Nicotine addiction: What is it?
Nicotine is the most widely used drug of abuse. It’s usually taken by smoking or chewing tobacco, which then releases the nicotine and is used by millions of people around the world. Nicotine works by travelling rapidly from lungs to brain (in about seven seconds) where it stimulates the release of dopamine – an important brain neurotransmitter involved in mood, appetite and other brain functions.
Although usually taken for its tranquillising and mildly mood-elevating properties, it actually seems to have both a stimulant and a depressant effect - the effect at any time may depend on the circumstances in which it is used. So it may help with concentration or relax the user. Nicotine is generally recognised to be one of the most addictive of all drugs. Users can quickly become dependent on its effects (in the most vulnerable, it takes just a few cigarettes to get hooked on the habit). If someone suddenly stops taking nicotine, they usually experience prolonged withdrawal symptoms such as anxiety and mood swings. This causes them to crave the drug in order to try to reverse these unpleasant feelings. As a result the habit is hard to break.
The fact that smoking or chewing tobacco is not illegal and has some social acceptance (although it has becoming much less so in recent years) make it harder to give up. Many argue that if tobacco were to be discovered today, it would be considered too dangerous to be licensed for human consumption.
As a pure drug, nicotine has few adverse effects on physical health, however it does raise blood pressure and accelerates the progression of heart and arterial disease. But it’s the other chemicals taken in along with nicotine which do much of the damage. When tobacco burns as a cigarette is smoked, it releases hundreds of other constituents. It is these chemicals, described below, that pose the greatest risk to health.
Smoking increases the risk of cancer in almost every organ and tissue of the body, but especially cancer of the lung, throat and stomach. Heart disease, stroke and serious lung disorders, such as chronic obstructive pulmonary disease (commonly known as chronic bronchititis and emphysema) are just some of the reasons why smokers are much more likely to die young, often years before their non-smoking peers. It's estimated that smoking accounts for more than 110,000 premature deaths in the UK each year.
What's in cigarettes?
As well as nicotine, there are more than 4,000 other chemicals in cigarette smoke, some of which are well known for their toxicity. Here are just a few:
•Nicotine - when tobacco smoke is inhaled, nicotine is absorbed into the bloodstream and takes effect very quickly. Immediate physiological effects include increased heart rate and a rise in blood pressure.
•Ammonia – also found in toilet cleaners.
•Acetone - found in nail varnish remover.
•Cadmium - a highly poisonous metal used in batteries.
•Vinyl chloride - used to make PVC.
•Napthtalene - used in moth balls.
•Carbon monoxide – A poisonous gas that is commonly given off by exhausts and gas fires as well as cigarette smoke. In large amounts, such as from a faulty gas fire, it is rapidly fatal, while in small amounts, as when someone smokes a cigarette, it will cut down the efficiency of the smoker's breathing.
•Tar – thick brown stuff in cigarette smoke that stains fingers and teeth a yellow-brown colour and which deposits in a smoker’s lungs, clogging them up.
•Cyanide – a lethal gas used in World War 2 gas chambers.
•Formaldehyde - used to preserve dead bodies.
•Arsenic - poison.
Some cigarettes include flavourings include childhood favourites such as cocoa, vanilla, liquorice, sugar and even honey.
Did you know ... ?
•Addiction to nicotine is usually established in young smokers within about a year of first experimenting with cigarettes , in many cases before reaching the age at which it is legal to buy cigarettes (on average at 12-13 years of age).
•It can take less than one pack of cigarettes – on average just six cigarettes – to suffer withdrawal symptoms if you try to stop – in other words to become addicted
•Smoking causes permanent changes in brain receptors – once hooked most people will have cravings for nicotine which will never completely leave them
•80 per cent of ex-smokers will return to a regular habit within one month of having just one cigarette even if they gave up years before.
•People who smoke mild cigarettes (usually women) simply drag longer and harder in order to get the same amount of nicotine. As a result they more often develop peripheral lung tumours at the edges of the lungs and vertical pursing lines around their lips
•Only about 5 per cent of smokers seek help to quit, even though this can increase their chances of stopping long term to as much as 30 per cent at one year if they get support from a trained adviser and use medications for nicotine dependency
Treatments and tips for quitting
About half of all smokers make at least one attempt to stop in a given year. A significant number may do well at first - the data varies but some studies suggest that over 40 per cent of those who use all available help, including nicotine replacement treatment and behavioural support are initially successful. But quitting completely is a different matter. Long term success is much less common and typically more than 95 per cent relapse within the first year, leaving only 2-3 per cent of those who try with willpower alone and no support from health professionals or medical treatments as successful long term quitters.
These are some of the strategies offered to help people stop smoking.
1. Assessment and advice
In most GP surgeries, there are doctors or nurses who offer a brief assessment of a smoker’s habit and advice on giving up. This is enough to help about 10 per cent of people to quit completely. Some studies have also shown that telephone contact with an ex-smoker can have a positive effect on increasing the proportion of people who are able to quit over the long term. There have also been some encouraging results from studies that have looked at personalised feedback about smoking and a personalised self-help manual.
2. Behavioural treatments
These are more intensive approaches that combine assessment and advice with help on people increasing their motivation and skills to resist the urge to light up and to cope with cravings. These behavioural treatments often involve the smoker joining a ‘Quit Smoking’ group or similar sort of programme where they work alone or with others, with a specially trained therapist. Study results show that about one person in seven is able to abstain for at least six months after taking part.
3. Nicotine replacement therapy (NRT)
NRT works by providing a source of nicotine after the person has stopped smoking, such as nicotine patches. This can be an effective method of reducing withdrawal symptoms and the cravings to smoke. Smokers get used to not having cigarettes, while still having a source of nicotine which they then slowly cut down. With this type of treatment, about 10 per cent of people stop smoking for more than one year (although figures vary), and for every 20 people who use NRT one will become a long term quitter.
Other types of nicotine therapy are available - nicotine gum, lozenges, nasal spray, sublingual (under the tongue) tablets and the nicotine 'inhaler'. Some recent studies have looked at combination treatment, which combines patches and gum and these seem to be even more effective than patches alone.
4. Other medicines
Bupropion (Zyban) and Varenicline (Champix) are other medicines which can help a person stop a nicotine habit. They may be preferred by people who would rather not use nicotine replacement therapy (NRT) or who suffer side effects.
Bupropion acts on the dopamine system in the brain to help reduce withdrawal symptoms and cravings (and also therefore acts as an antidepressant) . Generally, people taking this medication find that when they stop smoking, the withdrawal symptoms and cravings are much easier to deal with. As with any medicine there may be side effects – for example, some people complain they get a dry mouth and others have trouble sleeping, so it isn't suitable for everyone. For every 15 people who use bupropion, one will become a long term quitter.
Varenicline provides a constant low level stimulation of the nicotine receptors in the brain and makes cigarettes taste awful so the smoker they can’t see the point of taking them as there is no nicotine ‘hit’. For every 8 people who use varenicline one will become a long term quitter.
Remember, always consult your doctor first.
(Data from the Cochrane Review 2007).
The success rates quoted above are for when one medication is used at a time. It’s now known that if two different medicines are used in combination, success rates may be higher.
Friday, December 31, 2010
Effect of various drugs on driving
Effect of various drugs on driving- This does not need to be in English to be effective.
Thursday, December 30, 2010
Political views 'hard-wired' into your brain
Tories may be born not made, claims a study that suggests people with right wing views have a larger area of the brain associated with fear. The brains of MPs and students were examined.
By Richard Alleyne, Science Correspondent 5:00PM GMT 28 Dec 2010
Scientists have found that people with conservative views have brains with larger amygdalas, almond shaped areas in the centre of the brain often associated with anxiety and emotions. On the otherhand, they have a smaller anterior cingulate, an area at the front of the brain associated with courage and looking on the bright side of life. The "exciting" correlation was found by scientists at University College London who scanned the brains of two members of parliament and a number of students.
They found that the size of the two areas of the brain directly related to the political views of the volunteers. However as they were all adults it was hard to say whether their brains had been born that way or had developed through experience. Prof Geraint Rees, who led the research, said: "We were very surprised to find that there was an area of the brain that we could predict political attitude. "It is very surprising because it does suggest there is something about political attitude that is encoded in our brain structure through our experience or that there is something in our brain structure that determines or results in political attitude."
Prof Rees and his team, who carried out the research for the Today programme on BBC Radio 4, looked at the brain make up of the Labour MP Stephen Pound and Alan Duncan, the Conservative Minister of State for International Development using a scanner. They also questioned a further 90 students, who had already been scanned for other studies, about their political views.
The results, which will be published next year, back up a study that showed that some people were born with a "Liberal Gene" that makes people more likely to seek out less conventional political views. The gene, a neurotransmitter in the brain called DRD4, could even be stimulated by the novelty value of radical opinions, claimed the researchers at the University of California
By Richard Alleyne, Science Correspondent 5:00PM GMT 28 Dec 2010
Scientists have found that people with conservative views have brains with larger amygdalas, almond shaped areas in the centre of the brain often associated with anxiety and emotions. On the otherhand, they have a smaller anterior cingulate, an area at the front of the brain associated with courage and looking on the bright side of life. The "exciting" correlation was found by scientists at University College London who scanned the brains of two members of parliament and a number of students.
They found that the size of the two areas of the brain directly related to the political views of the volunteers. However as they were all adults it was hard to say whether their brains had been born that way or had developed through experience. Prof Geraint Rees, who led the research, said: "We were very surprised to find that there was an area of the brain that we could predict political attitude. "It is very surprising because it does suggest there is something about political attitude that is encoded in our brain structure through our experience or that there is something in our brain structure that determines or results in political attitude."
Prof Rees and his team, who carried out the research for the Today programme on BBC Radio 4, looked at the brain make up of the Labour MP Stephen Pound and Alan Duncan, the Conservative Minister of State for International Development using a scanner. They also questioned a further 90 students, who had already been scanned for other studies, about their political views.
The results, which will be published next year, back up a study that showed that some people were born with a "Liberal Gene" that makes people more likely to seek out less conventional political views. The gene, a neurotransmitter in the brain called DRD4, could even be stimulated by the novelty value of radical opinions, claimed the researchers at the University of California
Wednesday, December 29, 2010
Tuesday, December 28, 2010
In Map of Brain Junction, Avenues to Answers
By NICHOLAS WADE
Working with human brain tissue removed in surgery, researchers have identified the components of a critical part of the brain’s architecture: the synapse, or junction where one neuron makes a connection with another.
The work should help in understanding how the synapse works in laying down memories, as well as the basis of the many diseases that turn out to be caused by defects in the synapse’s delicate machinery.
The research team, led by Seth Grant of the Sanger Institute near Cambridge, England, compiled the first exact inventory of all the protein components of the synaptic information-processing machinery. No fewer than 1,461 proteins are involved in this biological machinery, they report in the current issue of Nature Neuroscience.
They have tied their catalog into the human genome sequence, connecting each protein to the gene that contains instructions for making it. This has allowed them to compare their findings in humans with other species whose genomes have been sequenced, such as the Neanderthals, who “would have suffered from the same range of psychiatric disease as humans,” Dr. Grant said.
Each neuron in the human brain makes an average 1,000 or so connections with other neurons. There are 100 billion neurons, so the brain probably contains 100 trillion synapses, its most critical working part.
At the side of a synapse that belongs to the transmitting neuron, an electrical signal arrives and releases packets of chemicals. The chemicals diffuse quickly across the minute gap between the neurons and dock with receptors on the surface of the receiving neuron.
These receptors feed the signals they receive to a delicate complex of protein-based machines that process and store the information.
The complex of proteins involved in this information processing is known to neuroanatomists as the post-synaptic density, because the proteins stick together as a visible blob, but the name does scant justice to its critical function.
The 1,461 genes that specify these synaptic proteins constitute more than 7 percent of the human genome’s 20,000 protein-coding genes, an indication of the synapse’s complexity and importance.
Dr. Grant believes that the proteins are probably linked together to form several biological machines that process the information and change the physical properties of the neuron as a way of laying down a memory.
The tolerances of these machines seem to be very fine because almost any mutation in the underlying genes leads to a misshapen protein and, consequently, to disease. Looking through a standard list of Mendelian diseases, which are those caused by alterations in a single gene, the Sanger team found that mutations in 169 of the synaptic genes led to 269 different human diseases.
