Libya and Canada sign nuclear deal

Libya and Canada have signed a memorandum of intent on nuclear power, the fourth signed by Tripoli in the past two years, an official said on Thursday.

The memorandum foresees cooperation between the two countries in research and the mining, processing and transport of uranium, as well as its use in medicine and desalination projects.

Since July 2007, Libya has signed another three similar agreements with France, Russia and Ukraine.

OPEC member Libya is also the African continent's third largest oil producer after Nigeria and Angola, pumping nearly two million barrels of crude oil per day. It hopes to increase production to three million bpd by 2013.

Glass leaf 'sweats' to generate electricity

Artificial photosynthesis has yet to be cracked, but electrical engineers in the US think that synthetic leaves could be used to generate electricity in a different way – by sweating.

Natural leaves constantly lose water through evaporation in a process called transpiration, which draws water from the roots to the very top of even the tallest trees.

The new synthetic leaves also lose water through evaporation to create that mechanical water pump effect, and use it to generate power.

Flowing bubbles

Michel Maharbiz at the University of California, Berkeley, working with colleagues at the University of Michigan and MIT, built their leaves from glass wafers shot through with a branching network of tiny water-filled channels arranged like the veins of a leaf.

The smaller channels extend to the edge of the plate and have open ends that allow water to evaporate, drawing fluid along the leaf's central stem at a rate of 1.5 centimetres per second.

The researchers added metal plates to the walls of the central stem and connected them to a circuit. The charged plates and the water within the stem create a sandwich of two conducting layers separated by an insulating layer – in effect, a capacitor.

The leaf is transformed into a source of power by periodically interrupting the water flowing into the leaf with air bubbles. Thanks to the different electrical properties of air and water, every time a bubble passes between the plates the capacitance of the device changes and a small electric current is generated, which passes to an external circuit where it's used to pump up the voltage on a storage capacitor.

"We use the mechanical energy in the liquid flow to change the capacitance and add energy to the capacitor," says Maharbiz.

Energy scavenger

Each bubble results in an increase in output voltage of some 2 to 5 microvolts, and the device has a power density of some 2 microwatts per cubic centimetre. "I think we could easily reach hundreds of microwatts per cubic centimetre [with modifications]," he says.

That is still a fraction of the power density of power systems such as fuel cells or batteries, but it's a respectable figure for an energy scavenging system, Maharbiz says.

The device could be scaled up to produce artificial trees that generate power entirely through evaporation wherever there's a cyclical change in humidity. Although the modest power output is not enough to rival solar technology, Maharbiz thinks it could act as a complementary technology – the sunlight that generates solar power could also drive transpiration to boost the electricity generated.

Breaking the tension

Abraham Stroock at Cornell University in Ithaca, New York, thinks this is the first attempt to generate electricity from evaporation-driven flow. Although he points out that one US firm Voltree has succeeded in generating tiny quantities of power from the pH difference between soil and the roots of real trees.

"One challenge with the new study is that a bubble is used to generate the current in the capacitor," Stroock says. Bubbles prevent transpiration taking place over long distances because they break the tension that allows the water column to be pulled along like a piece of string.

Maharbiz says he can get round this issue by using solid insulators instead of bubbles, that spin in place as the water is pulled passed like a water wheel to create the permittivity differences needed to generate power.

Study: Global warming speeds CO2 release

Global warming is speeding the release of carbon dioxide, a chief greenhouse gas, from underground peat in subarctic wetlands, Dutch research indicates.
The research suggests rising temperatures are adding to the magnitude and velocity of global warming, Free University plant ecologist Ellen Dorrepaal and colleagues write in the journal Nature.
Their research shows that raising temperatures about 1 degree Celsius accelerates total ecosystem respiration rates by as much as 60 percent, creating an effect that can last at least eight years.
This is greater than previously thought, highlighting the extreme sensitivity of northern peatland carbon reservoirs to global warming, the researchers say.
Peat is an accumulation of partially decayed plant matter that forms in wetlands, or peatlands. The peatlands, forming for 360 million years, cover about 2 percent of the earth's land mass and contain 550 gigatons (10 to the ninth power) of carbon.
The subarctic region is just south of the true arctic, covering much of Alaska, Canada, southern Greenland, the north of Scandinavia, Siberia, northern Mongolia and parts of China.

