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Mars Base

Writing in cursive with your eyes only - 0 views

medicalxpress.com/...2012-07-cursive-eyes.html

scibyte56 communication

shared by Mars Base on 27 Jul 12 - No Cached
  • A new technology
  • might allow people who have almost completely lost the ability to move their arms or legs to communicate freely
  • eye-writing technology tricks the neuromuscular machinery into doing something that is usually impossible: to voluntarily produce smooth eye movements in arbitrary directions
  • ...8 more annotations...
  • could be of great benefit for people deprived of limb movements, such as those with Lou Gehrig's disease (also known as ALS), the researchers say. It might also help to improve eye movement control in people with certain conditions such as dyslexia or ADHD and/or for experts, such as athletes or surgeons, whose activities strongly rely on eye movements
  • In everyday life, smooth pursuit eye movement is used to track moving targets
  • fact our eyes never cease to move
  • normally impossible to control those movements smoothly in any direction.
  • got a hint that smooth eye movements just might be possible in a completely accidental way
  • technology relies on changes in contrast to trick the eyes into the perception of motion
  • now working on a better version of his eye writer, and tests with ALS patients should start next year
  • He was moving his own eyes in front of an unusual visual display in his lab and discovered that it produced some odd effects. For one thing, he could see his own eye movements. With a little practice, he gradually discovered that he could control those eye movements, too.
Mars Base

Cholesterol-lowering eye drops could treat macular degeneration - 0 views

medicalxpress.com/...s-atherosclerosis-macular.html

scibyte89

shared by Mars Base on 03 Apr 13 - No Cached
  • A new study raises the intriguing possibility that drugs prescribed to lower cholesterol may be effective against macular degeneration, a blinding eye disease.
  • Researchers
  • have found that age-related macular degeneration, the leading cause of vision loss in Americans over 50, shares a common link with atherosclerosis
  • ...25 more annotations...
  • Both problems have the same underlying defect: the inability to remove a buildup of fat and cholesterol
  • researchers shed new light on how deposits of cholesterol contribute to macular degeneration and atherosclerosis and even blood vessel growth in some types of cancer
  • Patients who have atherosclerosis often are prescribed medications to lower cholesterol and keep arteries clear
  • This study suggests that some of those same drugs could be evaluated in patients with macular degeneration
  • we need to investigate whether vision loss caused by macular degeneration could be prevented with cholesterol-lowering eye drops or other medications that might prevent the buildup of lipids beneath the retina
  • The new research centers on macrophages, key immune cells that remove cholesterol and fats from tissues
  • In macular degeneration, the excessive buildup of cholesterol begins to occur as we age, and our macrophages begin to malfunction
  • In the "dry" form of age-related macular degeneration, doctors examining the eye can see lipid deposits beneath the retina
  • As those deposits become larger and more numerous, they slowly begin to destroy the central part of the eye, interfering with the vision needed to read a book or drive a car
  • As aging macrophages clear fewer fat deposits beneath the retina, the macrophage cells themselves can become bloated with cholesterol, creating an inflammatory process that leads to the formation of new blood vessels that can cause further damage
  • Those vessels characterize the later "wet" form of the disease
  • that inflammation creates a toxic mix of things that leads to new blood vessel growth
  • Most of the vision loss
  • is the result of bleeding and scar-tissue formation related to abnormal vessel growth
  • the scientists identified a protein that macrophages need to clear fats and cholesterol
  • As mice and humans age, they make less of the protein, and macrophages become less effective at engulfing and removing fat and cholesterol
  • team found that macrophages, from old mice and in patients with macular degeneration, have inadequate levels of the protein, called ABCA1, which transports cholesterol out of cells
  • As a result, the old macrophages accumulated high levels of cholesterol and couldn't inhibit the growth of the damaging blood vessels
  • when the researchers treated the macrophages with a substance that helped restore levels of ABCA1, the cells could remove cholesterol more effectively, and the development of new blood vessels was slowed
  • able to deliver the drug, called an LXR agonist, in eye drops
  • found that we could reverse the macular degeneration in the eye of an old mouse
  • could focus therapy only on the eyes, and we likely could limit the side effects of drugs taken orally
  • since macrophages are important in atherosclerosis and in the formation of new blood vessels around certain types of cancerous tumors, the same pathway also might provide a target for more effective therapies for those diseases
  • can reverse the disease cascade in mice by improving macrophage function, either with eye drops or with systemic treatments,
  • Some of the therapies already being used to treat atherosclerosis target this same pathway, so we may be able to modify drugs that already are available and use them to deliver treatment to the eye
Mars Base

