Stress, sickness and depression can generate inflammation in the brain, which is detrimental to learning. According to a new study T cells level the learning curve by producing a protein that combats inflammation, establishing a more learning-conducive environment in the brain. Source: ScienceDaily: Latest Science News | 4 May 2010 | 12:00 pm
Biologists have been able to change the brain of a developing fish embryo to resemble that of another species. Source: ScienceDaily: Latest Science News | 4 May 2010 | 12:00 pm
It can be difficult for parents of teenagers to come to terms with the fact their kids may have sex, particularly given widespread concerns about the consequences of teen sexual activity. In fact, a new study shows that many parents think that their children aren't interested in sex -- but that everyone else's kids are. Source: ScienceDaily: Latest Science News | 4 May 2010 | 12:00 pm
A new study on sex chromosomes in primates may have important consequences for research on human genetic diseases. The study of the genomes of the human, chimpanzee, macaque, and orangutan concluded that there is a strong sex-chromosome bias in the distribution of transposable elements, and provided other insights about these important DNA elements during the early stages of embryo development. Source: ScienceDaily: Latest Science News | 4 May 2010 | 12:00 pm
Scientists have discovered the structure of a protein that pinches off tiny pouches from cells' outer membranes. Cells use these pouches, or vesicles, to carry nutrients and other essential substances, but many medicines also hitch a ride inside them. Source: ScienceDaily: Latest Science News | 4 May 2010 | 12:00 pm
Researchers have created the first transgenic mouse to display the earliest signs of Parkinson's disease using the genetic mutation that is known to accompany human forms of the disease. Source: ScienceDaily: Latest Science News | 4 May 2010 | 12:00 pm
Fragile X syndrome is the most common known cause of inherited intellectual disability and autism. Now, researchers using advanced, noninvasive imaging techniques have shown how the brains of very young boys with fragile X syndrome differ from those of young boys without it, providing critical information for the development of treatments for the condition. Source: ScienceDaily: Latest Science News | 4 May 2010 | 9:00 am
A newe study finds that human growth hormone (HGH) improves sprint capacity in healthy recreational athletes. This is the first trial to demonstrate that HGH improves athletic performance. Source: ScienceDaily: Latest Science News | 4 May 2010 | 9:00 am
Some depressed patients who don't respond to or tolerate antidepressant medications may benefit from a non-invasive treatment that stimulates the brain with a pulsing electromagnet, a study suggests. This first industry-independent, multi-site, randomized, tightly controlled trial of repetitive transcranial magnetic stimulation found that it produced significant antidepressant effects in a subgroup of patients, with few side effects. Active rTMS treatment accounted for remissions in 14 percent of antidepressant-resistant patients actively treated. Source: ScienceDaily: Latest Science News | 4 May 2010 | 9:00 am
A new improved modeling system, developed by Chinese researchers, which attempts to incorporate more of the HIV virus' random behavioral dynamics, suggests that a particular type of T cell could be useful in the development of an AIDS vaccine. Source: ScienceDaily: Latest Science News | 4 May 2010 | 9:00 am
AP - BP PLC, Europe's biggest oil company, weighed on Britain's main stock index as investors returned from a long weekend increasingly worried about its exposure to the disastrous oil spill in the Gulf of Mexico.
Reuters - BP Plc pressed ahead on Tuesday with efforts to stop oil from continuing to spew from an offshore oil well off the U.S. coast deep in the Gulf of Mexico that ruptured almost two weeks ago.
An international team of researchers embarks on what is described as the "most ambitious tornado study in history". Source: BBC News | Science & Environment | UK Edition | 4 May 2010 | 3:30 am
Scientists push back the date for the earliest known presence of a magnetic field on Earth by about 250 million years. Source: BBC News | Science & Environment | UK Edition | 4 May 2010 | 3:19 am
AFP - Winds pushed a giant oil slick towards fragile wetlands on the US coast Tuesday as efforts intensified to bottle up a ruptured oil well in the Gulf of Mexico causing the growing environmental disaster.
For years, solar scientists have been confused as to why "coronal rain" falls so slowly through the sun's atmosphere... until now. Source: Discovery News - Top Stories | 4 May 2010 | 2:39 am
Governments will not meet the target of curbing the loss of species and nature by 2010, a major study confirms. Source: BBC News | Science & Environment | UK Edition | 4 May 2010 | 2:24 am
The first sequencing of a frog genome could help combat a disease killing amphibians around the world, scientists say. Source: BBC News | Science & Environment | UK Edition | 4 May 2010 | 2:23 am
Theo's Adventure Capitalists | The Story Of Science – Power, Proof And Passion | Luther | Sea Fever: For Those In Peril | True Stories: Erasing David | La La Land
Theo's Adventure Capitalists 8pm, BBC2
Theo Paphitis takes a break from lounging conceitedly in the Den's leather chairs to give "I-told-you-so" advice to three British entrepreneurs riskily setting up abroad. Amid unapologetic schmoozing and boozing, Paphitis oversees this episode's companies – publishers Haymarket, a luxury yacht agency, and a duo looking to set up an international school – as they try to wangle profitable business deals in beautifully filmed Vietnam.
