Inverse Problem for Identification of Infectivity and Recovery Rates in SIR Epidemic Models as Functions of Time Illustrated  with Corona Virus Dynamics  up to July 09, 2020

2020 ◽  
Author(s):  
Tchavdar Marinov ◽  
Rossitza Marinova
Keyword(s):  
Inverse Problem ◽  
United States Of America ◽  
Real Data ◽  
The United States ◽  
Sir Model ◽  
Recovery Rates ◽  
Sir Epidemic ◽  
Term Evolution ◽  
Sir Epidemic Models

Abstract This work deals with the inverse problem in epidemiology based on a SIR model with time-dependent infectivity and recovery rates, allowing for a better prediction of the long term evolution of a pandemic. The method is used for investigating the COVID-19 spread by first solving an inverse problem for estimating the infectivity and recovery rates from real data. Then, the estimated rates are used to compute the evolution of the disease. The time-depended parameters are estimated for the World and several countries (The United States of America, Canada, Italy, France, Germany, Sweden, Russia, Brazil, Bulgaria, Japan, South Korea, New Zealand) and used for investigating the COVID-19 spread in these countries.

scholarly journals An adaptive social distancing SIR model for COVID-19 disease spreading and forecasting

2021 ◽  
Vol 10 (s1) ◽  
Author(s):  
Said Gounane ◽  
Yassir Barkouch ◽  
Abdelghafour Atlas ◽  
Mostafa Bendahmane ◽  
Fahd Karami ◽  
...  
Keyword(s):  
Mathematical Theory ◽  
Real Data ◽  
Sir Model ◽  
Epidemic Threshold ◽  
Social Distancing ◽  
Sir Epidemic ◽  
Proposed Model ◽  
Disease Spreading ◽  
The Government ◽  
The Impact

Abstract Recently, various mathematical models have been proposed to model COVID-19 outbreak. These models are an effective tool to study the mechanisms of coronavirus spreading and to predict the future course of COVID-19 disease. They are also used to evaluate strategies to control this pandemic. Generally, SIR compartmental models are appropriate for understanding and predicting the dynamics of infectious diseases like COVID-19. The classical SIR model is initially introduced by Kermack and McKendrick (cf. (Anderson, R. M. 1991. “Discussion: the Kermack–McKendrick Epidemic Threshold Theorem.” Bulletin of Mathematical Biology 53 (1): 3–32; Kermack, W. O., and A. G. McKendrick. 1927. “A Contribution to the Mathematical Theory of Epidemics.” Proceedings of the Royal Society 115 (772): 700–21)) to describe the evolution of the susceptible, infected and recovered compartment. Focused on the impact of public policies designed to contain this pandemic, we develop a new nonlinear SIR epidemic problem modeling the spreading of coronavirus under the effect of a social distancing induced by the government measures to stop coronavirus spreading. To find the parameters adopted for each country (for e.g. Germany, Spain, Italy, France, Algeria and Morocco) we fit the proposed model with respect to the actual real data. We also evaluate the government measures in each country with respect to the evolution of the pandemic. Our numerical simulations can be used to provide an effective tool for predicting the spread of the disease.

scholarly journals PCV25 MANAGEMENT OF ACUTE ISCHEMIC STROKE AND ITS LONG TERM EVOLUTION IN THE UNITED STATES AND CANADA

2011 ◽  
Vol 14 (3) ◽  
pp. A36
Author(s):  
A. Rouleau ◽  
V. Gobaux ◽  
C. Guilhaume ◽  
A. Yiou ◽  
D. Milea
Keyword(s):  
United States ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
The United States ◽  
Long Term Evolution ◽  
Term Evolution

scholarly journals Biosynthesis of metal nanoparticles and metal oxidesand their use as components of fertilizers and preparations for plant growing (literature review)

2021 ◽  
Vol 22 (5) ◽  
pp. 627-640
Author(s):  
G. Yu. Rabinovich ◽  
N. A. Lyubimova
Keyword(s):  
Metal Nanoparticles ◽  
Plant Extracts ◽  
United States Of America ◽  
The United States ◽  
Nanometer Scale ◽  
Agricultural Crops ◽  
Biochemical Processes ◽  
China And India ◽  
Positive Effect

