Engineers have developed a prototype drone that dives like a gannet and launches like a flying fish, to collect water samples.
Gannets are the largest seabirds in the north Atlantic and hunt fish by diving from height into the sea at up to 60 miles per hour. Flying fish can make powerful, self-propelled leaps out of the water and into the sky, where their wing-like fins help them to glide over considerable distances.
The team from Imperial College London have taken inspiration from these behaviours in their prototype AquaMAV robot. The AquaMAV is designed to collect samples in situations such as monitoring water quality in reservoirs and measuring changes in ocean salinity to gauge the effects of climate change.
By examining the diving qualities of gannets and the leaping behaviour of flying fish, we can make an aerial drone that needs less on board control, making it more robust and more affordable to manufacture.
– Rob Siddall
Department of Aeronautics
Currently, researchers generally have to use boats to manually collect water samples. AquaMAV is designed to be rapid, efficient, and more cost effective than this method. It can also carry out tests in dangerous situations such as in disaster zones or from locations currently inaccessible to people, such as deep under the ocean.
One of the current drawbacks for small scale flying robots is that they generally lack sufficient power to make the transition from water to the air. The team in today’s study say they have potentially overcome this problem with their drone by mimicking the way flying fish make ‘impulsive’ leaps from the water.
The AquaMAV uses carbon dioxide, which is stored internally, to propel itself out of the water. In the air, retractable wings are deployed to help it glide, much in the same way that fins help flying fish.
The drone only weighs 200 grams and can currently achieve speeds of around 30 miles per hour from a starting point beneath the water. It can make the aerial leap even if conditions on the surface are rough. The researchers say AquaMAV can currently fly around five kilometres to and from an analysis. The team say the aerial range would enable those analysing the samples to be at a safe distance away from a potentially hazardous situation.
The research, part funded by the Engineering and Physical Sciences Research Council, is published in the journal Interface Focus.
Dr Mirko Kovac, the director of the Aerial Robotics Lab in Imperial’s Department of Aeronautics, said: “During an emergency scenario such as a major oil leak an AquaMav could fly and dive into isolated patch of water, where it could collect samples or loiter and record environmental data. The vehicle could then perform a short take-off and return to its launch site to submit samples for analysis. This would enable a fast, targeted response that could not be matched by the current methods.”
Previous studies have, for example, demonstrated the effectiveness of water sampling using drones that have large multi-rotational propellers. This approach is more complex, relying on very accurate sensing and control systems to maintain the drone in the air while sample probes are carefully lowered into the water to collect specimens.
The team say the advantage of their small, fixed-wing AquaMAV is that it can travel faster and over longer distances compared to hovering vehicles. The plunge diving approach, which mimics how the gannet dives, reduces the need for highly accurate control. This means that the AquaMAV would be more cost effective to manufacture because it needs less gadgetry, and more could be bought and deployed, to give a more in-depth analysis.
Rob Siddall, lead author and postgraduate from Imperial’s Department of Aeronautics, added: “We are really excited by our AquaMAV prototype. We believe we may have overcome the power density problem which makes launching out of the water so challenging for small drones. Nature often has an elegant way of solving engineering challenges. By examining the diving qualities of gannets and the leaping behaviour of flying fish, we can make an aerial drone that needs less on board control, making it more robust and more affordable to manufacture.”
The researchers are currently looking to collaborate with oceanographers and various water authorities to take their testing to the next stage. The aim is to deploy the robot in a wide variety of scenarios, to test the robot’s limits in waves, wind and weather, and examine the physics of high speed dives into water. An additional propulsion system is also under development to make the AquaMAV fully aquatic, capable of long periods of submarine operation.
A former constituent college of the federal University of London, it became fully independent on 9 July 2007, as part of the celebrations of its centenary. It is regarded as being one of the most prestigious universities in the world.
Imperial’s main campus is located in the South Kensington (Albertopolis) area of Central London, with additional campuses in Chelsea, Hammersmith, Paddington and Silwood Park. It has one of the largest estates of any higher education institution in the UK. Imperial is organised into four main faculties within which there are over 40 departments, institutes and research centres. Imperial has around 13,500 students and 3,330 academic and research staff and had a total income of £765 million in 2011/12, of which £314 million was from research grants and contracts.
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Technology could aid in elimination of malaria and treatment of many other diseases.
