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Mars Base

Robot snake automatically wraps around an object when thrown (w/ Video) - 0 views

phys.org/...utomatically-thrown-video.html

scibyte87 robot

shared by Mars Base on 23 Mar 13 - No Cached
  • Robot snakes have been developed in recent years to mimic the actions of their real life counterparts
  • researchers have developed such snakes that are able to travel over terrain in ways very similar to a real snake, and even to climb up objects such as a person's arm.
  • researchers have extended the capability of a robot snake to include wrapping and holding on to an object when thrown at it
  • ...6 more annotations...
  • researchers were able to give the snake such an ability by making use of accelerometers embedded in its body
  • It's able to detect the sudden stop that occurs when it strikes an object
  • taking advantage of programming that had already been done by the team to get it to wrap itself around the object that it had struck
  • there is a difference between wrapping and constricting
  • this robot snake does the former, but not the latter
  • it doesn't squeeze the target, it simply wraps itself around it to allow it to hold on
Mars Base

Mars Science Laboratory: Images - 0 views

mars.jpl.nasa.gov/...images

scibyte87 Curiosity

shared by Mars Base on 25 Mar 13 - No Cached
  • left image is the raw, unprocessed color, as it is received directly from Mars
  • center rendering was produced after calibration of the image to show an estimate of "natural" color, or approximately what the colors would look like if we were to view the scene ourselves on Mars
  • right image shows the result of then applying a processing method called white-balancing, which shows an estimate of the colors of the terrain as if illuminated under Earth-like, rather than Martian, lighting
Mars Base

Heart repair breakthroughs replace surgeon's knife - 0 views

medicalxpress.com/...eakthroughs-surgeon-knife.html

scibyte87 scibyte88 heart

shared by Mars Base on 25 Mar 13 - No Cached
  • Many problems that once required sawing through the breastbone and opening up the chest for open heart surgery now can be treated
  • through a tube
  • These minimal procedures used to be done just to unclog arteries and correct less common heart rhythm problems
  • ...42 more annotations...
  • Now some patients are getting such repairs for valves, irregular heartbeats, holes in the heart and other defects—without major surgery
  • Doctors even are testing ways to treat high blood pressure with some of these new approaches
  • Instead of opening the chest, we're able to put catheters in through the leg, sometimes through the arm
  • Many patients after having this kind of procedure in a day or two can go home
  • It may lead to cheaper treatment, although the initial cost of the novel devices often offsets the savings from shorter hospital stays
  • Not everyone can have catheter treatment, and some promising devices have hit snags in testing
  • Others on the market now are so new that it will take several years to see if their results last as long as the benefits from surgery do.
  • these procedures have allowed many people too old or frail for an operation to get help for problems that otherwise would likely kill them
  • You can do these on 90-year-old patients
  • also offer an option for people who cannot tolerate long-term use of blood thinners or other drugs to manage their conditions
  • Heart valves
  • Millions of people have leaky heart valves. Each year, more than 100,000 people in the United States alone have surgery for them
  • Without a valve replacement operation, half of these patients die within two years, yet many are too weak to have one.
  • just over a year ago,
  • Edwards Lifesciences Corp. won approval to sell an artificial aortic valve flexible and small enough to fit into a catheter and be wedged inside the bad one
  • At first it was just for inoperable patients. Last fall, use was expanded to include people able to have surgery but at high risk of complications.
  • Catheter-based treatments for other valves also are in testing. One for the mitral valve
  • mixed review by federal Food and Drug Administration advisers this week; whether it will win FDA approval is unclear. It is already sold in Europe
  • Heart rhythm problems
  • Catheters can contain tools to vaporize or "ablate" bits of heart tissue that cause abnormal signals that control the heartbeat
  • Now catheter ablation is being used for the most common rhythm problem—atrial fibrillation, which plagues about 3 million Americans and 15 million people worldwide.
  • Ablation addresses the underlying rhythm problem. To address the stroke risk from pooled blood, several novel devices aim to plug or seal off the pouch
  • The upper chambers of the heart quiver or beat too fast or too slow. That lets blood pool in a small pouch off one of these chambers
  • Clots can form in the pouch and travel to the brain, causing a stroke
  • a tiny lasso to cinch the pouch shut. It uses two catheters that act like chopsticks. One goes through a blood vessel and into the pouch to help guide placement of the device, which is contained in a second catheter poked under the ribs to the outside of the heart. A loop is released to circle the top of the pouch where it meets the heart, sealing off the pouch.
  • A different kind of device
  • sold in Europe and parts of Asia, but is pending before the FDA in the U.S
  • like a tiny umbrella pushed through a vein and then opened inside the heart to plug the troublesome pouch.
  • Early results from a pivotal study released by the company suggested it would miss a key goal, making its future in the U.S. uncertain.
  • Heart defects
  • St. Jude Medical Inc.'s Amplatzer is a fabric-mesh patch threaded through catheters to plug the hole
  • In two new studies, the device did not meet the main goal of lowering the risk of repeat strokes in people who had already suffered one, but some doctors were encouraged by other results
  • Сlogged arteries
  • The original catheter-based treatment—balloon angioplasty—is still used hundreds of thousands of times each year in the U.S. alone
  • A Japanese company, Terumo Corp., is one of the leaders of a new way to do it that is easier on patients—through a catheter in the arm rather than the groin
  • Newer stents that prop arteries open and then dissolve over time, aimed at reducing the risk of blood clots, also are in late-stage testing
  • High blood pressure
  • About
  • 1 billion people worldwide have high blood pressure, a major risk factor for heart attacks
  • Researchers are testing a possible long-term fix for dangerously high pressure that can't be controlled with multiple medications.
  • uses a catheter and radio waves to zap nerves, located near the kidneys, which fuel high blood pressure
  • At least one device is approved in Europe and several companies are testing devices in the United States
Mars Base

