New Delhi [India], February 27 (ANI): Researchers in a study suggests that implementing one-way customer traffic at retail stores can dramatically reduce COVID-19 transmission. The study was conducted by Robert A. Shumsky, Laurens Debo, Rebecca M. Lebeaux, Quang P. Nguyen and Anne G. Hoen.
The study was published by Proceedings of the National Academy of Sciences.
“To reduce the transmission of COVID-19, many retail stores use one-way aisles, while local governments enforce occupancy limits or require “safe shopping” times for vulnerable groups,” read the study.
To assess the value of these interventions, the study formulates and analyzes a mathematical model of customer flow and COVID-19 transmission. The study finds find that the value of specific operational changes depends on how the virus is transmitted, through close contact or suspended aerosols. If the transmission is primarily due to close contact, then restricting customers to one-way movement can dramatically reduce transmission. Other interventions, such as reductions in customer density, are effective at a distance but confront store operators with trade-offs between infection rates and customer flow.
The study examines how operational changes in customer flows in retail stores affect the rate of COVID-19 transmission. They combine a model of customer movement with two models of disease transmission: direct exposure when two customers are in close proximity and wake exposure when one customer is in the airflow behind another customer.
They find that the effectiveness of some operational interventions is sensitive to the primary mode of transmission. Restricting customer flow to one-way movement is highly effective if direct exposure is the dominant mode of transmission. In particular, the rate of direct transmission under full compliance with one-way movement is less than one-third of the rate under two-way movement.
Directing customers to follow the one-way flow, however, is not effective if wake exposure dominates. The study finds that two other interventions–reducing the speed variance of customers and throughput control–can be effective whether direct or wake transmission is dominant.
The study also examines the trade-off between customer throughput and the risk of infection to customers, and the study shows how the optimal throughput rate drops rapidly as the population prevalence rises.
By integrating knowledge about virology, epidemiology, and the physical flow of customers in retail stores, the study develops and analyze a model that connects the biology of COVID-19 with operational interventions to reduce the spread of the disease. The model calculates the disease transmission rate in a retail environment and determines how the rate depends on the customer flow policy (one-way versus two-way), the travel speed distribution, and store size. The study find that one-way restrictions are useful for reducing direct transmission but have no effect on wake transmission. Eliminating speed variability can reduce or even eliminate direct transmission when traffic is one-way but can only reduce (but not eliminate) transmission in two-way traffic. Finally, the study shows that the optimal admission rate to a store falls as the disease prevalence rises and the ratio of profit to infection cost falls.
The study also calibrates our model using published epidemiological data. For a medium-sized retailer in an area with a relatively high prevalence of COVID-19, our model predicts a total transmission rate (via direct and wake exposure) of 0.33 infections per day. Complete customer compliance with one-way flow reduces the direct transmission rate by 70%, while the partial compliance observed in one store reduces the transmission rate by 11 per cent. The study also compares the impact of direct and wake transmission by first defining a ratio between the wake and direct transmission probabilities for a single encounter between an infectious and a susceptible customer. Given two-way traffic, if this ratio is 200%200% or more, then wake exposure dominates direct exposure in its contribution to virus transmission. When retailers can control customer throughput, the optimal throughput drops significantly as COVID-19 prevalence increases up to 1%. Because estimates of some parameters vary substantially from region to region and will change over time, the study conduct sensitivity analysis to assess the robustness of our findings.
The study discusses some of our modeling assumptions and possible extensions. In the model of customer flow, the study ignores variation in both the speed and path of each customer, e.g., stopping to examine and pick products off shelves. Adding this additional variability would increase the number of customer interactions and direct exposure, although quantifying its impact and understanding the impact on wake exposure would require a more complex analytical model and/or simulation. The study also assumes Poisson arrivals, a reasonable assumption during short periods in many retail areas, but not a reasonable assumption in other contexts such as school hallways, where a fluid model may be more appropriate.
In addition, the study assumes that wake exposure ends as soon as an infectious customer leaves the area. This is a simplification, for infectious aerosols may remain in the air after customers depart (20). If the area is large, however, and if customers spend a significant amount of time on their journey, then the impact of edge effects when customers leave the area is small. For the numerical experiments described above, these edge effects are not significant.
Our model focuses on customer movement through store aisles and ignores interactions among customers and employees. Front-line workers for essential retailers, in particular, can face a high risk of exposure (47). Cashiers, for example, face both direct and wake exposure in checkout areas. Many stores now enforce social distancing standards around these areas and provide guidance such as floor stickers to indicate spacing between customers. While this can nearly eliminate direct exposure, wake exposure would be a concern around checkout areas. Incorporating a queuing model that includes customer movement and airflow may be a useful extension.
The specific infection rates predicted by our model depend upon many environmental variables, including ventilation systems and the proportion of customers who use masks. Given this uncertainty, the model highlights where gaps in the scientific knowledge of COVID-19 transmission need to be filled so that the study may redesign service operations to reduce spread. In particular, the effectiveness of these interventions is highly dependent on whether the virus is transmitted through heavy droplets or aerosols. In addition, the model may be adapted to analyze COVID-19 transmission in other service settings such as restaurants, airplanes (supplement to ref. 48), and hotels in which customer flow can be regulated. (ANI)

Guwahati (Assam) [India], February 27 (ANI): Sprinter Hima Das who had won a gold medal in Asian Games in 2018 has officially been inducted into Assam Police on Friday. She will be posted in Guwahati.
On the occasion, Assam Chief Minister Sarbananda Sonowal honoured her with a badge.
Briefly speaking to ANI, Das said, “This has come as a part of government’s policy. I will focus on sports for now. I will join the service after retiring from sports.”
“I feel honoured to be a part of Assam Police. I thank Union Minister Kiren Rijiju for showering his support on me,” Das said.