Researchers at MIT and Brigham and Women’s Hospital have developed a new drug capsule that remains in the stomach for up to two weeks after being swallowed, gradually releasing its drug payload. This type of drug delivery could replace inconvenient regimens that require repeated doses, which would help to overcome one of the major obstacles to treating and potentially eliminating diseases such as malaria.
In a study described in the Nov. 16 issue of Science Translational Medicine, the researchers used this approach to deliver a drug called ivermectin, which they believe could aid in malaria elimination efforts. However, this approach could be applicable to many other diseases, says Robert Langer, the David H. Koch Institute Professor at MIT and a member of MIT’s Koch Institute for Integrative Cancer Research.
“Until now, oral drugs would almost never last for more than a day,” Langer says. “This really opens the door to ultra-long-lasting oral systems, which could have an effect on all kinds of diseases, such as Alzheimer’s or mental health disorders. There are a lot of exciting things this could someday enable.”
Langer and Giovanni Traverso, a research affiliate at the Koch Institute and a gastroenterologist and biomedical engineer at Brigham and Women’s Hospital, are the senior authors of the paper. The paper’s lead authors are former MIT postdoc Andrew Bellinger, MIT postdoc Mousa Jafari, and former MIT postdocs Tyler Grant and Shiyi Zhang. The team also includes researchers from Harvard University, Imperial College London, and the Institute for Disease Modeling in Bellevue, Washington.
The research has led to the launching of Lyndra, a Cambridge-based company that is developing the technology with a focus on diseases for which patients would benefit the most from sustained drug delivery, including neuropsychiatric disorders, HIV, diabetes, and epilepsy.
Drugs taken orally tend to work for a limited time because they pass rapidly through the body and are exposed to harsh environments in the stomach and intestines. Langer’s lab has been working for several years to overcome this challenge, with an initial focus on malaria and ivermectin, which kills any mosquito that bites a person who is taking the drug. This can greatly reduce the transmission of malaria and other mosquito-borne illnesses.
The team envisions that long-term delivery of ivermectin could help with malaria elimination campaigns based on mass drug administration — the treatment of an entire population, whether infected or not, in an area where a disease is common. In this scenario, ivermectin would be paired with the antimalaria drug artemisinin.
“Getting patients to take medicine day after day after day is really challenging,” says Bellinger, now a cardiologist at Brigham and Women’s Hospital and chief scientific officer at Lyndra. “If the medicine could be effective for a long period of time, you could radically improve the efficacy of your mass drug administration campaigns.”
To achieve ultra-long-term delivery, drugs need to be packaged in a capsule that is stable enough to survive the harsh environment of the stomach and can release its contents over time. Once the drug is released, the capsule must break down and pass safely through the digestive tract.
Working with those criteria in mind, the team designed a star-shaped structure with six arms that can be folded inward and encased in a smooth capsule. Drug molecules are loaded into the arms, which are made of a rigid polymer called polycaprolactone. Each arm is attached to a rubber-like core by a linker that is designed to eventually break down.
After the capsule is swallowed, acid in the stomach dissolves the outer layer of the capsule, allowing the six arms to unfold. Once the star expands, it is large enough to stay in the stomach and resist the forces that would normally push an object further down the digestive tract. However, it is not large enough to cause any harmful blockage of the digestive tract.
“When the star opens up inside the stomach, it stays inside the stomach for the duration that you need,” says Grant, now a product development engineer at Lyndra.
In tests in pigs, the researchers confirmed that the drug is gradually released over two weeks. The linkers that join the arms to the core then dissolve, allowing the arms to break off. The pieces are small enough that they can pass harmlessly through the digestive tract.
“This is a platform into which you can incorporate any drug,” Jafari says. “This can be used with any drug that requires frequent dosing. We can replace that dosing with a single administration.”
This type of delivery could also help doctors to run better clinical trials by making it easier for patients to take the drugs, Zhang says. “It may help doctors and the pharma industry to better evaluate the efficacy of certain drugs, because currently a lot of patients in clinical trials have serious medication adherence problems that will mislead the clinical studies,” he says.
The new study includes mathematical modeling done by researchers at Imperial College London and the Institute for Disease Modeling to predict the potential impact of this approach. The models suggest that if this technology were used to deliver ivermectin along with antimalaria treatments to 70 percent of a population in a mass drug administration campaign, disease transmission could be reduced the same amount as if 90 percent were treated with antimalaria treatments alone.