Mars Science Laboratory: Sun in the Way Will Affect Mars Missions in April - 0 views

mars.jpl.nasa.gov/...index.cfm

scibyte87 Curiosity

shared by Mars Base on 26 Mar 13 - No Cached
  • The positions of the planets next month will mean diminished communications between Earth and NASA's spacecraft at Mars
  • Mars will be passing almost directly behind the sun, from Earth's perspective. The sun can easily disrupt radio transmissions between the two planets during that near-alignment
  • To prevent an impaired command from reaching an orbiter or rover, mission controllers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., are preparing to suspend sending any commands to spacecraft at Mars for weeks in April
  • ...13 more annotations...
  • NASA's Mars Odyssey
  • sixth conjunction for
  • The travels of Earth and Mars around the sun set up this arrangement, called a Mars solar conjunction, about once every 26 months
  • The Mars solar conjunctions
  • are not identical to each other. They can differ in exactly how close to directly behind the sun Mars gets, and they can differ in how active the sun is
  • which has been orbiting Mars since 2001
  • Both orbiters will continue science observations on a reduced basis compared to usual operations. Both will receive and record data from the rovers.
  • Odyssey will continue transmissions Earthward throughout April, although engineers anticipate some data dropouts, and the recorded data will be retransmitted later
  • The Mars Reconnaissance Orbiter will go into a record-only mode on April 4.
  • anticipates that the orbiter could have about 40 gigabits of data from its own science instruments and about 12 gigabits of data from Curiosity accumulated for sending to Earth around May 1.
  • Mars Exploration Rover Opportunity is approaching its fifth solar conjunction. Its team will send no commands between April 9 and April 26. The rover will continue science activities using a long-term set of commands to be sent beforehand.
  • Curiosity
  • can also continue making science observations from the location where it will spend the conjunction period. Curiosity's controllers plan to suspend commanding from April 4 to May 1.
Mars Base

ScienceShot: A New Class of Supernova - ScienceNOW - 0 views

news.sciencemag.org/...shot-a-new-class-of-super.html

scibyte88 Supernova

shared by Mars Base on 27 Mar 13 - No Cached
  • type Iax, release somewhere between 1% and 50% the energy of a type Ia supernova
  • spectra of type Iax stars don't include any signs of hydrogen
  • Type Iax supernovae most likely form in binary star systems when a superdense, carbon- and oxygen-rich white dwarf star (center of disk at left) robs material from its helium-rich partner, eventually accumulating enough mass on its surface to trigger an explosion
  • ...2 more annotations...
  • Astronomers likely have discovered so few type Iax supernovae only because they are faint, not because they are rare
  • estimates that for every 100 type Ia supernovae explosions that occur, there are about 31 type Iax supernovae
Mars Base

