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Mars Base

Student's flashlight works by body heat, not batteries - 0 views

phys.org/...flashlight-body-batteries.html

scibyte100 StudentDesign

shared by Mars Base on 02 Jul 13 - No Cached
  • her flashlight has got her into the finalist ranks for the Google Science Fair
  • Ann Makosinski from Victoria, British Columbia, has an LED flashlight powered by body heat
  • the Hollow Flashlight, which works according to the thermoelectric effect—creating electric voltage out of temperature difference
  • ...16 more annotations...
  • a Grade 10 student
  • designed a flashlight that provides bright light without batteries or moving parts
  • and only needs a five degree temperature difference to work and produce up to 5.4 mW at 5 foot candles of brightness
  • Using four Peltier tiles and the temperature difference between the palm of the hand and ambient air
  • bought Peltier tiles and tested them to see if they could produce sufficient power to light an LED
  • power was no problem but getting the needed voltage was, as the tiles did not generate enough of the voltage needed
  • some changes to the circuit design
  • used the Internet for information, experimented with different circuits
  • finding an energy-harvesting article
  • that made note of a circuit that could provide enough voltage when used with a recommended transformer
  • The final design included mounting the Peltiers on a hollow aluminum tube which was inserted in a larger PVC pipe with an opening that allowed ambient air to cool the tube
  • The palm wrapped around a cutout in the PVC pipe and warmed the tiles.
  • The result was a bright light at 5 degree Celcius [sic] of Peltier differential
  • Materials for the flashlight project cost her $26
  • The top winner gets a $50,000 scholarship and trip to the Galapagos Islands
  • The prize ceremony takes place in September. Winners will be chosen in different age categories—13-14, 15-16, 17-18.
Mars Base

Space Shuttle Atlantis Exhibit 'Incredible,' 'Breathtaking' | NASA Shuttle Program | Sp... - 0 views

www.space.com/exhibit-visitors-reaction.html

scibyte100 shuttle

shared by Mars Base on 01 Jul 13 - No Cached
  • The retired orbiter is displayed at an angle, with its cargo bay doors open and robotic arm outstretched
  • The public got its first official look at the display
  • June 29
  • ...3 more annotations...
  • when the Space Shuttle Atlantis exhibition opened
  • at NASA's Kennedy Space Center Visitor Complex
  • Atlantis dominates the center of a multistory building that allows views of the orbiter from many angles.
Mars Base

Researchers discover link between fear, sound perception - 0 views

medicalxpress.com/...2013-06-link-perception.html

scibyte100

shared by Mars Base on 01 Jul 13 - No Cached
  • our emotions can actually affect how we hear and process sound
  • When certain types of sounds become associated in our brains with strong emotions, hearing similar sounds can evoke those same feelings
  • a phenomenon commonly seen in combat veterans suffering from post-traumatic stress disorder (PTSD)
  • ...18 more annotations...
  • a pair of researchers
  • has discovered how fear can actually increase or decrease the ability to discriminate among sounds depending on context
  • study
  • emotional conditioning in mice to investigate how hearing acuity (the ability to distinguish between tones of different frequencies) can change following a traumatic event, known as emotional learning
  • In these experiments
  • animals learn to distinguish between potentially dangerous and safe sounds—called "emotional discrimination learning."
  • This type of conditioning tends to result in relatively poor learning, but
  • designed a series of learning tasks intended to create progressively greater emotional discrimination in the mice, varying the difficulty of the
  • The researchers found that, as expected, fine emotional learning tasks produced greater learning specificity than tests in which the tones were farther apart in frequency
  • animals presented with sounds that were very far apart generalize the fear that they developed to the danger tone over a whole range of frequencies
  • animals presented with the two sounds that were very similar exhibited specialization of their emotional response
  • pitch discrimination abilities were measured in the animals, the mice with more specific responses displayed much finer auditory acuity than the mice who were frightened by a broader range of frequencies
  • Another interesting finding of this study is that the effects of emotional learning on hearing perception were mediated by a specific brain region, the auditory cortex
  • The auditory cortex has been known as an important area responsible for auditory plasticity
  • Surprisingly
  • found that the auditory cortex did not play a role in emotional learning
  • the specificity of emotional learning is controlled by the amygdala and sub-cortical auditory areas
  • hypothesis is that the amygdala and cortex are modifying subcortical auditory processing areas. The sensory cortex is responsible for the changes in frequency discrimination, but it's not necessary for developing specialized or generalized emotional responses
Mars Base

Fear of Komodo dragon bacteria wrapped in myth - 0 views

phys.org/...modo-dragon-bacteria-myth.html

scibyte100

shared by Mars Base on 01 Jul 13 - No Cached
  • It has long been believed that Komodo dragon bites were fatal because of toxic bacteria in the reptiles' mouths
  • But ground-breaking research
  • has found that the mouths of Komodo dragons are surprisingly ordinary and the levels and types of bacteria do not differ from any other carnivore
  • ...3 more annotations...
  • Unlike people have been led to believe, they do not have chunks of rotting flesh from their meals on their teeth, cultivating bacteria
  • the poor hygiene of water buffalo is responsible for perceptions about deadly toxic bacteria in the dragons
  • They now populate the islands of Indonesia where they prey on the introduced water buffalo, and on pigs and deer
Mars Base

U.K. Government Plans to Allow Mitochondrial Replacement - ScienceInsider - 0 views

news.sciencemag.org/...ernment-plans-to-allow-mi.html

scibyte100

shared by Mars Base on 30 Jun 13 - No Cached
  • The U.K. government is moving toward allowing a new type of in vitro fertilization that would enable patients with mitochondrial diseases to avoid passing the condition to their children
  • The technique is controversial, because it involves introducing new DNA into a human embryo
  • The Department of Health announced
  • ...8 more annotations...
  • that it would draw up draft guidelines to allow fertility clinics to offer the technique
  • The proposed guidelines would be released for public comment later this year, and Parliament could vote on a final version next year
  • Mitochondria are the cell's power generators, and they carry their own DNA, called mtDNA
  • Mutations in those genes cause mitochondrial diseases, which can affect various organs, including the heart, liver, eyes, and brain
  • Such diseases are passed from mother to child, because the egg provides most of an embryo's mtDNA
  • The techniques
  • transfer the nuclear DNA from the sperm and egg of the potential parents into a second egg, provided by a donor who has healthy mitochondria, from which the nuclear DNA has been removed
  • The technique is still under development and isn't yet considered ready to try in humans
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