A Frasers spokesman said: "Despite the global pandemic, numerous lockdowns and the turbulence caused for British retail, the landlord hasn't been able to work mutually on a fair agreement, therefore resulting in the loss of 200 jobs and a vacant site for the foreseeable future, with no immediate plans.
Many Tesla fans view the electric carmaker as a world leader in self-driving technology. CEO Elon Musk himself has repeatedly claimed that the company is less than two years away from perfecting fully self-driving technology. But in an interview with Germany's Manager magazine, Waymo CEO John Krafcik dismissed Tesla as a Waymo competitor and argued that Tesla's current strategy was unlikely to ever produce a fully self-driving system. "For us, Tesla is not a competitor at all," Krafcik said. "We manufacture a completely autonomous driving system. Tesla is an automaker that is developing a really good driver assistance system."
On 3 June 2020, the VUB AI Experience Centre published a webinar on the topic of the role of AI in the COVID-19 crisis, focused on macro dynamics predictions in the COVID-19 crisis, explained by micro intentions. This webinar focused on AI reinforcement learning techniques and predictive modelling, decision making in defining prevention, and exit strategies. It was led by Prof. dr. Ann Nowé from the Artificial Intelligence Lab together with Prof. dr Kurt Barbé, member of the Digital Mathematics research group and the cross-faculty Artificial Intelligence Lab, and Prof. dr Tom Lenaerts who is a member of the VUB Artificial Intelligence Lab and the Machine Learning Group of the ULB. The AI Experience Centre is a joint project of 4 VUB research groups: the Artificial Intelligence Lab, Brubotics, SMIT and ETRO, and is located on the VUB campus Etterbeek.
SCI COMMUN SCIENTISTS' TERM LIMITS The Trump administration moved to impose 5-year term limits on top scientists at the U.S. Department of Health and Human Services (HHS). The rule, released on 15 January, requires that directors of seven centers at the Food and Drug Administration, as well as 17 positions at the Centers for Disease Control and Prevention, undergo a performance review that could lead to a new 5-year appointment, or to the staffer's transfer. A 2016 law mandates such 5-year reviews for institute and center directors at the National Institutes of Health. But some current and former officials worry the term limits will subject such positions to political interference from the White House, and they could face legal challenges, Politico reported. GLOBAL WARMING A surprise Environmental Protection Agency (EPA) rule finalized last week would effectively ban the government from regulating greenhouse gas emissions from heavy industries other than power plants. The agency substantially rewrote a draft rule originally focused on regulating carbon emissions from new power plants, expanding it to exempt other “stationary” sources, such as refineries and oil and gas wells. The exemption covers an entire class of sources if its collective emissions are less than 3% of the U.S. total. Only power plants, which produce 27% of U.S. carbon emissions, exceed that bar. Analysts say the rule is vulnerable to a court challenge, and the Biden administration can likely suspend its implementation. SPOTTED OWLS The U.S. Fish and Wildlife Service slashed protections for the endangered northern spotted owl on 13 January, declaring more than 1.4 million hectares of Pacific Northwest forests would no longer be considered critical habitat for the bird. The decision comes despite findings by agency scientists that the owl's population is declining and that it warrants stricter protection. The habitat reduction is part of a move by the outgoing Trump administration to settle a lawsuit by the timber industry and counties that earn revenue from logging. The land area is 17 times the amount that the agency initially proposed to remove from protections in August 2020. TRANSGENIC ANIMALS A push by the White House would essentially eliminate the Food and Drug Administration's (FDA's) authority to regulate genetically modified animals and put the U.S. Department of Agriculture (USDA) in charge. The two agencies had been negotiating on dividing the task, and critics of the White House move say it would put USDA in the problematic position of both promoting and regulating genetically modified animals. FDA opposes the shift, Politico reported. ARCTIC OIL DRILLING The first-ever auction of oil drilling rights inside the Arctic National Wildlife Refuge in Alaska, a policy priority for the Trump administration, met with a tepid response this month. Just three bidders paid $14.4 million to claim 11 parcels covering 220,000 hectares—about half of the land up for auction. In an unusual move, a state agency, the Alaska Industrial Development and Export Authority, won bids for nine of the parcels. It joined the auction