Friday, August 31, 2007

Print ad sales hit 10-year low

After six straight quarters of accelerating declines, newspaper print advertising sales in the first half of this year fell to the lowest level in a decade, according to statistics released today by the Newspaper Association of America.Print revenues in the first six months of this year totaled $20.3 billion, the lowest since the $19.7 billion in sales recorded in the first half of 1997. Print ad

Monday, August 27, 2007

Under a blood moon rising......!!!

A COSMIC ballet will bathe much of Australia's east coast in an ethereal red glow as the night sky becomes lit up by crimson moonshine.
But forget high-powered telescopes. A dark spot and roof tops will give some of the best views of tonight's Blood Moon eclipse.



At exactly 8.37pm (AEST) the Sun, Earth and Moon will be in total alignment, scattering light as it passes through the Earth's atmosphere and bounces off the moon in hues of bronze and red.




Tens of thousands of amateur astronomers are expected to turn outacross the city to catch a glimpse of the phenomenon.




NSW Astronomical Society astronomer Adrian Saw said that while a telescope or pair of binoculars would enhance the experience, it was not as important as finding a darkened location away from the city's lights.




"It's easily observable but the darker place you can find the better," Mr MOSi said. "There will be better views near the heads around Sydney Harbour or the Blue Mountains - anywhere away from street lamps."




The first stages of the eclipse will begin at 5.53pm but as the moon passes further into Earth's shadow at 6.51pm, it will gradually dim to an unusual golden colour.




When the total eclipse begins at 7.52pm it will become a bronze and reddish hue before turning blood red at its peak at 8.37pm.




"People will see things on the moon they've never seen before," Mr Saw, said.




The lunar kaleidoscope will reverse as the moon leaves Earth's shadow and becomes its bright white self again after 10.30pm.




It will be the first total lunar eclipse to be seen from start to finish in the city's skies since July 2000.




While they are not uncommon, it is rare to see one in its entirety, with the next blood moon not visible until 11.45pm on December 10, 2011.




Sydney, along with New Zealand, is in the perfect zone to view the eclipse - with people in Melbourne and Brisbane having to travel further north or south to find better views.




Stay up late - or get up early - for spectacular lunar eclipse




A lovely total lunar eclipse will be visible throughout the Bay Area and all of California before dawn Tuesday morning as the Earth's shadow darkens the bright full moon, and wherever skies are clear, it will be a time to look upward wide-eyed.




Astronomers say the eclipse should be a beauty, but only people willing to stay up very late or set their alarm clocks for long after midnight will see it.




It will last for a full hour and a half, and during that time, the moon's color could be anything from a dull and dusky red-brown to a reddish or even orange glow, depending on how much dust, pollution and mist is in the atmosphere, according to Andrew Fraknoi, chair of astronomy at Foothill College in Los Altos Hills, who has observed many in his time.




For the wide-awake, a partial eclipse will start at 1:51 a.m. Tuesday and become total starting at 2:52 a.m. By 4:22 a.m., the total phase will be over, but then as the moon begins to emerge from Earth's shadow, another partial phase will begin. The eclipse will end at 5:24 a.m., just as the sky lightens at dawn.




Lunar eclipses take place when the full moon and the sun are opposite each other in space, and the Earth in between them casts its shadow over the bright moon's face. But even when the eclipse is total, some indirect sunlight manages to reach the moon. The earth's atmosphere filters out most of the sun's blue light, leaving only the red frequencies to light the lunar surface.




"Since the moon is always safe to look at and the eclipse only makes the moon darker, there's no danger in watching this eclipse with your eyes or through a telescope," Fraknoi said.




Binoculars would be a neat way to watch the event, he said, because they could make some of the bigger craters stand out as the Earth's shadow begins to pass over the moon during the partial phase.




And watching the partial phase before totality should reveal something that the ancient Greeks discovered more than 2,000 years ago - that the Earth was round. So it wasn't Magellan whose voyage first showed that. It was Aristotle, who died in 322 B.C.




In eclipses of the moon, Aristotle wrote, the outline of the Earth's shadow is always curved, "and since it is the interposition of the earth that makes the eclipse, the form of this line will be caused by the form of the earth's surface, which is therefore spherical."




The lunar eclipse this year should be "really beautiful and like nothing you've ever seen before," said astronomer Ben Burress at the Chabot Space and Science Center high in the Oakland hills. "It's one of the longest lunar eclipses we've had."




The Chabot observatory is planning a big "Once in a Red Moon" all-night viewing party on its deck and in the planetarium with lunar-themed music. It will open at 10 o'clock tonight with hikes for the public and telescopes to see through. If the Bay Area's fog or clouds don't cooperate, the planetarium will show a simulation of the event.




Fred Espenak, an astronomer at NASA's Goddard Space Flight Center in Greenbelt, Md., has calculated the dates and times of past lunar eclipses from 2000 B.C. to the present, and on through to A.D. 3000. In that 5,000-year span, he said, there will have been 3,505 total eclipses of the moon, including 230 during the 21st century, and 4,213 partial eclipses, including 58 in this century.




Eclipses, of course, have long been harbingers of doom or evil in mythology, and lunar eclipses are no exception - mostly involving the moon swallowed up by gods or demons or other creatures.




According to some records, the Maya of Central America, for example, believed that a jaguar ate the moon and could devour people, too, while in ancient China it was a three-legged toad. To the Mongols it was a dragon named Alkha.




In Egypt in the time of the Pharaohs, lunar eclipses were bad omens indeed, because the moon was supposed to be the "ruler of the stars," and some ancient texts describe the entire sky as swallowing the moon during every eclipse.




While it wasn't Columbus who showed the Earth was round, the Great Navigator did use a lunar eclipse to save his crew during his last voyage to America in 1503, according to Bryan Brewer, author of the book "Eclipse."




After Columbus and his crew had been stranded on the island of Jamaica for months, the Indians finally refused to provide them with any food, Brewer said. But Columbus knew that a total eclipse of the moon would occur on Feb. 29, 1504. So on that night Columbus told his Indian neighbors that God was angry with them for not cooperating, and that God would make the moon disappear.




It did, and when the locals saw the eclipse ending, Columbus told them that God had forgiven them and the moon would return in full. It did, and Columbus and his crew ate heartily.












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Sunday, August 26, 2007

Air Taxi Service


Air taxi startup DayJet late last week was in the final stages of proving runs with its small fleet of Eclipse 500 Very Light Jets in preparation for the launch of commercial operations by the end of the month, founder, President and CEO Ed Iacobucci said last week. Completing the proving runs and adding the Eclipse aircraft to DayJet's Part 135 certificate are the final steps remaining for DayJet to begin its "per-seat" air taxi service, Iacobucci told BA in a telephone interview Thursday.
The company had flown more than 25 hours with an FAA inspector on board by last week, he said, adding that the flights "have been going very well." The DayJet Eclipse fleet had accrued 855 flight hours by last week and the first aircraft just underwent a 300-hour check.

