Science!: Murderous Robots and Pea Aphids


Amazing Pea Aphids Make Their Own Colors

The minuscule pea aphids are able to synthesize carotenoids, a feat once only achievable by vegetables. Carotenoids are the pigmentation you find in plants – the deep red of tomatoes and the bright orange of carrots.

Before the pea aphid, no animal was known to carry the necessary enzymes to produce their own carotenoids. Animals typically get carotenoids from ingestion, and the organic molecules are important in aiding eyesight, enhancing the immune system and harnessing free radicals. The most obvious use of carotenoids is in colorful ornamentation: Carotenoids are responsible for the pink of flamingos, the reds of clownfish and the oranges of puffin beaks.

Previously, scientists believed that pea aphids also ingested carotenoids in order to grow into a variety of colors, from green to red. However, the plants they eat do not contain the correct carotenoids to produce their specific coloration and the endosymbiotic bacteria within their digestive tract don’t produce it either. So, where does it come from?

Recently, the entire pea aphid genome was decoded and geneticist Nancy Moran, from the University of Arizona, decided to sit down and took a look at it. She found the genes responsible for carotenoid synthesis in plants also present in the genome of the pea aphid. The aphids picked up these carrot-colored genes from fungi, but it’s not sure exactly how.

“The DNA from a fungus went into the aphid somehow,” says Moran, “and then stayed there and continued to function. Animals have a lot of requirements that reflect ancestral gene loss. This is why we require so many amino acids and vitamins in the diet. Until now it has been thought that there is simply no way to regain these lost capabilities. But this case in aphids shows that it is indeed possible to acquire the capacity to make needed compounds.”

I don’t think we humans will be turning colors anytime soon, but it’s neat to think that we just may have the genes necessary to do so lurking somewhere in our genome.

Thanks Formica Archonis

Source: Byte Size Bio


What Are We Dumping Onto the Gulf Oil Spill?

On April 20th, an oil drilling rig exploded in the Gulf of Mexico, claiming the lives of 11 workers and causing 1,000 barrels of crude oil a day to seep into the ocean. Although some have claimed the spill is “natural,” most agree that it’s likely to be the most significant oil-related natural disaster that we’ve ever seen.

BP is working on several different methods of cleaning the oil spill, including spraying mass amounts of a dispersant called Corexit. This chemical binds to oil droplets, causing them to separate, sink, to eventually be washed away on the current. It’s not making the oil “disappear,” it’s just diluting it. Unfortunately, the chemical BP is using may be just as harmful to the environment as the crude oil is. In fact, The New York Times calls it the “largest and most aggressive experiment with chemical dispersants in the history of the country, and perhaps the world.”

Since the spill occurred, about 160,000 gallons of Corexit have been pumped onto the surface of the water, and an additional 6,000 gallons directly at the source of the spill. That is a whole bunch of dispersant – and it won’t remain in the Gulf for long. Currents will spread the stuff much further than it was originally sprayed, causing possible long-term, far-spread ramifications that we haven’t even began to consider.

It’s always a gamble: We have to clean up the oil spill before it drastically affects coastlines and wildlife, but the means we use to do so may cause even farther-reaching side effects.

Perhaps the most startling aspect of the story is that there are cleaner, safer alternatives to Corexit. Though the chemical passed its offshore safety tests, there are some concerning details posted in its Material Safety Data Sheet: “Eye and skin irritant. Repeated or excessive exposure … may cause injury to red blood cells, kidney or the liver. Harmful by inhalation, in contact with skin and if swallowed.” Of course, these are the results of exposure to a concentrated amount, and the risk to the environment in diluted form is billed as moderate to low. However, in Britain, this chemical did not pass on-shore tests, and there’s the rub. Further out to sea, using this chemical wouldn’t be (as much) of an issue. But with the spill so close to shore, and being carried ever closer, the effects to coastline environments may be severe. Use of the chemical damaged the limpet population in Britain, but what could it do to the Reddish Egret or Brown Pelican population that make their homes on the the Gulf shoreline?

Some of the ingredients of Corexit are listed as proprietary and the details about these ingredients are not shown. Without a complete list of the chemicals involved in the soup, it’s hard to determine what sort of effects they will have on the environment. Even more peculiar, reports that there are safer and more effective alternatives that BP could have used:

“Both Corexit and Dispersit were tested by the EPA, and according to those results, Corexit was 54.7 percent effective at breaking down crude oil from the Gulf, and Dispersit was 100 percent effective. Not only did Corexit do a worse job of dispersing oil, but it was three times as lethal to silverfish – used as a benchmark organism in toxicity testing – and more than twice as lethal to shrimp, another benchmark organism and an important part of Gulf fisheries.”

