scholarly journals Effects of Demographic and Weather Parameters on COVID-19 Basic Reproduction Number

2021 ◽  
Vol 8 ◽  
Author(s):  
Igor Salom ◽  
Andjela Rodic ◽  
Ognjen Milicevic ◽  
Dusan Zigic ◽  
Magdalena Djordjevic ◽  
...  

It is hard to overstate the importance of a timely prediction of the COVID-19 pandemic progression. Yet, this is not possible without a comprehensive understanding of environmental factors that may affect the infection transmissibility. Studies addressing parameters that may influence COVID-19 progression relied on either the total numbers of detected cases and similar proxies (which are highly sensitive to the testing capacity, levels of introduced social distancing measures, etc.), and/or a small number of analyzed factors, including analysis of regions that display a narrow range of these parameters. We here apply a novel approach, exploiting widespread growth regimes in COVID-19 detected case counts. By applying nonlinear dynamics methods to the exponential regime, we extract basic reproductive number R0 (i.e., the measure of COVID-19 inherent biological transmissibility), applying to the completely naïve population in the absence of social distancing, for 118 different countries. We then use bioinformatics methods to systematically collect data on a large number of potentially interesting demographics and weather parameters for these countries (where data was available), and seek their correlations with the rate of COVID-19 spread. While some of the already reported or assumed tendencies (e.g., negative correlation of transmissibility with temperature and humidity, significant correlation with UV, generally positive correlation with pollution levels) are also confirmed by our analysis, we report a number of both novel results and those that help settle existing disputes: the absence of dependence on wind speed and air pressure, negative correlation with precipitation; significant positive correlation with society development level (human development index) irrespective of testing policies, and percent of the urban population, but absence of correlation with population density per se. We find a strong positive correlation of transmissibility on alcohol consumption, and the absence of correlation on refugee numbers, contrary to some widespread beliefs. Significant tendencies with health-related factors are reported, including a detailed analysis of the blood type group showing consistent tendencies on Rh factor, and a strong positive correlation of transmissibility with cholesterol levels. Detailed comparisons of obtained results with previous findings, and limitations of our approach, are also provided.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hamid Khataee ◽  
Istvan Scheuring ◽  
Andras Czirok ◽  
Zoltan Neufeld

AbstractA better understanding of how the COVID-19 pandemic responds to social distancing efforts is required for the control of future outbreaks and to calibrate partial lock-downs. We present quantitative relationships between key parameters characterizing the COVID-19 epidemiology and social distancing efforts of nine selected European countries. Epidemiological parameters were extracted from the number of daily deaths data, while mitigation efforts are estimated from mobile phone tracking data. The decrease of the basic reproductive number ($$R_0$$ R 0 ) as well as the duration of the initial exponential expansion phase of the epidemic strongly correlates with the magnitude of mobility reduction. Utilizing these relationships we decipher the relative impact of the timing and the extent of social distancing on the total death burden of the pandemic.


2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Gang Lin ◽  
Jingying Fu ◽  
Dong Jiang ◽  
Jianhua Wang ◽  
Qiao Wang ◽  
...  

Epidemiological studies around the world have reported that fine particulate matter (PM2.5) is closely associated with human health. The distribution of PM2.5concentrations is influenced by multiple geographic and socioeconomic factors. Using a remote-sensing-derived PM2.5dataset, this paper explores the relationship between PM2.5concentrations and meteorological parameters and their spatial variance in China for the period 2001–2010. The spatial variations of the relationships between the annual average PM2.5, the annual average precipitation (AAP), and the annual average temperature (AAT) were evaluated using the Geographically Weighted Regression (GWR) model. The results indicated that PM2.5had a strong and stable correlation with meteorological parameters. In particular, PM2.5had a negative correlation with precipitation and a positive correlation with temperature. In addition, the relationship between the variables changed over space, and the strong negative correlation between PM2.5and the AAP mainly appeared in the warm temperate semihumid region and northern subtropical humid region in 2001 and 2010, with some localized differences. The strong positive correlation between the PM2.5and the AAT mainly occurred in the mid-temperate semiarid region, the humid, semihumid, and semiarid warm temperate regions, and the northern subtropical humid region in 2001 and 2010.


