New research into polar ice has shown that bacteria can survive deeper into ice sheets, raising the possibility of life in our solar systems' distant, icy planets.
For the first time, scientists have discovered living bacteria in polar ice and snow – an environment once considered sterile – altering perceptions about which planets in the universe could sustain alien life. The research also shows that humans may be having an even greater impact on levels of carbon dioxide (CO2) in Earth’s atmosphere than accepted evidence from climate history studies of ice cores suggests.
Gases captured and sealed in snow as it compresses into ice can provide researchers with snapshots of Earth’s atmosphere going back hundreds of thousands of years. Climate scientists use ice core samples to look at prehistoric levels of CO2 in the atmosphere so they can be compared with current levels in an industrial age. This analysis of ice cores relies on the assumption that there is limited biological activity altering the environment in the snow during its transition into ice.
The research, published in the Journal of the Royal Society Interface, revealed that the composition of small samples of gas trapped in the ice may have been affected by bacteria that remain active in snow while it is being compressed into ice – a process that can last decades. “As microbial activity and its influence on its local environment has never been taken into account when looking at ice-core gas samples it could provide a moderate source of error in climate history interpretations,” said Kelly Redeker from the University of York in the UK.
“Respiration by bacteria may have slightly increased levels of CO2 in pockets of air trapped within polar ice caps meaning that before human activity CO2 levels may have been even lower than previously thought,” said Redeker. “In addition, the fact that we have observed metabolically active bacteria in the most pristine ice and snow is a sign of life proliferating in environments where you wouldn’t expect it to exist,” he said.
“This suggests we may be able to broaden our horizons when it comes to thinking about which planets are capable of sustaining life,” he added. Research conducted in laboratories has previously shown that bacteria can stay alive at extremely cold temperatures, but this study is the first time that bacteria have been observed altering the polar snow environment in situ.
The researchers looked at snow in is natural state, and in other areas they sterilised it using UV sterilising lamps. When they compared the results the team found unexpected levels of methyl iodide – a gas known to be produced by marine bacteria – in the untouched snow. Researchers also detected the presence of gases at part-per-trillion levels, one million times less concentrated than atmospheric CO2 concentrations.
The results of the study also suggest that life can be sustained even in remote, cold, nutrient poor environments, offering a new perspective on whether the frozen planets of the universe could support microorganisms.
Courtesy - Indian Express
In a finding that could lead to better fuel cells and clean energy technologies, scientists have discovered that squeezing a platinum catalyst a fraction of a nanometre nearly doubles its activity.
A nanosize squeeze can significantly boost the performance of platinum catalysts that help generate energy in fuel cells, according to scientists at Stanford University in the US.
The team bonded a platinum catalyst to a thin material that expands and contracts as electrons move in and out, and found that squeezing the platinum a fraction of a nanometre nearly doubled its catalytic activity.
"In this study, we present a new way to fine-tune metal catalysts at the atomic scale," said Haotian Wang, a former graduate student at Stanford now at Harvard University.
"We found that ordinary battery materials can be used to control the activity of platinum and possibly for many other metal catalysts," said Wang.
The new technique can be applied to a wide range of clean technologies, Wang said, including fuel cells that use platinum catalysts to generate energy, and platinum electrolyzers that split water into oxygen and hydrogen fuel.
"Our tuning technique could make fuel cells more energy efficient and increase their power output," said Yi Cui, a professor of materials science and engineering at Stanford.
"It could also improve the hydrogen-generation efficiency of water splitters and enhance the production of other fuels and chemicals," said Cui.
Catalysts are used to make chemical reactions go faster while consuming less energy. The performance of a metal catalyst depends on its electronic structure - that is, how the electrons orbiting individual atoms are arranged.
The study focused on lithium cobalt oxide, a material widely used in batteries for cellphones and other electronic devices. The researchers stacked several layers of lithium cobalt oxide together to form a battery-like electrode.
"Applying electricity removes lithium ions from the electrode, causing it to expand by 0.01 nanometre. When lithium is reinserted during the discharge phase, the electrode contracts to its original size," Cui said.
For the experiment, the team added several layers of platinum to the lithium cobalt oxide electrode.
"Because platinum is bonded to the edge, it expands with the rest of the electrode when electricity is added and contracts during discharge," Cui said.
Separating the platinum layers a distance of 0.01 nanometre, or five per cent, had a significant impact on performance, Wang said.
