♥In this micrograph, the spherical Ag droplet (about 5 microns in diameter) is almost detached from the SiO2 base, yet it is in the clothing of a thin SiO2 layer.
Credit: Prof. Dr. Z. X. Cao
Source: Physics is Fun, Physics is Art; Prof. Dr. Ming-Wei Wu, Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China.
At the heart of science is an essential balance between two seemingly contradictory attitudes—an openness to new ideas, no matter how bizarre or counterintuitive they may be, and the most ruthless skeptical scrutiny of all ideas, old and new. This is how deep truths are winnowed from deep nonsense.
Carl Sagan (via philphys) ♥
♥A Duplicate Gene May Have Helped Our Brains Become “Human”
Among the ~25,000 or so genes in our genome, we find a handful of duplicates. Some of them, like the genes that make pieces of the ribosome (your cellular protein factories) are fully-functional exact copies. This allows your cells to make a whole mess of that gene product. But other duplicates are imperfect copies put there by accidents or errors, and often those copies can be a bit wonky.
One of those imperfect gene copies may have had a strong influence on our brains becoming more advanced and “human” during evolution. A group led by Evan Eichler looked at a gene called SRGAP2 and noted that it appeared to have been duplicated to a certain form about 2.4 million years ago, which is when the Homo lineage split from Australopithecus. That duplicate, called SRGAP2C, actually overpowers the function of the original gene.
Even cooler, when Franck Polleux at Scripps expressed that SRGAP2C in mice, it made their neurons look a lot more human! So perhaps when this imperfect duplicate popped up in our genome, it changed the way our neurons developed (as shown in the picture above). If those changes were significant enough, they could have helped our larger and more advanced Homo brains evolve beyond our simpler ancestors! It’s too early to make that claim just yet, but it’s a very cool idea.
This also means that because our neurons develop in a way that is so different from mice, we should reconsider whether they are a good model for disorders like autism. We may be looking at a brain that’s just too different from our own at its core.
For more, Ed Yong has some good coverage of this on his blog.
♥XNA: The Synthetic Super-Cousin of DNA That Can Replicate and Store Information
The DNA double helix that we’re all familiar with is a molecular ladder made of three key parts. The backbone of phosphates that tie everything together up and down, the sugar rings (“deoxyribose”) that serve as rungs, and the bases (A, C, G, T) that invisibly bond the two strands of the helix together, head to toe.
But that helix can be broken or mutated in nature, leading to mutations. And out of all the compounds in the world that could have evolved to carry our information, why just DNA and its cousin RNA? To answer that question, Vitor Pinheiro’s team created a completely new set of information molecules called XNA.
XNA replaces the deoxyribose sugar ring with other chemical rings like threose and cyclohexane. By evolving an enzyme that could read these funny bases, they were able to read DNA into XNA as well as the reverse. Plus it’s super-strong and resistant to breaking or cleaving.
Molecules like XNA could expand the information code for synthetic biology as well as help us answer the ultimate question about DNA: Why that, and not something else? Ed Yong has more great detail here.
♥I am a big fan of the minimalist black and white images that have been coming back from NASA’s Cassini Orbiter, but I think the ultraviolet-light images are pretty cool too.
Make that two fans! Awesome stuff. More views through the UV lens coming later today, coincidentally.
♥The Secret of the Ooze: Two Years After the Spill
Al Jazeera has a frightening, damning, and infuriating report on the ongoing damage to the Gulf of Mexico ecosystems since the Deepwater Horizon oil spill. It’s been nearly two years since the Macondo well was ruptured, spilling almost 5 million barrels of oil and requiring almost 2 million barrels of dispersants to clean it up.
Fishermen are reporting shrimp catches full of eyeless shrimp, as well as fish and shellfish with oozing sores and black gills. The damage doesn’t seem limited to oil, either. Manganese-heavy drilling mud and dispersant lefotvers are showing up at even higher rates than petroleum.
Head over to Al Jazeera to read the full article. The Gulf has not recovered, and it will likely take most of a lifetime to do so. It’s important that scientists continue to get financial support to monitor the area and that the government keep pressure on BP to do their part. Not just this year, but until the mistake is fixed.
This is one of the most diverse and fruitful ecosystems in America, and we must repair it.
♥24 Hours of the Sun, Stars and Earth in a Single Panoramic Image
A stereographic projection of an entire day stitched together to provide the view of one rotation of the Earth. Wow.
(via Colossal)
![”A man sits down before a gun, which is pointed at his head. This is no ordinary gun; it’s rigged to a machine that measures the spin of a quantum particle. Each time the trigger is pulled, the spin of the quantum particle — or quark — is measured. Depending on the measurement, the gun will either fire, or it won’t. If the quantum particle is measured as spinning in a clockwise motion, the gun will fire. If the quark is spinning counterclockwise, the gun won’t go off. There’ll only be a click.
