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Spacecraft Voyager 1 is closer to being the first human-made object to leave the solar system ? but what exactly ?closer? means is still unknown.
Researchers are waiting for Voyager 1, launched some 35 years ago and now more than 11 billion miles away, to exit the heliosheath,?a region that extends past all the planets in our solar system by about 8 billion miles, into interstellar space. But ?about? is the critical word here, because the trouble is that scientists don?t know exactly how big that region is.?
Still, three papers, published in Science, report that scientists have observed one of the signs that they expect to see as Voyager 1 nears the solar system?s edge: the total disappearance of charged particles, known as termination shock particles, that had been steadily present for seven years.
That means Voyager 1 entered a previously unknown space region called the magnetic highway, or the depletion region, on August 25th, 2012, when the disappearance was observed. In that zone, the charged particles travel in and out of the heliosheath along a smooth magnetic field line. Scientists believe that it is the final zone through which the spacecraft must pass before it reaches the heliopause, the exact boundary between the heliosheath and interstellar space.?
?We entered an entirely new region on August 25th,? Ed Stone, lead project scientist for the Voyager spacecraft told the Monitor. ?We think this is the zone that connects to interstellar space.?
Scientists have not yet seen the critical third sign that would mark Voyager 1?s actual passage into interstellar space: a shift in the direction of the magnetic field. The heliosheath's queen is our sun, and the sun?s east-west magnetic field governs the zone. As the space probe exits the solar system, scientists would expect to see a magnetic shift as it enters a regional field with a completely different orientation.
Another sign that Voyager 1 is still in our solar system is that the cosmic rays the craft has begun to detect from interstellar space are traveling unevenly in multiple directions. In interstellar space, scientists expect those rays to be distributed uniformly, Stone said.
Voyager 1 was launched with its sibling, Voyager 2, in 1977, and both craft have already made tours of Jupiter, Saturn, Uranus, and Neptune before veering toward interstellar space in 1990. Even though it was launched 15 days earlier, Voyager 2 is some 2 billion miles Voyager 1.
Voyager 1?s triumphant departure has been heralded before. In December 2004, the Voyager reached what is now known as the termination shock boundary, where particles blown outward from the sun suddenly slow down.?
Voyager 1 saw this solar wind hit a dead calm in April 2010, which again suggested that the craft was coming tantalizingly close to the edge of the solar system. That region is now known as the stagnation zone. At that time, the existence of the depletion zone up ahead was unknown.
Scientists aren?t being deliberately cruel by repeatedly announcing that Voyager 1 has departed. The heliosheath is a baffling, mysterious place, and information about its outer reaches is collected only as Voyager 1 continues its unprecedented journey.
So we don't know how long it will be before Voyager 1 leaves for good.
?It could be several more months, or it could also be several more years,? said Stone. ?There could be things we still don?t know about out there. Almost every day we?re learning something new.?
?That?s the nature of exploration ? you find out how nature really does things,? he said.
SEATTLE (Reuters) - Just because they're both emblems of American pride doesn't mean fireworks and bald eagles should share the same skyline.
The floating launch pad for next week's July Fourth fireworks display in suburban Seattle is being moved from its usual site to avoid frightening a pair of baby bald eagles nesting in a tree on the shore of Lake Washington, sponsors of the event said on Thursday.
A spokeswoman for the local National Audubon Society chapter said the two eaglets, still too young to fly, might be so startled by the pyrotechnics that they would jump out of their nest and plunge to the ground, leaving them injured or vulnerable to predators.
The fledgling national symbols, apparently unaware they are complicating the Independence Day festivities in the city of Kirkland, east of Seattle, currently spend their days perched in a tall lakeside Douglas fir in the town's Heritage Park.
They are believed to be six to eight weeks old, and probably won't start to fly until the beginning of August, said Mary Brisson, a board member and spokeswoman for Eastside Audubon.
