There is a plus side to global warming

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Since the early 1980s, scientists have noticed an increase in greenery around the world and a new study of arid regions indicates that it is, at least in part, due to higher levels of carbon dioxide in the atmosphere.

Across the globe, from the southwestern corner of North America, to Africa, the Middle East and the Australian Outback, there has been an 11% increase in foliage from 1982 to 2010, even after adjusting the data to allow for factors such as changes in rainfall and land use.

The ‘carbon dioxide fertilisation effect’ is the result of higher levels of the gas in the atmosphere which in turn allows a leaf to extract more carbon and lose less water during photosynthesis.

Since leaf cover is already at its maximum in places like tropical rain forests, it is only in warm, dry places where leaf cover is less that the change really benefits a plant and its natural response is to make more leaves. This increased greenery can be seen from satellite data and the changes are not just in the numbers of leaves. The dominant type of vegetation in an area can also change, with trees that benefit disproportionately from increased levels of carbon dioxide successfully invading grasslands.

How DID the turtle get it’s shell?

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Despite their extraordinary shells, turtles have always been thought of as a primitive sort of reptile but new evidence from their DNA has shown that they are related to the group that includes birds and crocodilians (not to mention the extinct dinosaurs).

Researchers believe they split from this group around 250 million years ago, during one of the mass extinction events that periodically cut a swathe through life on this planet. The turtle shell is made up of around 50 bones and turtles (and of course tortoises) are the only animals to form a shell by fusing their ribs and vertebrae. Other creatures, such as the armadillo, make their shells from bony scales on the surface of their skin – only turtles have actually gone so far as to stick their bones on the outsides of their bodies.

Turtles have fascinated scientists for years as they are an exceptional example of the sort of evolutionary change that occured in vertebrate history. It turns out that despite their unique anatomy, turtles still follow the basic pattern of development seen in, for example, bird embryos. Having established the basic body plan of vertebrates, the turtle embryo then moves into a turtle-specific stage, using part of the standard genetic programme for limb development to create their shell.

Because the ribs of mammals and reptiles are used to help them breathe, turtles have had to find a new way of ventilating their lungs and they do it by using  a muscular sling attached to their front legs.

Apparently the frantic race down the beach by a newly hatched turtle is crucial in getting these muscles working properly and preventing the baby turtle from drowning when it reaches the water.

Saturn has polar storms too

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When NASA’s Cassini spacecraft reached Saturn in 2004 its equipment detected an enormous vortex at the planet’s north pole, but it was impossible to see just what it might be as the pole was in the middle of its pitch-dark winter.

Saturn’s polar winters last a bit longer than ours, but by August 2009 the sun reappeared in the northern hemisphere and revealed a monster hurricane, apparently fixed over the polar region.

The hurricane looks remarkably like those we see on earth except for its size, with an eye 1,250 miles across or around 20 times larger than the average found down here. It is also spinning much faster than ours do, with the winds in the eye-wall blowing over four times as fast.

Our hurricanes feed off warm ocean water but there is no equivalent body of water on Saturn, just water vapour in the atmosphere, so scientists are hoping that by studying this huge, long-lasting storm they will learn more about how terrestrial hurricanes are generated and sustained.

Kingfishers help with train design

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The Shinkansen Bullet Train in Japan is the fastest train in the world, travelling at around 200 miles an hour, which is great for passengers but not so good for people living nearby. Every time the train burst out of a tunnel, it created a thunder clap that could be heard a quarter of a mile away. The problem was the rapid change in air pressure so the chief engineer, who also happened to be a keen bird watcher, looked to see if there was anything in nature than travelled quickly and smoothly from one medium to another.

He realised the kingfisher did exactly that every time it dived into water and so he remodelled the front of the train to resemble the kingfisher’s beak.

Now not only is the train quieter, but it uses 15% less electricity and travels 10% faster.

Seahorses have a tail to tell

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I’ve alway thought seahorses were one of the most extraordinary and enchanting creatures on the planet, but I never expected them to also give us ideas for biomimicry – they seem way too strange for that.

But what do I know? It turns out that the tail of the seahorse can be squashed to about half its original size before it is permanently damaged and researchers at the University of California are hoping to use a similar structure to create a flexible robotic arm.

The tail’s flexibility comes from its structure – a series of bony, armoured plates that slide past each other. The tail is made up of around 36 square-ish segments and each segment consists of 4 L-shaped corner plates that can either glide past each other or pivot.

The copycat robotic arm, with ‘muscles’ made of polymer, could be used in medical devices, underwater exploration and unmanned bomb detection and detonation.

Amazing photosynthesis

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Photosynthesis is such a remarkable process that it has only ever evolved once in the entire history of our planet – unlike say, vision or flight which, despite their apparent complexity, are two-a-penny in the animal kingdom.

