Digital textbooks adapt to your level as you learn

Struggling with chapter 3? Adaptive textbooks will give you extra, personalised help when you need it

TIRED of learning from a dusty old textbook? Try a book that learns from you. Students in Houston, Texas, are about to get their hands on the first digital schoolbooks that use artificial intelligence to personalise lessons. The aim, says the books' creator, is to "explode the book" and rethink how students learn from texts.

"We want to be able to create the perfect book for every person," saysRichard Baraniuk, director of the OpenStax project at Houston's Rice University, which is behind the books. "Ultimately, we want a system that turns reading the book into an exploration of knowledge."

OpenStax already offers an array of online and printed textbooks on subjects including economics, biology and history. For the past three years, researchers have tracked how students in 12 US schools use the books in their studies, including information on how they scored on questions.

That work is now being used to train machine-learning algorithms that give OpenStax's biology and physics textbooks the ability to adapt to individuals. If a reader seems to be struggling with a particular topic – acceleration, say – the book will slot in additional explanations and practice questions, and increase emphasis on related subjects, such as centripetal force, that could otherwise trip that person up.

The adaptive textbooks also incorporate a learning method called retrieval practice, in which material that students have already learned pops up again in occasional quizzes. This method has been shown to enhance students' ability to retain material, and the algorithmic textbooks will be able to decide when to ask questions based on past exercises.

Digital textbooks are not new – but despite their potential, they have yet to be widely adopted.

"Universities are just not suited for developing and serving such large-scale products. We need start-ups for that," says Peter Brusilovsky of the University of Pittsburgh in Pennsylvania, one of the designers of the interactive learning system ELM-ART (Episodic Learner Model – The Adaptive Remote Tutor). "If done right, adaptive textbooks could help us to learn faster and better."

Such personalised learning is designed to give students who are struggling time to understand subjects, while faster learners can surge ahead without getting bored. Software is a great way to do this – at Summit Preparatory Charter High School in Redwood City, California, students spend a portion of each week working independently with a computer program that suggests assignments and tracks progress, but students choose how to spend their time and set their own pace. This approach has helped Summit to becomeone of the top 20 schools in California, according to US News and World Report.

The initial roll-out of OpenStax in Houston high schools will be relatively small, but large institutions have also expressed interest.

Salt Lake Community College, which has more than 60,000 students and is the largest higher-education institution in Utah, wants to pilot OpenStax's algorithm-enhanced textbooks next year in political science, business and mathematics classes. Jason Pickavance, director of educational initiatives at the college, says he is curious to see whether the books improve student performance.

"We have such a varied student body in terms of college readiness," Pickavance says. "What they need is more individualised attention, more tutoring. The courseware has the potential for us to get that mix right."

Whether the books are successful will depend on teachers, says Ben du Boulay, who works on artificial intelligence at the University of Sussex, UK. They are the ones who will ensure that students make the most of their books – for instance, by working out what to do when the books identify a common problem area among their students.

"If all we needed was books, why have teachers?" de Boulay says. "It's the educational interactions around private study that make the difference."

Non-fatal diseases increasingly drive assisted suicide

It's a tourism boom, but not one to crow about. The number of people travelling to Switzerland to end their lives is growing. And it seems more and more people with a non-fatal disease are making the trip.

An ongoing study of assisted suicide in the Zurich area has found that the number of foreign people coming to the country for the purpose is rising. For example, 123 people came in 2008 and 172 in 2012. In total 611 people came over that period from 31 countries, with most coming from Germany or the UK, with 44 per cent and 21 per cent of the total respectively.

Neurological diseases, only some of which are fatal, were given as the reason for 47 per cent of assisted suicides for the years 2008 to 2012, up from 12 per cent in a similar study of the same region between 1990 and 2000. Rheumatic or connective tissue diseases, generally considered non-fatal, such as rheumatoid arthritis and osteoporosis, accounted for 25 per cent of cases in the new study. Between 1990 and 2000, they were cited in only 10 per cent of cases. There was also a tiny rise in the number of people coming to Switzerland because of mental health problems – 3.4 per cent in the latest study, up from 2.7 per cent.

Cancer, on the other hand, was cited in 37 per cent of cases between 2008 and 2012, a decrease of 10 per cent.

The researchers write that figures such as these suggest that diseases which are non-fatal, or those which could be terminal but have yet to reach their final stages, could be becoming increasingly common reasons to seek assisted suicide in Switzerland – although they also note that the earlier study looked at Swiss residents whereas theirs looks at foreign visitors.

Travelling while they can

One reason that people with non-terminal conditions might be travelling to Switzerland to die could be down to the fact that people with late-stage diseases, for example, are less mobile, according to Michael Charouneau of UK campaign group Dignity in Dying. "We know that many of those who travel do so earlier than they would wish, whilst they are still physically well enough to make the journey," he says.

