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Working alone won't get you good grades, study finds - 0 views

  • Students who work together and interact online are more likely to be successful in their college classes, according to a study
  • 80,000 interactions between 290 students in a collaborative learning environment for college courses
  • major finding was that a higher number of online interactions was usually an indicator of a higher score in the class
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  • High achievers also were more likely to form strong connections with other students and to exchange information in more complex ways
  • tended to form cliques, shutting out low-performing students from their interactions
  • Students who found themselves shut out were not only more likely to have lower grades; they were also more likely to drop out of the class entirely.
  • Elite groups of highly connected individuals formed in the first days of the course
  • "For the first time, we showed that there is a very strong correspondence between social interaction and exchange of information - a 72 percent correlation
  • almost equally interesting is the fact that these high-performing students form 'rich-clubs', which shield themselves from low-performing students, despite the significant efforts by these lower-ranking students to join them.
  • weaker students try hard to engage with the elite group intensively, but can't. This ends up having a marked correlation with their dropout rates
  • might better identify patterns in the classroom that can trigger early dropout alarms
  • allowing more time for educators to help the student and, ideally, reduce those rates through appropriate social network interventions.
  • work is part of
  • wider research effort at the intersection of the computer and social sciences
  • enhance our understanding of the ways in which people share information and how this impacts areas of national significance, such as the spread of health-related or political behavior.
Mars Base

Interesting Prospects for Comet A1 Siding Spring Versus the Martian Atmosphere - 0 views

  • This October, a comet will brush
  • giving scientists a chance to study how it possibly interacts with a planetary atmosphere
  • an impact of the comet on the surface of the Red Planet has long been ruled out
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  • interesting possibility of possible interactions of the coma of A1 Siding Spring and the tenuous atmosphere of Mars
  • researchers considered how active Comet A1 Siding Spring may be at the time of closest approach on October 19th, 2014
  • Discovered early last year by Robert McNaught from the Siding Spring Observatory in Australia
  • when it was found that it will pass extremely close to Mars later this year.
  • with a nominal passage of 138,000 kilometres from Mars. That’s about one third the distance from Earth to the Moon, and 17 times closer than the nearest recorded passage of a comet to the Earth, Comet D/1770 L1 Lexell in 1780.
  • And although the nucleus will safely pass Mars, the brush with its extended atmosphere might just be detectable by the fleet of spacecraft and rovers in service around Mars
  • NEOWISE and Hubble are already monitoring the comet for enhanced activity
  • The Opportunity rover is also still functioning, and Mars Odyssey and ESA’s Mars Express are still in orbit around the Red Planet and sending back data
  • India’s Mars Orbiter Mission and NASA’s MAVEN orbiter arrive just before the comet.
  • MAVEN was designed to study the upper atmosphere of Mars, and carries an ion-neutral mass spectrometer (NGIMS) which could yield information on the interaction of the coma with the Martian upper atmosphere and ionosphere.
  • Proposals for using Earth-based assets for further observations of the comet prior to the event in October are still pending
  • Amateur observers will be able to follow the approach telescopically
  • It’s also interesting to consider the potential for interactions of the coma with the surfaces of the moons of Mars as well, though the net amount of water vapor expected to be deposited will not be large
  • UPDATE: Check out this nifty interactive simulator which includes Comet A1 Siding Springs courtesy of the Solar System Scope
Mars Base

Researchers at Harvard University and MIT discover previously unobserved state of matte... - 0 views

  • The discovery
  • goes against what scientists previously understood of photons: that elementary light particles are massless loners that do not interact with each other.
  • Most of the properties of light we know about originate from the fact that photons are massless, and that they do not interact with each other
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  • researchers fired a couple of photons into a cloud of rubidium – a chemical element belonging to the metal group – in a vacuum chamber cooled to just a few degrees above absolute zero.
  • When the photons exited the other side of the cloud of atoms
  • were surprised to see the pair emerge as a single molecule.
  • special type of medium in which photons interact with each other
  • so strongly that they begin to act as though they have mass, and they bind together to form molecules
  • Rydberg blockade
  • states that when an atom has energy imparted to it, nearby atoms cannot be excited to the same degree
  • the pair of photons moved through the cloud of atoms, the first photon excited atoms, but had to move forward before the second photon could do the same.
  • the pair of photons pushed and pulled each other through the cloud
  • atomic interaction
  • makes these two photons behave like a molecule
  • team is hoping to use their newly discovered state of matter in the advancement of quantum computing
Mars Base

