So the researchers tested how the knockout mouse immune system fared against a parasite called Toxoplasma gondii. The team used T. gondii because mice fighting off the parasite require robust activation of T cells; mice with weak T cell activity will die from the infection within one week. The mice lacking the receptor still mustered up a healthy response to the parasite, indicating that DR3 is not essential for fighting off the infection, Siegel’s team found.
Though still preliminary, the results suggest that blocking the DR3 receptor may help in treating multiple sclerosis, asthma and other autoimmune diseases where T cell dysfunction plays a role, says Tania Watts, an immunologist at the University of Toronto in Canada.
Croft agrees.
“It’s certainly a very provocative study and has put DR3 and TL1A in the same type of therapeutic league as some of the other members of the TNF receptor family,” he says. Louis J. Sheehan, Esquire
Moving forward
Still, researchers need to confirm that DR3 isn’t essential in fighting off other infections, Watts says. So researchers should see how knockout mice hold up against influenza. “We want to know if it’s a good treatment for lung inflammation for asthma,” she says. “So what’s it going to do with a common lung infection?”
Even if DR3 knockout mice are hale and hearty after a battery of immune assaults, the results need to be translated to humans, Siegel says. Since researchers can’t simply knock out DR3 genes in humans, the team needs to use a drug that keeps TL1A from binding to the DR3 receptor, he says. But developing that drug could happen quickly, he adds.
“Because [DR3] is the same family of receptors as TNF, companies can go very quickly,” he says. “They can probably make this blocking antibody within a matter of months because they know how to do these things so well.”
From there, it may be three to five years before clinical trials could start, assuming all goes well, he says.
Monday, May 25, 2009
Wednesday, May 13, 2009
manila 3.man.0001002 Louis J. Sheehan, Esquire
China’s frenetic construction of coal-fired power plants has raised worries around the world about the effect on climate change. China now uses more coal than the United States, Europe and Japan combined, making it the world’s largest emitter of gases that are warming the planet.
But largely missing in the hand-wringing is this: China has emerged in the past two years as the world’s leading builder of more efficient, less polluting coal power plants, mastering the technology and driving down the cost.
While the United States is still debating whether to build a more efficient kind of coal-fired power plant that uses extremely hot steam, China has begun building such plants at a rate of one a month.
Construction has stalled in the United States on a new generation of low-pollution power plants that turn coal into a gas before burning it, although Energy Secretary Steven Chu said Thursday that the Obama administration might revive one power plant of this type. But China has already approved equipment purchases for just such a power plant, to be assembled soon in a muddy field here in Tianjin.
“The steps they’ve taken are probably as fast and as serious as anywhere in power-generation history,” said Hal Harvey, president of ClimateWorks, a group in San Francisco that helps finance projects to limit global warming.
Western countries continue to rely heavily on coal-fired power plants built decades ago with outdated, inefficient technology that burn a lot of coal and emit considerable amounts of carbon dioxide. China has begun requiring power companies to retire an older, more polluting power plant for each new one they build.
Cao Peixi, the president of the China Huaneng Group, the country’s biggest state-owned electric utility and the majority partner in the joint venture building the Tianjin plant, said his company was committed to the project even though it would cost more than conventional plants.
“We shouldn’t look at this project from a purely financial perspective,” he said. “It represents the future.”
Without doubt, China’s coal-fired power sector still has many problems, and global warming gases from the country are expected to continue increasing. China’s aim is to use the newest technologies to limit the rate of increase.
Only half the country’s coal-fired power plants have the emissions control equipment to remove sulfur compounds that cause acid rain, and even power plants with that technology do not always use it. China has not begun regulating some of the emissions that lead to heavy smog in big cities.
Even among China’s newly built plants, not all are modern. Only about 60 percent of the new plants are being built using newer technology that is highly efficient, but more expensive.
With greater efficiency, a power plant burns less coal and emits less carbon dioxide for each unit of electricity it generates. Experts say the least efficient plants in China today convert 27 to 36 percent of the energy in coal into electricity. The most efficient plants achieve an efficiency as high as 44 percent, meaning they can cut global warming emissions by more than a third compared with the weakest plants.