in part because the agency fears the Biden administration will slow or block further leasing, reducing the state's potential economic gains. The leases must still be finalized by the Bureau of Land Management. Wildlife scientists have warned that the drilling could harm caribou herds and other parts of the ecosystem. FETAL TISSUE RESEARCH Scientists who use fetal tissue obtained from elective abortions would need to comply with new rules under a proposal released by the Trump administration on 13 January. Among other changes, the policy would add new requirements to forms used to obtain informed consent from women who donate tissue for research. It would also limit the source of fetal tissue, which often comes from nonprofit clinics, to federally or state funded hospitals or academic medical centers. In 2019, Trump's administration banned fetal tissue research by federal researchers and required a new ethics review for studies by scientists receiving federal grants; research groups have urged the Biden administration to reverse that policy. The new proposal, which is open for comment for 30 days, is not expected to move forward. CENSUS FIGHT The Trump administration last week abandoned a 2-year effort to prod the Census Bureau to provide a separate tally of undocumented U.S. residents as part of the 2020 census. In 2019, the president had ordered that the separate tally, and a rushed compilation of the decennial head count used for apportioning the 435 seats of the U.S. House of Representatives, be delivered before he left office. Most demographers said it could not be done and called the directive political interference. On 11 January, U.S. government lawyers told a federal judge that the apportionment numbers would not be ready until 6 March. Civil rights organizations want Census Director Steven Dillingham to resign before his term ends in December, saying he has failed to uphold the agency's high standards for data quality. ### Leadership President Joe Biden on 15 January named Eric Lander to be his science adviser and director of the White House Office of Science and Technology Policy. A mathematician turned molecular biologist, the 63-year-old Lander will take leave from his post as president and founding director of the Broad Institute, jointly run by Harvard University and the Massachusetts Institute of Technology (MIT). The first biologist to hold the job, Lander spent 8 years as co-chair of the nation's top science advisory panel under former President Barack Obama. He also co-led the public Human Genome Project, which completed its first draft in 2001. Biden has picked chemistry Nobel laureate Frances Arnold and MIT's Maria Zuber to lead his science advisory panel. He named David Kessler, a former commissioner of the U.S. Food and Drug Administration, to direct Operation Warp Speed, the federal effort to speed development of COVID-19 vaccines. And Biden said Francis Collins has agreed to remain as director of the National Institutes of Health. ### Conservation To study one of Europe's rarest butterflies, researchers pioneered a new method of observation: rappelling down vertiginous mountainsides along the border of Italy and Switzerland. Scientists first described the orange-and-brown Raetzer's ringlet ( Erebia christi ) more than 100 years ago, but its dangerous, inaccessible habitat complicated population surveys. Drawing on decades of climbing experience, independent biologists Andrea Battisti and Matteo Gabaglio slid down ropes to count butterflies in several areas during the past 6 years. It was “like being an explorer … going where nobody has ever [gone],” Gabaglio says. Researchers sighted the ringlet 177 times at two key sites in Italy, they reported this month in the Journal of Insect Conservation . That's good news, they add: The ringlet appears to be more abundant that previous studies suggested. But because of climate change and other threats, they recommend reclassifying the species as endangered rather than vulnerable. ### Policy President Joe Biden announced a sweeping, $400 billion plan last week to tackle the “dismal failure” of the COVID-19 vaccine rollout, safely reopen schools by March, and ramp up testing people for the pandemic coronavirus. The measures are part of an ambitious, $1.9 billion “American Rescue Plan” unveiled by Biden ahead of his inauguration to help people who are struggling financially because of the pandemic—a proposal that depends on Congress providing the money. The federal government would pay for 100,000 new public health workers to assist states in vaccination and other pandemic response efforts. Biden promised to invoke the Defense Production Act to provide vaccinemakers with whatever they need to increase production. Biden's administration would also work more closely with pharmacies to move vaccines from freezers into arms. “The more people we vaccinate and the faster we do it, the sooner