Children with autism show increased positive social behaviors when animals are present - 0 views

  • authors compared how 5-13 year old children with ASD interacted with adults and typically-developing peers in the presence of two guinea pigs compared to toys
  • The presence of an animal can significantly increase positive social behaviors in children with autism spectrum disorders (ASD)
  • in the presence of animals, children with ASD demonstrated more social behaviors like talking, looking at faces and making physical contact
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  • also more receptive to social advances from their peers in the presence of the animals than they were when playing with toys
  • also increased instances of smiling and laughing, and reduced frowning, whining and crying behaviors in children with ASD more than having toys did.
  • Previous studies have shown that people are more likely to receive overtures of friendship from strangers when walking a dog than when walking alone
  • similar effects have been observed for people holding smaller animals like rabbits or turtles
  • authors suggest that this 'social lubricant' effect of animals on human social interactions can be particularly important for individuals with socio-emotional disabilities
  • the ability of an animal to help children with ASD connect to adults may help foster interactions with therapists, teachers or other adult figures
  • animal-assisted interventions may have applications in the classroom as well,
  • For children with ASD, the school classroom can be a stressful and overwhelming environment
  • If an animal can reduce this stress or artificially change children's perception
  • then a child with ASD may feel more at ease and open to social approach behaviors
Mars Base

Dark matter detector reports hints of WIMPs | Atom & Cosmos | Science News - 0 views

  • Ultracold crystals designed to catch particles of dark matter deep underground have come up with three potential detections
  • The researchers do not have enough evidence to say they have discovered dark matter particles
  • Theoretical physicists have put forth some ideas for particles that might constitute dark matter, including one called a weakly interacting massive particle, or WIMP.
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  • The experiment that made the newly reported detections is designed to pick up the signal of a WIMP as Earth passes through the galaxy
  • The Cryogenic Dark Matter Search consists of a network of silicon and germanium crystals cooled to near absolute zero
  • in the Soudan Underground Laboratory in Minnesota, a former iron mine more than 700 meters beneath the surface
  • If WIMPs exist, one should very occasionally slam into the nucleus of a silicon or germanium atom, causing a release of energy and a detectable vibration in the crystal
  • The hundreds of meters of earth above the experiment prevent other particles, such as protons and neutrons, from reaching the crystals and triggering a false positive
  • between July 2007 and September 2008, two of the experiment’s 11 silicon crystal detectors picked up three signals consistent with those expected from WIMP interactions
  • If the signals were caused by WIMPs
  • estimates the dark matter particle would weigh in at about 10 times the mass of the proton, well below many theoretical estimates
  • While the crystals’ underground setup provides plenty of shielding, some non-WIMP particles, such as electrons on the crystals’ surface, can cloud the results
  • it’s extremely unlikely that three events would show up from non-WIMP sources.
  • the energy released by the potential WIMPs is at the very lower limit of the detectors’ sensitivity
  • making erroneous WIMP detections more likely
  • concerns that the two crystals that picked up the signal could be more susceptible to false positives than the rest
  • In 2009, CDMS published a paper reporting that its germanium detectors had snagged two potential WIMPs, but further analysis revealed them to be surface electrons
  • more convinced if the detectors had picked up 10 or 12 signs of WIMPs, rather than just three
  • definitive detection would require multiple experiments worldwide to converge on the same characteristics for a dark matter particl
  • One in Italy called DAMA, short for Dark Matter, has made bold claims of dark matter detection that have drawn skepticism from many scientists
  • Other experiments have claimed to find signals at masses similar to this latest CDMS calculation but have not definitively said they have observed WIMPs
  • each experiment uses a different detection technique and has its own protocol for distinguishing WIMPs from background noise, making it hard to compare results
  • As for CDMS, the silicon detectors that found these signals are no longer collecting data
  • Researchers recently upgraded the Soudan facility with supersensitive germanium detectors
  • Over the next few years, the germanium detectors will move to a new, deeper underground home in Sudbury, Ontario, about 2 kilometers below the surface
Mars Base

