Why do some animals dump indiscriminately?

Well the telescope is in fact bigger than the Hubble Space Telescope. It's 6.5 metres, but it's designed to image in the infrared. Its images in the infrared will be as precise and as fine as the Hubble images are at the optical. So it will take as spectacular images as the Hubble does, but at infrared wavelengths. And so, for the first time, we'll see the universe in the infrared with the clarity and spectacular image quality of the Hubble Space Telescope. The size of the cameras is actually very large. We've used the latest infrared ray technology and one of our prime cameras, called the near infrared camera - not very imaginative I'm afraid - will actually take instantaneous pictures which are roughly 33 megapixels in size. So we'll get very large images.

A completely computer-generated model of the human heart that can successfully predict the effects of anti-arrhythmic drugs has been developed by scientists in the US.

Irregular heartbeat, or arrhythmia, occurs when there is abnormal electrical activity in the heart - if the electrical pulses among heart cells get out of sync the heart can't contract and beat normally. Drugs used to treat arrhythmia act on heart cell membrane channels to alter the flow of charged molecules called ions, which cause the electrical signals. At the wrong concentrations, these drugs can actually make arrhythmia more severe, or even lead to sudden cardiac death. Thorough testing is therefore vital to determine the doses at which they are safe to use.

Traditional methods of testing (using animal hearts or human clinical data) are incredibly inefficient, but Professor Colleen Clancy and her colleagues the University of California have come up with a completely different approach: a computerized model of the human heart.

In the model, mathematical equations represent the opening and closing of ion channels in individual cell membranes.  Other equations connect these events among single cells in order to simulate a whole heart. Drugs can then be mathematically 'fed' into the framework and their effects monitored.

Two existing anti-arrhythmic drugs - lidocaine and flecainide - were tested in this way at different concentrations, and remarkably the model's predictions were validated both by human clinical data and with similar tests on a rabbit heart.

This novel approach could potentially speed up the drug development process, helping treatments get to patients faster. Professor Clancy said, "Our plan for the next phase of this work is to expand this approach to cover all the existing classes of anti-arrhythmic drugs and develop a database. Our long term goal would be to scale this up so it could be used in a high-throughput manner to screen drugs that are currently in development."

The research was published this week in the journal Science Translational Medicine.

Click to hear the full interview with Colleen Clancy

Scientists have unveiled a way to control light beams, wave-by-wave.

Light is vitally important, not only in our everyday lives to avoid bumping into things, but to our technology, ranging from transmitting our phone calls down optic fibres to making computer chips. So any improvement in our control of light should help in all sorts of different ways.

Light will travel at right angles to its wave fronts, a wave front is the line along the top of a wave). Normally you do this with a mirror, or by using a material that slows down light like glass, allowing you to bend the wavefronts and therefore light in lenses or prisms, but this is very limited in what you can do with the light.

Federico Capasso and collegues have managed a much finer control, they have managed to make tiny gold rods onto a silicon wafer that are smaller than the wavelength of light, which when they are hit by light have electric currents induced in them which slosh up and down the rods. Depending on the  shape of the rods, these currents interact with the light and can slow down the wave fronts by different amounts.

This means that the wavefronts can be controlled by changing the pattern of rods. They have made light leaving the silicon bend in a direction they can control, and they have made the light form a spiralling pattern by creating a circle of different rods with different delays at different angles. This spiralling light will cause molecules it hits to spin and is useful for controlling individual atoms or even cells, and in quantum computing.

But the real power of this technique is that they have managed to produce a generalised form of the equations of reflection and refraction which will allow them to have almost complete control of light, so it should be possible to make patterns on a scale smaller than light's wavelength, completely flat lenses, perfect absorbers, and may other useful devices. Though it might be a while before they get used in glasses, as the present design will work differently for different colours.

The Rocky Road to Fertilising Forests

Meera -   Scientists studying how forests develop have discovered a new source of nitrogen that plants and trees can tap into, helping to boost their growth and so remove more carbon dioxide from the atmosphere.

By analysing samples of soils from coniferous forests in Northern California, a team at the University of California, Davis found that the underlying bedrock leaches nitrogen-containing chemicals into the soil, nourishing the plants and trees growing above. This source of nitrogen was previously unknown, according to Professor Benjamin Houlton who was part of the study...

