scholarly journals Quantitative analysis and mathematic modeling of the global outbreak of COVID-19

2020 ◽  
Vol 14 (10) ◽  
pp. 1106-1110
Author(s):  
Yanyan Jiang ◽  
Xuefeng Jiang ◽  
Wenjun Tong ◽  
Jingming Zhou

The coronavirus pandemic is the biggest in the past 100 years, affected over 200 countries and killed over 300 thousand people. To better understand the epidemics in different areas, the progress percentage was generated in this study by dividing everyday total confirmed case number by the up-to-date total case number, so data obtained from different countries and territories can be put together and compared directly regardless of the large difference in the magnitude of numbers. The global outbreak data were analyzed and categorized into 4 groups based on different epidemic curve stages. The grouping pattern suggests that the geographical position may not play a critical role in the progress of COVID-19 epidemic. In this report, we also used a mathematic model to predict the progress of COVID-19 outbreak in UK, USA and Canada in Group 3, providing valuable information for assessing the risk in these countries and the timing of reopening business.

Author(s):  
John T. Armstrong

One of the most cited papers in the geological sciences has been that of Albee and Bence on the use of empirical " α -factors" to correct quantitative electron microprobe data. During the past 25 years this method has remained the most commonly used correction for geological samples, despite the facts that few investigators have actually determined empirical α-factors, but instead employ tables of calculated α-factors using one of the conventional "ZAF" correction programs; a number of investigators have shown that the assumption that an α-factor is constant in binary systems where there are large matrix corrections is incorrect (e.g, 2-3); and the procedure’s desirability in terms of program size and computational speed is much less important today because of developments in computing capabilities. The question thus exists whether it is time to honorably retire the Bence-Albee procedure and turn to more modern, robust correction methods. This paper proposes that, although it is perhaps time to retire the original Bence-Albee procedure, it should be replaced by a similar method based on compositiondependent polynomial α-factor expressions.


Author(s):  
S. R. Singh ◽  
H. J. Fan ◽  
L. D. Marks

Since the original observation that the surfaces of materials undergo radiation damage in the electron microscope similar to that observed by more conventional surface science techniques there has been substantial interest in understanding these phenomena in more detail; for a review see. For instance, surface damage in a microscope mimics damage in the space environment due to the solar wind and electron beam lithographic operations.However, purely qualitative experiments that have been done in the past are inadequate. In addition, many experiments performed in conventional microscopes may be inaccurate. What is needed is careful quantitative analysis including comparisons of the behavior in UHV versus that in a conventional microscope. In this paper we will present results of quantitative analysis which clearly demonstrate that the phenomena of importance are diffusion controlled; more detailed presentations of the data have been published elsewhere.As an illustration of the results, Figure 1 shows a plot of the shrinkage of a single, roughly spherical particle of WO3 versus time (dose) driven by oxygen desorption from the surface.


2021 ◽  
Vol 14 (6) ◽  
pp. 587
Author(s):  
Zhaoyu Chen ◽  
Qinghua Cui ◽  
Michael Caffrey ◽  
Lijun Rong ◽  
Ruikun Du

Hemagglutinin (HA) plays a critical role during influenza virus receptor binding and subsequent membrane fusion process, thus HA has become a promising drug target. For the past several decades, we and other researchers have discovered a series of HA inhibitors mainly targeting its fusion machinery. In this review, we summarize the advances in HA-targeted development of small molecule inhibitors. Moreover, we discuss the structural basis and mode of action of these inhibitors, and speculate upon future directions toward more potent inhibitors of membrane fusion and potential anti-influenza drugs.


Author(s):  
Lauren Stewart ◽  
Katharina von Kriegstein ◽  
Simone Dalla Bella ◽  
Jason D. Warren ◽  
Timothy D. Griffiths

This article presents an overview of case studies of acquired disorders of musical listening. Like any cognitive faculty, music is multifaceted, and the identification of the neural basis of any complex faculty must proceed, hand in hand, with an elucidation of its cognitive architecture. The past decade has seen an evolution in the theoretical models of musical processing, allowing the development of theoretically motivated instruments for the systematic evaluation of musical disorders. Such developments have allowed reports of musical disorders to evolve from historical anecdotes to systematic, verifiable accounts that can play a critical role in contributing to our understanding of the cognitive neuroscience of music.


Author(s):  
Stephen C Frederickson ◽  
Mark D Steinmiller ◽  
Tiffany Rae Blaylock ◽  
Mike E Wisnieski II ◽  
James D Malley ◽  
...  