Study unravels central mystery of Alzheimer's disease - 0 views

  • Until recently, Polleux's laboratory has been focused not on Alzheimer's research but on the normal development and growth of neurons
  • In 2011
  • reported that AMPK overactivation by metformin, among other compounds, in animal models impaired the ability of neurons to grow output stalks, or axons
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  • Around the same time, separate research groups found clues that AMPK might also have a role in Alzheimer's disease
  • One group reported that AMPK can be activated in neurons by amyloid beta, which in turn can cause a modification of the protein tau in a process known as phosphorylation
  • a postdoctoral research associate
  • began by confirming that amyloid beta, in the small-aggregate ("oligomer") form that is toxic to synapses, does indeed strongly activate AMPK
  • amyloid beta oligomers stimulate certain neuronal receptors, which in turn causes an influx of calcium ions into the neurons
  • that this calcium influx triggers the activation of an enzyme called CAMKK2, which appears to be the main activator of AMPK in neurons
  • AMPK overactivation in neurons is the essential reason for amyloid beta's synapse-harming effect
  • neurons' dendritic spines—the rootlike, synapse-bearing input stalks that receive signals from other neurons
  • scientists showed that amyloid beta oligomers can't cause this dendritic spine loss unless AMPK overactivation occurs—and indeed AMPK overactivation on its own can cause the spine loss
  • the team used J20 mice, which are genetically engineered to overproduce mutant amyloid beta
  • when we blocked the activity of CAMKK2 or AMPK in these neurons, we completely prevented the spine loss
  • Recent studies have shown that amyloid beta's toxicity to dendritic spines depends largely on the presence of tau, but just how the two Alzheimer's proteins interact has been unclear
  • their colleagues are now following up with further experiments to determine what other toxic processes, such as excessive autophagy, are promoted by AMPK overactivation and might also contribute to the long-term aspects of Alzheimer's disease progression
  • also interested in the long-term effects of blocking AMPK overactivation in the J20 mouse model as well as in other mouse models of Alzheimer's disease, which normally develop cognitive deficits at later stages
  • the pharmaceuticals industry who are potentially interested in targeting either CAMKK2 or AMPK
  • show that brain damage in Alzheimer's disease is linked to the overactivation of an enzyme called AMPK
  • Researchers have known for years that people in the earliest stages of Alzheimer's disease begin to lose synapses in certain memory-related brain areas
  • findings, reported in the April
  • Small aggregates of the protein amyloid beta can cause this
  • but how they do so has been a mystery
  • Tangles of tau with multiple phosphorylations ("hyperphosphorylated" tau) are known to accumulate in neurons in affected brain areas in Alzheimer
  • investigate further, to determine whether the reported interactions of AMPK with amyloid beta and tau can in fact cause the damage seen in the brains of Alzheimer's patients
  • In addition
  • findings suggest the need for further safety studies on an existing drug, metformin.
  • , a popular treatment for Type 2 Diabetes, causes AMPK activation.
Mars Base

NASA rover's first soil studies help fingerprint Martian minerals - 0 views

  • results of the first analysis of Martian soil by the Chemistry and Mineralogy (CheMin) experiment on NASA's Curiosity rover
  • presence of crystalline feldspar, pyroxenes and olivine mixed with some amorphous (non-crystalline) material
  • similar to volcanic soils in Hawaii
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  • NASA's Mars rover Curiosity has completed initial experiments showing the mineralogy of Martian soil is similar to weathered basaltic soils of volcanic origin in Hawaii
  • used its Chemistry and Mineralogy instrument (CheMin)
  • quantitative results provide refined and in some cases new identifications of the minerals in this first X-ray diffraction analysis on Mars."
  • identification of minerals in rocks and soil is crucial for the mission's goal to assess past environmental conditions
  • mineral records the conditions under which it formed.
  • composition of a rock provides only ambiguous mineralogical information,
  • X-ray diffraction
  • minerals diamond and graphite, which have the same chemical composition, but strikingly different structures and properties.
  • CheMin uses X-ray diffraction,
  • reads minerals' internal structure by recording how their crystals distinctively interact with X-rays
  • provides more accurate identifications of minerals than any method previously used on Mars
  • The sample was processed through a sieve to exclude particles larger than 0.006 inch (150 micrometers), roughly the width of a human hair.
  • soil material CheMin has analyzed is more representative of modern processes on Mars
  • "We now know it is mineralogically similar to basaltic material
  • significant amounts of feldspar, pyroxene and olivine, which was not unexpected
  • Roughly half the soil is non-crystalline material, such as volcanic glass or products from weathering of the glass
  • ancient rocks, such as the conglomerates, suggest flowing water, while the minerals in the younger soil are consistent with limited interaction with water
  • "So far, the materials Curiosity has analyzed are consistent with our initial ideas of the deposits in Gale Crater recording a transition through time from a wet to dry environment
Mars Base