we can put this pandemic behind us,” Biden said. ### Infectious diseases All eight gorillas at the San Diego Zoo Safari Park were exposed to the coronavirus that causes COVID-19, and at least two have begun to cough, zoo officials said last week. Tests of fecal samples showed that two were infected, marking the first known cases in nonhuman apes. The officials suspect the western lowland gorillas caught the virus from an asymptomatic staff member who tested positive for SARS-CoV-2; the zoo has been closed to the public for weeks because of the pandemic. The news confirmed fears that the virus can infect endangered great apes. Human respiratory viruses are already a leading cause of death for chimpanzees in the wild. ### COVID-19 High virus levels in saliva are correlated with later hospitalization, serious illness, or death from COVID-19, raising the prospect that testing saliva for the coronavirus that causes the disease will help identify patients most at risk, a study has found. The standard test to detect the SARS-CoV-2 virus analyzes samples of nasal mucus taken with nasopharyngeal (NP) swabs. But patients with the worst outcomes were more likely to have high virus loads in their saliva, but not in their NP swabs, report Akiko Iwasaki of Yale University and colleagues in a 10 January preprint. That may reflect that nasal mucus comes from the upper respiratory tract, whereas severe disease is associated with damage deep in the lungs; coughing regularly brings up viral particles to the throat, where they can pervade saliva. If the results are confirmed, saliva tests could help doctors prioritize which patients in the early stages of the disease should receive medicines that drive down levels of the virus. ### Planetary science The Red Planet has claimed another robot. Scientists at NASA and the German Aerospace Center last week called off a 2-year effort to rescue the failed rod-shaped heat probe, or “mole,” of the InSight lander. The mole was designed to burrow 5 meters into the martian soil and tease out how quickly heat escapes from Mars—a clue to how the planet formed. But soil compacted instead of crumbling as the rod tried to dig in, leaving it stuck at the surface. Even after engineers used InSight's robotic arm to push the probe down and scraped dirt on top, the probe failed a final attempt this month to dig on its own, leaving the mole buried in a shallow grave. InSight's other primary instrument, a seismometer, continues to function normally. ### Foreign influences The U.S. Department of Justice (DOJ) has added another prominent scientist to its crackdown on U.S.-based academics with allegedly undisclosed ties to China. On 14 January, police arrested nanotechnologist Gang Chen of the Massachusetts Institute of Technology (MIT) at his Cambridge home, charging him with violating federal wire fraud, banking, and tax laws. DOJ alleges Chen held various appointments with Chinese institutions and provided technical advice, “often in exchange for financial compensation and awards.” He allegedly failed to disclose these affiliations as required when applying for U.S. Department of Energy grants, and did not tell tax authorities about a bank account in China. MIT said, “We take seriously concerns about improper influence in U.S. research.” Chen was born in China and is a naturalized U.S. citizen. He is a member of the National Academy of Engineering and fellow of AAAS (which publishes Science ). ### History of science Fans of Mary Anning are hoping to raise £33,000 by next month to fund a statue honoring the paleontological pioneer, who discovered and interpreted key fossils along England's Jurassic Coast. Anning, who lived in Lyme Regis in the early 1800s, was the first to correctly identify an ichthyosaur, and discovered England's first pterosaur. Her discoveries were profoundly influential, but as a self-taught, working-class woman she was excluded from meetings of the Geological Society of London. Its members discussed and built on her discoveries, but often failed to acknowledge her. The £100,000 statue project was inspired by 13-year-old local Evie Swire. Organizers hope the cause will be helped by the film Ammonite , starring Kate Winslet as Anning, which opened in U.S. theaters in November 2020. ### Publishing AAAS, which publishes the Science family of journals, said last week it will offer its authors a free way to comply with funder requirements that their papers be open access on publication. Under a new policy, authors may deposit near-final, peer-reviewed versions of papers accepted by paywalled Science titles in public repositories where they are free to read. This “green open-access” route will apply for now only to authors of papers funded by Coalition S, a group of mostly European funders and foundations behind a mandate for immediate open access that takes effect this month. AAAS said it will pilot the new policy for 1 year.