Benjamin - It was thought for a long time that the way nitrogen comes in to our environment is from the atmosphere only, and especially by way of a couple of interactions. One interaction involves bacteria known as Rhizobium and, in addition, nitrogen can come in from rain water. But it turns out that there's a tremendous amount of nitrogen that's in rock material. This is kind of a new discovery that nitrogen actually is in the rock material and it's also available to forests and other types of plant ecosystems.

Meera - This new source of nitrogen is released by the rocks as they erode according to the groups paper published in Nature this week. More nitrogen, which is an essential ingredient for the formation of proteins and DNA, means that plants and trees grow faster, storing more carbon dioxide from the atmosphere as a result. The findings could therefore be used, say the scientists, to identify fertile areas in which to site forests intended to function as carbon-offset schemes in the future.

Increased forest ecosystem carbon and nitrogen storage from nitrogen rich bedrock, Scott L. Morford, Benjamin Z. Houlton & Randy A. Dahlgren, Nature Volume: 477, Pages: 78-81 (01 September 2011)

Mobile Phones in Emergencies

Using mobile phones to track how people move about in emergencies has enabled scientists to develop better ways to target aid to where it's most needed.

Although relief agencies have contingency plans in place for tackling a range of disasters, the way victims actually behave under these circumstances remains poorly understood.

But now, publishing in the journal PLoS medicine, Linus Bengtsson and colleagues from the Karolinksa institute in Sweden used mobile phone signals to follow the movements of more than 1.9 million people affected by the 2010 Haiti earthquake and the ensuing cholera outbreak, to predict, with very high accuracy, where people will go, in what sorts of numbers and over what time period following an emergency...

Linus - What characterises a disaster is often total chaos and it's very, very difficult to understand where people are. Since we know which tower each mobile phone used, we can sort of follow each phone as it travels across the country. We could see that approximately 600,000 people left Port au Prince 19 days after the earthquake. So, our hope is that this will contribute to making aid delivery much more efficient.

Gething PW, Tatem AJ (2011) Can Mobile Phone Data Improve Emergency Response to Natural Disasters? PLoS Med 8(8): e1001085. doi:10.1371/journal.pmed.1001085

Anticancer Traps

A DNA-based "circuit" that "trips", and kills cancerous cells, has been engineered by scientists at the Swiss Institute of Technology and MIT.Described this week in the journal Science, the new system looks for specific microRNA molecules that are known to be present at higher-than-normal levels within cancer cells.

Once a threshold level of the microRNAs is detected, a DNA domino effect is triggered causing the cell to self-destruct by a process called apoptosis. Although the team have yet to solve the problem of how to achieve safe and large-scale delivery of these cancer-preventing trip-switches into a patients' cells, Lead Scientist Yakov Benenson believes the work could be a strong contender in the search for new, more specific, cancer therapies...

Yakov - If we think about what would be the ideal anti-cancer therapy, it has to be something that looks at each cell and determines whether it should be destroyed or should be left alone. We don't have any good ways right now to do so. I think our study shows how to look inside the cell and detect what's going on with the cell with high precision, based on the integration of multiple cancer signals and markers.

Multi-Input RNAi-Based Logic Circuit for Identification of Specific Cancer Cells, Zhen Xie, Liliana Wroblewska, Laura Prochazka, Ron Weiss, Yaakov Benenson, Science, 2 September 2011: Vol. 333 no. 6047 pp. 1307-1311

&nb

Star-Trek Style Sick Bay

A team of scientists at the University of Leicester have used space technology to develop a "Star Trek" style "sick bay" that can non-invasively detect a variety of illnesses, all at once.

Co-inventor Professor Paul Monks explains that how the technology can see, smell and feel diseases...

Paul - The first uses imaging technology, which has really been developed for use on the Mars rovers, to look at the colour of people's skin for instance, to see whether we can pick up disease from that. The second suite of  technology looks at the composition of people's breath. From that, you can actually tell how well people are. The third suite of monitors really looks inside the body, but non-invasively, to look at blood flow and how much oxygen is in the blood and muscles and skin at any given time. Put together, it's the first time that you'll get this holistic measure of a patient's well-being.

Meera - The whole diagnostic process should take just 15 minutes. and will be based at the Accident & emergency department of the Leicester Royal Infirmary, which sees 150,000 patients coming through its doors annually. 

