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for August, 2010.
Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.
Greetings! Today we’re going to investigate the wonderful world of animals. Specifically we’re going to visit some of the members of the dominant group of animals on the land part of Planet Earth. Ah, you’re thinking, didn’t she just do an article on medicine? Humans are definitely the lords of the Earth, aren’t they?
Well no, not in numbers and not in sheer body mass. That honor belongs to the six-legged animals, the insects, which represent over 90% of the differing metazoan life forms on land.
Love them or hate them, you probably wouldn’t be here without them since most of the plant food you depend on (even if you’re a thoroughgoing carnivore) is pollinated by them. So off we go into the wonderful world of insects.
If you’re talking size dominance and not numbers dominance, the largest land animal isn’t us either, it’s the elephant. And it turns out that elephants have something to say about insects. Literally.
Although they may be the largest land animal, it turns out that elephants (who are not stupid) produce an alarm call associated with the threat of bees, and have been shown to retreat when a recording of the call is played even when there aren’t any bees around.
A team of scientists from Oxford University, Save the Elephants, and Disney’s Animal Kingdom, made the discovery as part of an ongoing study of elephants in Kenya. They played the sound of angry bees to elephant families and studied their reactions. They found that elephants not only flee from the buzzing sound but also make a unique ‘rumbling’ call and shake their heads from side to side.
The team then isolated the specific acoustic qualities associated with the rumbling call and played the sounds back to the elephants to confirm that the recorded call triggered the elephants’ decision to flee even when there was no buzzing and no sign of any bees.
They tested their hypothesis by using both an original recording of the call and an identical recording with the frequency shifted. They also used a different elephant rumble as a control. They reported that the results were dramatic: six out of ten elephant families fled from the area of the loud speaker when they played the ‘bee rumble’ compared to just two families that left the area when they played both the control rumble and the frequency-shifted call. Moreover, they also found that the elephants moved much farther away when they heard the ‘bee’ alarm call than the other rumbles.
The researchers believe such calls may be an emotional response to a threat, a way to coordinate group movements and warn nearby elephants — or even a way of teaching inexperienced and vulnerable young elephants to beware. Further work is needed to confirm whether the rumble call is used for other kinds of threats, not just bees.
Earlier Oxford University research found that elephants avoid beehives in the wild and will also flee from the recorded sound of angry bees. In 2009 a pilot study showed that a fence made out of beehives wired together significantly reduced crop raids by elephants. The team hopes that the new findings could help develop new ways to defuse potential conflicts between humans and elephants.
Despite their thick hides adult elephants can be stung around their eyes or up their trunks, and calves could potentially be killed by a swarm of stinging bees as they have yet to develop thick protective skin.
Elephants run from bee sounds making ‘bee rumble’. (Credit: OU/Lucy King)
So why do you think the largest animals would flee from one of the smallest? Have you ever seen an elephant trunk up close and personal? Have you ever had a gnat fly up your nose? The openings in elephant trunks are large enough that a bee could get in there. Gnats don’t sting. Think about it.
And now an interesting (and more soothing) story about how insects may help protect your money. When I was younger, United States paper money didn’t change much. Each minor change was accompanied by much public wrangling and debate. Then in the 1990’s we got a whole bunch of new paper money with virtually no warning and no public debate. Did you ever wonder why?
The answer is simple. The advent of color copiers. All of a sudden, ANYBODY could easily produce virtually undetectable counterfeit money and I suspect a great many people did. Hence the ‘invisible portrait’ and other measures that make making money a lot harder than it used to be.
But counterfeiters are inventive and all countries are interested in protecting everybody’s money. Now, scientists have discovered a way of mimicking the bright and beautiful colors of butterfly wings. Their findings could have important applications in the security printing industry, helping to make bank notes and credit cards harder to forge.
BUTTERFLIES AND BETTER MONEY
The striking iridescent colors displayed by beetles, butterflies and other insects have long fascinated both physicists and biologists, but mimicking nature’s most colorful, eye-catching surfaces has proved difficult. That’s because pigments don’t create those iridescent colors. They’re produced by light bouncing off microscopic structures on the insects’ wings.
Researchers at the University of Cambridge studied the Indonesian Peacock butterfly (Papilio blumei). The wing scales of this beautiful butterfly have intricate, microscopic structures that resemble the inside of an egg carton on their surfaces. Because of their shape and the fact that they’re made from alternate layers of cuticle and air, the structures produce intense refracted colors.
The researchers used some nanofabrication procedures — including self-assembly and atomic layer deposition – to make structurally identical copies of the butterfly scales. These copies produced the same vivid colors as the butterflies’ wings. Not only does this discovery help researchers gain a deeper understanding of the physics behind butterfly’ colors, it may have promising applications in security printing.
The artificial structures could be used to encrypt information in optical signatures on banknotes or other valuable items to protect them against forgery. In the future we may find structures based on butterflies wings on a $20 bill or even our passports.
Interestingly enough, the butterfly may be using its colors to encrypt itself. It may appear to be one color to potential mates but another color to predators. The researchers discovered that the shiny green patches on the Peacock butterfly’s wings appear to be bright blue at certain wavelengths but green to the unaided eye. It’s possible that the Peacock butterfly appears bright blue to other Peacock butterflies, but a dull patchy green to potential predators like birds (and humans).