Operations could begin on a limited basis later this week if everything goes smoothly, Iacobucci said, but the company is actually targeting the end of the month to begin air taxi revenue flights.
Earlier this year DayJet was shooting for June to begin operations, but that schedule had to be scrapped after the Eclipse 500 experienced pitot heater problems and was limited to flights in visual meteorological conditions (BA, April 16/173). Those problems have since been resolved with a new design for the system. Iacobucci, however, said the pitot problems were only part of the reason for the delay in launch, and added that the additional time has proven useful to DayJet to ensure that all the necessary systems are in place for a smooth transition.
Launch comes just after DayJet secured $140 million in senior debt and financing. "Securing this initial debt facility is a significant milestone for DayJet, as it enables us to continue the uninterrupted growth of the world's first commercial VLJ fleet," Iacobucci said in the announcement of the finance deal. DayJet has taken delivery of nine Eclipses and should add three more this week, he said. DayJet hopes to continue to expand its Eclipse fleet in the upcoming months and have 30 to 40 aircraft by the end of the year -

if everything goes perfectly," he said.
The capital also is helping DayJet increase the number of pilots. DayJet had 30 pilots on staff and is in the process of adding seven more. Those numbers will continue to increase over the next several weeks, he said. The initial crews are comprised of high-time pilots, many of whom have experience with major airlines, while others come from regional airlines, corporate operations or the military. Iacobucci said the company wanted to ensure that the initial cadre of pilots had enough seniority to establish the proper culture for DayJet


Investors Waiting To See
The latest $140 million financing infusion comes on top of the more than $60 million already invested in the company, providing enough funding for the launch. "We're all set right now," Iacobucci said, adding the next round of funding that DayJet might seek would be "growth capital." But that wouldn't come until DayJet has established itself and proven its model over the next several months, he said. Iacobucci was confident that DayJet has attracted sufficient interest among potential investors, but those investors want to observe the company's initial in-service experience. "The next six months will validate whether the projections we made are or are not in synch with reality," he said, but added that he was pleased with early indicators.
DayJet is selling a membership service to potential travelers. Customers must register to fly on the air taxi service. Iacobucci said some 200 companies have subscribed and the number of individual members has grown to about 1,200, nearly double the number of members that DayJet had just a few months ago (BA, April 23/185). DayJet is now concentrating on spooling up its regional sales team to ensure membership is spread out throughout the network rather than concentrated at one location.
DayJet is initially operating permanent "Dayport" bases at five locations in Florida - Gainesville, Lakeland, Boca Raton, Tallahassee and Pensacola. But DayJet envisions expanding those Dayports to more than a dozen, covering four states over the next several months.


FAA in the past year has begun to scrutinize per-seat service - which the agency has termed "fractional charter" - and has narrowly defined what could be considered a Part 135 operation (BA, July 30/41). FAA told a couple of carriers that it viewed their negotiations with a second or third customer as a Part 121 transaction, not Part 135. FAA was primarily concerned that these carriers were guiding second or third customers to an already chartered flight.
Iacobucci said he was "very aware of this problem," calling the issue a complicated one. But he added that DayJet has worked very closely with both FAA and Transportation Department officials to ensure that the company's service is run in accordance with Part 135. The company retained a team of scientists and engineers to develop a sophisticated computer program that will mix and match customers and available aircraft with the customers' travel plans, he said


The service does not lure customers to particular flights, but matches based on customer needs, he said. Under the DayJet model, there is no pre-set flight or fixed schedule. "When DayJet members request flights online, the system 'individually negotiates' a price based on their travel window," Iacobucci said.
The company spent two years and $20 million developing the system, tweaking it as FAA and DOT continued to review the plans, he said. "Instead of saying you have to change the rules for us, we've said we want to embrace your rules," Iacobucci said. "This isn't something that we just whipped together."
Iacobucci acknowledged that DayJet is under a spotlight because the service is a new business model. "There are a lot of people watching us," he said. But that interest also has attracted business, he said, noting that DayJet has no shortage of people who have requested to be aboard the first flight.

A new research centre will focus on using human DNA to construct nanomolecules that can be used in battling disease



The University of Aarhus celebrated the opening of its new Centre for DNA Nanotechnology on Friday as a giant leap into the future of fighting disease using the building blocks of the human body.
Founded through a grant from the Danish National Research Foundation, the CDNA will develop new methods within nanotechnology for better treatment and diagnosis of diseases linked to DNA.
Researchers now work with materials so small that they can be difficult to work with using even the most powerful microscopes and equipment. CDNA researchers will focus specifically on using and developing nanotechnology with the most intricate, high-tech equipment available to manipulate the minute materials and create self-regulating units out of them.
‘We will then be able to produce medicines that only work in the precise areas of a person’s disease,’ Kurt Vesterager Gothelf, chemistry professor at CDNA, told Nyhedsavisen newspaper. ‘For example, we can make an anti-cancer drug that only attacks the cancer cells. It will result in far fewer side effects than traditional chemotherapy.’
These self-regulating molecules will be so specialised and so advanced that they will replace many of the bulky existing regulating devices, such as pacemakers.
In addition, nanotechnology can pave the way for substances which can locate bacteria in food or uncover dangerous substances during airport security checks.
The CDNA research team consists of three scientists from the University of Aarhus and two from the United States. The quality of the team is second to none, according to the university’s assistant dean, Mette Bock.
‘The new research centre and its team put us up in the international elite and give us many exciting development perspectives.’

More News.

DNA acts like a “piston”

Biophysicists have built a DNA nanomolecular device that expands and contracts with the addition of “fuel” DNA. Patrizia Alberti and Jean-Louis Mergny at the Muséum National d’Histoire Naturelle in Paris constructed the piston-like device using a single strand of nucleotides. They believe that it could be used as a structural component in nanomolecular machines (P Alberti and J-L Mergny 2003 Proc. Nat. Acad. Sci. to be published).
DNA is often called the “building block of life”. It consists of two linear strands wound into a double helix with one of four different “bases” attached to every sugar group along the strands. DNA is an attractive component for use in molecular machines because it can recognize specific base sequences. It self-assembles easily and complex molecular structures can be made from simple double helices. In addition, DNA can change its shape, which further expands the number of nanostructures possible.
Alberti and Mergny used an unusual “quadruplex” DNA structure, which contains four strands with twenty-one bases, folded in a special way. The structure is made to unfold by adding a fuel DNA strand, creating a “duplex” structure that resembles the more conventional double helix. To re-fold the duplex, the researchers add an “anti-fuel”, which combines with the fuel to form a waste product. The folding-unfolding cycle takes only a few seconds and fluorescence resonance energy-transfer spectroscopy shows that the expansion and contraction occurs over a distance of 5 to 6 nanometres.
The device oscillates between two well-defined states and can be compared to the movement of a piston in a cylinder, the researchers say. “This new type of extension-contraction movement ties in well with work by other groups who observe rotation and scissor-like opening and closing,” Mergny told PhysicsWeb. “From a nanotechnology point of view, it is possible to finely control the structure by the addition of strands with specific sequences.”
The sequence of bases along the chain chosen by the researchers is important biologically and the team now hopes to look at other sequences that exhibit the same type of movement. “We would also like to know if quadruplexes are able to form inside a human cell,” Mergny added.