"The idea of assisted suicide is more acceptable today than it was 10 or 20 years ago," says Ruth Horn, a medical ethics researcher at the University of Oxford. She suggests that this might be one reason why more people with non-fatal diseases are choosing to end their lives. "Subsequently it appears to have become more and more acceptable to extend the right to assisted death to patients with non-terminal conditions."

The legal standing of relatives and doctors implicated in euthanasia has been debated in both Germany and the UK in recent years. While efforts to change Germany's criminal code have stalled, in the UK a private member's bill on assisted dying is being debated in the House of Lords. "People choosing to go to Switzerland for assistance to die is one signal that the law is not working here in the UK," says Charouneau.

Race to electrify rural Africa could help the West too

Investments in mini grid systems aimed at powering up remote parts of Africa may provide a test bed for rural energy infrastructure elsewhere in the world

TURNING on the lights in Africa may help to power up the rest of the world sustainably. New investments in mini grid systems aimed at bringing power to rural Africa and other remote areas may provide a test bed for the rural energy infrastructure of the future.

Rich nations are taking an increasing interest in electrifying the rest of the world. At the Africa Leaders Summit in Washington DC this month, US president Barack Obama announced an additional $12 billion in funding for his administration's Power Africa initiative, which aims to help bring power to at least 60 million households and businesses across the continent.

But 85 per cent of the 1.3 billion people lacking electricity worldwide live in rural areas. That means powering Africa won't be as simple as hooking up villages to a centralised power grid. Localised "micro-grids" are beginning to take off. They can generate anything from a few watts to a few megawatts and provide power for tens to thousands of households at a time.

An increasing amount of this power is coming from renewable sources, such as wind, solar and hydro. "It creates an opportunity," says Subhes Bhattacharyya at De Montfort University in Leicester, UK. "You don't have to follow the old-fashioned way of doing things. You can jump the queue to new technologies."

For instance, international group Practical Action is building micro-hydro-power plants in Zimbabwe and Kenya, which harness falling water such as that in mountain rivers.

Another group, a Kenyan start-up called Access:energy, developed a model to teach Kenyans to make parts of wind turbines out of scrap metal and car parts, reducing the need for outside help should a part of the system break. A single turbine can generate about 2.5 kilowatt-hours per day, enough to power a micro-grid for 50 homes.

These sorts of local efforts are important – and not just for getting electricity to rural Africa. The continental US and other rich parts of the world have set goals for switching to renewable power and reinventing electricity grids as well. Lessons learned in Africa could help get parts of the US running on renewables and micro-grids.


"There are vulnerabilities because of the way our US grid is based on big, centralised power stations that are all very interdependent," says Gwen Holdmann at the Alaska Center for Energy and Power in Fairbanks. "If one component goes down, it can cause a cascading effect." Switching to local grids can ultimately help make the whole power infrastructure more robust in emergencies such as hurricanes or solar storms.

Not everyone agrees that renewable energy is the best option for Africa, however. Micro-grids may not be the cheapest option in the long run, as electricity from small grids tends to be three or four times as expensive per unit than that from centralised sources.

It hardly seems fair that the people who can least afford energy must use a more expensive system, says Bhattacharyya. "On the other hand, if they don't get electricity and remain in darkness, then it's unfair for them as well. That's the choice one has to make, and there's no single solution for all."

This article appeared in print under the headline "Africa's power surge"

Swelling Australian cities harbour ever bigger spiders

As if Australia's spiders weren't big and scary enough, it turns out denser, busier cities are allowing some of them to grow even bigger. The same thing could be happening the world over.

Most Australians will have seen the large but mostly harmless golden orb-weavers that sometimes congregate in people's gardens. Elizabeth Loweof the University of Sydney was surprised at just how large some were growing, and began investigating what could be behind this.

Lowe and colleagues found one species of this genus, Nephila plumipes, is gaining weight the more built-up Sydney gets. Examining more than 200 specimens around Sydney, they found that the more concrete there was, the further they were from bushland and the less leaf litter there was, the bigger the spiders tended to be. Lowe says the spiders in the bushland of Brisbane Water National Park, north of Sydney, had an average mass of 0.5 grams. But those in an inner-city park near Bondi Beach averaged 1.6 grams.

"It's probably because of the urban heat-island effect and prey availability," says Lowe. "Most invertebrates will grow to larger sizes if they are warmer. They are very sensitive to temperatures."

Urbanisation probably benefits these spiders in several ways, she says. The insects the spiders prey on tend to do very well in small fragments of bushland like urban parks, and even better when there is lighting at night. "The spiders have more to prey on and can put more energy into growing bigger."

Wealth effect

Surprisingly, the researchers also found that wealthier areas tended to have larger spiders. Lowe isn't sure why. It might be that wealthier areas tend to have more parks or more hard surfaces like concrete that heat up readily.

