Identifying airborne transmission as the dominant route for the spread of COVID-19. Various mitigation measures have been implemented to fight the coronavirus disease 2019 (COVID-19) pandemic, including widely adopted social distancing and mandated face covering.
Name : Renathan Agustianus
NIM : 20190900012
Major : Industrial Engineering
Faculty : Science and Technology
Courses : Bahasa Inggris 2
Lecturer : Harisa Mardiana
FInal Exam
The document discusses COVID-19 and the potential role of environmental factors in its transmission. It provides details about COVID-19, including that it is caused by SARS-CoV-2 and causes respiratory illness. It then discusses how the virus's behavior and susceptibility can vary in different environments. Factors like relative humidity, material of contaminated surfaces, and air temperature may influence how long the virus survives. The spread of the virus through fecal contamination of water is also a possible transmission route. Researchers are working to understand environmental factors that could affect COVID-19 transmission to help control outbreaks.
Informe de la OMS sobre el contagio del coronavirus20minutos
The document summarizes evidence on the modes of transmission of the COVID-19 virus. It finds that transmission occurs primarily through respiratory droplets and contact routes when people are within 1 meter of each other. Airborne transmission may occur during specific medical procedures that produce aerosols. Current WHO guidance recommends droplet and contact precautions for those caring for COVID patients, and airborne precautions for aerosol-generating procedures. While some studies have found virus in aerosols and air samples, more research is needed to determine the role of airborne transmission and viability of the virus in aerosols.
This document summarizes the current knowledge about coronavirus disease 2019 (COVID-19). It discusses that COVID-19 is caused by the virus SARS-CoV-2 which originated in bats. The main symptoms are fever, cough and difficulty breathing. The virus spreads through droplets and close contact between people. Diagnosis is done through RT-PCR testing of throat swabs. Currently there are no specific treatments, but research is being done into antiviral medications. Public health measures aim to control the spread and protect vulnerable populations.
The document discusses COVID-19, describing what it is, how it spreads, and who is most at risk. It then discusses factors in the environment that can affect the transmission of COVID-19, such as relative humidity, air temperature, and fecal contamination of water. Finally, it provides results of studies on how temperature, humidity, and wind speed can influence the spread and viability of the COVID-19 virus.
This article provides a review of COVID-19 (coronavirus disease 2019), the respiratory disease caused by the novel coronavirus SARS-CoV-2. It discusses the epidemiology, causes, clinical manifestations, diagnosis, and prevention/control of COVID-19. Key points include that COVID-19 symptoms can range from mild to severe/fatal, with the elderly and those with preexisting conditions most at risk of complications. Diagnosis is via PCR tests of respiratory samples. While there are no approved vaccines or treatments yet, prevention focuses on avoiding exposure, hand washing, and other hygiene/social distancing practices. The aim is to increase awareness and understanding of this ongoing public health threat.
COVID-19: советы ВОЗ по использованию масокPravotv
This document provides updated guidance from the WHO on the use of medical and non-medical masks in the context of the COVID-19 pandemic. It summarizes evidence that COVID-19 spreads via respiratory droplets and contact with infected surfaces. The guidance recommends medical masks for health workers providing direct care to COVID-19 patients without aerosol-generating procedures, and respirators for those performing such procedures. It also recommends targeted continuous use of medical masks by health workers in areas with community COVID-19 transmission.
Name : Renathan Agustianus
NIM : 20190900012
Major : Industrial Engineering
Faculty : Science and Technology
Courses : Bahasa Inggris 2
Lecturer : Harisa Mardiana
FInal Exam
The document discusses COVID-19 and the potential role of environmental factors in its transmission. It provides details about COVID-19, including that it is caused by SARS-CoV-2 and causes respiratory illness. It then discusses how the virus's behavior and susceptibility can vary in different environments. Factors like relative humidity, material of contaminated surfaces, and air temperature may influence how long the virus survives. The spread of the virus through fecal contamination of water is also a possible transmission route. Researchers are working to understand environmental factors that could affect COVID-19 transmission to help control outbreaks.
Informe de la OMS sobre el contagio del coronavirus20minutos
The document summarizes evidence on the modes of transmission of the COVID-19 virus. It finds that transmission occurs primarily through respiratory droplets and contact routes when people are within 1 meter of each other. Airborne transmission may occur during specific medical procedures that produce aerosols. Current WHO guidance recommends droplet and contact precautions for those caring for COVID patients, and airborne precautions for aerosol-generating procedures. While some studies have found virus in aerosols and air samples, more research is needed to determine the role of airborne transmission and viability of the virus in aerosols.
This document summarizes the current knowledge about coronavirus disease 2019 (COVID-19). It discusses that COVID-19 is caused by the virus SARS-CoV-2 which originated in bats. The main symptoms are fever, cough and difficulty breathing. The virus spreads through droplets and close contact between people. Diagnosis is done through RT-PCR testing of throat swabs. Currently there are no specific treatments, but research is being done into antiviral medications. Public health measures aim to control the spread and protect vulnerable populations.
The document discusses COVID-19, describing what it is, how it spreads, and who is most at risk. It then discusses factors in the environment that can affect the transmission of COVID-19, such as relative humidity, air temperature, and fecal contamination of water. Finally, it provides results of studies on how temperature, humidity, and wind speed can influence the spread and viability of the COVID-19 virus.
This article provides a review of COVID-19 (coronavirus disease 2019), the respiratory disease caused by the novel coronavirus SARS-CoV-2. It discusses the epidemiology, causes, clinical manifestations, diagnosis, and prevention/control of COVID-19. Key points include that COVID-19 symptoms can range from mild to severe/fatal, with the elderly and those with preexisting conditions most at risk of complications. Diagnosis is via PCR tests of respiratory samples. While there are no approved vaccines or treatments yet, prevention focuses on avoiding exposure, hand washing, and other hygiene/social distancing practices. The aim is to increase awareness and understanding of this ongoing public health threat.
COVID-19: советы ВОЗ по использованию масокPravotv
This document provides updated guidance from the WHO on the use of medical and non-medical masks in the context of the COVID-19 pandemic. It summarizes evidence that COVID-19 spreads via respiratory droplets and contact with infected surfaces. The guidance recommends medical masks for health workers providing direct care to COVID-19 patients without aerosol-generating procedures, and respirators for those performing such procedures. It also recommends targeted continuous use of medical masks by health workers in areas with community COVID-19 transmission.
Covid 19 - the Corona Virus Medical WhitepaperPete Surreal
This document provides an overview of COVID-19 including its biology, transmission, signs and symptoms, diagnosis, treatment and prognosis. Key points include:
- COVID-19 is caused by SARS-CoV-2, a coronavirus that binds the ACE2 receptor and causes ARDS through direct cell damage and possibly a cytokine storm response.
- Transmission occurs via respiratory droplets, contact with contaminated surfaces, and possibly aerosols. Virus can persist on surfaces for days.
- Symptoms are generally flu-like but can progress to viral pneumonia. Diagnosis involves PCR testing of respiratory samples. Treatment is supportive care.
- Prevention relies on hand hygiene, surface cleaning, and personal protective equipment like surgical
This is my first ever Presentation on Coronavirus Pandemic. It is made to grab attention of youngsters,school going children who might be unaware about some important facts of Corona Virus I hope this would be helpful to increase their current affairs.
Does Liuzijue Qigong affect anxiety in patients with chronic obstructive pulm...LucyPi1
Abstract Background: Anxiety is a common comorbidity associated with chronic obstructive pulmonary disease (COPD), but no well-recognized method can provide effective relief. Liuzijue Qigong (LQG) is a traditional Chinese fitness method, based on breath pronunciation. This study aimed to examine the efficacy of LQG to relieve anxiety in COPD patients and to explore the factors that influence anxiety, including whether LQG is effective during the coronavirus disease 2019 (COVID-19) outbreak. Methods: We conducted an open-label, randomized, controlled, clinical trial. A total of 60 patients with stable COPD were randomly assigned to two groups. Both groups were given routine medical treatment, and the patients in the pulmonary rehabilitation (PR) group were given an extra intervention in the form of LQG, performed for 30 minutes each day for 12 weeks. Data collection was performed at baseline and 12 weeks (during the COVID-19 epidemic). The primary outcomes were the self-rating anxiety scale (SAS) scores, and the secondary outcomes were relevant information during the epidemic and analyses of the related factors that influenced SAS scores during the COVID-19 outbreak. Results: Compared with baseline, patients in both groups demonstrated varying degrees of improvements in their SAS scores (all P < 0.01). An analysis of covariance, adjusted for baseline scores, indicated that the SAS scores improved more dramatically in the PR group than in the control group (F = 9.539, P = 0.004). During the outbreak, the SAS scores for sleep disorder were higher than all other factors, reaching 1.38 ± 0.67, and the scores for “I can breathe in and out easily” for the PR group were lower than the scores for the control group (Z = −2.108, P = 0.035). Significant differences were identified between the two groups for the categories “How much has the outbreak affected your life”, “Do you practice LQG during the epidemic” and “Do you practice other exercises during the epidemic” (all P < 0.05). Compared with current reports, LQG had a relatively high adherence rate (80.95%). A multiple linear regression analysis revealed multiple predictors for SAS scores during the outbreak: group (b = −3.907, t = −3.824, P < 0.001), COPD assessment test score (b = 0.309, t = 2.876, P = 0.006), SAS score at baseline (b = 0.189, t = 3.074, P = 0.004), and living in a village (b = 4.886, t = 2.085, P = 0.043). Conclusion: LQG could effectively reduce the risks of anxiety among COPD patients, even during the COVID-19 outbreak. For those COPD patients with high COPD assessment test and high baseline SAS scores or who live in villages, we should reinforce the management and intervention of psychological factors during the epidemic.
Forecasting the peak and fading out of novel coronavirus of 2019Islam Saeed
The document summarizes a statistical model that was developed to forecast the size, peak, and fading out of the 2019 novel coronavirus outbreak using confirmed case and death data. The model predicts that:
1) The outbreak will peak on February 20, 2020 with over 91,000 confirmed cases and 1,655 deaths worldwide.
2) The number of cases and deaths will then decline through the end of March 2020 as the outbreak fades out.
3) The outbreak will likely be completely died out by the first week of April 2020, according to the model.
Several new viral respiratory tract infectious diseases with epidemic potential that threaten global health security have emerged in the past 15 years. A severe viral illness caused by a newly discovered coronavirus was first reported in the 2003. In 2003, WHO issued a worldwide alert for an unknown emerging illness, later named severe
acute respiratory syndrome (SARS). The disease caused by a novel coronavirus (SARS-CoV) rapidly spread worldwide, Coronaviruses are enveloped viruses with plus-stranded RNA genomes of 26-32 kb, the
largest contiguous RNA genomes in nature. Symptoms of SARS include: high fever, cough pneumonia, breathing difficulties headache, chills, muscle aches and sore throat. According to the World Health Organization (WHO), From November 2002 to July 2003 a total of 8098 patients, in 25 countries, were affected by the atypical pneumonia which resulted in 774 deaths globally. The severe acute respiratory syndrome (SARS) is a febrile respiratory illness
primarily transmitted by respiratory droplets or close personal contact. There are several laboratory tests used to detect SARS-CoV and other causes of respiratory illness. Many methods used in the treatment of viral infections have been only partially effective. For example, the standard treatment in HCV (with ribavirin and interferon-alpha) is effective in 50% of cases.