The Story Of Science – Power, Proof And Passion 9pm, BBC2
What is the world made of? In order to answer this question, says Michael Mosley, you have to realise that "nothing is really solid" and "we consist almost entirely of empty space". That'll be quantum physics he's talking about, then. As to how we reached our understanding of the world's intrinsic weirdness, it's a story that Mosley traces largely via the history of chemistry. It's a discipline that has its roots in the work of alchemists, whose experiments included boiling down urine, a process that evidently smells even worse than you'd imagine, yet has a "phantasmagorical" pay-off.
Luther 9pm, BBC1
Idris Elba in his best post-Wire role to date. He's DCI John Luther, a detective coming back from gardening leave after a controversial case to investigate a baffling double homicide. The occasional generic note in the storyline (he's a maverick but his boss is still happy to bet on him, etc) doesn't deter from what is essentially a very enjoyable opening to this moody six-parter. Good support too from Ruth Wilson as physicist/femme fatale Alice Morgan (specialist subject: dark matter), and Indira Varma as Luther's estranged wife Zoe.
Sea Fever: For Those In Peril 9pm, BBC4
Part of a series exploring our relationship with the sea, as the title suggests, this programme focuses on those people who perform the vigilant and often dangerous task of rescuing those who've ended up in the drink without planning to. We meet Peter Halil and Gerry Douglas Sherwood, former lighthouse keepers who shot powerful video memoirs of their now all-but-automated way of life, and RAF winch man Eric Smith, who won the George Medal for the 1962 rescue of two French trawlermen from a capsized boat.
True Stories: Erasing David 10pm, More4
This social experiment by way of a documentary is an inventive and amusing way of tackling a serious point: the erosion of civil liberties in the UK. David Bond embarked on his project after being affected by the Child Benefit Office's loss of just two data CDs – meaning his address, bank details and date of birth were at large, along with those of 25 million other people. Here, he attempts to live away from public records for a whole 30 days, while tracked by private investigators – not an easy mission, considering Britain is behind only Russia and China in terms of surveillance. Its lack of worthiness and eye for humour make it even more effective at emphasising its point.
La La Land 10.30pm, BBC3
Episode two of the stunt show that starts out innocuously enough but soon accelerates to the point where you can scarcely believe what's taking place. Marc Wootton is seemingly never happier than when there's a real chance of being lamped out cold by whoever he's suckering. "You are in the wrong fucking industry if you think you're going to succeed in any way, shape or form," wannabe actor Gary Garner is informed after one run in … and that's one of the politer comebacks. Genius.
Research strongly suggests that people conform to expectations. Perhaps that's why legislation designed to end prejudice has only had limited success
Brent Staples was that rare bird in 70s America: a young black man who was also a gilt-edged success. At 22, he was already on the flightpath to a PhD from the University of Chicago; later he would become a bigshot on the New York Times. To strangers, however, he was just another "black man – a broad six feet two inches with a beard and billowing hair . . . indistinguishable from the muggers who occasionally seeped into the area from the surrounding ghetto".
On seeing him, white people would cross the street. Couples locked arms. Women ran. Staples knew the stats about street crime but, as he wrote in a 1986 essay: "These truths are no solace against the kind of alienation that comes of being ever the suspect, a fearsome entity with whom pedestrians avoid making eye contact."
To reassure everyone that this African American meant no harm, Staples took to whistling popular classics. "Virtually everybody seems to sense that a mugger wouldn't be warbling bright, sunny selections from Vivaldi's Four Seasons. It is my equivalent of the cowbell that hikers wear when . . . they are in bear country." A top student sporting a cowbell: Staples sums up the knottiness of modern prejudice – and the damage it can do.
Racism and sexism are usually talked about as treatable social diseases. You legislate against them. You wait for economics to take its course, as (horrible phrase, this) a "black middle class" emerges and businesses spot all this untapped talent. Then arrives utopia, where everyone at least has an equal shot at success.
In which case Britain must now be that promised land. Over the last few decades, we have published enough anti-discrimination laws and HR codes of conduct to wallpaper the Taj Mahal. We have thrown money at the problem in training schemes and diversity projects. Not enough, certainly – but sufficient to make a big dent. And then there is the talent and application of all those ethnic minorities and women who would simply like to get on.
The results are disappointing. When it comes to female representation in the House of Commons, the UK lags behind Afghanistan – with one in five MPs in Westminster versus two in five in Kabul. Indian and Chinese students in the UK now outperform their white counterparts, but the jobs and wages they go on to don't reflect that.