Lowe says this is probably also happening with other spiders in Australia likehuntsmen and redbacks, and is almost certainly happening elsewhere in the world. What's more, global warming will encourage spiders to grow bigger – although very hot weather will kill them, she says. "During the hot summer last year, most of these spiders died out in Sydney."

Michael Kasumovic from the University of New South Wales in Sydney said he is surprised by the results and expected the opposite would be true. "If it is an increase in heat, what that usually means is it increases development rates. Metabolic functions are going faster and they mature earlier – at a smaller size," he says.

Lowe notes the relationship between heat and body size is complicated. The heat could allow the spiders to hatch earlier in the year, giving them a longer growing season.

In any case, she says healthy spider populations in cities should be celebrated: they are mostly harmless to people, they eat pests and they provide food for birds. "I'm all about encouraging spiders in urban areas," she says.

China sting shows censors fear posts that incite unrest

Last year, violence broke out in a north-western corner of China, whenmembers of the local Uighur population – an ethnic minority in China – faced off against the police. Dozens of people were reportedly killed, and social media lit up with posts about the riots. But as China's many censors got to work, many posts also quickly disappeared. But how did the government decide which could stay and which had to go?

A group of US researchers can help answer that question. They have lifted the lid on Chinese online censorship – by pretending to be censors themselves. They found that the censors of China's social media sites are only worried about posts that may incite mass protests, rather than ones that poke fun at individual politicians, for example.

Acting like a social media start-up, Gary King at Harvard University and his colleagues built a fake website, bought a domain name and server space inside China, and populated the site with their own posts. Then, they obtained a copy of the software that helps Chinese website administrators censor their content so they stay out of trouble with the authorities. When questions about how the software worked came up, answers were just a phone call to customer service away.

"We could call customer service and say, 'How do we stay out of trouble with the Chinese government?' They would say, 'Let me tell you,'" says King. "Customer service was pretty good at their job."

Reverse engineering

The software could automatically block posts that came from banned IP addresses or contained problematic keywords. But many of the censorship choices were still deferred to human judgment. Some sites held posts for manual review within 24 hours; others automatically published the post, and a person would check in later to decide if it was OK.

If in-house human censors, rather than software, were calling the shots, then perhaps the researchers could divine insight into the minds of both government and independent censors by examining their choices carefully. King's team went back to real social media sites such as Sina Weibo. Of the 100 sites, 20 were run by central government, 25 were by overseen by local authorities, and 55 were privately owned.

The researchers wrote more than 1000 comments about controversial topics, such as artist Ai Weiwei's music, a village protest in Panxu, and the Uighur riots in Xinjiang. The researchers tracked if and when the posts were taken down.

"The censorship programme is like an elephant tiptoeing around. It leaves big footprints," says King. "We can look at those footprints and learn things about the intentions of the Chinese government that would be difficult to learn otherwise."

Collectivism a no-no

To their surprise, the posts that were most likely to be censored were those that mentioned collective action in the real world, like a protest or a boycott. Even posts that praised the government could be censored if they also referenced collective action.

Meanwhile, criticism and complaints often made it through to publication. A satirical post about the Uighur situation went viral, and only got censored about 10 per cent of the time.

King suspects this is because the government is more worried about regime stability than anything else, so they exert most of their pressure on posts that could jeopardise their power. "They don't care what anybody says about them in and of itself. They care what people will do with that information," he says.

Degrees of criticism

Before this study, we only had "very impressionistic understandings" of the Chinese government's priorities, says Susan Shirk, director of the 21st Century China Program at the University of California, San Diego. The findings suggest that censorship decisions are more nuanced than previously thought.

"It's really an amazing piece of work, to be able to do that kind of intervention and look at the impact of the intervention. Nobody has ever done anything quite like that before," Shirk says. In some ways, the censorship system is tighter than we thought, she says, and in some ways looser.

Artists protest in Hong Kong, demanding the release of then-detained Chinese artist Ai Weiwei on 23 April, 2011 (Image: Laurent Fievet/AFP/Getty)

Min Jiang at the University of North Carolina at Charlotte is more sceptical of the results. She suspects there are still some kinds of complaints that the government would want to censor, like Western media reports that expose abuses of power. "Criticism has many different degrees," she notes.

Earliest stars lived short, fiery lives

The first stars may have been big shots that went out in a blaze of glory. A stellar fossil has revealed new insights into a long-extinct species of primordial stars.

This group, sometimes called population III stars, were the first to form in the early universe. They forged the first elements heavier than the hydrogen and helium made in the big bang. Then they exploded as supernovae, expelling these elements into their surroundings, to be incorporated into the next generation of stars.

But the details depend on the masses of these first stars. Computer models suggested that they could be as much as 100 times the mass of our sun, meaning they would die too quickly to build anything heavier than iron. But they could also be as light as 10 times the mass of our sun and live longer. With no population III stars around today, it's hard to know what they looked like.