However, the decision that she will be inducted in Assam Police was decided two weeks ago.
Union Youth Affairs and Sports Minister Kiren Rijiju on February 11 said that sprinter Hima Das will continue running for the country even after the Assam government decided to appoint her as a Deputy Superintendent of Police in the state.
The 21-year-old is currently preparing for the upcoming Tokyo Olympics qualification at Netaji Subhas National Institute of Sports, Patiala. (ANI)

Hyderabad (Telangana) [India], February 26 (ANI): The Hyderabad police have rescued a businessman within three hours after he was kidnapped by unidentified assailants. The police also arrested four accused who were indulged in the incident.
The police informed about the incident on Friday according to which the victim, Amaranath Reddy was taken away by the assailants from his residence in Banjara Hills on Thursday and later the family alerted the police about his disappearance. The police swung into action and launched a search operation by forming teams.
Speaking to the media, Anjani Kumar, Hyderabad City Police Commissioner said, “The Hyderabad City Police on Thursday were able to arrest four kidnappers alongside rescuing the victim. The police were able to arrest the four accused — V Kumara Guru, Paluru Lokesh Kumar, S Jagadish and PK Ganesh Kumar.”
Two accused — Pradeep Natarajan and Keerthana are currently absconding, Kumar said.
Giving details of the incident, Commissioner said, “As per the complaint filed by the K Kalapana Reddy wife of K Amaranath Reddy, the kidnappers have demanded Rs 4 lakh for Amaranath Reddy to be released. The Kidnappers continuously called her and said that her husband has to give four lakhs rupees and demanded to immediately send to the bank account which they have given before 5 PM or else they will take her husband along with the car to Chennai and will kill him.”
During the course of the investigation, a police special team has been formed to trace out the victim K Amaranath Reddy and as well as the apprehension of the accused persons, he said.
“Due to non-availability of money, Police were able to arrange the Cash and sent the photos from the complainant cell phone to the kidnappers. On that kidnappers instructed the complainant to come to Srinagar Colony, Banjara Hills along with cash, at about 06:30 PM,” he said.
“The complainant along with the police special team proceeded to Srinagar Colony wherein police laid a trap where two kidnappers Pradeep Natarajan and Paluru Lokesh Kumar came to Srinagar Colony along with the victim car. While handing over the money, police apprehend Paluru Lokesh Kumar and interrogated him leading to the location of the rest of the gang members. The police have arrested three other accused while two others have absconded,” he added. (ANI)

Mayurbhanj (Odisha) [India], February 27 (ANI): Two persons were arrested in Mayurbhanj for possessing elephant tusks, according to the police official on Friday.
“We have recovered 8 pieces of elephant tusk weighing 44.9 kgs from the possession of two persons. We have seized their bike,” said Santosh Joshi, District Forest Officer.
“Further investigations are underway,” he said. (ANI)

New Delhi [India], February 27 (ANI): Temperatures in various parts of northwest India have increased by 6-7 degrees Celsius above normal, according to the World Meteorological Organization on Saturday.
“Parts of northwest India have seen daytime temperatures 6-7 degrees Celsius above normal over Rajasthan, Punjab, Haryana and Delhi,” informed WMO.
Odisha also witnessed a rise in temperature. The state broke the record of last 10 years.
“Bhubaneswar in the eastern Indian state of Odisha recorded temp of 40.4 degree Celsius today, second-highest temperature for February in the past 10 years,” stated WMO.
Similarly, the India Meteorological Department (IMD) on Friday tweeted, “The temperatures are above normal by 4-6 degrees Celsius over most parts of Northwest India and adjoining parts of Central and East India. It is likely to continue during the next 3 days and then fall by 2-4 degrees subsequently.” (ANI)

Bengaluru (Karnataka) [India], February 27 (ANI): Metro services on Bengaluru’s purple line will be curtailed on February 28, according to the official on Friday.
“There will be curtailment of metro services on Bengaluru’s purple line on Feb 28 due to civil maintenance work,” informed the Chief Public Relation Officer of Bangalore Metro Rail Corporation Limited.
“The services will be effected between Baiyappanahalli and MG Road metro stations from 7 am to 9 am,” the statement added.
Trains on Bengaluru’s Namma Metro resumed operations from September 7, 2020, between 8-11 am and 4:30-7:30 pm with a frequency of five minutes.
According to a release by the Bangalore Metro Rail Corporation Limited, while trains on the purple line resumed from September 7, those on the green line ran from September 9 onwards. (ANI)