The town's annual fireworks usually are set off from a barge floating in the lake near the park, and Brisson said her group recently asked that the display be moved from its traditional location for the sake of the young raptors. Organizers agreed.
As a result, the pyrotechnics company will relocate its launch site some 350 yards (meters) farther away from the nest, said Penny Sweet, founder of the civic group, Celebrate Kirkland, which oversees the fireworks.
The company also promised to tailor next Thursday's show to emphasize visual displays with less explosive noise to further minimize disturbing the eagle family.
"That's good for dogs and old people like me," Sweet said wryly.
She added that the new barge site will make the fireworks visible to more of the city as a whole.
Brisson said the revised plan adheres to U.S. Fish and Wildlife Service guidelines requiring fireworks displays to be located at least a half-mile from an active bald eagle nest.
As an added attraction, the Audubon Society plans to set up a July Fourth observation site at Heritage Park allowing visitors to view the eaglets and their parents through spotting scopes after the annual holiday parade and before the fireworks.
TAKING ACTION: Pope Francis took a key step Wednesday toward reforming the troubled Vatican bank, naming a five-person commission of inquiry to look into its activities amid a new money-laundering probe and continued questions about the very nature of the secretive financial institution.
WHAT ELSE: Last year there were revelations in leaked documents that told of dysfunction, petty turf wars and allegations of corruption in the Holy See's governance.
CHANGE AT THE TOP: Francis, who has made clear he has no patience for corruption and wants a "poor" church, has already named a separate commission of cardinals to advise him on the broader question of reforming the Vatican bureaucracy.
Stocks closed higher on Thursday, for a third-straight day, lifted by a string of upbeat economic reports and following several speeches from Federal Reserve policymakers suggesting the central bank has time before it starts reducing its bond-buying.
(Read More: US Economy Could Grow 5% in Late 2014: Fund Manager)
The Dow Jones Industrial Average rallied 114.35 points, to close at 15,024.49, boosted by Boeing and Hewlett-Packard, logging its first three-day rally since late April. The blue-chip index posted its 15th triple-digit move of the 19 trading sessions in June, the most in a month since October 2011.
The S&P 500 advanced 9.94 points, to finish at 1,613.20. And the Nasdaq jumped 25.64 points, to end at 3,401.86.
"If we consolidate during the next couple of sessions, the bulls need to hold the 1,600 line or this inverse head and shoulders formation will be negated," wrote Elliot Spar, market strategist at Stifel Nicolaus.
The CBOE Volatility Index (VIX), widely considered the best gauge of fear in the market, ended below 17.
Most key S&P sectors finished in positive territory, led by financials and consumer discretionary, while materials dipped.
Upbeat economic data from China also helped bolster sentiment. Industrial profits unexpectedly rose 15 percent in May year-on-year, defying expectations of a slowdown. Japan's Nikkei rallied nearly 3 percent, logging its biggest percentage gain in 13 sessions, while the Shanghai Composite Index finished flat.
"Any China data carries significant weight these days as investors are desperate for signs that the world's second biggest economy is still ticking along," wrote Stan Shamu, market strategist at IG.
On the economic front, weekly jobless claims fell 9,000 last week to a seasonally adjusted 346,000, according to the Labor Department, largely in line with expectations. The four-week moving average for new claims fell 2,750 to 345,750. And consumer spending rebounded 0.3 percent in May, matching estimates, after a revised 0.3 percent decline in the prior month, according to the Commerce Department.
"I think it makes the Fed even more confident that they're doing the right thing," said Drew Matus, senior U.S. economist and managing director at UBS. "And if you look at these numbers, they suggest that the second quarter's going to be better than the first quarter."
And pending home sales for May soared 6 percent to hit a six-year high, according to the National Association of Realtors.
New York Fed president William Dudley said the central bank's asset purchases would be more aggressive than the timeline Chairman Ben Bernanke outlined last week if economic growth and the labor market turn out weaker than expected.