Past warming shows gaps in climate knowledge: study

A dramatic warming of the planet 55 million years ago cannot be solely explained by a surge in carbon dioxide levels, a study shows, highlighting gaps in scientists' understanding of impacts from rapid climate change.
During an event called the Palaeocene-Eocene Thermal Maximum, global temperatures rose between 5 and 9 degrees Celsius within several thousand years. The world at that time was already warmer than now with no surface ice.
"We now believe that the CO2 did not cause all the warming, that there were additional factors," said Richard Zeebe, an oceanographer with the University of Hawaii at Manoa.
"There may have been an initial trigger," he told Reuters on Wednesday from Hawaii. This could be a deep ocean warming that caused a catastrophic release of methane from hydrate deposits under the seabed.
Methane is a potent greenhouse gas but much of it is oxidised into CO2 when it is released from hydrate deposits.
Zeebe and his colleagues estimated the amount of CO2 released during the Palaeocene-Eocene event by studying sediment cores from seabeds around the globe. Their study is published in the latest issue of Nature Geoscience.
FUTURE WARMING
They estimated about 3 trillion tons of carbon (11 trillion tons of CO2) was released over several thousand years from the methane deposits, leading to a 70 percent rise in atmospheric CO2 levels from pre-event levels.
But Zeebe said this could only explain a 1 to 3.5 degree Celsius rise in temperatures, adding that a commonly accepted scientific range for a doubling of CO2 is between 1.5 and 4.5 degrees Celsius.
This meant other factors must have been at work to drive up temperatures between 5 and 9 degrees Celsius.
"If this additional warming which we do not really understand, was caused as a response to the CO2 warming, then there is a chance that also a future warming could be more intense than people anticipate right now," Zeebe said.
He said the study suggested there could be atmospheric or ocean processes as yet unknown or poorly understood that might have accelerated the warming. Possibilities could be changes in ocean currents, a much larger release of methane or even greater impacts from higher CO2 levels than currently thought.
At present, CO2 levels have already risen from 280 parts per million to nearly 390 ppm since the Industrial Revolution and could exceed a 70 percent increase during this century, a rate much faster than the Palaeocene-Eocene event, Zeebe said.
While this would cause initial effects, much worse could follow in the coming decades and centuries as the oceans, land and atmosphere tried to deal with the higher CO2 levels, he said.
"The carbon that we put into the atmosphere right now is going to stay there for a very long time. Much of it will stay there for tens of thousands of years."

Swine flu striking pregnant women hard: CDC study

Pregnant women infected with the new H1N1 swine flu have a much higher risk of severe illness and death and should receive prompt treatment with antiviral drugs, U.S. government researchers said on Wednesday.
While pregnant woman have always had a higher risk of severe disease from influenza in general, the new H1N1 virus is taking an exceptionally heavy toll, the researchers said.
"We do see a fourfold increase in hospitalization rates among ill pregnant women compared to the general population," Dr. Denise Jamieson of the U.S. Centers for Disease Control and Prevention said in a telephone interview.
"We're also seeing a relatively large proportion of deaths among pregnant women. We report 13 percent in the paper, but that is a very unstable number based on a small number of deaths reported," said Jamieson, whose study appears in the journal Lancet.
The study was based on the deaths of six pregnant women out of 45 deaths related to H1N1 reported to the CDC between April 15 and June 16.
All of the women were healthy prior to infection, and all developed pneumonia and needed to be put on a ventilator.
Jamieson said 302 deaths have been officially reported to the CDC from the new H1N1 virus.
"Among those, we have relatively complete information on 266 deaths. And of those, 15 have been among pregnant women, which is about 6 percent," Jamieson said.
Pregnant women make up about 1 percent of the U.S. population, she said, so pregnant women "are definitely over-represented in terms of the proportion of deaths."
Jamieson said pregnant women who suspect they have influenza should call their doctors promptly. The CDC recommends pregnant women with influenza get antiviral drugs as soon as possible, within the first 48 hours to be most effective.
Dr. Keiji Fukuda of the World Health Organization said WHO has not yet decided on its policy on the use of antivirals for pregnant women withH1N1.
"Given the overall situation in many countries where the supplies of antivirals can be limited at times, to concentrate them on treating people who are sick makes a lot of sense," he said on Britain's Sky television.
Fukuda said researchers are debating whether it is best to use antivirals to prevent disease or to treat sick people.
Both the CDC's Advisory Committee on Immunization Practices and the American College of Obstetricians and Gynecologists recommend that all pregnant women get a seasonal flu shot, but less than 14 percent do, according to the CDC.
The ACIP, which advises the CDC, was meeting on Wednesday to decide who should be first to get the new H1N1 vaccine. Pregnant women are expected to be at the head of the line.