The new catalog of synaptic proteins “should open a major new window in mental disease,” said Jeffrey Noebels, an expert on the genetics of epilepsy at the Baylor College of Medicine. “We can go in there and systematically look for disease pathways and therefore druggable targets.”
Mendelian diseases, the ones that Dr. Grant has linked to his set of synaptic genes, are mostly rare and obscure, but they may turn out to overlap with the common mental diseases in terms of their symptoms and causative pathways, in which case some treatments might overlap too.
The brain tissue analyzed by Dr. Grant’s team was extracted by a surgeon, Ian Whittle of Edinburgh University. To reach certain regions deep in the brain he had to remove a thin tube of tissue which, with the patients’ consent, he froze immediately and sent to Dr. Grant.
Working with human brain tissue removed in surgery, researchers have identified the components of a critical part of the brain’s architecture: the synapse, or junction where one neuron makes a connection with another.
The work should help in understanding how the synapse works in laying down memories, as well as the basis of the many diseases that turn out to be caused by defects in the synapse’s delicate machinery.
The research team, led by Seth Grant of the Sanger Institute near Cambridge, England, compiled the first exact inventory of all the protein components of the synaptic information-processing machinery. No fewer than 1,461 proteins are involved in this biological machinery, they report in the current issue of Nature Neuroscience.
They have tied their catalog into the human genome sequence, connecting each protein to the gene that contains instructions for making it. This has allowed them to compare their findings in humans with other species whose genomes have been sequenced, such as the Neanderthals, who “would have suffered from the same range of psychiatric disease as humans,” Dr. Grant said.
Each neuron in the human brain makes an average 1,000 or so connections with other neurons. There are 100 billion neurons, so the brain probably contains 100 trillion synapses, its most critical working part.
At the side of a synapse that belongs to the transmitting neuron, an electrical signal arrives and releases packets of chemicals. The chemicals diffuse quickly across the minute gap between the neurons and dock with receptors on the surface of the receiving neuron.
These receptors feed the signals they receive to a delicate complex of protein-based machines that process and store the information.
The complex of proteins involved in this information processing is known to neuroanatomists as the post-synaptic density, because the proteins stick together as a visible blob, but the name does scant justice to its critical function.
The 1,461 genes that specify these synaptic proteins constitute more than 7 percent of the human genome’s 20,000 protein-coding genes, an indication of the synapse’s complexity and importance.
Dr. Grant believes that the proteins are probably linked together to form several biological machines that process the information and change the physical properties of the neuron as a way of laying down a memory.
The tolerances of these machines seem to be very fine because almost any mutation in the underlying genes leads to a misshapen protein and, consequently, to disease. Looking through a standard list of Mendelian diseases, which are those caused by alterations in a single gene, the Sanger team found that mutations in 169 of the synaptic genes led to 269 different human diseases.
The new catalog of synaptic proteins “should open a major new window in mental disease,” said Jeffrey Noebels, an expert on the genetics of epilepsy at the Baylor College of Medicine. “We can go in there and systematically look for disease pathways and therefore druggable targets.”
Mendelian diseases, the ones that Dr. Grant has linked to his set of synaptic genes, are mostly rare and obscure, but they may turn out to overlap with the common mental diseases in terms of their symptoms and causative pathways, in which case some treatments might overlap too.
The brain tissue analyzed by Dr. Grant’s team was extracted by a surgeon, Ian Whittle of Edinburgh University. To reach certain regions deep in the brain he had to remove a thin tube of tissue which, with the patients’ consent, he froze immediately and sent to Dr. Grant.
Monday, December 27, 2010
Enlarged brain region found in toddlers with autism: study
Instructional assistant Jessica Reeder touches her nose to get Jacob Day, who is autistic, to focus his attention on her during a therapy session in 2007. Toddlers with autism seem more likely to have a larger area of the brain linked with facial recognition and emotion, a brain scanning study suggests.Using MRI brain scans, researchers found the brain's amygdala region was on average 13 per cent larger in toddlers with autism compared with children without the disorder.
The study by Dr. Joseph Piven, a psychiatry professor at the University of North Carolina at Chapel Hill and his colleagues appears in the May issue of the Archives of General Psychiatry.Autism, or autistic spectrum disorder, is a neurodevelopmental disorder that affects aptitude for communication and personal interaction.The structural abnormality appeared to be linked with the ability to recognize faces and emotions and joint attention — taking cues from an adult's gaze to pay attention to an object of interest, the researchers said.
The findings build on previous research showing the amygdala is involved in social and emotional perception in autism.The MRI scans are currently a research tool and not a diagnostic one. But by understanding the pattern of early brain changes in autism, researchers hope to detect the disorder earlier, with the aim of predicting who is likely to benefit from early intervention.
Pinpointing growth time
In the study, the researchers took MRI scans of 50 autistic children and 33 children without the condition and gave tests to look for features of autism at age two (the earliest age the condition is generally diagnosed) and at age four.
The researchers took age, sex and IQ into account.
Scientists are trying to find out when the amygdala starts to grow larger in people with autism, and the results of this study suggest it happens by age two.
These findings suggest that, consistent with a previous report of head circumference growth rates in autism and studies of amygdala volume in childhood, amygdala growth trajectories are accelerated before age two years in autism and remain enlarged during early childhood," the study's authors wrote.The team continues to follow study participants to determine whether amygdala growth rates continue at the same rate, speed up or slow down in children with autism after age four.
The study was funded by the U.S. National Institutes of Health.
Read more: http://www.cbc.ca/health/story/2009/05/05/autism-brain-amygdala.html#ixzz19Kf4mHlt
The study by Dr. Joseph Piven, a psychiatry professor at the University of North Carolina at Chapel Hill and his colleagues appears in the May issue of the Archives of General Psychiatry.Autism, or autistic spectrum disorder, is a neurodevelopmental disorder that affects aptitude for communication and personal interaction.The structural abnormality appeared to be linked with the ability to recognize faces and emotions and joint attention — taking cues from an adult's gaze to pay attention to an object of interest, the researchers said.
The findings build on previous research showing the amygdala is involved in social and emotional perception in autism.The MRI scans are currently a research tool and not a diagnostic one. But by understanding the pattern of early brain changes in autism, researchers hope to detect the disorder earlier, with the aim of predicting who is likely to benefit from early intervention.
Pinpointing growth time
In the study, the researchers took MRI scans of 50 autistic children and 33 children without the condition and gave tests to look for features of autism at age two (the earliest age the condition is generally diagnosed) and at age four.
The researchers took age, sex and IQ into account.
Scientists are trying to find out when the amygdala starts to grow larger in people with autism, and the results of this study suggest it happens by age two.
These findings suggest that, consistent with a previous report of head circumference growth rates in autism and studies of amygdala volume in childhood, amygdala growth trajectories are accelerated before age two years in autism and remain enlarged during early childhood," the study's authors wrote.The team continues to follow study participants to determine whether amygdala growth rates continue at the same rate, speed up or slow down in children with autism after age four.
The study was funded by the U.S. National Institutes of Health.
Read more: http://www.cbc.ca/health/story/2009/05/05/autism-brain-amygdala.html#ixzz19Kf4mHlt
Damasio, one of the world experts comments on Consciousness
Neuroscientist Dr. Antonio Damasio has taken on the big questions — of consciousness, of self and of the nature of the mind — both in experiments and in bold, unifying scientific theories.
His first non-specialist book, Descartes' Error, which was published in 1994, was widely considered to revolutionize the understanding of the critical role emotion plays in human rationality and decision-making. His latest, Self Comes to Mind, explores the way humans — and some animals — develop a sense of self, and examines what this tells us about the nature of consciousness. Not surprisingly, Damasio says, emotion plays a big role. (More on Time.com: Why That Rich Guy is Being So Nice to You)
I had a fascinating and contemplative conversation with Damasio in his elegant mid-century modern Manhattan pied-a-terre, looking out on a balcony over the Upper East Side. Here's what we discussed.
Why is emotion so important in developing and generating a self?
Because when you look at the self and when you look at emotions, you see that they have, in the end, the same reason to be — and that reason is to regulate life.
Emotion is one of the most perfect instruments that evolved to make life regulation better. It allows us to cope with threats and with opportunities. And it turns out that the role of self is exactly the same.
We have developed a mind in order to get a better picture of the world, which is useful for survival. The self is sort of a passport into a concern for the organism.
Why do you think that we have this long philosophical history that sees emotions as irrational, as not supporting life and as getting in our way?
You can have fear or joy totally triggered at the non-conscious level. You don't need to think in order to get those emotions. But in order to decide where to go for dinner, you need to think. (More on Time.com: New Version of an Old Drug Could Treat Autism (and Addiction Too))
But, as you showed, you need to feel, too.
Exactly. [So] why did people fall into that error? Because it seemed on the surface that reason was something different and something better. It was time to get rid of things that made us not rational. [However], little by little, one tumbles to the fact that emotions have their own reasons and that's where evolution comes in handy.
If you don't have a perspective that is evolutionary, you don't know why on earth you have emotions: why fear, why have compassion? Well, when you start looking through the lens of evolution you realize that all those things have prevailed over all this long, history precisely because they are valuable.
Obviously, if you are going to be threatened by something right now, if you automatically engage a program to get you away from here, that is as rational as one can get. Emotions have their reasons, reasons have their reasons, and it turns out reason generally works better when it is aided by emotion.
You've looked at this in terms of brain lesions, with people who had damage to regions associated with emotion.
Correct. What brain lesions show very clearly is that in certain circumstances if people are deprived of all they have learned emotionally over a lifetime, they actually are not very good with their rationality alone.
So Star Trek's Mr. Spock would actually be either a sociopath or...?
He would not be fit by today's standards. To use the same analogy, when you have to decide where you're going to go out to dinner, it will come in handy to have guidelines acquired by your experience of going to restaurants. That is going to make you reason through the problem faster and more accurately. The emotion is aiding your rationality. (More on Time.com: 'Love Hormone' Oxytocin Enhances Men's Memories of Mom — Good or Bad)
And this is why when you're depressed, it becomes impossible to decide what to do because you can't tell whether anything is good or bad.
Yes, everything is neutral. Everything is equalized. [And then you have to] rely on making lists and finding out what's the teeny difference between this and that, which is of course very tedious.
[However], the fact that emotion is so valuable in rational decision-making does not mean that emotion is always good. If you have to decide something in an emergency and you start screaming bloody murder, you may not be able to think through the problem. That's where this whole idea of emotion being bad came from.
So, how do emotions help you generate a self?
In the new book, I have this whole discussion about the notion of primordial feelings. [These] are feelings generated at low levels in the brain, in the brainstem, telling you this very simple truth: I am alive, there is a body here.
And that primordial feeling is in the background of all consciousness?
It's in the background. It doesn't need to be engaged by another object. The object is your own organism, your own life in that organism. Primordial feelings are very important because they're the first step into [having a] self.
So I feel, therefore I am?
Exactly. If the first step of consciousness is having a feeling that you have your own body and are alive, the second step is having the feeling that your body has been changed by an interaction with an object.
So let's take something like a cat. The cat has maps of its body in its brain. The cat can also have emotions. But can a cat have feelings — the conscious perception of the experience of emotion?
Oh, yes, of course. The next question should be how do you know? The answer to that is a little bit by triangulation. Look at the cat or the dog and ask yourself the following question, do they behave in some circumstances the way we would? Yes. (More on Time.com: The Lab Rat: Can a Simple Writing Exercise Close the Gender Gap?)
Do they have a brain that resembles ours in its organization? They do. Then, I think you have to venture the possibility that they have minds, with feelings, in fact they have a self. With the dog its very easy, and with cats too.
When you look at human beings, we have something that is totally distinctive and it's not just language. Language is an easy target. But the other distinctions for me happen at the level of [what I call] the autobiographical self.
I was just going to ask you about that. Do cats have autobiographical selves that record the stories of their lives?
I think a very modest one. And dogs also have a modest, autobiographical self.
So they remember, "I went to the vet, and it sucked."
Probably, they don't picture it. [But] they will remember something.
If you try to put the cat in the carrier again, it's not going to want to get in there.
Exactly. Even the fact that it has a special relationship to the owner means that there is an autobiographical relationship that only has been learned as part of the story of that particular animal. But how much they tell that story to themselves is a different problem. Whereas we clearly do. We constantly tell our story to ourselves and we create reinterpretations and we edit. (More on Time.com: Are Stoners Really Dumb, or Do They Just Think They Are?)