Total Lunar Eclipse to Occur on Tuesday at 4:51 a.m. EDT.


The Earth's shadow will creep across the moon's surface early Tuesday, slowly eclipsing it and turning it shades of orange and red. The total lunar eclipse, the second this year, will be visible in North and South America, especially in the West. People in the Pacific islands, eastern Asia, Australia and New Zealand also will be able to view it if skies are clear.



People in Europe, Africa or the Middle East, who had the best view of the last total lunar eclipse in March, won't see this one because the moon will have set when the eclipse begins at 4:51 a.m. EDT. It will take an hour to reach full eclipse stage.



An eclipse occurs when Earth passes between the sun and the moon, blocking the sun's light. It's rare because the moon is usually either above or below the plane of Earth's orbit.



Since the Earth is bigger than the moon, the process of the Earth's shadow taking a bigger and bigger "bite" out of the moon, totally eclipsing it before the shadow recedes, lasts about 3 1/2 hours, said Doug Duncan, director of the University of Colorado's Fiske Planetarium. The total eclipse phase, in which the moon has an orange or reddish glow, lasts about 1 1/2 hours.



The full eclipse will be visible across the United States, but East Coast viewers will only have about a half-hour to see it before the sun begins to rise and the moon sets. Skywatchers in the West will get the full show.



In eastern Asia, the moon will rise in various stages of eclipse.



During the full eclipse, the moon won't be completely dark because some light still reaches it around the edges of the Earth. The light is refracted as it passes through our atmosphere, scattering blue light _ which is why the sky is blue _ but sending reddish light onto the moon.



"When someone asks why is it (the moon) red, you can say because the sky is blue," Duncan said.



The next total lunar eclipse occurs Feb. 21, 2008, and will be visible from the Americas, Europe and Asia.





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Saturday, August 25, 2007

Sony Defeats Truman


This just in from video-game reporting headquarters: Sony may be a consumer electronics giant, but its public relations folks aren’t so powerful when it comes to prognostication.Yesterday, said spinsters made a bold prediction about sales figures for video game consoles that were due out today. Sony said it was confident the figures would show that in July its PlayStation 3 outsold the Xbox 360, made by its chief rival, Microsoft.The actual figures from NPD Group, a market research firm, did not bear this out. Sony came in third, behind the still piping-hot Nintendo Wii and Sony’s aforementioned chief thorn-in-side, Microsoft.For the record, NPD reported domestic sales of 425,000 Nintendo Wiis, 170,000 Xbox 360s and 159,000 PlayStation 3s in July. Dave Karraker, the Sony spokesman who predicted the PS3 would overtake the 360, told me that: (1) He was only wrong by a bit, and (2) NPD doesn’t provide an exact count but estimates some portions of the market and (3) No, he would not care to make a prediction about August’s sales figures.The results, in fairness to Sony, do represent a marked improvement relative to Microsoft. In June, PS3 sales were roughly half of Xbox 360’s 200,000.Could it be that Sony’s price cut has shaken loose consumer demand?While Microsoft and Sony battled it out for second place in the next-generation console competition, Nintendo continues to ride its less powerful processor, simpler graphics and gyration-inspiring game controller to fad-defying results. Nintendo’s July sales bested its June figures by around 50,000 units, further stumping analysts and video game software companies who keep waiting for the Wii to peter out.At this point, predicting a quick demise for the Wii might not be the wisest maneuver; it’s something even the folks at Sony wouldn’t attempt — at least not this month.P.S. The overall game market is on the mend, in a big way. Through July, domestic sales of hardware, software and accessories were $7 billion, up from $5 billion for the first seven months of 2006

Thursday, August 16, 2007

Flat-lining online

Contrary to the chipper spin from publishers that online readership is growing robustly, the traffic at most newspaper websites has been flat – or worse – for the last year, according to a new report from Harvard University.In a study of 160 newspapers, the Joan Shorenstein Center on the Press, Politics and Public Policy found that the “record” readership gains heralded by the industry were

Thursday, August 9, 2007

Newsosaur nixes Gannett exit yarn

Notwithstanding shoot-from-the-hip speculation at the Wall Street Journal, it is unlikely Gannett is putting itself up for sale – or soon to be acquired by a media company or private-equity player.Seizing on some fine print in a new filing at the Securities and Exchange Commission in which Gannett’s top managers adjusted the rigging of their golden parachutes, a Journal blogger asked, “Is Gannett

Tuesday, August 7, 2007

Dead animals, large and small

With objective data in short supply as to the efficacy of the new media initiatives undertaken by the old media companies, the following is sure to depress mainstream publishers. But they need to hear it anyway.Three weeks ago, Newsosaur’s admittedly modest traffic spiked to an all-time daily high of more than 1,000 visits as the result of this link from a blog called, I kid you not, Small Dead