Now we have hints from a star named SDSS J0018-0939, that appears to have been born out of the dust left behind by an exploding primordial star. A team led by Wako Aoki of the National Astronomical Observatory (NAO) of Japan in Tokyo, analysed the different elements in the star's outer shell for clues to how the mysterious population III stars lived and died.

"It's a bit like a DNA fingerprint," says Volker Bromm of the University of Texas in Austin. "This study answers the overall question of how the cosmic dark ages ended."

Even-numbered clue

The fossil star, which was discovered via the NAO's Subaru telescope in Hawaii, appears to contain a fair amount of iron, but little by way of heavier metals like strontium and barium. It also has far more even-numbered elements than odd ones. Both of these features indicate that population III stars were short-lived, as building heavier and odd-numbered elements is a slower process.

This means the population III stars were probably even bigger than we thought – hundreds of times more massive than the sun. The "parent" star of SDSS J0018-0939 was about 140 times the sun's mass.

Its huge size means that the star probably exploded in a fiery thermonuclear explosion 10 to 100 times more powerful than typical supernovae we see today. Bromm thinks these explosions may have been bright enough that their embers will be seen by the James Webb Space Telescope, due to launch in 2018.

But it's not a dead certainty that the fossil star formed from the remnants of a single supernova, says John Wise of the Georgia Institute of Technology in Atlanta. It could instead contain dust from a few supernovae.

"It's not exactly a smoking gun," he says. "It is exciting that it's different from any of the other metal-poor stars that we've discovered in the Milky Way."

Hummingbirds turned savoury into sweet to taste nectar

It's the strangest sweet tooth in the world. Birds lost the ability to taste sugars, but nectar-feeding hummingbirds re-evolved the capacity by repurposing receptors used to taste savoury food.

To differentiate between tastes, receptors on the surface of taste buds on the tongue, known as T1Rs, bind to molecules in certain foods, triggering a neurological response.

In vertebrates such as humans, a pair of these receptors – T1R2 and T1R3 – work together to deliver the sweet kick we experience from sugar. But Maude Baldwin at Harvard University and her colleagues found that birds don't have the genes that code for T1R2. They are found in lizards, though, suggesting that they were lost at some point during the evolution of birds or the dinosaurs they evolved from.

But hummingbirds clearly can detect sugar: not only do they regularly sup on nectar, taste tests show they prefer sweet tasting foods over blander options. Now Baldwin and her team have worked out why: another pair of receptors – T1R1 and T1R3 – work together to detect sugar.

Savoury to sweet

Other vertebrates use T1R1 to taste savoury foods. It seems that in hummingbirds the proteins on the surface of the two receptors have been modified so that they respond to sugars instead.

"The change in the taste receptor was certainly not the only factor or aspect of hummingbird biology that was important [for them to feed on nectar], but it seems like it played an important role," says Baldwin. "There are many behavioural and physiological changes that have occurred between hummingbirds and their ancestors: small body size, a long bill and changes in the wing which allowed them to hover."

"We know a lot about bird vision and smell, but until recently very little was known about the genetic basis of taste in any bird species," says Hannah Rowland at the University of Cambridge, who was not involved in the study. "These findings should help researchers test sweet perception in other birds that eat fruit and nectar. The question for me is whether other nectar eating birds and frugivores have evolved this same capacity."

The re-evolution of sugar receptors may have happened multiple times, says study member Stephen Liberles, also at Harvard. "It will be exciting to see how other nectar feeding birds taste sugar, to compare whether evolution used the same or different strategies to solve the problem of sugar detection," he says.

Searching for survivors in Hiroshima's shattered homes

Rescue workers are searching for survivors in debris left by a landslide that hit Hiroshima, Japan, on Wednesday. People are still missing under the collapsed buildings, mud and rock that litter the base of the mountain on the outskirts of the city.

According to Hiroshima police, at least 39 people have been killed in the landslide, and 52 more are still missing. The slide was triggered by a sudden deluge: a month's worth of rain fell in 24 hours between Tuesday and Wednesday morning, causing whole hillsides to collapse.

One of those killed was a 53-year-old firefighter, Noriyoshi Masaoka, who died rescuing five people.

Around 3000 rescue personnel are working in the area, although further heavy rain halted search efforts on Thursday evening. There are now fears of a fresh collapse, with rain due to continue through to Saturday evening and the surrounding mountains becoming "misshapen", said a police spokesman.

Up to 100,000 residents have evacuated surrounding districts, fearing further landsides and floods. According to Fuji TV, 1100 residents have been unable to return to their homes and are sleeping in local schools.

Chimps show empathy by mimicking pupil size

Chimpanzees and humans may share the same ability to empathise with other individuals by involuntarily matching their pupil size. The mimicry only appears to work between two humans or between two chimpanzees but not between species, suggesting the signalling reinforces social bonds within species.

