Day: September 26, 2020

At a University of Maryland lab, people infected with the new coronavirus take turns sitting in a chair and putting their faces into the big end of a large cone. They recite the alphabet and sing or just sit quietly for a half hour. Sometimes they cough.The cone sucks up everything that comes out of their mouths and noses. It’s part of a device called “Gesundheit II” that is helping scientists study a big question: Just how does the virus that causes COVID-19 spread from one person to another?It clearly hitchhikes on small liquid particles sprayed out by an infected person. People expel particles while coughing, sneezing, singing, shouting, talking and even breathing. But the drops come in a wide range of sizes, and scientists are trying to pin down how risky the various kinds are.The answer affects what we should all be doing to avoid getting sick. That’s why headlines were made a few days ago when a U.S. health agency appeared to have shifted its position on the issue, but later said it had published new language in error.The recommendation to stay at least 6 feet (2 meters) apart — some authorities cite about half that distance — is based on the idea that larger particles fall to the ground before they can travel very far. They are like the droplets in a spritz of a window cleaner, and they can infect a person by landing on his nose, mouth or eyes, or maybe if they are inhaled.Smaller particlesBut some scientists are now focusing on tinier particles, the ones that spread more like cigarette smoke. Those are carried by wisps of air and even upward drafts caused by the warmth of our bodies. They can linger in the air for minutes to hours, spreading throughout a room and building up if ventilation is poor.The potential risk comes from inhaling them. Measles can spread this way, but the new coronavirus is far less contagious than that.For these particles, called aerosols, “6 feet is not a magic distance,” said Linsey Marr, a leading researcher who is studying them at Virginia Tech in Blacksburg. But she says it’s still important to keep one’s distance from others, “the farther the better,” because aerosols are most concentrated near a source and pose a bigger risk at close range.Public health agencies have generally focused on the larger particles for coronavirus.That prompted more than 200 other scientists to publish a plea in July to pay attention to the potential risk from aerosols. The World Health Organization, which had long dismissed a danger from aerosols except in the case of certain medical procedures, later said that aerosol transmission of the coronavirus can’t be ruled out in cases of infection within crowded and poorly ventilated indoor spaces.FILE – A view of the Centers for Disease Control and Prevention headquarters in Atlanta.The issue drew attention recently when the U.S. Centers for Disease Control and Prevention posted and then deleted statements on its website that highlighted the idea of aerosol spread. The agency said the posting was an error, and that the statements were just a draft of proposed changes to its recommendations.Dr. Jay Butler, CDC’s deputy director for infectious disease, told The Associated Press that the agency continues to believe larger and heavier droplets that come from coughing or sneezing are the primary means of transmission.Last month, Butler told a scientific meeting that current research suggests aerosol spreading of the coronavirus is possible, but it doesn’t seem to be the main way that people get infected. Further research may change that conclusion, he added, and he urged scientists to study how often aerosol spread of the coronavirus occurs, what situations make it more likely and what reasonable steps might prevent it.Marr said she thinks infection by aerosols is “happening a lot more than people initially were willing to think.”‘Superspreader’ eventsAs a key piece of evidence, Marr and others point to so-called “superspreader” events where one infected person evidently passed the virus to many others in a single setting.Butler said such events raise concern about aerosol spread but don’t prove it happens.There could be another way for tiny particles to spread. They may not necessarily come directly from somebody’s mouth or nose, said William Ristenpart of the University of California-Davis. His research found that if paper tissues are seeded with influenza virus and then crumpled, they give off particles that bear the virus. So people emptying a wastebasket with tissues discarded by somebody with COVID-19 should be sure to wear a mask, he said.Scientists who warn about aerosols say current recommendations still make sense.FILE – Public information messages are posted in Manchester, England, after British Prime Minister Boris Johnson issued new restrictions to slow the renewed spread of the coronavirus, Sept 22, 2020.Wearing a mask is still important, and make sure it fits snugly. Keep washing those hands diligently. And again, staying farther apart is better than being closer together. Avoid crowds, especially indoors.Their main addition to recommendations is ventilation to avoid a buildup of aerosol concentration. So, the researchers say, stay out of poorly ventilated rooms. Open windows and doors. One can also use air-purifying devices or virus-inactivating ultraviolet light.Best of all: Just do as much as you can outdoors, where dilution and the sun’s ultraviolet light work in your favor.”We know outdoors is the most spectacularly effective measure, by far,” said Jose-Luis Jimenez of the University of Colorado-Boulder. “Outdoors it is not impossible to get infected, but it is difficult.”FILE – In this July 15, 2020, photo, job seekers exercise social distancing as they wait to be called into the Heartland Workforce Solutions office in Omaha, Neb.The various precautions should be used in combination rather than just one at a time, researchers say. In a well-ventilated environment, “6 feet [of separation] is pretty good if everybody’s got a mask on” and nobody stays directly downwind of an infected person for very long, said Dr. Donald Milton of the University of Maryland School of Public Health, whose lab houses the Gesundheit II machine.Duration of exposure is important, so there’s probably not much risk from a short elevator ride while masked or being passed by a jogger on the sidewalk, experts say.Scientists have published online tools for calculating risk of airborne spread in various settings.At a recent meeting on aerosols, however, Dr. Georges Benjamin, executive director of the American Public Health Association, noted that preventive steps can be a challenge in the real world. Keeping apart from other people can be difficult in homes that house multiple generations. Some old buildings have windows that were “nailed shut years ago,” he said. And “we have far too many communities where they simply don’t have access to clean water to wash their hands.”It might seem strange that for all the scientific frenzy to study the new coronavirus, the details of how it spreads can still be in doubt nine months later. But history suggests patience.”We’ve been studying influenza for 102 years,” said Milton, referring to the 1918 flu epidemic. “We still don’t know how it’s transmitted and what the role of aerosols is.”
…