“What we showed is that we stand to significantly amplify the effect of those campaigns,” Traverso says. “The introduction of this kind of system could have a substantial impact on the fight against malaria and transform clinical care in general by ensuring patients receive their medication.”
Peter Agre, director of the Johns Hopkins Malaria Research Institute, who was not involved in the research, described the new approach as a “remarkable” advance that could improve treatment of malaria and any other disease that requires long-term treatment.
“If you could reduce the frequency of dosing, and one treatment would continue to release medicine until the course is completed, that would be very beneficial,” Agre says.
Researchers led by Traverso are working on developing similar capsules to deliver drugs against other tropical diseases, as well as HIV and tuberculosis.
Learn more: New capsule achieves long-term drug delivery
Researchers from the Wellcome Trust Sanger Institute and Imperial College London have developed Microreact, a free, real-time epidemic visualisation and tracking platform that has been used to monitor outbreaks of Ebola, Zika and antibiotic-resistant microbes.
The team have collaborated with the Microbiology Society to allow any researcher around the world to share their latest information about disease outbreaks. Details of the platform are published in the journal Microbial Genomicstoday (30 November).
Until now, disease data and geographic information about the movement of an infection or disease as it evolves and spreads has been locked up in databases that are often out of people’s reach. Researchers have been left to rely on published information in research papers, which may be many months out of date, containing static visuals which show only a small part of the whole disease or infection threat.
Microreact is a cloud-based system that combines the power of open data and the web, to provide real-time global data sharing and visualisation, allowing anyone to explore and examine outbreak information with unprecedented speed and detail. This is becoming increasingly important in the race to monitor and control fast-developing outbreaks like Ebola or Zika, or the growing threat of anti-microbial resistance.
Microreact allows data and metadata sets to be uploaded via a web browser, which can then be visualised, shared and published in a research paper via a permanent web link. The partnership with Microbial Genomics allows the journal to make data from prospective publications available through Microreact. This promotes open availability and access while also starting to build a unique resource for global health professionals and scientists.
“Until now, the global research community has been hamstrung because results are generally only shared in static pictures or tables in publications. Microreact allows everyone to explore the information dynamically – across both time and space – letting them see the whole picture. Using Microreact takes disease tracking out the hands of a privileged few and gives it to everyone who wants to understand disease evolution.”
Dr David Aanensen, Director of the Centre for Genomic Pathogen Surveillance (a joint initiative between Imperial College London and the Sanger Institute) and one of Microreact’s creators
One example of how Microreact can democratise genomic data and resulting insights is the work of Dr Kathryn Holt and Professor Gordon Dougan. They have recently published two papers on the global distribution of typhoid bacteria around the world, showing the epidemic spread of a multidrug resistant strain. But they also published their data to Microreact to help others build on their work.
“We gathered together data from almost 2000 samples Salmonella Typhi bacteria collected by 74 collaborators in 63 countries. By comparing the different strains and mapping them to when and where they were ‘caught’ we were able to show that a new drug-resistant strain emerged in Asia and has spread across that continent and into Africa. We have put all this information on Microreact and now anyone can see exactly what we saw – both scientists and those public health professionals tasked with controlling such outbreaks.”
Dr Kathryn Holt, from the University of Melbourne
By putting this information on Microreact, the researchers have ensured that the data continues to live on – allowing others to learn from their work and to use the information as a basis of comparison or foundation for future work. Microreact also allows individual researchers to share information globally and in real-time – crowdsourcing new discoveries and insights that could have immediate impact.
“We are delighted that our open-access, open-data journal Microbial Genomics is partnering with Microreact. All Microreact projects that appear in Microbial Genomics papers will be highlighted on the journal’s website to increase the discoverability and accessibility of researchers’ datasets.”
Leighton Chipperfield, Director of Publishing at the Microbiology Society
A naturally occurring predatory bacterium can work with the immune system to clear multi-drug resistant Shigella infections in zebrafish.
It is the first time the predatory bacterium Bdellovibrio bacteriovorus has been successfully used as an injected anti-bacterial therapy and represents an important step in the fight against drug-resistant infections, or ‘superbugs’.
