Carbon planets consisting of graphite, carbides and diamonds possibly hosted life in the early universe, according to a new study.Scientists suggest that searching a rare class of stars might help find these diamond worlds.
Our Earth consists of silicate rocks and an iron core with a thin veneer of water and life. But the first potentially habitable worlds to form might have been very different, researchers said.
"This work shows that even stars with a tiny fraction of the carbon in our solar system can host planets," said Natalie Mashian, graduate student at the Harvard University in the US.
"We have good reason to believe that alien life will be carbon-based, like life on Earth, so this also bodes well for the possibility of life in the early universe," she said.
The primordial universe consisted mostly of hydrogen and helium, and lacked chemical elements like carbon and oxygen necessary for life as we know it.
Only after the first stars exploded as supernovae and seeded the second generation did planet formation and life become possible.
Researchers examined a particular class of old stars known as carbon-enhanced metal-poor stars, or CEMP stars.
These anaemic stars contain only one hundred-thousandth as much iron as our Sun, meaning they formed before interstellar space had been widely seeded with heavy elements.
"These stars are fossils from the young universe," said Avi Loeb from the Harvard-Smithsonian Centre for Astrophysics.
"By studying them, we can look at how planets, and possibly life in the universe, got started," Loeb said.
Although lacking in iron and other heavy elements compared to our Sun, CEMP stars have more carbon than would be expected given their age.
This relative abundance would influence planet formation as fluffy carbon dust grains clump together to form tar-black worlds.
From a distance, these carbon planets would be difficult to tell apart from more Earth-like worlds. Their masses and physical sizes would be similar. Astronomers would have to examine their atmospheres for signs of their true nature.
Gases like carbon monoxide and methane would envelop these unusual worlds.
Researchers said that a dedicated search for planets around CEMP stars can be done using the transit technique.
"This is a practical method for finding out how early planets may have formed in the infant universe," said Loeb.
"We'll never know if they exist unless we look," said Mashian.
The study was published in the journal Monthly Notices of the Royal Astronomical Society.
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Arctic may become ice-free this year or next for the first time in more than 100,000 years, a leading Cambridge scientist has claimed.
According to the predictions of Professor Peter Wadhams of Cambridge University in the UK, we could see "an area of less than one million square kilometres for September of this year".
Provisional satellite data produced by the US National Snow and Ice Data Centre shows there were just over 11.1 million square kilometres of sea ice on June 1 this year, compared to the average of nearly 12.7 million square kilometres for the last 30 years, 'The Independent' reported.
"My prediction remains that the Arctic ice may well disappear, that is, have an area of less than one million square kilometres for September of this year," said Wadhams, head of the Polar Ocean Physics Group at Cambridge.
"Even if the ice does not completely disappear, it is very likely that this will be a record low year. I am convinced it will be less than 3.4 million square kilometres," he said.
"I think there is a reasonable chance it could get down to a million this year and if it does not do it this year, it will do it next year," Wadhams added.
The last time the Arctic was clear of ice is believed to be about 100,000 to 120,000 years ago.
Sea ice is usually at its lowest in September and starts to build again when the winter sets in.
Dr Peter Gleick, a leading climatologist, said he had "no idea" if Wadhams' prediction was correct.
Gleick, however, said that Wadhams was right to sound a warning about the rising temperatures in the region, adding it was "extraordinarily disturbing even in a world of disturbing news about accelerating climate change".
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Large animals hunted for their parts - such as elephant ivory and shark fins - are in double jeopardy of extinction due to their large body size and high value, according to a new study.
The study shows underappreciated risk to marine species similar to that of iconic terrestrial species, but elevated by key differences in the sea.
"We typically assume that if a species is reduced to low numbers, individuals will be hard to find, hunters will stop hunting, and populations will be given a chance to recover," said Loren McClenachan of Colby College in the US.
"But the extreme values of these species mean that without significant conservation intervention, they will be hunted to extinction," said McClenachan.
McClenachan, along with Andrew Cooper and Nicholas Dulvy from Simon Fraser University in Canada, identified a taxonomically diverse group of more than 100 large marine and terrestrial species that are targeted for international luxury markets.
They estimated the value of these species across three points of sale and explored the relationships among extinction risk, value and body size.
They also quantified the effects of two mitigating factors: poaching fines and geographic range size.
