Bacteria that normally live in a person’s mouth could contribute to gut diseases such as inflammatory bowel disease (IBD), ulcerative colitis and Crohn’s disease, a new study in mice suggests.
The study found that, when certain strains of bacteria from the mouth make their way to the gut and settle down in the intestine, they can triggerchronic inflammation under certain circumstances.
The findings are preliminary and more research is needed to confirm the results in people. But if true, the study suggests that finding ways to target oral bacteria living in the gut could provide a new treatment for IBD and other gut diseases, the researchers said. [5 Ways Gut Bacteria Affect Your Health]
Previous studies have suggested that oral bacteria don’t typically live in a healthy person’s gut, because these bacteria are out-competed by other bacterial species already living in the gut. However, higher levels of oral bacteria have been found living in the guts of people with certain diseases, including IBD and colon cancer, the researchers said.
To further examine the link between oral bacteria and gut diseases, the researchers took saliva samples from patients with Crohn’s disease and IBD, and transplanted the sampled bacteria into mice bred to not produce their own gut bacteria (called germ-free mice). They found that a strain of bacteria in the saliva called Klebsiella pneumoniae could inhabit the intestines of the germ-free mice and activate types of immune cells known as “T helper cells,” which, in turn, can trigger an inflammatory response.
When the researchers inserted this strain of Klebsiella pneumoniae in another type of mouse with healthy or “balanced” levels of gut bacteria, K. pneumoniae couldn’t establish itself in the gut. But when these mice were fed certain antibiotics, K. pneumoniae could persist in the intestine, the researchers said.
What’s more, when the researchers gave K. pneumoniae to mice that were genetically prone to developing colitis (inflammation of the colon), they found that K. pneumoniae persisted in the mice’s intestines and caused severe inflammation.
These findings suggest that the K. pneumoniae strain can elicit “severe gut inflammation in the context of a genetically susceptible host,” the researchers from the Keio University School of Medicine in Japan wrote in the Oct. 20 issue of the journal Science.
The researchers next analyzed information from a database of the human “fecal microbiome,” which includes data on the types of bacterial DNA found in people’s poop. They found that people with Crohn’s disease and IBD had higher amounts of Klebsiella species in their poop, compared with healthy people.
The researchers hypothesize that, in people with IBD or other gut diseases, inflammation in the intestine may create an environment that is more hospitable to bacteria from the mouth. Once these oral bacteria (such asKlebsiella) colonize the gut, they may “help perpetuate gut microbiota dysbiosis [imbalance] and chronic inflammation,” the researchers said.
“Thus, our findings indicate that targeting oral-derived bacteria, particularly Klebsiella, could provide a therapeutic strategy to correct IBD and many other disease conditions,” the researchers wrote. One way to do this could be to identify “good bacteria” that could block Klebsiella from colonizing the gut, they said.
First Detection of Gravitational Waves from Neutron-Star Crash Marks New Era of Astronomy
By Mike Wall, Space.com Senior Writer |
A new era of astronomy has begun.
For the first time ever, scientists have spotted both gravitational wavesand light coming from the same cosmic event — in this case, the cataclysmic merger of two superdense stellar corpses known as neutron stars.
The landmark discovery initiates the field of “multimessenger astrophysics,” which promises to reveal exciting new insights about the cosmos, researchers said. The find also provides the first solid evidence that neutron-star smashups are the source of much of the universe’s gold, platinum and other heavy elements. [How Gravitational Waves Work (Infographic)]
“This is a transformation in the way that we’re going to do astronomy,” O’Shaughnessy, who’s based at the Rochester Institute of Technology’s Center for Computational Relativity and Gravitation, told Space.com. “It’s fantastic.”
A new type of detection
Gravitational waves are ripples in the fabric of space-time generated by the acceleration of massive cosmic objects. These ripples move at the speed of light, but they’re much more penetrating; they don’t get scattered or absorbed the way light does.
Albert Einstein first predicted the existence of gravitational waves in histheory of general relativity, which was published in 1916. But it took a century for astronomers to detect them directly. That milestone came in September 2015, when LIGO saw gravitational waves emitted by two merging black holes.
That initial find won three project co-founders the 2017 Nobel Prize in physics. The LIGO team soon followed it up with three other discoveries, all of which also traced back to colliding black holes.
