Merry Christmas!

As 2013 draws to a close, it's been a wonderful year for us and we wanted to say a big thank-you to everybody that's been working with us, writing for us, and just reading our site! We've achieved so much this year, and we're confident 2014 will be even better.
So from all of us at TWDK,

MERRY CHRISTMAS!

Here's a little something we put together just for you, with more than a little help from Es Einsteinium:

See you in the new year!

Why do we sleep? [SCIENCE VIDEO]

We spend a third of our lives doing it, yet it still isn't clear why we need to sleep. In fact, there’s so many things we don’t know about sleep, that we don’t have time to talk about them all today.

This is the first of our articles to be made available as an animated video. 
An audio version of this article is also available!

What we do know is that we can’t function without it. After missing just one night’s sleep, you are likely to find yourself feeling hungry, emotional and unable to concentrate. Decisions will become difficult to make, your reactions will slow, you may become forgetful, and your vision can even be affected. Going without enough sleep can weaken the immune system, making you susceptible to colds and other infections, and can even increase your blood pressure.

So it is clear that sleep is vital, but why? Scientists just can’t agree…

TWDK launches "TWDK Kids!"

We're very happy to announce a new section of our website has gone live today - with the new mission of "explaining the things scientists can’t answer with fun and games".

Entamoeba histolytica – how and why does it cause disease?

There is a disease that you probably haven’t heard of, which infects 35-50 million people every year - mainly in areas of developing countries where wastewater isn’t kept separate from drinking water. It causes symptoms ranging from stomach cramps to life-threatening dysentery (bloody diarrhoea) and, in extreme cases, fatal liver abscesses. This disease, called Amoebiasis, kills up to 100,000 people annually, and is caused by the parasitic microbe Entamoeba histolytica.

When accidentally ingested by a human, the parasites stay as ‘armoured’ dormant cells called cysts, until they pass through the highly acidic stomach. Upon entering the large intestine, the environment becomes more hospitable for them and allows them to transform into their active form.

It was once thought that E. Histolytica infected 10% of the world's population - but although that figure has been reduced to just 1%, that's still a lot of people. Image credit: CDC / Dr. George Healy (1964)

Many of them will stay in the intestines but some pass out of the host in faeces, and transform into cysts again in order to survive in the more varied temperature and acidity levels they must endure before finding another host. But it is those that remain which (might) cause a problem. This is the main mystery of E. histolytica - not everybody infected will experience the same symptoms, if any. So what triggers the different levels of infection?