Scientists edge closer

Scientists have edged closer to growing replacement bones with stem cell technology.
Molly Stevens, professor at Imperial College London and author of a new study said: 'Our study brings us one step closer to developing materials that will have the highest chance of success when implanted into patients.'
The effort is on to create bone-like materials, derived from stem cells, to implant into patients who have damaged or fractured bones, or who have had parts of diseased bones removed.
The idea is that, eventually, these bone-like materials could be inserted into cavities so that real bone could meld with it and repair the bone.
So far, scientists have found they can grow small 'nodules' of what appeared to be bone-like material in the lab from different types of bone cells and stem cells.
All of these cell types are attracting considerable interest as promising candidates for future implants in people with clinical trials already underway.
However, scientists still need to thoroughly explore and understand the in-depth chemical properties and structure of the bone-like materials they are growing.
Now, scientists at Imperial College have compared the 'bone-like' material grown
from three different commonly used clinically relevant cell types and have discovered
significant differences between the quality of bone-like material that these can form.
For example, the researchers have discovered that the 'bone-like' materials that were grown from bone cells from mouse skull and mouse bone marrow stem cells successfully mimicked many of the hallmarks of real bone, which include stiffness.
However, they found that the 'bone-like' material grown from mouse embryonic stem cells was much less stiff and less complex in its mineral composition when compared to the other materials, said an Imperial College release.
These results were published in Nature Materials.

lack of temptation

Is honesty or truthfulness a by-product of lack of temptation? In a recent study, Harvard psychologists looked at the brain activity of people given the chance to gain money dishonestly by lying.
The study was designed to test the 'Will' theory that postulates honesty is a by-product of active resistance to temptation, and 'Grace' theory in which honesty stems from a lack of temptation.
Using neuroimaging, the researchers found that honest people showed no additional activity when telling the truth. However, those who behaved dishonestly, even while telling the truth, showed additional activity in brain regions that involve control and attention.
The results suggest that the 'Grace' theory is true, because the honest participants did not show any additional brain activity when telling the truth.
'Being honest is not so much a matter of exercising willpower as it is being disposed to behave honestly in a more effortless kind of way,' said Joshua Greene, psychologist at Harvard University.
To prompt participants to lie, they created a cover story about the focus of their study -- paranormal ability to predict the future.
Participants were told to predict the outcomes of a series of coin tosses, and were told that the researchers believed predicting the future was more likely when given a monetary incentive and when the prediction wasn't shared in advance of the outcome.
This gave the participants the opportunity to lie and say that they had correctly predicted the coin toss to win the money.
Individuals who reported improbably high levels of accuracy were classified as dishonest, and participants reporting statistically feasible levels of accuracy were classified as honest.
Using fMRI, Greene found that the honest individuals displayed little to no additional brain activity when reporting their prediction of the coin toss, said a Harvard release.
However, dishonest participants' brains were most active in control-related brain regions when they chose not to lie.
The study was published in Proceedings of the National Academy of Sciences.