The fifth gravitational-wave detection — which was announced today (Oct. 16) at news conferences around the world, and in a raft of papers in multiple scientific journals — is something altogether new. On Aug. 17, 2017, LIGO’s two detectors, which are located in Louisiana and Washington state, picked up a signal that lasted about 100 seconds — far longer than the fraction-of-a-second “chirps” spawned by merging black holes.
“It immediately appeared to us the source was likely to be neutron stars, the other coveted source we were hoping to see — and promising the world we would see,” David Shoemaker, a spokesman for the LIGO Scientific Collaboration and a senior research scientist at the Massachusetts Institute of Technology’s Kavli Institute for Astrophysics and Space Research, said in a statement. [How to Detect Gravitational Waves: LIGO Simply Explained (Video)]
Indeed, calculations by the LIGO team suggest that each of the colliding objects harbors between 1.1 and 1.6 times the mass of the sun, putting both objects in neutron-star territory in terms of mass. (Each of the merging black holes responsible for the other detected signals contained dozens of solar masses.)
Neutron stars, the collapsed remnants of massive stars that have died in supernova explosions, are some of the most exotic objects in the universe.
“They are as close as you can get to a black hole without actually being a black hole,” theoretical astrophysicist Tony Piro, of the Observatories of the Carnegie Institution for Science in Pasadena, California, said in a different statement. “Just one teaspoon of a neutron star weighs as much as all the people on Earth combined.”
A team effort
The Virgo gravitational-wave detector near Pisa, Italy, also picked up a signal from the Aug. 17 event, which was dubbed GW170817 (for the date of its occurrence). And NASA’s Fermi Gamma-ray Space Telescope spotted a burst of gamma-rays — the highest-energy form of light — at about the same time, coming from the same general location.
All of this information allowed researchers to trace the signal’s source to a small patch of the southern sky. Discovery team members passed this information on to colleagues around the world, asking them to search that patch with ground- and space-based telescopes.
This teamwork soon bore fruit. Just hours after the gravitational-wave detection, Piro and his colleagues spotted a matching optical light source about 130 million light-years from Earth, using a telescope at Las Campanas Observatory in Chile.
“We saw a bright-blue source of light in a nearby galaxy — the first time the glowing debris from a neutron star merger had ever been observed,” team member Josh Simon, also of the Carnegie Observatories, said in a statement. “It was definitely a thrilling moment.”
Then, about an hour later, researchers using the Gemini South telescope, also in Chile, spotted that same source in infrared light. Other teams using a variety of instruments soon studied the source across the electromagnetic spectrum, from radio to X-ray wavelengths.
This work revealed that some of the observed light was the radioactive glow of heavy elements such as gold and uranium, which were produced when the two neutron stars collided.
That’s a big deal. Scientists already knew the provenance of lighter elements — most hydrogen and helium was generated during the Big Bang, and other elements all the way up to iron are created by nuclear fusion processes inside stars — but the origin of the heavy stuff was not well understood. [The Big Bang to Now: 10 Easy Steps]
“We’ve shown that the heaviest elements in the periodic table, whose origin was shrouded in mystery until today, are made in the mergers of neutron stars,” Edo Berger, of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Massachusetts, said in a statement. Berger leads a team that studied the event using the Dark Energy Camera at the Cerro Tololo Inter-American Observatory in Chile.
“Each merger can produce more than an Earth’s mass of precious metals like gold and platinum and many of the rare elements found in our cellphones,” Berger said in a statement.
Indeed, GW170817 likely produced about 10 Earth masses’ worth of gold and uranium, researchers said.
Much more to come
The in-depth investigation of GW170817 has revealed other important insights.
For example, this work demonstrated that gravitational waves do indeed move at the speed of light, as theory predicts. (The Fermi space telescope detected the gamma-ray burst just 2 seconds after the gravitational-wave signal ended.) And astronomers now know a little more about neutron stars.
“There are some types of things that neutron stars could be made of that we’re sure they’re not made of, because they didn’t squish that much” during the merger, O’Shaughnessy said.
But GW170817 is just the beginning. For instance, such “multimessenger” observations provide another way to calibrate distances to celestial objects, said the CfA’s Avi Loeb, who also chairs Harvard University’s astronomy department.
Such measurements could, in theory, help scientists finally nail down the rate of the universe’s expansion. Estimates of this value, known as theHubble Constant, vary depending on whether they were calculated using observations of supernova explosions or the cosmic microwave background (the ancient light left over from the Big Bang), said Loeb, who was not involved in the newly announced discovery.
