Group items tagged

This CDC advisory group had previously recommended that health care workers and residents of long-term care facilities should be the first to receive a vaccine when it receives EUA. The first shipments of the vaccine will be limited, so states will have to prioritize who should receive the vaccine first.

Keeping doctors and nurses healthy will be important for the continuing fight against the virus, which will stretch on for months, even after a vaccine is authorized. But Romero said that first group includes other people working in health care institutions, like those who deliver food and perform housekeeping.

Residents of long-term care facilities like nursing homes also need the protection. So far, they account for about 40% of coronavirus deaths in the US.

"I would project by the time you get to April, it will be ... 'open season,' in the sense of anyone, even the non-high priority groups could get vaccinated," Fauci said.

"We'll be in facilities that day in states that choose to begin as soon as possible," spokesman Ethan Slavin said.

The FDA is set to make a decision on a separate vaccine candidate by Moderna in the coming days

it's possible that 20 million people could get vaccinated in the next several weeks

Phase 1a would be followed by Phases 1b and 1c, which could include essential workers at high risk of infection, other emergency personnel and people with underlying conditions who are at a higher risk of Covid-19 complications and death.

Army Gen. Gustave Perna, chief operating officer of the federal government vaccine initiative Operation Warp Speed, previously said he believed vaccine administration will be able to begin vaccinations within 96 hours of authorization.

In the meantime, it's important that people continue to wear masks and social distance. JUST WATCHEDDr. Fauci explains importance of vaccine approval processReplayMore Videos ...MUST WATCH Play</

It's important to note, however, that Pfizer's vaccine requires two doses administered several weeks apart to reach 95% efficacy. So 100 million doses would vaccinate half the number of people.

Azar said earlier this month that 6.4 million doses of Pfizer vaccine would be allocated for shipment the first week. The initial shipment would include half of the doses, followed by the second half three weeks later.

Slaoui said he believes most doses will be injected within three to four days, but after that, "I think it will take a week."

The first shipments of the vaccine departed a Pfizer plant in Michigan on Sunday morning. A total of 189 boxes of vials are expected to arrive in all 50 states Monday. Another 3,900 vials are expected to ship later Sunday to US territories. Another 400 boxes packed with about 390,000 vials are expected to ship Monday and arrive at their destinations on Tuesday.

The vaccines will then be flown across the country, and the Federal Aviation Administration has said its air traffic controllers will prioritize flights carrying the vaccines.

But Pfizer's vaccine needs to be stored at incredibly cold temperatures, making the logistics of delivery even more complicated.

According to a briefing document released by the FDA's vaccine advisory committee, the most common side effects were reactions at the point of injection on the body, fatigue, headache, muscle pain, chills, joint pain and fever.

Health authorities in the UK, where the vaccine roll out began earlier this week, said Wednesday that people with "significant history of allergic reactions" should not receive the vaccine. The advice came after two health care workers "responded adversely" following their shots.

“We can’t guarantee that a person who was vaccinated against smallpox is still going to be protected against monkeypox,” Dr. Fauci said.

In the United States, routine immunization for smallpox ceased in 1972. The military continued its vaccination program until 1991 as a precaution against a bioterrorism attack.

And many older adults, the group most likely to succumb to the monkeypox virus, are at least somewhat protected by decades-old smallpox vaccinations, studies suggest.

In the United States, the Centers for Disease Control and Prevention is tracking nine cases in seven states, not all of which have a history of travel to countries where monkeypox is endemic. That suggests that there may already be some level of community transmission, Dr. Rochelle Walensky, the agency’s director, told reporters on Thursday.

The agency is working to expand that capacity, she said, adding: “We’ve been preparing for this type of outbreak for decades.”

Each pustule contains live virus, and a ruptured blister can contaminate bed linens and other items, putting close contacts at risk. Infected people should also be very careful about rubbing their eyes because the virus can destroy sight.

“We’re lucky to have vaccines and therapeutics — things that can mitigate all that,” said Anne Rimoin, an epidemiologist at the University of California, Los Angeles, who has studied monkeypox in Africa. “We do have the ability to stop this virus.”

Monkeypox takes up to 12 days to cause symptoms, giving doctors a window of at least five days after exposure to vaccinate and forestall disease. (The approach, called post-exposure prophylaxis, is not an option for Covid patients because the coronavirus can start to ravage the body just a couple days after exposure.)

A majority of those infected currently are men under 50, and many identify as gay or bisexual, which may reflect the outbreak’s possible origins at a Gay Pride event in the Canary Islands. (The outbreak could just as easily have started among heterosexual people at a large event, experts said.)

No deaths have been reported. But experts are particularly concerned about close contacts who are children, older adults or who have weak immune systems for other reasons.

“Until we know more, we will be using available vaccine stocks for people who’ve had close contact with known cases, and people at highest risk for exposure through their jobs, like health care workers treating monkeypox patients,” he said.

Many of the most vulnerable groups may already be protected. In one study, Dr. Slifka and his colleagues drew blood from 306 vaccinated volunteers, some of whom had been immunized decades earlier, including one who had been immunized 75 years before. Most of them maintained high levels of antibodies to smallpox.

“We wouldn’t want to take the chance that somebody was left unprotected,” she said.

