Group items tagged

“So far we’re seeing basic agreement with our best model of the universe, but we’re also seeing some potentially interesting differences that could indicate that dark energy is evolving with time,”

When the scientists combined their map with other cosmological data, they were surprised to find that it did not quite agree with the otherwise reliable standard model of the universe, which assumes that dark energy is constant and unchanging. A varying dark energy fit the data points better.

“It’s certainly more than a curiosity,” Dr. Palanque-Delabrouille said. “I would call it a hint. Yeah, it’s not yet evidence, but it’s interesting.”

But this version of dark energy is merely the simplest one. “With DESI we now have achieved a precision that allows us to go beyond that simple model,” Dr. Palanque-Delabrouille said, “to see if the density of dark energy is constant over time, or if it has some fluctuations and evolution with time.”

“While combining data sets is tricky, and these are early results from DESI, the possible evidence that dark energy is not constant is the best news I have heard since cosmic acceleration was firmly established 20-plus years ago.”

praised the new survey as “superb data.” The results, she said, “open the potential for a new window into understanding dark energy, the dominant component of the universe, which remains the biggest mystery in cosmology. Pretty exciting.”

what if dark energy were not constant as the cosmological model assumed?

At issue is a parameter called w, which is a measure of the density, or vehemence, of the dark energy. In Einstein’s version of dark energy, this number remains constant, with a value of –1, throughout the life of the universe. Cosmologists have been using this value in their models for the past 25 years.

Dark energy took its place in the standard model of the universe known as L.C.D.M., composed of 70 percent dark energy (Lambda), 25 percent cold dark matter (an assortment of slow-moving exotic particles) and 5 percent atomic matter. So far that model has been bruised but not broken by the new James Webb Space Telescope

As a measure of distance, the researchers used bumps in the cosmic distribution of galaxies, known as baryon acoustic oscillations. These bumps were imprinted on the cosmos by sound waves in the hot plasma that filled the universe when it was just 380,000 years old. Back then, the bumps were a half-million light-years across. Now, 13.5 billion years later, the universe has expanded a thousandfold, and the bumps — which are now 500 million light-years across — serve as convenient cosmic measuring sticks.

The DESI scientists divided the past 11 billion years of cosmic history into seven spans of time. (The universe is 13.8 billion years old.) For each, they measured the size of these bumps and how fast the galaxies in them were speeding away from us and from each other.

When the researchers put it all together, they found that the usual assumption — a constant dark energy — didn’t work to describe the expansion of the universe. Galaxies in the three most recent epochs appeared closer than they should have been, suggesting that dark energy could be evolving with time.

Dr. Riess of Johns Hopkins, who had an early look at the DESI results, noted that the “hint,” if validated, could pull the rug out from other cosmological measurements, such as the age or size of the universe. “This result is very interesting and we should take it seriously,” he wrote in his email. “Otherwise why else do we do these experiments?”

Analyzing the relative sizes and frequencies of spots and ripples over the years has allowed astronomers to describe the birth of the universe to a precision that would make the philosophers weep. The new data have allowed astronomers to tweak their model a bit. It now seems the universe is 13.8 billion years old, instead of 13.7 billion, and consists by mass of 4.9 percent ordinary matter like atoms, 27 percent dark matter and 68 percent dark energy.

“Our ultimate goal would be to construct a new model that predicts the anomalies and links them together. But these are early days; so far, we don’t know whether this is possible and what type of new physics might be needed. And that’s exciting.”

The microwaves detected by the Planck date from 370,000 years after the Big Bang, which is as far back as optical or radio telescopes will ever be able to see, cosmologists say. But the patterns within them date from less than a trillionth of a second after the Big Bang, when the universe is said to have undergone a violent burst of expansion known as inflation that set cosmic history on the course it has followed ever since. Those patterns are Planck’s prize.

Within the standard cosmological framework, however, the new satellite data underscored the existence of puzzling anomalies that may yet lead theorists back to the drawing board. The universe appears to be slightly lumpier, with bigger and more hot and cold spots in the northern half of the sky as seen from Earth than toward the south, for example. And there is a large, unexplained cool spot in the northern hemisphere.

The biggest surprise here, astronomers said, is that the universe is expanding slightly more slowly than previous measurements had indicated. The Hubble constant, which characterizes the expansion rate, is 67 kilometers per second per megaparsec — in the units astronomers use — according to Planck. Recent ground-based measurements combined with the WMAP data gave a value of 69, offering enough of a discrepancy to make cosmologists rerun their computer simulations of cosmic history.

a Planck team member from the University of California, Berkeley, said it represents a mismatch between measurements made of the beginning of time and those made more recently, and that it could mean that dark energy, which is speeding up the expansion of the universe, is more complicated than cosmologists thought. He termed the possibility “pretty radical,” adding, “That would be pretty exciting.”

The data also offered striking support for the notion of inflation, which has been the backbone of Big Bang theorizing for 30 years. Under the influence of a mysterious force field during the first trillionth of a fraction of a second, what would become the observable universe ballooned by 100 trillion trillion times in size from a subatomic pinprick to a grapefruit in less than a violent eye-blink, so the story first enunciated by Alan Guth of M.I.T. goes.

Submicroscopic quantum fluctuations in this force field are what would produce the hot spots in the cosmic microwaves, which in turn would grow into galaxies. According to Planck’s measurements, those fluctuations so far fit the predictions of the simplest model of inflation, invented by Andrei Linde of Stanford, to a T. Dr. Tegmark of M.I.T. said, “We’re homing in on the simplest model.”

Cosmologists still do not know what might have caused inflation, but the recent discovery of the Higgs boson has provided evidence that the kinds of fields that can provoke such behavior really exist.

another clue to the nature of inflation could come from the anomalies in the microwave data — the lopsided bumpiness, for example — that tend to happen on the largest scales in the universe. By the logic of quantum cosmology, they were the first patterns to be laid down on the emerging cosmos; that is to say, when inflation was just starting.

Conservatives are mainly taking aim at a pair of Obama directives to ensure protections for LGBT employees of federal contractors and to direct public schools to provide access to locker rooms and bathrooms that correspond with their gender identity. 

Also on Wednesday, a measure by Alabama GOP Rep. Bradley Byrne passed to exempt religious groups from complying with the directives.

