Our skin is vital – it’s a physical barrier against disease. One way it protects us is with a cell layer called the stratum granulosum in which the cells form connections called tight junctions to prevent liquids passing in or out. However, this barrier is only several cells thick and needs to be maintained. Scientists recently found that the cells of the stratum granulosum (pictured) in 3D are a 14-sided shape called Kelvin’s tetrakaidecahedron, formed of six rectangles and eight hexagons. It’s a very effective shape for filling space, so it could help the cells pack together to form the barrier. Using imaging and computer modelling, they also found that the tight junctions move between cells in a very precise way, to make sure that the barrier stays sealed when cells are joining or leaving it. Why this important barrier is only several cells thick, however, remains to be discovered.
- Image from work by Mariko Yokouchi and colleagues
- Department of Dermatology, Keio University School of Medicine, Tokyo, Japan
- Image originally published under a Creative Commons Licence (BY 4.0)
- Published in eLife, November 2016
The Humble Weekly Bundle: IndieCade 2 runs for one week and will party out on Thursday, October 16, 2014 at 11:00 a.m. Pacific Time.
I can't wait to get my new iPhone 6 so I too can try out the new iOS Leopard predictions.
Previously, as we reported in May 2014, if law enforcement came to Apple with a seized device and a valid warrant, it was able to access a substantial portion of the data already on an iPad or iPhone. But under the latest version of iOS, even that will be impossible.
"On devices running iOS 8, your personal data such as photos, messages (including attachments), email, contacts, call history, iTunes content, notes, and reminders is placed under the protection of your passcode," the company wrote on its website Wednesday evening. "Unlike our competitors, Apple cannot bypass your passcode and therefore cannot access this data. So it's not technically feasible for us to respond to government warrants for the extraction of this data from devices in their possession running iOS 8."
This is a really cool picture, and it's worth to check out the video too. It really gives you a glimpse of how jam packed and complex cells really are. And this is just a tiny bit of one!
Inside the human brain, billions of neurons [nerve cells] communicate in an intricate network. To do this, they rely on chemical messengers, known as neurotransmitters, which propagate signals between cells across chemical synapses. Released by one cell, these molecules bind to specific receptors on a receiving neuron to transmit the signal. Pictured is a 3D representation of a synaptic bouton, the cellular compartment responsible for packaging neurotransmitters into membrane sacks, or vesicles, and exporting them out of the cell. Using microscopy and mass spectrometry, researchers have drawn up a detailed picture of this compartment. They identified 300,000 proteins found within the area, 60 of which are depicted in different colours in this diagram – the red tubes represent tubulin filaments, giving structure to the cell, while the white circles are vesicles. Providing new insights into neurotransmitter release, this study offers a tantalising glimpse into the exquisite complexity of the brain’s signalling machinery.
Yeah, that's pretty much true, if I still had them :(
Last week, scientists announced the discovery of Kepler-186f, a planet 492 light years away in the Cygnus constellation. Kepler-186f is special because it marks the first planet almost exactly the same size as Earth orbiting in the “habitable zone,” the distance from a star in which we might expect liquid water—and perhaps life.
What did not make the news, however, is that this discovery also slightly increases how much credence we give to the possibility of our own near-term extinction. This is because of a concept known as the Great Filter.
The Great Filter is an argument that attempts to resolve the Fermi Paradox: why have we not found aliens (or why have they not found us), despite the existence of hundreds of billions of exosolar systems in our galactic neighborhood in which life might evolve? As the namesake physicist Enrico Fermi noted, it seems rather extraordinary that not a single extraterrestrial signal or engineering project has been detected (UFO conspiracy theorists notwithstanding).
Over the past few years, materials scientists have developed super-thin silicon chips that dissolve safely in the body. Such microchips could be used in medical implants that disintegrate once they’re no longer useful, rather than being surgically removed. Powering these devices has been tricky, but researchers have created a neat solution: a completely biodegradable battery. The miniature power pack contains metals like magnesium that dissolve in the body and whose ions, which are released in the process, are non-toxic in low concentrations. Pictured is a four-cell battery (top left) breaking down in water over three weeks until it’s completely dissolved (bottom right). With a few improvements, the researchers suggest, a one-micrometer thick, 0.25cm2 single-cell battery – roughly the size of a pinhead but much thinner – could power a wireless implantable device for a day or more. If so, doctors might one day deploy self-powered devices that deliver therapies and then vanish.
- Image courtesy of John Rogers and colleagues
- University of Illinois at Urbana-Champaign, USA
- Adapted by permission from Macmillan Publishers Ltd: Nature 2014
- Research published in Advanced Materials, February 2014
When the Harvard-Smithsonian Center for Astrophysics announced a press conference for a "Major Discovery" (capital letters in the original e-mail) involving an unspecified experiment, rumors began to fly immediately. By Friday afternoon, the rumors had coalesced around one particular observatory: the BICEP microwave telescope located at the South Pole. Over the weekend, the chatter focused on a specific issue: polarization in the Cosmic Microwave Background left over from the Big Bang. With the start of the press conference, it's now clear that we've detected the first direct evidence of the inflationary phase of the Big Bang, in which the Universe expanded rapidly in size.
BICEP, the Background Imaging of Cosmic Extragalactic Polarization experiment, was built specifically to measure the polarization of light left over from the early Universe. This light, known as the cosmic microwave background (CMB), encodes a lot of information about the physical state of the cosmos from its earliest moments. Most observatories (such as Planck and WMAP) have mapped temperature fluctuations in the CMB, which are essential for determining the contents of the Universe.
