Nanodevice run from battery could help to desalinate seawater in disaster zones

March 22, 2010 By Leave a Comment

London, March 22 (ANI): Scientists at the Massachusetts Institute of Technology (MIT) in Cambridge and his colleagues have come up with a nanodevice that could be used as a simple, portable water-desalination system run from a battery or on solar power, which would help to desalinate seawater in disaster zones.

According to a report in Nature News, Jongyoon Han and colleagues at the MIT developed the device.

Han and his team were investigating the physics behind a phenomenon called ion-concentration polarization.

This occurs when a voltage is applied across a membrane, setting up an ion current.

Because only positive ions can pass through the membrane, a mismatch is created across it.

A higher proportion of positive ions amass on one side of the membrane together with the negative ions that were unable to traverse it.

The researchers decided to try to exploit this effect to scrub salts out of water.

Instead of a membrane, however, they used an ion-selective material called Nafion to make a nanojunction.

This connects to a larger, micrometre-sized channel that has sea water flowing through it.

When a voltage is turned on across the nanojunction, salts are repelled from the sea water as it flows by, although the sea water doesn”t actually touch the nanojunction.

The microchannel splits into two at the junction, with fresh water flowing straight on to be collected while the repelled salty water is pushed away through the second microchannel.

The sea water from Crane Beach in Ipswich, Massachusetts, repelled more than just salt, eliminating any charged particles, including many proteins and microorganisms.

The team tested this by contaminating the water with human blood that had been stained with fluorescent markers, and found that the markers flowed into the same channel as the salts.

Because the sea water doesn”t touch the nanojunction, the device is unlikely to get fouled up by microbes sticking to it.

The device is just a few centimetres square, and not enough water passes through one for practical purposes – just 250 nanolitres of fresh water can be collected per minute.

But Han said that if it were possible to put many of the devices onto some kind of chip he could produce something to rival portable household water filters.

“This would lead to flow rates of about 100 millilitres per minute,” he said. “If you hit that kind of flow rate, it”s going to be really useful,” he added.

According to Desmond Lawler, an engineer who works on water desalination at the University of Texas at Austin, said that such a device could be used in disaster zones, where small amounts of pure water are needed quickly and cheaply. (ANI)

Filed Under: International News Tagged With: , , , , , , , , , , , , , , , , , , ,

Fertilizing oceans with iron could spark growth of toxic blooms

March 16, 2010 By Leave a Comment

London, March 16 (ANI): Scientists have found that fertilizing the oceans with iron could spark the growth of toxic blooms, which comes in the way of the controversial idea of adding iron to the oceans to help suck up atmospheric carbon dioxide (CO2).

According to a report in Nature News, the finding, from a team led by ecologist Charles Trick of the University of Western Ontario in London, Canada, dampens the prospects for schemes to boost the growth of CO2-consuming organisms in surface waters.

“This is a real reminder that while we think we understand what’s going on in the environment, we really don’t,” said Trick. “There’s uncertainty with every large-scale experiment we do,” he added.

Trick and his colleagues found the neurotoxin domoic acid in samples of seawater from a site in the North Pacific, where iron-fertilization experiments have been conducted.

Shipboard experiments by the team confirmed that adding iron increased production of the toxin by plankton of the genus Pseudonitzschia.

In 2006 and 2007, Trick and his colleagues collected seawater at various depths from a research site south of Alaska.

They found domoic acid in the seawater, from which they also isolated two species of Pseudonitzschia.

The team grew the plankton in on-board incubators, spiking some of the tanks with iron.

The abundance of the plankton and concentrations of domoic acid increased relative to tanks that had no iron added to them.

Adding trace amounts of copper further pushed up the production of domoic acid.

From these results, Trick and his team estimate that proposed large-scale ocean iron enrichment could produce domoic acid in concentrations that might be high enough to shut down coastal fisheries.

“It doesn’t surprise me,” said David Caron, a marine biologist at the University of Southern California, Los Angeles.

“In the majority of iron-enrichment experiments, Pseudonitzschia has come up in abundance. It’s not unreasonable that sooner or later you’re going to find domoic acid,” he added. (ANI)

Filed Under: International News Tagged With: , , , , , , , , , , , , , , , , , , ,

Nano antennas could pave way for quantum computing networks

March 15, 2010 By Leave a Comment

London, March 15 (ANI): A team of scientists has developed a way to control the direction of light on the nanoscale, by developing miniaturized television aerials made from gold nanorods, which can pave the way for quantum computing networks in the future.

At the moment, quantum physicists use cumbersome apparatus to try to keep track of photons, for instance, building large vacuum cavities with mirrored walls to guide light.

“It’s funny that to control the small quantum world, you need huge pieces of equipment,” said Holger Hofmann, at the Department of Quantum Matter at Hiroshima University in Japan.

Now, according to a report in Nature News, Hofmann and his colleagues have developed a way to control the direction of light on the nanoscale.

Their technique is based on the workings of the ‘Yagi-Uda’ antenna commonly used to transmit and detect radio waves and often seen on rooftops as television aerials.

Hofmann stumbled on the idea by accident, while teaching his electromagnetism class how antennas work.

“The textbook didn’t explain it well, and while trying to come up with my own picture, I realized that the same technique could work on the nanoscale,” he said.

A standard Yagi-Uda antenna is made up of a set of parallel metal rods that gradually decrease in length.

An electrical signal is fed into the second longest rod, setting it vibrating and producing a driving electromagnetic wave that spreads out in all directions.

This stimulates the neighbouring rods to oscillate and emit secondary waves.

