Archive for July, 2010

Genetically Identical E. Coli Cells Show a Lot of Individuality

By Joseph Calamia | July 30, 2010 2:49 pm

250px-EscherichiaColi_NIAIDOne might think that identical-twin bacteria—clones of each other—would grow up and live very similarly. But a study published today in Science that examined individual bacterial cells in detail found that genetically identical E. Coli cells actually seem to express their genes quite differently, simply because of the random accidents of how their molecular machinery happens to operate.

“The paper is quite rich,” said Sanjay Tyagi, a molecular biologist at New Jersey Medical School who was not involved in the research [but published a perspectives piece on it]. “People think that if an organism has a particular genotype, it determines its phenotype [observable characteristics]–that there’s a one-to-one relationship,” said Tyagi. “But as it turns out, [differences in gene expression] can arise just from chance.” [The Scientist]

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CATEGORIZED UNDER: Health & Medicine, Living World

Found: Jupiter-sized Brown Dwarf, Hiding in a Tight Orbit Around a Young Sun

By Joseph Calamia | July 30, 2010 12:07 pm

comparisonsizeImagine an infantile version of our 4.6 billion-year-old sun. Now picture a “failed star,” a brown dwarf, about the size of Jupiter, tightly orbiting that 12 million year old stellar baby–at the distance Uranus orbits our sun. Astronomers have just found such a duo: a  star about the mass of our sun with an unusually close brown dwarf companion.

Of the similarly situated brown dwarfs that astronomers have imaged, most keep their distance, orbiting at about 50 AU (or 50 times the average distance from the Earth to the sun). A team of astronomers believe the distance between this young sun, called PZ Tel A, and its dwarf companion, PZ Tel B, is less than half that, a mere 18 AU.

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CATEGORIZED UNDER: Space

The Enemy Within: Deadly Viruses Show Up in Genomes of Humans & Other Animals

By Andrew Moseman | July 30, 2010 10:55 am

EbolavirusIn a medical sense, you’d be wise to steer clear of filoviruses, a group that includes the deadly Ebola, and bornaviruses, which cause neurological diseases. But in a genetic sense, it may not be possible to avoid them. A new study in PLoS pathogens shows that bits and pieces of these viruses have been floating around in the human genome, as well as those of other mammals and vertebrates, for millions of years.

It’s not that having genetic material left behind by viruses is odd—previous research had shown that viruses account for 8 percent of the human genome. But scientists thought most of that material came from retroviruses, which use their host’s DNA to replicate and leave some of their genetic material behind. What’s weird about this is that filoviruses and bornaviruses are not retroviruses—they’re RNA viruses, which don’t use the host to reproduce in the same way.

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CATEGORIZED UNDER: Health & Medicine, Living World

Researchers in Greenland Drill 8,000' Down to Study 120,000-Year-Old Climate

By Joseph Calamia | July 29, 2010 4:59 pm

bedrockResearchers camped on the Greenland ice sheet hit bedrock this week after almost three years of drilling, reaching a depth of 8,000 feet. They hope that the ice they’ve uncovered from some 120,000 years ago, might give them a better understanding of what a warmer future might look like, if Greenland has less ice and the sea level rises.

The team, which is part of the North Greenland Eemian Ice Drilling (NEEM) project, is looking to learn more about carbon dioxide levels during the Eemian period, when global temperatures were over 2-3 degrees Celsius warmer and sea level was about 15 feet higher. They believe these conditions might mirror effects caused by the earth’s changing climate during the next century.

Scientists believe that by the end of the 21st century the planet will experience similar conditions again. Over the Greenland ice sheet, temperatures at the height of the Eemian may have been around 5 degrees Celsius warmer–mirroring the Arctic amplification of modern climate change. . . There are large uncertainties concerning the response of ice sheets to warming air and ocean temperatures. Understanding what happened to the Greenland ice sheet during the Eemian could help constrain projections of future sea level rise. [Nature]

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CATEGORIZED UNDER: Environment

Solar Probes Facing Death Sentences May Get Second Lives as Moon Probes

By Joseph Calamia | July 29, 2010 10:48 am

153236main_THEMIS_medThey went to investigate solar wind-stirred storms in our planet’s magnetic field, but, after working for three years, two NASA solar-powered probes faced a dark demise, trapped in the Earth’s shadow. NASA researchers now think they can give the twin satellites another shot by altering their courses and sending them instead to study the moon.

NASA launched the probes in 2007 as a set of five identical satellites in the THEMIS Mission (Time History of Events and Macroscale Interactions during Substorms), meant to orbit Earth and send information during brief (2-3 hour) “substorms” when the magnetic field surrounding the Earth releases stored energy from solar winds. To understand the start of these “space tornadoes” responsible for the northern and southern lights, NASA placed the probes in very precise orbits, but for two craft that meant, one day, they would face prolonged battery-draining time in the Earth’s shadow.

“When we realized that the satellites would be going into very deep shadows, we started thinking of different methods for saving them–even before they were launched,” lead scientist Vassilis Angelopoulos, at the University of California, Berkeley, told Discovery News. “We realized that if we had enough fuel to change their orbits, the moon’s gravity would start pulling them up.”[Discovery News]

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CATEGORIZED UNDER: Space

That Killer Asteroid You Heard About Yesterday? We Knew About It Last Year

By Andrew Moseman | July 29, 2010 10:05 am

AsteroidsBeware death from above! So blared science headlines yesterday. Citing a study in the Journal Icarus that said a huge asteroid perhaps could have a 1 in 1,000 shot of striking earth late in the next century, stories broke such as,

Will a Giant Asteroid Kill Us All in 2182?