Over the past 2 decades, zebrafish, Danio rerio, have become a mainstream laboratory animal model, yet zebrafish husbandrypractices remain far from standardized. Feeding protocols play a critical role in the health, wellbeing, and productivity ofzebrafish laboratories, yet they vary significantly between facilities. In this study, we compared our current feeding protocol for juvenile zebrafish (30 dpf to 75 dpf), a 3:1mixture of fish flake and freeze-dried krill fed twice per day with live artemia twice per day (FKA), to a diet of Gemma Micro 300 fed once per day with live artemia once per day (GMA). Our results showed that juvenile EK wild-type zebrafish fed GMA were longer and heavier than juveniles fed FKA. As compared with FKA-fed juveniles, fish fed GMA as juveniles showed better reproductive performance as measured by spawning success, fertilization rate, and clutch size. As adults, fish from both feeding protocols were acclimated to our standard adult feeding protocol, and the long-term effects of juvenile diet were assessed. At 2 y of age, the groups showed no difference in mortality or fecundity. Reproductive performance is a crucial aspect of zebrafish research, as much of the research focuses on the developing embryo. Here we show that switching juvenile zebrafish from a mixture of flake and krill to Gemma Micro 300 improves reproductive performance, even with fewer feedings of live artemia, thus simplifying husbandry practices.


2021 ◽  
Author(s):  
Qing Wei ◽  
Xun Chen ◽  
Jing Liu ◽  
Yan Li ◽  
Guangmin Nong

Abstract Backgroud The studies in the immnue associated diffuse alveolar hemorrahge (DAH) animal models showed that monocytes/macrophages played an critical role in the pathogenesis.Whether monocytes/macrophages contribute to the pathogenesis of immune associated DAH in human is still unknow. The aim of this study was to explore the role of monocytes/macrophages in the pathogenesis of immune associated DAH in human.Methods This study was conducted in two parts. In the first part, 37 children with immune associated DAH were included (DAH group), and 18 healthy children were recruited as the controls (HC group). Peripheral blood monocyte subtype was analyzed using flow cytometry. In the second part, 24 children with immune associated DAH were included (DAH group), and 13 children with acute airway foreingn body or mild benign airway stenosis were included as the controls (HC group). Bronochoalveolar lavage fluid (BALF) was collected using bronchoscope. Cytokines in the BALF supernatant were detected using cytometric bread array. BALF supertanant was used to stimulated the macrophages in vitro. The mRNA relative expressions of IL-1β, TNFα, IL-6, TGM2, CD163 and MRC1 were detected using quantitative real-time PCR, and the expressions of CD14, CD80, CD86, CD163 and CD206 were detected using flow cytometry. Results 1. The percentage of classical monocyte was significantly increased, whereas the percentages of intermediate and non-classical monocyte were significantly decreased in the DAH group, when compared to those in the HC group. 2. The levels of MCP-1, IL-6 and IL-8 were all significantly higher in the BALF supernatant from the DAH group, when compared to those form the HC group. 3. The mRNA relative expressions of IL-1β and IL-6 as well as the expression of CD86 were significantly higher, whereas the mRNA relative expression of MRC1 as well as the expressions of CD163 and CD206 were significantly lower under the stimulation of BALF supernatant from the DAH group, when compared to that from the HC group. Conclusions Monocytes/macrophages might participate in the pathogenesis of immune associated DAH in human by enhanced M1 polarization.


Open Biology ◽  
2014 ◽  
Vol 4 (2) ◽  
pp. 130217 ◽  
Author(s):  
Puneet Sharma ◽  
Alo Nag

The ability of cullin 4A (CUL4A), a scaffold protein, to recruit a repertoire of substrate adaptors allows it to assemble into distinct E3 ligase complexes to mediate turnover of key regulatory proteins. In the past decade, a considerable wealth of information has been generated regarding its biology, regulation, assembly, molecular architecture and novel functions. Importantly, unravelling of its association with multiple tumours and modulation by viral proteins establishes it as one of the key proteins that may play an important role in cellular transformation. Considering the role of its substrate in regulating the cell cycle and maintenance of genomic stability, understanding the detailed aspects of these processes will have significant consequences for the treatment of cancer and related diseases. This review is an effort to provide a broad overview of this multifaceted ubiquitin ligase and addresses its critical role in regulation of important biological processes. More importantly, its tremendous potential to be exploited for therapeutic purposes has been discussed.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Rick Nishimura