"We found that compression makes platinum much more active. We observed a 90 per cent enhancement in the ability of platinum to reduce oxygen in water. This could improve the efficiency of hydrogen fuel cells," he said. The findings were published in the journal Science.
Courtesy – Deccan Herald
Scientists have developed a new nanoscale device which could be used to power artificial systems that can mimic the human brain.
The device called a memristor may find applications in pervasive sensing technologies to fuel real-time monitoring in harsh or inaccessible environments; a highly desirable capability for enabling the Internet of Things vision, researchers said.
Artificial neural networks (ANNs) exhibit learning abilities and can perform tasks which are difficult for conventional computing systems, such as pattern recognition, on-line learning and classification.
Practical ANN implementations are currently hampered by the lack of efficient hardware synapses; a key component that every ANN requires in large numbers.
Researchers from University of Southampton in the UK experimentally demonstrated an ANN that used memristor synapses supporting sophisticated learning rules in order to carry out reversible learning of noisy input data.
Memristors are electrical components that limit or regulate the flow of electrical current in a circuit and can remember the amount of charge that was flowing through it and retain the data, even when the power is turned off.
"If we want to build artificial systems that can mimic the brain in function and power we need to use hundreds of billions, perhaps even trillions of artificial synapses, many of which must be able to implement learning rules of varying degrees of complexity," said lead author Dr Alex Serb, from Southampton.
"Whilst currently available electronic components can certainly be pieced together to create such synapses, the required power and area efficiency benchmarks will be extremely difficult to meet without designing new and bespoke 'synapse components'," said Serb.
"Memristors offer a possible route towards that end by supporting many fundamental features of learning synapses in extremely compact volumes and at exceptionally low energy costs. If artificial brains are ever going to become reality, therefore, memristive synapses have to succeed," Serb said.
Acting like synapses in the brain, the metal-oxide memristor array was capable of learning and re-learning input patterns in an unsupervised manner within a probabilistic winner-take-all (WTA) network.
This is useful for enabling low-power embedded processors (needed for the Internet of Things) that can process in real-time big data without any prior knowledge of the data.
"Our work establishes such a technological paradigm shift, proving that nanoscale memristors can indeed be used to formulate in-silico neural circuits for processing big-data in real-time; a key challenge of modern society," said Themis Prodromakis from Southampton.
"We have shown that such hardware platforms can independently adapt to its environment without any human intervention and are very resilient in processing even noisy data in real-time reliably," said Prodromakis. The research was published in the journal Nature Communications.
Courtesy – Deccan Herald
The US space agency launched its first mission to collect dust from an asteroid, the kind of cosmic body that may have delivered life-giving materials to Earth billions of years ago.
The unmanned spacecraft, known as OSIRIS-REx, blasted off at 7:05 pm (local time) atop an Atlas V rocket in Cape Canaveral, Florida.
The USD 800 million mission will travel for two years on a journey to Bennu, a near-Earth asteroid about the size of a small mountain.
Bennu was chosen from the some 500,000 asteroids in the solar system because it orbits close to Earth's path around the sun, it is the right size for scientific study, and it is one of the oldest asteroids known to NASA.
"For primitive, carbon-rich asteroids like Bennu, materials are preserved from over four and a half billion years ago," explained Christina Richey, OSIRIS-REx deputy program scientist at NASA.
These "may be the precursors to life in Earth or elsewhere in our solar system." OSIRIS-REx's main goal is to gather dirt and debris from the surface of the asteroid and return it to Earth by 2023 for further study.
Learning more about the origins of life and the beginning of the solar system are key objectives for the SUV-sized OSIRIS-REx, which stands for Origins, Spectral Interpretation, Resource Identification and Security-Regolith Explorer.
The mission should also shed light on how to find precious resources such as water and metals in asteroids, a field that has generated increasing interest worldwide.
"We are going to map this brand-new world that we have never seen before," said Dante Lauretta, OSIRIS-REx principal investigator and professor at the University of Arizona, Tucson.
Using a suite of cameras, lasers and spectrometers, "we are really going to understand the distribution of materials across the surface of that asteroid," he added.
"We are a trailblazer for that kind of activity because our science requires it." The spacecraft is expected to reach Bennu in August 2018 and spend two years studying it before it begins the sample collection attempt in July 2020.