Housebound by a pandemic, humanity slowed its emissions of greenhouse gases in 2020. But Earth paid little heed: Temperatures last year tied the modern record, climate scientists reported last week. Overall, the planet was about 1.25°C warmer than in preindustrial times, a trend that puts climate targets in jeopardy, according to jointly reported assessments from NASA, Berkeley Earth, the U.K. Met Office, and the National Oceanic and Atmospheric Administration. The annual update of global surface temperatures—an average of readings from thousands of weather stations and ocean probes—shows 2020 essentially tied records set in 2016. But the years were nothing alike. Temperatures in 2016 were boosted by a strong El Niño, a weather pattern that warms the globe by blocking the rise of cold deep waters in the eastern Pacific Ocean. Last year, however, the Pacific entered La Niña, which has a cooling effect. That La Niña didn't provide more relief is an unwelcome surprise, says Nerilie Abram, a climate scientist at Australian National University. “It makes me worried about how quickly the global warming trend is growing.” The past 6 years are the six warmest on record, but the warming of the atmosphere is unsteady because of its chaotic nature. The ocean, which absorbs more than 90% of the heat from global warming, displays a steadier trend, and here, too, 2020 was a record year. The upper levels of the ocean contained 20 zettajoules (1021 joules) more heat than in 2019, and the rise was double the typical annual increase, scientists reported last week in Advances in Atmospheric Sciences . The subtropical Atlantic Ocean was particularly hot, fueling a record outbreak of hurricanes, says Lijing Cheng, a climate scientist at the Chinese Academy of Sciences's Institute of Atmospheric Physics who led the work. This heat, monitored down to 2000 meters by a fleet of 4000 robotic probes, is spreading deeper into the ocean while also migrating toward the poles. An extreme heat wave struck the northern Pacific, killing marine life. For the first time, warm Atlantic waters were seen penetrating into the Arctic Ocean, melting sea ice from below and reducing its extent nearly to a record low ( Science , 28 August 2020, p. ). The warming ocean and melting ice sheets are raising sea levels by 4.8 millimeters per year, and the rate is accelerating ( Science , 20 November 2020, p. ). On land, 2020 was even more relentless, with temperatures rising 1.96°C above preindustrial levels, a clear record, Berkeley Earth reported. It was the warmest year ever in Asia and Europe and tied for the warmest in South America. Russia was particularly hot, breaking its previous record by 1.2°C, while swaths of Siberia were 7°C warmer than in preindustrial times, leading to large-scale fires and thawing permafrost that caused buildings to founder and set off oil spills ( Science , 7 August 2020, p. ). “Siberia was crazy,” says Zeke Hausfather, a climate scientist at the Breakthrough Institute and co-author of the Berkeley Earth analysis. “That heat would effectively be impossible without the warming we've seen.” In Australia, record-setting heat and drought fueled catastrophic bushfires at the start of 2020. Fires torched nearly one-quarter of southeastern Australia's forests and destroyed 3000 homes. Climate change was to blame for the country's “Black Summer,” Abram and co-authors concluded in a study published this month in Communications Earth & Environment . Meanwhile, in the United States, unprecedented heat came to the desert Southwest, which is already warming faster than the rest of the country. Phoenix wilted under its hottest summer ever, averaging 36°C. Arizona's Maricopa county, home to Phoenix, is a leader in addressing heat exposure, yet its heat deaths have hit a new record each year since 2016. In 2020, the number approached 300, a jump of some 50% over the previous year, says David Hondula, a climatologist who studies heat mortality at Arizona State University, Tempe. “It was just off the charts in terms of heat.” ![Figure] Turning up the heatCREDITS: (GRAPHIC) N. DESAI/ SCIENCE ; (DATA) MET OFFICE; NASA; BERKELEY EARTH; NOAA Although the global economic slowdown of the COVID-19 pandemic cut carbon dioxide (CO2) emissions by some 7%, atmospheric CO2 is long-lived, and warming from previous emissions is preordained. In any case, the drop in emissions is unlikely to last. Later this year, in May, before photosynthesis in the Northern Hemisphere draws down CO2, the U.K. Met Office predicts that levels of atmospheric CO2 will pass 417 parts per million for several weeks, 50% higher than preindustrial levels. Only dramatic action by the world's countries, far beyond existing efforts, can begin to halt this build up, Cheng says. Should the current rate of warming continue, the world will breach the targets set in the Paris climate agreement—limiting warming to 1.5°C or 2°C—by 2035 and 2065, respectively. But Hausfather says it's quite possible that warming, which has largely held steady for the past few decades at 0.19°C per decade, will actually speed up. The rate of warming over the past 14 years is well above the long-term trend. The debate now, he says, is whether that is an omen of an even darker future. : https://www.sciencemag.org/content/369/6507/1043.full : https://www.sciencemag.org/content/370/6519/901.full : https://www.sciencemag.org/content/369/6504/612.full : pending:yes
