'Alliance for LS polls depends on how Cong treats us'

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of the American Medical Association, noted that the the current guidelines issued by the WHO and CDC are based on outdated models from the 1930s of how gas clouds from a cough, sneeze, or exhalation spread.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, June 29: The Karnataka government on Monday issued guidelines to conduct online classes for all students of ICSE, CBSE and SSLC under the directions of the High Court.

According to the guidelines, for the kindergarten students, online classes can be held 30 minutes a week and students in classes 1-5 will have online classes for 30-45 minutes divided into two periods for three alternate days every week.

For students in classes 6-8, the online classes will be for 30-45 minutes divided into two periods for five days every week while students in classes 9 and 10 can have the virtual classes for 30-45 minutes divided into four periods for five days a week.

Earlier, the state government barred online classes for the kids from LKG to class 5.

Minister for primary and secondary education S Suresh Kumar had said that online classes cannot be held for the kids from LKG to class V.

Bengaluru, July 14: Girls outshone boys in the Second Pre-University Board examinations in Karnataka, results of which were announced on Tuesday.

As many as 6.75 lakh students had written the examination of which 4.17 lakh students passed.

Thus, the pass percentage is 61.80 per cent, Primary and Secondary Education Minister S Suresh Kumar said while announcing the results.

He said 68.73 per cent girls cleared the exam against the boys whose pass percentage was 54.77 per cent.

In terms of urban versus rural, 62.60 per cent students passed in the urban area while 58.99 per cent were from rural areas.

The three districts where the students' performance was excellent were Udupi, Dakshina Kannada and Kodagu whereas the districts where students fared badly were Chitradurga, Raichur and Vijayapura, the minister said.

Both Dakshina Kannada and Udupi have recorded 90.71 percent results. Kodagu has bagged second position with 81.53 pass percentage. Vijayapura district has recorded lowest pass percentage (54.22)

Combination wise, the pass percentage of students in science stream is 82.57 per cent, Commerce 72.60 per cent and Arts 47.90 per cent, said the Minister.

He also said of those who passed the examination, 72. 45 per cent were from English medium and 47.56 from Kannada medium.

There are 68,866 distinction scorers, 2,21,866 students who got first division and 77,455 students who passed the exam in second division, the minister added.