- The document discusses the Covid-19 pandemic, providing an overview of the virus and its spread worldwide. It notes that Covid-19 has infected over 3.7 million people globally, causing over 259,000 deaths.
- Symptoms of Covid-19 range from mild to severe and can include fever, cough, shortness of breath. Around 14% of cases progress to pneumonia and 5% are critical. The elderly and those with preexisting conditions are at higher risk.
- Covid-19 is diagnosed through PCR tests of nasal and throat swabs. Antibody tests can also detect if a person has been infected. The case fatality rate of Covid-19 is around 2.
A Perspective Approach of Community Medicine in Corona Virus Disease COVID 19ijtsrd
Coronavirus disease COVID 19 is an infectious disease caused by the SARS CoV 2 coronavirus, which has spread rapidly across the world. The World Health Organization WHO proclaimed the COVID 19 outbreak a pandemic in March 2020. The pandemic has wreaked havoc on global health systems, as well as economic and social development. The rate of transmission is relatively high.As a result, regardless of vaccine history or previous infection, the CDC recommends that anyone with any signs or symptoms of COVID 19 be checked. Everyday Preventive Actions, as well as having the Covid 19 Vaccine when it is safe, will protect you and your loved ones. Prof. Dr. Anup Kumar Das | Dr. Humani Sharma | Dr. Hitarth Mehta "A Perspective Approach of Community Medicine in Corona Virus Disease (COVID 19)" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-4 , June 2021, URL: https://www.ijtsrd.compapers/ijtsrd43677.pdf Paper URL: https://www.ijtsrd.comother-scientific-research-area/other/43677/a-perspective-approach-of-community-medicine-in-corona-virus-disease-covid-19/prof-dr-anup-kumar-das
Correlation between Human Origin and the Severity of COVID19ijtsrd
It has been reported that the severity of coronavirus infectious disease COVID 19 is due to several factors such as age and the presence or absence of chronic disease. Furthermore, it has been reported that genetic factors affect the severity of COVID 19. A recently published study of the COVID 19 Host Genetics Initiative suggests that genetic manifolds in the region located on chromosome 3 may increase the risk of the severity of COVID 19. Takuma Hayashi | Ikuo Konishi "Correlation between Human Origin and the Severity of COVID19" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-6 , October 2020, URL: https://www.ijtsrd.com/papers/ijtsrd33684.pdf Paper Url: https://www.ijtsrd.com/medicine/other/33684/correlation-between-human-origin-and-the-severity-of-covid19/takuma-hayashi
Coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered coronavirus.
Most people infected with the COVID-19 virus will experience mild to moderate respiratory illness and recover without requiring special treatment.
Elderly people, and those with underlying medical problems like cardiovascular disease, diabetes, chronic respiratory disease, and cancer are more likely to develop serious illness.
WHO clearly stated that the COVID-19 virus spreads primarily through droplets of saliva or discharge from the nose when an infected person coughs or sneezes.
Pneumonia is a common respiratory infection that affects the lungs. It is broadly divided into community-acquired pneumonia (CAP) or hospital-acquired pneumonia (HAP). The causative microorganisms differ between CAP and HAP depending on whether the pneumonia was acquired in the community or healthcare setting. Mortality from pneumonia is highest in young children and older adults, and is influenced by treatment setting, age, comorbidities, and the specific type of pneumonia such as CAP or HAP.
COVID-19 is a respiratory infection caused by the SARS-CoV-2 virus that was first identified in Wuhan, China in December 2019. It causes symptoms like fever, cough, shortness of breath that appear 2-14 days after exposure. The virus spreads mainly through respiratory droplets from infected individuals coughing and sneezing, and possibly through touching contaminated surfaces. To prevent infection, one should wash hands frequently, avoid touching the face, disinfect surfaces, maintain distance from those coughing/sneezing, and cough/sneeze into the elbow. Droplets from coughs or sneezes can transfer from surfaces to hands and then to the face, causing infection if introduced to mucous membranes.
A Study to Assess the Knowledge, Attitude and Practice Regarding Prevention o...ijtsrd
Objective To assess the knowledge, attitude and practice toward coronavirus disease COVID 19 Background The World Health Organization declared COVID 19 as a pandemic on the 11th of March 2020 and declared as a global health emergency. Since then, many efforts are being carried out to control the rapid spread of the ongoing COVID 19 epidemic in India. The control measures COVID 19 is affected by their knowledge, attitudes, and practices KAP towards COVID 19. Knowledge attitude and practice of people should be directed towards strict preventive practices in order to prevents the spread of the virus. Materials and Methods The aim of the current electronic cross sectional study is to assess the knowledge, attitude and practice among selected rural community. Structured questionnaire was created in the google forms, the link was generated and distributed among the people though email and other media to participate in the survey. A total 153 subject was enrolled through convenient sampling technique. Collected data was analysed using descriptive statistics including frequency, percentage, mean and standard deviation. Results Majority of participant 91.50 were having the adequate information regarding the covid 19 and most of participants, 52.28 were got the information from multimedia included television, radio and newspaper regarding COVID 19. About 52.28 participants were the aware about the online training program by the government .Among 153 participants, 115 had adequate knowledge, 23 had moderately adequate and 15 had inadequate knowledge. Most 75.16 of the participants had adequate knowledge, in 15.03 moderately adequate and in 9.80 inadequate knowledge found regarding prevention of COVID 19. The mean knowledge score was 15.54 with standard deviation of 2.93. Most of the 102 66.66 had most favourable attitude, 31 20.26 had favourable and 20 13.07 had unfavourable attitude . The mean attitude score was 34.76 with standard deviation of 2.86.Majority of the participants, 129 had good practice, 20 had average practice and 4 had bad practice . Most 84.31 of the participants had good practice, in 13.07 average practice and in 2.61 bad practice found regarding prevention of COVID 19. The mean practice score was 25.2 with standard deviation of 2.56. Lalan Kumar "A Study to Assess the Knowledge, Attitude and Practice Regarding Prevention of Novel Coronavirus (COVID-19): An Electronic Cross-Sectional Survey among Selected Rural Community" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-3 , April 2020, URL: https://www.ijtsrd.com/papers/ijtsrd30657.pdf Paper Url :https://www.ijtsrd.com/medicine/nursing/30657/a-study-to-assess-the-knowledge-attitude-and-practice-regarding-prevention-of-novel-coronavirus-covid19-an-electronic-crosssectional-survey-among-selected-rural-community/lalan-kumar
Respiratory virus shedding in exhaled breath and efficacy of face masksValentina Corona
1) The study identified seasonal human coronaviruses, influenza viruses, and rhinoviruses in exhaled breath and coughs of children and adults with acute respiratory illness.
2) Surgical face masks significantly reduced detection of influenza virus RNA in respiratory droplets and coronavirus RNA in aerosols. There was also a trend toward reduced detection of coronavirus RNA in respiratory droplets.
3) The results indicate that surgical face masks could help prevent transmission of human coronaviruses and influenza viruses from symptomatic individuals.
Coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered coronavirus.
Most people infected with the COVID-19 virus will experience mild to moderate respiratory illness and recover without requiring special treatment. Older people, and those with underlying medical problems like cardiovascular disease, diabetes, chronic respiratory disease, and cancer are more likely to develop serious illness.
The best way to prevent and slow down transmission is to be well informed about the COVID-19 virus, the disease it causes, and how it spreads. Protect yourself and others from infection by washing your hands or using an alcohol-based rub frequently and not touching your face.
Coronaviruses are important human and animal pathogens. At the end of 2019, a novel coronavirus was identified as the cause of a cluster of pneumonia cases in Wuhan, in the Hubei Province of China. It is rapidly spreading, resulting in an epidemic throughout china, followed by an increasing number of cases in other countries throughout the world. In February 2020, the WHO designated the disease COVID 19, which stands for corona viruses 2019. The virus that causes COVID 19 is designated severe acute respiratory syndrome coronavirus 2 SARS COV 2 previously, it was referred to as 2019 nCoV. Anushka Bharti | Dr. Gaurav Kumar Sharma | Dr. Kaushal Kishore Chandul "COVID-19" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-6 , October 2021, URL: https://www.ijtsrd.com/papers/ijtsrd46439.pdf Paper URL : https://www.ijtsrd.com/pharmacy/pharmaceutics/46439/covid19/anushka-bharti
COVID 19 is a contagious disease caused by a betacoronavirus, which began in Wuhan, China in late 2019. Until now, this new illness has affected more than 6 million people worldwide, and has claimed more than 300 000 human lives. Governments around the globe were faced with the coronavirus pandemic crisis and designed strategies to slow or halt viral transmission. Measures undertaken included enforcing countrywide lockdowns, banning mass gatherings, closing schools and businesses and halting international travel.
Deadly H5N1 birdflu needs just five mutations to spread easily in peopleHarm Kiezebrink
Reference: Phys.org. 15 Apr 2014. Dutch researchers have found that the virus needs only five favorable gene mutations to become transmissible through coughing or sneezing, like regular flu viruses.
World health officials have long feared that the H5N1 virus will someday evolve a knack for airborne transmission, setting off a devastating pandemic. While the new study suggests the mutations needed are relatively few, it remains unclear whether they're likely to happen outside the laboratory.
Geographical Analysis of Covid 19 Its Relationship with Socio Economic Condit...YogeshIJTSRD
The present paper aims to analyse the spatial variations in spread of corona cases and corona deaths and level of socio economic conditions in India. The causal relationship between corona cases and corona deaths and twenty selected socio economic variables has been taken into account. The state union territory has been taken as the smallest unit of study. The entire research work is based on secondary sources of data. The study reveals states with better socio economic conditions recorded higher corona cases and states with poor socio economic conditions recorded lesser corona cases. States such as Maharashtra, Kerala, Andhra Pradesh, Tamil Nadu and Karnataka with better socio economic conditions recorded a greater number of corona deaths. Gyanendra Singh Chauhan "Geographical Analysis of Covid 19: Its Relationship with Socio-Economic Conditions in India" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-3 , April 2021, URL: https://www.ijtsrd.com/papers/ijtsrd39871.pdf Paper URL: https://www.ijtsrd.com/humanities-and-the-arts/geography/39871/geographical-analysis-of-covid-19-its-relationship-with-socioeconomic-conditions-in-india/gyanendra-singh-chauhan
1) A study analyzed the transmission of COVID-19 in indoor settings like hospitals in Wuhan, China. It found viral RNA in patient areas with concentrations highest in ICUs, and lower concentrations in outdoor public areas.
2) Past research on the 2003 SARS outbreak in Hong Kong found the virus spread primarily through airborne transmission in indoor apartment buildings, carried by airflow between buildings.
3) Studies of the Amoy Gardens outbreak linked greater risk of infection to middle and upper floors of buildings, and apartments facing the direction from which wind blew from an infected building. This supported the role of airborne transmission through virus-laden aerosols.
