Scientific American - Chemistry

Bombs bursting in air: What's in those 4th of July fireworks, anyway?

Fri, 03 Jul 2009 12:00:00 EST

Red, white and blue aside, how green will this weekend’s firework festivities be? Not very, argue some. [More]

How Fructose Impairs the Memory

Fri, 03 Jul 2009 09:00:00 EST

Americans consume more fructose than ever before, yet concerns remain that the sugar, used to sweeten beverages and processed foods, poses health risks. In animals, fructose-rich diets increase the production of fat and promote resistance to the energy-regulating hormone insulin. New research suggests that memory suffers as well, at least in rats.

Neuroscientist Marise B. Parent of Georgia State University and her colleagues fed 11 adolescent rats a diet in which fructose supplied 60 percent of the calories. For 10 other rats, cornstarch took the place of the sweetener. The scientists trained the rats to find a submerged platform in a pool, with the help of surrounding cues.

[More]

Pump Your Brain--And Other Stories from MIND

Wed, 01 Jul 2009 09:00:00 EST

Cognitive-enhancement drugs have been in the headlines a great deal lately--they stoke your gray matter, enabling greater focus and attention for longer periods of time, users say. But their long-term effects are uncertain and unknown, on both brain and body. In the meantime, there’s something you can do that helps both areas but that doesn’t have any known mental health risks. As study after study has shown, simple physical activity not only builds your physique and cardiovascular health: it also helps to sharpen the wetware in your skull and thwarts mental decline as you advance in years. Check out our feature story, “Fit Body, Fit Mind?” by psychologist Christopher Hertzog and his colleagues. You’ll be glad you did.

A different kind of brain performance question is explored in “Do ADHD Drugs Take a Toll on the Brain?” Of course, drugs that treat attention-deficit hyperactivity disorder have provided enormous benefits for many thousands of patients, and nobody should make any decisions about their suitability without consulting a professional. But the article, by Edmund S. Higgins, discusses evidence that raises concerns about the long-term consequences of such medications. Understanding about the related brain mechanisms will grow with further research, and we expect that such medicines ultimately could be improved in the future. Naturally, Scientific American Mind applauds all such efforts to provide better mental health for everyone.

[More]

Changing ocean chemistry might jam fish ears

Thu, 25 Jun 2009 14:01:00 EST

Just when you thought you’d heard it all about the effects of greenhouse gases, researchers have found that higher atmospheric carbon dioxide levels could lead to changes in fish anatomy involved in navigation. [More]

Presented By:

Review your Credits Reports Once a Year

Under FCRA laws, you are allowed to request your credit reports from Equifax, Experian and TransUnion once every 12 months. It is good practice to
check your credit reports and credit score every 3-6 months. Also, checking your credit reports before a a big purchase helps you spot potential dangers.

Additional Resources:
Proactive identity theft protection with Lifelock
Monitor your credit score to track improvement and spot identity theft red flags

Ads by Pheedo

Cutting Cow Flatulence with Garlic?

Tue, 23 Jun 2009 00:00:00 EST

Methane gas released as flatulence from livestock is a significant source of greenhouse gas, but entrepreneurs may have found a ready antidote to the problem: garlic. Mootral (“moo” and “neutral”), produced by Neem Biotech in Cardiff, Wales, contains a natural garlic extract--allicin--that when fed to cows and sheep limits the growth of certain methane-producing bacteria in the animals’ digestive systems. In two small trials, methane output in cows and sheep was reduced by 15 percent. David Williams, chair and CEO, expects further research will allow output to be cut in half; simulations using laboratory equipment have reached as high as 94 percent.

Tests are also being done to determine the best way to feed the natural antibiotic to the animals--as a food supplement or in their drinking water--and whether or not the allicin might taint their milk. But Williams is optimistic that the product will be available for livestock within two years.

[More]

Why Aren't More Women Tenured Science Professors?

Fri, 19 Jun 2009 17:55:00 EST

Women who apply for tenure-track positions at top-tier research universities in math and sciences these days have a slightly better chance of landing the job than their male colleagues, says a new study funded by the National Science Foundation. [More]

Energy Secretary: We Need New Ag Revolution

Thu, 18 Jun 2009 09:24:08 EST

[The following is an exact transcript of this podcast.]