In the United States, the most efficient plants achieve around 40 percent efficiency, because they do not use the highest steam temperatures being adopted in China. The average efficiency of American coal-fired plants is still higher than the average efficiency of Chinese power plants, because China built so many inefficient plants over the past decade. But China is rapidly closing the gap by using some of the world’s most advanced designs.
After relying until recently on older technology, “China has since become the major world market for advanced coal-fired power plants with high-specification emission control systems,” the International Energy Agency said in a report on April 20.
China’s improvements are starting to have an effect on climate models. In its latest annual report last November, the I.E.A. cut its forecast of the annual increase in Chinese emissions of global warming gases, to 3 percent from 3.2 percent, in response to technological gains, particularly in the coal sector, even as the agency raised slightly its forecast for Chinese economic growth. “It’s definitely changing the baseline, and that’s being taken into account,” said Jonathan Sinton, a China specialist at the energy agency.
But by continuing to rely heavily on coal, which supplies 80 percent of its electricity, China ensures that it will keep emitting a lot of carbon dioxide; even an efficient coal-fired power plant emits twice the carbon dioxide of a natural gas-fired plant.
Perhaps the biggest question now is how much further China can go beyond the recent steps. In particular, how fast will it move toward power plants that capture their emissions and store them underground or under the seafloor?
That technology could, in theory, create power plants that contribute virtually nothing to global warming. Many countries hope to develop such plants, though progress has been halting; Energy Secretary Chu has promised steps to speed up the technology in the United States.
China has just built a small, experimental facility near Beijing to remove carbon dioxide from power station emissions and use it to provide carbonation for beverages, and the government has a short list of possible locations for a large experiment to capture and store carbon dioxide. But so far, it has no plans to make this a national policy.
China is making other efforts to reduce its global warming emissions. It has doubled its total wind energy capacity in each of the past four years, and is poised to pass the United States as soon as this year as the world’s largest market for wind power equipment. China is building considerably more nuclear power plants than the rest of the world combined, and these do not emit carbon dioxide after they are built.
But coal remains the cheapest energy source in China by a wide margin. China has the world’s third-largest coal reserves, after the United States and Russia.
“No matter how much renewable or nuclear is in the mix, coal will remain the dominant power source,” said Ashok Bhargava, a China energy expert at the Asian Development Bank in Manila.
Another problem is that China has finally developed the ability to build high-technology power plants only at the end of a national binge of building lower-tech coal-fired plants. Louis J. Sheehan, Esquire Construction is now slowing because of the economic slump.
By adopting “ultra-supercritical” technology, which uses extremely hot steam to achieve the highest efficiency, and by building many identical power plants at the same time, China has cut costs dramatically through economies of scale. It now can cost a third less to build an ultra-supercritical power plant in China than to build a less efficient coal-fired plant in the United States.
But largely missing in the hand-wringing is this: China has emerged in the past two years as the world’s leading builder of more efficient, less polluting coal power plants, mastering the technology and driving down the cost.
While the United States is still debating whether to build a more efficient kind of coal-fired power plant that uses extremely hot steam, China has begun building such plants at a rate of one a month.
Construction has stalled in the United States on a new generation of low-pollution power plants that turn coal into a gas before burning it, although Energy Secretary Steven Chu said Thursday that the Obama administration might revive one power plant of this type. But China has already approved equipment purchases for just such a power plant, to be assembled soon in a muddy field here in Tianjin.
“The steps they’ve taken are probably as fast and as serious as anywhere in power-generation history,” said Hal Harvey, president of ClimateWorks, a group in San Francisco that helps finance projects to limit global warming.
Western countries continue to rely heavily on coal-fired power plants built decades ago with outdated, inefficient technology that burn a lot of coal and emit considerable amounts of carbon dioxide. China has begun requiring power companies to retire an older, more polluting power plant for each new one they build.
Cao Peixi, the president of the China Huaneng Group, the country’s biggest state-owned electric utility and the majority partner in the joint venture building the Tianjin plant, said his company was committed to the project even though it would cost more than conventional plants.
