Towards new schemes: A Lie-group approach of the CBKDV and its derived equations

The aim of this paper is to propose methods that enable us to build new numerical schemes, which preserve the Lie symmetries of the original differential equations. To this purpose, the compound Burgers-Korteweg-de Vries (\textit{CBKDV}) equation is considered. The particular case of the Burgers equation is taken as a numerical example, and the resulting semi-invariant scheme is exposed

Testing PPP for Central American real exchange rates. Evidence from new panel data stationary tests with structural breaks

The new panel data stationary test with multiple structural breaks developed by Carrion-i-Silvestre, Del Barrio-Castro and Lopez-Bazo (2005) is used along with standard stationary tests to study the long-run PPP hypothesis in a set of six Central American countries for the period 1976:1-2006:4. Contrary to standard tests, this new procedure provides strong support for PPP.

Optimizing the new formulation of the United Nations' human development index: An empirical view from data envelopment analysis.

In this paper, we propose a new way to simulate an optimal Human Development Index [HDI]. Indeed, the formulation of the original HDI established by the United Nations Development Programme [UNDP] relies on a major methodological shortcoming, namely the contestable assumption that all component indices have the same weights. So, we implement a new approach to determine the optimal weights of each sub-indicator in the light of Data Envelopment Analysis [DEA]. Accordingly, we follow the multiplicative optimization approach introduced by Zhou et al. (2010), to assess robustly the relative performance of a set of 169 economies around the world in terms of human development. Finally, the new world ranking is close to and highly correlated with the standard HDI one, giving then some support to the equal weighting method adopted by the UNDP.Human development index, data envelopment analysis, multiplicative optimization approach, optimal weights

Short Note on the Unemployment Rate of the “French overseas regionsâ€

This article analyzes the hysteresis hypothesis in the unemployment rates of the four “French overseas regions†(Guadeloupe, Martinique, Guyana, Reunion) [FORs] over the period 1993-2008. We use standard univariate and panel unit root tests, among them Choi (2006) and Lopez (2009) that account for cross-sectional dependence and have improved performance when the number of countries and the time dimension of the data are limited. Our results cannot reject the null hypothesis of a unit root and so find evidence supporting hysteresis in the unemployment rates for the FORs.Hysteresis, Unemployment, Panel unit root test, cross-section dependence, convergence

Knowledge Acquisition and Assimilation in Tourism-Innovation Processes

Author's accepted version (postprint).This is an Accepted Manuscript of an article published by Taylor & Francis in Scandinavian Journal of Hospitality and Tourism on 2014, available online: http://wwww.tandfonline.com/10.1080/15022250.2014.887609

Is memantine a safe and effective treatment for Alzheimer’s disease in patients over the age of 50?

OBJECTIVE The objective of this selective EBM review is to determine whether or not memantine is a safe and effective treatment for Alzheimer’s disease in patients over the age of 50. STUDY DESIGN Systematic review of two randomized controlled trials published in 2006 and 2013 and one randomized controlled trial pooled analysis published in 2014. DATA SOURCES Two randomized controlled trials and one pooled analysis were obtained using PubMed. OUTCOMES MEASURED Efficacy of memantine as compared to control groups based on cognition, behavior, and adverse events. These were measured using Severe Impairment Battery (SIB), Neuropsychiatric Inventory (NPI), and Behavioral Pathology in AD Rating Scale (BEHAVE-AD). RESULTS Herrmann et al. (2013) and Peskind et al. (2006) failed to show superiority of memantine over a placebo. Nakamura et al. (2014) showed that memantine produced statistically better outcomes compared to the placebo in terms of behavior and cognitive function. In all three studies, the overall incidence of adverse events was similar between the memantine and placebo groups. CONCLUSION The trials analyzed in this selective EBM review showed conflicting evidence regarding the efficacy of memantine in the treatment of Alzheimer’s disease. Further investigation is warranted to definitively evaluate the efficacy of memantine at improving cognition and behavior

Does the real GDP per capita convergence hold in the Common Market for Eastern and Southern Africa?

This article examines the convergence of real GDP per capita in the Common Market for Eastern and Southern Africa (COMESA) during the period 1950-2003. Income departures across countries were evaluated from several panel data unit root tests, especially we consider the absolute and conditional convergence. We find no evidence supporting the existence of convergence process for the income in the COMESA. Nevertheless, applying economic development criterion allows to identity two absolute convergence clubs into the COMESA, one for the most four developed countries (Egypt, Libya, Mauritius, Seychelles), and one other for the fourteen less developed ones. Thus, we show that most economies of COMESA are locked into a sustained poverty trap process.

Short Note on the Unemployment Rate of the French Overseas Regions

This article analyzes the hysteresis hypothesis in the unemployment rates of the four French overseas regions (Guadeloupe, Martinique, Guyana, Reunion) [FORs] over the period 1993-2008. We use standard univariate and panel unit root tests, among them Choi (2006) and Lopez (2009) that account for cross-sectional dependence and have improved performance when the number of countries and the time dimension of the data are limited. Our results cannot reject the null hypothesis of a unit root and so find evidence supporting hysteresis in the unemployment rates for the FORs.panel unit root, unemployment, hysteresis.

Lie group stability of finite difference schemes

Differential equations arising in fluid mechanics are usually derived from the intrinsic properties of mechanical systems, in the form of conservation laws, and bear symmetries, which are not generally preserved by a finite difference approximation, and leading to inaccurate numerical results. This paper proposes a method that enables us to build a scheme that preserves some of those symmetries.Comment: 10 page