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Biology subjects

Martineau, A.

Publications and source records attributed to Martineau, A..

2 recordsLinked to original sources

Projected dynamics of breeding habitat suitability for a steppe-land bird warrant anticipatory conservation actions

Understanding spatial and temporal variations of habitat suitability is fundamental for species conservation under global change. Steppic species are particularly sensitive to anthropogenic change and have undergone large declines in the last decades. We aimed to describe current and future breeding habitat suitability for the Eurasian stone-curlew Burhinus oedicnemus, a steppic species of conservation concern, and to identify critical areas for its conservation. We collected 1628 presence records covering the period 1992-2016. We developed a species distribution model using a dynamic Maxent algorithm and a set of pseudo-absences with a spatial density weighted on a fixed kernel density estimated on the presences, to mitigate the potential sampling bias. We projected this model under a set of carbon emission, socioeconomic and land-use/land-cover scenarios for the years 2030, 2050, 2070 and 2090. Finally, we described the cell-wise and mean change of breeding habitat suitability through consecutive time intervals and identified the areas critical for the species conservation. All scenarios predicted a short-term northward shift of suitable areas, followed by a period of stability. We found no consistent trends in the mean change of breeding habitat suitability, and similar extents of suitable areas under current and future scenarios. Critical areas for the conservation of the species are mainly located in Northern Europe, Israel and parts of North Africa, the Iberian Peninsula and Italy. According to our results, the Eurasian stone-curlew has the potential to maintain viable populations in the Western Palearctic, but dispersal limitations might hinder the colonization of shifted suitable areas. Targeted conservation interventions in the critical areas are therefore recommended to secure the future of the species under global change.

ecology

Cellular and Cytokine Responses in the Granulomas of Asymptomatic Cattle naturally infected with Mycobacterium bovis in Ethiopia

Cellular (CD3+ T cell and CD68+ macrophages), cytokines (IFN-{gamma}+ and TNF-+) and effector molecule (iNOS+) responses were evaluated in the lymph nodes and tissue of cattle naturally infected with Mycobacterium bovis. Detailed post mortem and immunonohistochemical examinations of lesions were performed on 16 cows positive for single intradermal cervical comparative tuberculin test (SICCTT) and identified from dairy farms located around the Addis Ababa City. The severity of the gross lesion was significantly higher (p=0.003) in M. bovis culture positive (n=12) cows than in culture negative (n=4). Immunohistochemical techniques showed that the mean percentage labelling of CD3+ T cells decreased as the stage of granuloma increased from stage I to stage IV in culture positive cows (p<0.001). On the other hand, the proportional fraction of CD68+ macrophages and the concentrations of IFN-{gamma}+, TNF-+ and iNOS+ increased significantly from stage I to stage IV (p< 0.001) in culture positive cows. At the early stage of the granuloma, the culture negative cows showed significantly higher mean proportions of CD68+ macrophages (p=0.03) as well as the concentrations of iNOS+ (p=0.007) compared to culture positive cows. Similarly, at advanced granuloma stages, culture negative cows demonstrated significantly higher mean proportions of CD3+ T cells (p< 0.001) compared to culture positive cows. Thus, the present study demonstrated that following natural infection of cows with M. bovis, as the stage of granuloma increases from stage I to stage IV, the proportion of CD3+ cells decreases while the immunolabeling fraction of CD68+ macrophages, IFN-{gamma}+, TNF- and iNOS+ increases.

immunology