Both the length and spacing of adjacent rods are carefully set at fractions of the wavelength of the driving wave, so that the secondary waves interfere with the driving wave, amplifying it along the forward direction and reducing it along the sideways and backward directions.

Hofmann and his colleagues realized that gold nanorods should produce the same effect on the nanoscale — but here, the length-to-width ratio of the rods, rather than their length and spacing, is important.

The team etched their mini gold antenna into a glass substrate and drove it directly with red laser light.

The tricky part was to ensure that just one nanorod was driven by the incoming light, just as only one metal rod is in the Yugi-Uda antenna.

To ensure this, the team tilted the chosen nanorod by 45 degrees relative to its neighbours and stimulated it using laser light that was polarized at the same angle.

They then monitored the direction of light transmitted out of the glass substrate.

The result was actually better than their theory predicted, according to Hoffman, with roughly two-thirds of the input light being directed largely forwards. (ANI)

Filed Under: International News Tagged With: , , , , , , , , , , , , , , , , , , ,

Snakes have ‘night vision’ to hunt for prey in the dark

March 15, 2010 By Leave a Comment

London, March 15 (ANI): In a new research, scientists have discovered the receptors that allow snakes to find prey in the dark.

Vipers, pythons and boas have holes on their faces called pit organs, which contain a membrane that can detect infrared radiation from warm bodies up to one metre away.

At night, the pit organs allow snakes to ‘see’ an image of their predator or prey — as an infrared camera does — giving them a unique extra sense.

According to a report by Nature News, a study by US researchers, has now revealed how this works at a molecular level.

Nerve cells in the pit organ contain an ion channel called TRPA1 — an infrared receptor that detects infrared radiation as heat, rather than as light, thus confirming theories of pit-organ function long held by behavioural ecologists.

The receptors are also found inside the heads of mammals, where TRPA1 channels, also known as wasabi receptors, detect pungent irritants from mustard plants or other sources.

The pit organ contains nerve fibres known as trigeminal ganglia.

The researchers reasoned that a good way to home in on the organ””s molecular heat detectors would be to compare the trigeminal ganglia with the dorsal root ganglia.

The latter supply the brain with sensory input from the neck down and would be less likely to produce proteins that only pit-organs need to detect heat.

The team looked at the different RNAs produced by each type of nerve — an indication of which genes are active and producing proteins.

They found only one, TRPA1, which was being expressed differently in the two types of ganglia, with the gene in the trigeminal ganglia producing 400 times more RNA than that in the dorsal root ganglia.

According to the team’s observations, rattlesnake TRPA1 is activated by temperatures higher than about 28 degree Celsius — roughly the temperature a snake would ‘feel’ from a mouse or a squirrel about a metre away.

“Although aspects of the findings contradict known behavioural and physiological work, the use of molecular genetic techniques is a new step in understanding how the facial pits work,” said herpetologist Aaron Krochmal from Washington College in Chestertown, Maryland. (ANI)

Filed Under: International News Tagged With: , , , , , , , , , , , , , , , , , , ,

New evidence points towards water on Moon

September 19, 2009 By Leave a Comment

London, September 19 (ANI): Two separate lunar missions have found evidence which indicates that the polar regions of the moon are chock full of water-altered minerals.

According to a report in Nature News, early results from NASA’s Lunar Reconnaissance Orbiter (LRO), launched on June 18, are offering a wide array of watery signals.

The Moon, in fact, has water in all sorts of places: not just locked up in minerals, but scattered throughout the broken-up surface, and, potentially, in blocks or sheets of ice at depth.

“We are on the verge of a renaissance in our thinking about the poles of the Moon, including how water ice gets there,” said Anthony Colaprete, principal investigator for the Lunar Crater Observation and Sensing Satellite (LCROSS), which on October 9, will slam into a polar crater with the intention of ploughing up a plume of water ice for many telescopic eyes to see.

The initial LRO results confirm what was long suspected as a way for ice to stay trapped on the Moon for billions of years.

A thermal mapping instrument showed that permanently shadowed regions within deep polar craters are as cold as 35o Kelvin (-238o Celsius).

Project scientist Richard Vondrak said that they are the coldest spots in the Solar System – even colder than the surface of Pluto.

Variations in the flux of neutrons suggests variability in water content among craters.

But, the surprise comes from a different instrument on LRO, which counts slow-moving neutrons as a way of measuring hydrogen abundance in the top metre or so of the surface.

This hydrogen is often interpreted as a proxy for water ice, although it could also be molecular hydrogen or hydrogen trapped in other molecules.

The LRO instrument has already found a significant excess of hydrogen at the poles.

But, with added resolution, it is seeing surprising variability within the polar regions. Some of the craters appear enriched in hydrogen. Others are not.

Stranger still, some areas outside the crater walls, which were thought to get too hot for water to linger, show an excess of hydrogen.

Vondrak said this shows that the water could have arrived more recently, or that it can persist if buried as impacts till the lunar soil.

If the LCROSS impact spews up ice, it will eliminate the last vestiges of doubt about water on the Moon.

It could also start a new hunt: to find a record of impact events, such as water-rich comet strikes, that put the ice there in the first place. (ANI)

Filed Under: Science News Tagged With: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

New evidence points towards water on Moon

September 19, 2009 By Leave a Comment

London, September 19 (ANI): Two separate lunar missions have found evidence which indicates that the polar regions of the moon are chock full of water-altered minerals.

According to a report in Nature News, early results from NASA’s Lunar Reconnaissance Orbiter (LRO), launched on June 18, are offering a wide array of watery signals.

