In a first, a team of Australian scientists has determined the precise location of a powerful one-off burst of cosmic radio waves.
The Commonwealth Scientific and Industrial Research Organisation (CSIRO) on Friday revealed that it made the discovery using its new Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope in Western Australia, Xinhua news agency reported.
Having discovered that the burst originated on the outskirts of a Milky Way-sized galaxy 3.6 billion light years from Earth, researchers were then able to image that galaxy using three of the world’s largest optical telescopes.
“This is the big breakthrough that the field has been waiting for since astronomers discovered fast radio bursts in 2007,” Keith Bannister, the lead author from the CSIRO, said in a media release.
In the 12 years since the radio bursts were first detected scientists across the world have detected another 85 bursts, most of which were “one-offs”.
The source of one of the few “repeater” bursts was discovered in 2017 but localising a one-off burst has proved more challenging because they last for only a millisecond.
In order to make the discovery Bannister’s team developed technology that can freeze and save data detected by the Australian Square Kilometre Array Pathfinder less than a second after it is detected.
“From these tiny time differences, just a fraction of a billionth of a second, we identified the burst’s home galaxy and even its exact starting point, 13,000 light years out from the galaxy’s centre in the galactic suburbs,” said team member Adam Deller of Swinburne University of Technology in Australia.
“It comes from a massive galaxy that is forming relatively few stars. This suggests that fast radio bursts can be produced in a variety of environments, or that the seemingly one-off bursts detected so far by ASKAP are generated by a different mechanism to the repeater.”
The results were published online in the journal Science. (IANS)
From a patient who recovered from COVID-19, scientists have isolated a pair of neutralising antibodies that could potentially block the virus responsible for the pandemic from entering into host cells.
The study, published in the journal Science, suggests that a “cocktail” containing both antibodies could provide direct therapeutic benefits for COVID-19 patients.
The new information detailed in the study could also aid the development of small molecule antivirals and vaccine candidates to fight the SARS-CoV-2 virus which causes COVID-19.
The twin antibodies identified by the researchers are named B38 and H4.
The study by Yan Wu from Chinese Academy of Sciences and colleagues found that the two antibodies bind to the glycoprotein spike of the SARS-CoV-2 virus and thereby block the entry of the virus into host cells.
Preliminary tests of the two antibodies in a mouse model resulted in a reduction of virus titers, suggesting that the antibodies may offer therapeutic benefits.
The researchers found that the antibodies can each bind simultaneously to different epitopes on the spike’s receptor binding domain (RBD), such that both antibodies together may confer a stronger neutralising effect than either antibody on its own — a prediction supported by in vitro experiments.
This feature also means that, should one of the viral epitopes mutate in a way that prevents the binding of one of the two antibodies, the other antibody may yet retain its neutralising activity. (IANS)
The National Centre of Seismology, under the Ministry of Earth Sciences, on Monday sought to assuage the people’s fear regarding frequent earthquakes in the national capital, asserting that tremors between two to three magnitude are usual and have hit the city 100 times in the last ten years.
The clarification came a day after a medium-intensity earthquake of magnitude 3.4 hit the city. Its epicentre was near Wazirpur in the northeast of the capital.
“Delhi has been witnessing earthquakes in the range of two to three magnitude frequently. There is nothing to worry about as they are a normal phenomenon. In the last ten years, the city has been hit by more than 100 earthquakes,” an official from the seismology centre told IANS.
Clearing the air, the founder of Live Weather of India also asserted that Delhi and its surrounding regions have always remained home to small quakes. “We just keep on releasing pressure from time to time with minor quakes,” Navdeep Dahiya assured.
On April 12, an earthquake of magnitude 3.5 had struck the city and tremors were felt in Noida and Ghaziabad as well.
According to data collated from the National Centre of Seismology’s website by Dahiya, the NCR region has been hit by 11 earthquakes between March 23 to May 10. As all these came amidst a nation-wide lockdown, they added more to worries of the people. (IANS)
Some political leaders are hailing a potential breakthrough in the fight against COVID-19: simple pin-prick blood tests or nasal swabs that can determine within minutes if someone has, or previously had, the virus.