NASA - NASA Spacecraft Images Offer Sharper Views of Apollo Landing Sites - 0 views

  • NASA's Lunar Reconnaissance Orbiter (LRO) captured the sharpest images ever taken from space of the Apollo 12, 14 and 17 landing sites
  • interactive shows two LRO images of the Apollo 17 landing site. Click and drag on the white slider bar to wipe from one to the other
  • This interactive shows two LRO images of the Apollo 12 landing site. Click and drag on the white slider bar to wipe from one to the other
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  • can retrace the astronauts' steps with greater clarity to see where they took lunar samples
  • In the Apollo 17 image, the foot trails, including the last path made on the moon by humans
  • One of the details that shows up is a bright L-shape in the Apollo 12 image. It marks the locations of cables running from ALSEP's central station to two of its instruments. Although the cables are much too small for direct viewing, they show up because they reflect light very well.
  • higher resolution of these images is possible because of adjustments made to LRO's orbit, which is slightly oval-shaped or elliptical
  • paths left by astronauts Alan Shepard and Edgar Mitchell on both Apollo 14 moon walks are visible in this image. (At the end of the second moon walk, Shepard famously hit two golf balls.)
Mars Base

How to find hidden treasures in the archive | ESA/Hubble - 0 views

  • How to find hidden treasures in the archive
  • The main interface to get at the Hubble data is the Hubble Legacy Archive website.
  • search box lets you look for objects based on their name or coordinates
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  • advanced search option is useful to restrict the search to specific instruments (cameras) on Hubble
  • recommend narrowing your search to give only results from ACS, WFC3 and WFPC2 – Hubble’s general purpose cameras.
  • Universe is a big place
  • there are many, many objects which Hubble has never studied
  • not all of Hubble’s observations are images
  • most observations are only released to the public a year after they have been made
  • scientists get the first chance to work with their data. These are marked “proprietary data, no preview”.
  • several options for how to display the results
  • easiest is to click on the images tab, which gives you preview images of all the results
  • Another useful view is the footprints tab, which shows the location of Hubble’s images overlaid on an image of the part of the sky where they are located
  • in most cases) offer an option to open the interactive display
  • opens the interactive tool which you can use to look at the image in more detail, and carry out basic image processing such as adjusting the zoom and changing the contrast and colour balance
  • lets you save your work as a JPEG.
  • process is entirely browser-based, and you need no special software
  • You can also download the data in FITS format
  • can then use
  • FITS Liberator
  • Photoshop
  • more sophisticated image processing
Mars Base

Darpa's Legged Squad Support System (LS3) to lighten troops' load - 0 views

  • Darpa's Legged Squad Support System (LS3)
  • The Army has identified physical overburden as one of its top five science and technology challenges
  • DARPA is developing a highly mobile, semi-autonomous legged robot, the Legged Squad Support System (LS3), to integrate with a squad of Marines or Soldiers.
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  • Recently the LS3 prototype underwent its first outdoor exercise
  • Over the course of the next 18 months, DARPA plans to complete development of and refine key capabilities to ensure LS3 is able to support dismounted squads of warfighters.
  • Features to be tested and validated include
  • ability to carry 400lbs on a 20-mile trek in 24-hours without being refueled
  • refinement of LS3’s vision sensors to track a specific individual or object, observe obstacles in its path and to autonomously make course corrections as needed
  • the addition of “hearing” technology, enabling squad members to speak commands to LS3 such as “stop,” “sit” or “come here.”
  • serves
  • mobile auxiliary power source— troops may recharge batteries for radios and handheld devices while on patrol
  • DARPA seeks to demonstrate that an LS3 can carry a considerable load from dismounted squad members, follow them through rugged terrain and interact with them in a natural way, similar to the way a trained animal and its handler interact.
  • LS3 seeks to have the responsiveness of a trained animal and the carrying capacity of a mule
  • The tests culminate in a planned capstone exercise where LS3 will embed with Marines conducting field exercises.
  • based on mobility technology advanced by DARPA’s Big Dog technology demonstrator, as well other DARPA robotics programs which developed the perception technology for LS3’s “eyes” and planned “ears.”
Mars Base

