Crowds don’t need to surge for the gathering to turn deadly—smaller movements and pushes by those on the outer edges can send currents through the group that grow in strength, creating a domino effect. Eventually, the pressure on people’s bodies turns suffocating. “They’ll not have done anything deliberately. It’s very difficult when you’re in a crowd to know that it’s dangerous,” says Martyn Amos, a professor at Northumbria University who studies crowds.

These types of disasters have been documented for decades at sporting events, concerts, and nightclubs, most recently in October when 135 died following a football match in Indonesia, and when 10 perished at the Astroworld music festival in Houston, Texas, in 2021. Experts say crushes are preventable but can occur due to the failings of authorities and organizers—and Amos thinks this is the case in Seoul, as well. “People were the medium through which the disaster occurred, but the root cause of this incident seems to be in a lack of preparation from the authorities,” he says.

How Crushes Happen

Amos says safe crowds act like a gas; people are like particles that can move around freely. But add too many people—about five or six for every square meter—and the crowd transforms to become more like a liquid. “Where the crowd is a fluid, that’s where we’ve got the potential for problems,” he says. “You’re essentially a particle at the mercy of physics.”

A small push from the back of the crowd can grow stronger as it ripples through the group like a wave. If it eventually reaches a person next to an obstruction, like a wall, fence, or immovable pack of people, that wave has nowhere to go. Without an outlet, that force can now crush the people in its path. In the Itaewon incident, a collapse in the crowd may have caused the obstruction, with one or more people falling in the densely packed group. And when people are trapped, Amos says, the force of the crowd can hem them in and prevent others from pulling them out.

Ultimately, people die in crowd crushes from asphyxiation, Amos says. When a person breathes out, their chest cavity contracts. But when they try to breathe in again, the force of people around them can be too strong, making it impossible for their chest to expand and take in new air. Five people pushing on one person can create a 3,000-newton force, says Amos, or the equivalent of 674 pounds, which can break a person’s ribs.

Take the 1989 Hillsborough disaster, a crush that resulted in 97 deaths at Hillsborough Stadium in England. The strength of the crowd broke steel barriers, a feat that required forces on them to exceed 4,500 newtons, Amos says. Gil Fried, an attorney and professor at the University of West Florida with an expertise in crowd management, says metal railings were also twisted after a 1993 incident at the University of Wisconsin-Madison’s Camp Randall Stadium. That destruction was the result of more than 1,000 pounds of pressure per square inch.

The US Centers for Disease Control and Prevention offers recommendations for surviving a crowd crush. One is to take a boxer’s stance, with feet apart and knees slightly bent, one in front of the other, and hands up. This may keep people from falling or having their arms pinned. Another is to move with the flow of the crowd instead of against it. Experts also encourage people not to waste breath screaming, and they caution against bending over to pick up dropped items.

But there’s little else individuals can do to protect themselves once the crowd’s pressure builds. Those on the outer edges of a crowd often have no idea their movements are crushing others in the group.

Preventing the Next Crush

Most crowded concerts and events are safe, thanks to advance planning from organizers. It’s typically a lack of proper safety planning that exposes crowds to danger. In Seoul, the blame has fallen on local police, who, according to The Washington Post, received calls about large crowds hours before the crush but did not disperse people from the area. South Korean prime minister Han Duck-soo said officials lacked a “crowd management system” and has called for a fix to the issue. “The government is responsible for lives and safety of the people, and it is our absolute duty.”

After the deaths at Astroworld, the organizers faced lawsuits over allegations that inadequate security and planning led to as many as 5,000 injuries. A human rights organization in Indonesia claims tear gas used by police triggered the panic at the stadium there, with people crushed to death trying to reach the only remaining exit.

Solutions for crowd crush are largely preemptive, says Fried. Venues should have a sufficient number of trained crowd managers, who are different from crowd control experts. Crowd control responds when an emergency occurs, but crowd managers plan in advance and monitor events. Crowd managers should also have ways to communicate with the attendees to direct behavior, whether on loudspeakers or via signs like scoreboards. Often, when people push from the back of the crowd and start to exert pressure on people in the middle or those pressed against barriers, they have no idea others are getting hurt. Clear instructions that address the whole crowd and get them to move can help.

At organized events, venues and planners spend money on risk assessments and simulations, planning for emergencies. But the Seoul disaster was an unticketed event in a public space, and police did not effectively plan for the large crowds, as investigating authorities have said. “The best prevention is the planning to make sure this doesn’t happen,” says Fried. “Once it happens, it is very difficult to stop it.”

How Peaceful Crowds Turn Into a Deadly Crush

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Possible Long March 5B reentry locations lie anywhere along the blue and yellow ground track. Areas not under the line are not exposed to the debris.

The Aerospace Corporation

 

The Chinese rocket that will fall back to Earth in a few days is equivalent in size to two semi-truck trailers, and as much as 40 percent of this metal will reach the Earth's surface, experts say.

 

Although the overall risk of harm to people is low—there is only a 0.5 percent chance of injury or death to a human, based on one model—these risks are nonetheless higher than accepted by most spacefaring nations, said Ted Muelhaupt, a reentry and debris expert at The Aerospace Corporation.

 

Muelhaupt and other analysts spoke with reporters during a teleconference Wednesday, about two days before the predicted reentry of the Long March 5B core stage. As it acquires more orbital data, the nonprofit Aerospace Corporation plans to continue updating its entry forecast. As of Thursday morning, it predicted a reentry of 7:17 pm ET Friday (23:17 UTC), plus or minus 10 hours.

 

A Long March 5B rocket launched the 23-ton Mengtian module to the Chinese Tiangong space station on Monday. This modified version of China's most powerful rocket uses the massive core stage to push space station modules all the way to low-Earth orbit. Because this core stage lacks the capability to relight its engines for a controlled reentry into a desolate part of the world's oceans, the rocket could ultimately come back anywhere in the tropics and most of the mid-latitudes of the planet.

 

On the three previous launches of the Long March 5B booster—in 2020, 2021, and 2022—chunks of debris damaged villages in the Republic of Côte d'Ivoire, fell harmlessly into the Indian Ocean, and landed near villages in Borneo, respectively. Fortunately, no one has yet been injured by this falling debris.

 

According to The Aerospace Corporation, the reentry of these 21.6-metric-ton core stages comprises four of the six largest uncontrolled reentries from space during the last 50 years. They are behind only NASA's Skylab space station, in 1971, and the Soviet Union's Salyut 7 station in 1991.

 

Based on the core stage's orbit, it has the potential to affect landmasses where about 88 percent of the world's population lives, Muelhaupt said. Based on a simple model, he estimates that the chance of a casualty—defined as a death or injury—is between 1-in-230 and 1-in-1,000. The individual risk to any single person is extraordinarily low, about 6 per 10 trillion. You are many, many more times likely to be struck by lightning.

 

However, one's individual risk from falling Chinese rocket debris is not really the point, officials from The Aerospace Corporation said. Space agencies and companies in the United States, Europe, and elsewhere follow "norms" of behavior for much lower risks. For example, the acceptable risk of casualty is 1-in-10,000 from a human-made object reentering from space.

 

There are probably about half a dozen launches of the Long March 5B remaining in this configuration, in which the core stage goes all the way to orbit. Muelhaupt acknowledged that the country is unlikely to change the design of this rocket now that it has proven successful at delivering large pieces of hardware to space. But he hopes that future Chinese rocket designs find a better way to dispose of such large hardware without dropping tons of metal back on Earth.

 

"We’re trying to get an accepted norm of behavior," he said. "Treaties and laws are hard. Accepted norms can come from the ground up. For the next time they make a design like this, we hope they will take the reaction to this one into account."

