Backing Up Evolution

I’ve said it before and no doubt I’ll say it again but we know science works because it makes predictions that we can then measure against the universe and determine if the models we have created to describe it are accurate or not. One of the more successful models is the theory of evolution by natural selection. A criticism levelled against the theory of evolution by detractors is the claim that new information can not be introduced into the system, only taken away. This is actually false but lets consider how we might tackle this question scientifically

First, the underlying assumption here isn’t unreasonable, let’s explore it. The accepted mechanism of introducing change in an organism, change that natural selection can then act upon, is mutation. Mutations involve a mistake in the copying of an organism’s DNA, this might consist of a change in a single base of a gene (an insertion of an extra base, deletion of an existing base or swapping one base for another) or it might involve large stretches of DNA. The basic principle that is relevant here is the same, a change is made to the blueprints of life in our cells.

As you might expect there are many more ways of being wrong than there are of being right, any random change is more likely to introduce a defect in the complicated machinery of life than it is to create an improvement (bearing in mind that “improvement” is a value judgement that really cannot be applied here but don’t focus on the wrong part of the story). So on the surface it would seem that random change is very definitely a bad thing, mutations would likely lead to loss of gene function, and by extension, loss of information and specifically death of the individual.

How might evolution get around such a problem? One solution would be to make copies of critical genes, this way is one copy is damaged through mutation the other can still function and produce a viable organism. The “spare” gene would then be free to mutate and the resulting gene may be selected for or against by natural selection (or human breeders).

If you have been reading closely you will have picked up on our prediction, the genomes of organisms should contain copies of various genes that allow mutations to occur without harming the individual that accumulates them. It turns out this is exactly what we find.  A recent study found a significant amount of redundancy in the genome of Zebrafish which allows mutations to occur in genes critical to development without lethal consequences to the fish.

The researchers intentionally gave mutagens to populations of Zebrafish and looked for changes in fish morphology indicative of mutations. In particular they created a mutation that lead to the loss of most of the fish’s scales, similar to that of Mirror Carp. The mutation was traced to a gene critical to normal development, further investigation revealed that the gene existed as a redundant pair, only one of which being required for normal development.

It is tempting to talk about this phenomenon in terms of intention, the gene was duplicated so that it could mutate and provide raw material for evolution. This is a mistake however, evolution can not move towards any putative desired future state. the genes that are duplicated in this way will be random and the mutations that affect the genes will be equally random, there are likely many genes in the Zebrafish that are not duplicated and would cause death to the individual if they were to change. This does not detract from the fact that a proposed mechanism for introducing new information into an organisms genome has proven correct.

Science is Awesome.

Disgust or Anger?

The ability to recognise the emotional states of those around us is a very useful tool which allows us to act appropriately in social situations. If this ability is impaired then it could lead to inappropriate reactions when dealing with others, this in turn could land us in hot water. An impairment like this has been suggested to explain the behaviour of delinquents, though it is unlikely to be a sole cause of antisocial behaviour.

A study published recently lends support to this hypothesis, published last month in the journal of  Child and Adolescent Psychiatry and Mental Health (or CAPMH for short, catchy) the study looked at 24 Japanese young adults that were serving time in correction facilities (in Japan). Simply put the researchers compared these so-called delinquents with a control batch of young people (matched for age and gender), in the ability to correctly match an emotion to a facial expression. Six basic emotions were represented with 8 different pictures each, so participants had to match a total of 48 pictures.

The emotions covered were anger, disgust, fear, happiness, sadness, and surprise, the prediction was that the incarcerated subjects would have difficulty interpreting some facial expressions and that this difficulty would skew the subjects towards misidentifying expressions as anger. This in fact did happen, the delinquent subjects actually identified disgust as anger more than the control group.

This interesting result is lessened in it’s impact somewhat due to the fact that the control group also made this mistake a large percentage of the time. This predilection in the delinquents however is an insight into how certain personalities might perceive some social situations as being more hostile than they really are. These personalities are also marked by being quick to anger and experiencing more intense anger than others so recognising how this occurs can be useful information in diffusing these situations and possibly diagnosis of individuals who might otherwise be labelled as simply “difficult”.