The Moon, in fact, has water in all sorts of places: not just locked up in minerals, but scattered throughout the broken-up surface, and, potentially, in blocks or sheets of ice at depth.

“We are on the verge of a renaissance in our thinking about the poles of the Moon, including how water ice gets there,” said Anthony Colaprete, principal investigator for the Lunar Crater Observation and Sensing Satellite (LCROSS), which on October 9, will slam into a polar crater with the intention of ploughing up a plume of water ice for many telescopic eyes to see.

The initial LRO results confirm what was long suspected as a way for ice to stay trapped on the Moon for billions of years.

A thermal mapping instrument showed that permanently shadowed regions within deep polar craters are as cold as 35o Kelvin (-238o Celsius).

Project scientist Richard Vondrak said that they are the coldest spots in the Solar System – even colder than the surface of Pluto.

Variations in the flux of neutrons suggests variability in water content among craters.

But, the surprise comes from a different instrument on LRO, which counts slow-moving neutrons as a way of measuring hydrogen abundance in the top metre or so of the surface.

This hydrogen is often interpreted as a proxy for water ice, although it could also be molecular hydrogen or hydrogen trapped in other molecules.

The LRO instrument has already found a significant excess of hydrogen at the poles.

But, with added resolution, it is seeing surprising variability within the polar regions. Some of the craters appear enriched in hydrogen. Others are not.

Stranger still, some areas outside the crater walls, which were thought to get too hot for water to linger, show an excess of hydrogen.

Vondrak said this shows that the water could have arrived more recently, or that it can persist if buried as impacts till the lunar soil.

If the LCROSS impact spews up ice, it will eliminate the last vestiges of doubt about water on the Moon.

It could also start a new hunt: to find a record of impact events, such as water-rich comet strikes, that put the ice there in the first place. (ANI)

Filed Under: Science News Tagged With: , , , , , , , , , , , , , , , , , , , , ,

Europe’s oldest axes discovered date back to half a million years

September 3, 2009 By Leave a Comment

London, September 3 (ANI): New analysis has dated hand axes from southern Spain to nearly half a million years old, suggesting that advanced Stone Age tools were present in Europe far earlier than was previously believed.

Acheulian axes, which date to at least 1.5 million years ago, have been found in Africa, and similar tools at least 700,000 years old have been found in Israel and China.

But in Europe, sophisticated tool-making was thought to stretch back only around 500,000 years.

According to a report in Nature News, the Iberian axes were found at two sites dated to at least 760,000 and 900,000 years old, respectively.

The cave sediment levels that included the two axes also held what some archaeologists believe may be small tools made using the so-called Levallois technique of shaping stone, known to have existed in Europe only about 300,000 years ago.

“Up to now, no one imagined this level of tool-making was going on in Europe about a million years ago,” said Michael Walker, an archaeologist at the University of Murcia who has studied the region near Granada where the axes were found.

Gary Scott and Luis Gibert of the Berkeley Geochronology Center in California dated the sites using palaeomagnetic analysis, which uses known changes in the orientation of Earth’s magnetic field over time.

“This (find) tells us some things about these early humans’ brains, like the development of spatial conception. But not much, as cognitive ability changes very, very slowly,” said Thomas Wynn, a cognitive evolutionary biologist from the University of Colorado at Colorado Springs.

The Quipar Valley has historically been home to a lake environment of marshes and shallow lagoons.

The Solana del Zamborino and Estrecho del Quípar caves in the valley, where the axes were found, were first thought to be only about 200,000 years old.

But, after dates of stone flakes at a nearby location indicated they were much older, Gibert and Scott homed in on the caves’ rich sediments.

In addition to the palaeomagnetic technique, Gibert notes that a record in rock layers of the remains of micro-mammals such as rodents, developed by Walker’s team at Estrecho del Quípar, was crucial in confirming the dates.

The older dates for the Spanish axes are now expected to generate new studies at other European rock shelters bearing Acheulian artefacts. (ANI)

Filed Under: Science News Tagged With: , , , , , , , , , , , , , , , , , , , ,

Genetic analysis challenges human-chimp interbreeding

August 29, 2009 By Leave a Comment

London, August 29 (ANI): A genetic analysis has called into question the controversial claim that early humans and chimpanzees interbred before splitting into separate species.

In 2006, David Reich and his colleagues at the Broad Institute in Cambridge, Massachusetts, compared the genomes of humans, chimps and three other primate species, and found that the separation of ancient humans from our closest cousins was more complex than a clean break.

The time from the beginning to the completion of human-chimp divergence ranged over more than four million years across different parts of the genome, and the X chromosome seemed youngest of all, they reported in Nature.

The authors argued that there were in fact two splits – an initial divide, followed by interbreeding, and then final separation in which only a young X chromosome was retained.

Many researchers took issue with this interpretation, arguing that large ancestral population sizes could explain the wide range in genetic divergence times, so there was no need to invoke a complex speciation process.

But these critiques still could not account for the youth of the X chromosome.

Now, according to a report in Nature News, evolutionary geneticist Soojin Yi of the Georgia Institute of Technology in Atlanta, together with Daven Presgraves of the University of Rochester in New York, have reanalyzed the data and suggest that species differences in the levels of female promiscuity can account for the chromosomal inconsistency.

Males competing for mates produce different amounts of sperm depending on the mating habits of the species. Chimps are highly promiscuous, humans less so and gorillas not much at all.

As such, male chimps face the stiffest competition, so they have the highest sperm counts and the largest testes of the three species.