Laboratory evidence of antibodies does not prove that smallpox vaccination can protect against monkeypox. But answering that question would require that study participants be deliberately infected with smallpox or a related virus, an obviously unethical experiment.

The other three vaccinated individuals had no symptoms at all. “They didn’t even know they had been infected,” Dr. Slifka said.

The eradication of smallpox, while one of the greatest achievements in public health, has left populations vulnerable to the virus and to its cousins.

“If monkeypox were to establish itself in a wildlife reservoir outside of Africa, the public health setback would be enormous,” Dr. Rimoin said. “That, I think, is a legitimate concern.”

Recent experiments suggest that XBB paid a steep price for its power to evade immunity. The mutations allow it to escape antibodies by altering the shape of the protein, called spike, that covers its surface. But some of those mutations also make it harder for XBB spike proteins to grab tightly to cells — the first step required for an infection.

That loose grip may have lessened XBB’s advantage against other forms of the virus. In late 2022, it jostled alongside a number of other Omicron subvariants. In Singapore, XBB caused a surge in October, for example, while remaining rare in many other parts of the world.

As XBB multiplied, it continued to mutate into new forms. The earliest samples of XBB.1.5 were isolated in October in New York. The new subvariant gained one crucial mutation, known as F486P.

Yunlong Cao of Peking University and his colleagues tested out XBB.1.5 in dishes of cells, comparing how it fared against earlier forms of XBB. The researchers found that the F486P mutation allowed XBB.1.5 to grab tightly to cells again. But the new subvariant could still evade antibodies as well as earlier forms of XBB.

In Connecticut, for example, Nathan Grubaugh at Yale University and his colleagues found that by mid-December, other Omicron subvariants were falling. Only XBB.1.5 cases were growing. Dr. Grubaugh estimates that it is about 20 percent more transmissible than BQ.1, which had been the dominant form.

How severe XBB.1.5 infections are compared with other forms of the coronavirus is not yet clear. “It’s serious,” Dr. Grubaugh said. “I just don’t necessarily know if it’s really more serious than some of the other Omicron lineages in terms of the overall impact.”

XBB.1.5 has already spread to other countries, and is growing rapidly in Germany, Denmark and elsewhere in Europe

Scientists are already scanning new sequences being uploaded to an international database called GISAID in the hopes of spotting an upgraded version of XBB.1.5. But their job is getting harder because governments are pulling back on sequencing efforts. “Worldwide, sequencing has taken a real hit,” Dr. Peacock said.

The United States, which once lagged behind other nations, has managed to maintain a fairly strong sequencing effort. Without it, Dr. Peacock said, XBB.1.5 might have stayed below the radar for much longer. If XBB.1.5’s next generation is evolving somewhere with little sequencing, it may go undetected for some time to come.

Dr. Lemieux said that paring back on sequencing was a mistake, given how many infections and deaths the virus is still causing. “This is a part of public health,” he said.

their daily energy expenditure is about the same as most Americans, suggesting physical activity is not the reason for their relative good health.

The prevailing notion in sleep medicine is that humans evolved to go to bed when the sun goes down, and that by and large we stay up much later than we should because we are flooded with artificial light

Dr. Siegel and his colleagues found no evidence of this. The hunter-gatherer groups they studied, which slept outside or in crude huts, did not go to sleep when the sun went down. Usually they stayed awake three to four hours past sunset, with no light exposure other than the faint glow of a small fire that would keep animals away and provide a bit of warmth in the winter. Most days they would wake up about an hour before sunrise.

In a typical night, they slept just six and a half hours — slightly less than the average American

“I think this paper is going to transform the field of sleep,” said John Peever, a sleep expert at the University of Toronto who was not involved in the new research. “It’s difficult to envision how we can claim that Western society is highly sleep deprived if these groups that live without all these modern distractions and pressing schedules sleep less or about the same amount

in the new study, the hunter-gatherer societies were found to have a sleep period — meaning the time they were actually in bed — of roughly seven to eight and a half hours, which he said was consistent with his group’s recommendations.

the question of how much sleep people require was a delicate one. “Really it’s just the amount that allows people to wake up feeling refreshed and alert,

Dr. Siegel said he worried that putting a number on the amount of sleep people require could push those who get less to resort to using sleeping pills, which carry severe side effects. About 5 percent of Americans take sleeping pills, a percentage that has doubled in the past two decades.

called the new study “excellent and very timely,” and he said it suggests that sleep quality is much more important than quantity.

Some historians have also argued that it is not natural for people to sleep straight through the night. They say that before the introduction of artificial light it was normal for people to sleep in two intervals separated by an hour of wakefulness, a phenomenon known as segmented sleep, or “first” and “second” sleep.

But Dr. Siegel said he always questioned those assertions because there were no rigorous studies of sleep behaviors back then. He and his colleagues decided that one way to get some insight was to study cultures relatively unaffected by artificial light.

Among those they chose to follow were the Hadza people, who spend their days hunting and foraging in northern Tanzania, much as their ancestors have for tens of thousands of years; the San of Namibia, who have lived as hunter-gatherers in the Kalahari for at least 20,000 years; and the Tsimané, a seminomadic group that lives in the Andean foothills of Bolivia, near the farthest reaches of the human migration out of Africa.