The developers expect to be using the system to pick up a range of diseases including infections, heart disease, skin conditions, respiratory problems and some cancers.  Liver disease,  asthma and even MRSA are earmarked for the future.So what was once considered to be science fiction looks set to become reality....

University of Leicester scientists deploy space-age technologies to detect illness at science-fiction style 'sick bay'

Chris -   Now we have a very special extra guest who's with us this week and that's Dr. Matt Mountain.  He's the Director of the Space Telescope Science Institute and he's been overseeing some of the groundbreaking work that's been done with the Hubble Space Telescope, as well as working on its successor the James Webb Space Telescope. He's with us to answer some of my questions, but also, more importantly, some of your questions this week, and to tell us a bit about the project.  Hello, Matt.

Matt -   Hello there, Chris.

Chris -   First of all, can you tell us what is the James Webb Space Telescope?  What will it do?

Matt -   Well the James Webb Space Telescope is designed to be the successor to the Hubble Space Telescope.  If you like, sort of Hubble 2.0.  It's designed to work not as the Hubble is, at optical wavelengths, but actually at infrared wavelengths and it's much bigger than the Hubble.  It's 6.5 metres across when the Hubble is only 2.4 metres across.  It is a very big telescope, which actually has to unfold on its way to orbit. It's orbit is roughly four times the distance between the moon to us away, roughly a million kilometres away. It's designed to look at the very first galaxies that ever formed in the Universe's history and, we hope, look at planets that are orbiting other stars and actually perhaps detect for the first time liquid water on those planets.

Chris -   How was it conceived and how is it being constructed and how far along are you?

Matt -   It was conceived by people at the Space Telescope Sciences and by the astronomical community in the US generally and now in Europe.  As the Hubble started work, we began to understand the limits of what we would be able to see with the Hubble.  For example, we began to understand there was actually a whole class of galaxies - very early galaxies - that the Hubble could only barely see. It could see the sort of peak of the iceberg and there's a whole sort of hidden Universe in the infrared which in fact we called the "Dark Ages."  It's the time from when the Big Bang and the background radiation, and the sort of irregularities in that radiation, turned into galaxies. Then galaxies appeared, and the galaxies that we see in the optical come from a certain point back in the Big Bang, roughly 13 billion years ago. But we know the Big Bang started 13.7 billion years ago, but that period in-between, these Dark Ages, was inaccessible.  We realised that there was a very rich Universe there and we needed a telescope that was much bigger than the Hubble that could operate in the infrared.  So, it's been under construction for over 5 to 6 years now and each of its mirrors are part of a hexagonal segment.  It's rather like a ground based Keck telescope, which is a very large telescope in Mauna Kea in Hawaii.  This telescope is made up of segmented mirrors that all have to operate as a single mirror. It's a very radical design and it will be flying far beyond the moon at a point called Lagrange point 2, which is a sort of stable point beyond the moon. There it will cool down to a ridiculously low temperature, roughly 40 degrees Kelvin, which, speaking from the US, is roughly minus 400 degrees Fahrenheit.  So it can be very, very cold and where we are right now is that all the mirrors have had been made.  In fact last week, they were completed.  We have had some problems with cost overruns and some technical problems.  We had to invent 10 new technologies to get this task going but we're hoping to get this thing launched by 2018.

Chris -   Yes, that's a bit of a sore point, wasn't it. Because if you look the history of the James Webb Space Telescope, it was conceived in, what - the mid-90s?  It was supposed to be flying by the mid "noughties" and it was supposed to have a price tag of half a billion.  That price tag is now nearly 9 billion.  So, how optimistic are you that you will be seeing this thing returning data to Earth by that date?

Matt -   Well it was never actually supposed to - yeah, I mean you're absolutely right.  There's a lot of controversy going on right now but it turns out that it was never supposed to be flown for half a billion Dollars.  That was an estimate that people thought you perhaps could actually get something like this going if you launched it by sort of the late '90s.  By the time people started studying this though, they realised that really something of this scale was going to cost between 3 to 4 billion Dollars if we could get it launched by sort of 2011.  But delays and some of the technology challenges really have pushed the whole launch date out and as you push the launch date out of this very, very complicated telescope, the cost goes up.  And on top of that, we then started actually realising we needed far more complicated instruments than had originally been put together. You stack all that up, and yes, you're looking at a price tag probably to get this thing launched of at least 8 billion Dollars, which of course is an enormous amount of money.  But the Hubble itself, to get it launched in today's Dollars, cost roughly 10 billion Dollars.  So for something of the order of the cost to get the Hubble launched, you're getting a telescope which is almost 4 times larger and incredibly more powerful and in a much more stable orbit than where the Hubble is.

