known limits based on the background fluxes (from cosmic rays, radiation and other forms of energy) and applies to potentially important epochs of PBH formation, resulting in quite strong constraints to $\Omega_{pbh}$.Comment: Latex file, 2 .ps figures. To appear in Classical and Quantum Gravit

Calibration of parameters in Dynamic Energy Budget models using Direct-Search methods

Dynamic Energy Budget (DEB) theory aims to capture the quantitative aspects of metabolism at the individual level, for all species. The parametrization of a DEB model is based on information obtained through the observation of natural populations and experimental research. Currently the DEB toolbox estimates these parameters using the Nelder–Mead Simplex method, a derivative-free direct-search method. However, this procedure presents some limitations regarding convergence and how to address constraints. Framed in the calibration of parameters in DEB theory, this work presents a numerical comparison between the Nelder–Mead Simplex method and the SID-PSM algorithm, a Directional Direct-Search method for which convergence can be established both for unconstrained and constrained problems. A hybrid version of the two methods, named as Simplex Directional Direct-Search, provides a robust and efficient algorithm, able to solve the constrained optimization problems resulting from the parametrization of the biological models.authorsversionpublishe

Caracterização de acessos de Paspalum notatum Fluegge por meio da análise de componentes principais.

A espécie Paspalum notatum e altamente cosmopoljta, tendo sido encontrados diversos ecótipos adaptados a regiões específicas. 0 objetivo é a identificação dos descritores morfológicos vegetativos e reprodutivos principais na caracterização de oito acessos de P.notatum e um acesso de Paspalum sp. coletados em deferentes regiões brasileiras. 0 trabalho foi desenvolvido na Embrapa Pecuária Sudeste localizada em São Carlos-SP, onde se encontra o Banco Ativo de Germoplasma do gênero Paspalum. Na coleta de dados foi utilizada uma lista de 1068 descritores morfológicos vegetativos e reprodutivos. Realizou-se a análise de componentes principais que, além da dispersão gráfica da divergência entre genótipo, possibilita a identificação dos caracteres majs representativos para explicar a variância total. Na análise foi utilizado o programa SAS/STAT 6.03. Previamente os descritores foram divididos em grupos de relação. A primeira seleção eliminou descritores cujas características não apresentavam variação entre os acessos, diminuindo-os para 272. A segunda seleção analisou a correlação entre os 272 descritores, dentro de cada grupo. Utilizaram-se as componentes com acúmulo de variância a 80%. Nos componentes foram selecionados os descritores de major valor absoluto, resultando em 81 descritores principais. Os caracteres descontínuos que se destacaram foram os de comprimento e largura do requis e lamina floral. Do grupo Planta/Inflorescência/Ráquis os principais foram a pilosidade do Ráquis e a forma da Inflorescência. Os da Lamina foliar foram 05 de pilosidade. Descritores de destaque do grupo Lígula e Bainha foram à pilosidade da lígula e da bainha e os do grupo Espigueta/Pedúnculo foram de pilosidade do Pedúnculo. 0 grupo Flor/ Antêcio pode ser caracterizado pelo tamanho do Lema Fértil e Lema Estéril em relação a Gluma e translucidez do Lema Estéril. Por fim, os descritores principais da Gluma são a forma, cor e translucidez da Prjmeira Gluma. A metodologia utilizada foi eficiente na detecção da presença de variabilidade intraespecífica de Paspalum notatum