Owen's Meanderings

BLUE IS THE NEW COLOUR

Not all lights were created equal. Some lights use more energy than others to create a glow. Incandescent globes shine white hot, wasting a lot of electricity as heat. Fluorescent lights use much less electricity, but better still are light emitting diodes, or LEDs.

LEDs are responsible for the light behind lots of computer screens, smartphones and other devices. They are very efficient, creating a lot of light for only a small amount of electricity. The Nobel Prize in Physics this year was awarded for the invention of blue LEDs to Isamu Akasaki and Hiroshi Amano, both from Japan, as well as Shuji Nakamura,spiderr from the United States.

Why blue? For 30 years, blue LEDs were the missing part of the puzzle. After red LEDs were invented, green ones soon followed. But blue was tricky, and without blue, we couldn’t make white light. White is made from the three primary colours of light – red, blue and green.

Eventually, scientists cracked the problem and created blue LEDs. They did it by growing crystals of a chemical called gallium nitride. That was made only 20 years ago, but already blue LEDs have become part of the devices many of us use each day.

The best thing about bright LEDs is that they need so little electricity to run. That makes it easy for them to be powered by solar energy. Cheap solar panel torches can give light to the 1.5 billion people in the world who live without access to an electricity grid. It can allow them to read, cook,  work and walk around safely after dark.

Many of us take light for granted. How many lights surround you right now? About a quarter of the world’s electricity is used to make light. If we switched to low-energy LEDs, we could make a real difference to the environment. Now that’s a brighter future.

Volcanoes

Our planet is not all it seems. Based on the soil at our feet, we might imagine that the world is rock and dirt all the way down. But what we can see is just the crust of Earth: the outer surface. Beneath is hot, flowing rock called the mantle.

Compare Earth to a hard-boiled egg. The egg’s shell is Earth’s crust, and the white layer of egg is Earth’s mantle. This is a handy model, but even the shell of an egg is too thick to represent the crust – that’s how thin it is compared with the rest of Earth.

We can see signs of the mantle in volcanoes, where the flowing rock from this hidden part of the planet rises to the surface. Underground, the hot rock is known as magma, but when it erupts to the surface, it is called lava – and it is extremely dangerous. Volcanoes are like a crack in the Earth’s shell, and they let lava, ash, gas and steam escape. Sometimes they even explode.

Last month, Japan’s Mount Ontake volcano erupted. Lives were lost, because there was very little warning before the eruption, and people were hiking around the volcano.

This recent eruption of Mount Ontake was explosive. The hot molten rock met liquid water, making the water expand into steam almost immediately. Steam has more energy than liquid water, and takes up more space. So, when the water around the volcano on Mount Ontake suddenly turned into steam, there was an explosion. The steam had enough energy to throw rocks into the sky.

On the other side of the world, in Iceland, the Bárðarbunga (Bardarbunga) volcano is erupting. It has been erupting for weeks and weeks. It has not exploded like Mount Ontake, but this is the largest eruption that Iceland has seen for centuries. Before the lava began to flow, there were more earthquakes in the area than usual – a warning that an eruption was on the way.

WORLDS BIGGEST SPIDER

The spider was a Goliath birdeater tarantula, and the lucky entomologist to make the rare sighting was Piotr Naskrecki. He spotted the spider in the deep rainforests of Guyana, South America.

The Goliath birdeater is the largest spider in the world: about the size of a dinner plate. It sports some rather imposing two-inch fangs, but its venom isn’t deadly to humans.

When Piotr made the discovery, he first thought it was a small, furry mammal. When he realised what he was looking at – as mentioned in his blog – he was “ecstatic about finally seeing one of these wonderful, almost mythical creatures in person”. Clearly, he was the right person to have had this unique experience.

Despite their potentially hair-raising qualities, these spiders are pretty interesting creatures. For starters, they make a distinct clicking noise as they walk, described by Piotr as “not unlike that of a horse’s hooves hitting the ground (albeit, admittedly, not as loud)”. When threatened, they create a hissing sound by rubbing their leg hairs together. They can even release a cloud of hair from their abdomen – something Piotr was the victim of, causing him to “itch and cry for several days”.

And, do they live up to their name by eating birds? Well, they can, but they generally feed on smaller creatures that are much easier to catch, such as earthworms. So, birds don’t have to worry too much, and neither do you unless you’re planning on a late-night stroll in a South American rainforest anytime soon.

THE POO TREATMENT

The idea behind using faeces as a medicine lies in the bacteria that live in your gut, which are known as gut flora. When you are sick, the balance of the gut flora is disrupted. Introducing a healthy strain of bacteria into the gut (via foreign fecal matter) is thought to restore the normal balance and help fight the problem.

In the past, this has been investigated by doctors who – believe it or not – transplanted fresh poo into the guts of patients who had an intestinal infection. The process is known as FMT, or fecal microbiota transplantation. It worked in treating the condition, but was rather impractical.

As an alternative, doctors at Massachusetts General Hospital in the United States tried giving frozen FMT capsules to 20 patients who had an intestinal infection of Clostridium difficile bacteria. This infection causes bloating, diarrhoea and pain. The current treatment is not working effectively, so doctors are looking to replace it using FMT. In the trial, patients took 15 FMT capsules over two consecutive days. After six months, 90 per cent of the patients were cured!

