“Virgin Birth” Record Broken by Hotel Shark
A wild zebra shark swims off Thailand (file picture). Photograph by Rodger Klein, Getty ImagesCharles Choi
Published January 6, 2012
She may be confined to a desert hotel, and far from any males, but a zebra shark named Zebedee is record-breakingly fertile.
The female shark, which lives in a restaurant aquarium in Dubai‘s Burj Al Arab, has experienced four straight years of “virgin births”—a feat never before documented among sharks, according to marine biologist David Robinson.
(Related: “Shark ‘Virgin Birth’ Confirmed.”)
Experts at the resort—billed as the world’s most luxurious—had seen Zebedee lay eggs before, but had assumed they held no offspring, because she is never in the presence of any male zebra sharks. Hotel staff first discovered she was reproducing asexually in 2007.
“We were actually moving the eggs, and one of the guys felt something move inside the egg, and we checked the eggs with light, and there were babies inside,” Robinson, assistant aquarium operations manager at the Burj Al Arab, told the BBC.
“We went looking for it, but I don’t think we were ever expecting to find it,” he said. “So we’re just awestruck.”
(See a picture of the Burj Al Arab surrounded by lightning.)
Virgin Birth Not So Rare in Sharks?
Zebedee is reproducing parthenogenetically, meaning that embryos are developing from eggs unfertilized by male sperm. Although her offspring are genetically very similar to her, they aren’t identical clones, since her DNA is recombined during the reproductive process.
Virgin births are known among many invertebrates and a variety of vertebrates, including hammerhead, blacktip, and bamboo sharks. (See “Hammerhead Shark Gave Virgin Birth in Omaha Zoo.”)
“Everyone’s looking for it in sharks now, and I think it’s always there to be found,” said marine biologist Demian Chapman of Stony Brook University in New York State.
“Since a very wide range of sharks can do it, I think it’s reasonable to speculate that all sharks can do this.”
(Related: “Virgin Birth Expected at Christmas—By Komodo Dragon.”)
Story Continues -> “Virgin Birth” Record Broken by Hotel Shark
“Tectonic Shifts” in Employment
By David Talbot
A job to do: Much as the Luddites feared mechanical looms 200 years ago, today’s middle-class workers have reason to worry that information technology erodes their employment prospects. Credit: Mary Evans Picture Library/Alamy
Information technology is reducing the need for certain jobs faster than new ones are being created.
The United States faces a protracted unemployment crisis: 6.3 million fewer Americans have jobs than was true at the end of 2007. And yet the country’s economic output is higher today than it was before the financial crisis. Where did the jobs go? Several factors, including outsourcing, help explain the state of the labor market, but fast-advancing, IT-driven automation might be playing the biggest role.
Since the beginning of the Industrial Revolution, people have feared that new technologies would permanently erode employment. Over and over again, these dislocations of labor have been temporary: technologies that made some jobs obsolete eventually led to new kinds of work, raising productivity and prosperity with no overall negative effect on employment.
There’s nothing to suggest that this dynamic no longer operates, but new research is showing that advances in workplace automation are being deployed at a faster pace than ever, making it more difficult for workers to adapt and wreaking havoc on the middle class: the clerks, accountants, and production-line workers whose tasks can increasingly be mastered by software and robots. “Do I think we will have permanently high unemployment as a consequence of technology? No,” says Peter Diamond, the MIT economist who won a 2010 Nobel Prize for his work on market imperfections, including those that affect employment. “What’s different now is that the nature of jobs going away has changed. Communication and computer abilities mean that the type of jobs affected have moved up the income distribution.”
Erik Brynjolfsson and Andrew McAfee study information-supercharged workplaces and the innovations and productivity advances they continually create. Now they have turned their sights to how these IT-driven improvements affect employment. In their new book, Brynjolfsson, director of the Center for Digital Business at MIT’s Sloan School of Management, and McAfee, its principal research scientist, see a paradox in the first decade of the 2000s. Even before the economic downturn caused U.S. unemployment to rise from 4.4 percent in May 2007 to 10.1 percent in October 2009, a disturbing trend was visible. From 2000 to 2007, GDP and productivity rose faster than they had in any decade since the 1960s, but employment growth was comparatively tepid.
