Evil Twin’s Downfall


So what if we have an evil twin, like in the movies? If he/she commits a murder, and DNA evidence is found in the crime scene, both you and your evil twin will be suspects, since you share the same genetic material. Although this is a rare and unlikely scenario, it is definitely a possibility, and has actually happened several times throughout the years.

Usually, this will end in no one being prosecuted, since it would be impossible to determine which twin did it, and sending both to jail would be terribly unfair to the innocent sibling. A new option for the police in these cases is to analyse the DNA of both twins in incredible detail, searching for any slight variations that may have randomly occurred due to mutations and changed the genetic code, but this option takes a lot of time (over a month) and also happens to be very costly.

twins

Now we can find out which twin actually did it

However, scientists have now come up with a sort of an upgrade to this method. Instead of looking for mutations, which occur randomly, they would look for differences in the DNA strands that have been caused by their way of life. These modifications are called epigenetic changes, and instead of causing a gene to change its sequence of bases, it just modifies how it is expressed into a protein. It can do this by adding a methyl group (-CH3) or by altering the histones in our DNA: the proteins that help condense our genetic information into a more compact shape so it can all fit into the nucleus of a cell.

These changes can be inherited, which would be unhelpful since both twins can have them, or caused by environmental factors, which would also be unhelpful if the twins have lived close together in the same conditions. Fortunately, very small differences can cause these changes, specifically in the early stages of the embryo’s development, so although still rare, these changes do exist in twins.

In the specific case of epigenetic changes by methylation, this would mean that the DNA strand is now larger, and has more molecules in it. This would increase the forces of attraction and increase its melting point. Since both twins will have different changes, and therefore different amounts of methyl groups, their DNA would not melt at the same temperature. So comparing their DNA’s melting temperature with that of the DNA found in the crime scene can tell the police which of the two twins did it, and solve the mystery in a much faster and cheaper process, as you only have to heat the suspects’ sample.

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The 6th Sense


We are used to people talking about the 5 senses: sound, sight, touch, smell and taste. But scientists are now working on improving these, and even creating a new sense that would enable us to experience the world in a much more heightened way.

For now, it’s all based on an experiment to help blind mice. Since this type of mice isn’t able to see, their sense of direction is severely handicapped. But in the University of Tokyo, a team used a compass like those found in smart phones, albeit a more complex version, and inserted it into the visual cortex of blind mice. It had two electrodes attached, each connected to a hemisphere of the brain. They fired up, sending electric impulses to the brain, whenever the mice’s head turned a certain amount of degrees away from the north direction. Depending on how many degrees, it would change the intensity of the signal on each hemisphere, so for example, when the mouse faced south, the neuroprosthesis would only send an impulse to the left hemisphere. After a week, the mouse managed to interpret these signals correctly and was able to orient itself using this compass, instead of the usual vision.

mouse compass

These mice have a compass in their brain, which helps them overcome their blindness

This was demonstrated by putting the mice in a labyrinth with a prize in the middle, and comparing normal mice, blind mice, and blind mice with the compass. After about 60 rounds of labyrinth trials, the normal mice and those with the compass behaved practically the same, finding the prize in a small amount of time, whereas the blind mice took longer. It seemed like the mice were able to create a map of the labyrinth in their heads, so no matter where they were placed within the maze, they managed to find their way around. Although this did not actually cure the blindness, it enabled them to find their sense of direction and be more independent.

What’s especially interesting is not only that the rats were actually able to ‘see’, but that they could detect this foreign type of stimuli and understand and interpret it correctly. Even though they spent their lives without a compass in their head, as soon as it started working they were able to use it to their advantage, showing the great adaptability of these organisms. This could be extrapolated to use in human beings, and gives hope for a cure/alternative to blindness. Other scientists go further and suggest that it could open a path towards new types of senses, using stimuli like UV or infra red light that, together with receptors like this compass, we could use to see the world in much more complex ways, adding more senses to the pre-existent ones.

A Chameleon’s Colourful Secret


Chameleons are definitely one of the most fascinating creatures on Earth, and their characteristic colour changes, to camouflage themselves or gain the attention of their mates, can impress both kids and adults alike. As if their ability to change their appearance into anything they’d like wasn’t enough, the mechanism by which they do so could also be unique and worth some credit.

