Astronomers detect 15 high-frequency ‘fast radio bursts’ from distant galaxy
Were these powerful bursts used by an extraterrestrial civilization to power exploratory spacecraft?
August 30, 2017
Green Bank Telescope in West Virginia (credit: Geremia/CC)
Using the Green Bank radio telescope, astronomers at Breakthrough Listen, a $100 million initiative to find signs of intelligent life in the universe, have detected 15 brief but powerful “fast radio bursts” (FRBs). These microwave radio pulses are from a mysterious source known as FRB 121102* in a dwarf galaxy about 3 billion light years from Earth, transmitting at record high frequencies (4 to 8 GHz), according to the researchers
This sequence of 14 of the 15 detected fast radio bursts illustrates their dispersed spectrum and extreme variability. The streaks across the colored energy plot are the bursts appearing at different times and different energies because of dispersion caused by 3 billion years of travel through intergalactic space. In the top frequency spectrum, the dispersion has been removed to show the 300 microsecond pulse spike. (credit: Berkeley SETI Research Center)
Andrew Siemion, director of the Berkeley SETI Research Center and of the Breakthrough Listen program, and his team alerted the astronomical community to the high-frequency activity via an Astronomer’s Telegram on Monday evening, Aug. 28.
A schematic illustration of CSIRO’s Parkes radio telescope in Australia receiving a fast radio burst signal in 2014 (credit: Swinburne Astronomy Productions)
First detected in 2007, fast radio bursts are brief, bright pulses of radio emission detected from distant but largely unknown sources.
Breakthrough Starshot’s plan to use powerful laser pulses to propel nano-spacecraft to Proxima Centauri (credit: Breakthrough Initiatives)
* FRB 121102 was discovered Nov 2, 2014 (hence its name) with the Arecibo radio telescope, and in 2015 it was the first fast radio burst seen to repeat. More than 150 high-energy bursts have been observed so far. (The repetition ruled out the possibility that FRBs were caused by catastrophic events.)
FRB 121102: Detection at 4 – 8 GHz band with Breakthrough Listen backend at Green Bank
On Saturday, August 26 at 13:51:44 UTC we initiated observations of the well-known repeating fast radio burst FRB 121102 [Spitler et al., Nature, 531, 7593 202-205, 2016] using the Breakthrough Listen Digital Backend with the C-band receiver at the Green Bank Telescope. We recorded baseband voltage data across 5.4375 GHz of bandwidth, completely covering the C-band receiver’s nominal 4-8 GHz band [MacMahon et al. arXiv:1707.06024v2]. Observations were conducted over ten 30-minute scans, as detailed in Table 1. Immediately after observations, the baseband data were reduced to form high time resolution (300 us integration) Stokes-I products using a GPU-accelerated spectroscopy suite. These reduced products were searched for dispersed pulses consistent with the known dispersion measure of FRB 121102 (557 pc cm^-3); baseband voltage data were preserved. We detected 15 bursts above our detection threshold of 10 sigma in the first two 30-minute scans, denoted 11A-L and 12A-B in Table 2. In Table 2, we include the detection signal-to-noise ratio (SNR) of each burst, along with a very rough estimate of pulse energy density assuming a 12 Jy system equivalent flux density, 300 us pulse width, and uniform 3800 MHz bandwidth. We note the following phenomenological properties of the detected bursts: 1. Bursts show marked changes in spectral extent, with characteristic spectral structure in the 100 MHz – 1 GHz range. 2. Several bursts appear to peak in brightness at frequencies above 6 GHz.
This autonomous MIT robot can follow rules of pedestrians
Filed on August 31, 2017 | Last updated on August 31, 2017 at 07.25 pm
Engineers at MIT have designed an autonomous robot with ‘socially aware navigation,’ that can keep pace with foot traffic while observing these general codes of pedestrian conduct. Engineers at MIT have designed an autonomous robot with ‘socially aware navigation,’ that can keep pace with foot traffic while observing these general codes of pedestrian conduct.
Engineers at Massachusetts Institute of Technology (MIT) have designed an autonomous robot that can keep pace with foot traffic while observing the general social codes that pedestrians follow to avoid oncoming obstacles while keeping up a steady walking pace.