From Fresh Ideas and Better Steel, Safer Bridges


From Fresh Ideas and Better Steel, Safer Bridges



The collapse of the eight-lane steel-deck truss bridge last week in Minneapolis focused attention on deficiencies in many older spans around the nation. Despite these troubles, engineers say, new ideas and technologies are making bridges safer — not to mention longer and more beautiful — than they have ever been.
Skip to next paragraph RelatedTimes Topics: Bridge DisastersEnlarge This Image Thomas Bender/Sarasota Herald-TribuneThe bridge has a cable-stayed mainspan. The advances are founded on better steel and concrete, smarter rules and designs and bursts of creativity that turn raw materials into works of art.
“It’s usually a case of slow and steady progress,” said Henry Petroski, a professor of history and civil engineering at Duke University. But past innovations, he said, suggest that the field has gone through periods of rapid progress and may do so again. Giant spans of steel and concrete may one day soar across the Strait of Gibraltar and the Bering Sea, uniting Africa and Europe, Asia and the Americas.
Today’s advances develop against a backdrop of decay as the nation’s aging bridges buckle under the strain of poor upkeep and steadily increasing traffic. In this decade, at least six have collapsed, often after being hit by trucks or boats. The failures have taken dozens of lives.
Experts say part of the problem is poor design, apparently a contributing factor in the Minneapolis collapse.
Another difficulty, Dr. Petroski said, is that America is in some ways a victim of its own early innovation. Early designers created the world’s most comprehensive system of bridges. Many spans set records, but they are now antiques.
Dr. Petroski said much of the progress in bridge design and construction is occurring in China and other countries undergoing rapid growth, not in developed nations with fewer opportunities for new construction. He said he recently traveled to China and saw many “world class bridges” going up on the Yangtze River, with some quite striking in design and “approaching record spans.”
“If there’s good news,” Dr. Petroski said, “it’s in the Far East.”
China is building thousands of bridges every year.
In the United States, many triumphs of bridge building occurred in the late 1800s and early 1900s. In 1874, the Eads Bridge opened over the Mississippi at St. Louis to become the world’s longest arch bridge. It was the first use of steel as a main structural element, making possible its extremely long arches.
The pace of innovation accelerated in 1883 with the opening of the Brooklyn Bridge over the East River. It was the world’s longest suspension bridge and the first hung from steel wires.
In 1931, records shattered again with the opening over the Hudson River of what became known as the George Washington Bridge. The elegant main span of the suspension bridge was the world’s longest, nearly twice the nearest rival.
The secret of its success lay in a novel idea, making the roadway deck much thinner and lighter, allowing the central span to be unusually long and graceful.
The theory worked over the Hudson, but it was a disaster elsewhere. In 1940, a bridge over the Tacoma Narrows in Washington, of the same design but with an even lighter deck, collapsed in high winds. No one died because worried officials had closed it earlier that day.
The biggest risk for bridges turned out to be not innovation but aging and increasing loads. In 1967, the Silver Bridge over the Ohio River, nearly 40 years old, collapsed, killing 46 people. It was one of the deadliest failures. The span had been designed for Model T Fords, but the weight of automobiles had more than tripled in the ensuing decades. The disaster prompted a national program of regular inspections, especially of the 1,100 highway bridges designed for Model Ts.
Today, innovation is again accelerating. Increasingly, designers use high-performance steels that are unusually strong and tough. Among other factors, their strength allows for the creation of spans of great length and beauty that are also more durable.
“They give you lots of building and design options that we didn’t have 20 years ago,” said Conn Abnee, executive director of the National Steel Bridge Alliance, an industry group based in Chicago.
The nation, he added, has some 400 bridges that use high-performance steel.
In 2000, a graceful bridge made from the superstrong material opened in Pennsylvania over the Allegheny River, its main span more than a football field long.
Designers and engineers are also starting to make use of a new generation of highly fluid concretes that flow better into constricted spaces. M. Myint Lwin, director of bridge technology at the Federal Highway Administration, recently said that the materials had “extraordinary potential for improving the quality of the finished product.”
Colin MacDougall, a professor of civil engineering at Queen’s University in Kingston, Ontario, said many advances in bridge design centered on subtle changes in how the elements are assembled. For instance, researchers are developing new recommendations for where to weld, lessening the risks of fatigue and cracks.
“A lot of the problems for old bridges are not in the strength of the steel, but how things are put together,” he said. “It comes down to design.”
A final improvement is forcing improvement whether designers like it or not. In October, the Federal Highway Administration will begin enforcing new rules for bridge design meant to make new structures more efficient, more reliable, safer and longer lasting.
Among other improvements, the rules should produce bridges better able to withstand peak traffic loads and brutal weather, as well as extreme events like ship collisions and earthquakes.
“We’re not switching because existing bridges are going to fall down,” said Kelley C. Rehm, program manager for bridges and structures at the American Association of State Highway and Transportation Officials, which wrote the new rules. But the regulations, she said, will produce “a more reliable way of designing a bridge.”

Visual soft


coming soon

Monday, August 6, 2007

Nanotech used to make flexible sensors

U.S. Department of Energy scientists used nanotechnology to create flexible sensors for use in fuel cells designed for hydrogen-powered vehicles.
In comparison with previously designed hydrogen sensors, which are rigid and use expensive pure palladium, the new sensors developed at the Argonne National Laboratory are flexible and use single-walled carbon nanotubes to improve efficiency and reduce cost. The development is expected to help to ensure economical benefits as well as environmental and societal safety, researchers said.
The new sensing devices, developed by Yugang Sun and H. Hau Wang, exhibit excellent sensing performance in terms of high sensitivity, fast response time and quick recovery, scientists said. And the use of plastic sheets reduces their overall weight and increases their mechanical flexibility and shock resistance, Sun added.
The sensors can be wrapped around curved surfaces, which proves useful in many applications in vehicles, aircraft and portable electronics.





More from Argonne National Laboratory






flexible sensors



Nanotechnology helps scientists make bendy sensors for hydrogen vehicles
ARGONNE, Ill. (July 31, 2007) — In recent years, Americans have been intrigued by the promise of hydrogen-powered vehicles. But experts have judged that several technology problems must be resolved before they are more than a novelty.
Recently, scientists at the U.S. Department of Energy's Argonne National Laboratory have used their insights into nanomaterials to create bendy hydrogen sensors, which are at the heart of hydrogen fuel cells used in hydrogen vehicles.
In comparison to previously designed hydrogen sensors, which are rigid and use expensive, pure palladium, the new sensors are bendy and use single-walled carbon nanotubes (SWNTs) to improve efficiency and reduce cost. The development of these hydrogen sensors will help to ensure economical, environmental and societal safety, as the nation is realizing the potential for a more hydrogen-based economy.
Yugang Sun and H. Hau Wang, researchers in Argonne's Center for Nanoscale Materials and Materials Science Division, respectively, fabricated the new sensing devices using a two-step process separated by high and low temperatures. First, at around 900 degrees C, researchers grow SWNTs on a silicon substrate using chemical vapor deposition. Then, researchers transfer the SWNTs onto a plastic substrate at temperatures lower than 150 degrees C using a technique called dry transfer printing.
This precise process is what allows the film of nanotubes to form on the plastic, after which the palladium nanoparticles can be deposited on the SWNTs to make the sensors. The palladium nanoparticles play an important role in increasing the interaction between hydrogen and the SWNTs to enhance the change of resistance of the device when it is exposed to hydrogen molecules.
According to Sun, these sensors exhibit excellent sensing performance in terms of high sensitivity, fast response time and quick recovery, and the use of plastic sheets reduces their overall weight and increases their mechanical flexibility and shock resistance. The sensors are also able to be wrapped around curved surfaces, and this proves useful in many applications, notably in vehicles, aircraft and portable electronics.
“The leakage of hydrogen caused by tiny pinholes in the pipe of a space shuttle, for example, could not be easily detected by individual rigid detectors because the locations of pinholes are not predetermined,” said Sun. “However, laminating a dense array of flexible sensors on the surfaces of the pipe can detect any hydrogen leakage prior to diffusion to alert control units to take action.”
Flexible hydrogen sensors show a change of 75 percent in their resistance when exposed to hydrogen at a concentration of 0.05 percent in air. The devices can detect the presence of 1 percent hydrogen at room temperature in 3 seconds. Even after bending—with a bending radius of approximately 7.5 mm—and relaxing 2,000 times, the devices still perform with as much effectiveness.
With employees from more than 60 nations, Argonne National Laboratory brings the world's brightest scientists and engineers together to find exciting and creative new solutions to pressing national problems in science and technology. The nation's first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America 's scientific leadership and prepare the nation for a better future. Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.















