Scientists have just uncovered a major difference between DNA and RNA

Time to update the textbooks.

A new study has shown for the first time that RNA - the older molecular cousin of DNA - splits apart when it tries to incorporate change, while DNA can contort itself and change its shape to compensate for any chemical damage.

The research could finally explain why the blueprint of life is made from DNA and not RNA - and it could also prompt a rewrite of the textbooks.

"For something as fundamental as the double helix, it is amazing that we are discovering these basic properties so late in the game," said lead researcher Hashim Al-Hashimi from the Duke University School of Medicine. "We need to continue to zoom in to obtain a deeper understanding regarding these basic molecules of life."

Back in 1953, Watson and Crick first published their model of the DNA double helix, and predicted how the base pairs - A & T and G & C - fit together.

You're probably pretty familiar with that formation by now - two strands of DNA are linked up by the bonding of the base pairs, forming ladder rungs that hold together the twisted ladder of DNA.

But researchers struggled to find evidence that the base pairs were bonding in the way that Watson and Crick had predicted - something they called Watson-Crick base pairs. Then in 1959, biochemist Karst Hoogsteen managed to take a picture of an A–T base pair, showing a slightly more skewed geometry, with one base rotated 180 degrees relative to the other.

Since then, researchers have observed both Watson-Crick and Hoogsteen base pairs in images of DNA.

But five years ago, Al-Hashimi and the Duke team found something that had never seen before: DNA base pairs constantly morphing back and forth between Watson-Crick and the Hoogsteen bonding configurations. This adds a whole other dimension and level of flexibility to DNA's structure.

It turns out that DNA appears to be using Hoogsteen bonding when there's a protein bond to a DNA site - or if there's chemical damage to any of its bases - and once the damage is fixed or the protein is released, the DNA goes back to Watson-Crick bonds.

That discovery was a big deal in itself, but now the team has shown for the first time that RNA doesn't have this ability, which could explain something that scientists have puzzled over for years: why DNA forms the blueprint for life, not RNA.

So, while DNA will absorb chemical damage and adapt to work around it, RNA becomes too stiff and falls apart, making DNA the better structure to pass genetic information down between the generations. 

"In DNA this modification is a form of damage, and it can readily be absorbed by flipping the base and forming a Hoogsteen base pair. In contrast, the same modification severely disrupts the double helical structure of RNA," said one of the team, Huiqing Zhou.

"The finding will likely rewrite textbook coverage of the difference between the two purveyors of genetic information, DNA and RNA," said a Duke Universitypress release. 

You can see DNA on the left performing Hoogsteen bonding to incorporate damaged base-pairs, while RNA on the right falls apart:

Huiqing Zhou

The researchers were able to figure this out by creating double-helices out of RNA and DNA, and using advanced imaging techniques to watch how its base pairs were bonding.

They were able to show that, at any one time, around 1 percent of the DNA bases were changing into Hoogsteen base pairs. But the same thing wasn't seen in the RNA strands.

They tested more of these RNA double-helices under a whole range of conditions, but none of them ever seemed to change to Hoogsteen base pairs. They even forced RNA into forming these Hoogsteen base pairs just to see if it could happen, but as soon as they did, the RNA strands fell apart.

The team explains that this is because the RNA double helical structure is more packed together compared to DNA, and because of that, one RNA base can't change direction without hitting another one or shifting atoms, and ripping the whole structure apart.

"There is an amazing complexity built into these simple beautiful structures, whole new layers or dimensions that we have been blinded to because we didn't have the tools to see them, until now," said Al-Hashimi.

Further research is needed to test the hypothesis that it's this flexibility of DNA, and not RNA, that led to DNA becoming the blueprint of life, but if confirmed, it could help us understand why life on Earth evolved to be the way it is.

And it's pretty cool that after all these years, we're still learning new things about the molecules that make us who we are.

Scientists have found 15 genetic variations that could be linked to depression

The first step to beating depression.

It’s the leading disability worldwide and it can kill.

Yet for decades, scientists have known surprisingly little about what genes are linked with the development of Major Depressive Disorder (MDD).