The tests could reveal the true extent of the outbreak and help separate the healthy from the sick. But some scientists have challenged their accuracy.
Hopes are hanging on two types of quick tests: antigen tests that use a nose or throat swab to look for the virus, and antibody tests that look in the blood for evidence someone had the virus and recovered. The tests are in short supply, and some of them are unreliable.
“The market has gone completely mad,” Spanish Health Minister Salvador Illa said Thursday, lamenting the l ack of face masks, personal protection equipment and rapid tests, “because everybody wants these products, and they want the good ones.”
The Spanish government on Thursday sent 9,000 rapid antigen tests that were deemed unreliable back to a manufacturer that, according to the Chinese government, had no license to sell them. British Prime Minister Boris Johnson this week called the rapid tests a “game changer” and said his government had ordered 3.5 million of them.
The U.K. hopes the tests will allow people who have had COVID-19 and recovered to go back to work, safe in the knowledge that they are immune, at least for now. That could ease the country’s economic lockdown and bring back health care workers who are being quarantined out of fears they may have the virus.
Many scientists have been cautious, saying it’s unclear if the rapid tests provide accurate results. In the past few months, much of the testing has involved doctors sticking something akin to a long cotton swab deep into a patient’s nose or throat to retrieve cells that contain live virus. Lab scientists pull genetic material from the virus and make billions of copies to get enough for computers to detect the bug. Results sometimes take several days.
Rapid antigen tests have shorter swabs that patients can use themselves to gather specimens. They are akin to rapid flu tests, which can produce results in less than 15 minutes. They focus on antigens — parts of the surface of viruses that trigger an infected person’s body to start producing antibodies.
Health authorities in China, the United States and other countries have offered few details on the rates of false positive and false negative results on any coronavirus tests. Experts worry that the rapid tests may be significantly less reliable than the more time-consuming method.
Lower accuracy has been a concern with rapid flu tests. Spanish scientists said the rapid tests for coronavirus they reviewed were less than 30% accurate. The more established lab tests were about 84% accurate.
Those results “would prevent its routine introduction,” according to a report by the Spanish Society of Infectious Disease and Clinical Microbiology that triggered the alarms in Spain and spurred the government’s rejection of the 9,000 antigen tests.
Similar questions swirl around new antibody tests involving blood samples. Some versions have been described as finger-prick tests that can provide important information in minutes.
Antibody tests are most valuable as a way of seeing who has been infected in the recent past, who became immune to the disease and — if done on a wide scale — how widely an infection has spread in a community.
The antibody tests also will allow scientists to get a better understanding of how deadly coronavirus is to all people, because they will provide a better understanding of how many people were ever infected, ranging from those who never showed symptoms to those who became fatally ill. The results will also guide vaccine development.
For most people, the coronavirus causes mild or moderate symptoms, such as fever and cough that clear up in two to three weeks. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia, and death. Most people recover.
More than 15 companies have notified the U.S. Food and Drug Administration that they have developed antibody tests, the agency said. The companies are permitted to begin distributing the tests to hospitals and doctors’ offices, provided they carry certain disclaimer statements, including: “This test has not been reviewed by the FDA.”
The prime minister’s spokesman was unable to say Thursday how much the U.K. had paid for the tests, which come from several suppliers, or whether the money would be refunded if they turned out to be unreliable.
The chief scientist at the World Health Organization said wider testing would allow health officials to pinpoint infections in people who appear healthy but may be carrying the virus.
“We know that if you really go out and test everyone in the community, you’re going to find people walking around with this virus in their nose who do not feel at all ill,” Dr. Soumya Swaminathan said in an interview.
WHO believes most transmissions of the virus occur through people who already show symptoms, but “the question is still open” about how asymptomatic people may spread infection, Swaminathan. (VOA)