New Kind of "Runt" Supernovae Could be Lurking Unseen - 0 views

www.universetoday.com/...rnovae-could-be-lurking-unseen

scibyte88 Supernova

shared by Mars Base on 27 Mar 13 - No Cached
  • Until now, supernovae have come in two main versions
  • In one scenario, a huge star, 10 to 100 times more massive as our Sun, collapses causing a colossal stellar explosion
  • Type Ia supernovae, occurs when material from a parent star streams onto the surface of a white dwarf. Over time, so much material falls onto the white dwarf that it raises the core temperature igniting carbon and causing a runaway fusion reaction. This event completely disrupts the white dwarf and results in a colossal stellar explosion
  • ...14 more annotations...
  • Now astronomers have found a third type that is fainter and less energetic than a Type Ia. Called a Type Iax supernova
  • essentially a mini supernova
  • only about one-hundredth as bright as their supernova siblings
  • calculates that Type Iax supernovae are about as third as common as Type Ia supernovae
  • The researchers also did not find them in elliptical galaxies, filled with older stars, suggesting that Type Iax supernovae come from young star systems
  • team identified 25 examples of this new type of supernova
  • Based on observations, the team found that the new Type Iax supernovae come from binary star systems containing a white dwarf and a companion star that has burned all of its hydrogen, leaving an outer layer that is helium rich
  • not sure what triggers the Type Iax supernova
  • One explanation involves the ignition of the outer helium layer from the companion star. The resulting shockwave slams into the white dwarf and disrupts it, causing the explosion.
  • Alternately, the white dwarf might ignite first due to the overlying helium shell it has collected from the companion star.
  • it appears that in many cases the white dwarf survives the explosion unlike in a Type Ia supernova where the white dwarf is completely destroyed
  • Supernovae explosions release so much energy as heat and light that they outshine entire galaxies for brief periods of time
  • The extremely hot conditions naturally create new heavier elements, such as gold, lead, nickel, zinc and copper
  • Type Iax supernovas aren’t rare, they’re just faint
Mars Base

New Type of Star Explosion Discovered | Type Iax Supernovas | Space.com - 0 views

www.space.com/upernovas-star-explosions.html

scibyte88 Supernova

shared by Mars Base on 27 Mar 13 - No Cached
  • It remains unclear what precisely happens
  • The helium in the companion star's outer shell might undergo nuclear fusion, blasting a shock wave at the white dwarf that makes it detonate
  • On the other hand, all the helium the white dwarf accumulated from its companion star could alter the density and temperature of the white dwarf's interior, forcing carbon, oxygen and maybe helium within the star to fuse, triggering an explosion
  • ...1 more annotation...
  • No Type Iax supernovas have been seen so far in elliptical galaxies, which are filled with old stars
Mars Base

Speed Of Light In Vacuum Is Not Actually Constant, Study Finds | Popular Science - 0 views

www.popsci.com/...um-varies-slightly-study-finds

scibyte88 Speed-of-Light

shared by Mars Base on 28 Mar 13 - No Cached
  • Mars Base on 28 Mar 13
     
    Speed Of Light In Vacuum
Mars Base

A new way to lose weight? Study shows that changes to gut microbiota may play role in w... - 0 views

medicalxpress.com/...-gut-microbiota-role-loss.html

scibyte88 WeightLoss

shared by Mars Base on 28 Mar 13 - No Cached
  • by colonizing mice with the altered microbial community, the mice were able to maintain a lower body fat, and lose weight – about 20% as much as they would if they underwent surgery
  • New research
  • has found that the gut microbes of mice undergo drastic changes following gastric bypass surgery
  • ...28 more annotations...
  • In some ways we were biasing the results against weight loss
  • the mice used in the study hadn't been given a high-fat, high-sugar diet to increase their weight beforehand
  • The question is whether we might have seen a stronger effect if they were on a different diet
  • finding ways to manipulate microbial populations to mimic those effects could become a valuable new tool to address obesity
  • study suggests that the specific effects of gastric bypass on the microbiota contribute to its ability to cause weight loss
  • need to learn a good deal more about the mechanisms by which a microbial population changed by gastric bypass exert its effects,
  • then we need to learn if we can produce these effects – either the microbial changes or the associated metabolic changes – without surgery
  • it may be years before they could be replicated in humans, and that such microbial changes shouldn't be viewed as a way to lose
  • pounds without going to the gym
  • the technique may one day offer hope to dangerously obese people who want to lose weight without going through the trauma of surgery.
  • may not be that we will have a magic pill that will work for everyone who's slightly overweight
  • But if we can, at a minimum, provide some alternative to gastric bypass surgery that produces similar effects, it would be a major advance
  • While there had been hints that the microbes in the gut might change after bypass surgery, the speed and extent of the change came as a surprise to the research team
  • In earlier experiments, researchers had shown that the guts of both lean and obese mice are populated by varying amounts of two types of bacteria
  • When mice undergo gastric bypass surgery, however, it "resets the whole picture
  • those changes occurred within a week of the surgery, and weren't short-lived – the altered gut microbial community remained stable for months afterward
  • the results may hold out the hope for weight loss without surgery
  • future studies are needed to understand exactly what is behind the weight loss seen in mice
  • A major gap in our knowledge is the underlying mechanism linking microbes to weight loss
  • certain microbes
  • found at higher abundance after surgery,
  • think those are good targets for beginning to understand what's taking place
  • the answer may not be the specific types of microbes, but a by-product they excrete.
  • In addition to changes in the microbes found in the gut, researchers found changes in the concentration of certain short-chain fatty acids
  • Other studies
  • have suggested that those molecules may be critical in signaling to the host to speed up metabolism, or not to store excess calories as fat.
  • hope to continue to explore those questions
  • such studies will allow us to understand how host/microbial interactions in general can influence the outcome of a given diet
Mars Base

