How close have you ever gotten to a wild bird? Can you remember the details of its plumage or the curvature of its beak? Did it sit in one place long enough for you to really study all of its colors and other characteristics? Probably not—at least if it was alive. The avid birders among us sometimes search their whole life for a glimpse of a particularly rare species. But if you are just a casual observer of the winged creatures around us, the ones you do see likely come and go as flashes of color and sound. For ornithologists, the elusive nature of birds is just part of the job. Beyond fieldwork, though, access to rare or extinct species or those with a limited range can be especially difficult to get. If you were, say, hoping to study the green-headed tanager (a riotously multicolored songbird native to South America) and unable to travel to the northeastern region of the continent where it can be found, you would have to ask a museum to send you a specimen in the mail. Access to rare specimens, such as those of extinct birds, can be especially difficult to get.
This revolutionary gene-editing system has taken science by storm. CRISPR is the basis of a revolutionary gene editing system. One day, it could make it possible to do everything from resurrect extinct species to develop cures for chronic disease.
CRISPR is a family of DNA sequences found in the genomes of prokaryotic organisms such as bacteria and archaea. These sequences are derived from DNA fragments of bacteriophages that had previously infected the prokaryote. They are used to detect and destroy DNA from similar bacteriophages during subsequent infections.
“The cornea, which in fish is simply a transparent protective cover for the eye, became an image-forming structure in its own right,” wrote the late Michael Land, a biologist at the University of Sussex in England, in a 2005 study in the journal Current Biology, “because it now had air on one side and water on the other.”
Some organisms have kept basic structures—flatworms and mollusks still have their simple pit eyes—while others sprouted mirrored components, elaborate pupil dynamics and arrangements that let their owner see above and below a waterline simultaneously. Even in animals that rely primarily on sensations besides sight, incredible eye features persist.
Vaccines are medicines that train the body to defend itself against future disease, and they have been saving human lives for hundreds of years. Vaccines are medicines that train the body to defend itself against future disease.
From Scientific American (March 1, 2021):
Enter the intranasal vaccine, which abandons the needle and syringe for a spray container that looks more like a nasal decongestant. With a quick spritz up the nose, intranasal vaccines are designed to bolster immune defenses in the mucosa, triggering production of an antibody known as immunoglobulin A, which can block infection. This overwhelming response, called sterilizing immunity, reduces the chance that people will pass on the virus.
The development of highly effective COVID vaccines in less than a year is an extraordinary triumph of science. But several coronavirus variants have emerged that could at least partly evade the immune response induced by the vaccines. These variants should serve as a warning against complacency—and encourage us to explore a different type of vaccination, delivered as a spray in the nose. Intranasal vaccines could provide an additional degree of protection, and help reduce the spread of the virus.