Australians implant 'world first' bionic eye - 0 views

medicalxpress.com/...-implant-world-bionic-eye.html

scibyte61 eyes

shared by Mars Base on 30 Aug 12 - No Cached
  • Bionic Vision Australia (BVA), a government-funded science consortium, said it had surgically installed an "early prototype" robotic eye in a woman with hereditary sight loss caused by degenerative retinitis pigmentosa
  • pre-bionic eye", the tiny device is attached to Dianne Ashworth's retina and contains 24 electrodes which send electrical impulses to stimulate her eye's nerve cells.
  • device only works when it is connected inside the lab
  • ...6 more annotations...
  • be used to explore how images were "built" by the brain and eye.
  • Feedback from the device will be fed into a "vision processor" allowing doctors to determine exactly what Ashworth sees when her retina is subjected to various levels of stimulation
  • team is working towards a "wide-view" 98-electrode device that will provide users with the ability to perceive large objects such as buildings and cars, and a "high-acuity" 1,024-electrode device
  • high-acuity device are expected to be able to recognise faces and read large print
  • Every time there was stimulation there was a different shape that appeared
  • switched on the device in their laboratory last month after Ashworth had fully recovered from surgery
Mars Base

Eye implants make vision-restoring progress - 0 views

medicalxpress.com/...implants-vision-restoring.html

Scibyte55 RestoringVision

shared by Mars Base on 18 Jul 12 - No Cached
  • Second Sight’s Argus II, a retinal prosthesis already on the market in Europe
  • Bio-Retina from NanoRetina, which is to start clinical trials next year
  • Argus II Retinal Prosthesis System was developed to provide electrical stimulation of the retina to induce visual perception
  • ...17 more annotations...
  • system includes an antenna, an electronics case, and electrode array
  • designed to bypass damaged photoreceptors altogether
  • video camera in the glasses captures a scene
  • video is sent to a small patient-worn computer VPU where it is processed and transformed into instructions sent back to the glasses via a cable
  • transmitted wirelessly to the antenna in the implant
  • signals are sent to the electrode array, which emits small pulses of electricity. The pulses bypass the damaged photoreceptors and stimulate the retina’s remaining
  • Users of the Argus II bionic eye say that they can see rough shapes and track the movement of objects; they can slowly read large writing.
  • Anticipation is high, meanwhile, for a bionic retina that has been designed to restore sight at less cost and with a different technique
  • Bio-Retina developed by Nano Retina does not make use of an external camera
  • vision-restoring sensor is placed inside the eye, on top of the damaged retina
  • 24×24-resolution (576-pixel) sensor atop the damaged retina. The device generates a grayscale image
  • implant is inserted through an incision in the eye
  • procedure takes 30 minutes and requires only local anesthesia
  • transforms naturally received light into an electrical signal that stimulates the neurons, which send the pictures received by Bio-Retina to the brain
  • rechargeable, battery-powered mini-laser on a pair of eyeglasses powers the implant wirelessly
  • anticipated recover time is up to one week
  • patients able to distinguish faces and to be able to look from side to side with their eyes rather than needing to turn their heads
Mars Base

