Dogs Can Accurately Sniff out 'Superbug' Infections

Dogs can sniff out Clostridium difficile (the infective agent that is responsible for many of the dreaded "hospital acquired infections") in stool samples and even in the air surrounding patients in hospital with a very high degree of accuracy, finds a study in the Christmas issue published on bmj.com today.

The findings support previous studies of dogs detecting various types of cancer and could have great potential for screening hospital wards to help prevent C. difficile outbreaks, say the researchers.

C. difficile infection most commonly occurs in older people who have recently had a course of antibiotics in hospital, but it can also start in the community, especially in care homes. Symptoms can range from mild diarrhoea to a life-threatening inflammation of the bowel.

Early detection is vital to prevent transmission, but diagnostic tests can be expensive and slow, which can delay treatment for up to a week.

Diarrhoea due to C. difficile has a specific smell, and dogs have a superior sense of smell compared with humans. This prompted researchers in the Netherlands to investigate whether a dog could be trained to detect C. difficile.

A two-year old male beagle (called Cliff) was trained by a professional instructor to identify C. difficile in stool samples and in patients with C. difficile infection. He was taught to indicate the presence of the specific scent by sitting or lying down.

The dog had not been trained for detection purposes before.

After two months of training, the dog's detection abilities were formally tested on 50 C. difficile positive and 50 C. difficile negative stool samples. He correctly identified all 50 positive samples and 47 out of 50 negative samples.

This equates to 100% sensitivity and 94% specificity (sensitivity measures the proportion of positives correctly identified, while specificity measures the proportion of negatives correctly identified).

The dog was then taken onto two hospital wards to test his detection abilities in patients. He correctly identified 25 out of 30 cases (sensitivity 83%) and 265 out of 270 negative controls (specificity 98%).

The researchers add that the dog was quick and efficient, screening a complete hospital ward for the presence of patients with C. difficile infection in less than 10 minutes.

They point to some study limitations, such as the unpredictability of using an animal as a diagnostic tool and the potential for spreading infections via the dog, and say some unanswered questions remain.

Read more at Science Daily

Higgs Hiccup: Contradictory Results Show Up at LHC

Something slightly odd seems to be going on with the Higgs boson. Separate measurements of its properties are showing two slightly different masses, according to scientists who presented their latest data on Dec. 13.

Ever since physicists found a particle that looks very much like the Higgs boson in July, they have been probing its properties, essentially running their experimental hands all over it to check out its features. They do this by smashing protons together at insanely high speeds in the Large Hadron Collider and watching the resulting rain of particles that gets produced. Within this melee, several Higgs bosons appear and almost immediately decay into other particles.

The LHC can detect the Higgs decaying in two different ways. One channel produces two characteristic photons while another creates four particles known as leptons. The two decay paths each give scientists a distinct value for the mass of the Higgs. But there’s a little problem.

“There turns out to be a slight tension between the two masses,” said physicist Beate Heinemann of the University of California, Berkeley, who works on ATLAS, one of the LHC’s Higgs-searching experiments. “They are compatible, just not super compatible.”

The two photon channel is saying that the Higgs mass is 126.6 gigaelectronvolts (GeV), or about 126 times the mass of a proton. The four lepton decay route suggests the mass is 123.5 GeV. A very tiny disagreement that is nonetheless very strange because the Higgs should have one identifiable mass. ATLAS scientists noticed the discrepancy in their data previously and thought it might simply be a problem with calibrating their machinery. Yet even after calibration and analyzing more data, the difference remained.

Several physics blogs have noted that one way to explain this would be to have two different Higgs bosons, each with a very similar mass. This would be a truly bizarre and unexpected result. But it’s much more probable that scientists are seeing a statistical mirage.

Heinemann said the four lepton channel has only analyzed about 10 Higgs bosons and the two photon channel about 500 Higgs. Physicists need to see the same result over and over in thousands or even millions of particle events before they are sure it’s not just a statistical coincidence. “The most likely explanation is that it’s one particle,” said Heinemann.

Read more at Wired Science

Hans Christian Andersen's First Fairy Tale Discovered

Danish experts believe they have found the first fairy tale written by Hans Christian Andersen (1805-1875).