Brynjolfsson and McAfee posit that more work was being done by, or with help from, machines. For example, Amazon.com reduced the need for retail staffers; computerized kiosks in hotels and airports replaced clerks; voice-recognition and speech systems replaced customer support staff and operators; and businesses of all kinds took advantage of tools such as enterprise resource planning software. “A classically trained economist would say: ‘This just means there’s a big adjustment taking place until we find the new equilibrium—the new stuff for people to do,’ ” says McAfee.
We’ve certainly made such adjustments before. But whereas agricultural advances played out over a century and electrification and factory automation rolled out over decades, the power of some information technologies is essentially doubling every two years or so as a consequence of Moore’s Law. It took some time for IT to fully replace the paper-driven workflows in cubicles, management suites, and retail stores. (In the 1980s and early 1990s productivity grew slowly, and then it took off after 1996; some economists explained that IT was finally being used effectively.) But now, Brynjolfsson and McAfee argue, the efficiencies and automation opportunities made possible by IT are advancing too fast for the labor market to keep up.
More evidence that technology has reduced the number of good jobs can be found in a working paper by David Autor, an economist at MIT, and David Dorn, an economist at the Center for Monetary and Financial Studies in Madrid. They too point to the crucial years of 2000–2005. Job growth happened mainly at the ends of the spectrum: in lower-paying positions, in areas such as personal care, cleaning services, and security, and in higher-end professional positions for technicians, managers, and the like. For laborers, administrative assistants, production workers, and sales representatives, the job market didn’t grow as fast—or even shrank. Subsequent research showed that things got worse after 2007. During the recession, nearly all the nation’s job losses were in those middle categories—the positions easiest to replace, fully or in part, by technology.
Brynjolfsson says the trends are “troubling.” And they are global; some of the jobs that IT threatens, for example, are at electronics factories in China and transcription services in India. “This is not about replacing all work, but rather about tectonic shifts that have left millions much worse off and others much better off,” he says. While he doesn’t believe the problem is permanent, that’s of little solace to the millions out of work now, and they may not be paid at their old rates even when they do find new jobs. “Over the longer term, they will develop new skills, or entrepreneurs will figure out ways of making use of their skills, or wages will drop, or all three of those things will happen,” he says. “But in the short run, your old set of skills that created a lot of value are not useful anymore.”
This means there’s a risk, unless the economy generates new high-quality jobs, that the people in the middle will face the prospect of menial jobs—whose wages will actually decline as more people compete for them. “Theory says the labor market will ‘clear.’ There are always things for people to do,” Autor says. “But it doesn’t say at what price.” And even as it gets crowded and potentially even less rewarding at the bottom, employees at the top are getting paid more, thanks to the multiplier effects of technology. Some 60 percent of the income growth in the United States between 2002 and 2007 went to the top 1 percent of Americans—the bulk of whom are executives whose companies are getting richer by using IT to become more efficient, Brynjolfsson and McAfee point out.
Story continues -> “Tectonic Shifts” in Employment
New Bandage Spurs, Guides Blood Vessel Growth
After the stamp is removed its pattern is revealed in the pattern of blood vessels below. (Credit: Photo courtesy Micro and Nanotechnology Lab)
Researchers have developed a bandage that stimulates and directs blood vessel growth on the surface of a wound. The bandage, called a “microvascular stamp,” contains living cells that deliver growth factors to damaged tissues in a defined pattern. After a week, the pattern of the stamp “is written in blood vessels,” the researchers report.
A paper describing the new approach will appear as the January 2012 cover article of the journal Advanced Materials.
“Any kind of tissue you want to rebuild, including bone, muscle or skin, is highly vascularized,” said University of Illinois chemical and biomolecular engineering professor Hyunjoon Kong, a co-principal investigator on the study with electrical and computer engineering professor Rashid Bashir. “But one of the big challenges in recreating vascular networks is how we can control the growth and spacing of new blood vessels.”
“The ability to pattern functional blood vessels at this scale in living tissue has not been demonstrated before,” Bashir said. “We can now write features in blood vessels.”
Other laboratories have embedded growth factors in materials applied to wounds in an effort to direct blood vessel growth. The new approach is the first to incorporate live cells in a stamp. These cells release growth factors in a more sustained, targeted manner than other methods, Kong said.
The stamp is nearly 1 centimeter across and is built of layers of a hydrogel made of polyethylene glycol (an FDA-approved polymer used in laxatives and pharmaceuticals) and methacrylic alginate (an edible, Jell-O-like material).
