jueves, 31 de julio de 2014
martes, 29 de julio de 2014
PANGEA with current borders
Massimo Pietrobon
Pangea was a supercontinent that existed during the late Paleozoic
and early Mesozoic eras. It
formed approximately 300 million years ago and then began to break apart after
about 100 million years.
domingo, 27 de julio de 2014
viernes, 25 de julio de 2014
The Secret to a Tattoo's Permanence: The Immune System
We rarely stop and think about the science of tattoos. In fact, some people don't even stop and think before getting tattooed.
We kind of know the reason they last forever ... because the ink goes so deep into your skin that it can never wash off ... or something?
It's not that simple. As this fascinating video from TED explains, tattoos are actually a complicated inflammatory process—a delicate balancing act between your body and the dye that's invading it.
It turns out your ethereal watercolored bird is kind of like an infection—and the reason it's permanent is because your body keeps on fighting it forever.
Tattoo needles punch through the epidermis, the outer layer of skin, and drive the ink into the dermis, the deeper layer that's mottled with nerves and blood vessels.
"Every time the needle penetrates, it causes a wound that alerts the body to begin the inflammatory process," the video explains. That signal sends immune system cells racing to the site of the wound (or multiple wounds, in the case of the five-inch dragon breathing fire across your chest).
Special cells called macrophages come to the rescue, eating up the dye in an attempt to "clean up" the inflammation it's causing. The rest of the dye gets soaked up by skin cells called fibroblasts. The fibroblasts, along with many of the macrophages, stay suspended in the dermis in perpetuity.
The dye in the bellies of the trapped macrophages and fibroblasts shows through the skin, projecting your Chinese word for "love" or constellation of tiny blue stars to the outside world.
And in case you accidentally got "Only god can fudge me"written on the nape of your neck, the video also explains how you can, um, get that fixed. No fudgment.
miércoles, 23 de julio de 2014
martes, 22 de julio de 2014
lunes, 21 de julio de 2014
domingo, 20 de julio de 2014
viernes, 18 de julio de 2014
jueves, 17 de julio de 2014
martes, 15 de julio de 2014
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