Perhaps with time these imbalances will level out. Trouble is, we are talking a very long time: a 2008 report for the Equality and Human Rights Commission projects that at the current rate it will take another 40 general elections for the number of women MPs to match men.
Or maybe the old levers of laws and market forces aren't enough. As Brent Staples could tell you, governments can't legislate against thought bubbles. And as the economists George Akerlof and Rachel Kranton argue, their profession has completely ignored the importance of people's identities in shaping their lives. Their new book, Identity Economics, points out that their discipline teaches that discrimination should largely have disappeared by now. After all, racism and sexism are inefficient ways to choose new undergraduates or workers – and economics has a hard time getting to grips with inefficiency.
Yet those phantom stereotypes continue to haunt even those who have made it. In his forthcoming book Whistling Vivaldi (the title is a reference to Staples), the social psychologist Claude Steele shows just how we end up conforming to the cliches of ethnicity and gender. He describes an experiment in which black and white students are asked to play 10 holes of golf in a university lab. The first lot are told this is a test of their "natural athletic ability" – and the white students play shockingly badly, living up to the old white-men-can't-jump stereotype. The black subjects are completely unaffected.
The next group are told that they are being tested for "sports strategic intelligence" – and there is a complete racial reversal. As Steele writes of the black putters, "any mistake makes them feel vulnerable to being judged and treated like a less intelligent black kid". They take on average four strokes more to get through the course. And these are Princeton students, among the brightest and best of their generation; just imagine doing a similar test on school dropouts.
Psychologists term this a "stereotype threat" and it can take many forms. Merely reminding a group of Asian women of their sex before a maths test means that they do badly (women can't handle numbers, of course). Asking another group of Asian women about their ethnic background produces a better performance – since Asians are supposed to be good at maths.
"Multitasking" is how Steele describes the effect on a person labouring under a negative stereotype: he or she has to get on with the job in hand at the same time as warding off the demons that say they shouldn't be doing it in the first place. And it can affect everyone, from the female head of a university science faculty to a black graduate student in mid-70s Chicago. Steele treats class as a creation of the land of Beefeaters, but it's easy to see how his work applies to that category, too.
"You can do everything right," he says. "Study hard, work hard, come from a good family. But mentally dealing with a stereotype is another challenge altogether." Dealing with the nuts and bolts of discrimination is hard enough; shadowboxing stereotypes is far trickier.
Using observatories in Chile, astronomers have spotted what appears to be the largest gravitational collapse of gas into a massive cluster ever seen. Source: Discovery News - Top Stories | 4 May 2010 | 12:54 am
After President Obama's new plans for NASA, Discovery News talks with Mars Society founder Robert Zubrin and SETI Institute planetary scientist Adrian Brown to find out why Mars exploration should be a priority. Source: Discovery News - Top Stories | 3 May 2010 | 10:22 pm
As crude oil keeps gushing into the Gulf of Mexico, the Deepwater Horizon rig spill is looking like it could easily end up being one of the worst environmental disasters in our nation's history. What's especially tragic is that a ... Source: Discovery News - Top Stories | 3 May 2010 | 10:00 pm
AP - Muddy waters poured over the banks of Nashville's swollen Cumberland River on Monday, spilling into Music City's historic downtown streets while rescuers using boats and Jet Skis plucked stranded residents away from their flooded homes as the death toll from the weekend storms climbed to 28 people in three states.
At least 25 sea turtles have washed up dead on Mississippi beaches over the past few days. Tests are ongoing to determine if the recent oil spill is to blame. Source: Discovery News - Top Stories | 3 May 2010 | 7:43 pm
Oil giant BP says it is "absolutely responsible" for cleaning up the massive oil spill off the US Gulf of Mexico coast. Source: BBC News | Science & Environment | UK Edition | 3 May 2010 | 5:30 pm
Avantis, unlicensed for use against blindness, under consideration as bills rise for more expensive drug Lucentis
The Department of Health is preparing the ground for a possible roll-out of a cheap, but unlicensed drug which can help prevent older people going blind, as NHS bills for an approved but much more costly drug soar.
Avastin does have a licence, but as a treatment for bowel cancer. However, in the United States and across the rest of the world it has increasingly been used – split into tiny doses and injected into the eye – to stop people going blind from wet age-related macular degeneration (AMD), the commonest cause of blindness.
The manufacturers of Avastin, US-based Genentech, have resisted this use of their drug. They produce Lucentis, which was derived from Avastin, but is made in the right-size doses. It can cost as much as 100 times the price of an Avastin injection.
Lucentis was put through clinical trials and received a licence and was then assessed for cost-effectiveness by the National Institute for Health and Clinical Excellence (Nice).
