Seven new Earth-like planets discovered, may host life: NASA

In a study conducted in 117 countries, researchers have found that the world is experiencing the most dramatic reduction in the seismic noise (the hum of vibrations in the planet's crust) in recorded history due to global COVID-19 lockdowns.

Measured by instruments called seismometers, seismic noise is caused by vibrations within the Earth, which travel like waves and the waves can be triggered by earthquakes, volcanoes, and bombs - but also by daily human activity like travel and industry.

This quiet period was likely caused by the total global effect of social distancing measures, closure of services and industry, and drops in tourism and travel, the study published in the journal Science, reported.

The new research, led by the Royal Observatory of Belgium and five other institutions around the world including Imperial College London (ICL), showed that the dampening of 'seismic noise' caused by humans was more pronounced in more densely populated areas.

"Our study uniquely highlights just how much human activities impact the solid Earth, and could let us see more clearly than ever what differentiates human and natural noise," said study co-author Stephen Hicks from ICL in the UK.

For the findings, the research team looked at seismic data from a global network of 268 seismic stations in 117 countries and found significant noise reductions compared to before any lockdown at 185 of those stations.

Researchers tracked the 'wave' of quietening between March and May as worldwide lockdown measures took hold.

The largest drops in vibrations were seen in the most densely populated areas, like Singapore and New York City, but drops were also seen in remote areas like Germany's the Black Forest and Rundu in Namibia.

Citizen-owned seismometers, which tend to measure more localised noise, noted large drops around universities and schools around Cornwall, UK and Boston, US - a drop in noise 20 per cent larger than seen during school holidays.

The findings showed that countries like Barbados, where lockdown coincided with the tourist season, saw a 50 per cent decrease in noise.

"The changes have also given us the opportunity to listen in to the Earth's natural vibrations without the distortions of human input," the study authors wrote.

Earlier in April, a study published in the journal Nature, reported at least a 30 per cent reduction in that amount of ambient human noise since lockdown began in Belgium.

May 30: Patients undergoing surgery after contracting the novel coronavirus are at an increased risk of postoperative death, according to a new study published in The Lancet journal which may lead to better treatment guidelines for COVID-19.

In the study, the scientists, including those from the University of Birmingham in the UK, examined data from 1,128 patients from 235 hospitals from a total of 24 countries.

Among COVID-19 patients who underwent surgery, they said the death rates approach those of the sickest patients admitted to intensive care after contracting the virus.

The scientists noted that SARS-CoV-2 infected patients who undergo surgery, experience substantially worse postoperative outcomes than would be expected for similar patients who do not have the infection.

According to the study, the 30-day mortality among these patients was nearly 24 per cent.

The researchers noted that mortality was disproportionately high across all subgroups, including those who underwent elective surgery (18.9 per cent), and emergency surgery (25.6 per cent).

Those who underwent minor surgery, such as appendicectomy or hernia repair (16.3 per cent), and major surgery such as hip surgery or for colon cancer also had higher mortality rates (26.9 per cent), the study said.

According to the study, the mortality rates were higher in men versus women, and in patients aged 70 years or over versus those aged under 70 years.

The scientists said in addition to age and sex, risk factors for postoperative death also included having severe pre-existing medical problems, undergoing cancer surgery, undergoing major procedures, and undergoing emergency surgery.

"We would normally expect mortality for patients having minor or elective surgery to be under 1 per cent, but our study suggests that in SARS-CoV-2 patients these mortality rates are much higher in both minor surgery (16.3%) and elective surgery (18.9%)," said study co-author Aneel Bhangu from the University of Birmingham.

Bhangu said these mortality rates are greater than those reported for even the highest-risk patients before the pandemic.

Citing an example from the 2019 UK National Emergency Laparotomy Audit report, he said the 30-day mortality was 16.9 per cent in the highest-risk patients.

Based on an earlier study across 58 countries, Bhangu said the 30-day mortality was 14.9 per cent in patients undergoing high-risk emergency surgery.

"We recommend that thresholds for surgery during the SARS-CoV-2 pandemic should be raised compared to normal practice," he said.

"For example, men aged 70 years and over undergoing emergency surgery are at particularly high risk of mortality, so these patients may benefit from their procedures being postponed," Bhangu added.

The study also noted that patients undergoing surgery are a vulnerable group at risk of SARS-CoV-2 exposure in hospital.

It noted that the patients may also be particularly susceptible to subsequent pulmonary complications, due to inflammatory and immunosuppressive responses to surgery and mechanical ventilation.

The scientists found that overall in the 30 days following surgery 51 per cent of patients developed a pneumonia, acute respiratory distress syndrome, or required unexpected ventilation.

Nearly 82 per cent of the patients who died had experienced pulmonary complications, the researchers said.

"Worldwide an estimated 28.4 million elective operations were cancelled due to disruption caused by COVID-19," said co-author Dmitri Nepogodiev from the University of Birmingham.

"Our data suggests that it was the right decision to postpone operations at a time when patients were at risk of being infected with SARS-CoV-2 in hospital," Nepogodiev said.

According to the researchers, there's now an urgent need for investment by governments and health providers in to measures which ensure that as surgery restarts patient safety is prioritised.

They said this includes the provision of adequate personal protective equipment (PPE), establishment of pathways for rapid preoperative SARS-CoV-2 testing, and consideration of the role of dedicated 'cold' surgical centres.

Washington, Jan 7: Facebook will ban deepfake videos ahead of the US elections but the new policy will still allow heavily edited clips so long as they are parody or satire, the social media giant said Tuesday.

Deepfake videos are hyper-realistic doctored clips made using artificial intelligence or programs that have been designed to accurately fake real human movements.

In a blog published following a Washington Post report, Facebook said it would begin removing clips that were edited--beyond for clarity and quality--in ways that "aren't apparent to an average person" and could mislead people.

Clips would be removed if they were "the product of artificial intelligence or machine learning that merges, replaces or superimposes content onto a video, making it appear to be authentic," the statement from Facebook vice-president Monika Bickert said.

However, the statement added: "This policy does not extend to content that is parody or satire, or video that has been edited solely to omit or change the order of words."

US media noted the new guidelines would not cover videos such as the 2019 viral clip -- which was not a deepfake -- of House Speaker Nancy Pelosi that appeared to show her slurring her words.

Facebook also gave no indication on the number of people assigned to identify and take down the offending videos, but said videos failing to meet its usual guidelines would be removed, and those flagged clips would be reviewed by teams of third-party fact-checkers -- among them AFP.

The news agency has been paid by the social media giant to fact-check posts across 30 countries and 10 languages as part of a program starting in December 2016, and including more than 60 organisations.

Content labeled "false" is not always removed from newsfeeds but is downgraded so fewer people see it -- alongside a warning explaining why the post is misleading.