Babies Lip-read Before Talking - Science News - 0 views

www.sciencenews.org/...Babies_lip-read_before_talking

scibyte30 babies

shared by Mars Base on 20 Jan 12 - No Cached
  • infants start babbling at around age 6 months in preparation for talking
  • shift from focusing on adults’ eyes to paying special attention to speakers’ mouths
  • tots become able to blurt out words and simple statements at age 1, they go back to concentrating on adults’ eyes
  • ...8 more annotations...
  • babbling babies match up what adults say with how they say
  • budding talkers can afford to look for communication signals in a speakers’ eyes
  • tested 179 infants from English-speaking families at age 4, 6, 8 or 12 months
  • devices tracked where babies looked when shown videos of women speaking English or a foreign language
  • also report that on average, infants’ pupils increasingly dilated between ages 8 months and 1 year in response to Spanish speakers, a sign of surprise at encountering unfamiliar speech
  • By 2 years of age, children with autism avoid eye contact and focus on speakers’ mouths
  • new findings raise the possibility of identifying kids headed for this developmental disorder even earlier
  • hasn’t yet been demonstrated that children who continue to look at the mouths of native-language speakers after age 1 develop autism or other communication problems more frequently than those who shift to looking at speakers’ eyes
Mars Base

EyeWire gamers help researchers understand retina's motion detection wiring - 0 views

medicalxpress.com/...mers-retina-motion-wiring.html

scibyte130 eyes

shared by Mars Base on 06 May 14 - No Cached
  • A team of researchers working at MIT has used data supplied by gamers on EyeWire to help explain how it is that the retina is able to process motion detection
  • the team describes how they worked with gamers at EyeWire and then used the resulting mapped neural networks to propose a new theory to describe how it is the eye is able to understand what happens when something moves in front of it.
  • Scientists have known for quite some time that light enters the eye and strikes the back of the eyeball where photoreceptors respond
  • ...18 more annotations...
  • Those photoreceptors send information they receive to another type of neural cell known as bipolar cells
  • they in turn convert received signals to another signal format which is then sent to what are known as starburst amacrine cells (SACs)
  • Signals from the SAC are sent via the optic nerve to the brain
  • scientists believe they have a pretty good idea about how the whole process works for static images, they have not been able to get a handle on what happens when images sent to the eyeball have information about things that are moving
  • In this new effort, the researchers sought to do just that—via assistance from thousands of gamers on the EyeWire game playing site
  • The problem with figuring out how nerve cells work in the eye, of either mice or humans, is the inability to watch what happens in action—everything is too tiny and intricate
  • To get around that problem, researchers have been building three dimensional models on computers
  • even that gets untenable when considering the complexity and numbers of nerves involved
  • That's where the EyeWire gamers came in, a game was created that involved gamers creating mouse neural networks—the better they were at it the more points they got
  • only the best at it were invited to play
  • The result was the creation of a model that the researchers believe is an accurate representation of the cells involved in processing vision, and the networks that are made up of them
  • the rest was up to the research team
  • They noted that in the model, there were different types of bipolar cells connecting to SACs—some connected to dendrites close to the cells center, and others connected to dendrites that were farther away
  • Prior research had shown that some bipolar cells take longer to process information than others
  • The researchers believe that the bipolar cells that connect closer to the center are of the type that take longer to process signals
  • This, they contend, could set up a scenario where the center of the SAC receives information from both types of bipolar cells at the same time—and that, they suggest, could be how the SAC comes to understand that motion—in one direction—is occurring
  • The researchers suggest their theory can be real-world tested in the lab, and expect other teams will likely do so
  • If they are right, the mystery of how our eyes detect motion will finally be solved.
Mars Base

Write to Me Only With Thine Eyes - ScienceNOW - 0 views

news.sciencemag.org/...o-me-only-with-thine-eyes.html

scibyte56 communication

shared by Mars Base on 26 Jul 12 - No Cached
  • People "locked in" by paralyzing disorders
  • have long relied on blinks or facial twitches to build sentences one letter at a time
  • Over three 30-minute sessions, he trained six volunteers
  • ...4 more annotations...
  • For the volunteers, who couldn't see what they were writing, it was like writing with a pen that had run out of ink
  • some participants had a harder time of learning to control their eye movements than others
  • by the end of the sessions most could freely draw legible letters and numbers
  • reverse phi motion." The illusion helped reveal that when the brightness of an object changes rapidly; our brain "sees" the object moving in the opposite direction.
  • Mars Base on 26 Jul 12
     
    ckly as they can write with a pen. In addition to providing a new medium for self-expression, the technique challenges traditional ideas about the limits of human vision. In 1970, illusionist and cognitive psychologist Stuart Anstis of the University of California, San Diego, was playing around
Mars Base

