Waste space in cities isn’t a waste of space. Most people see vacant and abandoned land as an eyesore, or being ripe for development, but it has a substantial ecological value in its own right. The abandoned land in a single city can be worth hundreds of millions of dollars.

All ecosystems provide us with free “ecosystem services“: useful things that we would otherwise have to do ourselves. Forests clean the rivers that pass through them, providing safe drinking water, and growing plants remove carbon dioxide from the air, slowing global warming. That means wild ecosystems like rainforests have a kind of economic value, which can be estimated.

Gunwoo Kim and of Virginia Tech in Blacksburg have applied the same reasoning to vacant lots in cities, which are home to urban ecosystems. Such ecosystems are less rich than wild ones, but they still help us out.

Kim and Miller have calculated the economic value of the services provided by vacant land in the city of Roanoke, Virginia. Roanoke has about 32 square kilometres of vacant land, 29 per cent of its total area, says Kim. He mapped the vacant zones and identified the plants that live there using aerial images. Kim presented at the in Sacramento, California in August.

Valuable wasteland

About a third of the vacant land is covered by trees, Kim found. They currently hold about 107,000 tonnes of carbon, valued at $7.65 million. They also remove another 23,000 tonnes of carbon, and 91 tonnes of pollution, every year. That adds $164,000 and $916,000, respectively, to their worth each year.

The trees also cut energy costs for nearby residents by $211,000 per year, by creating shade and thus reducing the need for air conditioning.

However, the big money comes from the structural value of the land: the money it would take to cut the trees down, plant new ones and let them grow to their current size is a whopping $169 million.

The strongest ecosystem benefits come from natural sites like forests and fields, says Kim. But abandoned sites with lots of biodiversity are valuable too – not least because they offer space for other species.

Cooling cities

Trees also mitigate the high temperatures of cities in summer, says of CSIRO, Australia’s national research organisation, in Aspendale.

She has studied Sydney, where as a result of rapid urbanisation and temperatures have subsequently gone up. Her results suggest that a 10 per cent increase in vegetation can alleviate this urban heat island effect, bringing average local temperatures down by nearly 0.5 °C.

Kim and Lin are independently pushing for cities to make the best use of urban green spaces, on private and on public land. Kim says that if local governments offered tax breaks to the owners of vacant land if they used it better, everyone would benefit.

Some cities are already starting to integrate abandoned land into their planning. Los Angeles has been turning small plots of unclaimed city land into “” for public use. Meanwhile, cities like Chicago, and Milwaukee in Wisconsin, have been taking advantage of abandoned properties by .

Historically, heroin users in the US have faced an uphill battle not only against addiction and the associated health risks, but also against the judicial system. In most states anyone found possessing the drug is arrested and prosecuted to the fullest extent of the law – even after a near-fatal overdose. But times are changing as addiction gains recognition as a chronic disease rather than a personal choice.

For example, show that while the total heroin deaths in the city rose by 41 per cent from 2010 to 2013, they levelled off in Staten Island after a peak in 2011. That’s probably due to a harm-reduction policy begun in Staten Island in 2012. This included equipping police, first responders, and emergency rooms with the anti-overdose drug naloxone to reduce deaths. The city now plans to roll out the policy more widely.

Treatment, not jail

The state of Vermont has gone one further. Under a bill signed into law in June – which will be expanded on later this year – heroin addicts will be able to avoid prosecution by enrolling in treatment programmes, and will have better access to heroin substitutes to wean them off the drug.

These moves are part of a wider trend to deal with the increase in heroin use across the country. In recent years, about half of US states have passed laws that allow at least some naloxone administration, while 20 or so states have a form of Good Samaritan law that allows heroin users to reach out for help in a medical emergency without fear of arrest.

“Right now we’re riding the second wave of the opioid crisis in the US,” says , policy director for the Harm Reduction Coalition, a US-based advocacy group for people affected by drug use. “The first wave started in the 1990s, when doctors’ offices started pumping out [opioid] prescriptions that drove production and circulation. Now that we’ve got that problem stabilised, we’re riding the second wave as users resort to cheaper, more dangerous options like heroin.”

While there has not yet been significant policy changes on a federal level, increasing support for harm reduction was reflected in the and the federal budget issued by the US administration in January. Forty three per cent of this year’s national drug budget is dedicated to drug treatment and prevention efforts – the highest portion in 12 years and 20 per cent more than that for domestic drug law enforcement and incarceration.

