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(Phys.org)—A team of researchers with Harvard University and the University of Cambridge has successfully improved the accuracy of a synthetic clock known as a repressilator. In their paper published in the journal Nature, the team describes the steps they took to reduce the amount of noise in the biological system and how well it worked. Xiaojing Gao and Michael Elowitz with the California Institute of Technology offer a News & Views piece on the work done by the team and explain how their results could improve understanding of natural gene circuits.

Scientists have noted the high precision that some living cells demonstrate in keeping track of time, such as those that are part of the circadian clock, and have tried to duplicate the process. Sixteen years ago, Michael Elowitz and Stanislas Leibler developed what is now known as the repressilator—a synthetic oscillating genetic circuit. Their results demonstrated that it was possible for genetic circuits to be designed and built in the lab. The resulting circuit functioned, but was noisy, and therefore much less accurate than natural cell clocks. In this new effort, the researchers improved several of the design of the repressilator, each greatly reducing the amount of noise, and in so doing, increased the precision.

The repressilator was made using repressor proteins that would bind to DNA sequences that were adjacent to a gene to be targeted for inhibition. Three repressors were created such that each one represented the expression of the next cycle—when the protein in one repressor increased, it caused a decrease in the expression of the second, which in turn caused an increase in expression of the third, and so on, resulting in oscillations—the actions were monitored by reporters. Unfortunately, each was bothered by random fluctuations known as noise. To reduce the noise, the researchers integrated the reporters into the repressilator, engineered the repressor proteins to degrade in order to reduce the number of copies made, and increased the binding threshold between one of the repressors and the DNA sequence.

For decades the efficient coding hypothesis has been a guiding principle in determining how neural systems can most efficiently represent their inputs. However, conclusions about whether neural circuits are performing optimally depend on assumptions about the noise sources encountered by neural signals as they are transmitted. Here, we provide a coherent picture of how optimal encoding strategies depend on noise strength, type, location, and correlations. Our results reveal that nonlinearities that are efficient if noise enters the circuit in one location may be inefficient if noise actually enters in a different location. This offers new explanations for why different sensory circuits, or even a given circuit under different environmental conditions, might have different encoding properties.

Citation: Brinkman BAW, Weber AI, Rieke F, Shea-Brown E (2016) How Do Efficient Coding Strategies Depend on Origins of Noise in Neural Circuits? PLoS Comput Biol 12(10): e1005150. doi:10.1371/journal.pcbi.1005150

Editor: Jeff Beck, Duke University, UNITED STATES

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Watching millions of neurons in the brain interacting with each other is the ultimate dream of neuroscientists! A new imaging method now makes it possible to observe the activation of large neural circuits, currently up to the size of a small-animal brain, in real time and three dimensions. Researchers at the Helmholtz Zentrum München and the Technical University of Munich have recently reported on their new findings in Nature’s journal ‘Light: Science & Applications’.

Nowadays it is well recognized that most brain functions may not be comprehended through inspection of single neurons. To advance meaningfully, neuroscientists need the ability to monitor the activity of millions of neurons, both individually and collectively. However, such observations were so far not possible due to the limited penetration depth of optical microscopy techniques into a living brain.

A team headed by Prof. Dr. Daniel Razansky, a group leader at the Institute of Biological and Molecular Imaging (IBMI), Helmholtz Zentrum München, and Professor of Molecular Imaging Engineering at the Technical University of Munich, has now found a way to address this challenge. The new method is based on the so-called optoacoustics*, which allows non-invasive interrogation of living tissues at centimeter scale depths.

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The nerves we feel before a stressful event—like speaking in public, for example—are normally kept in check by a complex system of circuits in our brain. Now, scientists at Rockefeller University have identified a key molecule within this circuitry that is responsible for relieving anxiety. Intriguingly, it doesn’t appear to reduce anxiety in female mice, only in males.

“This is unusual, because the particular cell type involved here is the same in the male and female brain—same in number, same in appearance,” says Nathaniel Heintz, head of the Laboratory of Molecular Biology and a Howard Hughes Medical Institute investigator. “It’s a rare case where a single cell type is activated by the same stimulus but yields two different behaviors in each gender.”

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Friday, October 14, 2016 by: Ethan A. Huff, staff writerTags: trees, social communication, plant science (NaturalNews) If trees could talk, what would they say? Emerging research suggests that if they had mouths, they might just say a whole lot because, believe it or not, trees have brains and intelligence, and are able to communicate with other trees much like humans do with other humans when in social situations.

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The elders declare that the sun rises at a different position now, not where it used to previously. They also have longer daylight to hunt now, the sun is much higher than earlier, and it gets warmer much quickly.


Global Climate Change: The Earth Has Shifted, Say Inuit Elders. A new warning has come to NASA from the Inuits. They are warning that the change in climate is not due to global warming but rather, because of the Earth shifting a bit.

The Inuits are local people that live in the Arctic regions of Canada, the United States and Greenland. They are excellent weather forecasters and so were their ancestors. Presently they are warning NASA that the cause of change in weather, earthquakes etc, are not due to global warming as the world thinks. They also report that.

The Tesla Gigafactory is key to the automaker’s planned production ramp up to 500,000 cars per year by 2018. It is expected to both significantly reduce the cost of Tesla’s battery packs, which will enable Tesla to reach the $35,000 price point for the Model 3, and to secure a large supply of battery cells.

Those two products, battery cells and battery packs, were until now the only products expected to be manufactured at the factory.

We now learn that Tesla plans to also manufacture drive units at the plant. With vehicle battery packs, the automaker will be closer to producing its entire next generation powertrains at what is expected to be the largest factory in the world by footprint.

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We are seeing lot of inventions being made prior to the upcoming Mars missions. However, you don’t have to be into science-fiction to understand that NASA still needs to get a grip on many technical hurdles before our astronauts can put their boots on the red planet safely.

Yes, [Mark Watney](http://www.imdb.com/title/tt3659388/) has become quite a Martian but real humans need more to survive and especially have to consider the *less obvious* things like how to deal with injuries that far away from mother Earth. That can be overlooked, but certainly is important.

As there’s only so much space on a trip to Mars, there will be limited access to medical care due to supply restrictions. Expertise to manage complex medical conditions might also be hard to come by.

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I really love this topic – questioning what’s out there for humanity besides a singularity that may or may not happen or a discovery of the source powering an uber sophisticated kind of video game a.k.a. the *simulated* and likely *holographic universe*… Yes, evolution gets me all excited.

What follows now are possible futures for all of us, based on circulating theories on (continuing) evolution.

These futures show either a grinding halt to evolution, a continuing mutation and selection here on earth, some new form of evolution driven by technology, and (in a way related to technology, as well) a differentiation introduced by mimicking and adapting to a life on speculative space colonies.

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