Titled "Tællelyset" (The Tallow Candle), the ink-written manuscript was found by local historian Esben Brage at the bottom of an archive box. Brage made the discovery in October in the historical archive on the island of Funen, where the Danish author was born.

Two months later, historians confirmed that the six-page manuscript was indeed written by Andersen. They dated the document to the mid-1820s, when the writer was in his late teens.

"I am in no doubt that it has been written by Andersen," Ejnar Stig Askgaard of the Odense City Museum told the Danish daily Politiken.

The newspaper has translated and published a version of the story in English.

The front page of the document reads "To Madam Bunkeflod from her devoted H.C. Andersen."

A vicar’s widow, Mme Bunkeflod lived opposite Andersen’s childhood home. Historians know that the writer visited her often as a child, borrowing her books.

"The fairy tale was a present. A present of thanks to a woman whose home had been very important to him," Askgaard said.

The Bunkeflod family then sent the manuscript to another family close to Andersen, the Plum family, in whose archives the story was found. A dedication written on the document later in blue ink reads: "To P Plum from his friend Bunkeflod."

Experts believe that the neatly written document is likely the copy of an original manuscript that has since been lost.

The story is about a neglected and dirty tallow candle which finds happiness when a tinder box sees its inner beauty and lights its wick.

"The Tallow Candle had found its right place in life – and shown that it was a real candle, and went on to shine for many a year, pleasing itself and the other creations around it," Andersen wrote.

Although the tale is not at the level of Andersen’s later works, it is the most important find since the 1920s, when the writer's memoirs were discovered at the Royal Library.

"This is a sensational discovery. Partly because it must be seen as Andersen’s first fairy tale, and partly because it shows that he was interested in the fairy tale as a young man, before his authorship began,"Askgaard said.

Read more at Discovery News

Historic Camp Site Discovered on Antarctica

Norwegian Roald Amundsen and Englishman Robert Falcon Scott were the explorers who led teams of their countrymen on grueling journeys across the frigid continent in an effort to be the first to go where no man had gone before. Amundsen won the race, reaching the pole on Dec. 14, 1911. Scott also made it there, on Jan. 17, 1912, but perished with the remainder of his crew on the arduous trek back to the edge of the continent.

Scott and his team camped on the slopes of Mount Erebus, the southernmost volcano, during their journey. The spot was known as "the highest camp," according to a National Science Foundation release.

Clive Oppenheimer, a volcanologist at Cambridge University in England and working at Erebus as part of an NSF team, found what he thinks is the same camp site using written accounts and historic images from the Scott Polar Research Institute in Great Britain, the NSF release said. (The institute was founded by one of the men from Scott's party who climbed Erebus as part of the 1912 Terra Nova expedition.)

The site Oppenheimer located features a ring of stones where a tent once stood and appears to match historic photos taken during the 1912 expedition. "Conservators from the New Zealand-based Antarctic Heritage Trust have been asked to verify the historic find," the NSF wrote.

The area will be recorded and searched to look for artifacts from the original expedition. Tents and other sites from early 20th century expeditions have also been found and preserved, some with a wealth of artifacts.

The team that climbed Mount Erebus in 1912 included geologist Raymond Priestley; they took geological specimens and mapped the area. Scott's expedition was more focused on gleaning scientific research from their mission than Amundsen's was.

The 1912 expedition was preceded at Erebus by the 1907-1909 Nimrod Expedition, mounted by explorer Ernest Shackleton, which failed to reach the South Pole.

Read more at Discovery News

Why Bugs Outnumber Us (And Other Mammals) 312 to 1

A headcount of arthropods, a group that includes insects, arachnids and crustaceans, finds that these creatures outnumber mammals -- including humans -- by a ratio of about 312 to 1.

The scrappy organisms also outnumber plants 17 to 1, the study, published in the latest journal Science, suggests.

"There are different reasons to explain this," project leader Yves Basset told Discovery News. "They are small and can make a living out of nearly everything, including other arthropods, decomposing matter, plant tissues, etc."

Basset also pointed out that often bug larvae don't compete with adults since they feed on different foos resources.