Bionic retina runs on laser power - 0 views

optics.org/1

Scibyte55 RestoringVision

shared by Mars Base on 18 Jul 12 - No Cached
  • tiny implant that is inserted into the eye and attached to the retina in a minimally invasive procedure no more complicated than conventional cataract surgery
  • consists of photodetectors, microelectrodes and electronic circuitry that act together to replace the eye’s natural photoreceptors that have been damaged by AMD and feed visual information to the brain
  • photoreceptors in a healthy retina convert light into a series of electrical signals which are transmitted to the brain via complex neural pathways
  • ...14 more annotations...
  • AMD, the photoreceptors do not function, which prevents the brain from receiving these signals from the eyes
  • bio-retina implant is essentially a combined imaging circuit and neural interface which is glued rather than sutured to a patient’s macula
  • area of the retina responsible for high-resolution central vision
  • Measuring 3 x 4 mm and 1 mm thick, the implant is designed to capture light through the normal optical track of the eyeball and stimulate neurons to transmit information to the brain, essentially restoring the function of the damaged photoreceptors
  • Light incident on the implant is collected by an array of CMOS pixels
  • first-generation bio-retina will use an array of 600 pixels, although the aim is to increase this to 5000 pixels in future generations
  • Nano Retina has dedicated a substantial amount of time developing a proprietary algorithm that translates the received visual information and image into the neuron language
  • translating circuitry that discriminates 100 gray-scale levels and responds to varying light levels. It is a sophisticated process
  • implant uses an array of micro-electrodes that first penetrate into the retina, then connect closely to the neurons and thereafter transmit the information. The goal is that every pixel will connect to a neuron, so that every pixel in the array would use a micro-electrode
  • neurons must be stimulated electrically
  • the bio-retina implant also requires a source of electrical power
  • Patients who undergo surgery to implant a bio-retina will need to wear a special set of glasses
  • glasses feature a built-in battery and an infrared diode laser. “The infrared laser light is transmitted into the eye and captured by a miniature photovoltaic cell on the bio-retina
  • harvests the energy, which in turn powers the electronic circuitry. Our goal is for the imager and the electronics to consume no more than 1mW
Mars Base

GRAIL First Results Provide Most Precise Lunar Gravity Map Yet - 0 views

www.universetoday.com/...most-precise-lunar-gravity-map

scibyte74 Grail

shared by Mars Base on 06 Dec 12 - No Cached
  • first science results from NASA’s twin GRAIL lunar orbiters provide incredible detail of the Moon’s interior and the highest resolution gravity field map of any celestial body, including Earth
  • Ebb and Flow, send radio signals to each other and any changes in distance between the two as they circle the Moon are measured, down to changes as small as
  • 1/ 20,000th the velocity that a snail moves
  • ...19 more annotations...
  • new gravity maps reveals an abundance of features such as tectonic structures, volcanic landforms, basin rings, crater central peaks and numerous simple, bowl-shaped craters
  • the moon’s gravity field is unlike that of any terrestrial planet in our solar system.
  • Ninety-eight percent of local gravity is associated with topography, while 2 percent are other gravitational features
  • You can see bull’s-eyes of the lunar mascons, but otherwise we see a smooth inner surface
  • The only way this could happen is if impacts to the early Moon shattered the inner surface
  • also revealed evidence for ancient volcanic activity under the surface of the Moon and strange linear gravitational anomalies
  • identified a large population of linear gravitational anomalies. We don’t see any expression of them on topography maps, so we infer that these are an ancient internal structures
  • Basin, which forms one of the ‘man on moon’s’ eyes, the gravity maps shows a linear feature crossing the basin while topography maps show no such correlating feature
  • the gravity anomaly formed before the impacts
  • Additional data reveal that the Moon’s inner crust in almost completely pulverized
  • Using GRAIL gravity data, we found the average thickness of the crust is 32-34 kilometers which is about 10 km less than previous studies
  • We found the bulk abundance of aluminum on Moon is nearly the same as that of the Earth
  • consistent with a recent hypothesis that the Moon is derived of materials from the Earth when it was formed during a giant impact event
  • GRAIL finishes the primary science mission in May and are currently working in an extended mission where the spacrafts’ altitude was lowered to just 23 km above the surface
  • During its prime mission, the two GRAIL spacecraft orbited just 55 km above the Moon’s surface
  • hearing results from the new data sets soon
  • the team will lower the GRAIL spacecraft down to just 11 km above the lunar surface.
  • extended mission will end soon, in mid-December, and soon after that, the two spacecraft will be crashed intentionally onto the lunar surface
  • they are still formulating ideas for the impact scenario, and looking at the possibility of aiming the crashes so they are within the field-of-view of instruments on NASA’s Lunar Reconnaissance Orbiter
Mars Base

