Super strong spider silk

Regular spider silk (you know, what spider webs are made of) is really amazing stuff. For its size, it’s stronger than anything humans can make. But they can really up their game just by being sprayed with water that has carbon nanotubes and graphene flakes in it. That’s all it took to make the spiders weave super strong silk, stronger than anything else.

These guys have found a way to incorporate carbon nanotubes and graphene into spider silk and increase its strength and toughness beyond anything that has been possible before. The resulting material has properties such as fracture strength, Young’s modulus, and toughness modulus higher than anything ever measured.

The researchers don’t know how the spiders manage to incorporate the nanotubes and graphene into their silk, and there isn’t a good way to harvest the resulting fibers to mass produce materials.

NOVA Evolution Lab

What could you possibly have in common with a mushroom, or a dinosaur, or even a bacterium? More than you might think. In this Lab, you’ll puzzle out the evolutionary relationships linking together a spectacular array of species. Explore the tree of life and get a front row seat to what some have called the greatest show on Earth. That show is evolution.

Nova has made a cool game where you can explore how different species are related to each other. It’s over at NOVA Evolution Lab. It’s a cool game where you drag different species to create a phylogenetic tree. You also have to identify what characteristics cause the different branches of the tree.

Google Maps for the body

Australian scientists have managed to get imaging of the human body at many different levels. This is giving views from joints to the cellular level.

“For the first time we have the ability to go from the whole body down to how the cells are getting their nutrition and how this is all connected,” said Professor Knothe Tate. “This could open the door to as yet unknown new therapies and new preventions.”

This kind of imagery involves terabyte sized data sets, and the Google Maps software helps them use it effectively.

Brain Dissections

While I teach general science, my schools Gifted and Talented teacher goes into more advanced work with some of the students. Today she brought in a biology expert to do sheep brain dissection in my classroom.

Students were finding the parts of the brain they’ve learned about, from the pituitary gland to the olfactory lobes to the optic nerve crossover. Looking at the gray matter and the white matter.

Some parents came in to do this with their kids. Most kids had fun, but one or two were kind of squeamish.

Sheep brain

Sheep brain

Why do we have allergies?

Allergies are really annoying, and sometimes deadly. They are caused by our immune system overreacting to a stimulus and causing the allergy symptoms, sometimes even death. So, how is this an evolutionary advantage? Why hasn’t natural selection removed this?

A good article at Gizmodo explains how a Russian researcher, Ruslan Medzhitov, has studied allergies and the immune response.

Allergies make a lot more sense in terms of evolution when seen as a home-alarm system, argues Medzhitov. Toxic chemicals, whether from venomous animals or plants, have long threatened human health. Allergies would have protected our ancestors by flushing out these chemicals. And the discomfort our ancestors felt when exposed to these allergens might have led them to move to safer parts of their environment.

It looks like the allergic response isn’t triggered by the presence of an allergen, but when that allergen starts harming the body–destroying cells. Essentially, allergies are your body’s way of trying to remove the allergen. Coughing, itching, sneezing, and tears are all ways that bodies try to get things out of the body. More research needs to be done on this.

Sitting on Cullen’s lab bench is a plastic box that houses a pair of mice. There are dozens more of these boxes in the basement of their building. Some of the mice are ordinary, but others are not: using genetic engineering techniques, Medzhitov’s team has removed the animals’ ability to make IgE. They can’t get allergies.

Medzhitov and Cullen will be observing these allergy-free mice for the next couple of years. The animals may be spared the misery of hay fever caused by the ragweed pollen that will inevitably drift into their box on currents of air. But Medzhitov predicts they will be worse off for it. Unable to fight the pollen and other allergens, they will let these toxic molecules pass into their bodies, where they will damage organs and tissues.

This would show that allergies are helpful to the body and there would be selective pressure for allergies as an adaptation.

Walking on ice is hard

Researchers at the Salk Institute have found where nerve signals are preprocessed to help the brain maintain balance on slippery surfaces. They think a group of nerves in the spinal cord called RORα serve as a link between the brain and the feet. Studies with mice showed that mice without the RORα nerves had trouble maintaining balance.

“We think these neurons are responsible for combining all of this information to tell the feet how to move,” says Steeve Bourane, a postdoctoral researcher in Goulding’s lab and first author on the new paper. “If you stand on a slippery surface for a long time, you’ll notice your calf muscles get stiff, but you may not have noticed you were using them. Your body is on autopilot, constantly making subtle corrections while freeing you to attend to other higher-level tasks.”


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Prototype of Ebola diagnosing on paper substrate

Scientists have developed prototype testing strips that don’t need to use cultures to check for infection. They use paper with genetic material built into the fibers to do cell-like processes that normally take days down to 90 minutes. Some saliva or a drop of blood is all this system needs to work. They already have a prototype that detects Ebola. This is kind of like a computer that uses genes as the program, and paper as the operating system.

Since this is in the prototype stage, there is a lot of work still to be done before this technology can become available.

If I only had a brain

Could you live with half a brain? Some people have. The cerebellum is a small part of the brain by volume, but contains about half of the brain’s neurons. Some people have managed to live their entire lives without a cerebellum. Since the cerebellum handles lots of fine motor control, balance, and more, these people have had trouble walking properly, had slurred speech, trouble with coordination, and more.

But recently, a Chinese woman was found to have lived without a cerebellum. She first stood at 4 years old, and couldn’t walk unaided until she was 7. Her symptoms are not as severe. It seems that her brain grew so that many of the functions of the cerebellum were controlled by other parts of the brain.

 

Nervous system may be more distributed than we thought

Your nervous system might be more sophisticated than we thought. Classically, nerves send signals to the brain for processing. The brain does all the heavy lifting of figuring out what was observed.

That may not be the case. Researchers at Umeå University in Sweden have found that the nerves in skin do some preprocessing of the signals before they send them to the brain.

Our work has shown that two types of first-order tactile neurons that supply the sensitive skin at our fingertips not only signal information about when and how intensely an object is touched, but also information about the touched object’s shape

In particular, they found that the neurons in the skin perform the same type of calculations that the cerebral cortex does.