|Although not as easily delivered as weaponized anthrax, ricin in purified form can be just as deadly
By Erin Brodwin
Earlier this week, the U.S. Post Office intercepted letters addressed to Sen. Roger Wicker (R–Miss.) and Pres. Barack Obama that contained a mysterious white powder. The substance turned out to be ricin, a deadly toxin that can kill within days. But just how dangerous were these attacks?
Since the Obama administration was first warned about the dangers of new ricin attacks in 2010, it has requested periodic updates on the white, powdery substance—from where it is being produced to the places it’s being shipped. In 2011 U.S. counterterrorism officials received word that al Qaeda’s affiliate in Yemen was making efforts to get large amounts of castor beans, the plant source from which the toxin is produced. That same year four American men—Frederick Thomas, Dan Roberts, Ray Adams and Samuel Crump—were arrested for plotting to poison hundreds with ricin as well as blow up government buildings.
Is High-Tech Security at Public Events Counterproductive?
|High-security measures of public events like the Boston Marathon may not be feasible--and they could make things worse
By David Biello
Which is more intrusive: security screening and metal detectors every few blocks, or a drone flying high above it taking video of every little thing you do?
"The best thing would have been a dog," explains Joseph King, professor of terrorism and organized crime at John Jay College of Criminal Justice and former chief of counterterrorism for U.S. Customs and Border Protection. "They don't need to be at a choke point; they can move through the crowd."
In the wake of the tragedy at the Boston Marathon on April 15 security experts are pondering the use of bomb-sniffing dogs and other tools of the security trade during public events, at the risk of making those events as much fun as catching a flight. Ultimately, the costs of such extra measures—both in terms of money and loss of privacy—would have to be weighed against their actual ability to prevent tragedies.
New Solar-Cell Coating Could Enable a Major Boost in Efficiency
|Massachusetts Institute of Technology
Apr. 18, 2013 — Throughout decades of research on solar cells, one formula has been considered an absolute limit to the efficiency of such devices in converting sunlight into electricity: Called the Shockley-Queisser efficiency limit, it posits that the ultimate conversion efficiency can never exceed 34 percent for a single optimized semiconductor junction.
Now, researchers at MIT have shown that there is a way to blow past that limit as easily as today's jet fighters zoom through the sound barrier -- which was also once seen as an ultimate limit.
Their work appears this week in a report in the journal Science, co-authored by graduate students including Daniel Congreve, Nicholas Thompson, Eric Hontz and Shane Yost, alumna Jiye Lee '12, and professors Marc Baldo and Troy Van Voorhis.
The principle behind the barrier-busting technique has been known theoretically since the 1960s, says Baldo, a professor of electrical engineering at MIT. But it was a somewhat obscure idea that nobody had succeeded in putting into practice. The MIT team was able, for the first time, to perform a successful "proof of principle" of the idea, which is known as singlet exciton fission. (An exciton is the excited state of a molecule after absorbing energy from a photon.)
Boston bombings: How facial recognition can cut investigation time to seconds
|Videos taken at the crime scene could hold important clues. But it's a different kind of fast-forward investigators can now use to review all the footage. CNET's Kara Tsuboi goes face-to-face with facial recognition and surveillance.
by Mariel Myers
After the Boston Marathon bombings, police in the city made a plea for people with cell phone video and pictures to turn over their footage, adding to the hours of surveillance video from nearby businesses. But what would normally take investigators hundreds of hours to review can now take minutes or even seconds, thanks to technology like facial recognition. The software, which can help pick a person out of crowd, looks for differentiating features -- from the shape of a mouth to the ridge on a nose to the distance between a pair of eyes.
3VR in San Francisco has developed software that extracts information from video and then makes it searchable for its clients, which include retailers, banks, security firms, and law enforcement.
The video stream can come from surveillance cameras and smartphones. "We will identify each person and extract the facial biometrics of each person in the field of view, and we'll save a snapshot of that person," explains 3VR CEO Al Shipp.