Here’s a clip from last week’s CalTech commencement address by Secretary of Energy and physics Nobel Laureate Steven Chu:

[More]

Second hydrogen leak shuts down NASA's Endeavour launch until July

Wed, 17 Jun 2009 11:49:00 EST

Another hydrogen leak will keep the space shuttle Endeavour's crew on the ground for another month while NASA investigates the problem. The space agency scrubbed today's scheduled launch early this morning when a gaseous hydrogen leak was detected at the same location where a similar leak halted the shuttle's original June 13 launch. [More]

LHC rapper returns to drop knowledge about rare isotopes

Fri, 12 Jun 2009 13:09:00 EST

Kate McAlpine, the rapper who garnered much notice (including from this site) and millions of YouTube views for her track about the Large Hadron Collider (LHC), is back with a new track on a new subject: rare isotopes. [More]

Being Green: 11 Environmentally Friendly Habits

Thu, 11 Jun 2009 00:00:00 EST

The Tissue Issue“Ultra” brands of toilet paper such as Charmin, Cottonelle and Quilted Northern may feel soft on your bum, but they’re hard on the environment because they’re made from virgin fiber and bleached with chlorine. Virgin fiber typically comes from trees grown for pulp production or from sawmill leftovers after trees are cut into lumber. The alternative: brands made from 100 percent recycled fiber, preferably with at least 80 percent postconsumer content. You can download a wallet-size buyer’s guide from Greenpeace (www.greenpeace.org/usa/campaigns/forests/tissueguide) or the Natural Resources Defense Council (www.nrdc.org/land/forests/gtissue.asp).

[More]

Helen Wiersma: Fighting Weeds--And Mental Illness

Mon, 08 Jun 2009 11:00:00 EST

Her finalist year: 2000

Her finalist project: Developing a new way to control weeds

[More]

Hudson Plane: Out-of-Town Geese Did It

Mon, 08 Jun 2009 09:55:08 EST

[The following is an exact transcript of this podcast.]

Back on January 15th, US Airways Flight 1549 made that amazing water landing in the Hudson after both engines were taken out by Canada geese, which can weigh eight pounds each. Now scientists have used forensic techniques to clear local geese--the perpetrators were out-of-towners. The study appears June 8th in the journal Frontiers in Ecology and the Environment. [More]

Phosphorus Famine: The Threat to Our Food Supply

Wed, 03 Jun 2009 08:00:00 EST

As complex as the chemistry of life may be, the conditions for the vigorous growth of plants often boil down to three numbers, say, 19-12-5. Those are the percentages of nitrogen, phosphorus and potassium, prominently displayed on every package of fertilizer. In the 20th century the three nutrients enabled agriculture to increase its productivity and the world’s population to grow more than sixfold. But what is their source? We obtain nitrogen from the air, but we must mine phosphorus and potassium. The world has enough potassium to last several centuries. But phosphorus is a different story. Readily available global supplies may start running out by the end of this century. By then our population may have reached a peak that some say is beyond what the planet can sustainably feed.

Moreover, trouble may surface much sooner. As last year’s oil price swings have shown, markets can tighten long before a given resource is anywhere near its end. And reserves of phosphorus are even less evenly distributed than oil’s, raising additional supply concerns. The U.S. is the world’s second-largest producer of phosphorus (after China), at 19 percent of the total, but 65 percent of that amount comes from a single source: pit mines near Tampa, Fla., which may not last more than a few decades. Meanwhile nearly 40 percent of global reserves are controlled by a single country, Morocco, sometimes referred to as the “Saudi Arabia of phosphorus.” Although Morocco is a stable, friendly nation, the imbalance makes phosphorus a geostrategic ticking time bomb.

[More]

Rising stars of the sea: Will global warming benefit starfish?