Neutrino Detector Finds Elusive Extraterrestrial Particles in 'Major Breakthrough' | Sp... - 0 views

  • scientists have pondered the source of cosmic rays, which contain the energy of a rifle bullet in a single atomic nucleus
  • It's thought that objects such as supernovas, black holes or gamma ray bursts mayproduce cosmic rays, but their origin is difficult to detect
  • Instead, scientists look for neutrinos — subatomic particles with no charge and very little mass — produced when cosmic rays interact with their surroundings
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  • Billions of neutrinos pass through a square centimeter of Earth every second, and only a tiny fraction of them interact with matter
  • IceCube is located inside a cubic kilometer of ice beneath the South Pole. The observatory consists of 5,160 digital optical modules suspended from 86 strings
Mars Base

Astronomers discover first Thorne-Zytkow object, a bizarre type of hybrid star -- Scien... - 0 views

  • While normal red supergiants derive their energy from nuclear fusion in their cores, TŻOs are powered by the unusual activity of the absorbed neutron stars in their cores
  • Thorne-Żytkow objects (TŻOs) are hybrids of red supergiant and neutron stars that superficially resemble normal red supergiants,
  • They differ, however, in their distinct chemical signatures
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  • TŻOs are thought to be formed by the interaction of two massive stars―a red supergiant and a neutron star formed during a supernova explosion―in a close binary system
  • the most commonly held theory suggests that, during the evolutionary interaction of the two stars
  • the much more massive red supergiant essentially swallows the neutron star, which spirals into the core of the red supergiant
  • Studying these objects
  • represents a completely new model of how stellar interiors can work
  • In these interiors we also have a new way of producing heavy elements in our universe
  • The astronomers
  • examined the spectrum of light emitted from apparent red supergiants, which tells them what elements are present
  • When the spectrum of one
  • star -- HV 2112
  • were quite surprised by some of the unusual features
  • took a close look at the subtle lines in the spectrum they found that it contained excess rubidium, lithium and molybdenum
  • Past research has shown that normal stellar processes can create each of these elements
  • high abundances of all three of these at the temperatures typical of red supergiants is a unique signature of TŻOs
  • careful to point out that HV 2112 displays some chemical characteristics that don't quite match theoretical models
  • There are some minor inconsistencies between some of the details of what we found and what theory predicts
  • But the theoretical predictions are quite old, and there have been a lot of improvements in the theory since then
Mars Base

ISEE-3 Reboot Project | Astronomy News - 0 views

  • The IEEE-3 spacecraft was launched on 12 August 1978
  • Originally the mission was cooperative effort between NASA and ESRO/ESA to study the interaction between the Earth’s magnetic field and the solar wind.
  • On 10 June 1982 IEEE-3 became the International Cometary Explorer with the primary scientific objective of ICE was to study the interaction between the solar wind and a cometary atmosphere
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  • The mission required the spacecraft to leave the Earth/moon system and orbit around the sun instead
  • After encounters with comet Giacobini-Zinner in 1985 and the famous Halley’s comet in 1986 and the study of CME’s from the sun in 1991, the “plug” was pulled in the spacecraft on 5 May 1997
Mars Base

NASA - NASA Researchers Discover Ancient Microbes in Antarctic Lake - 0 views

  • In one of the most remote lakes of Antarctica, nearly 65 feet beneath the icy surface, scientists
  • , have uncovered a community of bacteria
  • one of Earth's darkest, saltiest and coldest habitats
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  • increase our limited knowledge of how life can sustain itself in these extreme environments on our own planet and beyond.
  • Lake Vida, the largest of several unique lakes found in the McMurdo Dry Valleys, contains no oxygen, is mostly frozen and possesses the highest nitrous oxide levels of any natural water body on Earth
  • approximately six times saltier than seawater
  • average temperature is minus 8 degrees Fahrenheit
  • the brine harbors a surprisingly diverse and abundant variety of bacteria that survive without a current source of energy from the sun
  • Previous studies of Lake Vida dating back to 1996 indicate the brine and its inhabitants have been isolated from outside influences for more than 3,000 years.
  • the best analog we have for possible ecosystems in the subsurface waters of Saturn's moon Enceladus and Jupiter's moon Europa
  • collaborators
  • developed stringent protocols and specialized equipment for their 2005 and 2010 field campaigns to sample from the lake brine while avoiding contaminating the pristine ecosystem
  • expands our knowledge of environmental limits for life and helps define new niches of habitability
  • To sample unique environments such as this, researchers must work under secure, sterile tents on the lake's surface
  • The tents kept the site and equipment clean as researchers drilled ice cores, collected samples of the salty brine residing in the lake ice and assessed the chemical qualities of the water and its potential for harboring and sustaining life
  • analyses suggest chemical reactions between the brine and the underlying iron-rich sediments generate nitrous oxide and molecular hydrogen
  • may provide the energy needed to support the brine's diverse microbial life.
  • Additional research is under way to analyze the abiotic, chemical interactions between the Lake Vida brine and its sediment
  • investigating the microbial community by using different genome sequencing approaches
Mars Base