Europe’s Carbon Market Crisis: Why Does it Matter?
|The European Union's eight-year-old Emissions Trading System (ETS), the world's largest cap-and-trade carbon market, is broken.
Thomas K. Grose in London
The European Parliament this week voted 334-315 (with 60 abstentions) against a controversial "back-loading" plan that aimed to boost the flagging price of carbon, which since 2008 has fallen from about 31 euros per tonne to about 4 euros (about $5.20). Since the vote, the price has fallen even farther, to 2.80 euros. The collapsing market is hardly the kind of firm foundation needed for building a clean-energy economy.
"Now, the market is dead, as far as I can see," said Steffen Böhm, director of the Essex Sustainability Institute at Britain's Essex Business School.
What will be the aftermath of the ETS collapse? Here's a quick primer on what happened, and what it could mean elsewhere, particularly in California, which inaugurated a new carbon market at the start of this year. (Related: "California Tackles Climate Change, But Will Others Follow?")
Q: First of all, what's a carbon market?
A: The U.S. introduced the concept of using market forces to rein in greenhouse gas emissions during the talks that lead to the 1997 Kyoto Protocol, an international agreement to combat climate change. Ironically, Europe wasn't initially keen on the idea. But after it failed to enact an EU-wide carbon tax, Europe ultimately launched the ETS in 2005.
Healing the Ozone Layer: Chemist Says Treaty Is Working
|The Montreal Protocol, enacted in 1987, put controls on use of aerosol CFCs.
“The Montreal Protocol is working,” says chemist Mario Molina, who shared the Nobel Prize for his work on the effects of chlorofluoro-carbons (CFCs). “CFCs are a global environmental problem that is being solved by society.”
The international treaty, which opened for signature in 1987, created controls on the use of CFCs, gases used as coolants in refrigerators and to propel aerosols like hair spray out of cans. The problem was that CFCs spread out in the stratosphere, where they led to a hole in the ozone layer.
When Molina started studying CFCs in the 1970s and discovered their role in ozone depletion, each U.S. household averaged 30 to 40 spray cans. Since the late ’90s, CFC production has all but stopped, making modern spray cans ozone safe.
The ozone layer itself? Though scientists say it will take until beyond 2050 to return to pre-1980s levels of CFCs—they take about a hundred years to decompose—the amounts in the atmosphere are steadily decreasing. (See chart below.)
Disputed signs of consciousness seen in babies’ brains
|Infants display neural responses linked to visual awareness by 5 months of age
By Bruce Bower
Babies’ brains emit electrical bursts that signal a budding awareness of the visual world by the time they are 5 months old, a new study concludes. But some researchers are skeptical that these neural surges correspond to conscious experience.
From age 5 months to 15 months, the brain begins to develop the ability to register and remember sights, according to the research by cognitive neuroscientist Sid Kouider of École Normale SupÉrieure in Paris and his colleagues. The researchers showed babies images that included faces flashed increasingly slowly on a screen. They started at a speed so fast that even adults wouldn’t consciously notice the images, and then the researchers increased the amount of time each image appeared. Infants displayed a sequence of rapid brain responses that first signaled unconscious and then conscious perception of faces, Kouider’s team reports April 18 in Science.
“We weren’t expecting to see any evidence of a neural marker for consciousness in 5-month-olds,” Kouider says. Babies at that age exhibited a weak, delayed version of a brain response that occurs when adults report seeing a face flashed just long enough to be consciously perceived, Kouider asserts.
Epidemiological Endgame: Is Polio on the Brink of Eradication?
|All it will take is raising $5.5 billion (that’s the easy part) and a whole lot of people working together
By Christine Gorman
Despite the pointless political assassinations of vaccine workers or the police officers who guard them in a few deeply troubled areas, enough progress has been made against polio in the past year that health experts are now planning for the grand finale—its complete eradication by 2018. The official to-do list of what needs to be done and when to obliterate the crippling childhood disease—which goes by the name Polio Eradication and Endgame Strategic Plan 2013–2018 (pdf)—will be formally presented at an international health meeting in Abu Dhabi on April 25.