 

Falling Chinese rocket expected to enter Earth’s atmosphere in <2 days

The Omicron variant of concern has splintered into multiple subvariants. So we’ve had to get our heads around these mutated forms of SARS-CoV-2, the virus that causes Covid-19, including BA.1 and the more recent BA.5.

We’ve also seen recombinant forms of the virus, such as XE, arising by genetic material swapping between subvariants. More recently, XBB and BQ.1 have been in the news. No wonder it’s hard to keep up.

The World Health Organization (WHO) has had to rethink how it describes all these subvariants, now labeling ones we need to be monitoring more closely.

Omicron and its subvariants are still causing the vast majority of Covid cases globally, including in Australia.

Omicron subvariants have their own specific mutations that might make them more transmissible, cause more severe disease or evade our immune response.

Omicron and its subvariants have pushed aside previous variants of concern, the ones that led to waves of Alpha and Delta earlier in the pandemic.

Now, in Australia, the main Omicron subvariants circulating are BA.2.75, and certain versions of BA.5. More on these later.

Viral genomes from Australia: once we had Alpha and Delta waves. Now we have waves of Omicron subvariants. Author provided

We still don’t fully understand the driving forces behind the emergence and spread of certain SARS-CoV-2 subvariants.

We can, however, assume the virus will keep evolving, and new variants (and subvariants) will continue to emerge and spread in this wave-like pattern.

To monitor these subvariants, the WHO has defined a new category, known as “Omicron subvariants under monitoring.”

These are ones that have specific combinations of mutations known to confer some type of advantage, such as being more transmissible than others currently circulating.

Researchers and health authorities keep track of circulating subvariants by sequencing the genetic material from viral samples (for instance, from PCR testing or from wastewater sampling). They then upload the results to global databases (such as GISAID) or national ones (such as AusTrakka).

These are the Omicron subvariants authorities are keeping a closer eye on for any increased risk to public health.

Newer versions of BA.5

The BA.5 subvariant that arose in early February 2022 is still accumulating more mutations.

The WHO is monitoring BA.5 versions that carry at least one of five additional mutations (known as S:R346X, S:K444X, S:V445X, S:N450D and S:N460X) in the spike gene.

The spike gene codes for the part of the virus that recognizes and fuses with human cells. We are particularly concerned about mutations in this gene as they might increase the virus’ ability to bind with human cells.

Throughout recent months, BA.5 has been the dominant subvariant in Australia. However, BA.2.75 has now established a foothold.

BA.2.75 or Centaurus

The BA.2.75 subvariant, sometimes called Centaurus, was first documented in December 2021. It possibly emerged in India but has been detected around the globe.

This includes in Australia, where more than 400 sequences have been uploaded to the GISAID database since June 2022.

This subvariant has up to 12 mutations in its spike gene. It seems to spread more effectively than BA.5. This is probably due to being better able to infect our cells, and avoiding the immune response driven by previous infection with other variants.

BJ.1

This was first detected in early September 2022 and has a set of 14 spike gene mutations.

It has mostly been detected in India or in infections coming from this area.

We know very little about the impact of its mutations and at the time of writing, there was only one Australian sequence reported.

BA.4.6 or Aeterna

BA.4.6, sometimes called Aeterna, was detected in January 2022 and has been spreading rapidly in the United States and the United Kingdom.

There have been more than 800 sequences uploaded to the GISAID database in Australia since May 2022.

It may be more easily transmitted from one person to the next due to its spike gene mutations.

Early data suggests it is better able to resist cocktails of therapeutic antibodies compared with BA.5. This makes antibody therapies, such as Evusheld, less effective against it.

BA.2.3.20

This was first detected in the US in August 2022. It has a set of nine mutations in the spike gene, including a rare double mutation (A484R).

Like BA.2.75, this subvariant is probably better able to infect our cells and avoid the immune response driven by previous infection.

There are more than 100 Australian genomic sequences reported in the GISAID database, all from August 2022.

China is more concerned than the West about Covid’s enduring risks. Image: Screengrab / HBO

XBB

This recombinant version of the virus was detected in August 2022. It is a result of the swapping of genetic material between BA.2.10.1 and BA.2.75. It has 14 extra mutations in its spike gene compared with BA.2.

Although there have only been 50 Australian genomic sequences reported in GISAID since September, we anticipate cases will rise. Lab studies indicate therapeutic antibodies don’t work so well against it, with XBB showing strong resistance.

Although XBB appears to be able to spread faster than BA.5, there’s no evidence so far it causes more severe disease.

How about BQ.1?

Although it is not on the WHO list of subvariants under monitoring, cases of the BQ.1 subvariant are rising in Australia. BQ.1 contains mutations that help the virus evade existing immunity. This means infection with other subvariants, including BA.5, may not protect you against BQ.1.

In the meantime, your best protection against severe Covid, whichever subvariant is circulating, is to make sure your booster shots are up-to-date. Other ways to prevent SARS-CoV-2 infection include wearing a fitted mask, avoiding crowded spaces with poor ventilation and washing your hands regularly.

Ash Porter is research officer, The Peter Doherty Institute for Infection and Immunity and Sebastian Duchene, Australian Research Council Future Fellow, The University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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 Another Twitter employee was able to view a group on Slack, the workplace chat tool, in which company administrators appeared to be finalizing the precise number of workers to be laid off, and how much they’d receive in severance.

By day’s end, word had spread across the company that layoffs — half the staff — would probably come Friday, and that Musk would require Twitter’s remaining employees to return to the office full-time. But that word didn’t come from Musk, or anyone on his leadership team. It came via Blind, the anonymous workplace gossip site that some Twitter employees say has become their best, and often only, source of information about what’s going on inside the company in the chaotic, surreal week since Musk acquired it for $44 billion.

Twitter did not immediately respond to a request for comment, and the company’s leadership has not confirmed the layoff plans.

Since Musk closed the deal on Oct. 27, employees say, they have not received a single official communication from anyone in a leadership position at the company. They have not been told that Musk completed the purchase, that their CEO and top executives were summarily fired, or that Musk dissolved the board and installed himself as chief executive.

< Watch the video at the source page. >

 Instead, they have read about Musk’s dramatic plans to overhaul the company via media reports, Musk’s tweets, back-channel private chats and Blind. Twitter’s formerly open corporate culture, centered on all-staff meetings and freewheeling Slack channels where employees and managers shared ideas, plans and jokes, has turned suspicious and secretive, several Twitter employees told The Wasington Post, speaking on the condition of anonymity because they feared retribution.

“It’s like Twitter’s culture has been completely turned inside out overnight,” one employee said. “Mass trauma event over here.”

The last official communication to the Twitter staff came the day before Musk took over, when Twitter’s head of people, Leslie Berland, sent a cheery email with the subject line “Elon office visit.”

“If you’re in SF and see him around, say hi!” Berland wrote. “For everyone else, this is just the beginning of many meetings and conversations with Elon, and you’ll all hear directly from him on Friday.”

But workers did not hear directly from Musk on Friday, when his planned introduction to the company was quietly canceled, or anytime since. The company’s regular all-hands meeting, scheduled for Wednesday, disappeared from everyone’s calendars on Tuesday.

On Tuesday, Berland left the company, according to people familiar with the situation, who spoke on the condition of anonymity to discuss sensitive matters. Berland’s apparent departure, along with those of several other executives in recent days, was not announced either internally or externally, leaving employees to speculate on Blind about which of their bosses have quit or been fired.

Since Friday, employees have posted memes and comments on the company Slack noting each day that has passed without word from management. One person posted an image of a skeleton with a caption that read, “me waiting on updates from leadership,” according to documents obtained by The Post.