The researchers found that in addition to sleeping roughly similar amounts each night, the three groups rarely took naps during the day and did not sleep in two separate intervals at night.

“The Hadza and the San live in the area where we know humans evolved, and then the Tsimané live in some sense at the end of the human migration,” he said. “The fact that we see very similar sleep times gives me great confidence that this is how all of our ancestors slept.”

Their sleep did not seem to be problematic. Chronic insomnia, which affects 20 percent to 30 percent of Americans, occurred in just 2 percent of the hunter-gatherers. The San and the Tsimané did not even have a word for it in their languages.

ambient temperature may be a major factor. The groups did not go sleep at sunset and they did not wake up at sunrise, suggesting that light exposure did not have much influence on their sleep patterns. But they almost always fell asleep as temperatures began to fall at night, and they would wake up right as the temperatures were rising again.

This suggests that humans may have evolved to sleep during the coldest hours of the day, perhaps as a way to conserve energy

“Today we sleep in environments with fixed temperatures, but none of our ancestors did,” Dr. Siegel said. “We evolved to sleep in a natural environment where the temperature falls at night. Whether we can treat insomnia by putting people in an environment where the temperature is modulated in this way is something to be studied in the future.

The Mal’ta people are not related to the Asians who live in the region today. But before they disappeared, they also passed down their DNA to Europeans. Later research revealed the route those genes took from Asia to Europe

Dr. Willerslev and his colleagues discovered Mal’ta-like DNA in Bronze Age nomads called the Yamnaya, who lived 4,300 to 5,500 years ago in what is now southwestern Russia. About 5,000 years ago, the Yamnaya expanded into Europe, where they added their DNA to the gene pool.

In 2010, he found a piece of hair collected in Australia in the 1920s at the University of Cambridge. He and his colleagues retrieved DNA from the hair and reconstructed the owner’s genome.Their analysis revealed that the ancestors of aboriginal Australians split off from other non-Africans about 70,000 years ago. That finding supports the idea that the first settlers in Australia were the ancestors of today’s aboriginals

“Aboriginal people feel exonerated in showing the broader community that they are by far the oldest continuous civilization in the world,” the council said in a statement.

The Kennewick Man genome, like the Anzick child’s, revealed an ancient continuity between living Native Americans and the earliest people in the New World. A

Since the Kennewick Man project, Dr. Willerslev has hosted visits from a number of Native American tribes to his laboratory in Copenhagen. His guests have helped him see how differently he, as a European, treats history than they do.

Dr. Willerslev once proudly showed off a collection of ancient Danish skulls to Native American visitors, only to find them upset by the sight.“‘How can you treat your ancestors like that, so disrespectfully?” he recalls them asking.

When pressed by Schakowsky for an “unequivocal answer,” Miller replied, “You asked the question whether I thought there was a link, and certainly based on Dr. McKee’s research there’s a link, because she’s found CTE in a number of retired football players. I think the broader point, and the one that your question gets to, is what that necessarily means and where do we go from here with that information.”

Schakowsky referred to comments made shortly before the Super Bowl by Dr. Mitch Berger, a member of the NFL’s&nbsp;Head, Neck and Spine Committee, that denied&nbsp;the existence of a clear&nbsp;link. At a league event on Feb. 4, Berger, who, like Nowinski, played football at Harvard, was asked by Toronto Star columnist Bruce Arthur if there was&nbsp;a link between football and degenerative brain disorders.&nbsp;“No,” replied&nbsp;Berger, according to Arthur

On Monday, Nowinski said, “I can’t imagine that this [Miller’s&nbsp;admission] was on purpose.”

“I honestly think that Dr. McKee made such a clear answer to the question of whether there’s a link, and provided such strong evidence that, I think, Miller got caught up in it,” Nowinski told The Post, adding with a chuckle, “and, unfortunately, the truth came out of his mouth.

the biggest impact of&nbsp;the NFL’s denials of the football-CTE link&nbsp;has not even been on its own players.&nbsp;“The dramatic mistake they’ve made is pouring money into recruiting children to play the game,” he said.

The 37-year-old Massachusetts native wants to see kids only begin playing tackle football in high school, likening it to young people not being allowed to drive cars until they reach the age of 16. The more years people&nbsp;play tackle football and expose themselves to concussive impacts, he asserted, the greater their risk of developing CTE or other neurodegenerative diseases.

Comparing genomes, scientists concluded that today’s humans outside Africa carry an average of 2.5 percent Neanderthal DNA, and that people from parts of Oceania also carry about 5 percent Denisovan DNA. A study published in November found that Southeast Asians carry about 1 percent Denisovan DNA in addition to their Neanderthal genes.

as few as six couplings all those tens of thousands of years ago might have led to the current level of ancient immune alleles.

This means that our modern era, since H. floresiensis died out, is the only time in the four-million-year human history that just one type of human has been alive,

Were they romantic couplings? More likely they were aggressive acts between competing human groups, Dr. Stringer said. For a model, he pointed to modern hunter-gatherer groups that display aggressive behavior among tribes.