A new study aims to change that. In their paper, published Monday in the journal Nature Genetics, a team of scientists pinpointed 17 genetic tweaks, or SNPs (pronounced 'snips'), that appear to be tied to MDD.

The researchers combed through a trove of genetic data from thousands of people who submitted their information to the personal genomics company 23andMe.

Scientists have been looking for such genetic hallmarks of depression for years. And while some, including a 2013 study in the journal The Lancet and a 2015 paper in the journal Nature, have yielded some promising clues, none have been able to spot any precise, reliable genetic hallmarks of the disease.

And least, not until now.

"My group has been chasing depression genes for more than a decade without success, so as you can imagine we were really thrilled with the outcome,"Harvard psychiatry professor Roy Perlis, one of the leading authors of the paper and the Associate Director of the Psychiatric Genetics Program at Massachusetts General Hospital, told Business Insider.

The hope is that identifying these watermarks in our DNA - tiny areas on genes where high amounts of variation tend to occur among individuals - will help usher in a series of new, more precise treatments for people suffering from the disease.

"But this is really just the beginning. Now the hard work is understanding what these findings tell us about how we might better treat depression," said Perlis.

Using 23andMe data to uncover clues about depression

23andMe is a personal genomics company that lets you spit in a tube and get your DNA analysed for US$199. Most of the attention they have attracted recently has been focused on its tiffs with federal regulatory agencies like the FDA, who threatened to pull its tests because they were giving unauthorised 'medical advice'.

But other research that the company is involved with has attracted less fanfare.

In a recent StarTalk interview with host Neil de Grasse Tyson, 23andMe CEO Anne Wojcicki said:

"We are about individuals accessing, understanding, and benefiting from the human genome. The genome has a massive potential to transform healthcare. And we got a million people genotyped, so now we have a million people running around going to their doctors and talking about genetics, and that has the potential to be disruptive."

This study - which drew from 23andMe data - could be one example of this disruptive potential.

Psychiatric diseases, since they are the result of a complex mix of genetics, environment, and behavioural factors, require large numbers of people, or what’s known as a large sample size.

In the past, recruiting these large numbers of people, not to mention screening and interviewing each potential participant, has been extremely expensive and labour-intensive. In contrast, the current study drew from research that had already been done.

"We thought, what can we do with this huge set of data that’s already been collected by 23andMe?" said Perlis.

Quite a lot, it turns out.

Using data from more than 75,600 people who said they’d been clinically diagnosed with depression and from more than 231,700 people who reported no history of depression, Perlis and his team were able to identify 15 areas on our DNA that appear to be linked with Major Depressive Disorder.

They also found some ties between these areas and those which have been previously identified as possibly playing a role in other psychiatric disorders, such as schizophrenia.

Still, the data has some limitations. For one thing, it’s based on self-reports, meaning that only people who were experiencing problematic symptoms and went to a doctor to seek help were included.

As a result, the data could exclude the many people who experience major depressive disorders, but have not yet been diagnosed. On the other hand, it could also include people who have been wrongfully diagnosed.

"What we might be identifying here is something much more to do with help-seeking behaviour than anything to do with a psychiatric illness," University of California, Los Angeles professor of psychiatry Jonathan Flint told The Guardian.

Regardless of its limitations, however, the research hits home the message that diseases of the brain, such as depression or Alzheimer’s are no less real - and no less serious - than diseases of the body, like cancer.

"Beyond giving us this so much data to explore," said Perlis, "being able to show that depression is a brain disease, that there is biology associated with it, I think that’s really critical for people to understand that these are brain diseases. They’re not someone’s fault. They are diseases, like any other."

Computers will require more energy than the world generates by 2040

Moore's Law is about to hit a wall.

Scientists have predicted that unless radical improvements are made in the way we design computers, by 2040, computer chips will need more electricity than what our global energy production can deliver.

The projection could mean that our ability to keep pace with Moore's Law – the idea that the number of transistors in an integrated circuit doubles approximately every two years – is about to slide out of our grasp.

The prediction about computer chips outpacing electricity demand was originally contained in a report released late last year by the Semiconductor Industry Association (SIA), but it's hit the spotlight now, due to the group issuing its final roadmap assessment on the outlook for the semiconductor industry.