Claims of fairness in apes have critics crying foul | Zoology | Science News - 0 views

  • Chimpanzees often share and share alike when cooperating in pairs, suggesting that these apes come close to a human sense of fairness, a controversial new study finds.
  • chimps tend to fork over half of a valuable windfall to a comrade in situations where the recipient can choose to accept the deal or turn it down and leave both players with nothing
  • Yerkes National Primate Research Cente
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  • just as people do, chimps turn stingy when supplied with goodies that they can share however they like
  • But psychologis
  • of the Max Planck Institute for Evolutionary Anthropology
  • considers the new results “far from convincing.
  • In Proctor’s experiments, pairs of chimps interacted little with each other and showed no signs of understanding that some offers were unfair and could be rejected
  • study suggests that there is no fairness sensitivity in chimpanzees
  • coauthored two earlier studies in which chimps given food generally shared as little as possible with partners, who accepted most offers
  • Apes on the receiving end affirmed an offer by pulling food within reach using a mechanical device or refused an offer by doing nothing for 30 seconds.
  • In the new study, chimps and preschool children were tested in a way that Proctor contends is closer to a cooperation task known as the ultimatum game that is used in experiments with adults.
  • In the game’s standard version, one player splits a pot of money with another player
  • If the receiver accepts the proposer’s offer, both players keep their shares.
  • If the receiver rejects the offer, both players get nothing.
  • Proposers fork over 40 percent to 50 percent of the pot in most human cultures
  • A concern with fairness and a fear of retaliation for lowball offers prompts these generous offers
  • Her group studied six adult chimps at an outdoor research facility and 20 preschool children ages 2 to 7
  • Four pairs of chimps and 10 pairs of kids played a modified ultimatum game, in which a proposer can offer one of two tokens to a receiver
  • Accepted tokens got handed to an experimenter in exchange for rewards
  • Proposers opted for even splits much more frequently when a partner could reject offers
  • Two pairs of chimps split banana slices equally substantially more often than expected by chance
  • In both species, receivers exchanged all tokens for rewards, even those for unfair deals.
  • Neither chimps nor kids were trained that refusal was an option, but the mere threat of a partner’s retaliation motivated proposers to share equally
  • Jensen disagrees with that conclusion. Receivers’ acceptance of all offers “suggests that they were not sensitive to unfairness but were motivated only by getting rewards,
  • undermines any suggestion that chimp or child proposers assumed that their offers could be rejected
Mars Base