That means that they also undergo more rounds of sperm cell division and make more DNA copying mistakes, leading to higher mutation rates in males than in females.

Reich and others had assumed that all primates had the same mutation bias, but Yi and Presgraves argue that mating relationships should be taken into account.

Because females have two X chromosomes and males have only one, the X spends more of its evolutionary history in females, whereas non-sex chromosomes split their time evenly between each gender.

Thus, a male-biased mutation rate will lead to proportionally fewer genetic changes on the X and will seem to be younger when using a molecular clock, even if all the chromosomes diverged at around the same time, the researchers argue.

Complex speciation is therefore unlikely to be the cause, according to the researchers. (ANI)

Filed Under: Science News Tagged With: , , , , , , , , , , , , , , , , , , , ,

Costs of adapting to climate change could be much greater than expected

August 28, 2009 By Leave a Comment

London, August 28 (ANI): A new study has determined that the global cost of adapting to climate change has been grossly underestimated, and it could be much greater than expected.

According to a report in Nature News, although it doesn’t provide concrete new estimates, the report suggests that the total cost of adapting to climate change could be at least 2-3 times more than the previous estimate from the United Nations Framework Convention on Climate Change (UNFCCC).

That figure, published in 2007, suggested that the annual cost from 2030 would be between 49 billion dollars and 171 billion dollars.

The main difference, according to the study, is that the UN number did not account for climate change’s effects on key sectors such as energy, manufacturing, tourism and natural ecosystems.

“The UNFCCC’s estimations were made in a few weeks and weren’t independently reviewed,” said the study’s lead author, Martin Parry, a visiting research fellow at the Grantham Institute for Climate Change at Imperial College London and a former co-chair of a working group of the Intergovernmental Panel on Climate Change (IPCC).

The UNFCCC numbers were initially intended to come from a literature review of other economic studies, according to Sudhir Sharma, manager of financial cooperation and capacity building at the UNFCCC secretariat in Bonn, Germany.

But the team working on the estimates soon realized that there were massive gaps in the information needed.

The cost of adapting to climate change requires knowledge about what effects climate change will have, what the options are for responding to those changes, and how much those options will cost, according to Sharma.

Sharma argues his group’s estimates weren’t intended to be the final word, but rather a ball-park figure to get the negotiations rolling.

“We clearly indicated that this was not an exhaustive study,” he said. “Our objective was to kick-start the process of putting numbers on the cost of adaptation so that other groups could pick up the baton and refine them,” he added.

The latest study, published by the IIED and the Grantham Institute, has picked up that baton.

It suggests that the UNFCCC estimate of 11 billion dollars per year for adapting to changes in water supply overlooks the expenses of floods and of transporting water from areas of plenty to areas to that need it.

But although the report says previous estimates for adaptation are too low, it doesn’t provide numbers, he admits.

“We didn’t try to come up with new numbers – we pointed out the gaps,” said Sharma. (ANI)

Filed Under: Uncategorized Tagged With: , , , , , , , , , , , , , , , , , , ,

Costs of adapting to climate change could be much greater than expected

August 28, 2009 By Leave a Comment

London, August 28 (ANI): A new study has determined that the global cost of adapting to climate change has been grossly underestimated, and it could be much greater than expected.

According to a report in Nature News, although it doesn’t provide concrete new estimates, the report suggests that the total cost of adapting to climate change could be at least 2-3 times more than the previous estimate from the United Nations Framework Convention on Climate Change (UNFCCC).

That figure, published in 2007, suggested that the annual cost from 2030 would be between 49 billion dollars and 171 billion dollars.

The main difference, according to the study, is that the UN number did not account for climate change’s effects on key sectors such as energy, manufacturing, tourism and natural ecosystems.

“The UNFCCC’s estimations were made in a few weeks and weren’t independently reviewed,” said the study’s lead author, Martin Parry, a visiting research fellow at the Grantham Institute for Climate Change at Imperial College London and a former co-chair of a working group of the Intergovernmental Panel on Climate Change (IPCC).

The UNFCCC numbers were initially intended to come from a literature review of other economic studies, according to Sudhir Sharma, manager of financial cooperation and capacity building at the UNFCCC secretariat in Bonn, Germany.

But the team working on the estimates soon realized that there were massive gaps in the information needed.

The cost of adapting to climate change requires knowledge about what effects climate change will have, what the options are for responding to those changes, and how much those options will cost, according to Sharma.

Sharma argues his group’s estimates weren’t intended to be the final word, but rather a ball-park figure to get the negotiations rolling.

“We clearly indicated that this was not an exhaustive study,” he said. “Our objective was to kick-start the process of putting numbers on the cost of adaptation so that other groups could pick up the baton and refine them,” he added.

The latest study, published by the IIED and the Grantham Institute, has picked up that baton.

It suggests that the UNFCCC estimate of 11 billion dollars per year for adapting to changes in water supply overlooks the expenses of floods and of transporting water from areas of plenty to areas to that need it.

But although the report says previous estimates for adaptation are too low, it doesn’t provide numbers, he admits.

“We didn’t try to come up with new numbers – we pointed out the gaps,” said Sharma. (ANI)

Filed Under: Uncategorized Tagged With: , , , , , , , , , , , , , , , , , , ,

Biofuels to have greatest impact on land use and habitat

August 26, 2009 By Leave a Comment

London, August 26 (ANI): A new study has determined that biomass production for fuel or electricity generation will have the biggest impact on landscape and habitats.

According to a report in Nature News, the broad analysis of potential US energy and climate-mitigation scenarios compared the land and habitat impacts of various energy mixes – from nuclear power to biofuels – resulting from an array of policy options.

