Eyes on the skin. In the teamâs first experiment, the scientists were looking to see whether UV light instigated a calcium signaling response. They found nothing. But guessing that the skin might sense light like the eyes do, they added retinal, a co-factor of opsin receptors including rhodopsin.
Economy shipping takes 1 to 10 business days within the United States and 11 to 20 business days for international. Exact time depends on how far the package must travel. Standard international shipping takes 5 to 10 days.
USPS offers Standard Post and Media Mail as economy shipping options. As of February 2015, both can take up to 8 business days, and Media Mail is only an option for materials that are deemed educational.