May 17, 2013 11:26 am
Since fire ants first invaded the U.S. through cargo ships docking in Mobile, Alabama, the aggressive pest has taken a firm hold in the South and Southwest. More than $5 billion is spent each year on medical treatment and fire ant control, according to Food and Drug Administration, and the ants cost an additional $750 million in agricultural damage.
Now, however, there’s a new ant on the block. The crazy ant – also an invader from South America – is displacing fire ants in the U.S. by gobbling them up. But this unprescribed cure is likely worse than the disease it’s treating. The Los Angeles Times reports:
Like fire ants, these South American invaders seem to be fond of electrical equipment. But unlike their stinging red counterparts, the tawny crazy ants create mega-colonies, sometimes in homes, and push out local populations of ants and arthropods.
Thus far, the crazy ants are not falling for the traditional poisons used to eliminate fire ant mounds. And when local mounds are destroyed manually, they are quickly regenerated.
Though the crazy ants don’t deliver the same burning bite as fire ants, they do stubbornly make their nests in bathroom plumbing or in walls. So far, researchers haven’t documented any native animals preying on the crazy ants, so their colonies are allowed to run amok, sometimes growing 100 times the size of other species of ants living in the area.
This isn’t the first time one ant invader has been displaced by another. The Argentine ant arrived back in 1891, followed by the black ant in 1918. But the fire ant put an end to those two invasive species when it arrived a couple decades later. Now, the fire ant’s own day of invasive reckoning may have arrived, but rather than feel relieved, researches are worried. Southern ecosystems have had time to adjust to fire ants. Crazy ants—well, who knows what they’ll do?
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May 16, 2013 3:41 pm
Pregnancy tests did not always come in an easy-to-use, sterile kit that provided almost immediate results. Less than a century ago, women had to rely upon frogs instead. In 1938, Dr. Edward R. Elkan wrote in the British Medical Journal:
The discovery of what is now known as the xenopus pregnancy test is based on experiments conducted by Hogben (1930, 1931), who observed that hypophysectomy produced ovarian retrogression, and the injection of anterior pituitary extracts ovulation, in the female South African clawed toad.
The African clawed frog, as its better known today, was imported around the world for its use in pregnancy tests. Doctors would ship urine samples to frog labs, where technicians would inject female frogs with a bit of the urine into their hind leg. The animals would be placed back into their tanks, and in the morning the technicians would check for tell-tale frog eggs dotting the water. If the female frog had ovulated, that meant the woman who provided the urine was pregnant and the pregnancy hormone, human chorionic gonadotropin, had kicked off ovulation in the frog. Researchers referred to this procedure as the Hogben test.
Among the 295 tests which I have done so far and in which 2,112 frogs were used I have not seen one clear positive that did not indicate a pregnancy. There were a few negative results which when repeated after a fortnight became positive, but I do not think that these can be regarded as failures.
Frogs were actually a great improvement on the previous means of testing whether or not a woman was pregnant. Welcome History describes:
Prior to Xenopus, female mice and rabbits had been used, but these had to be slaughtered, dissected and carefully examined for ovarian changes. Because toads were reusable and could be conveniently kept in aquaria, Xenopus made pregnancy testing practical on a larger scale than before.
Thousands of the frogs were exported across the world from the 1930s to 1950s for use as pregnancy testers.
Immunological test kits finally replaced Xenopus in the 1960s and were rapidly taken up by private companies and feminist organisations offering diagnostic services directly to women. The first over-the-counter home test was sold in pharmacies in the early 1970s, but it resembled a small chemistry set and so was not user-friendly. It was not until 1988 that the first recognisably ‘modern’ one-step-stick hit the shelves.
But the frogs’ legacy lives on. African clawed frogs can be found living around many urban centers today, where they were likely released into the wild after hospitals no longer had use for them. Additionally, the imported frogs are common pets, and no doubt some of those pets wear out their welcome and get chucked into a local stream or pond.
In 2006, researchers realized that the frog may be carriers for the deadly amphibian chytrid fungus, which has caused the extinction and decline of around 200 amphibian species around the world. Now, research published in PLoS One shows for the first time that populations of African clawed frogs living in California carry the fungus. The frogs can carry the disease for long periods without being affected themselves, so researchers suspect that they may be the original vectors that introduced the fungus around the world—a sort of revenge for being used as egg-laying research subjects for all those years.
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May 16, 2013 3:39 pm
There’s an interesting relationship, borne out in polling numbers, between the “general public’s” belief in global climate change and the weather. When it’s hot out, people believe in climate change. When it’s cold, they don’t. When summer heat and drought and wildfires tore through the U.S. last summer, 74 percent of Americans believed that climate change was affecting the weather. Only 46 percent of Americans think that this climate change is caused by human activities – most directly the burning of fossil fuels.
The numbers are a little different when it is climate scientists, and the scientific research conducted on climate change, that are polled.
Writing in the Guardian, Dana Nuccitelli and John Abraham describe a new study that polled the recent research to see what scientists thought of climate change. (Nuccitelli is one of the voices behind the website Skeptical Science and one of the authors of the new scientific study.) They found that the vast, overwhelming majority of climate scientists agree that humans are causing climate change.
