66% of women's work unpaid in India: WEF

New Delhi, Jun 29: Witnessing azure skies and breathable air for the last three months, Delhi on Monday recorded deterioration in its air quality, with particulate matter with diameter of 2.5 and 10 microns -- too small to be filtered out of the human body -- standing at 52 and 297 micrograms per cubic respectively.

Gufran Beig, Project Director of System of Air Quality Weather Forecasting and Research (SAFAR), said that the sudden spike in air pollution is due to a mild dust storm blowing from Rajasthan.

"Since the wind direction is changing and moist air is coming in, the air quality in Delhi will become better by tomorrow," Beig told IANS.

Central Pollution Control Board (CPCB) data showed that the overall air quality near Delhi Technical University (DTU) area stood at 326 micrograms per cubic, followed by 308 at Narela and 307 at Mundka.

Out of 36 stations, the AQI in as many as 30 stations was above 200 micrograms per cubic till 1 pm on Monday.

The System of Air Quality Weather Forecasting and Research categorises air quality in the 0-50 range as good, 51-100 as satisfactory, 101-200 as moderate, 201-300 as poor, 301-400 as very poor, and above 400 as severe.

According to SAFAR's website, "PM 10 (coarser dust particle) is the lead pollutant. AQI is likely to improve to moderate category by tomorrow, and further improvement is expected by July 1."

Researchers indicated that PM 10 and PM 2.5 will be 170 and 47 micrograms per cubic on Tuesday.

With no vehicles plying on the roads or industries shut due to the lockdown since March 25, Delhi's air quality had improved drastically.

According to a study conducted by the Indian Institute of Technology (IIT), Delhi, if the low levels of air pollution reached during the lockdown period are maintained, India's annual death toll could reduce by 6.5 lakh.

Washington D.C., Feb 6: An international team of astronomers has found an unusual monster galaxy that existed about 12 billion years ago when the universe was only 1.8 billion years old.

The team of astronomers was led by scientists at the University of California, Riverside.

Dubbed XMM-2599, the galaxy formed stars at a high rate and then died. Why it suddenly stopped forming stars is unclear.

"Even before the universe was 2 billion years old, XMM-2599 had already formed a mass of more than 300 billion suns, making it an ultra massive galaxy," said Benjamin Forrest, a postdoctoral researcher in the UC Riverside Department of Physics and Astronomy and the study's lead author.

"More remarkably, we show that XMM-2599 formed most of its stars in a huge frenzy when the universe was less than 1 billion years old and then became inactive by the time the universe was only 1.8 billion years old," Forrest added.

The team used spectroscopic observations from the W. M. Keck Observatory's powerful Multi-Object Spectrograph for Infrared Exploration or MOSFIRE, to make detailed measurements of XMM-2599 and precisely quantify its distance.

The study results appear in the Astrophysical Journal.

"In this epoch, very few galaxies have stopped forming stars, and none are as massive as XMM-2599," said Gillian Wilson, a professor of physics and astronomy at UCR in whose lab Forrest works.

"The mere existence of ultramassive galaxies like XMM-2599 proves quite a challenge to numerical models. Even though such massive galaxies are incredibly rare at this epoch, the models do predict them."

"The predicted galaxies, however, are expected to be actively forming stars. What makes XMM-2599 so interesting, unusual, and surprising is that it is no longer forming stars, perhaps because it stopped getting fuel or its black hole began to turn on. Our results call for changes in how models turn off star formation in early galaxies," the professor stated.

The research team found XMM-2599 formed more than 1,000 solar masses a year in stars at its peak of activity -- an extremely high rate of star formation. In contrast, the Milky Way forms about one new star a year.

"XMM-2599 may be a descendant of a population of highly star-forming dusty galaxies in the very early universe that new infrared telescopes have recently discovered," said Danilo Marchesini, an associate professor of astronomy at Tufts University and a co-author on the study.

"We have caught XMM-2599 in its inactive phase," Wilson said, who led the W. M. Keck Observatory data acquisition
Co-author Michael Cooper, a professor of astronomy at UC Irvine, said this outcome is a strong possibility.

"Perhaps during the following 11.7 billion years of cosmic history, XMM-2599 will become the central member of one of the brightest and most massive clusters of galaxies in the local universe," he said.