This document summarizes a research article that examines the relationship between certain viruses and environmental factors like latitude, air pollution, and humidity. It presents figures and maps showing the spread of SARS, MERS, influenza, and COVID-19. It also shows maps of global and regional air pollution. The authors hypothesize that increased air pollution may facilitate the spread of viruses and note reduced COVID-19 spread and air pollution in China following restrictions. Several studies finding links between respiratory illness and air pollution, and mixed effects of temperature on COVID-19 transmission, are discussed. The authors theorize that natural selection can occur in polluted atmospheric environments.
Covid 19 - the Corona Virus Medical WhitepaperPete Surreal
This document provides an overview of COVID-19 including its biology, transmission, signs and symptoms, diagnosis, treatment and prognosis. Key points include:
- COVID-19 is caused by SARS-CoV-2, a coronavirus that binds the ACE2 receptor and causes ARDS through direct cell damage and possibly a cytokine storm response.
- Transmission occurs via respiratory droplets, contact with contaminated surfaces, and possibly aerosols. Virus can persist on surfaces for days.
- Symptoms are generally flu-like but can progress to viral pneumonia. Diagnosis involves PCR testing of respiratory samples. Treatment is supportive care.
- Prevention relies on hand hygiene, surface cleaning, and personal protective equipment like surgical
This is my first ever Presentation on Coronavirus Pandemic. It is made to grab attention of youngsters,school going children who might be unaware about some important facts of Corona Virus I hope this would be helpful to increase their current affairs.
Does Liuzijue Qigong affect anxiety in patients with chronic obstructive pulm...LucyPi1
Abstract Background: Anxiety is a common comorbidity associated with chronic obstructive pulmonary disease (COPD), but no well-recognized method can provide effective relief. Liuzijue Qigong (LQG) is a traditional Chinese fitness method, based on breath pronunciation. This study aimed to examine the efficacy of LQG to relieve anxiety in COPD patients and to explore the factors that influence anxiety, including whether LQG is effective during the coronavirus disease 2019 (COVID-19) outbreak. Methods: We conducted an open-label, randomized, controlled, clinical trial. A total of 60 patients with stable COPD were randomly assigned to two groups. Both groups were given routine medical treatment, and the patients in the pulmonary rehabilitation (PR) group were given an extra intervention in the form of LQG, performed for 30 minutes each day for 12 weeks. Data collection was performed at baseline and 12 weeks (during the COVID-19 epidemic). The primary outcomes were the self-rating anxiety scale (SAS) scores, and the secondary outcomes were relevant information during the epidemic and analyses of the related factors that influenced SAS scores during the COVID-19 outbreak. Results: Compared with baseline, patients in both groups demonstrated varying degrees of improvements in their SAS scores (all P < 0.01). An analysis of covariance, adjusted for baseline scores, indicated that the SAS scores improved more dramatically in the PR group than in the control group (F = 9.539, P = 0.004). During the outbreak, the SAS scores for sleep disorder were higher than all other factors, reaching 1.38 ± 0.67, and the scores for “I can breathe in and out easily” for the PR group were lower than the scores for the control group (Z = −2.108, P = 0.035). Significant differences were identified between the two groups for the categories “How much has the outbreak affected your life”, “Do you practice LQG during the epidemic” and “Do you practice other exercises during the epidemic” (all P < 0.05). Compared with current reports, LQG had a relatively high adherence rate (80.95%). A multiple linear regression analysis revealed multiple predictors for SAS scores during the outbreak: group (b = −3.907, t = −3.824, P < 0.001), COPD assessment test score (b = 0.309, t = 2.876, P = 0.006), SAS score at baseline (b = 0.189, t = 3.074, P = 0.004), and living in a village (b = 4.886, t = 2.085, P = 0.043). Conclusion: LQG could effectively reduce the risks of anxiety among COPD patients, even during the COVID-19 outbreak. For those COPD patients with high COPD assessment test and high baseline SAS scores or who live in villages, we should reinforce the management and intervention of psychological factors during the epidemic.
Forecasting the peak and fading out of novel coronavirus of 2019Islam Saeed
The document summarizes a statistical model that was developed to forecast the size, peak, and fading out of the 2019 novel coronavirus outbreak using confirmed case and death data. The model predicts that:
1) The outbreak will peak on February 20, 2020 with over 91,000 confirmed cases and 1,655 deaths worldwide.
2) The number of cases and deaths will then decline through the end of March 2020 as the outbreak fades out.
3) The outbreak will likely be completely died out by the first week of April 2020, according to the model.
Several new viral respiratory tract infectious diseases with epidemic potential that threaten global health security have emerged in the past 15 years. A severe viral illness caused by a newly discovered coronavirus was first reported in the 2003. In 2003, WHO issued a worldwide alert for an unknown emerging illness, later named severe
acute respiratory syndrome (SARS). The disease caused by a novel coronavirus (SARS-CoV) rapidly spread worldwide, Coronaviruses are enveloped viruses with plus-stranded RNA genomes of 26-32 kb, the
largest contiguous RNA genomes in nature. Symptoms of SARS include: high fever, cough pneumonia, breathing difficulties headache, chills, muscle aches and sore throat. According to the World Health Organization (WHO), From November 2002 to July 2003 a total of 8098 patients, in 25 countries, were affected by the atypical pneumonia which resulted in 774 deaths globally. The severe acute respiratory syndrome (SARS) is a febrile respiratory illness
primarily transmitted by respiratory droplets or close personal contact. There are several laboratory tests used to detect SARS-CoV and other causes of respiratory illness. Many methods used in the treatment of viral infections have been only partially effective. For example, the standard treatment in HCV (with ribavirin and interferon-alpha) is effective in 50% of cases.
- The document discusses the Covid-19 pandemic, providing an overview of the virus and its spread worldwide. It notes that Covid-19 has infected over 3.7 million people globally, causing over 259,000 deaths.
- Symptoms of Covid-19 range from mild to severe and can include fever, cough, shortness of breath. Around 14% of cases progress to pneumonia and 5% are critical. The elderly and those with preexisting conditions are at higher risk.
- Covid-19 is diagnosed through PCR tests of nasal and throat swabs. Antibody tests can also detect if a person has been infected. The case fatality rate of Covid-19 is around 2.
A Perspective Approach of Community Medicine in Corona Virus Disease COVID 19ijtsrd
Coronavirus disease COVID 19 is an infectious disease caused by the SARS CoV 2 coronavirus, which has spread rapidly across the world. The World Health Organization WHO proclaimed the COVID 19 outbreak a pandemic in March 2020. The pandemic has wreaked havoc on global health systems, as well as economic and social development. The rate of transmission is relatively high.As a result, regardless of vaccine history or previous infection, the CDC recommends that anyone with any signs or symptoms of COVID 19 be checked. Everyday Preventive Actions, as well as having the Covid 19 Vaccine when it is safe, will protect you and your loved ones. Prof. Dr. Anup Kumar Das | Dr. Humani Sharma | Dr. Hitarth Mehta "A Perspective Approach of Community Medicine in Corona Virus Disease (COVID 19)" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-4 , June 2021, URL: https://www.ijtsrd.compapers/ijtsrd43677.pdf Paper URL: https://www.ijtsrd.comother-scientific-research-area/other/43677/a-perspective-approach-of-community-medicine-in-corona-virus-disease-covid-19/prof-dr-anup-kumar-das
Correlation between Human Origin and the Severity of COVID19ijtsrd
It has been reported that the severity of coronavirus infectious disease COVID 19 is due to several factors such as age and the presence or absence of chronic disease. Furthermore, it has been reported that genetic factors affect the severity of COVID 19. A recently published study of the COVID 19 Host Genetics Initiative suggests that genetic manifolds in the region located on chromosome 3 may increase the risk of the severity of COVID 19. Takuma Hayashi | Ikuo Konishi "Correlation between Human Origin and the Severity of COVID19" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-6 , October 2020, URL: https://www.ijtsrd.com/papers/ijtsrd33684.pdf Paper Url: https://www.ijtsrd.com/medicine/other/33684/correlation-between-human-origin-and-the-severity-of-covid19/takuma-hayashi
Coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered coronavirus.
Most people infected with the COVID-19 virus will experience mild to moderate respiratory illness and recover without requiring special treatment.
Elderly people, and those with underlying medical problems like cardiovascular disease, diabetes, chronic respiratory disease, and cancer are more likely to develop serious illness.
WHO clearly stated that the COVID-19 virus spreads primarily through droplets of saliva or discharge from the nose when an infected person coughs or sneezes.
Pneumonia is a common respiratory infection that affects the lungs. It is broadly divided into community-acquired pneumonia (CAP) or hospital-acquired pneumonia (HAP). The causative microorganisms differ between CAP and HAP depending on whether the pneumonia was acquired in the community or healthcare setting. Mortality from pneumonia is highest in young children and older adults, and is influenced by treatment setting, age, comorbidities, and the specific type of pneumonia such as CAP or HAP.
COVID-19 is a respiratory infection caused by the SARS-CoV-2 virus that was first identified in Wuhan, China in December 2019. It causes symptoms like fever, cough, shortness of breath that appear 2-14 days after exposure. The virus spreads mainly through respiratory droplets from infected individuals coughing and sneezing, and possibly through touching contaminated surfaces. To prevent infection, one should wash hands frequently, avoid touching the face, disinfect surfaces, maintain distance from those coughing/sneezing, and cough/sneeze into the elbow. Droplets from coughs or sneezes can transfer from surfaces to hands and then to the face, causing infection if introduced to mucous membranes.
A Study to Assess the Knowledge, Attitude and Practice Regarding Prevention o...ijtsrd
Objective To assess the knowledge, attitude and practice toward coronavirus disease COVID 19 Background The World Health Organization declared COVID 19 as a pandemic on the 11th of March 2020 and declared as a global health emergency. Since then, many efforts are being carried out to control the rapid spread of the ongoing COVID 19 epidemic in India. The control measures COVID 19 is affected by their knowledge, attitudes, and practices KAP towards COVID 19. Knowledge attitude and practice of people should be directed towards strict preventive practices in order to prevents the spread of the virus. Materials and Methods The aim of the current electronic cross sectional study is to assess the knowledge, attitude and practice among selected rural community. Structured questionnaire was created in the google forms, the link was generated and distributed among the people though email and other media to participate in the survey. A total 153 subject was enrolled through convenient sampling technique. Collected data was analysed using descriptive statistics including frequency, percentage, mean and standard deviation. Results Majority of participant 91.50 were having the adequate information regarding the covid 19 and most of participants, 52.28 were got the information from multimedia included television, radio and newspaper regarding COVID 19. About 52.28 participants were the aware about the online training program by the government .Among 153 participants, 115 had adequate knowledge, 23 had moderately adequate and 15 had inadequate knowledge. Most 75.16 of the participants had adequate knowledge, in 15.03 moderately adequate and in 9.80 inadequate knowledge found regarding prevention of COVID 19. The mean knowledge score was 15.54 with standard deviation of 2.93. Most of the 102 66.66 had most favourable attitude, 31 20.26 had favourable and 20 13.07 had unfavourable attitude . The mean attitude score was 34.76 with standard deviation of 2.86.Majority of the participants, 129 had good practice, 20 had average practice and 4 had bad practice . Most 84.31 of the participants had good practice, in 13.07 average practice and in 2.61 bad practice found regarding prevention of COVID 19. The mean practice score was 25.2 with standard deviation of 2.56. Lalan Kumar "A Study to Assess the Knowledge, Attitude and Practice Regarding Prevention of Novel Coronavirus (COVID-19): An Electronic Cross-Sectional Survey among Selected Rural Community" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-3 , April 2020, URL: https://www.ijtsrd.com/papers/ijtsrd30657.pdf Paper Url :https://www.ijtsrd.com/medicine/nursing/30657/a-study-to-assess-the-knowledge-attitude-and-practice-regarding-prevention-of-novel-coronavirus-covid19-an-electronic-crosssectional-survey-among-selected-rural-community/lalan-kumar
Respiratory virus shedding in exhaled breath and efficacy of face masksValentina Corona
1) The study identified seasonal human coronaviruses, influenza viruses, and rhinoviruses in exhaled breath and coughs of children and adults with acute respiratory illness.
