Lotus meets lizard

Improving on nature...

Improving on nature...

While the water repelling properties of the lotus leaf are the stuff of legend, like much in nature, scientists have found a way to replicate them. Superhydrophobic surfaces (as lotus leaf mimicking materials are known) have been around for years and they do repel water very well but, to date, the lotus has always had a leg up on them. Scratch a lotus leaf and, while its water repelling nature will be temporarily lost, the tissues will heal and the water repelling trait will return. Scratch any superhydrophobic surface and the water repelling trait is permanently lost. Now a team has found a way to help these surfaces heal themselves by mimicking another living organism: the lizard. The researchers created multiple layers of water proof material that were sandwiched together using water soluble glue. When the top layers became compromised, water seeped in, dissolved the glue, drove the top layer to fall off and exposed the undamaged water proof layer below. The material literally sheds its skin like a reptile. You can read more in The Economist article that I wrote on this here.

Colour me safer

In 1907 the Chicago Yellow Cab Company chose the colour of its cars based on a survey conducted at a nearby university. The survey showed that yellow was the most noticeable colour and led the company to infer that this would make it easier for potential passengers to spot their taxis in the sea of mass produced black cars prevalent at the time. Now, more than a century later, it turns out that yellow was a wise choice for a new study is revealing that taxis of that colour are much less likely to get into accidents than taxis of other colours.

The new work made use of a merger that took place between two taxi companies in Singapore during 2002. One of the companies used yellow cars and the other one used blue cars. Today, the company owns 4,175 yellow taxis and 12,525 blue ones. 

The researchers analysed 36 months of detailed taxi, driver, and accident data that the taxi company supplied to them and found that there is an unquestionable link between colour and accidents. In total, yellow taxis had 6.1 fewer accidents per 1,000 taxis per month than blue taxis. That suggested that colour alone granted a 9% reduction in accident probability. The researchers found this hard to swallow so they set off to explore whether the driver populations had any significant differences. To do this, they analysed the demography and driving behavior of a random sample of 3,341 drivers for 3 months using 15 second interval location and status data from the taxis. This amounted to more than 150 million data points and showed that the drivers were driving nearly identically. Mechanical differences were also ruled out since the taxi company uses a single car model and all cars undergo the same service schedules.

This led the team to question whether yellow taxis were protected by simply being more noticeable than blue taxis. To test this idea, the researchers delved into detailed accident reports and looked for the nature of the accident and the lighting conditions in which it occurred. They theorised that if yellow had a protective effect, a yellow taxi would be less likely than a blue taxi to be involved in an accident when the taxi was clearly in the other driver’s view. This proved true. They also theorised that yellow would grant an even greater advantage at night since yellow has a stronger contrast than blue against a dark background. You can read more in The Economist article that I wrote on this here.

The rise of robot bees

About to see meet some competition. Image courtesy of John Severns.

About to see meet some competition.

Image courtesy of John Severns.

Pollinators are in trouble and ecologists are scrambling to try to keep populations healthy. Economically this matters since a serious decline in pollinators has the potential to doom much modern agriculture but, just in case the ecologists fail, engineers are getting ready to handle the problem. Interested in creating pollinators from tiny drones, a team of researchers has designed and synthesised ionic liquid gels that will allow pollen to stick and be transported artificially.

Honey bees get covered in pollen when they enter flowers to collect nectar and then drop that pollen off in other flowers as they forage. This pollination allows plants to sexually reproduce and is vital to their survival. To date, nobody has been able to find a substance similar to honey bee fur that could readily capture and release pollen grains but the researchers behind the new work suspected that they could manufacture such a substance with ionic liquid gels.    

Ionic liquid gels are composed of electrolyte liquids trapped inside solid polymers. They are often electrically conductive, sturdy and have highly variable adhesive properties. This led the team to wonder whether it might be possible to create an ionic liquid gel that was sticky enough to collect pollen grains upon initial exposure to them but then capable of dropping the grains a minute later just as honey bee fur does as the insects rummage around inside flowers.     

To test this idea out, the researchers used an acrylic to polymerise an imidazolium salt, which is well known to function as an effective ionic liquid, by baking a mixture of the materials in an oven at 80˚C. Once the ionic liquid gel formed, they measured its tackiness with a probe by monitoring how much load it took for the gel to adhere and how much load was needed for the gel to release the probe once it was stuck to it. This test revealed that the gel was able to rapidly adhere under a very light load but would then release just as quickly when the same small load was applied in reverse. Crucially, the gel did not lose its adhesive properties after multiple attach and release events.  