The bright green wings of the P. blumei butterfly result from the mixing of the different colors of light that are reflected from different regions of the scales found on the wings of these butterflies. (Credit: Mathias Kolle, University of Cambridge)
And now we come to an insect that has a rep that’s a lot worse than butterflies or even bees. I mean, how often have you looked someone in the eye and shouted “You bee!” But I’d be willing to bet money that you’ve said “You louse!” to somebody at least once. Or called them a lousy (insert pejorative here).
Lice. Not wonderful dinnertime conversation. Head lice, body lice, pelvic lice. We’ve all had encounters with them and none of them were pleasant. Now a research team reports it has sequenced the body louse genome, an achievement that will yield new insights into louse — and human — biology and evolution.
THAT’S JUST LOUSY
The blood-sucking parasite [now, THERE’S a pejorative for you] Pediculus humanus humanus L. has been around for millions of years of human history. The body louse spread epidemic typhus and trench fever to Napoleon’s retreating army in Russia in 1812, and body lice plagued Lewis and Clark on their adventures in the New World.
The human body louse feeds on human blood and is closely related to the head louse, Pediculus humanus capitis, which feeds on human blood too. But the body louse lives in clothing and, unlike the head louse, can spread bacterial diseases.
The human body louse has the smallest genome of any insect sequenced so far and that probably reflects its protected habitat and predictable diet. After all, lice ecology is very simple. It lives only on humans and it eats only human blood. So it has no need for genes that control sensing or responding to varied environments. The genome analysis found very few genes for light-sensing receptors and significantly fewer taste and odor receptors than other insects.
The body louse is completely dependent on humans for its survival; it will die if separated from its host for very long. It is also completely dependent on a microbe that lives inside it: the bacterium Candidatus pediculicola.
The researchers also sequenced the bacterium genome and discovered that it makes an e nutrient, Vitamin B5, which the louse must have and can’t make on its own. This, the researchers report, will make the body louse a useful tool for understanding the co-evolution of disease-carrying parasites and their bacterial co-conspirators.
Not only is studying the human body louse important in the context of human health, it’s also useful in understanding insect evolution. It’s only the second genome sequenced so far of an insect with gradual development. Although most insect species undergo complete metamorphosis, gradual metamorphosis is the older developmental program. The body louse genome can provide a baseline for understanding how complete metamorphosis, a key to insect domination of the planet, came to evolve.
The human body louse, Pediculus humanus humanus L., has been a witness to, and participant in, millions of years of human history. (Credit: CDC Photo, Courtesy of Frank Collins, Ph.D.)
Well, I hope you haven’t decided that this column is just lousy!
Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.
Greetings everyone and welcome to yet another excursion through the headlines of science. You don’t see this stuff much of anywhere else but here, which is sad. It implies that there isn’t much interest in science but of course, Americans are notorious about their news preferences. The Australian government is currently undergoing a crisis and we get news about bedbugs in the Empire State Building. Although that’s something I would write about, I’m not sure it’s worthy of major headline news.
Today we’re going to take a little excursion into what ails us, and the news for the most part is good. The most dangerous animal on the face of the planet, the one that kills the most humans every single year is sitting somewhere in your back yard right now. Strangely enough, you’re not afraid of it like you are the shark and the grizzly bear and the crocodile. What is this dreadful killer? The mosquito! But there’s good news on the malaria front.
VACCINATION FOR A KILLER
The real problem about malaria which sickens almost a quarter of a billion people each year and kills a child every 30 seconds is that there is no vaccine to prevent the mosquito from infecting you with it. That may soon change. Researchers at Rockefeller University have genetically transformed the yellow fever vaccine to prime the immune system to fend off the mosquito borne parasites that cause the disease. They’ve discovered that the modified vaccine, along with a booster, provided mice with immunity to the deadly disease.
Malaria is one of the most pressing health crises of developing countries: in communities stricken by infection, attendance at work and school drops, and poverty deepens. It’s been known since the ‘60’s that one form of the malaria parasite — called the sporozoite; — can trigger the human immune system and help to protect against future infection. The only way to gather sporozoites, however, is to pluck them one-by-one from the salivary glands of irradiated, malaria-ridden mosquitoes. Then the parasites must be injected into people and you have to use a lot of them. This takes lots of time, lots of lab space and lots of people and it isn’t economically feasible for large-scale use.
Researchers from Rockefeller University and colleagues at New York University decided that fighting infection with infection might be the key. They began experimenting with the attenuated yellow fever strain used in the yellow fever vaccine, known as YF17D, which has been used to successfully vaccinate more than 400 million people since 1937. Previous work in the Rice laboratory and by others had shown that this vaccine strain could be modified to include short sequences from other pathogens, including malaria.
The researchers inserted the nearly complete sequence of a malaria gene into the YF17D vaccine and found that the malaria gene could produce its protein in cultured cells. The protein they chose, called CSP, covers the surface of the malaria sporozoite and is thought to be the main reason that this form of the parasite stimulates the immune system so effectively.