ESTCube-1 - Wikipedia, the free encyclopedia - 0 views

  • scheduled to be launched to orbit in second half of 2013
  • Student Satellite is an educational project that university and high school students can participate in
  • The CubeSat standard for nanosatellites was followed during the engineering of ESTCube-1, resulting in a 10x10x11.35 cm cube, with a volume of 1 liter and a mass of 1.048 kg.
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  • According to the CubeSat standard there are three different sized CubeSats corresponding to size 1U, 2U and 3U. Base side lengths are the same but height is 2 to 3 times bigger than 1U CubeSats
  • Mass is also set in CubeSat standard, the highest possible mass for 1U CubeSat is 1300 grams, 2U CubeSat 2600 grams and 3U CubeSat 4000 grams
  • CubeSat base side length must be 100.0±0.1 millimeters and satellite height must be 113.5±0.1 mm
  • the Estonian satellite
  • a 1U CubeSat
  • Although
  • its main purpose was to educate students, the satellite does have a scientific purpose.
  • On board of the satellite is an electric solar wind sail (e-sail) which was created by a Finnish scientist Pekka Janhunen
  • it is the first real experimentation of the e-sail
  • 10 meters of e-sail 50 to 20 micrometers thick wire of high-technology structure so-called Heytether will be deployed from the satellite.
  • The deployment of the Heytether can be detected by decrease of the satellite's speed of rotation or by a on-board camera
  • To control the loaded solar wind sail elements interaction with the plasma surrounding the earth and the effect it has on the spacecraft spinning speed the spacecraft has two on-board nanotechnologic electron emitters/gun
  • The electron emitters are connected to the e-sail element and by shooting out electrons it loads the e-sail element positively to 500 volts
  • The positive ions in the plasma push the e-sail element and have an influence on the satellites rotation speed
  • The effect of the e-sail is measured by the change in rotation speed
  • The camera is used to take a picture of Earth and the successfully deployed Heytether. [edit]
  • ESTCube-1 will be sent to orbit by the European Space Agency's rocket Vega in spring of 2013
  • Start in spring of 2013
  • Half an hour after the satellites deployment from the start capsule satellites antennas will be opened and radio transmitter and important subsystems will be switched on
  • First days or weeks will be used to test the satellite and set it to work on full capacity.
  • Orienting the satellite so the on-board camera will be faced to earth
  • trying to take a picture of Estonia
  • Rotating the satellite on an axis with a speed of 1 revolution per second
  • E-sail element deployment from the satellite by a centrifugal force and confirming the deployment via the on-board camera
  • Activating the electron emitter and loading the e-sail
  • Measuring the e-sails and Lorentz force by satellites revolutions per second
  • If possible using the negatively charged e-sail to take the satellite off orbit and burn it in the earths atmosphere
  • If everything goes perfect the mission can be completed within a few weeks to a month
  • Lifespan of the satellite
  • Measurements and weight
  • Scientific purpose
  • Communicating with the satellite
  • held by two International Amateur Radio Unions three registered frequencies
  • Periodic but very slow communication is done on a telegraphic signal on a frequency of 437.250 MHz
  • the most important satellite parameters are transmitted every 3 to 5 minutes
  • For fast connections FSK-modulation radio signal on a frequency of 437.505 MHz with a 9600 baud connection speed and AX.25 standard is used.
  • Somewhat slow connection speed is caused by the usage of amateur radio frequencies which allow a maximum of 25 kiloherz bandwidth
  • Fast connection is used only when the satellite has been given a specific
  • Using the GFSK-modulation maximum possible connection speed is 19,200 bits per second
  • Software
  • FreeRTOS on the satellite's Command and Data Handling System and camera module
  • TinyOS on the satellite's communication module
  • Financing and costs
  • Cheapest possibility to send a satellite onto orbit is offered by European Space Agency. Because Estonia is an associated member of ESA most of the launch expenses (about 70,000 euros) will be covered from Estonian member fee for educational expenses. With the launch total expenses for the project are approximately 100,000 euros.
Mars Base

