Sir

We find that your News story 'Scientists rally to Mexican researchers' plea' (Nature 454, 143; 2008) is unjustifiably biased in favour of Harold Kroto and the research group of the Terrones brothers whom he defends.

Our institute for scientific and technological research, IPICYT, is one of 27 nationwide research centres coordinated by Mexico's national council of science and technology (CONACYT). This relies on long-established mechanisms for selecting the best researchers and directors. The present director of IPICYT, David Rios Jara, is supported by all the other CONACYT directors and by different Mexican academic organizations in his stand on the Terrones brothers affair.

IPICYT comprises five highly successful multidisciplinary divisions and the national supercomputing centre, which between them operate four prestigious graduate programmes. The advanced-materials department (AMD) where the Terrones work represents about 20% of IPICYT's academic output.

The conflict involving the Terrones brothers attracted international attention because of their scientific reputation and connections with foreign scientists. These would not have been possible without the exceptional treatment and financial support they received at the hands of the former and current IPICYT directors. The AMD researchers, students, postdocs and technicians continue to work normally, despite the Terrones' claim that their group is being harassed and thwarted. The group remains the most well supported at IPICYT.

In relieving Humberto Terrones of his administrative duties, after more than seven years as AMD's head, Rios Jara was not persecuting him but was simply complying with the recommendation by the last external evaluating committee and the CONACYT governing board. One intention in removing these duties was to improve relations between the Terrones group and the rest of the AMD.

Mexican science is definitely not under threat, neither will it be affected by changing a single division head of a CONACYT centre. Indeed, the new measures enable the Terrones to enjoy more time on their research, which should help to boost their scientific output.