But, where did the poo come from? Where else, but volunteer donations! Before the donated feces were used in the treatment, they went through a careful process of screening and testing.

While the trial was successful, it was only a small study. Larger studies are needed to confirm the results and improve the treatment. As for us, we can all be thankful that doctors are hard at work to keep us healthy – even if the medicine doesn’t sound all that appetising.

CATCHING A COMET

The Rosetta spacecraft has just completed a high-speed chase to catch comet 67P/Churyumov-Gerasimenko. Rosetta was launched ten years ago from Earth. Since then, it has travelled over six billion kilometres, going around the Sun five times before meeting the comet halfway between the orbits of Jupiter and Mars.

It’s been a tricky trip to the comet. Over the last few months, Rosetta has made many manoeuvres to make sure it is going the right way. It had to change its speed to match how fast the comet was moving. If it didn’t do that, it would fly right past it.

This will be the most detailed study of a comet ever. Rosetta carries the gear for 11 science experiments, including tools to measure the gas and dust around the comet. It has already found out that the comet is releasing water vapour, and loses two small glasses worth of water each second.

The lander Philae detached from Rosetta successfully and arrived softly on the comet, but it seems its harpoons didn’t fire. The harpoons were supposed to tether the lander to the comet, and Philae might have landed in a tricky spot. As people figure out more details about the landing, Philae is getting started on its primary mission. It carries a multi-purpose sensor to study the comet’s surface. The lander also has tools to drill into the comet, take samples and analyse them.

Comets are like pieces of history frozen in time. They haven’t changed much since the solar system formed over four thousand billion years ago. Rosetta and Philae may well find out new details about the start of our solar system.

PENGUIN ROVER 
 

Animal scientists often need to approach their research subjects in the wild. But, this can be very disruptive to the animals and change their behaviour. If an animal behaves differently when people are around, it is hard for people to observe the animal’s natural behaviour.

As an alternative, French researchers sent rovers into a penguin colony in Antarctica. The rovers used a radio-frequency identification (RFID) antenna to successful identify a colony of king penguins. But, the researchers really wanted to know whether the rovers affected the penguins more or less than a human observer.

To find out, the scientists first attached heart rate monitors to 34 incubating king penguins. Later on, they found that when a person was collecting data, the penguins’ heart rates rose four times more than when a rover was doing the same job. When people were nearby, fights broke out between penguins and the colony became disorganised. The rover caused much less disturbance to the colony than a person did.

The rover was also tested in a colony of emperor penguins. This time, the rover caused some distress. But, when the rover was disguised as a baby penguin chick, the birds allowed it to approach – and some even tried to communicate with it!

The researchers hope these promising results will be seen with other animals, and that the rovers can be used for other purposes, such as carrying recording devices to study animal sounds. For some animals, though, scientists will have to perfect their rover disguises first!

DODOs

A team of scientists created a detailed, digital 3D model of the dodo by scanning skeletons of the bird with modern laser scanning technology. The skeletons included the world’s only complete dodo skeleton, housed at the Natural History Museum in Port Louis, Mauritius.

“The scans enable us to reconstruct how the dodo walked, moved and lived to a level of detail that has never been possible before,” says team leader, Leon Claessens. Leon is a vertebrate paleontologist at the college of the Holy Cross in Worcester, the United States.

Dodos once lived on Mauritius, an island in the Indian Ocean about 2000 kilometres from Africa. They were around one metre tall and weighed 10–18 kilograms. Dodos became extinct in the 1600s, in one of the first known cases of human-caused extinction. The birds disappeared only 90 years after humans settled on the island.

Very little is actually known about these birds and details of their biology and behaviour have remained a mystery – until now.

The 3D scans revealed dodo knee and ankle bones that were previously unknown to science. The research team also found that the dodo has only a small keel, the bone that extends from the sternum (breastbone) and is attached to the wing muscles. The dodo’s keel is smaller than the one found in their closest relative, the extinct Rodrigues solitaire, who used its wings in combat. With a small keel, scientists think the dodo didn’t use its wings in this way and was less aggressive.

“All the new information on the dodo is providing scientists with a much clearer picture of this iconic bird”, says Leon. He adds that it “appears to have been a lot less clumsy and cumbersome than portrayed in popular culture, but instead was a successful and dynamic bird adapted to life on Mauritius, which had no place to escape once humans arrived on the island.”

In future work, the scientists plan to use the 3D models to examine exactly how fast a dodo could walk or run, and what it might have been eating with its massive beak.

BRAIN TO BRAIN COMMUNICATION

Researchers from the University of Washington hope to explore new ways for humans to communicate with each other. They have set up a demonstration in which a video game is played using the brain of one person – and the hand of another.

The researchers used two machines in the demonstration. The first, an electroencephalography (EEG) machine, picks up activity in the brain. The second, a transcranial magnetic stimulation (TMS) coil, delivers information to another brain using pulses of electricity.