Legitimate Use of Magnets in Therapies

I have to say I cringe every time I see an advertisement for some magnet based item that promises health benefits. I’ve ragged on these Magnet Therapies before but today I’d like to cover one of the ways that magnets are legitimately being used to treat medical problems. A couple of months ago a study was published in the The Journal of the American College of Cardiology: Cardiovascular Interventions (a mouthful huh?) that detailed the use of magnetic nanoparticles and an externally applied magnet in guiding cells inside the body to a site of injury.

Specifically the study attempted to tag a particular type of stem cell, Endothelial Progenitor Cells (EPCs), with iron oxide superparamagnetic* nanoparticles. This was rather simply achieved by the addition of the particles to the growth medium of the cells. The cells then took up the particles via endocytosis. Once this was done they injected the cells into rats whose carotid artery had been damaged by angioplasty. A magnet was then applied to the outside of the rat to attract the tagged cells to the site of the damage. This technique showed a 5-fold increase in cells attaching to the damaged area compared to not using the magnet.

The difficulty of getting the cells to the right place without the magnet is due to the rapid blood flow past the injury. Imaging being swept down a fast flowing river with the goal of grabbing onto the river bank at a particular spot, not that easy, if there are thousands of you doing it some will manage but most will be carried right past. The addition of the magnet is like throwing a rope out to the hapless swimmers, once they get that helping hand they can then clamber onto the bank on their own. The EPCs will naturally attach themselves to places where damage is evident but under the high flow rates in arteries this process is inefficient.

This technique is specifically tailored to helping repair damage caused by angioplasty and it is hoped that it’s use might reduce the occurrence of Restenosis, or the re-narrowing of arteries after they have been widened by the angioplasty procedure. Even so, the guidance of the cells by magnetic field has obvious applications for other types of stem cell therapies as well as targeting drugs and gene therapies to specific organs of areas of the body.

Magnets are awesome.

*This sounds like a good name for a cheesy super hero, Superparamagnetic Powers Activate!.

Managing Multi-tasking

It is virtually taken for granted nowadays that multi-tasking is a must. The demands on our time seem to be coming ever faster and in more complicated ways than we ever had to deal with before. Most of us are resigned to the fact that we are expected to be able to type up emails while on the phone and organise our calendar at the same time. If you’re a teenager (or ultra-hip oldie), throw in txting friends, updating your Facebook status and keeping a running commentary on pointless activities on Twitter. Previous studies on multi-tasking have shown that switching rapidly between tasks incurs a cost in time but what is actually happening when we do two (or more) things at once?

It certainly seems when we perform two tasks we are familiar with that we drop into “autopilot” where we might do one task without conscious thought while we focus our attention on another task, say driving while talking to a passenger. While we are deep in discussion it seems as though we are allowing the actions required for driving to be  handled by a “lower” part of our brain while we actively think about appropriate responses to the conversation. Anyone who has accidentally “driven to work” while meaning to go somewhere else would swear this interpretation is true.

Recent work published in the July16th issue of Neuron however disputes this interpretation of how our brain works. The study seems to show that instead of tasks becoming automatic and thus not requiring oversight by the pre-frontal cortex (responsible for conscious control), this area actually works more efficiently and switches tasks faster. In other words we are still only doing one thing at a time but swapping between tasks fast enough that it gives the appearance of multi-tasking. In the words of the researchers:

“The effect of training is to speed up information processing through this pre-frontal bottleneck, thereby reducing temporal processing overlap of the sensory-motor tasks in this brain region”

So, next time you boast of being a multi-tasking maven you can add that this actually means your brain works faster than those lounging in non-multitasking mediocrity. On the other hand, no need to inspire unnecessary ire among your peers unless you can handle the multiple tasks of running away and dodging projectiles.

WAKE UP SHEEPLE!*

A few weeks ago my wife went out dancing with friends, when she came back the one thing that had stood out for her in the evening was how similarly certain groups of people had been dressed. As the youngsters dancing around her left and were replaced each new batch had it’s own discernible style, this type of clothing with that kind of jewelry. Of course there were variations within each group but the similarities, at least to her, were far more striking. We all know of people around us that seem to slavishly follow the crowd, who wear the popular clothes, style their hair the popular way, listen to to popular music or in other ways agree with the popular opinion. We are certainly not as easily influenced as them, we are individuals.