Republican leaders have tried to steer lawmakers away from wading into the hot-button debate on the House floor.

The speaker this week cautioned GOP members at a closed-door session that Democrats were likely to keep trying to force them into uncomfortable votes on LGBT discrimination, according to aides and members who were present.

He floated the idea of modifying House rules in a move that would likely restrict the number of amendments that could be offered on the floor, which would allow leaders to get out ahead of controversial votes and avoid any potentially embarrassing floor fights.

The GOP leadership is trying to “thread the needle,” according to aides, between conservatives itching for another chance to challenge Obama and those who don’t want to tackle on an issue they think is best left for the states to resolve. 

For their part, Democrats are exploiting the rift, looking to draw attention to the GOP infighting after a measure that would have banned federal contractors from discriminating against LGBT employees failed in the House last week.

Democrats see LGBT rights as a prime opportunity to prove that House Republicans are intolerant of minorities. 

The vote on Maloney’s original measure turned heated last week when it appeared that seven Republicans switched their votes after the bill seemed to have passed.

Ryan told reporters on Wednesday that the breakdown — which involved Democrats shouting “shame, shame” across the aisle at their GOP colleagues —  was just a misunderstanding.

Then, Democrats successfully rallied support from moderate Republicans to ban the flag on federal property. Southern Republicans were enraged and threatened to vote against the overall bill, forcing former House Speaker John A. Boehner (R-Ohio) to give up on the entire appropriations process to avoid an embarrassing failure.

The stakes are much higher this year for Ryan who has vowed to return the House to working order, starting with passing spending bills and allowing any member to offer amendments.

Democratic supporters of safety net programs can use Jencks’s finding that poverty has dropped below 5 percent as evidence that the war on poverty has been successful.

At the same time liberals are wary of positive news because, as Jencks notes:It is easier to rally support for such an agenda by saying that the problem in question is getting worse

The plus side for conservatives of Jencks’s low estimate of the poverty rate is the implication that severe poverty has largely abated, which then provides justification for allowing enemies of government entitlement programs to further cut social spending.

At the same time, however, Jencks’s data undermines Republican claims that the war on poverty has been a failure – a claim exemplified by Ronald Reagan’s famous 1987 quip: “In the sixties we waged a war on poverty, and poverty won.”

Jencks’s conclusion: “The absolute poverty rate has declined dramatically since President Johnson launched his war on poverty in 1964.” At 4.8 percent, Jencks’s calculation is the lowest poverty estimate by a credible expert in the field.

his conclusion — that instead of the official count of 45.3 million people living in poverty, the number of poor people in America is just under 15 million — understates the scope of hardship in this country.

There are strong theoretical justifications for the use of a relative poverty measure. The Organization for Economic Cooperation and Development puts it this way:In order to participate fully in the social life of a community, individuals may need a level of resources that is not too inferior to the norms of a community. For example, the clothing budget that allows a child not to feel ashamed of his school attire is much more related to national living standards than to strict requirements for physical survival

using a relative measure shows that the United States lags well behind other developed countries:If you use the O.E.C.D. standard of 50 percent of median income as a poverty line, the United States looks pretty bad in cross-national relief. We have a relative poverty rate exceeded only by Chile, Turkey, Mexico and Israel (which has seen a big increase in inequality in recent years). And that rate in 2010 was essentially where it was in 1995

While the United States “has achieved real progress in reducing absolute poverty over the past 50 years,” according to Burtless, “the country may have made no progress at all in reducing the relative economic deprivation of folks at the bottom.”

the heart of the dispute: How severe is the problem of poverty?

Kathryn Edin, a professor of sociology at Johns Hopkins, and Luke Schaefer, a professor of social work at the University of Michigan, contend that the poverty debate overlooks crucial changes that have taken place within the population of the poor.

welfare reform, signed into law by President Clinton in 1996 (the Personal Responsibility and Work Opportunity Act), which limited eligibility for welfare benefits to five years. The limitation has forced many of the poor off welfare: over the past 19 years, the percentage of families falling under the official poverty line who receive welfare benefits has fallen from to 26 percent from 68 percent. Currently, three-quarters of those in poverty, under the official definition, receive no welfare payments.

he enactment of expanded benefits for the working poor through the earned-income tax credit and the child tax credit.According to Edin and Schaefer, the consequence of these changes, taken together, has been to divide the poor who no longer receive welfare into two groups. The first group is made up of those who have gone to work and have qualified for tax credits. Expanded tax credits lifted about 3.2 million children out of poverty in 2013

he second group, though, has really suffered. These are the very poor who are without work, part of a population that is struggling desperately. Edin and Schaefer write that among the losers are an estimated 3.4 million “children who over the course of a year live for at least three months under a $2 per person per day threshold.”

ocusing on these findings, Mishel argues, diverts attention from the more serious problem of “the failure of the labor market to adequately reward low-wage workers.”To support his case, Mishel points out that hourly pay for those in the bottom fifth grew only 7.7 percent from 1979 to 2007, while productivity grew by 64 percent, and education levels among workers in this quintile substantially improved.

it could signal the beginning of a new era of virtual assistants that will redefine our relationships with intelligent machines.

providing someone with valuable insights about their productivity, stress levels during meetings or lifestyle habits that impact their ability to perform their job

“We set out to discover whether there was a way to move the needle from an almost backward way of assessing people’s workplace performance to using more objective measures.

research shows that conscientious people, who are often more detailed-oriented and disciplined, tend to be more productive

If it was possible to predict someone’s mental health by analyzing their social media feeds and smartphone data, Campbell wondered, could similar data be leveraged to improve employee performance evaluations?

The workers were fitted with a wearable fitness tracker that monitored heart functions, sleep, stress, and measurements such as weight and calorie consumption, as well as a smartphone app that tracked their physical activity, location, phone usage and ambient light.

Location beacons placed in the home and office measured participants time at work and breaks from their desk, giving researchers a comprehensive window into their day from one hour to the next.

The information was processed by cloud-based machine-learning algorithms that classified performance using factors such as the amount of time spent at the workplace, quality of sleep, physical activity and phone usage

“We want to use that information to empower workers to tell them whether they’re being influenced by levels of stress or sleep or other factors that may not be immediately obvious to them.”

What the research does not explain, he said, is what habits make someone conscientious in the first place, leaving a gap in knowledge that researchers hoped to fill.