Nice had reservations about the price, which is £761.20 an injection, or £10,700 for a year's course of 14 injections, but after an offer by Novartis, which markets the drug in Britain, to pay for treatment after 14 injections, Nice agreed in 2008 that the NHS should routinely use it.
The bill to the NHS, however, has been higher than expected, as thousands of people flock for treatment – and stay on it longer than expected. There are 26,000 new cases of wet AMD in Britain every year. Normally, Nice assesses only licensed drugs, but the Department of Health has now asked it to consider assessing Avastin for eyes.
The department "has asked Nice to explore with stakeholders what value we can add in advising the NHS on the clinical and cost effectiveness of Avastin (bevacizumab) to treat wet age-related macular degeneration, the leading cause of blindness in the UK," Nice said in a statement.
The move is likely to upset the drug companies and send a shot across the bows of an industry frequently criticised for high prices. The government has already shown interest in the cheaper drug by funding a head-to-head trial of Lucentis and Avastin in wet AMD. The industry has been critical of the trial, called IVAN,claiming it is badly designed and of poor quality.
But the Macular Disease Society gave a cautious welcome to the idea of a Nice review. "We have quite a lot of anecdotes from around the country not just associated with the cost of Lucentis but the pressure on services because of the sheer numbers of people," said Cathy Yelt. "There are more people in the system having treatment than was originally foreseen."
It had been expected that many people would have only a few injections and then stabilise, or die of old age or give up on the treatment, but that had not proved to be the case. In some areas people were having trouble accessing treatment – one woman could only get treatment for both eyes by going to two different clinics. "Everybody has been caught by surprise by the numbers," she said.
Richard Smith, vice president of the Royal College of Opthalmologists, said they had called on several occasions for trials to compare the drugs. "Our paramount concern is the safety of patients and it is reasonable for the Department of Health to examine whether there are safe, efficacious and cost-effective alternatives to existing treatments," he said.
"Whatever the motivation of the review, any conclusions drawn from it should be entirely based on firm scientific evidence of safety and efficacy."
The Royal National Institute for the Blind, which has funding from Novartis and campaigned for the introduction of Lucentis, had reservations. "As we don't have further details at this time, we are cautious in our response," said Steve Winyard, head of policy and campaigns.
"However, RNIB would be greatly concerned by any steps that could undermine the current regulatory system, which is rightly based on assessing clinical evidence, primarily from randomised-control trials. This level of investigation ensures any treatments that are subsequently approved have been shown to be safe and effective."
We are sure that carbon capture and storage can stall the effects of climate change
Your article reported Houston University research which claims that "governments wanting to use carbon capture and storage have overestimated its value" (US paper raises doubts over viability of carbon capture, 26 April).
The carbon dioxide storage method injects the gas into the microscopic pores of reservoir sediments below 800 metres underground, in order to reduce atmospheric levels of this greenhouse gas. Scientists internationally are attempting to evaluate it. The argument you report is derived from a notorious pair of articles by Michael Economides and Christine Ehlig-Economides.
Economides says: "It would be hard to inject CO2 into a closed system without eventually producing so much pressure that it fractured the rock and allowed the carbon to migrate to other zones and possibly escape to the surface." That proposition is clearly wrong. The largest storage site in the world has injected 12m tonnes of CO2 over the last 13 years, not "a million tonnes over three years" as they asserted.
Consider the oil trapped in subsurface reservoirs. It is well understood that oil is not generated where it is discovered, but has moved many kilometres vertically and laterally through layers of sediment. That informs petroleum geologists (such as us) and should inform petroleum engineers (such as Economides and his co-author) that a reservoir is not a "closed system", but transmits fluids to its surroundings. The pressure spreads into a large subsurface volume (like a leaky car tyre) and does not increase in the reservoir rocks as they suggest.
The Economides calculations rely on bizarre assumptions, leading to the erroneous claim that "it would take a reservoir the size of a small US state to hold the CO2 produced by one power station". Their argument is, literally, full of holes. Firstly, storage capacity estimates differ between the first and second of their articles by a factor of 10, with no explanation and no change in their conclusions. Secondly, the calculation assumes that the "small US state" is underlain by just one reservoir, just 10 metres thick.
Economides professes that "geologists [do] not understand flow and the laws of physics", but he clearly fails to understand the geology. Multiple porous sandstones often exist below ground, with cumulative thicknesses of many hundreds of metres. Thirdly, there have been some 20 experiments of CO2 injection over the past decade. Only one has experienced the alleged pressure problem of "a bicycle pump against the wall".
By contrast, detailed work on six continents has convinced hundreds of impartial geoscientists that massive capacity for CO2 storage exists. The UK is especially fortunate as rocks similar to those which host our oil are anticipated to store 100 years of CO2 from all north-west Europe's power plants. This can buy us time while truly sustainable energy sources develop to limit climate change. But climate change is something else Economides and his co-author don't believe in.