2018 ◽  
Vol 15 (2) ◽  
pp. 207-214
Author(s):  
I Hossain ◽  
MMH Khan ◽  
SMH Jahan

The study was conducted to know the reproductive performance of spiralling whitefly on guava. Number of colony, eggs, 1st instar, 2nd instar, 3rd instar and 4th instar nymphs per five leaves ranged from 6 to 15, 8 to 32, 0 to 44, 0 to 22, 0 to 45 and 0 to 28, respectively. Maximum number of adults and nymphs were found in the month of January. Highest longevity of Aleurodicus dispersus (21.5 days) was recorded in adult while the lowest was in 2nd instar nymph (6.4 days). The number of colony/leaf and number of 3rd and 4th instar nymphs of A. dispersus had significant positive correlation with minimum and maximum temperature while non-significant positive correlation is observed between the number of egg/colony, the number 1st and 2nd instar nymphs with minimum and maximum temperature. A. dispersus showed nonsignificant positive correlation with minimum and maximum relative humidity regarding number of colony/leaf, 2nd instar nymph while nonsignificant negative correlation with 4th instar nymph.SAARC J. Agri., 15(2): 207-214 (2017)


2020 ◽  
pp. 126-126
Author(s):  
Milovan Stojanovic ◽  
Marina Deljanin-Ilic ◽  
Stevan Ilic ◽  
Dejan Petrovic ◽  
Bojan Ilic

Background / Aim. Well-organized cardiovascular rehabilitation (CVR) reduces cardiovascular burden by influencing cardiovascular risk factors, improving the quality of life and reducing mortality and hospital readmission. However, its effects on hemodynamic status are largely unknown. The aim of our study was to evaluate the influence of three-week CVR program on hemodynamic status and to investigate if there is a correlation between physical strain tolerance and hemodynamic parameters measured by impedance cardiography (ICG) before and after CVR program in patients with coronary artery disease. Methods. Fifty-two patients attended a three-week CVR program. At the beginning and at the end of rehabilitation program laboratory tests, exercise stress tests (EST) and ICG measurements were taken. Results. Patients showed better strain tolerance on the second exercise stress test (EST2) by achieving higher strain level (Z=2,315; p=0,021) and longer duration of test (Z=2,305; p=0,021). There was a strong positive correlation between the level of EST2 and cardiac output (CO) (r=0,538; p<0,001) and stroke volume (SV) (r=0,380; p=0,017) on the second ICG (ICG2). Also, there was a strong negative correlation between EST2 level and systemic vascular resistance (SVR) (r=-0,472; p=0,002) and SVR index (SSVRI) (r=-0,407; p=0,010) on ICG2. There was a strong positive correlation between EST2 duration and CO (r=0.517; p=0.001) as well as between EST2 duration and SV (r=0.340; p=0.034), and a strong negative correlation between EST2 duration and SVR (r=-0.504; p=0.001) as well as between EST2 duration and SVRI (r=-0.448; p=0.004), according to ICG2. Conclusion. Our study showed that a well-designed CVR program can lead to better physical strain tolerance. Furthermore, CVR led to a significant positive correlation between EST and cardiac output as well as between EST and stroke volume measured by ICG. On the other hand, there was a significant negative correlation between EST and vascular related parameters according to ICG at the end of the CVR program.


2020 ◽  
Vol 3 (3) ◽  
pp. 315-328
Author(s):  
Herbert Mapira Tendayi ◽  
Jerome Ndayisenga ◽  
Solange Nyiramahirwe ◽  
Jacqueline Mukanshuti ◽  
Valens Karenzi ◽  
...  

Background Infertility remains a highly prevalent global condition in the second decade of the new millennium. Reproductive hormones determine sperm quality as they initiate and maintain spermatogenesis. Hormonal imbalance can cause abnormal sperm quality that can be treated by hormonal replacement therapy. Objective To assess the relationship between sperm quality and male reproductive hormones among male partners with fertility complications attending CHUB. Methods The study was a descriptive cross-sectional, and a convenient sampling strategy was used to recruit subjects at CHUB. Sixty-two male subjects with fertility complications provided both semen and blood sample to analyze sperm quality and reproductive hormones. Descriptive statistics were used to analyze data. Results Both FSH and LH showed a strong negative correlation with sperm count which is more profound with FSH (r= -0.722) than LH (r= -0.545). Testosterone showed a strong positive correlation with sperm count (r= 0.712). FSH and LH showed a negative correlation with sperm motility which is more profound in FSH (r= -0.312) than LH (r= -0.302). Testosterone also showed a positive correlation with sperm motility (r= 0.360). Conclusion Our study found a correlation between sperm quality and male reproductive hormones. We further suggest other studies to investigate predictive power of male reproductive hormones. Rwanda J Med Health Sci 2020;3(3):315-328