“Very often when people try to detect what drives performance, they rely on personality, which actually reveals little about someone’s ability to do their job well,” he said. “Evaluations can be biased because they are infused with stereotyping of people or political influences inside an office. But when you can extract a pattern over weeks and months, we can be more certain that assessment is objective and neutral.

the results showed, perhaps not surprisingly, that high performers tended to have lower rates of phone usage.

They also experience deeper periods of sustained sleep and are more physically active than their lower performing colleagues.

Researchers discovered that high-performing supervisors tended to be more mobile during the day, but they visited a smaller number of distinct places during their working hours

High-performing non-supervisors, meanwhile, tend to spend more time at work during the weekends,

Future versions, they said, could be tailored to individual jobs and provide workers with meaningful information about changes in their mental well-being during meetings or suggestions for reducing stress each week

But they also acknowledge that the valuable private data could prove volatile if it falls into a company’s hands without employee consent. Campbell suggested there might be a middle ground, such as companies offering incentives to employees who opt into a program that treats precise assessment data as one tool among several for evaluating performance.

“If there was any point down the road where I could have an application on my phone that could provide an objective assessment of my performance, that might be an incentive for workers to use it," he said. “Imagine being able to say, ‘Here’s the evidence that I deserve to be promoted or that my boss is standing in my way.’"

“I can’t really look into a crystal ball, but I’m hopeful this passive sensing technology will be used to empower the workforce rather than used against them," he added.

Facts First: This is partly true. As the experience of Italy and other countries shows, having universal coverage and a government-run health system is not enough on its own to stem the spread of coronavirus. But the US is at a disadvantage in fighting the coronavirus because tens of millions of Americans are uninsured or face high out-of-pocket costs before their insurance kicks in -- which may make people hesitant to seek testing or treatment.

"Addressing coronavirus with tens of millions of people without health insurance or with inadequate insurance will be a uniquely American challenge among developed countries," tweeted Larry Levitt, executive vice president for health policy at Kaiser. "It will take money to treat people and address uncompensated care absorbed by providers."

President Donald Trump has tweeted his support of the package. The Senate is expected to take up the measure when it returns to session this week.

Laboratories in Germany developed tests to detect the coronavirus which the WHO adopted and by last week, the WHO sent out tests to 120 countries. Other countries, like the US and China, chose to develop their own tests, according to the Washington Post.

On February 12, the Center for Disease Control reported that some of the coronavirus test kits shipped to labs across the country were not working as they should.

Dr. Anthony Fauci, Director of the National Institute of Allergy and Infectious Diseases and one of the experts leading the administration's response to the coronavirus told Congress Thursday that the US was "failing" when it came to getting Americans tested.

In an exchange about how the government bailed out banks during the 2008 financial crisis, Biden asserted that Sanders voted against a bailout for the auto industry.

Facts First: Sanders is right, but this needs context. Sanders voted for a bill that would have bailed out the auto industry -- but it failed to pass the Senate. He voted against a different bailout measure, the $700 billion Troubled Asset Relief Program, or TARP, which passed. That program released money to banks -- and a portion of that money eventually went to automakers.

Facts First: Biden's claim is misleading by omission. Biden was an advocate of ending the Saddam Hussein regime for more than a year before the war began in 2003. While Biden did begin calling his 2002 vote a "mistake" in 2005, he was a public supporter of the war in 2003 and 2004 -- and he made clear in 2002 and 2003, both before and after the war started, that he had known he was voting to authorize a possible war, not only to try to get inspectors into Iraq. It's also unclear whether Bush ever made Biden any kind of promise related to the use of force.

Facts First: The true number of Americans who die because they are uninsured or lack adequate coverage is not known. Some studies suggest the number is in the tens of thousands per year, but other experts have expressed skepticism that the number is as high as Sanders says.

Biden, who was a US senator at the time of his vote, responded, "I learned that I can't take the word of a President when in fact they assured me that they would not use force. Remember the context. The context was the United Nations Security Council was going to vote to insist that we allow inspectors into determining whether or not...they were, in fact, producing nuclear weapons or weapons of mass destruction. They were not."

Sanders on Sunday cited two figures about the number of people he claimed die because of the inadequacy of the US health care system.

During an exchange about Sanders' views on authoritarian countries, Biden claimed that China's income gains have been "marginal."

One way to measure standard of living is through a country's gross domestic product per capita at purchasing power parity. In other words, looking at a country's GDP per person in international dollars, a hypothetical currency used to measure purchasing parity between different countries.

Fact First: This Sanders' claim needs a lot of context. Biden did repeatedly support freezes in Social Security spending and at times called for raising the retirement age. In 2011, he said "changes" would have to be made to entitlements, saying they wouldn't be sustainable -- but he didn't specify what changes. Overall, the claim leaves out that Biden was typically talking about any changes to entitlements in the context of a broader legislative package.

And comments Biden made during a 1995 speech on the Senate floor show he was willing to make cuts to Medicare, but only as part of a broader deal that did not advocate cuts as big as Republicans want.

"If we are serious about saving Social Security, not raising taxes on the middle class, and not cutting back on benefits desperately needed by many senior citizens, we must adjust this artificial ceiling on Social Security taxes and make the Social Security tax more progressive."

Biden said upon his June 2019 reversal that he made "no apologies" for his past support of the amendment. He argued that "times have changed," since, he argued, the right to choose "was not under attack as it is now" from Republicans and since "women's rights and women's health are under assault like we haven't seen in the last 50 years."

Facts First: While it's unclear which ad Sanders was referring to, at least one super PAC connected to Biden, Unite the Country, ran a large television ad campaign that implicitly criticized Sanders without mentioning him by name..

For instance, it includes a clip from a Biden speech, in which Biden says" Democrats want a nominee who's a Democrat" -- an apparent challenge to the party bonafides of Sanders, who serves as an independent in the US Senate and describes himself as a democratic socialist.

They worried that a vaccine would initially elude scientists, that weary citizens would abandon restrictions despite the risks, that the virus would be with us from now on.

Most experts believed that once the crisis was over, the nation and its economy would revive quickly. But there would be no escaping a period of intense pain.