Basset is scientific coordinator of the CTFS Arthropod Initiative at the Smithsonian Tropical Research Institute. To better understand arthropod diversity, he and 102 other researchers looked for the organisms in the San Lorenzo forest reserve of Panama.

Bugs tend to thrive in tropical rainforests, but the population at this particular reserve in Panama is thought to be average. The scientists chose to work there because the Smithsonian has a canopy crane and other devices at the site that facilitate access to everything from the canopy forest to the substrate below.

Using this crane, inflatable platforms, balloons, climbing ropes, and by crawling on their knees to get a better look, the researchers sorted and identified 130,000 arthropods. These represented more than 6,000 species.

By scaling up the diversity values obtained from twelve other intensively sampled areas, the team calculated that the 23.2-square-mile rainforest reserve harbors an excess of 25,000 arthropod species. These calculations, in turn, contributed to the estimated ratios comparing numbers of arachnids to plants and mammals.

Basset thinks that these ratios hold true for cities as well, and may even skew higher in favor of arthropods at urban settings.

"The mammal fauna in cities is rather depleted, but not necessarily that of arthropods," he explained. "For example, a small urban park may not host many mammal species, because it may be a too small area to sustain species requirements, such as food and living space. However, let's say you have 10 species of trees in this park, then they may well support as many as 200 arthropod species, according to our data."

Humans tend to view insects mostly as being detrimental. They can at times spread disease and destroy crops.

"But we forget that these represent only a few species in comparison to the whole of arthropod biodiversity," Basset said. "The majority of insects live in forests and are responsible for the maintenance of these forests via the different services of pollination, decomposition and herbivory. In addition, many arthropods are efficient predators or parasites that suppress the levels of herbivores."

Outbreaks of pests do not exist in tropical forests, he pointed out, suggesting that arthropods help to keep ecosystems in balance.

These organisms additionally "represent a formidable, but untapped, reserve of DNA, genes and molecules -- again about 20 times more species-rich than plants from which we nevertheless get most of our medications," he continued. "Who knows what may be concealed in these arthropod molecules and how we could use them? We also need to discover most of these species/molecules before they disappear from Earth."

This latest study and others indicate that we may be sharing the planet with about 6 million arthropod species. Out of these, we only know about 1 million, with the rest  and many others possibly threatened by pollution, habitat loss, and other human-related problems.

Read more at Discovery News

Untouched 18th Century Woodworking Shop Found

Imagine peeking into an old garden shed and discovering the oldest woodworking shop in United States. It's a kind of traditional woodworker's dream. This is basically what happened to a University of Delaware professor recently.

"The first time I saw it, I about fell over,” said Ritchie Garrison, professor of history professor and director of the Winterthur Program in American Material Culture at the University of Delaware. "It was a bit like walking into the past."

The discovery was entirely accidental. Garrison and Michael Burrey were in the process of revamping Garrison's 19th century house in Plymouth, Mass. Burrey was also working on a project at a local preschool in Duxbury, Mass., where he discovered what turns out to be a 18th century joiner's shop. Garrison invited several experts in material culture got to see the shop for themselves.

"I said 'holy cow!'" recalled Garrison, of his first look. If the date painted on the building is accurate the shop could trace back to at least 1789. Eighteenth century shops are extremely rare, unlike the more common 19th-century shops, said Garrison.

The shop provided all sorts of clues to its uses and even the local ecology 200 years ago. And although the school used the shed, many of the features of the shop are essentially untouched. The original workbenches, for instance, are still intact and in good condition. Those benches show different kinds of uses and even the woods they were made of contain clues about the local forests in the 1700s. There was also a conspicuously removed fireplace.

"The fireplace told me that they were doing things that required warmth, such as using glue," said Garrison after explaining that 18th-century glue needed to reach a certain temperature temperature to work.

As for the wood itself, dendrochronology shows that it's from the second or third generation of trees replanted after original New England settlement by Europeans.

According to local records, the workshop belonged to a master carpenter named Luther Sampson, according to Garrison.

Read more at Discovery News

Animal's Body Preserved for 425 Million Years

The remains of a tiny animal, preserved for 425 million years in rocks located in what is now the U.K., have just been discovered by an international team of researchers.