In lieu of communicating with employees, Musk and his new deputy Jason Calacanis, who appeared in a company directory over the weekend, have been brainstorming, focus-grouping and announcing new products and policies in public, via their personal Twitter accounts. Twitter’s employees have quickly learned to follow their new leaders’ Twitter feeds for updates essential to their work.

It’s on Twitter that Musk confirmed that he had appointed himself chief executive, three days after taking ownership. It’s also where he has floated plans to charge users $8 a month for a verification badge, among other benefits; announced that he’ll form a content moderation council to review Twitter’s speech policies; and sought to soothe skittish advertisers that he won’t let Twitter become a “free-for-all hellscape.”

On the company’s Slack boards, employees have been posting Musk’s tweets about new features, asking whether they should begin working to implement them or continue standing by, according to another employee, who spoke on the condition of anonymity because they were not authorized to discuss internal matters. When Musk tweeted what features the company’s paid subscription tier should have, it caught most employees in the department running that product by surprise, the employee said.

“We’re all working for the Trump White House,” the worker said, comparing the atmosphere to Donald Trump’s administration, where tweets from the president announcing policies that hadn’t been discussed internally could come at any time.

The culture shock at Musk’s Twitter represents a collision between the company’s famously relaxed work environment and the walled-off climate typical of Musk’s companies, where leaks are punished swiftly and underperformers may be subject to “rage firings.” It’s also the product of fear of job losses, which was stoked when The Post reported before his takeover that Musk had told bankers he planned to cut as much as 75 percent of the company’s workforce.

Inside Tesla and SpaceX, two of Musk’s other companies, workers are bound by the expectation that they will not speak of their work outside the company — knowing that a lens is trained on their celebrity CEO at all times. They are measured by their output and ability to execute on tight deadlines, and minor disagreement with the CEO can sometimes escalate into questions about fitness for the job.

At Tesla, some leaks are investigated vigorously, and an employee was fired after he published videos to his YouTube channel showing the company’s Full Self-Driving Beta software in action — even though the videos did not reveal internal secrets, CNBC reported.

While some Twitter employees say they have languished since Musk took over, unsure of what to work on, other teams have been ordered to develop new products on tight deadlines. An internal email obtained by The Post on Tuesday showed that the company is aiming to launch a paid-video feature, which could be used to monetize adult content, within one to two weeks, despite an internal assessment that it poses a high liability risk.

Blind has emerged as a way for Twitter employees to share what they’re hearing with others in the company anonymously, reducing the risk that they’ll be punished for saying the wrong thing on company tools such as Slack or email. Launched in 2015, Blind has caught on with Silicon Valley tech companies, each of which has its own private channel that workers can access only by verifying their company email address.

It’s there that many Twitter employees are hearing of the latest fired executive or layoff rumor and commiserating over the bizarre turn their professional lives have taken.

One Blind post from a Twitter worker, viewed by The Post on Wednesday, said simply, “This level of silent treatment is totally unprofessional.” Another Twitter employee replied, “It’s not silent treatment it is psychological warfare.”

The sense that it’s no longer safe for managers to share information with the staff via Slack was reinforced by an anecdote that appeared on Blind this week.

On Tuesday, Twitter’s chief of accounting, Robert Kaiden, had posted a Slack message — viewed by The Post — explaining some basic details of the company’s plan for paying out employees’ vested stock shares after Musk purchased them. By Wednesday, his Slack account showed that it had been deactivated. A post on Blind said he had been “walked out” of the Twitter building.

As with all the other executives who are rumored to have left since Musk took charge, Twitter declined to comment.

Faiz Siddiqui, Gerrit De Vynck, Elizabeth Dwoskin, Cat Zakrzewski and Taylor Lorenz contributed to this report.

Source

Why it matters: A combined vaccine could simplify immunizations and simultaneously fight two respiratory diseases that require repeated vaccinations.

•     Moderna and Novavax are also developing combination COVID and flu shots.

Details: Pfizer and BioNTech aim to enroll 180 U.S. volunteers between the ages of 18 and 64 for an early-stage trial to assess the safety, efficacy and optimal dosage. The first participant received a dose of the combination shot this week.

•     The candidate vaccine combines an mRNA influenza vaccine with the companies' COVID-19 shot based on the BA.4 BA.5 variants.

Between the lines: While COVID case counts remain low in the U.S., public health efforts are increasingly focused on new ways to address multiple threats, like a "tripledemic" of more transmissible variants, a major uptick in RSV cases and worse-than-usual flu season.

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•     A Twitter software engineer said he was fired on Tuesday, just days after Elon Musk took control.

•     Emmanuel Cornet said he believes the new management didn't want to deal with a "troublemaker."

•     Twitter HR last year asked him to take down cartoons he tweeted and published internally.

A cartoon-drawing Twitter employee believes he was fired following Elon Musk's takeover because the new management didn't want to deal with a "troublemaker."

Emmanuel Cornet, who is also known as Manu, joined Twitter last year as a software engineer after leaving Google, where he spent a decade poking fun at the company with his satirical cartoons.

Insider has reported that Musk plans to sack about half of Twitter's staff and Cornet is one of those who has lost his job.

The 41-year-old software engineer said in a blog post seen by Insider: "Since I was one of the early layoffs after the Oct 2022 acquisition of Twitter, some people have been curious about the reasons. My current understanding is that I was too much of a potential troublemaker for the new management."

He wrote that after he tweeted a cartoon last year, Twitter HR asked him to take it down, along with one he had posted internally.

Cornet believed it was very unlikely that Twitter fired him for poor performance: "I hope those never come or remain minimal, but the 'poor performance' layoffs haven't started yet."

 The software engineer gave his cartoon to Elon Musk, to which the billionaire reportedly responded: "Well I bought it anyway."

Manu Cornet © Manu Cornet

As Musk visited Twitter's San Francisco headquarters last week, Cornet handed him a cartoon with a note that read: "I hope you don't mind a 'court jester' at Twitter or you'll have to get me fired," signed with an emoji sticking his tongue out.

Musk reportedly responded: "Well, I bought it anyway."

Cornet concluded: "I don't hold any grudges against people who were just doing their job when confronted with a naive and mildly idealistic troublemaker like me, and I loved my time at Twitter, especially my coworkers."

Twitter did not immediately respond to Insider's request for comment.

Source

SpaceX is now building a Raptor engine a day, NASA says

Panasonic breaks ground on $4 billion EV battery plant in Kansas

Honda aims for a solid-state-powered EV by the end of the decade

Why Pfizer’s RSV vaccine success is a big deal, decades in the making

The earliest gibbon fossil has been found by a team of researchers, filling a long-missing evolutionary gap in the history of apes.

The study, which was published in the Journal of Human Evolution, focuses on the hylobatid family of apes, which comprises 20 species of living gibbons that are found throughout tropical Asia from northeastern India to Indonesia.

“Hylobatids fossil remains are very rare, and most specimens are isolated teeth and fragmentary jaw bones found in cave sites in southern China and southeast Asia dating back no more than 2 million years ago,” explains Terry Harrison, a professor of anthropology at New York University and one of the paper’s authors. “This new find extends the fossil record of hylobatids back to 7 to 8 million years ago and, more specifically, enhances our understanding of the evolution of this family of apes.”

The fossil, found in the Yuanmou area of Yunnan Province in southwestern China, is of a small ape called Yuanmoupithecus xiaoyuan. The study’s analysis concentrated on the teeth and cranial specimens of Yuanmoupithecus, which included an upper jaw from a young child who was less than two years old at the time of its death.

Using the size of the molar teeth as a guide, Yuanmoupithecus was estimated to be close in size to modern-day gibbons, with a body weight of roughly 6 kilograms—or about 13 pounds.