Exactly how the pandemic will end depends in part on medical advances still to come. It will also depend on how individual Americans behave in the interim. If we scrupulously protect ourselves and our loved ones, more of us will live. If we underestimate the virus, it will find us.

More Americans may die than the White House admits.

The epidemiological model often cited by the White House, which was produced by the University of Washington’s Institute for Health Metrics and Evaluation, originally predicted 100,000 to 240,000 deaths by midsummer. Now that figure is 60,000.

The institute’s projection runs through Aug. 4, describing only the first wave of this epidemic. Without a vaccine, the virus is expected to circulate for years, and the death tally will rise over time.

Fatality rates depend heavily on how overwhelmed hospitals get and what percentage of cases are tested. China’s estimated death rate was 17 percent in the first week of January, when Wuhan was in chaos, according to a Center for Evidence-Based Medicine report, but only 0.7 percent by late February.

Various experts consulted by the Centers for Disease Control and Prevention in March predicted that the virus eventually could reach 48 percent to 65 percent of all Americans, with a fatality rate just under 1 percent, and would kill up to 1.7 million of them if nothing were done to stop the spread.

A model by researchers at Imperial College London cited by the president on March 30 predicted 2.2 million deaths in the United States by September under the same circumstances.

China has officially reported about 83,000 cases and 4,632 deaths, which is a fatality rate of over 5 percent. The Trump administration has questioned the figures but has not produced more accurate ones.

The tighter the restrictions, experts say, the fewer the deaths and the longer the periods between lockdowns. Most models assume states will eventually do widespread temperature checks, rapid testing and contact tracing, as is routine in Asia.

In this country, hospitals in several cities, including New York, came to the brink of chaos.

Only when tens of thousands of antibody tests are done will we know how many silent carriers there may be in the United States. The C.D.C. has suggested it might be 25 percent of those who test positive. Researchers in Iceland said it might be double that.

China is also revising its own estimates. In February, a major study concluded that only 1 percent of cases in Wuhan were asymptomatic. New research says perhaps 60 percent were.

The virus may also be mutating to cause fewer symptoms. In the movies, viruses become more deadly. In reality, they usually become less so, because asymptomatic strains reach more hosts. Even the 1918 Spanish flu virus eventually faded into the seasonal H1N1 flu.

The lockdowns will end, but haltingly.

it is likely a safe bet that at least 300 million of us are still vulnerable.

Until a vaccine or another protective measure emerges, there is no scenario, epidemiologists agreed, in which it is safe for that many people to suddenly come out of hiding. If Americans pour back out in force, all will appear quiet for perhaps three weeks.

The gains to date were achieved only by shutting down the country, a situation that cannot continue indefinitely. The White House’s “phased” plan for reopening will surely raise the death toll no matter how carefully it is executed.

Every epidemiological model envisions something like the dance

On the models, the curves of rising and falling deaths resemble a row of shark teeth.

Surges are inevitable, the models predict, even when stadiums, churches, theaters, bars and restaurants remain closed, all travelers from abroad are quarantined for 14 days, and domestic travel is tightly restricted to prevent high-intensity areas from reinfecting low-intensity ones.

In his wildly popular March 19 article in Medium, “Coronavirus: The Hammer and the Dance,” Tomas Pueyo correctly predicted the national lockdown, which he called the hammer, and said it would lead to a new phase, which he called the dance, in which essential parts of the economy could reopen, including some schools and some factories with skeleton crews.

Even the “Opening Up America Again” guidelines Mr. Trump issued on Thursday have three levels of social distancing, and recommend that vulnerable Americans stay hidden. The plan endorses testing, isolation and contact tracing — but does not specify how these measures will be paid for, or how long it will take to put them in place.

On Friday, none of that stopped the president from contradicting his own message by sending out tweets encouraging protesters in Michigan, Minnesota and Virginia to fight their states’ shutdowns.

China did not allow Wuhan, Nanjing or other cities to reopen until intensive surveillance found zero new cases for 14 straight days, the virus’s incubation period.

Compared with China or Italy, the United States is still a playground.Americans can take domestic flights, drive where they want, and roam streets and parks. Despite restrictions, everyone seems to know someone discreetly arranging play dates for children, holding backyard barbecues or meeting people on dating apps.

Even with rigorous measures, Asian countries have had trouble keeping the virus under control

But if too many people get infected at once, new lockdowns will become inevitable. To avoid that, widespread testing will be imperative.

Reopening requires declining cases for 14 days, the tracing of 90 percent of contacts, an end to health care worker infections, recuperation places for mild cases and many other hard-to-reach goals.

Immunity will become a societal advantage.

Imagine an America divided into two classes: those who have recovered from infection with the coronavirus and presumably have some immunity to it; and those who are still vulnerable.

“It will be a frightening schism,” Dr. David Nabarro, a World Health Organization special envoy on Covid-19, predicted. “Those with antibodies will be able to travel and work, and the rest will be discriminated against.”

Soon the government will have to invent a way to certify who is truly immune. A test for IgG antibodies, which are produced once immunity is established, would make sense

Dr. Fauci has said the White House was discussing certificates like those proposed in Germany. China uses cellphone QR codes linked to the owner’s personal details so others cannot borrow them.

As Americans stuck in lockdown see their immune neighbors resuming their lives and perhaps even taking the jobs they lost, it is not hard to imagine the enormous temptation to join them through self-infection

My daughter, who is a Harvard economist, keeps telling me her age group needs to have Covid-19 parties to develop immunity and keep the economy going,”

It would be a gamble for American youth, too. The obese and immunocompromised are clearly at risk, but even slim, healthy young Americans have died of Covid-19.

The virus can be kept in check, but only with expanded resources.

Resolve to Save Lives, a public health advocacy group run by Dr. Thomas R. Frieden, the former director of the C.D.C., has published detailed and strict criteria for when the economy can reopen and when it must be closed.

once a national baseline of hundreds of thousands of daily tests is established across the nation, any viral spread can be spotted when the percentage of positive results rises.

To keep the virus in check, several experts insisted, the country also must start isolating all the ill — including mild cases.

“If I was forced to select only one intervention, it would be the rapid isolation of all cases,”

In China, anyone testing positive, no matter how mild their symptoms, was required to immediately enter an infirmary-style hospital — often set up in a gymnasium or community center outfitted with oxygen tanks and CT scanners.

