Why Is Ice Slippery?

Our Solar System may not be alone in having an abundant supply of water. That's according to a paper published this week in the Journal Science. Michiel Hogerheijde and his colleagues have been using the Herschel Space Observatory to study the star TW Hydrae -- a star so young, only around 10 million years old, that it's arguably still forming, but which we expect will eventually end up at around 60% of the mass of our own Sun.  TW Hydrae is a very well-studied system because it's the closest example to us of such a very young star, and of particular interest is the disk of gas and dust which surrounds it, which we expect will eventually form into a planetary system not dissimilar our own Solar System.

It's interesting to ask how similar to our Solar System that planetary system might turn out to be. One of the really important characteristics of our Solar System, certainly in terms of making life possible in it, is that it has an abundant supply of water in the form of comets. We have models for where we think that water came from in the Sun's planet-forming disk. Very close in to the Sun, in the hottest part of the disk, it would have sublimed (boiled) and been in the form of water vapour or steam. But out beyond the asteroid belt, beyond what we call the ice line, it would have been frozen into solid lumps of ice, which explains why the Solar System has rocky bodies in the asteroid belt, but icy comet-like bodies further out. Those comets played a vital role in bringing the oceans to the Earth, because the Earth formed inside the Solar System's ice line, as a dry planet: only through later bombardment of comets onto its surface did water arrive and make Earth a wet planet.

Looking at TW Hydrae from the outside, we've had no trouble in the past in detecting water vapour in its inner central regions. But detecting whether ice is present further out has proven problematic. What Michiel Hogerheijde has done in this new study is to make use of the fact that, if ice is exposed to ultraviolet light, you'd expect a tiny fraction of the water molecules to break away from the solid lumps and form very cold gaseous water vapour. In TW Hydrae, there does indeed appear to be evidence for very cold water vapour extending a long way out in the disk, where it couldn't have formed by straightforward sublimation. So, this appears to be evidence that there is a vast amount of water ice -- several thousand times the total amount in the Earth's oceans -- around TW Hydrae, and suggests that this system has the potential to form both comets, and eventually wet habitable planets like our own Earth.

Emily - Well it's a good question and the answer is that they will brown faster in the fridge. It's mainly due to the formation of ice crystals, so if you put your banana in the fridge, the ice crystals grow, and they actually rupture the cells of the banana skin. This releases an enzyme called polyphenol oxidase and as the name suggests it acts to oxygenate phenols, which have a ring-like structure, into quinones, and these quinones can then all join together or polymerise and produce a black, brown, or red pigment called polyphenol and this is what gives it the brown colour. So, if you have your banana in the fridge, this will occur and you'll get a brown banana. But another interesting thing about bananas is that if you have them in the fruit bowl, they'll release ethene and this will make the other fruits in the bowl ripen faster because it's a ripening hormone.

Chris - So, the question is though, if this is a chemical reaction making this brown pigment, if you slow down the reaction by lowering the temperature, then it should happen more slowly, therefore, going in the fridge should make the bananas go black slower?

Emily - I can see why you're thinking that but actually, it's more the rupturing of the cells. So if you have a banana on your table, the cells are going to be intact, the enzymes contained, and the reaction is not happening at all whereas if you put in the fridge, the enzyme is released and the reaction can happen - although yes, it might happen slower.

A patient receiving treatment for lymphoma simultaenously recovered from chronic fatigue syndrome, revealing a novel way to combat the conditions, researchers have revealed.

Chronic fatigue syndrome (CFS), also known as ME (myalgic encephalomyelitis),  is associated with a constellation of symptoms that include severe unexplained exhaustion, disturbed sleep, headaches, muscle and joint pains as well as cognitive, sensory and even bowel disturbances. The cause of the condition, however, remains unknown. But now Norwegian scientists have found evidence to suggest that the disease may have an immune cause that can be treated by temporarily removing one class of white blood cells, called B lymphocytes, from the body.