It’s easy to drift in space, but it’s harder to drift off to sleep. The most comprehensive study to date of sleep patterns in astronauts reveals that they suffer sleep deficiency during space flight and even before they take off – and sleeping pills may not be the solution.

Astronauts have complained of fatigue and sleep deficiency since the beginning of human space travel.

“Trying to sleep in space is a neat kind of disorientation,” says six-time NASA astronaut . “There’s no clock, no day or night, no up or down, and no tension on your body so you can even lose the sense of where your limbs are when you sleep.”

Most astronauts can expect a relatively quick return to normal, as most space missions last a year or less. But as space agencies prepare for longer journeys to Mars or elsewhere in the solar system, it will become ever more important to understand how best to manage sleep in space.

Now, researchers from Brigham and Women’s Hospital and Harvard Medical School in Boston have performed the most extensive analysis to date. They monitored the sleep patterns of 64 astronauts from 80 space shuttle missions, as well as 21 astronauts who spent time on the International Space Station. They fitted the astronauts with a wrist device that records sleep and waking cycles and required them to keep a diary of their sleep habits before, during and after space flight, logging more than 4200 nights in space and over 4000 on Earth in total.

Despite having 8-and-a-half hours in every 24 designated for sleep during space flight, the average astronaut slept just under 6 hours on shuttle missions, and just over 6 hours on ISS visits. Only 12 per cent of shuttle astronauts and 24 per cent of those on the ISS slept more than 7 hours at a time.

The researchers found that preflight sleepless nights are also common, and sleep deficiency can build up in astronauts from as early as three months before lift-off. Astronauts in training average only 6.5 hours per night – although that is not far off from average adults during the work week, says researcher of Harvard Medical School.

Things improved once the astronauts were back on the ground, though. Post-flight data recorded for the same astronauts showed that they slept more than 7 hours nearly half the time once they returned to Earth.

Lack of sleep has been consistently linked to decreased performance, and more effective measures are needed to keep crew members as alert as possible. While some astronauts cope with disorientation by sleeping in a closet in a sort of sleeping bag, or strapping down their knees or head, Barger and her colleagues found that more than 75 per cent of astronauts turn to sleep medication at some point.

“Medication is essential. After two to three days of bad sleep, your performance begins to suffer, and often medication is the only relief,” says Musgrave.

While this strategy is common, it might not the best remedy. “If astronauts had to be awakened in an emergency situation, they run the risk of their performance being impaired if they’ve been using hypnotic sleep aids,” says Barger.

The ISS is testing out new lighting that provides more short-wavelength light to promote alertness. Future research will explore behavioural changes and schedule modifications that might help astronauts to sleep through the “night”.

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THINK having a baby is a drain on your time? An octopus mother brooded her eggs for four and a half years – the longest brooding period of any known animal.

Egg-laying animals brood to protect their eggs from potential predators, ensuring they hatch successfully. Female octopuses also regularly blow water on their eggs to bathe them in the oxygen they need to survive.

and his colleagues at the Monterey Bay Aquarium Research Institute in California were surveying deep-sea animals in 2007 when they spotted a female octopus in a submarine canyon at the centre of Monterey Bay in the Pacific Ocean (pictured). The octopus, a member of the species , was clinging to a rocky ledge some 1400 metres down, protecting a brood of 160 eggs.

Over the following four and a half years, the team returned to the site 18 times. On every visit, the group found the same octopus – identified by her distinctive scars – in the same location. Finally, on a visit in 2011, one month after their last visit, the researchers found only the remnants of hatched egg capsules (PLoS One, ).

The four-and-a-half-year brood is the longest known for any animal, beating the previous record held by .

The marathon brood was no easy ride. As the octopus’s translucent eggs grew larger, she gradually lost weight, and her skin became loose and pale.

“It’s not impossible that she fed at some point during her brood, but it’s not characteristic of any known octopus species to do so, and we have never observed unattended octopus eggs,” says Robison. The brisk 3 °C water may have helped the octopus survive by slowing her metabolism and energy requirements.

But ultimately the octopus will have sacrificed her life for her brood. Reproduction is the final stage of life for all female octopuses, says at the Field Museum in Chicago. During this stage, their bodies change to direct their energy to producing and caring for eggs.

