Pigeons weigh danger, stability and efficiency in the aerial acrobatics they use to avoid obstacles, study shows.
Courtesy of C. David Williams
To dodge obstacles, pigeons have to know when to hold ‘em and when to fold ‘em. By altering their wing posture, the birds can successfully navigate tight spots, researchers report March 2 in the Proceedings of the National Academy of the
'Hoff' crabs live in the strange realm of deep-sea vents. NERC Chesso Consortium One-and-a-half miles below the icy surface of the Southern Ocean, some of the world’s coldest seawater meets one of the seafloor’s hottest environments, at undersea hot springs – known as hydrothermal vents – on the ocean floor. Recent research in the Journal of Animal Ecology reveals the private lives of “Hoff crabs” – so-called because of their hairy chest – in this remarkable environment.
At this depth there is no sunlight to support life. But a lost world of deep-sea creatures thrives around the undersea hot springs, ultimately nourished by a process called chemosynthesis. Akin to photosynthesis (the process by which plants use energy from sunlight to make food), chemosynthetic bacteria use chemical energy in warm sulfide-rich fluids gushing from the deep-sea vents to build organic molecules, forming the base of the food chain in these environments.
This bacterial bounty supports abundant animal populations around the deep-sea vents, and different species dominate at different distances from the sources of hot fluids, forming patterns similar in scale to those found among animals on rocky shores.
Unlike rocky shores, however, ecologists cannot stroll around deep-sea volcanic vents with ease, and need to use technology such as remotely operated vehicles (ROVs) to investigate patterns of life in these environments.
In 2010, a British research expedition revealed the marine life at deep-sea vents in the Southern Ocean. The species and patterns of life at these vents were different to those previously found at vents elsewhere, such as in the Pacific and Atlantic Oceans.
The zone closest to where hot fluids jet from the vents is dominated by the Hoff crab (belonging to a genus called Kiwa). These crabs bustle in warm waters of around 20°C, with hundreds of crabs per square metre. To survive, they “farm” chemosynthetic bacteria on their chest hairs for food, using comb-like mouthparts to harvest them.
Because of the conflicting demands of feeding and raising young in the conditions at deep-sea vents, male and female crabs lead largely separate lives.
At the base of the mineral spires that form at the vents, males mingle with females in spectacular piles many crabs deep, where they get together to mate. The females then crawl away from the bustling piles of crabs and the warm mineral-rich fluids seeping from the seafloor, which can be toxic to their young.
Away from the mineral spires and warm fluids, the few crabs found are either small juveniles, or females carrying developing offspring under their curled-up tails.
Moving away from the warmer waters of the hydrothermal vents takes the females across a gauntlet of predators, such as large sea anemones and seven-arm seastars. Away from the vents, the cold water of the deep Antarctic also slows down the metabolism of the adult female crabs, making them less active than in the warmer waters of the jostling heaps. However, the conditions away from the vents may be more stable and less harmful to their offspring for their early development, making the journey of the females worthwhile.
For the small juveniles, strength may be found in numbers. These crabs appear to be heading back towards the vents, where conditions are better for gardening bacteria on their hairy chests, providing the food they need to grow. Hundreds of these small individuals were found nestled amongst the piles of larger crabs, fighting together en masse for the warmer sulfide-rich waters provided by the vents.
Males, meanwhile, don’t share in child-care arrangements with the females, and instead can climb up the mineral spires of the vents to take advantage of the warmth and conditions best suited for growing bacteria on their hairy chests – growing much larger than the females as a result.
Deep-sea exploration over the last four decades, including our scientific research cruise to the Southern Ocean, has revealed that undersea vents from different regions of the world’s oceans are dominated by different species of animals, and why we find these differences remains an unanswered question in ecology – but every discovery is another piece in the puzzle.
Neutrality in style and substance. mindscanner/Shutterstock The net neutrality debate in the US has ended, at least for now, with the Federal Communications Commission ruling for stricter regulation of telecoms and internet service providers (ISPs) in order to maintain a level playing field. But why hasn’t the same debate been had in the UK?