The more TV a toddler watches, the higher the likelihood they will do badly at school and have poor health at the age of 10, researchers warn. Source: BBC News | Science & Environment | UK Edition | 3 May 2010 | 5:03 pm
AP - The latest satellite image of the oil slick in the Gulf of Mexico indicates it has shrunk since last week. But scientists say that only means some of the oil has gone underwater. Source: Yahoo! News: Science News | 3 May 2010 | 4:19 pm
LiveScience.com - Apple has sold a million iPads in less than a month, a runaway tech
success story that is shaking up the tablet computer and netbook
marketplace, according to analysts. Source: Yahoo! News: Science News | 3 May 2010 | 4:05 pm
AP - Necropsies completed on five of at least 30 dead sea turtles found along Mississippi beaches in the past few days show no evidence of oil killing the reptiles.
While the massive Gulf Oil is undoubtedly a massive ecological disaster, it presents few health risks for humans. Even as oil begins washing up on the Louisiana sure, citizens have little to fear from the oil. Source: Livescience.com | 3 May 2010 | 1:51 pm
In the early days of the space program, when launching was even dicier than it is today, Pad Leader Guenter Wendt sent the early astronauts into space. He died today at the age of 86. Source: Discovery News - Top Stories | 3 May 2010 | 1:47 pm
How did this man manage to journey from Tunisia to Ipswich, England, during the 13th century? Source: Discovery News - Top Stories | 3 May 2010 | 1:45 pm
The world’s smallest horse was born in late April on a farm in New Hampshire. Weighing in at 6 pounds at birth, Einstein appears to have beaten the previous record holder by three whole pounds.
But Einstein probably won’t hold his place in the Guinness Book of World Records forever, because there may be no limit to how tiny we can make our horses, said equine geneticist Samantha Brooks of Cornell University. But to get teacup horses will take many generations of breeding.
“In the last 50 years, breeders have made very good progress at making a very small horse, but they periodically hit these speed bumps,” said Brooks. “It takes a while to work them out so that you end up with a horse that not only fits in the palm of your hand but is happy and healthy.”
In recent years, the genetic underpinnings of height and size in mammals have generated increasing interest from scientists. In 2007, genetics researchers made the surprising finding that a single gene plays a very large role in regulating dog size, a fact that partially accounts for the tremendous variation in dog size that we see from tiny chihuahuas to enormous bull mastiffs.
Brooks is attempting to do similar genomic studies of horses, drawing on a new genetic data set she’s created from the DNA of 1,300 horses ranging in size from 29-inch tall mini horses to draft horses that are more than 6.5 feet tall at the shoulder.
Until that work is done, the molecular biological systems that make Einstein so little will remain a mystery.
“In a horse, we don’t really know yet what the genetics are behind the size variation,” said animal geneticist Rebecca Bellone of the University of Tampa.
We also don’t know why people like them so much, but they do. Since pictures and video of Einstein were posted on the internet, Cantrell, an entertainment producer who lives part-time in Barnstead, New Hampshire, has been deluged with around 1,000 e-mails a day from fans and the media. The YouTube video of the horse has been viewed 750,000 times.
“I love to ride, but when I’m around a mini, it’s more of a friend thing. It warms your heart,” said owner Charlie Cantrell. “A lot of people use minis like medical assist dogs or companion animals in hospitals and I understand why they do.”
And even if we did understand the genetics of these tiny horses, conventional breeding techniques practically require bringing some traits that humans don’t want along with the ones that we do. Two of the best examples of this problem in breeding have to do with the special pigmentation patterns in dalmatians and Appaloosa horses.
Appaloosa horses’ spotting is controlled by a set of genes called the leopard complex. When they get a certain combination of these genes from the parents, they get beautiful patterning, but some genetic variations associated with desirable spots also lead to night blindness in the horses. The spots dalmatians are famous for are associated with deafness in the dogs. A full 30 percent of the dalmatians in the United States are deaf.
“This is a standard problem. Animal breeders create as many problems as we solve,” said animal scientist Tom Famula of the University of California, Davis. “When we push an animal in a direction that humans want, there’s usually some side effect. To the animal that has evolved in balance, we’re trying to move some trait out of balance to the others. We usually mess something up.”
Brooks says that this kind of problem is part and parcel of trying to breed animals with certain tightly defined characteristics.
“The trick is you have two copies of every gene,” Brooks said. “Sometimes a particular mutation with only one copy may be recognized as beneficial but later down the line if you have an individual with two copies, the recessive effect might actually produce a disease.”
