Science & Health
Every human gut may have a unique viral composition
The first comprehensive database of the communities of viruses, or “viromes,” living in our guts reveals that they vary enormously from person to person. The database offers new opportunities to identify viruses that could potentially play a role in treating antibiotic-resistant bacterial infections. Share on PinterestResearch suggests that each human gut may have a unique…
The first comprehensive database of the communities of viruses, or “viromes,” living in our guts reveals that they vary enormously from person to person. The database offers new opportunities to identify viruses that could potentially play a role in treating antibiotic-resistant bacterial infections. Share on PinterestResearch suggests that each human gut may have a unique composition, with viral diversity being particularly high in infants.The bacteria that colonize the human digestive system are known to have a profound effect on health, but the viruses that coexist alongside them are likely to be just as important.According to the newly created Gut Virome Database (GVD) from Ohio State University (OSU) in Columbus, 97.7% of the viruses in our gut are bacteriophages, meaning that they use bacteria as hosts in which to replicate themselves.Early in the 20th century, scientists began to investigate the potential of bacteriophages to combat bacterial infections, but the discovery of antibiotics largely superseded their work.Now, with the growing threat of antibiotic resistance, there has been a resurgence of interest in bacteriophage therapy.Scientists have discovered a great deal about the “bacteriome” — the community of bacteria that make their home in the gut — but characterizing the virome has proved more challenging. Bacteria have certain genetic sequences in common, which makes identifying their DNA relatively easy, but there is no such universal marker for viruses.To make it easier to study the virome, microbiologists at OSU decided to establish a database dedicated to human gut viruses.The team built the GVD using genetic data from 32 studies that aimed to identify gut viruses in a total of 1,986 people living in 16 different countries. After processing the data to account for the wide variety of different methods that these studies used, they identified 33,242 “unique viral populations,” which are the viral equivalent of species.On average, each viral metagenome — the collective viral genome in a sample from an individual’s gut — contained 542 viral populations.No single viral population was present in every metagenome. In fact, the researchers found the most widespread viral population in only 39% of the metagenomes. In their new study paper, published in the journal Cell Host & Microbe, they suggest that each person’s gut virome is highly personalized and most likely unique.The team will continually update the database to provide a free resource for other researchers.“We’ve established a robust starting point to see what the virome looks like in humans,” says study co-author Olivier Zablocki, a postdoctoral researcher at OSU. “If we can characterize the viruses that are keeping us healthy, we might be able to harness that information to design future therapeutics for pathogens that can’t otherwise be treated with drugs.”Looking to the future, bacteriophages (or “phages”) isolated from the guts of healthy people have the potential to combat antibiotic-resistant bacteria. They could also help restore a healthy balance to microbial communities in the gut.“Phages are part of a vast interconnected network of organisms that live with us and on us, and when broad spectrum antibiotics are used to fight against infection, they also harm our natural microbiome,” says senior study author Matthew Sullivan. “We are building out a toolkit to scale our understanding and capabilities to use phages to tune disturbed microbiomes back toward a healthy state,” he adds.Using the new database, the researchers conducted the first survey of changes in the diversity of gut viruses across the human lifespan.They found that in Western individuals with a good health status, viral diversity was high in infants before the age of 3 years, before dropping in childhood. It then rose as people entered adulthood, before declining after 65 years of age.The authors attribute the rich diversity of viruses in infants’ guts to their weak, underdeveloped immune systems. Infants may also lack the bacteria that typically protect the lining of the gut from viral infection in later life.The researchers believe that their database will be an important tool for investigating how the gut virome changes over time and its effect on individuals’ vulnerability to particular diseases:“For example, here, we used the GVD database to uncover the age-dependent patterns of virome diversity in healthy, Western individuals. However, the GVD could also have much broader implications, including helping better classify individuals’ native gut microbiomes and viromes to determine how it affects a person’s predisposition to diseases like COVID-19.”– The study authorsInterestingly, the scientists discovered that people living in non-Western countries had more diverse gut viral populations than Westerners. Other research has shown that non-Westerners who move to Western countries lose some of their gut microbial diversity, which suggests that diet or other environmental factors may play a role in shaping the virome. In addition, the database revealed that individuals in good health had more diverse viral populations than those who were sick.“A general rule of thumb for ecology is that higher diversity leads to a healthier ecosystem,” says first author Ann Gregory, who worked on the new database while she was a graduate student at OSU. “We know that more diversity of viruses and microbes is usually associated with a healthier individual. And we saw that healthier individuals tend to have a higher diversity of viruses, indicating that these viruses may be potentially doing something positive and having a beneficial role.”The authors acknowledge that the GVD has some limitations in terms of its scope. For example, they write that its representation of different geographic regions and ethnic groups is not yet sufficiently broad.
Science & Health
Indian lunar orbiter hit by heat rise
From Harmeet Shah Singh CNN NEW DELHI, India (CNN) — Scientists have switched off several on-board instruments to halt rising temperatures inside India’s first unmanned lunar spacecraft. The spacecraft carrying India’s first lunar probe, Chandrayaan-1, lifts off from Sriharikota. Mylswamy Annadurai, the project director for the lunar mission, told CNN that temperatures onboard Chandrayaan-1 had…
From Harmeet Shah Singh
NEW DELHI, India (CNN) — Scientists have switched off several on-board instruments to halt rising temperatures inside India’s first unmanned lunar spacecraft.