"Alternatively, it could continue to exist in isolation. Or we could have a scenario that lies between these two outcomes," he stated.

The study was supported by grants from the National Science Foundation and NASA.

Beijing, Jun 18:  Besides washing hands and wearing masks, it is also important to close the toilet lid before flushing to contain the spread of COVID-19, as per a new study.

According to a new study cited by The Washington Post, scientists who simulated toilet water and airflows, have found that flushing a toilet can generate a plume of virus-containing aerosol particles that is widespread and can linger in the air long enough to be inhaled by others. The novel coronavirus has been found in the faeces of COVID-19 patients, but it remains unknown whether such clouds could contain enough virus to infect a person.

"Flushing will lift the virus up from the toilet bowl," co-author Ji-Xiang Wang, who researches fluids at Yangzhou University in Yangzhou, China, said in an email. Wang stressed that bathroom users "need to close the lid first and then trigger the flushing process" and wash hands properly if the closure is not possible. As one flushes the toilet with the lids open, bits of faecal matter swish around so violently that they can be propelled into the air, become aerosolised and then settle on the surroundings.

Experts call it the "toilet plume".Age-old studies have been made to understand the potential for airborne transmission of infectious disease via sewage, and the toilet plume's role. Scientists who have seeded toilet bowls with bacteria and viruses have found contamination of seats, flush handles, bathroom floors and nearby surfaces. This is one reason we are told to wash our hands after visiting the toilet. Public bathrooms are well known to contribute to the spread of viruses that transmit via ingestion, such as the noroviruses that haunt cruise ships. However, their role in the transmission of respiratory viruses has not been established, said Charles P Gerba, a microbiologist at the University of Arizona."The risk is not zero, but how great a risk it is, we do not know. The big unknown is how much virus is infectious in the toilet when you flush it ... and how much virus does it take to cause an infection," said Gerba, who has studied the intersection of toilets and infectious disease for 45 years.

A study published in March in the journal Gastroenterology found significant amounts of coronavirus in the stool of patients and determined that viral RNA lasted in faeces even after the virus cleared from the patients` respiratory tracts. While another study in the journal Lancet found coronavirus in faeces up to a month after the illness had passed.

Scientists around the world are now studying sewage to track the spread of the virus. According to the researchers, the presence of the virus in excrement and the gastrointestinal tract raises the prospect of transmission via toilets, because many COVID-19 patients experience diarrhoea or vomiting.

A study of air samples in two hospitals in Wuhan, China found that although coronavirus aerosols in isolation wards and ventilated patient rooms were very low, "it was higher in the toilet areas used by the patients".The Centers for Disease Control and Prevention (CDC) says it remains "unclear whether the virus found in faeces may be capable of causing COVID-19," and "there has not been any confirmed report of the virus spreading from faeces to a person".For now, the CDC characterises the risk as low based on observations from previous outbreaks of other coronaviruses such as severe acute respiratory syndrome (SARS) and the Middle East respiratory syndrome (MERS). Wang decided to use computer models to simulate toilet plumes while isolating at home, as per Chinese government orders and thinking about how a fluids researcher "could contribute to the global fight against the virus".

Published in the journal Physics of Fluids, the study found that flushing of both single-inlet toilets, which push water into the bowl from one port, and annular-inlet toilets, which pour water into the bowl from the rim's surrounding edge with even greater energy, results in "massive upward transport of virus".

Particles can reach heights of more than three feet and float in the air for more than a minute, it found. The paper recommends not just lid-closing and hand-washing, it urges manufacturers to produce toilets that close and self-clean automatically. It also suggests that toilet-users should wipe down the seat. Gerba, however, said seats should not be a major concern.

Research has found that public and household toilet seats are typically the cleanest surfaces in restrooms, he said, probably because so many people already wipe them off before using them. Also, he said of SARS-CoV-2, the virus that causes COVID-19, "I don't think it's butt-borne, so I don`t think you have to worry."Gerba, who has been studying coronavirus transmission for two decades to investigate the role of a toilet flushing in a SARS outbreak stresses "flush and run" when using a public toilet without a lid. Gerba also said that people should wash hands well post-flushing and use hand sanitiser after leaving the restroom. "Choose well-ventilated bathrooms if possible and do not hang around the restroom in any case," added Gerba.