Seeing the world differently

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A new surgical tool - the IKEA pencil

The IKEA pencil: A surprising find in the NHS

IKEA pencils are better at marking out cuts in the bone for facial and head surgery than traditional felt tipped pens, say two surgeons in the Christmas issue published on today.

Karen Eley, from the Nuffield Department of Surgical Sciences at the University of Oxford, and Stephen Watt-Smith, from the Department of Maxillofacial Surgery at the John Radcliffe Hospital in Oxford, say that while the popularity of the IKEA pencil is widely known - there is a Facebook page called “Ikea pencil stealing appreciation” – sourcing pencils from IKEA for surgery has surprised doctors.

They say “as popular as these little pencils are, we were still surprised to be handed one halfway through a surgical case … the use of a pencil to mark osteotomy cuts in craniofacial and maxillofacial surgery is well established, proving superior to methylene, Bonney’s blue and felt tipped skin markers that struggle to transfer an ink mark to bone, or are washed away by irrigation or tissue fluids”.

Unfortunately, they say, repeated sterilisation means that some of the pencils split but even this problem has been overcome by wrapping silicon cuffs around the pencil.

Perhaps the designers at IKEA could act on this idea, suggest the authors.

Could starfish inspire new cure for inflammation?

By Rebecca Morelle Science reporter, BBC News

Lurking in the seas of Scotland is an unlikely candidate for a medical breakthrough.

But scientists believe the starfish could hold the key to finding a new treatment for inflammatory conditions such as asthma, hay fever and arthritis. The species they are interested in is the spiny starfish (Marthasterias glacialis), and in particular the slimy goo that covers its body. The team says that chemicals in this coating could inspire new medicines.

While most man-made structures that are placed in the water rapidly get caked with a mixture of marine life, starfish manage to keep their surface clear.

The spiny starfish can be found on the west coast of Scotland

Dr Charlie Bavington, from GlycoMar, a marine biotechnology company based at the Scottish Association for Marine Science in Oban, explained: "Starfish live in the sea, and are bathed in a solution of bacteria, larvae, viruses and all sorts of things that are looking for somewhere to live.

"But starfish are better than Teflon: they have a very efficient anti-fouling surface that prevents things from sticking." And it is this non-stick property that has grabbed medical scientists' attention, particularly in the field of inflammation.

Sticky problem

Inflammation is the body's natural response to an injury or infection, but inflammatory conditions are caused when the immune system begins to rage out of control. White blood cells, which normally flow easily through our blood vessels, begin to build up and stick to the blood vessel wall, and this can cause tissue damage.

The idea is that a treatment based on starfish slime could effectively coat our blood vessels in the same way the goo covers the marine creature, and prevent this problem.

Dr Bavington said: "It is a very similar situation to something sticking to a starfish in the sea.

"These cells have to stick from a flowing medium to a blood vessel wall, so we thought we could learn something from how starfish prevent this so we could find a way to prevent this in humans."

While many inflammatory conditions can be effectively treated, for example with steroids, these drugs can often cause unwanted side effects. But scientists at King's College London (KCL) think starfish could offer a better solution, and they have been analysing the chemicals in the creature's non-stick slime.

Clive Page, professor of pharmacology at KCL, said: "The starfish have effectively done a lot of the hard work for us. "Normally when you are trying to find a new drug to go after a particular target in human beings, you have to screen hundreds of molecules to find something that will give you a lead. "The starfish is effectively providing us with something that is giving is different leads: it has had billions of years in evolution to come up with molecules that do specific things."

Having identified promising compounds, the team is now working on creating their own versions of them in the laboratory. They want to create a treatment that is inspired by starfish goo rather than one that is made from it.

Professor Page said: "Conceptually we know this is the right approach. "It's not going to happen tomorrow afternoon, but we are learning all the time from nature about how to find new medicines."