SHANGHAI/WASHINGTON — The United States government has imposed restrictions on exports to China’s biggest silicon chip maker after concluding there is an “unacceptable risk” that equipment supplied to it could be used for military purposes.
 
Suppliers of certain equipment to Semiconductor Manufacturing International Corporation (SMIC) will now have to apply for individual export licenses, according to a letter from the Commerce Department dated Friday and seen by Reuters.
 
SMIC becomes the second leading Chinese technology company to face U.S. trade curbs after telecoms giant Huawei Technologies, whose access to high-end chips has been curtailed by its addition to a so-called entity list.
 
The Pentagon said earlier this month that it was weighing blacklisting SMIC, which the U.S. authorities have identified as a threat due to an alleged “fusion” of civilian and military technologies.
 
Asked for comment, SMIC said it had not received any official notice of the restrictions and said it has no ties with the Chinese military.
 
“SMIC reiterates that it manufactures semiconductors and provides services solely for civilian and commercial end-users and end-uses,” SMIC said.
 
“The Company has no relationship with the Chinese military and does not manufacture for any military end-users or end-uses.”
 
The Commerce Department declined on Saturday to comment specifically on SMIC, but said its Bureau of Industry and security was “constantly monitoring and assessing any potential threats to U.S. national security and foreign policy interests.”
 
…

The U.S. Justice Department asked a federal judge in San Francisco on Friday to allow the government to bar Apple Inc. and Alphabet Inc.’s Google from offering WeChat for download in U.S. app stores pending an appeal.The filing asked U.S. Magistrate Judge Laurel Beeler to put on hold her preliminary injunction issued Saturday. That injunction blocked the U.S. Commerce Department order that was set to take effect late September 20 and that would also bar other U.S. transactions with Tencent Holding’s WeChat, potentially making the app unusable in the United States.Beeler responded late Friday by setting a hearing for October 15 on the motion but said she could potentially hold it on “a tighter time period.”The Justice Department filing said Beeler’s order was in error and “permits the continued, unfettered use of WeChat, a mobile application that the Executive Branch has determined constitutes a threat to the national security and foreign policy of the United States.”Tencent had put forward a “mitigation proposal” that sought to create a new U.S. version of the app, deploy specific security measures to protect the new apps source code, partner with a U.S. cloud provider for user data storage, and manage the new app through a U.S.-based entity, the filing said.However, its proposal still allowed Tencent to retain ownership of WeChat and did not address U.S. concerns over the company, it added.Tencent declined to comment.Lawyers for U.S. WeChat Users Alliance, the group behind the legal challenge to the WeChat ban, questioned the urgency of the government’s request, noting the time it took for the government to seek a stay.”The government’s decision to sit tight for five days shows that there is no emergency,” they wrote.In support of its argument, the Justice Department made public portions of a September 17 Commerce Department memo outlining the WeChat transactions to be banned.”The WeChat mobile application collects and transmits sensitive personal information on U.S. persons, which is accessible to Tencent and stored in data centers in China and Canada,” the memo said. Beeler said WeChat users who filed a lawsuit “have shown serious questions going to the merits of the First Amendment claim.”The Justice Department filing said, “The First Amendment does not bar regulation of WeChat simply because it has achieved the popularity and dependency sought by (China), precisely so it can surveil users, promote its propaganda, and otherwise place U.S. national security at risk.”WeChat has had an average of 19 million daily active users in the United States, analytics firms Apptopia said in early August. It is popular among Chinese students, Americans living in China and some Americans who have personal or business relationships in China.Beeler wrote “certainly the government’s over-arching national-security interest is significant. But on this record — while the government has established that China’s activities raise significant national security concerns — it has put in scant little evidence that its effective ban of WeChat for all U.S. users addresses those concerns.”WeChat is an all-in-one mobile app that combines services similar to Facebook, WhatsApp, Instagram and Venmo. The app is an essential part of daily life for many in China and boasts more than 1 billion users.TikTok on Wednesday sought a similar preliminary injunction from a U.S. judge in Washington. A judge on Friday said he would hold a hearing Sunday morning about whether to halt the U.S. app store ban on new TikTok downloads set to take effect Sunday night.  
…