Researchers in Australia, using a technique called micro-spectrophotometry, looked at the retinal cells of 17 species of shark caught off Queensland and Western Australia.
In all 17 species, the commonest kind of light receptors were “rod” cells, which are highly sensitive to light and allow night vision but cannot tell colours apart, they found.
Yet the sharks lacked cone cells, which respond individually to light at specific wavelengths. In human eyes, a variety of cone cells helps us to distinguish between colours.
In 10 of the 17 shark species, no cone cells were found at all. Cone cells were found in the other seven species, but they were all of a single type, sensitive to wavelengths of around 530 nanometres, which is green. Continue reading
The premise behind paid to upload services is simple: You upload large files, such as MP3s, videos, movies, eBooks or applications, and share your link. Meanwhile, the service gives you the opportunity to earn a fraction of a cent for each download or cash money for referring premium memberships.
In the past few years, a couple such paid to upload services have risen and fallen. Some—such as Megaupload and Uploading.com—have even endured for some time, which hints at the notion that this paid to upload business may be the real deal. Continue reading
When you’re a hardcore Evernote power user, performance in the app might start to lag after you’ve got a few thousand notes under your belt. At that point I would call you an Evernote master, and bow before your awesome clipping prowess. But, to be a Evernote Ninja you will need not only skills, but speed. Let’s optimize Evernote and get your groove back by using a trick from the Evernote Debug Menu!