The value of the interbreeding shows up in the immune system, Dr. Parham’s analysis suggests. The Neanderthals and Denisovans had lived in Europe and Asia for many thousands of years before modern humans showed up and had developed ways to fight the diseases there

When modern humans mated with them, they got an injection of helpful genetic immune material, so useful that it remains in the genome today. This suggests that modern humans needed the archaic DNA to survive. The downside of archaic immune material is that it may be responsible for autoimmune diseases like diabetes, arthritis and multiple sclerosis, Dr. Parham said, stressing that these are preliminary results.

little is known about the Denisovans — the only remains so far are the pinky bone and the tooth, and there are no artifacts like tools. Dr. Reich and others suggest that they were once scattered widely across Asia, from the cold northern cave to the tropical south. The evidence is that modern populations in Oceania, including aboriginal Australians, carry Denisovan genes.

The researchers found several genetic variants at different locations in the genome that were unusually common in the Inuit, compared with people in Europe or China. Several of these variations occurred within a cluster of genes that direct construction of enzymes called fatty acid desaturases. (The genes are called FADS, for short.)

This discovery was particularly tantalizing, because the scientists knew that these enzymes helped regulate the different fats in our bodies, including omega-3 fatty acids.

one of these gene variants was present in almost every Inuit in the study. It is much less common in other populations: About a quarter of Chinese people have it, compared with just 2 percent of Europeans.

Natural selection is the only known way this gene variant could have become so common in the Inuit. Dr. Nielsen said this adaptation might have arisen as long ago as 20,000 years, when the ancestors of the Inuit were living in the Beringia region, which straddles Alaska and Siberia

To uncover the effect of this variant gene, the scientists compared the Inuit in their study with others with more European ancestry. Some had inherited a European version of the variant. People with two copies of the Inuit gene had different blood levels of fatty acids than people without them, the researchers found.

The adaptation did more than just change blood levels of fatty acids, the scientists found. Inuit who carried two copies of the variant gene were on average an inch shorter and 10 pounds lighter than those without a copy.“That’s quite extreme,” said Dr. Nielsen.

Indeed, it’s rare to find a single gene that can influence height and weight so drastically. In recent years, scientists have run a number of large studies pinpointing hundreds of genes that affect height and weight, but each one played a minuscule role in the variation from person to person.

Those studies missed this influential gene variant because they focused mostly on people of European ancestry. So Dr. Nielsen and his colleagues also investigated how it affects Europeans. As it turns out, the gene variant is linked to a drastic drop in height and weight in that population, too.

natural selection might not have favored the FADS variant but a neighboring, as yet unknown piece of DNA that conferred evolutionary advantages.As that gene spread through the Inuit population, the FADS variant might simply have been passed down with it.

Dr. Nielsen and his colleagues are planning to investigate the long-term health effects of the gene variants they’ve found. They may help explain why some of us metabolize fats more effectively than others, and why omega-3s haven’t been the heart panacea once hoped.

It’s the kind of theory situated between the hyper-theory of Marx or Hegel and the thick description that certain anthropologists and historians aim at,” he said.

it provides “a new foundation for understanding political development.” It is neither Eurocentric nor monocausal, but provides a complex, multifactor explanation of political development, Dr. Sorensen said. “In terms of discussing political order this will be a new classic,

The book traces the development of political order from the earliest human societies, which were small groups of hunter-gatherers. The first major social development, in Dr. Fukuyama’s view, was the transition from hunter-gatherer bands to tribes, made possible by religious ideas that united large numbers of people in worship of a common ancestor. Since a tribe could quickly mobilize many men for warfare, neighboring bands had to tribalize too, or be defeated.

Warfare also forced the second major social transition, from tribe to state. States are better organized than tribes and more stable, since tribes tend to dissolve in fighting after the death of a leader. Only because states offered a better chance of survival did people give up the freedom of the tribe for the coercion of the state.

Much of Dr. Fukuyama’s analysis concerns how states develop from tribes. This transition, in his view, is affected by geography, history, and in particular by the order in which the different institutional components of the state are put in place. Depending on the order of events, several very different kinds of state emerged in China, India, the Islamic world and Europe, and even within Europe there have been several major variations on a common theme.

In the past, drug abuse deaths were more common in middle-aged blacks than in middle-aged whites. Now they are more common in whites. The same pattern holds for deaths from alcoholic cirrhosis of the liver. The suicide rate for whites was four times that of blacks.

Could people be taking drugs and killing themselves as a response to the economic slowdown? Maybe. But, if so, Dr. Deaton and Dr. Case said, then why aren’t people in other countries responding the same way?

Recent reports of illness and disability might provide some clues. More middle-aged whites report that their general health is not good; and, more report chronic pain

older people are actually doing better — less addiction, disability rates falling.

how much of what they are seeing might be attributed to the explosive increase in prescription narcotics.

the people who report pain in middle age are the people who report difficulty in socializing, shopping, sitting for three hours, walking for two blocks.

Dr. Deaton envisions poorly educated middle-aged white Americans who feel socially isolated are out of work, suffering from chronic pain and turning to narcotics or alcohol for relief, or taking their own lives. Starting in the 1990s, he said, there was a huge emphasis on controlling pain, with pain charts going up in every doctor’s office and a concomitant increase in prescription narcotics.

Dr. Deaton noted that blacks and Hispanics may have been protected to an extent. Some pharmacies in neighborhoods where blacks and Hispanics live do not even stock those drugs, and doctors have been less likely to prescribe them for these groups.