2) Surgical face masks significantly reduced detection of influenza virus RNA in respiratory droplets and coronavirus RNA in aerosols. There was also a trend toward reduced detection of coronavirus RNA in respiratory droplets.
3) The results indicate that surgical face masks could help prevent transmission of human coronaviruses and influenza viruses from symptomatic individuals.
Coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered coronavirus.
Most people infected with the COVID-19 virus will experience mild to moderate respiratory illness and recover without requiring special treatment. Older people, and those with underlying medical problems like cardiovascular disease, diabetes, chronic respiratory disease, and cancer are more likely to develop serious illness.
The best way to prevent and slow down transmission is to be well informed about the COVID-19 virus, the disease it causes, and how it spreads. Protect yourself and others from infection by washing your hands or using an alcohol-based rub frequently and not touching your face.
Coronaviruses are important human and animal pathogens. At the end of 2019, a novel coronavirus was identified as the cause of a cluster of pneumonia cases in Wuhan, in the Hubei Province of China. It is rapidly spreading, resulting in an epidemic throughout china, followed by an increasing number of cases in other countries throughout the world. In February 2020, the WHO designated the disease COVID 19, which stands for corona viruses 2019. The virus that causes COVID 19 is designated severe acute respiratory syndrome coronavirus 2 SARS COV 2 previously, it was referred to as 2019 nCoV. Anushka Bharti | Dr. Gaurav Kumar Sharma | Dr. Kaushal Kishore Chandul "COVID-19" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-6 , October 2021, URL: https://www.ijtsrd.com/papers/ijtsrd46439.pdf Paper URL : https://www.ijtsrd.com/pharmacy/pharmaceutics/46439/covid19/anushka-bharti
COVID 19 is a contagious disease caused by a betacoronavirus, which began in Wuhan, China in late 2019. Until now, this new illness has affected more than 6 million people worldwide, and has claimed more than 300 000 human lives. Governments around the globe were faced with the coronavirus pandemic crisis and designed strategies to slow or halt viral transmission. Measures undertaken included enforcing countrywide lockdowns, banning mass gatherings, closing schools and businesses and halting international travel.
Deadly H5N1 birdflu needs just five mutations to spread easily in peopleHarm Kiezebrink
Reference: Phys.org. 15 Apr 2014. Dutch researchers have found that the virus needs only five favorable gene mutations to become transmissible through coughing or sneezing, like regular flu viruses.
World health officials have long feared that the H5N1 virus will someday evolve a knack for airborne transmission, setting off a devastating pandemic. While the new study suggests the mutations needed are relatively few, it remains unclear whether they're likely to happen outside the laboratory.
Geographical Analysis of Covid 19 Its Relationship with Socio Economic Condit...YogeshIJTSRD
The present paper aims to analyse the spatial variations in spread of corona cases and corona deaths and level of socio economic conditions in India. The causal relationship between corona cases and corona deaths and twenty selected socio economic variables has been taken into account. The state union territory has been taken as the smallest unit of study. The entire research work is based on secondary sources of data. The study reveals states with better socio economic conditions recorded higher corona cases and states with poor socio economic conditions recorded lesser corona cases. States such as Maharashtra, Kerala, Andhra Pradesh, Tamil Nadu and Karnataka with better socio economic conditions recorded a greater number of corona deaths. Gyanendra Singh Chauhan "Geographical Analysis of Covid 19: Its Relationship with Socio-Economic Conditions in India" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-3 , April 2021, URL: https://www.ijtsrd.com/papers/ijtsrd39871.pdf Paper URL: https://www.ijtsrd.com/humanities-and-the-arts/geography/39871/geographical-analysis-of-covid-19-its-relationship-with-socioeconomic-conditions-in-india/gyanendra-singh-chauhan
Geographical Analysis of Covid 19 Its Relationship with Socio Economic Condit...
Similar to Airborne COVID Study (2020) - Texas A&M, The University of Texas at Austin, California Institute of Technology, University of California (San Diego)
1) A study analyzed the transmission of COVID-19 in indoor settings like hospitals in Wuhan, China. It found viral RNA in patient areas with concentrations highest in ICUs, and lower concentrations in outdoor public areas.
2) Past research on the 2003 SARS outbreak in Hong Kong found the virus spread primarily through airborne transmission in indoor apartment buildings, carried by airflow between buildings.
3) Studies of the Amoy Gardens outbreak linked greater risk of infection to middle and upper floors of buildings, and apartments facing the direction from which wind blew from an infected building. This supported the role of airborne transmission through virus-laden aerosols.
This document summarizes a research article that examines the relationship between certain viruses and environmental factors like latitude, air pollution, and humidity. It presents figures and maps showing the spread of SARS, MERS, influenza, and COVID-19. It also shows maps of global and regional air pollution. The authors hypothesize that increased air pollution may facilitate the spread of viruses and note reduced COVID-19 spread and air pollution in China following restrictions. Several studies finding links between respiratory illness and air pollution, and mixed effects of temperature on COVID-19 transmission, are discussed. The authors theorize that natural selection can occur in polluted atmospheric environments.
This document discusses bioaerosols and factors related to the transmission of coronaviruses. It summarizes research on the size and properties of airborne viruses, how they bind to carriers in aerosols, and the impact of environmental conditions on viral survival. The document reviews studies showing that viruses like influenza, SARS-CoV-2, and others can remain infectious in aerosols for hours or days, with their survival affected by temperature, humidity, and other physicochemical properties. Understanding these transmission mechanisms could help public health institutions improve prevention strategies for pandemics.
This document summarizes research on the physicochemical properties of coronaviruses and how they affect airborne transmissibility. It discusses how characteristics like virus size, electrical features, and envelope composition influence diffusion properties and a virus's ability to evade the immune system. The authors investigate these physicochemical aspects of coronaviruses and hypothesize that airborne transmission may help explain the rapid spread of COVID-19 beyond direct contact and droplets. Figures and literature are cited to support the role of aerosols in transmitting viruses like coronaviruses.
Thank you for the detailed summary and critical appraisal of the document. This will help provide important context and evaluation of the information presented.
The document discusses the COVID-19 pandemic, including the origins and spread of SARS-CoV-2. It describes key events like the virus being first identified in Wuhan, China in late 2019, the WHO declaring a public health emergency in January 2020, and the virus spreading widely in the United States between late January and February 2020. It also discusses recommendations from the CDC on preventive measures like social distancing and mask-wearing during surges. Finally, it lists common comorbidities and risk factors like older age, obesity, and heart or lung conditions that are associated with more severe COVID-19 outcomes.
This document summarizes research on the relationship between air pollution, climate factors like temperature and humidity, and the spread of viruses. It reviews literature showing links between increased air pollutants like PM2.5 and PM10 and higher risk of influenza-like illness. Studies found COVID-19 transmission was highest at certain temperatures and reduced slightly with higher minimum temperatures. Experiments demonstrated influenza virus transmission was enhanced at cold, dry conditions. The document hypothesizes that air pollution levels in highly industrialized areas like Wuhan, China could have implications for new virus emergence and transmission.
The document provides information on the COVID-19 pandemic as of April 2020. It discusses the epidemiology and spread of the virus globally. Key points include:
- COVID-19 originated in Wuhan, China in late 2019 and has since spread to over 210 countries. As of April 2020, there were over 29 lakh confirmed cases and 200,568 deaths worldwide, with the US becoming the new epicenter.
- The virus spreads mainly person-to-person via respiratory droplets. Common symptoms include fever, cough and shortness of breath, though many cases are asymptomatic. Chest CT scans show bilateral lung involvement like ground-glass opacities or consolidation.
- While most cases are mild, the elderly and those
The document provides information on the novel coronavirus (COVID-19) pandemic, including:
1) It describes the epidemiology and spread of COVID-19 globally, with over 29 lakh reported cases across 210 countries as of April 2020, and identifies the United States as the new epicenter.
2) It summarizes the natural history and clinical presentation of COVID-19, which commonly includes fever, cough, and shortness of breath, and can progress to severe pneumonia and multi-organ failure in vulnerable groups.
3) It discusses diagnosis of COVID-19 using RT-PCR testing of respiratory samples and treatment being primarily supportive care and ventilation for severe cases, as there is no proven antiviral treatment yet.
1) The article investigates the chemical-physical properties of coronaviruses and how they may influence airborne transmission. Characteristics like virus size, electrical features, and envelope composition can impact diffusion properties and the virus's ability to evade the immune system.
2) Studies have shown coronaviruses have a distinct chemical-physical pattern that may help shield them and influence Brownian motion, aiding airborne spread. Their envelopes also seem to play a role in immune evasion.
3) The rapid spread of the second COVID-19 wave in some countries suggests airborne transmission may be an important hypothesis to consider in addition to direct and droplet contact. Understanding the virus's chemical-physical traits
diseases_Saliva_Exhibits_High_Sensitivity_and_Spec.pdfDr Faraz Mohammed
This document summarizes a review of 10 studies that evaluated the use of saliva samples for detecting SARS-CoV-2, the virus that causes COVID-19. The review found that saliva exhibits high diagnostic sensitivity (87%) and specificity (98%) for detecting the virus. Saliva offers advantages over nasopharyngeal and oropharyngeal samples as it is non-invasive, easy to collect, stable, and has a lower risk of cross-infection. Given challenges with invasive sample collection, saliva provides an effective sample type for widespread screening in workplaces, schools, and home testing to help control the pandemic.
Future Prediction Using Supervised Machine Learning for COVID-19IRJET Journal
This document discusses using machine learning methods to predict future cases of COVID-19. It proposes using the long short-term integrated average (LSTIA) method to predict the number of COVID-19 cases in the next 30 days and examine the effects of preventive measures. The LSTIA method and support vector machine (SVM) and least absolute shrinkage and selection operator (LASSO) algorithms are used to analyze COVID-19 case data and make predictions about newly infected cases, deaths, and recoveries. The document concludes the LSTIA method can accurately predict short-term COVID-19 indicators and provide information to help control measures.