In a supplement to the study paper, the authors re-ran their estimates to take account of the likely impact of the American Clean Energy and Security Act of 2009, also known as the Waxman-Markey bill.

The bill, which is awaiting approval by the US Senate, includes a cap-and-trade system to regulate greenhouse gases.

The researchers estimate that regardless of whether the Waxman-Markey bill were enacted, the amount of land affected by energy development by 2030 will be between 21-70 million hectares – an area which is, even at its lower bound, about the size of the state of Wyoming.

“A cap-and-trade bill may have some incremental effect in increasing energy sprawl, but most of the development that’s going to happen is because of other laws that are already in place,” said study author Robert McDonald, a landscape ecologist with The Nature Conservancy, a non-profit environmental organization based in Arlington, Virginia.

Those other laws include the US renewable fuel standard, which requires that the volume of renewable fuel blended into gasoline is increased from 34 billion litres in 2008 to 136 billion litres by 2022.

That increase will require an area of between 19 and 31 million hectares – the largest component of McDonald’s projected energy sprawl, despite the fact that biofuels are expected to comprise less than 5 percent of the country’s total energy budget.

The US Energy Information Administration predicts that ethanol derived from corn alone might reach annual production levels of 39 billion litres by 2030.

McDonald and his colleagues calculate that this would require more than 9 million extra hectares of land to be planted with corn (maize), an area about the size of the state of Indiana.

“If we are to prevent serious, damaging climate change, it will require one of the largest land-use changes in the history of the country,” said Jimmie Powell, a policy expert at The Nature Conservancy and a co-author of the study.

“Because the change is so big, it’s important that we do it carefully to minimize the environmental impacts of these new energy resources,” he added. (ANI)

Filed Under: Science News Tagged With: , , , , , , , , , , , , , , , , , , ,

Lung damage from inhaling nanoparticles sparks off health fears

August 19, 2009 By Leave a Comment

London, August 19 (ANI): A new study, which analyzed seven Chinese factory workers developing severe lung damage from inhaling nanoparticles, has triggered off debate over the environmental-health effects of nanotechnology.

According to a report in Nature News, the study claims to be the first to document cases of ill health caused by nanoparticles in humans.

“The study raises the bar for doing appropriate research as fast as possible to find out where the dangers might lie when working with nanomaterials,” said Andrew Maynard, a nanotechnology expert at the Woodrow Wilson International Center for Scholars in Washington DC.

The study described seven women, aged 18-47 years, who worked in an unidentified printing factory in China. Two of them later died.

They all had pleural granulomas – ball-like collections of immune cells in the lining of the lung that form when the immune system is unable to remove a foreign body.

They also had excessive, discoloured fluid in the lung lining. Particles around 30 nanometres in diameter were found in lung fluid and tissue.

According to the study, the symptoms were caused by inhaling fumes produced when the workers heated polystyrene boards to 75-100 degrees Celsius.

The boards had previously been sprayed with a ‘paste material’ made from a plastic identified as a polyacrylate ester.

The workroom, of around 70 square metres, had one door and no windows. The ventilation unit had broken down five months before symptoms started to manifest, and the door had been kept closed to keep the room warm.

The workers wore cotton gauze masks only on an “occasional basis”.

Electron microscopy found nanoparticles around 30 nanometres in diameter in the paste and in dust particles that had collected at the inlet of the broken ventilation unit.

“It is obvious the disease is not due to microparticles or vapours, because the pulmonary epithelial cells are full of nanoparticles,” said lead author Yuguo Song, a clinical toxicologist at Beijing Chaoyang Hospital.

Maynard said that the symptoms seen in the patients are “similar” to those seen in animals exposed to nanoparticles.

He added that damage to the areas surrounding the lungs suggests that larger particles are not to blame, as these tend to be constrained within the lungs. (ANI)

Filed Under: Science News Tagged With: , , , , , , , , , , , , , , , , , , , , ,

India to build capsule to carry two-person crew into space by 2015

July 10, 2009 By Leave a Comment

London, July 9 (ANI): Despite the economic slowdown, the Indian government plans to hike its science budget, with special emphasis on developing semi-cryogenic rocket engines, building a space capsule to carry a two-person crew into space by 2015 and for setting up the Indian Regional Navigational Satellite System.

According to a report in Nature News, India will spend 289 billion rupees on research and development this year, 19 percent more than last year, according to the budget for 2009-2010 announced on July 6.

The largest allocations are for atomic energy (71.7 billion rupees), the space programme (49.6 billion rupees) and defence research (47.6 billion rupees), while eight ‘national missions’ or programmes to combat climate change – announced by the government last year – are to be launched.

The 40 percent hike in the space budget from last year’s 35 billion rupees is largely to go towards developing semi-cryogenic rocket engines, building a space capsule to carry a two-person crew into space by 2015 and for setting up the Indian Regional Navigational Satellite System along the lines of the US GPS (Global Positioning System), space department spokesman S. Satish told Nature News.

Heads of government scientific departments say that although none of their projects has been shot down because of the economic slowdown, the increase in their budgets is less this year than in previous years.

“Allocations for us had been increasing by 30% each year, but this year it is only 20 percent,” said Thirumalachari Ramasami, secretary of the Department of Science and Technology.

The departments of health research, biotechnology and industrial research have received only 4-12 percent increases, but “none of us feels that our projects will suffer,” Ramasami told Nature News.