“In extreme habitats like the deep ocean, which is harsh and demanding, animals have two reproductive options: one is to make a million eggs and send them on their way, and the other is to produce just a few eggs and make every effort to ensure their success,” says Robison.

This evolutionary strategy appears to have worked well for G. boreopacifica, which is one of the most abundant and long-lived species of deep-sea octopus in the north-east Pacific Ocean.

This article appeared in print under the headline “Octopus mum performs record-breaking brood”

Leaving home can change you – and the moon is no exception. As it drifted away from its parent, Earth, the pull of our planet’s gravity gave it an odd bulge on each side and a tilted axis. Uncovering the mystery behind its unusual shape is a step towards finding out exactly when and how the moon formed.

Most rocky planets and moons formed from a spinning ball of magma, which gives them a fairly predictable spherical shape.

Earth’s moon is thought to have formed when a Mars-sized object smacked into the infant Earth and shot hot rocky material out into space. That should mean normal rules apply, but instead, the moon has a weird bulge on both the near and far side, giving it a shape like a lemon.

There are several ideas for how these bulges formed, but studying them has been difficult because since it formed, the moon has been marred with large basins that mask its original shape. One of them, the South Pole-Aitken basin, is the biggest, deepest impact crater in the solar system.

at the Massachusetts Institute of Technology and her colleagues made a model that filled in 12 of the largest basins, to see what the moon would have looked like before they formed.

The results suggest the lemon-like bulges formed in the first 200 million years, when Earth’s gravity pulled at the moon’s magma, building the crust up more on the points closest to and furthest from Earth.

That left the mystery of the moon’s puzzling tilt. When the bulge formed, the points of the lemon should have been pointing directly at Earth, but today they are offset by 36 degrees. The researchers suggest that as the moon moved away from the Earth, the density of the cooling crust was uneven. The crust became lopsided and tilted the moon’s polar axis to the angle we see today.

Journal reference: Nature, DOI: 10.1038/nature13639

Pack it in, pricey lab gear. Bubble wrap can be a cheap, easy way to run a variety of tests on medical and environmental samples.

Standardised and stackable, are the gold standard for running small sample diagnostics and simple liquid reaction tests in chemistry labs. But at $1 to $5 a piece, this can be too much for labs around the world with limited resources.

at the Wyss Institute for Biologically Inspired Engineering at Harvard University was on the hunt for low-cost diagnostic tools made from things that are already mass-produced with high quality but low cost.

“We like the idea of using materials that are readily available and seeing how much we can do with them, going far beyond their intended purpose and adapting them to address local problems,” says Whitesides. Previously, his team has found uses for paper as devices for testing water quality, egg beaters and CD players as centrifuges and bicycles as power sources.

Bubble basics

Whitesides says that the idea of bubble wrap for chemical assays popped into his head because it is readily available, cheap, lightweight and the bubbles come in a range of sizes. The interior of the bubbles are sterile, alleviating the need for expensive sterilisation equipment.

The bubbles are permeable to gas, but to inject the reagents needed to react with the things being tested, the bubbles have to be punctured with syringes. The team found that clear nail hardener from a pharmacy can be used to seal them back up.

The transparent compartments would be most useful for simple diagnostic tests that can be analysed visually, such as reactions that change colour, says Whitesides.

For instance, the team successfully ran blood tests for anaemia and diabetes, cultured the common food-borne bacteria Escherichia coli and raised the nematode Caenorhabditis elegans, which is widely used as a model organism in biology experiments.

Journal reference: Analytical Chemistry,

Video: Asimo robot runs, hops and uses sign language

It’s what’s on the inside that counts. It might look very like the older models, but the latest evolution on Honda’s iconic white android, Asimo, combines athletic running with a delicate and dextrous touch.

Satoshi Shigemi, the robot’s lead developer, the little robot has advanced from an “automatic machine” to an “autonomous machine”.

Asimo can now look at what’s around and modify its behaviour accordingly – for example, to avoid colliding with a person walking towards it. Its sensitive hands can grasp a paper cup without crushing it and it is fluent in both American and Japanese sign language.

It has even beaten its own world record for a humanoid robot’s running speed, now clocking in at 9 kilometres per hour.

Honda launched the first Asimo in 2000, with past breakthroughs including planning a route through a constantly changing environment and recognising up to three voices at a time.