That’s because every gene in a mammal’s body isn’t just being used for one thing. The protein it encodes is a multipurpose tool. “Each of these genes is multitasking. It’s a pretty efficient way to do things,” Brooks said. “Sometimes the negative effects are in some of these other things that a gene does. When we make a change in gene X, what are the other processes that it might affect?”
The same gene that helps control appaloosas’ melanin expression in their coats also plays a role in their eyes. The situation is similar in miniaturizing horses. As they get smaller, the genes that limit the growth of their skeletons can cause negative impacts. Sometimes breeders attempting to create miniature horses end up with dwarfs that have malfunctioning jaws and legs. They can be crippled. While breeders obviously try to avoid that situation, it can be difficult for them to know which mating pairs will lead to negative outcomes.
The real limits then, may not be genetic, but cultural. At some point, it may become difficult to get healthy, tiny horses. To breed ever smaller horses, we might have to deal with a lot of deformed animals.
“It brings up this question of personal responsibility and what’s humane and what’s inhumane. That’s something the tone of which will be set by public opinion,” Brooks said. “I don’t think we’re at the point that we’re breeding monsters. I don’t think we’re there but maybe we will be.”
The way Cantrell sees it, avoiding the downsides of mini breeding comes down to the individual breeders. “It’s just like with dogs: There are puppy mills, and there are mini mills,” he noted. Einstein is more a lucky break than an attempt to breed the smallest horse. Both of his parents are champion 30-inch show horses. He just happened to come out lilliputian.
Cantrell argued that despite the difficulty of breeding the minis, it’s worth it because they provide humans with a special feeling that standard horses cannot.
“When you get up close and personal to a miniature horse that is 30 inches tall, there is something about being able to touch him and walk with him in a very calm and safe manner, where you don’t feel like you’re going to be stomped to death,” Cantrell said.
Shooting lasers at the sky can make the germ of a rain cloud, a new study shows. In an experiment that smacks of science fiction, scientists used a high-powered laser to squeeze water from air, both indoors and out.
Although the technique is unlikely to be an instant rainmaker anytime soon, it could plant the seeds for more eco-friendly cloud manipulation.
“This is the first time that a laser was used to condense water from both laboratory experiments and from the atmosphere,” says Jérôme Kasparian of the University of Geneva, a coauthor of the study. The work appeared in the May 2 Nature Photonics.
Atmospheric scientists have been trying to build artificial clouds since the 1940s, with mixed success. The most popular method, shooting particles of silver iodide into the sky, relied on the fact that raindrops need something to condense around.
“It’s just like when you take a shower with hot water — it’s very humid in your bathroom, but it’s not raining,” Kasparian says. Water droplets need a surface to condense on, like a mirror in a bathroom or a speck of dust or pollen in the atmosphere.
Previous experimenters hoped droplets would form around flakes of silver, salt or other materials just like on a bathroom mirror. “The idea is, you provide more condensation nuclei, you get more condensation,” Kasparian says. “It seems obvious, but in practice no one could really prove that it works.”
Kasparian and colleagues took inspiration from a mist-making apparatus that was invented in 1911 to detect cosmic rays, highly energetic subatomic particles that come from deep space. A physicist named Charles Wilson noticed that when cosmic rays strike a sealed container filled with water vapor, they leave a visible trail of water droplets behind them. This works because the cosmic rays knock electrons off the water molecules, leaving behind charged particles that act like specks of dust for water to congeal around.
“Our idea was to mimic what happens in a Wilson chamber,” Kasparian says. “If you get some condensation with cosmic rays, we should get even more condensation with a laser.”
Kasparian and his colleagues tested this idea by shooting a high-powered infrared laser into a cloud chamber. The laser shot extremely short pulses of intense light, which each carrying several terawatts — or a trillion watts — of energy.
The view fogged up immediately. Droplets about 50 micrometers in diameter formed first, and grew to about 80 micrometers in diameter over the next three seconds. “The effect in the cloud chamber was very spectacular and visible by bare eye,” Kasparian says. “We expected an effect, definitely. But that magnitude was pretty much a surprise.”
Next, the researchers took the laser out in the backyard to try it on the sky. They rolled the laser, called “Teramobile” for its terawatt power and its mobility, onto the lawn behind the physics building at the Free University of Berlin on several nights in the fall of 2008. The clouds, if they formed, would be too distant to see with the naked eye, so the team used a second laser to confirm the cloudy view.
“It also worked quite well in the free atmosphere,” Kasparian says. “That was quite surprising, and a very good surprise.”
Kasparian thinks lasers could provide a more reliable and environmentally friendly way to build clouds. “If you can seed clouds and get some control or at least modulation on the weather, the implications are huge for agriculture, many other economic sectors, many aspects of human life,” Kasparian says. “There are potentially huge consequences.”