Tue, 26 May 2009 17:10:00 EST

Increasing temperatures and carbon dioxide levels in the world’s oceans may actually speed the growth of starfish, according to research published this week in the Proceedings of the National Academy of Sciences. The results contrast with previous findings of global warming’s negative effects on the five-armed fish’s relatives. [More]

Carbon capture success in Wisconsin

Wed, 20 May 2009 16:20:00 EST

Capturing the carbon dioxide that wafts up the smokestack after burning coal (or any other fossil fuel) has been identified by everyone from President Obama to the United Nations Intergovernmental Panel on Climate Change as a critical technology to help keep the lights on while combating climate change. And now there has been yet another successful demonstration that the technology to capture that CO2 from flue gas might actually work: chilled ammonia can capture more than 88 percent of the greenhouse gas before it goes up the smokestack. [More]

Dragon's Bite Bloodier Than Believed

Wed, 20 May 2009 06:30:08 EST

[The following is an exact transcript of this podcast.]

The Komodo dragon is the largest living lizard and a fearsome predator. It’s long been thought that some of its hunting prowess was due to a mouth teeming with bacteria. An attack that didn’t immediately kill the dragon’s victim--often a deer, but sometimes a person--would cause fatal bacterial infections. But a report released May 18th by the Proceedings of the National Academy of Sciences finds a more likely cause of death. [More]

Unlikely Suns Reveal Improbable Planets

Wed, 20 May 2009 00:00:00 EST

Among the most poignant sights in the heavens are white dwarfs. Although they have a mass comparable to our sun’s, they are among the dimmest of all stars and becoming ever dimmer; they do not follow the usual pattern relating stellar mass to brightness. Astronomers think white dwarfs must not be stars so much as the corpses of stars. Each white dwarf was once much like our sun and shone with the same brilliance. But then it began to run out of fuel and entered its stormy death throes, swelling to 100 times its previous size and brightening 10,000-fold, before shedding its outer layers and shriveling to a glowing cinder the size of Earth. For the rest of eternity, it will sit inertly, slowly fading to blackness.

As if this story were not gloomy enough, it gets worse. We and our colleagues have found more than a dozen white dwarfs in our galaxy that are orbited by asteroids, comets and perhaps even planets--entire graveyards of worlds. While the stars were still alive, they rose every day in the skies of these worlds. They gently warmed the soil and stirred the wind. Living organisms may have soaked up their rays. But when the stars died, they vaporized or engulfed and incinerated their inner planets, leaving only the bodies that resided in the chilly outposts. Over time the dwarfs shredded and consumed many of the survivors as well. These decimated systems offer a grim look at the fate of our own solar system when the sun dies five billion years from now.

[More]

Komodo dragon kills with venom, not bacteria

Mon, 18 May 2009 17:15:00 EST

Komodo dragons (Varanus komodoensis) can't chomp as hard as crocodiles and aren't as massive as grizzly bears, so how do they kill huge deer and even humans? [More]

Slo-Mo Flow: Modeling Combustion to Pump Up Engine Efficiency

Mon, 18 May 2009 12:15:00 EST

Despite decades of fine-tuning, the average internal combustion engine still converts only about 20 percent of its fuel into power and spews a variety of emissions harmful to people and the environment. [More]

Scientific American 10: Guiding Science for Humanity

Mon, 18 May 2009 08:00:00 EST

The ethical and policy ramifications of deploying science and technology in the service of society hold the same importance as the act of invention itself. Getting antiretroviral treatments to HIV/AIDS patients in sub-Saharan Africa. Ensuring that the world’s largest chip manufacturer takes every possible step to reduce the company’s environmental footprint. Lending the currency of one’s celebrity (as well as cold, hard cash) to a global campaign to abolish smoking.

Leadership in these realms requires vision and imagination that transcends mere engineering ingenuity. This year’s Scientific American 10 pays tribute to the exceptional foresight and accomplishment of a select group whose achievements, particularly during the past year, stand out from those of their peers. The 10 winners have demonstrated that establishing a public health program or running a green business requires more than administrative efficiency and good public relations. Bringing creativity to bear in overcoming institutional and bureaucratic impediments to adoption of not just new technology but innovative procedural methods is crucial for improving health care and the environment.

[More]