Countries' readiness to deal with large-scale crises: analysis, measure, and World classification.

A country's preparedness to face crises is a multidimensional competence that depends on several attributes (economic factors, governance features, infrastructure and institutional endowments). This paper proposes a new approach to rank countries based on their degree of preparedness to deal with large-scale crises. The measured characteristics of countries have made it possible to compile an index of preparedness to face shocks and, therefore, predict their performance against the COVID-19 health crisis to verify the relevance of the proposed composite index. Fortunately, it appears that countries with a high degree of preparedness according to our aggregate index were able to respond adequately and effectively to this crisis. This is reflected in a lower mortality rate and more administered tests.

Laccase-based biocathodes: Comparison of chitosan and Nafion.

Chitosan and Nafion(®) are both reported as interesting polymers to be integrated into the structure of 3D electrodes for biofuel cells. Their advantage is mainly related to their chemical properties, which have a positive impact on the stability of electrodes such as the laccase-based biocathode. For optimal function in implantable applications the biocathode requires coating with a biocompatible semi-permeable membrane that is designed to prevent the loss of enzyme activity and to protect the structure of the biocathode. Since such membranes are integrated into the electrodes ultimately implanted, they must be fully characterized to demonstrate that there is no interference with the performance of the electrode. In the present study, we demonstrate that chitosan provides superior stability compared with Nafion(®) and should be considered as an optimum solution to enhance the biocompatibility and the stability of 3D bioelectrodes.