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Phoenix666 writes:

Ancient DNA provides new insights into the early peopling of the Caribbean:

The researchers analysed the genomes of 93 ancient Caribbean islanders who lived between 400 and 3200 years ago using bone fragments excavated by Caribbean archaeologists from 16 archaeological sites across the region.

Due to the region's warm climate, the DNA from the samples was not very well preserved. But using so-called targeted enrichment techniques, the researchers managed to extract enough information from the remains.

"These methods allowed us to increase the number of ancient genome sequences from the Caribbean by almost two orders of magnitude and with all that data we are able to paint a very detailed picture of the early migration history of the Caribbean," says Johannes Krause, Director of the Max Planck Institute for the Science of Human History, and another senior author of the study.

The researchers' findings indicate that there have been at least three different population dispersals into the region: two earlier dispersals into the western Caribbean, one of which seems to be linked to earlier population dispersals in North America, and a third, more recent "wave," which originated in South America.

Pre-Columbian maritime trade and movement may have been more robust than thought.

Journal Reference:
Kathrin Nägele, Cosimo Posth, Miren Iraeta Orbegozo, et al. Genomic insights into the early peopling of the Caribbean [$], Science (DOI: 10.1126/science.aba8697)

Original Submission

DannyB writes:

From Earth to orbit with Linux and SpaceX

SpaceX's Crew Dragon [...] successfully delivered NASA astronauts Bob Behnken and Doug Hurley into orbit. Taking them was SpaceX's reusable Falcon 9, powered by rocket fuel and Linux.

Like supercomputers, Internet of Things (IoT) devices, and many mission-critical devices, the Falcon 9 flies with Linux. SpaceX's software engineers explained several years ago how the Falcon 9 programming works.

[...] The Falcon 9's onboard operating system is a stripped-down Linux running on three ordinary dual-core x86 processors. The flight software itself runs separately on each processor and is written in C/C++.

[...] Because the first stage of the Falcon 9 lands itself, its chips don't need to be radiation hardened.

[...] as explained on StackExchange Space Exploration, SpaceX uses an Actor-Judge system to provide safety through redundancy. In this system, every time a decision is made, it's compared to the results from the other cores. If there's any disagreement, the decision is thrown out and the process is restarted. It's only when every processor comes up with the same answer that a command is sent to the PowerPC microcontrollers.

[...] The point of this triple "tell-me three times" redundancy is to give the fault tolerance it needs without having to pay for expensive space-specific chips. Modern planes, like the newer Airbus planes, use a similar approach in their fly-by-wire systems.

The Dragon spacecraft also runs Linux with flight software written in C++. The ship's touchscreen interface is rendered using Chromium and JavaScript. If something were to go wrong with the interface, the astronauts have physical buttons to control the spacecraft.

Chromium and JavaScript are used for the Dragon 2's interactive displays -- with 100% test coverage.

Original Submission

Phoenix666 writes:

The day is dawning on a four-day work week:

A true four-day workweek entails full-timers clocking about 30 hours instead of 40. There are many reasons why this is appealing today: families are struggling to cover child care in the absence of daycares and schools; workplaces are trying to reduce the number of employees congregating in offices each day; and millions of people have lost their jobs.

A shorter work week could allow parents to cobble together child care, allow workplaces to stagger attendance and, theoretically, allow the available work to be divided among more people who need employment.

The most progressive shorter work week entails no salary reductions. This sounds crazy, but it rests on peer-reviewed research into shorter work weeks, which finds workers can be as productive in 30 hours as they are in 40, because they waste less time and are better-rested.

30 hours is for pikers. The !Kung work about 20.

Original Submission

upstart writes in with an IRC submission:

New High Precision Chip-Based Laser Gyroscope Can Measure Earth's Rotation:

Optical gyroscopes are used in applications such as aircraft navigation systems, while MEMS gyroscopes are found in devices like smartphones. For the last few decades, researchers have wondered whether it would be possible to bridge the gap between these two technologies and create a new type of gyroscope that combines the precision of laser gyroscopes with the ease of manufacture of MEMS gyroscopes. Now, Caltech scientists have developed an optical gyroscope that marries some of the best characteristics of each into one device.

In a new paper published in Nature Photonics, Kerry Vahala (BS '80, MS '81, PhD '85), Caltech's Ted and Ginger Jenkins Professor of Information Science and Technology and Applied Physics, describes a laser gyroscope his lab built from a piece of silicon-based material in much the same way that MEMS devices are manufactured. The new type of gyroscope has achieved something considered a benchmark for gyroscopes: the ability to measure the rotation of the earth.