We already know that pupils change shape in response to a new, unfamiliar target: they tend to constrict initially and, after a fraction of a second, readjust and dilate. There's evidence that human pupils dilate more rapidly while adjusting if their owner is interacting with another human whose pupils are also dilating. The dilation-adjustment happens more slowly if the other human's pupils are constricting. But it is unclear when this pupil mimicry began in evolutionary terms.

To investigate, Mariska Kret at the University of Amsterdam in the Netherlands and her colleagues studied pupil mimicry in humans and, for the first time, looked for the phenomenon in chimps too. Chimps and human volunteers viewed images of pairs of chimp or human eyes for 4-second-long periods. Kret and her colleagues digitally manipulated the eye images so that after one-sixth of a second, the pupils on view started either dilating or constricting by a fixed amount, reaching their new size within a second and staying that size for the remaining 3 seconds of viewing time.

Unobtrusive binocular eye-trackers monitored and recorded whether pupil size in the viewer – whether chimp or human – changed as they gazed at the various images.

The pupil dilation in humans and chimpanzees did indeed subtly alter in response to the different images. In keeping with expectations, after initially constricting, a human's pupils dilated more slowly when they viewed a human whose pupils were constricting. If the human on view's pupils were dilating, the volunteer's pupils dilated more rapidly after the initial constriction. At the end of the 4-second-long viewing period there was a 0.2 millimetre difference in the volunteers' pupil size, on average, depending on whether the eyes in the image had dilated or constricted.

Mother phenomenon

Interestingly, the same applied to the chimpanzees: their pupils, too, dilated more slowly when they viewed a chimp with constricting pupils. The effect was a great deal more subtle in the chimps, but a statistical analysis showed the differences were nonetheless significant. The most striking effects in chimps were seen in three mothers, suggesting that motherhood increases a chimp's subconscious awareness of pupil size.

The experiments also revealed something else: pupil dilation in humans is not altered by viewing images of chimps with either dilating or constricting pupils, and vice versa.

The results suggest that pupil mimicry might have a long evolutionary history, says Kret, because if the phenomenon is present in both humans and chimps it is possible it originally evolved in a common ancestor of the two species.

Neil Harrison at the Brighton and Sussex Medical School at the University of Sussex, UK, says that finding pupil mimicry for the first time in chimps is extremely significant, especially the accentuated effect observed in the three chimp mothers, as this suggests they are more sensitive empathetically.

All white now

The findings might even hint at a new reason for why humans evolved sclera, the whites of our eyes. "Traditionally, it's been thought that the evolution of white sclera was driven by its enhanced ability to indicate gaze direction, and hence share attention," says Harrison.

In a landmark paper in 2006, he showed that the pupils of human viewers tend to match those in images of people expressing sadness – but not other emotions.

Given that the human volunteers in Kret's study were more responsive than the chimps to changes in pupil size, it might be that the whites of our eyes evolved to help us subconsciously spot those changes more readily, says Harrison.

Pupils also dilate when someone is aroused, stressed, making decisions or – obviously – in darker conditions. Kret speculates that the involuntary changing of pupil size in response to looking at someone else may be a subconscious attempt to reinforce bonding by showing you are interested in them, or share an emotional state.

I feel you, fellow chimp (Image: Brad Wilson/Getty)

Botox blitz could work against stomach cancers

Could the destroyer of wrinkles also work on cancer? Gastric cancer is the fifth most common cancer in the world and can be hard to treat. Chemotherapy is often not enough to stop tumour growth, but it seems that botox injections could help.

One method for treating stomach cancer is to sever the branches of the vagus nerve that innervate the stomach, a procedure known as a vagotomy. That's because the nervous system influences how certain cells behave, in some cases encouraging tumour growth But a vagotomy is a very invasive procedure.

Timothy Wang of Columbia University, New York, and his colleagues wondered whether the same effect could be achieved with a drug.

Lethal toxin

One way nerves are thought to stimulate cancer is through the release of signalling chemicals. To prevent nerve fibres from doing this, Wang's team used botox, the lethal botulinum toxin produced by the Clostridium botulinumbacterium, which is sometimes injected to prevent wrinkles. Botox enters the nerve cells and prevents them from releasing the signalling chemicals that can influence tumour growth.

The team injected botox into mice with gastric cancer and compared their tumour growth with that in mice that had received a vagotomy. They found that the botox was as effective at limiting tumour growth as surgery when used in early stages of the disease.

For advanced gastric cancer, botox cannot reduce the size of tumours that have already developed. It can, however, stop new growths from increasing in size, so the team tried combining botox treatment with chemotherapy. While botox and chemotherapy on their own had a small effect on new tumours, mice that received both treatments had tumours that were about half the size of those that received no treatment at all.

Prolonged survival

"In a patient with an advanced stage disease that you don't want to do surgery on, you could use botox in combination with chemotherapy. The injections may help control the growth of further tumours, and allow for prolonged survival," says Wang.