Dave -   And, I mean, one of the first things you said was this thing has got to unfold - that immediately rings alarm bells for a telescope! You're trying to position your mirrors to within a wavelength of light - I guess, for a really good quality telescope - so that's got to be a serious challenge?

Matt -   Absolutely, and in fact when you first watch the movie (you can go to one of our websites and you can watch this thing unfolding) people do actually turn to you and say, "Are you kidding?".  What they've forgotten of course is, on the ground for example, the 10-metre Keck telescope on Mauna Kea. It has lots of segmented mirrors, and it holds its figure perfectly in wind at all conditions on Mauna Kea.  What we use is a thing called a wave front sensor where we actually measure a star from the mirrors and we measure the wave front and then correct, because each of these mirrors has an individual adjustment on it.  so we're constantly adjusting these mirrors to actually have them line up as a perfect single mirror. That technology was in fact mastered back in the '80s by the Keck telescope on the ground.

Yes. They're both molecules which are structurally related to each other [and work to suppress the growth of bacteria via the same mechanism, which is by binding to the "A" sites in bacterial ribosomes and blocking the process of protein translation].

Emma -   One of the most promising technologies for tackling rising carbon dioxide levels in the atmosphere is known as carbon capture and storage.  The idea is to trap carbon dioxide from power stations inside rocks rather than release it into the atmosphere.  But what if, instead of just storing the carbon, you could turn it into something useful - like bricks?  Planet Earth podcast presenter Richard Hollingham reports from the University of Nottingham for us this week on a new technique dubbed:  Carbon Capture and Utilisation.

Richard -   They look like large boiled sweets or perhaps something you'd use to make gravy, but when you bang them together, they're as hard as bricks.  Anthony Benham is Business Development Manager at the National Centre for Carbon Capture and Storage.

Anthony -   One of the experiments that we're trying to do here is to react carbon dioxide with naturally occurring minerals.  In this reaction process you actually produce a new type of mineral that can effectively be used in the construction industry, for example, producing aggregates, and things like that.

Richard -   This process of combining carbon dioxide with rock turns out to be nothing new.

Anthony -   What we're trying to do is accelerate the natural process of weathering that occurs in the environment. So certain types of rocks react with the carbon dioxide that naturally occurs in the air and produce new minerals.  This occurring in the normal every day environment is a very, very slow process. So what we're trying to do is accelerate that process; and in doing so, you produce these effectively OXO cubes of different sort of minerals if you like. So this one's quite a brown colour and we've got this one here which is almost pure white, it looks a bit like chalk.

Richard -   If you bump them together, the white one's quite soft, this brownish tan-coloured one, both of which fit in the palm of your hand, that one's quite hard so you can make different things out of them.

Anthony -   Yeah, that's right and the products that you get will essentially depend on the materials that you use at the start of the reaction.  For example, we use a lot of silicate minerals here - magnesium silicates and calcium silicate minerals - and depending on the quantities that you use will partly determine the end products and therefore the colour that you get at the end of the reaction.

Marco -   So we close the cylinder over there.

Richard -   The reaction itself takes place in a sealed metal flask with a mixing paddle.  It looks a bit like an industrial kitchen mixer.

Marco -   We tighten the screws....

Richard -   In the lab, researcher, Marco Drea talked me through the process which even sounds like it could be a recipe.

Marco -   We just mix our feed stock with the CO₂, so we mix them together and we produce our final product which is the mineral carbonate.

Richard -   But at the moment that final product isn't very big, even though each domino-sized tablet contains three litres of carbon dioxide, you'd still need a lot of these tablets to make even a single house brick, let alone a house.  Mercedes Maroto-Valer is the Chief Scientific Officer for the National Centre.

Mercedes -   Yes, you are absolutely right.  We need quite a few of these to actually build a house.  These are just demo pieces that we build because they're easy for us to take around and it is easy for people to think about these as something that the CO₂ has been solidified into and now they can walk out the room with this on their hands or in their pockets.  But you are right, we need to scale up the process and we are currently involved in a series of projects looking at scaling up, so actually we can see the potential and feasibility of the technology in the UK.