The reasoning for using Corexit instead of other, less toxic alternatives is likely an issue of name-brands: Corexit is the go-to dispersant for most oil spills, and stockpiles of it likely make it more accessible than its alternatives. There’s been a push to market Dispersit as the next “big thing” when it comes to dispersants, but it’s been a hard sell. Just like we’re more likely to purchase name brands instead of generic, Corexit is the dispersant that everyone knows – Dispersit is not. The lack of open field testing of the product doesn’t help the case, either, though lab results show that it’s twice as effective at breaking up oil than Corexit.

The type of dispersant used depends heavily on temperature, salinity and what state the oil is in. Fresh oil is more viscous than weathered oil (present within a few days of an oil spill), which tends to form a mass on the surface of the water. Different types of dispersants are more effective on different types of oil. A study performed by researchers at the National Marine Fisheries Service in Juneau, Alaska, shows that several versions of Corexit are ineffective at dispersing weathered oil, but effective against fresh oil.

Similarly, determining the effect of Corexit on wildlife depends on a host of factors such as exposure conditions, species and life stage. Another study from Exxon showed that crustaceans are more sensitive to concentrations of Corexit 9500 and 9580 than fish. The situation is not black and white: making a choice on dispersant also comes with a choice of which species will be most affected. One thing is clear: If we do nothing, all of them will be harmed.

Source: Discover Magazine


Murderous Robots Practice Stabbing Techniques on Humans

Beware, those of you who seek to get between a robot and its rocks. Last year in Stockholm, a worker trying to repair a defective rock-lifting machine found himself in a struggle that broke four limbs and nearly cost him his life.

Though it was an isolated case, a few German scientists aren’t taking any chances. A group of researchers programmed a robotic arm, teaching it to stab, strike and slice using a variety of weapons: steak knife, kitchen knife, scissors and a screwdriver. When testing the robot on dead pig flesh, the researchers determined its aim to be true, strong and completely lethal.

No, the intent wasn’t to construct a lean, mean killing robotic arm. Researchers were trying to determine how best to avoid a future robotic uprising. After installing a prototype safety system, human volunteers were asked to subject their tender flesh to the slices and dices of the robot. A torque sensor will notice when the arm hits a different substance (say, your fleshy thumb) and immediately freeze, allowing you to retreat with your digits intact.

There’s even a video!

Source: Popular Science



Hand-Washing Wipes Away Doubts, Damned Spots

After a big decision, do you still find yourself wondering if you made the right choice? Instead of dwelling over the possibilities, head to the bathroom and wash your hands for a few minutes. You’ll feel much better.

Oh, and shouting “Out, damn’d spot!” while soaping up helps, too.

A study conducted by psychologists Spike W.S. Lee (wonder if he’s ever done studies on jungle fever – ha!) and Norbert Schwarz shows that washing your hands after making a decision – any decision, be it large or small – may also wash away any lingering doubts.

“It’s not just that washing your hands contributes to moral cleanliness as well as physical cleanliness,” explains Lee. “Our studies show that washing also reduces the influence of past behaviors and decisions that have no moral implications whatsoever.”

30 undergraduate students were asked to look through 30 CD covers and then choose 10 they’d like to own, ranked by preference. Later, they were offered a choice between the their 5th and 6th ranked CDs as a thanks for taking part in the survey. 15 of the students were then asked to complete another survey about liquid soap. Half just looked at the soap bottle, while the other half took it for a field test and washed their hands. Afterwards, everyone was asked to re-rank their list of CDs.

The half that just took a gander at the soap bottle re-ranked their chosen CD higher on the list than before. Those that washed their hands kept their CD choices at about the same rankings as before.

“As in hundreds of other earlier studies, once they had made a choice, they saw the chosen CD as much more attractive than before and rejected CD much less attractive,” states Schwarz. “Once participants had washed their hands, they no longer needed to justify their choice when they ranked the CDs the second time around.”

I wonder if hand-washing eliminates regret over eating an entire large pepperoni pizza by yourself, too. Not that I, you know, do that.

Source: Science Daily


Lauren Admire wants to live in the Seed Cathedral.

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