NASA hopes the solar-powered OSIRIS-REx will bring back the largest payload of space samples since the Apollo era of the 1960s and 1970s, when American explorers collected and carried back to Earth some 800 pounds (360 kilogrammes) of moon rocks.
The collection device, known as the Touch-and-Go Sample Acquisition Mechanism (TAGSAM), should pick up about two ounces (60 grams) from the asteroid, but in tests so far it has generally picked up five times that amount.
TAGSAM contains a type of reverse-vacuum mechanism that was invented by a Lockheed Martin engineer who tested the concept a decade ago using a red plastic Solo cup in his driveway.
Courtesy – Deccan Herald
Scientists have developed a novel four-dimensional lung scanning technology that has the potential to transform treatment for millions of people with lung disease around the world.
The platform developed at Monash University in Australia by Professor Andreas Fouras has been commercialised by his medical technology company 4Dx.
Dr Rajeev Samarage, joint lead author from Monash's Laboratory for Dynamic Imaging said the technology would potentially help millions of people.
"With this technology, not only will clinicians have a clearer image of what is happening in the patient's lungs, but it is our aim to detect changes in lung function much earlier than in the past, which will allow clinicians to quantify the effects of treatment by simply comparing measurements from one scan to the next," said Samarage.
Fouras said the 4Dx pre-clinical scanner generates high-resolution images of lung-tissue motion and airflow throughout the lungs, which allows investigators to view and measure abnormal function in specific areas of the lung, before a disease progresses and spreads.
"Current tools are out of date and require two or three pieces of diagnostic information to piece together what is happening in someone's lungs.
"Our game-changing diagnostic tool offers images of the breathing lungs, making it possible to see what is really important - not what they look like - but how they work," Fouras said.
Professor Greg Snell, Head of Lung Transplant Service at the Alfred hospital in Melbourne said it was a significant step.
"This technology has great potential as a new tool for both early diagnosis and management of many very common lung conditions. I think this will be the start of a new way of thinking about diagnostic imaging," said Snell. The study was published in the journal Scientific Reports.
Courtesy – Deccan Herald
In a bid to validate concepts for the future manned journey to Mars, NASA has approved the Asteroid Redirect Mission (ARM) to proceed to the next phase of design and development for the mission's robotic segment.
ARM is a two-part mission that will integrate robotic and crewed spacecraft operations in the proving ground of deep space to demonstrate key capabilities needed for NASA's journey to the red planet.
The robotic component of ARM will demonstrate the world's most advanced and most efficient solar electric propulsion system as it travels to a near-Earth asteroid (NEA).
NEAs are asteroids that are fewer than 194 million km from the Sun at the closest point in their orbit.
Although the target asteroid is not expected to be officially selected until 2020, NASA is using 2008 EV5 as the reference asteroid while the search continues for potential alternatives.
A target asteroid such as 2008 EV5 is particularly appealing to the scientific, exploration, and industrial communities because it is a primitive, C-type (carbonaceous) asteroid, believed to be rich in volatiles, water and organic compounds, NASA said.
The ability to extract core samples from the captured boulder will allow us to evaluate how its composition varies with depth and could unlock clues to the origins of our solar system.
Astronaut sampling and potential commercial activities could indicate the value of C-type asteroids for commercial mining purposes, which in turn could have significant impacts on how deep space missions are designed in the future.
After collecting a multi-tonne boulder from the asteroid, the robotic spacecraft will slowly redirect the boulder to an orbit around the Moon, using its gravity for an assist, where NASA plans to conduct a series of proving ground missions in the 2020s.
There, astronauts will be able to select, extract, collect and return samples from the multi-tonne asteroid mass, and conduct other human-robotic and spacecraft operations in the proving ground that will validate concepts for NASA's journey to Mars.
The crewed segment, targeted for launch in 2026, remains in an early mission concept phase, or pre-formulation.
ARM will demonstrate advanced, high-power, high-throughput solar electric propulsion; advanced autonomous high-speed proximity operations at a low-gravity planetary body; controlled touchdown and liftoff with a multi-tonne mass from a low-gravity planetary body.
It will also demonstrate astronaut spacewalk activities for sample selection, extraction, containment and return; and mission operations of integrated robotic and crewed vehicle stack - all key components of future in-space operations for human missions to Mars.
