Deep sea mining and an extraordinary CIA plot – http://www.bbc.co.uk/news/science-environment-42994812
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Unlike other insects, praying mantises have a pair of large, forward-facing eyes. Humans and other primates use this kind of stereo sight setup to compare two slightly different viewpoints in order to gauge depth. However, it seems that praying mantises see things differently than we do.
Using beeswax as an adhesive, a team led by Vivek Nityananda at the University of Newcastle affixed lenses to praying mantises’ faces, being careful not to cause injury. One lens was green and the other was blue, a setup that allowed the scientists to control what each eye could see.
The scientists then projected films onto a screen in front of the insects. The first film featured a moving dot, which the mantises attacked, demonstrating that they could perceive depth if an object moved. Then, the dot was manipulated to move in two different directions, a disparity that would prevent human eyes from comprehending the image, but the mantises still attacked it.
This suggests that mantises have a previously unknown type of vision. It relies on targets moving around, but those movements don’t necessarily have to match between one eye and the other. It’s based on motion over time, rather than a direct comparison.
Being insects, mantises have fewer than a million neurons, far fewer than the 85 billion possessed by humans. However, thanks to this unique form of vision they use, they can still see in three dimensions, just like we can.
The researchers noted in a press release that their discovery could lead to the development of an algorithm based on mantis vision. Small robots, such as those used to respond to disasters, could use this algorithm to assess their surroundings without the need for a sophisticated “brain.”
A Key Enzyme
A new study has been able to extend the lifespan of worms and flies by inhibiting RNA polymerase III (Pol III). Since the enzyme is common to all animal species, including humans, researchers hope the discovery could lead to groundbreaking new therapies.
Researchers have long known that Pol III plays a key role in cell growth and the production of proteins, but recent insights revealed that when its activity was reduced during adulthood, the survival of yeast cells (as well as the longevity of flies and worms) could be extended by an average of 10 percent.
“We’ve uncovered a fundamental role for Pol III in adult flies and worms: its activity negatively impacts stem cell function, gut health and the animal’s survival,” commented first author Danny Filer of the UCL Institute of Healthy Ageing, in a press release. “When we inhibit its activity, we can improve all these. As Pol III has the same structure and function across species, we think its role in mammals and humans warrants investigation as it may lead to important therapies.”
Yeast, flies, and worms were selected for the study as they are not closely related, but all bear the enzyme. Various techniques, including insertional mutagenesis and RNA mediated interference, were used to inhibit Pol III and observe the results.
When it was inhibited in the gut of flies and worms, they lived longer. This was also the case when it was inhibited in only the flies’ intestinal stem cells.
The results of Pol III inhibition have been compared to reactions to the immune-suppressing drug rapamycin, which is taken by cancer patients and organ transplant recipients. The drug has previously been shown to extend the lifespan of dogs. This latest study could help researchers better understanding exactly how rapamycin actually works.
“We now think that Pol III promotes growth and accelerates aging in response to a signal inhibited by rapamycin and that inhibiting Pol III is sufficient to result in flies living longer as if they were given rapamycin,” said co-author Dr. Nazif Alic. “If we can investigate this mechanism further and across a wider range of species, we can develop targeted antiaging therapies.”
The rapamycin compound was first discovered on Easter Island and has since been used to create drugs capable of extending the lives of several species. However, there hasn’t been a study of its effects on human subjects — at least not yet.
Gaining a further understanding of the mechanism behind rapamycin could certainly make the idea of a human trial more tenable. The team plans to continue their research into how inhibiting Pol III effects an adult organism, and why doing so results in a longer lifespan. An anti-aging pill is still a long way off, but this type of research could provide some key foundational knowledge.
Why Guyana’s rainforests are a scientist’s dream – and how indigenous people are the first scientists of the forest. Scientists rely on tribal knowledge of the land and species within, then simply promote themselves using or knowledge. Then they leave us forgotten, no acknowledgement, not resources to protect the land, not to become university trained scientists. http://www.bbc.co.uk/news/world-latin-america-42492619
The human brain contains a little over 80-odd billion neurons, each joining with other cells to create trillions of connections called synapses.
The numbers are mind-boggling, but the way each individual nerve cell contributes to the brain’s functions is still an area of contention. A new study has overturned a hundred-year-old assumption on what exactly makes a neuron ‘fire’, posing new mechanisms behind certain neurological disorders.
A team of physicists from Bar-Ilan University in Israel conducted experiments on rat neurons grown in a culture to determine exactly how a neuron responds to the signals it receives from other cells.
To understand why this is important, we need to go back to 1907 when a French neuroscientist named Louis Lapicque proposed a model to describe how the voltage of a nerve cell’s membrane increases as a current is applied.
Once reaching a certain threshold, the neuron reacts with a spike of activity, after which the membrane’s voltage resets.
What this means is a neuron won’t send a message unless it collects a strong enough signal.
Lapique’s equations weren’t the last word on the matter, not by far. But the basic principle of his integrate-and-fire model has remained relatively unchallenged in subsequent descriptions, today forming the foundation of most neuronal computational schemes.
Image credit: NICHD/Flickr
According to the researchers, the lengthy history of the idea has meant few have bothered to question whether it’s accurate.
“We reached this conclusion using a new experimental setup, but in principle these results could have been discovered using technology that has existed since the 1980s,” says lead researcher Ido Kanter.
“The belief that has been rooted in the scientific world for 100 years resulted in this delay of several decades.”
The experiments approached the question from two angles – one exploring the nature of the activity spike based on exactly where the current was applied to a neuron, the other looking at the effect multiple inputs had on a nerve’s firing.
Their results suggest the direction of a received signal can make all the difference in how a neuron responds.
A weak signal from the left arriving with a weak signal from the right won’t combine to build a voltage that kicks off a spike of activity. But a single strong signal from a particular direction can result in a message.
This potentially new way of describing what’s known as spatial summation could lead to a novel method of categorising neurons, one that sorts them based on how they compute incoming signals or how fine their resolution is, based on a particular direction.
Better yet, it could even lead to discoveries that explain certain neurological disorders.
It’s important not to throw out a century of wisdom on the topic on the back of a single study. The researchers also admit they’ve only looked at a type of nerve cell called pyramidal neurons, leaving plenty of room for future experiments.
But fine-tuning our understanding of how individual units combine to produce complex behaviours could spread into other areas of research. With neural networks inspiring future computational technology, identifying any new talents in brain cells could have some rather interesting applications.
This research was published in Scientific Reports.
Misophonia: Scientists crack why eating sounds can make people angry – http://www.bbc.co.uk/news/health-38842561