All optical gyroscopes, including the one developed by Vahala, make use of something known as the Sagnac effect to measure rotation. Two light waves traveling in opposite directions around a ring-like path will have equal propagation times. However, when the path rotates, the time to reach a specific point on the rotating path will be different for each wave. This difference provides a measure of the rate of rotation and can be determined very precisely by measuring the interference between the two light waves.

[...] In Vahala's gyroscope, the pathway is a circular silica disk, and the laser light is generated by high frequency vibrations in the disk through a process called stimulated Brillouin scattering.

Although the shorter light path in Vahala's gyroscope helps to keep the device smaller, it could also result in lower sensitivity. To make up for that, the light is "recycled," says Yu-Hung Lai, co-author on the paper. "The light is allowed to circulate around the path again and again, creating a stronger Sagnac effect and greater sensitivity to rotation."

Journal Reference:
Yu-Hung Lai, Myoung-Gyun Suh, Yu-Kun Lu, et al. Earth rotation measured by a chip-scale ring laser gyroscope, Nature Photonics (DOI: 10.1038/s41566-020-0588-y)

Original Submission

takyon writes:

A lost Maxis "Sim" game has been discovered by an Ars reader, uploaded for all

We at Ars Technica are proud to be members of video game archiving history today. SimRefinery, one of PC gaming's most notoriously "lost" video games, now exists—as a fully playable game, albeit an unfinished one—thanks to an Ars Technica reader commenting on the story of its legend.

Two weeks ago, I reported on a story about Maxis Business Solutions, a subdivision of the game developer Maxis created in the wake of SimCity's booming success. Librarian and archivist Phil Salvador published an epic, interview-filled history of one of the game industry's earliest examples of a "serious" gaming division, which was formed as a way to cash in on major businesses' interest in using video games as work-training simulators.

[...] The anonymous Ars user returned to our comments section on Thursday to confirm that they'd uploaded the disk's contents, after an apparently annoying extraction process, to archive.org for everyone in the world to download and play.

Original Submission

upstart writes in with an IRC submission:

Mothers ensure their offspring's success through epigenetics:

Parents pass genes along to their offspring traits that equip them for life. In recent years, research has shown that the reality is much more complex and that parents endow much more than just genes. A new study in Cell by the laboratory of Asifa Akhtar at the Max Planck Institute of Immunobiology and Epigenetics reveals that active epigenetic modifications are also passed from one generation to the next.

Human mothers grow babies for nine months, and after giving birth, proceed to spend years raising and nurturing their children, teaching them how to perform both basic and advanced survival tasks. Fruit flies, on the other hand, lay eggs that are left to develop on their own. This makes them seem like irresponsible parents, just abandoning their young. However, a new study by the laboratory of Asifa Akhtar at the Max Planck Institute of Immunobiology and Epigenetics in Freiburg suggests that fruit fly moms do, in fact, ensure the success of their offspring by providing them with an instruction manual for life encoded deep in their epigenomes.

[...] "The fact that fly mothers ensure their offspring's success through epigenetics even before they are conceived is a fascinating result," says Asifa Akhtar. The researchers next turned to mammals and found that female mice also pass the H4K16ac histone modification to their progeny through their oocytes. This raises the intriguing possibility that humans might also use H4K16ac from the mother as a "blueprint" for successful embryonic development. Whether this is the case and what information this blueprint might encode are open questions for future investigation.

More information: Maria Samata, et. al., Intergenerationally Maintained Histone H4 Lysine 16 Acetylation Is Instructive for Future Gene Activation,Cell (2020). DOI: 10.1016/j.cell.2020.05.026

Original Submission

takyon writes:

Robotic Third Arm Can Smash Through Walls

When we've written about adding useful robotic bits to people in the past, whether it's some extra fingers or an additional arm or two, the functionality has generally been limited to slow moving, lightweight tasks. Holding or carrying things. Stabilizing objects or the user. That sort of thing. But that's not what we want. What we want are wearable robotic arms that turn us into a superhero, like Marvel Comics' Doc Ock, who I'm just going to go ahead and assume is a good guy because those robotic arms strapped to his torso look awesome.

At ICRA this week, researchers from Université de Sherbrooke in Canada are finally giving us what we want, in the form of a waist-mounted remote controlled hydraulic arm that can help you with all kinds of tasks while also being able, should you feel the need, to smash through walls.