The editorial discusses the Covid-19 outbreak caused by a novel coronavirus. It summarizes a study describing the first 425 cases in Wuhan, China, noting the median age was 59 and higher mortality in the elderly and those with preexisting conditions. While the current fatality rate is around 2%, it may ultimately be closer to seasonal flu if asymptomatic cases are accounted for. The virus has an estimated reproduction number of 2.2, indicating rapid spread. Countries have implemented travel restrictions and should prepare for broader community spread, potentially using social distancing and isolation measures. Research efforts are underway to develop treatments and a vaccine.
This document discusses lessons that can be learned from past influenza pandemics and applied to understanding the future course of the COVID-19 pandemic. It outlines three possible scenarios for the future trajectory of COVID-19 based on patterns seen in influenza. Scenario 1 involves repetitive smaller waves over 1-2 years as immunity gradually increases. Scenario 2 consists of a large second peak in cases around 6 months after the first. Scenario 3 follows a seasonal pattern with peaks in winter. The pandemic may last 18-24 months until 60-70% of the population is immune through natural infection or vaccination.
1) The document discusses the link between air pollution and the spread and severity of COVID-19. It analyzes literature showing that air pollutants like particulate matter can act as carriers for viral particles and other toxins, worsening the inflammatory response in lungs.
2) Areas with high air pollution were hit harder by the first wave of COVID-19 and the emergence of variants may be related to factors in polluted air acting as mutagens.
3) Reducing global air pollution is needed to curb the effects of COVID-19. The rapid spread of the virus, especially variants, suggests it can be airborne, with implications for prevention measures and international responsibility in addressing pollution.
1) The document provides an overview of COVID-19 (coronavirus disease 2019) and implications for clinical dental care. It summarizes the epidemiology, symptoms, transmission routes, and recommendations for dental practice during the pandemic.
2) Key recommendations for dental practices include screening patients remotely or at arrival, managing suspected COVID-19 cases separately, using appropriate PPE, prioritizing urgent dental care only, and following infection control guidelines to prevent nosocomial spread.
3) Dental professionals face a high risk of infection due to procedures like aerosol generation and patient proximity, so vigilance is important to provide care safely and stop transmission during the outbreak.
Severe Acute Respiratory Syndrome In TaiwanLindsey Jones
Severe Acute Respiratory Syndrome (SARS) hit Taiwan in March 2003, severely impacting the tourism system and economy. The Taiwanese government imposed travel restrictions in response to the SARS outbreak, which led to a huge decrease in international tourist arrivals. All of these events caused global economic downturn in tourism and negatively affected industries like hotels, airlines, and other tourist services, impacting Taiwan's economic status.
The document provides an overview of coronavirus disease 2019 (COVID-19). It discusses the definition, epidemiology, virology, transmission, pathophysiology, clinical features, risk factors, diagnosis, treatment, and prevention of COVID-19. Key points include that COVID-19 is caused by the SARS-CoV-2 virus, it was first identified in Wuhan, China in 2019 and has since spread globally resulting in a pandemic, transmission occurs via respiratory droplets, clinical features range from mild to severe/critical illness, risk factors include older age and comorbidities, diagnosis involves nucleic acid or antigen testing, and treatment is generally supportive.
The first three months of the COVID-19 epidemic:
Epidemiological evidence for two separate strains of SARSCoV-2 viruses spreading and implications for prevention
strategies
Similar to Airborne COVID Study (2020) - Texas A&M, The University of Texas at Austin, California Institute of Technology, University of California (San Diego) (20)
OECD: The impact of the Covid-19 outbreak on economic (Presentation)chaganomics
The impact of the Covid-19 outbreak on economic prospects is severe Growth was weak but stabilising until the coronavirus Covid-19 hit. Restrictions on movement of people, goods and services, and containment measures such as factory closures have cut manufacturing and domestic demand sharply in China. The impact on the rest of the world through business travel and tourism, supply chains, commodities and lower confidence is growing.
Economics Realities of China's Global Influence chaganomics
China's economy faces risks from its high debt levels and complex web of private sector debt guarantees. The private sector accounted for most bond defaults in 2018. While companies like Alibaba have been successful and generated wealth for investors, ultimately the Chinese state maintains control over private enterprises and uses them to achieve political goals rather than maximizing economic growth. China's model can be described as state-controlled capitalism, and as its power and influence grows globally through initiatives like the Belt and Road project, other countries can expect to see more of this approach. The level of private sector and true market forces in China may be overstated, with the state sector potentially accounting for the majority of the economy.
This document analyzes China's rapid growth in pork production and consumption, known as China's "pork miracle." It describes how China has industrialized its pork industry through government support of large-scale operations, the rise of agribusiness firms that control production through contracts with farmers, and growing consumer demand for pork, especially processed and packaged pork. This industrial model has driven consolidation in the industry and the decline of small-scale hog farmers in China.
The United States trades over $20 trillion in goods annually. The 100 largest metropolitan areas drive the majority of this trade, with over 80% of goods starting or ending in these areas. Just 10% of trade corridors account for 79% of all goods traded, with the most valuable corridors concentrated between the largest metropolitan areas. Metropolitan areas tend to trade more goods with each other the closer they are in proximity, the more logistics workers they employ, and the larger their populations. With over 77% of goods traded between states, the national freight network must be better coordinated across public and private sectors.
The document outlines a proposed act called the Financial CHOICE Act. It aims to provide regulatory relief for financial institutions and promote economic growth. Some key points include: allowing financial institutions to opt-out of certain post-crisis regulations if they maintain high capital levels; repealing provisions that designate certain firms as "too big to fail"; reforming the Consumer Financial Protection Bureau to have a dual mission of consumer protection and competitive markets; increasing accountability of financial regulators; and promoting capital formation for small businesses and innovators.
Brookings: Looting: The Economic Underworld of Bankruptcy for Profit chaganomics
This paper analyzes the phenomenon of "bankruptcy for profit", or "looting", where owners of firms drive otherwise solvent companies bankrupt to extract value for themselves at a social cost. The authors develop a simple three-period model showing that limited liability gives owners the incentive to exploit lenders if debt contracts allow it. When M (the maximum owners can extract) exceeds V (the firm's true value), owners will intentionally bankrupt a profitable firm. Looting causes social losses far greater than private gains to owners. The authors argue this dynamic helps explain financial crises like the S&L crisis in the US and collapse of the junk bond market in the 1980s.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
Harvard Kennedy School: Eurozone Study Jan. 2017 chaganomics
This document summarizes a paper that examines the resilience of the Eurozone in the face of crises. Deep financial integration created interdependence among Eurozone members, providing mechanisms to reallocate resources and absorb economic shocks. Global market pressures forced political leaders to reinforce the monetary union through fiscal and monetary backstops. Ongoing progress on banking supervision and regulation has further strengthened the currency union. While the Eurozone still falls short as an optimal currency area, financial integration may drive further integration through banking reforms, even amid populist opposition to other reforms.
The document discusses the economic impact of Brexit on the global economy. It finds that Brexit will negatively impact UK and EU growth in the short-term due to increased uncertainty from the withdrawal process. UK GDP growth is projected to slow from 2.5% to 1.7% in the coming years as investment and consumption weaken. EU growth will also slow but only modestly given the UK's smaller share of EU trade. The impact on other regions is expected to be small.
Bank of Greece Balance Sheet May 2015 - English chaganomics
This document presents the balance sheet of the Bank of Greece as of May 31, 2015. The balance sheet shows assets of 163.3 billion euros, including gold reserves, foreign currency reserves, claims on euro area institutions related to monetary policy operations, and securities holdings. Liabilities include banknotes in circulation, deposits from euro area credit institutions, and intra-Eurosystem liabilities. Off-balance sheet items include government securities and eligible collateral totaling 258.9 billion euros. The balance sheet complies with European Central Bank accounting principles and rules.
Attributed to:
Lebret, Hervé, Serial Entrepreneurs: Are They Better? - A View from Stanford University Alumni (August 21, 2012). Available at SSRN: http://ssrn.com/abstract=2133127 or http://dx.doi.org/10.2139/ssrn.2133127
Posted on Chaganomics.com
An Act to make provision with respect to the administration of the estates of the Duchy of Lancaster, and with respect to the solicitor for the affairs of the said Duchy. Example of a corporation sole.
Performance Persistence by Harvard Business Schoolchaganomics
Performance Persistence Harvard Business School on why serial entrepreneurs are often more successful in their pursuits. for an article at chaganomics.com
8 Surprising Reasons To Meditate 40 Minutes A Day That Can Change Your Life.pptxHolistified Wellness
We’re talking about Vedic Meditation, a form of meditation that has been around for at least 5,000 years. Back then, the people who lived in the Indus Valley, now known as India and Pakistan, practised meditation as a fundamental part of daily life. This knowledge that has given us yoga and Ayurveda, was known as Veda, hence the name Vedic. And though there are some written records, the practice has been passed down verbally from generation to generation.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of the physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar lead (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
6. Describe the flow of current around the heart during the cardiac cycle
7. Discuss the placement and polarity of the leads of electrocardiograph
8. Describe the normal electrocardiograms recorded from the limb leads and explain the physiological basis of the different records that are obtained
9. Define mean electrical vector (axis) of the heart and give the normal range
10. Define the mean QRS vector
11. Describe the axes of leads (hexagonal reference system)
12. Comprehend the vectorial analysis of the normal ECG
13. Determine the mean electrical axis of the ventricular QRS and appreciate the mean axis deviation
14. Explain the concepts of current of injury, J point, and their significance
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. Chapter 3, Cardiology Explained, https://www.ncbi.nlm.nih.gov/books/NBK2214/
7. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Here is the updated list of Top Best Ayurvedic medicine for Gas and Indigestion and those are Gas-O-Go Syp for Dyspepsia | Lavizyme Syrup for Acidity | Yumzyme Hepatoprotective Capsules etc
- Video recording of this lecture in English language: https://youtu.be/kqbnxVAZs-0
- Video recording of this lecture in Arabic language: https://youtu.be/SINlygW1Mpc
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
ABDOMINAL TRAUMA in pediatrics part one.drhasanrajab
Abdominal trauma in pediatrics refers to injuries or damage to the abdominal organs in children. It can occur due to various causes such as falls, motor vehicle accidents, sports-related injuries, and physical abuse. Children are more vulnerable to abdominal trauma due to their unique anatomical and physiological characteristics. Signs and symptoms include abdominal pain, tenderness, distension, vomiting, and signs of shock. Diagnosis involves physical examination, imaging studies, and laboratory tests. Management depends on the severity and may involve conservative treatment or surgical intervention. Prevention is crucial in reducing the incidence of abdominal trauma in children.
Cell Therapy Expansion and Challenges in Autoimmune DiseaseHealth Advances
There is increasing confidence that cell therapies will soon play a role in the treatment of autoimmune disorders, but the extent of this impact remains to be seen. Early readouts on autologous CAR-Ts in lupus are encouraging, but manufacturing and cost limitations are likely to restrict access to highly refractory patients. Allogeneic CAR-Ts have the potential to broaden access to earlier lines of treatment due to their inherent cost benefits, however they will need to demonstrate comparable or improved efficacy to established modalities.