That's very natural because we are born storytellers. But there's something in that autobiographical self that I think should be emphasized, which is the fact that it's not just about the past. It's about the past and about the anticipated future. We are constantly caught in a present that is moving in time. Behind it is the lived past and in front of it are the things we have planned.
So when you ask me, well, do other species have feelings, I'd say, yes. But do other species have, for example, the same degree of suffering that we have when we have a loss? They probably have some, but our losses are amplified. If we lose somebody that we love, its not just losing there and then. It is losing that person in the perspective of the past and also the perspective of what you thought would happen in the future. That is a colossal difference.
Some people say that if you lived for centuries or forever, you wouldn't really be the same self.
I think that that's a different issue. Because I think actually it will be easier to find ways in which we could live forever than to find ways in which we could, say, download our self into a computer.
Would that not work because of emotions and the need for a body?
It may well be. First of all, the idea of making us live forever, I think is quite possible. It's really a matter of how you do the reverse engineering of our biology enough to have the ability to control it. I think that's a distinct possibility.
The downloading depends on how much detail we can get into the understanding of the signals that are going through and the incredible riches of brain circuitry. We could get potentially to a point where we would have something that you could transfer into another medium. I don't think it's impossible; I just find it extremely unlikely because of the complexity.
Now say you could have yourself downloaded into a computer. Would it be you or would it just think that it was you?
I don't think it would be me, because the me is so tied to my body. (More on Time.com: Mind Reading: Terrorism Expert Jessica Stern on Her Own Terror and Trauma)
But it would think it was you.
Yeah, it might.
In terms of the anatomical construction of the self in the brain, the brainstem is important. What other key areas matter?
In the brainstem, [self-related regions include a] variety of nuclei — especially the nuclei that are related to our life regulation. In the cerebral cortex, there are certain regions that are very, very critical.
Especially in relation to consciousness, there are certain [regions called the] posteromedial cortices. We have every reason to believe that they play a very important role.
And how do we know that?
We know that through lesions. Also, for example, people with Alzheimer's disease very late in the disease generally get to be almost vegetative in the way they look. [Their selves have been worn away.] We know that this is one of the areas where anesthetics work very powerfully. And we know that this is one of the areas in people in a vegetative state or coma, the ones that are lucky enough to wake up from that, this is the first region that recovers cerebral blood flow.
I once had a very strange experience at the dentist on nitrous oxide. It was like my self dissolved, and it was terrifying — I didn't understand the concept of a dentist or where or what I was.
Interesting. It all has to do with the induction of the anesthetic effect, because a lot of the times if one goes through anesthesia, your — literally — your self goes. And you don't know anything because the whole thing about consciousness is that it is our means of knowing. No consciousness, no knowledge — you don't know that you are or who anybody else is, you don't know that there's a world. (More on Time.com: Is a Wandering Mind an Unhappy One?)
How do you think the Internet is affecting consciousness?
I think that there are certain things that the Internet is doing to our minds that have to do with the speed at which we process information — especially for children. They are developing and they are doing all this multitasking and we don't know if that's going to be good or bad. In a way it's likely it to be good because it expands the speed of operation. The question is whether there will be a tradeoff in terms of what you remember.
Read more: http://healthland.time.com/2010/12/06/mind-reading-how-humans-%e2%80%94-and-some-animals-%e2%80%94-develop-a-sense-of-self/#ixzz19FwI10ii
His first non-specialist book, Descartes' Error, which was published in 1994, was widely considered to revolutionize the understanding of the critical role emotion plays in human rationality and decision-making. His latest, Self Comes to Mind, explores the way humans — and some animals — develop a sense of self, and examines what this tells us about the nature of consciousness. Not surprisingly, Damasio says, emotion plays a big role. (More on Time.com: Why That Rich Guy is Being So Nice to You)
I had a fascinating and contemplative conversation with Damasio in his elegant mid-century modern Manhattan pied-a-terre, looking out on a balcony over the Upper East Side. Here's what we discussed.
Why is emotion so important in developing and generating a self?
Because when you look at the self and when you look at emotions, you see that they have, in the end, the same reason to be — and that reason is to regulate life.
Emotion is one of the most perfect instruments that evolved to make life regulation better. It allows us to cope with threats and with opportunities. And it turns out that the role of self is exactly the same.
We have developed a mind in order to get a better picture of the world, which is useful for survival. The self is sort of a passport into a concern for the organism.
Why do you think that we have this long philosophical history that sees emotions as irrational, as not supporting life and as getting in our way?
You can have fear or joy totally triggered at the non-conscious level. You don't need to think in order to get those emotions. But in order to decide where to go for dinner, you need to think. (More on Time.com: New Version of an Old Drug Could Treat Autism (and Addiction Too))
But, as you showed, you need to feel, too.
Exactly. [So] why did people fall into that error? Because it seemed on the surface that reason was something different and something better. It was time to get rid of things that made us not rational. [However], little by little, one tumbles to the fact that emotions have their own reasons and that's where evolution comes in handy.
If you don't have a perspective that is evolutionary, you don't know why on earth you have emotions: why fear, why have compassion? Well, when you start looking through the lens of evolution you realize that all those things have prevailed over all this long, history precisely because they are valuable.
Obviously, if you are going to be threatened by something right now, if you automatically engage a program to get you away from here, that is as rational as one can get. Emotions have their reasons, reasons have their reasons, and it turns out reason generally works better when it is aided by emotion.
You've looked at this in terms of brain lesions, with people who had damage to regions associated with emotion.
Correct. What brain lesions show very clearly is that in certain circumstances if people are deprived of all they have learned emotionally over a lifetime, they actually are not very good with their rationality alone.
So Star Trek's Mr. Spock would actually be either a sociopath or...?
He would not be fit by today's standards. To use the same analogy, when you have to decide where you're going to go out to dinner, it will come in handy to have guidelines acquired by your experience of going to restaurants. That is going to make you reason through the problem faster and more accurately. The emotion is aiding your rationality. (More on Time.com: 'Love Hormone' Oxytocin Enhances Men's Memories of Mom — Good or Bad)
And this is why when you're depressed, it becomes impossible to decide what to do because you can't tell whether anything is good or bad.
Yes, everything is neutral. Everything is equalized. [And then you have to] rely on making lists and finding out what's the teeny difference between this and that, which is of course very tedious.
[However], the fact that emotion is so valuable in rational decision-making does not mean that emotion is always good. If you have to decide something in an emergency and you start screaming bloody murder, you may not be able to think through the problem. That's where this whole idea of emotion being bad came from.
So, how do emotions help you generate a self?
In the new book, I have this whole discussion about the notion of primordial feelings. [These] are feelings generated at low levels in the brain, in the brainstem, telling you this very simple truth: I am alive, there is a body here.
And that primordial feeling is in the background of all consciousness?
It's in the background. It doesn't need to be engaged by another object. The object is your own organism, your own life in that organism. Primordial feelings are very important because they're the first step into [having a] self.
So I feel, therefore I am?
Exactly. If the first step of consciousness is having a feeling that you have your own body and are alive, the second step is having the feeling that your body has been changed by an interaction with an object.
So let's take something like a cat. The cat has maps of its body in its brain. The cat can also have emotions. But can a cat have feelings — the conscious perception of the experience of emotion?
Oh, yes, of course. The next question should be how do you know? The answer to that is a little bit by triangulation. Look at the cat or the dog and ask yourself the following question, do they behave in some circumstances the way we would? Yes. (More on Time.com: The Lab Rat: Can a Simple Writing Exercise Close the Gender Gap?)
Do they have a brain that resembles ours in its organization? They do. Then, I think you have to venture the possibility that they have minds, with feelings, in fact they have a self. With the dog its very easy, and with cats too.
When you look at human beings, we have something that is totally distinctive and it's not just language. Language is an easy target. But the other distinctions for me happen at the level of [what I call] the autobiographical self.
I was just going to ask you about that. Do cats have autobiographical selves that record the stories of their lives?
I think a very modest one. And dogs also have a modest, autobiographical self.
So they remember, "I went to the vet, and it sucked."
Probably, they don't picture it. [But] they will remember something.
If you try to put the cat in the carrier again, it's not going to want to get in there.
Exactly. Even the fact that it has a special relationship to the owner means that there is an autobiographical relationship that only has been learned as part of the story of that particular animal. But how much they tell that story to themselves is a different problem. Whereas we clearly do. We constantly tell our story to ourselves and we create reinterpretations and we edit. (More on Time.com: Are Stoners Really Dumb, or Do They Just Think They Are?)
That's very natural because we are born storytellers. But there's something in that autobiographical self that I think should be emphasized, which is the fact that it's not just about the past. It's about the past and about the anticipated future. We are constantly caught in a present that is moving in time. Behind it is the lived past and in front of it are the things we have planned.
So when you ask me, well, do other species have feelings, I'd say, yes. But do other species have, for example, the same degree of suffering that we have when we have a loss? They probably have some, but our losses are amplified. If we lose somebody that we love, its not just losing there and then. It is losing that person in the perspective of the past and also the perspective of what you thought would happen in the future. That is a colossal difference.
Some people say that if you lived for centuries or forever, you wouldn't really be the same self.
I think that that's a different issue. Because I think actually it will be easier to find ways in which we could live forever than to find ways in which we could, say, download our self into a computer.
Would that not work because of emotions and the need for a body?
It may well be. First of all, the idea of making us live forever, I think is quite possible. It's really a matter of how you do the reverse engineering of our biology enough to have the ability to control it. I think that's a distinct possibility.
The downloading depends on how much detail we can get into the understanding of the signals that are going through and the incredible riches of brain circuitry. We could get potentially to a point where we would have something that you could transfer into another medium. I don't think it's impossible; I just find it extremely unlikely because of the complexity.
Now say you could have yourself downloaded into a computer. Would it be you or would it just think that it was you?
I don't think it would be me, because the me is so tied to my body. (More on Time.com: Mind Reading: Terrorism Expert Jessica Stern on Her Own Terror and Trauma)
But it would think it was you.
Yeah, it might.
In terms of the anatomical construction of the self in the brain, the brainstem is important. What other key areas matter?
In the brainstem, [self-related regions include a] variety of nuclei — especially the nuclei that are related to our life regulation. In the cerebral cortex, there are certain regions that are very, very critical.
Especially in relation to consciousness, there are certain [regions called the] posteromedial cortices. We have every reason to believe that they play a very important role.
And how do we know that?
We know that through lesions. Also, for example, people with Alzheimer's disease very late in the disease generally get to be almost vegetative in the way they look. [Their selves have been worn away.] We know that this is one of the areas where anesthetics work very powerfully. And we know that this is one of the areas in people in a vegetative state or coma, the ones that are lucky enough to wake up from that, this is the first region that recovers cerebral blood flow.
I once had a very strange experience at the dentist on nitrous oxide. It was like my self dissolved, and it was terrifying — I didn't understand the concept of a dentist or where or what I was.
Interesting. It all has to do with the induction of the anesthetic effect, because a lot of the times if one goes through anesthesia, your — literally — your self goes. And you don't know anything because the whole thing about consciousness is that it is our means of knowing. No consciousness, no knowledge — you don't know that you are or who anybody else is, you don't know that there's a world. (More on Time.com: Is a Wandering Mind an Unhappy One?)
How do you think the Internet is affecting consciousness?
I think that there are certain things that the Internet is doing to our minds that have to do with the speed at which we process information — especially for children. They are developing and they are doing all this multitasking and we don't know if that's going to be good or bad. In a way it's likely it to be good because it expands the speed of operation. The question is whether there will be a tradeoff in terms of what you remember.
Read more: http://healthland.time.com/2010/12/06/mind-reading-how-humans-%e2%80%94-and-some-animals-%e2%80%94-develop-a-sense-of-self/#ixzz19FwI10ii
Sunday, December 26, 2010
In Map of Brain Junction, Avenues to Answers
By NICHOLAS WADE
Working with human brain tissue removed in surgery, researchers have identified the components of a critical part of the brain’s architecture: the synapse, or junction where one neuron makes a connection with another.
The work should help in understanding how the synapse works in laying down memories, as well as the basis of the many diseases that turn out to be caused by defects in the synapse’s delicate machinery.
The research team, led by Seth Grant of the Sanger Institute near Cambridge, England, compiled the first exact inventory of all the protein components of the synaptic information-processing machinery. No fewer than 1,461 proteins are involved in this biological machinery, they report in the current issue of Nature Neuroscience.