Immunization of mice with the YF17D-CSP vaccine led to a measurable jump in immune activity against the malaria protein, but the single shot was not enough to protect the animals from infection with the mouse form of the malaria parasite.
The group therefore added a booster shot to the vaccination regimen. Animals that had been immunized with YF17D-CSP, or with a saline solution control, were given a low dose of irradiated sporozoites. While the saline-sporozoite group was only partially protected from challenge with viable parasites, vaccination with YF17D-CSP plus the sporozoites protected 100 percent of the animals against infection.
"These results are exciting because they show the YF17D-CSP vaccine can prime the immune response against a malaria parasite," says lead author Cristina Stoyanov. Although the utility of this approach for human immunization is not yet clear, the team hopes that further studies in other animal models might eventually lead to an effective vaccine.
By inserting a gene for the malaria parasite into a vaccine that originally targeted yellow fever, scientists have shown they can boost the immune system’s response to infection in mice. (Credit: James Gathany/CDC)
Guam has the mosquito that carries malaria. All it takes is someone with malaria who comes here from somewhere else. Here’s hoping that this vaccine proves to be cheap and effective!
There’s also some news about a different vaccine that isn’t quite as positive. It highlights the point that sometimes humans meddle with things that they don’t quite understand and perhaps can’t control.
We all breathed a sigh of relief when one of the most dreadful scourges known to man was finally declared eliminated after a massive worldwide vaccination campaign. I’m referring, of course, to smallpox and I am one of the last U.S. citizens to receive a smallpox vaccination. They were no longer routinely given to Americans, but I was traveling to Southeast Asia where it had not been declared eradicated. Shortly after I made my trip, smallpox was declared officially eradicated worldwide and routine vaccinations for smallpox stopped. It turns out that may not have been such a good idea.
TWO BIRDS WITH ONE STONE?
Of course, they say that you stamp out one problem and another arises. That certainly was the case with smallpox because shortly after it was eradicated, the world witnessed another explosive killer disease: HIV or AIDS. Now, researchers have discovered that the two things just could be linked.
According to researchers who published their work in the open access journal BMC Immunology, the smallpox vaccination produces a five-fold reduction in HIV replication in the laboratory. They raise the possibility that the end of smallpox vaccination in the mid-20th century may have caused a loss of protection that contributed to the rapid contemporary spread of HIV.
There have been several proposed explanations for the rapid spread of HIV in Africa, including wars, the reuse of unsterilized needles and the contamination of early batches of polio vaccine. However, all of these have been either disproved or do not sufficiently explain the behavior of the HIV pandemic.
Smallpox immunization was gradually withdrawn from the 1950s to the 1970s following the worldwide eradication of the disease, and HIV has been spreading exponentially since approximately the same time period. The scientists propose that smallpox vaccination may confer protection against HIV by producing long-term alterations in the immune system, possibly including the expression of a certain receptor, CCR5, on the surface of a person’s white blood cells, which is exploited by both viruses.
Although the results are interesting, the researchers say they are very preliminary and it is far too soon to recommend the general use of smallpox vaccinations for fighting HIV.
So now we have two instances of using a bullet for one problem to kill a completely different. Here’s hoping they both work!
Photograph of a Nigerian child being immunized during the Smallpox Eradication and Measles Control Program of West Africa in 1960. (Credit: CDC/Dr. J.D. Millar)
Although we have the malaria mosquito here and most of us know at least one person living with HIV, the place that is the mother lode for both diseases is Africa and the poor countries there have no money to make even the most basic inroads into solving their medical crises. Another disease that is more of a problem here and also a big problem world-wide is diabetes. German researchers are trying to make an economic impact on another of the world’s great killers.
A CHEAP SHOT
There are 25 MILLION people in the U.S. with diabetes and you don’t need to be told that it’s the biggest killer on Guam. But India is the country with the most diabetics with over 50 million people. No one on Guam goes without insulin if they seek help, but that isn’t the case in developing countries. Now German scientists have developed a new method to cheaply produce insulin for the treatment of diabetes.
The researchers wanted to develop a new procedure to increase the yield of an insulin precursor from which the actual insulin can be obtained, and in this way reduce costs. They used a type of yeast to produce the building blocks to make insulin.
In the early 1980s, insulin was the first recombinant product approved by the FDA for human application. Today, human insulin is produced as a recombinant protein, using two major routes. One route involves the production of the insulin precursor using the bacterium Escherichia coli. The other route involves baker’s yeast Saccharomyces cerevisiae. The yeast product is easier to use because the yeast secretes a soluble insulin precursor into the culture medium. This makes it easier to collect.
The newly described method from Ursula Rinas and her group also uses this route but the yeast they used produces much more of the insulin precursor. Insulin produced with this new method is identical to human insulin. The researchers are also working on a method to produce a vaccine against dengue fever using the same system.
For most people in developing countries medicine is too expensive and insulin is often difficult to obtain and very expensive. The researchers hope that this new method of producing insulin will be used in developing countries to produce insulin that everybody can afford.
Taking new shots at old killers. Cruise on over to the Deep Website at www.thedeepradioshow.com to learn more about the frontiers of medicine and many other topics. Enjoy!
Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.
Hello everyone and welcome to yet another trek down the wonderful corridors of science. I discovered this week that the space file doesn’t have any, so our trip this week will be into “everything else”. As I tell my Astronomy students “Every other course you take at this University concerns the happenings on an extremely small parcel of real estate. In this class, we study everything else.” Our first excursion however is happening right here on Earth.
PREPARING FOR THE TRIP
Something interesting and probably very important happened back on the 3rd of June and you heard nothing about it. Space stories aren’t big news in the popular press and although there is a thriving space community all over the world, NASA usually generates what little space news does get picked up and unfortunately bureaucrat-riddled NASA isn’t doing much.
What happened on 3 June happened in Moscow and on that day six men were sealed into a capsule at the Moscow Institute of Biomedical Problems for 520 days. They won’t emerge again until November 2011.
The six-man crew has three Russians, a Frenchman, a Colombian-born Italian and a man from China. Their goal is to create a journey to Mars complete with simulated emergency situations and real psychological pressures. It is the longest space simulation experiment ever attempted.
Their trip to Mars will last 250 days. They have a scheduled 30-day stay on the red planet and then they will embark for their 240-day return journey to Earth. With the exception of weightlessness and exposure to radiation, in-space conditions will be simulated as realistically as possible. The crew will experience isolation, food and emergency situations of the kind they would encounter on a real long-duration mission. During these 520 days, about 100 tests are planned, covering the fields of psychology, psychophysiology, clinical diagnostics, physiology and microbiology.
The capsule will be sealed and all supplies for the year and a half ‘journey’ will be sealed in with the ‘astronauts’. There is a small greenhouse in the module. Each ‘astronaut’ has a separate room that’s about eight feet square. No television, but each crew member can send e-mails and communicate with ‘ground control’ with an authentic built-in time delay that will lengthen as the capsule gets ‘farther’ from Earth.
A crew on a real journey to Mars would have to solve their own problems and the crew of this simulated journey will also maintain and service their technical systems without help from any external source. The effects of isolation on their psychological and physiological health and performance capabilities are of particular interest to the scientists involved.
German scientists will be investigating group dynamics and the performance capabilities of the crew. They’ll also examine how astronauts deal with illness or emergency situations. Another group of researchers will examine what happens on the microbiological level when six men are stuck inside a sealed system.
The German scientists will also be monitoring the crew’s salt and fluid levels, blood pressure regulation and bone metabolism. To investigate physiological questions associated with nutrition, eight German companies have provided food products similar to those consumed on the International Space Station.
Since this enormous experiment has nothing to do with NASA, don’t expect to hear much about it in the US popular press. But there’s always the Internet to keep current on what’s happening on a simulated voyage to Mars.
Exterior view of the containers in the Moscow-based Institute for Biomedical Problems (IBMP). The ‘trip to Mars’ is taking place inside these containers. (Credit: ESA)
So . . . . other than the adventure of it all, why on Earth (or off it!) would anyone want to seal themselves in a container and take a year and a half voyage to another world? Well, one reason could be that there may be life on Mars after all. Read on!
CONSIDERING THE NEIGHBORS
Several months ago, I featured some big news about Mars. Methane has been detected in the atmosphere of the red planet. Since Mars’ atmosphere destroys methane, something is producing it and there are only two likely sources. One is volcanic activity. There are no active volcanoes on Mars because if there were, we would see them with the cameras of our orbiting spacecraft, but there could be gas seeps that are releasing methane into Mars’s tenuous atmosphere.
The other thing on Earth that produces vast quantities of methane is life. Cows do it, we do it and so does every other living thing. However it’s being produced, the methane means that Mars is NOT a ‘dead world’.
Now Canadian researchers have discovered that methane-eating bacteria survive in a highly unique spring located on Axel Heiberg Island in Canada’s extreme north. They feel that if the Lost Hammer Spring can support microbial life, that similar springs on Mars could support life too.
The subzero water of Lost Hammer Spring is so salty that it doesn’t freeze despite the cold, and it contains no consumable oxygen. There are, however, big bubbles of methane that periodically break the surface. This provoked the researchers’ curiosity as to whether the gas was being produced geologically or biologically and if it was being produced biologically just what sort of organism could survive the extreme hypersaline subzero environment.
What they found surprised them. There were no methane-producing bacteria at Lost Hammer but they did find some very unique organisms that were eating the methane and apparently breathing sulfur instead of oxygen.
The Mars Orbiter has shown us that there’s both methane and frozen water on Mars. There are also new gullies being formed, but no one knows what forms them. One answer could be that there are springs like Lost Hammer on Mars.
The researchers say it doesn’t matter where the methane is coming from. Cold salty water could support a microbial community. Axel Heiberg Island is an inhospitable place and the Lost Hammer spring is even more so. There are places on Mars where the temperature rises above freezing and the minimum temperature on Axel Heiberg Island can get down to around minus 60 or 70 degrees. The Lost Hammer spring is the most extreme subzero and salty environment researchers have ever found and it provides a model of how a methane seep could form in a frozen world like Mars, providing a potential mechanism for both possible scenarios that have produced the recently discovered Martian methane plumes.