This new research offers a novel treatment for gastric cancer, says Michael Khan of the University of Southern California's Norris Comprehensive Cancer. "Unfortunately, gastric cancer is not particularly sensitive to chemotherapy," he says. He suggests that combining it with botox treatments could be an effective approach.

Wang's team next plans to test the use of botox in advanced gastric cancer patients who have shown resistance to chemotherapy.

Eye implant turns smartphone into a glaucoma monitor

It's a selfie that might save your sight. An implanted sensor could help people with glaucoma monitor the pressure in their eyes using a smartphone camera.

The second biggest cause of blindness after cataracts, glaucoma occurs when fluid builds up in the eye. This raises the pressure, damaging the optic nerve. Accurate pressure readings are crucial for giving the right treatment, but one-off measurements during check-ups produce variable results and can be misleading.

Yossi Mandel at Bar-Ilan University in Ramat Gan, Israel, and his colleagues have developed a pressure sensor which can be inserted into the eye during surgery to provide easy, regular monitoring from home.

A few millimetres in length, the sensor can be embedded into the synthetic lenses used to replace the natural lenses of people with cataracts. It works like a miniature barometer, and contains a fluid column that rises with eye pressure. The level can be read at any time using a smartphone camera fitted with a special optical adapter. Software then analyses the image and calculates the reading.

"Continuous monitoring is a clear unmet need in glaucoma," says Francesca Cordeiro, a glaucoma researcher at University College London.

Mandel believes self-monitoring will lead to better treatment of glaucoma, and could enable people to skip unnecessary appointments when their eye pressures are on target.

Several eye pressure probes have been developed since the early 1990s. These include a contact lens made by Sensimed, based in Lausanne, Switzerland, that can estimate eye pressure based on how the cornea bends. Sensimed's sensor is the only wearable pressure device that is commercially available, but it is intended for short-term use only. Mandel says his sensor could be installed in a patient's eye for many years.

Implanting the synthetic lens that contains the sensor would require invasive surgery, something only suitable for patients who need new lenses anyway due to cataracts.

"Ultimately, only a small proportion of glaucoma patients could benefit from this sensor," says Cordeiro. Developing a standalone sensor that could be implanted in front of the iris could solve this problem, suggests Mandel.

Google's fact-checking bots build vast knowledge bank

The search giant is automatically building Knowledge Vault, a massive database that could give us unprecedented access to the world's facts

GOOGLE is building the largest store of knowledge in human history – and it's doing so without any human help.
Instead, Knowledge Vault autonomously gathers and merges information from across the web into a single base of facts about the world, and the people and objects in it.
The breadth and accuracy of this gathered knowledge is already becoming the foundation of systems that allow robots and smartphones to understand what people ask them. It promises to let Google answer questions like an oracle rather than a search engine, and even to turn a new lens on human history.
Knowledge Vault is a type of "knowledge base" – a system that stores information so that machines as well as people can read it. Where a database deals with numbers, a knowledge base deals with facts. When you type "Where was Madonna born" into Google, for example, the place given is pulled from Google's existing knowledge base.
This existing base, called Knowledge Graph, relies on crowdsourcing to expand its information. But the firm noticed that growth was stalling; humans could only take it so far.
So Google decided it needed to automate the process. It started building the Vault by using an algorithm to automatically pull in information from all over the web, using machine learning to turn the raw data into usable pieces of knowledge.
Knowledge Vault has pulled in 1.6 billion facts to date. Of these, 271 million are rated as "confident facts", to which Google's model ascribes a more than 90 per cent chance of being true. It does this by cross-referencing new facts with what it already knows.
"It's a hugely impressive thing that they are pulling off," says Fabian Suchanek, a data scientist at Télécom ParisTech in France.
Google's Knowledge Graph is currently bigger than the Knowledge Vault, but it only includes manually integrated sources such as the CIA Factbook.
Knowledge Vault offers Google fast, automatic expansion of its knowledge – and it's only going to get bigger. As well as the ability to analyse text on a webpage for facts to feed its knowledge base, Google can also peer under the surface of the web, hunting for hidden sources of data such as the figures that feed Amazon product pages, for example.
Tom Austin, a technology analyst at Gartner in Boston, says that the world's biggest technology companies are racing to build similar vaults. "Google, Microsoft, Facebook, Amazon and IBM are all building them, and they're tackling these enormous problems that we would never even have thought of trying 10 years ago," he says.
The potential of a machine system that has the whole of human knowledge at its fingertips is huge. One of the first applications will be virtual personal assistants that go way beyond what Siri and Google Now are capable of, says Austin. "Before this decade is out, we will have a smart priority inbox that will find for us the 10 most important emails we've received and handle the rest without us having to touch them," Austin says. Our virtual assistant will be able to decide what matters and what doesn't.
Other agents will carry out the same process to watch over and guide our health, sorting through a knowledge base of medical symptoms to find correlations with data in each person's health records. IBM's Watson is already doing this for cancer at Memorial Sloan Kettering Hospital in New York.
Knowledge Vault promises to supercharge our interactions with machines, but it also comes with an increased privacy risk. The Vault doesn't care if you are a person or a mountain – it is voraciously gathering every piece of information it can find.
"Behind the scenes, Google doesn't only have public data," says Suchanek. It can also pull in information from Gmail, Google+ and Youtube."You and I are stored in the Knowledge Vault in the same way as Elvis Presley," Suchanek says.
Google researcher Kevin Murphy and his colleagues will present a paper on Knowledge Vault at the Conference on Knowledge Discovery and Data Mining in New York on 25 August.
As well as improving our interactions with computers, large stores of knowledge will be the fuel for augmented reality, too. Once machines get the ability to recognise objects, Knowledge Vault could be the foundation of a system that can provide anyone wearing a heads-up display with information about the landmarks, buildings and businesses they are looking at in the real world. "Knowledge Vault adds local entities – politicians, businesses. This is just the tip of the iceberg," Suchanek says.
Knowledge vault
Richer vaults of knowledge will also change the way we study human society "This is the most visionary thing," says Suchanek. "The Knowledge Vault can model history and society."
Google already has a way to track mentions of names over time using historical texts, measuring the popularity of Albert Einstein vs Charles Darwin, for instance. By adding knowledge bases – which know the gender, age and place of birth of myriad people – historians would be able to track more in-depth questions, such as the popularity of female singers over tim
Suchanek has already carried out a version of this kind of data-driven history. By combining a knowledge base called YAGO with data from French newspaper Le Monde, he was able to show how the gender gap in French politics changed over time. This was only possible because YAGO knows the gender of every French politician, and can apply that knowledge to names mentioned in Le Monde. He will present the work at the Very Large Databases Conference in Hangzhou, China, in September.
It might even be possible to use a knowledge base as detailed and broad as Google's to start making accurate predictions about the future based on analysis and forward projection of the past, says Suchanek.
"This an entirely new generation of technology that's going to result in massive changes – improvement in how people live and have fun, and how they make war," says Austin. "This is a quantum leap."

