Hainan is an island province in south China with a high frequency of unconventional emergencies due to its special geographic location and national military defense role.Given the limited transportation route from Hai...Hainan is an island province in south China with a high frequency of unconventional emergencies due to its special geographic location and national military defense role.Given the limited transportation route from Hainan to the outside world,self-rescue is more important to Hainan Province than other provinces in China and it is therefore imperative to establish an independent, scientific as well as efficient provincal disaster medical system in Hainan.The regulatory role for vulnerability analysis/assessment has been demonstrated in establisment of disaster medical system in varoius countries and or regions.In this paper,we attempt to describe/propose how to adopt vulnerability assessment through mathematical modeling of major biophysical social vulnerability factors to establish an independent,scientific,effieicnt and comprehensive provincial disaster medical system in Hainan.展开更多
Although significant achievements have shown that the coronavirus disease 2019(COVID‐19)resurgence in Beijing,China,was initiated by contaminated frozen products and transported via cold chain transportation,internat...Although significant achievements have shown that the coronavirus disease 2019(COVID‐19)resurgence in Beijing,China,was initiated by contaminated frozen products and transported via cold chain transportation,international travelers with asymptomatic symptoms or false‐negative nucleic acid may have another possible transmission mode that spread the virus to Beijing.One of the key differences between these two assumptions was whether the virus actively replicated since,so far,no reports showed viruses could stop evolution in alive hosts.We studied severe acute respiratory syndrome coronavirus 2(SARS‐CoV‐2)sequences in this outbreak by a modified leaf‐dating method with the Bayes factor.The numbers of single nucleotide variants(SNVs)found in SARS‐CoV‐2 sequences were significantly lower than those called from B.1.1 records collected at the matching time worldwide(P=0.047).In addition,results of the leaf‐dating method showed ages of viruses sampled from this outbreak were earlier than their recorded dates of collection(Bayes factors>10),while control sequences(selected randomly with ten replicates)showed no differences in their collection dates(Bayes factors<10).Our results which indicated that the re‐emergence of SARS‐CoV‐2 in Beijing in June 2020 was caused by a virus that exhibited a lack of evolutionary changes compared to viruses collected at the corresponding time,provided evolutionary evidence to the contaminated imported frozen food should be responsible for the reappearance of COVID‐19 cases in Beijing.The method developed here might also be helpful to provide the very first clues for potential sources of COVID‐19 cases in the future.展开更多
基金supported by 2010 Natural Science foundation of China(81060160)2008 Natural Science Foundation of China(30860082)+1 种基金2009 Natural Science Foundation of China(090209)2010 Key Scientific and Technological Project of Hainan Province(zdxm20100043)
文摘Hainan is an island province in south China with a high frequency of unconventional emergencies due to its special geographic location and national military defense role.Given the limited transportation route from Hainan to the outside world,self-rescue is more important to Hainan Province than other provinces in China and it is therefore imperative to establish an independent, scientific as well as efficient provincal disaster medical system in Hainan.The regulatory role for vulnerability analysis/assessment has been demonstrated in establisment of disaster medical system in varoius countries and or regions.In this paper,we attempt to describe/propose how to adopt vulnerability assessment through mathematical modeling of major biophysical social vulnerability factors to establish an independent,scientific,effieicnt and comprehensive provincial disaster medical system in Hainan.
基金This work was supported by the National Natural Science Foundation of China(Grant number:82041023)the Bill&Melinda Gates Foundation(Grant number:INV‐016826)China Mega‐Projects for Infectious Disease(2018ZX10711001,2017ZX10104001).
文摘Although significant achievements have shown that the coronavirus disease 2019(COVID‐19)resurgence in Beijing,China,was initiated by contaminated frozen products and transported via cold chain transportation,international travelers with asymptomatic symptoms or false‐negative nucleic acid may have another possible transmission mode that spread the virus to Beijing.One of the key differences between these two assumptions was whether the virus actively replicated since,so far,no reports showed viruses could stop evolution in alive hosts.We studied severe acute respiratory syndrome coronavirus 2(SARS‐CoV‐2)sequences in this outbreak by a modified leaf‐dating method with the Bayes factor.The numbers of single nucleotide variants(SNVs)found in SARS‐CoV‐2 sequences were significantly lower than those called from B.1.1 records collected at the matching time worldwide(P=0.047).In addition,results of the leaf‐dating method showed ages of viruses sampled from this outbreak were earlier than their recorded dates of collection(Bayes factors>10),while control sequences(selected randomly with ten replicates)showed no differences in their collection dates(Bayes factors<10).Our results which indicated that the re‐emergence of SARS‐CoV‐2 in Beijing in June 2020 was caused by a virus that exhibited a lack of evolutionary changes compared to viruses collected at the corresponding time,provided evolutionary evidence to the contaminated imported frozen food should be responsible for the reappearance of COVID‐19 cases in Beijing.The method developed here might also be helpful to provide the very first clues for potential sources of COVID‐19 cases in the future.