The spacecraft carrying India’s first lunar probe, Chandrayaan-1, lifts off from Sriharikota.
Mylswamy Annadurai, the project director for the lunar mission, told CNN that temperatures onboard Chandrayaan-1 had risen to 49 degrees Celsius (120 degrees Fahrenheit).
The increase occurred as the craft, the moon — which it is orbiting — and the sun lined up, a phenomenon which Annadurai said was not unexpected and which would likely last until the end of December.
“We have switched off the systems (aboard) that are not needed to be on,” Annadurai said, ruling out the possibility of damage and adding that the temperature was now down to 40 degrees Celsius (104 degrees Fahrenheit).
Heat on board the Chandrayaan-1 should not exceed 50 degrees Celsius (122 degrees Fahrenheit), Annadurai said — but insisted the orbiter is designed to withstand up to 60 degrees Celsius (140 degrees Fahrenheit).
The Chandrayaan-1 — Chandrayaan means “moon craft” in Sanskrit — was successfully launched from southern India on October 22. Watch the launch of India’s first lunar mission »
Its two-year mission is to take high-resolution, three-dimensional images of the moon’s surface, especially the permanently shadowed polar regions. It also will search for evidence of water or ice and attempt to identify the chemical composition of certain lunar rocks, the group said.
Earlier this month the Moon Impact Probe detached from Chandrayaan-1 and successfully crash-landed on the moon’s surface.
Officials say that the TV-size probe, which is adorned with a painting of the Indian flag, hit the moon’s surface at a speed of 5,760 kilometers per hour (3,579 mph).
It transmitted data to Chandrayaan-1 ahead of impact but was not intended to be retrieved after that.
Chandrayaan-1 is carrying payloads from the United States, the European Union and Bulgaria. India plans to share the data from the mission with other programs, including NASA.
Science & Health
Shuttle lands at California air base
(CNN) — Space shuttle Endeavour landed safely Sunday afternoon at California’s Edwards Air Force Base after NASA waved off two opportunities for a Florida landing because of poor weather. Endeavour glides in for a landing Sunday at California’s Edwards Air Force Base. The shuttle, steered by commander Christopher Ferguson, landed at 1:25 p.m., ending a…
(CNN) — Space shuttle Endeavour landed safely Sunday afternoon at California’s Edwards Air Force Base after NASA waved off two opportunities for a Florida landing because of poor weather.
Endeavour glides in for a landing Sunday at California’s Edwards Air Force Base.
The shuttle, steered by commander Christopher Ferguson, landed at 1:25 p.m., ending a mission that lasted more than two weeks.
Wind, rain and reports of thunderstorms within 30 miles of the shuttle landing facility at Florida’s Kennedy Space Center prompted NASA to cancel the landing attempts there. Those had been scheduled for 1:19 p.m. and 2:54 p.m. ET.
After determining Monday’s weather forecast at Kennedy Space Center was equally unpromising, flight controllers decided they would try to land the shuttle and its seven astronauts at Edwards AFB, about 100 miles from Los Angeles, California, where Sunday’s forecast was sunny.
Flight controllers prefer landings at Kennedy Space Center because of cost and schedule. NASA has estimated it costs about $1.7 million to bring a shuttle home to Kennedy Space Center from California. Watch Endeavour’s Sunday landing in California »
It also takes at least a week to get the shuttle ready for the trip, but schedule is not a major factor for the Endeavour; it is not scheduled to fly again until May.
Endeavour‘s 15-day mission to the international space station began on November 14 and included four spacewalks.
During that time, the crew brought key pieces — including exercise equipment, more sleeping berths and a urine recycling system — for a project to double the capacity of the station from three in-house astronauts to six.
The recycling system was installed to turn urine and sweat from the astronauts into drinking water.
Other modules are scheduled to arrive on a February shuttle flight. The goal of expanding the station’s capacity to six astronauts is expected to be reached by the summer.
The crew also worked on a joint that helps generate power for the space station. Heidemarie Stefanyshyn-Piper and Steve Bowen spent hours cleaning and lubricating the Solar Alpha Rotary Joint, which is designed to allow the solar panels on the left side of the station to rotate and track the sun.
The astronauts also removed and replaced several trundle bearing assemblies.
The mission went according to plan, despite a minor interruption on the first spacewalk when a grease gun in Stefanyshyn-Piper tool’s bag leaked, coating everything inside with a film of lubricant. While she was trying to clean it up, the bag — with $100,000 in tools — floated away.
CNN’s Kate Tobin and Miles O’Brien contributed to this report.
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Science & Health
Inspiration for ‘Contact’ still listening
(CNN) — From a remote valley in Northern California, Jill Tarter is listening to the universe. Jill Tarter at the Allen Telescope Array in California, which monitors radio signals for signs of alien life. Her ears are 42 large and sophisticated radio telescopes, spread across several acres, that scan the cosmos for signals of extraterrestrial…
(CNN) — From a remote valley in Northern California, Jill Tarter is listening to the universe.