“The teeth and the lower face of Yuanmoupithecus are very similar to those of modern-day gibbons, but in a few features the fossil species was more primitive and points to it being the ancestor of all the living species,” observes Harrison, part of NYU’s Center for the Study of Human Origins.

Ji discovered the child’s upper jaw during a field survey, and by comparing it with modern gibbon skulls kept at the Kunming Institute of Zoology, he was able to identify it as a hylobatid. In 2018, he invited Harrison and other colleagues to work on specimens gathered over the previous 30 years that were housed in the Yunnan Institute of Cultural Relics and Archaeology and the Yuanmou Man Museum.

“The remains of Yuanmoupithecus are extremely rare, but with diligence, it has been possible to recover enough specimens to establish that the Yuanmou fossil ape is indeed a close relative of the living hylobatids,” notes Harrison.

The Journal of Human Evolution study also found that Kapi ramnagarensis, which has been claimed to be an earlier species of hylobatid, based on a single isolated fossil molar from India, is not a hylobatid after all, but a member of a more primitive group of primates that are not closely related to modern-day apes.

“Genetic studies indicate that the hylobatids diverged from the lineage leading to the great apes and humans about 17 to 22 million years ago, so there is still a 10-million-year gap in the fossil record that needs to be filled,” Harrison cautions. “With the continued exploration of promising fossil sites in China and elsewhere in Asia, it is hoped that additional discoveries will help fill these critical gaps in the evolutionary history of hylobatids.”

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The loss of any life is devastating, but the loss of life due to suicide is exceptionally saddening.

Suicide is the primary cause of mortality for Australians aged 15 to 44, taking the lives of almost nine people daily. According to some estimates, suicide attempts happen up to 30 times more often than fatalities.

“Suicide has large effects when it happens. It impacts many people and has far-reaching consequences for family, friends, and communities,” says Karen Kusuma, a University of New South Wales Ph.D. candidate in psychiatry at the Black Dog Institute, who investigates suicide prevention in adolescents.

Recent research conducted by Ms. Kusuma and a group of scientists from the Black Dog Institute and the Centre for Big Data Research in Health investigated the evidence supporting machine learning models’ ability to predict potential suicidal behaviors and thoughts. They evaluated the efficacy of 54 machine learning algorithms that were previously created by researchers to predict suicide-related outcomes of ideation, attempt, and death.

The meta-analysis, published in the Journal of Psychiatric Research, found that machine learning models outperformed conventional risk prediction models in predicting suicide-related outcomes, which had traditionally performed poorly.

“Overall, the findings show there is a preliminary but compelling evidence base that machine learning can be used to predict future suicide-related outcomes with very good performance,” Ms Kusuma says.

Traditional suicide risk assessment models

In order to prevent and manage suicidal behaviors, it is crucial to identify those who are at risk of suicide. However, predicting risk is challenging.

In emergency departments (EDs), doctors often employ risk assessment tools, such as questionnaires and rating scales, to pinpoint patients who are at a high risk of suicide. Evidence, however, indicates that they are ineffective in accurately determining suicide risk in practice.

“While there are some common factors shown to be associated with suicide attempts, what the risks look like for one person may look very different in another,” Ms. Kusuma says. “But suicide is complex, with many dynamic factors that make it difficult to assess a risk profile using this assessment process.”

A post-mortem analysis of people who died by suicide in Queensland found, of those who received a formal suicide risk assessment, 75 percent were classified as low risk, and none was classified as high risk. Previous research examining the past 50 years of quantitative suicide risk prediction models also found they were only slightly better than chance in predicting future suicide risk.

“Suicide is a leading cause of years of life lost in many parts of the world, including Australia. But the way suicide risk assessment is done hasn’t developed recently, and we haven’t seen substantial decreases in suicide deaths. In some years, we’ve seen increases,” Ms. Kusuma says.

Despite the shortage of evidence in favor of traditional suicide risk assessments, their administration remains a standard practice in healthcare settings to determine a patient’s level of care and support. Those identified as having a high risk typically receive the highest level of care, while those identified as low risk are discharged.

“Using this approach, unfortunately, the high-level interventions aren’t being given to the people who really need help. So we must look to reform the process and explore ways we can improve suicide prevention,” Ms. Kusuma says.

Machine learning suicide screening

Ms. Kusuma says there is a need for more innovation in suicidology and a re-evaluation of standard suicide risk prediction models. Efforts to improve risk prediction have led to her research using artificial intelligence (AI) to develop suicide risk algorithms.

“Having AI that could take in a lot more data than a clinician would be able to better recognize which patterns are associated with suicide risk,” Ms. Kusuma says.

In the meta-analysis study, machine learning models outperformed the benchmarks set previously by traditional clinical, theoretical and statistical suicide risk prediction models. They correctly predicted 66 percent of people who would experience a suicide outcome and correctly predicted 87 percent of people who would not experience a suicide outcome.

“Machine learning models can predict suicide deaths well relative to traditional prediction models and could become an efficient and effective alternative to conventional risk assessments,” Ms. Kusuma says.

The strict assumptions of traditional statistical models do not bind machine learning models. Instead, they can be flexibly applied to large datasets to model complex relationships between many risk factors and suicidal outcomes. They can also incorporate responsive data sources, including social media, to identify peaks of suicide risk and flag times when interventions are most needed.

“Over time, machine learning models could be configured to take in more complex and larger data to better identify patterns associated with suicide risk,” Ms. Kusuma says.

The use of machine learning algorithms to predict suicide-related outcomes is still an emerging research area, with 80 percent of the identified studies published in the past five years. Ms. Kusuma says future research will also help address the risk of aggregation bias found in algorithmic models to date.

“More research is necessary to improve and validate these algorithms, which will then help progress the application of machine learning in suicidology,” Ms. Kusuma says. “While we’re still a way off implementation in a clinical setting, research suggests this is a promising avenue for improving suicide risk screening accuracy in the future.”

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It’s gradually sinking in that the Biden administration has launched perhaps the greatest industrial policy experiment in history – stopping China from assuming technological leadership over the United States and the rest of the world.

The two major thrusts are (1) sweeping, coordinated restrictions on the sale of semiconductors and chip-making equipment to China and (2) massive investments in semiconductors and other advanced technologies in the United States.

I’ve been following these issues since the 1980s when we were worried that the Japanese were penetrating our semiconductor supply chain. It was a Republican president, George H W Bush, who created Sematech, an overt exercise in government-university-industry cooperation.

That was in 1987 and Japan made some gains in semiconductors but the US lead was not completely eroded. In other words, the policy worked. Sematech still exists and is now headquartered in Albany, New York, which is the center of an upstate New York semiconductor boom.

We saw another burst of industrial policy after the Obama administration took over in 2000 and tried to jump-start an electric car industry on the basis of lithium-ion batteries.

That had mixed results after Republicans created such pressure on the Department of Energy, which was administering the grants and loan guarantees, that the administration withdrew funding from Solyndra and A123 Systems. Both went bankrupt (and A123’s assets were acquired by the Chinese.)

Only one recipient of funding did really well: Elon Musk’s Tesla was given a lease on life that has really paid off. Another car company, Fisker, never made it.

Elon Musk at the Tesla factory in Fremont, California. File photo

What have we learned that we need to apply to this next exercise in industrial policy? One reality is that the key American weakness is not basic research. Our laboratories are filled with cutting-edge ideas.

Our key weakness is commercializing those ideas – meaning getting the technologies out of the labs and into commercially viable enterprises that scale and dominate their niches globally.

Being a technology entrepreneur in America is like being asked to walk a gauntlet of torment for years: They face enormous challenges in raising capital, in particular. Seed capital providers, venture capitalists and others obviously attempt to make money in the short term. Most of them are not terribly interested in five-year bets.

I see the Biden administration giving lots of money to the National Institutes of Health, for example, which is all well and good. But NIH knows little about commercializing technologies.

