In the science news this week, coldest spring in 50 years, long term tamoxifen use improves breast cancer survival rates, asteroid has a close encounter with the Earth, and finally… one in 13 of us have chimp-like feet.
Spring will be coldest in 50 years
Early figures from the Met Office suggest that the spring of 2013 will have been the coldest for more than 50 years, reported the BBC .
The UK’s mean temperature based on figures from 1 March to 28 May was 6C, making this spring the coldest since 1962, and the fifth coldest since records began in 1910.
Figures taken from earlier on in May had predicted that this spring was on track to be the sixth coldest spring since records began, but the cooler than average weather over the past fortnight has pushed the mean temperature for the season even lower.
The below average temperature goes against the trend seen in recent years, the Met Office explained. Eight of the past 10 years have seen spring temperatures that were warmer than the average of 7.7C (based on data from 1981-2010).
The cooler temperatures this year have been caused by easterly and northerly winds, bringing cold air to the UK from polar and northern European regions.
May has also been wetter than average, although both March and April were below average, so it is likely that overall this spring will be drier than the average although not as dry as the springs of 2010 and 2011.
Tamoxifen reduces risk of recurrence of breast cancer
New research from the University of Oxford has shown that the drug tamoxifen reduces the risk of breast cancer recurring in patients when taken for 10 years following initial treatment, when compared to taking the drug for the recommended five years.
This study was part of a larger international trial which announced similar results last year, reported the Guardian .
"Until now, there have been doubts whether continuing tamoxifen beyond five years is worthwhile," said lead study author Richard Gray, professor of medical statistics at the University of Oxford.
Between 1991 and 2005, 6953 women in the UK who had been taking tamoxifen for five years were randomly assigned to a group that either continued with the drug or stopped immediately.
For the 10-year group, breast cancer was found to recur for 16.7% of the women, compared to 19.3% of the women in the five-year group.
Longer treatment also reduced the death rate. Women in the 10-year group had a 25% lower recurrence rate and a 23% lower breast cancer mortality rate than the women in the other group.
Tamoxifen works by blocking the female hormone oestrogen. Around 70% of breast cancers are oestrogen-receptor positive, meaning they are fuelled by the hormone.
The drug has been used for a long time as a treatment for younger, premenopausal women with early-stage breast cancer.
Dr Julia Wilson, director of research at Breakthrough Breast Cancer, said: "These findings are extremely exciting for women who are diagnosed with the most common type of breast cancer.
"The study proved that 10 years of taking tamoxifen has a much higher survival rate than the current five years, which is vital in helping us to stop breast cancer coming back and more importantly to help us stop women dying of breast cancer.
"Tamoxifen is a well-established and cheap treatment, which means the guidelines for usage should be easy to amend. We do however encourage all women taking this treatment to speak to their doctor about their individual circumstances as there can be side effects involved."
Asteroid 1998 QE2 passed by the Earth
An asteroid that is nearly 2.7km (1.7 miles) across has flown past the Earth, getting within 5.8million km (3.6million miles) of our planet when at its closest, reported the BBC .
1998 QE2 was about 200 times further away than the asteroid which flew past the Earth earlier this year, but is more than 50,000 times larger – so large in fact that it has its own orbiting moon.
Professor Alan Fitzsimmons, from Queen's University Belfast, said: "It's a big one. And there are very few of these objects known - there are probably only about 600 or so of this size or larger in near-Earth space.
"And importantly, if something this size did hit us one day in the future, it is extremely likely it would cause global environmental devastation, so it is important to try and understand these objects."
The fly-by has given astronomers an opportunity to study the asteroid in greater detail by using radar telescopes to find out what it is made of.
Prof Fitzsimmons said: "We already know from the radar measurements, coupled with its brightness, that it appears to be a relatively dark asteroid - that it comes from the outer part of the asteroid belt."
Astronomers have already seen that the asteroid has another object orbiting it – a smaller piece of rock that is about 600m (2000ft) across.
1998 QE2 is one of more than 9,000 near-Earth asteroids that we know about. But as telescopes and observing techniques improve this number is increasing on average by 800 new objects each year.
One in 13 of us have bendy feet
Until recently, it was thought that human feet have evolved to be fairly rigid in order to make walking upright more efficient. However, researchers from Boston University have found evidence to the contrary and believe that around 8% of us have feet that bend in the middle, similar to the foot flexibility seen in tree-climbing apes.
The study involved filming 400 adults walking around barefoot and although the bendy-footed showed no noticeable differences in their gait, it was clear that their feet did bend both at the ball of the foot and also halfway between the heel and the ball, reported New Scientist .
One of the study authors, Jeremy DeSilva, explained that the owners of the flexible feet were unaware of anything unusual, and he himself was pretty surprised by the results of the study.
Robin Huw Crompton from the University of Liverpool will soon be publishing his own work on flexible feet, and suggests that it may even be more common that one in 13.