“We shouldn’t look at this project from a purely financial perspective,” he said. “It represents the future.”
Without doubt, China’s coal-fired power sector still has many problems, and global warming gases from the country are expected to continue increasing. China’s aim is to use the newest technologies to limit the rate of increase.
Only half the country’s coal-fired power plants have the emissions control equipment to remove sulfur compounds that cause acid rain, and even power plants with that technology do not always use it. China has not begun regulating some of the emissions that lead to heavy smog in big cities.
Even among China’s newly built plants, not all are modern. Only about 60 percent of the new plants are being built using newer technology that is highly efficient, but more expensive.
With greater efficiency, a power plant burns less coal and emits less carbon dioxide for each unit of electricity it generates. Experts say the least efficient plants in China today convert 27 to 36 percent of the energy in coal into electricity. The most efficient plants achieve an efficiency as high as 44 percent, meaning they can cut global warming emissions by more than a third compared with the weakest plants.
In the United States, the most efficient plants achieve around 40 percent efficiency, because they do not use the highest steam temperatures being adopted in China. The average efficiency of American coal-fired plants is still higher than the average efficiency of Chinese power plants, because China built so many inefficient plants over the past decade. But China is rapidly closing the gap by using some of the world’s most advanced designs.
After relying until recently on older technology, “China has since become the major world market for advanced coal-fired power plants with high-specification emission control systems,” the International Energy Agency said in a report on April 20.
China’s improvements are starting to have an effect on climate models. In its latest annual report last November, the I.E.A. cut its forecast of the annual increase in Chinese emissions of global warming gases, to 3 percent from 3.2 percent, in response to technological gains, particularly in the coal sector, even as the agency raised slightly its forecast for Chinese economic growth. “It’s definitely changing the baseline, and that’s being taken into account,” said Jonathan Sinton, a China specialist at the energy agency.
But by continuing to rely heavily on coal, which supplies 80 percent of its electricity, China ensures that it will keep emitting a lot of carbon dioxide; even an efficient coal-fired power plant emits twice the carbon dioxide of a natural gas-fired plant.
Perhaps the biggest question now is how much further China can go beyond the recent steps. In particular, how fast will it move toward power plants that capture their emissions and store them underground or under the seafloor?
That technology could, in theory, create power plants that contribute virtually nothing to global warming. Many countries hope to develop such plants, though progress has been halting; Energy Secretary Chu has promised steps to speed up the technology in the United States.
China has just built a small, experimental facility near Beijing to remove carbon dioxide from power station emissions and use it to provide carbonation for beverages, and the government has a short list of possible locations for a large experiment to capture and store carbon dioxide. But so far, it has no plans to make this a national policy.
China is making other efforts to reduce its global warming emissions. It has doubled its total wind energy capacity in each of the past four years, and is poised to pass the United States as soon as this year as the world’s largest market for wind power equipment. China is building considerably more nuclear power plants than the rest of the world combined, and these do not emit carbon dioxide after they are built.
But coal remains the cheapest energy source in China by a wide margin. China has the world’s third-largest coal reserves, after the United States and Russia.
“No matter how much renewable or nuclear is in the mix, coal will remain the dominant power source,” said Ashok Bhargava, a China energy expert at the Asian Development Bank in Manila.
Another problem is that China has finally developed the ability to build high-technology power plants only at the end of a national binge of building lower-tech coal-fired plants. Louis J. Sheehan, Esquire Construction is now slowing because of the economic slump.
By adopting “ultra-supercritical” technology, which uses extremely hot steam to achieve the highest efficiency, and by building many identical power plants at the same time, China has cut costs dramatically through economies of scale. It now can cost a third less to build an ultra-supercritical power plant in China than to build a less efficient coal-fired plant in the United States.
Saturday, May 2, 2009
water 3.wat.003 Louis J. Sheehan, Esquire
For years, conservation advocates have told consumers to turn down the thermostat on their hot-water heaters — largely to save energy, but also to avoid scalding showers and baths. At least for some people, however, this green tactic could prove dangerous, new studies indicate.