Some part of the billions of dollars being provided by the CHIPS and Science Act and the Inflation Reduction Act (which includes funding for electric batteries) should be funneled into investment funds administered by real industry experts.

This is what China does. It makes massive amounts of funding available to develop ideas that have been stolen or “licensed” from scientists in the United States and elsewhere.

Another lesson is that we must de-politicize this latest burst of industrial policy.

With Republicans poised to make gains in the election this month, it’s easy to see how they might start using committees in Congress to launch investigations and seek to embarrass President Biden in the run-up to the 2024 presidential elections. That would be a tragic mistake.

Industrial policy can only work when it is consistently administered over a long period of time. With technological leadership of the world at stake, I hope Republicans can avoid politicizing the policies now being rolled out.

The last lesson I will offer for now is that we have to get serious, finally, about stopping Chinese espionage in all its many forms. It will achieve absolutely nothing if we create the next generation of extreme ultraviolet (EUV) semiconductor lithography only to have it stolen by the Chinese.

Stopping the espionage will require facing up to some unpleasant truths. The Chinese have penetrated many of, if not most of, our computer systems, as co-author Michael McLauglin and I demonstrate in our forthcoming book Battlefield Cyber.

If they are not presently inside a system, their Ministry of State Security probably has inserted a backdoor that makes access possible. Our researchers have to use secure systems and that costs money.

The academic and scientific community is also going to have to face up to a truth that runs entirely counter to their prevailing culture and mindset: We need to retreat from unfettered, international sharing of research and scientists.

Chinese students are allegedly taking US tech secrets back to China. Image: Screengrab / CNN

Purists would argue that an open international environment is what creates great ideas. That may be true. But it also creates an environment in which the Chinese can pretend to be engaged in genuine international collaboration and then simply steal ideas from others.

Lastly, and this is even more explosive, we need to recognize that the People’s Republic of China uses the presence of 360,000 Chinese students at American universities and the Chinese-American community to pilfer ideas.

This strikes at the core of how we define ourselves as a nation. We want to believe that everyone, of every race and ethnicity, will work to protect American secrets from authoritarian regimes.

A percentage of these students are learning in American laboratories and taking the ideas home – which is considered fair game. But other Chinese researchers and scientists are operating shadow labs in China paid for by the Chinese government or simply selling technologies to the Ministry of State Security and other arms of the Chinese party-state.

We don’t want to start another McCarthy-like Red Scare, but we need to understand that the PRC is very cynically using Chinese and Chinese Americans precisely because they are in a blind spot for us. We don’t want to be accused of racism. But if we want our grand, new industrial policy to work, we have to develop the sophistication to stop this avenue of thievery.

Making industrial policy work isn’t easy. We should learn from history.

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Esther Crawford, a Twitter product director who is leading the development of Musk’s paid verification system, retweeted a photo of her in a sleeping bag in a conference room and said: “When your team is pushing round the clock to make deadlines sometimes you #SleepWhereYouWork.”

I previously reported that Musk told the team building the new Twitter Blue subscription that they have until November 7th to release it or be fired.

    When your team is pushing round the clock to make deadlines sometimes you #SleepWhereYouWork https://t.co/UBGKYPilbD

    — Esther Crawford ✨ (@esthercrawford) November 2, 2022

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The ideas have come so fast that it’s hard to keep track of it all, let alone parse a coherent strategy. But if you take a few steps back, there’s a fairly straightforward theme: Twitter needs to make money and fast. The ideas have been haphazard, but they’ve been fairly consistent, seeking new sources of non-advertising revenue and desperately cutting costs.

This is the sort of thing you do when you’re desperate to improve your new company’s balance sheet and you’re willing to consider just about anything.

If this seems unexpected, it’s because Musk spent so much time publicly insisting that the buyout wasn’t about money. In a TED interview in April, he said it straight out: “This is not a way to make money…. Having a platform that is maximally trusted and broadly inclusive is extremely important to the future of civilization. This is not about the economics at all.”

Crucially, though, he said this before Twitter agreed to his offer and he got a closer look at the company’s books. Once that happened, he spent the next six months trying unsuccessfully to wriggle out of the deal. So even if he came into the deal with altruistic motives, it’s safe to say his thinking has evolved.

Even very, very rich people can overextend themselves

At the same time, there are clear reasons why an incoming CEO might panic about the company’s balance sheet. In its last quarterly earnings report before the acquisition, Twitter posted a loss of $344 million. With users stagnant, investors had become increasingly pessimistic about the platform’s financial outlook. That chilliness was part of what drove the price low enough to allow Musk’s takeover in the first place.

Now, Musk’s takeover has added billions of dollars in debt to the company’s balance sheet, which will make the problem even more urgent. To finance the deal, Musk took out $13 billion worth of loans against the company itself. As noted by DealBook, that raises the company’s annual interest payments to roughly $1 billion a year — more than Twitter’s total profits for 2021. If there was a path to profitability before the takeover, that path is now much, much steeper.

There’s also reason to think Twitter’s ad business (its primary source of revenue) has grown shakier since Musk proposed the deal in April. Overall ad spending declined all summer, and even more established companies like Facebook and Google are feeling the pinch as digital markets dry up. In the wake of Musk’s takeover, a number of major ad agencies have advised clients to pause Twitter advertising completely, either because of the sudden chaos, the broader economy, or a combination of the two. Musk has tried to shore up advertiser support — most notably, publishing an open letter to assure them the platform would not become “a free-for-all hellscape” — but it’s hard to believe he’s in a better place than when he started.

The result is an urgent need to make money from sources other than advertising, but what’s been proposed so far doesn’t come close to filling the gap. Musk’s most ambitious plan is the new $8-a-month verification scheme, which would establish a new kind of premium account on the service. But even if every one of Twitter’s 400,000 verified accounts signed up for the plan, it would only generate $38 million a year — a fraction of the $1 billion interest payments owed by the company as a result of the new debt.

This wasn’t how it was supposed to work. Whether you agree with him or not, Musk has real ideas about how Twitter should be run, and the point of buying the company was to try them out. He’s wildly, obscenely rich, and he just spent tens of billions of dollars insulating Twitter from public markets. But private companies can go bust just as easily as public ones, and even very, very rich people can overextend themselves. If Elon’s first week on the job is any indication, he’s now much more attuned to that possibility than the abstractions of free speech.

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“I was really scared because I would never imagined at my first job I would be getting robbed let alone having a gun pointed at me,” Tenia Hill, 16, told WDSU on Tuesday. “I was very worried because I didn’t want my mom to have to bury her youngest child. I could have lost my life, but she saved my life. I was very happy.”

    New Orleans teen forced into freezer during McDonalds armed robbery called 911 only to hear mother’s voice https://t.co/jTDCIVA5cU

    — AUBRY KILLION (@AubryKWDSU) October 31, 2022

Prior to the phone call, an armed woman entered the McDonald’s and demanded all employees go into the freezer, KKTV reported. Hill then called 911 from inside the freezer and realized her mother, Teri Clark, was on the receiving end. Clark’s shift as an assistant operations manager had ended by the time of the incident, but she’d decided to stay late to help staff, according to the outlet.

“Mama, please hurry up. She got a gun,” Hill told her mother, KKTV continued.

Although “in a state of shock,” Clark helped her daughter stay calm and was able to obtain enough information to get the New Orleans Police Department on the scene as soon as possible, according to WDSU.

Clark had worked at the Orleans Parish Communications District for 24 years, but she’d never received a phone call from a family member before, according to the outlet. “She is the GOAT. Greatest of all time, that is the greatest dispatcher I know,” Hill said of her mother.

No arrests have been made following the incident, the outlet reported.