To play the video game, people had to fire cannons at the right time. One volunteer, or ‘sender’, watched the game. When they thought about firing a cannon, their brain activity was picked up by the EEG. The electrical signals were sent to the TMS coil, which was positioned over the brain of the ‘receiver’ volunteer. The receiver was sitting in another room with their hand positioned over the game’s control pad. When the TMS coil fired, the receiver’s hand moved, hitting the control pad and firing the cannon.

Dr Marc Kamke, Research Fellow from the Queensland Brain Institute, says the demonstration is a good example of what neuroscientists can do and the techniques they can use.

Marc adds that the demonstration setup was novel, but doesn’t add a lot to what neuroscientists already know. The brain-to-brain connection was also very specific to the setup, and if the TMS was positioned over another part of the brain – for example, the visual cortex – it would have caused the receiver to see flashes of light.

The University of Washington researchers are next looking to transmit more complex processes, such as concepts, thoughts and rules.

ARTIFICIAL GECKO FEET

Inspired by gecko feet, a research lab at Stanford University in America developed the climbing device, which recently allowed a person who weighed 70 kilograms to climb a sheer glass wall. The team have also used the structure of gecko feet to design super-sticky tape and climbing robots called Stickybots.

To walk on walls and ceilings, geckos have hair-like fibres called setae on their feet that stick to surfaces. These fibres are tipped with hundreds of spatulas, so small they are on the nanoscale.

Mimicking the gecko’s feet, there are tiny wedges of silicon polymer on the surface of the new climbing device. These wedges are made from similar stuff as some kitchen spatulas, but are about the same thickness as a human hair. They are not sticky when touched lightly to a surface. But when you place a load on them, such as your body, the wedges flatten out, pressing on to the surface and sticking.

These tiny wedges can be removed and repositioned by the climber many times and will stick to surfaces including glass, plastic, varnished wood and metals.

If you copied gecko feet exactly, a human would need giant sticky pads on their hands about the size of two tennis rackets. To make the hand pads smaller and dependable, the researchers tweaked the gecko’s sticky system. They made sure the climber’s weight is distributed evenly over the surface of each hand’s sticky pad.

To do this, each pad is divided up into postage stamp-sized tiles that all flatten and stick to the surface, even if that surface is uneven. An array of springs and flexible cords within the pad distributes the load evenly – making sure that all of the tiles have the same maximum load. If they didn’t do this, one tile would become overloaded and fail, overloading its neighbours and causing a wave of failing tiles over the entire pad.

Could this technology mean we could climb buildings like Tom Cruise in Mission Impossible? Maybe, but as we are not built like geckos, keeping our climbs to small walls might be the best idea until the technology develops.

THE FISH SMELL LIKE CORAL

On the Great Barrier Reef, the harlequin filefish shelters in coral branches overnight. Researchers have found that these fish not only look like coral, they smell like it too.

“By feeding on corals, the harlequin filefish ends up smelling enough like its food that predators have a hard time distinguishing it from the surrounding coral habitat,” says study lead author Dr Rohan Brooker, a marine biologist at James Cook University. “For many animals, vision is less important than their sense of smell,” he adds.

On the reef there are many predators, so it’s worth having a good way of camouflaging yourself. Although these sneaky smells are effective, the harlequin filefish still has to be careful. Each fish has to shelter in the same coral it has eaten otherwise predators will sniff it down. And what does it smell like? We will never know, as people can’t smell underwater.

The experiment took place off the coast of Far North Queensland, at the science research station on Lizard Island. Researchers studied harlequin filefish and a fish that eats them, the blue-spotted rock cod. They also studied the reaction of a small crab that lives on coral branches.

After the fish had eaten coral, the cod were less likely to notice them. The small crabs couldn’t tell the fish from coral and went towards them, thinking they were shelter.

We don’t know many animals that chemically camouflage themselves by smelling like their environment, but perhaps it’s because we haven’t looked. We tend to use our eyes more than our noses when we investigate the world. This research could be the beginning of following our noses to find a whole new world of smell-a-likes.

THE SECRET LIFE OF SOILS

We use antibiotics to help fight infections, such as a festering sore on your arm or a chest infection. Growing in these infections are unwelcome bacteria that your immune system is having a hard time fighting off. Antibiotics can kill the bacteria for us.

Unfortunately, infectious bacteria are becoming resistant to the antibiotics we already have.  Researchers are now working hard looking for new antibiotics.

Most of the antibiotics we use today come from soil bacteria. Bacteria produce these molecules to keep other bacteria away from their turf. But we can only use antibiotics from bacteria that can be grown in the lab. These only make up a tiny proportion of all the bacteria living in soil. Most bacteria, around 99 per cent, cannot be grown outside their natural homes, be it soil or on the surface of a glacier.

To get round this problem, researchers have developed a tiny growing cell, called an iChip. It grows bacteria while keeping them in their snug soil home. They first catch a single cell and surround it with membranes that let food and water through, and then they place the whole thing back in the soil.

Using this technique, researchers have found thousands of new bacteria in soil from their own backyards! One extract from one of these bacteria is a molecule called teixobactin that might work as an antibiotic. Trials of this molecule on humans will start in a couple of years.