Showing posts with label Technology. Show all posts
Showing posts with label Technology. Show all posts

Why Blind Mole Rats Don't Get Cancer



By Ian Steadman, Wired UK


Blind mole rats don’t get cancer, and geneticists have worked out why: Their cells kill themselves with a poisonous protein when they multiply too much.


Mole rats, which live in underground burrows throughout Southern and Eastern Africa, and the Middle East, are fascinating creatures. The naked mole rat, in particular, is the only cold-blooded mammal known to man, doesn’t experience pain, and is also arguably the only mammal (along with the Damaraland mole rat) to demonstrate eusociality — that is, they live in large hierarchical communities with a queen and workers, like ants or bees.

They’re also cancer-proof, which was found in 2011 to be down to a gene that stops cancerous cells from forming. The same team thought that two other cancer-proof mole rat species might have similar genes, but instead it turns out that they do develop cancerous cells. It’s just that those cells are programmed to destroy themselves if they become dangerous.



The two species examined by the University of Rochester’s Vera Gorbunova and her team were the Judean Mountains blind mole rat (Spalax judaei) and the Golan Heights blind mole rat (Spalax golani), which live within small regions of Israel. The team took cells from the rodents and put them in a culture that would force them to multiply beyond what would happen within the animals’ bodies. For the first seven to 20 multiplications, things looked fine, but beyond 20 multiplications the cells started rapidly dying off.


Examining the cells as they died revealed that they had started to produce a protein, IFN-β, that caused them to undergo “massive necrotic cell death within three days”. In effect, once the cells had detected that they had multiplied beyond a certain point, they killed themselves.


It contrasts with the self-preservation method seen in the cells of naked mole rats, which have a hypersensitivity to overcrowding, which stops them from multiplying too much. In the Proceedings of the National Academy of Sciences, Gorbunova hypothesizes that the blind mole rats’ unique habitat — almost entirely underground — might mean that they “could perhaps afford to evolve a long lifespan, which includes developing efficient anti-cancer defences”. Blind mole rats have extremely long lifespans by rodent standards, often living beyond 20 years at a time.


The reasons why this is, though, are still all hypothetical, as the precise mechanism that triggers the production of the IFN-β is still unknown. The hope is that this research could eventually lead to new therapies for cancer in humans.


Source: Wired.co.uk


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Math Problems Can Be Physically Painful



By Ian Steadman, Wired UK


How much do you hate doing sums? Long division? Fractions? Calculus?


For many people the thought of these kinds of problems is horrible. Painful, even. A study by psychologists Ian Lyon and Sian Beilock has shown that that’s not hyperbole — some people who dislike math do so because the thought of working out things with numbers is experientially similar to physical pain. For people with “high levels of mathematics-anxiety” (HMAs), maths hurts.

Lyon and Beilock, from the University of Chicago and Western University, respectively, were intrigued by other studies that had shown that some people experience social rejection in a way comparable to actual pain, and that it seems to be experienced relative to the amount of anxiety people feel. Maths, they figure, also generates a fair bit of anxiety in people: “Mathematics … anxiety is an ideal test bed for expanding our understanding of how physically innocuous situations might elicit a neural response reflective of actual physical pain,” they wrote.



The hypothesis was that the expectation of having to do maths would be the thing to generate the anxiety, which would in turn generate pain. They asked for participants to answer survey questions about how anxious maths problems made them feel, whittling it down to two samples of 14 people each — one group of HMAs, and one group of LMAs (that is, low anxiety about mathematics). The criteria for quantifying anxiety was based on the Short Math Anxiety Rating-Scale (SMARS), a scale specifically designed in 1972 for measuring how anxious people get about the idea of getting maths (and it says something about how widespread an issue this is that there’s already a psychological scale for measuring it).


The 28 people were asked a series of word and number puzzles while their brains were scanned with an MRI machine. As they lay inside the machine, a coloured light would flash up before each set of questions appeared, signalling whether it would be language or maths questions that followed, and what difficulty (either easy or hard) they would be. This was key to testing the hypothesis that it’s the expectation that triggers the unpleasant sensations, not the actual puzzles themselves.


When it came down to easier maths and word questions, there was no difference between the two groups of HMAs and LMAs. For the harder questions, though, HMAs “significantly” underperformed LMAs, which makes sense — people who are very anxious tend to perform worse at tasks that require lots of thought.


Looking at the differences in brain activity between the HMAs and LMAs when working on the harder maths questions, Lyon writes that “four regions — bilateral dorso-posterior insula, mid-cingulate cortex, and a dorsal segment of the right central sulcus — showed a significant interaction, driven by a positive relation between SMARS and math-cue-activity and a negative relation between SMARS and word-cue-activity”. For HMAs, their ability to perform harder maths problems was impacted more the greater their score on the SMARS assessment; there was no such correlation when it came to word problems. Interestingly, the correlation also only held for HMAs — for LMAs, their scores on the SMARS had a “non-significantly negative” relation to their ability to solve any of the maths problems.