Funding for Earth sciences has, however, increased by 50 percent to 12.1 billion rupees, with a provision of 5.48 billion rupees for oceanographic research, including the setting up of a third Indian station in Antarctica and purchase of research vessels.

The budget for higher education increased by nearly 41 billion rupees to 154 billion rupees, including 4.5 billion rupees for new institutes of technology.

In a move to draw students to science, the budget provides for interest-free loans for those pursuing approved courses of study in technical and professional schools.

Another 5.4 billion rupees has been set aside for a National Knowledge Network of gigabit bandwidth to connect educational institutions across the country. (ANI)

Filed Under: Science News Tagged With: , , , , , , , , , , , , , , , , , , ,

New model postulates existence of shape-shifting ‘chameleon’ particle

May 30, 2009 By Leave a Comment

London, May 30 (ANI): Cosmologists have come up with a model postulating the existence of a ‘chameleon’ particle, which would change its mass depending on its environment, and might be used to explain the accelerating expansion of the Universe.

According to a report in Nature News, a new research has claimed to have spotted signs of this elusive particle, whose existence was first postulated in 2003 to explain the accelerating expansion of the Universe, which has been attributed to some unknown ‘dark energy’.

The changing mass of a chameleon particle would modify the range at which its force can act, thus possibly explaining why whatever causes the Universe’s acceleration hasn’t been detected on Earth.

On Earth, the chameleon would be too heavy to create any noticeable force, but in the tracts of empty space, its effect would be huge.

In theory, photons that travel through magnetic fields can turn into chameleons, reducing the amount of light that reaches Earth from distant sources.

The amount of dimming depends on the light’s frequency.

By comparing light emitted across a range of frequencies from the luminous centres of 77 active galaxies, Douglas Shaw at Queen Mary University of London and his colleagues have found what they call “good evidence” that some photons have gone missing in transit.

“It’s absolutely an interesting way of looking for (exotic) particles, and the results are certainly intriguing,” said Frank Wilczek, a particle physicist at the Massachusetts Institute of Technology (MIT) in Cambridge.

By themselves, the observations of dimmed light by Shaw and his colleagues can’t distinguish between models that rely on chameleons and models in which photons turn into other ‘axion-like’ particles.

Either “would be an interesting discovery,” said Shaw.

However, only the chameleon model predicts that the photons’ polarizations should be aligned with the magnetic fields they traversed.

So far, the team has studied data on light from three stars in the Milky Way galaxy and in each case found the required polarization.

As part of the research into the Chameleon particle, Amanda Weltman at the University of Cambridge, UK, along with the GammeV group at the Fermi National Accelerator Laboratory in Batavia, Illinois, is attempting to shine laser light through a tube with windows at either end that is immersed in a magnetic field.

The chameleon model predicts that some photons should convert to chameleon particles. When the laser is switched off, the chameleons should slowly turn back to photons and create a faint afterglow.

The experiment has completed its first phase without seeing any signs of a chameleon.

However, the team has not yet searched for the chameleons with parameters that match those possibly sighted by Shaw’s team.

The GammeV group is now preparing to test for chameleons in that “interesting range,” said Weltman. (ANI)

Filed Under: Science News Tagged With: , , , , , , , , , , , , , , , , , , , ,

Mud stirred up by sea worms lead to sulphate hike in oceans 500 mln yrs ago

May 19, 2009 By Leave a Comment

London, May 19 (ANI): In a new research, scientists have suggested that a jump in the concentration of sulphate in the world’s oceans 500 million years ago was caused by mud stirred up by sea-floor animals like worms, clams and crustaceans.

During that period, known as the Cambrian explosion, something put the evolutionary pedal to the metal, and the stately, subdued pace of animal life on Earth revved up.

Alongside this spurt in speciation, came a jump in the concentration of sulphate in the world’s oceans.

“It hasn’t been clear why,” said Don Canfield of the University of Southern Denmark in Odense.

But, Canfield and his collaborator, James Farquhar of the University of Maryland in College Park, have a theory to explain it.

According to a report in Nature News, in a new study published in the Proceedings of the National Academy of Sciences, Canfield and Farquhar attribute the rise in sulphate to the onset of bioturbidity – the burrowing, sluicing, pumping and mixing caused by masses of worms, clams, crustaceans and other animals that began to appear around this time in Earth’s history.

Before these sea-floor animals began their steady churn, sulphate, arriving in seas in the run-off from rivers, would largely be turned into hydrogen sulphide by bacteria living in the ocean floor.

The sulphide would then be converted to pyrite (FeS2), which, once buried, removes the sulphate from the system.

Once bioturbation turned on, however, oxygen in the deep ocean could mix more freely with the sediments, allowing bacteria and other processes to recycle pyrite and turn it back to sulphate.

This excess sulphate would have reached a saturation point, giving rise to the formation of gypsum deposits – a mineral that, along with sulphate levels, also happened to rise in the rock record around this time.

The researchers roughly sketched changes in ocean sulphate concentrations through time by directly analyzing tiny amounts of brine trapped in salt crystals.

But these samples are few and far between, so to get a more complete timeline, the team analyzed sulphide and sulphate isotopes in thousands of ancient sedimentary rock samples.

This analysis doesn’t track sulphate concentration changes directly, but shows how much of the sulphur ended up in pyrite versus gypsum.

Finally, the researchers built a simple model for the effects of bioturbation and found that its output – both in the timing and the magnitude of the sulphate signals – matched what they were seeing in the data. (ANI)

Filed Under: Uncategorized Tagged With: , , , , , , , , , , , , , , , , , , , ,

‘Hobbit’ was a dwarf with large feet

May 7, 2009 By Leave a Comment

London, May 7 (ANI): In a new research, the fossils of so-called ‘hobbits’ that date back to between 17,000 and 95,000 years ago, have been analyzed by scientists as belonging to a distinct species of dwarfs who had large feet.