They have tied their catalog into the human genome sequence, connecting each protein to the gene that contains instructions for making it. This has allowed them to compare their findings in humans with other species whose genomes have been sequenced, such as the Neanderthals, who “would have suffered from the same range of psychiatric disease as humans,” Dr. Grant said.
Each neuron in the human brain makes an average 1,000 or so connections with other neurons. There are 100 billion neurons, so the brain probably contains 100 trillion synapses, its most critical working part.
At the side of a synapse that belongs to the transmitting neuron, an electrical signal arrives and releases packets of chemicals. The chemicals diffuse quickly across the minute gap between the neurons and dock with receptors on the surface of the receiving neuron.
These receptors feed the signals they receive to a delicate complex of protein-based machines that process and store the information.
The complex of proteins involved in this information processing is known to neuroanatomists as the post-synaptic density, because the proteins stick together as a visible blob, but the name does scant justice to its critical function.
The 1,461 genes that specify these synaptic proteins constitute more than 7 percent of the human genome’s 20,000 protein-coding genes, an indication of the synapse’s complexity and importance.
Dr. Grant believes that the proteins are probably linked together to form several biological machines that process the information and change the physical properties of the neuron as a way of laying down a memory.
The tolerances of these machines seem to be very fine because almost any mutation in the underlying genes leads to a misshapen protein and, consequently, to disease. Looking through a standard list of Mendelian diseases, which are those caused by alterations in a single gene, the Sanger team found that mutations in 169 of the synaptic genes led to 269 different human diseases.
The new catalog of synaptic proteins “should open a major new window in mental disease,” said Jeffrey Noebels, an expert on the genetics of epilepsy at the Baylor College of Medicine. “We can go in there and systematically look for disease pathways and therefore druggable targets.”
Mendelian diseases, the ones that Dr. Grant has linked to his set of synaptic genes, are mostly rare and obscure, but they may turn out to overlap with the common mental diseases in terms of their symptoms and causative pathways, in which case some treatments might overlap too.
The brain tissue analyzed by Dr. Grant’s team was extracted by a surgeon, Ian Whittle of Edinburgh University. To reach certain regions deep in the brain he had to remove a thin tube of tissue which, with the patients’ consent, he froze immediately and sent to Dr. Grant.
Working with human brain tissue removed in surgery, researchers have identified the components of a critical part of the brain’s architecture: the synapse, or junction where one neuron makes a connection with another.
The work should help in understanding how the synapse works in laying down memories, as well as the basis of the many diseases that turn out to be caused by defects in the synapse’s delicate machinery.
The research team, led by Seth Grant of the Sanger Institute near Cambridge, England, compiled the first exact inventory of all the protein components of the synaptic information-processing machinery. No fewer than 1,461 proteins are involved in this biological machinery, they report in the current issue of Nature Neuroscience.
They have tied their catalog into the human genome sequence, connecting each protein to the gene that contains instructions for making it. This has allowed them to compare their findings in humans with other species whose genomes have been sequenced, such as the Neanderthals, who “would have suffered from the same range of psychiatric disease as humans,” Dr. Grant said.
Each neuron in the human brain makes an average 1,000 or so connections with other neurons. There are 100 billion neurons, so the brain probably contains 100 trillion synapses, its most critical working part.
At the side of a synapse that belongs to the transmitting neuron, an electrical signal arrives and releases packets of chemicals. The chemicals diffuse quickly across the minute gap between the neurons and dock with receptors on the surface of the receiving neuron.
These receptors feed the signals they receive to a delicate complex of protein-based machines that process and store the information.
The complex of proteins involved in this information processing is known to neuroanatomists as the post-synaptic density, because the proteins stick together as a visible blob, but the name does scant justice to its critical function.
The 1,461 genes that specify these synaptic proteins constitute more than 7 percent of the human genome’s 20,000 protein-coding genes, an indication of the synapse’s complexity and importance.
Dr. Grant believes that the proteins are probably linked together to form several biological machines that process the information and change the physical properties of the neuron as a way of laying down a memory.
The tolerances of these machines seem to be very fine because almost any mutation in the underlying genes leads to a misshapen protein and, consequently, to disease. Looking through a standard list of Mendelian diseases, which are those caused by alterations in a single gene, the Sanger team found that mutations in 169 of the synaptic genes led to 269 different human diseases.
The new catalog of synaptic proteins “should open a major new window in mental disease,” said Jeffrey Noebels, an expert on the genetics of epilepsy at the Baylor College of Medicine. “We can go in there and systematically look for disease pathways and therefore druggable targets.”
Mendelian diseases, the ones that Dr. Grant has linked to his set of synaptic genes, are mostly rare and obscure, but they may turn out to overlap with the common mental diseases in terms of their symptoms and causative pathways, in which case some treatments might overlap too.
The brain tissue analyzed by Dr. Grant’s team was extracted by a surgeon, Ian Whittle of Edinburgh University. To reach certain regions deep in the brain he had to remove a thin tube of tissue which, with the patients’ consent, he froze immediately and sent to Dr. Grant.
Saturday, December 25, 2010
Friday, December 24, 2010
New solar fuel machine 'mimics plant life
New solar fuel machine 'mimics plant life'By Neil Bowdler
In the prototype, sunlight heats a ceria cylinder which breaks down water or carbon dioxide A prototype solar device has been unveiled which mimics plant life, turning the Sun's energy into fuel. The machine uses the Sun's rays and a metal oxide called ceria to break down carbon dioxide or water into fuels which can be stored and transported.
Conventional photovoltaic panels must use the electricity they generate in situ, and cannot deliver power at night. Details are published in the journal Science.
The prototype, which was devised by researchers in the US and Switzerland, uses a quartz window and cavity to concentrate sunlight into a cylinder lined with cerium oxide, also known as ceria. Ceria has a natural propensity to exhale oxygen as it heats up and inhale it as it cools down.If as in the prototype, carbon dioxide and/or water are pumped into the vessel, the ceria will rapidly strip the oxygen from them as it cools, creating hydrogen and/or carbon monoxide.Hydrogen produced could be used to fuel hydrogen fuel cells in cars, for example, while a combination of hydrogen and carbon monoxide can be used to create "syngas" for fuel.
It is this harnessing of ceria's properties in the solar reactor which represents the major breakthrough, say the inventors of the device. They also say the metal is readily available, being the most abundant of the "rare-earth" metals. Methane can be produced using the same machine, they say.
The prototype is grossly inefficient, the fuel created harnessing only between 0.7% and 0.8% of the solar energy taken into the vessel. Most of the energy is lost through heat loss through the reactor's wall or through the re-radiation of sunlight back through the device's aperture.But the researchers are confident that efficiency rates of up to 19% can be achieved through better insulation and smaller apertures. Such efficiency rates, they say, could make for a viable commercial device."The chemistry of the material is really well suited to this process," says Professor Sossina Haile of the California Institute of Technology (Caltech). "This is the first demonstration of doing the full shebang, running it under (light) photons in a reactor."
She says the reactor could be used to create transportation fuels or be adopted in large-scale energy plants, where solar-sourced power could be available throughout the day and night.
However, she admits the fate of this and other devices in development is tied to whether states adopt a low-carbon policy."It's very much tied to policy. If we had a carbon policy, something like this would move forward a lot more quickly," she told the BBC. It has been suggested that the device mimics plants, which also use carbon dioxide, water and sunlight to create energy as part of the process of photosynthesis. But Professor Haile thinks the analogy is over-simplistic."Yes, the reactor takes in sunlight, we take in carbon dioxide and water and we produce a chemical compound, so in the most generic sense there are these similarities, but I think that's pretty much where the analogy ends." The PS10 solar tower plant near Seville, Spain. Mirrors concentrate the sun's power on to a central tower, driving a steam turbine
Daniel Davies, chief technology officer at the British photovoltaic company Solar Century, said the research was "very exciting"."I guess the question is where you locate it - would you put your solar collector on a roof or would it be better off as a big industrial concern in the Sahara and then shipping the liquid fuel?" he said.Solar technology is moving forward apace but the overriding challenges remain ones of efficiency, economy and storage.
New-generation "solar tower" plants have been built in Spain and the United States which use an array of mirrors to concentrate sunlight onto tower-mounted receivers which drive steam turbines. A new Spanish project will use molten salts to store heat from the Sun for up to 15 hours, so that the plant could potentially operate through the night.
In the prototype, sunlight heats a ceria cylinder which breaks down water or carbon dioxide A prototype solar device has been unveiled which mimics plant life, turning the Sun's energy into fuel. The machine uses the Sun's rays and a metal oxide called ceria to break down carbon dioxide or water into fuels which can be stored and transported.
Conventional photovoltaic panels must use the electricity they generate in situ, and cannot deliver power at night. Details are published in the journal Science.
The prototype, which was devised by researchers in the US and Switzerland, uses a quartz window and cavity to concentrate sunlight into a cylinder lined with cerium oxide, also known as ceria. Ceria has a natural propensity to exhale oxygen as it heats up and inhale it as it cools down.If as in the prototype, carbon dioxide and/or water are pumped into the vessel, the ceria will rapidly strip the oxygen from them as it cools, creating hydrogen and/or carbon monoxide.Hydrogen produced could be used to fuel hydrogen fuel cells in cars, for example, while a combination of hydrogen and carbon monoxide can be used to create "syngas" for fuel.
It is this harnessing of ceria's properties in the solar reactor which represents the major breakthrough, say the inventors of the device. They also say the metal is readily available, being the most abundant of the "rare-earth" metals. Methane can be produced using the same machine, they say.
The prototype is grossly inefficient, the fuel created harnessing only between 0.7% and 0.8% of the solar energy taken into the vessel. Most of the energy is lost through heat loss through the reactor's wall or through the re-radiation of sunlight back through the device's aperture.But the researchers are confident that efficiency rates of up to 19% can be achieved through better insulation and smaller apertures. Such efficiency rates, they say, could make for a viable commercial device."The chemistry of the material is really well suited to this process," says Professor Sossina Haile of the California Institute of Technology (Caltech). "This is the first demonstration of doing the full shebang, running it under (light) photons in a reactor."
She says the reactor could be used to create transportation fuels or be adopted in large-scale energy plants, where solar-sourced power could be available throughout the day and night.
However, she admits the fate of this and other devices in development is tied to whether states adopt a low-carbon policy."It's very much tied to policy. If we had a carbon policy, something like this would move forward a lot more quickly," she told the BBC. It has been suggested that the device mimics plants, which also use carbon dioxide, water and sunlight to create energy as part of the process of photosynthesis. But Professor Haile thinks the analogy is over-simplistic."Yes, the reactor takes in sunlight, we take in carbon dioxide and water and we produce a chemical compound, so in the most generic sense there are these similarities, but I think that's pretty much where the analogy ends." The PS10 solar tower plant near Seville, Spain. Mirrors concentrate the sun's power on to a central tower, driving a steam turbine
Daniel Davies, chief technology officer at the British photovoltaic company Solar Century, said the research was "very exciting"."I guess the question is where you locate it - would you put your solar collector on a roof or would it be better off as a big industrial concern in the Sahara and then shipping the liquid fuel?" he said.Solar technology is moving forward apace but the overriding challenges remain ones of efficiency, economy and storage.
New-generation "solar tower" plants have been built in Spain and the United States which use an array of mirrors to concentrate sunlight onto tower-mounted receivers which drive steam turbines. A new Spanish project will use molten salts to store heat from the Sun for up to 15 hours, so that the plant could potentially operate through the night.
Thursday, December 23, 2010
New Human Species
New Human species
Scientists say an entirely separate type of human identified from bones in Siberia co-existed and interbred with our own species. The ancient humans have been dubbed "Denisovans" after the caves in Siberia where their remains were found. There is also evidence that this population was widespread in Eurasia.
A study in Nature journal shows that Denisovans co-existed with Neanderthals and interbred with our species - perhaps around 50,000 years ago. An international group of researchers sequenced a complete genome from one of the ancient hominins (human-like creatures), based on nuclear DNA extracted from a finger bone.
'Sensational' find
According to the researchers, this provides confirmation there were at least four distinct types of human in existence when anatomically modern humans (Homo sapiens sapiens) first left their African homeland.
DNA from a tooth (pictured) and a finger bone show the Denisovans were a distinct group.Along with modern humans, scientists knew about the Neanderthals and a dwarf human species found on the Indonesian island of Flores nicknamed "The Hobbit". To this list, experts must now add the Denisovans.