Writing in PLoS One, Haukeland University Hospital, Bergen-based researcher Olav Mella and his colleagues decribe a double-blind clinical trial in which 30 patients diagnosed with CFS were randomly assigned to receive either a B lymphocyte-depleting drug called rituximab, or a placebo. Followed up over 12 months, 67% of the patients in the rituximab arm of the trial showed significant improvements in their own as well as physician-based assessments of their condition. Only one patient in the placebo group showed similar improvements. This strongly suggests that CFS has an immunological underpinning, which fits with the onset often following an antecedent infection of some kind.

Interestingly, the rituximab-treated patients only began to show improvements in their symptoms after about 3 months. This, say the scientists, would be consistent with the time it takes for antibodies released previously into the blood by the B cells to disappear.

The trial was initiated in the first place after the researchers administered rituximab to a patient with lymphoma, a cancer of B lymphocytes. The patient was delighted when his CFS, from which he was also suffering, simultaneously regressed alongside the lymphoma. This spurred the team to set up the present trial, the results from which, they say, strongly suggest that CFS has an immune cause and "will impact future research efforts" into the condition.

Jane -   If conjugating verbs isn't your idea of an interesting way to learn a language, the latest research at Newcastle University could be just the thing for you.  Language experts and computer scientists have developed an innovative kitchen that gives lessons in cooking and French at the same time.  It tracks your actions with motion sensor technology and it speaks to you as you prepare your dish.  Professor Paul Seedhouse is involved in the linguistic side of the project.

Paul -   This research has been based on previous research done by my colleague Patrick Olivier in Computing Science in Newcastle.  He developed a digital kitchen for people with dementia.  So for example, if they left the oven on for too long, it would tell them to turn it off and when I saw that, I thought that the technology could be adapted for use with language learning and teaching.

Paul -   When you enter the kitchen, it looks pretty much like an ordinary kitchen.  Some of the differences you'll notice if you look at the kitchen equipment, the handles are larger than normal and that's because they have sensors embedded.  And this technology you may be familiar with already, it's similar to Nintendo Wii technology, so there are sensors and they detect movement in all directions.  The kitchen will then speak to you in French.

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Paul -   When you're actually doing the cooking, you have a number of alternatives open to you.  You can request a repetition or you can ask for a translation or you can pause a program, you can go backwards and forwards.  But a really important point about this learning environment is that we put people in pairs.  Typically, one person is better at French, one person is better at cooking, and that means that they transfer the skills and they help each other to learn.

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Paul -   The recipe we've got is called a pear clafoutis and it tells you first of all to peel the pears.  So first of all, it tells you to take four pairs and the system then detects that you've taken the package of pears and you've moved it onto the work surface.  It then tells you to take the peeler and so, the sensor in the peeler will then detect that you've taken it over.  It's being moved and then the system will then detect whether you've made the correct peeling motion with your peeler on the pears.  When you've done that, it'll tell you to cut the pears into four so then it will look and see, have you taken the knife, has the knife moved over to the surface, and then have you made the correct chopping motion with the knife.  If you don't make a chopping motion with the knife - let's say you move it from side to side, it won't detect that as correct and so, the system will loop back and give you the instructions again.

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Jane -   Dan Jackson and Jurgen Wagner are involved in the technical aspects of the project.  They explained more about the small sensing devices that are embedded in the kitchen utensils

Dan -   Fundamentally, we're interested in understanding how the objects are used and how they're being manipulated.  We've developed this hardware that actually detects the motion, uses something called an accelerometer which is a device that measures the acceleration.

Jurgen -   The accelerometer inside tracks the smallest movements you do with your hands, the smallest movement you do with the utensils.  These are called motion primitives and this information is sent over to a computer which acts as a base station and this base station translates these simple activities, these motion primitives into something more meaningful. Whether it was it a chopping activity, a stirring activity, or whatever activity we can measure.

Dan -   So for instance, if you pick up a utensil, the device will wake up from a sleep state and it will start broadcasting its motion to the computer.  And then on the computer, we can analyse that information and work out what that object is being used for.  Chopping with a knife would give us a different signal to someone scraping or slicing with the same knife.

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Jane -   As well as making learning fun, Paul Seedhouse says the kitchen builds on the proven technique of task based language learning.  There are now further plans to take the concept out to wider a audience.