The stamp is porous, allowing small molecules to leak through, and contains channels of various sizes to direct the flow of larger molecules, such as growth factors.
Story Continues -> New Bandage Spurs, Guides Blood Vessel Growth
How 3-D Photovoltaics Could Revolutionize Solar Power
Story from MIT’s Technology Review website
Replacing flat panels with three dimensional structures can significantly change the economics of solar power generation, say engineers
The Sun sends some 87 Petawatts of power our way and converting some small fraction of this into usable power is one of the key battlefronts in the fight to free the world from its addiction to oil.
One way to do this conversion is to turn light into electricity using flat photovoltaic panels. This form of power generation is rapidly expanding all over the world.
But it suffers from various problems that prevent its more widespread adoption, particularly at higher latitudes where the amount of energy that can be converted varies dramatically throughout the day and by season too.
This variation can be mitigated by solar tracking mounts but these are expensive and potential points of failure.
Today, Marco Bernardi and pals at the Massachusetts Institute of Technology in Cambridge say there is a simple fix that could dramatically increase the performance of photovoltaics. Instead of two dimensional flat panels, Bernadi and co suggest using three dimensional structures.
They’ve simulated the performance of various shapes and tested several of these on the roof of a building at MIT. Their results indicate that 3D structures can increase the amount of energy that can be generated by a given footprint by as much as 20 times. These structures can also double the number of useful peak hours of generation and reduce seasonal variation to boot.
There are two effects at work. The 3D structure can pick up light when the Sun is at lower angles and internal reflections within the structure help increase the amount of captured light.
These structures needn’t be complex. A simple cube, open at the top and covered inside and out with photovoltaic cells, can generate as much 3.8 times the power of a flat panel with the same footprint. By comparison, a solar tracking mount produces an increases of only up to 1.8 times.
The ultimate test for this idea is in the economics, of course. A cube has a much higher surface area than a flat panel and is more expensive to produce in the first place. But Bernadi and co say the extra power it generates more than compensates up for this.
If the numbers work out as these guys say, 3D structures could significantly change the photovoltaics market. Bernadi and co suggest their 3D structures could be shipped as flat packages that easily “pop up” into 3D structures when assembled.
And there may be significant improvements to be had in future too. They say the inspiration for this work is “the three-dimensionality of sunlight collecting structures found in Nature.” Presumably, they mean trees and plants.
These are far from the box-like shapes studied so far. Instead, nature seems to rely on fractal structures for solar energy capture. Just how much better these shapes are needs to be established. Copying these shapes will also be difficult with today’s methods of manufacture so advances will be needed in this area too.
But clearly, there’s plenty of potential for further work here. .
Ref: arxiv.org/abs/1112.3266: Solar Energy Generation in Three-Dimensions
Discovery of a ‘Dark State’ Could Mean a Brighter Future for Solar Energy
The efficiency of conventional solar cells could be significantly increased, according to new research. (Credit: © Elenathewise / Fotolia)
The efficiency of conventional solar cells could be significantly increased, according to new research on the mechanisms of solar energy conversion led by chemist Xiaoyang Zhu at The University of Texas at Austin.
Zhu and his team have discovered that it’s possible to double the number of electrons harvested from one photon of sunlight using an organic plastic semiconductor material.
“Plastic semiconductor solar cell production has great advantages, one of which is low cost,” said Zhu, a professor of chemistry. “Combined with the vast capabilities for molecular design and synthesis, our discovery opens the door to an exciting new approach for solar energy conversion, leading to much higher efficiencies.”
Zhu and his team published their groundbreaking discovery Dec. 16 in Science.
The maximum theoretical efficiency of the silicon solar cell in use today is approximately 31 percent, because much of the sun’s energy hitting the cell is too high to be turned into usable electricity. That energy, in the form of “hot electrons,” is instead lost as heat. Capturing hot electrons could potentially increase the efficiency of solar-to-electric power conversion to as high as 66 percent.
Zhu and his team previously demonstrated that those hot electrons could be captured using semiconductor nanocrystals. They published that research in Science in 2010, but Zhu says the actual implementation of a viable technology based on that research is very challenging.
“For one thing,” said Zhu, “that 66 percent efficiency can only be achieved when highly focused sunlight is used, not just the raw sunlight that typically hits a solar panel. This creates problems when considering engineering a new material or device.”
