Errors galore in voters list: Khader

The current physical distancing guidelines provided by the World Health Organisation (WHO) and by the US Centers for Disease Control and Prevention (CDC) may not be adequate to curb the coronavirus spread, according to a research which says the gas cloud from a cough or sneeze may help virus particles travel up to 8 metres. The research, published in the Journal of the American Medical Association, noted that the the current guidelines issued by the WHO and CDC are based on outdated models from the 1930s of how gas clouds from a cough, sneeze, or exhalation spread.

Study author, MIT associate professor Lydia Bourouiba, warned that droplets of all sizes can travel 23 to 27 feet, or 7-8 metres, carrying the pathogen.

According to Bourouiba, the current guidelines are based on "arbitrary" assumptions of droplet size, "overly simplified", and "may limit the effectiveness of the proposed interventions" against the deadly pandemic.

 She explained that the old guidelines assume droplets to be one of two categories, small or large, taking short-range semi-ballistic trajectories when a person exhales, coughs, or sneezes.

However based on more recent discoveries, the MIT scientist said, sneezes and coughs are made of a puff cloud that carries ambient air, transporting within it clusters of droplets of a wide range of sizes.

Bourouiba warned that this puff cloud, with ambient air entrapped in it, can offer the droplets moisture and warmth that can prevent it from evaporation in the outer environment.

"The locally moist and warm atmosphere within the turbulent gas cloud allows the contained droplets to evade evaporation for much longer than occurs with isolated droplets," she said.

"Under these conditions, the lifetime of a droplet could be considerably extended by a factor of up to 1000, from a fraction of a second to minutes," the researcher explained in the study.

The MIT scientist, who has researched the dynamics of coughs and sneezes for years, added that these droplets settle along the trajectory of a cough or sneeze contaminating surfaces, with their residues staying suspended in the air for hours.

"Even when maximum containment policies were enforced, the rapid international spread of COVID-19 suggests that using arbitrary droplet size cutoffs may not accurately reflect what actually occurs with respiratory emissions, possibly contributing to the ineffectiveness of some procedures used to limit the spread of respiratory disease," Bourouiba wrote in the study

Bengaluru, May 20: A mysterious "boom" heard in large parts of Bengaluru this afternoon left residents of the city and social media users puzzled. While the source of the sound is being investigated, the Indian Air Force (IAF) indicated that it could be the result of "routine test flights that necessitate going supersonic a times".

The sound was heard from as far as the Bengaluru airport in Devanahalli to the IT hub of Electronic City 54 km away. It was also heard in Kalyan Nagar in east Bengaluru, central Bengaluru's MG Road and areas such as Marathahalli, Whitefield, Sarjapur and Hebbagodi.

IAF said no aircraft of training command was flying in the area. "However, ASTE (Aircraft and Systems Testing Establishment) and HAL (Hindustan Aeronautics Limited) could have been undertaking their routine test flying, which necessitates going supersonic at times. These are done well beyond the city limits in specified sectors. However, considering the atmospheric conditions and reduced noise levels in the city during these times, the aircraft sound may become clearly audible even if it happened way out from the city," said the air force statement.

Many people had speculated that the sound could have been caused by a fighter jet such as a Mirage 2000.

"We have also asked the Air Force Control Room to check if it was a jet or supersonic sound. Bengaluru police are awaiting confirmation from the Air Force," Bengaluru police commissioner Bhaskar Rao said in a statement.

It was not an earthquake, Karnataka's state disaster monitoring centre had tweeted earlier.

"Earthquake activity will not be restricted to one area and will be widespread. We have checked our sensors and there is no earthquake activity recorded today," the Karnataka State Natural Disaster Monitoring Centre said, quoting its director Srinivas Reddy.

"The activity reported in Bengaluru is not due to an earthquake. The seismometers did not capture any ground vibration as generally happens during a mild Tremor. The activity is purely a loud unknown noise," the agency tweeted.

#Bangalore and #BangaloreBoom was among the top trends on Twitter this afternoon.

"We are trying to ascertain the source of the noise," a senior police officer said. "In Whitefield area, we have searched on the ground and so far, there is no damage to any property," he added. There were no calls to the police control room reporting any damage.

Bengaluru, Apr 5: An elderly couple from Bengaluru

with a travel history to Dubai joined the list of coronavirus patients in the state, taking the total number of cases to 146, the health department said on Sunday.

The list includes four deaths and 11 discharges.

The 68-year old man and his 62-year old wife, hailing from Madiwala in the city, had returned from Dubai on March 22.

They were quarantined at a private hospital and have been asymptomatic.

Meanwhile, the government appealed to people who had attended the Tablighi Jamaat Congregation in New Delhi to contact 080-29711171 Arogya Sahayavani, the medical helpline number.