There does seem to be this tendency to be able to recognize conformist behaviour in those around us while simultaneously denying such influences in ourselves. Our peers follow the pack while we make reasoned and informed choices. This effect is the focus of a study performed by Stanford and Princeton Universities. Students were subjected to a number of different surveys and situations designed to show how much they deemed their own choices were dictated by social influences versus their peer group. From university policy decisions to political party positions, driving behaviour  and why they bought an iPod respondents consistently followed popular behaviour themselves while ascribing to their fellows more susceptibility to such influences.

This pattern seemed to hold whether or not such conformity was described as positive or negative behaviour. In other words even when making the same choices as their peers was set up as being desirable they still denied that it was a factor in their own choices. As discussed in the final paragraphs of the study this difference in perception of other’s behaviour compared to our own is likely to contribute to exacerbation conflict and misunderstandings when dealing with those whose views disagree with our own. In such circumstances if we regard ourselves as rational and others as blindly following the crowd (and vice versa) then this makes finding common ground more difficult and demonising the enemy easier. So it may be more constructive not to wonder why are they behave the way they do but to step back and consider why do I think the way I do?

* Obviously this title is ironic, I am of course trying to show people that they are following the pack even while admitting that I must do so myself.

Vitamins and Exercise

I think it’s safe to say that in recent years the push to “Become Healthier” has become much stronger than it was previously. Statistics like 1/4 of New Zealand adults are obese and New Zealand being the “3rd Fattest” country in the world are used to promote a lifestyle that is aimed at making us healthier. Many of us have taken this message to heart (pun intended) and attempted to shape up but sometimes it’s not clear exactly what is healthy. The primary action people are urged to take is exercise and it’s a good one. There are many recognised benefits to regular exercise including reducing risk of Type II diabetes and possibly even reversing the condition.

Another item that is also touted as a general health promoter is antioxidants. Here’s where things start to get tricky, in order to reap the benefits of excersise there has to be some way that the fact that you are exerting yourself is communicated to the cells of your body. A promising candidate for this signal is ROS, or Reactive Oxygen Species. In other words – Oxidants. This brings up an interesting question, if you are taking antioxidants and exercising in your attempt to be healthy – what happens? A study released early this year suggests that the antioxidants reduce the beneficial effects of excersise in the body.

Researchers looked at two markers of insulin sensitivity: Glucose infusion rates and plasma adiponectin levels (high Glucose infusion rate and high adiponectin levels correlates with high insulin sensitivity = no diabetes for you). They found that taking two antioxidants (Vitamins C and E) while engaging in exercise (not literally, friends don’t let friends jog and pill-pop) actually reduced the before and after exercise difference in these markers. This result strengthens the evidence that ROS are involved in signalling changes in cells and that taking antioxidants interferes with this process.

The drawback of this study is that the participant numbers were quite small. The intial group was made up of forty men, 20 that had athletic backgrounds and 20 that didn’t. These where then split into two goups either recieving supplements or not. So the end was 4 groups of ten, not exactly a significant cross-section of the population. Even so the results are compelling and should be investigated further.

I think the moral still holds, beware of taking too many suplements, you don’t always know what the side effects will be.

Cancer is Depressing

I don’t think the observation that cancer contributes to depression would win any awards for profundity, it’s likely such news would put a crimp in anyone’s day. Indeed, the very fact that the news of cancer itself can influence our emotions  makes it difficult to examine the contributing factors toward depression in those suffering from cancer. Our ability to foresee our own possible demise and react emotionally to it confounds attempts to tease out the strands of cause and effect. Approximately 10% of cancer sufferers are diagnosed with clinical depression and up-to two thirds experience some sort of mood disorder.

In order to separate out the effect of conscious knowledge of the disease from the psychological symptoms researchers have to turn to rats. How do you tell if a rat is depressed? To find out the scientists monitored the rat’s Twitter and Facebook pages for negative statements, no actually the rats are subjected to a swimming test, the longer the rats floated in the water without trying to escape the more depressed the animal is. The researchers found that rats with cancer showed signs of depression but not other behaviours normally associated with sickness, implying the rats were not simply feeling unwell.