There, they recuperated under the eyes of nurses. That reduced the risk to families, and being with other victims relieved some patients’ fears.

Still, experts were divided on the idea of such wards

Ultimately, suppressing a virus requires testing all the contacts of every known case. But the United States is far short of that goal.

In China’s Sichuan Province, for example, each known case had an average of 45 contacts.

The C.D.C. has about 600 contact tracers and, until recently, state and local health departments employed about 1,600, mostly for tracing syphilis and tuberculosis cases.

China hired and trained 9,000 in Wuhan alone. Dr. Frieden recently estimated that the United States will need at least 300,000.

There will not be a vaccine soon.

any effort to make a vaccine will take at least a year to 18 months.

the record is four years, for the mumps vaccine.

for unclear reasons, some previous vaccine candidates against coronaviruses like SARS have triggered “antibody-dependent enhancement,” which makes recipients more susceptible to infection, rather than less. In the past, vaccines against H.I.V. and dengue have unexpectedly done the same.

A new vaccine is usually first tested in fewer than 100 young, healthy volunteers. If it appears safe and produces antibodies, thousands more volunteers — in this case, probably front-line workers at the highest risk — will get either it or a placebo in what is called a Phase 3 trial.

It is possible to speed up that process with “challenge trials.” Scientists vaccinate small numbers of volunteers, wait until they develop antibodies, and then “challenge” them with a deliberate infection to see if the vaccine protects them.

Normally, it is ethically unthinkable to challenge subjects with a disease with no cure, such as Covid-19.

“Fewer get harmed if you do a challenge trial in a few people than if you do a Phase 3 trial in thousands,” said Dr. Lipsitch, who recently published a paper advocating challenge trials in the Journal of Infectious Diseases. Almost immediately, he said, he heard from volunteers.

The hidden danger of challenge trials, vaccinologists explained, is that they recruit too few volunteers to show whether a vaccine creates enhancement, since it may be a rare but dangerous problem.

if a vaccine is invented, the United States could need 300 million doses — or 600 million if two shots are required. And just as many syringes.

“People have to start thinking big,” Dr. Douglas said. “With that volume, you’ve got to start cranking it out pretty soon.”

Treatments are likely to arrive first.

The modern alternative is monoclonal antibodies. These treatment regimens, which recently came very close to conquering the Ebola epidemic in eastern Congo, are the most likely short-term game changer, experts said.

as with vaccines, growing and purifying monoclonal antibodies takes time. In theory, with enough production, they could be used not just to save lives but to protect front-line workers.

Having a daily preventive pill would be an even better solution, because pills can be synthesized in factories far faster than vaccines or antibodies can be grown and purified.

Goodbye, ‘America First.’

A public health crisis of this magnitude requires international cooperation on a scale not seen in decades. Yet Mr. Trump is moving to defund the W.H.O., the only organization capable of coordinating such a response.

And he spent most of this year antagonizing China, which now has the world’s most powerful functioning economy and may become the dominant supplier of drugs and vaccines. China has used the pandemic to extend its global influence, and says it has sent medical gear and equipment to nearly 120 countries.

This is not a world in which “America First” is a viable strategy, several experts noted.

“If President Trump cares about stepping up the public health efforts here, he should look for avenues to collaborate with China and stop the insults,”

If we alienate the Chinese with our rhetoric, I think it will come back to bite us,” he said.“What if they come up with the first vaccine? They have a choice about who they sell it to. Are we top of the list? Why would we be?”

Once the pandemic has passed, the national recovery may be swift. The economy rebounded after both world wars, Dr. Mulder noted.

In one of the most provocative analyses in his follow-up article, “Coronavirus: Out of Many, One,” Mr. Pueyo analyzed Medicare and census data on age and obesity in states that recently resisted shutdowns and counties that voted Republican in 2016.

He calculated that those voters could be 30 percent more likely to die of the virus.

In the periods after both wars, Dr. Mulder noted, society and incomes became more equal. Funds created for veterans’ and widows’ pensions led to social safety nets, measures like the G.I. Bill and V.A. home loans were adopted, unions grew stronger, and tax benefits for the wealthy withered.

If a vaccine saves lives, many Americans may become less suspicious of conventional medicine and more accepting of science in general — including climate change

Finally, if the British government quickly went all-out to suppress viral spread — aiming to reverse epidemic growth and reduce the case load to a low level — then the number of dead in the country could drop to below 20,000. To do this, the researchers said, Britain would have to enforce social distancing for the entire population, isolate all cases, demand quarantines of entire households where anyone is sick, and close all schools and universities — and do this not for weeks but for 12 to 18 months, until a vaccine is available.

“We might be living in a very different world for a year or more,” Ferguson told reporters.

The modelers did not give numbers for the United States for the most intense suppression efforts.

Johnson said the virus “would overwhelm any health system in the world” if quarantines and limits on social contact are not taken.

“Although the measures we have already announced are extreme, we may have to go further in the coming days,” the prime minister said Tuesday.

Roy Anderson, an infectious disease specialist at Imperial College, who was not a part of the study, said Britain probably had much more to do. “I don’t know if these measures are enough yet,” he said. “And I wish we had done them last week.”

There are currently 7,000 ventilators available for all of England, the largest nation within the United Kingdom, with a population of 56 million

“The major challenge of suppression is that this type of intensive intervention package . . . will need to be maintained until a vaccine becomes available (potentially 18 months or more), given that we predict that transmission will quickly rebound if interventions are relaxed,” the study concludes.

The study’s authors said their research made it clear that people in the United States might be advised to continue with draconian restrictions on their daily lives for far longer than Mr. Trump and the task force indicated on Monday.

“The major challenge of suppression,” the British scientists concluded, is the length of time that intensive interventions would be needed, given that “we predict that transmission will quickly rebound if interventions are relaxed.”

The authors said that so-called mitigation policies alone — isolating people suspected of having the virus at home, quarantining their contacts and separating the most vulnerable people from others — might reduce the peak demand on the health care system by two-thirds and deaths by half if applied for three months. But that would still result in hundreds of thousands of deaths and in health systems “overwhelmed many times over,” they said.

This was why the authors also recommended measures to distance the entire population, such as school closures.

The researchers said that the long-term “social and economic effects” were likely to be “profound,” and that the measures were not guaranteed to succeed and could themselves have “significant impact on health and well-being.”

