The relationship between time to a high COVID-19 response level and timing of peak daily incidence:an analysis of governments’Stringency Index from 148 countries

Background The transmission dynamics and severity of coronavirus disease 2019(COVID-19)pandemic is different across countries or regions.Differences in governments’policy responses may explain some of these differences.We aimed to compare worldwide government responses to the spread of COVID-19,to examine the relationship between response level,response timing and the epidemic trajectory.Methods Free publicly-accessible data collected by the Coronavirus Government Response Tracker(OxCGRT)were used.Nine sub-indicators reflecting government response from 148 countries were collected systematically from January 1 to May 1,2020.The sub-indicators were scored and were aggregated into a common Stringency Index(SI,a value between 0 and 100)that reflects the overall stringency of the government’s response in a daily basis.Group-based trajectory modelling method was used to identify trajectories of SI.Multivariable linear regression models were used to analyse the association between time to reach a high-level SI and time to the peak number of daily new cases.Results Our results identified four trajectories of response in the spread of COVID-19 based on when the response was initiated:before January 13,from January 13 to February 12,from February 12 to March 11,and the last stage—from March 11(the day WHO declared a pandemic of COVID-19)on going.Governments’responses were upgraded with further spread of COVID-19 but varied substantially across countries.After the adjustment of SI level,geographical region and initiation stages,each day earlier to a high SI level(SI>80)from the start of response was associated with 0.44(standard error:0.08,P<0.001,R2=0.65)days earlier to the peak number of daily new case.Also,each day earlier to a high SI level from the date of first reported case was associated with 0.65(standard error:0.08,P<0.001,R2=0.42)days earlier to the peak number of daily new case.Conclusions Early start of a high-level response to COVID-19 is associated with early arrival of the peak number of daily new cases.This may help to reduce the delays in flattening the epidemic curve to the low spread level.

Establishment of a Multi-color Genomic in situ Hybridization Technique to Simultaneously Discriminate the Three Interspecific Hybrid Genomes in Gossypium

To identify alien chromosomes in recipient progenies and to analyze genome components in polyploidy, a genomic in situ hybridization （GISH） technique that is suitable for cotton was developed using increased stringency conditions. The increased stringency conditions were a combination of the four factors in the following optimized state： 100：1 ratio of blocking DNA to probe, 60% formamide wash solution, 43 ℃ temperature wash and a 13 min wash. Under these specific conditions using gDNA from Gossypium sturtianum （C1 C1 ） as a probe, strong hybridization signals were only observed on chromosomes from the C1 genome in somatic cells of the hybrid F1 （G. hirsutum x G. sturtianum） （AtDtC1）. Therefore, GISH was able to discriminate parental chromosomes in the hybrid. Further, we developed a multi-color GISH to simultaneously discriminate the three genomes of the above hybrid. The results repeatedly displayed the three genomes, At, Dt, and C1, and each set of chromosomes with a unique color, making them easy to identify. The power of the multi-color GISH was proven by analysis of the hexaploid hybrid F1 （G. hirsutum x G. australe） （AtAtDtDtG2G2）. We believe that the powerful multi-color GISH technique could be applied extensively to analyze the genome component in polyploidy and to identify alien chromosomes in the recipient progenies.

The COVID-19 Pandemic and Consumption of Food away from Home:Evidence from High-frequency Rcstaurant Transaction Data

This article investigates how the COVID-19 pandemic and related public health measures affected the consumption of food away from home(FAFH)among Chinese consumers.We obtained access to the complete sales records from a major restaurant chain in China,for 111 sites located in 12 cities,covering over 5.6 million high-frequency dining transactions made between 1 January 2019 and 31 December 2020.By applying a high-dimensional fixed-effects model,we found that,on average,consumers spent more and ordered more calories(as well as carbohydrates,protein,fat,and sodium)after the COVID-19 outbreak than in thepre-COVID-19period.Our results do not support the hypothesis that COVID-19 led to healthier eating behaviors during and after the pandemic.Our results underline the importance of nutrition education and awareness programs to mitigate unhealthy eating habits generated by the pandemic and of the continued role of FAFH after the pandemic.