2021 ◽  
Author(s):  
Anthony R Green ◽  
Daniel Keep ◽  
Ian Piper

The outbreak of the pandemic disease, COVID-19, has shown that the approaches by different countries has resulted in a range of infection rates through their societies. This has arisen from the varying personal behaviour and tactical use of lockdown strategies within each country. We report the use of microsimulation of a simulated community in Australia, using a discrete infection model within a community of residences, places of work and recreation to demonstrate the applicability of this method to both the current pandemic and to infection more generally. Simulations without any societal intervention on infection spread provided base simulations that could be compared with social and societal controls in the future and which were compared with the initial doubling times of country outbreaks across the world. Different population sizes were represented in some simulations and in other simulations the effects of either social distancing or the use of facial masks as personal behaviours was investigated within the community. Good agreement is found between the initial doubling times for several countries and the simulations that suggests that modelling infection as a collection of individual infections provides an alternative to current epidemiological models. The variation of the basic reproductive number, R0, with time and population size, suggests that one of the fundamentals assumptions in SIR type models is wrong, but varies according to the properties of the population being modelled. Investigation of the infection spread shows that the number of super-spreaders varies with the size of the population and occurs through contacts in clubs, supermarkets, schools and theatres where the source of infection is an employee and where there are high numbers of contacts. The simulations of individual control show that the benefits of social distancing or wearing masks is only fully realised where there is considerable compliance within society to these measures.


Author(s):  
Hamid Khataee ◽  
Istvan Scheuring ◽  
Andras Czirok ◽  
Zoltan Neufeld

AbstractA better understanding of how the COVID-19 epidemic responds to social distancing efforts is required for the control of future outbreaks and to calibrate partial lock-downs. We present quantitative relationships between key parameters characterizing the COVID-19 epidemiology and social distancing efforts of nine selected European countries. Epidemiological parameters were extracted from the number of daily deaths data, while mitigation efforts are estimated from mobile phone tracking data. The decrease of the basic reproductive number (R0) as well as the duration of the initial exponential expansion phase of the epidemic strongly correlates with the magnitude of mobility reduction. Utilizing these relationships we decipher the relative impact of the timing and the extent of social distancing on the total death burden of the epidemic.


Author(s):  
J. Karzis ◽  
E.F. Donkin ◽  
I.M. Petzer

The length of the antibiotic withdrawal period after intramammary treatment was influenced by the milk yield of dairy goats during this trial. Shorter withdrawal periods were seen in relatively high yielding dairy goats (production above 1.5 ℓ per day) compared to low producers (less than 1.3 ℓ per day). High yielding goats treated with Curaclox LC (Norbrook [Pharmacia AH]) had a withdrawal period of 42 h, while low yielding goats, treated with the same product, had a withdrawal period of 74 h. The recommended withdrawal period for Curaclox LC for use in cattle is 72 h. Relatively high yielding goats treated with Rilexine 200 LC (Logos Agvet [Virbac]) had a significantly shorter withdrawal period (37 h) than that recommended for use in cattle (96 h). Low yielding goats treated with Spectrazol Milking Cow (Schering-Plough Animal Health) had a significantly longer (95 h) withdrawal period than that recommended for use in cattle (60 h). Withdrawal periods were also influenced by stage of lactation and parity. There was a moderate positive correlation between lactation number and withdrawal period, as measured by TRIS (R2 = 0.621), and a moderate negative correlation between stage of lactation and withdrawal period (R2 = -0.669). In Trials 1, 2 and 3 combined there was a moderate negative correlation between withdrawal period and volume (R2 = -0.511) and a strong positive correlation between withdrawal period and lactation number (R2 = 0.720). The differences in percentage milk fat, protein and lactose before, during and after treatment were not statistically significant except in Trial 3 (Curaclox LC and Rilexine 200 LC) where protein and lactose differed significantly. In Trial 2 (Spectrazol Milking Cow) milk fat percentages differed significantly between treatment and control groups as did protein percentages in Trial 3. These differences are however, not biologically meaningful.