"2012 was a very important year for the polio program,” says Hamid Jafari, who directs the World Health Organization’s Global Polio Eradication Initiative. Speaking by telephone in April to group of journalists gathered in New York City to learn about the proposed plan, Jafari said, “We had the fewest number of cases in the fewest countries in the fewest number of districts.”
Most Earthlike planets yet seen bring Kepler closer to its holy grail
|Compared with our world, globes are slightly larger and orbit a smaller star
By Andrew Grant
They’re not quite Earth’s twins, but they might be its big sisters. Two planets slightly larger than Earth have been found by NASA’s Kepler space telescope. The planets circle their star at a distance seemingly just right for life. Detailed in research published April 18 in Science, the two planets are likely the first of many that, at least from a distance, look a whole lot like home.
“It’s just the tip of the iceberg,” says Sara Seager, an astronomer at MIT who was not part of the study. “When one type of object is found, there are many more just under the surface waiting to be discovered.”
Kepler’s latest discovery is a five-planet system around a star called Kepler 62, some 1,200 light-years away in the constellation Lyra. Astronomers found the planets by analyzing nearly three years’ worth of data. The inner three worlds are too hot for life, but planets Kepler-62e and Kepler-62f are far more accommodating. They are 1.6 and 1.4 times the diameter of Earth, respectively, and their orbits are within the boundaries of the habitable zone in which scientists think liquid water could exist.
Distant Blazar Is a High-Energy Astrophysics Puzzle
|University of California - Santa Cruz
Apr. 18, 2013 — Blazars are the brightest of active galactic nuclei, and many emit very high-energy gamma rays. New observations of the blazar known as PKS 1424+240 show that it is the most distant known source of very high-energy gamma rays, but its emission spectrum now appears highly unusual in light of the new data.
A team led by physicists at the University of California, Santa Cruz, used data from the Hubble Space Telescope to set a lower limit for the blazar's redshift (z ≥ 0.6035), which corresponds to a distance of at least 7.4 billion light-years. Over such a great distance, a substantial proportion of the gamma rays should be absorbed by the extragalactic background light, but calculations that account for the expected absorption yield an unexpected emission spectrum for the blazar.
"We're seeing an extraordinarily bright source which does not display the characteristic emission expected from a very high-energy blazar," said Amy Furniss, a graduate student at the Santa Cruz Institute for Particle Physics (SCIPP) at UCSC and first author of a paper describing the new findings. The paper has been accepted for publication in Astrophysical Journal Letters.
Survival of the Funniest: Celebrating Bad Evolutionary Theory
|Michael Dhar, LiveScience Contributor
A beautiful scientific hypothesis can reduce the chaos of the world to a few, simple principles. Of course, it also helps if that explanation is true. A different kind of science festival on April 20, however, will celebrate exquisitely argued evolutionary hypotheses — that just happen to be hopelessly, terribly wrong.
The first-ever BAH! (Festival of Bad Ad Hoc Hypotheses) will treat an audience at MIT to seven lectures on internally coherent, even convincing — but ultimately hilariously absurd — explanations of evolutionary adaptation.
The event was inspired by a joke in the science-obsessed Web comic "Saturday Morning Breakfast Cereal" (SMBC), which is co-sponsoring the festival, along with the comic's publisher Breadpig (also behind the science-geek comic XKCD), and the MIT Lecture Series. In the comic, a scientist imagines a prehistoric advantage to punting newborns into neighboring villages.
The ridiculous argument, made in absolute sincerity by the illustrated scientist, posits that infants are hairless to minimize drag, "football-shaped" to maximize puntability, and filled with soft bones to cushion the impact. Airmailing infants would have allowed early humans to spread their genes, the scientist argues to great applause, earning her a trophy of "Darwin looking doubtful."