Underwater pharmacy

While the starfish-based cure might be some years off, the race to explore the oceans for its medical potential is only just beginning. A sea snail has already formed the basis of a new painkiller, and scientists are starting to look at a whole range of marine life, from sea cucumbers to seaweed.

Dr David Hughes, an ecologist from the Scottish Association for Marine Science, explained: "Some of the most widespread, widely used medicines come from nature. "Penicillin is a mould that grows on bread, aspirin comes from willow trees, so it's not too surprising turning to nature to find useful drugs. But we've only very recently begun to look to the sea for a useful source of medicines."

And with the oceans covering nearly three quarters of the Earth's surface, scientists have likened the deep to an untapped underwater pharmacy.

Dr Hughes told the BBC: "There is such a huge diversity of animals and plants living in the oceans and very few of them have been tested and investigated in any way. "We know marine animals and plants produce a huge range of compounds, sometimes very different compounds from those produced by animals and plants on land. "So many might have useful properties that could be brought into medicine and other medicinal applications."

Shine On, Zirconium Star

By Jennifer Ouellette

Located some 2000 light years from the sun, just between the constellations Capricornus and Aquarius, this star's atmosphere features glittery clouds of zirconium - more commonly known as "fake diamond."

Other stars, like our Sun, might have trace amounts of zirconium - maybe one atom in two billion - but LS IV-14 116 has one zirconium atom for every 200,000 atoms. How does such a rare object form in the first place? Most ordinary stars with insufficient mass to go supernova when they die - about 97% of all the stars in the Milky Way - will puff up into a red giant once they deplete their hydrogen fuel and start fusing helium into carbon and oxygen.

If a red giant is big enough (has sufficient mass), once it runs out helium it will move on to fusing other elements. If it's not massive enough, the star "stalls out," as it were. All that carbon and oxygen - byproducts of the helium fusion process - build up in its core. At that point the star will shed its outer layers and the core will form a white dwarf. In rare cases, a star will shed its hydrogen layers prematurely during that first stage, before its core starts burning helium, and you end up with a helium-rich hot sub-dwarf, a progenitor to a white dwarf.

That's the class of star that Naslim and Jeffery were studying, hoping to ferret out clues as to why this category of star has so much less hydrogen on their surfaces than other similar stars.

They used spectroscopy for their analysis: a technique that breaks the light from celestial objects into a spectrum with telltale emission lines indicating which elements are present. (Each element has its own unique spectral pattern, like a chemical fingerprint.) That's how we know that hydrogen is the most abundant element in the universe, with helium close behind.

Naslim and Jefferey expected to see certain common elements, most notably hydrogen and helium, carbon, oxygen and the like. What they didn't expect: huge amounts of a form of zirconium that can only exist at temperatures above 20,000 degrees Celsius.

It's not a small excess either: there is 10,000 times more zirconium in LS IV-14 116 than in the sun. (There's also strontium, germanium and yttrium, between 1000 and 10,000 times more abundant than usual.) That translates to about 4 billion tons of zirconium here on Earth.

Those abundances were "a complete surprise," according to Naslim. That's why they titled their paper "An extremely peculiar hot sub-dwarf with a ten-thousand fold excess of zirconium, yttrium and strontium." They argue in their paper that all those extra elements comes from the formation of cloud layers in the star's atmosphere.

Yes, stars can have atmospheres; that's typically the only part of a star we can see directly. In general, the heavier atoms in the atmosphere sink and the light ones remain at the surface, which is why some white dwarfs, for example, have mostly pure hydrogen or helium atmospheres. Under the atmosphere, scientists think there is a very think crust of carbon and oxygen.

What's unusual about LS IV-14 116 is the high concentration of metals heavier than calcium in those cloud layers. In fact, theoretical models of that atmosphere indicate that there could be several very thin cloud layers, each comprised of a different metal. The star might even be shrinking as it cools, causing various elements to float into the atmosphere or sink to the bottom - with that glittery zirconium layer front and center. I'll bet LS IV-14 116 doesn't even care that it isn't made of real diamonds.