Shigella infection is responsible for over 160 million illnesses and over 1 million deaths every year – and is a common cause of ‘travellers’ diarrhoea.’ Cases of drug-resistant Shigella are also on the rise as, although the diarrhoea usually clears up without treatment, antibiotics are often used even in mild cases to stop the diarrhoea faster. Resistance to antibiotics has prompted a team of researchers from Imperial College London and Nottingham University to look to the natural environment for creative solutions to this problem.
‘PREDATORY ACTION’ – ABOUT THE STUDY
To investigate Bdellovibrio’s ability to control drug resistant Gram-negative infections, researchers injected zebrafish larvae with a lethal dose of Shigella flexneri strain M90T which is resistant to both streptomycin and carbenicillin antibiotics. Bdellovibrio was then injected into the larvae’s infection site, and a decrease in the number of Shigella was seen. In the absence of Bdellovibrio, zebrafish were unable to control the replication of Shigella and levels of the bacteria rose.
Co-lead author Dr Serge Mostowy from the Department of Medicine at from Imperial College London said: “This study really shows what a unique and interesting bacterium Bdellovibrio is as it presents this amazing natural synergy with the immune system and persists just long enough to kill prey bacteria before being naturally cleared. It’s an important milestone in research into the use of a living antibiotic that could be used in animals and humans.”
Bdellovibrio can invade and kill a range of Gram-negative bacteria, such as E. coli and Salmonella, in the natural environment. Previous research has shown that it can reduce pathogen numbers in the stomach of chickens when taken as an oral therapy, but there is growing need to develop therapies to target infections in wounds and organs. Successful use of Bdellovibrio highlights its potential uses in tackling a range of drug-resistant Gram-negative bacterial infections that can develop in hospital patients.
The urgent requirement for new antimicrobials calls for increasingly creative solutions
– Dr Alex Willis
Co-lead author from Imperial’s Department of Medicine
Dr Mostowy and co-lead author Dr Alex Willis from the Department of Medicine at Imperial said: “The urgent requirement for new antimicrobials calls for increasingly creative solutions. The zebrafish has been a fantastic model for us to generate rapid understanding of how a living antibiotic can work in an animal. Our findings here provide the basis for testing Bdellovibrio in higher vertebrates and ultimately, humans.
“The translucent zebrafish facilitates powerful microscopy that enables striking understanding more difficult to achieve using other animal models. Being able to visualise the infection as well as the predatory bacteria and host immune cells has been invaluable in helping us understand how Bdellovibrio can function in an animal.”
Professor Liz Sockett, co-lead author from The University of Nottingham said: “This has been a truly ground-breaking collaboration that shows therapeutic Bdellovibrio in action inside the translucent living zebrafish. The predatory action of the Bdellovibrio breaks the Shigella-pathogen cells and this stimulates the white blood cells; redoubling their ‘efforts’ against the pathogen and leading to increased survival of the zebrafish ‘patients’.”
Remarkably, Bdellovibrio is also able to reduce pathogen load in immunocompromised zebrafish larvae that have been depleted of white blood cells. However, survival is significantly greater in immune-competent zebrafish, showing that Bdellovibrio’s maximum therapeutic benefit comes from its ability to work cooperatively with the host’s own immune system.
Dr Michael Chew, Science Portfolio Advisor at Wellcome said: “It may be unusual to use a bacterium to get rid of another, but in the light of the looming threat from drug resistant infections the potential of beneficial bacteria-animal interactions should not be overlooked. We are increasingly relying on last line antibiotics, and this innovative study demonstrates how predatory bacteria could be an important additional tool to drugs in the fight against resistance.”
Thousands of new immune system signals have been uncovered with potential implications for immunotherapy, autoimmune diseases and vaccine development.
The researchers behind the finding say it is the biological equivalent of discovering a new continent.
It’s as if a geographer would tell you they had discovered a new continent, or an astronomer would say they had found a new planet in the solar system. And just as with those discoveries, we have a lot of exploring to do.
– Professor Michael Stumpf
Our cells regularly break down proteins from our own bodies and from foreign bodies, such as viruses and bacteria. Small fragments of these proteins, called epitopes, are displayed on the surface of the cells like little flags so that the immune system can scan them. If they are recognised as foreign, the immune system will destroy the cell to prevent the spread of infection.
In a new study, researchers have discovered that around one third of all the epitopes displayed for scanning by the immune system are a type known as ‘spliced’ epitopes.
These spliced epitopes were thought to be rare, but the scientists have now identified thousands of them by developing a new method that allowed them to map the surface of cells and identify a myriad of previously unknown epitopes.