So we're all the same after all.Under the right conditions - no control over your life, low pay, no job, little in the way of job prospects, no healthcare, little education, families break down when the man can't be the breadwinner, and then along comes poor health, substance abuse, depression, despair - all those ills that were blamed on black people's supposed lack of morals.Now that white kids are dying of heroin we need to change the laws, end the war on drugs, legalize pot, and change how we talk about what were formerly known as 'junkies'.White men are in despair as a result of economic problems, white kids are doing hard drugs in numbers that everyone's starting to notice, and AIDS is plaguing white communities, and now we need to care. So we're all human?

Because white people are depressed over their diminution in society by the policies of the Federal Government, the education system, racial animosity and biased media outlets that are rampant through the society. These doctors are clueless liberals that will try to find any reason to blame, other than the truth. It's not the drugs, it's what is causing them to want the drugs. White males have been denigrated for the past 50 years. The effects have to be building up and weighing on them.

John is a trusted commenter Boston 6 hours ago No, their diminution in society came from globalized capitalism. A lot of these working class white people were Reagan voters. I'm the same age as them, I saw it happen. They thought they were getting "Morning in America" but instead they got morning for Walmart and sunset for the working class. That's enough to make anybody turn to pills and booze.

DougH Lithonia, GA 7 hours ago To some extent, it's of their own making. High school educated whites tend to vote Republican. Over the last 30 years, Republicans have sold them a bill of goods. They abandoned unions, opposed increases in the minimum wage, and opposed regulation, including safety, wage fairness, etc.So now they are paid less. They have no way of changing that (short of high education) and the big beneficiaries of lower taxes have been the businesses and owners that for which they work. Did those owners bless the workers with the fruits of their benefits? Of course not. They kept the reduced expenses as profit, increased CEO wages, and kept cutting benefits before finally shipping their jobs overseas.Perhaps, if they stopped voting against their own interests, they would fair better.

dw659 Chicago 8 hours ago Why? Simple. Because to males, a 'loss of control' is an unacceptable change. 200 years of being 'in control' just because you are born white and male is ending. Many men can't face a world where they are of 'lower status' than women, blacks, Hispanics, Asians, etc. They don't want to live in that world.....

dale south africa 5 hours ago Its true ! I am a conservative man and i live i johannesburg. I cant imagine what it must be like respecting all things under the suns . From females, gays blacks etc Children of slaves dictating societies . oprah picking presidents. the bully is not allowed to be at his natural best and strongest with this new liberal socialist agenda , everyone equal attitude. im not white but if I was who would want that

Linda is a trusted commenter Oklahoma 54 minutes ago I know so many white men in this small town I live in who never had anything to do with their children. They didn't care about anybody through their productive years and now they're surprised that nobody cares about them.

AC USA 5 hours ago Could it be because these guys have no close family ties? They are the ages that their parents are probably in nursing homes or already passed away. These blue collar, high school educated guys fathered unwanted children with women to whom they may or may hot have been married and divorced. But now at middle age comes time for them to feel wanted and valued by their progeny (dad, dispense some life wisdom to us, help us with college, getting married, a down payment on a house, take your grand-kids fishing, etc.), but they dumped their kids by not wanting to pay child support, or having a bad attitude and not helping their kids at all past age 18. So they kids moved on without dad's love and "support" (monetary or emotionally). The "all for myself mentality" they have espoused has finally come home to roost. There is no going back in time, they are all alone, have no purpose as jobs are hard to come by at that age - even more-so blue collar ones - so they drink/take pills to dull the pain, then overdo it.

suzinne bronx 5 hours ago Think white families more often DO NOT stick together. At middle age and white, have ZERO contact with any family members. By the time I was 16 most had died, moved away or become estranged. Know this amps up my chances for suicide, and that's probably going to pan out too. Flag

Paul '52 is a trusted commenter NYC 2 hours ago The is the first cohort to experience the phenomenon that if you do the same job as your parents you won't do as well or better. These are the auto workers, the airport baggage handlers, the truck drivers. They are, in fact, more productive than their fathers, but they're not paid as well and they don't have pensions. And the disappointment is taking its toll.

What they found is that, in almost every city they considered, the more global temperatures rose, the more people will die

The 2003 heat wave in Europe is a good example. That year, an estimated 1,050 people died in London and Paris because of soaring temperatures

There are some caveats. For example, as temperatures warm people tend to adapt

But in 2010, even though similar temperatures hit Europe, far fewer people in Western Europe died. (An estimated 56,000, however, died in Russia.)

“People become aware of the dangers,” Dr. Wehner said. “They changed their behaviors so that they were more likely to survive.”

A key form of adaptation is air-conditioning. But in cities like Seattle, where heat mortality is expected to increase, only a third of residents have air-conditioners. And air-conditioners pose their own problems both as contributors to climate change through energy consumption and because they pump warm air outside, further increasing urban temperatures

“The people that are at risk in cities are the very young, the very ill, and, generally, the poor,” Dr. Wehner said. “It’s people who don’t have access to air-conditioning.

The core of Dr. Gott’s reasoning (independently advanced by two other physicists, Brandon Carter and Holger Bech Nielsen) is known to statisticians as the “German tank problem.”

After the war, captured German records revealed that the statisticians’ estimates were almost exactly right.