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Humans may be just as vulnerable to environmental change as other animals, according to our new research analyzing genetic data from more than a thousand people who lived across Europe and Asia over the past 45,000 years.

We found traces of more than 50 "hard sweeps" in which a rare genetic variant rapidly swept through a population – most likely after a change in conditions in which those lacking the variant died out. The most striking sweep occurred among early Anatolian farming people, in a genetic region associated with the immune system called MHC-III.

Hard sweeps have often been seen in other species, but until now there has been little sign of them in humans. The traces of the hard sweeps had been hidden by frequent mixing between populations over the past 8,000 years.

Our results show humans' famed ability to adapt our behavior and develop new tools and techniques has not always been enough to survive when times have grown tough.

How natural selection works

Modern humans live in a huge variety of natural environments, from the frozen Arctic to sweltering tropical rainforest.

Unlike most animals, humans can draw on cultural innovations – such as fire and clothing – to overcome the challenges these environments present.

However, these innovations may not always have been enough to cope with new environmental conditions. This is when genetic variability among individuals comes into play.

Individuals with genetic variations that make them better equipped to deal with the new conditions will tend to leave more offspring. As a result, these beneficial variants become more common in future generations.

This process of genetic adaptation was dubbed "natural selection" by Charles Darwin nearly 200 years ago.

How humans adapt

Using statistical tools to search for evidence of hard sweeps, researchers have found ample evidence for past adaptive events in many animals and plants, but little in human genomes. More specifically, hard sweeps are conspicuously rare in humans.

As a result, some have speculated that genetic adaptation in humans is rare, perhaps because cultural innovations have made it largely unnecessary. Others have suggested selection has occurred across many moderately beneficial genetic variants, leading to subtle and hard-to-detect signals.

Hidden signals

Almost 40 years ago, new technologies to extract tiny amounts of DNA from archaeological skeletal remains were developed. This has made it possible to study the genomes of ancient populations, and changed our view of how ancient human groups and civilizations are related to each other.

Ancient DNA research revealed that over the past 10,000 years in Eurasia, intermixing between genetically divergent populations has been particularly frequent.

We thought these events might have erased historical sweep signals from modern human genomes – but that ancient genomes predating these intermixing events may still retain traces of the signals.

Around 10,000 years ago, after the end of the last ice age, there was much more genetic variety among the hunter-gatherers living in Europe than there is among the humans living there today.

In fact, the genetic differences between groups of ancient European hunter-gatherers were as large as the differences now observed between contemporary populations in western Europe and east Asia.

This extreme genetic differentiation collapsed over the past 8,000 years due to several migrations and mixing events, making modern Europeans much more genetically homogeneous.

'Hard sweeps' in human history

In our new research, published in Nature Ecology & Evolution, we revisited this question by scanning more than a thousand ancient human genomes sourced from across Eurasia.

We wondered: could these relatively recent mixing events have masked historical selective sweeps, so they were invisible in modern human genomes?

To test this idea, we first carried out some computer simulations based on estimates of genetic mixing from studies of ancient Eurasian genomes.

The simulation results suggested ancient selection signals could indeed be strongly diluted in modern genomes.

Next, we compiled and analyzed genetic information from more than 1,000 ancient human remains, with the oldest sample being around 45,000 years old.

We compared selection signals in ancient genomes with those from modern genomes. The ancient data contained many more hard sweep signals than the modern samples. More recent sweeps were particularly prone to erasure, due to being rare or absent in at least one of the mixing populations.

Our results confirm hard sweeps were indeed part of the repertoire of human genetic adaptation. This suggests we may not be so different from other animal species after all.

The genetic basis of adaptation

Genetic evidence for historical mixing events between different populations is growing. This is not only in humans but also in other species, suggesting such mixing may be reasonably common in nature.

If these mixing events are widespread, our study suggests hard sweeps may also have been more common than we currently think. Overall, we may have a biased view of how species have genetically adapted to environmental pressures.

To more fully understand how adaptation works at a genetic level, we will need to develop new statistical methods to disentangle signals of hard sweeps and other selection events.

Yassine Souilmi, Group Leader, Genomics and Bioinformatics, Australian Centre for Ancient DNA, University of Adelaide; Christian Huber, Assistant Professor of Biology, Penn State, and Ray Tobler, Postdoctoral fellow, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Colonoscopies, for example, screen for colon cancer, while mammograms screen for breast cancer.

While important, getting all these tests done can be logistically challenging, expensive, and sometimes uncomfortable for patients. But what if a single blood test could screen for most common cancer types all at once?

This is the promise of multicancer early detection tests, or MCEDs. This year, President Joe Biden identified developing MCED tests as a priority for the Cancer Moonshot, a US$1.8 billion federal effort to reduce the cancer death rate and improve the quality of life of cancer survivors and those living with cancer.

As a laboratory medicine physician and researcher who develops molecular tests for cancer, I believe MCED tests are likely to transform cancer screening in the near future, particularly if they receive strong federal support to enable rapid innovation.

How MCED tests work

All cells in the body, including tumor cells, shed DNA into the bloodstream when they die. MCED tests look for the trace amounts of tumor DNA in the bloodstream. This circulating "cell-free" DNA contains information about what type of tissue it came from and whether it is normal or cancerous.

Testing to look for circulating tumor DNA in the blood is not new. These liquid biopsies – a fancy way of saying blood tests – are already widely used for patients with advanced-stage cancer.

Doctors use these blood tests to look for mutations in the tumor DNA that help guide treatment. Because patients with late-stage cancer tend to have a large amount of tumor DNA circulating in the blood, it's relatively easy to detect the presence of these genetic changes.

MCED tests are different from existing liquid biopsies because they are trying to detect early-stage cancer, when there aren't that many tumor cells yet. Detecting these cancer cells can be challenging early on because noncancer cells also shed DNA into the bloodstream.

Since most of the circulating DNA in the bloodstream comes from noncancer cells, detecting the presence of a few molecules of cancer DNA is like finding a needle in a haystack.

Making things even more difficult, blood cells shed abnormal DNA naturally with aging, and these strands can be confused for circulating cancer DNA. This phenomenon, known as clonal hematopoiesis, confounded early attempts at developing MCED tests, with too many false positive results.

Fortunately, newer tests are able to avoid blood cell interference by focusing on a type of "molecular barcode" embedded in the cancer DNA that identifies the tissue it came from. These barcodes are a result of DNA methylation, naturally existing modifications to the surface of DNA that vary for each type of tissue in the body.

For example, lung tissue has a different DNA methylation pattern than breast tissue. Furthermore, cancer cells have abnormal DNA methylation patterns that correlate with cancer type. By cataloging different DNA methylation patterns, MCED tests can focus on the sections of DNA that distinguish between cancerous and normal tissue and pinpoint the cancer's origin site.

Testing options

There are currently several MCED tests in development and in clinical trials. No MCED test is currently FDA-approved or recommended by medical societies.

In 2021, the biotech company GRAIL launched the first commercially available MCED test in the US. Its Galleri test claims to detect over 50 different types of cancers. At least two other US-based companies, Exact Sciences and Freenome, and one Chinese company, Singlera Genomics, have tests in development.

Some of these tests use different cancer detection methods in addition to circulating tumor DNA, such as looking for cancer-associated proteins in blood.

MCED tests are not yet typically covered by insurance. GRAIL's Galleri test is currently priced at $949, and the company offers a payment plan for people who have to pay out of pocket. Legislators have introduced a bill in Congress to provide Medicare coverage for MCED tests that obtain FDA approval.

It is unusual for Congress to consider legislation devoted to a single lab test, and this highlights both the scale of the medical market for MCED and concerns about disparities in access without coverage for these expensive tests.

How should MCED tests be used?