The findings should help scientists to better understand the immune system, including autoimmune diseases, as well as provide potential new targets for immunotherapy and vaccine design.
The research was led by Dr Juliane Liepe from Imperial College London and Dr Michele Mishto from Charité – Universitätsmedizin Berlin in Germany in collaboration with the LaJolla Institute for Allergy and Immunology and Utrecht University, and it is published today in Science.
Co-author of the study Professor Michael Stumpf from the Department of Life Sciences at Imperial said: “It’s as if a geographer would tell you they had discovered a new continent, or an astronomer would say they had found a new planet in the solar system.
“And just as with those discoveries, we have a lot of exploring to do. This could lead to not only a deeper understanding of how the immune system operates, but also suggests new avenues for therapies and drug and vaccine development.”
Prior to the new study, scientists thought that the machinery in a cell created signalling peptides by cutting fragments out of proteins in sequence, and displaying these in order on the surface of the cell.
However, this cell machinery can also create ‘spliced’ peptides by cutting two fragments from different positions in the protein and then sticking them together out of order, creating a new sequence.
Scientists knew about the existence of the spliced epitopes, but they were thought to be rare. The new study suggests that spliced epitopes actually make up a large proportion of signalling epitopes: they make up around a quarter of the overall number of epitopes, and account for 30-40 per cent of the diversity – the number of different kinds of epitopes.
PROS AND CONS
These extra epitopes give the immune system more to scan, and more possibilities of detecting disease. However, as the spliced epitopes are mixed sequences, they also have the potential to overlap with the sequences of healthy signallers and be misidentified as harmful.
This could help scientists understand autoimmune diseases, where the immune system turns against normal body tissues, such as in Type 1 diabetes and multiple sclerosis.
The study’s lead author, Dr Juliane Liepe from the Department of Life Sciences at Imperial, said: “The discovery of the importance of spliced peptides could present pros and cons when researching the immune system.
“For example, the discovery could influence new immunotherapies and vaccines by providing new target epitopes for boosting the immune system, but it also means we need to screen for many more epitopes when designing personalised medicine approaches.”
Novel study identifies an area of the mosquito brain that mixes taste and smell
A new study by Johns Hopkins researchers suggests that a specialized area of the mosquito brain mixes tastes with smells to create unique and preferred flavors. The findings advance the possibility, they say, of identifying a substance that makes “human flavor” repulsive to the malaria-bearing species of the mosquitoes, so instead of feasting on us, they keep the disease to themselves, potentially saving an estimated 450,000 lives a year worldwide.
A report on the research appeared online on Oct. 3 in the journal Nature Communications. Malaria is an infectious parasite disease of humans and animals transmitted by the bite of the female Anopheles gambiaemosquito. In 2015, experts estimate it affected 214 million people, mostly in Africa, despite decades of mosquito eradication and control efforts. There is no malaria vaccine, and although the disease is curable in early stages, treatment is costly and difficult to deliver in places where it is endemic.
“All mosquitoes, including the one that transmits malaria, use their sense of smell to find a host for a blood meal. Our goal is to let the mosquitoes tell us what smells they find repulsive and use those to keep them from biting us,” says Christopher Potter, Ph.D., assistant professor of neuroscience at the Johns Hopkins University School of Medicine.
Because smell is essential to mosquito survival, each mosquito has three pairs of “noses” for sensing odors: two antennae, two maxillary palps and two labella. The maxillary palps are thick, fuzzy appendages that protrude from the lower region of the mosquito’s head, more or less parallel to its proboscis, the long, flexible sheath that keeps its “feeding needle” under wraps until needed. At the very tip of the proboscis are the labella, two small regions that contain both “gustatory” neurons that pick up tastes and olfactory neurons for recognizing odorants.
To better understand how An. gambiae mosquitoes that cause malaria receive and process olfactory information from so many sensory regions, Potter’s team wanted to see where olfactory neurons from those regions go to in the brain.
They used a powerful genetic technique — never before accomplished in mosquitoes, according to Potter — to make certain neurons “glow” green. The green glowing label was designed to appear specifically in neurons that receive complex odors through proteins called odorant receptors (ORs), since OR neurons are known to help distinguish humans from other warm-blooded animals in Aedes aegypti mosquitoes, which carry the Zika virus.