Polarization is the orientation of the electric field of light, which conveys additional information not available from the temperature fluctuations. While much of CMB polarization is due to later density fluctuations that gave rise to galaxies, theory predicts that some of it came from primordial gravitational waves. Those waves are ripples in space-time left over from quantum fluctuations in the Universe's earliest moments.
It's also the only time I'll turn 29 in this system!
Researchers in the US have overcome a key barrier to making nuclear fusion reactors a reality. In results published in Nature, scientists have shown that they can now produce more energy than put into igniting fuel, at least on an experimental scale. The use of fusion as a source of energy remains a long way off, but the latest development is an important step toward that goal.
Nuclear fusion is the process that powers the Sun and billions of other stars in the Universe. If mastered, it could provide an unlimited source of clean energy because the raw materials are plentiful and the operation produces no carbon emissions.
During the fusion process, smaller atoms fuse into larger ones, releasing huge amounts of energy. To achieve this on Earth, scientists have to create conditions similar to those at the center of the Sun, which involves creating very high pressures and temperatures.
Intel is introducing at CES several new products and projects focused on wearables:
- Jarvis, a headset that can automatically integrate with a personal assistant app like Siri on a phone without touching it.
- A smartwatch with “geo-fencing” to monitor the person who’s wearing it. For example: in case of an emergency and a person steps out of the geo-fence, the watch can send out an alert.
- Wearable reference devices to accelerate wearable-device innovation, including smart earbuds that provide biometric and fitness capabilities, and a smart wireless charging bowl.
- Collaborations with Barneys New York, the Council of Fashion Designers of America and Opening Ceremony to explore and bring to market new smart wearable technologies, and to increase dialogue and cooperation between the fashion and technology industries.
Intel also introduced Intel Edison, a new Intel Quark technology-based computer housed in an SD card form factor with built-in wireless capabilities and support for multiple operating systems. Intel says it will “enable rapid innovation and product development by a range of inventors, entrepreneurs and consumer product designers when available this summer.”
Ah, one of my favourite Douglas Adams quotes!
The Federal Aviation Administration has finally seen the error of its ways and will permit airlines to allow passengers to use electronic devices during takeoff and landing. Because, no, playing Dots isn’t going to bring down Boeing’s latest high-tech airliner.
The ban on mobile devices has been in effect since the early 1990s, when cellphones began to crop up, and the FAA and airlines summarily freaked the hell out for no good reason. Despite no direct evidence that the use of mobile phones or other electronic devices would interfere with the plane’s systems, the ban continued — even after the FAA hired an outside safety agency to find if anything could go wrong. They didn’t. But the FAA and airlines decided to continue the policy. Until today.
The FAA’s announcement requires airlines to prove that electronic devices are safe to use on their planes from gate to gate, and the agency expects all carriers to get the thumbs-up from the Feds by the end of the year.
E-book devices, handheld gaming systems, tablets, and phones will be allowed during takeoff and landing, although the FAA recommends that you still switch to airplane mode because you’re not going to get a signal 30,000 feet in the air — the only hit you’ll take is a dead battery when you land. However, larger devices like laptops will have to be stowed away because of their potential to become silicon-filled projectiles if there’s an emergency — which was the real reason many airlines preferred the ban to be in effect.
Magnetic hard discs can store data for little more than a decade. But nanotechnologists have now designed and built a disk that can store data for a million years or more.
Back in 1956, IBM introduced the world’s first commercial computer capable of storing data on a magnetic disk drive. The IBM 305 RAMAC used fifty 24-inch discs to store up to 5 MB, an impressive feat in those days. Today, however, it’s not difficult to find hard drives that can store 1 TB of data on a single 3.5-inch disk. But despite this huge increase in storage density and a similarly impressive improvement in power efficiency, one thing hasn’t changed. The lifetime over which data can be stored on magnetic discs is still about a decade.
That raises an interesting problem. How are we to preserve information about our civilisation on a timescale that outlasts it? In other words, what technology can reliably store information for 1 million years or more?
Today, we get an answer thanks to the work of Jeroen de Vries at the University of Twente in the Netherlands and a few pals. These guys have designed and built a disk capable of storing data over this timescale. And they’ve performed accelerated ageing tests which show it should be able to store data for 1 million years and possibly longer.
These guys start with some theory about aging. Clearly, it’s impractical to conduct an ageing experiment in real time, particularly when the periods involved are measured in millions of years. But there is a way to accelerate the process of aging.
This is based on the idea that data must be stored in an energy minimum that is separated from other minima by an energy barrier. So to corrupt data by converting a 0 to a 1, for example, requires enough energy to overcome this barrier.
The probability that the system will jump in this way is governed by an idea known as Arrhenius law. This relates the probability of jumping the barrier to factors such as its temperature, the Boltzmann constant and how often a jump can be attempted, which is related to the level of atomic vibrations.
Some straightforward calculations reveal that to last a million years, the required energy barrier is 63 KBT or 70 KBT to last a billion years. “These values are well within the range of today’s technology,” say de Vries and co.
The disk is simple in conception. The data is stored in the pattern of lines etched into a thin metal disc and then covered with a protective layer.
The metal in question is tungsten, which they chose because of its high melting temperature (3,422 degrees C) and low thermal expansion coefficient. The protective layer is silicon nitride (Si3N4) chosen because of its high resistance to fracture and its low thermal expansion coefficient.
The results are impressive. According to Arrhenius law, a disk capable of surviving a million years would have to survive 1 hour at 445 Kelvin, a test that the new disks passed with ease. Indeed, they survived temperatures up to 848 Kelvin, albeit with significant amounts of information loss.
That's one charming motherfucker!