Richard -   How would this work in practice?  Would you have a brick plant next to a power station?  How would this work in practice, if it did work?

Mercedes -   That's one of the things that we are now involved in in a project together with the Energy Technology Institute, Caterpillar, and also Shell; and what we're looking at is the feasibility of this technology in the UK. So we will be able to see in which locations it makes sense to build plants that will actually take the CO₂ and mineralise it.

Richard -   One of the other considerations is that the process itself uses energy which rather defeats the object if making the bricks involves generating more carbon dioxide.  Anthony Benham...

Anthony -   We're looking at ways of accelerating the reaction using typical atmospheric pressures and temperatures and varying the conditions, and the concentration of carbon dioxide that you use, and the quantity of material that you use in the reaction because ultimately, if we are to produce this at a large scale then you want this to be using the lowest amount of energy that you can.

Richard -   So if they succeed in scaling up this technology, future power stations could be built with bricks using emissions from power stations...

Well, pins and needles occur when there's too little blood flow to a nerve or when a nerve has been damaged. The fancy name for pins and needles is parasthesia and what's actually happening is that you don't have enough blood flow to a nerve, or you squeeze a nerve. What happens is that the blood which is supplying the nerve comes from tiny blood vessels in the wall of the nerve, so the pressure closes those vessels off. Nerves have an extremely high metabolic rate. They consume energy faster than almost any other tissue in the body, so if they don't have a regular blood supply then they cannot keep themselves charged up and active. So they start to deactivate and the first fibres to deactivate are the ones that are the smallest and those ones are the ones that subserve pain. So that's why you feel these little jagged pin prick type sensations because the nerves stop firing normally and they start to either discharge spontaneously, or the cells in the spinal cord that respond to them just start to fire off spontaneous nerve impulses because they can't hear the signal coming in from the nerve that's been squashed or deprived of its blood flow. That's why you get the pins and needles. As long as you move your arm quickly or your leg, or whatever body part to restore the circulation to it, it goes away very, very fast. Except...this can be a big problem in people who fall asleep drunk on a Saturday night with their arm over the back of a chair. This is called Saturday night palsy because, in these individuals, they actually squash the nerve in the arm and the blood vessels there. As a result the nerve actually never recovers and they can end up with this Saturday night palsy and you get a limp arm that dangles; not terribly helpful!

Emma - Right. The answer is actually rather messy, if you forgive the pun, because there isn't a definitive answer and I don't know if there is zoological term for animals that just go whenever and wherever versus those who can hold it. I think it's just termed bowel control or lack of bowel control. Whether an animal goes everywhere or they go off to do it somewhere specific depends on the nature of the poo itself, which might be dependent on the food that the animal eats. It tends to be that very non-toxic vegetarian poo, which is no harm to the animal at all, can be done wherever and there's no danger to the animal being around that poo. You'll definitely notice if you have rabbits or guinea pigs that they just poo all over the place. In fact, guinea pigs even eat their poo, which is really disgusting to us but great for the guinea pig because it gets an extra meal. In comparison, animals with more nasty, parasite laden poo tend to go off and poo somewhere else. Horses in a field tend to poo in clumps and they never feed around that clump so the grass gets really long. They do this because they can have some really nasty kinds of worms and parasites that get inside them if they ingest anything which lives in their poo. Birds as well, you'll notice, always have clumps of poo below the bird's nest, but they don't intend to pooh in their nest. In fact, some birds actually remove poo out of their nest and carry it off and drop it somewhere else. That's thought to be to do with the parasite burden. Another dimension to this is actually communication. You'll know that many animals communicate using smell. Big cats such as cheetahs or lions out in the savannah tend to poo out in the open deliberately to mark their territories. In fact, that's often how they're tracked. Hippos use their tail to actually swirl poo around in the water where they go, again to mark their territory [and to flick it into trees and shrubs on land, for the same reason]. As you mentioned in the question, being caught as a sitting duck and not wanting to be caught by predators, that could also have something to do with it. So again, horses and animals such as deer can definitely poo while they're actually running along. So I should think that's useful. I hope that answers the question.

Dave - I guess, also, there's a big difference between herbivores and carnivores in that herbivores have got to eat a huge amount more food, which means there's a lot more to go out the other end [so pooping on the move is definitely advantageous...]