Planck's most detailed map ever reveals an almost perfect Universe - 0 views

  • the most detailed map ever created of the cosmic microwave background
  • the relic radiation from the Big Bang
  • was released
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  • revealing the existence of features that challenge the foundations of our current understanding of the Universe
  • The image is based on the initial 15.5 months of data from Planck and is the mission's first all-sky picture of the oldest light in our Universe, imprinted on the sky when it was just 380 000 years old.
  • At that time, the young Universe was filled with a hot dense soup of interacting protons, electrons and photons at about 2700ºC
  • protons and electrons joined to form hydrogen atoms, the light was set free
  • As the Universe has expanded, this light today has been stretched out to microwave wavelengths, equivalent to a temperature of just 2.7 degrees above absolute zero.
  • that correspond to regions of slightly different densities at very early times, representing the seeds of all future structure: the stars and galaxies of today
  • According to the standard model of cosmology, the fluctuations arose immediately after the Big Bang and were stretched to cosmologically large scales during a brief period of accelerated expansion known as inflation.
  • Planck was designed to map these fluctuations across the whole sky with greater resolution and sensitivity than ever before
  • By analysing the nature and distribution of the seeds in Planck's CMB image, we can determine the composition and evolution of the Universe from its birth to the present day
  • because precision of Planck's map is so high, it also made it possible to reveal some peculiar unexplained features that may well require new physics to be understood
  • Since the release of Planck's first all-sky image in 2010, we have been carefully extracting and analysing all of the foreground emissions that lie between us and the Universe's first light
  • revealing the cosmic microwave background in the greatest detail yet
  • One of the most surprising findings is that the fluctuations in the CMB temperatures at large angular scales do not match those predicted by the standard model
  • their signals are not as strong as expected from the smaller scale structure
  • Another is an asymmetry in the average temperatures on opposite hemispheres of the sky
  • This runs counter to the prediction made by the standard model that the Universe should be broadly similar in any direction we look
  • a cold spot extends over a patch of sky that is much larger than expected.
  • The asymmetry and the cold spot had already been hinted at with Planck's predecessor
  • NASA's WMAP mission, but were largely ignored because of lingering doubts about their cosmic origin
  • One way to explain the anomalies is to propose that the Universe is in fact not the same in all directions on a larger scale than we can observe
  • In this scenario, the light rays from the CMB may have taken a more complicated route through the Universe than previously understood, resulting in some of the unusual patterns observed today.
  • ultimate goal would be to construct a new model that predicts the anomalies and links them together
  • we don't know whether this is possible and what type of new physics might be needed
  • the Planck data conform spectacularly well to the expectations of a rather simple model of the Universe, allowing scientists to extract the most refined values yet for its ingredients
  • dark energy, a mysterious force thought to be responsible for accelerating the expansion of the Universe, accounts for less than previously thought.
  • Normal matter that makes up stars and galaxies contributes just 4.9% of the mass/energy density of the Universe
  • Dark matter, which has thus far only been detected indirectly by its gravitational influence, makes up 26.8%, nearly a fifth more than the previous estimate.
  • Planck data also set a new value for the rate at which the Universe is expanding today, known as the Hubble constant
  • At 67.15 kilometres per second per megaparsec, this is significantly less than the current standard value in astronomy
  • The data imply that the age of the Universe is 13.82 billion years.
  • We see an almost perfect fit to the standard model of cosmology, but with intriguing features that force us to rethink some of our basic assumptions
Mars Base

Particle looking 'more and more' like Higgs, LHC scientists say - 0 views

  • in the latest update, physicists told a conference in La Thuile, Italy, that more analysis is needed before a definitive statement can be made
  • Key to a positive identification of the particle is a detailed analysis of its properties and how it interacts with other particles
  • Since scientists' announcement last July that they had found a particle likely to be the Higgs, much data has been analysed, and its properties are becoming clearer
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  • One property that will allow several teams researching the particle to declare whether or not it is a Higgs, is called spin
  • A Higgs must have spin-zero
  • All the analysis conducted so far strongly indicates spin-zero, but it is not yet able to rule out entirely the possibility that the particle has spin-two
  • Until we can confidently tie down the particle's spin, the particle will remain Higgs-like
  • looking "more and more"
Mars Base

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

  • 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
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  • 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

Billion-year-old water could hold clues to life on Earth and Mars - 0 views

  • A UK-Canadian team of scientists has discovered ancient pockets of water, which have been isolated deep underground for billions of years and contain abundant chemicals known to support life
  • This water could be some of the oldest on the planet and may even contain life
  • the similarity between the rocks that trapped it and those on Mars raises the hope that comparable life-sustaining water could lie buried beneath the red planet's surface
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  • Researchers
  • analysed water pouring out of boreholes from a mine 2.4 kilometres beneath Ontario, Canada
  • found that the water is rich in dissolved gases like hydrogen, methane and different forms – called isotopes – of noble gases such as helium, neon, argon and xenon
  • there is as much hydrogen in the water as around hydrothermal vents in the deep ocean, many of which teem with microscopic life
  • The hydrogen and methane come from the interaction between the rock and water, as well as natural radioactive elements in the rock reacting with the water
  • These gases could provide energy for microbes that may not have been exposed to the sun for billions of years.
  • The crystalline rocks surrounding the water are thought to be around 2.7 billion years old. But no-one thought the water could be the same age, until now
  • Using ground-breaking techniques
  • researchers show that the fluid is at least 1.5 billion years old, but could be significantly older.
  • interconnected fluid system in the deep Canadian crystalline basement that is billions of years old, and capable of supporting life
  • Before this finding, the only water of this age was found trapped in tiny bubbles in rock and is incapable of supporting life
  • the water found in the Canadian mine pours from the rock at a rate of nearly two litres per minute
  • don't yet know if the underground system in Canada sustains life
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