Supernumerary 3DOF Robotic Arm (2m50s video)

Multifunctional 3-DOF Wearable Supernumerary Robotic Arm Based on Magnetorheological Clutches

Original Submission

takyon writes:

Linus Torvalds rejects 'beyond stupid' AWS-made Linux patch for Intel CPU Snoop attack

Linux kernel head Linus Torvalds has trashed a patch from Amazon Web Services (AWS) engineers that was aimed at mitigating the Snoop attack on Intel CPUs discovered by an AWS engineer earlier this year. [...] AWS engineer Pawel Wieczorkiewicz discovered a way to leak data from an Intel CPU's memory via its L1D cache, which sits in CPU cores, through 'bus snooping' – the cache updating operation that happens when data is modified in L1D.

In the wake of the disclosure, AWS engineer Balbir Singh proposed a patch for the Linux kernel for applications to be able to opt in to flush the L1D cache when a task is switched out. [...] The feature would allow applications on an opt-in basis to call prctl(2) to flush the L1D cache for a task once it leaves the CPU, assuming the hardware supports it.

But, as spotted by Phoronix, Torvalds believes the patch will allow applications that opt in to the patch to degrade CPU performance for other applications.

"Because it looks to me like this basically exports cache flushing instructions to user space, and gives processes a way to just say 'slow down anybody else I schedule with too'," wrote Torvalds yesterday. "In other words, from what I can tell, this takes the crazy 'Intel ships buggy CPU's and it causes problems for virtualization' code (which I didn't much care about), and turns it into 'anybody can opt in to this disease, and now it affects even people and CPU's that don't need it and configurations where it's completely pointless'."

Original Submission

takyon writes:

Proxima Centauri b confirmed as nearest exoworld

Four years ago, scientists made one of the most exciting exoplanet discoveries so far, a rocky planet similar in size to Earth orbiting the nearest star to the sun, Proxima Centauri. While the detection seemed solid, more confirmation is always good, and now the ESPRESSO spectrograph on the Very Large Telescope (VLT) in Chile has provided that extra and more detailed confirmation. The news was announced by the University of Geneva (UNIGE) on May 28, 2020.

[...] Proxima Centauri b is very similar in size to Earth, with a mass of 1.17 Earth masses. It orbits its star in only 11.2 days, in contrast to our Earth's year-long orbit around our sun. That means Proxima Centauri b is a lot closer to its star than Earth is to the sun. But, because the star is a red dwarf – much smaller and cooler than our sun – its orbit is indeed within the habitable zone of Proxima Centauri. Interestingly, Proxima Centauri b receives about the same amount of solar energy from its star that Earth does from our sun.

[...] The mass of Proxima b was previously estimated to be 1.3 Earth masses. The accuracy of the new measurement of 1.17 Earth masses is unprecedented, according to Michel Mayor, the "architect" of all ESPRESSO-type instruments:

ESPRESSO has made it possible to measure the mass of the planet with a precision of over one-tenth of the mass of Earth. It's completely unheard of.

The new confirmation of Proxima Centauri b is exciting, but there may be more surprises in store ... there is also possible evidence of another and smaller planet in the newest data. A secondary detection was also made, although it isn't certain whether it is actually a planet. If it is, it is even smaller than Proxima Centauri b. [...] If it is a planet, it would be more akin to Mars or Mercury in size and mass – estimated at a minimum Earth mass of 0.29 ± 0.08 – and orbits the star in only 5.15 days. It wouldn't be too surprising, though, in that low-mass stars like red dwarfs tend to have multiple planets in their systems. More observations will be required to either confirm or refute this possible second planet.

Journal Reference
Mascareño, A. Suárez, Faria, J. P., Figueira, P., et al. Revisiting Proxima with ESPRESSO, (https://arxiv.org/abs/2005.12114v1)

Proxima Centauri - Planetary system

Previously: ESO Confirms Reports of Proxima Centauri Exoplanet
Proxima b May Have Oceans
Dust Belts and Possible Additional Exoplanet Spotted Around Proxima Centauri
First Light for VLT's ESPRESSO Exoplanet Hunter
Very Large Telescope's ESPRESSO Combines Light From All Four Unit Telescopes for the First Time
Proxima Centauri's No Good, Very Bad Day
High Levels of Ultraviolet Radiation Should Not Preclude Life on Exoplanets
Icy second planet potentially spotted orbiting Proxima Centauri

Original Submission

c0lo writes:

A serious divide exists among Trump advisers over how to address nights of protests and riots in US after Floyd's death

Trump is being urged by some advisers to formally address the nation and call for calm, while others have said he should condemn the rioting and looting more forcefully or risk losing middle-of-the-road voters in November, according to several sources familiar with the deliberations.