In nature, colours are usually produced by pigments: substances that have a specific colour. For example, our skin gets tan because of a pigment called melanin which darkens it. In chameleons, it was originally thought that they showed one colour because a pigment of that same colour covered their skin, and when they wanted to change colour, a pigment of a new colour just substituted the original one. But it has now been discovered that their colour change, contrary to popular belief, had nothing to do with pigments. It’s actually all because of crystals.

A chameleon’s skin has an outer layer full of specialised cells called superficial iridophores, which have tiny guanine crystals embedded that can reflect light at different wavelengths and so produce different colours. Guanine not only plays an important role for this process, but is also one of the four bases in our DNA, which code for all the substances in our body. When the chameleon wants to change colour, it simply twist these cells around so the distance between crystals changes, which causes the reflection pattern, and subsequently the colour it produces, to change.

chameleon coloured

Chameleon’s can express a wide variety of colours thanks to guanine crystals

This is a very smart design which saves the chameleons a lot of energy and resources on producing and transporting the pigments around. If the animal wants a bluish colour, it just needs to push all these crystals together. For a reddish/yellow colour, just spread them out.

The only thing yet to be discovered is how the chameleons actually modify the superficial iridophores’ shape. In the experiment they carried out to test this new theory, they used salt water to expand and contract the cells and see what effect this had on the colour. But the natural process in chameleons is not necessarily chemical, it could be mechanical. Finding out which one it is is the team from the University of Geneva’s new objective.

Either way, discovering the truth behind this ingenious technique is not only an interesting fact to know about, but could also have real-life applications, for example, in developing computer screens.

A Bacterial Lunch


The secrets to weight loss may not lie on strange synthetic chemicals or unhealthy new fad diets, but actually in some simple bacteria we’ve known for as long as we’ve been born.

The bacteria in our intestines help us digest the food we intake; from carbohydrates to proteins to fats. But there’s something we humans can’t actually digest: fibre, so instead we use it to push the rest of the food through our guts and prevent constipation. However, since we should eat plenty of fibre, some bacteria use the excess and digest it too, and when doing so, release a substance scientists call propionate. This chemical triggers a reaction in our cells which results in them releasing a specific type of hormones: satiety hormones, such as PYY and GLP-1. As their name suggest, they are used by the body to make people feel ‘full’, by sending messages to the brain telling it to stop eating. In people, it usually takes a decent amount of fibre to trigger this response, so the person has to ingest a large amount of food before this reaction happens.

bacteria lunch

Don’t they look delicious?

But in developed countries, there is an excess of food, so people over indulge and end up over weight or obese. To stop this, scientists have been working with these bacteria in our guts and have come up with a possible solution.

In the form of IPE (inulin-propionate ester), propionate is in a concentration 8 times as large as that of a normal dinner, high enough to trigger the “I’m full” response despite not eating enough fibre. In theory, if a person takes this at some point during the day, they will produce the satiety hormones that will tell the body they are full so the person won’t feel the impulse to eat. The objective of the drug is therefore to reduce weight gain by reducing food intake.

To test this drug, some interesting experiments were carried out. The most curious one consisted of having two groups of people: one taking IPE and one not (the control) face a buffet and an open invitation to eat as much as they wanted (a.k.a. heaven). People with IPE in their system ate 14% less than those without IPE. And if the drug was given to people leading normal lives for six months, those taking the drug ate on average 9% less than those with no drug.

So although eating bacteria’s remains doesn’t sound like the most appealing plate in the book, it could produce long-term improvements in our health.

Life is all about Change


In an experiment in Michigan State University, scientist Richard Lenski started growing a group of E. coli bacteria in 1988. The bacteria have kept reproducing since then, making the incredible amount of more than 50,000 generations. But there is a purpose to this experiment: study evolution and answer a very simple question: Is there an end to evolution?

Lenski grew about 12 different groups of E.coli bacteria in a simple, constant medium. He used bacteria because this type of organism grows and reproduces very quickly and they are fairly easy to manipulate and study. It was important that the environment was kept constant, because any little change could affect the evolutionary process.

