Tani e di!
Tani e di!
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contemplatingmadness:

Ten Things You Probably Didn’t Know About DNA

It may be the basis of all life on Earth, but we’re betting there’s still a lot you don’t know about deoxyribonucleic acid. Who discovered it? What makes it “right-handed”? And what does it have to do with LSD? Find out after the jump.
10. James Watson and Francis Crick did not discover DNANeither did Rosalind Franklin or Maurice Wilkins, for that matter. In actuality, the credit for discovering DNA goes to oneFriedrich Miescher. In 1869, the Swiss biochemist was inspecting the pus on used surgical bandages (yay, science!) when a substance he didn’t recognize passed into his microscope’s field of view. He called the substance “nuclein,” because, he noted, it was located within the nuclei of cells.
9. Good Call, MiescherWhich is funny, because you can actually find a fair bit of DNA in mitochondria, as well. What’s interesting, though, is that out of all your DNA, it’s the stuff in your nuclei that play the most important role from a hereditary standpoint; remarkably, Miescher would later speculate in a letter to his uncle that this mysterious “nuclein” might actually play a role in heredity.
8. It took decades to prove Miescher’s hunch was rightMiescher’s insight was years, if not decades, ahead of its time. By the turn of the 20th century, scientists had begun to strongly suspect that chromosomes — densely packed structures of DNA and protein — were involved in the transmission of traits from one generation to the next, but it wasn’t until researcher Thomas Hunt Morgan showed that molecular differences in chromosomes actually corresponded to heritable physical characteristics in fruit flies that anybody truly appreciated the fundamental role of said chromosomes in the transfer of genetic information.
7. Wait… what genetic information?What’s interesting about the phrase “genetic information” is that even as late as 1933, the year Morgan received a Nobel Prize for his groundbreaking work on chromosomes, many scientists still doubted the existence of so-called “genes” — information, presumably housed within chromosomes, that gave rise to the physical traits Morgan had observed in his experiments. At the time, Morgan wrote that there was no consensus “as to what the genes are — whether they are real or purely fictitious.”
The concept of genes only really found its footing in 1944, when molecular biologistOswald Avery (pictured here) showed thatgenes were not only real, but that they were composed of DNA (and not, for example, proteins, which — also being contained in chromosomes — many scientists had assumed comprised our true “genetic” blueprint).
6. LSD May have played a role in the discovery of DNA’s structureJust nine years after Avery’s discovery, James Watson and Francis Crick published an article inNature describing the double helical structure of DNA — a structure which, according to some accounts, Crick claims to have perceived while high on LSD.
5. Why is it Watson and Crick and not Crick and Watson?Joe Hanson actually posed this excellent question last week on It’s Okay to be Smart:

How did they decide whose name would come first on their paper? That’s where we get the comfortable meter of their paired and classic name pairing from. I mean, did they flip a coin? It was a fairly even collaboration, and I don’t know why their names weren’t on the paper in alphabetical order.
I mean, just think of that. What if it had been Crick & Watson? A huge part of the biological lexicon would be changed:
“Well Steve, you can clearly see the canonical Crick & Watson base-pairing there in the hairpin.”

It turns out they did just flip a coin, though to hear James Watson tell it, it sounds like he felt he deserved to be first author, anyway.
4. DNA is Right-HandedWhen you see DNA depicted as a double helix, you can clearly see that its structure is twisted. That twist makes DNA a “chiral” molecule, meaning it is asymmetric in such a way that a DNA molecule and its mirror image are not superimposable. Examples of chirality are everywhere. Take your hands, for example. For all intents and purposes, your left hand and right hand are mirror images of one another, but no matter how you twist or position either hand, you’ll find that it is impossible to orient the two of them in exactly the same way. Chirality is the reason you can’t shake a person’s right hand with your left, or wear your left shoe on your right foot.
Chiral molecules are said to possess “handedness,” and in DNA, that handedness is characterized by the direction of its twisting strands. DNA’s right-handedness can be identified by a simple trick involving your hands. Take your right hand and, with your thumb pointing upward, imagine grasping the spiral pictured here (in this diagram there is only one helix… in DNA there are two, but this rule still applies). Now imagine your hand twisting around the outside of the spiral, tracing its grooves in the direction that your fingertips are pointing. Your hand should rotate upward along the helix. If you try this trick with your left hand, again grasping the helix with your thumb pointing up, you’ll notice that following the rotation of the helix in the direction your fingertips are pointing will cause your hand to move downward.
That means that if you’re reading an article online or in a magazine and it features a picture of aleft-handed double helix, that picture is wrong, wrong, wrong.
3. Except when it isn’tYes, most DNA is right-handed. The DNA molecule that Watson and Crick described, for example, was right-handed. But DNA can actually exist in a variety of biologically active helical conformations. The one most people are familiar with is called B-DNA (depicted at center in the image shown here). On the far left is another conformation of DNA, (called A-DNA) that is also right-handed, but more tightly wound than B-DNA. On the far right, however, is a left-handed conformation, known (awesomely) as Z-DNA. So before you go on a pedantic rampage about left- and right-handed DNA, make sure you’re not getting all bent out of shape over some Z-DNA (or a plot point in the upcoming Spider-Man movie… watch for the left-handed helices around 1:30).
2. DNA can exist in a variety of bizarre and unfamiliar formsYou want a triple helix? You got it. A transient, four-stranded super-molecule (that just happens to be the lynchpin step in the process of genetic recombination)?Coming right up. How about a smiley face, a map of the Americas, or a nanodrug-carrying box, complete with lock and key? Yeah, we’ve got those, too. For years, DNA has been growing in popularity as a nano-scale building material for applications in everything from medicine to technology. And we’ve only just begun to appreciate what these DNA nanomachines are capable of. [DNA tetrahedron via]
1. We can make synthetic DNAStrands of DNA and RNA are formed by stringing together long chains of molecules called nucleotides. A nucleotide is made up of three chemical components: a phosphate (labeled here in red), a five-carbon sugar group (labeled here in yellow, this can be either a deoxyribose sugar - which gives us the “D” in DNA - or a ribose sugar - hence the “R” in RNA), and one of five standard bases (adenine, guanine, cytosine, thymine or uracil, labeled in blue).
By swapping out artificial molecules in place of any of these chemical components, researchers can actually make synthetic DNA. One of the most commonly created forms of synthetic DNA is XNA, which swaps out the sugar group for any number of artificially produced molecules. Just last month, researchers succeeded in creating a genetic system that allowed this XNA to replicate and evolve. And to top it all off, this “alien” XNA is actually stronger than the real thing.
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contemplatingmadness:

XNA is synthetic DNA that’s stronger than the real thing

New research has brought us closer than ever to synthesizing entirely new forms of life. An international team of researchers has shown that artificial nucleic acids - called “XNAs” - can replicate and evolve, just like DNA and RNA.
We spoke to one of the researchers who made this breakthrough, to find out how it can affect everything from genetic research to the search for alien life.

The researchers, led by Philipp Holliger and Vitor Pinheiro, synthetic biologists at the Medical Research Council Laboratory of Molecular Biology in Cambridge, UK, say their findings have major implications in everything from biotherapeutics, to exobiology, to research into the origins of genetic information itself. This represents a huge breakthrough in the field of synthetic biology.
Read more
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abaldwin360:

Woodrow Wilson, 1922
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christinetheastrophysicist:

UCSD Physicist Uses Math to Beat Traffic Ticket
A physicist at the Univeristy of California San Diego used his knowledge of measuring bodies in motion to show in court why he couldn’t be guilty of a ticket for failing to halt at a stop sign. The argument, a four-page paper delving into the differences between angular and linear motion, got the physicist out of a $400 ticket. 
Read More.
Read his paper titled “The Proof of Innocence.”
christinetheastrophysicist:

UCSD Physicist Uses Math to Beat Traffic Ticket
A physicist at the Univeristy of California San Diego used his knowledge of measuring bodies in motion to show in court why he couldn’t be guilty of a ticket for failing to halt at a stop sign. The argument, a four-page paper delving into the differences between angular and linear motion, got the physicist out of a $400 ticket. 
Read More.
Read his paper titled “The Proof of Innocence.”
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Isomorphismes: in search of Original Ideas
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"Only once in your life, I truly believe, you find someone who can completely turn your world around. You tell them things that you’ve never shared with another soul and they absorb everything you say and actually want to hear more. You share hopes for the future, dreams that will never come true, goals that were never achieved and the many disappointments life has thrown at you. When something wonderful happens, you can’t wait to tell them about it, knowing they will share in your excitement. They are not embarrassed to cry with you when you are hurting or laugh with you when you make a fool of yourself. Never do they hurt your feelings or make you feel like you are not good enough, but rather they build you up and show you the things about yourself that make you special and even beautiful. There is never any pressure, jealousy or competition but only a quiet calmness when they are around. You can be yourself and not worry about what they will think of you because they love you for who you are. The things that seem insignificant to most people such as a note, song or walk become invaluable treasures kept safe in your heart to cherish forever. Memories of your childhood come back and are so clear and vivid it’s like being young again. Colours seem brighter and more brilliant. Laughter seems part of daily life where before it was infrequent or didn’t exist at all. A phone call or two during the day helps to get you through a long day’s work and always brings a smile to your face. In their presence, there’s no need for continuous conversation, but you find you’re quite content in just having them nearby. Things that never interested you before become fascinating because you know they are important to this person who is so special to you. You think of this person on every occasion and in everything you do. Simple things bring them to mind like a pale blue sky, gentle wind or even a storm cloud on the horizon. You open your heart knowing that there’s a chance it may be broken one day and in opening your heart, you experience a love and joy that you never dreamed possible. You find that being vulnerable is the only way to allow your heart to feel true pleasure that’s so real it scares you. You find strength in knowing you have a true friend and possibly a soul mate who will remain loyal to the end. Life seems completely different, exciting and worthwhile. Your only hope and security is in knowing that they are a part of your life."
Bob Marley (via beautemillesimee)
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futurescope:

The Potential of Synthetic Biology in Space

A lot of proposed synthetic biology applications can seem pretty out there, but some are really out there. NASA is currently advertising open postdoctoral positions in synthetic biology, with particular emphasis on food production in space. Engineered organisms have the potential to do lots of things that would be useful for space colonists, from producing food and fuel to treating wastewater. Because organisms replicate themselves, future astronauts would only have to bring some spores and seeds and empty bioreactors, the organisms would do the rest of the work. […]

[via] [Synthetic Biology @ NASA] [photo credit by Matt Mansell]
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scienceside:

Carbon Dating