“No public health intervention with such disruptive effects on society has been previously attempted for such a long duration of time,” they added. “How populations and societies will respond remains unclear.”

There might be other explanations. With any infection, there are four basic questions to ask when looking at broad differences in death rates. Is the virus different here versus there? NO. Right now, there is no evidence that the virus is mutating toward a more potent strain in the US.Is one country diagnosing the virus sooner than another? YES. As above, this may be skewing German and South Korean results by identifying asymptomatic and mildly symptomatic persons unlikely to require medical care. Hospitalization rates by country, currently not tracked, would help sort out the contribution of aggressive testing to survival rates. Is the infected patient different here versus there? YES. South Korea (young patients) and Italy (old patients) are unique in the outbreak, and the characteristics in Iran are not well known. All other countries with specific information, from China to even the US epicenter of New York City, have shown the same basic distribution with respect to age, sex (more men than women) and smoking. Is the health care system different here versus there? OH YES. Health care system differences at the country level are hard to examine: information is sparse and, given the 50,000-foot view, possibly misleading. However, health care experts typically can rely on "structural measures" to determine the quality of a hospital or a state or a country.

The World Bank tracks health care information by country on three relevant structural measures (though recentness of information varies country to country), each measured per 1,000 general population: doctors, nurses and hospital beds. They and other sources also track two other relevant variables: lifespan per country and health care spending per individual. Neither of these demonstrate differences in affected Western European countries that might explain a difference in Covid-19 survival.

Among the nine countries with the highest number of Covid-19 cases, the country that has the highest nurse rate also has the lowest death rate from the disease. Germany has 13.2 nurses per 1,000 (echoing a trend for high nurse numbers throughout Northern Europe) far above the other heavily Covid-19 affected countries. This may be just another armchair epidemiologist observation of course. But higher numbers of nurses may reflect one of two beneficial factors (or both): first, that nurses, the backbone of hospital (and especially ICU) care, are essential to patient management and, ultimately, survival.

Either way, it is a reminder that Covid-19 will continue to reveal the strengths and weaknesses of health care systems across the world. The current observed differences also mandate that, when we finally are out from underneath the weight of the current crisis, we must work to determine how we can deliver better health care to large populations across the world.

The half-life is a measurement of the time it takes for a given amount of the virus to become reduced by half.

the half-life of the virus, in the absence of sunlight (indoors), lowers from 18 hours to one hour when the temperature rises from around room temperature (70 to 75 degrees) to 95 degrees and the humidity increases from 20 percent to 80 percent.

The laboratory experiment also tested how the virus decays when exposed to various elements while suspended in the air. When the airborne virus at temperatures between 70 and 75 degrees is exposed to sunlight, its half-life decreases from around 60 minutes before exposure to 1.5 minutes after.

The laboratory results show that increases in temperature, humidity and sunlight all can speed up how fast the virus is destroyed, based on measurements of its half-life when exposed to these elements.

The weather is no panacea when it comes to the coronavirus pandemic, considering that warm states, such as Georgia and Florida, already are seeing significant outbreaks, as are warm and humid countries, including Singapore. Even if the virus were to wane during the summer, a dreaded second wave would still be likely in the fall, as has happened with past pandemic flu outbreaks.

A slide presented by Bryan also recommended moving activities outside.

in the real world, the virus on a playground surface exposed to direct sunlight would die quickly, but the virus could survive longer in shaded areas.

If the summer months reduce the transmission rates of the virus, that would help officials’ efforts to squelch its spread without resorting to drastic mitigation measures, such as stay-at-home orders, that have had massive economic repercussions.

“It would be irresponsible for us to say summer will kill the virus,” Bryan said, calling summer conditions “another tool in toolbox” to use against the virus.

“Increasing the temperature and humidity of potentially contaminated indoor spaces appears to reduce the stability of the virus,” he said. “And extra care may be warranted for dry environments that do not have exposure to solar light.”

That report pointed to shortcomings in the studies published so far that trace the spread of the coronavirus and connect the pattern of spread to temperature and humidity, stating they “should be interpreted with caution.”

The NAS report states: “There is some evidence to suggest that SARS-CoV-2 may transmit less efficiently in environments with higher ambient temperature and humidity; however, given the lack of host immunity globally, this reduction in transmission efficiency may not lead to a significant reduction in disease spread” without mitigation measures, such as social distancing

GOP leaders justify the voter suppression measures by arguing that they are needed to crack down on fraud and to restore the public's faith that US elections are fair. But multiple courts and Trump's own Justice Department found there was no widespread electoral fraud in 2020.

The Georgia bill is only one example of GOP efforts in multiple states -- including many crucial electoral battlegrounds -- to hold back a diverse demographic tide in cities that favor Democrats, which critics see as an attempt to cement minority rule in the United States.

Georgia Republicans also lost two US Senate seats that handed Democrats control of the 50-50 chamber on the basis of huge Black turnout in runoff elections in January.close dialogSign up for CNN's CNN's Chris Cillizza cuts through the political spin and tells you what you need to know. Sign Me UpNo ThanksBy subscribing, you agree to ourprivacy policy.Sign up for CNN's CNN's Chris Cillizza cuts through the political spin and tells you what you need to know. Please enter above Sign Me UpNo ThanksBy subscribing, you agree to ourprivacy policy.You're on the list for CNN'sCNN's Chris Cillizza cuts through the political spin and tells you what you need to know. close dialog/* effects for .bx-campaign-1245919 *//* custom css .bx-campaign-1245919 *//* custom css from creative 47804 */@-ms-keyframes bx-anim-1245919-spin { from {

"This should be marked as Exhibit A in making the case that discriminatory voter suppression is alive and well, and makes clear why we need federal voting rights legislation to stop these laws in their tracks," Hewitt said. "We stand ready to take action and protect the fundamental right to vote through the courts."

as a remnant of the Jim Crow era that institutionalized racism and hinted that he could ultimately back abolishing the Senate filibuster to get the Democrats' House-passed bill through the chamber. But Biden declined to reveal his strategy for getting the voting rights bill into law.

Georgia's action threw a political grenade into the debate over a Washington campaign by many Democrats to abolish Senate supermajority rules that Republicans could use to block their sweeping election bill, known as the For the People Act.

