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Erik Stokstad
With few natural predators left, deer are running rampant across much of eastern North America and Europe. In addition to damaging crops, raising the risk of Lyme disease, and smashing into cars, white-tailed deer are eating their way through forests. "This is a widespread conservation problem," says Lee Frelich of the University of Minnesota, Twin Cities. Indeed, in the article in Science , a detailed, 5-year forest survey of ginseng reveals that deer, if not checked, will almost certainly drive the economically valuable medicinal plant to extinction in the wild.
The survey was conducted by James McGraw, a plant ecologist at West Virginia University in Morgantown, and his graduate student Mary Ann Furedi. Ginseng is one of the most widely harvested medicinal plants in the United States; in 2003, 34,084 kilograms were exported, mainly to Asia, where wild ginseng root fetches a premium. Although the plant (Panax quinquefolius) ranges from Georgia to Quebec, it is slow-growing and scarce everywhere.
To determine the population trends of ginseng, McGraw and Furedi began a census in West Virginia forests. For 5 years, they checked seven populations of wild ginseng every 3 weeks during the spring and summer. They quickly noticed that plants were disappearing. In some places, all of the largest, most fertile plants were gone by mid-August. At first they suspected ginseng harvesters, but the valuable roots were left. Cameras confirmed that deer were at work. The nibbled plants are less likely to reproduce, and after repeated grazing, they die. Indeed, during the study, populations declined by 2.7% per year on average.
McGraw and Furedi then ran a ginseng population viability analysis. By plugging in the sizes of plants in various populations, mortality rates, and other factors, they learned that current ginseng populations must contain at least 800 plants in order to have a 95% chance of surviving for 100 years.
That's bad news. A broader survey they conducted of 36 ginseng populations across eight states revealed that the median size was just 93 plants and the largest was only 406 plants. At the current rate of grazing, all of these populations "are fluctuating toward extinction," McGraw concludes. Even the biggest population has only a 57% chance of surviving this century.
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Mark Peplow
First field results prove plant can remove soil contaminants.
Genetically modified Indian mustard plants have successfully cleaned up excessive selenium in a California field.
This is the first field trial for a pollution-busting transgenic plant, and it proves that the technology can work outside the laboratory, say the researchers who carried out the test.
Farmland in certain parts of California is heavily irrigated, and the water dissolves selenium in shale found in the region. As the water evaporates on the surface soil, selenium is concentrated to levels that are toxic to plants. But Indian mustard (Brassica juncea) has a natural resistance to the element, and absorbs it as it takes in water through its roots.
"Indian mustard is able to grow fast and attain a high biomass even under environmentally stressful conditions," says Norman Terry, a plant biologist at the University of California, Berkeley, who led the study. The researchers boosted Indian mustard's abilities by adding extra genes that produce selenium-hungry enzymes.
They found that the transgenic plants could accumulate up to 4.3 times as much selenium as conventional, wild-type Indian mustard. The research is published online in Environmental Science & Technology.
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Massachusetts legislators are bracing for a tough political battle over stem cell research following a surprise announcement by Republican governor Mitt Romney. Responding to a bill introduced this week in the state Senate, Romney said he's all for research with human embryonic stem cells, but "the law should prohibit all human cloning and the creation of new human embryos for the purpose of research." Scientists and lawmakers fear the announcement could hamper university and biotech research in the state.
While Massachusetts is home to many leading stem cell researchers, state laws bearing on research with human embryonic stem cells have been discouragingly vague, requiring county district attorneys to interpret the law for researchers in their jurisdictions. Efforts to clear the way have been quashed in the past by conservative Catholic politicians.
This year legislators hope to break through the impasse with a new bill, introduced by Senate president Robert Travaglini (D-Boston), that allows research on surplus embryos generated at fertilization clinics, and sets up a new ethics body to oversee the research. The definition of embryos in the bill explicitly includes those created by cloning, or somatic cell nuclear transfer, a procedure scientists say is crucial for realizing the promise of such research.
Scientists and lawmakers had been optimistic that they would get backing from Romney, who has expressed support of stem cell research and whose wife, Ann, has multiple sclerosis, one of the diseases that researchers hope to ultimately treat with stem cells.
After receiving the governor's response, Travaglini held a press conference in which Harvard stem cell researchers George Daley and Leonard Zon deplored efforts to "criminalize" what they characterized as vital research.
The governor's action was "very surprising to all of us," says Robert Lanza of Advanced Cell Technologies, Inc. in Worcester, which does research on somatic cell nuclear transfer. "We had all thought he would sign the legislation." Now, he says, "this throws everything up in the air."
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By CURT WOODWARD, Associated Press Writer
Months after samples of a promising biotech wheat variety were uprooted from research plots and destroyed, some farm-country lawmakers are trying to raise the financial stakes for bringing the wheat back.
Their proposals would hold seed developers responsible for money damage claims from organic farmers and other producers who shun biotech wheat. They have been praised as ways to protect family farms, and denounced as attempts to block revolutionary technology.