This is Lost Hammer Spring on Axel Heiberg Island, Nunavut Territory, Canada. (Credit: Dept. Natural Resource Sciences, McGill University, Montreal.)
So, perhaps there is microbial life on Mars and when we go there in person instead of by simulation, we may find it. But Mars isn’t the only place in the solar system that may harbor life. At least three of the solar system’s moons apparently contain vast liquid water oceans with solidly frozen surfaces. What swims in those oceans is a discovery that will change mankind forever.
AND THEY ARE NOT LIKE US!
Astrobiologists also count Saturn’s largest moon Titan as a possible place for life. The surface of Titan is extremely cold; so cold that both methane and ethane can exist as liquids. Recent data from the Cassini spacecraft has shown that isn’t nearly as much hydrogen and acetylene on the surface of Titan as there should be. There is some speculation that something ‘living’ is consuming it. There could be alien life on Titan.
But one of the things that we must remember about aliens is that they will NOT be humans dressed up in alien suits. Dr. William Bains, a British astrobiologist thinks that there could definitely be life on Titan but it would be nothing like life here on Earth.
"Hollywood would have problems with the aliens of Titan" says Dr. Bains. "Beam one onto the Starship Enterprise and it would boil and then burst into flames, and the fumes would kill everyone in range. Even a tiny whiff of its breath would smell unbelievably horrible. But I think it is all the more interesting for that reason. Wouldn’t it be sad if the most alien things we found in the galaxy were just like us, but blue and with tails?"
Dr Bains is seeking to work out just how extreme the chemistry of life can be. Life on Titan, Saturn’s largest moon, represents one of the more bizarre scenarios being studied. Titan is twice as large as our Moon and has a thick atmosphere of frozen, orange smog. It’s ten times farther away from the Sun, and has a surface temperature of –350 degrees F. It’s so cold on Titan that water is not a liquid or even ice; it’s the ‘rocks’ that the surface of Titan is made from. The only liquids are methane and ethane, which form ponds and lakes on the surface of the moon.
"Life needs a liquid; even the driest desert plant on Earth needs water for its metabolism to work. So, if life were to exist on Titan, it must have blood based on liquid methane, not water. That means its whole chemistry is radically different. The molecules must be made of a wider variety of elements than we use, but put together in smaller molecules. It would also be much more chemically reactive," said Dr Bains.
Most chemicals won’t dissolve in liquid methane so life on Titan would be made with smaller molecules than life on Earth. Energy is another factor that would affect the type of life that could evolve on Titan. The permanent cloud cover on Titan and Titan’s distance from the Sun means that the surface receives less than one percent of the energy that’s available on Earth.
"Rapid movement or growth needs a lot of energy, so slow-growing, lichen-like organisms are possible in theory, but velociraptors are pretty much ruled out," said Bains.
Titan’s Ethane Lake: This artist’s concept shows a mirror-smooth lake on the surface of the smoggy moon Titan. Cassini scientists have concluded that at least one of the large lakes observed on Saturn’s moon Titan contains liquid hydrocarbons, and have positively identified ethane. (Credit: NASA/JPL)
Life. Not as we know it. It’s a big universe out there and we are stuck on a tiny planet. But hopefully not for forever!!
Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.
Greetings! Well, last week we had good news, and now, I’m afraid it’s time for some bad news. The global warming file is getting bigger. We’re all familiar with news about giant icebergs calving off the coasts of Antarctica, but it’s August, and we all saw the news release that Greenland has calved a hundred square mile iceberg from its northwestern shore that may choke an island-filled strait and cause other problems. But that’s not all that’s been going on in Greenland. So, screw your courage to the sticking place and read on!
Ice loss from the Greenland ice sheet, which has been increasing during the past decade over its southern region, is now moving up its northwest coast, according to a new international study.
Researchers from the Denmark Technical Institute’s National Space Institute in Copenhagen and the University of Colorado at Boulder have conducted a study that indicates ice-loss acceleration began moving up the northwest coast of Greenland starting in late 2005. The team drew their conclusions by comparing data from NASA’s Gravity and Recovery Climate Experiment satellite system, or GRACE, with continuous GPS measurements made from long-term sites on bedrock on the edges of the ice sheet.
The data from the GPS and GRACE provided the researchers with monthly averages of crustal uplift caused by ice-mass loss. The team combined the uplift measured by GRACE over California-sized chunks of Greenland while the GPS receivers monitor crustal uplift on scales of just tens of miles.
The team found that uplift rates near Thule Air Base on Greenland’s northwest coast rose by roughly 1.5 inches, or about 4 centimeters, from October 2005 to August 2009. Although the low resolution of GRACE — a swath of about 155 miles, or 250 kilometers across — is not precise enough to pinpoint the source of the ice loss, the fact that the ice sheet is losing mass nearer to the ice sheet margins suggests the flows of Greenland outlet glaciers there are increasing in velocity, said the study authors. They speculate that some of the big glaciers in this region are sliding downhill faster and dumping more ice in the ocean.
