Recently a New York Times article on Russian submarine activity near undersea communications cables dredged up Cold War politics and generated widespread recognition of the submerged systems we all depend upon.
Not many people realize that undersea cables transport nearly 100% of transoceanic data traffic. These lines are laid on the very bottom of the ocean floor. They’re about as thick as a garden hose and carry the world’s internet, phone calls and even TV transmissions between continents at the speed of light. A single cable can carry tens of terabits of information per second.
While researching my book The Undersea Network, I realized that the cables we all rely on to send everything from email to banking information across the seas remain largely unregulated and undefended. Although they are laid by only a few companies (including the American company SubCom and the French company Alcatel-Lucent) and often funneled along narrow paths, the ocean’s vastness has often provided them protection.
Far from wireless
The fact that we route internet traffic through the ocean – amidst deep sea creatures and hydrothermal vents – runs counter to most people’s imaginings of the internet. Didn’t we develop satellites and Wi-Fi to transmit signals through the air? Haven’t we moved to the cloud? Undersea cable systems sound like a thing of the past.
The reality is that the cloud is actually under the ocean. Even though they might seem behind the times, fiber-optic cables are actually state-of-the-art global communications technologies. Since they use light to encode information and remain unfettered by weather, cables carry data faster and cheaper than satellites. They crisscross the continents too – a message from New York to California also travels by fiber-optic cable. These systems are not going to be replaced by aerial communications anytime soon.
Using sugar, silicone, and a 3D printer, bioengineers and surgeons have created an implant with an intricate network of blood vessels. The work points toward a future of growing replacement tissues and organs for transplantation.
The research may provide a method to overcome one of the biggest challenges in regenerative medicine: How to deliver oxygen and nutrients to all cells in an artificial organ or tissue implant that takes days or weeks to grow in the lab prior to surgery.
A research team led by Jordan Miller, assistant professor of bioengineering at Rice University, and Pavan Atluri, assistant professor of surgery at the University of Pennsylvania, conducted the study. Published in the journal Tissue Engineering Part C: Methods, it shows that blood flowed normally through test constructs that were surgically connected to native blood vessels.
KEEPING LIVERS AND KIDNEYS ALIVE
Miller says one of the hurdles of engineering large artificial tissues, such as livers or kidneys, is keeping the cells inside them alive. Tissue engineers have typically relied on the body’s own ability to grow blood vessels—for example, by implanting engineered tissue scaffolds inside the body and waiting for blood vessels from nearby tissues to spread to the engineered constructs.
Miller says that process can take weeks, and cells deep inside the constructs often starve or die from lack of oxygen before they’re reached by the slow-approaching blood vessels.
“We had a theory that maybe we shouldn’t be waiting,” Miller says. “We wondered if there were a way to implant a 3D-printed construct where we could connect host arteries directly to the construct and get perfusion immediately. In this study, we are taking the first step toward applying an analogy from transplant surgery to 3D-printed constructs we make in the lab.”
Miller and his team thought long-term about what the needs would be for transplantation of large tissues made in the laboratory. “What a surgeon needs in order to do transplant surgery isn’t just a mass of cells; the surgeon needs a vessel inlet and an outlet that can be directly connected to arteries and veins,” he says.
Bioengineering graduate student Samantha Paulsen and research technician Anderson Ta worked together to develop a proof-of-concept construct—a small silicone gel about the size of a small candy gummy bear—using 3D printing. But rather than printing a whole construct directly, the researchers fabricated sacrificial templates for the vessels that would be inside the construct.
It’s a technique pioneered by Miller in 2012—and inspired by the intricate sugar glass cages crafted by pastry chefs to garnish desserts.
Using an open-source 3D printer that lays down individual filaments of sugar glass one layer at a time, the researchers printed a lattice of would-be blood vessels. Once the sugar hardened, they placed it in a mold and poured in silicone gel. After the gel cured, Miller’s team dissolved the sugar, leaving behind a network of small channels in the silicone.
“They don’t yet look like the blood vessels found in organs, but they have some of the key features relevant for a transplant surgeon,” Miller says. “We created a construct that has one inlet and one outlet, which are about 1 millimeter in diameter, and these main vessels branch into multiple smaller vessels, which are about 600 to 800 microns.”