There is an idea in game theory (a branch of economics) called the price of anarchy which tries to represent a measure of how badly a system (such as a market) operates due to the selfish behaviour of those involved in it.
This seems like a rather good way to look at net neutrality, the debate around which is about how well the internet as a system is able to function in the presence of competition between the ISPs and telecom firms that provide access to it.
For us customers, think of this in terms of the neutrality of ISPs – these are the firms that connect individuals, homes, businesses, and institutions to the internet. How they act can be seen as a measure of how well they are able to compete.
For example, the degree to which ISPs use traffic management or “middlebox” network appliances to adjust the traffic flowing through their networks might be a measure of how well or poorly they are able to compete with their direct competitors – other ISPs. The same could be said for the degree to which they may try to play the vertical market – their suppliers and customers – by either reducing their costs for carrying bulky (and therefore expensive) content such as video, or by improving performance for a particular group of users who have preference for a particular service or content such as TV-on-demand (and who may be willing to pay for it).
In the US, the FCC has found it necessary to rule in favour of enforcing neutrality with regulation because there was a lot of this sort of gaming of the market going on. Its ruling stated:
The nature of broadband internet access service has … changed [and] broadband providers have even more incentives to interfere with internet openness today.
The regulations therefore dictate that there is to be no blocking, no throttling, and no fast lanes by ISPs.
In the UK’s broadband market, as in Europe, Japan and South Korea, it seems the market is operating properly and so effective competition has reigned in the selfish behaviour of operators – anarchy is working well. In other words, the regulators here have tested the market and found there’s a fairly reasonable collection of price/performance points that customers can choose to buy or rent services at. Despite some bleating to the contrary, there doesn’t appear to be too much in the way of arbitrary interference from ISPs in the way they treat traffic and content travelling over their networks.
Indeed, in the most populated parts of Europe there are quite a few different ways customers can get internet access: ADSL over the telephone network is most common, with internet over the cable television network and more recently the roll-out of fibre optic connections to street cabinets or directly to the home offered in many cities by more than one provider each. Further options such as the increasingly fast 3G and 4G mobile broadband internet on phones and tablets offer further competition to “keep each other honest”.
Having said that, there are certainly aspects to how mobile phone providers treat data on their networks that are not really “neutral” in the same sense, but it would appear most of these are types of traffic management that is aimed at maximising the value of the spectrum to the customers (and therefore the operator), rather than deliberately treating different content providers in different ways.
Of course things could change, so regulators keep a close watch on the operations of the market, using frequent detailed traffic measurement reports to make sure things are not too out-of-kilter. An approach that seems to have worked, for the moment.
More than half of Earth’s land surface has seen major changes in plant growth patterns such as leaf-on date and how much vegetation grows in a season.
K. Travis
Patterns in when and how much plants grow have changed markedly over the past 30 years, scientists report March 2 in Nature Climate Change.
Researchers looked at satellite data of vegetation on the Earth’s surface from 1981 to 2012. They examined 21 markers of plant growth, including the dates when plants start sprouting and losing leaves each year and how much vegetation grows in a season.
Plant growth patterns have shifted noticeably on 95 percent of Earth’s land surface, the scientists found. In the Northern Hemisphere, growing seasons have generally become longer, while in the Southern Hemisphere some areas had more abundant plant growth over time, and others less.
New experiments show that the asteroids that slammed into Earth and the moon more than 4 billion years ago were vaporised into a mist of iron. The findings, published in Nature Geoscience, suggest that the iron mist thrown up from the high velocity impacts of these asteroids travelled fast enough to escape the moon’s gravity, but stayed gravitationally stuck on more massive Earth. And these results may help explain why the chemistry of the Earth and the moon differ.
When and how Earth’s metallic core formed is uncertain. Clues come from known differences in the preferences of certain elements incorporated in the silicate mantle or the metal core. In a mixture of silicate rock and iron metal, the atoms of certain elements, such as gold and platinum, tend to prefer to enter the metal, while others, such as hafnium, prefer the silicate.