“Here’s another path that is open that was not available before,” he told Space.com.
Many other such paths are likely to open, O’Shaughnessy stressed, and where they may lead is anyone’s guess.
“I think probably the most exciting thing of all is really that it’s the beginning,” O’Shaughnessy said of the new discovery. “It resets the board for what astronomy is going to look like in the years to come, now that we have multiple ways of simultaneously probing a transient and violent universe.”
400 Mysterious Ancient Stone Structures Discovered in Saudi Arabia
By Owen Jarus, Live Science Contributor |
Almost 400 mysterious stone structures dating back thousands of years have been discovered in Saudi Arabia, with a few of these wall-like formations draping across old lava domes, archaeologists report.
Many of the stone walls, which archaeologists call “gates” because they resemble field gates from above, were found in clusters in a region in west-central Saudi Arabia called Harrat Khaybar.
The gates come in a number of different shapes and sizes. Some of the gates, which archaeologists call “I-type” gates, contain one wall with heaps of rock at the ends of the wall. Two I-type gates, built side by side, can be seen in this picture along with other gates.
Discovered mainly through satellite images, a few of the gates are actually located on the side of a volcanic dome that once spewed basaltic lava, researchers found.
The gates “are stone-built, the walls roughly made and low,” David Kennedy, a professor at the University of Western Australia, wrote in a paper set to be published in the November issue of the journal Arabian Archaeology and Epigraphy. The gates “appear to be the oldest man-made structures in the landscape,” Kennedy noted, adding that “no obvious explanation of their purpose can be discerned.”
Another cluster of gates. The longest gate in this picture is about 950 feet. Why the gates cluster together is unknown. The gates tend to be located in lavafields that are inhospitable for human life. However thousands of years ago these areas would have been wetter and contained more life.
The smallest of the gates extends about 43 feet (13 meters), while the longest is 1,699 feet (518 m) long, or longer than an NFL football field. Many have multiple stone walls that, in some instances, form a rectangular design; some of the others, called “I” type gates, have only one stone wall with heaps of stone at each end.
“Gates are found almost exclusively in bleak, inhospitable lava fields with scant water or vegetation, places seemingly amongst the most unwelcoming to our species,” Kennedy wrote. Thousands of years ago, he noted, the landscape was more hospitable to human life. Other types of stone structures — such as “kites,” which were used to hunt animals, and “wheels,” named for their shape — have also been discovered in these lava fields.
Other types of stone structures have also been found in Saudi Arabia. Often these stone structures are built on top of or even inside gates. This suggests that the gates are older than the other stone structures. This picture shows a gate that has a triangle stone structure with heaps of stone that lead to a bullseye shaped stone structure (possibly a tomb).
The kites, wheels and other types of stone structures were typically found to be built on top of these gate-like walls, suggesting that the gates predate these stone structures, Kennedy said. The remains of lava flows are also sometimes found on top of the gates, indicating that the gates are also older than some of the flows, Kennedy said.
Need for fieldwork
Most of the gates were discovered through satellite surveys, and no archaeological fieldwork has been conducted on them. However, in the 1980s, before the gates were discovered, volcanologists Vic Camp and John Roobolmapped an area of the Harrat Khaybar that included a lava dome festooned with gates and other stone structures. This lava dome is located near a taller lava dome, called Jabal Abyad,which means “white mountain” in Arabic.
This picture of the lava dome that has gates on it was taken in the 1980s by Vic Camp. The taller lava dome behind it is called “Jabal Abyad” a name which means “white mountain” in Arabic. The lava domes are no longer active although in the past basalt lava poured from them.
The lava domes are no longer active, Camp said, adding that in the past, basaltic lava covered some of the stone structures, including the gates.
“We see several areas where the younger lavas are devoid of such [stone] structures, although surrounded by several [stone structures],” Camp told Live Science. One of the stone structures is partially covered in hardened lava, photographs show. Camp estimates that some of the gates around the lava dome were built around 7,000 years ago.
Archaeological fieldwork is necessary to determine what the gates are and when, exactly, they date to, Kennedy said.
A new online, virtual-reality experience will bring you face to face with one of the most famous shipwreck-diving sites in the world: the British freighter SS Thistlegorm. German bombers sunk the ship in 1941 near the mouth of the Gulf of Suez at the northern end of the Red Sea.