In addition to infrastructure and capacity constraints, CAR-Ts face a very different risk-benefit dynamic in autoimmune compared to oncology, highlighting the need for tolerable therapies with low adverse event risk. CAR-NK and Treg-based therapies are also being developed in certain autoimmune disorders and may demonstrate favorable safety profiles. Several novel non-cell therapies such as bispecific antibodies, nanobodies, and RNAi drugs, may also offer future alternative competitive solutions with variable value propositions.
Widespread adoption of cell therapies will not only require strong efficacy and safety data, but also adapted pricing and access strategies. At oncology-based price points, CAR-Ts are unlikely to achieve broad market access in autoimmune disorders, with eligible patient populations that are potentially orders of magnitude greater than the number of currently addressable cancer patients. Developers have made strides towards reducing cell therapy COGS while improving manufacturing efficiency, but payors will inevitably restrict access until more sustainable pricing is achieved.
Despite these headwinds, industry leaders and investors remain confident that cell therapies are poised to address significant unmet need in patients suffering from autoimmune disorders. However, the extent of this impact on the treatment landscape remains to be seen, as the industry rapidly approaches an inflection point.
Cell Therapy Expansion and Challenges in Autoimmune Disease
Airborne COVID Study (2020) - Texas A&M, The University of Texas at Austin, California Institute of Technology, University of California (San Diego)
1. Identifying airborne transmission as the dominant
route for the spread of COVID-19
Renyi Zhanga,b,1
, Yixin Lib
, Annie L. Zhangc
, Yuan Wangd
, and Mario J. Molinae,1
a
Department of Atmospheric Sciences, Texas A&M University, College Station, TX 77843; b
Department of Chemistry, Texas A&M University, College Station,
TX 77843; c
Department of Chemistry, College of Natural Sciences, The University of Texas at Austin, Austin, TX 78712; d
Division of Geological and Planetary
Sciences, California Institute of Technology, Pasadena, CA 91125; and e
Department of Chemistry and Biochemistry, University of California San Diego, La
Jolla, CA 92093
Contributed by Mario J. Molina, May 16, 2020 (sent for review May 14, 2020; reviewed by Manish Shrivastava and Tong Zhu)
Various mitigation measures have been implemented to fight the
coronavirus disease 2019 (COVID-19) pandemic, including widely
adopted social distancing and mandated face covering. However,
assessing the effectiveness of those intervention practices hinges
on the understanding of virus transmission, which remains uncer-
tain. Here we show that airborne transmission is highly virulent and
represents the dominant route to spread the disease. By analyzing
the trend and mitigation measures in Wuhan, China, Italy, and New
York City, from January 23 to May 9, 2020, we illustrate that the
impacts of mitigation measures are discernable from the trends of
the pandemic. Our analysis reveals that the difference with and
without mandated face covering represents the determinant in
shaping the pandemic trends in the three epicenters. This protective
measure alone significantly reduced the number of infections, that
is, by over 78,000 in Italy from April 6 to May 9 and over 66,000 in
New York City from April 17 to May 9. Other mitigation measures,
such as social distancing implemented in the United States, are in-
sufficient by themselves in protecting the public. We conclude that
wearing of face masks in public corresponds to the most effective
means to prevent interhuman transmission, and this inexpensive
practice, in conjunction with simultaneous social distancing, quaran-
tine, and contact tracing, represents the most likely fighting oppor-
tunity to stop the COVID-19 pandemic. Our work also highlights the
fact that sound science is essential in decision-making for the cur-
rent and future public health pandemics.
COVID-19 | virus | aerosol | public health | pandemic
The novel coronavirus outbreak, coronavirus disease 2019
(COVID-19), which was declared a pandemic by the World
Health Organization (WHO) on March 11, 2020, has infected
over 4 million people and caused nearly 300,000 fatalities over 188
countries (1). Intensive effort is ongoing worldwide to establish
effective treatments and develop a vaccine for the disease. The
novel coronavirus, named as severe acute respiratory syndrome
coronavirus 2 (SARS-CoV-2), belongs to the family of the path-
ogen that is responsible for respiratory illness linked to the
2002–2003 outbreak (SARS-CoV-1) (2). The enveloped virus
contains a positive-sense single-stranded RNA genome and a
nucleocapsid of helical symmetry of ∼120 nm. There exist several
plausible pathways for viruses to be transmitted from person to
person. Human atomization of virus-bearing particles occurs from
coughing/sneezing and even from normal breathing/talking by an
infected person (3–6). These mechanisms of viral shedding pro-
duce large droplets and small aerosols (3), which are conven-
tionally delineated at a size of 5 μm to characterize their distinct
dispersion efficiencies and residence times in air as well as the
deposition patterns along the human respiratory tract (3, 7). Virus
transmission occurs via direct (deposited on persons) or indirect
(deposited on objects) contact and airborne (droplets and aero-
sols) routes (3). Large droplets readily settle out of air to cause
person/object contamination; in contrast, aerosols are efficiently
dispersed in air. While transmission via direct or indirect contact
occurs in a short range, airborne transmission via aerosols can
occur over an extended distance and time. Inhaled virus-bearing
aerosols deposit directly along the human respiratory tract.
Previous experimental and observational studies on interhu-
man transmission have indicated a significant role of aerosols in
the transmission of many respiratory viruses, including influenza
virus, SARS-CoV-1, and Middle East Respiratory Syndrome
coronavirus (MERS-CoV) (8–11). For example, airborne coro-
navirus MERS-CoV exhibited strong capability of surviving, with
about 64% of microorganisms remaining infectious 60 min after
atomization at 25 °C and 79% relative humidity (RH) (9). On the
other hand, rapid virus decay occurred, with only 5% survival
over a 60-min procedure at 38 °C and 24% RH, indicative of
inactivation. Recent experimental studies have examined the
stability of SARS-CoV-2, showing that the virus remains in-
fectious in aerosols for hours (12) and on surfaces up to days
(12, 13).
Several parameters likely influence the microorganism survival
and delivery in air, including temperature, humidity, microbial
resistance to external physical and biological stresses, and solar
ultraviolet (UV) radiation (7). Transmission and infectivity of
airborne viruses are also dependent on the size and number
concentration of inhaled aerosols, which regulate the amount
(dose) and pattern for respiratory deposition. With typical nasal
breathing (i.e., at a velocity of ∼1 m·s−1
) (4), inhalation of airborne
viruses leads to direct and continuous deposition into the human
respiratory tract. In particular, fine aerosols (i.e., particulate
Significance
We have elucidated the transmission pathways of coronavirus
disease 2019 (COVID-19) by analyzing the trend and mitigation
measures in the three epicenters. Our results show that the
airborne transmission route is highly virulent and dominant for
the spread of COVID-19. The mitigation measures are discern-
able from the trends of the pandemic. Our analysis reveals that
the difference with and without mandated face covering rep-
resents the determinant in shaping the trends of the pandemic.
This protective measure significantly reduces the number of
infections. Other mitigation measures, such as social distancing
implemented in the United States, are insufficient by them-
selves in protecting the public. Our work also highlights the
necessity that sound science is essential in decision-making for
the current and future public health pandemics.
Author contributions: R.Z. designed research; R.Z., Y.L., and Y.W. performed research;
R.Z., Y.L., Y.W., and M.J.M. analyzed data; and R.Z., A.L.Z., and M.J.M. wrote the paper.
Reviewers: M.S., Pacific Northwest National Laboratory; and T.Z., Peking University.
The authors declare no competing interest.
This open access article is distributed under Creative Commons Attribution License 4.0
(CC BY).
1
To whom correspondence may be addressed. Email: renyi-zhang@tamu.edu or
mjmolina@ucsd.edu.
This article contains supporting information online at https://www.pnas.org/lookup/suppl/
doi:10.1073/pnas.2009637117/-/DCSupplemental.
First published June 11, 2020.
www.pnas.org/cgi/doi/10.1073/pnas.2009637117 PNAS | June 30, 2020 | vol. 117 | no. 26 | 14857–14863
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2. matter smaller than 2.5 μm, or PM2.5) penetrate deeply into the
respiratory tract and even reach other vital organs (14, 15). In
addition, viral shedding is dependent on the stages of infection
and varies between symptomatic and asymptomatic carriers. A
recent finding (16) showed that the highest viral load in the upper
respiratory tract occurs at the symptom onset, suggesting the peak
of infectiousness on or before the symptom onset and substantial
asymptomatic transmission for SARS-CoV-2.
The COVID-19 outbreak is significantly more pronounced
than that of the 2002/2003 SARS, and the disease continues to
spread at an alarming rate worldwide, despite extreme measures
taken by many countries to constrain the pandemic (1). The
enormous scope and magnitude of the COVID-19 outbreak re-
flect not only a highly contagious nature but also exceedingly
efficient transmission for SARS-CoV-2. Currently, the mecha-
nisms to spread the virus remain uncertain (17), particularly
considering the relative contribution of the contact vs. airborne
transmission routes to this global pandemic. Available epidemi-
ological (1) and experimental (12, 18) evidence, however, im-
plicates airborne transmission of SARS-CoV-2 via aerosols as a
potential route for the spreading of the disease.
Distinct Pandemic Trends in the Three Epicenters
To gain insight into the mechanism of the virus transmission
routes and assess the effectiveness of mitigation measures, we
analyzed the trend of the pandemic worldwide from January 23 to
May 9, 2020 (Fig. 1). The COVID-19 outbreak initially emerged
during December 2019 in Wuhan, China (1). The numbers of
confirmed infections and fatalities in China dominated the global
trend during January and February 2020 (Fig. 1A), but the in-
creases in the newly confirmed cases and fatalities in China have
exhibited sharp declines since February (Fig. 1B). In contrast to
the curve flattening in China, those numbers in other countries have
increased sharply since the beginning of March. The epicenter
shifted from Wuhan to Italy in early March and to New York City
(NYC) in early April. By April 30, the numbers of confirmed
COVID-19 cases and deaths, respectively, reached over 200,000
and 27,000 in Italy and over 1,000,000 and 52,000 in the United
States, compared to about 84,000 and 4,600 in China (Fig. 1B).
Notably, the curves in Italy exhibit a slowing trend since mid-April,
while the numbers in the world and the United States continue to
increase. Remarkably, the recent trends in the numbers of infec-
tions and fatalities in the world and in the United States exhibit
striking linearity since the beginning of April (Fig. 1C).
5
00
ConfirmedInfections
(x106)
10
1.0
3.0
2.0 15
A
0.2
0
0.4
0.6
0.8
B
20
25
1.0
Jan. 23 Mar. 19Feb. 20 Apr. 16
2
4
ConfirmedFatalities(104)
6
0
4.0 30
1.2
1.4 8
China
U.S.
Italy
May. 14
C
Apr. 1 Apr. 22Apr. 8 Apr. 15
Date
Apr. 29 May 6
5
0
10
15
20
25
30
0
1.0
3.0
2.0
4.0
World
World
US
ConfirmedInfections
(x106)
ConfirmedInfections
(x106)
ConfirmedFatalities(104)ConfirmedFatalities(104)
Fig. 1. Distinct global trends of the COVID-19 pandemic. (A) Confirmed infections and fatalities worldwide. (B) Comparison of the confirmed infections and
fatalities between China, Italy, and United States. (C) Linear regression of the confirmed infections and fatalities worldwide and in United States from April 1
to May 9, 2020; the linear regression is, respectively, y = 79,398x + 810,167 (R2
= 0.999) for infections and y = 6,075x + 39,409 (R2
= 0.998) for fatalities
worldwide and y = 28,971x + 201,187 (R2
= 0.999) for infections and y = 2,059x + 243 (R2
= 0.995) for fatalities in the United States. The left axis and black color
correspond to the numbers of confirmed infections, and the right axis and red color represent the confirmed fatalities.