Large Hadron Collider (LHC) -Supercollisions on the horizon?


The project staggers the imagination: a machine that would stretch 20 miles through the bedrock 400 feet beneath Kane, DuPage and perhaps Will Counties. It could help physicists discover mysterious forces of the universe and new dimensions in the fabric of space and time.
But there are other mysteries to resolve before the first spade is turned for a proposed, multibillion-dollar International Linear Collider scientists hope to center under Fermi National Accelerator Laboratory's Batavia campus.
What would the neighbors think about subatomic particles being fired at nearly the speed of light under west suburban homes, back-yard pools and cornfields? And how to accommodate any criticisms in advance and bring folks onboard?
There's no guarantee the collider -- which experts think could be one of the century's great scientific leaps forward -- will be built. Or that it'll be built in Illinois. Even in the best-case scenario, it will be more than a decade before the first particles fly.
But officials are planning ahead, making sure that what happened about 20 years ago -- when criticism from residents helped doom Fermilab's quest to land a superconducting supercollider -- doesn't happen again.
Fermilab has organized a 24-member ILC Citizens' Task Force to help it plan. The Department of Energy facility has included a wide range of volunteers, from village trustees to the same activists who fought Fermilab's proposed supercollider in the 1980s.
Members are asking questions, offering suggestions and learning about the project firsthand from some of the world's leading physicists and engineers. Their job is to draw up recommendations for the project by early next year so the changes can be incorporated into the design.
All this for an international project Europe and Japan might also compete for and that wouldn't be finished until 2019 at the earliest -- and could take until 2030. The project would employ the equivalent of 2,000 people worldwide during each of the seven years the machine is being built.
If completed, however, the machine would assert Fermilab's position on the frontier of science for decades, employing physicists, engineers and others at the lab after its Tevatron particle accelerator's scheduled shutdown in 2009.
But first, Fermilab wants to win over the neighbors.
In a recent meeting, Dan Lobbes, a task-force member and director of land preservation with the Conservation Foundation, said Fermilab had better prepare itself to answer questions such as, "'Will my kids and my dog get radiated?' Or, 'How will we know we'll get treated fairly?' Or, 'Do we get money if the thing goes under my house?'"
Fermilab officials seem to delight in such bruising questions, nodding and scribbling notes when the interrogation gets tough. They genuinely want to be guided by the public, they say, and it is better to get everything out in the open now -- with informed citizens, not folks spooked by 1950s Godzilla scenarios.
"It's just openness," said Craig Jones, who fought the supercollider and now serves on the task force. "That's what we're talking about -- establishing trust, and treating you like you're something other than some bumpkin from Kane County."
The proposed linear collider could help scientists overcome humankind's humbling ignorance of much of the cosmos. Physicists can only account for 5 percent of the components of the universe. The remaining 95 percent are believed to be dark matter and dark energy, which are invisible but can be detected in the mass and rotational speed of galaxies and galaxy clusters.
The collider would hurl billions of electrons and their antiparticles -- positrons -- toward each other at nearly the speed of light, Fermilab said. The collisions would create new particles that could offer hints about the nature and origin of the universe.
"It's a little bit mind-boggling that to study the smallest particles in the universe, you need the largest machines that mankind has ever built," said Kurt Riesselmann, a Fermilab spokesman.
But there is the problem of where to park a machine that would extend miles beyond the 6,800-acre lab campus.
The collider is so vast and so expensive -- rough estimates start at $6.7 billion -- no single government could afford to build it, Riesselmann said.
An international team is designing it, and the cash would come from many countries. A similar collaboration led to the Geneva-based CERN particle physics laboratory's Large Hadron Collider, scheduled to start up in May 2008.
If Fermilab is chosen for the new collider, it could stir up a hornet's nest of local planning issues. Contractors would bore 44 miles of tunnel -- including a parallel service tunnel -- with a diameter of 15 feet or greater. Thirteen access shafts would be spaced every few miles, and 92 new buildings would have to be built above ground, roughly a third of them off-campus on land Fermilab would acquire.

Task-force member John Carlson of Geneva wanted to know how much blasting would be required."In the Deep Tunnel project, there was a lot of blasting in Chicago, broken windows and that sort of thing," he said. "So I think the objection of the communities will be in the blasting phase."Vic Kuchler, a Fermilab staff member who is part of the collider's global design effort, said most of the tunnels would be drilled, but some blasting would be necessary to create underground rooms and alcoves

Fermilab officials said the machine would meet environmental standards on radiation and other matters. "It's not a nuclear reactor or anything like that," said Riesselmann. The particle collision point would be on Fermilab property, and a power failure would harmlessly shut down the collider, as it does the lab's Tevatron.The surface work could prove more problematic. Fermilab would have to build mini-campuses of an undetermined size where the shafts emerge.Jones, a St. Charles resident who opposed the supercollider in the late 1980s, said the approach now is a far cry from those days. Officials then didn't involve property owners during the design, he said, and were condescending to those who questioned the project.A retired pilot, Jones wrote and distributed a paper disputing the state's claims about the jobs that project would create. He and other opponents undermined it further by gathering 18,000 signatures in opposition.Texas ended up winning the supercollider project, which was later canceled by Congress amid cost overruns.This time, Jones said, Fermilab is going out of its way to listen to citizens. Jones sees his task as not to become an advocate for the linear collider, but to ensure a fair process for the communities it passes under."Am I personally interested in that kind of science?" Jones said. "As a matter of fact, I am. I'm very interested. But I don't want to see people get squashed, having family farms taken and being treated badly, just for the sake of science that I may like."



Large Hadron Collider (LHC) (primary research/costs/upgrades)

Research



When in operation, about seven thousand scientists from eighty countries will have access to the LHC, the largest national contingent (seven hundred) being from the United States. Physicists hope to use the collider to enhance their ability to answer the following questions:



Is the popular Higgs mechanism for generating elementary particle masses in the Standard Model violated? If not, how many Higgs bosons are there, and what are their masses?


Will the more precise measurements of the masses of baryons continue to be mutually consistent within the Standard Model?


Do particles have supersymmetric ("SUSY") partners?


Why are there apparent violations of the symmetry between matter and antimatter?


Are there extra dimensions, as predicted by various models inspired by string theory, and can we "see" them?


What is the nature of dark matter and dark energy?

Why is gravity so many orders of magnitude weaker than the other three fundamental forces?