Young blood to be used in ultimate rejuvenation trial

In California, people with Alzheimer’s will be given transfusions of young blood to see if improves their cognition – there's good reason to hope it might

IT SOUNDS like the dark plot of a vampire movie. In October, people with Alzheimer's disease will be injected with the blood of young people in the hope that it will reverse some of the damage caused by the condition.

The scientists behind the experiment have evidence on their side. Work in animals has shown that a transfusion of young mouse blood can improve cognition and the health of several organs in older mice. It could even make those animals look younger. The ramifications for the cosmetics and pharmaceutical industries could be huge if the same thing happens in people.

Disregarding vampire legends, the idea of refreshing old blood with new harks back to the 1950s, when Clive McCay of Cornell University in Ithaca, New York, stitched together the circulatory systems of an old and young mouse – a technique called heterochronic parabiosis. He found that the cartilage of the old mice soon appeared younger than would be expected.

It wasn't until recently, however, that the mechanisms behind this experiment were more clearly understood. In 2005, Thomas Rando at Stanford University in California and his team found that young blood returned the liver and skeletal stem cells of old mice to a more youthful state during heterochronic parabiosis. The old mice were also able to repair injured muscles as well as young mice (Nature, doi.org/d4fkt5).

Spooky things seemed to happen in the opposite direction, too: young mice that received old blood appeared to age prematurely. In some cases, injured muscles did not heal as fast as would be expected.

Several other experiments have shown similar effects. In 2012, Amy Wagersat Harvard University showed that young blood can reverse heart decline in old mice. Her team paired healthy young mice with old mice that had cardiac hypertrophy – a condition which swells the size of their heart – and connected their circulatory systems. After four weeks, the old mouse's heart had shrunk to the same size as its younger partner. In this experiment, the young mouse was seemingly unaffected by the old blood, its heart not changing in size.

Once the researchers had ruled out the effect of reduced blood pressure on the older mice, they identified a protein in the blood plasma called growth differentiation factor 11 (GDF11) that appeared to fall with age. To see if it was linked to the rejuvenating effects, the team gave old mice with enlarged hearts daily injections of GDF11 for 30 days. Their hearts decreased in size almost as much as they had in the parabiosis experiments (Cell, doi.org/q2f).

A year later, the same team showed in mice that daily injections of GDF11 also increases the number of blood vessels and the number of stem cells in the brain – both factors known to improve brain function. A separate team led by Tony Wyss-Coray at Stanford performed similar experiments. His team injected blood plasma from young mice into old mice and showed animprovement in the old mice's physical endurance and cognitive function(Nature Medicine, DOI: 10.1038/nm.3569).

In both mice and humans, GDF11 falls with age. We don't know why it declines, but we know it is involved in several mechanisms that control growth. It is also thought to mediate some age-related effects on the brain, in part by activation of another protein that is involved in neuronal growth and long-term memory.