Terry Wanzek, a rural Jamestown farmer who is president of the North Dakota Grain Growers Association, said increasing biotech companies' legal exposure would discourage them from attempting to remedy common wheat diseases, or developing varieties that thrive in harsh climates.
"I can't imagine sitting in a rocking chair on my porch telling my kids, 'I fought biotech,'" Wanzek said. "It'll sound as absurd as saying, 'I fought Louis Pasteur' or 'I fought Thomas Edison.'"
Others, like Montana state Sen. Jon Tester, say farmers must be able to seek damages from biotech companies if their crops are contaminated once the altered wheat takes root. He says claims that research would be limited are "a smoke screen."
"I think that if this stuff is well thought out and well researched, then step up to the plate and stand behind it," he said.
Tester is among the supporters of legislation that would assign strict financial liability to companies that produce biotech wheat. The measures are being considered in North Dakota and Montana, with similar bills applying to all biotech crops introduced in Hawaii and Vermont.
The legislation would shield farmers from most financial claims if a biotech crop creeps into a field or grain elevator where it isn't wanted, and contaminates non-biotech supplies. The idea has been proposed before, but has not become law in any state, according to the National Conference of State Legislatures.
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WASHINGTON (Reuters) - Pig embryos could provide sources of new organ and tissue transplants for people, and they may pose fewer risks than using material from adult animals, Israeli researchers reported on Monday.
They found that if cells were taken from pig embryos at precisely the right time, they grew into liver, pancreas and lung tissues in mice.
"Considering the ethical issues associated with human embryonic stem cells or with precursor tissue obtained from human abortions, we believe that the use of embryonic pig tissue could afford a more simple solution to the shortage of organ donors," said Yair Reisner of the Weizmann Institute of Science, who led the study.
Writing in the Proceedings of the National Academy of Sciences, Reisner and colleagues said their findings also help explain why earlier experiments did not work. If transplanted at the wrong time, they found the pig embryo cells grew into tumors called teratomas instead of the desired tissue.
Not only is there a shortage of whole organs for transplant, but tissue transplants could be used to treat diseases such as diabetes, Parkinson's and liver failure. Experiments have been done using cells from human fetuses as well as from animals.
Many researchers are working on the possibility of animal to human transplants, also called xenotransplants. Pigs are a popular choice because they are about the same size as humans and have a similar physiology.
But there are big hurdles, not the least of which is massive rejection by the human body of animal tissue.
Reisner noted that other researchers are working to genetically engineer pigs that do not carry the protein responsible for the immune response. And embryos may have less of it, he added in an e-mail.
"We anticipate that immune suppression required might be less intense compared to that employed in the context of adult tissue transplantation," he said.
It may be easier to work with embryonic cells than with more mature tissue, Reisner added.
"The great advantage of embryonic tissue implantation is that it does not require any manipulation ex-vivo (outside of the body). The precursor tissue is simply implanted and grows in the recipient," he wrote.
The other hurdle involves porcine endogenous retroviruses, found in pig cells. While they are likely to be found in embryonic tissue he said, he believes they are unlikely to infect a human transplant recipient.
Xenotransplant researchers have agreed to a voluntary moratorium on transplanting pig tissue into people until the question is fully resolved.
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Roxanne Khamsi
Plant that contains vaccine shows promise in human trials.
Genetically modified potatoes can deliver the disease protection that normally comes from a vaccine shot, say scientists, which could be good news for developing nations.
The hepatitis B virus attacks the liver and claims the lives of more than half a million people each year. But conventional vaccines require cold storage, which can be hard to guarantee in the remote areas of developing countries with warm climates. And medical workers often have a tough time determining whether a delivery of the relatively costly hepatitis B vaccine has received accidental exposure to heat, rendering it ineffective, says biologist Charles Arntzen of Arizona State University in Tempe, who worked on the research.
So Arntzen and his colleagues have designed an edible vaccine that can be stored without refrigeration inside a humble potato. They took a gene out of the hepatitis B virus and incorporated it in the potato plant, which responded by producing the virus antigen. Once ingested, this antigen protein creates an immune response in the human body that acts as a booster shot against the hepatitis B virus.
The team says that although this approach is unlikely to supersede initial vaccinations, it could replace the repeated booster injections needed to maintain immunity. "This has the potential for a big impact on global health," says immunologist Julian Ma of St George's Hospital Medical School in London.
An edible vaccine would reduce the need for needles and make it simpler to administer on multiple occasions. This gives it an advantage over the full vaccination programme, which involves a series of three injections given over many months.
Participants in the study had already received the primary injections against hepatitis B between 1 and 15 years ago. Arntzen and his colleagues found that 19 of the 33 people in their study produced more antibodies against hepatitis B after eating the potatoes. One subject's protective antibodies increased 56-fold, the team reports in the Proceedings of the National Academy of Sciences1.
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