LHC as an ion collider


The LHC physics program is mainly based on proton-proton collisions. However, shorter running periods, typically one month per year, with heavy-ion collisions are included in the programme. While lighter ions are considered as well, the baseline scheme deals with lead (Pb) ions.This will allow an advancement in the experimental programme currently in progress at the Relativistic Heavy Ion Collider (RHIC).


LHC proposed upgrade


After some years of running, any particle physics experiment typically begins to suffer from diminishing returns. The way around the diminishing returns is to upgrade the experiment, either in energy or in luminosity.
A luminosity upgrade of the LHC, called the Super LHC, has been proposed, to be made after ten years of LHC operation. The optimal path for the LHC luminosity upgrade includes an increase in the beam current (i.e., the number of protons in the beams) and the modification of the two high luminosity interaction regions, ATLAS and CMS. To achieve these increases, the energy of the beams at the point that they are injected into the (Super) LHC should also be increased to 1 TeV. This will require an upgrade of the full pre-injector system, the needed changes in the Super Proton Synchrotron being the most expensive.


COST

The construction of LHC was originally approved in 1995 with a budget of 2600 million Swiss francs (currently about 1.7 billion euro), with another 210 million francs (€140 m) towards the cost of the experiments. However, cost over-runs, estimated in a major review in 2001 at around 480 million francs (€300 m) in the accelerator, and 50 million francs (€30 m) for the experiments, along with a reduction in CERN's budget pushed the completion date out from 2005 to April 2007.180 million francs (€120 m) of the cost increase has been the superconducting magnets. There were also engineering difficulties encountered while building the underground cavern for the Compact Muon Solenoid.


Safety concerns

While many have voiced concerns that the LHC will destroy the Universe, engineers close to the project claim that the possibility is infinitesimally small. As CERN has pointed out, if the Earth were in danger of any such fate, it would have happened billions of years ago from the bombardment of protons the planet receives that are millions of times more energetic than anything that could be produced by the LHC.


As with the Relativistic Heavy Ion Collider (RHIC), people both inside and outside of the physics community have voiced concern that the LHC might trigger one of several theoretical disasters capable of destroying the Earth or even our entire Universe. RHIC has been running since 2000 and has generated no major problems; however the Large Hadron Collider is set to create an environment significantly more alien to nature than the RHIC has ever created, and therefore the probability of catastrophe is greater.[citation needed]
Theoretical disasters include:
Creation of a stable black hole inside the earth which would destroy our planet within 4 to 6 minutes.[citation needed]
Creation of strange matter that is more stable than ordinary matter
Creation of magnetic monopoles that could catalyze proton decay
Triggering a transition into a different quantum mechanical vacuum (see False vacuum)
It is possible that the Large Hadron Collider will create tiny black holes within the Earth . Most physicists expect that Hawking Radiation will cause these black holes to dissipate. The primary cause for concern is the fact that Hawking Radiation - the only means by which these black holes could be dissipated, is entirely theoretical.
CERN performed a study to investigate whether such dangerous events as micro black holes, strangelets, or magnetic monopoles could occur. The report concluded, "We find no basis for any conceivable threat." If black holes are produced, they are expected to evaporate almost immediately via Hawking radiation and thus be harmless, although the existence of Hawking radiation is currently unconfirmed. It has been claimed that a strong argument for the safety of colliders such as the LHC comes from the simple fact that cosmic rays with energies up to twenty million times the LHC's 1.4×10¹³ eV capacity have been bombarding the Earth, Moon and other objects in the solar system for billions of years with no such effects.
However many people remain concerned about the safety of the LHC such as the science watchdog group called the Lifeboat Foundation which has covered these dangers in detail. As with any new and untested experiment, it is not possible to say with utter certainty what will happen. John Nelson at the University of Birmingham stated of RHIC that "it is astonishingly unlikely that there is any risk—but I could not prove it."Furthermore, in academia there is some question, albeit among a minority of scientists, of whether the Hawking radiation theory is correct.

Construction accidents
On October 25, 2005, a technician was killed in the LHC tunnel when a crane load was accidentally dropped

On March 27, 2007, there was an incident during a pressure test involving one of the LHC's inner triplet magnet assemblies provided by Fermilab and KEK. No people were injured, but a cryogenic magnet support broke. Analysis revealed that its design, made as thin as possible for better insulation, was not strong enough to withstand the forces generated by a sudden shutdown. Details are available in a statement from Fermilab, with which CERN is in agreementRepairing the broken magnet and reinforcing the eight identical copies used by LHC caused a postponement of the planned November 26, 2007 startup date [19] to May 2008.[20]

[edit] See also
Fermilab
International Linear Collider
http://en.wikipedia.org/wiki/LHC@home
Superconducting Super Collider
Tevatron


Notes and references


^ New start-up schedule for world's most powerful particle accelerator
^ Symmetry magazine, April 2005
^ "...in the public presentations of the aspiration of particle physics we hear too often that the goal of the LHC or a linear collider is to check off the last missing particle of the standard model, this year’s Holy Grail of particle physics, the Higgs boson. The truth is much less boring than that! What we’re trying to accomplish is much more exciting, and asking what the world would have been like without the Higgs mechanism is a way of getting at that excitement." -Chris Quigg, Nature's Greatest Puzzles
^ Ions for LHC
^ PDF presentation of proposed LHC upgrade
^ Maiani, Luciano (16 October 2001). LHC Cost Review to Completion. CERN. Retrieved on 2001-01-15.
^ Feder, Toni (December 2001). "CERN Grapples with LHC Cost Hike". Physics Today 54 (12): 21. Retrieved on 2007-01-15.
^ Tiny Black Holes - Physicist Dave Wark of Imperial College, London reporting for NOVA scienceNOW
^ Dimopoulos, S. and Landsberg, G. Black Holes at the Large Hadron Collider. Phys. Rev. Lett. 87 (2001).
^ American Institute of Physics Bulletin of Physics News, Number 558, September 26, 2001, by Phillip F. Schewe, Ben Stein, and James Riordon
^ Blaizot, J.-P. et al. Study of Potentially Dangerous Events During Heavy-Ion Collisions at the LHC. (PDF)
^ R. A. Mewaldt "Cosmic Rays" — an article accepted for publication in the Macmillan Encyclopedia of Physics in 1996
^ Jonathan Leake:Big Bang machine could destroy Earth, Sunday Times
^ Adam D. Helfer: General Relativity and Quantum Cosmology
^ Hewett, JoAnne (25 October 2005). Tragedy at CERN (Blog). Cosmic Variance. Retrieved on 2007-01-15. author and date indicate the beginning of the blog thread
^ CERN (26 October 2005). Message from the Director-General (in English and French). Press release. Retrieved on 2007-01-15.
^ LHC Magnet Test Failure
^ Updates on LHC inner triplet failure
^ The God Particle. www.bbc.com. Retrieved on 2007-05-22.
^ CERN (2007-06-22). CERN announces new start-up schedule for world’s most powerful particle accelerator. Press release. Retrieved on 2007-07-01.