Author(s):  
Hao Lei ◽  
Xifeng Wu ◽  
Xiao Wang ◽  
Modi Xu ◽  
Yu Xie ◽  
...  

Abstract Background Nonpharmaceutical interventions (NPIs) against coronavirus disease 2019 (COVID-19) are vital to reducing transmission risks. However, the relative efficiency of social distancing against COVID-19 remains controversial, since social distancing and isolation/quarantine were implemented almost at the same time in China. Methods In this study, surveillance data of COVID-19 and seasonal influenza in 2018–2020 were used to quantify the relative efficiency of NPIs against COVID-19 in China, since isolation/quarantine was not used for the influenza epidemics. Given that the relative age-dependent susceptibility to influenza and COVID-19 may vary, an age-structured susceptible/infected/recovered model was built to explore the efficiency of social distancing against COVID-19 under different population susceptibility scenarios. Results The mean effective reproductive number, Rt, of COVID-19 before NPIs was 2.12 (95% confidence interval [CI], 2.02–2.21). By 11 March 2020, the overall reduction in Rt of COVID-19 was 66.1% (95% CI, 60.1–71.2%). In the epidemiological year 2019–20, influenza transmissibility was reduced by 34.6% (95% CI, 31.3–38.2%) compared with transmissibility in epidemiological year 2018–19. Under the observed contact pattern changes in China, social distancing had similar efficiency against COVID-19 in 3 different scenarios. By assuming the same efficiency of social distancing against seasonal influenza and COVID-19 transmission, isolation/quarantine and social distancing could lead to 48.1% (95% CI, 35.4–58.1%) and 34.6% (95% CI, 31.3–38.2%) reductions of the transmissibility of COVID-19, respectively. Conclusions Though isolation/quarantine is more effective than social distancing, given that the typical basic reproductive number of COVID-19 is 2–3, isolation/quarantine alone could not contain the COVID-19 pandemic effectively in China.


2017 ◽  
Vol 10 ◽  
pp. 117862211772078 ◽  
Author(s):  
Biman Gati Gupta ◽  
Jayanta Kumar Biswas ◽  
Krishna M Agrawal

Hazardous bleaching and dyeing units are rapidly increasing in developing countries due to growing global demand of textile products. The aim of the study is to assess long-term respiratory effect of air pollution generated from textile bleaching and dyeing industries on the residents living in such industrial setting. Such types of long-term (2012-2016) studies have been conducted first time in this area. The control area of Chatta and Kalikapur under Maheshtala textile cluster (10.45°N latitude to 75.90°E longitude) has been identified for the study. Ambient air monitoring with particulate matters (PMs; PM2.5 and PM10), NO2, and SO2 of 72 air samples has been done with air sampler machine during different seasons. The concentrations of PM2.5 and PM10 have been found higher than Central Pollution Control Board (India) and World Health Organization norms. Using data on 73 respondents on age, education, occupation, and income, impact on different causes of respiratory ailments has been examined. The survey shows that 67% of total population are having different respiratory complaints. The regression analysis ( R2 = 0.9998) and correlation matrix show that cold, cough, bronchitis, asthma, and chronic obstructive pulmonary disease (COPD) have a strongly significant positive correlation with fever ( r = 0.98, P < 0.05); breathing trouble has a significant strong positive correlation with cold, cough, bronchitis, asthma, COPD, and fever ( r = 0.877, P < 0.05); high blood pressure has a negative correlation with cold and fever ( r = −0.655, P < 0.05); cardiovascular problem has a strong positive correlation with high blood pressure ( r = 0.989, P < 0.05) and strong negative correlation with cold, cough, asthma, bronchitis, and cold-related fever ( r = −0.54, P < 0.05) due to PM2.5 and PM10 concentration. About 56% of villagers who have opted for this occupation have school-level education (class I-IV) with annual income of Rs 60 000 ($870) only. Studies express present scenario of air pollution in the subject area which is still unnoticed and propose to take control of air pollution.


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