Monthly Archives: December 2010

Coffee and cake can be good for you!

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Maria Panagiotidi

Coffee and cake might be bad for your waistline but not for your brain! At least that is what a recent study published in the journal “Human Psychopharmacology: Clinical and Experimental” suggests.

Caffeine and glucose are part of our everyday life and are known to have stimulant effects. Previous studies have suggested that caffeine can have positive effects on cognitive function when consumed in moderation.  Other studies focused on the effects of glucose have found similar effects. However, only a few researchers so far had looked at the synergistic effect of those two substances on behaviour and cognitive function.

A group from the University of Barcelona have now done a novel study to investigate whether the consumption of caffeine and glucose, alone and combined, has any effect on cognitive performance. They tested their hypothesis by asking seventy-two healthy subjects to perform a variety of tasks after being administered either doses of water, water with caffeine, water with glucose, or water with both caffeine and glucose. The tests examined a number of functions like attention, memory, fine motor skills, and reaction time.

The most robust effects were observed in the group that consumed caffeine and glucose. More specifically, these participants performed better on tasks requiring attention, learning and verbal memory. The consumption of caffeine alone also lead to improvements in simple reaction time tasks. Similarly, glucose was associated with improved performance on reaction time and fine motor skills task.

 

Adan, A. and Serra-Grabulosa, J. M. (2010). Effects of caffeine and glucose, alone and combined, on cognitive performance. Hum. Psychopharmacol. Clin. Exp., 25(4):310-317. http://onlinelibrary.wiley.com/doi/10.1002/hup.1115/abstract

Life, but not as we know it

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Michaela Livingstone


A newly discovered bacterium uses the deadly arsenic to grow and live.


The only organism able to use a different chemical from the accepted fundamental building blocks of life has been found living in a lake in California, substituting phosphorus for the usually poisonous element arsenic, opening up questions on what other forms of life might be possible in the universe.


Until now, all life on Earth has been found to use the same basic building blocks for life, the elements carbon, hydrogen, oxygen, nitrogen, phosphorus and sulphur. These elements make up the various cellular parts and machinery from DNA to proteins and lipids.


The bacterial strain, named the not-so-exotic GFAJ-1, was isolated from mud samples collected from the shores of the briny Mono Lake in California, known to have high levels of arsenic, by NASA researcher Felisa Wolfe-Simon and was reported in a research article in this week’s issue of the journal Science.

Phosphorus is contained in a phosphate form (phosphorus and oxygen) in the backbone of DNA and RNA, as well as energy-carrying molecules such as ATP. There had been suggestions that arsenic in the form of arsenate could be used by life as it is chemically similar to phosphate, which is why it is usually deadly.


The bacterium was shown to have arsenate incorporated in to its DNA and other cellular parts when grown in media lacking phosphorus but containing a relatively high level of arsenic. The organism was however still able to grow faster in the presence of phosphorus.


Some researchers have hailed this as evidence that it is possible for life elsewhere in the universe to use different chemicals as their building blocks, opening up many possibilities for extraterrestrial environments where life could thrive, where before it was thought impossible. It suggests that anything is possible and that alien life may look very different from what we have assumed, if we ever come face to face with it.


Others say it opens up questions as to how, and how many times, life may have evolved here on Earth speculating that life may have evolved in harsh environments with high levels of arsenic such as volcanic vents on sea beds before later incorporating phosphorus.


Clara Chan, a geomicrobiologist from the University of Delaware, Newark was reported by the journal Science as saying that the strongly held belief is that the chemistry of life is so specific that any changes would not be tolerated, “The implication of this work is that life can be quite different from what we know.”


Other scientists are less convinced by the data, withholding belief that the organism really is able to use arsenate in place of phosphate until more data is produced to show that the arsenate isn’t simply being stored in the bacterium.


GFAJ-1 at least shows that is possible for life to exist in the absence of phosphorus. Wolfe-Simon hopes now to find bacteria growing naturally in high-arsenic but low phosphate-containing environments to find proof of life that depends on arsenic.