Courtesy – Deccan Herald
'Wonder material' graphene may be ideal for developing plasmonic lasers, or spasers, that are capable of detecting even single molecule of explosive materials and toxic chemicals, a new study has found.
A spaser is a device similar to a laser and operating on the same basic principle.
However, to produce radiation the particles emitted are surface plasmons, as opposed to photons produced by a laser.
"The graphene spaser could be used to design compact spectral measurement devices capable of detecting even a single molecule of a substance, which is essential for many potential applications," said Alexander Dorofeenko, from Moscow Institute of Physics and Technology (MIPT).
"Such sensors could detect organic molecules based on their characteristic vibrational transitions ('fingerprints'), as the light emitted/absorbed falls into the medium infrared region, which is exactly where the graphene-based spaser operates," said Dorofeenko.
Scientists have long been fascinated by the potential applications of a quasiparticle called the plasmon, a quantum of plasma oscillations.
In the case of a solid body, plasmons are the oscillations of free electrons.
Of special interest are the effects arising from the surface interactions of electromagnetic waves with plasmons - usually in the context of metals or semimetals, as they have a higher free electron density.
Harnessing these effects could bring about a breakthrough in high-accuracy electronics and optics. One possibility opened up by plasmonic effects is the subwavelength light focusing, which increases the sensitivity of plasmonic devices to a point where they can distinguish a single molecule.
Such measurements are beyond what any conventional (classical) optical devices can achieve.
However, plasmons in metals tend to lose energy quickly due to resistance, and for this reason they are not self-sustained, ie they need continuous excitation.
Scientists are trying to tackle this issue by using composite materials with predefined microstructure, including graphene.
Although, plasmonic devices have seemed an exciting prospect to pursue from the start, to take advantage of them, it was first necessary to find out whether the technology behind them was feasible.
To do this, scientists had to find a numerical solution to the relevant quantum-mechanical equations.
Researcher formulated and solved the necessary equation which led them to develop a quantum model that predicts plasmonic behaviour in graphene.
As a result, the scientists described the operation of a surface-plasmon-emitting diode (SPED) and the nanoplasmonic counterpart of the laser - known as the spaser - whose construction involves a graphene layer.The research was published in the journal Physical Review B.
Courtesy – Deccan Herald
British scientists say they have developed a pioneering new treatment to prevent bacterial skin infections, which could also be used in the battle against 'superbugs' such as MRSA.
The new treatment, developed by researchers at the University of Sheffield and funded by Age UK is a new way to prevent skin wounds, such as bed-sores and ulcers, becoming infected.
This treatment has been proven to work on antibiotic-resistant bacteria, such as Methicillin-resistant Staphylococcus aureus (MRSA), which is currently one of the biggest threats to global healthcare and medicine.
Bacterial skin infections are a major problem for older people and people with chronic health conditions, such as diabetes.
Infected wounds heal more slowly, causing pain and distress for the patient, and are a significant cost to the NHS in the UK.
To launch an infection, bacteria attach tightly to skin cells and have learned to hijack 'sticky patches' on human cells to achieve this.
Using proteins called tetraspanins, from human cells, the Sheffield scientists have made these patches much less sticky, allowing bacteria to be harmlessly washed away.
The research has shown that these proteins prevent bacterial infections in a model of human skin, which the scientists say give a clear indication that this treatment is both safe and effective.
This treatment was trialled on a model of 3D tissue engineered skin (TEskin) developed by engineers at the University.
The engineered skin, pioneered by Professor Sheila MacNeil from the University's Department of Materials Science and Engineering, can model infected wounds in human skin and mimics the tissue structure of normal adult skin.
It can be used to analyse the penetration of peptides and bacteria.
Pete Monk from the University's Department of Infection, Immunity and Cardiovascular Science, who led the study, said: "This development is a huge breakthrough in the fight against antibiotic-resistance. Skin infections, such as bed-sores and ulcers, can be incredibly troubling for patients who may already be dealing with other debilitating conditions. They are also a significant problem for modern healthcare".
"We hope that this new therapy can be used to help relieve the burden of skin infections on both patients and health services while also providing a new insight into how we might defeat the threat of antimicrobial drug resistance".
"The therapy could be administered to patients using a gel or cream and could work well as a dressing. We're hoping it can reach clinical trials stage in the next three to five years," Monk said.
Courtesy – Deccan Herald
NASA is launching an airborne mission that will map the contours of the Earth's atmosphere to discover how much pollution exists in the most remote corners of the planet and assess how the environment has changed as a result.