Dudley added that the recent market forecasts for an earlier rate gain are "quite out of sync" with the statements and expectations of the policy-making Federal Open Market Committee. Dudley is a voting member of the FOMC.
Fed Board Governor Jerome Powell agreed that markets over-reacted to the central bank's statements on tapering.
"Market adjustments since May have been larger than would be justified by any reasonable reassessment of the path of policy," Powell said in a speech. "To the extent the market is pricing in an increase in the federal funds rate in 2014, that implies a stronger economic performance than is forecast either by most FOMC participants or by private forecasters."
Atlanta Federal Reserve Bank President Dennis Lockhart, meanwhile, said the U.S. economy's path will determine the fate of the central bank's bond buying, but it would be appropriate to pull back a bit if the economy performs as expected.
"There is no 'predetermined' pace of reductions in the asset purchases, nor is the stopping point fixed," Lockhart said in remarks prepared for delivery to the Kiwanis Club of Marietta. "The pace of purchases, the composition of purchases and the ultimate size of the Fed's balance sheet still depend on how economic conditions evolve."
Markets have been fixated on Fed commentary this week, after Bernanke said last week that the central bank could begin to wind down its $85 billion monthly bond purchases before the end of the year. That sent already rising yields higher and sent stocks on a roller-coaster ride.
Treasury prices extended their gains as yields tumbled to session lows following the data and after the auction of $29 billion in seven-year notes saw healthy demand.
JOHANNESBURG (AP) ? The South African presidency says the health condition of Nelson Mandela has become critical.
The office of President Jacob Zuma said that the president had visited the 94-year-old anti-apartheid leader on Sunday evening and was informed by the medical team that Mandela's condition had become critical in the past 24 hours.
Zuma says in a statement that the doctors are "doing everything possible to get his condition to improve."
Mandela, who became South Africa's first black president after the end of apartheid in 1994, was hospitalized on June 8 for what the government said was a recurring lung infection.
Powerful gene-editing tool appears to cause off-target mutations in human cellsPublic release date: 23-Jun-2013 [ | E-mail | Share ]
Contact: Sue McGreevey smcgreevey@partners.org 617-724-2764 Massachusetts General Hospital
Results indicate need to improve precision of CRISPR-Cas RNA-guided nucleases
In the past year a group of synthetic proteins called CRISPR-Cas RNA-guided nucleases (RGNs) have generated great excitement in the scientific community as gene-editing tools. Exploiting a method that some bacteria use to combat viruses and other pathogens, CRISPR-Cas RGNs can cut through DNA strands at specific sites, allowing the insertion of new genetic material. However, a team of Massachusetts General Hospital (MGH) researchers has found a significant limitation to the use of CRISPR-Cas RGNs, production of unwanted DNA mutations at sites other than the desired target.
"We found that expression of CRISPR-Cas RGNs in human cells can have off-target effects that, surprisingly, can occur at sites with significant sequence differences from the targeted DNA site," says J. Keith Joung, MD, PhD, associate chief for Research in the Massachusetts General Hospital (MGH) Department of Pathology and co-senior author of the report receiving online publication in Nature Biotechnology. "RGNs continue to have tremendous advantages over other genome editing technologies, but these findings have now focused our work on improving their precision."
Consisting of a DNA-cutting enzyme called Cas 9, coupled with a short, 20-nucleotide segment of RNA that matches the target DNA segment, CRISPR-Cas RGNs mimic the primitive immune systems of certain bacteria. When these microbes are infected by viruses or other organisms, they copy a segment of the invader's genetic code and incorporate it into their DNA, passing it on to future bacterial generations. If the same pathogen is encountered in the future, the bacterial enzyme called Cas9, guided by an RNA sequence the matches the copied DNA segment, inactivates the pathogen by cutting its DNA at the target site.
