Les forêts de montagne de la Nouvelle-Calédonie

L'existence d'un gradient local de température plus prononcé près des montagnes isolées abaisse l'altitude moyenne de formation des masses nuageuses, créant ainsi des conditions propices au développement des forêts de montagne en Nouvelle-Calédonie à des altitudes inférieures à 1 600 m. Ces forêts sont d'une grande importance pour la biodiversité et la compréhension de la phytogéographie et phylogénie de certains groupes, comme celui des conifères ou ceux des genres Metrosideros (Myrtaceae) et Cunonia (Cunoniaceae). Elles constituent aussi des refuges pour la faune menacée et jouent un rôle de régulateur hydrologique non négligeable. Relativement bien protégées, elles sont peu menacées par l'exploitation forestière, un peu plus par les activités minières. Le plus grand risque semble, toutefois, être le réchauffement climatique global, qui pourrait entraîner une disparition des conditions écologiques particulières nécessaires à leur existence. (Résumé d'auteur

Guidance for better governance towards a sustainable, participatory and inclusive wild meat sector.

Agenda item 4 at the twenty-first meeting of the Subsidiary Body on Scientific, Technical and Technological Advice (SBSTTA) established under Article 25 of the Convention will be held in Montreal, Canada, at the Palais des Congrès, from 11 to 14 December 2017

The COVID-19 Pandemic Endangers Africa’s Indigenous Pygmy Populations

Forest-dependent populations are affected by environmental pressures that include deforestation and forest degradation. Their lives and livelihoods have also been transformed by political decisions in the countries where they live. In Africa, the Pygmy peoples living in the dense tropical forests (4 million km2) that span west–east along the central African belt of the Congo Basin are made up of genetically and ethno-linguistically distinct groups (Bahuchet 2014). They are broadly subdivided into western groups, including Baka and Aka, and eastern groups including Mbuti, Efe, and Asua. All have a similar way of life associated with forest hunting and gathering even though some have taken up some form of agriculture. Additionally to their mode of subsistence, they share distinctive cultural and phenotypic traits such as the “Pygmy phenotype” of small adult body size (Perry and Dominy 2009). The demographic and evolutionary split between Pygmy and non-Pygmy populations is amongst the oldest for modern humans with the divergence estimated from genetic data to be roughly between 60,000 and over 100,000 years ago and the split between Western and Eastern Pygmy groups about 20,000 years ago (Hsieh et al. 2016). The Baka in south-eastern Cameroon, formerly strict hunters-gatherers, still practice a subsistence economy, but also maintain a close association with sedentary Bantu-speaking swidden agriculturalists with whom they have a complex social, economic, and symbolic relationship (Joiris 1998). Although less isolated than other Pygmy groups, especially the Mbuti and Efe, the Baka, like other forest-dependent populations in the Congo Basin, have been affected by a plethora of environmental pressures that include direct impacts from extractive industries (logging, mining), conflict with conservation areas, encroachment into their territories both peacefully along roads or aggressively by poachers and militias, as well as the effects of resettlement and sedentarization (Olivero et al. 2016). Such combination of threats impacts their health and food security. Currently, COVID-19 has reached Africa though apparently with an overall surprisingly low prevalence and mortality (Mbow et al. 2020). We argue that Pygmy communities may be silently ravaged by the disease yet there is a lack of policies or initiatives to monitor their health systematically throughout the Congo Basin. Understanding the impact of COVID-19 on these forest-dependent peoples has never been more important to develop ways of helping them

Bushmeat, human impacts and human health in tropical rainforests: The ebola virus case

Viande de brousse, impacts anthropiques et santé humaine dans les forêts tropicales humides : le cas du virus Ebola At a time when more than 5million tonnes of bush meat are harvested annually from tropical forests, and which account for a significant, but unrecorded, share of the gross domestic product of many forest countries, decision makers are encouraged, within conservation and food security policies, to understand the role that wildlife can play in the conservation of ecosystem services. In this article, we present an analysis of the problem, describing the role played by bush meat in human diets, and the health risks linked to the consumption of bush meat, in particular with regard to Ebola disease. The aim is to provide insights on the direction of possible strategies to manage the use of wildlife while meeting the needs of local populations and reducing risks to human health

Effects of the Brookite Phase on the Properties of Different Nanostructured TiO2 Phases Photocatalytically Active Towards the Degradation of N-Phenylurea

Different sol-gel synthesis methods were used to obtain four nanostructured mesoporous TiO2 samples for an efficient photocatalytic degradation of the emerging contaminant N-phenylurea under either simulated solar light (1 Sun) or UV light. Particularly, two TiO2 samples were obtained by means of as many template-assisted syntheses, whereas other two TiO2 samples were obtained by a greener template-free procedure, implying acidic conditions and, then, calcination at either 200 °C or 600 °C. In one case, anatase was obtained, whereas in the other three cases mixed crystalline phases were obtained. The four TiO2 samples were characterized by X-ray powder diffraction (followed by Rietveld analysis); Transmission Electron Microscopy; N2 adsorption/desorption at −196 °C; Diffuse Reflectance UV/Vis spectroscopy and ζ-potential measurements. A commercial TiO2 powder (i. e., Degussa P25) was used for comparison. Differences among the synthesized samples were observed not only in their quantitative phase composition, but also in their nanoparticles morphology (shape and size), specific surface area, pore size distribution and pHIEP (pH at isoelectric point), whereas the samples band-gap did not vary sizably. The samples showed different photocatalytic behavior in terms of N-phenylurea degradation, which are ascribed to their different physico-chemical properties and, especially, to their phase composition, stemming from the different synthesis conditions

Critical Strain Region Evaluation of Self-Assembled Semiconductor Quantum Dots

A novel peak finding method to map the strain from high resolution transmission electron micrographs, known as the Peak Pairs method, has been applied to In(Ga) As/AlGaAs quantum dot (QD) samples, which present stacking faults emerging from the QD edges. Moreover, strain distribution has been simulated by the finite element method applying the elastic theory on a 3D QD model. The agreement existing between determined and simulated strain values reveals that these techniques are consistent enough to qualitatively characterize the strain distribution of nanostructured materials. The correct application of both methods allows the localization of critical strain zones in semiconductor QDs, predicting the nucleation of defects, and being a very useful tool for the design of semiconductor device