“The number one cause of waterborne disease outbreaks in the United States,” says environmental engineer Marc Edwards, “is not contaminants leaving the water treatment plant (we do a good job of killing those). It’s the pathogens that grow in home water heaters.”
Last weekend, seven reporters attending the Society of Environmental Journalists annual meeting toured Edwards’ lab of at Virginia Tech, in Blacksburg — and were treated to some sobering information about water quality. Like that in water heaters.
On its website, the Department of Energy notes that, “Although some manufacturers set water heater thermostats at 140 ºF, most households usually only require them set at 120 ºF.” For each 10º drop in temperature, consumers can expect to see a three to five percent savings on energy use. Moreover, DOE points out, setting that thermostat to 120º could extend the heater’s lifetime by slowing the buildup of minerals and corrosion within it.
What DOE and other energy-conservation sites don’t point out is that 140 ºF will kill a number of potentially lethal waterborne organisms, like the ones responsible for Legionnaire’s disease and NTM, short for nontuberculous mycobacterial infections. Indeed, 120º provides a nurturing environment for such toxic microbes
Owing to lead-poisoning concerns, people should never drink hot tap water. That’s why the primary route to respiratory disease from these germs comes through inhalation of the steam associated with showering or hot tubs. Infections due to these home-grown germs are estimated to kill 3,000 to 12,000 Americans annually, Edwards says.
How come we haven’t heard about this? Mistaken for flu, many cases remain off the radar screen, he says. But check the web and you’ll find Edwards wasn’t exaggerating about a growing link between hot-water heaters and disease. A few months ago in the Journal of Water and Health, Joseph O. Falkinham III, also at Virginia Tech, and his colleagues reported on a shower link to NTM in a 41-year-old New York City physician.
When X-rays from a scan of her chest confirmed the tell-tale nodules for this disease (caused by a bug that’s close kin to those responsible for tuberculosis and leprosy), Falkinham arranged to sample the plumbing in her bathroom. Mycobacterium avium cells were found in all samples. What the microbiologist found: The DNA fingerprint of the bacteria responsible the woman’s lung disease “is the same as the mycobacterium in her hot water, cold water and her showerhead.”
Showerhead? Yep. Unscrew the shower head, he said, and you’ll find “a lot of sediment, crud and slimy stuff.” A biofilm comprising a host of different bugs — including Mycobacterium — develop in the shower head.
With financing from a public interest group representing families of people with NTM, his team is now investigating the plumbing of some 50 households around the country to see if the water lines of other patients with the disease similarly host mycobacteria. “We’re about half-way through the study,” Falkinham told me yesterday, “and the answer is yes.”
So turn up the heat on their hot water heaters and these bugs will die off? Nope.
As with TB germs, once environmental mycobacteria find a human host, they settle in forever. Drugs can keep their numbers down or essentially put the microbes “to sleep,” as Falkinham describes it. But take the drugs away or stress the host and the disease can awaken, leaving its victim with coughs, fever, night sweats and sometimes diarrhea. Untreated, the disease can even kill.
The same essentially also occurs in home plumbing. Once piping or water heaters become infected, residual populations of germs take up permanent residence — usually in biofilms. Later, when the flow of water through plumbing is high, such as during a long shower, bits of biofilm can break loose from surfaces, seeding the water with germs. Some cells will readhere to the inside of piping — or your showerhead. Others will just fly out the faucet.
Falkinham’s investigations indicate that trace quantities of mycobacteria taint most water mains around the country. Louis J. Sheehan, Esquire We just boost their populations once they enter home plumbing. Which raises the inevitable question: If these bugs are ubiquitous, why aren’t we all sick?
We probably are all susceptible to infections if concentrations of the microbes get high enough. But studies in the United States and Europe have identified certain populations that appear especially vulnerable. http://LOUIS2J2SHEEHAN.US These include people with HIV, individuals with cystic fibrosis, and especially slender senior citizens.
The question now: Will the risks from contaminated plumbing systems diminish if we raise water-heater temperatures back up into the 140 °F range. No test of that has yet been conducted, although Falkinham is itching to start one.