The implications of the finding have been described by Professor Chris Stringer of the Natural History Museum in London as "nothing short of sensational".Scientists were able to analyse DNA from a tooth and from a finger bone excavated in the Denisova cave in southern Siberia. The individuals belong to a genetically distinct group of humans that were distantly related to Neanderthals but even more distantly related to us.
The finding adds weight to the theory that a different kind of human could have existed in Eurasia at the same time as our species. Researchers have had enigmatic fossil evidence to support this view but now they have some firm evidence from the genetic study carried out by Professor Svante Paabo of the Max Planck Institute in Leipzig, Germany.
"A species of early human living in Europe evolved," according to Professor Paabo. "There was a western form that was the Neanderthal and an eastern form, the Denisovans."
The study shows that Denisovans interbred with the ancestors of the present day people of the Melanesian region north and north-east of Australia. Melanesian DNA comprises between 4% and 6% Denisovan DNA.
David Reich from the Harvard Medical School, who worked with Svante Paabo on the study, says that the fact that Denisovan genes ended up so far south suggests they were widespread across Eurasia: "These populations must have been spread across thousands and thousands of miles," he told BBC News. One mystery is why the Denisovan genes are unique in modern Melanesians and are not found in other Eurasian groups that have so far been sampled.
Scientists say an entirely separate type of human identified from bones in Siberia co-existed and interbred with our own species. The ancient humans have been dubbed "Denisovans" after the caves in Siberia where their remains were found. There is also evidence that this population was widespread in Eurasia.
A study in Nature journal shows that Denisovans co-existed with Neanderthals and interbred with our species - perhaps around 50,000 years ago. An international group of researchers sequenced a complete genome from one of the ancient hominins (human-like creatures), based on nuclear DNA extracted from a finger bone.
'Sensational' find
According to the researchers, this provides confirmation there were at least four distinct types of human in existence when anatomically modern humans (Homo sapiens sapiens) first left their African homeland.
DNA from a tooth (pictured) and a finger bone show the Denisovans were a distinct group.Along with modern humans, scientists knew about the Neanderthals and a dwarf human species found on the Indonesian island of Flores nicknamed "The Hobbit". To this list, experts must now add the Denisovans.
The implications of the finding have been described by Professor Chris Stringer of the Natural History Museum in London as "nothing short of sensational".Scientists were able to analyse DNA from a tooth and from a finger bone excavated in the Denisova cave in southern Siberia. The individuals belong to a genetically distinct group of humans that were distantly related to Neanderthals but even more distantly related to us.
The finding adds weight to the theory that a different kind of human could have existed in Eurasia at the same time as our species. Researchers have had enigmatic fossil evidence to support this view but now they have some firm evidence from the genetic study carried out by Professor Svante Paabo of the Max Planck Institute in Leipzig, Germany.
"A species of early human living in Europe evolved," according to Professor Paabo. "There was a western form that was the Neanderthal and an eastern form, the Denisovans."
The study shows that Denisovans interbred with the ancestors of the present day people of the Melanesian region north and north-east of Australia. Melanesian DNA comprises between 4% and 6% Denisovan DNA.
David Reich from the Harvard Medical School, who worked with Svante Paabo on the study, says that the fact that Denisovan genes ended up so far south suggests they were widespread across Eurasia: "These populations must have been spread across thousands and thousands of miles," he told BBC News. One mystery is why the Denisovan genes are unique in modern Melanesians and are not found in other Eurasian groups that have so far been sampled.
Life goes online after death with 'memory boxes'
By Dave Lee BBC World Service
The Timecard machine will save a Flickr account for safe keeping for many years. The death of a close, elderly relative can often mean a sombre weekend or two going through old things, sorting through photographs, donating old clothes to charity. But in an age when so much of our lives are online, little thought has been given to how we handle a person's digital world when they are no longer with us.
By the time the "Facebook generation" become old and grey, their whole lives may be spread out with a million updates on Twitter, thousands of photos on Flickr, hours and hours of video on YouTube and maybe their own website too.As a person dies, should their online presence end too? What should happen to all that personal information?
"In the past we might have worried about physical love letters and coming across those when you're going through your grandfather's things and being shocked by it.”
Richard Banks believes he may have the solution. He is an interaction designer for Microsoft and his team, based in Cambridge, have been working on the concept of digital memories - and how, even if a person is no longer with us, their digital self can still be enjoyed.
He told BBC Radio 4's All in the Mind about how the death of his grandfather few years ago inspired him to think about the future of bereavement.
"After he passed away, I became the recipient of a suitcase full of photos of his life.
"Inside there was about 200 shots of different periods of his life, all old analogue photos, printed out, stored away in envelopes.
"It got me thinking about what the difference would be, now, with my photographic practices, and the kind of things I might leave behind for my own children." He has created several devices that run independently from any computer or other internet device, instead acting like a traditional box of pictures and memories. Rather than physical photos, however, the pictures in this device are displayed via an interactive touchscreen.
"If I touch one of those photos at any point, then I get taken to a timeline," explained Mr Banks.
"What appears then is a whole range of photos spread over time.
"Suddenly it's a way of thinking can we start to take advantage of the digital qualities of some of this content, so that we can start to make objects that maybe represent a person's life, or maybe give a sense of their evolution over time, or where they spent time at different points in their life."
Mr Banks hopes that his devices would mean digital memories would far outlive the technology they were created on - much like the old photographs in his grandfather's suitcase.
The cloud
This task is made easier by our increasing reliance on "the cloud" to host our information - rather than physical storage such as hard drives for floppy disks.
The boxes are designed to work independently, so do not rely on keeping certain hardware ."I think we tend to think about the physical limitations of digital things through objects like floppy discs and DVDs and CDs that we've stored our content on.
"I think actually some of those physical limitations are going to go away as we start to store more and more content online. We'll put them in places and they'll pretty much just stay there."This, however, offers up another issue. Will there be simply too much data? If these systems save every utterance online, the suitcase of 200 precious pictures could suddenly become a vast collection of pointless data."I think that sense of quantity, and overwhelming numbers of content, is a tougher thing to handle," says Mr Banks."I think there are ways to deal with that computationally - getting a sense of when photos were taken or who might be in the photos and those kinds of things."
Secrets beyond the grave
Our online personas can offer a candid look back at a persons' life giving glimpses into personalities and friendships. But with it comes a risk of sharing too much. Abigail Sellen is also part of the team working on the project. She says that we may, while we're still alive, have to consider what could be left behind when we pass away.
"A lot of those materials may in fact be quite sensitive or personal. "
"So if you leave all of that stuff behind to somebody that you care about, is that person going to be comfortable going through all of it?"
Ms Sellen says that finding secrets left behind by a deceased relative is nothing new, but e-mail archives and other information could be misinterpreted."In the past we might have worried about physical love letters and coming across those when you're going through your grandfather's things and being shocked by it. "At least in that case you know that they kept them for a reason and maybe it was important to them." In future, it may be that as we write our wills and maybe even burn our secret letters, we may have to also spend time cleaning out our online lives, ready to be put on show to those closest to us.
The Timecard machine will save a Flickr account for safe keeping for many years. The death of a close, elderly relative can often mean a sombre weekend or two going through old things, sorting through photographs, donating old clothes to charity. But in an age when so much of our lives are online, little thought has been given to how we handle a person's digital world when they are no longer with us.
By the time the "Facebook generation" become old and grey, their whole lives may be spread out with a million updates on Twitter, thousands of photos on Flickr, hours and hours of video on YouTube and maybe their own website too.As a person dies, should their online presence end too? What should happen to all that personal information?
"In the past we might have worried about physical love letters and coming across those when you're going through your grandfather's things and being shocked by it.”
Richard Banks believes he may have the solution. He is an interaction designer for Microsoft and his team, based in Cambridge, have been working on the concept of digital memories - and how, even if a person is no longer with us, their digital self can still be enjoyed.
He told BBC Radio 4's All in the Mind about how the death of his grandfather few years ago inspired him to think about the future of bereavement.
"After he passed away, I became the recipient of a suitcase full of photos of his life.
"Inside there was about 200 shots of different periods of his life, all old analogue photos, printed out, stored away in envelopes.
"It got me thinking about what the difference would be, now, with my photographic practices, and the kind of things I might leave behind for my own children." He has created several devices that run independently from any computer or other internet device, instead acting like a traditional box of pictures and memories. Rather than physical photos, however, the pictures in this device are displayed via an interactive touchscreen.
"If I touch one of those photos at any point, then I get taken to a timeline," explained Mr Banks.
"What appears then is a whole range of photos spread over time.
"Suddenly it's a way of thinking can we start to take advantage of the digital qualities of some of this content, so that we can start to make objects that maybe represent a person's life, or maybe give a sense of their evolution over time, or where they spent time at different points in their life."
Mr Banks hopes that his devices would mean digital memories would far outlive the technology they were created on - much like the old photographs in his grandfather's suitcase.
The cloud
This task is made easier by our increasing reliance on "the cloud" to host our information - rather than physical storage such as hard drives for floppy disks.
The boxes are designed to work independently, so do not rely on keeping certain hardware ."I think we tend to think about the physical limitations of digital things through objects like floppy discs and DVDs and CDs that we've stored our content on.
"I think actually some of those physical limitations are going to go away as we start to store more and more content online. We'll put them in places and they'll pretty much just stay there."This, however, offers up another issue. Will there be simply too much data? If these systems save every utterance online, the suitcase of 200 precious pictures could suddenly become a vast collection of pointless data."I think that sense of quantity, and overwhelming numbers of content, is a tougher thing to handle," says Mr Banks."I think there are ways to deal with that computationally - getting a sense of when photos were taken or who might be in the photos and those kinds of things."
Secrets beyond the grave
Our online personas can offer a candid look back at a persons' life giving glimpses into personalities and friendships. But with it comes a risk of sharing too much. Abigail Sellen is also part of the team working on the project. She says that we may, while we're still alive, have to consider what could be left behind when we pass away.
"A lot of those materials may in fact be quite sensitive or personal. "
"So if you leave all of that stuff behind to somebody that you care about, is that person going to be comfortable going through all of it?"
Ms Sellen says that finding secrets left behind by a deceased relative is nothing new, but e-mail archives and other information could be misinterpreted."In the past we might have worried about physical love letters and coming across those when you're going through your grandfather's things and being shocked by it. "At least in that case you know that they kept them for a reason and maybe it was important to them." In future, it may be that as we write our wills and maybe even burn our secret letters, we may have to also spend time cleaning out our online lives, ready to be put on show to those closest to us.
Wednesday, December 22, 2010
Immune system has a back up plan
December 22, 2010
New research by scientists at the University of California, San Diego School of Medicine and Skaggs School of Pharmacy and Pharmaceutical Sciences reveals that the immune system has an effective backup plan to protect the body from infection when the "master regulator" of the body's innate immune system fails. The study appears in the December 19 online issue of the journal Nature Immunology
The innate immune system defends the body against infections caused by bacteria and viruses, but also causes inflammation which, when uncontrolled, can contribute to chronic illnesses such as heart disease, arthritis, type 2 diabetes and cancer. A molecule known as nuclear factor kappa B (NF-κB) has been regarded as the "master regulator" of the body's innate immune response, receiving signals of injury or infection and activating genes for microbial killing and inflammation.
Led by Michael Karin, PhD, Distinguished Professor of Pharmacology, the UC San Diego team studied the immune function of laboratory mice in which genetic tools were used to block the pathway for NF-κB activation. While prevailing logic suggested these mice should be highly susceptible to bacterial infection, the researchers made the unexpected and counterintuitive discovery that NF-κB-deficient mice were able to clear bacteria that cause a skin infection even more quickly than normal mice.
"We discovered that loss of NF-κB caused mice to produce a potent immune-activating molecule known as interleukin-1 beta (IL-1β), which in turn stimulated their bone marrow to produce dramatically increased numbers of white blood cells known as neutrophils," said Karin. Neutrophils are the body's front-line defenders against infection, capable of swallowing and killing bacteria with a variety of natural antibiotic enzymes and proteases.
The new research demonstrates that the innate immune system deploys two effective strategies to deal with invasive bacterial infection, and that the IL-1β system provides an important safety net when NF-κB falls short.
"Having a backup system in place is critical given the diverse strategies that bacterial pathogens have evolved to avoid bacterial clearance," said Victor Nizet, MD, professor of pediatrics and pharmacy, whose laboratory conducted the infectious challenge experiments in the study. "A number of bacteria are known to suppress pathways required for NF-κB activation, so IL-1β signaling could help us recognize and respond to these threats."