Jill Tarter at the Allen Telescope Array in California, which monitors radio signals for signs of alien life.
Her ears are 42 large and sophisticated radio telescopes, spread across several acres, that scan the cosmos for signals of extraterrestrial origin. If intelligent life forms do exist on other planets, and they try to contact us, Tarter will be among the first to know.
Are we citizens of Earth alone in the universe? It’s a question that has long fascinated astronomers, sci-fi authors, kids with backyard telescopes and Hollywood executives who churn out spectacles about alien encounters. Polls have found that most Americans believe that some form of life exists beyond our planet.
“It’s a fundamental question,” said Tarter, the real-life inspiration for Jodie Foster’s character in the 1997 movie “Contact.” “And it’s a question that the person on the street can understand. It’s not like a … super-collider or some search for neutrinos buried in the ice. It’s, ‘Are we alone? How might we find out? What does that tell us about ourselves and our place in the universe?’
“We’re trying to figure out how the universe began, how galaxies and large-scale structures formed, and where did the origins of life as we know it take place?” Tarter said.
“These are all valid questions to ask of the universe. And an equally valid question is whether the same thing that happened here [on Earth] has happened elsewhere.” Watch a preview of CNN’s “In Search of Aliens” series »
Thanks to advancements in technology, scientists hope to get an answer sooner rather than later. Rovers have snapped photographs of the surface of Mars that show fossil-like shapes. NASA hopes to launch within a decade a Terrestrial Planet Finder, an orbiting observatory that would detect planets around nearby stars and determine whether they could support life.
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Such developments are catnip to scientists like Geoffrey Marcy, a professor of astronomy at the University of California-Berkeley who has discovered more extrasolar planets than anyone else.
“It wasn’t more than 13 years ago that we hadn’t found any planets around the stars, and most people thought that we never would. So here we are not only having found planets, we are looking for habitable planets, signs of biology on those planets,” Marcy told CNN. “It’s an extraordinary explosion of a field of science that didn’t even exist just a few years ago.”
Then there’s Tarter, whose quest for signs of extraterrestrial life kept her on the fringes of mainstream science for decades. While pursuing her doctorate at UC-Berkeley, Tarter came across an engineering report that floated the idea of using radio telescopes to listen for broadcasts by alien beings.
It became her life’s work. In 1984 Tarter founded the Search for Extraterrestrial Intelligence Institute (SETI) in California. Using telescopes in Australia, West Virginia and Puerto Rico, she conducted a decade-long scouring of about 750 nearby star systems for extraterrestrial radio signals.
None was found, although Tarter had some false alarms. In 1998, she intercepted a mysterious signal that lasted for hours. Tarter got so excited she misread her own computer results: The signal was coming from a NASA observatory spacecraft orbiting the sun.
Today, Tarter listens to the heavens with the Allen Telescope Array, a collection of 20-foot-wide telescopes some 300 miles north of San Francisco. The dish-like scopes are a joint effort of SETI and UC-Berkeley’s Radio Astronomy Lab and have been funded largely by Microsoft co-founder Paul Allen, who donated more than $25 million to the project.
Unlike previously existing radio telescopes, which scan the sky for limited periods of time, the Allen Telescope Array probes the universe round the clock.
Each of the 42 scopes is aimed at a different area of the sky, collecting reams of data that are continually studied by computers for unusual patterns. Then the listeners must filter out noise from airplanes and satellites.
“We’re listening for something that we don’t think can be produced by Mother Nature,” Tarter said. “We’re using the radio frequency, other people are using optical telescopes … and in both cases we’re looking for an artificial nature to a signal.
“In the case of radio, we’re looking for a lot of power being squished into just one channel on the radio dial. In the optical, they’re looking for very bright flashes that last a nanosecond … or less, not slow pulsing kinds of things. To date we’ve never found a natural source that can do that.”
Signals that any extraterrestrials might be transmitting for their own use would be difficult to detect, Tarter said. Astronomers are more likely to discover a radio transmission broadcast intentionally at the Earth, she said.
Astronomers at SETI, however, are not sending a signal into space in an attempt to communicate with aliens.
University of California professor Marcy is skeptical about the existence of intelligent alien life and believes our galaxy’s vast distances would make communication between Earth and beings on other planets almost impossible.
“The nearest neighbor might be halfway across our galaxy, 50,000 light-years away. Communicating with them will take a hundred thousand years for a round-trip signal,” he said.
Still, Tarter remains undaunted. The Allen Telescope Array already does in 10 minutes what once took her scientists 10 days. When the project is completed, it will have 350 telescopes that, combined, can survey tens of thousands of star systems.
“We can look in more places and more frequencies faster than we ever could. And that will just get better with time. We’re doing something now we couldn’t do when we started, we couldn’t do five years ago,” she said.
“Think of it as a cosmic haystack. There’s a needle in there somewhere. If you pull out a few straws, are you going to get disappointed because you haven’t found the needle yet? No. We haven’t really begun to explore.”
CNN correspondent Miles O’Brien contributed to this story.
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