[edit] External links

Wikimedia Commons has media related to:
Large Hadron Collider
LHC - The Large Hadron Collider webpage
Challenges in Accelerator Physics
LHC UK webpage
UK Science Museum, London Exhibition supported by the Science and Technology Facilities Council
The Alice experiment
Compact Muon Solenoid (CMS) Main Page
Compact Muon Solenoid Page (U.S. Collaboration)
Energising the quest for 'big theory'
LCG - The LHC Computing Grid webpage
The Large Hadron Collider ATLAS Experiment - Virtual Reality (VR) photography panoramas (requires QuickTime)
LHC startup plan. Includes dates, energies and luminosities
Seed short film - Lords of the Ring
symmetry magazine LHC special issue
BBC Horizon, The six billion dollar experiment
New Yorker: Crash Course. The world’s largest particle accelerator (ca. 6 500 words)
NYTimes: A Giant Takes On Physics’ Biggest Questions (ca. 4 300 words)
Beam Parameters and Definitions. The chapter of the LHC Technical Design Report (TDR) that



lists of all the beam parameters for the LHC.
by www.24hoursnews.blogspot.com

Large Hadron Collider (LHC) (about/technical desing)


LHC
The Large Hadron Collider (LHC) is a particle accelerator and collider located at CERN, near Geneva, Switzerland (46°14′N, 6°03′E). Currently under construction, the LHC is scheduled to begin operation in May 2008.[1] The LHC is expected to become the world's largest and highest energy particle accelerator. The LHC is being funded and built in collaboration with over two thousand physicists from thirty-four countries, universities and laboratories.
When switched on, it is hoped that the collider will produce the elusive Higgs boson particle — often dubbed the God Particle — the observation of which could confirm the predictions and 'missing links' in the Standard Model of physics, and explain how other elementary particles acquire properties such as mass.


Technical Desing

Technical DesignThe collider is contained in a 27 kilometre (17 mi) circumference tunnel located underground at a depth ranging from 50 to 175 metres.[2] The tunnel was formerly used to house the LEP, an electron-positron collider.
The three metre diameter, concrete-lined tunnel actually crosses the border between Switzerland and France at four points, although the majority of its length is inside France. The collider itself is located underground, with many surface buildings holding ancillary equipment such as compressors, ventilation equipment, control electronics and refrigeration plants.
The collider tunnel contains two pipes enclosed within superconducting magnets cooled by liquid helium, each pipe containing a proton beam. The two beams travel in opposite directions around the ring. Additional magnets are used to direct the beams to four intersection points where interactions between them will take place.
The protons will each have an energy of 7 TeV, giving a total collision energy of 14 TeV. It will take around ninety microseconds for an individual proton to travel once around the collider. Rather than continuous beams, the protons will be "bunched" together into approximately 2,800 bunches, so that interactions between the two beams will take place at discrete intervals never shorter than twenty-five nanoseconds apart. When the collider is first commissioned, it will be operated with fewer bunches, to give a bunch crossing interval of seventy-five nanoseconds. The number of bunches will later be increased to give a final bunch crossing interval of twenty-five nanoseconds.
Prior to being injected into the main accelerator, the particles are prepared through a series of systems that successively increase the particle energy levels. The first system is the linear accelerator Linac2 generating 50 MeV protons which feeds the Proton Synchrotron Booster (PSB). Protons are then injected at 1.4 GeV into the Proton Synchrotron (PS) at 26 GeV. The Low-Energy Injector Ring (LEIR) will be used as an ion storage and cooler unit. The Antiproton Decelerator (AD) will produce a beam of anti-protons at 2 GeV, after cooling them down from 3.57 GeV. Finally the Super Proton Synchrotron (SPS) can be used to increase the energy of protons up to 450 GeV.
Six detectors are being constructed at the LHC. They are located underground, in large caverns excavated at the LHC's intersection points. Two of them, ATLAS and CMS are large, "general purpose" particle detectors. The other four (LHCb, ALICE, TOTEM, and LHCf) are smaller and more specialized.
The LHC can also be used to collide heavy ions such as lead (Pb) with a collision energy of 1,150 TeV.
The size of the LHC constitutes an exceptional engineering challenge with unique safety issues. While running, the total energy stored in the magnets is 10 GJ, and in the beam, 725 MJ. Loss of only 10−7 of the beam is sufficient to quench a superconducting magnet, while the beam dump must absorb an energy equivalent to a typical air-dropped bomb. For comparison, 725 MJ is equivalent to the detonation energy of approximately 157 kg (347 pounds) of TNT, and 10 GJ is about 2.5 tons of TNT.

Condensed matter physics has solved



Northeastern University Physics professor Sergey V. Kravchenko along with colleagues Svetlana Anissimova (Northeastern University), A Punnoose (City College if the City University of New York), AM Finkelstein (Weizmann Institute of Science, Israel) and TM Klapwijk (Delft University of Technology, Netherlands), has published an important new paper in the August issue of Nature Physics which answers a long standing question in the field of condensed matter physics.
The discovery of the metal-insulator transition (MIT) in two-dimensional electron systems by Kravchenko and colleagues in 1994 challenged the veracity of one of the most influential conjectures in the physics of disordered electrons by Abrahams, Anderson, Licciardello and Ramakrishnan (1979) which stated that "in two dimensions, there is no true metallic behavior."




However, the 1979 theory did not account for interactions between electrons. In this new paper, Kravchenko and colleagues investigate the interplay between the electron-electron interactions and disorder near the MIT using simultaneous measurements of electrical resistivity and magnetoconductance.




The researchers show that both the resistance and interaction amplitude exhibit a fan-like spread as the MIT is crossed. From this data, the researchers have constructed a resistance-interaction flow diagram of the MIT that clearly reveals a quantum critical point, as predicted by the recent two-parameter scaling theory by two of the authors (A. Punnoose and A.M. Finkelstein). The metallic side of this diagram is accurately described by the renormalization-group theory without any fitting parameters. In particular, the metallic temperature dependence of the resistance sets in when the interaction amplitude reaches a value in remarkable agreement with the one predicted by theory.




"To the best of our knowledge, this is the first observation of the temperature dependence of the strength of the electron-electron interactions," said Kravchenko. "We found that the interaction grows in the metallic phase as the temperature is reduced and is suppressed in the insulating phase."




"Whether or not the electrons can conduct in two dimensions at very low temperatures is a question that has been hotly debated for more than a decade," said Kravchenko. "We now know that, because of the interactions between them, they can, and we have a theory that quantitatively and qualitatively explains things."