At the time, the WWII merchant ship was carrying hundreds of tons of Allied war supplies — including tanks, train engines, trucks and motorcycles — to the Egyptian city of Alexandria.
Since the 1990s, the Thistlegorm, with its spectacular sunken cargo, has become one of the most famous wreck-diving sites in the world, said Jon Henderson, a marine archaeologist at the University of Nottingham in the United Kingdom. Hundreds of people dive on the site each day, he said. [Dive Through the WWII-Era Shipwreck with 3D Virtual Reality Images]
Henderson is the coordinator of the Thistlegorm Project, a virtual reality tour of the wreck that was released online Oct. 6, exactly 76 years to the day after German bombers sunk the ship.
The online experience combines a highly detailed 3D model of the sunken ship, based on thousands of photographs, with 360-degree underwater video of divers exploring key sections of the wreck.
Henderson told Live Science that only divers would be able to directly see most of the world’s underwater heritage sites. But with virtual reality technology, the wider public can now experience the shipwreck.
“There are something like 6 million divers in the world, so less than 0.1 percent of the world’s population ever gets access to these sites,” he said. “But we’re now at the point where we’ve got technology where we can reconstruct them in photo-realistic detail, and we can now create models that people can explore and interact with on their mobile phones or in their homes.”
A team of divers and archaeologists from the University of Nottingham and Egypt’s Alexandria University spent five days moored above the Thistlegorm wreck, west of the tip of the Sinai Peninsula and about 18 miles (30 kilometers) by sea from the Egyptian dive resort of Sharm El Sheikh.
The team’s photogrammetry specialist, Simon Brown, made 12 dives to the Thistlegorm wreck in that time, totaling more than 13 hours underwater, Henderson said. In those dives, Brown gathered thousands of photographs using a conventional Nikon camera fitted with a 6mm fish-eye lens. The camera and two strobe lights were mounted on an underwater scooter, so Brown could cover more ground during his dives.
Brown later processed and combined images of the shipwreck with photogrammetric software, which can extract 3D data from sets of 2D photographs.
The result was the highly detailed 3D model of the giant wreck, based on 24,307 photographic images — the largest photogrammetric survey yet made of a shipwreck, covering an area of about 7 acres (28,300 square meters), Henderson said.
While Brown shot the photographs for the 3D model, Henderson focused on recording 360-degree video of key points on the wreck.
Henderson said he had been inspired to apply the technology to a wreck after seeing 360-degree underwater video of a coral reef at a conference earlier this year. “I just thought, ‘This would be amazing on a shipwreck,’ because the 360-degree video, for me, is the closest you can come to actually diving,” he said.
The researchers secured a grant from the Newton Fund in the United Kingdom for a knowledge-sharing program involving the University of Nottingham, Alexandria University and Ain Shams University in Cairo, which houses a virtual-reality laboratory. Next, the researchers chose the Thistlegorm wreck for a public-outreach project because of its well-deserved fame as a dive site, Henderson said.
“It’s an absolutely amazing wreck to dive,” he said. “There’s the cargo — Bedford trucks, armored vehicles, motorcycles, Bren guns, ammunition, aircraft parts … and the massive steam locomotives on the decks themselves. Every time you dive on it, you find something else.”
The popularity of the wreck has come at a cost. Since the development of nearby Sharm El Sheikh as a diving center in the 1990s, the Thistlegorm has suffered damage from dive boats mooring directly onto the wreck and from souveniring done by some insensitive divers, Henderson said. [In Photos: WWII-Era Shipwrecks Illegally Plundered in Java Sea]
Although Egypt joined the 2001 UNESCO Convention on the Protection of Underwater Heritage in September, that convention protects onlyshipwrecks that are more than 100 years old. So, many World War I and all World War II wrecks in the Red Sea are not covered, Henderson said.
“What we hope this website will do is help to monitor what is going on,” he said. “One of the basic things for finding out how sites have been damaged is to carry out a baseline survey such as this, and then we can start to chart changes over time.”
Showing the wonders of the Thistlegorm to a wider audience would also benefit other wrecks and submerged archaeological sites in the region, he said.
“The Red Sea is an amazing resource, but we don’t know what’s actually in there — there has never been an official survey carried out,” Henderson said. “I think once people know about this heritage, then hopefully they will start to care about it, and that will increase the level of protection, particularly for wrecks like the Thistlegorm.”