Encouraged by these findings, the researchers applied the gel to horse hairs collected from paint brushes and then attached these hairs to their drones. They then manually piloted the drones to the flowers of the Japanese privet where they guided them to stick the hairs into the male and female organs of the plants. They studied the gel-coated hairs under the microscope between many of the flower visits and confirmed that they were getting coated in pollen. They then used fluorescent microscopy to confirm that pollination was indeed being initiated in the flowers that their drones visited. An abridged version of the research can be found in The Economist article that I wrote on this here.

The price of secrecy

While secrecy is common and consequential, there has been little research on it. Now a new study is revealing the sorts of secrets that people commonly keep. More importantly, it is revealing the first systematic analysis of how people experience the act of keeping a secret. As you can imagine, keeping secrets is hard work but whether having lots of secrets is actually harmful to our well being varies with how often we decide to think about them. You can read more in The Economist article that I wrote on this here.

Drunk crayfish

Woohoo!!! Image courtesy of Jens Herberholz

Woohoo!!!

Image courtesy of Jens Herberholz

Precisely what happens in the brain when we get drunk is still something of a mystery. This is largely because of the complex interactions between alcohol and the nervous system and one of the best ways of studying these interactions is to study the effects of alcohol on other animals. To this end a team of researchers ran a rather amusing experiment with juvenile crayfish. They found that, like many species, the crayfish were behaviourally sensitive to alcohol exposure and that they progressed through stages of intoxication that are strikingly similar to those seen in people. What came as an outright shock though was that the social history of the animals significantly modified the effects that alcohol had on them. Yeah, you read that right. Crayfish raised in tanks with many others got drunk far more quickly and became more dependent on alcohol than crayfish raised in isolation. The big question is whether social interactions during youth in people makes the brain vulnerable to alcohol in the same way. You can read more in The Economist article that I wrote on this here.

Chemical weapon detection at a touch

Chemical weapons are easy enough to detect with the right equipment but such equipment is often not at arm's reach when the use of such weapons is first suspected. Samples of contaminated surfaces need to be taken and run through detection devices and this takes valuable minutes. It would be better if soldiers could automatically detect the presence of dangerous compounds right when they are encountered and now a new system that integrates detection systems into a glove looks like it can grant this ability.     

The new technology is a flexible glove with a tiny electro-chemical lab stitched into it that is designed to transmit its findings in real time to a nearby phone. The glove can, quite literally, sound the alarm by triggering an application installed on the phone to vibrate or beep. You can read more in The Economist article that I wrote on this here. Alternatively, if you would like to hear me describe the research on The Economist's science podcast, you can do so here.

Tornado transport

Carrying more than just dust. Image courtesy of NASA.

Carrying more than just dust.

Image courtesy of NASA.

Read any geology textbook and it will tell you that winds only routinely transport sediment grains that are smaller than 2 millimeters in diameter. Thus, sand, silt and clay are all regularly moved around by wind but gravel, cobbles and boulders only get picked up by occasional fierce storms.

These rules have left geologists working in the Chilean desert perplexed by the discovery over the years of hundreds of mounds containing tens of thousands large crystal shards of the mineral gypsum. Many of the crystals are over 20 centimeters in length and clearly did not grow in the dry environment where they are being found. How the crystals got where they are has been a long standing mystery but now a new study is revealing the story of how they got there... tiny tornadoes that routinely pass through the area. You can read more in The Economist article that I wrote on this here. Alternatively, if you would like to hear me describe the research on The Economist's science podcast, you can do here.

 

A record of ancient sunspot activity

Spotted! Image Courtesy of The European Space Organisation.

Spotted!

Image Courtesy of The European Space Organisation.

Every 11.2 years there is slight change in the degree of solar radiation that reaches Earth. This is caused by spots forming on the sun and known as the sunspot cycle. We know that the cycle shapes plant growth today but have little evidence of what solar cycles once were. Botanists are perfectly capable of looking at recently felled trees to infer solar cycle information but applying these methods to fossil plants has been really hard. To make matters worse, trees with the relevant structures preserved in them are almost never fossilised in a good enough state to be used in this manner. Thus it is all the more remarkable that a team of researchers are revealing the discovery of spectacularly well preserved fossil trees which show evidence of sun spot cycles that took place 290 million years ago. You can read more in The Economist article that I wrote on this here.

Deep sea pollution

We thought that the trenches at the base of the ocean were effectively untouched environment due to their incredible depth and isolation. Well, that notion has now proved to be totally incorrect as a team of researchers has now revealed the presence of some rather nasty pollutants in them. You can read more in The Economist article that I wrote on this here. Alternatively, you can listen to my podcast on the subject here.