Tau Ceti: Sun-like star only twelve light years away may have a habitable planet - 0 views

phys.org/...ceti-sun-like-star-twelve.html

scibyte76 HabitablePlanet

shared by Mars Base on 23 Dec 12 - No Cached
  • An international team of astronomers has discovered that Tau Ceti, one of the closest and most Sun-like stars, may host five planets, including one in the star's habitable zone
  • twelve light years from Earth and visible to the naked eye in the evening sky, Tau Ceti is the closest single star that has the same spectral classification as our Sun
  • five planets are estimated to have masses between two and six times the mass of the Earth,
  • ...13 more annotations...
  • the lowest-mass planetary system yet detected.
  • One of the planets lies in the star's habitable zone
  • and has a mass around five times that of Earth
  • making
  • the smallest planet found to be orbiting in the habitable zone of any Sun-like star
  • The international team of astronomers
  • combined more than six-thousand observations from three different instruments and intensively modeled the data
  • Using new techniques, the team has found a method to detect signals half the size previously thought possible
  • We are now beginning to understand that nature seems to overwhelmingly prefer systems that have multiple planets with orbits of less than 100 days
  • researchers chose Tau Ceti for this noise-modeling study because they had thought it contained no signals
  • As it is so bright and similar to our Sun, it is an ideal benchmark system to test out our methods for the detection of small planets
  • Tau Ceti is one of our nearest cosmic neighbors and so bright that we may be able to study the atmospheres of these planets
  • researchers discovered this planetary system using data from three state-of-the-art spectrographs
Mars Base

Comet PanSTARRS: How to See it in March 2013 - 0 views

www.universetoday.com/...rs-how-to-see-it-in-march-2013

scibyte83 scibyte84

shared by Mars Base on 23 Feb 13 - No Cached
  • we could have the first naked eye comet of 2013 for northern hemisphere observers in early March
  • if it performs
  • The projected brightness curve
  • ...21 more annotations...
  • Panoramic Survey Telescope and Rapid Response System (PanSTARRS) based on the summit of Haleakala on the island of Maui
  • comet brightened ahead of expectations and was first picked up by an amateur astronomer on March 28th of last year
  • Comet PanSTARRS is already an impressive sight for southern hemisphere observers
  • Comet PanSTARRS will then begin curving northward during the last week of February
  • the comet has a hyperbolic orbit inclined 84.2° degrees relative to the ecliptic
  • On an 110,000+ year orbit, this is more than likely Comet PanSTARRS first journey through the inner solar system
  • Comet PanSTARRS will reach an altitude of greater than 5° at dusk for northern hemisphere observers based around 30° north latitude looking low to the southwest starting on March 5th.
  • The comet will then begin gaining altitude
  • Keep in mind, Daylight Saving Time begins
  • looking for the comet around 7:00 pm local on the first week of March, it’ll be at 8:00 pm on the second week
  • After gaining
  • elevation from our northern hemisphere vantage point
  • will then begin running roughly parallel to the western horizon on each successive evening for mid-northern latitude observers
  • This first half of March is also when Comet PanSTARRS will have the potential to appear at its brightest
  • best case scenario, we’ll have a comet with a -1st magnitude coma and a tail pointing straight up from the horizon like an exclamation point.
  • worst case situation, we’ll have a +3rd magnitude fuzzy comet only visible through binoculars
  • if you observe the comet on no other night, be sure to check it out on the evening of March 12-13th
  • will be joined by a slim crescent Moon just over a day old.
  • Comet PanSTARRS will then continue its trek northward
  • for the remainder of March
  • By May 1st, Comet PanSTARRS will have dipped back down below naked eye visibility
Mars Base

