The effectiveness of value-based messages to engage gun owners on firearm policies: a three-stage nested study.

Background: Although gun owners overwhelmingly support violence prevention policies, they are hesitant to speak up publicly to advocate for these policies. We tested a series of communication messages on gun owners' level of support for various firearm violence prevention policies and on their willingness to engage in gun violence prevention advocacy.

Methods: We conducted three consecutive experiments, testing a total of thirteen messages on a sample of gun owners over 18 years old who live in the U.

Tropicalisation of epidemiological models in Africa: A mixed and hybrid approach to better predict COVID-19 indicators.

Context: Since the outbreak of the SARS-COV2 epidemic turned into a COVID-19 pandemic, international bodies such as the WHO as well as governments have announced projections for morbidity and mortality indicators related to COVID-19. Most of them indicated that the health situation would be worrying. Although using artificial intelligence with mathematical algorithms and/or neural networks, the results of the SIR models were poorly performing and not very accurate in relation to the observed reality in the African states in general and in Senegal in particular.