Some day, millions of years from now, LS IV-14 116 will cool off to the point where it becomes a bona fide white dwarf. Those are amazing objects in their own right, and also rather rare (perhaps because they're so difficult to spot): there's eight known white dwarfs in the hundred nearest star systems to our sun.

What makes a white dwarf so amazing is that it has no internal source of energy - its core material is done with fusion - to counter gravitational collapse. So gravity just smashes all those atoms together until the electrons literally have nowhere to go. At that point, the star is so dense, it becomes "degenerate." And quantum mechanics literally stops that gravitational crunch in its tracks.

Eventually, LS IV-14 116 will radiate away enough energy to cool down until it won't emit enough heat to be visible at all. That's known as a black dwarf, but since the process takes longer than the present age of the universe, there are no known black dwarfs in existence. Maybe LS IV-14 will be the first.

Researchers establish new rule to predict risk of stroke, death from surgery that prevents it

DALLAS – It's a medical Catch-22: carotid artery surgery can itself cause stroke, but so can asymptomatic carotid disease if left untreated.

UT Southwestern Medical Center researchers have now developed a clinical risk prediction rule using factors such as sex, race and health history to assess the danger the surgery poses, while a modified version will help patients make a more fully informed choice about whether to have the procedure.

"It may take a thief to catch a thief, but physicians don't want to cause stroke while trying to prevent stroke, so being able to carefully weigh an individual's benefits and risk from carotid surgery is critically important," said Dr. Ethan Halm, chief of the William T. and Gay Solomon Division of General Internal Medicine and senior author of the study published in the journal Stroke.

Researchers drew on factors that increase the risk for postsurgical death or stroke for people with silent, or asymptomatic, carotid disease to predict which patients were at highest risk for complications.

Those most at risk were female, non-white and had certain neurologic and heart diseases.

The carotid arteries, which run on the sides of the neck, are main blood vessels that supply oxygen to the brain. These arteries can become narrowed by fatty cholesterol deposits called plaque.

If pieces of plaque break free, they can lodge in the brain, causing stroke.

In carotid endarterectomy (CEA), one of the most common types of vascular surgery performed in the U.S., surgeons open the artery and remove the plaque. Silent, or symptom-free, carotid artery disease usually is found by chance during unrelated medical tests.

"Asymptomatic patients achieve only a modest benefit from surgery – their chance of stroke decreases from 2 percent annually to 1 percent annually – because they have a lower chance of having a stroke in the first place," Dr. Halm said.

"For patients with several other medical risk factors, the upfront risk of surgery can outweigh any potential long-term benefits."

To create a predictive model to help determine a patient's risk, Dr. Halm and colleagues reviewed cases from the New York Carotid Artery Surgery study (NYCAS). The NYCAS evaluated outcomes of carotid surgeries performed on elderly patients in 167 hospitals in New York state between January 1998 and June 1999.

Of the 9,308 surgeries, 6,553 were performed on asymptomatic patients. The average patient was 75 years old. Nearly 75 percent of patients had hypertension; 62 percent had coronary artery disease; and 29 percent had diabetes. Within 30 days of surgery, there were 55 deaths and 165 strokes.

The UT Southwestern researchers found that eight factors were independent predictors of death or stroke – being female, a minority, or severely disabled, or having a history of stroke, having arteries narrowed more than 50 percent, coronary artery disease, congestive heart failure or valvular heart disease.

They assigned each risk factor one point, except for disability which counts as 2. Patients with a score of 0 to 2 are low risk; those with 3 points are at moderate risk; more than 4 are high risk. Using this CEA-8 rule, they determined that one-fourth of the NYCAS patients had a higher probability of death and stroke than the recommended national guidelines.

They then created the CEA-7, a patient-friendly model, that eliminates non-operative stenosis. Patients can also determine their own risk, even if they don't know whether their arteries are more than 50 percent blocked.