Discovered on the Indonesian island of Flores in 2003 and dubbed ‘the Hobbit’, the species triggered a worldwide debate about its origins.

In particular, a hard-core cadre of critics said that the skeleton was that of a human who was suffering from microcephaly – a disorder in which the head is much smaller than normal – limiting its brain to 417 cm3, a third the size of the average human brain.

The team, hailing from Indonesia and Australia that discovered the bones argued that the species’ brain had probably shrunk owing to its isolation on an island with sparse resources, a phenomenon experienced by other insular animals.

Now, according to a report in Nature News, Eleanor Weston and Adrian Lister of London’s Natural History Museum have used brain-scaling data from extinct species of dwarf Madagascan hippopotamuses to show how the Hobbit’s brain could easily have reached its proportions.

William Jungers of Stony Brook University in New York and his colleagues report that analysis of the near-complete left foot and parts of the right foot indicate that the animal derives from a more primitive species than was previously believed.

Daniel Lieberman, a Harvard University biological anthropologist, called the results “considerable evidence” that H. floresiensis is a bona fide species.

In the case of H. floresiensis, Jungers said, “It is a real mosaic of primitive and derived features”.

The foot was long in relation to lower limb length, he says. The big toe was in line with the other toes, but it was short, whereas the other toes were long.

According to Jungers, “No human on Earth has proportions like that.”

He added that the features suggest that H. floresiensis derived from either the earliest Homo erectus, which reached Southeast Asia by about 1.6 million years ago, or the more primitive Homo habilis, thought to have arrived about 1.8 million years ago.

To address the brain-size debate, mammal palaeontologists Weston and Lister examined about 50 skulls of two types of dwarf hippo, some of which lived as recently as about 1,200 years ago.

The researchers scaled brain mass to body mass in these species.

By applying a model of this scaling, they determined that H. floresiensis’ brain could have shrunk to about the size known from the lone skull.

“Whatever the explanation for the tiny brain of H. floresiensis relative to its body size, the evidence presented here suggests that the phenomenon of insular dwarfism could have played a part in its evolution,” said the researchers. (ANI)

Filed Under: Science News Tagged With: , , , , , , , , , , , , , , , , , , ,

Africans are the most diverse people on Earth, suggests DNA analysis

May 3, 2009 By Leave a Comment

London, May 1 (ANI): In a new DNA based study, an international team of scientists has suggested that the Africans are the most diverse people on Earth, as they originated from 14 ancestral groups that mixed freely with each other to create the distinct populations that exist today.

According to a report in Nature News, the study, which included a wide-ranging DNA analysis of Africans, revealed a detailed picture of the continent’s rich genetic diversity, as well as traces of the evolutionary history and migrations of various groups.

Modern humans first evolved in Africa about 200,000 years ago, before migrating to other parts of the world. Today, Africa has more than 2,000 groups with different ethnicities and languages.

But, genetic studies of Africans have been limited to small numbers of populations or have not covered large parts of the genome.

Although geneticists knew that Africans show more genetic diversity within groups than non-Africans do, the details of genome-wide variation in many populations remained unclear.

“We just didn’t know as much as we should about African population genetics,” said Molly Przeworski, from the University of Chicago.

A team led by geneticist Sarah Tishkoff of the University of Pennsylvania in Philadelphia has now published research that includes DNA samples from 2,432 Africans from 113 populations, including groups in Nigeria, Cameroon, Tanzania, Kenya and the Sudan plus non-African samples from Yemen.

They looked for differences at 1,327 sites in the genome and combined the results with existing genetic data from 8 African and 59 non-African groups.

The team then ran statistical analyses to cluster the individuals by genetic similarity and determine their ancestry.

The results confirm that Africans have the highest within-population diversity worldwide, and suggest that they originated from 14 ancestral groups.

Most African populations seem to show genetic traces from multiple ancestral groups, supporting previous archaeological and linguistic evidence for migrations across the continent that would have led to mixing.

The analysis also suggests that hunter-gatherers from different regions and cultures, including pygmies in central Africa and click-language groups in southern Africa, may have descended from one ancestral population.

The genetic clusters generally aligned with ethnicity and language, although the team found exceptions in cases where groups had lost, or possibly replaced, their languages.

While the overall results are not surprising, the study gives a fine-scaled view of genetic variation across a large number of African populations, according to Noah Rosenberg, a geneticist at the University of Michigan, Ann Arbor, who plans to collaborate with Tishkoff.

“They show just how much diversity in Africa actually exists,” he said. (ANI)

Filed Under: Science News Tagged With: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

China’s plants absorb a third of its carbon emissions

April 23, 2009 By Leave a Comment

London, April 23 (ANI): In a new study, an international team of scientists has found that the plants in China absorb a third of its carbon emissions.

According to a report in Nature News, similar work has been done for the United States, but this study provides the first comprehensive analysis of China’s terrestrial carbon uptake, which is critical for calculating the country’s net emissions.

Led by Shilong Piao, an ecologist at Peking University in Beijing, the team estimated carbon uptake during the 1980s and 1990s using three different methods: ecosystem modelling, plant and soil inventories, and an analysis of atmospheric CO2 trends.

The authors estimate a net carbon sink of between 0.19 and 0.26 billion tonnes of carbon per year, which translates to 28 to 37 percent of China’s emissions during the period in question.