Another study published in 2009 showed that between April 2002 and February 2009, the Greenland ice sheet shed roughly 385 cubic miles of ice. The mass loss is equivalent to about 0.5 millimeters of global sea-level rise per year.
The changes on the Greenland ice sheet are happening fast, and the researchers say they are seeing more ice mass loss than they anticipated. The ice mass loss is also occurring in Antarctica, a sign that warming temperatures really are having an effect on ice in all of Earth’s cold regions.
Researchers have been gathering data from GRACE since NASA launched the system in 2002. Two GRACE satellites whip around Earth 16 times a day separated by 137 miles and measure changes in Earth’s gravity field caused by regional shifts in the planet’s mass, including ice sheets, oceans and water stored in the soil and in underground aquifers.
In addition to monitoring the Thule GPS receiver in northwest Greenland as part of the new GRL study, the team also is taking data from GPS receivers in southern Greenland near the towns of Kellyville and Kulusuk. An additional 51 permanent GPS stations recently set up around the edges of the Greenland ice sheet should be useful to measure future crustal uplift and corresponding ice loss.
If the activity in northwest Greenland continues and really accelerates some of the major glaciers in the area — like the Humboldt Glacier and the Peterman Glacier — Greenland’s total ice loss could easily be increased by an additional 50 to 100 cubic kilometers (12 to 24 cubic miles) within a few years.
Greenland is about one-fourth the size of the United States and the massive ice sheet covers about 80 percent of its surface. It holds about 20 percent of the world’s ice, the equivalent of about 21 feet of global sea rise. Air temperatures over the Greenland ice sheet have increased by about 4 degrees Fahrenheit since 1991, which most scientists attribute to a build-up of greenhouse gases in the atmosphere.
A 2006 study using the GRACE satellite indicated that Greenland lost roughly 164 cubic miles of ice from April 2004 to April 2006 — more than the volume of water in Lake Erie.
Changes in Greenland’s ice mass as measured by NASA’s Gravity Recovery and Climate Experiment (Grace) mission between September 2005 (left) and September 2008 (right). (Credit: NASA/JPL)
The Peterman Glacier is the one that lost that 100 square mile ice sheet last month so things (like icebergs) are indeed accelerating! And that’s not all that’s happening as Greenland loses its ice cover!
The island of Greenland is currently covered with a thick layer of ice and snow that’s over a mile thick. That much ice weighs a lot and it presses down on the land beneath and compresses it and lowers its elevation. Now, scientists at the University of Miami say Greenland’s ice is melting so quickly that the land underneath is rising at an accelerated pace.
According to the study, some coastal areas are rising by an inch per year and if current trends continue, that number could accelerate to as much as two inches per year by 2025.
Tim Dixon, a geophysics professor says, "It’s been known for several years that climate change is contributing to the melting of Greenland’s ice sheet. What’s surprising, and a bit worrisome, is that the ice is melting so fast that we can actually see the land uplift in response. Even more surprising, the rise seems to be accelerating, implying that melting is accelerating."
Using specialized global positioning system (GPS) receivers stationed on the rocky shores of Greenland, the scientists looked at data from 1995 onward. The raw GPS data were analyzed for high accuracy position information, as well as the vertical velocity and acceleration of each GPS site.
The measurements are restricted to places where rock is exposed, limiting the study to coastal areas. However, previous data indicate that ice in Greenland’s interior is in approximate balance: yearly losses from ice melting and flowing toward the coast are balanced by new snow accumulation, which gradually turns to ice. Most ice loss occurs at the warmer coast, by melting and iceberg calving and where the GPS data are most sensitive to changes. In western Greenland, the uplift seems to have started in the late 1990’s.
Melting of Greenland’s ice contributes to global sea level rise. If the acceleration of uplift and the implied acceleration of melting continue, Greenland could soon become the largest contributor to global sea level rise. The team plans to continue its studies, looking at additional GPS stations in sensitive coastal areas, where ice loss is believed to be highest.
This is a satellite image of Western Greenland, acquired by NASA’s MODIS satellite. The narrow grey band in the center of the image is melting ice, between the rocky coast to the left (west) and thicker, non-melting, higher altitude ice to the right (east). The arrow points to a darker grey zone of rapidly thinning ice near the outlet of Jacobshavn glacier, which also loses mass due to iceberg calving. (Credit: Courtesy of NASA)
Melting and rising, melting and rising. So . . . if that’s what’s going on in Greenland, what’s happening over the rest of the Arctic Ocean in this summer of incredible heat?
Less ice covers the Arctic today than at any time in recent geologic history.
Go ahead, read that sentence again. If it doesn’t send cold chills down your spine, it should. It’s the conclusion of an international group of researchers, who have compiled the first comprehensive history of Arctic ice.
For decades, scientists have strived to collect sediment cores from the difficult-to-access Arctic Ocean floor, to discover what the Arctic was like in the past. Their most recent goal: to bring a long-term perspective to the ice loss we see today.
Now, a team led by researchers at Ohio State University has re-examined the data from past and ongoing studies — nearly 300 in all — and combined them to form a big-picture view of the pole’s climate history stretching back millions of years.