Dr. Gott recognized that demographers have already roughly estimated the number of humans so far. They put the total number of people who ever lived, from the beginnings of Homo sapiens to the present day, at about 100 billion.

Since it is equally likely that those of us living today are in the first or second half of all past and future human births, let’s say that we are in the second half—which would mean that there are no more than 100 billion births yet to come

There is a 50% chance that is true, which at the current global birthrate (about 131 million a year) translates to a 50% chance that we have at most 760 more years of births. A changing birthrate would modify that estimate, but the calculation is that simple.

Using more precise variables, the Carter-Leslie predictions are just as grim as Dr. Gott’s or more so.

Dr. Gott has put the chance that humans will one day settle throughout our galaxy’s star systems at 1 in a billion. This claim has struck a nerve—and not just with Trekkies. The doomsday argument all but rules out the final frontier to which many technophiles aspire.

He’s an engaging storyteller who has illustrated his predictive method by applying it in simple form to the staying power of marriages and Broadway plays, based on how long they have lasted already. When he predicted a range of closing dates for 44 Broadway and off-Broadway shows and checked back four years later, all 36 that had closed had done so within his predicted window

A New York Times investigation in Brazil found that, time and again, videos promoted by the site have upended central elements of daily life

YouTube’s recommendation system is engineered to maximize watchtime, among other factors, the company says, but not to favor any political ideology.

Some parents look to “Dr. YouTube” for health advice but get dangerous misinformation instead, hampering the nation’s efforts to fight diseases like Zika. Viral videos have incited death threats against public health advocates.

And in politics, a wave of right-wing YouTube stars ran for office alongside Mr. Bolsonaro, some winning by historic margins. Most still use the platform, governing the world’s fourth-largest democracy through internet-honed trolling and provocation

Teachers describe classrooms made unruly by students who quote from YouTube conspiracy videos or who, encouraged by right-wing YouTube stars, secretly record their instructors

But the emotions that draw people in — like fear, doubt and anger — are often central features of conspiracy theories, and in particular, experts say, of right-wing extremism

As the system suggests more provocative videos to keep users watching, it can direct them toward extreme content they might otherwise never find. And it is designed to lead users to new topics to pique new interest

The system now drives 70 percent of total time on the platfor

Zeynep Tufekci, a social media scholar, has called it “one of the most powerful radicalizing instruments of the 21st century.”

Danah Boyd, founder of the think tank Data &amp; Society, attributed the disruption in Brazil to YouTube’s unrelenting push for viewer engagement, and the revenues it generates.

Maurício Martins, the local vice president of Mr. Bolsonaro’s party in Niterói, credited “most” of the party’s recruitment to YouTube — including his own.

“Before that, I didn’t have an ideological political background,” Mr. Martins said. YouTube’s auto-playing recommendations, he declared, were “my political education.”

“It was like that with everyone,”

Sometimes I’m watching videos about a game, and all of a sudden it’s a Bolsonaro video,”

More and more, his fellow students are making extremist claims, often citing as evidence YouTube stars like Mr. Moura, the guitarist-turned-conspiracist.

“If social media didn’t exist, I wouldn’t be here,” he said. “Jair Bolsonaro wouldn’t be president.”

In the months after YouTube changed its algorithm, positive mentions of Mr. Bolsonaro ballooned. So did mentions of conspiracy theories that he had floated. This began as polls still showed him to be deeply unpopular, suggesting that the platform was doing more than merely reflecting political trends.

Jonas Kaiser and Yasodara Córdova, with Adrian Rauchfleisch of National Taiwan University, programmed a Brazil-based server to enter a popular channel or search term, then open YouTube’s top recommendations, then follow the recommendations on each of those, and so on.

By repeating this thousands of times, the researchers tracked how the platform moved users from one video to the next. They found that after users watched a video about politics or even entertainment, YouTube’s recommendations often favored right-wing, conspiracy-filled channels like Mr. Moura’s

Crucially, users who watched one far-right channel would often be shown many more.

The algorithm had united once-marginal channels — and then built an audience for them

One of those channels belonged to Mr. Bolsonaro, who had long used the platform to post hoaxes and conspiracies

The conspiracies were not limited to politics. Many Brazilians searching YouTube for health care information found videos that terrified them: some said Zika was being spread by vaccines, or by the insecticides meant to curb the spread of the mosquito-borne disease that has ravaged northeastern Brazi

The videos appeared to rise on the platform in much the same way as extremist political content: by making alarming claims and promising forbidden truths that kept users glued to their screens.

Doctors, social workers and former government officials said the videos had created the foundation of a public health crisis as frightened patients refused vaccines and even anti-Zika insecticides.

Not long after YouTube installed its new recommendation engine, Dr. Santana’s patients began telling him that they’d seen videos blaming Zika on vaccines — and, later, on larvicides. Many refused both.

Medical providers, she said, were competing “every single day” against “Dr. Google and Dr. YouTube” — and they were losing

Brazil’s medical community had reason to feel outmatched. The Harvard researchers found that YouTube’s systems frequently directed users who searched for information on Zika, or even those who watched a reputable video on health issues, toward conspiracy channels

As the far right rose, many of its leading voices had learned to weaponize the conspiracy videos, offering their vast audiences a target: people to blame

Eventually, the YouTube conspiracists turned their spotlight on Debora Diniz, a women’s rights activist whose abortion advocacy had long made her a target of the far right

Bernardo Küster, a YouTube star whose homemade rants had won him 750,000 subscribers and an endorsement from Mr. Bolsonaro, accused her of involvement in the supposed Zika plots.