Phase separation, an idea about how cells organize their contents and functions into dropletlike compartments, has divided biologists. For 7 years as president of the Howard Hughes Medical Institute, Robert Tjian helped steer hundreds of millions of dollars to scientists probing provocative ideas that might transform biology and biomedicine. So the biochemist was intrigued a couple of years ago when his graduate student David McSwiggen uncovered data likely to fuel excitement about a process called phase separation, already one of the hottest concepts in cell biology. Phase separation advocates hold that proteins and other molecules self-organize into denser structures inside cells, like oil drops forming in water. That spontaneous sorting, proponents assert, serves as a previously unrecognized mechanism for arranging the cell's contents and mustering the molecules necessary to trigger key cellular events. McSwiggen had found hints that phase separation helps herpesviruses replicate inside infected cells, adding to claims that the process plays a role in functions as diverse as switching on genes, anchoring the cytoskeleton, and repairing damaged DNA. “It's pretty clear this process is at play throughout the cell,” says biophysicist Clifford Brangwynne of Princeton University. The pharmaceutical industry is as excited as some academic researchers, given studies linking phase separation to cancer, amyotrophic lateral sclerosis (ALS), diabetes, and other diseases. Dewpoint Therapeutics, a startup pursuing medical treatments targeting cellular droplets, recently signed development deals worth more than $400 million with pharma giants Merck and Bayer. And three other companies looking to exploit the process opened their doors late last year. Reflecting that enthusiasm, Science picked phase separation as a runner-up in its 2018 Breakthrough of the Year issue. Tjian says he was agnostic at first about the importance of the process. But after McSwiggen's findings inspired him and colleagues to look more closely at the range of claims, the researchers began to have doubts. Tjian and a camp of similarly skeptical biologists now argue that the evidence that liquidlike condensates arise naturally in cells is largely qualitative and obtained with techniques that yield equivocal results—in short, they believe much of the research is shoddy. Moreover, the contention that those intracellular droplets perform important roles “has gone from hypothetical to established dogma with no data,” says Tjian, who stepped down as president of Howard Hughes in 2016 and now co-directs a lab at the University of California (UC), Berkeley. “That to me is so perverse and destructive to the scientific discovery process.” Although proponents of phase separation bridle at some of those criticisms, many scientists agree that the research requires a jolt of rigor. “I don't think the whole field is bunk,” says biophysicist Stephanie Weber of McGill University. “But we do need to be more careful” in identifying instances of phase separation in cells and ascribing functions to them. The process may be less important than many scientists now assert, adds quantitative cell biologist Amy Gladfelter of the University of North Carolina, Chapel Hill. Some researchers, she says, have tried to make it “the answer to everything.” PHASE SEPARATION COULD ANSWER a fundamental question that has nagged biologists for more than 100 years: How do cells arrange their contents so that the molecules necessary to carry out a particular job are in the right place at the right time? One obvious way is with internal membranes, such as those fencing off the Golgi bodies and mitochondria. Yet many other well-known cellular structures, including the nucleolus—an organelle within the nucleus—and the RNA-processing Cajal bodies, lack membranes. Phase separation is an appealing answer. Many proteins sport sticky patches that attract other proteins of the same or a different type. Test tube studies have shown that under certain conditions, such as when protein concentration climbs above a certain level, the molecules may begin to huddle, forming dropletlike condensates. Researchers understand the mechanics best for proteins, but nucleic acids such as RNA could also aggregate with proteins. If the process happens in the cell, it could generate and maintain organelles and permit unique functions. “It's a principle that could explain how many things in the cell and nucleus are organized,” says biophysicist Mustafa Mir of the University of Pennsylvania, who as a postdoc once worked with Tjian. Although biologists mooted a role for intracellular