COULD this be the fairest mirror of them all? It may be the most valuable. This $20-million, honeycomb-like block is one of 18 mirrors that will slot into the .

The huge structure is set to succeed the Hubble Space Telescope when it is eventually launched into orbit in 2018, seven years behind schedule. After settling 1.5 million kilometres from Earth, the telescope will collect infrared light emitted by galaxies more than 13 billion light years away, enabling astronomers to look back through time at the early stages of the universe鈥檚 life.

To fit inside its rocket, the JWST鈥檚 6.5-metre-high reflector, six times larger than Hubble鈥檚, is folded into 18 hexagonal pieces, which will assemble to function as a single giant mirror once the telescope is in orbit.

Each piece of the mirror is made of beryllium 鈥� a material that despite its lightness is strong enough to survive a rocket鈥檚 violent launch and temperatures of -223 掳C or lower. The honey glow comes from a thin coating of gold, added to improve the reflection of infrared rays.

鈥淚t is an amazing piece of technology,鈥� says artist , pictured left, who is photographing the telescope for his multimedia performance project Outer Space. Najjar is set to become the first artist in space in 2014 鈥� ahead of the mirror he is photographing.

Who wants to live forever? Apparently, some humans do 鈥� and many think eating less could help. But hungry monkeys who died at a normal age have cast doubt on the power of calorie restriction.

Laboratory animals on sparse diets enjoy impressive increases in lifespan, with calorie-controlled mice living up to 50 per cent longer than average. In 1987, a study began into the effects of calorie restriction on rhesus monkeys. The idea was to test if larger animals can reap the same benefits from eating less. If they can, it is possible humans can too.

鈥淣ow that the monkeys are reaching their maximal lifespan, we can start looking at the effects of calorie restriction on longevity,鈥� says , who, along with his colleagues, inherited the long-running study at the National Institute of Aging (NIA) in Bethesda, Maryland.

The team鈥檚 latest results show that monkeys eating 30 per cent less than control animals did not have longer lives. Dieting monkeys also died from age-related diseases just as often as controls.

The results not only conflict with findings from worms, flies, rats and mice, but also with those of a very similar study of rhesus monkeys at the University of Wisconsin-Madison, published in 2009.

Differing methodologies

, the lead author on the 2009 study, attributes the inconsistent results to differences in methodology. He says the higher-quality and slightly restricted diet of the NIA control monkeys meant they were already living longer than expected. By contrast, the monkeys in Weindruch鈥檚 study were fed a refined diet high in fat and sucrose, more similar to a Western diet.

at the University of Arizona in Tuscon, who was not involved in either study, is not surprised by the conflicting results. He noted that they are in keeping with previous tests, which show that the effects of calorie restriction vary with sex, genetics and environmental conditions.

at the Washington University School of Medicine in St Louis, Missouri, was not involved in either report. He believes both studies should have paid more attention to dietary composition.

鈥淔ifteen per cent of the monkey diet came from protein 鈥� that鈥檚 too much,鈥� he says. 鈥淥ur work suggests lowering protein, rather than calories, may be the key to increasing longevity 鈥� so reducing protein intake could have led to better results.鈥�

De Campo agrees that dietary composition might play a role in lengthening life, but claims the benefits of calorie restriction are still strong. 鈥淎lthough we don鈥檛 have the same lifespan findings as the Wisconsin group, what鈥檚 really important is that we did show similar improvements in health,鈥� he says.

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Wake up and smell the coffee. Or stay asleep and smell it. You might learn something either way. People can make new scent associations while they slumber, which suggests that sleep has real learning potential.

鈥淲e know we can consolidate the day鈥檚 information while we sleep,鈥� says at the Weizmann Institute of Science in Rehovot, Israel. 鈥淏ut attempts to teach new facts using verbal information have failed.鈥�

Arzi and colleagues tried a different tact. They used smells instead of words. While subjects slept, the team played different sounds, each followed by the release of a specific aroma. Just as they would when awake, the sleeping subjects took deeper sniffs in response to pleasant scents and shallower sniffs in response to unpleasant scents.