[...] During a staff call Friday, Trump's top domestic policy aide Brooke Rollins argued for a measured response to riots the night before, advice that was echoed by Trump's son-in-law Jared Kushner. Several advisers feared, and hoped to avoid, another Charlottesville moment, when Trump was criticized after declaring in 2017 that "very fine people" were among the Nazi mobs that descended upon Charlottesville, Virginia.

[...] While aides like Kushner have pushed for a more restrained response, Trump is also hearing from several advisers who warned that by not condemning the protests after the death of Floyd, an unarmed 46-year-old black man, that turned into rioting and looting, he is risking losing some demographics that will be key to his election victory in November, like suburban women voters.

As Protests and Violence Spill Over, Trump Shrinks Back

The president spent Sunday out of sight, berating opponents on Twitter, even as some of his campaign advisers were recommending that he deliver a televised address to an anxious nation.

how the George Floyd protests left Donald Trump exposed

“Americans watching this address tonight have seen the recent images of violence in our streets and the chaos in our communities. Many have witnessed this violence personally, some have even been its victims. I have a message for all of you: the crime and violence that today afflicts our nation will soon – and I mean very soon – come to an end.”
These were the words of Donald Trump, not in May 2020 but July 2016, as he accepted the Republican presidential nomination at the national convention in Cleveland.

Phoenix666 writes:

UNM researchers document the first use of maize in Mesoamerica:

The research, titled Early isotopic evidence for maize as a staple grain in the Americas and published by Prufer and his team in the journal Science Advances, reveals new information about when the now-ubiquitous maize became a key part of people’s diets. Until now, little was known about when humans living in the tropics of Central America first started eating corn. But the “unparalleled” discovery of remarkably well-preserved ancient human skeletons in Central American rock shelters has revealed when corn became a key part of people’s diet in the Americas.

[...] Maize was domesticated from teosinte, a wild grass growing in the lower reaches of the Balsas River Valley of Central Mexico, around 9,000 years ago. There is evidence maize was first cultivated in the Maya lowlands around 6,500 years ago, at about the same time that it appears along the Pacific coast of Mexico. But there is no evidence that maize was a staple grain at that time.

The first use of corn may have been for an early form of liquor.

Why eat tortillas when you can make booze?

Journal Reference:
Douglas J. Kennett, Keith M. Prufer, Brendan J. Culleton, et al. Early isotopic evidence for maize as a staple grain in the Americas [open], Science Advances (DOI: 10.1126/sciadv.aba3245)

Original Submission

canopic jug writes:

FiveThirtyEight is covering the efficacy of fact-checking and other methods to combat the spread of misinformation and disinformation. Fact-checking, after the fact, is better than nothing, it turns out. There are some common factors in the times when it has been done successfully:

Political scientists Ethan Porter and Thomas J. Wood conducted an exhaustive battery of surveys on fact-checking, across more than 10,000 participants and 13 studies that covered a range of political, economic and scientific topics. They found that 60 percent of respondents gave accurate answers when presented with a correction, while just 32 percent of respondents who were not given a correction expressed accurate beliefs. That’s pretty solid proof that fact-checking can work.

But Porter and Wood have found, alongside many other fact-checking researchers, some methods of fact-checking are more effective than others. Broadly speaking, the most effective fact checks have this in common:

1. They are from highly credible sources (with extra credit for those that are also surprising, like Republicans contradicting other Republicans or Democrats contradicting other Democrats).
2. They offer a new frame for thinking about the issue (that is, they don’t simply dismiss a claim as “wrong” or “unsubstantiated”).
3. They don’t directly challenge one’s worldview and identity.
4. They happen early, before a false narrative gains traction.

It is as much about psychology as actually rebutting the disinformation because factors like partisanship and worldview have strong effects, and it is hard to reach people inside their social control media echo chambers from an accurate source they will accept.

[Though often incorrectly attributed to Mark Twain, one is reminded of the adage: “A lie can travel halfway around the world while the truth is still putting on its shoes”. --Ed.]

Previously:
(2020) Nearly Half of Twitter Accounts Pushing to Reopen America May be Bots
(2019) Russians Engaging in Ongoing 'Information Warfare,' FBI Director Says
(2019) How Fake News Spreads Like a Real Virus
(2019) More and More Countries are Mounting Disinformation Campaigns Online
(2019) At Defcon, Teaching Disinformation Campaigns Is Child's Play
(2018) Why You Stink at Fact-Checking
(2017) Americans Are “Under Siege” From Disinformation
(2015) Education Plus Ideology Exaggerates Rejection of Reality

Original Submission

takyon writes:

Project Gutenberg Public Domain Library Blocked in Italy For Copyright Infringement:

Project Gutenberg, a volunteer effort to digitize and archive books, is sometimes described as the world’s oldest digital library.