amieson said pregnant women need to be aware of the risks if they become ill, but they do not need to change the way they live because of the new H1N1 flu.
"We do not have evidence that pregnant women have increased susceptibility or are more likely to acquire influenza," Jamieson said.
"It's just that when they have influenza they are at increased risk of having severe disease," she said.

House Democrats clinch healthcare deal

Democrats broke a logjam in President Barack Obama's drive to revamp the costly U.S. healthcare system on Wednesday when a group of party conservatives accepted a compromise that allowed an overhaul bill to advance in the House of Representatives.
The agreement with four conservative congressmen from Obama's Democratic Party sparked immediate grumbling from liberals, Republicans and others even as the breakthrough allowed a key House committee to take up the bill.
Obama, whose chief of staff, Rahm Emanuel, worked with members of Congress to craft the compromise, said he was grateful that lawmakers "are working so hard to find common ground."
"Those efforts are extraordinarily constructive in strengthening this legislation and bringing down its cost," Obama said.
Since taking office six months ago, Obama has made an overhaul of healthcare, which accounts for one-sixth of the U.S. economy, his top legislative priority.
He insists it is crucial to a broader economic recovery and has pushed lawmakers -- due to recess for a month soon -- to forge a deal quickly to rein in healthcare costs, improve care and cover most of the 46 million uninsured Americans.
Representative Mike Ross, a leader of the conservative Democrats known as the "Blue Dogs," told reporters the agreement, which followed lengthy negotiations with party leaders and the White House, would shave $100 billion off the bill's price tag of at least $1 trillion, making it more palatable to fiscal conservatives in both parties.
The Blue Dogs had put the brakes on the bill in the Energy and Commerce Committee, the last of three House committees to vote on it, over concerns about costs and other issues.
With the agreement, the bill was to move through that committee by Friday, even if House leaders later change it before the full House votes in September.
But Democratic Representative Eliot Engel said House leaders had left liberals on the panel with little choice but to vote for it as it stands or stall its progress.
"In a way, a number of us feel we've been held hostage," Engel said.
While the bill still includes a government-run insurance program, liberals said a requirement that Washington negotiate prices with doctors and hospitals -- putting the public plan on the same footing as private insurers -- would make coverage unaffordable for many.
The compromise would exempt 86 percent of small businesses from being required to contribute to health insurance for their workers. It would also allow states to set up insurance cooperatives alongside a national government health insurance plan.
Democrats on the Energy and Commerce Committee met in closed session to go over the details before a full panel meeting and votes on Thursday, and probably on Friday.

Global warming to change life here

What will life be like in Lancaster County 40 years from now?
A climate more like Georgia or Maryland, depending on the severity of global warming, according to a new state-issued report on the long-term effects of climate change in Pennsylvania.
It will be rainier, especially in winter, though droughts also will be more common. There will be more summertime cloudbursts.
There will be less snow and more cold-rain events. You'll have to go out of state to use your snowmobiles, cross-country skis or ice-fishing poles.
Spring-thaw flooding on the lower Susquehanna may be less likely.
You'll spend more on air conditioning while saving on winter heating bills.
Fall colors here will be less showy as many maples will struggle to grow here. Instead, pine plantations are a possibility.