In drive tests, the robot, which resembles a knee-high kiosk on wheels, successfully avoided collisions while keeping up with the average flow of pedestrians, said the researchers who have detailed their robotic design in a paper scheduled to be presented at the IEEE Conference on Intelligent Robots and Systems to be held in Vancouver, Canada, in September.
“Socially aware navigation is a central capability for mobile robots operating in environments that require frequent interactions with pedestrians,” said lead author of the study Yu Fan (Steven) Chen.
“For instance, small robots could operate on sidewalks for package and food delivery. Similarly, personal mobility devices could transport people in large, crowded spaces, such as shopping malls, airports, and hospitals,” Chen said.
In order for a robot to make its way autonomously through a heavily trafficked environment, it must solve four main challenges – localisation (knowing where it is in the world), perception (recognising its surroundings), motion planning (identifying the optimal path to a given destination), and control (physically executing its desired path).
Chen and his colleagues used standard approaches to solve the problems of localisation and perception.
For the latter, they outfitted the robot with off-the-shelf sensors, such as webcams, a depth sensor, and a high-resolution lidar sensor.
For the problem of localisation, they used open-source algorithms to map the robot’s environment and determine its position. To control the robot, they employed standard methods used to drive autonomous ground vehicles.
For motion planning, the researchers used reinforcement learning, a type of machine learning approach, in which they performed computer simulations to train a robot to take certain paths, given the speed and trajectory of other objects in the environment.
The team also incorporated social norms into this offline training phase, in which they encouraged the robot in simulations to pass on the right, and penalised the robot when it passed on the left.
“We want it to be travelling naturally among people and not be intrusive,” study co-author Michael Everett said.
“We want it to be following the same rules as everyone else,” Everett added.
Reducing carbohydrates, not fat, should be focus of dietary guidelines, study says
A McMaster University study found a higher-fat diet was actually associated with a lower risk of early death.
By SHERYL UBELACKERThe Canadian Press
Tues., Aug. 29, 2017
A large Canadian study is challenging conventional wisdom that says a low-fat diet is optimal for cardiovascular health and reduces the risk of premature death.
The McMaster University study of more than 135,000 people in 18 countries found that eating a moderate amount of all types of fat is linked to a reduced risk of early mortality compared to the much-touted low-fat diet — while consuming a high-carbohydrate diet is associated with an increased risk of dying early.
“Contrary to popular belief, increased consumption of dietary fats is associated with a lower risk of death,” said lead author Mahshid Dehghan, a nutrition epidemiologist at the Hamilton university’s Population Health and Research Institute.
“Those with a high fat intake, about 30 per cent of energy intake, had a 23 per cent lower risk of mortality and an 18 per cent lower risk of stroke, compared to the low-intake group, which had 11 per cent energy from fat,” Dehghan said from Barcelona, where she presented the findings Tuesday to the European Society of Cardiology Congress.
“The association with lower mortality was also seen with all major types of fat, by which I mean saturated, monounsaturated and polyunsaturated fatty acids.”
Saturated fat is found in meat and dairy products, while monounsaturated fat is contained in nuts, avocados, and vegetable and olive oils. Polyunsaturated fat is found in walnuts, sunflower and flax seeds, fish, corn, soybean and safflower oils.
Current global guidelines recommend that 50 to 65 per cent of daily calories come from carbohydrates, and less than 10 per cent from saturated fats. But Dehghan said that advice is mostly based on evidence from studies in North America and Europe.
Cardiovascular disease is a global epidemic, with 80 per cent of the burden of disease in low- and middle-income countries. Diet is a key modifiable risk factor for cardiovascular disease, experts say.
Dehghan said the healthiest diet would be made up of 50 to 55 per cent carbohydrates and 35 per cent total fat, including both saturated and unsaturated types.
“We found no evidence that below 10 per cent of energy from saturated fat is beneficial — and going below 7 per cent is even harmful,” she said, adding that a diet containing 10 per cent to 13 per cent of energy from saturated fat was found to be beneficial.