"These models are the first for asymptomatic patients and are a practical and easy-to-use tool for doctors and patients to evaluate what is best for them in the long term," Dr. Halm said.

"These aren't the only factors a patient should consider – individual health and experience of the surgeon and hospital team count, too – but hopefully with these models, patients and doctors can more accurately individualize the risk of complications."

The authors are now developing an interactive educational program that helps patients better understand the different risks and benefits of surgical versus medical management of asymptomatic carotid disease.

Other UT Southwestern researchers participating in the study were Dr. Linda Calvillo King, assistant professor of internal medicine; Lei Xuan, biostatistical consultant in clinical sciences; and Dr. Song Zhang, assistant professor of clinical sciences. Researchers from Mount Sinai School of Medicine also participated.

The study was funded by the National Institute of Neurological Disorders and Stroke, Agency for Healthcare Research and Quality, Centers for Medicare & Medicaid Services, and the Robert Wood Johnson Foundation.

Scientists give insight into 200-year-old riddle

( - University of Manchester researchers have played a vital role in an international study that has revived the 200-year-old question: why do different species share similar stages of embryonic development?

Dr Casey Bergman and Dr Dave Gerrard at Manchester’s Faculty of Life Sciences collaborated on the project with Pavel Tomancak, at the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden, and Uwe Ohler, at Duke University, on a study funded by the Human Frontiers of Science Program published in Nature today.

The team looked at differences in the embryonic development of species in search of what unites animal groups at the level of embryos and their genes, bringing the power of modern molecular techniques to bear on what is a classic problem in biology.

It has long been noted that there are striking similarities between the embryonic development of animals and their evolutionary histories. This relationship between how animals develop and deep evolutionary time hints at the existence of profound connections between different animal species and has therefore captured the imagination of both biologists and the wider public.

However, ever since the first observations were discussed by leading 19th century biologists, such as von Baer, Darwin, and Haeckel, the existence and meaning of these similarities has been fraught with controversy arising from the subjective nature of the comparisons of different animal forms.

While the pioneers of embryology believed that animal species are most similar at the earliest stages of their embryonic development, the arrival of improved observational methods in the 20th century led to a revised proposal.

It was noticed that the middle periods of embryonic development exhibit the highest similarity between species belonging to the same broad taxonomic group, known as a ‘phylum’, with earlier and later periods often showing remarkable divergence in form. This so-called 'hourglass model,' has so far been supported by the same types of evidence available to 19th century biologists, namely subjective comparisons of embryo appearance.

Taking advantage of advancements in large-scale gene-based methods, the international team compared the embryonic development of six different fruit fly species at the molecular level. Instead of subjective assessment of a handful of visible traits, they made objective measurements of expression levels for several thousand genes.

The team found that the developmental period when insects are most similar in form is indeed underpinned by a corresponding similarity in gene expression. “This discovery both confirms the conclusions of previous anatomical studies and extends our understanding of the relationship between development and evolution to the molecular level,” explained Dr Kalinka, who led the analysis of the data.

The team also shed light on the reason why there is a period of similarity in the middle of animal embryonic development, a fundamental problem that has so far remained unanswered. Dr Bergman explained: “Our study provides the first solid evidence that this period of similarity between animal species is being actively preserved by natural selection as opposed to being a period that is simply resistant to change for other reasons.”

The results open up new horizons, as the fruit-fly species used are one of the best-studied experimental model systems for genetics, development and evolution.

Detecting the hourglass pattern among such closely related species is for biologists equivalent to obtaining a time machine into processes that led to the initial branching on the animal tree 600 million years ago, as these species are very much alive today and can be probed and studied by modern technologies such as genome manipulation and high-resolution imaging.

Pavel Tomancak, who led the study, concludes: “In the future we hope to use these new tools to gain deeper insight into the evolutionary processes that shaped the remarkable diversity of animal forms observed today.”