The analysis showed a threshold above which economic value is the key driver of extinction risk. Although lower-value species are influenced primarily by their biology, the most valuable species are at high risk of extinction no matter their size.
Once mean product values are greater than USD 12,557 per kilogramme, body size no longer drives risk, the report shows.
Researchers also uncovered important differences between marine and terrestrial species that point to elevated risk in the sea: although marine products are generally less valuable on a per kilogramme basis, individual animals are still just as valuable as the most valuable terrestrial species.
An individual whale shark, for example, is about as valuable as the most valuable terrestrial species: rhinoceroses and tigers.
"Hunters don't kill kilogrammes, they kill individuals, so we need to pay attention to these high values of individual animals," McClenachan said.
The risk to marine species is not reduced for species with larger ranges as it is on land, either.
"The assumption that large ranges protect species from extinction is based on conservation science done on land - where animals found in multiple countries have a higher chance of protection in at least one location - and appears not to apply to marine species, where widespread and little-policed hunting contrasts with tighter controls on land," McClenachan said.
The study points to the importance of considering trade of marine animals and differences between terrestrial and marine animals when it comes to conservation.
The study was published in the journal Current Biology.
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In a breakthrough towards mitigating climate change, scientists have discovered a quick and permanent method to remove human-produced carbon dioxide from the atmosphere - by turning it into harmless rock.
A new study has shown for the first time that the greenhouse gas carbon dioxide (CO2) can be permanently and rapidly locked away from the atmosphere, by injecting it into volcanic bedrock.
The CO2 reacts with the surrounding rock, forming environmentally benign minerals, researchers said.
Measures to tackle the problem of increasing greenhouse gas emissions and climate change are numerous. One approach is Carbon Capture and Storage (CCS), where CO2 is physically removed from the atmosphere and trapped underground.
Geoengineers have long explored the possibility of sealing CO2 gas in voids underground, such as in abandoned oil and gas reservoirs, but these are susceptible to leakage. So attention has now turned to the mineralisation of carbon to permanently dispose of CO2.
Until now it was thought that this process would take several hundreds to thousands of years and is therefore not a practical option.
The new study led by Columbia University, University of Iceland, University of Toulouse and Reykjavik Energy has demonstrated that it can take as little as two years.
"Our results show that between 95 and 98 per cent of the injected CO2 was mineralised over the period of less than two years, which is amazingly fast," said lead author Dr Juerg Matter, from University of Southampton in the UK.
The gas was injected into a deep well at the study site in Iceland. As a volcanic island, Iceland is made up of 90 per cent basalt, a rock rich in calcium, magnesium and iron that are required for carbon mineralisation.
The CO2 is dissolved in water and carried down the well. On contact with the target storage rocks, at 400-800 metres under the ground, the solution quickly reacts with the surrounding basaltic rock, forming carbonate minerals.
"Carbonate minerals do not leak out of the ground, thus our newly developed method results in permanent and environmentally friendly storage of CO2 emissions," said Matter.
"On the other hand, basalt is one of the most common rock type on Earth, potentially providing one of the largest CO2 storage capacity," Matter said.
To monitor what was happening underground, the team also injected 'tracers', chemical compounds that literally trace the transport path and reactivity of the CO2.
The researchers discovered that by the time the groundwater had migrated to the monitoring wells, the concentration of the tracers - and therefore the CO2 - had diminished, indicating that mineralisation had occurred.
"Storing CO2 as carbonate minerals significantly enhances storage security which should improve public acceptance of Carbon Capture and Storage as a climate change mitigation technology," Matter added.
The study was published in the journal Science.
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Indoor air in Delhi is not fit to breathe and the elderly and children who spend a lot of time in offices and homes are the worst sufferers, a survey has found.
As per the survey, conducted by Artemis Hospitals as part of Clean Air India Movement (CLAIM), there is a correlation between indoor air quality and lung health of the people.
Due to unhealthy indoor air quality, about 34 per cent of people have one or the other airway disease and 47 per cent showed symptoms of respiratory diseases.
Eighty-two per cent of offices and houses surveyed have unhealthy air quality, according to the survey.
"Generally, we give more importance to outdoor air quality but we should be aware of both outdoor and indoor air pollution. Considering the amount of time people spend breathing indoor air, it is important to keep a check on indoor air quality.
"We hope the survey results will help initiate and channelise the discussions on the issue and draw meaningful conclusions," said Dr Himanshu Garg, Head of the Department of Respiratory and Critical Care, Artemis Hospitals.