Nervously, the man takes a breath and pulls the trigger. The gun clicks. He pulls the trigger again. Click. And again: click. The man will continue to pull the trigger again and again with the same result: The gun won’t fire. Although it’s functioning properly and loaded with bullets, no matter how many times he pulls the trigger, the gun will never fire. He’ll continue this process for eternity, becoming immortal.
Go back in time to the beginning of the experiment. The man pulls the trigger for the very first time, and the quark is now measured as spinning clockwise. The gun fires. The man is dead.
But, wait. The man already pulled the trigger the first time — and an infinite amount of times following that — and we already know the gun didn’t fire. How can the man be dead? The man is unaware, but he’s both alive and dead. Each time he pulls the trigger, the universe is split in two. It will continue to split, again and again, each time the trigger is pulled [source: Tegmark].
This thought experiment is called quantum suicide. It was first posed by then-Princeton University theorist Max Tegmark in 1997 (now on faculty at MIT). A thought experiment is an experiment that takes place only in the mind. The quantum level is the smallest level of matter we’ve detected so far in the universe. Matter at this level is infinitesimal, and it’s virtually impossible for scientists to research it in a practical manner using traditional methods of scientific inquiry.”](http://25.media.tumblr.com/tumblr_m2hdj7qQ5S1qiq0h3o1_400.gif)
”A man sits down before a gun, which is pointed at his head. This is no ordinary gun; it’s rigged to a machine that measures the spin of a quantum particle. Each time the trigger is pulled, the spin of the quantum particle — or quark — is measured. Depending on the measurement, the gun will either fire, or it won’t. If the quantum particle is measured as spinning in a clockwise motion, the gun will fire. If the quark is spinning counterclockwise, the gun won’t go off. There’ll only be a click.
Nervously, the man takes a breath and pulls the trigger. The gun clicks. He pulls the trigger again. Click. And again: click. The man will continue to pull the trigger again and again with the same result: The gun won’t fire. Although it’s functioning properly and loaded with bullets, no matter how many times he pulls the trigger, the gun will never fire. He’ll continue this process for eternity, becoming immortal.
Go back in time to the beginning of the experiment. The man pulls the trigger for the very first time, and the quark is now measured as spinning clockwise. The gun fires. The man is dead.
But, wait. The man already pulled the trigger the first time — and an infinite amount of times following that — and we already know the gun didn’t fire. How can the man be dead? The man is unaware, but he’s both alive and dead. Each time he pulls the trigger, the universe is split in two. It will continue to split, again and again, each time the trigger is pulled [source: Tegmark].
This thought experiment is called quantum suicide. It was first posed by then-Princeton University theorist Max Tegmark in 1997 (now on faculty at MIT). A thought experiment is an experiment that takes place only in the mind. The quantum level is the smallest level of matter we’ve detected so far in the universe. Matter at this level is infinitesimal, and it’s virtually impossible for scientists to research it in a practical manner using traditional methods of scientific inquiry.”
♥
♥Despite millions of years of isolation, cave bacteria resist modern antibiotics
Antibiotic resistance is not a new problem. Almroth Wright and Alexander Fleming predicted penicillin resistance almost as soon as it was discovered. But we like to think that the modern scourge of dangerously resistant bacteria is a problem of not enough drug options, and misuse of the ones we have.
Turns out that nature’s way ahead of us. A team exploring Carlsbad’s Lechuguilla Cave, a 122-mile expanse of acidic pools and metallic outcroppings, isolated 93 bacteria that had evolved in the cave over millions of years. These bacteria, a handful of what likely lives in the cave, have never met our antibiotic drugs.
Yet they turned out to be resistant to nearly all of them, and some in ways we’ve never seen before. Why?
Antibiotics like penicillin, or tetracycline, or even daptomycin (one of our toughest weapons) come from natural sources. They were used by microbes to kill each other long before we stole their chemicals for our own use. So it’s no surprise that millions of years of evolution has created pathways of resistance to these weapons.
Dig into soil, rock or other bacterial habitats, and you’ll be looking at a war that’s been waged for millions of years, with weapons we have yet to describe. And nature has built up defenses of equal strength.
From enzymes that eat plastic or chew up cellulose to make ethanol to pathways that digest even our toughest antibiotics, microbial biology is a vast ocean of exotic chemistry. It’s time for a change of attitude for fighting bugs. No matter how powerful the chemical we take from nature, chances are that she’s already figured out a way to kill it with fire. It’s time to assume that all antibiotics are already beaten, and use them accordingly.
Want some advice? Wash your hands. Soap still works, at least until we explore the next cave.
