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Archive for the ‘Chemistry’ Category

Obsession

Conservation biologists often obsess over counting animals in the wild.

“How many [insert animal name] are in [insert habitat name] this month? How do those population figures compare to last year at this time?”

If you think such questions are exciting, head to your nearest research university to start your Ph.D. in conservation biology. For the rest of us, take a few moments to appreciate how difficult it is to answer those questions. Counting animals? For the 2010 Census alone, the United States government has hired over 400,000 people to help count the total number of Americans, at a cost of over $11 billion. Even the most optimistic of scientific grants for counting another animal species wouldn’t cover a fraction of that budget.

Thus, to count their targets, conservationists have to get creative. A popular method for larger animals involves setting up motion-triggered cameras in the wild: an animal comes close to the camera, sensors record that motion and activate the camera, and the camera records a few seconds of footage for scientists to view later. Over time, the camera can record multiple images of animals passing by the camera, and scientists can extrapolate the total number of animals from a particular species based on the number of appearances of that species in the camera footage. They have to take other measures into account as well (the distance between cameras, what is known about the roaming or migratory patterns of the species in question, etc.), but this passive method sure beats hiring 400,000 Americans to count the number of jaguars in Guatemala.
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National Public Radio has a fantastic set of stories out this morning about the growing controversy surrounding Corexit, the chemical BP is using to disperse oil pouring form the uncapped well of the sunken Deepwater Horizon rig. In short, BP has been pouring Corexit into the Gulf of Mexico to the tune of tens of thousands of gallons each day to help disperse the thick oil. However, we simply do not know the consequences of long-term Corexit toxicity to ocean life — everything from the fish we eat to the microbes which form the basis of ocean ecosystems.

The concern isn’t that Corexit itself will kill all ocean life. Instead, the real fear is that Corexit will act as an endocrine disruptor on marine life. Endocrine disruptors are compounds that mimic biological hormones. They get into the body, chemically masquerade as hormones, and disrupt the body’s natural signaling processes. Hormones govern everything from metabolism to sexual development — so, endocrine disruptors in the environment have the potential to devastate whole ecosystems, even in small doses. Plus, endocrine disruptors can settle into the environment and persist for decades, as we’re seeing with the many endocrine disruptors leaching out from today’s plastic compounds.  We’re not sure what the effects of these endocrine disruptors will be for tomorrow’s world.

Thus, in trying to lessen the impact form one environmental catastrophe, BP may be unleashing another. Only time and research will tell.

Both of these stories from NPR delve into further details. The second link is an audio file to a terrific interview with Jon Hamilton, one of NPR’s science correspondents.

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Scientists from the Maryland and California-based J. Craig Venter Institute announced today that they successfully created a partially synthetic lifeform. <a href="Their efforts appear in the journal Science, and include a detailed description of the steps they took to create life.

The lifeform in question is a single-celled bacterium called Mycoplasma mycoides. A bacterial cell, like all living organisms, stores “instructions” or “blueprints” for making and maintaining itself in the form of DNA (deoxyribonucleic acid). DNA is the genome of an organism — it is a long strand of chemicals stored within living cells. In single-celled organisms like bacteria, each cell is an individual, and each cell contains a copy of the genome. The instructions for making and maintaining the cell are “read” from the genome by the cell. Thus, the complex chemicals and molecules that cells make to do work, maintain integrity, survive, and reproduce are all made using these DNA-based “instructions.” When a cell divides, DNA is copied, so that each daughter cell has a complete copy of the genome.

A colony of Mycoplasma mycoides cells.

I harp so much on DNA because much of the work done by the J. Craig Venter Institute centers on the Mycoplasma mycoides genome. Scientists had already “read” the full chemical sequence of the DNA strand (also known as the complete genome sequence) from Mycoplasma mycoides. Researchers at the Venter Institute set out to use that known Mycoplasma mycoides genome sequence to create their own Mycoplasma mycoides cell from scratch.
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The Deepwater Horizon oil rig exploded and sank some twenty days ago. Since then, oil has been gushing from the uncapped well to the tune of at least 5,000 barrels per day, though some estimate the daily hemorrhage to be at a rate of about 25,000 barrels. As the flow of oil continues, and the massive spill assaults the U.S. coast of the Gulf of Mexico, some are starting to ask why we have chosen to invest plenty time and resources into new drilling technologies, but practically no resources into new oil spill clean-up techniques.

It’s true: we will be using a lot of older and more cumbersome means to clean up the beaches, ocean, and wildlife for quite some time. However, some groups are using this environmental catastrophe to promote new “green” approaches to cleaning up our black gold problems. One group, Matter of Trust, has been promoting a new variation on an old approach: oil booms and oil-soaking mats made from hair.

Their approach is slowly making its way through the press, and I hope this movement continues to gain momentum. It’s ingenious: hair naturally clings to oils from the environment (which is why unwashed hair gets so oily). It’s practical: salons, sheep farms, and pet grooming businesses accumulate pounds and pounds of trimmed hair and fur daily, which is usually thrown out unceremoniously. It’s simple: businesses which accumulate hair and fur trimmings simply need to sweep up the bounty and ship it to Matter of Trust. They manufacture oil-clinging mats and booms (also made from used nylons, of course) to use as part of the clean-up effort. Of course, these mats and booms are also useful for the thousands of other oil spills that occur each year. These products could also be used in urban areas to prevent oil from reaching the watershed.

Most important of all: it’s accessible. Very few of us live along the Gulf coast in areas directly affected by the oil spill. Of course, we are all indirectly harmed by the spill, but the effects may take some time to reach us. However, many of us do get our hair trimmed, and do see the floor littered with hair trimmings. The argument advocated by Matter of Trust is simple: put these trimmings to good use and make a real difference in our approach to oil spills!

So, the next time you go for a haircut, mention three simple words to the salon employees: Matter of Trust. Perhaps your salon or pet groomer already participates? It certainly doesn’t hurt to ask.

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I wanted to post this article from yesterday’s New York Times about the synthesis of a new element. But, I feel I can only do this remarkable discovery justice by explaining it in the context of two words form chemistry that are often used, but seldom defined: element and atom.
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