A promising direction in agriculture is the use of metal nanoparticles as nanofertilizers, which can increase the yield of agricultural crops and, at the same time, minimize the frequency of fertilization due to the long-term release of nutrients. One of the environmentally safest and cheapest methods of synthesizing metal nanoparticles is biosynthesis using plant extracts. During the redox reaction, proteins, carbohydrates, organic acids, phenols and other metabolites are able to transfer electrons to metal cations, restoring their charge to zero on the nanometer scale. This article, based on publications on the issue under study by authors from the United States of America, Europe and the Middle East, China and India, describes the biosynthesis of nanoparticles of zinc oxide, copper and copper oxide, iron and iron oxide, as well as manganese and manganese oxide using the formation of plant extracts, and data on the use of these metals and their oxides as nanofertilizers and preparations for plant growing are presented. It has been shown that the use of metal nanoparticles and their oxides as fertilizers is more effective than conventional compounds used as fertilizers. This is probably due to the fact that it is easier for nanoparticles to penetrate through the plant membrane, as well as to pass into a form accessible to plants in comparison with conventional analogs. The positive effect of the influence of nanoparticles on plants is expressed in the elongation of the roots and shoots of model plants and an increase in the biomass of seedlings. In addition, the amount of chlorophyll in the leaves increases, and some biochemical processes also change, for example, the amount of antioxidant enzymes increases, which makes it possible to increase the stress resistance of plants.

Social and cultural policies to confront the Takfiri speech in Iraq after the year 2003

2020 ◽  
pp. 37
Author(s):  
Ahmed Ghaleb Mohi
Keyword(s):  
United States ◽  
Middle East ◽  
United States Of America ◽  
Political System ◽  
The United States ◽  
Cultural Policies ◽  
American Occupation ◽  
East Region ◽  
Middle East Region

The American occupation of Iraq in 2003 represented a detailed event whose repercussions and repercussions affected not only the level of changing the Iraqi political system, but this event had geo-political and strategic long-term dimensions, as the United States of America was able to redraw the paths of the Middle East region again, in line with The strategic dimensions that I planned to achieve.

Properties of Pavement Bitumens Assessed Using European and American Approach

2017 ◽  
Vol 737 ◽  
pp. 554-559
Author(s):  
Pavel Coufalik ◽  
Ondrej Dasek ◽  
Petr Hyzl ◽  
Iva Krcmova
Keyword(s):  
United States Of America ◽  
Fatigue Behavior ◽  
Asphalt Binder ◽  
The United States ◽  
Asphalt Binders ◽  
Short Term ◽  
European Standards ◽  
Unites States ◽  
Key Parameter

This paper compares the different approaches to assessing asphalt binders used in Europe and the Unites States. A series of pavement bitumens is assessed using European standards and also by the Performance Graded Asphalt Binder Specification based on AASHTO MP 1, which was developed as part of the Strategic Highway Research Program (SHRP) in the United States of America. The results show that the European approach places high requirements on the pavement bitumens in relation to their behavior at low-temperatures, while in case of the American approach, the key parameter is fatigue behavior after short-term and long-term aging. It is evident that it is necessary to evaluate properties of pavement bitumens after long-term aging in Europe, too.

Modeling Approach to Determine Short- and Long-Term Thermal and Thermomechanical Effects of Waste Emplacement in a Repository in Basalt

1981 ◽  
Vol 11 ◽  
Author(s):  
Terry F. Lehnhoff ◽  
K. Thirumalai ◽  
Alan D. Krug
Keyword(s):  
Pacific Northwest ◽  
United States Of America ◽  
The United States ◽  
Department Of Energy ◽  
Nuclear Waste Repository ◽  
Columbia River Basalts ◽  
The Pacific ◽  
Short And Long Term ◽  
Selection Of

The Columbia River basalts, which underlie a large portion of the Pacific Northwest of the United States of America, are being investigated as one of the candidate media for a nuclear waste repository. The Basalt Waste Isolation Project (BWIP) of Rockwell Hanford Operations (Rockwell) is conducting these investigations for the U.S. Department of Energy (DOE). Since the inception of the program in 1976, a number of studies have led to the selection of a reference repository location and the start of construction of an exploratory shaft.1-3

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