More information: The paper ‘Gene expression divergence recapitulates the developmental hourglass model’ (Nature, December 9, 2010) is available at http://www.nature. … re09634.html Provided by University of Manchester (news : web)

Fungus out! The frog resistance is here

* 10 December 2010 by Wendy Zukerman

FROGS across Australia and the US may be recovering from a fungal disease that has devastated populations around the world.

"It's happening across a number of species," says Michael Mahony at the University of Newcastle in New South Wales, who completed a 20-year study of frogs along the Great Dividing Range in Australia for the Earthwatch Institute. Between 1990 and 1998 the populations of several frog species crashed due to chytridiomycosis infection (chytrid) caused by the pathogen Batrachochytrium dendrobatidis, but Mahony's surveys suggest that the frogs are re-establishing.

Barred river frogs (Mixophyes esiteratus) disappeared, he says, but now up to 30 of the animals have returned to streams across Australia's Central Coast. The tusked-frog (Adelotus) and several tree frog species (Litoria) have also returned there. Ross Alford at James Cook University in Townsville, Queensland, says tree frogs are also repopulating other areas of the state after their numbers nosedived. Some have even reached pre-infection levels.

In the US there are also signs of recovery. Roland Knapp at Sierra Nevada Aquatic Research Laboratory at the University of California says mountain yellow-legged frogs (Rana muscosas) - once "driven virtually to extinction" - are returning. The big question is: are frogs now beating chytrid?

Using electronic tagging to track frogs, Knapp (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0912886107) and Mahony have separately found that recovering frogs are living with low-level infections of the fungus.

It is possible, they say, that the fungus has weakened in recovering areas. Knapp says there is evidence that the frogs are evolving. Initial findings from his team show that frogs from recovered populations can survive when challenged with a fungal strain, unlike frogs with no previous exposure to the fungus, which died after it colonised their skin.

At Vanderbilt University Medical Centre, Nashville, Alford and Louise Rollins-Smith found that a population of Australian green-eyed tree frogs previously decimated by the fungus produced more anti-microbial peptides - which inhibit fungal growth - on their skin than a less affected population (Diversity and Distribution, vol 16, p 703). "It's quite likely that populations are adapting and developing better defences," says Rollins-Smith.

Worldwide, most amphibian communities are not recovering, though earlier this year Ursina Tobler at the University of Zurich, Switzerland, showed for the first time that even in devastated populations, some tadpoles can survive infection (PLoS One, DOI: 10.1371/journal.pone.0010927).

Study finds statin use linked to rare autoimmune muscle disease

Johns Hopkins researchers have discovered how statins, the most commonly prescribed class of medication in the United States, appear to trigger a rare but serious autoimmune muscle disease in a small portion of the 30 million Americans who take the cholesterol-lowering drugs.

Johns Hopkins researchers have discovered how statins, the most commonly prescribed class of medication in the United States, appear to trigger a rare but serious autoimmune muscle disease in a small portion of the 30 million Americans who take the cholesterol-lowering drugs.

Taking statins, they found, can sometimes cause the body to produce antibodies against its own proteins, creating a condition that gets progressively worse - not better - even after the medication is discontinued. As the painful and debilitating disorder is uncommon and can be treated with steroids and other immune-suppressing drugs, the Hopkins researchers caution that people who must be on statins to reduce serious risk of heart disease and stroke should not avoid the drugs.

“We have long known that there must be environmental triggers to the development of autoimmune disorders,” says Andrew L. Mammen, M.D., Ph.D., an assistant professor of neurology and medicine at the Johns Hopkins University School of Medicine. “Now we have evidence that this medication is just such a trigger and, under certain circumstances, provokes a sustained autoimmune disease.”

Beyond the “proof of principle” in Mammen’s findings, published online in the journal Arthritis & Rheumatism, they could also lead to lab tests that identify early autoimmune muscle disease, guide treatment before symptoms escalate and, possibly, predict who is at risk before statins are prescribed.