Asimo may ultimately be more fun than it is practical, but the team is using many of the Asimo capabilities for other applications, including robotic prosthetics.

Is it time to ditch the hardware? Adult heart cells can be trained to act like electronic pacemakers with a little genetic encouragement, says a team that has achieved the feat in pigs.

In healthy hearts, a few thousand naturally occurring pacemaker cells are responsible for controlling the electrical signal that initiates each heartbeat and maintains a regular heart rate. In a condition known as heart block, which can be caused by overly vigorous exercise and some medicines, this signal is disrupted. Heart block can occur as early on as during fetal development and results in abnormal heart rhythms, causing anything from wooziness to full-on cardiac arrest.

To return the heart’s electrical signals to normal, people with heart block are fitted with an electronic pacemaker. The device monitors the heart’s rhythm and sends corrective electrical pulses if it skips a beat or slows down.

Every year 300,000 people in the US get pacemakers, and although the devices are generally reliable, they only last around 7 years. The implantation procedure also puts the recipient at risk – around two per cent of adults receiving pacemakers can develop life-threatening infections, says from the Cedars-Sinai Heart Institute in Los Angeles.

Marbán and his colleagues wondered if they might be able to recruit other heart cells to a pacemaker role. The team turned to a gene called TBX18, which is normally switched on only during embryonic development to aid the formation of the heart’s pacemaker cells.

The beat goes on

The group injected this gene into the hearts of adult pigs with heart block. The researchers only targeted a small region of cells, close to the site of the block. Within 48 hours, Marbán’s team found that those cells had become pacemaker cells, and were delivering electrical signals to the rest of the heart. The treated pigs were able to exercise normally, and their heart rate appropriately matched their activity level for the two weeks they were monitored following the therapy.

Marbán thinks the effects could be permanent. Inserting the gene mimics the formation of the pacemaker cells during early development, so once the cells are converted it is unlikely that they would revert back. “Everything we know about the action would have us believe that this TBX18 can function as a light switch,” he says. “The effects of the gene remain forever.”

The researchers hope to translate the therapy to humans within three years, testing it first as a temporary solution in patients with pacemaker-related infections and in fetuses with no other treatment options.

of the Albert Einstein College of Medicine of Yeshiva University in New York thinks the approach is promising for adults, but less so for fetuses. Heart block in fetuses works differently to that in adults, and it would be impossible to inject the gene into a fetal heart, she says.

Journal reference: Science Translational Medicine,

The ocean is known for its waves and rhythms, and so it turns out, are its microbes. Not only do photosynthetic species adopt a night and day cycle, as you might anticipate, but even their non-photosynthetic cousins dance to the same tune.

Cyanobacteria belonging to the Prochlorococcus genus dominate the surface of the open ocean far from land and are possibly the most abundant photosynthetic organisms on the planet. They are autotrophs, which means they produce organic compounds that serve as nutrients for many other marine microbes, known as heterotrophs.

While Prochlorococcus species predictably time gene expression to fit with a day and night cycle, a study shows non-photosynthetic microbes that don’t usually do this join in.

of the Massachusetts Institute of Technology used a robotic ocean sampler to examine communities of bacterioplankton that drift in the massive circular current of the North Pacific subtropical gyre. They noticed that all the species collected showed daily patterns of behaviour such as rising to the surface during the day and sinking at night.

To look deeper into the genetics behind such patterns, the team extracted RNA, a chemical present in the microbes that shows which genes were being expressed and when, says , who was involved in the research. This allowed them to better understand how Prochlorococcus and other marine microbes change gene expression in response to light and time of day.

As expected, patterns of gene expression in Prochlorococcus and some other sun-dependent bacteria were highly tuned to the time of day. What was unusual, however, was that similar patterns were seen in all types of bacterioplankton in the community.

In isolation in the lab, the non-photosynthetic bacteria did not express day to night patterns, but in the ocean they did. To Ottensen, this indicated that the organisms within each population coordinate not just with the sun, but with one another in a sort of “genetic choreography”. The researchers think this might be a result of the low nutrient levels in the open ocean, and the need for organisms to rely on one another for metabolic functions

“We usually think of the ocean as a big stew, but now we see a coordination that could involve ‘talking’ between microbes, timing with the day, and responding to the environment,” says Ottesen.

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