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Humans smell better than we thought
The human nose can detect one trillion different odours, far more than we previously thought, say US scientists. Until now, the long-held belief was that we can sniff out about 10,000 smells. New estimates published in Science suggest the human nose outperforms the eye and the ear in terms of the number of stimuli it can distinguish between. Researchers at the Rockefeller University say we use only a tiny part of our olfactory powers.

Purple GM tomatoes
The chemical that gives blackberries, blackcurrants, blueberries and some red grape varieties their distinctive purple colour is Anthocyanin. It’s been shown to have some possible anti-cancer properties as well as some protection against cardiovascular disease. So scientists at the John Innes Centre have inserted the ‘purple gene’ into tomatoes to try and boost their health-giving properties. This step is relatively easy, compared to navigating the rules and regulations of getting to the stage of producing purple ketchup. Gareth Mitchell asks the School reporters what they think about Genetic Modification of food crops.

Low back pain
Low back pain is pain at the bottom of the back. It can sometimes spread to the top of the leg when it is known as lumbago or sciatica. We know that back pain bad enough to affect what you do is very common. But for the first time it has been looked at in a comprehensive way. The 2010 Global Burden of Disease Study assessed the prevalence of back pain and the impact it has on people in 187 different countries and the findings have just been published in the Annals of Rheumatic Diseases. Professor Tony Woolf, from the Royal Cornwall Hospital in the UK and co-author of the paper outlines the main findings.

South Africa TB trial
The rise of drug-resistant bacteria is preventing the control of numerous diseases worldwide, including tuberculosis or TB. The most extensive form of resistance is known as extensively drug-resistant tuberculosis, which has now been reported in 92 countries worldwide.
In some countries like South Africa, resistance has progressed so far that in some cases, doctors have run out of treatment options and patients are being sent home into their communities without treatment. Drug-resistant TB consumes more than a third of the total national budget for TB, which is unsustainable and threatens to destabilise national TB programmes. South Africa is one of only two countries worldwide where the incidence of TB is continuing to rise.

Animal freedom
Is free will unique to humans or a biological trait that evolved over time and across species? Whilst the existence and nature of free will has been hotly debated by philosophers through the centuries, the basic idea that we determine our own destiny is fundamental to human experience. We can even decide to act in ways which may threaten our very existence. Biology underpins how we behave but it is the human mind that decides to act. As part of the Freedom 2014 season, entomologist Adam Hart explores the biology of freedom, meeting researchers working with apes, birds, insects and even single-celled microbes, who are redefining the way we think about free will and its origins.

Teenagers online
Parents the world over worry about their children's use of and access to technology, but do they need to be concerned? Danah Boyd, a principal researcher at Microsoft Research, argues that ultimately the tools of social media will not replace the primacy of direct human contact. Teenagers may appear to be hanging out on Instagram or WhatsApp rather than on street corners. But, as Boyd writes in the book It's Complicated, young people's interactions with each other are not that different from the generation that preceded them. Boyd joins Click to share her research.