A diet that provides more than 60 per cent of energy from carbohydrates — one common among populations in China and South Asia — was associated with a 28 per cent higher risk of premature death, researchers found.
“The message of our study is moderation as opposed to very low or very high intake in consumption of both fats and carbohydrates.”
“We’re not advocating an extreme diet,” agreed co-author Andrew Mente. “We’re not saying that people should go on a low-carb, very high-fat diet because we didn’t find any benefit with a very low-carb diet either.
“There’s a sweet spot for carbohydrates, which is about 55 per cent of energy intake.”
The PURE (Prospective Urban Rural Epidemiology) study was published Tuesday in The Lancet. In a linked commentary in the journal, Drs. Christopher Ramsden and Anthony Domenichiello of the U.S. National Institute on Aging called the research “an impressive undertaking that will contribute to public health for years to come.”
“The relationships between diet, cardiovascular disease and death are topics of major public health importance . . . Initial PURE findings challenge conventional diet-disease tenets that are largely based on observational associations in European and North American populations, adding to the uncertainty about what constitutes a healthy diet. This uncertainty is likely to prevail until well-designed randomized controlled trials are done.”
Mente, also a nutrition epidemiologist at the Population Health and Research Institute, was lead author of a second analysis from the PURE study presented Tuesday at the cardiology meeting.
That paper — one of three from PURE published in The Lancet — found that eating three to four servings of fruit, vegetables and legumes per day reduces the risk of premature death.
“And consuming higher amounts, pretty much you have the same level of risk,” Mente said from Barcelona. “There’s no added benefit with consuming more than four servings.
“This is important because existing guidelines recommend that people consume at least five servings per day, which is less affordable in the poorer countries because fruits and vegetables — particularly fruits — are more expensive as a proportion of people’s incomes.”
Lower-income Canadians may also be unable to afford the five to 10 daily servings of fruits and vegetables recommended in the country’s Food Guide.
“So what our study shows is you can achieve maximum benefit through fruits and vegetables and legumes, and it’s also affordable at the same time.”
Mente said the study also showed raw vegetables appear to confer greater health benefits than those that are cooked because of a loss of nutrients from being exposed to heat.
With the federal government in the process of revamping Canada’s Food Guide, the research could be a timely addition to consultations on what Canadians should be eating, Mente suggested.
“We would hope that independent thinkers perhaps reconsider the guidelines and look at our data, and perhaps rather than putting limits on total fat and saturated fat, perhaps we should be putting limits on the amount of carbohydrates that people consume.”
Reprogrammed cells relieve Parkinson’s symptoms in trials
Monkeys implanted with neurons derived from stem cells showed sustained improvement after two years.
B. Bick, . Poindexter, UT Med. School/SPL
A depletion of brain cells that produce dopamine is responsible for the mobility problems seen in people with Parkinson’s disease.
Japanese researchers report promising results from an experimental therapy for Parkinson’s disease that involves implanting neurons made from ‘reprogrammed’ stem cells into the brain. A trial conducted in monkeys with a version of the disease showed that the treatment improved their symptoms and seemed to be safe, according to a report published on 30 August in Nature1.
The study’s key finding — that the implanted cells survived in the brain for at least two years without causing any dangerous effects in the body — provides a major boost to researchers’ hopes of testing stem-cell treatments for Parkinson’s in humans, say scientists.
Jun Takahashi, a stem-cell scientist at Kyoto University in Japan who led the study, says that his team plans to begin transplanting neurons made from induced pluripotent stem (iPS) cells into people with Parkinson’s in clinical trials soon.
The research is also likely to inform several other groups worldwide that are testing different approaches to treating Parkinson’s using stem cells, with trials also slated to begin soon.
Nature breaks down the latest research — and what it means for the future of stem-cell treatments.
Why are stem cells a promising treatment for Parkinson’s disease?
Parkinson’s is a neurodegenerative condition caused by the death of cells called dopaminergic neurons, which make a neurotransmitter called dopamine in certain areas of the brain. Because dopamine-producing brain cells are involved in movement, people with the condition experience characteristic tremors and stiff muscles. Current treatments address symptoms of the disease but not the underlying cause.
