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Insects are the best example of biodiversity.
They represent the third of the living species and scientists discover new specie every day.
One group in particular has survived through many geological events : the insects.
While climate was changing regularly, they were able to adjust and develop.
Today, it is the human’s impact that is presenting a threat to insects.
With Philippe Le Gall, entomologist from IRD, we try to understand how, in this area of Cameroun mountains, the living is always in motion...
The coleoptera group accounts for about 350,000 species which is about a fourth of the total known species of one million.
Using the insects and their major biodiversity, availability and size, scientists have now a fundamental model that they can use for their research.
The Saharan cousin of Mediterranean olive trees remains largely unknown. However, this subspecies (called the Laperinne's olive tree) is of great interest for several reasons. IRD researchers and their partners showed that its longevity is ensured by its original vegetative reproduction. Extremely drought-resistant, this "relict" tree could act as a genetic resource to improve its domestic counterparts, provided conservation actions are implemented to prevent its disappearance.
In 2010, a study revealed that the main agent of malaria in humans, called Plasmodium falciparum , arose from the gorilla. Today, the vector which transmitted the parasite from apes to humans has just been identified. A Franco-Gabonese research consortium has determined which species of anopheles mosquitoes transfer the disease to apes. Among them is Anopheles moucheti , known for biting humans! Therefore, it must be the species which originally infected us through our cousins. And it could do it again today.
The waters off the coast of Senegal have been stripped of their false cods, also known as "thiof" or groupers. How is it possible that this country's iconic fish is nearly extinct? A French-Senegalese team recently demonstrated that the collapse of stocks is due to the boom in the small-scale fishery sector – generally viewed as a sustainable alternative to industrial fisheries. Over 30 years, the number of pirogues has quadrupled. Technological progress continuously improves the fishing power of the fleet. In order to reduce pressure on the resource, researchers recommend the implementation of a management system to control small-scale fisheries and regulate exportation, which pushes up prices per kilo and makes thiof a very profitable commodity, despite the scarcity of the fish.
In Africa, more than 25 million people, most of them women, are currently infected by the AIDS virus. However, a study conducted by Epicentre( 1) and IRD researchers shows that men are less responsive to treatment. The provision of healthcare is intended to restore the level of lymphocyte cells, called T-CD4, reduced by HIV. Based on 13,000 patients monitored through four programmes carried out by Médecins sans frontières France in Malawi, Uganda and Kenya, the study shows that the reconstitution of these white blood cells is slower in men than in women.
Due to stigmatisation and work- and transport-related constraints, among others, men often receive healthcare at a later stage and are less responsive to treatment. However, this gender-based difference could also stem from biological causes, such as physiologically lower rates of T-CD4 lymphocytes.
This study underlines the fact that men should therefore receive special attention from programmes aimed at fighting the disease.