Letters archive

It is interesting that the anti-inflammatory treatment infliximab has been found effective in cases of drug-resistant depression (27 June, p 38) . Several studies have indicated that the conventional antidepressants known as selective serotonin reuptake inhibitors (SSRIs) owe at least part of their success to anti-inflammatory actions. SSRIs have been shown to act on microglial …

Brian Horton's letter suggests that infection with the parasite Toxoplasma gondii serves the interests of cats (13 June) . The domestication of the cat coincided in human history with the rise of cities, which was helped along by cats' ability to control rodents – enabling the stockpiling of grain. This created the opportunity for small …

I was struck by the ability of Toxoplasma to produce a precursor to dopamine, and by the correlation between infection with it and schizophrenia (30 May, p 42) . In the same issue you report on fetal cell treatments for Parkinson's disease, which is caused by an underactive dopamine system (p 11) . It would …

Michael Slezak reports on the challenges coral faces in the Caribbean and elsewhere (20 June, p 36) . It's funny to see that years of sanctions can sometimes inspire people to move towards self-reliance. Along Cuba's coast one of the largest and best-preserved coral reefs in the Caribbean has been thriving – although it now …

David Nutt discusses "the unscientific and primitive... strategy" followed by a number of countries in legislating on recreational drugs (13 June, p 24) . He fails to point out that these are motivated by an unshakeable belief among influential parts of their populations that it is morally wrong to get high. For these people, regardless …

While most New Scientist readers will welcome the pope's encyclical on sustainability (27 June, p 24) , the Catholic church is also implicated in the current parlous situation. Take as an example the Philippines, a country which is around 80 per cent Catholic. The population has grown from 16 million in 1939 to roughly 60 …

• In a leader article we expressed the hope that the pope would embrace evidence-based change in areas beyond climate change, including contraception (17 January, p 5) . But note that religiosity is not always coincident with increased birth rate: consider, for example, that Italy's birth rate is one of the lowest in the European …

In her article on personality traits, Clare Wilson reports Ivan Robertson saying that adopting a more accurate model based on six traits will make it harder to compare work to the existing five-trait model (13 June, p 11 ). But the sixth – known as "Machiavellian" or honesty-humility – is just another trait. Why can …

• It would be useful to compare newer studies using the six-trait model with older ones using five. But the five common factors are not identical across both models – there have been some changes to two of them.

Part of Jessica Hamzelou's fascinating article on heavy fats and longevity puzzled me (16 May, p 8) . A molecule of linoleic acid contains 32 hydrogen atoms: if all were replaced with deuterium the mass per mole would increase by 32 grams to 312, not the 282 stated. Lethbridge, Victoria, Australia

• In the heavy linoleic acid used by the team, two hydrogen atoms were replaced with deuterium.

Claire Ainsworth observes that "blueprint" is a lousy metaphor for what DNA does (13 June, p 42) . The more that we have discovered about how genes function, the more the genome seems like an orchestra, performing a composition in successive movements. But the dynamism and interaction is something like an improvised jazz performance. Maybe …

I noted with interest the mention of Robert Maxwell's Pergamon Press holding rights to the translations of the Soviet Academy of Sciences (Letters, 6 June) . Not long after Maxwell's death, I was asked to value a large collection of works held at a warehouse in Wolverton, Buckinghamshire. The collection included translations of Academy works, …

Anil Ananthaswamy's review of potential methane release from the seabed on the East Siberian Arctic Shelf reminded me of work at Newcastle University Ocean Engineering Research Group in the 1970s (23 May, p 38) . My research associate, Alan Judd, found thousands of seabed pockmarks, ranging from less than a metre to tens of metres …

• Researchers indeed blamed shallow gas, and suggested that it may still have been erupting ( 12 July 1979, p 90 ).

• At least we were consistent in being off by 1000: the solar system travels at 200,000 metres per second around the galactic centre; the Earth at 29,800 metres per second around the sun; and the International Space Station at 7700 metres per second around the Earth (27 June, p 28) . We must speed …