“The number one cause of waterborne disease outbreaks in the United States,” says environmental engineer Marc Edwards, “is not contaminants leaving the water treatment plant (we do a good job of killing those). It’s the pathogens that grow in home water heaters.”
Last weekend, seven reporters attending the Society of Environmental Journalists annual meeting toured Edwards’ lab of at Virginia Tech, in Blacksburg — and were treated to some sobering information about water quality. Like that in water heaters.
On its website, the Department of Energy notes that, “Although some manufacturers set water heater thermostats at 140 ºF, most households usually only require them set at 120 ºF.” For each 10º drop in temperature, consumers can expect to see a three to five percent savings on energy use. Moreover, DOE points out, setting that thermostat to 120º could extend the heater’s lifetime by slowing the buildup of minerals and corrosion within it.
What DOE and other energy-conservation sites don’t point out is that 140 ºF will kill a number of potentially lethal waterborne organisms, like the ones responsible for Legionnaire’s disease and NTM, short for nontuberculous mycobacterial infections. Indeed, 120º provides a nurturing environment for such toxic microbes
Owing to lead-poisoning concerns, people should never drink hot tap water. That’s why the primary route to respiratory disease from these germs comes through inhalation of the steam associated with showering or hot tubs. Infections due to these home-grown germs are estimated to kill 3,000 to 12,000 Americans annually, Edwards says.
How come we haven’t heard about this? Mistaken for flu, many cases remain off the radar screen, he says. But check the web and you’ll find Edwards wasn’t exaggerating about a growing link between hot-water heaters and disease. A few months ago in the Journal of Water and Health, Joseph O. Falkinham III, also at Virginia Tech, and his colleagues reported on a shower link to NTM in a 41-year-old New York City physician.
When X-rays from a scan of her chest confirmed the tell-tale nodules for this disease (caused by a bug that’s close kin to those responsible for tuberculosis and leprosy), Falkinham arranged to sample the plumbing in her bathroom. Mycobacterium avium cells were found in all samples. What the microbiologist found: The DNA fingerprint of the bacteria responsible the woman’s lung disease “is the same as the mycobacterium in her hot water, cold water and her showerhead.”
Showerhead? Yep. Unscrew the shower head, he said, and you’ll find “a lot of sediment, crud and slimy stuff.” A biofilm comprising a host of different bugs — including Mycobacterium — develop in the shower head.
With financing from a public interest group representing families of people with NTM, his team is now investigating the plumbing of some 50 households around the country to see if the water lines of other patients with the disease similarly host mycobacteria. “We’re about half-way through the study,” Falkinham told me yesterday, “and the answer is yes.”
So turn up the heat on their hot water heaters and these bugs will die off? Nope.
As with TB germs, once environmental mycobacteria find a human host, they settle in forever. Drugs can keep their numbers down or essentially put the microbes “to sleep,” as Falkinham describes it. But take the drugs away or stress the host and the disease can awaken, leaving its victim with coughs, fever, night sweats and sometimes diarrhea. Untreated, the disease can even kill.
The same essentially also occurs in home plumbing. Once piping or water heaters become infected, residual populations of germs take up permanent residence — usually in biofilms. Later, when the flow of water through plumbing is high, such as during a long shower, bits of biofilm can break loose from surfaces, seeding the water with germs. Some cells will readhere to the inside of piping — or your showerhead. Others will just fly out the faucet.
Falkinham’s investigations indicate that trace quantities of mycobacteria taint most water mains around the country. Louis J. Sheehan, Esquire We just boost their populations once they enter home plumbing. Which raises the inevitable question: If these bugs are ubiquitous, why aren’t we all sick?
We probably are all susceptible to infections if concentrations of the microbes get high enough. But studies in the United States and Europe have identified certain populations that appear especially vulnerable. http://LOUIS2J2SHEEHAN.US These include people with HIV, individuals with cystic fibrosis, and especially slender senior citizens.
The question now: Will the risks from contaminated plumbing systems diminish if we raise water-heater temperatures back up into the 140 °F range. No test of that has yet been conducted, although Falkinham is itching to start one.
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