“Everyone has been scrambling around to come up with an estimate for China, because we don’t have a lot of information,” said Kevin Gurney, a climate researcher at Purdue University in West Lafayette, Indiana.

“They really have been methodologically thorough. They have tackled it from three different angles, and the nice thing is that all three of those converge on the same estimate,” he added.

“This is an impressive paper,” said Gregg Marland, a climate researcher at Oak Ridge National Laboratory.

He credits the researchers with analyzing the question in three ways and getting a fair amount of agreement in their results.

“In spite of that, there is still a considerable amount of uncertainty, and that uncertainty cascades through the system,” he said.

Although studies such as this can give broad estimates of carbon uptake, Marland said that the only way to pin down some of these numbers might be via satellites, like the Orbiting Carbon Observatory that plunged into the sea earlier this year.

“It’s going to be a long while before we have the kind of satellite data that we want,” he added. (ANI)

Filed Under: Science News Tagged With: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

CO2 spewing rocks can influence destructive potential of mass extinction events

April 23, 2009 By Leave a Comment

London, April 22 (ANI): In a new research, scientists have determined that big volcanic eruptions don’t always fuel mass extinctions because the destructive potential of the blasts seems to depend upon carbon dioxide (CO2) spewing non-volcanic rocks in the region.

Earlier, geologists have found evidence of many huge ancient volcanic eruptions that seem to not be connected to mass extinctions at all.

Now, according to a report in Nature News, a team of researchers has analyzed just how much CO2 non-volcanic rocks around volcanoes might release if they are super-heated.

They have found that in some cases, the rocks might spew out much more CO2 than the volcano itself.

Clement Ganino and Nicholas Arndt at Joseph Fourier University in Grenoble, France, went to explore a volcanic site roughly 260 million years old in southwestern China that seems to have formed at the same time as a mass extinction wiped out 35 percent of all genera on the planet.

Ganino and Arndt looked closely at dolomite, one of the most common rocks in the region of the mid-Permian eruption.

Dolomite is composed of calcium, magnesium, and carbonate; when heated, it breaks down into magnesium oxide, calcium carbonate and CO2.

The researchers calculated that 1 kilogram of dolomite heated by a volcanic source would produce 240 grams of carbon dioxide.

They also found that impure marbles in the area would have released between 220 and 290 grams of CO2 per kilogram of rock when heated.

Based on the abundance of heated sedimentary rocks that would have released carbon dioxide, Ganino and Arndt estimate that between 61,600 and 145,600 gigatonnes of CO2 were released.

This would have overwhelmed the mere 16,800 gigatonnes of CO2 typically emitted by magma alone during eruptions, explained Ganino.

“The mass of CO2 released from sedimentary rock is 3.6 to 8.6 times larger than the mass of CO2 released from magma. We did not expect such a huge difference,” he said.

According to Henrik Svensen at the University of Oslo, Norway, “More than 99 percent of all carbon on the Earth’s surface is stored in sedimentary rocks, and heating those rocks with the high-temperature material that comes out of volcanoes is a good way to put a lot of carbon into the atmosphere quickly.”

“Destructive potential seems to depend upon the sedimentary rocks in the region,” said Svensen. (ANI)

Filed Under: Science News Tagged With: , , , , , , , , , , , , , , , , , , , ,

Electronic bendy displays may change the face of reading

April 2, 2009 By Leave a Comment

London, April 2 (ANI): If some companies have their way, reading would never be the same again, with Hitachi, Fujitsu and Hewlett-Packard racing to develop bigger e-paper devices that are flexible and can display colour and video.

According to a report in Nature News, the technology uses tiny capsules 0.1 millimeters wide that are filled with a non-conducting fluid that contains particles of positively charged white and negatively charged black pigments.

Applying a positive charge causes the black particles to move to the top of the capsule and the white ones to the bottom, so that the surface appears black.

A negative charge switches the surface back to white.

An added plus is that once the particles have migrated, they stay in place, so no electricity is needed to maintain the image – only to change it, such as when turning a page.

Combined with the lack of an energy-devouring backlight, e-paper is much easier on batteries than devices such that use typical liquid-crystal displays (LCDs), such as desktop computers and laptops.

To make sheets of e-paper, a thin-film of the capsules is then applied to a board that contains the circuitry needed to give the pixel pattern.

One of the leaders in making these circuit boards, which are called backplanes, is Plastic Logic, a spin-off from the University of Cambridge, UK.

The firm plans to start shipping an all-plastic flexible reader later this year, ramping up to mass commercial production in early 2010.

Its first flexible device, which uses a backplane of organic thin-film transistors, and E Ink’s e-paper, displays in black and white, but is magazine-size and weighs just 450 grams.

The firm expects to begin marketing colour versions in around three years.

The first commercial colour e-reader appeared in March, Fujitsu’s FLEPia reader. Rather than using e-ink, the device is based on the company’s cholesteric LCD technology, which like e-ink, doesn’t need power to maintain text or images.

A promising technology for improving colour displays is electrowetting, which has produced the brightest of all e-paper displays and seems to be the only e-paper technology with refresh rates that are fast enough to display video.

Whatever technologies prevail, magazine-sized monochrome displays will hit the shelves this year, followed by colour versions in 2-5 years, with video coming after that.

By then, e-paper displays will likely be everywhere, creating a multi-billion-dollar market from magazines and newspapers to advertising billboards, and that is likely to be just the start of a revolution in new media. (ANI)

Filed Under: Science News Tagged With: , , , , , , , , , , , , , , , , , , , ,
« Older Posts