About a year ago, scientists reported the first use of programmed CRISPR-Cas RGNs to target and cut specific DNA sites. Since then several research teams, including Joung's, have succesfully used CRISPR-Cas RGNs to make genomic changes in fruit flies, zebrafish, mice and in human cells including induced pluripotent stem cells which have many of the characteristics of embryonic stem cells. The technology's reliance on such a short RNA segment makes CRISPR-Cas RGNs much easier to use than other gene-editing tools called zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs), and RGNs can be programmed to introduce several genetic changes at the same time.
However, the possibility that CRISPR-Cas RGNs might cause additional, unwanted genetic changes has been largely unexplored, so Joung's team set out to investigate the occurrence of "off-target" mutations in human cells expressing CRISPR-Cas RGNs. Since the interaction between the guiding RNA segment and the target DNA relies on only 20 nucleotides, they hypothesized that the RNA might also recognize DNA segments that differed from the target by a few nucleotides.
Although previous studies had found that a single-nucleotide mismatch could prevent the action of some CRISPR-Cas RGNs, the MGH team's experiments in human cell lines found multiple instances in which mismatches of as many as five nucleotides did not prevent cleavage of an off-target DNA segment. They also found that the rates of mutation at off-target sites could be as high or even higher than at the targeted site, something that has not been observed with off-target mutations associated with ZFNs or TALENs.
"Our results don't mean that RGNs cannot be important research tools, but they do mean that researchers need to account for these potentially confounding effects in their experiments. They also suggest that the existing RGN platform may not be ready for therapeutic applications," says Joung, who is an associate professor of Pathology at Harvard Medical School. "We are now working on ways to reduce these off-target effects, along with methods to identify all potential off-target sites of any given RGN in human cells so that we can assess whether any second-generation RGN platforms that are developed will be actually more precise on a genome-wide scale. I am optimistic that we can further engineer this system to achieve greater specificity so that it might be used for therapy of human diseases."
###
Jeffry D. Sander, PhD, of the MGH Molecular Pathology Unit is co-senior author of the Nature Biotechnology report. Additional co-authors are lead author Yanfang Fu, PhD; Jennifer Foden, Cyd Khayter, Morgan Maeder and Deepak Reyon, PhD, all of MGH Molecular Pathology. Support for the study includes National Institutes of Health (NIH) Director's Pioneer Award DP1 GM105378; NIH grants R01 GM088040 and P50 HG005550, DARPA grant W911NF-11-2-0056, and the Jim and Ann Orr MGH Research Scholar Award.
Massachusetts General Hospital, founded in 1811, is the original and largest teaching hospital of Harvard Medical School. The MGH conducts the largest hospital-based research program in the United States, with an annual research budget of more than $775 million and major research centers in AIDS, cardiovascular research, cancer, computational and integrative biology, cutaneous biology, human genetics, medical imaging, neurodegenerative disorders, regenerative medicine, reproductive biology, systems biology, transplantation biology and photomedicine. In July 2012, MGH moved into the number one spot on the 2012-13 U.S. News & World Report list of "America's Best Hospitals."
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AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.
Powerful gene-editing tool appears to cause off-target mutations in human cellsPublic release date: 23-Jun-2013 [ | E-mail | Share ]
Contact: Sue McGreevey smcgreevey@partners.org 617-724-2764 Massachusetts General Hospital
Results indicate need to improve precision of CRISPR-Cas RNA-guided nucleases
In the past year a group of synthetic proteins called CRISPR-Cas RNA-guided nucleases (RGNs) have generated great excitement in the scientific community as gene-editing tools. Exploiting a method that some bacteria use to combat viruses and other pathogens, CRISPR-Cas RGNs can cut through DNA strands at specific sites, allowing the insertion of new genetic material. However, a team of Massachusetts General Hospital (MGH) researchers has found a significant limitation to the use of CRISPR-Cas RGNs, production of unwanted DNA mutations at sites other than the desired target.