Analysis of the rats tumours, blood and brain showed an increase in specific cytokines that have been linked to behavioural changes. In other words the presence of the tumour triggers changes in the brain that influence behaviour. This means that depression could be considered another symptom of cancer and not merely a by-product of knowledge of the cancer. This could have implications for how we treat depression in cancer patients and help them deal with the side-effects, simply knowing that being depressed is not something under their own control might itself be helpful.

Man Flu, the Disappointing Reality

Man Flu, scourge of modern Manly life. Struck down by this dreaded disease men are reduced to a shadow of their former glory, unable to maintain the meager level of household responsibility they usually get away with or even care for their own well being. Reduced to mewling invalids, men afflicted with Man Flu have little recourse beyond bed rest and watching daytime television while a significant other tends to their every need. After being ridiculed by wives and girlfriends for decades science has come to the rescue and vindicated us, the Man Flu exists!*
*The preceding is a work of fiction and any resemblance to real people or events is coincidental.
Despite what the media would have us believe recent advances in scientific research has not in fact established that Man Flu is a real phenomena beyond simply showing our inability to deal with sickness effectively. The real science behind the hype, as usual, is much more modest in it’s scope and consequences.

So what was actually studied? The research was carried out by McGill University in Canada and looked at the effects of a certain protein, caspase-12. The study involved investigating how the activity of this protein affects immune response against Listeria monocytogenes bacteria, a microbe that can cause serious food poisoning, in mice. Part of the study also investigated the effect of gender on the activity of the protien and whether any difference was mediated by the hormone oestrogen. To do this researchers infected mice with the bacteria and looked at spleen and liver bacteria levels in male and female mice with and without the gene for the protein and male mice with the gene and being treated with estrogen. 

The interesting thing is that this gene did have a different effect on how sick the mice got depending on the presence or absence of estrogen. Those male mice with the gene were more susceptible to the infection than females or males recieving hormone treatment, but the gene is inactive in most humans. Only about 20% of native Africans have a working version of the gene, so this research has virtually no applicability to general differences in flu severity between men and women. I guess Man Flu remains a myth, for now.

Folic Acid Fortification, a extra tidbit

It seems topical to discuss folic acid fortification as it has recently been in the news and by the end of the year it will be a legal requirement that breads contain approximately 135µg of folate per 100g. I will actually not wade into the debate directly, fortuitously a study was published mid last month on one of the potential benefits of folate supplementation. The study looked at the effect of supplementation on the number of very preterm births and found that it had a protective effect.

First a little background might be in order, Folic acid is one of the B vitamins and is important in cellular metabolism. As a vitamin it is a nutrient that we must obtain through our diet. Food stuffs such as leafy vegetables and liver (mmm, liver) are good sources of folate however it is still a part of our diet that tends to be lacking. Because of this many western countries now mandate fortification of grain products with the vitamin. This is because of the important role it also plays in pregnancy and in particular the prevention of Neural Tube Defects, notably Spina bifida.

The study looking at folate supplementation and preterm births found that the important factor seemed to be duration of supplementation prior to pregnancy rather than the dosage of supplementation. In particular durations of greater than 12 months seemed to be most beneficial. However as the study was undertaken in the US the supplementation was taking place in conjunction with an existing fortification of bread products, this implies that the fortification alone was not sufficient to prevent all preterm births and that women that are planning pregnancies should continue to supplement with folate even after fortification is introduced.

In addition the folate supplementation was self reported by the women in the study at enrolment and after pregnancy had begun rather than being proscribed prior to attempts to conceive. This seems to mean that we must rely on the memory of the women to be accurate regarding the duration of supplementation. Despite this limitation there still seems to be a good correlation between supplementation and reduction in preterm births. Bottom line appears to be that supplementation in addition to fortification is a good idea for the childbearing among us.

Scientific Debate

No matter what the issue you can find scientists to support any view. Is this a failing of science? or is something else at work here?

