Astronomy
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NASA Tests Life-Detecting Mars Rover Tech In Brutal Chilean Desert
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NASA's Atacama Rover Astrobiology Drilling Studies (ARADS) team just concluded their second season in Chile, testing out their KREX-2 rover. Thirty-five researchers, scientists, engineers, and support staff spent a month testing out this prototype rover, sending it on various mission to use its drill and life-detection instruments. Using the unforgiving landscape, they were able to demonstrate the technical feasibility and scientific value of a mission that searches for evidence of life on Mars.
"Putting life-detection instruments in a difficult, Mars-analog environment will help us figure out the best ways of looking for past or current life on Mars, if it existed," said Dr. Brian Glass, a scientist at the NASA Ames Research Center and the principal investigator of ARADS. He also led the first expedition in 2016. "Having both subsurface reach and surface mobility should greatly increase the number of biomarker and life-target sites we can sample in the Atacama."
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The KREX-2 rover carries a lightweight, low-power, two-meter drill, along with a robotic sample transfer arm. This year, the team tested out three life-detection instruments, positioned nearby, which were fed samples acquired by the rover's drill.
The instruments included the Wet Chemistry Laboratory, an instrument developed by NASA's Jet Propulsion Laboratory that flew on the 2007 Phoenix mission to Mars, and the Signs of Life Detector, from Spain's Center for Astrobiology. This instrument uses biochemical tests to search for 512 different biological compounds.
Another instrument making its first trial run is the Microfluidic Life Analyzer from JPL, which processes extremely small samples of any water found under or inside of rocks. It can isolate amino acids, a building block of life.
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What’s On The Surface Of Venus?
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Soviets were racing to be the first to explore the Solar System. First satellite to orbit Earth (Soviets), first human to orbit Earth (Soviets), first flyby and landing on the Moon (Soviets), first flyby of Mars (Americans), first flyby of Venus (Americans), etc.
The Soviets set their sights on putting a lander down on the surface of Venus. But as we know, this planet has some unique challenges. Every place on the entire planet measures the same 462 degrees C (or 864 F).
Furthermore, the atmospheric pressure on the surface of Venus is 90 times greater than Earth. Being down at the bottom of that column of atmosphere is the same as being beneath a kilometer of ocean on Earth. Remember those submarine movies where they dive too deep and get crushed like a soda can? Finally, it rains sulphuric acid. I mean, that’s really irritating.
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Before I continue, I’d like to talk a little bit about landing on planets. As we’ve discussed in the past, landing on Mars is really really hard. The atmosphere is thick enough that spacecraft will burn up if you aim directly for the surface, but it’s not thick enough to let you use parachutes to gently land on the surface.
Landing on the surface of Venus on the other hand, is super easy. The atmosphere is so thick that you can use parachutes no problem. If you can get on target and deploy a parachute capable of handling the terrible environment, your soft landing is pretty much assured. Surviving down there is another story, but we’ll get to that.
[Editors Note: This is a very good article about the attempts by the Soviets to land a probe on Venus that could collect, process, analyze, and transmit data back to Earth. Some cool pics also too.]
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Biology
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Indigenous South American Group Has Healthiest Arteries Of All Populations Yet Studied, Providing Clues To Healthy Lifestyle
The Tsimane people -- a forager-horticulturalist population of the Bolivian Amazon -- have the lowest reported levels of vascular aging for any population, with coronary atherosclerosis (hardening of the arteries) being five times less common than in the US, according to a study published in The Lancet and being presented at the American College of Cardiology conference.
The researchers propose that the loss of subsistence diets and lifestyles in contemporary society could be classed as a new risk factor for heart disease. The main risk factors are age, smoking, high cholesterol, high blood pressure, physical inactivity, obesity and diabetes.
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While industrial populations are sedentary for more than half of their waking hours (54%), the Tsimane spend only 10% of their daytime being inactive. They live a subsistence lifestyle that involves hunting, gathering, fishing and farming, where men spend an average of 6-7 hours of their day being physically active and women spend 4-6 hours.
Their diet is largely carbohydrate-based (72%) and includes non-processed carbohydrates which are high in fibre such as rice, plantain, manioc, corn, nuts and fruits. Protein constitutes 14% of their diet and comes from animal meat. The diet is very low in fat with fat compromising only 14% of the diet -- equivalent to an estimated 38 grams of fat each day, including 11g saturated fat and no trans fats. In addition, smoking was rare in the population.
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Based on their CT scan, almost nine in 10 of the Tsimane people (596 of 705 people, 85%) had no risk of heart disease, 89 (13%) had low risk and only 20 people (3%) had moderate or high risk. These findings also continued into old age, where almost two-thirds (65%, 31 of 48) of those aged over 75 years old had almost no risk and 8% (4 of 48) had moderate or high risk. These results are the lowest reported levels of vascular aging of any population recorded to date.