Human Antibody Library - Full Length IgG in CHO High Quality & Content - www.BioAtla.com
New research by scientists at the University of California, San Diego School of Medicine and Skaggs School of Pharmacy and Pharmaceutical Sciences reveals that the immune system has an effective backup plan to protect the body from infection when the "master regulator" of the body's innate immune system fails. The study appears in the December 19 online issue of the journal Nature Immunology
The innate immune system defends the body against infections caused by bacteria and viruses, but also causes inflammation which, when uncontrolled, can contribute to chronic illnesses such as heart disease, arthritis, type 2 diabetes and cancer. A molecule known as nuclear factor kappa B (NF-κB) has been regarded as the "master regulator" of the body's innate immune response, receiving signals of injury or infection and activating genes for microbial killing and inflammation.
Led by Michael Karin, PhD, Distinguished Professor of Pharmacology, the UC San Diego team studied the immune function of laboratory mice in which genetic tools were used to block the pathway for NF-κB activation. While prevailing logic suggested these mice should be highly susceptible to bacterial infection, the researchers made the unexpected and counterintuitive discovery that NF-κB-deficient mice were able to clear bacteria that cause a skin infection even more quickly than normal mice.
"We discovered that loss of NF-κB caused mice to produce a potent immune-activating molecule known as interleukin-1 beta (IL-1β), which in turn stimulated their bone marrow to produce dramatically increased numbers of white blood cells known as neutrophils," said Karin. Neutrophils are the body's front-line defenders against infection, capable of swallowing and killing bacteria with a variety of natural antibiotic enzymes and proteases.
The new research demonstrates that the innate immune system deploys two effective strategies to deal with invasive bacterial infection, and that the IL-1β system provides an important safety net when NF-κB falls short.
"Having a backup system in place is critical given the diverse strategies that bacterial pathogens have evolved to avoid bacterial clearance," said Victor Nizet, MD, professor of pediatrics and pharmacy, whose laboratory conducted the infectious challenge experiments in the study. "A number of bacteria are known to suppress pathways required for NF-κB activation, so IL-1β signaling could help us recognize and respond to these threats."
Human Antibody Library - Full Length IgG in CHO High Quality & Content - www.BioAtla.com
Tuesday, December 21, 2010
Monday, December 20, 2010
How is a Plane 'De-iced'?
Because salt is corrosive to a plane's aluminium frames de-icing chemicals such as glycol are sprayed on its body before takeoff. Glycol works like antifreeze in a car, reducing the freezing point of water to as low as minus 50C.
Ice changes the shape of the wings, creating a drag effect and making the steering flaps difficult to control.So de-icing chemicals like glycol are sprayed on the plane to melt it.But in low temperatures, planes will need to take off almost immediately after being sprayed.It is usually applied through high-pressure jets at temperatures as warm as 65C. And, says Mr Learmount, it will normally contain a coloured dye so that staff applying it can see they have not left any part of the plane out.
Special vehicles with a nozzle on the end of a hydraulic cab are used to reach all parts of the aircraft.
Usually a precautionary anti-icer solution - which helps prevent the build-up of ice - is applied after the de-icer. However, in very low temperatures, this may have little impact.
Jamie Bowden, an aviation analyst and former BA customer services manager, says the "hand-over time" between a plane being sprayed and it needing to take off before it freezes again can be as low as 20 minutes."They have to be de-iced relatively close to the take-off point," he says. "You can't just do it early in the morning if you're flying in the afternoon." In a busy terminal like Heathrow, he adds, with a limited amount of de-icing equipment and hundreds of flights needing to be co-ordinated, this can create a logistical nightmare."I know from years of working in terminals that when the weather does change, you have no option but to shut the place down," he adds.
Although there are many reasons why airports close in this weather, such disruption is a source of irritation for passengers. But history suggests that it is better to be safe than sorry. In January 1982, Air Florida Flight 90 crashed into a bridge shortly after take-off from Washington National Airport in Washington DC, killing 74 people. An investigation found that ice and snow had been sucked into the engines. It also concluded that de-icing procedures had not been properly followed.
Ice changes the shape of the wings, creating a drag effect and making the steering flaps difficult to control.So de-icing chemicals like glycol are sprayed on the plane to melt it.But in low temperatures, planes will need to take off almost immediately after being sprayed.It is usually applied through high-pressure jets at temperatures as warm as 65C. And, says Mr Learmount, it will normally contain a coloured dye so that staff applying it can see they have not left any part of the plane out.
Special vehicles with a nozzle on the end of a hydraulic cab are used to reach all parts of the aircraft.
Usually a precautionary anti-icer solution - which helps prevent the build-up of ice - is applied after the de-icer. However, in very low temperatures, this may have little impact.
Jamie Bowden, an aviation analyst and former BA customer services manager, says the "hand-over time" between a plane being sprayed and it needing to take off before it freezes again can be as low as 20 minutes."They have to be de-iced relatively close to the take-off point," he says. "You can't just do it early in the morning if you're flying in the afternoon." In a busy terminal like Heathrow, he adds, with a limited amount of de-icing equipment and hundreds of flights needing to be co-ordinated, this can create a logistical nightmare."I know from years of working in terminals that when the weather does change, you have no option but to shut the place down," he adds.
Although there are many reasons why airports close in this weather, such disruption is a source of irritation for passengers. But history suggests that it is better to be safe than sorry. In January 1982, Air Florida Flight 90 crashed into a bridge shortly after take-off from Washington National Airport in Washington DC, killing 74 people. An investigation found that ice and snow had been sucked into the engines. It also concluded that de-icing procedures had not been properly followed.
Sunday, December 19, 2010
Cognitive skills of Fighter pilots
By Helen Briggs Health reporter, BBC News
Differences in white matter (pink) and the connections between those areas (orange and blue) Continue reading the main story
Fighter pilots may owe their ability to perform under pressure to the way their brains are wired-up, scans suggest.The study found differences in the white matter and connections of the brain's right hemisphere, compared with healthy volunteers who were not pilots.It is not clear whether pilots are born like that, or develop the differences as a result of their training.
The research by University College London (UCL) is published in the Journal of Neuroscience.
Royal Air Force fighter pilots are trained to fly at supersonic speeds at low altitude, requiring fine control with very little room for error. The discipline is considered to be at the limits of human cognitive performance, prompting doctors at UCL to study their brain function.The research team looked at how 11 front-line RAF Tornado fighter pilots performed in two standard visual cognitive tests to assess their powers of thought.Their test scores were compared with healthy people of the same age and sex who had no experience of piloting aircraft. The subjects were also given MRI scans to look at the structure of their brains.
Cognitive tests
The first test, known as the Eriksen Flanker, measures how quickly and accurately someone can respond to a target stimulus, while being distracted by symbols like arrows or letters. In the second test, participants have to respond as quickly as possible to the signal "go", unless they are told to change their plan before they have made a response.The two visual tests measure how quickly and accurately someone can respond to a target, while being distracted.The pilots were found to respond more accurately than the control group in the first test, but there was no difference in the second test, suggesting their brain performance was highly particular to specific tests, say the authors.Professor Masud Husain of the UCL Institute of Neurology and UCL Institute of Cognitive Neuroscience said his research team was interested in the pilots as an expert group capable of making precision choices at high speed.
Born or bred?
He said their ability to perform more accurately in certain tasks was associated with differences in the wiring of the right hemisphere of the brain. The findings suggested that optimal cognitive control is accompanied by structural alterations in the brain - not only are the relevant areas of the brain larger but connections between key areas are different, he said. He told the BBC: "An interesting question is whether these pilots were born like that - and so are good as pilots - or have done this through training.
"There's a suggestion it may be they are born like that." He said the team hopes to look at other professional groups, such as sporting stars and bankers, to see whether there were more differences in brain structure."What makes them different?" he added. "Are there signatures in the brain you can see in a scan?"
Differences in white matter (pink) and the connections between those areas (orange and blue) Continue reading the main story
Fighter pilots may owe their ability to perform under pressure to the way their brains are wired-up, scans suggest.The study found differences in the white matter and connections of the brain's right hemisphere, compared with healthy volunteers who were not pilots.It is not clear whether pilots are born like that, or develop the differences as a result of their training.
The research by University College London (UCL) is published in the Journal of Neuroscience.
Royal Air Force fighter pilots are trained to fly at supersonic speeds at low altitude, requiring fine control with very little room for error. The discipline is considered to be at the limits of human cognitive performance, prompting doctors at UCL to study their brain function.The research team looked at how 11 front-line RAF Tornado fighter pilots performed in two standard visual cognitive tests to assess their powers of thought.Their test scores were compared with healthy people of the same age and sex who had no experience of piloting aircraft. The subjects were also given MRI scans to look at the structure of their brains.
Cognitive tests
The first test, known as the Eriksen Flanker, measures how quickly and accurately someone can respond to a target stimulus, while being distracted by symbols like arrows or letters. In the second test, participants have to respond as quickly as possible to the signal "go", unless they are told to change their plan before they have made a response.The two visual tests measure how quickly and accurately someone can respond to a target, while being distracted.The pilots were found to respond more accurately than the control group in the first test, but there was no difference in the second test, suggesting their brain performance was highly particular to specific tests, say the authors.Professor Masud Husain of the UCL Institute of Neurology and UCL Institute of Cognitive Neuroscience said his research team was interested in the pilots as an expert group capable of making precision choices at high speed.
Born or bred?
He said their ability to perform more accurately in certain tasks was associated with differences in the wiring of the right hemisphere of the brain. The findings suggested that optimal cognitive control is accompanied by structural alterations in the brain - not only are the relevant areas of the brain larger but connections between key areas are different, he said. He told the BBC: "An interesting question is whether these pilots were born like that - and so are good as pilots - or have done this through training.
"There's a suggestion it may be they are born like that." He said the team hopes to look at other professional groups, such as sporting stars and bankers, to see whether there were more differences in brain structure."What makes them different?" he added. "Are there signatures in the brain you can see in a scan?"
Saturday, December 18, 2010
Mummified forest in Canadian Arctic gives scientists climate change clues
On a remote island in the Canadian Arctic where no trees now grow, a newly unearthed mummified forest is giving researchers a peek into how plants reacted to ancient climate change.
That knowledge will be key as scientists begin to tease out the impacts of global warming in the Arctic.The ancient forest found on Ellesmere Island, which lies north of the Arctic Circle in Canada, contained dried out birch, larch, spruce and pine trees. Research scientist Joel Barker of Ohio State University discovered it by chance while camping in 2009.
"At one point I crested a small ridge and the cliff face below me was just riddled with wood," he recalled.
Armed with a research grant, Barker returned this past summer to explore the site, which was buried by an avalanche 2 million to 8 million years ago. Melting snow recently exposed the preserved remains of tree trunks, leaves and needles.
About a dozen such frozen forests exist in the Canadian Arctic, but the newest site is farthest north.
The forest existed during a time when the Arctic climate shifted from being warmer than it is today to its current frigid state. Judging by the lack of diverse wood species and the trees' small leaves, the team suspected that plants at the site struggled to survive the rapid change from deciduous forest to evergreen.
"This community was just hanging on," said Barker, who presented his findings Thursday at the American Geophysical Union meeting in San Francisco. The next step is to examine tree rings to better understand how past climate conditions stressed plant life and how the Arctic tundra ecosystem will respond to global warming. Since 1970, temperatures have climbed more than 4.5 degrees in much of the Arctic, much faster than the global average.Barker also plans to conduct DNA tests on the remains.
That knowledge will be key as scientists begin to tease out the impacts of global warming in the Arctic.The ancient forest found on Ellesmere Island, which lies north of the Arctic Circle in Canada, contained dried out birch, larch, spruce and pine trees. Research scientist Joel Barker of Ohio State University discovered it by chance while camping in 2009.
"At one point I crested a small ridge and the cliff face below me was just riddled with wood," he recalled.
Armed with a research grant, Barker returned this past summer to explore the site, which was buried by an avalanche 2 million to 8 million years ago. Melting snow recently exposed the preserved remains of tree trunks, leaves and needles.
About a dozen such frozen forests exist in the Canadian Arctic, but the newest site is farthest north.
The forest existed during a time when the Arctic climate shifted from being warmer than it is today to its current frigid state. Judging by the lack of diverse wood species and the trees' small leaves, the team suspected that plants at the site struggled to survive the rapid change from deciduous forest to evergreen.