"We found that expression of CRISPR-Cas RGNs in human cells can have off-target effects that, surprisingly, can occur at sites with significant sequence differences from the targeted DNA site," says J. Keith Joung, MD, PhD, associate chief for Research in the Massachusetts General Hospital (MGH) Department of Pathology and co-senior author of the report receiving online publication in Nature Biotechnology. "RGNs continue to have tremendous advantages over other genome editing technologies, but these findings have now focused our work on improving their precision."
Consisting of a DNA-cutting enzyme called Cas 9, coupled with a short, 20-nucleotide segment of RNA that matches the target DNA segment, CRISPR-Cas RGNs mimic the primitive immune systems of certain bacteria. When these microbes are infected by viruses or other organisms, they copy a segment of the invader's genetic code and incorporate it into their DNA, passing it on to future bacterial generations. If the same pathogen is encountered in the future, the bacterial enzyme called Cas9, guided by an RNA sequence the matches the copied DNA segment, inactivates the pathogen by cutting its DNA at the target site.
About a year ago, scientists reported the first use of programmed CRISPR-Cas RGNs to target and cut specific DNA sites. Since then several research teams, including Joung's, have succesfully used CRISPR-Cas RGNs to make genomic changes in fruit flies, zebrafish, mice and in human cells including induced pluripotent stem cells which have many of the characteristics of embryonic stem cells. The technology's reliance on such a short RNA segment makes CRISPR-Cas RGNs much easier to use than other gene-editing tools called zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs), and RGNs can be programmed to introduce several genetic changes at the same time.
However, the possibility that CRISPR-Cas RGNs might cause additional, unwanted genetic changes has been largely unexplored, so Joung's team set out to investigate the occurrence of "off-target" mutations in human cells expressing CRISPR-Cas RGNs. Since the interaction between the guiding RNA segment and the target DNA relies on only 20 nucleotides, they hypothesized that the RNA might also recognize DNA segments that differed from the target by a few nucleotides.
Although previous studies had found that a single-nucleotide mismatch could prevent the action of some CRISPR-Cas RGNs, the MGH team's experiments in human cell lines found multiple instances in which mismatches of as many as five nucleotides did not prevent cleavage of an off-target DNA segment. They also found that the rates of mutation at off-target sites could be as high or even higher than at the targeted site, something that has not been observed with off-target mutations associated with ZFNs or TALENs.
"Our results don't mean that RGNs cannot be important research tools, but they do mean that researchers need to account for these potentially confounding effects in their experiments. They also suggest that the existing RGN platform may not be ready for therapeutic applications," says Joung, who is an associate professor of Pathology at Harvard Medical School. "We are now working on ways to reduce these off-target effects, along with methods to identify all potential off-target sites of any given RGN in human cells so that we can assess whether any second-generation RGN platforms that are developed will be actually more precise on a genome-wide scale. I am optimistic that we can further engineer this system to achieve greater specificity so that it might be used for therapy of human diseases."
###
Jeffry D. Sander, PhD, of the MGH Molecular Pathology Unit is co-senior author of the Nature Biotechnology report. Additional co-authors are lead author Yanfang Fu, PhD; Jennifer Foden, Cyd Khayter, Morgan Maeder and Deepak Reyon, PhD, all of MGH Molecular Pathology. Support for the study includes National Institutes of Health (NIH) Director's Pioneer Award DP1 GM105378; NIH grants R01 GM088040 and P50 HG005550, DARPA grant W911NF-11-2-0056, and the Jim and Ann Orr MGH Research Scholar Award.
Massachusetts General Hospital, founded in 1811, is the original and largest teaching hospital of Harvard Medical School. The MGH conducts the largest hospital-based research program in the United States, with an annual research budget of more than $775 million and major research centers in AIDS, cardiovascular research, cancer, computational and integrative biology, cutaneous biology, human genetics, medical imaging, neurodegenerative disorders, regenerative medicine, reproductive biology, systems biology, transplantation biology and photomedicine. In July 2012, MGH moved into the number one spot on the 2012-13 U.S. News & World Report list of "America's Best Hospitals."
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AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.
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Public release date: 23-Jun-2013
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