So the billion-dollar question is: would a GDF11 boost have the same effect in humans? Wyss-Coray thinks it will, having taken the next step of injecting young human blood plasma into old mice. His preliminary results suggest that human blood has similar rejuvenating benefits for old mice as young mouse blood does.

"We saw these astounding effects," he says. "The human blood had beneficial effects on every organ we've studied so far."

Now, the final step – giving young human blood plasma to older people with a medical condition – is about to begin. Getting approval to perform the experiment in humans has been relatively simple, says Wyss-Coray, thanks to the long safety record of blood transfusions. He warns against swapping blood at home because transfusions need to be screened for disease, matched for blood type and the plasma needs to be separated out. "Certainly you can't drink the blood," he says. "Although obviously we haven't tried that experiment."

So in early October, a team at Stanford School of Medicine will give a transfusion of blood plasma donated by people under 30 to older volunteers with mild to moderate Alzheimer's.

Following the impressive results in animal experiments, the team hopes to see immediate improvements in cognition, but Wyss-Coray cautions that it is still very experimental. "We will assess cognitive function immediately before and for several days after the transfusion, as well as tracking each person for a few months to see if any of their family or carers report any positive effects," he says. "The effects might be transient, but even if it's just for a day it is a proof of concept that is worth pursuing."

Open schools later so teens can lie in, say US doctors

American teenagers, rejoice! The American Academy of Pediatrics wants all US schools attended by children aged 10 to 18 to delay their opening times to 8.30 am or later. Currently, only 15 per cent start after this time.

The aim is to tackle widespread sleep deprivation by helping teenagers manage the shift in their body clocks that coincides with puberty. This turns them into "night owls" who favour going to bed and rising 2 hours later than when they were younger. Research has shown that this results in more car accidents, increased late arrivals at school as well as lower grades, and higher risks of depression, moodiness and obesity.

A poll published in 2006 by the US National Sleep Foundation found that 59 per cent of middle school students and 87 per cent of high school students were failing to get the recommended 8.5 to 9.5 hours sleep on school nights.

No snooze you lose

About 1000 schools in 70 US school districts have independently switched to later starting times. The academy is the most influential organisation yet to call for a wholesale change in start times across the entire nation to help redress the issue.

"The demonstrated benefits are widespread and include more sleep, less daytime sleepiness, and improvements in academic, health, mood, and safety parameters," says Judith Owens, director of Sleep Medicine at Children's National Health System in Washington DC, and lead author of the AAP's policy statement.

For example, research published in February by Kyla Wahlstrom of the University of Minnesota in St Paul highlights the benefits of later starts following a three-year study of 9000 students from eight high schools in three states. "She found improved grades and standardised test scores, and a 65 to 70 per cent reduction in teen car accidents," says Owens.

"This is a terrific step forward," says Russell Foster of the University of Oxford, an advocate for later start times. He was involved in a UK pilot study that found that switching the start of school from 8.50 to 10 am had a "significant impact" on educational performance. "Anything is better than 8 am, and moving to 8.30 will make a difference, but a 10 o'clock start would be even better," he says.

Foster says that despite the demonstrated benefits, resistance to later start times remains strong in the UK. He hopes to begin a randomised trial soon to assess the value and practicality of earlier starts in UK schools.

4.Star Factories in Sagittarius

The golden age of star formation in the Milky Way is long past, but there’s still plenty of activity in dusty spiral arms of the Milky Way. In this astonishing wide-field composite image by astrophotographer +Terry Hancock of Downunder Observatory, for example, you see a half dozen emission nebulae in the Sagittarius Arm of our galaxy in which new stars ignite and set aglow the clouds of gas and dust from which they form.

In this image you see some of the jewels of the Sagittarius Arm. The Eagle Nebula, Messier 16, also known as the “Star Queen” nebula is at the upper right. The open star cluster Messier 25 is at upper left. Between the two is the mottled glow of Messier 17, the Swan Nebula. Each of these nebula lies some 5,000 to 7,000 light years away. At bottom, just left of center, you see the Little Sagittarius Star Cloud, Messier 24, a shimmering patch of stars about 1ºx2º in apparent size and some 9,000 light years away, about 1/3 the way to the center of the galaxy. The annotated image below helps you see which object is which… -

The image above covers about 7º x 4.2º in a region above the “Teapot” of Sagittarius, so it’s roughly what you see in a pair of binoculars (see image below). Of course you see more detail here because light was collected for many hours for each of the four images that make up this composite. Each image was taken with an H-alpha filter, so it favors the reddish-pink light emitted by hydrogen atoms when their electrons recombine after ionization from bright blue-white stars.

Like all emission nebulae, these glowing regions are short-lived blisters of light that only last a few million years. The brightest stars within these regions will eventually push away the remaining gas and dust and leave behind loose clusters of newly minted stars.