Collaborating surgeons at Penn in Atluri’s group connected the inlet and outlet of the engineered gel to a major artery in a small animal model. Using Doppler imaging technology, the team observed and measured blood flow through the construct and found that it withstood physiologic pressures and remained open and unobstructed for up to three hours.
“This study provides a first step toward developing a transplant model for tissue engineering where the surgeon can directly connect arteries to an engineered tissue,” Miller says. “In the future we aim to utilize a biodegradable material that also contains live cells next to these perfusable vessels for direct transplantation and monitoring long term.”
A John S. Dunn Collaborative Research Award supported the research.
NASA has found an amazing new way to track ocean currents from space, which will help to provide more data for understanding climate change using the Gravity Recovery and Climate Experiment (GRACE) satellites.
An excellent and informative article on the NASA website provides discusses the details:
A team of NASA and university scientists has developed a new way to use satellite measurements to track changes in Atlantic Ocean currents, which are a driving force in global climate. The finding opens a path to better monitoring and understanding of how ocean circulation is changing and what the changes may mean for future climate.
In the Atlantic, currents at the ocean surface, such as the Gulf Stream, carry sun-warmed water from the tropics northeastward. As the water moves through colder regions, it sheds its heat. By the time it gets to Greenland, it’s so cold and dense that it sinks a couple of miles down into the ocean depths. There it turns and flows back south. This open loop of shallow and deep currents is known to oceanographers as the Atlantic Meridional Overturning Circulation (AMOC) — part of the “conveyor belt” of ocean currents circulating water, heat and nutrients around the globe and affecting climate.
Continue reading to learn why it’s vitally important to track the AMOC…
It’s an unusual situation, but one that gives astronomers an opportunity to study at least one planet outside of our solar system in greater detail: a planet that has “lost” its star. The orphan planet, named PSO J318.5-22, was likely ejected from its star system, but researchers have no idea why. However, as astronomers have been studying the Jupiter-sized planet, they noticed fluctuations in its brightness that may mean that we’ve detected weather on this wandering planet.
An excellent story on the New Scientist website provides the background and details:
The starless planet, PSO J318.5-22, was discovered in the Pan-STARRS survey in 2013. At about eight times the mass of Jupiter, it’s much more like the giant planets we see orbiting other stars than the small, failed stars called brown dwarfs.
That means it probably formed around a star and was somehow shot out of its orbit into lonely deep space (see artist’s impression, above). That also makes this planet much easier to study than those that are almost lost in the dazzle from the stars they circle.
“You have to work really hard to even see them, whereas this object is just by itself,” says Beth Biller at the University of Edinburgh, UK.
Biller’s team measured the planet’s brightness and found that it could vary by up to 10 per cent in just a few hours. The explanation, they say, could lie in its weather systems.
The article relates that the the planet, unlike Jupiter, has retained a scorching surface temperature of 1100 kelvin, meaning that its molten core has never cooled due to having been evicted from its star system. Therefore, the storms on this planet would most likely be made up of molten metals “These are likely hot silicates and iron droplet clouds,” Biller says. “This makes Venus look like a nice place.”
A surprising discovery made by a business manager in the relatively new nation of Kazakhstan has started a buzz in the world of archaeology. Inspired by a television show on the Egyptian pyramids, Dmitriy Dey went looking for evidence of large, ancient artifacts in his home country using Google Earth as his research tool.
An amazing article on the National Geographic website chronicles the discovery and the mystery surrounding the ancient structures that he did find:
After watching a television show about ancient pyramids built outside Egypt, Dmitriy Dey wondered if his own Central Asian nation of Kazakhstan might harbor such exotic ruins. A business manager in the northern city of Kostanay, Dey began to study satellite images on Google Earth during his off hours.
He found no pyramids, but he did spot dozens of odd, human-made features scattered across a remote area of the steppe that’s half the size of New Jersey.
Eight years after he saw the TV show, Dey’s unusual discovery is stoking a public debate about these peculiar mounds and earthworks. Though barely noticeable on the ground, the forms take on a dazzling array of shapes—including huge circles, crosses, squares, and swastikas—when seen from high above.