"This community was just hanging on," said Barker, who presented his findings Thursday at the American Geophysical Union meeting in San Francisco. The next step is to examine tree rings to better understand how past climate conditions stressed plant life and how the Arctic tundra ecosystem will respond to global warming. Since 1970, temperatures have climbed more than 4.5 degrees in much of the Arctic, much faster than the global average.Barker also plans to conduct DNA tests on the remains.
Friday, December 17, 2010
Free will and the animal kingdom
A growing idea holds that the chances of our choices are written in our brains. The free will that humans enjoy is similar to that exercised by animals as simple as flies, a scientist has said.The idea may simply require "free will" to be redefined, but tests show that animal behaviour is neither completely constrained nor completely free.The paper, in Proceedings of the Royal Society B, suggests animals always have a range of options available to them."Choices" actually fit a complex probability but, at least in humans, are perceived as conscious decisions.The idea tackles one of history's great philosophical debates, and Bjoern Brembs of the Berlin Free University brings the latest thinking from neurobiology to bear on the question.
What has been long established is that "deterministic behaviour" - the idea that an animal poked in just such a way will react with the same response every time - is not a complete description of behaviour.
"Even the simple animals are not the predictable automatons that they are often portrayed to be," Dr Brembs told BBC News. However, the absence of determinism does not suggest completely random behaviour either.
Experiments including Dr Brembs' own 2007 work with flies has shown that although animal behaviour can be unpredictable, responses do seem to come from a fixed list of options."Free will is not that lofty metaphysical thing that it was until the 1970s or so," Dr Brembs said."More and more people are realising that it's a biological property, a trait; the brain possesses the freedom to generate behaviours and options on its own."The exact mechanism by which brains - from those of flies up to humans - do that generation remains a matter for experiments to more fully prove.
"There is no way the conscious mind, the refuge of the soul, could influence the brain without leaving tell-tale signs; physics does not permit such ghostly interactions” Christof Koch
California Institute of Technology
Dr Brembs and others have used mathematical models to simulate brain activity on a computer, finding that what worked best was a combination of deterministic behaviour and what is known as stochastic behaviour - which may look random but actually, in time, follows a defined set of probabilities.
This "stochasticity" shows up in, for example, earthquakes. While they cannot be accurately predicted, a given fault will over time show earthquake timings that neatly fit a curve.
As with animal behaviour, there is an underlying order and probability to a process that may appear random.
"It is a probability, and that's as far as we can take it if we try to abstract it from thinking," he explained.
"In thinking, we have all the options, and theoretically all the options have the same probability attached to them. However, this is not how it's going to turn out." While we imagine having the option of choosing to walk off the edge of a cliff, Dr Brembs said, it is an option that would only very, very rarely be chosen.
Dr Brembs said brains are likely to include mechanisms that can ramp up or down the probabilistic element of the behaviour, depending on the situation at hand, and that in sum, the whole system was an evolved survival strategy.
"The variability that is inherent in the behaviour is something that is a prerequisite for survival in a competitive environment."That is, a predator should not be able to always guess its prey's actions, but the actions should not be so random as to include options even more dangerous than the predator.
'Ghostly interactions'
The idea holds a certain currency in the world of neurobiology, but it is clear that what is needed is more experimental results that match the mathematical models. Christof Koch, a biologist from the California Institute of Technology and frequent author on topics of free will and biology, said that the work hits at the heart of "one of the oldest problems in philosophy".
Tethered fruit flies proved their choices to be neither deterministic nor random In writing about Dr Brembs' research, he suggested that "the strong, Cartesian version of free will—the belief that if you were placed in exactly the same circumstances again, you could have acted otherwise—is difficult to reconcile with natural laws". "There is no way the conscious mind, the refuge of the soul, could influence the brain without leaving tell-tale signs. Physics does not permit such ghostly interactions." Professor Koch told BBC News that "it is entirely possible that 'indeterminism' - under certain conditions - is a useful trait - but not usually: when you drive your car at high speeds down the freeway, you want to be highly deterministic."
Dr Brembs stressed that the current debate did not address the even stickier debate about consciousness, its origins, or whether animals share it. "I would not expect fruit files or worms to comtemplate their options; I would think this is something that is clearly more built in than it is with us. But I would then say that most of the decisions we're making are also built in," he explained.
"[Free will as described in the paper] is a very low-level, necessary prerequisite, but it's not even close to being sufficient for addressing things like morality and responsibility.
"But without this very basic capability of choosing between options, we wouldn't have to think about all the other things that come on top: consciousness, upbringing and what have you."
What has been long established is that "deterministic behaviour" - the idea that an animal poked in just such a way will react with the same response every time - is not a complete description of behaviour.
"Even the simple animals are not the predictable automatons that they are often portrayed to be," Dr Brembs told BBC News. However, the absence of determinism does not suggest completely random behaviour either.
Experiments including Dr Brembs' own 2007 work with flies has shown that although animal behaviour can be unpredictable, responses do seem to come from a fixed list of options."Free will is not that lofty metaphysical thing that it was until the 1970s or so," Dr Brembs said."More and more people are realising that it's a biological property, a trait; the brain possesses the freedom to generate behaviours and options on its own."The exact mechanism by which brains - from those of flies up to humans - do that generation remains a matter for experiments to more fully prove.
"There is no way the conscious mind, the refuge of the soul, could influence the brain without leaving tell-tale signs; physics does not permit such ghostly interactions” Christof Koch
California Institute of Technology
Dr Brembs and others have used mathematical models to simulate brain activity on a computer, finding that what worked best was a combination of deterministic behaviour and what is known as stochastic behaviour - which may look random but actually, in time, follows a defined set of probabilities.
This "stochasticity" shows up in, for example, earthquakes. While they cannot be accurately predicted, a given fault will over time show earthquake timings that neatly fit a curve.
As with animal behaviour, there is an underlying order and probability to a process that may appear random.
"It is a probability, and that's as far as we can take it if we try to abstract it from thinking," he explained.
"In thinking, we have all the options, and theoretically all the options have the same probability attached to them. However, this is not how it's going to turn out." While we imagine having the option of choosing to walk off the edge of a cliff, Dr Brembs said, it is an option that would only very, very rarely be chosen.
Dr Brembs said brains are likely to include mechanisms that can ramp up or down the probabilistic element of the behaviour, depending on the situation at hand, and that in sum, the whole system was an evolved survival strategy.
"The variability that is inherent in the behaviour is something that is a prerequisite for survival in a competitive environment."That is, a predator should not be able to always guess its prey's actions, but the actions should not be so random as to include options even more dangerous than the predator.
'Ghostly interactions'
The idea holds a certain currency in the world of neurobiology, but it is clear that what is needed is more experimental results that match the mathematical models. Christof Koch, a biologist from the California Institute of Technology and frequent author on topics of free will and biology, said that the work hits at the heart of "one of the oldest problems in philosophy".
Tethered fruit flies proved their choices to be neither deterministic nor random In writing about Dr Brembs' research, he suggested that "the strong, Cartesian version of free will—the belief that if you were placed in exactly the same circumstances again, you could have acted otherwise—is difficult to reconcile with natural laws". "There is no way the conscious mind, the refuge of the soul, could influence the brain without leaving tell-tale signs. Physics does not permit such ghostly interactions." Professor Koch told BBC News that "it is entirely possible that 'indeterminism' - under certain conditions - is a useful trait - but not usually: when you drive your car at high speeds down the freeway, you want to be highly deterministic."
Dr Brembs stressed that the current debate did not address the even stickier debate about consciousness, its origins, or whether animals share it. "I would not expect fruit files or worms to comtemplate their options; I would think this is something that is clearly more built in than it is with us. But I would then say that most of the decisions we're making are also built in," he explained.
"[Free will as described in the paper] is a very low-level, necessary prerequisite, but it's not even close to being sufficient for addressing things like morality and responsibility.
"But without this very basic capability of choosing between options, we wouldn't have to think about all the other things that come on top: consciousness, upbringing and what have you."
Thursday, December 16, 2010
Herbal products may contain dangerous ingredients
U.S. cracks down on dangerous supplements
Herbal products containing drugs and banned substances a big problem
Last Updated: Thursday, December 16, 2010 | 9:59 AM ET
CBC News
Companies that produce and market dietary supplements that contain undeclared drugs and dangerous ingredients will face the long arm of the law, warns the U.S. Food and Drug Administration.
Canada and the United States have seen a surge in the sale of products marketed as herbal supplements, but contain drugs that can cause serious harm.
An FDA scientist presents an example of an illegal imported product, called Morning Skatto, marketed as a dietary supplement. The U.S. health watchdog is cracking down on dietary supplements. (FDA)So far in 2010, Health Canada has issued 14 advisories about "natural" health products that contain undeclared prescription medications.
They include the active ingredients in erectile dysfunction drugs such as Cialis and Viagra, along with steroids, and the banned weight loss drug sibutramine.
'These tainted products can cause serious adverse effects, including strokes, organ failure, and death.'—Dr. Margaret Hamburg, FDA
The FDA reports in recent years nearly 300 products have been found to contain similar substances. It says there have been numerous instances of injury reported as a result of taking the tainted supplements.
"These tainted products can cause serious adverse effects, including strokes, organ failure, and death," said FDA Commissioner Dr. Margaret Hamburg, "The manufacturers selling these tainted products are operating outside the law."
Public health agencies face enforcement challenges
But tackling the issue poses serious challenges for public health agencies. With many of the supplements sold through websites, distributed through multi-level marketing schemes, and at shady retail outlets, agencies — such as Health Canada — can do little more than warn the public and order a recall when a tainted product is found through random testing.
The FDA has enlisted the support of five industry trade associations and is in the process of issuing warning letters to manufacturers and distributors.
An FDA field inspector presents an assortment of illegal imported products marketed as dietary supplements. FDA is working to stop the sale and distribution of such products, which may contain undisclosed and potentially dangerous ingredients. (FDA)It's warning that companies that sell and market tainted dietary supplements will face product seizures, injunctions and criminal prosecution.
Sexual enhancement, weight loss and bodybuilding products are the most common supplements to contain illegal, deceptive or undeclared products, notes the FDA.
"The labelling of these tainted products may claim that they are 'alternatives' to FDA-approved drugs, or 'legal' alternatives to anabolic steroids," notes the FDA's director of drug evaluation and research, Michael Levy.
"Consumers should avoid products marketed as supplements that claim to have effects similar to prescription drugs."
The FDA move is applauded by Consumers Union, the organization the publishes the Consumer Reports.
"Tainted dietary supplements can send you to the hospital or kill you," said Ellen Bloom, senior director of policy at Consumers Union.
"The FDA should be commended for prioritizing this issue and alerting consumers about dangerous supplements. Unfortunately the challenge is that more dangerous products keep popping up."
Read more: http://www.cbc.ca/health/story/2010/12/16/con-dangerous-supplements.html#ixzz18I1oUgC2
Wednesday, December 15, 2010
Revamping the Periodic table
Canadian leads revamp of periodic table
Last Updated: Wednesday, December 15, 2010 | 1:47 PM ET
CBC News
Science's ubiquitous periodic table of the elements is getting a fresh face courtesy of a team led by an Alberta researcher.
As part of the revamp, the atomic weights of at least 10 elements — among them oxygen, carbon and nitrogen — are to be restated, said Michael Wiesner, an associate professor at the University of Calgary.
A University of Calgary professor is leading a change to the periodic table which includes restating the atomic weights of 10 elements. (iStock)The update is meant to better reflect how the elements vary in the natural world.
To start with, an international group of scientists will restate the weights of 10 elements, classifying them as a low and a high, known as an interval. The interval varies depending on where the elements are found in nature.
"These are the 10 where we've completed the review," Wieser said on Tuesday. "There's another series we're working on right now."
An 11th element, germanium, has had its atomic weight revised. More changes are expected.
Wiesner, who is secretary of the Commission on Isotopic Abundances and Weights for the International Union of Pure and Applied Chemistry, has co-authored a paper outlining the revisions in the journal Pure and Applied Chemistry.
"People have used atomic weight data to look at nuclear processes occurring in the solar system … we can say something about the formation of the solar system and the planets," he said.
"People are probably comfortable with having a single value for the atomic weight, but that is not the reality for our natural world.
Practical applications in sports, food inspection
"There is so much information encoded in the atomic weight that I think we can get people excited about science if we can sort of explore why these atomic weights vary the way they do."