14858 | www.pnas.org/cgi/doi/10.1073/pnas.2009637117 Zhang et al.
3. We interpreted the differences in the pandemic trends by
considering the mitigation measures implemented worldwide.
The curve flattening in China can be attributed to extensive
testing, quarantine, and contact tracing; other aggressive mea-
sures implemented in China include lockdown of all cities and
rural areas in the whole country, isolation of residents having
close contact with infected people, and mandated wearing of
face masks in public. However, the effectiveness of those miti-
gation measures has yet to be rigorously evaluated. Differentia-
tion of the effects of those mitigation measures in China is
challenging (19), since the implementation occurred almost si-
multaneously in January 2020. While similar quarantine, iso-
lation, and city lockdown measures were also implemented on
March 9 in Italy after the country became the second epicenter,
the curve of infections has yet to show complete flattening. In the
United States, guidelines for social distancing, quarantine, and
isolation were issued by the federal government on March 16,
and stay-at-home orders were implemented by many state and
local governments starting, for example, on March 19 and April 3
and on March 22 in NYC. The social distancing measures
implemented in the United States include staying at least 6 feet
(∼2 m) away from other people, no gathering in groups, staying
out of crowded places, and avoiding mass gatherings (20). Ob-
viously, the continuous rise in the US infected numbers casts
doubt on the effectiveness of those preventive measures alone
(Fig. 1 B and C).
In contrast to China, wearing of face masks was not mandated
and was unpopular in most of the western world during the early
outbreak of the pandemic. Advice on the use of face masks was
not issued until April 6, 2020 by the WHO (1), claiming that it is
important only to prevent infected persons from viral trans-
mission by filtering out droplets but that it is unimportant to
prevent uninfected persons from breathing virus-bearing aero-
sols. The regions heavily plagued by COVID-19 in northern
Italy, such as Lombard, ordered face covering in public starting
on April 6, and the Italian authorities required nationwide
mandatory use of face masks on May 4. All New Yorkers were
mandated to use face covering in public starting on April 17,
when social distancing was not possible. With measures imple-
mented in the United States seemingly comparable to those in
China, social distancing, quarantine, and isolation exhibited little
impact on stopping the spreading of the disease in the United
States, as reflected by the linearity from April 1 to May 9
(Fig. 1C). It is possible, however, that these measures likely alter
the slope of the infection curve, that is, by reducing the rate of
infections during the early stage of the pandemic (Fig. 1). No-
tably, the recommended physical separation for social distancing
is beneficial to prevent direct contact transmission but is in-
sufficient (without face masks) to protect inhalation of virus-
bearing aerosols (or even small droplets at intermediate prox-
imity), owing to rapid air mixing (7).
Understanding the Impacts of Face Covering
Compared to the simultaneous implementation of measures in
China, intervention measures were successively implemented in
the western world (Fig. 2A), providing an opportunity for
assessing their relative effectiveness. We quantified the effects of
face covering by projecting the number of infections based on the
data prior to implementing the use of face masks in Italy on
April 6 and NYC on April 17 (Fig. 2A; see Methods). Such
projections are reasonable considering the excellent linear cor-
relation for the data prior to the onset of mandated face covering
(Fig. 2 B and C and SI Appendix, Fig. S1). Our analysis indicates
that face covering reduced the number of infections by over
78,000 in Italy from April 6 to May 9 and by over 66,000 in NYC
from April 17 to May 9. In addition, varying the correlation from
15 d to 30 d prior to the onset of the implementation reveals
little difference in the projection for both places, because of the
high correlation coefficients (SI Appendix, Fig. S1). Notably, the
trends of the infection curves in Italy and NYC contrast to those
in the world and in the United States (Fig. 1C), which show little
deviation from the linearity due to the nonimplementation of
face-covering measures globally and nationally, respectively. The
inability of social distancing, quarantine, and isolation alone to
curb the spread of COVID-19 is also evident from the linearity
of the infection curve prior to the onset of the face-covering rule
in Italy on April 6 and in NYC on April 17 (Fig. 2 B and C).
Hence, the difference made by implementing face covering sig-
nificantly shapes the pandemic trends worldwide.
We further compared the numbers of daily new cases between
NYC and the United States (excluding the data in NYC) from
March 1 to May 9 (Fig. 3). The daily numbers of newly con-
firmed infections in NYC and the United States show a sharp
increase in late March and early April. There exists a slower
increase in the number after implementation of the stay-at-home
order (about 14 d in New York and shortly after April 3 in the
United States), which is attributable to the impacts of this
measure. After April 3, the only difference in the regulatory
measures between NYC and the United States lies in face cov-
ering on April 17 in NYC. We applied linear regression to the
data between April 17 and May 9 in NYC and between April 5
and May 9 in the United States. While the daily numbers of
newly confirmed infections fluctuate considerably, the slope of
the regression unambiguously reflects the trend in both data. The
daily new infection in NYC decreases with a slope of 106 cases
per day after April 17, corresponding to a decreasing rate of
∼3% per day (relative to April 17). For comparison, the daily
new infections in the United States (excluding NYC) increase,
with a slope of 70 cases per day after April 4, corresponding to an
increasing rate of ∼0.3% per day (relative to April 5). Hence, the
decreasing rate in the daily new infections in NYC with man-
dated face covering is in sharp contrast to that in the United
States with only social-distancing and stay-at-home measures,
further confirming the importance of face covering in in-
tervening the virus transmission.
Dominant Airborne Transmission
We further elucidated the contribution of airborne transmission to
the COVID-19 outbreak by comparing the trends and mitigation
measures during the pandemic worldwide and by considering the
virus transmission routes (Fig. 4). Face covering prevents both
airborne transmission by blocking atomization and inhalation of
virus-bearing aerosols and contact transmission by blocking viral
shedding of droplets. On the other hand, social distancing, quar-
antine, and isolation, in conjunction with hand sanitizing, mini-
mize contact (direct and indirect) transmission but do not protect
against airborne transmission. With social distancing, quarantine,
and isolation in place worldwide and in the United States since the
beginning of April, airborne transmission represents the only vi-
able route for spreading the disease, when mandated face covering
is not implemented. Similarly, airborne transmission also con-
tributes dominantly to the linear increase in the infection prior to
the onset of mandated face covering in Italy and NYC
(Fig. 2 B and C and SI Appendix, Fig. S1). Hence, the unique
function of face covering to block atomization and inhalation
of virus-bearing aerosols accounts for the significantly reduced
infections in China, Italy, and NYC (Figs. 1–3), indicating that
airborne transmission of COVID-19 represents the dominant
route for infection.
Recent measurements identified SARS-Cov-2 RNA on aerosols
in Wuhan’s hospitals (18) and outdoor in northern Italy (21),
unraveling the likelihood of indoor and outdoor airborne trans-
mission. Within an enclosed environment, virus-bearing aerosols
from human atomization are readily accumulated, and elevated
levels of airborne viruses facilitate transmission from person to
person. Transmission of airborne viruses in open air is subject to
Zhang et al. PNAS | June 30, 2020 | vol. 117 | no. 26 | 14859
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4. dilution, although virus accumulation still occurs due to stagnation
under polluted urban conditions (7, 22). Removal of virus-bearing
particles from human atomization via deposition is strongly size
dependent, with the settling velocities ranging from 2.8 × 10−5
m·s−1
to 1.4 × 10−3
m·s−1
for the sizes of 1 and 10 μm, respectively (7). For
comparison, typical wind velocity is about 1 m·s−1
to 3 m·s−1
indoors
(23) and is ∼1 m·s−1
horizontally and 0.1 m·s−1
vertically in stable air
(7, 22). Under those indoor and outdoor conditions, the residence
time of virus-bearing aerosols reaches hours, due to air mixing (7).
We also examined ambient conditions relevant to the out-
breaks in Wuhan, Italy, and NYC. The initial outbreak of
COVID-19 in Wuhan coincided with the winter haze season in
China (7, 22), during which high levels of PM2.5 were prevalent
in air (SI Appendix, Figs. S2 and S3). On the other hand, the daily
average PM2.5 concentrations were much lower during the
outbreaks in Rome, Italy, and in NYC (SI Appendix, Fig. S2).
The airborne transmission pathways (i.e., indoor or outdoor) as
well as the effects of ambient PM2.5 levels on virus transmission
may be variable among urban cities. For example, the winter
haze conditions in China likely exacerbated outdoor virus
spreading (24, 25), because of low UV radiation, air stagnation
(lacking ventilation on the city scale), and low temperature (7,
22). Also, there may exist a synergetic effect of simultaneous
exposure to the virus and PM2.5 to enhance the infectivity, se-
verity, and fatalities of the disease (14, 26). In addition, nascent
virus-bearing aerosols produced from human atomization likely
undergo transformation in air, including coagulation with am-
bient preexisting PM and/or growth on a time scale of a
few hours in typical urban air (27–29). Such transformation, as
recently documented on coarse PM in Italy (21), may mitigate
Jan. 23 Mar. 19Feb. 6 Feb. 20 Mar. 5 Apr. 2 Apr. 16
0
1
2
Confirmedinfections(in105)
Apr. 30
Wuhan
Italy
NYC
3
Lockdown in Wuhan
Lockdown in Italy
Social distancing in US
Stay-at-home in NYC
4
May. 14
A
B
Confirmedinfections(in105)
0
1
2
3
Mar. 26 Apr. 23 May 7Apr. 9Mar. 12
Confirmedinfections(in105)
Apr. 20 May 4Apr. 6Mar. 23
Date
0
1
2
3C
Italy
NYC y = 4757x + 22522 (R2 = 0.996)
y = 5006x + 4672 (R2 = 0.997)
Fig. 2. The evolving epicenter from Wuhan, to Italy, to NYC. (A) Comparison of the trends and mitigation measures between Wuhan, Italy, and NYC in 2020.
The vertical lines mark the date for implementing mitigation measures. The two black circles label the dates when face covering was implemented: April 6 in
northern Italy and April 17 in NYC. The black dashed lines represent the projection without face covering based on linear regression of 26-d data prior to
implementing this measure. (B) Linear regression of the number of confirmed infections for 26-d data prior to implementing face covering in Italy. The shaded
vertical line denotes the date when face covering was implemented on April 6 in northern Italy. (C) Linear regression of the number of confirmed infections
for 26-d data prior to implementing face covering in NYC. The shaded vertical line denotes the date when face covering was implemented on April 17 in NYC.
In B and C, the circles are reported values, and the dotted line represents fitting and projection of the confirmed infections before and after face-covering,
respectively.
14860 | www.pnas.org/cgi/doi/10.1073/pnas.2009637117 Zhang et al.