Figuring out how MCED tests should be implemented in the clinic will take many years.

Researchers and clinicians are just beginning to address questions on who should be tested, at what age, and how past medical and family history should be taken into account. Setting guidelines for how doctors will further evaluate positive MCED results is just as important.

There is also concern that MCED tests may result in overdiagnoses of low-risk, asymptomatic cancers better left undetected. This happened with prostate cancer screening.

Previously, guidelines recommended that all men ages 55 to 69 regularly get blood tests to determine their levels of PSA, a protein produced by cancerous and noncancerous prostate tissue. But now the recommendation is more nuanced, with screening suggested on an individual basis that takes into account personal preferences.

Another concern is that further testing to confirm positive MCED results will be costly and a burden to the medical system, particularly if a full-body scan is required. The out-of-pocket cost for an MRI, for example, can run up to thousands of dollars.

And patients who get a positive MCED result but are unable to confirm the presence of cancer after extensive imaging and other follow-up tests may develop lifelong anxiety about a potentially missed diagnosis and continue to take expensive tests in fruitless search for a tumor.

Despite these concerns, early clinical studies show promise. A 2020 study of over 10,000 previously undiagnosed women found 26 of 134 women with a positive MCED test were confirmed to have cancer.

A 2021 study sponsored by GRAIL found that half of the over 2,800 patients with a known cancer diagnosis had a positive MCED test and only 0.5 percent of people confirmed to not have cancer had a false positive test. The test performed best for patients with more advanced cancers but did detect about 17 percent of the patients who had very-early-stage disease.

MCED tests may soon revolutionize the way clinicians approach cancer screening. The question is whether the health care system is ready for them.

Colin Pritchard, Professor of Laboratory Medicine and Pathology, School of Medicine, University of Washington

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Two Falcon rockets returning to the roost on Tuesday morning after launching a military mission into space.

A close-up on the nearest booster burning a single Merlin engine to slow down.

Two Falcons almost down on the ground.

Kicking up some dust.

On Tuesday morning, a Falcon Heavy rocket launched from Kennedy Space Center, carrying a pair of satellites for the US Space Force to geostationary orbit.

This was the fourth overall launch of the Falcon Heavy rocket, but it marked the first time that SpaceX invited a handful of photographers to set up remote cameras next to Landing Zone 2, which is located at Cape Canaveral Space Force Station in Florida. This is one of two concrete pads where Falcon 9 rockets launched from Florida occasionally land.

Each of the circular landing pads, which measure 86 meters in diameter, was busy on Tuesday morning with the return of a pair of side-boosters from the Falcon Heavy launch. After separating from the core stage of the heavy rocket, these boosters then made a propulsive descent. The first touched down 8 minutes and 15 seconds after launch. The second followed five seconds later.

Trevor Mahlmann, shooting for Ars, was among those invited to capture the moment of touchdown. The official video of the launch and landing is impressive, but Mahlmann's shots (and video) do a great job of capturing the fire and fury of the rockets as a single engine burns to bring the rocket's velocity to near zero.

SpaceX will now refurbish these side boosters for reuse on the military's next Falcon Heavy mission, USSF-67, as early as next January. The center core was not recovered and landed far down range in the Atlantic Ocean.

Listing image by Trevor Mahlmann

The close-up view of two Falcon rockets landing is as majestic as you think

High-speed video captures how cannibalistic mosquito larvae snag their prey

The study builds on the realization that in recent decades the widespread use of antibiotics to fight infections with disease-causing bacteria killed off species most vulnerable to available drugs, leaving in place more species that are resistant to antibiotics. Additionally, disruptions in gut bacterial ratios have previously been linked to more severe COVID-19.

However, until now it has remained unclear which came first, according to researchers. Does the coronavirus infection disrupt the gut microbiome or is an already weakened gut making the body more vulnerable to the virus? The new study appears to favor the former explanation. The new investigation also revealed that antibiotic-resistant species can escape into the bloodstream, putting patients at greater risk for life-threatening secondary infections.

The investigation involved 96 men and women hospitalized with COVID-19 in 2020 in New York City and in New Haven, Connecticut, and was led by researchers at NYU Grossman School of Medicine. Results showed that the majority of patients had low gut microbiome diversity, with a full quarter dominated by a single type of bacteria. At the same time, populations of several microbes known to include antibiotic-resistant species increased, possibly due to widespread antibiotic use early in the pandemic.

In 20% of patients, these antibiotic-resistant bacteria found in the gut were also observed to have migrated into the bloodstream. The study authors note that further research is needed to uncover why this group was at higher risk for a secondary infection while others remained protected.

“Our findings suggest that coronavirus infection directly interferes with the healthy balance of microbes in the gut, further endangering patients in the process,” says study co-senior author and microbiologist Ken Cadwell, PhD. “Now that we have uncovered the source of this bacterial imbalance, physicians can better identify those coronavirus patients most at risk of a secondary bloodstream infection,” adds Cadwell.

The new study is the first to show that the coronavirus infection alone, and not the initial use of antibiotics to treat the disease as other experts had thought, damages the gut microbiome, says Cadwell, also a professor in the Departments of Microbiology and Medicine at NYU Langone Health. He adds the study also provides the first evidence that the very same bacteria in the gut are also entering the bloodstream of patients, causing dangerous infections.

For the investigation, researchers first infected dozens of mice with the coronavirus and analyzed the makeup of bacterial species in their stool samples. This step allowed them to untangle whether the coronavirus could directly disrupt the microbiome independently of hospitalization and treatment.

Next, they collected stool samples and blood tests from COVID-19 patients at NYU Langone Health and Yale University hospitals to assess gut microbe composition and the presence of secondary infection. If any bacteria group made up a majority of the bacteria living in the gut, they were considered dominant.

“Our results highlight how the gut microbiome and different parts of the body’s immune system are closely interconnected,” says study senior author Jonas Schluter, PhD, an assistant professor in the Department of Microbiology at NYU Langone and a member of its Institute for Systems Genetics. “An infection in one can lead to major disruptions in the other.” Schluter cautions that since the patients received different kinds of treatments for their illness, the investigation could not entirely account for all factors that may have contributed to the disruption of their microbiome and worsened their disease.

According to Schluter, the study team next plans to examine why certain microbial species are more likely to escape the gut during COVID-19. The researchers say they also intend to explore how different microbes interact, which may contribute to this migration into the bloodstream.

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In the study, investigators examined the connectivity of the tract between the prefrontal cortex (PFC), a brain region critical for regulating higher-order executive functions, and the habenula, a region that plays a critical role in reward and reward-associated learning. In animal models of addiction, the habenula has emerged as a key driver of drug-seeking behaviors. Specifically, signaling from the PFC to the habenula is disrupted in rodent cocaine addiction models, implicating this PFC-habenula circuit in withdrawal and cue-induced relapse behaviors. However, until now, the PFC-habenula path has remained poorly understood in the human brain. Furthermore, its involvement in the neuropathological effects of drugs other than cocaine has not been previously explored.

Structural connections with the prefrontal cortex modeled from targeted nuclei in the subcortex (blue: habenula, yellow: anterior thalamus, red: ventral tegmental area) using diffusion MRI tractography. Microstructural properties of the habenula tract were uniquely reduced in individuals with cocaine or heroin use disorder. Results highlight the potential specificity of distinct prefrontal cortical connections to the neuropathology of drug addiction. Credit: Mount Sinai Health System

 

For the first time in the human brain, a team of scientists used diffusion magnetic resonance imaging (MRI) tractography to investigate the microstructural features of the PFC-habenula circuit in people with cocaine or heroin addiction compared to healthy control participants. Diffusion MRI tractography uses noninvasive brain imaging to model fiber bundles in the living human brain.