Later, the sounds alone were enough to provoke deeper or shallower breaths 鈥� even when the volunteers were awake.

鈥淲e are able to do more than we thought while we sleep,鈥� says Arzi. 鈥淚t鈥檒l be great to find the limits of what we can learn.鈥�

at New York University Langone Medical Center in Orangeburg, who was not involved in the current work, is particularly excited by this new insight into odour-processing. 鈥淲e thought the olfactory system went offline during sleep, but this study shows that some information is going in and being retained,鈥� he says.

Although it is hard to imagine translating algebra into odours, Wilson envisages practical uses for developing scent associations during sleep. They could help train people with breathing disorders like sleep apnoea to inhale deeply on cue.

Journal reference: , DOI: 10.1038/nn.3193

Aphids may recharge their batteries as they sit in the sun.

A handful of animals live in symbiosis with photosynthetic microbes or plants, but none have been found that harness light directly. Now there are hints that aphids increase their production of ATP 鈥� the biological energy molecule 鈥� in response to light. While this doesn鈥檛 prove they photosynthesise, it is an intriguing hint that they might.

Carotenoids are common in algae and some bacteria and fungi, where they harvest light for photosynthesis. Aphids are the only insects known to have the genes to produce carotenoids; the molecules give them their colour.

of the University of Nice in France and colleagues found that light boosted ATP production in aphids that have carotenoids, but not in lines bred to lack them.

Capovilla says this suggests the aphids may have the elements of a photosynthesis-like mechanism. Christopher Howe of the University of Cambridge points out that the experiment does not prove the existence of such a mechanism. Rather than driving the reaction, light could be playing an as-yet unknown and indirect role in the production of ATP.

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Citizen science is alive and well. Species nominated for legal protection by US citizens face higher levels of biological threat than those identified by the US Fish and Wildlife Service. The finding looks set to silence critics who question citizens鈥� motivation for nominating species for protection.

The US of 1973 gives citizens, as well as the government, a role in selecting which species should be legally protected by the US Fish and Wildlife Service. It also allows citizens to take to court any decisions they don鈥檛 like.

Not everyone is happy with the situation. The Bush administration unsuccessfully requested a limit on citizen input in 2001, and the Fish and Wildlife Service repeated the request, again unsuccessfully, in 2011.

鈥淚 was picking up on a lot of criticism of this part of the Act鈥�, says , an environmental researcher at Emory University in Atlanta, Georgia. 鈥淐itizens were accused of overwhelming the government with paperwork, and of being politically motivated 鈥� using the Act to block developments like new shopping malls that they didn鈥檛 like.鈥�

Along with , a law professor at the University of California in Berkeley, Brosi set about comparing animals selected for protection by citizens with those selected by the FWS. If there were ulterior motives at play in the citizen nominations, their selected species should be at lower risk of extinction than the FWS-nominated species.

In fact, Brosi and Biber found the opposite. Species chosen by citizens faced significantly greater risk. The researchers conclude that citizens play a valuable role in spotting endangered animals.

鈥淭here are probably two things going on here,鈥� says Brosi. 鈥淔irstly, people might be under less political pressure than the government to ignore at-risk animals conflicting with big-dollar developments. Secondly, citizens help cover the diverse expertise needed to select endangered species across a country as big as the US.鈥�

Kieran Suckling, executive director of the , an NGO that has petitioned for many of the species now on the protected list, is not surprised by the finding.

鈥淢any scientists and local experts put a lot of time into identifying imperilled species, and they can help government agencies with limited resources,鈥� he says. 鈥淐onservation in the US relies on the Endangered Species Act as a check. It allows us to get better scientific results by focusing on the most threatened species rather than the most politically convenient.鈥�

The Fish and Wildlife Service has not responded to New 女生小视频鈥榮 requests for a comment on the new study.