“It is a clever technique,” says John Latham of the National Center for Atmospheric Research in Boulder, Colorado. But he’s skeptical that laser-built clouds could actually make it rain on demand. “Rainfall production requires many conditions to be met,” he cautions.
More than half a century after DEET’s invention, scientists still don’t know how the popular mosquito repellent works.
Now, using a combination of artificially accelerated evolution and painstaking anatomical observation, researchers have answered a fundamental question about DEET’s mechanisms – and in the process showed that mosquitoes may become resistant to it.
“It’s a fundamental piece of research. It will give us a lot more knowledge, rather than just going out and spraying something,” said study co-author Linda Field, a molecular biologist at England’s Rothamsted Research institute.
How DEET — short for N,N-diethyl-meta-toluamide – actually works has been a subject of scientific controversy since its discovery after World War II by U.S. Army researchers who tested thousands of man-made compounds, and were simply happy to find one that repelled bugs.
Researchers later hypothesized that DEET prevented insects from detecting lactic acid, one of the odors mosquitoes follow to unlucky animals. But DEET still worked in the absence of lactic acid, leading some scientists to speculate that DEET interferes with some other molecule’s detection. However, other scientists think DEET acts directly on an as-yet-unidentified olfactory receptor, irritating them instead of just hindering them.
The argument would be of little interest to anyone except entomologists, but for the fact that some mosquitoes aren’t deterred by DEET. For people in the developed world, that’s annoying. For people in tropical areas where insect repellents and insecticides control mosquito-borne disease, it’s a pressing concern.
Field and Nina Stanczyk, a University of Nottingham biochemist, started their study by resting a DEET-sprayed arm on a mesh cage, just out of reach of female Aedes aegypti mosquitoes. (Only female mosquitoes bite; like males, they typically feed on flower nectar, but require nutrients from blood in order to lay eggs). Those that tried to feed were removed and bred separately. Within a few generations, more than half were DEET-resistant.
Field cautioned that laboratory results shouldn’t be automatically extrapolated to the natural world, but a similar dynamic could well exist, especially in heavily populated areas where humans are the predominant source of blood. “If a small percentage are insensitive, they have a much better chance of getting a blood meal, and are much more likely to pass on their genes. You’d likely see a buildup of the trait,” said Field.
The researchers then attached electrodes to their mosquitoes’ antennae, allowing them to monitor responses to DEET and other compounds. DEET indeed proved to have an effect on its own, in the absence of any other odor. Stanczyk proceeded to painstakingly attach electrodes to the mosquitoes’ sensillum — tiny, single molecule-detecting structures found by the thousands on each antenna. She identified the type of sensillum that responded to DEET. In DEET-resistant mosquitoes, those sensillum are shaped unusually.
For now, that’s the extent of the researchers’ knowledge.
“Somewhere inside that sensillum, the odor molecule gets in, is picked up by a binding protein, goes to a receptor protein, and that triggers the behavioral response,” said Field. “Our question now is, what has changed? The next step is finding out what’s going on inside.”
Image: 1) James Jordan/Flickr. 2) Mosquito sensillum./Linda Field.
Citation: “Behavioral insensitivity to DEET in Aedes aegypti: A genetically determined trait residing in changes in sensillum function.” By Nina Stanczyk, John Brookfield, Rickard Ignell, James Logan, and Linda Field.” Proceedings of the National Academy of Sciences, Vol. 107 No. 18, May 4, 2010.
Too much TV at a young age is associated with academic, social and health problems later in life, a new study finds. Source: Livescience.com | 3 May 2010 | 12:27 pm
Children often copy everything an adult does, even when more efficient alternatives exist. But rather than spreading bad habits, this mimicry helps perpetuate human culture. Source: Livescience.com | 3 May 2010 | 12:25 pm
If this is your first exposure to the Friday News Feedbag...we're glad to have you in the club. Welcome to Feedbag Nation, which stems from our weekly science news podcast that you can subscribe to here on iTunes and chat ... Source: Discovery News - Top Stories | 3 May 2010 | 11:22 am
Pope Benedict XVI said the Shroud of Turin's message is keeping up hope. But is the supposed burial cloth of Jesus real? Source: Livescience.com | 3 May 2010 | 10:59 am
Indian scientists wield sophisticated mathematics to dissect and analyse the traditional meditation chanting sound 'Om'
Two Indian scientists are wielding sophisticated mathematics to dissect and analyse the traditional meditation chanting sound "Om". The Om team has published six monographs in academic journals. These plumb certain acoustic subtleties of Om, which these researchers say is "the divine sound".
Om has many variations. In a study published in the International Journal of Computer Science and Network Security, the researchers explain: "It may be very fast, several cycles per second. Or it may be slower, several seconds for each cycling of [the] Om mantra. Or it might become extremely slow, with the mmmmmm sound continuing in the mind for much longer periods but still pulsing at that slow rate. It is somewhat like one of these vibrations:
'OMmmOMmmOMmm...