The team searched a database of scientific studies for the words “global climate change” or “global warming.” They found 11,944 relevant studies published between 1991 and 2012. Then, they read through the study’s summaries to figure out whether the study supported, rejected, was uncertain about or said nothing at all about our role in causing climate change. They also asked the scientists behind the papers whether their research supported or refuted the idea of man-made global warming.
Of the studies that expressed some sort of position on global warming, of which there were 4,000, the team write in their paper, “97.1% endorsed the consensus position that humans are causing global warming.” When the climate scientists themselves said whether or not their work supported the idea of anthropogenic climate change, “97.2% endorsed the consensus.”
For the papers that didn’t seem to have an opinion on whether humans were causing climate change, the reason, they write, is not that the scientists don’t know. Rather, it’s that the debate is so fully and completely settled within the scientific community that they aren’t going to use space re-hashing old fights.
Some people may mention that the scientific community is conflicted over the cause of climate change. This new survey would like to remind that that is not true.
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May 16, 2013 11:16 am
In the small city of Timmins, Ontario, a town nestled half way between Michigan and Hudson Bay, there is a mine. Actually, there are many mines—it’s a mining town. But this story is about just one, a mile and a half deep, where there is water bubbling up from below that has been cut off from the rest of the world for at least a billion years—maybe as much as 2.6 billion years.
The longer end of that timeline, Ivan Semeniuk points out in the Globe and Mail, is about half the age of the Earth. This water hasn’t been in contact with the rest of the planet since before the rise of multicellular life.
But like the water trapped in frozen lakes below Antarctica’s massive ice sheets, researchers suspect there might be life in these flows.
“What we have here,” says Sherwood Lollar, a microbiologist at the University of Toronto in Canada, “is a plate of jelly donuts.” While she has yet to confirm whether the water is inhabited, she says the conditions are perfect for life.
The scientists don’t know whether there is any life in the ancient, isolated water. But they’re working on it. The water is young enough that it would have been locked away after life arose on Earth. But it’s been trapped for so long that any life that does exist would likely be unique—a relic of an ancient world. The CBC:
Some Canadian members of the team are currently testing the water to see if it contains microbial life — if they exist, those microbes may have been isolated from the sun and the Earth’s surface for billions of years and may reveal how microbes evolve in isolation.
One can’t help but be reminded of the Balrog: “Moria! Moria! Wonder of the Northern world. Too deep we delved there, and woke the nameless fear.”
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May 16, 2013 10:11 am
In 1700, a massive earthquake struck the west and northwest coast of the United Sates. Modern scientists first caught wind of the natural disaster through the scars it left on the land—massive, toppled red cedar trees and sand deposits washed far inland. Written records weren’t being kept in that region when the earthquake happened, but several years ago, scientists managed to pinpoint the date of that mysterious earthquake. In 2005, Smithsonian explained how they unraveled the mystery:
In Japan, officials had recorded an “orphan” tsunami—unconnected with any felt earthquake— with waves up to ten feet high along 600 miles of the Honshu coast at midnight, January 27, 1700. Several years ago, Japanese researchers, by estimating the tsunami’s speed, path and other properties, concluded that it was triggered by a magnitude 9 earthquake that warped the seafloor off the Washington coast at 9 p.m. Pacific Standard Time on January 26, 1700. To confirm it, U.S. researchers found a few old trees of known age that had survived the earthquake and compared their tree rings with the rings of the ghost forest cedars. The trees had indeed died just before the growing season of 1700.
The earthquake occurred along the Cascadia Subduction Zone, a major fault line running from the Pacific Northwest to Vancouver. In recent decades, scientists have determined that this fault line may produce mega-earthquakes of 9.0 or higher on the Richter scale.
Considering all the geologic evidence, scientists now say a major earthquake strikes the Pacific Northwest every few hundred years—give or take a few hundred years. That means the next one could strike tomorrow.
This is why researchers hope to learn as much as they can, as quickly as they can about the devastating quake that rocked the land back in 1700. Earthquake prediction remains notoriously sketchy (just look at the recent example of researchers in Italy who failed to predict an earthquake in L’Aquila), so the more scientists can learn about what happened in the past, the better prepared they can be for the next disaster. And that next one could be coming soon, according to new research:
The Cascadia subduction zone is of particular interest to geologists and coastal managers because geological evidence points to recurring seismic activity along the fault line, with intervals between 300 and 500 years. With the last major event occurring in 1700, another earthquake could be on the horizon. A better understanding of how such an event might unfold has the potential to save lives.
The University of Pennsylvania team turned to a fossil-based technique for studying the Cascadia Subduction Zone. They took core samples throughout the region and then picked through the samples to find microscopic foraminifera fossils, a type of single-celled aquatic protist. They used radiocarbon dating to estimate the age of these ancient creatures and to recreate past changes in land and sea level along the coastline. Through their analyses, they saw that the coastline ruptured in a heterogenous manner, or that the earthquake struck in different locations with different severity.
The earthquakes that occurred in this part of North America, they report, behaved similarly to recent major earthquakes in Japan and Chile, which arrived with very little warning. While the results are useful for modeling and understanding the next West Coast mega-earthquake, the researchers warn that some areas in Oregon will likely have just 20 minutes to evacuate before the tsunami waves arrive.
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