 

Find the original research article here:

http://www.sciencemag.org/content/early/2010/12/01/science.1197258

 

What Causes a Static Shock?

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Once again I was called upon for the public service of South Yorkshire and to help out Michelle Mustard on Hallam FM find an answer to a question that had been bugging her all week: What causes static shocks and how can you avoid them?

To understand what causes static shocks, those annoying zaps that seem to come from seemingly innocuous objects without warning, we have to look at what the universe and everything in it is made of.

Atoms, which are the building blocks for all matter in the universe, are made up themselves of particles that look this:

The centre, or nucleus, of the atom has electrons zipping around the outside. These electrons have a negative charge (think electricity).  Any time two surfaces come in to contact with each other electrons are exchanged. Some materials are more likely to lose their electrons from their surfaces and others are more likely to gain electrons.

Ultimately this means that the material that has gained the electrons will have more of a negative charge. If these ions (charged particles) cannot move because the material doesn’t conduct electricity (i.e., it’s an insulator) then those electrons hang about (literally they are static, in the sense that they don’t move).

That is until something that DOES conduct electricity comes in to contact with them, this is any conductor that is ‘earthed’, so that the electrons can flow from the insulator through to earth. This usually isn’t a massive energy, but because it happens over such a short amount of time it can sometimes look like a spark of electricity, and more often than not is felt as a little shock.

So I’m painting this as harmless, but these are the babies of the daddies of static shocks: lightning. Static electricity builds up in big storm clouds where ice has formed and the particles rub against each other until the charge has built up to such an extent that it can no longer be contained and draws up positive ion streamers from the ground – when the negative and positive streamers meet the ions are discharged with such power that they super-heat the air creating light (lightning) and the air expands so quickly from the heat that it causes a a loud sound wave to be produced (thunder).

And it doesn’t end there… flour, as you may or may not know, is highly explosive. There have been recorded instances where a spark arising from static charge building up in grain silos where flour dust particles have rubbed against each other have actually caused massive and seemingly spontaneous explosions.

How do you avoid getting static shocks then? Well my advice is to not drag your feet on carpets, especially in those generic flat, sheep-skin boots, and then touch taps, radiators, or any other metallic, earthed object. Secondly, avoid travellators and escalators (those rubber handles brushing against the metal…) and finally avoid synthetic fibres, or at least rubbing around in them too much.

Antimatter and Black Holes

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(Due to Blog problems this is a little later being posted than when I wrote it)

The past weeks have seen two significant discoveries in the Physics world encompassing modern ideas in physics.

First Antimatter atoms confined

A team collaborating with physicists at the CERN (the European organisation for nuclear research) have managed to confine single anti Hydrogen atoms, the antimatter equivalent of Hydrogen for times in excess of 170 milliseconds. The collaboration so far has only been able to confine 38 single atoms of anti Hydrogen so far from many attempts so Star Trek’s antimatter warp-drives and Dan Brown’s antimatter bombs are some way off yet.

Anti Hydrogen is comprised of a positron and an antiproton, the anti particles of an electron and proton. The physicists created the anti Hydrogen through slow, low energy collisions of the two antiparticles that comprise it. This method was first discovered and used in 2002, however the anti Hydrogen immediately annihilated upon interaction with matter in the walls of the collision chamber. To get around this problem the current set up employs magnetic fields that are strongest at the walls and weakest in the centre of the chamber which contain the single atoms in the middle of the chamber therefore to be studied.

The confinement of anti Hydrogen has significant implications for research into the standard model, in this case proving weather energy levels withing the anti Hydrogen are the same as those in regular Hydrogen. The standard model of particle physics ties together the fundamental forces of the subatomic world which in turn mediate the dynamics of the zoo of subatomic particles.

Young Black Hole Discovered

On the much larger scale, the past week has seen NASA’s Chandra X-ray observatory detect evidence of the youngest black hole known to us. This discovery allows astronomers to watch how black holes develop in their infancy.