Pollutants emitted to the atmosphere - soot, hydrocarbons, nitrogen oxides - are dispersed over the whole globe, but remote regions are cleaner, by factors of 1000 or more, than areas near the continents, researchers said.
The Atmospheric Tomography (ATom) mission is the first to survey the atmosphere over the oceans. Scientists aboard NASA's DC-8 flying laboratory will journey from the North Pole south over the Pacific Ocean to New Zealand and then across to the tip of South America and north up the Atlantic Ocean to Greenland.
"We've had many airborne measurements of the atmosphere over land, where most pollutants are emitted, but land is only a small fraction of the planet," said Michael Prather, an atmospheric scientist and ATom's deputy project scientist at University of California Irvine.
"The oceans are where a lot of chemical reactions take place, and some of the least well understood parts are hard to get to because they are so remote," Prather said.
"With ATom we're going to measure a wide range of chemically distinct parts of the atmosphere over the most remote areas of the ocean that have not been measured before," he said.
While the majority of the flight path takes the DC-8 over the ocean, the science team expects to see influence from human pollution that originates on land.
"Humans produce a lot of pollution, and it doesn't just disappear when it's blown off the continents. It goes somewhere," said atmospheric scientist Steve Wofsy, ATom principal investigator at Harvard University.
"We know it gets diluted in the atmosphere, it gets washed out by rain, but we want to understand the processes that do that and where and how long they take," Wofsy said.
The suite of 20 instruments aboard the DC-8 will measure airborne particles called aerosols and more than 200 gases in each sampled air patch, documenting their locations and allowing scientists to determine interactions.
The team will use ATom's collected data on the air's chemical signatures to understand where pollutants originate, and where and how quickly these climate gases react chemically and eventually disappear from the atmosphere.
ATom is particularly interested in methane, ozone and airborne particles called black carbon, which have strong effects on climate and which all have both human and natural origins.
ATom's first flight is planned for July 28, a round trip over the tropics between Palmdale, California and the equator.
On July 31, the mission begins its around-the-world trip lasting 26 days. It is the first of four deployments that will take place over the next three years in different seasons.
Courtesy – Deccan Herald
Scientists have found a new genetic scoring technique that may predict a student's academic achievement from DNA alone and help identify children who are at risk of having learning difficulties.
The technique is the strongest prediction of behaviour from DNA to date, researchers said.
The research shows that a genetic score comprising 20,000 DNA variants explains almost 10 per cent of the differences between children's educational attainment at the age of 16.
The findings from King's College London mark a 'tipping point' in predicting academic achievement and may help identify children who are at greater risk of having learning difficulties.
Twin studies can tell us the overall genetic influence on a trait in a population. Polygenic scores, however, estimate genetic influence from common variants only, which explains the discrepancy between these DNA-based studies and twin studies (10 per cent vs 60 per cent).
As human traits are so complex and influenced by thousands of gene variants of very small effect, it is useful to consider the joint effects of all of these trait-associated variants - and this principle underlies the polygenic score method.
Calculating an individual's polygenic score requires information from a genome-wide association study (GWAS) that finds specific genetic variants linked to particular traits, in this case academic achievement.
Some of these genetic variants, known as single nucleotide polymorphisms (SNPs), are more strongly associated with the trait, and some are less strongly associated.
In a polygenic score, the effects of these SNPs are weighed by the strength of association and then summed to a score, so that people with many SNPs related to academic achievement will have a higher polygenic score and higher academic achievement, whereas people with fewer associated SNPs will have a lower score and lower levels of academic achievement.
The new research examined almost 10 million SNPs and identified 74 genetic variants that were significantly associated with years of completed education.
'Years of education' was used as a proxy measure for education achievement and related traits.
Researchers measured academic achievement in Mathematics and English at ages 7, 12 and 16, in a sample of 5,825 individuals from the Twins Early Development Study (TEDS).
Their findings show that what makes students achieve differently in their educational achievement is strongly affected by DNA differences.
On average those with a higher polygenic score would obtain a grade between A and B, while those with lower score obtained an entire grade below at age 16.
About 65 per cent of people in the higher polygenic group went on to do A-levels, whereas only 35 per cent from the lower group did so.
The findings appear in the journal Molecular Psychiatry.
Courtesy – Deccan Herald