Researchers have pursued the idea that pluripotent stem cells, which can form any cell type in the body, could replace dead dopamine-making neurons in people with Parkinson’s, and thus potentially halt or even reverse disease progression. Embryonic stem cells, derived from human embryos, have this capacity, but they have been the subject of ethical debates. Induced pluripotent stem (iPS) cells, which are made by coaxing adult cells into an emybronic-like state, have the same versatility without the associated ethical concerns.
What did the latest study find?
Takahashi’s team transformed iPS cells derived from both healthy people and those with Parkinson’s into dopamine-producing neurons. They then transplanted these cells into macaque monkeys with a form of the disease induced by a neuron-killing toxin.
The transplanted brain cells survived for at least two years and formed connections with the monkey’s brain cells, potentially explaining why the monkeys treated with cells began moving around their cages more frequently.
Why is the research important?
Crucially, Takahashi’s team found no sign that the transplanted cells had developed into tumours — a key concern with treatments that involve pluripotent cells — or that they evoked an immune response that couldn’t be controlled with immune-suppressing drugs.
“It’s addressing a set of critical issues that need to be investigated before one can, with confidence, move to using the cells in humans,” says Anders Bjorklund, a neuroscientist at Lund University in Sweden.
When will clinical trials begin and how will they work?
“I hope we can begin a clinical trial by the end of next year,” says Takahashi. Such a trial would be the first iPS cell trial for Parkinson’s. In 2014, a Japanese woman in her 70s became the first person to receive cells derived from iPS cells, to treat her macular degeneration.
In theory, iPS cells could be tailor-made for individual patients, which would eliminate the need to use drugs that suppress a possible immune response to foreign tissues.
But customized iPS cells are expensive to make and can take a couple months to derive and grow, Takahashi notes. So his team instead plans to establish iPS cell lines from healthy people and then use immune cell biomarkers to match them to people with Parkinson’s in the hope of minimizing the immune response (and therefore the need for drugs to blunt the attack).
In a study described in an accompanying paper in Nature Communications2, Takahashi’s team implanted into monkeys iPS-cell-derived neurons from different macaques. They found that transplants between monkeys carrying similar white blood cell markers triggered a muted immune reaction.
What other stem-cell approaches are being tested for Parkinson’s?
Earlier this year, Chinese researchers began a Parkinson’s trial that used a different approach: giving patients neural-precursor cells made from embryonic stem cells, which are intended to develop into mature dopamine-producing neurons. A year earlier, in a separate trial, patients in Australia received similar cells. But some researchers have expressed concerns that the immature transplanted cells could develop tumour-causing mutations.
Meanwhile, researchers who are part of a Parkinson’s stem-cell therapy consortium called GForce-PD, of which Takahashi’s team is a member, are set to bring still other approaches to the clinic. Teams in the United States, Sweden and the United Kingdom are all planning trials to transplant dopamine-producing neurons made from embryonic stem cells into humans. Previously established lines of embryonic stem cells have the benefit that they are well studied and can be grown in large quantities, and so all trial participants can receive a standardized treatment, notes Bjorklund, also a consortium member.
Jeanne Loring, a stem-cell scientist at the Scripps Research Institute in La Jolla, California, favours transplanting iPS-derived neurons made from a patient’s own cells. Although expensive, this approach avoids dangerous immunosuppressive drugs, she says. And because iPS cells are established anew for each patient, the lines go through relatively few cell divisions, minimizing the risk that they will develop tumour-causing mutations. Loring hopes to begin her team’s trial in 2019. “This shouldn’t be a race and we’re cheering for success by all,” she says.
Lorenz Studer, a stem-cell scientist at the Memorial Sloan Kettering Cancer Center in New York City who is working on a trial that will use neurons made from embryonic stem cells, says that there are still issues to work out, such as the number of cells needed in each transplant procedure. But he says that the latest study is “a sign that we are ready to move forward”.
Apple Watch is about to get a MAJOR update to one of its biggest features, code hints
THE Apple Watch looks set to get a major overhaul to its fitness tracking capabilities – one of the biggest selling-points behind the smartwatch – that could prove invaluable in owners’ everyday lives.