The survey was conducted on 1,500 people across Delhi, Gurgaon and Noida, having mean age of 39 years.
"Since we spend more time indoors, the risk associated with indoor air is more. Women and children are most vulnerable...," said Dr Raj Kumar, Head of the Department of Respiratory Allergy and Applied Immunology, Vallabhbhai Patel Chest Institute.
Founder of Clean Air India Movement Vijay Kannan said "we all should plant more trees to reduce pollution."
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The ancient underwater remains of a long lost Greek city were actually created by a naturally occurring phenomenon, and not man-made, a new study has found.
When underwater divers discovered what looked like paved floors, courtyards and colonnades, they thought they had found the ruins of a long-forgotten civilisation that perished when tidal waves hit the shores of the Greek holiday island Zakynthos.
But new research uncovered that the site was created by a natural geological phenomenon that took place in the Pliocene era -- up to five million years ago.
"The site was discovered by snorkelers and first thought to be an ancient city port, lost to the sea. There were what superficially looked like circular column bases, and paved floors. But mysteriously no other signs of life - such as pottery," said Julian Andrews from University of East Anglia (UEA) in the UK.
Researchers from UEA and University of Athens in Greece investigated in detail the mineral content and texture of the underwater formation in minute detail, using microscopy, X-ray and stable isotope techniques.
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"We investigated the site, which is between two and five metres under water, and found that it is actually a natural geologically occurring phenomenon," said Andrews.
"The disk and doughnut morphology, which looked a bit like circular column bases, is typical of mineralisation at hydrocarbon seeps - seen both in modern seafloor and palaeo settings," he said.
"We found that the linear distribution of these doughnut shaped concretions is likely the result of a sub-surface fault which has not fully ruptured the surface of the sea bed. The fault allowed gases, particularly methane, to escape from depth," he added.
Microbes in the sediment use the carbon in methane as fuel. Microbe-driven oxidation of the methane then changes the chemistry of the sediment forming a kind of natural cement, known to geologists as concretion, researchers said.
"In this case the cement was an unusual mineral called dolomite which rarely forms in seawater, but can be quite common in microbe-rich sediments," said Andrews.
"These concretions were then exhumed by erosion to be exposed on the seabed today. This kind of phenomenon is quite rare in shallow waters. Most similar discoveries tend to be many hundreds and often thousands of meters deep underwater," he said.
"These features are proof of natural methane seeping out of rock from hydrocarbon reservoirs. The same thing happens in the North Sea, and it is also similar to the effects of fracking, when humans essentially speed up or enhance the phenomena," he added. The findings were published in the journal Marine and Petroleum Geology.
Obese people who avoid undertaking a weight-loss surgery are at a greater risk of dying than those who take it, a new study suggests.
Christina Persson from University of Gothenburg in Sweden and colleagues studied 48,693 obese patient, aged 18-74 years.
Out of those patients, 22,581 underwent bariatric surgery (gastric bypass 92.8 per cent) while 26,112 obese patients did not undergo surgery.
The mortality rate was higher in the non-surgical group (4.21 per cent) compared to the surgical group (1.1 percent). This means there were 7.7 vs 2.1 deaths per 1000 people per year, researchers said.
Mean follow-up time for the surgical group was 5.4 years and 5.5 for the non-surgical group.
The overall mortality decreased by 57 per cent in the surgery group compared with the non-surgical group, researchers said.
The most common cause of death in the non-surgical group was cardiovascular disease, followed by cancer.
In the surgical obese patients, the most common cause of death was external causes of mortality (such as accidents and suicide), followed by cardiovascular disease and cancer, researchers said.
Although accidents and suicide were the main causes of death in the surgical group, the incidence of death from these causes was still lower than in the non-surgical group, they said.
"This population-based cohort observational study indicates that the overall all-cause mortality is considerably lower among obese individuals who undergo bariatric surgery compared to non-surgical obese individuals, and the differences lies mainly in cardiovascular disease and cancer," researchers said.
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A NASA astronaut will enter the first human-rated expandable module deployed in space to investigate the potential challenges and benefits of such habitats for deep space exploration and commercial low-Earth orbit applications.
Jeff Williams' entry on Monday will mark the beginning of a two-year data collection process.