Mammen cautions that the Hopkins research describes a rare side effect, noting that statins are a “fantastic medication” that have proven value. “No one who needs statins should be afraid to take them because of the slim risk of developing this autoimmune disease,” he says.

“Statins save a huge number of lives. They dramatically reduce the risk of strokes and heart attacks,” Mammen adds. “The ultimate goal of our research is to determine before patients start taking statins who might be sensitive to the medication and who might be susceptible to its potentially toxic effects on the muscle. We want to prevent this autoimmune disease.”

Although statins are tolerated by most patients, about 5 percent who take them experience muscle pain and/or weakness severe enough to warrant stopping the medication. Most of those people will make a full recovery once they are off the drug, but there appears to be a group who will develop this progressive autoimmune muscle disease. They get weaker even after the medication is stopped, some end up in wheelchairs and at least one has died. Immunosuppressive therapy with steroids or other drugs are effective in reversing the disease in most patients, Mammen says.

In his initial research, Mammen and his colleagues focused on 26 patients at the Johns Hopkins Myositis Center with necrotizing myopathy, a muscle-wasting disorder with no known cause. Sixteen were found to have a previously unknown antibody. Of the 16 patients with this novel antibody, 12 were over the age of 50 and, of those, more than 80 percent had taken statins before their muscle pain and weakness began. The frequency of statin use in patients with similar muscle diseases is significantly lower. In his latest research, Mammen identified the target of the antibodies as HMG-CoA reductase, or HMGCR. HMGCR is the enzyme responsible for making cholesterol - and it is the same enzyme that statins target.

In their collection of over 750 patients with muscle symptoms, 45 patients with HMGCR antibodies were identified. Of those over 50 years of age, greater than 90 percent had a prior statin exposure. The younger patients, he says, had not been on statins, and how the disease is triggered has not been determined. However, Mammen suspects that they may suffer from other cholesterol issues, a factor that could play a role in the development of the disease.

Antibodies are typically made by healthy people to recognize and destroy foreign invaders. But in patients with autoimmune diseases, the body makes auto-antibodies - antibodies that attack the body’s own proteins. In the case of statin-associated autoimmune muscle disease, the body attacks its own HMGCR. When a patient takes statins, HMGCR levels rise as the body tries to compensate for the reduction in the enzyme caused by the medication. Mammen hypothesizes that the extra HMGCR in the body may sometimes stimulate the immune system to make autoantibodies.

Compounding the problem is the finding that while normal muscle tissue makes low levels of HMGCR, regenerating muscle cells make very high levels of HMGCR. This suggests that once the autoimmune muscle disease process is initiated by statin use, high levels of HMGCR in regenerating muscle cells continue to fuel the aggressive and painful autoimmune response, even after statins are withdrawn.

Although doctors don’t yet know how many people have statin-associated autoimmune muscle disease, Mammen and his colleagues believe it is rare. Even in the Myositis Center, just four percent of patients have been diagnosed with it. Mammen says the lab test he and his team have developed, which has not yet been approved by regulators, enables them to diagnose the disease with near certainty.

Some of his patients, however, continue to need the very medication that caused their pain.

“One of the questions that remain is: Can you safely restart statins? It’s important because some of our patients were put on statins for very good reasons, like they’ve had a heart attack,” Mammen says. “We would like to find out if there is a way for these patients to begin taking the medication again.”

Provided by Johns Hopkins University

Laser incidents on rise; aviation officials worried

By JOAN LOWY Associated Press

Federal Aviation Administration officials are worried about a substantial increase in the number of people pointing lasers at aircraft cockpits, saying the intense light can distract and temporarily blind pilots and has caused some to relinquish control to their co-pilots or abort landings.

This year, there have been more than 2,200 incidents reported to the Federal Aviation Administration, up from fewer than 300 in 2005. California, Texas and Florida have recorded the most, but the problem is widespread across the country. There hasn't been an air crash so far, but the incidents have aviation officials concerned.