droplets as far back as the 1890s, evidence that they are vital began to coalesce a little over 10 years ago. Brangwynne, then a postdoc at the Max Planck Institute of Molecular Cell Biology and Genetics, was tracing P granules, flecks of protein and RNA that, in nematode embryos, mark the cells that go on to produce sperm and eggs. To observe the granules' movements, Brangwynne squeezed worm gonads that harbor the structures between two microscope cover slips. Under pressure, P granules responded not like solids but like liquids, flowing along the surface of the nucleus and dripping off, he and colleagues reported in Science in 2009. The granules' watery behavior “was mind-blowing. It was so different than anything in cells,” says Weber, a former postdoc of Brangwynne's. In 2012, Brangwynne and colleagues saw similar fluid features in the nucleolus, a dense mix of proteins, RNA, and DNA that manufactures ribosomes, the cell's protein factories. The same year, biophysicist Michael Rosen of the University of Texas Southwestern Medical Center and colleagues showed that three proteins that collaborate to organize part of the cytoskeleton form liquid droplets in a test tube solution. They found that the process speeds the assembly of one type of skeletal fiber in vitro—and might do the same in the cell. Scientists have since reported dozens of examples of cellular structures that are round, prone to fuse, and tend to bead on or flow across surfaces—hallmarks of droplets formed by phase separation (see graphic, p. 338). To confirm that a molecular gathering in a cell is a liquid and not something more solid, scientists often deploy a technique called fluorescence recovery after photobleaching (FRAP). Using a cell that contains fluorescent proteins, researchers zap the region in question with a laser to darken the molecules and then trace how long the fluorescence takes to diffuse back in from other parts of the cell. A liquid, which the fluorescent proteins easily penetrate, should light up more quickly than a solid. Another test involves applying 1,6-hexanediol, a compound that fractures some of the molecular interactions that hold droplets together, to determine whether the structure dissolves. Rosen notes that three papers published last year in Cell offer some of the strongest evidence for phase separation in cells. One, from Brangwynne's lab, showed a particular protein had to reach a threshold concentration in cells to allow formation of stress granules—organelles that pop up during hard times and have been attributed to phase separation. The other two studies also identified threshold conditions for phase separation. Because a threshold is an attribute of the process, the studies provide “good but not perfect data that these structures are going through phase separation,” Rosen says. Many researchers are now convinced that phase separation explains many aspects of cell organization and function. Several research groups have reported that the mechanism helps convene the hundreds of proteins that carry out transcription, the process of reading DNA to produce the RNA instructions for making proteins. Similar molecular corralling may underlie functions including memory in fruit flies, immune cells' responses to pathogens, DNA silencing, transmission of nerve impulses across synapses, and reproduction of SARS-CoV-2, the pandemic coronavirus. Conversely, phase separation may cause disease when it goes awry. In 2018, for example, biophysicist Tanja Mittag of St. Jude Children's Research Hospital and colleagues revealed that mutations that promote several kinds of tumors disrupt the ability of the protein SPOP, which helps eliminate proteins that spur growth of cancer cells, to form droplets in test tube solutions. The researchers proposed that phase separation is key to SPOP's cleanup function in cells, and thwarting it allows cancer-promoting proteins to accumulate. Faulty phase separation could also spur damage by aiding the formation of the toxic intracellular inclusions, or protein globs, that amass in neurodegenerative illnesses such as ALS, Alzheimer's disease, and Parkinson's disease. For example, in some ALS patients the protein FUS is mutated and forms inclusions in their neurons. In the test tube, the mutated protein condenses into droplets that then morph into furry knots of fibers resembling the inclusions. In 2018, biochemist Dorothee Dormann of the Ludwig Maximilian University of Munich and colleagues discovered a possible reason: The mutated version of FUS shrugs off a protein bodyguard that prevents the normal variety from undergoing phase separation and clumping in the test tube. YET THAT SATISFYING PICTURE may be growing murky as more researchers have raised doubts about phase separation. In 2019, for instance, scientists organized a debate at Wiston House, a posh 16th century manor south of London, in part to mull whether the process helped control gene activity. About 30 participants hashed over the evidence that the process occurs in cells with the help