Asteroid Could Destroy Human Life on Earth by 2200

Huge asteroid on possible collision course with Earth (172 years from now)

Mark your calendars: Potentially hazardous asteroid might collide with Earth in 2182

They’re correct in that there’s a giant asteroid out there called 1999 RQ36, and there’s a small chance it might hit us in a just less than couple hundred years. There’s just one problem: It isn’t news, though you wouldn’t have gotten that from the articles. The study everyone is referring to came out last year—it was in Icarus last October.

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CATEGORIZED UNDER: Space
MORE ABOUT: asteroids, astronomy

New Glucose Monitor Keeps Tabs on Diabetics From Inside

By Joseph Calamia | July 28, 2010 5:03 pm

monitorA new device may one day save those with diabetes from the frequent finger-pricking and cumbersome external monitors required to check glucose levels–by instead keeping tabs from inside their torsos. In a study published online today in Science Translational Medicine, researchers report that an implantable glucose sensor has worked in pigs. Ultimately, clinical trials and FDA approval will determine if the device holds any promise for humans, but researchers say this animal test is an important first step.

“You can run the device for a year or more with it constantly working, and recording glucose quite satisfactorily. Now, we are focused on getting the human clinical trials going. We hope to begin the first human trial within in a few months,” said [lead author, David Gough.] “If all goes well with the human clinical trials, we anticipate that in several years, this device could be purchased under prescription from a physician,” said Gough.[University of California – San Diego]

As Popular Science reports, the device is “just a bit smaller than a Double-Stuf Oreo”–around 1.5 inches wide and half an inch thick. Gough and colleagues implanted the device in two pigs: one for 222 and and another for 520 days. It works by monitoring oxygen consumed in a chemical reaction with the enzyme glucose oxidase–the amount of oxygen consumed is proportional to the amount of glucose in the user’s blood. Though some already use similar sensors, none have lasted this long.

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CATEGORIZED UNDER: Health & Medicine, Technology

NOAA's Conclusive Report: 2000s Were Hottest Decade on Record

By Andrew Moseman | July 28, 2010 4:49 pm

Global_warmingThe 2000s, the “aughts”—whatever you want to call the first decade of the 21st century, you can also call it the warmest 10 years on record. The National Oceanic and Atmospheric Administration just released its annual “State of the Climate” report, and after sampling 37 climate indicators including the biggies like sea surface temperature, glacier cover, and sea level, they came to that conclusion.

The NOAA report—published in the Bulletin of the American Meteorological Society—is different from other climate publications, because it’s based on observed data, not computer models, making it the “climate system’s annual scorecard,” the authors wrote… “It’s telling us what’s going on in the real world, rather than the imaginary world,” said Kevin Trenberth, a senior scientist at the Boulder, Colorado-based National Center for Atmospheric Research [National Geographic].

While one climate group trumpets its mountain of climate data, the scientists at the University of East Anglia are just climbing out from the scandal that broke out over theirs. This month another investigation cleared the Climate Research Unit of scientific misconduct or dishonesty, without condoning the emails’ tone or the unit’s handling of the controversy.

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CATEGORIZED UNDER: Environment

Study Finds BPA in Store Receipts; Health Effects as Yet Unclear

By Joseph Calamia | July 28, 2010 1:46 pm

receiptWhen you hear mention of BPA, or bisphenol-A, plastic bottles and food containers likely come to mind. Now, a report presented by activists at the Environmental Working Group says the chemical is also in some paper store receipts.

In the study, which has not been peer reviewed, the environmental group looked for BPA in 36 sales receipts. They found that about forty percent used thermal paper (which has a chemical coating that changes colors when heated) that contained 0.8 to nearly 3 percent pure BPA by weight, 250 to 1,000 times greater than the amount of BPA typically found in a can of food or a can of baby formula. Other research, their report says, shows that BPA can transfer from receipts to a person’s skin, but how much BPA transfers or if it penetrates into the bloodstream remains uncertain. A chemical-industry trade group says the amount transferred is low:

“Available data suggests that BPA is not readily absorbed through the skin,” a spokeswoman from [The American Chemistry Council] said. “Biomonitoring data from the U.S. Centers for Disease Control shows that exposure to BPA from all sources, which would include typical exposure from receipts, is extremely low.”[Washington Post]

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CATEGORIZED UNDER: Health & Medicine

Toshiba's Ultra-Long-Lasting Battery May Be in Cars as Early as Next Year

By Andrew Moseman | July 28, 2010 11:43 am

SCiBIs this battery the one? Toshiba’s Super-Charge Ion Batteries, which reportedly lose hardly any capacity after thousands of charges, could be coming to cars next year.

As Slashdot noted today, this battery technology has been a long time coming. In 2007 Toshiba announced the creation of the SCiB, and unveiled the prototype the next year. It lasts 5,000 to 6,000 cycles as opposed to the 500 for standard lithium-ion batteries, and charges to 90 percent of capacity within five minutes. Earlier this month, the company announced it has been working with car maker Mitsubishi on electric vehicle batteries, and could be making SCiBs for cars staring next year.

For EV applications Toshiba has developed a new anode material and a new electrolyte to improve safety and rapid recharging. According to Toshiba, the long life will promote reduction in the waste that results from battery replacement, reducing the impact on the environment [Gizmag].

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CATEGORIZED UNDER: Technology
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