As Earth’s iron-rich core formed it “sucked” the metal-loving elements out of the planet’s rocky mantle. However, measurements of the silicate mantle by James Day have previously shown that there are more of them left in the shallower Earth than would be expected. This has often been attributed to a late veneer of asteroids that delivered an extra dose of metal-loving elements to the rocky mantle.
One problem with this picture has been that the abundance of the metal-loving elements on Earth is ten to a hundred times greater than that measured on the moon, which should by this argument have the same veneer. The chemical difference between Earth and the moon has been perplexing, and casts a shadow over the prevalent idea that the moon formed from the same stuff as Earth after an impact from a Mars-sized planet early in the history of the Solar System.
The new paper seems to reconcile these differences. The experiment relied on Sandia National Laboratory’s “Z-machine”: a huge electromagnetic gun – twice as powerful as the world’s total generating capacity – that can launch projectiles into iron targets at ultra-high velocity.
The impact experiments by Richard Kraus and colleagues show that iron vaporises under the conditions created when an asteroid crashes into Earth or the moon. A cloud of iron mist will have wrapped around the globe after any such collision, falling to Earth as metal rain. These well-mixed droplets will have become incorporated into the mantle, delivering the excess metal-loving chemicals.
The same experiments, however, indicate that the velocity of the iron rain droplets will have been greater than the escape velocity on the moon, but below that of Earth. Earth would therefore have captured the metal cores of colliding asteroids, while the moon will have failed to. William Anderson of Los Alamos National Laboratory, US, said: “The moon may have received, but not retained, a significant portion of the late veneer.”
The results could imply that models for estimating the time scales of Earth’s core formation could be out by as much as a factor of ten, with the core forming much earlier in Earth’s history than previously recognised.
Yellow Rust spores can be seen bursting out of a wheat leaf from the inside, tearing their way through the epidermis. Kim Findlay/John Innes Centre, CC BY-NC-SA One of the major diseases of wheat is caused by the yellow rust fungus, Puccinia striiformis, which threatens all major wheat-producing areas of the world. Ominously, we have discovered that the UK population of this pathogen is shifting dramatically, with the emergence of new strains which can overcome some of our most important wheat varieties.
We have developed a genetic technique that helps us characterise the pathogen, allowing farmers to make informed decisions about which wheat varieties to plant.
Wheat is a critical staple crop, providing 20% of the calories and 25% of the protein consumed globally by humankind. Despite modern agricultural practices, diseases of major food crops can cause pre-harvest yield losses of up to 15%.
In 2013, I joined forces with colleagues at the John Innes Centre and The Sainsbury Laboratory in Norwich with the National Institute of Agricultural Botany in Cambridge to develop a new genomics-driven surveillance method to track the devastating yellow rust fungus and investigate the genetic basis of the new pathogen population.
Our new “field pathogenomics” method is a fast way to analyse fungal diseases from field samples and pinpoint the exact genotype. Current techniques rely on time-consuming phenotypic characterisation – checking the response of different plant varieties to infection by the pathogen – or costly in-lab processes. These methods can only sample a relatively small proportion of the fungal population.
With help from contributors to the UK Cereal Pathogen Virulence Survey, we collected wheat samples infected with the wheat yellow rust pathogen from 17 different counties across the UK. We then used our newly developed “field pathogenomics” method to characterise the genotypes of the samples. As each field sample consists of both the pathogen and its host plant, we were able to analyse both the pathogen and the susceptible host. In the future, this will provide a rapid means for confirming the presence of disease on wheat varieties that may have previously been resistant to disease.
We found that the wheat yellow rust pathogen population has undergone a major shift in recent years. Interestingly, the yellow rust population detected in the UK in 2013 was completely different at the genetic level to previous UK populations. This difference seems to represent a number of recent exotic introductions into the UK and could have serious implications for wheat production in the UK.
A subset of the new pathogen population was able to infect the same wheat varieties as a subset of the older UK pathogen population. Because the same varieties are infected, this new pathogen population would have been missed if analysis were based on traditional phenotypic characterisation alone. Spotting this new pathogen population is important, because even if it infects the same wheat varieties it could still have serious implications for disease incidence. The new pathogen population may have other important traits or infect other wheat varieties not included in our test set.