Paul -   Well, from the point of view of language learning and teaching, it's unique because it's taking the ideas, the excellent ideas of task based learning and teaching out of the classroom and if you like, into the kitchen. You're combining it with a real world task.  It's also unique and that you're learning two skills at the same time:  in other words, French and cooking skills.  So we already have the full scale digital kitchen in Newcastle University but we have now developed a series of portable kitchens which we take out on road shows.  It's basically a tablet PC, 6 implements and a pair of speakers, so it's very portable.  We're going to be placing portable kitchens in four different countries in Europe and trying them out there.

Jane -   The research is supported by the digital economy program run by the Engineering and Physical Sciences Research Council.  In the future, this way of learning could be used to teach people any number of skills ranging from nursing to driving.  This new type of kitchen could be available for schools, universities, and even the domestic market by the end of 2012. 

Seaweeds, also known as macroalgae, can unleash a chemical arsenal toxic to corals, scientists have found.

Writing in PNAS, Georgia Institute of Technology researcher Douglas Rasher and his colleagues studied the sensitivities of 3 different coral species to 8 different types of seaweed. Bringing the two together, as might occur on a reef, resulted in bleaching, reduced photosynthesis and even death of the corals in almost 80% of cases. Physical proximity wasn't the cause, the scientists confirmed. When plastic models of the offending macroalgae were substituted for the real thing, the corals remained healthy. Instead, it turns out that the seaweeds secrete a cocktail of oil-soluble chemicals called terpenes. These can rub off on the corals, killing them.

The seaweed most likely use the chemicals as a means of anti-microbial defense. But corals can become croppers when reefs damaged by human activities and climate change are then invaded by the macroalgae, which are able to gain a toe-hold in the first place because the ruining the reef also renders the habitat untenable for herbivorous fish that would previously have kept the weeds in check. This, say the scientists, may well explain the lack of recovery seen on many present-day reefs...

Dominic - First of all, to measure the temperature of a star, it's really about the colour of the star. If you take a piece of coal and set fire to it, as it gets hotter, it will start to glow red hot and then perhaps if it's very hot, it will start to glow yellow hot and then an intense fire will start to appear white or maybe even blue. So, by applying that logic back to a star, a blue star is a hot star and a red star is a cooler star. Chris - What about what's in the star? Dominic - Now what's in the star is more difficult, but different elements emit a very specific wavelength and produce what we called spectral lines. If you have a spectroscope that splits up the light of that star into different colours, you can see that certain colours are either not present or there's a huge amount of light at that particular wavelength, and that tells you there must atoms of a particular element emitting light in that star so you can tell what that star must be made of.

Chris:: Terrific, Dominic. In fact, Robert Bunsen was the forefather of the science of spectroscopy, so Bunsen of burner fame also discovered that you could work out what things were by looking at the certain absorption pattern they make, and what wavelengths of light they soak up. And ironically, after working for many, many years in his laboratory on identifying some rare compounds, he unfortunately left a big sheaf of notes with 10 years work in the sun in his lab, went off to the pub - well I don't know he went off to the pub, but I suspect he went out for lunch - came back and the sun set fire to it. He lost a lot and had to start all over again. But because a very good scientist and he did the whole lot again from scratch.

Drugs targeting herpes simplex virus (HSV), the agent that causes cold sores, might also abate Alzheimer's, new research has shown.

Previous research has tied HSV to dementing diseases like Alzheimer's since scientists showed that the DNA of the virus crops up in the brain in the same spots as the beta-amyloid plaques and neurofibrillary tangles that characterise the condition in the brain. HSV-infected neurones also make more of the enzymes and proteins that produce these pathological hallmarks of the disease. But with 80% of people testing positive for herpes simplex infection, it was unclear what, if anything, doctors could do to reduce the risk of Alzheimer's, which currently afflicts about 18 million sufferers worldwide.