The dorso-posterior insula and mid-cingulate cortex are parts of the brain that are associated with the experience of pain — the results showed that, when HMAs saw the light that corresponded to a hard maths problem, their brains anticipated the questions as a “a visceral, aversive bodily reaction”.


In the conclusion, Lyon writes: “We provide the first neural evidence indicating the nature of the subjective experience of math anxiety. Previous research on the overlap between pain processing and psychological experience of social rejection has focused primarily on the actual experience of being rejected [but] our data go beyond these results and suggest that even anticipating an unpleasant event is associated with activation of neural regions involved in pain processing.”


There are also implications for the theory that this kind of experience of pain is something inherent in humans thanks to evolution. Lyon considers it “unlikely that a purely evolutionary mechanism would drive a neural pain response elicited by the prospect of doing math (as math is a recent cultural invention)”. That means the pain pathways in the brain can be activated by things that have no relation to painful experiences — which could shed light on other psychological phenomena like phobias.


Since it’s the anticipation of mathematics that seems to get people the most, rather than the actual sums themselves, it might be worth investigating whether there’s a different way of teaching maths in schools. It could also mean taking the time to simplify the process for returning a tax return, for example. Governments often wring their hands over how many adults are effectively mathematically illiterate after leaving school, but maybe it’s not their fault they couldn’t concentrate in class. They might well have just been scared of the number seven (because, after all, seven ate nine).


Source: Wired.co.uk


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Asteroid Belts Could Be Key to Finding Alien Life



By Ian Steadman, Wired UK


If we want to find intelligent life elsewhere in the universe, it might be wise to look for stars with asteroid belts similar the one in our own Solar System.


According to the theory of punctuated equilibrium, evolution goes faster and further when life has to make rapid changes to survive new environments — and few things have as dramatic an effect on the environment as an asteroid impact. If humans evolved thanks to asteroid impacts, intelligent life might need an asteroid belt like our own to provide just the right number of periodic hits to spur evolution on. Only a fraction of current exoplanet systems have these characteristics, meaning places like our own Solar System — and intelligent aliens — might be less common than we previously thought.


Astronomers Rebecca Martin of the University of Colorado in Boulder and Mario Livio of the Space Telescope Institute in Baltimore have hypothesised that the location of the Solar System’s asteroid belt — between Jupiter and Mars — is not an accident, and actually necessary for life. As the Solar System formed, the gravitational forces between Jupiter and the Sun would have pulled and stretched clumps of dust and planetoids in the inner Solar System. The asteroid belt lies on the so-called “snow line” — fragile materials like ice will stay frozen further out, but closer in they will melt and fall apart.

During the formation of the Solar System, cold rock and ice coalesced into the planets as we know them. However, as Jupiter formed, it shifted in its orbit closer to the Sun just a little bit before stopping. The tidal forces at work between Jupiter and the Sun would have torn apart the material on the snow line, preventing a planet forming and leaving behind an asteroid belt — which today has a total mass only one percent of that which would have been there originally.


Those asteroids would have bombarded the inner Solar System — including Earth — and, in theory, provided the raw materials needed for life (like water) and also giving evolution a kickstart by drastically changing the early Earth’s climate and environment. To check that this wasn’t just something restricted to our Solar System, Martin and Livio looked at data from Nasa’s Spitzer telescope, which has so far found infrared signals around 90 different stars which can indicate the presence of an asteroid belt. In every case, the belts were located exactly where Martin and Livio had predicted the snow line should be relative to each star’s mass, supporting their snow line theory of asteroid belt formation.


If these are the circumstances which allow intelligent life to evolve somewhere, then it will make the task of finding aliens we can chat with a lot harder — few stars with exoplanets that we’ve found so far have the right setup of a dusty asteroid belt on the snow line with a gas giant parked just outside it.


If the gas giant has formed but not shifted in slightly, as Jupiter did, then the belt will become so full of large objects that the inner planets will be bombarded too frequently for life to fully take hold; if the gas giant continues to move inwards as it orbits, it won’t just stop the belt turning into a planet — it’ll suck everything of any serious size up and leave behind only minor fragments of space rock and dust, including any planets life could evolve on.


Martin and Livio then looked at 520 gas giants found orbiting other stars — in only 19 cases were they outside of where that star’s snow line would be expected to be. That means fewer than four percent of exoplanet systems will have the right setup to support the evolution of advanced, intelligent life in accordance with the punctuated equilibrium theory.


Martin, the lead author of the research, published in Monthly Notices of the Royal Astronomical Society, writes: “Our study shows that only a tiny fraction of planetary systems observed to date seem to have giant planets in the right location to produce an asteroid belt of the appropriate size, offering the potential for life on a nearby rocky planet. Our study suggests that our Solar System may be rather special.”


Source: Wired UK


Image: NASA/JPL-Caltech


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