On the instability of a nonlocal conservation law

We are interested in a nonlocal conservation law which describes the morphodynamics of sand dunes sheared by a fluid flow, recently proposed by Andrew C. Fowler. We prove that constant solutions of Fowler's equation are non-linearly unstable. We also illustrate this fact using a finite difference scheme

«SYNTHESE , CARACTERISATION PAR LA DIFFRACTION DES RX ET ETUDE DES PROPRIETES PIEZOELECTRIQUES DE LA SOLUTION SOLIDE 0,51 PbZrO3-0,47 PbTiO3-0,01Pb (Ni1/3, Sb2/3) O3-0,01Pb (Ni1/3, Nb2/3) O3 »

Ce travail a pour objet la synthèse des céramiques piézoélectriques de type PZT de structure perovskite au voisinage de la frontière morphotropique de phase où les phases tétragonale et rhomboédrique coexistent. Cette étude ce rapporte à la synthèse de la solution solide PZT dans le système quaternaire : xPbZrO3-y PbTiO3-z Pb(Ni1/3, Sb2/3)O3-zPb(Ni1/3, Nb2/3)O3 avec x=0.51 ;y=0.47 et z=0.02. Ces céramiques ont été préparés par voie solide selon les méthodes classiques de synthèse thermique des mélanges d’oxydes. L’intérêt de notre travail, a porté sur l’étude réactionnelle de formation de la solution solide Zirconate Titanate de Plomb PZT, en présence des dopants : NiO, Sb2O3 et Nb2O5 à l’aide de la méthode de diffraction des rayons X, l’analyse différentielle (ATD) et l’analyse thermogravimétrique (ATG). L’effet de la température de frittage sur la densité et la porosité, nous a permis d’atteindre une température qui correspond au produit de meilleure qualité. Le deuxième objectif, de notre travail est l’étude des propriétés électriques en fonction de la température et de fréquence

Does education engender cultural values that matter for economic growth?

Empirical research has shown that cultural values matter for economic growth and has specifically identified the achievement motivation as an aspect of culture that engenders economic growth. If specific cultural values engender economic growth, how then can societies promote them? This paper attempts to answer this question using the 2005 wave of the World Values Survey data for 43 countries. We test the contention that education significantly impacts the relative importance an individual places on economic achievement vis-à-vis traditional social norms. Results suggest that individuals with higher education levels attach higher importance to values related to autonomy and economic achievement as compared to conformity to traditional social norms. The results have an important implication for efforts to promote economic development; institutions and specifically public policy on education could be used to encourage people to adopt values that are considered important for economic development.Cultural Values, Education, Ordered Probit, Semi-Nonparametric Estimation

Economic Incentives for Entry and Exit in Gum Arabic Agroforestry System in Sudan

The gum tree (Acacia senegal) in the Sahel-Sudan zone has many environmental benign functions. An important function is to control desertification. In this paper we analyze farmers' economic incentives to preserve the existing gum trees and their incentives to create new plantations using a real options approach. Results indicate that agricultural crops provide higher economic benefits as compared to gum agroforestry system. However, on the one hand, as gum arabic is produced during the dry period and land is abundant, there are low incentives for deforestation. Instead, farmers' tend to leave the land idle and let the tree growing. On the other hand, our results suggest that an increase in the prices of gum arabic of about 330 per cent is needed to induce entry and a shift in land use system from continuous agricultural production to gum agroforestry system.gum arabic, deforestation, entry and exit, real options, Sudan, Crop Production/Industries, D4, N5, O13, Q12, Q23,

As estrelas estão alinhadas: As enfermeiras devem exercer a sua voz

The author develops in this editorial a claiming discourse whose purpose is to draw attention to the nurses to make their voices heard at a particularly propitious time for it (the stars are aligned). Afaf Meleis describes the current situation as the ideal for the nursing profession, finally, exercise your voice and contribute to optimizer health care through greater presence of nursing in all areas related to health. Demographic, educational, social and health changes, increasingly require the presence of nurses to optimize the quality of care, especially self-care.La autora desarrolla en esta editorial un discurso reivincativo cuyo propósito es llamar la atención a los profesionales de enfermería para que hagan oír sus voces en un momento especialmente propicio para ello (las estrellas están alineadas). Afaf Meleis describe la situación actual como la idónea para que el colectivo enfermero, por fin, ejercite su voz y contribuya a optimizar los cuidados de salud mediante una mayor presencia de la enfermería en todos los ámbitos relacionados con la salud. Los cambios demográficos, educativos, sociales y de salud, requieren cada vez más la presencia de las enfermeras para optimizar la calidad de los cuidados, especialmente de los autocuidados.O autor desenvolve neste editorial discurso um vingativo cujo objetivo é chamar a atenção para os enfermeiros para fazer suas vozes ouvidas em um momento particularmente propício para isso (as estrelas estão alinhadas). Afaf Meleis descreve a situação atual como o ideal para a profissão de enfermagem, finalmente, exercer a sua voz e contribuir para o otimizador de cuidados de saúde através de uma maior presença de enfermagem em todas as áreas relacionadas com a saúde. Mudanças sociais e demográficas de educação em saúde, cada vez mais exigem a presença de enfermeiros para otimizar a qualidade dos cuidados, especialmente auto-cuidado

What determines workers’ preferences for efficiency over equity wages?

What makes workers consider it fair for wages to be indexed on job performance or efficiency? In this paper we attempt to answer this question using the 2005 wave of the World Values Survey data for 43 countries to investigate what socio-economic characteristics condition employees’ preference for efficiency over equity wages. Our results suggest that employees’ preference for efficiency wages increases with education and globalization while it decreases with unemployment, income inequality and income tax rates. Given that conventional economic theory demonstrates the importance of labour efficiency, which improves when workers are remunerated according to their efficiency, for economic growth; our results suggest that institutions and specifically public policies that promote education, and globalization, along with policies that reduce unemployment, income inequality and income tax rates could be used to promote efficiency-based wages.

Consultation etiquette in general practice: A qualitative study of what makes it different for lay cancer caregivers

Background: It is commonplace for lay caregivers to overlook their own health concerns when supporting someone with advanced cancer. During this time, caregivers’ needs as patients are often marginalised by health professionals, including General Practitioners (GPs), who may miss the breadth of caregivers’ needs by focusing on the practicalities of caregiving. GPs traditionally rely on patients to raise their concerns, and then respond to these concerns, but caregivers as patients may be disinclined to cue their GP. The norms of engagement when caregivers consult their GP are less defined, and how they interact with their GP regarding their own health is under-explored. This sub-study investigates the norms, assumptions and subtleties which govern caregiver-GP consultations, and explores factors affecting their interaction regarding caregivers’ own health concerns. Methods: We conducted semi-structured interviews with six lay caregivers and 19 health professionals in Brisbane, Australia, and analyzed the interview transcripts thematically. Results: Traditional norms of engagement are subjected to assumptions and expectations which caregivers and GPs bring to the consultation. Practice pressures also influence both parties’ capacity and willingness to discuss caregivers’ health. Nonetheless, some GPs monitor caregivers’ health opportunistically. Their interaction is enhanced by the quality of the caregiver-GP relationship and by the GP’s skills. Conclusions: Caregivers are caught in a paradox whereby their health needs may become subsumed by the care recipient’s needs in a setting where patient needs are normally scrutinised and supported. Caregivers may not raise their health concerns with their GP, who instead may need to cue them that it is timely and safe to do so. The routine use of a prompt may help to address caregivers’ needs systematically, but it needs to be complemented by GPs’ desire and capacity to engage with patients in a caregiving role. The potential difference GPs can make to the health of these patients is substantial