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The brain drain is real. There is a network of previously unrecognised vessels that rid the brain of unwanted extracellular fluids and other substances, including amyloid-beta 鈥� a peptide that accumulates in the brain of people with Alzheimer鈥檚. The new discovery looks set to add to our understanding of the disease.

at the University of Rochester Medical Center, New York, and his colleagues, were intrigued by the fact that there are no obvious lymphatic vessels in the brain. Among other things, the lymphatic system removes waste interstitial fluids from body tissue.

鈥淚t seemed strange that such an important and active organ wouldn鈥檛 have a specialised waste-removal system,鈥� says Iliff.

When the researchers added fluorescent and radioactive tracers to the cerebrospinal fluid of live mice, the tracers quickly spread throughout the rodents鈥� brains. Using two-photon microscopy to visualise the movement in real-time, the team saw cerebrospinal fluid permeating the entire brain through 鈥榩ipes鈥� surrounding blood vessels, similar to the lymphatic system that services all other organs.

The pipes work on hydraulic principles, though, and so the system breaks upon opening, making it hard to identify it outside living organisms.

Flushing system

Further study showed that the flow of cerebrospinal fluid ground to a halt if the researchers inactivated a second system, which helps transport water around the central nervous system and involves star-shaped cells called astroglia. That finding suggests that glial cells, which support and protect neurons, play a key role in the newly identified drainage network. Iliff鈥檚 team has named the new network the glymphatic system, in recognition of the importance of glial cells and the resemblance to the lymphatic system.

The researchers found that the glymphatic system flushes waste from the brain through large drainage veins. That waste includes 55 per cent of the amyloid-beta removed from the rodent鈥檚 brains.

鈥淩emoving waste is as vital to organ function as receiving nutrients,鈥� says Iliff. 鈥淪o the failure of the glymphatic system is probably involved in many disease states 鈥� for example, Alzheimer鈥檚 with its hallmark accumulation of amyloid-beta.鈥�

of the Cajal Institute in Madrid, Spain, who was not a member of the study team, says the finding heralds an exciting time in Alzheimer鈥檚 research. 鈥淒ata suggests amyloid-beta is responsible for most deleterious effects of Alzheimer鈥檚, so this 鈥榖rain cleaning system鈥� could be used as a therapeutic target in individuals with Alzheimer鈥檚 disease.鈥�

of King鈥檚 College London, who was also not involved in the new work, is fascinated by the discovery, but cautious about the implications for Alzheimer鈥檚 research. 鈥淚t is uncertain whether treatments effective in clearing amyloid-beta in humans do anything to slow the progression of dementia,鈥� he says. 鈥淎ssuming a failure to clear amyloid-beta is at the root of Alzheimer鈥檚 disease is likely to be an oversimplification.鈥�

Journal reference: , DOI: 10.1126/scitranslmed.3003748

Two earthquakes that struck Iran on 11 August have left 306 dead, with more than 3000 people reported injured. The country continues to experience aftershocks.

The northwest of Iran was hit by a 6.4-magnitude quake at 16:54 local time (12:23 GMT), 23 kilometres southwest of the city of Ahar and 58 kilometres northeast of Tabriz. Some 11 minutes later, a 6.3-magnitude quake struck 聽 10聽kilometres to the west.

The worst effects were felt in small villages, where houses are usually made from concrete blocks or mud bricks. No deaths have been reported among the 1.7 million inhabitants of the city of Tabriz, where houses are more substantially built.

The two earthquakes each occurred at a depth of around 9.9 kilometres 300聽km east of the border between the Eurasian and Arabian tectonic plates. That places them too far from the plate boundary to readily locate the faults responsible. But an initial analysis by the US Geological Survey suggests they were a result of movement along a strike-slip fault 鈥� where neighbouring blocks move horizontally past one another 鈥� travelling in a roughly east-west direction within the Eurasian plate.

Iran is home to several major geological faults, making it prone to seismic activity. Most of the country鈥檚 earthquakes are caused by collisions between the Eurasian and Arabian tectonic plates, as the Arabian plate moves 26 mm per year north towards the Eurasian plate.

Since the turn of the century, Iran has suffered six earthquakes with a magnitude greater than 6. The most serious occurred in December 2003, destroying the ancient city of Bam and killing an estimated 31,000 people.