In a statement to CNN, Georgia Secretary of State Brad Raffensperger, a Republican who defied Trump's pleas in a telephone call to find votes to overturn Biden's victory, said he would still stand up for voter freedoms but did not criticize the law."In implementing this law, I will ensure that no eligible Georgia voter is hindered in exercising their right to vote, and I will continue to further secure our elections so that every Georgian can have confidence in the results of our elections," Raffensperger said

"As the FBI continue to round up seditionists who spilled blood to defend a lie about our elections, Republican state leaders willfully undermine democracy by giving themselves authority to overturn results they do not like," Abrams said in a statement. "Now, more than ever, Americans must demand federal action to protect voting rights as we continue to fight against these blatantly unconstitutional efforts that are nothing less than Jim Crow 2.0."

Black voters hampered by the restrictions of voting in urban areas have often found themselves lining up for hours to vote in inclement weather. The clear targeting of African American voters in Georgia and elsewhere recalls some of the ugliest racial episodes of America's past, and is fueling claims of open Republican racism.

Former President Donald Trump's campaign of lies about a stolen election just delivered a huge victory with a new Georgia law that could suppress the votes of many of the citizens who helped eject him from the White House.

Republican state lawmakers rushed through a broad law Thursday making it harder to vote that disproportionately targets Democratic and Black voters

The move confirms the Peach State as the epicenter of the fight for American democracy

The Georgia law raises the question of whether election safeguards that prevented Trump's energetic efforts to rig the 2020 White House race after the fact in the state will stand firm in future elections amid false claims of electoral fraud by a president.

"What I'm worried about is how un-American this whole initiative is. It's sick. It's sick," President Joe Biden

Republicans in multiple states pursue new laws to limit voting.

Georgia Republicans also lost two US Senate seats that handed Democrats control of the 50-50 chamber on the basis of huge Black turnout in runoff elections in January.close dialogSign up for CNN What Matters NewsletterEvery day we summarize What Matters and deliver it straight to your inbox.Sign me upNo thanksBy subscribing you agree to ourprivacy policy.By subscribing you agree to ourprivacy policy.Sign up for CNN What Matters NewsletterEvery day we summarize What Matters and deliver it straight to your inbox.Please enter aboveSign me upNo thanksBy subscribing you agree to ourprivacy policy.By subscribing you agree to ourprivacy policy.Sign up for CNN What Matters NewsletterEvery day we summarize What Matters and deliver it straight to your inbox.//assets.bounceexchang

After leaving office, Trump demanded that Republican state legislatures pass laws to ban mail-in voting and to prevent courts from weighing in on electoral disputes.

the former President has made the acceptance of his false conspiracy theories about voter fraud in 2020 a litmus test for Republican candidates

Iowa has already passed a measure to limit absentee balloting and voting hours. Texas is taking steps to cut voting hours and absentee balloting in big Democratic cities like Houston. New voting laws are being pushed by Republicans in another swing state Trump lost, Arizona.

GOP leaders justify the voter suppression measures by arguing that they are needed to crack down on fraud and to restore the public's faith that US elections are fair. But multiple courts and Trump's own Justice Department found there was no widespread electoral fraud in 2020.

voter mistrust was largely fueled by Trump's blatantly false claims

Georgia's action threw a political grenade into the debate over a Washington campaign by many Democrats to abolish Senate supermajority rules that Republicans could use to block their sweeping election bill, known as the For the People Act.

The drama in the Georgia Legislature unfolded as Biden condemned restrictive state legislation as a remnant of the Jim Crow era that institutionalized racism and hinted that he could ultimately back abolishing the Senate filibuster to get the Democrats' House-passed bill through the chamber.

The law allows any Georgian to make unlimited challenges to voter registrations, and, incredibly, makes it a misdemeanor crime for anyone to offer food and water to voters stuck in long lines to cast ballots.

The clear targeting of African American voters in Georgia and elsewhere recalls some of the ugliest racial episodes of America's past, and is fueling claims of open Republican racism.

The Georgia law was quickly signed by Republican Gov. Brian Kemp, who incurred the wrath of Trump last year for refusing to play along with his attempt to override Biden's victory by 12,000 votes in the state, which was confirmed by several audits.

"In implementing this law, I will ensure that no eligible Georgia voter is hindered in exercising their right to vote, and I will continue to further secure our elections so that every Georgian can have confidence in the results of our elections," Raffensperger said.

Kemp is up for reelection in 2022 and could face Democrat Stacey Abrams, a former state lawmaker and prominent voting rights advocate

"As the FBI continue to round up seditionists who spilled blood to defend a lie about our elections, Republican state leaders willfully undermine democracy by giving themselves authority to overturn results they do not like," Abrams said in a statement. "Now, more than ever, Americans must demand federal action to protect voting rights as we continue to fight against these blatantly unconstitutional efforts that are nothing less than Jim Crow 2.0."

the measure directly targeted voters of color who took part in record numbers in the 2020 election.

The For the People Act awaiting action in the Senate would create automatic voter registration nationwide and restore portions of the Voting Rights Act that were gutted by the Supreme Court. It would also strengthen mail-in voting and permit early voting across the country, while taking steps to cut wait times at the polls.

is not aerosol-generating – in fact, the aerosols are reduced compared to just normal breathing and speaking,”

“However, cough really is a potent generator of aerosols.”

“It goes along with a growing body of evidence, which is telling us that activities such as talking, and coughing in particular, are aerosol-generating.

Dodd and his colleagues recruited healthy volunteers to receive CPAP or a related treatment called high flow nasal oxygen (HFNO) in a highly ventilated operating theatre.

This enabled them to precisely measure the aerosols emitted in the absence of any background particles. They also took measurements when the volunteers breathed, talked and coughed normally, and separately measured aerosol emissions from Covid-19 patients – the first time such measurements have been taken.

Coughing generated at least 10 times more aerosols than speaking or breathing, and all of these activities generated more airborne particles than CPAP – even when the volunteers wore a surgical mask.

Aerosol emissions were similar between Covid patients and healthy individuals.

The measure passed by a voice vote, signaling that Democrats were not attempting to defeat it. Mr. Biden’s stimulus package would increase the wage to $15 per hour by 2025, and Senator Bernie Sanders, independent of Vermont, who has been leading the push for the wage increase in the Senate, said he would not contest Ms. Ernst’s effort because he had never sought to raise it during the pandemic.