“This is the first time researchers managed to specifically target sensory neurons in mosquitoes. Previously, we had to use flies as a proxy for all insects, but now we can directly study the sense of smell in the insects that spread malaria,” says Olena Riabinina, Ph.D., the lead author of the study and a postdoctoral fellow now at the Imperial College London. “We were pleasantly surprised by how well our genetic technique worked and how easy it is now to see the smell-detecting neurons. The ease of identification will definitely simplify our task of studying these neurons in the future.”
As expected, Potter says, the OR neurons from the antennae and maxillary palps went to symmetrical areas of the brain called antennal lobes, just as they do in flies. But Potter was quite surprised when he saw that the OR neurons from the labella went to the so-called subesophageal zone, which, he says, had never before been associated with the sense of smell in any fly or insect; it had only been associated with the sense of taste.
“That finding suggests that perhaps mosquitoes don’t just like our smell, but also our flavor,” says Potter. “It’s likely that the odorants coming off our skin are picked up by the labella and influence the preferred taste of our skin, especially when the mosquito is looking for a place to bite.”
Potter says the finding potentially offers researchers one more way to repel mosquitoes. The antennae and maxillary palps are more specialized for picking up long-range signals, while the labella come into direct contact with our skin. In fact, Potter says, before injecting their needlelike proboscis, mosquitoes use the labella to probe about on a victim’s skin. “We don’t really know why they do that, but we suspect that they’re looking for sensory cues that hint at easy access to a blood vessel,” he says. “This suggests that a combination of repellants could keep mosquitoes from biting us in two ways. One could target the antennal neurons and reduce the likelihood that they come too close, while another could target the labellar neurons and make the mosquitoes turn away in disgust — before sucking our blood — if they got close enough to land on us.”
The two-part genetic system Potter devised to generate the glowing neurons will make it much easier for his and other laboratories to mix and match genetically altered mosquitoes to generate new traits, he says. His group has already created a strain of An. gambiaemosquitoes whose OR neurons glow green upon activation. Scientists can thus see which neurons light up in response to a specific smell.
“Using this method, we hope to find an odorant that is safe and pleasant-smelling for us but strongly repellant to mosquitoes at very low concentrations,” says Potter.
His group was also able to compare the brains of male and female mosquitoes. Since only females use their sense of smell to find humans and males feed only on nectar, it was previously thought that males had just a rudimentary sense of smell. The Potter group found instead that males have the same level of complexity in their brains to detect odors as females but have fewer olfactory neurons. “It appears that males might just have a scaled-down version of a female’s sense of smell. So they can still smell everything a female smells, just not as well,” Potter says.
His group plans to study other types of neurons to better understand how signals from the mosquitoes’ three types of olfactory receptors interact to influence their behavior. For example, why is lactic acid not attractive on its own but highly attractive when mixed with carbon dioxide?
“We’d like to figure out what regions and neurons in the brain lead to this combined effect,” says Potter. “If we can identify them, perhaps we could also stop them from working.”
Researchers have created an interactive web tool to estimate the amount of energy that could be generated by wind or solar farms at any location.
The tool, called Renewables.ninja, aims to make the task of predicting renewable output easier for both academics and industry.
The creators, from Imperial College London and ETH Zürich, have already used it to estimate current Europe-wide solar and wind output, and companies such as the German electrical supplier RWE are using it to test their own models of output.
To test the model, Dr Iain Staffell, from the Centre for Environmental Policy at Imperial, and Dr Stefan Pfenninger, who is now at ETH Zürich, have used Renewables.ninja to estimate the productivity of all wind farms planned or under construction in Europe for the next 20 years. Their results are published today in the journal Energy.
We built our models so they can be easily used by other researchers online, allowing them to answer their questions faster, and hopefully to start asking new ones.
– Dr Iain Staffell
They found that wind farms in Europe current have an average ‘capacity factor’ of around 24 per cent, which means they produce around a quarter of the energy that they could if the wind blew solidly all day every day.
This number is a factor of how much wind is available to each turbine. The study found that because new farms are being built using taller turbines placed further out to sea, where wind speeds are higher, the average capacity factor for Europe should rise by nearly a third to around 31 percent.
This would allow three times as much energy to be produced by wind power in Europe compared to today, not only because there are more farms, but because those farms can take advantage of better wind conditions.