First off I would like to point out that the sometimes combative nature of science is a good thing. When new data is published the the authenticity and reliability should be closely examined and criticized if found wanting. Despite public perception scientific quality assurance does not stop with peer reviewed publishing, that is just the beginning. In addition the willingness of researchers to question established knowledge is also good, this is how progress is made.

Concerning my original assertion, that a scientist can be found to uphold any view, one thing to remember is that science is performed by scientists. That may seem an obvious statement but my point is that science is not a simple monolithic block of knowledge, it is contributed to by human beings and human beings have failings. We are all susceptible to biases, some of them are cultural and some of them are a by-product of how our mind works, we are more likely to accept information that confirms our preconceptions for instance. But part of science is the effort to overcome these biases, we perform controlled experiments, we use reliable sources, we replicate others’ experiments, in short we try to remove the human component as much as possible.

All of this means that individual scientists can fall on a spectrum of how well they divorce the outcomes of their work from their personal biases. In certain cases there are those that embrace their personal ideologies in their work, they let it inform and guide the course of research. Sometimes this can be a boon, leading research to new places with novel conclusions but all too often it leads to confounding factors and unreliable data.

A contributing factor is the concept of “balance” in the media, to the point that dissenting opinions will be put forward whether or not they constitute a legitimate scientific controversy. All are presented as equally valid even though some are simply wrong. Not all opinions are equal, not all conclusions valid and not all sources reliable. Consider the Evolution vs Creationism debate, this is an extreme case and so it is easy to see that it is a political debate not one based on actual scientific conclusions. Evolution is a corner stone of biological science, in light of which everything else makes sense. Creationism arises from literal adherence to certain religious traditions. Add to this that is an almost uniquely American phenomenon and the claim that it is science based practically refutes itself.

For the public presented with these opposing view points it can be difficult to separate the real controversy from the manufactroversy, or the tendency to create a debate where none exists. The general public does not usually have the tools to uncover the true state of affairs and so is left with the impression that science is unreliable or can be bent however you wish and is therefore useless. This is unfortunate as science is the most powerful way yet devised to discover the nature of the world around us, from Neutron stars to hydrothermal vents, Dark matter and DNA, all of these things can be studied by science and slowly but surely they are yielding their secrets.

Chilling Research

Recently a study was published on the free science journal site PLoSmedicine that looked at the effect of political climate and controversy on scientific research. In particular this study investigated the effect on research regarding sexual behaviour, during 2003 more than 200 NIH-funded grants, most of which examined behaviours that affect the spread of HIV/AIDS came under attack as being “much less worthy of taxpayer funding” than research on “devastating diseases”. I would just like to note that none of the studies that had their funding subsequently reviewed lost their funding, so the controversy was not directly halting research, but it did have an effect.

So what kind of effects did it have? in this study multiple consequences were found, from simply removing potentially controversial words from grants to the extreme – leaving the research for more secure positions. Such self-censuring tactics were employed by close to half of the respondents in the survey sent out as part of the study. While some may see this as simply the price of doing science in the current political climate I see it as a disturbing precedent where political ideologies, independent of whether they have any scientific validity, are influencing the kind and quality of research being performed. This seems to be to be a first baby step towards the kind of society where scientists must carefully proscribe their activities to avoid harmful repercussions.

What other practices did the researchers engage in to avoid the notice of ideologues? Approximately 7% of those who responded reported that they changed the focus of studies in order to be less politically damaging, for instance studying sexual health in monogamous, heterosexual couples rather than single individuals who were considered to have more fringe preferences. Possibly more concerning a larger percentage (17%) actually discontinued studies they thought were politically “non-viable”. It’s not all doom and gloom however, approximately half of the scientists surveyed declared that no amount of controversy would discourage them from continuing their research and 37% felt pride at their inclusion on the list of studies to be reviewed and several researchers considered their role in the affair to be a “badge of honour”.

Resources

http://medicine.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pmed.0050222&ct=1

http://www.sciencemag.org/cgi/content/full/313/5785/292?ijkey=zIglYpRwGQY36&keytype=ref&siteid=sci - Article showing where State approved censureship can lead, even in the modern world.

Are People Affected by Non-Ionising Radiation?