The basic idea is, that as computer chips become ever more powerful thanks to their greater transistor counts, they'll need to suck more power in order to function (unless efficiency improves).

Semiconductor manufacturers can counter this power draw by clever engineering, but the SIA says there's a limit to how far this goes in current methods.

"Industry's ability to follow Moore's Law has led to smaller transistors but greater power density and associated thermal management issues," the 2015 report explains.

"More transistors per chip mean more interconnects – leading-edge microprocessors can have several kilometres of total interconnect length. But as interconnects shrink they become more inefficient."

In the long run, the SIA calculates that, at the rate things are going using today's approaches to chip engineering, "computing will not be sustainable by 2040, when the energy required for computing will exceed the estimated world's energy production".

You can see the problem graphed in the image below, with the power draw of today's mainstream systems – the benchmark line, represented in orange – eclipsing the world's projected energy production sometime between 2035 and 2040.

These days, chip engineers stack ever-smaller transistors in three dimensions in order to improve performance and keep pace with Moore's Law, but the SIA says that approach won't work forever, given how much energy will be lost in future, progressively denser chips.

SIA

"Conventional approaches are running into physical limits. Reducing the 'energy cost' of managing data on-chip requires coordinated research in new materials, devices, and architectures," the SIA states.

"This new technology and architecture needs to be several orders of magnitude more energy efficient than best current estimates for mainstream digital semiconductor technology if energy consumption is to be prevented from following an explosive growth curve."

The challenge then is well and truly on for today's computer engineers and scientist, with the SIA's new roadmap report also advising that, beyond 2020, it will become economically unviable to improve chip performance by traditional scaling methods, such as shrinking transistors.

It's a huge ask, but the next leaps in computing efficiency and research might need to come then from areas not strictly related to transistor counts – and hopefully the spirit, if not the specifics, of Moore's Law continues in the coming decades.

"That wall really started to crumble in 2005, and since that time we've been getting more transistors but they're really not all that much better," computer engineer Thomas Conte from Georgia Tech told Rachel Courtland at IEEE Spectrum.

"This isn't saying this is the end of Moore's Law. It's stepping back and saying what really matters here – and what really matters here is computing."

Physicists observe brand-new state of matter in an unexpected material

                                                    Curiouser and curiouser.

Back in April, the physics world freaked out when scientists confirmed that they'd made the first direct observation of a brand-new state of matter - known as quantum spin liquid - for the first time.

But now a team of physicists has just announced that they've observed quantum spin liquid state again... and this time in a material where it should be impossible.

The discovery could change our understanding of how to make quantum computing work.

"We have proved empirically that interesting quantum states like spin liquids can also occur in considerably more complex crystals with different constellations of magnetic interactions," said lead researcher Christian Balz, from the Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) in Germany.

"This could be important for the advancement of quantum computers in the future because spin liquids are one of the possible building blocks for carrying the smallest unit of quantum information, known as a qubit," added one of the senior researchers Bella Lake.

Let's back up a second, because all this isn't as confusing as it sounds.

Spin in the quantum world doesn't actually mean an electron is physically spinning. It refers to a type of intrinsic angular momentum that simply describes how an electron is behaving. In quantum computing we often simplify this by saying the spin state is down, up, or in superposition (both at the same time).

Quantum spin liquid is a state of matter that, very simply, occurs when the spin of electrons continue to fluctuate in a fluid manner even at very low temperatures, when they should be frozen in place.

It's like atoms inside regular materials. When they're in a fluid state, they're moving freely. But when temperatures drop, they'll freeze in place in a solid arrangement. That should happen with spin orientation in magnetic materials, but in quantum spin liquid state, it doesn't.

Even though it was predicted in 1973, the new state of matter was only observed for the first time this year, in a two-dimensional, graphene-like material.

That discovery made a lot of sense, because the material fit our understanding of how spin liquid state arises.

Basically, the criteria is that a material has to have has anti-ferromagnetic - or antiparallel - interactions, which, as the name suggests, is the opposite to ferromagnetic interactions in materials such as iron and nickel.

It means that if one electron has a 'down' spin, the one next to it has to have an 'up' spin, and so on.  