How jet lag induces cancer

For years, the main cause of liver cancer was heavy drinking but that is no more the case. Non-alcoholic fatty liver disease is now the prime force behind most liver cancers. Obesity is widely been blamed for this but there is also evidence suggesting that disrupted circadian rhythms play a part too. How and why circadian disruption has this effect has been a mystery but now a new study is revealing details.

The researchers worked with mice and found that jet lag induced the livers of the animals to produce and store far more fat than they otherwise would. Worse, they noticed that jet lag drove the mice to produce compounds that both induced mutations and helped their liver cells to replicate rapidly. The combination of increased cellular replication with mutagens around proved utterly toxic and ultimately produced cancer cells. This is unpleasant stuff but the researchers point out that understanding the chemical pathways responsible for spawning liver cancer can give us the edge as we attempt to prevent this terrible disease. You can read more in The Economist article that I wrote on this here

Orca research explains menopause

Image courtesy of NOAA.

Image courtesy of NOAA.

Why menopause happens in some animals is a longstanding evolutionary mystery. Many biologists have argued that menopause forces grandmothers to support the offspring of their own children rather than continuing to have kids of their own but number-crunchers have dismissed this "grandmother hypothesis" on the grounds that the magnitude of the benefits granted by grandmotherly support are insufficient to account for the monumental genetic cost of giving up reproduction. In recent years an alternative theory has emerged suggesting that menopause reduces the cost of inter-generational reproductive conflict by preventing weakening older females from becoming pregnant and using up valuable resources that could go to their actively reproducing daughters. It is a nice idea but proving it has been difficult. Now a team is demonstrating that this theory is correct by cleverly making use of an animal that lives for decades after menopause sets in: the orca.

The researchers tapped into a long-term dataset on wild resident killer whales where females frequently live for 20 to 40 years after menopause begins. Using 43 years of orca data they were able to show that when mothers and daughters co-breed, mortality in calves from older generation females was 1.7 times that of calves from younger generation females. They point out that when the cost of this intergenerational effect is combined with the known benefits conveyed to grandchildren by grandmothers, the numbers to do work out and it becomes clear that menopause is a wise biological investment for a long lived species. You can read more in The Economist article that I wrote on this here.

Podcast: Robobee

Bees are in big trouble. Their populations are declining rapidly all over the world and if they vanish entirely agriculture is going to suffer. The reason is down to pollination. Many plants depend upon bees to carry pollen from one plant to another. This allows the plants to sexually reproduce and is essential to maintaining genetic diversity. If bees perish, plant sexual reproduction will grind to a halt. For this reason, ecologists are working very hard at keeping bees around but, just in case they fail, engineers have their backs with drones that can pollinate plants in the absence of insects. You can listen to the full story on The Economist's science podcast Babbage here.

Toxin tracking

Chemotherapy drugs are a lot like cats, release them into space and you never really know where they are going to go. Even when the same drug is used against the same sort of cancer in two different patients its behaviour can be very different. The worst part about this is that medics often can only work out where a drug has gone by monitoring patient health. It would be better to know immediately whether a drug is accumulating where medics want it to and now a team is revealing that they have found a way to do this.

The researchers behind the new work developed a tactic for attaching labels made of radionucleotides to specific cancer drugs that are carried inside tiny capsules called liposomes. They then used positron emission tomography scans to monitor the movement of the drugs in mice with different sorts of cancers. 

With mice suffering from breast and ovarian cancer, the team were encouraged to find that the drugs accumulated in tumours and bone tissue at levels well above those in normal tissues. However, in some female mice belonging to a specific genetic strain the drugs concentrated in their uteruses where no cancer cells were present. This is useful information and will become doubly so when this technique starts getting used in people. You can read more in The Economist article that I wrote on this here.

Detecting speech disorders with computers

Last year a team revealed that psychological depression and post traumatic stress disorder pepper adult speech with telltale signs that computers can potentially detect. Now a new study conducted by a different lab is revealing the development of a computer system that can detect childhood speech and language disorders whilst they are still easily treatable in their initial stages. 

Language disorders in kids often go undetected until the age of five or six when when significant learning damage has already been done. The researchers behind the new work are aiming to resolve this problem with their new computer system which analyses audio recordings of kids' voices as they retell a story presented to them in their own words. You can read more in The Economist article that I wrote on this here.

Feeding off fish pee

I was really here to feed on your urea. Image courtesy of University of Aberdeen.

I was really here to feed on your urea.

Image courtesy of University of Aberdeen.