SUPER SUNNY DAYS
In another research paper also published today in Energy, the pair modelled the hourly output of solar panels across Europe. They found that even though Britain is not the sunniest country, on the best summer days solar power now produces more energy than nuclear power. However, the pattern of this solar output through the year substantially changes how the rest of the power system will have to operate.
Wind and solar energies have a strong dependence on weather conditions, and these can be difficult to integrate into national power systems that requires consistency. If there is excess power generated by all energy sources, then some supplies have to be turned off.
Currently, wind and solar power generators are the easiest to switch on and off, so they are often the first to go, meaning the power they generate can be wasted.
Making use of a larger capacity for solar energy generation relies on changes to the national energy system, such as adding new types of electricity storage or small and flexible generators to balance the variable output from solar panels.
MAKING MODELS FASTER
Renewables.ninja uses 30 years of observed and modelled weather data from organisations such as NASA to predict the wind speed likely to influence turbines and the sunlight likely to strike solar panels at any point on the Earth during the year.
Renewables.ninja has already allowed us to answer important questions about the current and future renewable energy infrastructure across Europe and in the UK, and we hope others will use it to further examine the opportunities and challenges for renewables in the future.
– Dr Stefan Pfenninger
These figures are combined with manufacturer’s specifications for wind turbines and solar panels to give an estimate of the power output that could be generated by a farm placed at any location.
Dr Staffell said he spent two years crunching the data for his own research and thought that creating this tool would make it quicker for others to answer important questions: “Modelling wind and solar power is very difficult because they depend on complex weather systems. Getting data, building a model and checking that it works well takes a lot of time and effort.
“If every researcher has to create their own model when they start to investigate a question about renewable energy, a lot of time is wasted. So we built our models so they can be easily used by other researchers online, allowing them to answer their questions faster, and hopefully to start asking new ones.”
He and Dr Pfenninger have been beta testing Renewables.ninja for six months and now have users from 54 institutions across 22 countries, including the European Commission and the International Energy Agency.
Dr Pfenninger said: “Renewables.ninja has already allowed us to answer important questions about the current and future renewable energy infrastructure across Europe and in the UK, and we hope others will use it to further examine the opportunities and challenges for renewables in the future.”
Most molecular biologists look at how to switch on and regulate single genes. Scientists at the MRC Clinical Sciences Centre (CSC) have gone further, and have explored how to reawaken an entire set of inactive genes, a chromosome, that is present in every female human cell.
This reactivation happens when a ‘normal’ cell is turned back into a stem cell. The CSC team are the first to identify the earliest changes in this process. Understanding exactly how it happens could eventually help researchers to direct it, and produce stem cells tailored for use in therapies.
Stem cells found in early development have the ability to become any one of the many types of cell that make up our bodies. Differentiation into these cell types involves a series of “decisions” by the cell until it has only one role, for example being a skin cell. Scientists are interested in reversing these “decisions” to turn specialised cells back into their stem cell state. The goal is to be able to produce a pool of stem cells, which could then be directed to develop into any type of cell, and used to replace damaged or diseased tissue.
As a cell commits to a particular role, changes are made to its DNA so that genes no longer needed for that role can be retired from use. When scientists reverse this process, using a technique called ‘reprogramming’, these changes need to be undone so that the genes can be turned back on. The CSC team is the first to have identified the very earliest events that occur when ‘retired’ genes on the X chromosome are turned back on. The findings are published today in Nature Communications.
The DNA strands in each cell are organised into clusters, which are the chromosomes. There are two special chromosomes, called X and Y, which carry the information that determines sex. Every cell has two of these special chromosomes. Males have one X and one Y, while females have two Xs. Female cells only need one X, and using both would mean that an extra set of genes would be active. To avoid this, one chromosome gets randomly turned off in favour of the other. The CSC researchers explored how to turn the inactive X chromosome back on.
When the cell “chooses” an X chromosome to be turned off, it marks it with specific molecules. Some of these molecules bind to the DNA, which is wrapped up into a large coil, whilst others bind to proteins on the coil. These marks determine whether genes are turned on or not. They are called ‘epigenetic’ marks and are passed on to each cell’s “daughters” as it divides.
To reprogram a specialised cell back into a stem cell, scientists need to remove the epigenetic marks. If some of these marks remain, the stem cell will retain a tendency to make “decisions” that may lead it to become the same type of cell that it used to be. This limits its ability to become any type of cell in the body, and so limits its potential use in medical treatments.