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A King Snake’s Strength Is In Its Squeeze
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King snakes wrap around their food and squeeze with about twice as much pressure as rat snakes do, says David Penning, a functional morphologist at Missouri Southern State University in Joplin. Penning, along with colleague Brad Moon at the University of Louisiana at Lafayette, measured the constriction capabilities of almost 200 snakes. “King snakes are just little brutes,” Penning says.
King snakes, which are common in North American forests and grasslands, are constrictor snakes that “wrestle for a living,” Penning says. They mainly eat rodents, birds and eggs, squeezing so hard, they can stop their prey’s heart [...]. In addition, about a quarter of the king snake diet is other snakes. King snakes can easily attack and eat vipers because they’re immune to the venom, but when they take on larger constrictors, such as rat snakes, it has been unclear what gives them the edge. “That’s not how nature goes,” Penning says, because predators are usually larger than their prey.
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To determine what makes these snakes kings, Penning and Moon compared their muscle size, ability to escape attack and the strength of their squeeze to that of rat snakes. In one test, the researchers shook dead rodents enticingly in front of the snakes to goad them into striking and squeezing. Sensors on the rodents recorded the pressure of the squeeze.
The king snakes constricted with an average pressure of about 20 kilopascals, stronger than the pumping pressure of a human heart. Rat snakes in the same tests applied only about 10 kilopascals of pressure.
But the king snakes weren’t bigger body builders. Controlling for body size, the two kinds of snakes “had the exact same quantity of muscle,” Penning says. The snakes’ more powerful constriction is probably due to how they use their muscles, not how much muscle they have, the researchers conclude. They observed that the majority of king snakes in the study wrapped around their food like a spring in what Penning calls the “curly fry pattern.” Rat snakes didn’t always coil in the same way and often ended up looking like a “weird pile of spaghetti,” he says.
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Chemistry
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Blowing Minds
‘People don’t realise that when you heat glass up, suddenly gravity comes in,’ chuckles Phillip Sliwoski, from the University of Southern California (USC), US. ‘Glass flows and it wants to drop in your lap. That’s a quick reality check.’
Scientific glassblowing conjures many romantic images, but Sliwoski is quick to shatter illusions about the skills he’s developed over 37 years in the craft. ‘I don’t make things from scratch,’ he stresses. ‘I could theoretically make you a lightbulb. Mine would probably last for 10 seconds before it burned out – or you could go to the local hardware store and buy one for 50 cents that lasts forever.’
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Glass ceilings
Terri Adams from the University of Oxford, UK, ‘stumbled’ into scientific glassblowing. She was touring the University of Bristol’s chemistry department while waiting to take up a job in forensic science. ‘I had never seen anything like the complexity of the glassware items which were on display, let alone given a thought to how they’d been designed and made or by whom,’ she recalls. ‘I was completely captivated and spent a significant amount of time talking to the glassblower at the display.’ She then saw an advert for a trainee scientific glassblowing technician at Bristol and applied for the role. ‘The rest, as they say, is history.’
Adams acknowledges that such training opportunities are ‘few and far between’ in the UK, which limits the sustainability of the craft. ‘There are no longer any schools or colleges in the UK teaching scientific glassblowing so the future of this skill is almost entirely dependent on university-based glassblowers and a few businesses that are willing to undertake in-house training. The cost of training is high in both time and materials so it’s a big ask for employers.’
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The Oxford glassblower is also optimistic both that there are people in the UK who could develop such skills, and that there will be jobs for them in the long term. ‘Artistic glassblowing, studio glass and bead making are on the increase,’ Adams says. ‘There are certainly transferable skills so if an accredited teaching base or model can be established there is already a pool of skilled hands which we might tap into. And there is a definite role in scientific research for a skilled scientific glassblower who can produce bespoke apparatus, perform emergency repairs or in-situ work. This I do not see changing.’
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Ecology
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World’s First Fluorescent Frog Found In The Amazon
Scientists have discovered the world’s first known naturally fluorescent amphibian — the South American polka-dot tree frog.
The finding happened very much by accident. Researchers at the Bernardino Rivadavia Natural Sciences Museum in Buenos Aires, Argentina were studying a pigment in the frog, a common species found throughout the Amazon basin, when they noticed it glowed greenish-blue under UV light.
Polka-dot tree frogs measure about 3 centimeters long, are pale green with white or reddish spots, and are active mostly at night. The scientists traced the frogs’ ability to glow to three molecules — hyloin-L1, hyloin-L2, and hyloin-G1 — located in the lymph tissue, skin, and glandular secretions. The fluorescence increased the frogs’ brightness, or glow, by 19 percent at night with a full moon, and 30 percent during dusk. The scientists, who published their findings recently in the journal the Proceedings of the National Academy of Sciences, say they aren’t sure exactly what function the frogs’ fluorescence serves, but that it could play some role in communication.