As we move forward, “field pathogenomics” could be applied to the surveillance of many pathogens besides wheat yellow rust pathogens, and could contribute to addressing human, animal and plant health issues. Such detailed knowledge of shifts in pathogen populations is important for both understanding and managing emerging diseases. For wheat yellow rust, our new technology could provide farmers with early indications of changes in the pathogen population, and have a positive impact on decisions regarding which varieties to plant in the field.
SIM cards contain the key to unlock your phone. Oleksiy Mark/Shutterstock Is it true spies hack technology companies? Can governments really listen to your phone calls? Should we care? The latest details of NSA and GCHQ intelligence agency activities to come from files leaked by Edward Snowden are of the apparently massive theft of mobile phone SIM card encryption keys from the Dutch firm Gemalto.
This “great SIM heist” targeted Gemalto because it produces billions of mobile phone SIM cards for 450 telecoms providers worldwide, and acquiring copies of encryption keys would make it possible to eavesdrop on cell phone calls with comparative ease. While press reports state these attempts were successful, after a brief internal audit – far too brief, some experts say – Gemalto has stated that nothing was stolen.
Who is right? Whether this is resolved or not, in this particular case the handbags will no doubt fly. But the fact of the matter is that there are bigger issues we should all be considering.
In the physical world we do a fairly good job of keeping ourselves secure. I assume, for example, that you locked your front door when you left your house this morning. In the digital world we tend to be a lot more careless. We tend to leave doors wide open. In many cases we don’t even put doors between the outside world and our data. For intelligence agencies this is very fortunate since our emails, social media posts, and browsing habits are usually conveniently just lying around.
Encryption, on the other hand, provides a secure place with a front door behind which data is inaccessible. That is, unless you have the front door key. Encrypted data is meaningless and of little use to an intelligence agency – to make sense of it the keys to decrypt it are needed.
Mobile phones encrypt calls between the phone and the nearest mobile phone mast, preventing anyone who intercepts the call as it travels through the air from making any sense of it. The encryption key used is derived from the phone’s SIM key, which is a personal key that comes pre-installed on your SIM card. Anyone who knows the SIM key – normally only your phone and your mobile operator – can decrypt the call if they listen in.
Gemalto’s business is putting SIM keys into SIM cards; if someone breaks into Gemalto’s systems then it is certainly possible that they could make off with SIM encryption keys. This isn’t great news for the security of whatever mobile phones they later end up in.
Bad though this sounds, it’s really just the latest of many revelations of this type that have leaked out of the Snowden files. The picture that has emerged is of intelligence agencies clearly frustrated by the increasing use of encryption in our everyday technology. As the encryption is (mostly) too good to break, so the intelligence agencies have been using every technique imaginable to find a way around it.
Broadly speaking, there are really only two ways to get around good encryption. Option one is to try to access data either before it is encrypted or after it is decrypted – Snowden’s files suggest the intelligence agencies have been doing plenty of that. Option two is to try to get hold of the keys needed to decrypt the data. The Great SIM Heist seems to be the latest example of attempts at this second strategy.
In one sense this is not a new development. As encryption has been deployed more widely, its use has created tension between the rights of the individual to privacy and the duties of the state to protect society. Over the last few decades governments have made several attempts to mediate between these, attempts which appeared to have concluded in favour of strong encryption and individual privacy.
Prior to Snowden it was publicly believed that the “crypto wars” had largely been lost by the intelligence agencies; instead, leaked files such as these reveal that the wars have just become bloodier than any of us really imagined.
Many people are outraged by the many Snowden revelations. Others take the view that this is the intelligence agencies' job and they ought to be left to get on with it. There are good arguments supporting both of these viewpoints.
So, should you care? If you do, then there has never been a better time to stand up and make your feelings known. We as a society really ought to form an opinion on what “security norms” we wish to see developing around our increasing use of the internet as a place where we, partially, live our lives. If we don’t, then clearly others, with perhaps very different agendas, will decide them for us.
Imagine a bustling law firm in the heart of a skyscraper-filled city. The air is thick with the scent of expensive espresso and the frantic...