Diastolic dysfunction plays a critical role in the pathophysiology of producing signs and symptoms of heart failure. Heart failure with a normal ejection fraction (HFnlEF) is one of the leading causes of hospital admissions today and is associated with significant morbidity and mortality. It is thus important to understand the pathophysiology of diastolic dysfunction, which itself is a complex series of multiple interrelated events, including relaxation, suction, ventricular interaction, ventricular arterial coupling, pericardial restraint, and myocardial viscoelastic forces. It was difficult for the clinician to understand “diastology” in the past. Initial studies were limited to complex equations derived from animal models and were difficult to apply to patient care. The development of radionuclide angiography and Doppler echocardiography allowed noninvasive rapid assessment of volumetric filling and flow velocity curves, which began to provide insight into the complex process of diastolic filling for the clinician. As our understanding of diastology evolved over the past 2 decades, it has become clear that we now need to pursue new areas to understand this fascinating subject and apply it to patient care. These areas include the underlying mechanism HFnlEF (ventricular-vascular coupling versus true myocardial stiffness), relationship of rest versus exercise hemodynamics, and the complex ventricular fiber “twisting and shortening” of both contraction and relaxation.


2021 ◽  
Author(s):  
Dayana Benny

BACKGROUND Turin, a province in the Piedmont region sees second highest new COVID-19 infections in Northern part of Italy as of March 31, 2021. During the first wave of pandemic, many restrictive measures were introduced in this province. There are many studies that conducted time series analysis of various regions in Italy, but studies that are analysing the data in province level are limited. Also, no applications of Cross Correlation Function(CCF) have been proposed to analyse relationships between COVID-19 new cases and community mobility at the provincial level in Italy. OBJECTIVE The goal of this time series analysis is to find how the restrictive measures in Turin province, Italy impacted community mobility and helped in flattening the epidemic curve during the first wave of the pandemic. METHODS A simple time series analysis is conducted in this study to analyse whether there is an association between COVID-19 daily cases and community mobility. In this study, we analysed whether the time series of the parameter that estimates the reproduction of infection in the outbreak is related to the past lags of community mobility time series by performing cross-correlation analysis. RESULTS Multiple regression is carried out in which the R0 variable is a linear function of past lags 6, 7, 8, and 1 of the community mobility variable and all coefficients are statistically significant where P = 0.024043, 2.69e-05, 0.045350 and 0.000117 respectively. The cross-correlation between data fitted from the significant past lags of community mobility and transformed basic reproduction number (R0) time-series is obtained in such a manner that the R0 of a day is related to the past lags of community mobility in Turin province. CONCLUSIONS Our analysis shows that the restrictive measures are having an impact on community mobility during the first wave of COVID-19 and it can be related to the reported secondary cases of COVID-19 in Turin province at that time. Through further improvement, this simple model could serve as preliminary research for developing right preventive methods during the early stages of an epidemic.


2021 ◽  
Author(s):  
Dayana Benny

BACKGROUND Turin, a province in the Piedmont region sees second highest new COVID-19 infections in Northern part of Italy as of March 31, 2021. During the first wave of pandemic, many restrictive measures were introduced in this province. There are many studies that conducted time series analysis of various regions in Italy, but studies that are analysing the data in province level are limited. Also, no applications of Cross Correlation Function(CCF) have been proposed to analyse relationships between COVID-19 new cases and community mobility at the provincial level in Italy. OBJECTIVE The goal of this time series analysis is to find how the restrictive measures in Turin province, Italy impacted community mobility and helped in flattening the epidemic curve during the first wave of the pandemic. METHODS A simple time series analysis is conducted in this study to analyse whether there is an association between COVID-19 daily cases and community mobility. In this study, we analysed whether the time series of the parameter that estimates the reproduction of infection in the outbreak is related to the past lags of community mobility time series by performing cross-correlation analysis. RESULTS Multiple regression is carried out in which the R0 variable is a linear function of past lags 6, 7, 8, and 1 of the community mobility variable and all coefficients are statistically significant where P = 0.024043, 2.69e-05, 0.045350 and 0.000117 respectively. The cross-correlation between data fitted from the significant past lags of community mobility and transformed basic reproduction number (R0) time-series is obtained in such a manner that the R0 of a day is related to the past lags of community mobility in Turin province. CONCLUSIONS Our analysis shows that the restrictive measures are having an impact on community mobility during the first wave of COVID-19 and it can be related to the reported secondary cases of COVID-19 in Turin province at that time. Through further improvement, this simple model could serve as preliminary research for developing right preventive methods during the early stages of an epidemic.


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