Ebola virus disease is a lethal human and primate disease that currently requires a particular attention from the international health authorities due to important outbreaks in some Western African countries and isolated cases in the UK, the USA and Spain. Regarding the emergency of this situation, there is a need for the development of decision tools, such as mathematical models, to assist the authorities to focus their efforts in important factors to eradicate Ebola. In this work, we propose a novel deterministic spatial-temporal model, called Between-Countries Disease Spread (Be-CoDiS), to study the evolution of human diseases within and between countries. The main interesting characteristics of Be-CoDiS are the consideration of the movement of people between countries, the control measure effects and the use of time-dependent coefficients adapted to each country. First, we focus on the mathematical formulation of each component of the model and explain how its parameters and inputs are obtained. Then, in order to validate our approach, we consider two numerical experiments regarding the 2014-2015 Ebola epidemic. The first one studies the ability of the model in predicting the EVD evolution between countries starting from the index cases in Guinea in December 2013. The second one consists of forecasting the evolution of the epidemic by using some recent data. The results obtained with Be-CoDiS are compared to real data and other model outputs found in the literature. Finally, a brief parameter sensitivity analysis is done. A free MATLAB version of Be-CoDiS is available at: http://www.mat.ucm.es/momat/software.htm.

Ngom et al J. Appl. Biosci. 2013. Caractéristiques écologiques du peuplement ligneux de la réserve de biosphère du Ferlo, Sénégal ABSTRACT Objectives : This study aims to characterize the various structural parameters of the woody vegetation in Ferlo Biosphere Reserve (FBR). Methods and Results: In 2011 measurement of dendrometric characteristics of trees and an inventory of the woody flora was carried out in 110 plots of 900 m² each. The total specific richness was 49 species and the Journal of Applied Biosciences 65:5008 -5023 ISSN 1997-5902 Ngom et al J. Appl. Biosci. 2013. Caractéristiques écologiques du peuplement ligneux de la réserve de biosphère du Ferlo, Sénégal 5009 average of the specific richness was 5.8 species / plot. The analysis of centesimal frequencies showed that Guiera senegalensis (75%), Combretum glutinosum (65.5%), Boscia senegalensis (63.6%) and Pterocarpus lucens (60.9%) are the most common species. Tree density is higher in the central area (392 ind / ha) while the basal area and the recovery are higher in the buffer zone with respectively 9.17 m²/ha and 43%. Concerning the structure, the woody trees have a relatively high proportion of seedlings. In fact, over 90% of trees surveyed have heights between 0 and 6 m and circumference between 10 and 100 cm, which shows the importance of the shrub layer in the FBR. With regard to the ecological importance, three species are distinguished : Pterocarpus lucens (18%), Guiera senegalensis (16%) and Combretum glutinosum (13%). The rate of regeneration of plant population is 72% in the FBR. It is twice higher in the core area (79%) which is less anthropized than the buffer zone (36%) and the transition zone (39%). Guiera senegalensis has the highest potential of regeneration with a specific regeneration index more than 62%. Conclusion and applicability of the results: These results demonstrate the potential of the FBR to ensure the dual role of biodiversity conservation and provision of ecosystem services to local communities.

& Key message Selection of the best salt-tolerant combination of Casuarina sp. and arbuscular mycorrhizal fungi (AMF) is one of the key criteria for successful setup of saline land rehabilitation program. & Context Land salinization is a serious problem worldwide that mainly leads to soil degradation and reduces crop productivity. These degraded areas could be rehabilitated by planting salt-tolerant species like Casuarina glauca Sieb. and Casuarina equisetifolia L. These are pioneer plants, able to form symbiotic associations with arbuscular mycorrhizal fungi (AMF), ectomycorrhizal fungi (EMF), and nitrogen-fixing bacteria. & Aims The aim of this study was to select the highest salt-tolerant combination of Casuarina/AMF that can be used for the rehabilitation of lands degraded by salinity. & Methods C. equisetifolia and C. glauca were grown in sandy sterile soil in the greenhouse and inoculated separately with Rhizophagus fasciculatus (Thaxt.) C. Walker & A. Schüßler, Rhizophagus aggregatus (N.C. Schenck & G.S. Sm.) C. Walker, and Rhizophagus intraradices (N.C. Schenck & G.S. Sm.) C. Walker & A. Schüßler. After confirming the establishment of a symbiosis, the plants were watered with gradually increasing concentrations of saline solution. After harvest, size and biomass of the seedlings, root colonization by AMF, and AMF metabolic activities were evaluated.

Salinity is one of the main abiotic stresses limiting plant growth and development. However, the use of salt-tolerant plants combined with beneficial soil microorganisms could improve the effectiveness of biological methods for saline soil recovery. The aim of this study is to identify the Casuarina obesa/ Arbuscular Mycorrhizal fungi (AMF)/Plant Growth Promoting Rhizobacteria (PGPR) association that could be used in salt-land rehabilitation programs. Thus, the plants were grown under greenhouse on sandy soil, inoculated either with PGPR (Pantoea agglomerans and Bacillus sp.), or with AMF (Rhizophagus fasciculatus and Rhizophagus aggregatum) or co inoculated with PGPR and AMF and watered with a saline solution (0, 150, and 300 mM). After 4 months of cultivation, the plants were harvested and the results obtained showed that inoculation improves the survival rate, height and biomass of the plants compared to the control plants. The results also showed that inoculation increases the total amount of chlorophyll and the accumulation of plant proline at all levels of salt concentration. However, P. agglomerans and Bacillus sp. strains alone or in combination with R. fasciculatus increased plant growth. This study showed that these strains of PGPR, whether or not associated with AMF, could be biological tools to improve C. obesa performance under saline stress conditions.