But archaeologists disagree on the age, purpose, and even the number of the features, which are reaping widespread publicity thanks to dramatic satellite images released recently by NASA.
The featured image for our article here shows one pattern type of the earthworks. Continue on to the next page to see an image of another pattern…
A team of physicists has discovered an unusual form of matter—not a conventional metal, insulator, or magnet, for example, but something entirely different.
This phase, characterized by an unusual ordering of electrons, offers possibilities for new electronic device functionalities and could hold the solution to a long-standing mystery in condensed matter physics having to do with high-temperature superconductivity—the ability for some materials to conduct electricity without resistance, even at “high” temperatures approaching –100 degrees Celsius.
“The discovery of this phase was completely unexpected and not based on any prior theoretical prediction,” says David Hsieh, an assistant professor of physics at California Institute of Technology (Caltech), who previously was on a team that discovered another form of matter called a topological insulator.
“The whole field of electronic materials is driven by the discovery of new phases, which provide the playgrounds in which to search for new macroscopic physical properties.”
Hsieh and his colleagues describe their findings in Nature Physics. Liuyan Zhao, a postdoctoral scholar in Hsieh’s group, is lead author.
Above, an artist’s rendition of spatially segregated domains of multipolar order in the Sr2IrO4 crystal. The orientation of the multipolar order in each domain is depicted by the multi-lobed object. (Credit: Liuyan Zhao)
PICTURE ELECTRONS IN A CRYSTAL
The physicists made the discovery while testing a laser-based measurement technique that they recently developed to look for what is called multipolar order. To understand multipolar order, first consider a crystal with electrons moving around throughout its interior. Under certain conditions, it can be energetically favorable for these electrical charges to pile up in a regular, repeating fashion inside the crystal, forming what is called a charge-ordered phase. The building block of this type of order, namely charge, is simply a scalar quantity—that is, it can be described by just a numerical value, or magnitude.
In addition to charge, electrons also have a degree of freedom known as spin. When spins line up parallel to each other (in a crystal, for example), they form a ferromagnet—the type of magnet you might use on your refrigerator and that is used in the strip on your credit card. Because spin has both a magnitude and a direction, a spin-ordered phase is described by a vector.
Over the last several decades, physicists have developed sophisticated techniques to look for both of these types of phases. But what if the electrons in a material are not ordered in one of those ways? In other words, what if the order were described not by a scalar or vector but by something with more dimensionality, like a matrix?
This could happen, for example, if the building block of the ordered phase was a pair of oppositely pointing spins—one pointing north and one pointing south—described by what is known as a magnetic quadrupole. Such examples of multipolar-ordered phases of matter are difficult to detect using traditional experimental probes.
As it turns out, the new phase that the Hsieh group identified is precisely this type of multipolar order, they just had to figure out how to detect it. Find out how they approached that puzzle on the next page…
If you think life would be better without bats, scientists Holly Ober offers 5 reasons why you should think again.
Ober is a researcher at the University of Florida who studies the Florida bonneted bat, one of the world’s rarest species and the largest bat east of the Mississippi River. She says there are many reasons why having plenty of bats around should make us grateful, not fearful.
1. RAISE A GLASS—OR A GUAVA—TO BATS
If you like tequila or mangoes or bananas thank a bat for providing them. The agave plant, from which tequila is made, and more than 300 other plants depend on bats for pollination.
2. WITHOUT BATS, BUGS WOULD BUG YOU MORE
As the primary predators of nighttime insects, bats cut down on the bugs that bite us after dark. Their contribution to cutting down on pests also benefits agriculture. One study placed their value to North American farms around $23 billion a year.
“The world would be a very different place without bats controlling the insect population,” Ober says.
Read on to the next page for the other 3 reasons to love bats…
But it’s a mistake to scoff at climate change because Hurricane Patricia caused so little damage compared to previous hurricanes. Instead, we should recognize the warning it portends for stronger storms that could form over even warmer oceans in the future.
This was caused primarily by its path over Mexico’s 10,000-foot and higher Sierra Madres, which began weakening the storm even before its eyewall came ashore. Even more fortuitously, Patricia’s relatively narrow core of hurricane-force winds thread the needle between the cities of Puerto Vallarta and Manzanillo, averting more populated areas. Furthermore, the deep ocean near that region hinders the storm surge that can be so devastating in Gulf of Mexico storms.