More news
About Nature Physics:




Nature Physics publishes papers of the highest quality and significance in all areas of physics, pure and applied. The journal content reflects core physics disciplines, but is also open to a broad range of topics whose central theme falls within the bounds of physics. Theoretical physics, particularly where it is pertinent to experiment, also features. The impact factor for Nature Physics is 12.040, according to the ISI Journal Citation Reports. This places Nature Physics first among all primary research journals in physics.




The journal features two primary research paper formats: Letters and Articles. In addition to publishing primary research, Nature Physics serves as a central source for top-quality information for the physics community through Review Articles, News & Views, Research Highlights on important developments published throughout the physics literature, Commentaries, Book Reviews, and Correspondence.








About Northeastern




Founded in 1898, Northeastern University is a private research university located in the heart of Boston. Northeastern is a leader in interdisciplinary research, urban engagement, and the integration of classroom learning with real-world experience. The university's distinctive cooperative education program, where students alternate semesters of full-time study with semesters of paid work in fields relevant to their professional interests and major, is one of the largest and most innovative in the world. The University offers a comprehensive range of undergraduate and graduate programs leading to degrees through the doctorate in six undergraduate colleges, eight graduate schools, and two part-time divisions. For more information, please visit http://www.northeastern.edu/.




From wiki




Condensed matter physics is the field of physics that deals with the macroscopic physical properties of matter. In particular, it is concerned with the "condensed" phases that appear whenever the number of constituents in a system is extremely large and the interactions between the constituents are strong. The most familiar examples of condensed phases are solids and liquids, which arise from the bonding and electromagnetic force between atoms. More exotic condensed phases include the superfluid and the Bose-Einstein condensate found in certain atomic systems at very low temperatures, the superconducting phase exhibited by conduction electrons in certain materials, and the ferromagnetic and antiferromagnetic phases of spins on atomic lattices.




Condensed matter physics is by far the largest field of contemporary physics. Much progress has also been made in theoretical condensed matter physics. By one estimate, one third of all American physicists identify themselves as condensed matter physicists. Historically, condensed matter physics grew out of solid-state physics, which is now considered one of its main subfields. The term "condensed matter physics" was apparently coined by Philip Anderson when he renamed his research group - previously "solid-state theory" - in 1967. In 1978, the Division of Solid State Physics at the American Physical Society was renamed as the Division of Condensed Matter Physics.[1] Condensed matter physics has a large overlap with chemistry, materials science, nanotechnology and engineering.




One of the reasons for calling the field "condensed matter physics" is that many of the concepts and techniques developed for studying solids actually apply to fluid systems. For instance, the conduction electrons in an electrical conductor form a type of quantum fluid with essentially the same properties as fluids made up of atoms. In fact, the phenomenon of superconductivity, in which the electrons condense into a new fluid phase in which they can flow without dissipation, is very closely analogous to the superfluid phase found in helium 3 at low temperatures.






Technorati :

Ovarian Tissue Successfully Transplanted



For the first time, a woman whose ovaries were damaged by drug and radiation treatments has undergone a successful transplant of ovaries from her genetically non-identical sister, Belgian researchers report.
According to the report, the 2005 transplant restored ovarian function to Teresa Alvaro, now 35, and she started to menstruate. After a year, two oocytes (precursors to the ovum) were taken from the patient's ovaries and fertilized producing two embryos, according to the report in the Aug. 2 issue of Human Reproduction. Those embryos did not lead to successful pregnancies, however.
Nevertheless, the procedure does support the "restoration of ovarian function after transplantation of ovarian tissue from genetically un-identical sisters," said lead researcher Dr. Jacques Donnez, head of the department of gynecology and professor and chairman at the Catholic University of Louvain in Brussels.
Previously, other researchers had successfully transplanted ovarian tissue between genetically identical twin sisters.
The most important factor here is that it does not seem necessary to use powerful immunosuppressive therapy to maintain the transplant, Donnez said. Drugs typically used to suppress an immune response against the transplant can damage a growing embryo, he explained.
This method of restoring ovarian function might be used when a woman has undergone chemotherapy or radiation, which can destroy ovarian function, Donnez said. "Women can also have ovarian tissue frozen before undergoing treatment and transplanted back after the end of chemotherapy," he said.
But oncologists don't often propose this option, Donnez said.
Although the possibility of oocyte donation from her sister, Sandra Alvaro, was discussed, the patient refused this option, Donnez said. Teresa wanted the transplant, because she considered that having a baby of her own was more natural than egg donation, Donnez said.
Teresa Alvaro had lost ovarian function due to treatments she received to fight a rare blood disorder called beta-thalassemia. In 1990, when she was 20, she underwent bone marrow transplant to help cure the disorder, using marrow donated by Sandra, then 17 years of age. It was discovered that the sisters had an identical "human leukocyte antigen" (HLA) type -- meaning that Teresa's immune system would not reject her sister's marrow or other tissue as "foreign."
Donnez's team knew that because the sisters' HLA type allowed their genetically different cells to coexist successfully, there was no need for immunosuppressive treatment to prevent the ovarian transplant from being rejected.
After six months, Teresa Alvaro started menstrual bleeding. That, along with her hormone levels, confirmed that ovarian function had been restored. Her menstrual cycles have continued ever since, the researchers reported.
After a year, doctors took two oocytes from her ovary and fertilized them with her husband's sperm. One of the embryos developed to the two-cell stage and the other to the three-cell stage. However, both stopped developing, so they were not transferred to her uterus.
Why the embryos didn't develop is not clear, but this also happens during normal cycles of IVF, Donnez said. However, it's too early to know whether this procedure would ever be successful in letting a woman get pregnant and give birth to a live baby, he said.
"The first thing the gynecologist and oncologist need to think about before chemotherapy is to propose cryopreservation [freezing] of ovarian tissue before chemotherapy. That's the first option," Donnez said. "The second option is cryopreservation of embryos," he said. "But even when tissue isn't preserved, we have some hope that transplanting ovarian tissue will restore function."
Donnez hopes in the future that immunosuppressive drugs can be developed that will not be toxic to embryos, making ovarian tissue transplantation a wider option for women.
One expert is unsure about the practicality of ovarian transplantation.
"This is another step in ovarian transplantation," said Dr. Richard J. Paulson, a professor of obstetrics and gynecology and chief of the division of reproductive endocrinology and infertility at the University of Southern California Keck School of Medicine, Los Angeles.
Paulson is skeptical, however, that the technique is very practical. "Why on earth would you bother to do this, when you can clearly do egg donation from the one sister to the other," he said. "That would have had a higher success rate -- instead, they are goofing around with this transplantation of the ovarian cortex."




News Origin.




SOURCES: Jacques Donnez, M.D., head, department of gynecology, professor and chairman, Catholic University of Louvain, Brussels; Richard J. Paulson, M.D., professor of obstetrics and gynecology, chief, Division of Reproductive Endocrinology and Infertility, University of Southern California Keck School of Medicine, Los Angeles; Aug. 2, 2007, Human Reproduction