Study Reveals Secret of Zebrafish:
Scientists at Monash University in Australia have found how the zebrafish heals its spinal cord after injury.
The zebrafish, Danio rerio, is a tropical fish belonging to the family Cyprinidae. This species is a popular aquarium fish and is also an important model organism in scientific research. It has the amazing ability to regenerate fins, skin, the heart and the brain.A new study in the describes the role of a protein in the remarkable self-healing ability of the fish. The finding could eventually lead to ways to stimulate spinal cord regeneration in humans.
“When the spinal cord is severed in humans and other mammals, the immune system kicks in, activating specialized cells called glia to prevent bleeding into it,” explained study co-author Prof Peter Currie.
“Glia are the workmen of nervous system. The glia proliferate, forming bigger cells that span the wound site in order to prevent bleeding into it. They come in and try to sort out problems. A glial scar forms.”
However, the scar prevents axons, threadlike structures of nerve cells that carry impulses to the brain, of neighboring nerve cells from penetrating the wound. The result is paralysis.
“The axons upstream and downstream of the lesion sites are never able to penetrate the glial scar to reform. This is a major barrier in mammalian spinal cord regeneration,” Prof Currie said.
In contrast, the zebrafish glia form a bridge that spans the injury site but allow the penetration of axons into it. The fish can fully regenerate its spinal cord within two months of injury. “You can’t tell there’s been any wound at all,” Prof Currie said.
If asked, would you rank polio among the world’s most severe infectious diseases?
No, I wouldn’t either - but it’s worth remembering that it took a lot of hard work to get it off of that list. Poliovirus, a human enterovirus of the family Picornaviridae, has persisted throughout history with fascinating success. It can be seen everywhere from ancient Egyptian paintings and carvings of otherwise healthy people with withered limbs, to, more recently, the 20th century polio epidemics that became a seasonal plague, paralysing children and adults alike and causing the ultimate race for a vaccine. While 90-95% of poliovirus infections are asymptomatic, the symptoms of polio - when they present - are both devastating and deadly.
Several poliovirus vaccines have been developed to date; in particular, one live, attenuated vaccine and one IPV (inactivated poliovirus vaccine). In a recent Nature News article, “A war not yet won”, the financial implications of poliovirus - which is still endemic in developing countries, despite a worldwide push for eradication - were examined alongside various strategies for moving forward with changes to the proposed eradication scheme. One such change was the use of the injectable IPV vaccine in conjunction with the oral vaccine - the live, weakened attenuated virus - that’s currently being used to treat poliomyelitis in endemic populations.
Although the fight to eradicate poliovirus is far from over - and it’s definitely too early to start congratulating - complementing the inexpensive, highly effective oral vaccine with its injected dead-virus counterpart is a promising start. With sufficient funding and a better global understanding about the benefits of vaccination, we’ll see the end of poliomyelitis in our lifetimes.
Top Image: Coloured transmission electron micrograph (TEM) of clusters of polio viruses, the cause of poliomyelitis (infantile paralysis). There are three serotypes of the polio virus; pictured here is type 1, which causes most epidemics.
Bottom Image: A computer’s 3D rendering of poliovirus virions.
“In this episode of the Hubblecast, scientists Jay Anderson and Roeland van der Marel show how they have used Hubble observations to predict the future of the Andromeda Galaxy and the Milky Way.
Projecting the motion of Andromeda’s stars over the next 8 billion years, the astronomers now know the path that galaxy is taking through space. And it’s heading straight for us! Computer simulations based on Hubble observations show how the two galaxies will crash together in around 4 billion years’ time.”
Credit: ESA/Hubble & NASA/STScI
(Source: youtube.com)
Univers Revolved
Letters are an inherently two-dimensional affair. They can convey deep meaning, but are confined to the flat surface of the page. Ji Lee, a designer now with Facebook, was playing around with some 3-D software and noticed that he could rotate litters around their central axis. All of a sudden, they became toy-like shapes.
He was able to use the letter as a physical object, to break away from the linear and build visual representations made from the actual letters of the word.
For starters, can you figure out the words in the lower left? If you feel like that’s too easy, Lee created the world in the bottom right for you to explore (Hint: Try to find “ROCKET”).
See more at Univers Revolved, test your 3-D knowledge, and check out the book on Amazon.
This. Is. So. AWESOME! Can this be a font?
Why yes, it can be! Check out the page on Univers Revolved where you can download the alphabet as a font for PC and Mac!
This is an image taken by the McNeil lab of a hippocampal growth cone exploring. Growth cones are the part of the neuron (from the axon which has to make connections) that grow outward to seek out other neurons and make connections/synapses. For more information, see this post.
Oh shit, too bad WWII is one of the first impressions outer space gets of us. Great timing, everyone.
*Insert golf clap here.*
(Source: fyeahcarlsagan)
Toddler received world’s smallest artificial heart as he waited for a transplant
Italian doctors have saved the life of a 16-month-old boy by implanting the world’s smallest artificial heart to keep the infant alive until a donor was found for a transplant.
The tiny titanium pump weighs only 11 grams and can handle a blood flow of 1.5 liters a minute. An artificial heart for adults weighs 900 grams.
Surgeon Antonio Amodeo said the baby had become family and his team wanted to do everything to help him.
“Every day, every hour, for more than one year he was with us. So when we had a problem we couldn’t do anything more than our best,” he said. (Photo: Alessandro Bianchi/Reuters)
(Source: nationalpost)
“ Two things are infinite: the universe and human stupidity; and I’m not sure about the universe.
Albert Einstein (via kari-shma)
The inside of a human hand. I find this photo fascinating.
Explore the Map of Life!
MappingLife.org is live, and incredibly informative. It has collected biodiversity survey data for tens of thousands of terrestrial and aquatic species around Earth. And it’s all there for you to search and draw maps with.
The data comes from field observations as well as other sources, like museum specimens. You can toggle several different types of observations for each species that you choose, and overlay them on customized Google-based maps.
The map above is one I made just now, showing the known habitats of a few bluefin tuna species (genus Thunnus, because they are critically threatened), African elephants (Loxodonta africana, also fighting with humans to retain their habitat) and sea otters (Enhydra lutris, because I love otters). Here’s a tutorial video.
It’s a tool that’s as much educational as it is fun, and a way for anyone to take part in biodiversity research. It’s all of our planet. They’re all of our species.
Go. Play. Learn. Conserve.
