The top three news stories of the week, as chosen by our resident students. This week’s top stories include artificial T cells, horses tuning in to our emotions and invisibility science.
By Iveta Ivanova
Researchers Create Artificial T-cells
T-cells (or T-lymphocytes) are a type of white blood cells which are crucial for our defences against foreign pathogens. A number of autoimmune diseases, infections and cancer are at least partly caused by inappropriate activation or regulation of T-cells. While patrolling the human body as part of their immunological surveillance, T-cells can deform to reduce their size down to 25% of their original size in order to squeeze in miniature pores! Once they recognise a foreign marker on the surface of another type of immune cells called Antigen Presenting Cells they become activated. Upon activation, they can significantly increase their flexibility and size by reducing their stiffness – about three-fold! The unique property to stretch and contract to such a large extent has inspired numerous attempts to replicate the T-cell shape and size using biomaterials. Similar physical properties are observed in some cancer cells, with their reduced stiffness allowing them to squeeze and spread to narrow locations less accessible by healthy cells. Hence T-cells are an intriguing subject of study in the area of biomimicry – using models, systems and processes from nature as inspiration to develop new models to solve human problems.
A team of researchers at UCLA utilised the power of microfluidics to produce biomaterials with properties closely mimicking those of T-cells, but this time utilising their unique mechanic properties mentioned above. The researchers used mineral oil and a biopolymer mixture to successfully create microparticles with identical elasticity, structure and form to that of our own T-cells. They then coated the structures with lipids, similar to the coating real cells have, and added a number of signalling molecules crucial to the immune function of T-cells. Finally, they developed a miniature 3D scaffold to test the microparticles’ ability to penetrate different environments. Once they managed to mimic the mechanic as well as the biological properties as well, these miniature polymer materials could behave exactly as our very own T-cells – targeting infections and releasing special chemicals to fight them.
Understanding and replicating the mechanic properties of T-cells could therefore be a huge stepping stone to the engineering of more effective drug carriers for cancer or autoimmune therapies.
How horses read our emotions
Horses are often overlooked when it comes to the title “man’s best friend” – it is fascinating to consider the fact that they have been living and working closely with humans in agriculture, in battlefields, in sports and leisure for more than 5 000 years. Throughout all these years, humans and horses have developed an impeccable way to communicate with each other, in the language of … emotion.
It has long been noticed that horses are particularly sensitive creatures, but scientists are now interested in backing this up with solid scientific facts – as we do. Previous research in this area has shown that horses can distinguish between different moods and they can even remember human emotion. They then use this emotion memory in their future interactions with the given human – much like us people do! The sophisticated ability of horses to read human facial expressions is one that has only been seen before in dogs – our even longer-standing best friend in the animal world.
People are now interested to find out the mechanisms behind this extraordinary ability. Most recently, researchers from University of Hokkaido, Japan set to find out whether horses can interlink various human features in order to read us – they refer to this concept as cross-modallity. The scientists discovered that horses integrate both voice tones and facial expressions when interpreting human emotions, and this happens whether the person is familiar to them or a total stranger.
They presented the horses with individual photographs of human faces – some less happy than others – each photo accompanied with a pre-recorded voice that either matched the facial expression or not. They found that when the facial expression and voice were not in harmony (i.e. a happy face was accompanied by a scolding voice), horses stared significantly longer at the screen, if the person was familiar to them. They also responded up to 2 times more quickly to such mismatched human behaviour, regardless whether the person was familiar or not. This shows that horses experienced confusion as there was a clear discrepancy in the expected vs observed voice tone accompanying the facial expression.
One step closer to being invisible
The science story creating the biggest buzz in the last week has been the quest of a team of researchers from Montreal to take the invisibility cloak out of the Harry Potter books and into the real world.
Actually, the idea of making objects at least partially invisible has been around for a number of years, and in the scientific world is known as “optical cloaking”. It works by manipulating the way light interacts with the material and has been achieved in a number of ways – such as forcing the light waves to bypass the object and most often –concealing the object from one wavelength (colour) of the electromagnetic spectrum, .
The problem with this is that most light sources, such as the Sun, possess a broad range of colours, not only one wavelength. Some of the light is absorbed or freely transmitted through the object, while other parts of it are scattered or reflected. The reflected light is what makes the object visible to us. In other words, the reason something appears green to us is because it absorbs all the other colours it is illuminated with, only reflecting back the green light.
The team, led by José Azaña, have found a way to bypass this well-known physical effect using a so-called cloaking device. In simple terms, as the light reaches the object, its wavelength is transformed in a different state that allows it to freely go through the object – i.e. in a “colour” that the given object does not absorb or scatter. It is then transformed back to its exact original state so the light exits the object as if no change ever occurred – apart from the fact it freely penetrated through the object, instead of being reflected off it. They call this development “spectral cloaking”.
Currently its effect has been proven on a one-dimensional object that absorbs a very specific colour, but the researchers claim this is an important stepping stone to making 3D objects under broad daylight invisible. Its impact on security and military could be huge. Spectral cloaking could be used to create aircrafts invisible to radar, create hacker-proof ultra-secure internet cables, as well as to secure fibre optic lines from unwanted evesdroppers.