The researchers were led by Rita Z. Goldstein, PhD, and Junqian Xu, PhD. Dr. Goldstein is the Mount Sinai Professor in Neuroimaging of Addiction and Director of the Neuroimaging of Addictions and Related Conditions Research Program at Icahn Mount Sinai. Dr. Xu is Associate Professor of Radiology, and Psychiatry, at Baylor College of Medicine.

“In addition to identifying microstructural differences, specifically reduced coherence in the orientation of the white matter fibers in the cocaine-addicted group that comprised both current cocaine users and those with short-term abstinence, we extended results beyond cocaine (a stimulant) to heroin (an opioid), suggesting that abnormalities in this path may be generalized in addiction,” said Sarah King, who led the analyses and is first author of the paper. “Importantly, we found that across all addicted individuals, greater impairment was correlated with earlier age of first drug use, which points to a potential role for this circuit in developmental or premorbid risk factors.” King is a PhD student in Neuroscience in the Graduate School of Biomedical Sciences at Icahn Mount Sinai.

The results advance ongoing research in the field by targeting a previously unexplored circuit in the pathophysiology of addiction in humans, where deficits may predispose an individual to both the development of drug addiction and to relapse and which may be potentially amenable for individually tailored treatment or prevention efforts.

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After finding that the western Arctic Ocean’s acidity levels are rising three to four times faster than other ocean waters, an international team of scientists has sounded new alarm bells about the changing chemistry of the ocean.

The team, which includes Wei-Jun Cai of the University of Delaware, found a strong correlation between the rate of ocean acidification and the accelerated rate of ice melting in the region. This is a dangerous combination that puts the survival of plants, shellfish, coral reefs, other marine life, and other biological processes throughout the planet’s ecosystem at risk.

The new study, published in the prestigious journal Science, is the first to analyze Arctic acidification data covering more than two decades, from 1994 to 2020.

Researchers, including the University of Delaware’s Zhangxian Ouyang, traveled aboard the icebreaker R/V Xue Long into an active melting zone in the Arctic Ocean to get samples for analysis. Credit: Zhangxian Ouyang, Wei-Jun Cai, and Liza Wright-Fairbanks/ University of Delaware

 

Arctic sea ice in this region is expected to disappear by 2050, if not sooner due to the region’s increasingly warm summers. Without a persistent ice cover to slow or otherwise mitigate the advance, the ocean’s chemistry will become more acidic as a consequence of this sea-ice retreat each summer.

This poses serious risks to the extremely diversified population of marine animals, plants, and other living things that rely on a healthy ocean for existence. Crabs, for example, live in a crusty shell made of calcium carbonate, which is abundant in ocean water. Polar bears depend on healthy fish populations for food, fish and sea birds rely on plankton and plants, and seafood is an important part of many people’s diets.

That makes the acidification of these distant waters a big deal for many of the planet’s inhabitants.

Scientists collect samples on the ice in the Arctic. Credit: Zhangxian Ouyang, Wei-Jun Cai, and Liza Wright-Fairbanks/ University of Delaware

 

First, a quick refresher course on pH levels, which indicates how acidic or alkaline a given liquid is. Any liquid that contains water can be characterized by its pH level, which ranges from 0 to 14, with pure water considered neutral with a pH of 7. All levels lower than 7 are acidic, and all levels greater than 7 are basic or alkaline, with each full step representing a tenfold difference in the hydrogen ion concentration. Examples on the acidic side include battery acid, which checks in at 0 pH, gastric acid (1), black coffee (5), and milk (6.5). Tilting toward basic are blood (7.4), baking soda (9.5), ammonia (11), and drain cleaner (14). Seawater is normally alkaline, with a pH value of around 8.1.

Cai, the Mary A.S. Lighthipe Professor in the School of Marine Science and Policy in UD’s College of Earth, Ocean, and Environment, has published significant research on the changing chemistry of the planet’s oceans and this month completed a cruise from Nova Scotia to Florida, serving as the chief scientist among 27 aboard the research vessel. The work, supported by the National Oceanic and Atmospheric Administration (NOAA), includes four areas of study: The East Coast, the Gulf of Mexico, the Pacific Coast, and the Alaska/Arctic region.

The new study in Science included UD postdoctoral researcher Zhangxian Ouyang, who participated in a recent voyage to collect data in the Chukchi Sea and Canada Basin in the Arctic Ocean.

The first author of the publication was Di Qi, who works with Chinese research institutes in Xiamen and Qingdao. Also collaborating on this publication were scientists from Seattle, Sweden, Russia, and six other Chinese research sites.

“You can’t just go by yourself,” Cai said. “This international collaboration is very important for collecting long-term data over a large area in the remote ocean. In recent years, we have also collaborated with Japanese scientists as accessing the Arctic water was even harder in the past three years due to COVID-19. And we always have European scientists participating.”

Cai said he and Qi both were baffled when they first reviewed the Arctic data together during a conference in Shanghai. The acidity of the water was increasing three to four times faster than in ocean waters elsewhere.

That was stunning indeed. But why was it happening?

Cai soon identified a prime suspect: the increased melt of sea ice during the Arctic’s summer season.

Historically, the Arctic’s sea ice has melted in shallow marginal regions during the summer seasons. That started to change in the 1980s, Cai said, but waxed and waned periodically. In the past 15 years, the ice melt has accelerated, advancing into the deep basin in the north.

For a while, scientists thought the melting ice could provide a promising “carbon sink,” where carbon dioxide from the atmosphere would be sucked into the cold, carbon-hungry waters that had been hidden under the ice. That cold water would hold more carbon dioxide than warmer waters could and might help to offset the effects of increased carbon dioxide elsewhere in the atmosphere.

When Cai first studied the Arctic Ocean in 2008, he saw that the ice had melted beyond the Chukchi Sea in the northwest corner of the region, all the way to the Canada Basin — far beyond its typical range. He and his collaborators found that the fresh meltwater did not mix into deeper waters, which would have diluted the carbon dioxide. Instead, the surface water soaked up the carbon dioxide until it reached about the same levels as in the atmosphere and then stopped collecting it. They reported this result in a paper in Science in 2010.

That would also change the pH level of the Arctic waters, they knew, reducing the alkaline levels of the seawater and reducing its ability to resist acidification. But how much? And how soon? It took them another decade to collect enough data to derive a sound conclusion on the long-term acidification trend.

Analyzing data gathered from 1994 to 2020 – the first time such a long-term perspective was possible — Cai, Qi, and their collaborators found an extraordinary increase in acidification and a strong correlation with the increasing rate of melting ice.

They point to sea-ice melt as the key mechanism to explain this rapid pH decrease because it changes the physics and chemistry of the surface water in three primary ways:

• The water under the sea ice, which had a deficit of carbon dioxide, now is exposed to atmospheric carbon dioxide and can take up carbon dioxide freely.
• The seawater mixed with meltwater is light and cannot mix easily into deeper waters, which means the carbon dioxide taken from the atmosphere is concentrated at the surface.
• The meltwater dilutes the carbonate ion concentration in the seawater, weakening its ability to neutralize the carbon dioxide into bicarbonate and rapidly decreasing ocean pH.

Cai said more research is required to further refine the above mechanism and better predict future changes, but the data so far show again the far-reaching ripple effects of climate change.

“If all of the multiple-year ice is replaced by first-year ice, then there will be lower alkalinity and lower buffer capacity and acidification continues,” he said. “By 2050, we think all of the ice will be gone in the summer. Some papers predict that will happen by 2030. And if we follow the current trend for 20 more years, the summer acidification will be really, really strong.”

No one knows exactly what that will do to the creatures and plants and other living things that depend on healthy ocean waters.

“How will this affect the biology there?” Cai asked. “That is why this is important.”

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