What is image processing? | ESA/Hubble - 0 views

www.spacetelescope.org/...imageprocessing

scibyte40 hubble Contest esa

shared by Mars Base on 28 Mar 12 - No Cached
  • What is image processing?
  • Hubble takes pictures which capture many more colours and gradations of light and dark than the human eye (or consumer digital cameras) can see
  • are also quirks in how its cameras work
  • ...7 more annotations...
  • designed to make scientifically useful observations rather than being optimised for pretty pictures.
  • most of these quirks have already been corrected in the data you find in the archive,
  • images are still scientific data rather than photographs like those from a normal digital camera
  • still contain far more information than the eye can see.
  • beautiful Hubble images that we all know have all been extensively tweaked and optimised by hand, in order to reveal as much of the data as possible
  • brightening the glowing gas in nebulae or compressing the dynamic range of galaxy images so that the core and spiral arms can both be seen equally clearly
  • Image processing is the name for this process of selecting data, adjusting colour, contrast and dynamic range to reveal the hidden detail in Hubble’s scientific data.
Mars Base

Study identifies how muscles are paralyzed during sleep - 0 views

medicalxpress.com/...2012-07-muscles-paralyzed.html

SleepDisorder GrabBag

shared by Mars Base on 12 Jul 12 - No Cached
  • Two powerful brain chemical systems work together to paralyze skeletal muscles during rapid eye movement (REM) sleep
  • During REM sleep — the deep sleep where most recalled dreams occur — your eyes continue to move but the rest of the body's muscles are stopped
  • In a series of experiments
  • ...10 more annotations...
  • neuroscientists
  • found that the neurotransmitters gamma-aminobutyric acid (GABA) and glycine caused REM sleep paralysis in rats by "switching off" the specialized cells in the brain that allow muscles to be active
  • reversed earlier beliefs that glycine was a lone inhibitor of these motor neurons.
  • By identifying the neurotransmitters and receptors involved in sleep-related paralysis, this study points us to possible molecular targets for developing treatments for sleep-related motor disorders
  • Previous research suggested neurotransmitter receptors called ionotropic GABAA/glycine receptors in the motor neurons caused REM sleep paralysis
  • when the researchers blocked these receptors, REM sleep paralysis still occurred.
  • to prevent REM sleep paralysis, they had to block both the ionotropic receptors and metabotropic GABAB receptors, a different receptor system
  • when the motor cells were cut off from all sources of GABA and glycine, the paralysis did not occur
  • suggest the two neurotransmitters must both be present together to maintain motor control during sleep
  • finding could be especially helpful for those with REM sleep disorder, a disease that causes people to act out their dreams
Mars Base

Bio-Retina Implant Could Give Laser-Powered Sight to the Blind | Popular Science - 0 views

www.popsci.com/...d-give-sight-blind-laser-power

Scibyte55 RestoringVision

shared by Mars Base on 18 Jul 12 - No Cached
  • The near-infrared laser beam, gentle enough to shine harmlessly through the eye onto the implant, provides up to three milliwatts of power to a photovoltaic cell on the eye implant
  • Six hundred needle electrodes (wrapped in biocompatible silicon and sapphire to prevent the formation of scar tissue) penetrate the retina
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