Modern living can have it’s drawbacks as well as it’s advantages, nobody died in plane crashes 500 years ago. Some of the disadvantages come as a direct result of our increase in scientific and technological knowledge, there would be no antibiotic resistant bacteria without antibiotics. Some people worry about ever more subtle forms of danger in the modern world, there are those who classify themselves as “Electrosensitive”. Electrosensitives consider the electromagnetic fields produced by electronic products such as computers, cell phones, T.V.s, well almost everything these days, to be harmful in general and to affect them in particular in a variety of ways. Symptoms may include but not be limited to: headache, fatigue, tinnitus, dizziness, memory deficits and irregular heart beat, in fact there are lists including over thirty symptoms ranging from asthma to epilepsy and Alzheimer’s.

Earlier this year researchers at the University of Regensburg conducted a study of self identified electrosensitive sufferers comparing their reactions to non-sufferers when exposed to a heat-emitting thermode and a cell phone. The sufferers experienced discomfort from both stimuli where as non-sufferers only experienced discomfort from the thermode. This was backed up by brain scans of the subjects which indicated that the pain experienced was real. Unfortunately the phone used in the experiment was fake, there were no electromagnetic fields being produced. The sufferers were not making up the pain they felt, it was real to them, but in the same way that a placebo treatment can (allegedly*) make people feel better it appears that the anticipation of pain by the sufferers lead them to feel it, in a sort of nocebo response to the sham phone.

It seems that while these electrosensitive people are not merely attention seeking, as the discomfort they feel is undoubtedly real, neither are they suffering from a disability brought on by exposure to fields that are generally considered harmless. What’s going on here? I have no idea but I’ll be interested to see how further research sheds light on this.

Resources

http://www.sciam.com/podcast/episode.cfm?id=cell-phones-sometimes-cause-real-pa-08-10-13

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WNP-4SB7TW1-4&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_version=1&_urlVersion=0&_userid=10&md5=993618adacb00f6dc3c58a70d580feb2

http://en.wikipedia.org/wiki/Electrical_sensitivity

http://www.electrosensitivity.org/

* It’s complicated, it could be that what we refer to as a placebo response doesn’t actually exist and is really a mislabelling of other factors that have nothing to do with response to treatment. Who knows.

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Superstition Arises from Powerlessness

I’ve written before about the connection between superstitious thinking and feelings of powerlessness, now there is a study that looked at exactly that. Previous connections have mostly been anecdotal or based on the behaviour of people in the real world. In this study the researchers induced a sense of lack of control in participants and then measured how likely they were to report connections between unrelated events or see patterns in noise.

Subjects were preconditioned in at least two ways to create these feelings, in one scenario they were given a task to complete with the help of feedback from a computer, half of the subjects received meaningful feedback that allowed them to complete the task successfully and the other half received random feedback that left them confused. In another experiment the subjects were asked to relate an experience in their lives, again half were to relate an experience were they were in control and the other half one were they were powerless.

Those subjects that that been preconditioned to simulate powerlessness in their lives were more likely than their confident counterparts to see patterns in pictures of “Snow” and more likely to connect unrelated sequences of events. For example in one experiment the subjects read short stories in which superstitious behaviour such as “Knocking on wood” or stamping three times preceded favourable outcomes such as success at work. These subjects were more likely to see a causal relation between these events and to express fear of what might happen if these behaviours were not repeated in future.

Fortunately the researchers also found that self affirming techniques such as focusing on a positive personal value could restore a sense of control and reduce superstitious and false pattern-seeking behaviour. So next time you feel the need to slip into your lucky underwear before an important meeting, just think about how awesome you are instead. That’s what I do.

Resources

http://www.sciencemag.org/cgi/content/abstract/322/5898/115

http://www.eurekalert.org/pub_releases/2008-10/msl-wsi092608.php

http://bhascience.blogspot.com/2008/10/what-connects-superstition-conspiracy.html

http://blogs.mccombs.utexas.edu/mccombs-today/2008/10/whitson-in-science-loss-of-control-behind-superstitions-rituals-conspiracy-theories/

http://arstechnica.com/news.ars/post/20081003-loss-of-control-may-leave-us-looking-for-four-leaf-clovers.html

Rat Brained Robot

This news story has been around for almost a month now but I’m sure there are people who have not encountered it yet, not everyone follows science and technology news. Researchers at the University of Reading in the UK are experimenting with controlling a simple robot with cultures of rat neurons, that’s cool. Rather than attempting to create our hyper intelligent organic/machine successors however these experiments appear to be directed towards understanding brain function and how neurons deal with changes to their environment and cope with disrupting influences. In this way we may make advances in degenerative brain disorders and disruptive syndromes such as Alzheimer’s and epilepsy.