Anti-ferromagnetic materials on their own don't necessarily enter quantum spin liquid state, unless they also happen to have a triangular atomic arrangement, which makes this alignment impossible. 

So, just imagine three atoms at the corner of a triangle - they're never all going to be in parallel alignments because as soon as one changes to match the one to its right, the one on its left will have to change, and so on and so on. They'll keep flipping their alignment even at absolute zero temperature - hence, quantum spin liquid state.

But the new research suggests that our criteria isn't quite right, because the German team were able to observe the new state of matter occurring in a material that doesn't fit that profile.

The material in question is a monocrystal of calcium chromium oxide (Ca10Cr7O28).

Calcium-chromium oxide is made up of what are known as Kagomé lattices - named after the pattern of triangles and hexagons woven in Japanese baskets.

Basically that means the material has a complex mix of anti-ferromagnetic interactions, but also much stronger ferromagnetic interactions, which, according to conventional understanding, should prevent quantum spin liquid behaviour.

But through a range of scattering and spectrometry experiments in Germany, France, England, Switzerland, and the US, the team was able to show that this wasn't the case - quantum spin liquid state was happening even at temperatures as low as 20 millikelvin (around –273 degrees Celsius).

So what's going on here? Fortunately, the team has already come up with a hypothesis to explain why this material could behave like a quantum spin liquid without breaking our conventional understanding of the state of matter.

Using numerical simulations, they've shown that competition is the key to the strange behaviour - different magnetic interactions in the materials are competing with each other, and keeping the spins flip-flopping around.

You can see that happening in the illustration below, which shows the competing interactions on each atom (the grey and black balls). The green and red sticks represent ferromagnetic interactions, while the blue sticks represent anti-ferromagnetic interactions, which are forcing the spins to keep changing.

HZB

"The work expands our understanding of magnetic materials, and also shows us that there are potentially far more candidates for spin liquids than expected,"said Lake.

The research has been published in Nature Physics, and now needs to be verified by other teams before we say for sure that quantum spin liquid state can exist in these new types of materials.

But it's a pretty exciting study that hugely widens the potential pool of materials that we could use in future to build quantum computers. We can't wait to find out more.

Scientists just found an advanced form of malware that's been hiding for at least 5 years

                                                        Welcome to Project Sauron.

Security researchers have announced the discovery of an advanced malware platform that has operated undetected for at least five years.

According to experts, "ProjectSauron" is so advanced and well designed that it's likely the work of a state-sponsored hacking group – ie. backed by a government intelligence organisation.

The malware has been active since at least 2011, targeting high-profile networks in Russia, China, Sweden, and other countries.

Researchers at computer security firms Symantec and Kaspersky Lab detected the malware in a joint effort, and say it's been discovered in more than 30 infected sites so far – including an airline in China, an embassy in Belgium, and an unidentified organisation in Sweden.

Unlike the kind of consumer-targeting malware that affects regular PCs, ProjectSauron – which also goes by the name Remsec – has a more specific focus, although it does run on common Microsoft Windows platforms.

The malware is designed to infiltrate computer networks run by organisations such as governments, military sites, scientific research centres, and corporate IT systems.

It aims to spy on infected networks, opening a back door to compromised systems, logging keystrokes, and stealing personal information, like user credentials and passwords.

Kaspersky Lab

The ProjectSauron name comes from references to "Sauron" in the malware's code (see the image above), and Symantec says it's been created by a previously unknown hacking group called Strider – who are clearly fond of their The Lord of the Rings references.

One of the reasons it took so long for security experts to detect ProjectSauron is that the program is designed to be almost invisible, with the attackers using unique code for each separate target. This means the malware doesn't trigger the red flags computer scientists usually look for in malicious code.

Despite being active since 2011, Kaspersky Lab only discovered the hackers' work last year, when the company was asked by one of its clients to look into some anomalous network traffic.

"The attackers clearly understand that we as researchers are always looking for patterns," researchers from Kaspersky Lab explain. "Remove the patterns and the operation will be harder to discover."

Symantec describes ProjectSauron as having a number of "stealth features", including storing its components in executable objects that make it harder for traditional antivirus software to properly detect. It's also capable of infecting 'air-gapped' computers that aren't connected to the internet, through the use of USB keys.

