La réintroduction du castor en (Castor fiber) France: Essai de synthèse et réflexions

Rouland Patrick, Migot Pierre. La réintroduction du castor en (Castor fiber) France: Essai de synthèse et réflexions. In: Revue d'Écologie. Supplément n°5, 1990. pp. 145-158

Recovery of soil macrofauna communities after forest clearance in Eastern Amazonia, Brazil

International audienc

Application of the new eLIFT test for the non-invasive diagnosis of advanced liver fibrosis in people with type 2 diabetes

IF 12.486Lettre à l'éditeur ("Journal of Hepatology", vol. 68, n°3, pp. 603-604, available online 4 October 2017)https://www.sciencedirect.com/science/article/pii/S0168827817323292?via%3Dihu

: IOP in vivo measurement

International audienceGlaucoma is an ocular disease clinically manifested by an abnormal rise of the Intra Ocular Pressure (IOP) that causes lesions of the optic nerve and can lead to blindness. Ophthalmologists currently use aplanation tonometers whose utilization induces multiple constraints. We propose an investigative method being at one and the same time atraumatic and ambulatory. This original device, taking profit of a physical relation between frequency of mechanical vibration of the ocular globe and IOP, involves vibrometry by laser interferometry and spectral analysis of a mechanical impulse using a temporal micro hammer. The laser energy delivered to the eye by the device was confirmed to be safe and in full agreement with the authorized security norms. After preliminary in vitro experiments performed using enucleated animal eyes, we made a clinical study on 25 volunteers to evaluate the innocuity and the reliability of this device and to quantify the reproducibility of measurements. All patients declared that discomfort is comparable with that felt during similar tests. Reliability is good and the intra individual reproducibility reveals a high value (R¿ 0.93). These works will be carried on to check the correlation between the variation of measured values (resonance frequency of the eye-ball) and the variation of reference (IOP) values

Spatial patterns of grasses influence soil macrofauna biodiversity in Amazonian pastures

Grasslands are often characterized by small-scale spatial heterogeneity due to the juxtaposition of grass tufts and bare ground. Although the mechanisms generating plant spatial patterns have been widely studied, few studies concentrated on the consequences of these patterns on belowground macrofauna. Our objective was to analyze the impact of grass tuft (Brachiaria bryzantha cv. marandu) spatial distribution on soil macrofauna diversity in Amazonian pastures, at a small scale (less than 9 m(2)). Soil macrofauna was sampled among B. bryzantha tufts, which showed a variable spatial distribution ranging from dense to loose vegetation cover. The vegetation configuration explained 69% of the variation in total soil macrofauna density and 68% of the variation in total species richness. Soil macrofauna was mainly found in the upper 10 cm of soil and biodiversity decreased with increasing distances to the nearest grass tuft and increased with increasing vegetation cover. The size of the largest grass tuft and the microlandscape connectivity also had a significant effect on biodiversity. The density and species richness of the three principal soil ecological engineers (earthworms, ants and termites) showed the best correlations with vegetation configuration. In addition, soil temperature significantly decreased near the plants, while soil water content was not influenced by the grass tufts. We conclude that soil macrofauna diversity is low in pastures except close to the grass tufts, which can thus be considered as biodiversity hotspots. The spatial arrangement of B. bryzantha tussocks influences soil macrofauna biodiversity by modifying soil properties in their vicinity. The possible mechanisms by which these plants could affect soil macrofauna are discussed

Spatial patterns of grasses influence soil macrofauna biodiversity in Amazonian pastures

Grasslands are often characterized by small-scale spatial eterogeneity due to the juxtaposition of grass tufts and bare ground. Although the mechanisms generating plant spatial patterns have been widely studied, few studies concentrated on the consequences of these patterns on belowground macrofauna. Our objective was to analyze the impact of grass tuft (Brachiaria bryzantha cv. marandu) spatial distribution on soil macrofauna diversity in Amazonian pastures, at a small scale (less than 9 m2). Soil macrofauna was sampled among B. bryzantha tufts, which showed a variable spatial distribution ranging from dense to loose vegetation cover. The vegetation configuration explained 69% of the variation in total soil macrofauna density and 68% of the variation in total species richness. Soil macrofauna was mainly found in the upper 10 cm of soil and biodiversity decreased with increasing distances to the nearest grass tuft and increased with increasing vegetation cover. The size of the largest grass tuft and the microlandscape connectivity also had a significant effect on biodiversity. The density and species richness of the three principal soil ecological engineers (earthworms, ants and termites) showed the best correlations with vegetation configuration. In addition, soil temperature significantly decreased near the plants, while soil water content was not influenced by the grass tufts. We conclude that soil macrofauna diversity is low in pastures except close to the grass tufts, which can thus be considered as biodiversity hotspots. The spatial arrangement of B. bryzantha tussocks influences soil macrofauna biodiversity by modifying soil properties in their vicinity. The possible mechanisms by which these plants could affect soil macrofauna are discussed