Apple Watch users could soon be getting a brand new feature that would be absolutely essential for all their fitness needs.
After scouring through the latest iOS 11 beta code, some assets have been found that could hint at new features coming to watchOS 4.
The Apple Watch looks set to soon support virtually every workout you can think of, according to Engadget.
Sports such as football, boxing, baseball and fitness activities like core training and pilates look set to benefit from Apple Watch tracking.
Interestingly, other sports that aren’t normally supported also look set to be supported by the Apple Watch.
Activities like sailing, dancing, bowling, surfing, skiing look set to receive Apple Watch tracking support.
While these tracking features look like they’re heading to the Apple Watch, which models will benefit from it is still up in the air.
Some of these workouts are available currently to watchOS 4 beta users, while others aren’t.
Apple Watch Series 2 – In Pictures
Thu, September 22, 2016
Apple Watch Series 2 includes an in-built GPS, faster processor and brighter screen. It’s also water resistant to a depth of 50 metres.
Deezer expands Hi-Fi beyond Sonos to Google Cast and Chromecast speakers
Once nipping at the heels of Spotify in the world of music streaming services, we don’t hear too much about Deezer these days. Little surprise: today, the company originally based out of Paris only has around 12 million active users, just a fraction of Spotify’s 140 million, across its 185-country footprint and 43 million tracks.
Today, the company is launching a service that it hopes will help it boost those numbers, specifically among higher-margin users who are willing to pay rather than simply use Deezer’s freemium tier. It’s expanding Deezer HiFi, a $19.99/month high fidelity tier, to any wireless speaker system that supports Google Cast, Chromecast Audio or on any Chromecast built-in speaker using Deezer’s mobile app. This will mean that HiFi is expanding to speakers from Sony, Samsung, Yamaha and Bang & Olufsen, Onkyo, Pioneer, AudioPro and Devialet.
The expansion comes about two years after Deezer took its first baby step into partnerships with speaker companies: it originally announced a global expansion of the service, previously called Deezer Elite, in partnership with Sonos.
It’s now clear how many users Deezer has picked up to date from its Sonos partnership (we’re asking). You have to wonder, though, about whether Deezer is being pushed into these expansions by virtue of other market movements. Sonos has been working on its own voice-controlled smart speaker to compete with the Echo from Amazon and Google’s Home service, which is excepted to be fully revealed in September to work with a number of content and voice service providers.
Deezer HiFi is part of the somewhat-crowded throng of music services and products that have been built in recent years to cater to listeners who want sound quality significantly better than what you can get on an average streaming service and average speakers.
Others that are part of this trend include Tidal, the music service owned by Shawn Carter (Jay-Z) with lots of buy-in from other big-name musicians; and speaker makers like Devialet(also based out of Paris, like Deezer, and like Tidal backed by Carter, but also Foxconn, Andy Rubin and others). Spotify is reportedly working on launching its own Hi-Fi service soon, too.
Deezer’s service specifically promises “lossless capture of original analog audio source quality at 5x the bitrate at 1,411 kbps” using the FLAC codec.
While part of the significance of this deal is about how it’s showing the Deezer is trying to grow its business by focusing on specific, higher-end tiers of users, it’s also notable because it is one more sign of how streaming music is being drawn into the connected home experience, as one of the main use cases for voice-activated hubs.
“With more and more consumers embracing voice-activated services and a clear market for high quality audio, it is important that we are in a position to offer both to ensure the best possible experience,” said Riad Hawa, Deezer VP of Hardware Partnerships, in a statement. “Through deepening our relationship with existing partners and expanding our product offering, we believe that we deliver just this.”
This is not the only move that Deezer has made to scale its business. The company tried(but ultimately failed) to list itself publicly. And according to this report, it was among the companies that considered buying Soundcloud before the latter troubled streaming service secured emergency funding instead. Deezer also later raised some funding in the wake of its IPO cancellation. Since being founded in 2007, Deezer has raised about $217 million, with backers including Access Industries (which owns Warner Music), Orange (France Telecom), and Xavier Niel.