Scientific newssheets
Page 1 : Results 1 to 5 on 389
398 - Retreating glaciers are a threat to biodiversity
March 2012
Thawing is taking place the world over as a result of global warming, and the diversity of mountain ecosystems is thus under threat. IRD researchers and their partners( 1), writing in the journal Nature Climate Change , have just revealed that the retreating glaciers may lead to the extinction of between 10 to 40% of aquatic fauna depending on the region - tropical, temperate or arctic. Ecologists have been studying the biodiversity of streams created by meltwater in the the páramos, a typical landscape feature in the Andes) situated at an altitude of between 3,500 and 5,000m. The species that make these streams their home, mostly insects, are endemic to these extreme environments and subjected to a combination of ice and intense sunlight, aggressive winds, etc. The disappearance of such exceptional fauna would lead to a loss in the conservation of such ecosystems, which are unique in the world. However invertebrates also have a role to play as bio-indicators, particularly regarding the quality of the water that supplies downstream towns and cities such as Quito, the capital of Ecuador.
397 - Education in Senegal: inequality in development
February 2012
The rate of primary education across the world has increased remarkably during the last decade, rising from 82% in 1999 to 88% in 2008, according to Unesco. The countries with the lowest education rates, in Sub-Saharan Africa and Western Asia, are also those who have demonstrated the largest increases. Beyond these figures, researchers have been questioning the reality in terms of inequalities and their reduction, and have shown that they have not yet disappeared. Two studies in Dakar have demonstrated this. They have provided a clearer picture of the consequences of the changes observed in Senegal, where an increasing number of girls are starting school, but remain less likely to proceed to secondary education than boys. The research has also underlined the boom in private education, now closing the gap with public schools: this is particularly the case for denominational private schools, with a success rate of almost 90% for the end-of-primary certificate, as opposed to just over 50% in the public sector.
The democratisation of primary schools has ushered in new educational norms and does not necessarily mean equal opportunities.
396 - Rehabilitation of eroded land in Mexico
February 2012
More than three quarters of the land in Mexico is suffering from erosion. Desertification is accentuated partly by the aggressive climate and rugged topography but mostly by human activity. The phenomenon has led to much activity since 1995: politicians, authorities and local communities have been working together to create sustainable management of the natural resources in water, forests and soil.
The drainage basin of Morelia, the capital of Michoacán, is emblematic of the situation. A Franco-Mexican team of researchers from the IRD, UNAM, UMSNH and ColPos( 1) have selected the region as a pilot study as part of the REVOLSO, STREAMS and DESIRE( 2) programmes, to define the runoffs and develop suitable strategies. Actions have included hydrological monitoring, agronomic essays and socio-economic studies, with participation from local communities, political bodies and the authorities( 3). Cultivation of alternative crops such as agave – used in the production of mezcal( 4) – has been initiated, enabling a reduction in harm to the environment and also a improvement in revenue and quality of life for local inhabitants.
395 - Vietnam: sharing the Red River basin
January 2012
The Red River is the second largest river in Vietnam after the Mekong, providing a livelihood for nearly one third of the country’s population, including the inhabitants of the capital Hanoi. A centuries-old river management system is in place, which controls both the river’s violent floods and water availability.
Over the last 10 years, with the backing of international institutions and donors, the Vietnamese government has established a new water governance structure. Three River Basin Organizations, including the Red River Basin Organization, were superimposed over pre-existing authorities, leading to a greater complexity of water management. The IRD and International Water Management Institute scientists studying the water sector reorganization in Vietnam have shown the lack of effectiveness of this reform. The reorganization, disconnected from established structures, has proved to be disappointing: pricing water resources did not produce the expected benefits, integrated river basin management is proving to be difficult to implement, conflicts have emerged between various authorities… In the long term, this confusion may have a positive effect by triggering some changes, and this study demonstrates that reforms in the water sector must take into account existing management structures.
394 - Malaria: how did it reach the Americas?
January 2012
The malaria parasite, Plasmodium falciparum , originates from Africa, and is found on every continent. Over 200 million people are infected every year from Africa to Asia, as well as in America and the Middle East. How did it spread to the entire planet? It is not entirely clear how it conquered the New World. Scientists from the UMR Migevec ( 1) and their partners ( 2) have recently shown in the journal PNAS that the pathogen was introduced by ship during the slave trade. The research team collected samples of infected blood taken across the whole distribution area of the disease. Analysis of genetic material extracted showed that the American P. falciparum is a close cousin of its African counterpart. In addition, two separate genetic groups exist in Latin America, as a result of two distinct slave routes, one towards the Spanish empire in the North – West Indies and present-day Mexico and Colombia – and the other towards the Portuguese empire – today’s Brazil. Nearly half of the 2.7 million annual cases of malaria in America are now occurring in Brazil.
This recent expansion of the disease shows the parasite’s ability to spread.