The creature -- related to crabs, lobsters and shrimp -- is an ostracod, or a type of crustacean sometimes known as seed shrimp. It represents a new species, Pauline avibella, in memory of the late wife of David Siveter, who led the research project.

The 0.4-inch-long animal was found, not only with its shell, but also with its soft parts -- body, limbs, eyes, gills and digestive system. Such well-preserved remains from that ultra prehistoric period are near unheard of in the fossil record.

"The two ostracod specimens discovered represent a genus and species new to science, named Pauline avibella," Siveter, of the University of Leicester Department of Geology, said in a press release. "The genus is named in honor of a special person and avibella means 'beautiful bird,' so-named because of the fancied resemblance of a prominent feature of the shell to the wing of a bird."

The discovery of the tiny shelled animal was made in Herefordshire, Welsh Borderland. The rocks at the site date to a time when southern Britain was a sea area on a small continent situated in warm, southerly subtropical latitudes. The ostracods and associated marine animals living there were covered by a fall of volcanic ash that preserved them frozen in time.

"Ostracods are the most abundant fossil arthropods, occurring ubiquitously as bivalved shells in rocks of the last 490 million years, and are common in most water environments today," Siveter said. "The find is important because it is one of only a handful preserving the fossilized soft-tissues of ostracods."

He continued, "The preservation of soft-parts of animals is a very rare occurrence in the fossil record and allows unparalleled insight into the ancient biology, community structure and evolution of animals - key facts that that would otherwise be lost to science."

As the image here shows, the fossils were reconstructed virtually, by using a technique that involves grinding each specimen down, layer by layer, and then photographing it at each stage. It took 500 such "slices" to create the image.

Read more at Discovery News

Hubble Detects Furthest Oldest Galaxy... Again?!

Yes, I know. I know! It seems like every other day astronomers have discovered the "oldest most distant galaxy." Although "breaking the record" alone is of little scientific value, you're going to be hearing a lot more of these stories in the coming years. And you know what? The science involved is still really cool.

Remember the Hubble Ultra Deep Field? The deep, mind blowing, time-traveling expanse of galaxies that reminds us of how truly itty-bitty we all are? Well, it still keeps providing astronomers with new objects of study with more observations.

The new observing campaign with Wide Field Camera 3 on Hubble finished up last September. The goal was to find more galaxies in the redshift range of 8.5 to 10, a crucial but understudied time in galaxy formation. In more tangible numbers, according to my favorite cosmology calculator, that is when the Universe was about 500 million years old, a mere fraction of its current 13.75 billion years.

Just stop for a moment and process that this camera detected photons from over 13 BILLION light years away. Yes, that's really far.

This is a time in the universe when the very first galaxies were forming. Little is known about this epoch, but our telescopes and techniques getting better and better, allowing us to probe this period of creation a little more every year. When the James Webb Space Telescope* (JWST) launches, it will further open up these proto-galaxies to our explorations with a large mirror deployed away from the distorting effects of the Earth's atmosphere and with sensitivity to infrared light. Since these baby galaxies are so heavily redshifted by the expansion of the universe over such great distances, infrared is the best way to study them.

In this new image (top), seven such distant galaxies were identified, including one that had tentatively been announced with a redshift of 10.3 and now has a tentative redshift of 11.9, making it the new record-holder, pending confirmation. Though seven is not a large sample by any means, it at least allows us to put the first data points on a plot describing this sample. It appears as though, when you go further back in time to this epoch, that the brightness and star formation rate of these galaxies drop off a bit, as if this were just a period of "ramping up" before the fireworks really began.

These galaxies would have been emitting ultraviolet light that ionized the hydrogen gas that pervaded the Universe at this early time. That means the ultraviolet photons would cause the electron to be stripped from a hydrogen atom. Much effort has been put into detecting this neutral hydrogen and studying its ionization with low frequency radio telescopes.

Read more at Discovery News

Prehistoric Farmers Made Cheese

About 7,000 years ago, dairy farmers in modern-day Poland used clay strainers to turn cow's milk into cheese.

