The initial phase dynamics of an epidemic without containment measures is commonly well modelled using exponential growth models. However, in the presence of containment measures, the exponential model becomes less appropriate. Under the implementation of an isolation measure for detected infectives, we propose to model epidemic dynamics by fitting a flexible growth model curve to reported positive cases, and to infer the overall epidemic dynamics by introducing information on the detection/testing effort and recovery and death rates. The resulting modelling approach is close to the Susceptible-Infectious-Quarantined-Recovered model framework. We focused on predicting the peaks (time and size) in positive cases, active cases and new infections. We applied the approach to data from the COVID-19 outbreak in Italy. Fits on limited data before the observed peaks illustrate the ability of the flexible growth model to approach the estimates from the whole data.

No abstract

The Ouémé catchment abounds an important diversity of woody plant species. However, harvesting pressure on these species seems to lead to threats of their sustainability. Despite this fact, few published studies concerning their conservation have been undertaken. In this regard, our study focused on (1) assessment of impact of socio-demographic factors and climatic zones on knowledge and use of the woody plant species; (2) assessment of the use status of each of these species and (3) ranking within each climatic zone these species according to their priority for conservation. A total of 411 randomly selected informants were interviewed through a semi-structured survey followed by a field survey in 69 random plots of 0.15 ha. Data from available literature were used to complete the surveys. Ecological and ethnobotanical parameters were computed, and the highest priority species for conservation were identified. The results showed significant difference in plant use between women and men, ethnic groups and climatic zones. However, age was not a determinant of plant knowledge. The findings also revealed that more than 50% of native species in the study area are underutilized or widely used by few people. Moreover, six species were identified as priorities and need high conservation efforts in the two climatic zones, namely: Parkia biglobosa, Pterocarpus erinaceus, Milicia excelsa, Prosopis africana, Afzelia africana and Khaya senegalensis. Non-governmental organizations, governments and agroforestry research institutions are entreated to incorporate these species in local development strategies aiming at sustainable management and long-term conservation of native species.

No abstract

The initial phase dynamics of an epidemic without containment measures is commonly well modeled using exponential growth models. However, in the presence of containment measures, the exponential model becomes less appropriate. Under the implementation of an isolation measure for detected infectives, we propose to model epidemic dynamics by fitting a flexible growth model curve to reported positive cases and to infer the overall epidemic dynamics by introducing information on the detection/testing effort and recovery and death rates. The resulting modeling approach is close to the SIQR (Susceptible- Infectious-Quarantined-Recovered) model framework. We focused on predicting the peaks (time and size) in positive cases, actives cases and new infections. We applied the approach to data from the COVID-19 outbreak in Italy. Fits on limited data before the observed peaks illustrate the ability of the flexible growth model to approach the estimates from the whole data.