Influence of COVID-19 vaccination on the dynamics of new infected cases in the world.

The initial COVID-19 vaccinations were created and distributed to the general population in 2020 thanks to emergency authorization and conditional approval. Consequently, numerous countries followed the process that is currently a global campaign. Taking into account the fact that people are being vaccinated, there are concerns about the effectiveness of that medical solution.

The influence of passenger air traffic on the spread of COVID-19 in the world.

Countries in the world are suffering from COVID-19 and would like to control it. Thus, some authorities voted for new policies and even stopped passenger air traffic. Those decisions were not uniform, and this study focuses on how passenger air traffic might influence the spread of COVID-19 in the world.

Cross-Validation Comparison of COVID-19 Forecast Models.

Many papers have proposed forecasting models and some are accurate and others are not. Due to the debatable quality of collected data about COVID-19, this study aims to compare univariate time series models with cross-validation and different forecast periods to propose the best one. We used the data titled "Coronavirus Pandemic (COVID-19)" from "'Our World in Data" about cases for the period of 31 December 2019 to 21 November 2020.

Carbon dioxide emissions from transport and anemia influence on under-five mortality in Benin.

This work is the first study about the joint effect (influence) of carbon dioxide emissions (CO) from transport and anemia influence on under-five mortality in the Republic of Benin. We focused on that interaction effect and provide scientific pieces of evidence through multiple linear and multinomial regression models. Therefore, the World Bank yearly data about Benin has been used.