5. virus inactivation (9, 12), by providing a medium to preserve its
biological properties and elongating its lifetimes. However, key
questions remain concerning transformation and transmission of
virus-bearing aerosols from human atomization in air. Specifi-
cally, what are the impacts of transformation of human-atomized
aerosols on viral surviving and infectivity in air?
While the humidity effect on viral surviving is uncertain (3, 9), the
conditions during the outbreaks in Wuhan, Rome, and NYC corre-
spond to high RH yet low absolute humidity because of low tem-
perature (SI Appendix, Fig. S3). Early experimental work (9) showed
remarkable survival for the analogous coronavirus MERS-CoV at the
RH level characteristic of the COVID-19 outbreaks in Wuhan,
Rome, and NYC. For comparison, indoor temperature and RH
typically range from 21 °C to 27 °C and 20 to 70%, respectively (23).
Of particular importance are the considerations that render
airborne SARS-CoV-2 the most efficient among all transmission
routes. Even with normal nasal breathing, inhalation of virus-
bearing aerosols results in deep and continuous deposition into
the human respiratory tract, and this transmission route typically
requires a low dose (8). Also, airborne viruses have great mo-
bility and sufficiently long surviving time for dispersion (9, 12),
and residents situated in densely populated environments are
highly vulnerable. In addition, nascent micrometer-size aerosols
produced from coughing/sneezing of infected people have the
potential of containing many viruses, particularly for asymp-
tomatic carriers (16).
Future research is critically needed to assess the transmission,
transformation, and dispersion of virus-bearing aerosols from
human atomization under different environmental conditions, as
well as the related impacts on virus infectivity. It is equally im-
portant to understand human atomization of airborne viruses:
What are the number and size distributions of nascent aerosols
as well as the viral load per particle from coughing/sneezing? It is
also imperative to evaluate human inhalation of airborne viruses:
How are aerosols deposited along the respiratory tract, and what
is the minimum dose of airborne viruses required for infection?
It is also important to evaluate the performance of face masks to
quantify the efficiency to filtrate airborne viruses relevant to
human atomization and inhalation. Elucidation of these mech-
anisms requires an interdisciplinary effort.
A Policy Perspective
The governments’ responses to the COVID pandemic have so
far differed significantly worldwide. Swift actions to the initial
outbreak were undertaken in China, as reflected by nearly si-
multaneous implementation of various aggressive mitigation mea-
sures. On the other hand, the response to the pandemic was
generally slow in the western world, and implementation of the
intervention measures occurred only consecutively. Clearly, the re-
sponsiveness of the mitigation measures governed the evolution,
scope, and magnitude of the pandemic globally (Figs. 1 and 2).
Curbing the COVID-19 relies not only on decisive and sweep-
ing actions but also, critically, on the scientific understanding of
the virus transmission routes, which determines the effectiveness
of the mitigation measures (Fig. 5). In the United States, social
distancing and stay-at-home measures, in conjunction with hand
sanitizing (Fig. 5, path a), were implemented during the early stage
of the pandemic (March 16) (20). These measures minimized
short-range contact transmission but did not prevent long-range
airborne transmission, responsible for the inefficient containing of
the pandemic in the United States (Figs. 1 and 3). Mandated face
covering, such as those implemented in China, Italy, and NYC,
effectively prevented airborne transmission by blocking atomiza-
tion and inhalation of virus-bearing aerosols and contact transmission
by blocking viral shedding of droplets. While the combined face-
covering and social distancing measures offered dual protection
0
4
6
Dailynewconfirmed
cases(in103)
8
NYC
Social
distancing
Stay-at-home Face-covering
A
B
Mar. 1 Apr. 26Mar. 15 Apr. 12
Date
May 10Mar. 29
0
1
Dailynewconfirmed
cases(in104)
2
3
4
2
U.S.
y = 70x + 21207
y = -106x +3304y = -39x + 5078
Social
distancing
Stay-at-home
Fig. 3. Contrasting the trends of new infections between NYC and the
United States. Daily new confirmed infections in (A) NYC and (B) the United
States. The dotted lines represent linear fitting to the data between April 17
and May 9 in NYC and between April 4 and May 9 in the United States. In B,
the number in NYC was subtracted from that in the United States. The
vertical lines label the dates for social distancing, stay-at-home orders, and
mandated face-covering.
Fig. 4. Transmission of COVID-19. Human atomization of viruses arises from coughing or sneezing of an infected person, producing virus-containing droplets
(>5 μm) and aerosols (<5 μm). Virus transmission from person to person occurs through direct/indirect contact and airborne aerosol/droplet routes. Large
droplets mainly settle out of air to cause person/object contamination, while aerosols are efficiently dispersed in air. Direct and airborne transmissions occur in
short range and extended distance/time, respectively. Inhaled airborne viruses deposit directly into the human respiration tract.
Zhang et al. PNAS | June 30, 2020 | vol. 117 | no. 26 | 14861
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6. against the virus transmission routes, the timing and sequence in
implementing the measures also exhibited distinct outcomes during
the pandemic. For example, social distancing measures, including city
lockdown and stay-at-home orders, were implemented well before
face covering was mandated in Italy and NYC (Fig. 5, path b), and
this sequence left an extended window (28 d in Italy and 32 d in
NYC) for largely uninterrupted airborne transmission to spread the
disease (Figs. 2 and 3). The simultaneous implementation of face
covering and social distancing (Fig. 5, path c), such as that undertaken
in China, was most optimal, and this configuration, in conjunction
with extensive testing and contact tracing, was responsible for the
curve flattening in China (Fig. 1). Also, there likely existed remnants
of virus transmission after the implementation of regulatory mea-
sures, because of circumstances when the measures were not practical
or were disobeyed and/or imperfection of the measures. Such limi-
tations, which have been emphasized by the WHO (1), spurred on
controversial views on the validity of wearing face masks to prevent
the virus transmission during the pandemic (30). However, it is im-
plausible that the limitations of mitigation measures alone contrib-
uted dominantly to the global pandemic trend, as exemplified by the
success in China. Our work suggests that the failure in containing the
propagation of COVID-19 pandemic worldwide is largely attributed
to the unrecognized importance of airborne virus transmission (1, 20).
Pandemic
Face-
covering
DropletsAerosols
Airborne
transmission
Contact
transmissionB
Testing &
Contact-tracing
C
A
Social
distancing
Social
distancing
Face-
covering
Social
distancing
Quarantine
& isolation
Quarantine
& isolation
Fig. 5. Mitigation paradigm. Scenarios of virus transmission under the distancing/quarantine/isolation measure only (path a), the measures with distancing/quar-
antine/isolation followed by face covering (path b), and the measures with simultaneous face covering and distancing/quarantine/isolation (path c). The short-dashed
arrows label possible remnants of virus transmission due to circumstances when the measure is not possible or disobeyed and/or imperfection of the measure.
14862 | www.pnas.org/cgi/doi/10.1073/pnas.2009637117 Zhang et al.
7. Conclusions
The inadequate knowledge on virus transmission has inevitably
hindered development of effective mitigation policies and
resulted in unstoppable propagation of the COVID-19 pandemic
(Figs. 1–3). In this work, we show that airborne transmission,
particularly via nascent aerosols from human atomization, is
highly virulent and represents the dominant route for the
transmission of this disease. However, the importance of air-
borne transmission has not been considered in establishment of
mitigation measures by government authorities (1, 20). Specifi-
cally, while the WHO and the US Centers for Disease Control
and Prevention (CDC) have emphasized the prevention of
contact transmission, both WHO and CDC have largely ignored
the importance of the airborne transmission route (1, 20). The
current mitigation measures, such as social distancing, quaran-
tine, and isolation implemented in the United States, are in-
sufficient by themselves in protecting the public. Our analysis
reveals that the difference with and without mandated face
covering represents the determinant in shaping the trends of the
pandemic worldwide. We conclude that wearing of face masks in
public corresponds to the most effective means to prevent
interhuman transmission, and this inexpensive practice, in con-
junction with extensive testing, quarantine, and contact tracking,
poses the most probable fighting opportunity to stop the
COVID-19 pandemic, prior to the development of a vaccine. It is
also important to emphasize that sound science should be ef-
fectively communicated to policy makers and should constitute
the prime foundation in decision-making amid this pandemic.
Implementing policies without a scientific basis could lead to
catastrophic consequences, particularly in light of attempts to
reopen the economy in many countries. Clearly, integration be-
tween science and policy is crucial to formulation of effective
emergency responses by policy makers and preparedness by the
public for the current and future public health pandemics.
Methods
Projection of the pandemic trend without implementing face covering in Italy
and NYC was performed first by establishing the linear correlation between
the infection number and date. We considered the data for both 15 and 30 d
prior to the onset of face covering (SI Appendix, Fig. S1). The slope and the
reported infection number were used for the projections. The avoided in-
fection number due the face covering was determined from the difference
between the projected and reported values on May 9, 2020.
The data for accumulative confirmed infections and fatalities in Wuhan,
Italy, and NYC were taken from the reports by Wuhan Municipal Health
Commission (http://wjw.wuhan.gov.cn/), European CDC (https://www.ecdc.
europa.eu/en), and NYC government (https://www1.nyc.gov/site/doh/covid/
covid-19-data.page), respectively. The data of accumulative confirmed in-
fections and fatalities worldwide were taken from WHO COVID-19 situation
report (https://www.who.int/emergencies/diseases/novel-coronavirus-2019/
situation-reports) (1), and the numbers in China, Italy, and United States
were from taken from European CDC.
Ground-based measurements of PM2.5 and RH in Wuhan were taken from
the China National Environmental Monitoring Centre (http://beijingair.
sinaapp.com/). The PM2.5 data in NYC were taken from US Environmental
Protection Agency (https://www.epa.gov/outdoor-air-quality-data). The
PM2.5 data in Rome were taken were from Centro Regionale della Qualità
dell’aria (http://www.arpalazio.net/main/aria/). The RH data in Rome and
NYC were taken from the 6-hourly interim reanalysis of the European Centre
for Medium-range Weather Forecasts (https://www.ecmwf.int/en/forecasts/
datasets/reanalysis-datasets/era5).
We used spaceborne measurements of aerosol optical depth (AOD) to
characterize the regional aerosol pollution during the COVID-19 outbreak
(January 23 to February 10, 2020) in China. The green band AODs at 0.55 μm
are available from Terra and Aqua combined Moderate Resolution Imaging
Spectroradiometer Version 6 Multiangle Implementation of Atmospheric
Correction (https://lpdaac.usgs.gov/products/mcd19a2v006/). The Level-2
product has daily global coverage with 1-km pixel resolution. The AOD re-
trieval is only available for the clear sky.
Data Availability. All data relevant to this research are available in the main
text and SI Appendix.
ACKNOWLEDGMENTS. This work was supported by the Robert A. Welch
Foundation (Grant A-1417). A.L.Z. acknowledges the support of a fellowship
from the Robert A. Welch Foundation. We are grateful to Fang Zhang for
the PM2.5 data in Wuhan, China.
1. World Health Organization, Coronavirus disease (COVID-2019) situation reports. https://www.
who.int/emergencies/diseases/novel-coronavirus-2019/situation-reports/. Accessed 9 May 2020.
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Zhang et al. PNAS | June 30, 2020 | vol. 117 | no. 26 | 14863
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