Previously, scientists knew of several ocean creatures — including some corals, fish, and sharks — which could fluoresce. On land, however, the only animals known to do it were parrots and some scorpions.
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China's Severe Winter Haze Tied To Climate Change
Modeling and data analysis done by researchers at the Georgia Institute of Technology suggest that sea ice and snowfall changes have shifted China's winter monsoon, helping create stagnant atmospheric conditions that trap pollution over the country's major population and industrial centers. Those changes in regional atmospheric conditions are frustrating efforts to address pollution through emission controls.
"Emissions in China have been decreasing over the last four years, but the severe winter haze is not getting better," said Yuhang Wang, a professor in Georgia Tech's School of Earth and Atmospheric Sciences. "Mostly, that's because of a very rapid change in the high polar regions where sea ice is decreasing and snowfall is increasing. This perturbation keeps cold air from getting into the eastern parts of China where it would flush out the air pollution."
Reported March 15 in the journal Science Advances, the research was sponsored by the National Science Foundation and Environmental Protection Agency. The paper presents a clear example of how large-scale perturbations caused by global climate change can have significant regional impacts, and is believed to be the first to link sea ice and snowfall levels to regional air pollution.
Haze problems in the East China Plains – which include the capital Beijing – first gained worldwide attention during the winter of 2013 when an instrument at the U.S. embassy recorded extremely high levels of PM 2.5 particles. The haze prompted the Chinese government to institute strict targets for reducing emissions from industry and other sources.
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“The reductions in sea ice and increase in snowfall have the effect of damping the climatological pressure ridge structure over China,” Wang said. “That flattens the temperature and pressure gradients and moves the East Asian Winter Monsoon to the east, decreasing wind speeds and creating an atmospheric circulation that makes the air in China more stagnant.”
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Physics
Wi-fi On Rays Of Light—100 Times Faster, And Never Overloaded
Slow wi-fi is a source of irritation that nearly everyone experiences. Wireless devices in the home consume ever more data, and it's only growing, and congesting the wi-fi network. Researchers at Eindhoven University of Technology have come up with a surprising solution: a wireless network based on harmless infrared rays. The capacity is not only huge (more than 40Gbit/s per ray) but also there is no need to share since every device gets its own ray of light. This was the subject for which TU/e researcher Joanne Oh received her PhD degree with the 'cum laude' distinction last week.
The system conceived in Eindhoven is simple and, in principle, cheap to set up. The wireless data comes from a few central 'light antennas', for instance mounted on the ceiling, which are able to very precisely direct the rays of light supplied by an optical fiber. Since there are no moving parts, it is maintenance-free and needs no power: the antennas contain a pair of gratings that radiate light rays of different wavelengths at different angles ('passive diffraction gratings'). Changing the light wavelengths also changes the direction of the ray of light. Since a safe infrared wavelength is used that does not reach the vulnerable retina in your eye, this technique is harmless.
No interference
If you walk around as a user and your smartphone or tablet moves out of the light antenna's line of sight, then another light antenna takes over. The network tracks the precise location of every wireless device using its radio signal transmitted in the return direction. It is a simple matter to add devices: they are assigned different wavelengths by the same light antenna and so do not have to share capacity. Moreover, there is no longer any interference from a neighboring wi-fi network.
Data capacity of light rays
Current wi-fi uses radio signals with a frequency of 2.5 or 5 gigahertz. The system conceived at TU Eindhoven uses infrared light with wavelengths of 1500 nanometers and higher; this light has frequencies that are thousands of times higher, some 200 terahertz, which makes the data capacity of the light rays much larger. Joanne Oh even managed a speed of 42.8 Gbit/s over a distance of 2.5 meters. For comparison, the average connection speed in the Netherlands is two thousand times less (17.6 Mbit/s). Even if you have the very best wi-fi system available, you won't get more than 300 Mbit/s in total, which is some hundred times less than the speed per ray of light achieved by the Eindhoven study. The Eindhoven system has so far used the light rays only to download; uploads are still done using radio signals since in most applications much less capacity is needed for uploading.
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Many devices at the same time
Koonen's group is not the only one working on 'indoor optical wireless networks'. A few other universities and research institutes around the world are also studying whether data can be transmitted via a room's LED lighting. However, the drawback here is that the bandwidth is not high and that the connected devices still have to share. A few other groups are investigating network concepts in which infrared light rays are directed using movable mirrors. The disadvantage here is that this requires active control of the mirrors and therefore energy, and each mirror is only capable of handling one ray of light at a time. The grating used by Koonen and Oh can cope with many rays of light and, therefore, devices at the same time.