The black hole has developed from a star in excess of 20 times the mass of the Sun that exploded in a supernova in 1975, approximately 50 million light years away. In the period of 1995-2007 a steady X-ray signal has been detected from this region of the sky by the German ROSAT satellite, the European space agency’s XMM Newton satellite and NASA’s Swift Satellite. As black holes are by definition hard to see as they emit no visible light, X-ray emission is significant in detecting possible black hole candidates. As matter falls towards the black hole it emits X-ray radiation due to a change of the matter’s gravitational potential energy.

This discovery suggests a black hole and if so it will be ideal to spread new insight on the physics surrounding black holes and their formation. However, it may also be a pulsar (a rotating neutron star) which again are too small to see but emit radiation in relation to their rotation speed. If it does turn out to be a neutron star it’ll be the youngest known pulsar beating the current of 920 years.  

What Does Nuclear Energy Bring to the Table?

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OK, so we now know briefly how nuclear energy is produced alongside a little background history, but what are the real benefits of such an energy source?
If we look at the largest sources of energy in today’s society we find that they are not evenly distributed over the planet. Over 68% of oil is concentrated in the volatile region of the Middle East and around 67% of gas reserves are concentrated in Russia. This introduces a risk in terms of reliability on the supply of energy for other countries, it also allows these regions to monopolise  these resources of energy. Furthermore with the introduction of the Kyoto agreement which demanded that signatories decreased their CO2 emissions in order to reduce global warming, nuclear power plants seemed like an extremely attractive option. Some countries utilised nuclear energy more than others. As we can see from the graph below showing the percentage of electricity produced from nuclear sources from 1980-2004, there is a huge increase in France from 22% to 80%. This is due to the fact that France is very poor in natural fossil fuel sources and therefore a large emphasis is placed on nuclear energy.

Japan is researching methods in which energy in the transportation sector can also be generated by nuclear energy. This involves replacing the hydrocarbons such as gasoline and diesel oil with hydrogen, electricity or synthetic liquid fuels. Using nuclear energy we can produce these energy carriers, or if not we can combine nuclear energy and fossil fuels by a synergistic process. Again this eradicates or at least minimises the emission of carbon dioxide. In order to produce hydrogen, nuclear electricity can be used to electrolyse water, or with the addition of heat can be used in high-temperature electrolysis of steam. Hydrogen energy can be used in various sectors such as fuel cell vehicles and fuel cells to supply electricity to rail trains and marine vessels, also hydrogen can be used in jet engines to propel aircrafts. With regards to electricity, the Japanese government are introducing electric automobiles into the market which allow supply of nuclear energy in the transportation sector through the battery-powered car. However the batteries in these cars are very expensive and therefore production is low. The introduction of a hybrid plug-in car (illustrated below) combined the benefits of nuclear energy and the low costs of using fossil fuels. It was illustrated that on average a hybrid plug-in car could cover 70% of the distance that a Japanese car travels per day running on electricity generated by nuclear energy, and then travels the remaining 30% of the distance using petroleum. This means that around 70% of CO2 emissions resulting from fossil fuel burning can be cut down if these plug-in hybrid cars were mass-produced and introduced into society.

 

As well as being used in the generation of electricity, nuclear energy was also used in propulsion. The nuclear energy is compacted into vehicles that must travel long distances without refuelling. This is used in naval vessels such as submarines and aircraft carriers. For example in the Cold War there were 100 nuclear powered submarines and a significant number of aircraft carriers in the US fleet. The first aircraft carrier to be deployed was the enterprise used in 1961 and illustrated below. You can see as a tribute the  men on board the ship are standing in a formation on the flight deck spelling out Einstein’s formula.

It’s obvious from this that nuclear energy does pose very beneficial for the economy, yet it is still one of the smaller contributors to energy in today’s society. Why is this? Possibly because alongside the benefits it also brings problems and dangers to the table….