Food scientists are meeting in Cusco, Peru, this week to find ways of boosting world potato production to ease the strain of surging cereal prices on the world's poorest countries. Potato production already reached a record high last year as cereal prices rose, partly as a consequence of grain producers - such as the US - switching to bio-fuel crops. The impact of more expensive cereals has been harshest on developing countries that are dependent on imports.

In Africa, hard-hit by HIV, the proportion of TB drug-resistance is no less alarming. In former Soviet Union, almost half of all TB cases are resistant to at least one anti-TB drug -Bobby Ramakant

Abstract Black carbon in soot is the dominant absorber of visible solar radiation in the atmosphere. Anthropogenic sources of black carbon, although distributed globally, are most concentrated in the tropics where solar irradiance is highest. Black carbon is often transported over long distances, mixing with other aerosols along the way. The aerosol mix can form transcontinental plumes of atmospheric brown clouds, with vertical extents of 3 to 5 km.

In the 7 December 2007 issue, L. Roberts and M. Enserink discuss malaria eradication in the News Focus Story "Did they really say..eradication?" Information from India's 5-year economic plans shows that even if complete eradication cannot be secured, economic gains and reduced suffering may be worth the effort. (Letters)

Rinderpest, an animal disease that devastated cattle and other animals-and their human keepers-across Eurasia and Africa for millennia, may join smallpox as the only viral diseases to have been eradicated.

Sir, It is appalling that in 2008 you still publish articles such as "Africa's greatest challenge is to reduce fertility' (March 14) by John May and Jean-Pierre Guengant.

In parts of the world already facing unreliable food supplies, an uncertain climate adds to the future stress for soils, plants and people. March 20, 2008

China's growing influence in Africa is inimical to democracy in the region, according to Reporters Without Borders. The Paris-based media watchdog's annual report notes that China must take part of

plague cases are on the rise and are afflicting countries more frequently than before. A who report says there were around 1,900 cases worldwide in 2002, which increased to 2,100 cases in 2003. In

The price of food is soaring. The threat of hunger and malnutrition is growing. Millions of the world's most vulnerable people are at risk. An effective and urgent response is needed.