There is no reason to rest assured that future storms will take such a damage-limiting path as Patricia. Instead, we should see in Patricia just how quickly and intensely a hurricane can develop over warm waters.
The crucial question moving forward, though, is not what roles greenhouse warming and El Niño played in this particular storm. Instead, we should focus on the fact that the largest amount of warming and its impacts are yet to come. Warming to date has been about a degree Celsius overall, and slightly less over oceans.
However, projections show that our current path of emissions could cause more than twice as much warming as has occurred so far. As warmer surface ocean conditions become a more prevalent feature in the eastern Pacific even outside of El Niño years, there would be more opportunity for tropical storm systems to intensify into major hurricanes.
Even if tropical storms become no more frequent than today, warmer waters and moister air could make them more likely to intensify, and to intensify more rapidly. Hurricane Patricia and other near-record storms of this season have shown what the fuel of warm oceans can produce. Other factors like wind shear matter too, but the role of warm waters can no longer be doubted.
Scientific understanding of how warming will accelerate storm intensification remains incomplete. Most experts expect tropical storms to be become more intense, though not necessarily more frequent.
A study published last month in the Journal of Climate projected that the eastern Pacific could experience five times as many days with Category 4 or 5 hurricanes by the end of this century.
Some amount of continued warming of surface oceans is now inevitable, as Earth’s climate and oceans have yet to fully change in reaction to greenhouse gases already in the atmosphere.
However, our efforts to curtail greenhouse gas emissions could substantially slow the additional warming that occurs. Rapidly intensifying hurricanes are by no means the only reason to pursue such efforts – the impetus of mitigating more established climate impacts such as sea level rise, heat waves, extreme weather and ecosystem damage gives more than enough reason to do so.
Nevertheless, Hurricane Patricia should serve as yet another harbinger of the substantial changes that may accompany further warming, rather than as a reason to dismiss the need for urgency.
Nontrivial numbers of Americans believe in the paranormal. These beliefs have spawned thousands of groups dedicated to investigating paranormal phenomena and a proliferation of ghost-hunting entries in the reality television market. Anecdotal evidence even suggests that ghost-hunting reality shows have increased public openness to paranormal research, which usually entails a small group traipsing through reportedly haunted locales at night with various ghost-hunting technologies.
Audio recorders figure prominently in paranormal researchers’ toolkits. Microphones capture ambient sounds during the investigation. Later, the audio recordings are scoured in search of messages from spirits. The premise is that audio recording devices can register otherwise inaudible communications from discarnate entities.
These purported communications have been dubbed electronic voice phenomena (EVP). The sounds are generally brief – most examples consist of single words or short phrases. Perceived contents of EVP range from threatening (“You’re going to hell”) to bizarre (“Egypt Air”).
Part of the attraction of the audio recorder for paranormal researchers is its apparent objectivity. How could a skeptic refute the authenticity of a spirit captured by an unbiased technical instrument? To the believers, EVP seem like incontrovertible evidence of communications from beyond. But recent research in my lab suggested that people don’t agree much about what, if anything, they hear in the EVP sounds – a result readily explained by the fallibility of human perception. Despite the technological trappings, EVP research bears several characteristics of pseudoscience.
What are the EVP sounds?
The chain of evidence for most purported EVP makes hoaxes difficult to rule out, but let’s assume that many of these sounds are not deliberate fraud. In some instances, alleged EVP are the voices of the investigators or interference from radio transmissions – problems that indicate shoddy data collection practices. Other research, however, has suggested that EVP have been captured under acoustically controlled circumstances in recording studios. What are the possible explanations for these sounds?
The critical leap in EVP research is the point at which odd sounds are interpreted as voices that communicate with intention. Paranormal investigators typically decode the content of EVP by arriving at consensus among themselves. EVP websites advise paranormal researchers to ask themselves, “Is it a voice…are you sure?” or to “Share results among fellow investigators and try to prevent investigator bias when reviewing data.” Therein lies a methodological difficulty.