Founded in 1971, Project Gutenberg‘s archives now stretch to a total of more than 62,000 books, with a focus on titles that entered the public domain after their copyrights expired. The library does carry some and in-copyright books but these are distributed with the express permission of their owners.

The project has an excellent reputation and its work is considered a great contribution to education and culture. However, it now transpires that the site has been rendered inaccessible by ISPs in Italy under the instructions of the Public Prosecutor at the Court of Rome.

[...] The seizure/blocking notice states that all of the targeted domains “distributed, transmitted and disseminated in pdf format, magazines, newspapers and books (property protected by copyright) after having illegally acquired numerous computer files with their content, communicating them to the public, [and] entering them into a system of communication networks.”

[...] “The investigation, conducted by a special unit of the Guardia di Finanza, has been developed in the context of monitoring the targeted Internet networks to combat economic and financial offenses perpetrated online.

“In this context, the operators identified some web resources registered on foreign servers which make content and magazines available to the public early in the morning, allowing users to view or download digital copies,” the court document reads. (translated from Italian)

Original Submission

takyon writes:

HAMR-Jr Is a Speedy Quadrupedal Robot the Size of a Penny:

The last time we checked in with the Harvard Ambulatory MicroRobot (HAMR) was in 2018, when I spent far too much time trying (with a very small amount of what might charitably be called success) to adapt some MC Hammer lyrics for an article intro. Despite having “micro robot” right in the name, if we’re talking about insect scale, HAMR was a bit chunky, measuring about 5 centimeters long and weighing around 3 grams. At ICRA this week, we’ve been introduced to a new version of HAMR, called HAMR-Jr, which is significantly smaller: just a tenth of the weight, and comes up to about knee-high on a cockroach.

HAMR-Jr may be tiny, but it’s no slouch—piezoelectric actuators can drive it at nearly 14 body lengths (30 cm [~12 inches]) per second, at a gait frequency of 200 hertz. The actuators can be cranked up even more, approaching 300 Hz, but the robot actually slows down past 200 Hz, because it turns out that 200 Hz hits a sort of resonant sweet spot that gives the robot as much leg lift and stride length as possible.

It’s worth mentioning that even the fastest legged insects don’t reach a gait frequency of 200 Hz. While the Australian tiger beetle seems to be the world’s fastest legged insect, able to reach about 2.5 m/s (!) when chasing prey with a gait frequency of just a few tens of hertz, what’s more relevant here is probably the fastest insect relative to its size (so, fastest speed measured in body lengths per second). That award goes to a tiny species of mite found in California, able to run at nearly 200 body lengths per second. This works out to something like 0.25 m/s because the mites are seriously tiny (sesame-seed sized), but juveniles managed to hit a stride frequency of 135 Hz, which is the same ballpark as HAMR-Jr, albeit on a much smaller scale.

YouTube video

“Scaling down an insect-size microrobot, HAMR-VI into HAMR-Jr,” by Kaushik Jayaram, Jennifer Shum, Samantha Castellanos, E. Farrell Helbling, and Robert J. Wood from Harvard and UC Boulder, is being presented at ICRA 2020.

ICRA 2020: "2020 IEEE International Conference on Robotics and Automation - ICRA 2020, Paris, Virtual Conference, IEEE Robotics and Automation Society."

Original Submission

upstart writes in with an IRC submission:

Expect the Unexpected: Solar Orbiter to Pass Through the Tails of Comet ATLAS:

ESA's Solar Orbiter will cross through the tails of Comet ATLAS during the next few days. Although the recently launched spacecraft was not due to be taking science data at this time, mission experts have worked to ensure that the four most relevant instruments will be switched on during the unique encounter.

Solar Orbiter was launched on February 10, 2020. Since then, and with the exception of a brief shutdown due to the coronavirus pandemic, scientists and engineers have been conducting a series of tests and set-up routines known as commissioning.

The completion date for this phase was set at June 15, so that the spacecraft could be fully functional for its first close pass of the Sun, or perihelion, in mid-June. However, the discovery of the chance encounter with the comet made things more urgent.

Serendipitously flying through a comet's tail is a rare event for a space mission, something scientists know to have happened only six times before for missions that were not specifically chasing comets. All such encounters have been discovered in the spacecraft data after the event. Solar Orbiter's upcoming crossing is the first to be predicted in advance.