Their conclusion? The ice loss that we see today — the ice loss that started in the early 20th Century and sped up during the last 30 years — appears to be unmatched over at least the last few thousand years according to the lead author of the paper.
Satellites can provide detailed measures of how much ice is covering the pole right now, but sediment cores are the fossils of the ocean’s history. Sediment cores are a record of everything that settled at the sea floor, layer by layer. They record the conditions of the ocean system during the time they settled. When scientists look at the various chemical and biological components of the sediment, and how the sediment is distributed, they can with a certain amount of luck reconstruct the conditions at the time the sediment was deposited.
For example, scientists can search for a biochemical marker that is tied to certain species of algae that live only in ice. If that marker is present in the sediment, then that location was likely covered in ice at the time. Scientists call such markers "proxies" for the thing they actually want to measure — in this case, the geographic extent of the ice in the past.
While knowing the loss of surface area of the ice is important, unfortunately sediment research can’t reveal an even more important fact: how the total volume of ice — thickness as well as surface area — has changed over time.
To review and combine the data from hundreds of studies, the researchers had to combine information on many different proxies as well as modern observations. They searched for patterns in the proxy data that fit together like pieces of a puzzle.
Their conclusion: the current extent of Arctic ice is at its lowest point for at least the last few thousand years.
During the summer of 2011, the team hopes to draw cores from beneath the Chukchi Sea, just north of the Bering Strait between Alaska and Siberia. The Kyushu Current delivers tropically warmed waters that may play an important role in melting the ice across the Arctic. The researchers expect that the ice history of this location will prove very important. They hope to drill cores that date back thousands of years at the Chukchi Sea margin, providing a detailed history of interaction between oceanic currents and ice.
Pack ice near the Arctic island Spitsbergen/Svalbard. (Credit: iStockphoto/Michel De Nijs)
So why was this section titled “Oceanfront Property”? Because the big message of this whole article is “Don’t buy any!”
Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.
Well, the medical file is overflowing and I’ve decided to feature only good news. The global warming file is also filling up and that one only has bad news, so this week let’s go take a positive look at what ails us.
I know several people who have really atrocious teeth. In some cases, it’s because they can’t afford to go to the dentist, but in many cases, money has nothing to do with it. It’s the awful nightmares of the dentist chair that they retain from their childhood.
Unfortunately, you’ll never convince them that dentistry has changed. No more spitting into the porcelain bowl, no more pain. Of course, the drill can still send vibrations down your spine, but at least they don’t hurt.
The one thing that still hurts is the needle to administer the anesthesia that keeps everything else from hurting and the first good news is that that may too, be a thing of the past.
LOOK MA NO CAVITIES!
Still afraid of the needle? A new discovery may just replace that needle for many procedures. Researchers are reporting that a common local anesthetic, when administered into the nose as nose drops or a nasal spray, travels through the main nerve in the face and collects in high concentrations in the teeth, jaw, and other structures in the mouth. The discovery could lead to a new generation of drugs for ‘needle-less’ treatment of dental pain, migraine, and other painful conditions of the human face.
The researchers note that drugs administered in the nose travel along nerves and go directly to the brain. One of those nerves is the trigeminal nerve, which controls the face, nose and mouth. Until now, however, scientists never checked to see whether intranasal drugs passing along that nerve might reach the teeth, gums and other areas of the face and mouth and aid in reducing pain.
They found that lidocaine or Xylocaine, sprayed into the noses of laboratory rats, quickly traveled down the trigeminal nerve and collected in their teeth, jaws, and mouths at levels 20 times higher than in the blood or brain. This approach could provide a more effective and targeted method for treating dental pain/anxiety, trigeminal neuralgia (severe facial pain), migraine, and other conditions, the scientists say.
Furthermore, the scientists discovered an improved future location to administer anesthetic, the maxillary sinus. The maxillary sinus is a golfball-sized space located underneath each cheek where drugs can be sprayed. Delivery into this confined space may provide an even more rapid and focused delivery of anesthetic.
The needle used by dentists to block pain could be replaced by the simple sniff of a local anesthetic thanks to a new discovery. (Credit: iStockphoto)
I know first-hand about fear of the dentist because my boyfriend Mariano had that problem. He also had a less common problem; he had a nasty scar from a ruptured appendix. So what could possibly be good news about a ruptured appendix? Well, researchers have discovered some interesting things about that useless remnant that only causes problems and they’ve discovered that it isn’t so useless after all!
IT GETS NO RESPECT
The lowly appendix, long-regarded as a useless evolutionary artifact, won newfound respect two years ago when researchers at Duke University Medical Center discovered that it actually serves a critical function. The appendix, they said, is a safe haven where good bacteria hang out until they’re needed to repopulate the gut after a nasty case of diarrhea, for example.
Now, some of those same researchers are back, with a report of the first-ever study of the appendix through the ages. Writing in the Journal of Evolutionary Biology, Duke scientists and collaborators from the University of Arizona and Arizona State University conclude that Charles Darwin was wrong: The appendix is a whole lot more than an evolutionary remnant. Not only does it appear in nature much more frequently than previously acknowledged, but it has been around much longer than anyone had suspected.