The new discovery offers the earliest evidence yet of cheese-making, which began before people developed the ability to digest the lactose sugars in unprocessed milk.

Not only did cheese, which contains very little lactose, provide a valuable source of nutrition for prehistoric Europeans. It also allowed them to store milk in a form that was easy to transport and would keep for months without spoiling.

"The interesting thing is that people at that stage could not digest the lactose in the milk, so processing milk into cheese would have given them the benefit from the nutritious effects of milk without having the side-effect of being ill," said Mélanie Salque, a chemist at the University of Bristol in the United Kingdom.

"It was a very good product for them because you don't have to kill animals to get the milk out of them," she added. "Milk was a big development and cheese was as well."

Some 30 years ago, archaeologists described sieve-like pottery fragments found in a region of north-central Poland, where some of the region's earliest farmers settled. The shards dated back to between 7,200 and 6,800 years ago. And the holes in the sieves were tiny, just two or three millimeters (about a tenth of an inch) wide.

Alongside the clay fragments were lots of cattle bones, leading some scientists to speculate that the reconstructed bowl-shaped containers were cheese-strainers. But without proof, other hypotheses have endured, including the possibility that the vessels were used to strain chaff while making beer.

In an attempt to figure out once and for all what the containers were for, Salque and colleagues conducted detailed chemical analyses on 50 fragments from 34 vessels. They were looking specifically for residues of fats, which get absorbed by pores in clay during food processing and can remain trapped for millennia.

After crushing a small amount of each fragment into a powder, mixing the powder with solvents, and running the solution through their instruments, the researchers detected milk residues in all but one of the pieces.

People wouldn't have strained milk before drinking it, and butter is not processed that way. The only possible explanation for what they found, the team reports today in the journal Nature, is that people were coagulating milk and then using the sieves to separate semi-solid curds from liquid whey to make cheese.

"They have these vessels that look like they could be strainers for making cheese, but what they've really done now is confirmed that that's the case," said Mark Thomas, an evolutionary geneticist at University College London.

Read more at Discovery News

Iron Age Feast Found in England

Remnants of an Iron-Age feast, including cattle skulls and 13 cauldrons, have been unearthed in Chiseldon, United Kingdom, according to a report in the latest British Archaeology

The discovery marks the largest grouping of early cauldrons ever found in Europe. One cauldron features a handle plate in the form of a cow's head; zoomorphic decoration is otherwise unknown on a British cauldron.

"Analysis of the interiors of the cauldrons has even revealed traces of animal fats, a tantalizing suggestion that these objects might have been used in cooking and serving meat-rich stews at Iron-Age feasts over 2,000 ago," Julia Farley, curator of European Iron Age collections at the British Museum, told Discovery News.

Farley's colleague Jody Joy, as well as Alexandra Baldwin and Jamie Hood from the museum, are still studying the artifacts, which were found buried in a 6.6-feet-wide pit. The cauldrons were made from iron and copper alloy in the second or first century B.C.

Each was built to last, with an iron rim and band supporting circular suspension handles. The main body of the cauldrons consisted of a central band and bowl of sheet copper alloy riveted together. "The iron rim and handles gave strength and rigidity, while the copper-alloy bowl acted as an excellent heat conductor," the researchers note.

When the cauldrons were buried, nearby Barbury Castle still might have been occupied. Another hill fort, Liddington Castle, likely had been abandoned. Nevertheless, given the possible fort protection and open space, "Chiseldon looks to be an ideal meeting place," the researchers believe.

What the cauldrons were last used for is a bit of a mystery, but Joy and team suspect "large quantities of food and drink were probably consumed." Feasts at the time "would have marked significant events in the calendar or special occasions, such as marriages."

Beef was the star attraction at the last big feast involving the cauldrons, the evidence suggests. The two cattle skulls, cow cauldron decoration and traces of animal fats all theoretically point to beef.

But the experts say it's too soon to make that conclusion.

Archaeologist Mike Pitts, who also edits British Archaeology, told Discovery News that "notwithstanding the cattle skulls, it might well have been pork. Pigs were important animals in feasting. Of course, whatever was in the cauldrons was boiled."

Read more at Discovery News