Goats Could Increase the Risk of a Rare Lung Cancer, Researchers Find 0

Exposure to goats could increase the risk of a certain type of lung cancer, according to French researchers.

The study, presented at the European Respiratory Society's Annual Congress in Amsterdam, has linked a professional exposure to goats with a distinct subset of lung cancer, known as pneumonic-type lung adenocarcinoma (P-ADC).
This form of lung cancer has a weak association with tobacco smoking when compared with other types of the disease. In attempting to identify other triggers that may cause the disease, scientists have previously noticed similarities between P-ADC and a viral infection which causes growths in the lungs of sheep. Given these similarities, the researchers have investigated whether a viral agent found in sheep and goats could be easily transferred to people who work with the animals, leading to a partiality for P-ADC.
The current epidemiologic study involved 44 patients with P-ADC and 132 controls without the disease. All participants were given a questionnaire assessing a number of risk factors including their smoking status, their personal history of cancer and their exposure to goats.
The results showed that people who had experienced a professional exposure to goats during their lifetime were five times more likely to get P-ADC compared with other types of lung cancer.
The findings also showed that P-ADC was significantly associated with females, and people who had never smoked or had any personal history of cancer.
Dr Nicolas Girard, from the Louis Pradel Hospital, Hospices Civils de Lyon, said: "Scientists have noticed similarities between P-ADC and a contagious viral infection in sheep before. This led us to explore the possibility that professional exposure to cattle could make humans more susceptible to P-ADC. These findings demonstrate that exposure to goats could be a risk factor for this type of lung cancer, however further studies are needed to assess other potential risk factors for the disease."
via ScienceDaily

Hot Rocks Could Help Trigger Earthquakes 0

The heat from rocks scraping against each other could be a major cause of faults weakening in the beginning stages of earthquakes, scientists have found.
When rocks grind against each other, they generate extreme temperatures at scattered microscopic bumps, called asperities, where they make contact. This process is similar to producing heat by rubbing your hands together, but on an extreme scale.
At major faults such as the San Andreas in California, researchers think flashes of heat from rocks shearing past each other melts the rock. This makes the rocks slippery at those microscopic contact points, lowering the friction between them enough to trigger a significant amount of stress and setting the stage for an earthquake.
To learn more about this flash heating, scientists rubbed together different types of rocks commonly found in faults, such as quartzite, granite and gabbro. They simulated earthquake speeds of close to 1.6 feet per second (0.5 meters per second). The bumps, or asperities, each had a surface area of less than 10 microns wide, or about a tenth of the diameter of a human hair.
The researchers found that intense flash heating could heat asperities dramatically, perhaps up to 3,270 degrees Fahrenheit (1,800 degrees Celsius), enough to melt most rock types associated with earthquake faults. Remarkably, this intense heat was confined to the hot spots — the temperature of the surrounding rock remained largely unaffected. Still, it could cause friction between rocks to drop significantly across distances of just 1.7 inches (4.5 centimeters).
These findings hint that flash heating may be a major contributor to the weakening of faults during both small earthquakes and the early stages of large quakes.
"These findings give us a much clearer picture of what might be happening at faults during an earthquake, and has implications on how earthquake ruptures travel within the earth," researcher David Goldsby, a geophysicist at Brown University, told OurAmazingPlanet.
Although this current work slid bare rock surfaces past each other, future research could see what heating might occur when surfaces covered with ground-up rock are rubbed against each other for a potentially even more realistic scenario, Goldsby said.
Goldsby and his colleague Terry Tullis detail their findings in tomorrow's (Oct. 14) issue of the journal Science.

(Via OurAmazingPlanet )

Climate Change Could Shrink Animals 0

Climate change could result in a planet full of cold-blooded runts.

 A whale shark feasts on plankton. (Wikimedia Commons)

In a warming world, copepods, tiny crustaceans that make up the bulk of the ocean's animal plankton, could end up stunted. Copepods cope with warmer temperatures by maturing faster, but they don't grow as fast as they mature, so they end up runts.
The same phenomenon, called the “temperature-size rule,” affects most cold-blooded animals, so as the planet heats up, many animals' sizes may go down.
Researchers at the University of London examined the case of the incredible shrinking organisms in the journal The American Naturalist.
“We’ve shown that growth and development increase at different rates as temperatures warm. The consequences are that at warmer temperatures a species grows faster but matures even faster still, resulting in them achieving a smaller adult size,” said lead author Andrew Hirst in a press release.
Since copepods are food for marine animals, from fish to whales, what happens developmentally to the shrimp-y crustaceans could affect the entire ocean's food web.
“Decoupling of these rates could have important consequences for individual species and ecosystems,” Hirst added.

Black Death genome reconstructed 0

(Photo: Museum of London)

It's hard to comprehend the impact of the Black Death. The "Great Pestilence" is believed to have originated somewhere in Northern Asia in the 1330s before hitting Europe in 1347. It killed an estimated 75 million people worldwide - that's around 25 per cent of all humans in existence at the time. Now in an effort to better understand modern infectious diseases, scientist have sequenced the entire genome of the Black Death.
The research is based on analysis of skeletal remains from the East Smithfield "plague pits" in London using a previously developed methodology for extracting degraded DNA fragments of the bacteria that caused the plague - Yersinia pestis.

(LEFT IMAGE: Hendrik Poinar, associate professor and director of the McMaster Ancient DNA Centre)

The international team, led by researchers from McMaster University and the University of Tubingen, say this is the first time a reconstructed genome of any ancient pathogen has been drafted.
So why is this relevant in the 21st Century?
Descendants of the specific variant of the Yersinia pestis found in the 14th Century remain exist today, killing an estimated 2,000 people a year. By drafting the reconstruction of the genome scientist are able to see changes in the pathogen's evolution - which in this case have been minor - and gain a better understanding of such deadly infections.
"The genomic data show that this bacterial strain, or variant, is the ancestor of all modern plagues we have today worldwide," says Hendrik Poinar, associate professor and director of the McMaster Ancient DNA Centre. "Every outbreak across the globe today stems from a descendant of the medieval plague. With a better understanding of the evolution of this deadly pathogen, we are entering a new era of research into infectious disease."
There are still questions that remain unanswered about why the Black Death was so devastating however.
"We found that in 660 years of evolution as a human pathogen, there have been relatively few changes in the genome of the ancient organism, but those changes, however small, may or may not account for the noted increased virulence of the bug that ravaged Europe," says Poinar. "The next step is to determine why this was so deadly."

 Close-up of teeth from a plague victim (Photo: Museum of London)

In other words, the research may have knocked out one of the main contenders in establishing why the Black Death had such a deadly impact. The Paper states that because the Black Death may not have been due to bacterial phenotype, "factors other than microbial genetics, such as environment, vector dynamics and host susceptibility, should be at the forefront of epidemiological discussions regarding emerging Y. pestis infections."
It has also been shown that the variation of Yersinia pestis that caused the medieval plague originated sometime around the 12th Century, which means that it was not the cause of the Justinian plague that struck the Byzantine Empire around 540 CE was not caused by the same pathogen as once thought.
"Using the same methodology, it should now be possible to study the genomes of all sorts of historic pathogens," says Johannes Krause of the University of Tubingen Krause. "This will provide us with direct insights into the evolution of human pathogens and historical pandemics."
The research is published online in the scientific journal Nature

Source: McMaster University