After every 500 generations, a sample was taken and frozen, so at some point, a group of bacteria from different generations was put together and their aptitude at surviving compared to each other is be measured.

The results are very surprising and revealing. Every generation, Lenski found, had a minor improvement over the former one. The grandson was always fitter than the grandfather; no matter how many times the experiment was repeated. But this was expected. The news is that, at some point, the improvements were less and less obvious, so even though there were still changes, they weren’t so useful or noticeable with each generation.

E. Coli bacteria

E. Coli bacteria

This is an example of power law, a mathematical term used to describe a sequence that is ever increasing, but the amount by which it grows, decreases.

This information is interesting because, up until now, it was thought that organisms had a limit as to how adapted they could be. This applies only to constant mediums. In the real world, there is always going to be changes, because the environment or the habitat changes all the time, however small the changes are. So the answer to our first question was no. There are always changes around us, so we are always going to be changing. Even if the world stopped changing in every minute detail, we would still be developing new ways in which to be fitter for survival.

Some people say that this could not be applied to humans or other species, but the idea is the same. Just like your parents said, there is always something you can do to be better.

Death for CMV


A cytomegalovirus (CMV) cell

For many years, the cytomegalovirus (CMV for short) has infected between 50 and 80 percent of the population in the USA, UK and Australia, and in some parts of Africa, the number of infected is even higher.

This herpes virus can cause a faster cognitive decline, a poorer physical health, blindness, more chances of dying of a cardiovascular disease and can even shorten the life of the victim up to 5 years, the same amount that smoking and drinking alcohol can reduce.

 

What’s important of this disease is the way in which it attacks the immune system.

With more common viruses, the immune system sends T-cells (lymphocytes) to recognise and remember them, so if they attack in the future, they will be able to produce antibodies before the virus really infects the organism.

With CMV, the immune system works the same way, but the virus itself tricks the T-cells so instead of remembering it, the body trains more cells to make T-cells, shortening the supply of untrained cells, which, altogether decreases the immune system’s life expectancy and leaves the body more defenceless against other infections.

Researchers are now divided about how to treat this infection.

On one hand, some scientists want to give the diseased people a treatment consisting of anti-viral drugs to avoid loosing lifetime.

Experiments were carried out in mice were successful with this treatment: they infected some mice with the cytomegalovirus, and whilst the ones without the treatment lost many of their untrained cells, the ones with the treatment had a healthy number of untrained cells in their immune system.

This treatment method is soon going to be introduced to people over 65, the target people of the investigation.

The other scientists working in this virus want to stop the disease before the infection occurs, so they are trying to create a vaccine.

They believe it is much easier for the patient to have a vaccine than to follow a treatment for months and even years. However, their solution is not that easy to carry out. They will also need to know how the virus infects people, to block the entrance of the virus and make a vaccine. To do this, they carried out experiments on mice too, the results of this showing the virus enters the body through the nose.

Further investigation will take place to try to produce an efficient vaccine.

Sources:

http://www.newscientist.com/article/mg21428702.000-stealthy-virus-that-robs-years-of-life-could-be-beaten.html

A Robotic Dream


Finally, an era where robots can help disabled people to fulfil their dreams has arrived.

This incredible news come from Brown University in Providence, Rhode Island, USA, where, thanks to an aspirin sized set of electrodes implanted in her brain, the amazing 58 year old Cathy Hutchinson with a stroke that paralysed most of her brain and lost her use of the limbs, was able to drink alone again.

The experiment consisted in implanting a small device in the person’s motor cortex (which is the part of the brain that controls movement in the body) and connect this to some computers. These computers were able to receive the patient’s neurological signals, match them to their corresponding movement order, and send this information to other computers which accomplished all the tasks.

One of the tests was to make the two other volunteers (the woman and a 66 year old man) reach out, with the robotic arm, a foam sphere, and grab it. The results were really good: one of them got the ball in 46% of all the attempts and the other a 62%.

Another test, the most famous one as it demonstrated how this new project can help our society, was the experiment in which the woman took part. The robot arm was supposed to move according to the Hutchinson’s orders, and grab a cup of coffee, move it to her mouth so she could drink from the straw, and leave it back in the table again.