He will take an air sample, place caps on the now closed ascent vent valves, install ducting to assist in Bigelow Expandable Activity Module (BEAM's) air circulation, retrieve deployment data sensors and manually open the tanks used for pressurisation to ensure all of the air has been released, a NASA statement said.
Jeff will then install sensors over the following two days that will be used for the project's primary task of gathering data on how an expandable habitat performs in the thermal environment of space, and how it reacts to radiation, micrometeoroids and orbital debris.
During BEAM's test period, the module typically will be closed off to the rest of the space station. Astronauts will enter the module three to four times each year to collect temperature, pressure and radiation data, and to assess its structural condition, NASA said.
After two years of monitoring, the current plan is to jettison the BEAM from the space station to burn up on re-entry into Earth's atmosphere.
Expandable habitats are designed to take up less room when being launched but provide greater volume for living and working in space once expanded, NASA said.
This first test of an expandable module will allow scientists to gauge how well the habitat performs and specifically, how well it protects against solar radiation, space debris and the temperature extremes of space.
Launched on April 8 aboard a SpaceX Dragon cargo spacecraft from Cape Canaveral Air Force Station in Florida, the BEAM was attached to the International Space Station's Tranquility module about a week later, NASA said.
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A long lost British Second World War submarine that vanished 73 years ago has been found with 71 dead bodies of crew off the coast of Italy.
The 1,290 tonne vessel was found by a diving team at a depth of 100 metres, close to the island of Tavolara, off the northeast coast of Sardinia.
The submarine vanished without a trace around Janaury 2, 1943 and is believed was hit by a mine in the Gulf of Olbia.
"Immediately I thought of the destiny of the men who met their deaths down there. It was a fate shared by so many men, submariners in particular, fighting on all both sides of the conflict," diving team leader Massimo Domenico Bordone told Italian media.
The submarine had left Malta on December 28, 1942 for its first mission to destroy two Italian battleships when they lay anchor at the port of La Maddalena.
But after sending a signal on December 31 the vessel disappeared without a trace. Military officials assumed the submarine had been sunk, 'Daily Express' reported.
The wreck was found in excellent condition with only a small amount of damage from the explosion.
"It looks like she probably went down with air sealed inside, meaning the crew eventually died of oxygen deprivation. It's important to have the utmost respect for wrecks in cases like this," Bordone said.
The Royal Navy said it expects the wreck to be treated with respect while they work to confirm the identity of the submarine.
"We are examining our records to determine whether or not this is a Royal Navy submarine," a Royal Navy spokesperson said.
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Scientists, including zMM one of Indian-origin, have discovered a new way of triggering cell death, a finding that may lead to drugs for treating cancer and autoimmune diseases.
Programmed cell death, also called apoptosis, is a natural process that removes unwanted cells from the body. Failure of apoptosis can allow cancer cells to grow unchecked or immune cells to inappropriately attack the body.
The protein known as Bak is central to apoptosis. In healthy cells Bak sits in an inert state but when a cell receives a signal to die, Bak transforms into a killer protein that destroys the cell.
Researchers from Walter and Eliza Hall Institute of Medical Research in Australia and colleagues have discovered a novel way of directly activating Bak to trigger cell death.
The researchers, including Sweta Iyer, discovered that an antibody they had produced to study Bak actually bound to the Bak protein and triggered its activation.
"We were excited when we realised we had found an entirely new way of activating Bak," said Ruth Kluck, from the Walter and Eliza Hall Institute. She hopes to use this discovery to develop drugs that promote cell death.
"There is great interest in developing drugs that trigger Bak activation to treat diseases such as cancer where apoptosis has gone awry," she said.
"This discovery gives us a new starting point for developing therapies that directly activate Bak and cause cell death," she said.
The researchers used information about Bak's 3D structure to find out precisely how the antibody activated Bak.
"It is well known that Bak can be activated by a class of proteins called 'BH3-only proteins' that bind to a groove on Bak. We were surprised to find that despite our antibody binding to a completely different site on Bak, it could still trigger activation," Kluck said.
Drugs that target this new activation site could be useful in combination with other therapies that promote cell death by mimicking the BH3-only proteins.
"The advantage of our antibody is that it can't be 'mopped up' and neutralised by pro-survival proteins in the cell, potentially reducing the chance of drug resistance occurring," Kluck said.
The researchers are now working with collaborators to develop their antibody into a drug that can access Bak inside cells.
The findings were published in the journal Nature Communications.
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