As far-right and conspiracy channels began citing one another, YouTube’s recommendation system learned to string their videos together

However implausible any individual rumor might be on its own, joined together, they created the impression that dozens of disparate sources were revealing the same terrifying truth.

When the university where Ms. Diniz taught received a warning that a gunman would shoot her and her students, and the police said they could no longer guarantee her safety, she left Brazil.

“The YouTube system of recommending the next video and the next video,” she said, had created “an ecosystem of hate.

“‘I heard here that she’s an enemy of Brazil. I hear in the next one that feminists are changing family values. And the next one I hear that they receive money from abroad” she said. “That loop is what leads someone to say ‘I will do what has to be done.’

In Brazil, this is a growing online practice known as “linchamento” — lynching. Mr. Bolsonaro was an early pioneer, spreading videos in 2012 that falsely accused left-wing academics of plotting to force schools to distribute “gay kits” to convert children to homosexuality.

Mr. Jordy, his tattooed Niterói protégé, was untroubled to learn that his own YouTube campaign, accusing teachers of spreading communism, had turned their lives upside down.One of those teachers, Valeria Borges, said she and her colleagues had been overwhelmed with messages of hate, creating a climate of fear.

Mr. Jordy, far from disputing this, said it had been his goal. “I wanted her to feel fear,” he said

The group’s co-founder, a man-bunned former rock guitarist name Pedro D’Eyrot, said “we have something here that we call the dictatorship of the like.”

Reality, he said, is shaped by whatever message goes most viral.

Even as he spoke, a two-hour YouTube video was captivating the nation. Titled “1964” for the year of Brazil’s military coup, it argued that the takeover had been necessary to save Brazil from communism.Mr. Dominguez, the teenager learning to play guitar, said the video persuaded him that his teachers had fabricated the horrors of military rule.

Their study, published on Thursday in the journal Cell, concludes that a wave of modern humans departed Africa far earlier than had been known: some 200,000 years ago.

The ancestors of humans and Neanderthals lived about 600,000 years ago in Africa

The scientists also found evidence that people living somewhere in western Eurasia moved back to Africa and interbred with people whose ancestors never left. The new study suggests that all Africans have a substantially greater amount of Neanderthal DNA than earlier estimates.

The research offers a view of human history “almost as a spider web of interactions, rather than a tree with distinct branches.”

These people interbred with Neanderthals, the new study suggests. As a result, Neanderthals were already carrying genes from modern humans when the next big migration from Africa occurred, about 140,000 years later.

The Neanderthal lineage left the continent; the fossils of what we describe as Neanderthals range from 200,000 years to 40,000 years in age, and are found in Europe, the Near East and Siberia.

The human genome is detailed in units called base pairs, about 3 billion such pairs in total. The scientis

ts found that Europeans on average had 51 million base pairs that matched Neanderthal DNA, and East Asians had 55 million.Dr. Akey’s previous research had indicated that East Asians carried far more Neanderthal ancestry than did Europeans.Africans on average had 17 million base pairs that matched Neanderthal DNA — far higher than predicted by the original models describing how humans and Neanderthals interbred.

They concluded that a group of modern humans expanded out of Africa perhaps 200,000 years ago and interbred with Neanderthals. Those modern humans then disappeared. But Neanderthals who lived after that disappearance inherited some modern human DNA.

sitation over the analysis of African DNA, Dr. Reich said the new findings do make a strong case that modern humans departed Africa much earlier than thought

It’s possible that humans and Neanderthals interbred at other times, and not just 200,000 years ago and again 60,000 years ago. But Dr. Akey said that these two migrations accounted for the vast majority of mixed DNA in the genomes of living humans and Neanderthal fossils.

In recent years, Dr. Reich and other researchers have found evidence that ancient people from the Near East moved back into Africa in the past few thousand years and spread their DNA to many African populations.

Both are in bad shape. The last time the group assessed African elephants, in 2008, it listed them as vulnerable. Now it says savanna elephants are endangered, one category worse.

Alfred Roca, a geneticist at the University of Illinois at Urbana-Champaign, said the I.U.C.N.’s recognition of two African elephant species was a little tardy. More than two decades ago, a study of 295 skulls in museums found “enormous differences” between the two types of elephants, he said.

Even during those few decades, the changes were drastic. The population of savanna elephants has fallen at least 60 percent, the team found. Forest elephants have declined by more than 86 percent.

Dr. Okita said that considering the two elephant species separately was helping to reveal just how bad things are, especially for the forest elephant.

The shy forest elephants have lost nearly nine-tenths of their number in a generation and are now critically endangered — just one step from extinction in the wild.

It will be especially hard for forest elephants to bounce back, Dr. Roca added, because of how long they wait to reproduce — six years longer than the savanna elephants.

As they knock down trees and chew up huge amounts of plant material, both forest and savanna elephants change their environments in ways that create new habitat for other species.