For this, the scientists told her to imagine she was moving the robot arm, which caused neuronal signals the computers were able to detect and transform into orders the robot arm carried out.

The inventor of BrainGate, the technology used in this experiment, John Donoghue, explains how happy the woman was after completing the experiment and how you could see her brilliant smile when she knew she could do some things finally by herself.

This invention can’t only stop here, and other projects to develop this idea are already being carried out.

For example, scientists can see how this creation can be attached to wheelchairs and other devices to help assist the disabled.

Also, although this looks more into the future, Leigh Hochberg, the leader of this , says these studies can help create a technology so that people with paralysis or amputations can recover

This outstanding experiment was not only an important scientific breakthrough, but it also made a woman that has been in silence for 15 years able to ‘move’ by herself and even drink only using her mind.

Sources Used:

http://www.newscientist.com/article/mg21428654.100-braincontrolled-arm-could-beat-paralysis.html

http://www.nytimes.com/2012/05/17/science/bodies-inert-they-moved-a-robot-with-their-minds.html?_r=1

http://www.bbc.co.uk/news/health-18087949

The Scientific Event of the Year: Debate: Darwin vs. God: Part 2


Dawkins and Williams after the debate

Dawkins and Williams after the debate

Yesterday, people from all around the world were able to watch one of the most important events of the year at Oxford University or by the Internet.

At Sheldonian Theatre, zoologist Richard Dawkins debated about the origin of human nature and the universe with Archbishop of Canterbury Rowan Williams. The debate, considered as a battle between science and religion, was calm and polite, but with some sense of humour of the debaters.

Each debater respected and admired each other’s arguments, although after they had to argue it.

Anthony Kenny

The debate started with the philosopher Anthony Kenny asking for no applauses, and continued with the funny comment ‘I come representing ignorance’.

He actively collaborated in the debate, sometimes looking as a third debater. He gave the debate a relaxed but formal atmosphere, and asked new discussions to both debators.

Rowan Williams

One of the head of the Anglican Church’s arguments debated about conscience, and of the need of God to explain it. He also had to admit that the Bible didn’t explain scientifically the creation of the Universe, but he argued that the Bible’s authors just wrote what God told them to.

Richard Dawkins

The biologist occupied the major part of the debate, defending Darwin’s ideas about evolutionism and stating that humans are a product of only evolution, with no intervention by God.

He was sarcastic about the existence of God, but had to admit he can’t disprove the existence of God, and once, he even had to admit he did not disbelief in God totally, but thought the chances of it existing were very, very low.

If you weren’t able to see the debate, you can watch it again at http://fsmevents.com/sophiaeuropa/

The Scientific Event of the Year: Debate: Darwin vs. God


Today’s special report is dedicated to Richard Dawkins and the archbishop of Canterbury Rowan Williams.

Richard Dawkins is one of the world’s most known biologists and one of the major supporters of Darwinism. Studying zoology at Oxford, he then moved to teaching at California University. His known books, The Selfish Genes and The Extended Phenotype, have given him the title of Darwin’s Bulldog, due to its fierce defence of Darwin’s ideas.

On the other side, there is the Archbishop of Canterbury, Rowan Williams. He is also worldwide known as one of the most passionate teologists, defender of the Anglican Church, and is the 104th Archbishop of Canterbury. As Dawkins, he studied at Oxford, but theology. He’s done lectures in numerous universities, specially in Cambridge, where he was awarded the degree of Doctor of Divinity, in 1989.

Returning to the news, today, Thursday the 23rd, Oxford University holds one of the most interesting and passionate debate of the year, the eternal debate of Darwin and God, at the Sheldonian Theatre.

In this debate, being the theme the nature of human beings and their origin, the biologist will defend Darwin’s ideas of evolutionism and natural selection, whilst the Archbishop will state the Church’s point of view, debating about creationism and Adam and Eve.

The tickets to this outstanding event, organised by the University Of Oxford Theology Department have already been sold out, being chaired by philosopher Anthony Kenny.

At 16:00 and until 17:30 (London UTC), people without tickets will be able to watch it live at www.originsofnature.com