of “free-flowing champagne,” recalls Mir, one of the presenters. The group's conclusion, he says, was that the support for many putative cases of phase separation in cells is shaky. Tjian, who was not at the meeting, came around to a similar conclusion because of new data from McSwiggen. McSwiggen's early evidence showed that in herpesvirus-infected cells, the replication compartments—clusters of protein and DNA that help produce new copies of the pathogen—are round and merge with each other, suggesting they result from phase separation. After tracking individual proteins within cells, though, McSwiggen and colleagues determined the molecules diffuse just as fast through the compartments as through the rest of the nucleus. In a true condensate, molecular crowding should have hindered diffusion. Other researchers found the negative evidence compelling when it was published later in 2019, soon after the Wiston House debate. The study is “a really important cautionary tale,” Weber says. The results spurred Tjian, McSwiggen, Mir, and Xavier Darzacq, a cell biologist who co-directs the UC Berkeley lab with Tjian, to scrutinize the phase separation literature. Later that year, in a December 2019 issue of Genes and Development , they published a scathing review of 33 studies that claimed to detect the process in cells. Tjian says he was “really disappointed by the quality of the papers.” The evidence, he and his co-authors wrote, was “often phenomenological and inadequate to discriminate between phase separation and other possible mechanisms.” Too often, he and the other review authors asserted, researchers looking for phase separation rely on qualitative indicators—shape, for example—rather than quantitative data. Moreover, because many intracellular structures possibly formed by phase separation are so small, they are near what's known as the diffraction limit of traditional light microscopes. As a result, the structures may look like fuzzy orbs, but their real shape isn't discernible. Tjian and colleagues also chastised researchers for often assuming the protein concentration in a cell is high enough to trigger phase separation, instead of actually measuring it. Overinterpretation “is rampant” in this type of research, Tjian says. The scientists questioned the FRAP measurements that underpin many claims of phase separation. In the hands of different scientists, the group noted, FRAP recovery rates for the same molecule can range from less than 1 second to several minutes, indicating the technique is too variable to confirm phase separation. Darzacq adds that FRAP “only shows you have a liquid. You have liquid everywhere in the cell.” Many of the congregations that researchers have identified with FRAP or other techniques are probably transient collections of molecules that only last a few seconds, Darzacq and Tjian say. ![Figure] Dropping inCREDITS: (GRAPHIC) V. ALTOUNIAN/ SCIENCE ; (IMAGE) C. BRANGWYNNE ET AL., SCIENCE , 324, 5935, 1729 (2020) The review was “an invitation for all of us to proceed with a more careful and thoughtful in-depth analysis of cellular condensates,” says molecular biophysicist Sua Myong of Johns Hopkins University. Although some scientists have been meticulous, “it has not been true of the field,” Rosen adds. Brangwynne says he, too, sees value in the critique. “I agree that we need quantitative approaches.” For example, he concurs that researchers need to be more rigorous when interpreting imaging results so that “every diffraction-limited blob” isn't declared an example of phase separation. Other recent papers have also raised doubts about cases of phase separation. In 2019 in Non-Coding RNA , Weber and a co-author weighed the support for phase separation in the cell nucleus and concluded that solid data back its role in forming three structures, including the nucleolus, but not two other structures commonly attributed to the process. And in April 2020 in Molecular Cell , biophysicist Fabian Erdel of the Center for Integrative Biology in Toulouse, France, and colleagues published a new investigation of heterochromatin—silenced regions of the genome in which DNA coils tightly with various proteins. Previous work suggested phase separation of the intracellular protein HP1 helped stretches of heterochromatin bunch up. But Erdel's team discovered that HP1 didn't form stable liquid droplets in mouse cells and that the size of the densely packed DNA regions didn't depend on the amount of the protein. Brangwynne and other researchers argue that even if some individual findings cited by Tjian and colleagues remain in dispute, the field is making progress toward more solid results. To provide some of the rigor of test tube studies, he and his team have developed a technique for seeding cells with what they call corelets, combinations of molecular fragments that cluster when exposed to light. The corelets trigger droplet formation in cells, allowing the researchers to more precisely probe what protein concentrations are necessary for phase separation