Ammonia is toxic to aquatic animals and yet there is ample evidence that sharks and their kin are attracted to it. Many experts have argued that sharks use ammonia to track down their prey and, while that might be true, a new study is now revealing evidence that sharks are capable of converting the toxin into a valuable resource with their gills.

The new work began when a previous study noted that ammonia can be actively taken up by shark gills and transformed into urea. While interesting on its own, the finding led the biochemists behind the new research to question whether the sharks were getting something more out of this conversion. After working through the chemistry associated with the process, they speculated that sharks were obtaining a net nitrogen gain from the ammonia uptake. This was intriguing because nitrogen has to be obtained by sharks through meat. Moreover, it is required not only for them to grow but also for them to manage the salt in their blood. When the researchers monitored what sharks did with ammonia laced waters in the lab, they were stunned to discover that the predators use it to cover 31% of their daily nitrogen demands and can thus get by on considerably less meat. You can read more in The Economist article that I wrote on this here.

Sticking around

The best medicines in the world cannot do much if the patients who need them do not take them as prescribed. This problem is particularly serious in rural areas where attempts to eliminate malaria are at work. One key drug, ivermectin, is excellent at killing off mosquitoes that feed on the blood of people taking it and can effectively create a firewall against malaria if everyone in an area is on it. The trouble is that ivermectin has an 18 hour half life in the body and needs to be taken daily by everyone for it to be effective at controlling malaria's movements. A solution has been badly needed and now a team is revealing that they have found one.

The researchers behind the new work have developed an oral, ultra–long-acting capsule that dissolves in the stomach and deploys a star-shaped structure that slowly releases ivermectin while assuming a position in the digestive tract that prevents it from passing into the intestines while still allowing food to get by. In tests run on pigs, the team found that the specially designed structures were able to release mosquito killing doses of ivermectin for two weeks at a time. Moreover, they suspect that with further engineering they can extend their drug release period to be several months. Furthermore, they suggest that there is a real potential for other drugs to be housed in their devices that could help medicate patients suffering from diseases that impair their ability to take drugs in the first place (like diabetes and Alzheimer's). You can read more in The Economist article that I wrote on this here.

You can read more in The Economist article that I wrote on this here.

Carnivorous origins

Wicked! Image courtesy of Luis Lopez.

Wicked!

Image courtesy of Luis Lopez.

Palaeontologists have found a fossil that has all of the skeletal features which reveal it to be the great great grandparent of the sauropod dinosaurs like diplodocus, brachiosaurus and apatosaurus. The sauropods are well known for having been gentle giants. While they were absolutely enormous, their teeth make it clear that they never ate anything other than plants. We always figured that their ancestors were likely to have only eaten plants too and we were clearly wrong.

You do not have to be a palaeontologist to look at these teeth and know they were definitely not for chewing on leaves! It is a very cool finding that raises tonnes of questions like "what animals was this sauropod hunting" and "what forces drove its descendants to ultimately go vegetarian". You can read more in The Economist article that I wrote on this here.

Growing drugs to combat malaria

Sweet wormwood yields invaluable artemisinin, a compound that is highly effective against drug-resistant malaria. The trouble with artemisinin is that it is very expensive. A major part of the cost stems from the fact that wormwood is tricky to grow and artemisinin is challenging to extract from its tissues. Elimination of these challenges would make the antimalarial far more affordable and have the potential to save a lot of lives. Now researchers are reporting that they have found a way to do this by getting tobacco plants to produce artemisinin in copious amounts. 

The team behind the new work genetically engineered tobacco to produce artemisinin. This has been done before but the plants always yielded precious little of the compound and often did not grow very well. The team discovered a clever biochemical way around this. More importantly, they are reporting that the artemisinin produced by their engineered plants could be delivered orally to mice infected with malaria and that the drug proved very effective even when it was delivered while still encapsulated within the cells of the tobacco plant. 

You can read more in The Economist article that I wrote on this here.

Predatory pollination

Come closer dearie... Image courtesy of Stefan Doetterl.

Come closer dearie...

Image courtesy of Stefan Doetterl.

With its needle-like teeth and pitcher shape the South African parachute plant looks like it ought to be carnivorous. It very nearly is. Flies that enter fall into a pit of pollen and cannot get out until the pod they are in begins to wilt and the teeth holding them captive weaken. Yet many mysteries have remained. Flies are not known for their intelligence but it seems odd that they would be so willing to crawl into such a treacherous looking cavity.  Now a new study is revealing that the plant is releasing chemicals that dupe the insects into believing that their favourite prey are lying wounded within. 

You can read more in The Economist article that I wrote on this here.