The idea is that if they can connect neurons to an interactive system such as a robot they can then determine how throwing a spanner in the works affects learning and motor control. To do this the researchers remove the cortical material from a rat fetus and reduce it to individual neurons in solution. Once this is achieved they can then introduce the electrodes to a set of approximately 300,000 of the neurons and allow them to grow and make connections between themselves. At this point the neurons begin communicating in earnest and patterns of activity can be seen. The cells are now connected to the output of an ultrasonic sensor and are exposed to the sensor’s electrical output and the teaching begins. Actually, it is difficult to say whether true learning is taking place as the cells are simply monitored for their response to repeated stimulus and repeatable responses are then used to make the robot turn to avoid an obstacle. Once the culture has been “trained” in this way they can alter it chemically, electrically or physically to upset this controllability, they hope to be able to work out some causes and effects that throw light on the disorders mentioned above.

Interesting and enlightening as this work is, I think that for shear creepy coolness it is surpassed by somewhat related research performed in 2002 at the State University of New York Downstate Medical Center that implanted electrodes into a rat to manipulate it’s movement, creating in effect a remote controlled rat. I want one of those.

Resources

http://technology.newscientist.com/channel/tech/mg19926696.100-rise-of-the-ratbrained-robots.html

http://en.wikipedia.org/wiki/Hybrot

http://www.sciam.com/article.cfm?id=researchers-guide-rats-by

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GM Cassava

With the news last week of products containing trace amounts of GM rice being removed from sale here in NZ, I thought I would cover the engineering of another food crop. The Cassava plant is apparently the third largest source of carbohydrates for human food in the world, I’d never heard of it before last week. This plant can be the prime source of sustenance for families in Africa, however it also produces significant levels of cyanide when it is harvested and must be extensively processed before consumption, a task that can take up to several days. It is also relatively poor in vitamins and minerals. As if this wasn’t enough the plant is susceptible to infection by the geminivirus which can reduce yields by 30 percent to 50 percent in many areas in sub-Saharan Africa. With these drawbacks in mind it has been the subject of a genetic engineering project at Ohio State University, the Biocassava project funded by the Gates foundation, to make it a more complete food as well as safer to eat.

The plant does have it’s good points though, one of which being that it can be left in the ground growing for up to three years and so can provide a sustained food source. Given that the plant is often the primary source of calories for a great many people, and for some of those people may make up the bulk of the only meal they eat a day, the project has attempted to make the root a more complete food. The researchers have been able to help the plant accumulate more minerals eg iron and retain precursor vitamins to help your body make A, E, + some B complex vitamins. They have also given the plant increased virus resistance and attempted to reduce the amount of cyanide int the root.

All of which means that the Cassava plant will soon become more productive (through reduced incidence of disease) as well as easier to process and a more healthful meal. It is possible that these changes may even turn the Cassava from a subsistence farming type crop into an income generation crop. The engineered crop is currently undergoing field trails in Puerto Rico with further testing in African countries slated for 2009. Reflecting on the great strides we have made in this sort of engineering and the enormous rewards that can be gained by it’s use I occasionally despair of those who dismiss it with a knee-jerk reaction. I shake my head every time I see a “Keep NZ GE Free” bumper sticker wondering if the driver even understands what they are protesting against.

Resources

http://www.nzherald.co.nz/section/1/story.cfm?c_id=1&objectid=10524361

http://www.nzfsa.govt.nz/publications/media-releases/2008/bt63-rice-080730.htm

http://www.mos.org/events_activities/podcasts&d=2734

http://researchnews.osu.edu/archive/tropicalag.htm

http://biocassavaplus.org/

http://en.wikipedia.org/wiki/Cassava

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