Now, Manchester University scientist Ruth Itzhaki has shown that treatment with the safe antiviral agent aciclovir can, in the dish at least, reduce the rate of beta-amyloid formation, thereby mitigating the risk of Alzheimer's. By using a variety of mutant viruses lacking key genes, Itzhaki and her colleagues were able to interrupt the growth of the virus at different stages of its infectious cycle to discover what aspects of viral replication might increase beta-amyloid production. DNA synthesis - when the virus copies its DNA code - they found, appears to be the critical step. Luckily this is the very stage that is targeted by anti-herpes drugs like aciclovir and, sure enough, treating the cells with this agent reduced the rate of production of the tangle-forming proteins and, indirectly, beta-amyloid also.

The results are based only on an in-vitro study, but suggest, given the safety and relative low cost of aciclovir, that a clinical trial is warranted to explore whether antivirals can cut dementia rates in the elderly. As the scientists themselves point out, although a high fraction of the population carry HSV infection for life, in the majority the virus remains in the peripheral nervous system. It's chiefly in the elderly that the virus appears to invade the brain. Therefore, antiviral agents could arrest this process and reduce the risk of progression to Alzheimer's.

Virgin Galactic Spaceport

The World's first commercial spaceport has opened in the deserts of New Mexico.

Targeting all budding astronauts, Spaceport America is Virgin Galactics gateway to space providing members of the public five minutes of weightlessness at a cost of £127,000.

The eco-designed building will house seven spaceships, mission control and a visitor experience area for those that can't afford the flight itself.

Sir Richard Branson spoke at the launch.

Richard -   These beautiful ships will shortly be ready to welcome the first of more than 450 people paid up and waiting to fly.  The building has achieved the lead gold standard using local materials and regional construction techniques and we have minimised energy requirements through the use of geothermal heating and cooling, and extensive energy management practices.  Simply put, it's a 21st century building for a 21st century business.

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Improving the Success of IVF

A new test could significantly boost the success of IVF treatment.

The technique developed by Dagan Wells and his team at the University of Oxford screens potential embryos for genetic and chromosomal abnormalities before they're implanted, improving  chances of pregnancy by up to 70%.

Currently in the UK and many other countries globally, the healthy appearance of an embryo is enough for it to be used in a cycle.

Dagan -   The embryo that looks the best can often harbour lethal genetic abnormalities.  So the new test really combines a bunch of different aspects of embryo biology assessment, so we're looking at the chromosomes, we're looking at the mitochondria which power the cell, we're looking at the telomeres which protect the chromosomes.  And together, that's giving us a very deep insight into the health and biology of the embryo.

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Malaria Vaccine Trial

A Malaria vaccine could be on the horizon after promising results from a clinical trial taking place across Africa.

The RTS,S Malaria vaccine is the most advanced Malaria vaccine to date, currently targeting children under 18 months of age. Involving over 15,000 participants across seven African countries,  preliminary results from the Phase III clinical trials found infants aged 5 to 17 months receiving the vaccine had about half the risk of developing Malaria than those without it.

Tsiri Abenyega is principle investigator on the trial site in Ghana.

Tsiri -   Our results showed that RTS,S reduced the risk of children aged 5 to 17 months, experiencing clinical Malaria by 56% over a 12-month follow up period.  The study also found that RTS,S reduced the risk of severe Malaria by 47%.  This is remarkable when you consider that there has never been a successful vaccine against a human parasite.

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Life on a Bamboo Diet

And finally, new insight into the eating habits of the Giant Panda.

Unlike other meat-eating bears, the giant panda is an omnivore with a diet consisting mainly of bamboo - eating up to 12kg of the plant every day.  But their ability to digest the cellulose and hemicellulose fibres dominating a bamboo plant has long been a mystery as they lack the digestive enzyme usually found in other herbivores.

Using gene sequencing techniques, Fuwen Wei and his team from the Chinese Academy of Sciences identified unique enzymes and bacteria helping Pandas make a meal of this low nutrient plant.

Fuwen -   We found in the panda some special bacteria that could help the pandas digest the fibre.  Also, we found some genes coding for enzymes to do this kind of job.  But the nutrition is very low, they content, low protein, sugar and fat.  So the panda needs to get some part of its nutrients from the fibres.

Despite having these methods of digestion, the bamboo remains low in nutrition explaining just why the Pandas have to eat such large quantities of the bamboo on a daily basis. However the reason they choose to eat this above other foods remains a mystery.