“A $15 federal minimum wage would be devastating for our hardest-hit small businesses at a time they can least afford it,” Ms. Ernst said on the Senate floor. “We should not have a one-size-fits-all policy set by Washington politicians.”

Among the amendments that passed with bipartisan support — by a vote of 99 to 1 — on Thursday was a measure from Mr. Manchin and Senator Susan Collins, Republican of Maine, to restrict $1,400 direct checks included in Mr. Biden’s plan from going to high earners, though it did not specify what income level was too high. Democrats have largely agreed to limit payouts for Americans with higher incomes.

They joined a handful of others, including Senator Marco Rubio of Florida, Senator Josh Hawley of Missouri and Senator Lindsey Graham of South Carolina, who have backed increasing the checks to $2,000.

While Democrats all support larger checks, they are unlikely to endorse a hasty overhaul of the legal shield currently in place for social media companies, especially measures put forward by Republican senators aimed at confronting what they believe is anti-conservative bias.

The House voted on Monday evening to increase the size of the checks to $2,000, daring Senate Republicans to either approve the heftier sum or defy Mr. Trump.

In signing the relief bill on Sunday night, Mr. Trump claimed in a statement that the Senate would “start the process for a vote” on legislation that would increase direct payments and pledged that “much more money is coming.”

Republican lawmakers in the House were visibly frustrated with Mr. Trump’s demand. Some of the president’s closest allies, including Representatives Steve Scalise of Louisiana, the No. 2 Republican, and Jim Jordan of Ohio, voted against the measure, and Representative Kevin Brady of Texas, the top Republican on the Ways and Means Committee, complained on the House floor that the proposal had been “hastily dropped on us at the last minute” and wouldn’t assist those who needed it most.

As part of the order, USPS must send a memo by 9 p.m., local time, Sunday evening to processing plant managers and division directors saying the extraordinary measures "must be put in place to ensure we delivery every ballot possible by the cutoff time on Election Day."

In addition to the USPS' daily sweeps for election mail, USPS processing plant managers must also certify that all local ballots have been sent to the local election or post office by 10 a.m., local time, on Monday and Tuesday.

In New Jersey and three key states in the election -- Minnesota, North Carolina and Pennsylvania -- USPS must issue "targeted written communication, and make all reasonable efforts to orally convey" to plant managers and division directors that ballots should be processed prior to the deadline in which they need to arrive at election offices on Election Day.

And by 9 a.m., local time, on Monday, USPS is required to send a memo to every local post office reiterating that they must postmark all ballots they receive. Properly postmarked ballots are important because some states allow for pre-Election Day postmarked ballots to arrive after Election Day.

In a document filed in US District Court Sunday, USPS said that on a national level, they moved fewer ballots on time on Saturday than on Friday and their processing score dropping from 93% to 91%

More critical battlegrounds states are now experiencing a drop in scores -- below 90% -- and those already below that did not improve substantially and some dropped even lower.

Of all the measures South Africa put in place, Dawood said the most important against the flu was school closures. Studies have shown that children exhibit the highest rates of infection and illness due to influenza. “I think that was the one that interrupted flu’s whole chain,”

experts have offered numerous explanations for why it is more infectious than the seasonal flu. Foremost is the extent to which it spreads when those who carry it are asymptomatic. Flu is almost always transmitted through symptoms such as sneezing and coughing.

Many people also carry “background immunities” for influenza, Dawood said. Repeated infections, as well as worldwide annual vaccination campaigns, have given large portions of the global population at least some influenza antibodies, although new strains appear nearly every year.

People also began taking extra health precaution

With coronavirus cases climbing steeply at the beginning of the country’s flu season, many people rushed to clinics to get flu shots, hoping to avoid at least one co-morbidity.

The continued implementation of personal protective measures may be so effective against flu transmission that entire strains of the virus that relied on incubation in the Southern Hemisphere’s winter before being passed back north might be eliminated for good

“If it works out like this, it would be a very beautiful positive side effect of covid, one of the few good things to come of it.”

The main threat to that possibility is reintroduction from the Northern Hemisphere, where many countries, and parts of the United States in particular, have not required mask-wearing and school closures.

those that could draw on deep reservoirs of resilience born of relatively recent hardship

Compared to what their people had been through not long ago, the stringent lockdowns seemed less arduous, apparently prompting a larger social buy-in.

The nations include many in the former Communist East, as well as Greece and Croatia

“I was a kid, I remember playing soccer and seeing mortars falling out of the sky,” he said. He believes the disciplined, collected way in which Croats have responded to the pandemic harks back to wartime and the legacy of communism.

“People today are afraid, and the discipline we all learned helps us get in line and creates some sort of forced unity,”

Analyzing the different pandemic responses, academics at Oxford University have developed a stringency scale, an effort to rank the toughness of the measures governments took to stop the spread of the virus.

n Croatia, which has among the world’s top stringency scores on the Oxford scale, 86 people have died of Covid-19, putting the country’s death rate at 2.1 per 100,000. In New York State, that figure is 137 per 100,000.

“Croatia went to the max of our stringency scale, there is a strong official response,” Mr. Hale said. Echoing Mr. Morovic’s thoughts on discipline, he added, “It is possible that people are less willing to push back and they are willing to accept harsher measures.”

A word sometimes applied to societies in these parts of Europe is “resilient,

the trait was best defined as a person or society doing well in spite of experiencing acute stress or long-term adversity.

resilience alone does not explain why some countries are handling the crisis better: The positive outcomes rely on citizens believing the measures a government is taking are appropriate, leading to trust and compliance.

Greece is emerging from a lockdown with a low death toll and relatively high morale, even as it faces a recession.

The country has recorded the relatively tiny number of 151 virus deaths so far, just 1.4 per 100,000 people, and Professor Motti-Stefanidi credited the government’s frank and persuasive approach for motivating citizens to respect the tight lockdown measures.

“We’ve been through a lot, we are hardened, so I think we’re going to be able to rebuild,” she said. “We thought we were spoiled before the financial crisis, but now we can see we are resilient,”

In Croatia, Mr. Morovic said he was confident that the country was on track to stay healthy even as it reopened, but he was ready to go back into lockdown if the virus returned.