“We don’t know exactly how to erase the previous memory, and this is extremely important if we want to use these cells again for therapy,” says Irene Cantone, of the CSC’s Lymphocyte Development group, and who helped to lead the research. The CSC team developed a technique that allowed them to watch what happened to an inactive X chromosome when it was woken up and readied for action. The technique involves fusing together a human female skin cell, which contains an inactive X chromosome, with a stem cell from a mouse embryo.
Fusing the cells together reprograms the skin cell towards a stem cell state. This happens because the mouse stem cell, unlike the human skin cell, contains all of the biological factors needed to reprogram a specialised cell. These factors invade the control centre, or nucleus, of the human cell and begin to adjust the epigenetic marks, allowing genes that had been retired to start afresh. The researchers constructed a timeline of these epigenetic changes. “I now have a better idea of what is needed for these genes to be reactivated,” says Cantone.
A pivotal moment is when the two nuclei fuse together. By observing the changes that take place before and after the nuclei fuse, scientists can begin to work out which cellular mechanisms play a role in reprogramming the cell and reactivating the dormant X chromosome.
Cantone and colleagues have shown that two molecules, called XIST (X-inactive specific transcript) and H3K27me3, play a key role in events before the nuclei fuse. The normal role of these molecules in a skin cell is to help silence the inactive X chromosome. They coat the DNA to prevent the cellular machinery from accessing certain genes, and in doing so turn them off. The researchers showed that when the skin cell begins to be reprogrammed, these markers are lost or move away from the chromosome before genes are turned back on.
Not all genes on the silent X chromosome are woken up during this process. “What we found is that only some genes are re-activated, and many stay silent. We now need to know what is the basis of this difference. Why are some sensitive, and others not?” says Amanda Fisher, also of the CSC’s Lymphocyte Development group, and a lead scientist on the study.
If scientists can understand how to reverse the biological process of gene silencing that exists inside cells, they may one day be able to produce stem cells suitable to replace damaged and diseased tissue.
The results also have relevance to diseases linked to the X chromosome, such as Duchenne muscular dystrophy, red-green colour blindness and Rett syndrome. “If we can understand how to reactivate specific genes on an inactive chromosome and in certain cells, this could lead to improved treatments in the future,” says Cantone.
Learn more: Reawakening a sleeping giant
New research suggests that it is possible to create a new form of light by binding light to a single electron, combining the properties of both.
According to the scientists behind the study, from Imperial College London, the coupled light and electron would have properties that could lead to circuits that work with packages of light – photons – instead of electrons.
The results of this research will have a huge impact on the way we conceive light.
– Dr Vincenzo Giannini
It would also allow researchers to study quantum physical phenomena, which govern particles smaller than atoms, on a visible scale.
In normal materials, light interacts with a whole host of electrons present on the surface and within the material. But by using theoretical physics to model the behaviour of light and a recently-discovered class of materials known as topological insulators, Imperial researchers have found that it could interact with just one electron on the surface.
This would create a coupling that merges some of the properties of the light and the electron. Normally, light travels in a straight line, but when bound to the electron it would instead follow its path, tracing the surface of the material.
In the study, published today in Nature Communications, Dr Vincenzo Giannini and colleagues modelled this interaction around a nanoparticle – a small sphere below 0.00000001 metres in diameter – made of a topological insulator.
Their models showed that as well as the light taking the property of the electron and circulating the particle, the electron would also take on some of the properties of the light.
Normally, as electrons are travelling along materials, such as electrical circuits, they will stop when faced with a defect. However, Dr Giannini’s team discovered that even if there were imperfections in the surface of the nanoparticle, the electron would still be able to travel onwards with the aid of the light.
If this could be adapted into photonic circuits, they would be more robust and less vulnerable to disruption and physical imperfections.
Dr Giannini said: “The results of this research will have a huge impact on the way we conceive light. Topological insulators were only discovered in the last decade, but are already providing us with new phenomena to study and new ways to explore important concepts in physics.”
Dr Giannini added that it should be possible to observe the phenomena he has modelled in experiments using current technology, and the team is working with experimental physicists to make this a reality.
He believes that the process that leads to the creation of this new form of light could be scaled up so that the phenomena could observed much more easily.
Currently, quantum phenomena can only be seen when looking at very small objects or objects that have been super-cooled, but this could allow scientists to study these kinds of behaviour at room temperature.