and which parts of the molecule are required for the behavior. Even Tjian and colleagues give the approach high marks. Mir, who has been skeptical of much of the evidence for phase separation, agrees that the field seems to be moving away from the “everything is phase separation” stage to a more nuanced discussion of the formation and functions of condensates. “It's like any supertrendy thing in science. The noise subsides, and you are left with the truth.” To get to that truth, however, researchers “desperately need” new tools and a better understanding of the basic rules for how condensates form in cells, Gladfelter says. Scientists also need patience, she says, noting the field “tried to grow up and answer everything really fast.” But she's confident researchers will eventually sort out the real importance of phase separation in cells. “Give us time. We'll get there.” : pending:yes
To stop algorithms from charging unfair prices when we shop online, the UK's competition watchdog is launching a new investigation into the ways that AI systems might harm consumers – an issue that has so far lacked in-depth research and analysis, says the organization, and yet affects most of us in our everyday lives. While a lot of attention has focused on algorithmic harms in general, the Competition and Markets Authority (CMA) suggested that little work has been done in the specific area of consumer and competition harms, and reported that almost no research on the topic exists in the UK. There is particularly little insight into the ways that automated systems tailor costs, shopping options or rankings to each individual's online behavior, often leading to consumers paying higher prices than they should. For this reason, the CMA has asked academics and industry to submit evidence about the potential misdeeds caused by the misuse of algorithms, and is launching a program called "Analyzing Algorithms", which could even help identify specific firms that are violating consumers' rights, so that cases can be taken forward if needed. Kate Brand, director of data science at CMA, said: "We want to receive as much information as possible from stakeholders in academia, the competition community, firms, civil society and third sector organizations in order to understand where the harm is occurring and what the most effective regulatory approach is to protect consumers in the future."
While face masks were once rare sightings, they're now compulsory in a range of settings across the UK. The face coverings play a key role in stopping the spread of Covid-19, yet many iPhone users have been frustrated that their masks have prevented them from unlocking their iPhones using Apple's facial recognition technology, Face ID. Now, a report indicates that Apple could be bringing back its Touch ID technology in its 2021 iPhone, in the form of an in-screen fingerprint reader, to help users unlock their smartphones without having to remove their masks. Rather than being a replacement for Face ID, Touch ID would be an additional method of unlocking the iPhone, according to the report. Many iPhone users have been frustrated that their masks have prevented them from unlocking their iPhone using Apple's facial recognition technology, Face ID (stock image) The report, by Bloomberg, indicates that changes to this year's iPhone will be minor.
As politicians play whack-a-mole with COVID-19 infection rates and try to balance the economic damage caused by lockdowns, stay-at-home orders have also impacted those out there in the dating scene. No longer able to meet up for a drink, a coffee, or now even a walk in the park, organizing an encounter with anyone other than your household or support bubble is banned and can result in a fine in the United Kingdom -- and this includes both dates and overnight stays. Therefore, the only feasible option available is online connections, by way of social networks or dating apps. Dating is hard enough at the best of times but sexual desire doesn't disappear just because you are cooped up at home. Realizing this, a number of healthcare organizations worldwide have urged us not to contribute to the spread of COVID-19 by meeting up with others for discreet sex outside of our social bubbles, bringing new meaning to the phrase, "You are your safest sex partner."
In the last decades, artificial intelligence has shown to be very good at achieving exceptional goals in several fields. Chess is one of them: in 1996, for the first time, the computer Deep Blue beat a human player, chess champion Garry Kasparov. A new piece of research shows now that the brain strategy for storing memories may lead to imperfect memories, but in turn, allows it to store more memories, and with less hassle than AI. The new study, carried out by SISSA scientists in collaboration with Kavli Institute for Systems Neuroscience & Centre for Neural Computation, Trondheim, Norway, has just been published in Physical Review Letters. Neural networks, real or artificial, learn by tweaking the connections between neurons.