'OMmmmmOMmmmmOMmmmm...
'OMmmmmmmmOMmmmmmmmOMmm'."
The important technical fact is that no matter what form of Om one chants at whatever speed, there is always a basic Omness to it.
Ladhake is the principal at Sipna's College of Engineering and Technology in Amravati, India. Gurjar is an assistant professor in that institution's department of electronics and telecommunication. Both specialise in electronic signal processing. They now sub-specialise in analysing the one very special signal.
In the introductory paper, Gurjar and Ladhake explain (in case there is someone unaware of the basics): "Om is a spiritual mantra, outstanding to fetch peace and calm. The entire psychological pressure and worldly thoughts are taken away by the chanting of Om mantra."
No one has explained the biophysical processes that underlie this fetching of calm and taking away of thoughts. Gurjar and Ladhake's time-frequency analysis is a tiny step along that hitherto little-taken branch of the path of enlightenment.
They apply a mathematical tool called wavelet transforms to a digital recording of a person chanting "Om". Even people with no mathematical background can appreciate, on some level, one of the blue-on-white graphs included in the monograph. This graph, the authors say, "depicts the chanting of 'Om' by a normal person after some days of chanting". The image looks like a pile of nearly identical, slightly lopsided pancakes held together with a skewer, the whole stack lying sideways on a table. To behold it is to see, if nothing else, repetition.
At the end, Gurjar and Ladhake say: "Our attentiveness and our concentration are pilfered from us by the proceedings take place around us in the world in recent times ... By this analysis we could conclude steadiness in the mind is achieved by chanting Om, hence proves the mind is calm and peace to the human subject."
Much as people chant the sound "Om" over and over again, Gurjar and Ladhake repeat much of the same analysis in their other five studies, managing each time to chip away at some slightly different mathematico-acoustical fine point.
(Thanks to Martin Gardiner for bringing the Om team to my attention.)
Marc Abrahams is editor of the bimonthly Annals of Improbable Research and organiser of the Ig Nobel prize
The ice cap on Uganda's highest peak has split because of global warming, the country's wildlife authority says. Source: BBC News | Science & Environment | UK Edition | 3 May 2010 | 8:30 am
Biological determinism has been attacked for underpinning gender stereotypes but this is to misunderstand our work
Natasha Walter suggests women are invisible in public life because of "boxing them up into tired old stereotypes" and because of a "resurgence of biological determinism". I totally agree we need to sweep away the tired old stereotypes and think imaginatively about how to work towards a more equal society for men and women.
However, I don't think biological determinist theories have much to do with this issue, and rejecting biological determinism makes no sense. We don't want to revert to the 1960s view that human behaviour is purely culturally determined, since we now know that view was profoundly mistaken. No one disputes that culture is important in explaining sex differences, but it can't be the whole story.
Men and women don't just differ in terms of their genitalia, but in other important ways. For example, there are more than 1,000 genes on the X chromosome. Since women have two X chromosomes but men only have one, this genetic difference has an impact. Genes on the X chromosome are responsible for why 1 in 20 men but only 1 in 400 women have red-green colour blindness. Genes on the X chromosome are also responsible for why 1 in 5,000 men, but hardly any women, have haemophilia type A. Science continues apace to unravel the functions of genes. Just last year our group published new findings of genes related to empathy – a skill that women are, on average, better at than men.
Biological determinists don't dismiss the importance of culture. They simply don't deny the role of biology. It is a moderate position, recognising the interaction of social and biological factors. Nor, in my opinion, is biological determinism necessarily sexist. It can be sexist, if it is used to claim that all women do X and all men do Y (since sex differences don't apply to all individuals of one sex) or if it is used to perpetuate social inequalities. Such sexist applications of biological determinist theories are abhorrent.
In our research, we use biological determinist theories in more nuanced ways. We find, for example, that it is your brain type, not your sex, which predicts how you will behave. Some brain types are more common in one sex than another, but because an individual can be atypical for their sex, it is meaningless to try to predict anything about a person's behavior based on their sex. A brain type that leans towards strong "systemising", for example, is more common in males, but there are plenty of men who don't have this profile, and quite a lot of females who do. Systemising happens when you try to figure out how things work, be it a computer program, a car engine, or a maths equation. We don't yet know if strong systemising is associated with particular sex-linked genes, but we should keep an open mind on this possibility, given that only 10% of professors of mathematics are female.
But back to Walter's plea for more women in public life: I strongly echo her call. There is plenty we can do to make public life both more attractive and more accessible to women, including making prime ministerial debates less like a boxing fight, general elections less like tribal warfare, and the House of Commons working practices more family-friendly. None of this is likely to have anything to do with biological determinism.