"It sounds silly, but this is a serious problem," FAA Administrator Randy Babbitt wrote Wednesday in a post on a Transportation Department blog. "We know that laser pointers are an important tool for astronomers and casual stargazers," Babbitt wrote. "But we just can't stress enough the importance of being careful when you are shining them into the night sky."

The rise in incidents has coincided with a growing hobbyist market for handheld lasers that are far more powerful - and potentially dangerous - than the typical laser pointer. At the same time prices have dropped. Lasers that once cost more than $1,000 can now be bought online for a few hundred dollars or less.

Some lasers are marketed with holsters that can be clipped onto a belt, creating a gunslinger-like appearance. Earlier this year, Lucasfilm threatened legal action against Wicked Lasers, a Hong Kong-based company whose lasers have aluminum handles that resemble the lightsabers of the "Star Wars" movies. Lucasfilm later dropped the threat. "Wicked Lasers defeats dark forces of George Lucas," the laser company's website brags.

The American Academy of Ophthalmology issued a statement in September warning parents that new, powerful laser devices can easily cause eye damage and blindness. The academy pointed to the case of a 15-year-old boy who suffered severe eye damage while playing with a laser in front of a mirror. Lasers don't have to be pointed at someone's eyes to cause harm; reflected light can cause damage as well.

A laser pointer like those used by lecturers typically generates about 5 milliwatts of power. Wicked Laser's website offers a 1,000-milliwatt handheld laser.

The laser company didn't respond to an e-mail request for comment.

Dozens of people in the United States and around the world have been arrested for pointing lasers at aircraft cockpits, most often near airports during takeoffs and landings. Those are the most critical phases of flight, when pilots need to be their most alert. Interference with air navigation is a federal crime.

Last year, an Orange, Calif., man was sentenced to 2 1/2 years in prison for aiming a handheld laser at two Boeing jets as the passenger planes were about to land at John Wayne Airport.

In August, a Baltimore police helicopter pilot was temporarily "flash blinded" by a laser, preventing him from helping fellow officers chasing a suspect. The pilot recovered, circled around and spotlighted the house where the beam had come from as officers on the ground rushed in to arrest the culprit.

The same month, green lasers were pointed at the cockpits of two medical helicopters transporting patients in Pittsburgh, including a 5-year-old boy injured in a bicycle accident.

There are red, blue and violet lasers as well, but the green is the most visible against a night sky. The green lasers are also 35 times brighter than equivalently powered red lasers because humans are much more sensitive to green light, according to the Congressional Research Service.

In July, a Maryland state police helicopter pilot was briefly blinded by several green lasers while trying to land in Ocean City to pick up a trauma patient, but no one was injured. Two Coast Guard helicopters made precautionary landings this summer after the pilots were flashed with lasers while patrolling Los Angeles beaches and ports.

Last year, pilots of dozens of planes taking off and landing at Seattle-Tacoma International Airport reported being flashed with green lasers. Online:
Haitian cholera strain could dominate the Americas

* 16:12 10 December 2010 by Debora MacKenzie

The DNA of the cholera bacteria ravaging Haiti has been sequenced, and the news is not good. It is carrying a mutation that seems to cause more intense disease.

This has already helped the strain to dominate in south Asia, and the Haitian epidemic could spread it still further.

The US Centers for Disease Control and Prevention (CDC) reported on 8 December that in its first six weeks, the Haitian cholera has been 11.5 times as likely to kill its victims as the cholera that reached Peru in 1991, even though Peruvians, like Haitians, had no prior immunity to the bacteria.

The death rate could partly be because medical care, nutrition and HIV levels are worse in earthquake- and poverty-stricken Haiti than Peru, says Matt Waldor of Brigham and Women's Hospital in Boston. But it could also be due to a nastier cholera toxin.

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