To circumvent that problem, Zhu and his team have found an alternative. They discovered that a photon produces a dark quantum “shadow state” from which two electrons can then be efficiently captured to generate more energy in the semiconductor pentacene.
Zhu said that exploiting that mechanism could increase solar cell efficiency to 44 percent without the need for focusing a solar beam, which would encourage more widespread use of solar technology.
The research team was spearheaded by Wai-lun Chan, a postdoctoral fellow in Zhu’s group, with the help of postdoctoral fellows Manuel Ligges, Askat Jailaubekov, Loren Kaake and Luis Miaja-Avila. The research was supported by the National Science Foundation and the Department of Energy.
Story Continues -> Discovery of a ‘Dark State’ Could Mean a Brighter Future for Solar Energy
Tiny solar cell dots printed for powerful array
Scientist Keith Emery checks out at a prototype Semprius solar concentrator at NREL’s testing lab. Inside each square is a solar cell sized the diameter of a dot made by a ball point pen. (Credit: Dennis Schroeder/NREL)
A technique first developed to print flexible electronics has helped engineers at start-up Semprius reinvent the shape of concentrating solar technology.
The company’s tiny solar cells, each a dot the size of a ballpoint pen tip, have been validated to convert 41 percent of solar energy to electricity, the National Renewable Energy Laboratory announced yesterday. Semprius is in the process of building a manufacturing facility in Henderson, N.C., to make concentrating solar arrays using its “micro-transfer printing” technique, according to the Department of Energy.
The semiconductor printing technique can be used for many applications, including improving LED lighting performance, better hard drives, or sensors for medical device.
But Durham, N.C.-based Semprius has first chosen to build a concentrating photovoltaic (CPV) collector that uses lenses to concentrate light 1,000 times onto its tiny solar cells. By having smaller cells, the company hopes to bring down the cost of concentrating solar power, which works in areas with lots of direct sunlight, such as the southwest U.S.
To build an array of “micro cells,” Semprius grows a tiny semiconductor on a substrate and then a machine transfers those cells to a wafer. Additional layers are automatically added to the wafer so that a very efficient, triple-junction solar cell is constructed.
By essentially stamping micro cells onto a wafer, the technique allows for thousands of cells to be printed at once. It can also work with different semiconductor materials, including gallium arsenide and silicon, according to the company.
“This approach uses micro-cells and transfer printing to significantly reduce the use of materials in highly concentrated PV modules. And it provides a highly parallel method to manufacture the module, based on established microelectronics processes and equipment,” Kanchan Ghosal, CPV applications engineering manager at NREL, said in a statement.
Story Continues -> Tiny solar cell dots printed for powerful array
Independent, skeptic-funded study confirms Global Warming is real
The Berkeley Earth Surface Temperature study has just released a summary of a recently completed global land warming analysis showing “reliable evidence of a rise in average world land temperature by approximately one degree Celsius since the mid-1950s.” Yeah, we’ve heard that before, but this is one study that even skeptics may have to believe.
Here’s why the Berkeley Earth Project is different from all previous studies on global warming:
- It’s independent. No government sponsored or directed the Berkeley Earth Project, so none of the researchers involved had to deal with the same kind of political pressure as previous studies.
- It’s non-profit, supported by donations. The private sector is almost entirely responsible for funding the Berkeley Earth Project, and the largest single donation ($150,000) came from the Charles G. Koch Charitable Foundation, noted multi-million dollar supporter of climate change skepticism.
- It’s open source. Got a problem with the results? The entire data set along with the programs used to analyze said data set are all online, ready for anyone to explore.
- It uses more data than any other study. The Berkeley Earth Project’s temperature database consists of records from 39,000 temperature stations around the world, amounting to 1.6 billion individual measurements. This is about five times the amount of data used in most previous climate change studies.
- It directly addresses the concerns that skeptics raised about previous studies. This includes the potential effect of urban heat islands, the quality of temperature monitoring stations, and selection bias risk.
Let’s just assume, for a moment, that the Berkeley Earth Surface Temperature study is legit. What exactly did they find? Well, in a nutshell, global warming is definitely real. Since the mid-1950s, average global land temperatures have risen by nearly two degrees Fahrenheit. For what it’s worth, this agrees very closely with previous global warming studies that were dismissed by skeptics for one reason or another. The Berkeley study also found that pretty much everything that climate change skeptics used to discredit previous studies ultimately made no statistically significant differences to the overall result.