Gut microbes may be behind weight loss after gastric bypass | Genes & Cells | Science News - 0 views

www.sciencenews.org/...ight_loss_after_gastric_bypass

scibyte88 WeightLoss

shared by Mars Base on 28 Mar 13 - No Cached
  • Roux-en-Y, the most common technique for gastric bypass, diverts food around most of the stomach and upper small intestine
  • Previous studies of people and rats have found that the natural mix of microbes in the intestines changes after gastric bypass, with some groups growing more prominent and others diminishing in number
  • No one knew whether the altered microbial composition was merely a side effect of the surgery, or whether shifting bacterial populations could help people lose weight.
  • ...13 more annotations...
  • To find out
  • fattened up mice then performed either bypass or a sham surgery on the animals
  • Mice in the bypass group lost about 29 percent of their body weight within three weeks of the procedure
  • even before the mice dropped weight, those in the bypass group already had an altered mix of intestinal bacteria
  • Compared with the sham operation group, the bypass mice had more of certain types of microbes
  • Some species of
  • are pathogens, but others help prevent inflammation and maintain intestinal health
  • Bypass mice also had more
  • bacteria, which can feed on mucus lining the intestines, particularly when the host is cutting calories
  • researchers speculate that the microbes somehow trigger fat-burning changes in the host’s metabolism
  • Then the researchers transplanted bacteria from the intestines of bypass mice into mice that had been raised without any bacteria
  • The formerly germ-free mice slimmed down, trimming about 5 percent of their body weight, even though they started out lean
  • Germ-free mice that received bacteria from the guts of sham surgery mice actually packed on a bit of fat
Mars Base

Microbes May Slim Us Down After Gastric Bypass - ScienceNOW - 0 views

news.sciencemag.org/...robiomes-surgical-weight-.html

scibyte88 WeightLoss

shared by Mars Base on 28 Mar 13 - No Cached
  • In many people with type 2 diabetes, the disease vanishes almost immediately after surgery, too quickly to be explained by the gradual weight loss that happens later
  • Patients also describe not being as hungry, or craving foods like salad that they hadn't liked much before
  • Because it bypasses part of the stomach and small intestine, the surgery alters the intestinal environment, changing elements such as pH and bile concentrations
  • ...3 more annotations...
  • Another important question
  • is whether the transplants will have the same effect in animals who weren't raised in a sterile environment and who already have their own gut microbiome
  • These animals would more closely mimic people undergoing gastric bypass surgery
Mars Base

True colors of some fossil feathers now in doubt (w/ Video) - 0 views

phys.org/...rue-fossil-feathers-video.html

scibyte88 Fossil-Feather

shared by Mars Base on 29 Mar 13 - No Cached
  • evidence for the colors of feathers—especially melanin-based colors—can be altered during fossilization
  • past reconstructions of the original colors of feathers in some fossil birds and dinosaurs may be flawed
  • In modern birds, black, brown, and some reddish-brown colors are produced by tiny granules of the pigment melanin
  • ...7 more annotations...
  • These features—called melanosomes—are preserved in many fossil feathers, and their precise size and shape have been used to reconstruct the original colors of fossil feathers.
  • had no idea whether melanosomes could survive the fossilisation process intact
  • experiments show that this is not the case. Our results cast a cautionary light on studies of fossil feather color and suggest that some previous reconstructions of the original plumage colors of fossils may not be accurate
  • experimental technique pioneered in the group's recent study on the colors of fossil insects
  • simulated high pressures and temperatures that are found deep under the Earth's surface
  • team used feathers of different colors and from different species, but the geometry of the melanosomes in all feathers changed during the experiments
  • This study will lead to better interpretations of the original plumage colors of diverse feathered dinosaurs and fossil birds
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