Put simply, once upon a time some early organism managed, by chance, to use sunlight to transform water and carbon dioxide into sugar and so the plant kingdom was born. Other organisms then found it easier to eat the plant rather than do the heavy lifting themselves and so the animal kingdom evolved.

We have recently started fermenting the plant sugars created by photosynthesis to make biofuels, but it is  a difficult and not very efficient process. Now researchers in Georgia have created a micro-organism that can absorb carbon dioxide directly from the air and turn it into something useful for us, like biofuels and chemicals, without having to go through the plant middle-man.

The Georgian organism is a genetically altered version of a micro-organism found feeding on carbohydrates in the super-heated waters near deep-sea geothermal vents. This variant can feed at much lower temperatures on carbon dioxide and researchers can create a chemical reaction that produces an industrial chemical used to make acrylics. Other genetic mutations could create versions capable of generating many other useful industrial products including fuel which would be carbon neutral, releasing the same amount of carbon dioxide on burning as it originally absorbed.

New Antarctican life

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Antarctica may be a freezing hell on the surface but that blanket of ice is trapping the earth’s geothermal heat, allowing vast lakes of liquid water to exist thousands of feet below the sub-zero surface. The largest of these, Lake Vostok, lies under some 12,000 feet of ice and has been completely isolated for at least 14 million years.

Now Russian scientists have managed to drill down – not quite as far as the lake itself because of concerns about contaminating the pristine water with bacteria in the drilling fluid. Instead they stopped just before they broke through the ice and gave the water time to percolate up into the bore-hole, where it froze and could safely be collected.

This ancient water apparently contains bacteria with DNA that is unlike that of any of the known species listed in world databases, making it a completely new life form on the planet.

Another group of scientists have drilled down to Lake Whillens, which is much nearer the surface, lying ‘only’ 2,000 feet below sea level and registering a balmy temperature of around 31 degrees Fahrenheit. They have not only sampled the water in the lake, but also taken sediments and surveyed the lake floor by video. They too found living bacteria, although they haven’t yet announced whether or not they are new to science.

Fireflies can light up our world

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Scientists have been copying fireflies’ chemical reaction – the interaction of a light-emitting substance, Luciferin, and its related enzyme Luciferase – to make electricity-free glows for ambient lighting. So far the light is not particularly bright but it has improved considerably with the use of nanorods and can produce more colours than the fireflies’ standard yellow – greens, reds and oranges have been seen as well as infrared.

Now scientists are planning to go one step further and reverse-engineer the fireflies’ unique lights to improve the efficiency of LEDs. It seems the part of the fireflies’ exoskeleton where the light is emitted – the cuticle – has a specific geometry that minimizes internal reflections and lets more light escape. By replicating this geometry on LEDs, they have improved their efficiency by 55%.

Pounds and pence

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When the Roman Empire replaced the earlier Greek one, it naturally wanted to replace the Greek silver drachma with a coin of its own and it chose to use bronze. These coins each weighed a pound or ‘libra’, which actually translates as ‘to hang freely’ as the coins were always weighed to ensure they hadn’t been clipped or adulterated with other metals.

The English ‘lb’ comes from ‘libra’ and other English words such as ‘pound’ itself and ‘expense’ come from the Latin ‘pendere’, which means ‘to hang’.

Because bronze was common throughout the Italian peninsula it was an ideal metal to use, but as the Roman Empire grew, a higher value coin was needed and the Romans copied the Greek silver drachma. Their version was called the denarius and because the biblical references to this coin were translated into English as ‘penny’, our pennies were recorded, until decimalization in 1971, as ‘d’, as in ‘£.s.d.’.

With so many different coins circulating, money-changing became a very important function in every town and Italian financiers set up their benches or ‘banchi’ in the town marketplaces where traders congregated. If a money-changer failed, his bench was symbolically broken or ‘banchi rotto’, which is where we get our word ‘bankrupt’.

3-D printers

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3-D printers can be used to make just about anything which, once they become widespread, will transform trade and manufacturing across the planet. Free software can be downloaded from sites like ‘Thingiverse’, which has over 54,000 open source designs for everything from a kitchen tray to a classical statue and a basic open source 3D printer can be bought for less than $500.

The printers work by laying down thin layers of plastic in a specific pattern and can be used to create just about anything you can imagine, making the shipping of goods from one side of the planet to the other  a thing of the past.

One thing holding back the use of these printers is the availability (and price) of the plastic filament they use to ‘print’ the object, but now a group of scientists at Michegan Tech led by Joshua Pearce think they may have the answer. They have found a way to recycle the common plastic milk container and turn it into the sought-after and valuable filaments. Their recycling unit, called Recycle Bot, is also available from Thingiverse and could help to change the world – especially the third world, which has plenty of plastic junk and no way of affording useful consumer goods.