The ability to measure atomic weight of elements with greater precision thanks to modern analytical techniques can help with anti-doping in sports.
The atomic weight of carbon found in natural human testosterone, for instance, is higher than in pharmaceutical testosterone, which could help doctors detect performance-enhancing testosterone in athletes' bodies.
The food industry could also benefit, as the revised table could help detect food adulteration. For example, scientists could analyze the carbon in sugar to check if a product has been sweetened artificially.
The first elements to change from a fixed atomic weight to an interval include:
- Hydrogen
- Lithium
- Boron
- Carbon
- Nitrogen
- Oxygen
- Silicon
- Sulphur
- Chlorine
- Thallium
Read more: http://www.cbc.ca/technology/story/2010/12/15/science-periodic-table.html#ixzz18ED3TROx
Tuesday, December 14, 2010
Malaria control is 'Best in Decades': WHO
Malaria control 'best in decades': WHO
Current strategies are working, health organization says
Last Updated: Tuesday, December 14, 2010 | 12:06 PM ET
CBC News
A mother sits with her daughter, who has malaria, in hospital in Robertsport, Liberia. (WHO/Benoist Carpentier)Scaling up malaria control programs since 2008 has helped to protect more than 578 million people in sub-Saharan Africa, the World Health Organization says.
World Malaria Report 2010 describes progress in expanding access to insecticide-treated mosquito nets, indoor spraying and anti-malarial medications.
Last year, WHO director general Dr. Margaret Chan certified Morocco and Turkmenistan as having eliminated malaria, the report noted.
"The results set out in this report are the best seen in decades," Chan said in a statement. "After so many years of deterioration and stagnation in the malaria situation, countries and their development partners are now on the offensive. Current strategies work."
In Africa, 11 countries showed a drop of 50 per cent in either confirmed malaria cases or malaria admissions and deaths over the past decade, according to the report.
Outside Africa, a decrease of more than 50 per cent in the number of confirmed cases of malaria was also found in 32 of the 56 malaria-endemic countries during this same period.
Resurgences were seen in Rwanda, Sao Tome and Principe, and Zambia. The reasons are unknown but show the need to maintain coverage even when cases fall, WHO said.
The number of deaths as a result of malaria is estimated to have decreased from 985,000 in 2000 to 781,000 in 2009.
The United Nations aims to end malaria deaths by 2015.
Malaria is treatable if caught early but is especially deadly in children under five, who make up most of its victims.
Scientists are working on different strategies to fight malaria. A potential vaccine is being tested but is only about 50 per cent effective.
Earlier this year, WHO recommended that all suspected cases of malaria be confirmed by fast, inexpensive diagnostic tests before giving antimalarial drugs to keep resistance to combination therapies at bay.
Funding for malaria control appears to have levelled off this year at an estimated at $1.8 billion US a year, compared with the estimated more than $6 billion US needed to fully control malaria, WHO said.
With files from The Associated PressRead more: http://www.cbc.ca/health/story/2010/12/14/malaria-who-africa.html#ixzz187MsIVnn
Saturday, December 11, 2010
Sex differences in Concussion symptoms
Boys and girls' concussion symptoms can differ
A study on concussions in high school athletes finds that girls describe them differently than boys, which could mean that some parents and coaches miss the brain injury's signs. The study, presented this week at the National Athletic Trainers' Association Youth Sports Safety Summit in Washington, D.C., looked at 812 sports-related concussions suffered by 610 male and 202 female high school athletes over two years.
The researchers found that while headaches were the most frequently reported symptom of concussions in both girls and boys, secondary symptoms tended to differ between the sexes. About half of boys, for example, reported being confused or disoriented after a head injury. Yet only a little more than a third of girls reported being confused.
As well, more than twice as many boys as girls reported having amnesia as part of a concussion. Girls, on the other hand, were three times more likely to report being sensitive to noise after being hit in the head. And almost one in three girls reported feeling drowsy, compared to just one in five boys. Study co-author R. Dawn Comstock, an associate professor at the Ohio State University College of Medicine, notes that diagnosing concussions is a tricky matter that's based mostly on evaluating symptoms. "No biological markers exist to detect concussion, so diagnosis largely depends on a patient's own report," she said in a news release.
"Diagnosing concussion is further complicated by the tendency of many athletes to under-report or hide symptoms from their doctors, athletic trainers, coaches and parents." Even with the differences in symptoms between the genders, the time needed for the athletes to recover before returning to play did not differ, the report noted.
"Physicians, athletic trainers, coaches and parents should understand that each symptom of a possible concussion must be evaluated, monitored and fully resolved, before an athlete returns to play," said Comstock. While boys tend to participate in sports at a higher rate than girls, female athletes are more likely than male athletes to suffer sport-related concussions. And as more girls and young women participate in rough-and-tumble sports, understanding possible differences in concussion symptoms between the two genders has become increasingly important, Comstock said
The study will be published in the January 2011 issue of the Journal of Athletic Training.
A study on concussions in high school athletes finds that girls describe them differently than boys, which could mean that some parents and coaches miss the brain injury's signs. The study, presented this week at the National Athletic Trainers' Association Youth Sports Safety Summit in Washington, D.C., looked at 812 sports-related concussions suffered by 610 male and 202 female high school athletes over two years.
The researchers found that while headaches were the most frequently reported symptom of concussions in both girls and boys, secondary symptoms tended to differ between the sexes. About half of boys, for example, reported being confused or disoriented after a head injury. Yet only a little more than a third of girls reported being confused.
As well, more than twice as many boys as girls reported having amnesia as part of a concussion. Girls, on the other hand, were three times more likely to report being sensitive to noise after being hit in the head. And almost one in three girls reported feeling drowsy, compared to just one in five boys. Study co-author R. Dawn Comstock, an associate professor at the Ohio State University College of Medicine, notes that diagnosing concussions is a tricky matter that's based mostly on evaluating symptoms. "No biological markers exist to detect concussion, so diagnosis largely depends on a patient's own report," she said in a news release.
"Diagnosing concussion is further complicated by the tendency of many athletes to under-report or hide symptoms from their doctors, athletic trainers, coaches and parents." Even with the differences in symptoms between the genders, the time needed for the athletes to recover before returning to play did not differ, the report noted.
"Physicians, athletic trainers, coaches and parents should understand that each symptom of a possible concussion must be evaluated, monitored and fully resolved, before an athlete returns to play," said Comstock. While boys tend to participate in sports at a higher rate than girls, female athletes are more likely than male athletes to suffer sport-related concussions. And as more girls and young women participate in rough-and-tumble sports, understanding possible differences in concussion symptoms between the two genders has become increasingly important, Comstock said
The study will be published in the January 2011 issue of the Journal of Athletic Training.
Cancun: The chihuahua that roared
Richard Black
11:29 UK time, Saturday, 11 December 2010
From the UN climate summit in Cancun, Mexico:If Copenhagen was the Great Dane that whimpered, Cancun has been the chihuahua that roared.
And what a surprise it was. Before the summit, expectations were so low that simply keeping the UN show on the road was all many observers (and some players) thought possible.In the late morning of the final day, I came across Indian Environment Minister Jairam Ramesh explaining to a couple of delegates that "this process is dead".
Yet half a day later, Cancun produced almost global consensus on words that spell out a need to step up, urgently, action to curb greenhouse gas emissions.The agreement here "affirms that climate change is one of the greatest challenges of our time".
It "recognises that deep cuts in global greenhouse gas emissions are required according to science", and that countries should "take urgent action" to meet the goal of holding the increase in global temperatures below 2C, measured against pre-industrial times. It establishes mechanisms for transferring funds from rich countries to poor and helping them to spend it well on climate protection, acknowledging the rich world's historical responsibility for climate change. It sets out parameters for reducing emissions from deforestation and for transferring clean technology from the west to the rest, Achieving this needed a couple of fudges.
The US partly achieved its main priorities - giving the World Bank first go at running the big new fund, and having some degree of international monitoring on China's emissions - but the wording also allows China and other developing countries to escape with their sovereignity, as they see it, unaffected. And Japan and Russia have been given a way to slide away from the Kyoto Protocol while maintaining the pledges they made around the Copenhagen summit. Given the constraints of time, Copenhagen's legacy of mistrust and the domestic political concerns of countries from Japan to the US to India, this is much more than anyone had expected.
The back stories of how these deals are made are always long, involved and - at this timescale - untold.
But clearly the Mexican host government constructed a process that sought to include everyone, and that addressed the really knotty issues in small groups of interested parties, and kept at it until a way through was found. Unlike Copenhagen, there was listening as well as talking.
So that's the roar.
However, if the agreement here acknowledges the need for deeper and faster emission curbs, it doesn't provide a visible way to achieve them - merely "urging" rich countries to do more. The Kyoto Protocol text itself is still full of square brackets and options - on many, many issues. And some of the important, tough details have been kicked into the long grass - notably, the issue of "legal form" - whether the next climate agreement should seek to be legally-binding or not.
So in terms of the most vital question for any climate accord - how much will it contribute to restricting man-made climate change? - you would have to answer, not as far as to meet the needs that it identifies.
But in the view of many observers here, it's laid the foundations for the comprehensive agreement they want.
Eyes now turn to Durban in South Africa, where next year's summit will be held.
In a sense, that's the last chance to get further targets under the Kyoto Protocol agreed, because the current targets run to 2012 only. Building the deal that's desired by small island states, African nations, other "vulnerable" developing countries, the EU and many environmental groups won't be easy - far from it. There are many political obstacles on that road.
But the dog is rescuscitated and up and running... we'll see how far it goes.
11:29 UK time, Saturday, 11 December 2010
From the UN climate summit in Cancun, Mexico:If Copenhagen was the Great Dane that whimpered, Cancun has been the chihuahua that roared.
And what a surprise it was. Before the summit, expectations were so low that simply keeping the UN show on the road was all many observers (and some players) thought possible.In the late morning of the final day, I came across Indian Environment Minister Jairam Ramesh explaining to a couple of delegates that "this process is dead".
Yet half a day later, Cancun produced almost global consensus on words that spell out a need to step up, urgently, action to curb greenhouse gas emissions.The agreement here "affirms that climate change is one of the greatest challenges of our time".
It "recognises that deep cuts in global greenhouse gas emissions are required according to science", and that countries should "take urgent action" to meet the goal of holding the increase in global temperatures below 2C, measured against pre-industrial times. It establishes mechanisms for transferring funds from rich countries to poor and helping them to spend it well on climate protection, acknowledging the rich world's historical responsibility for climate change. It sets out parameters for reducing emissions from deforestation and for transferring clean technology from the west to the rest, Achieving this needed a couple of fudges.
The US partly achieved its main priorities - giving the World Bank first go at running the big new fund, and having some degree of international monitoring on China's emissions - but the wording also allows China and other developing countries to escape with their sovereignity, as they see it, unaffected. And Japan and Russia have been given a way to slide away from the Kyoto Protocol while maintaining the pledges they made around the Copenhagen summit. Given the constraints of time, Copenhagen's legacy of mistrust and the domestic political concerns of countries from Japan to the US to India, this is much more than anyone had expected.
The back stories of how these deals are made are always long, involved and - at this timescale - untold.
But clearly the Mexican host government constructed a process that sought to include everyone, and that addressed the really knotty issues in small groups of interested parties, and kept at it until a way through was found. Unlike Copenhagen, there was listening as well as talking.
So that's the roar.
However, if the agreement here acknowledges the need for deeper and faster emission curbs, it doesn't provide a visible way to achieve them - merely "urging" rich countries to do more. The Kyoto Protocol text itself is still full of square brackets and options - on many, many issues. And some of the important, tough details have been kicked into the long grass - notably, the issue of "legal form" - whether the next climate agreement should seek to be legally-binding or not.
So in terms of the most vital question for any climate accord - how much will it contribute to restricting man-made climate change? - you would have to answer, not as far as to meet the needs that it identifies.
But in the view of many observers here, it's laid the foundations for the comprehensive agreement they want.
Eyes now turn to Durban in South Africa, where next year's summit will be held.
In a sense, that's the last chance to get further targets under the Kyoto Protocol agreed, because the current targets run to 2012 only. Building the deal that's desired by small island states, African nations, other "vulnerable" developing countries, the EU and many environmental groups won't be easy - far from it. There are many political obstacles on that road.
But the dog is rescuscitated and up and running... we'll see how far it goes.
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