"[M]uch of the malware's functionality is deployed over the network, meaning it resides only in a computer's memory and is never stored on disk," the researchers write in a blog post. "This also makes the malware more difficult to detect and indicates that the Strider group are technically competent attackers."

The good news is that Kaspersky says ProjectSauron activity appears to have largely ceased this year in terms of the infected sites the company's researchers are aware of – but there's no guarantee things will stay that way.

After all, the teams think that such a sophisticated malware platform had to have government backing from somewhere – which means a lot of planning and money went into this attack, and it's probably not over yet.

"We think an operation of such complexity, aimed at stealing confidential and secret information, can only be executed with support from a nation-state,"Kaspersky Lab explains. "ProjectSauron is likely to have required several specialist teams and a budget probably running into millions of dollars… We are aware of more than 30 organisations attacked, but we are sure that this is just a tiny tip of the iceberg."

Don't worry - your genes aren't the only thing controlling your intelligence

                                       Genes are not destiny.

Recent research has suggested that academic performance, reading ability andIQ have a genetic basis. This reinforces the popular notion that intelligence and related cognitive capacities are somehow 'in our genes'.

This has led some people to reject the importance of educational interventionson the grounds that spending money on nurture isn’t going to significantly affect the abilities nature has given us. However, genes are not destiny. There is good evidence to show how effective environmental interventions can be for educational outcomes.

The way in which genes actually contribute to intelligent individuals is often overlooked.

Genes can act in a variety of ways to produce their effects. Some genes may alter brain chemistry so that a person is better able to learn. Other genes could cause behavioural differences, causing some people to self-select more stimulating environments.

And it is likely that the genetics of intelligence works at least in part by a genetic influence on the environment. This means that a genetic basis for intelligence is as much about one’s nurture as about one’s nature.

Intelligence is the most widely studied trait in behavioural genetics. It is correlated with a suite of other characteristics ranging from income to lifespan, to happiness.

Researchers have found a significant genetic contribution to intelligence differences using the method of heritability estimates.

These studies compare populations of identical (monozygotic) and fraternal (dizygotic) twins. Identical twins are genetically identical – they’re nature’s clones. Fraternal twins, like siblings, share an average of 50 percent of their genes.

If there is a heritable basis for intelligence, then identical twins should be more similar than fraternal twin pairs. This method gives researchers an idea of how heritable intelligence is but tells us nothing about the actual genes involved.

Since the advent of gene sequencing, new techniques have allowed scientists to identify specific candidate genes that are correlated with intellectual outcomes.

More recently, researchers have investigated the relative effects of many specific genes working together. Earlier this year researchers at Kings College London used this method to explain a substantial proportion of exam score differences.

The standard interpretation of these kinds of results is that intelligence genes work through innate biological processes, causing individual differences. But this may not always be the case.

A thought experiment

Imagine two groups of children who have different versions of a candidate intelligence gene: Gene X.

Children with one version of this gene have an insatiable love for the musty smell of books. The other group of children feel the opposite way and detest the smell.

You can imagine the first group actively seeking out and surrounding themselves with books, while the second group actively avoids them. As a result, the first group of children will likely attain better reading scores than the second group, simply because of their increased exposure to books.

A genetic analysis of these results could easily lead researchers to declare thatGene X is the gene for reading ability. But it makes more sense to think of Gene Xas a gene for smell preferences.

These smell preferences then cause environmental differences between the two groups, and it is the environment that plays the final part in generating differences in reading scores.

Nature via nurture

Genes can cause differences in brain development. But they can also predispose individuals to experience different kinds of environments. In behaviour genetics this is termed gene-environment correlation.

There are many ways in which people behave that could influence their environment. Personality differences will influence whether or not a child has the confidence to attend an extracurricular class. Differences in temperament will affect the kinds of resources children will seek out for themselves.

More social children might spend less time constructing an academically rich environment than those spending more time alone. If personality differences of this kind are correlated with academic performance, then it is likely that associated genetic effects are thought of as due to "intelligence genes".

A danger with the genetic research of human abilities is the way in which findings are understood. If results are interpreted prematurely or incorrectly, then ineffective and potentially disastrous policy decisions could follow.