So at this point, what’s obviously going to happen is that global warming skeptics and deniers will get together and say, “okay, you’ve convinced us, we’re sorry for all that merciless slandering and we should get together and talk about what climate change means for the future of our planet.” Right?
Yeah, probably not. What’s probably going to happen is that deniers will continue to deny the science without much of a foundation just because they can, or they’ll shift the topic from whether global warming exists to whether humans are causing it. What it really comes down to, though, is that the Earth’s climate is changing, and those changes are starting to have a direct impact on our lives. That impact is only going to increase, and whatever the cause is, if there are things we can do to help keep this planet stable, it just seems like a no-brainer to try our best to make that happen.
Berkeley Earth, via Discover
Independent, skeptic-funded study confirms Global Warming is real
Ultra HDTV technical standards agreed on, more pixels is a good thing
By Mat Smith
The high-definition pride of your living room may not want to hear it, but it looks like ultra high-definition TV (or UHDTV) has now taken another step towards reality. While shop-floor products remain years away, experts in the ITU Study Group on Broadcasting Service have made several agreements on technical standards for your (next?) next TV purchase. Increasing pixel count in future sets is also expected to improve viewing angles on glasses-free 3D, which needs more dots to work its lenticular magic. 33 megapixels sounds like it should be enough to work with.
Ultra HDTV technical standards agreed on, more pixels is a good thing
New ‘Diamond?’ New Form of Superhard Carbon Is as Strong as a Diamond
Carbon is the fourth-most-abundant element in the universe and takes on a wide variety of forms, called allotropes, including diamond and graphite. Scientists have now discovered a new form of carbon, which is capable of withstanding extreme pressure stresses that were previously observed only in diamond. (Credit: © adimas / Fotolia)
Carbon is the fourth-most-abundant element in the universe and takes on a wide variety of forms, called allotropes, including diamond and graphite. Scientists at Carnegie’s Geophysical Laboratory are part of a team that has discovered a new form of carbon, which is capable of withstanding extreme pressure stresses that were previously observed only in diamond.
his breakthrough discovery will be published in Physical Review Letters.
The team was led by Stanford’s Wendy L. Mao and her graduate student Yu Lin and includes Carnegie’s Ho-kwang (Dave) Mao, Li Zhang, Paul Chow, Yuming Xiao, Maria Baldini, and Jinfu Shu. The experiment started with a form of carbon called glassy carbon, which was first synthesized in the 1950s, and was found to combine desirable properties of glasses and ceramics with those of graphite. The team created the new carbon allotrope by compressing glassy carbon to above 400,000 times normal atmospheric pressure.
This new carbon form was capable of withstanding 1.3 million times normal atmospheric pressure in one direction while confined under a pressure of 600,000 times atmospheric levels in other directions. No substance other than diamond has been observed to withstand this type of pressure stress, indicating that the new carbon allotrope must indeed be very strong.
However, unlike diamond and other crystalline forms of carbon, the structure of this new material is not organized in repeating atomic units. It is an amorphous material, meaning that its structure lacks the long-range order of crystals. This amorphous, superhard carbon allotrope would have a potential advantage over diamond if its hardness turns out to be isotropic — that is, having hardness that is equally strong in all directions. In contrast, diamond’s hardness is highly dependent upon the direction in which the crystal is oriented.
Story Continues -> New ‘Diamond?’ New Form of Superhard Carbon Is as Strong as a Diamond
MESSENGER’s First (Mercury) Day
From NASA – Astronomy Picture of the Day
Explanation: One solar day on a planet is the length of time from noon to noon. A solar day lasts 24 hours on planet Earth. On Mercury a solar day is about 176 Earth days long. And during its first Mercury solar day in orbit the MESSENGER spacecraft has imaged nearly the entire surface of the innermost planet to generate a global monochrome map at 250 meters per pixel resolution and a 1 kilometer per pixel resolution color map. Examples of the maps, mosaics constructed from thousands of images made under uniform lighting conditions, are shown (monochrome at left), both centered along the planet’s 75 degrees East longitude meridian. The MESSENGER spacecraft’s second Mercury solar day will likely include more high resolution targeted observations of the planet’s surface features. (Editor’s note: Due to Mercury’s 3:2 spin-orbit resonance, a Mercury solar day is 2 Mercury years long.)
Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Phillip Newman Specific rights apply.
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