Sweet corn will grow faster. Potato and apple yields are likely to decline.
Dairy farmers here will have to become even more efficient to offset heat stress to cows, poorer yields of on-the-farm feed and possible challenges from milk producers in New Zealand and Australia.
Trout fishing may decline, while swimming, boating, golf and fishing for warm-water fish will likely increase.
"Certainly climate change is going to be happening, so preparing and adapting is something that needs to be done," Dr. James Shortle, a Penn State professor of agricultural and environmental economics and one of 10 lead researchers from Penn State who authored the report, said.
Among the be-prepared recommendations in the report: Communities should build more ballfields and bike paths.
The 350-page analysis, "Pennsylvania Climate Impact Assessment," was required by the Pennsylvania Climate Change Act passed by the Legislature in 2007. It was released by the state Department of Environmental Protection and is available online at www.depweb.state.pa.us. Fill in "Climate Change" in the keyword space.
The report states that global warming is already occurring and will accelerate, regardless of what the world does now.
However, the Pennsylvania scientists predict climate-change effects on two levels. One, if global-warming emissions continue to increase through the 21st century. Another scenario assumes the world reduces emissions and changes will be far more moderate.
Regardless of what action the world takes, "It is very likely that Pennsylvania will warm throughout the 21st century," the report states.
Following is a summary of key changes the state faces, according to the report.
ClimateBy the end of the century, the median temperature will increase by 7 degrees in the worst-case scenario and 3.5 degrees if emissions are decreased in the next 40 years.
The growing season will be extended by three weeks under lower emissions and by five weeks if global warming is not moderated.
Expect more extreme weather, whether storms or dry periods. "Flashier" storms may mean more runoff and erosion of soil and pollution into local streams and the Chesapeake Bay.
AgricultureEffects may be mixed for farmers.
Warmer temperatures and longer growing seasons may help yields of hay, corn and soybeans, but it may also raise yields elsewhere, increasing global production and pushing down prices for Pennsylvania farmers.
Warmer temperatures may continue to drive poultry and hog farming farther north to Pennsylvania.
State wineries may be able to grow higher-value European grapes for the first time.
"Among Pennsylvania farmers, dairy producers may experience the greatest challenges from climate change given their reliance on own-crop production, animal heat stress due to housing in the ambient environment, and impacts to forage quality that will affect productivity," the report said.
However, Don McNutt, director of the Lancaster County Conservation District, has faith in local farmers to adapt to any curves coming their way.
"Agriculture will step to the plate on that challenge, I think, really well. Never count the Lancaster County farmer out. They will think of a way to ingeniously step over the next hurdle. They've been doing it for more than 300 years."
McNutt predicted that continued genetic engineering will help farmers grow more heat-tolerant crops. Warmer feedlots could be cooled with geo-thermal systems, he said.
And the fact that local dairy farmers are within a day's drive of one-third of the nation's population puts them in better standing to weather fluctuating markets, McNutt thinks.
"We have a lot going for us."
The report said organic agriculture may get a boost with its moisture-retaining matter, but an increase in weeds may offset that advantage.
Forests"Climate change will likely cause many changes in Pennsylvania's forests," the report notes.
Northern hardwood trees such as the aspens and birches are expected to become extinct under worst-case scenarios. Southern species such as oaks and hickories will likely become more common.
The eight most common species currently in Pennsylvania — red and sugar maple, black birch, black cherry, beech, hemlock, white ash and northern red oak — are all projected to shrink, maybe even disappear.
Production of maple syrup in the state looks bleak.
Forest pests may increase, as well as invasive plants such as kudzu and Canada thistle.
Effects on the state's timbering industry are expected to be dramatic. The most valuable commercial tree, black cherry, is predicted to decline substantially, if not disappear.
Instead, loblolly and shortleaf pines, now in southern states, may be grown here, changing the makeup of trees grown for commercial sale.
Once new species are established, warmer temperatures, more precipitation and carbon dioxide fertilization may increase growth rates.
Waterways and fishDiversity of life in streams and wetlands will likely suffer from increased water temperatures and conditions that favor invasive species.
One big casualty: wild brook trout, the state fish, which survives only in pristine, cold water.
Human HealthMore intense summer heat will lead to more heat-related deaths, especially among those who don't have access to air conditioning. But people freezing to death will decline.
Smog and its harm to people with respiratory problems will increase.
Tourism, Outdoor RecreationThe report predicts that even with snow-making equipment, in the worst-case scenario ski resorts in the state may not survive.
The demand for fishing, boating and swimming is likely to increase, and the Fish and Boat Commission may want to increase access to streams and lakes and, perhaps, even consider building more reservoirs.
Deer may survive over winter at a higher rate, presenting new management challenges.
Golf, tennis and biking similarly will see upticks.
"Local communities should plan for this increase in demand for sports fields, bicycle paths, etc.," the report notes