Savanna elephants are “thriving,” Dr. Okita said, in the Kavango Zambezi Transfrontier Conservation Area, which overlaps five countries in southern Africa. In some parts of Gabon and the Republic of Congo, forest elephant populations have stabilized or even grown. Where people are protecting elephants against poachers and planning land use carefully, Dr. Okita said, there has been progress

“We fear that we are going to fill all these beds and then we will have nowhere else to continue to care for Covid patients,” said Mangu Kendino, an emergency physician and the chair of the Covid-19 committee at Port Moresby General Hospital.

“They have challenges accessing health care at the best of times,” said Rob Mitchell, an emergency physician specializing in triage in the Pacific.

“When the pandemic was first announced by the W.H.O. and we went into lockdown, the government reacted pretty quickly,” said Dr. William Pomat, the director of the PNG Institute of Medical Research.

But late last year, he added, “many of us became very complacent. A lot of the things we were supposed to be doing, we didn’t do anymore.”

In one of the field hospitals, Dr. Nou said, he and others, dressed in full protective equipment, often work in humid conditions as they struggle to keep their patients cool and hydrated.

In response, Australia has donated 8,000 doses of the AstraZeneca vaccine, as well as protective equipment and ventilators. It has also deployed a small team to the country.

Fearing spread of the virus, the Australian authorities have ramped up efforts to vaccinate the population of the Torres Strait Islands, an archipelago bordering northern Australia and Papua New Guinea.

“They’re our family. They’re our friends. They’re our neighbors. They’re our partners,” Scott Morrison, Australia’s prime minister, said last week.

“Even for the educated health worker, it’s causing a lot of doubt,” said Dr. Nou, the Port Moresby-based physician, who has conducted a survey of health care workers’ views about the pandemic.

“It’s not good enough to just respond to Covid and then have someone die of another cause,” said Dr. Suman Majumdar, an infectious diseases specialist at the Burnet Institute, an Australian medical research facility. “We have feared the worst,” he added, “and this is happening.”

Where elephants disappear, they leave a big gap — not just physically, but also in the work they do. Some tree species depend entirely on forest elephants to eat their fruits, swallow their large seeds and deposit them elsewhere in a pile of dung.

Savanna elephants are “thriving,” Dr. Okita said, in the Kavango Zambezi Transfrontier Conservation Area, which overlaps five countries in southern Africa. In some parts of Gabon and the Republic of Congo, forest elephant populations have stabilized or even grown. Where people are protecting elephants against poachers and planning land use carefully, Dr. Okita said, there has been progress.

The report did not name any of the 35 world leaders that were allegedly on in the list. However, few months after the initial reports, the German government publicly said it had information that suggested the US might have monitored Merkel's cell phone.

Denmark's independent public service broadcaster, DR, published a report on Sunday saying that the Danish Defense Intelligence Service (FE) had launched an internal investigation in 2014 over whether the NSA used its partnership with FE, and Danish internet cables in and out of Denmark, to spy on senior European officials, according to Reuters.

Merkel on Monday said she agreed with French President Emmanuel Macron's assertion that wiretapping between allies was unacceptable. "Nothing has changed in our stance to the clarification given by the predecessor at the time," Merkel said, referencing the initial claims raised in 2013.

The DR report also found that the NSA spied on Germany's then-foreign minister, Frank-Walter Steinmeier, who is now the country's president, and the former German opposition leader Peer Steinbrück, Reuters reported.

DR reported that the intelligence was gathered through an analysis of software known as Xkeyscore, developed by the NSA. Reuters reported that the agency "intercepted both calls, texts and chat messages to and from telephones of officials in the neighbouring countries," citing the DR report.

But that October, Biogen announced it found benefit in one trial after evaluating data from 318 participants who finished before the trials were stopped but after the cutoff point for results the monitoring committee assessed.

Both trials were stopped early, in March 2019, when an independent data monitoring committee said aducanumab didn’t appear to be working. Consequently, 37 percent of participants never completed the 78-week trials.

Aducanumab, a monoclonal antibody, targets a protein, amyloid, that clumps into plaques in the brains of Alzheimer’s patients. Many amyloid-reducing drugs failed to slow symptoms in trials, a history that, some experts say, makes it especially important that aducanumab’s data be convincing. If effective, it would support a long-held, unproven theory that attacking amyloid can help if done early enough.

By contrast, Dr. Stephen Salloway, who has received research and consulting fees from Biogen but wasn’t paid for being an aducanumab trial site principal investigator, called himself a “passionate” supporter of approval. He considers the evidence sufficient because Alzheimer’s is so disabling.

Advocates and many patients say delaying deterioration even slightly is meaningful. But some experts say the single trial’s slowing of 0.39 on an 18-point scale rating memory, problem-solving skills and function may be imperceptible to patients’ experience and doesn’t justify approving a drug that floundered in another trial and carries risk of harm.

Dr. Salloway said one trial patient whose dementia had remained mild considerably longer than he’d expected was Henry Magendantz, a retired obstetrician-gynecologist in Providence, R.I. Dr. Magendantz, 84, started the safety trial after his wife, Kathy Jellison, noticed him having trouble following steps to assemble furniture.

Dr. Woskie said the couple yearns for treatments but that if the F.D.A. told Biogen, “‘No, we don’t fast-track approve you; come back when you have more data,’ that wouldn’t surprise me, and it might make sense.”