This was illustrated in the 1960s when prominent geneticist Arthur Jensencriticised the Head Start education program, which offers compensatory education to children from disadvantaged backgrounds.

One reason for its instigation was to bridge the divide in school performance between black and white American students. Jensen claimed that interventions of this type would be of no use because of the genetic basis of intelligence.

This sparked debate about the causes of intelligence differences between racial groups, fuelling racism at a cultural and political level. Genetic accounts of intelligence differences between racial groups have since been debunked. We now know that these differences are due to associated environmental differences, including the prejudices some groups face within society today.

Unfortunately, racism still persists, as does prejudice in many other forms. Because of this, scientists and media professionals should be extra careful when they present findings about genetic causes.

There is more work to be done to uncover the environmental factors associated with genes. But we should pay close attention, as this information can be used to create a fairer education system for all.

Scientists have set a new record for data transmission using li-fi

                                               Sorry, wi-fi.

Back in November, a wireless technology called li-fi made a splash, proving to be 100 times faster than average wi-fi speeds in its first 'real world' tests.

Unlike wi-fi, which is based on radio frequencies, li-fi uses a much faster system based on visual light, and researchers in Saudi Arabia have just developed a lightbulb that can transmit data more than 40 times faster than any existing li-fi devices.

The invention of li-fi has been credited to Scottish communications expertHarald Haas from the University of Edinburgh, when he demonstrated for the first time back in 2011 that by flickering the light from a single light-emitting diode (LED), he could transmit far more data than a cellular tower.

The technology is based on something called Visible Light Communication (or VLC), which piggy-backs on visible light frequencies between 400 and 800 terahertz (THz). 

Using these light frequencies, li-fi works like an incredibly complex form of Morse code - by flicking an LED on and off at extreme speeds imperceptible to the human eye, you can write and transmit data in binary code. 

Imagine having smart LEDs installed in your home and office ceilings that can wirelessly connect to your computers, phones, printers, and air-conditioning units as they illuminate the space.

In November last year, a team from the Estonian tech company, Velmenni, managed to take this technology out of the lab for the first time, and when they tested it in offices and industrial environments in their local area, achieved speeds of 224 gigabits per second.

Not only was that 100 times faster than average wi-fi speeds at the time, it’s the equivalent of 18 movies of 1.5 GB each being downloaded every single second.

Now times that by 40.

Researchers from the King Abdullah University of Science and Technology in Saudi Arabia have figured out how to take li-fi to the next level, by setting a brand new speed limit.

Many VLC devices rely on LEDs that produce white light. These devices work by taking blue diodes and combining them with phosphorous, and some of the resulting radiation is converted into red and green light. 

As we learned in primary school, if you combine red, green, and blue light, you get white, and that’s how LED lights illuminate our houses and phone and laptop displays. 

"VLC using white light generated in this way is limited to about 100 million bits per second," says one of the team, electrical engineer Boon Ooi.

As Daniel Oberhaus explains for Motherboard, the reason for this limit is the fact that the time it takes to convert this blue light into white light takes longer than how quickly an LED light can be turned on and off. 

This effectively limits LED-based li-fi devices to a maximum bandwidth of about 12 megahertz (MHz).

"The rate at which the light can turn on and off is important, because this is the method that the LED light uses to communicate," says Oberhaus.

"By turning on and off faster than the eye can see, the LED communicates in binary code with a receiver - the faster this transition happens, the greater the bandwidth, which dictates how much information can be conveyed."

Ooi and his team decided to use something completely different for their li-fi lightbulb - they’re based theirs on nanocrystals of caesium lead bromide, combined with a solution of nitride phosphor.

When illuminated by a blue laser light, the nanocrystals emit some green light, while the nitride emits red light, and - you guessed it - we have white light.

The team reports that their new device can produce this reaction at a frequency of 491 Megahertz, and can transmit data at a rate of 2 billion bits per second - that's 40 times faster than the absolute limit using phosphorus.

To make things fair, they will have to demonstrate this achievement in a 'real-world' setting, like the Estonian researchers did last year, but li-fi might have just gotten a whole lot more awesome before it’s even started.