"Maybe it’s time to correct the textbooks," says William Parker, Ph.D., assistant professor of surgical sciences at Duke and the senior author of the study. "Many biology texts today still refer to the appendix as a ‘vestigial organ.’"
Parker and his colleagues found that the appendix has evolved at least twice, once among Australian marsupials and another time among rats, lemmings and other rodents, selected primates and humans. They theorize that the appendix has been around for at least 80 million years, much longer than we would estimate if Darwin’s ideas about the appendix were correct. Darwin said that the appendix in humans and other primates was the evolutionary remains of a larger structure, called a cecum, which was used by now-extinct ancestors for digesting food.
The latest study demonstrates two major problems with that idea. First, several living species, including certain lemurs, several rodents and a type of flying squirrel, have a large cecum which helps them digest their food. But it also has an appendix attached to it. Second, the appendix is actually quite widespread in nature. The scientists have found that more than 70 percent of all primate and rodent families contain species with an appendix. Darwin had thought the appendix appeared in only a small handful of animals.
But Darwin didn’t have access to information on all the animals that have been discovered in the last hundred years or so. If he had known that there were species with an appendix attached to a large cecum, and if he had known how common they were he probably wouldn’t have thought the appendix was a “vestige of evolution."
He also didn’t know that appendicitis, or inflammation of the appendix, is not caused by a faulty appendix, but because of industrialized society and improved sanitation. Our immune systems don’t have much to do anymore and more and more often, as is the case in appendicitis, the immune system is turning on us instead of invading germs.
That notion wasn’t proposed until the early 1900’s, and medicine didn’t get a really good grip on the concept until the mid 1980’s. Darwin had no way of knowing that the function of the appendix could be rendered obsolete by cultural changes that included widespread use of sewer systems and clean drinking water.
Dr. Parker says that since we now understand the normal function of the appendix, a critical question to ask is whether we can do anything to prevent appendicitis. He thinks the answer may lie in devising ways to challenge our immune systems today in much the same manner that they were challenged back in the Stone Age. "If modern medicine could figure out a way to do that, we would see far fewer cases of allergies, autoimmune disease, and appendicitis."
Normal location of the appendix relative to other organs of the digestive system (frontal view). (Credit: Wikimedia Commons)
So, I think you’ll agree that a less painful trip to the dentist is really good news and figuring out how to avoid appendicitis is also good for us. But as a general rule, bad teeth and appendicitis aren’t likely to kill you, so our next good news story may be a little more important. Doctors are slowly but surely zeroing in on a silent killer.
STALKING A KILLER
Ovarian cancer kills nearly 15,000 women in the United States each year, and fewer than half of the women diagnosed with the disease survive five years. The major reason is that ovarian cancer doesn’t have many overt symptoms. It doesn’t cause pain until the very late stages, there’s no suspicious discharge or color changes, no coughing, no swelling. By the time symptoms develop, it too late. A screening test that detects ovarian cancer early, when it is still treatable, would definitely reduce the high mortality rate, but scientists didn’t know where the tumors originated or what they looked like in the early stages.
Now, researchers at the Fox Chase Cancer Center in Philadelphia think they may have answered both questions. Their study states that they’ve found early tumors and precancerous lesions called inclusion cysts that fold into the ovary from its surface.
"This is the first study giving very strong evidence that a substantial number of ovarian cancers arise in inclusion cysts and that there is indeed a precursor lesion that you can see, put your hands on, and give a name to," says Jeff Boyd, Ph.D., Chief Scientific Officer at Fox Chase and lead author on the study, which also involved colleagues at the Memorial Sloan-Kettering Cancer Center. "Ovarian cancer most of the time seems to arise in simple inclusion cysts of the ovary, as opposed to the surface epithelium."
Clinicians and researchers have been looking for early ovarian tumors and the precancerous lesions from which they develop for years without success. In this study, Boyd and colleagues used a combination of traditional microscopy and molecular approaches to reveal the early cancers.
To learn how and where the tumors arise, the researchers examined ovaries removed from women with BRCA mutations, who have a 40% lifetime risk of developing ovarian cancer, and from women without known genetic risk factors. In both groups, they found that the cells in the inclusion cysts were dramatically different compared to the normal ovarian surface cells. The cells in the inclusion cysts had a much higher rate of control cell division and chromosome movement. And, of course, cancer is simply uncontrolled cell division.
They also used a technique that can be used to identify individual chromosomes in cells. When they did this, they saw that cells from very early tumors and precursor lesions frequently carried extra chromosomes. In fact, the team found that 9% of the normal cells isolated from the cysts had extra chromosomes, even though the tissue appeared completely benign under the microscope. By contrast, virtually none of the cells isolated from the surface of the ovary, which was previously thought to be the site of early ovarian cancers, carried extra chromosomes.
Using these new data on the origin of ovarian cancer, Boyd and others can now start to develop screening tests, perhaps based on molecular imaging that could be used to detect early ovarian cancers in asymptomatic women.
Jim is, above all, a passionate eco-humanitarian who has developed his own science talk-radio show to inform The DEEP’s listeners about such newsy topics as global warming, shark-finning and reef protection as well as to explore earth’s many underwater and space mysteries.
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