scholarly journals Quantifying the contribution of asymptomatic infection to the cumulative incidence

2017 ◽  
Vol 145 (6) ◽  
pp. 1256-1258 ◽  
Author(s):  
D. CHAMPREDON ◽  
S. M. MOGHADAS
Keyword(s):  
Mathematical Model ◽  
Infectious Diseases ◽  
Cumulative Incidence ◽  
Analytical Formula ◽  
Asymptomatic Infection ◽  
Simple Analytical Formula

SUMMARYMany infectious diseases in humans may manifest with no or mild symptoms. While numerous studies have estimated the proportion of infectious individuals in whom symptoms are absent during the entire course of infection, the contribution of asymptomatic cases to the overall cumulative incidence is difficult to untangle. Here, with a mathematical model, we provide a simple analytical formula to quantify this contribution and highlight the potential for large errors that can arise when naively estimating it.

Pre-Impact Configuration Designing of a Robot Manipulator for Impact Minimization

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
Jingchen Hu ◽  
Tianshu Wang
Keyword(s):  
Impact Force ◽  
Robot Manipulator ◽  
Analytical Formula ◽  
Joint Space ◽  
Collision Problem ◽  
Spatial Operator ◽  
Inertia Ellipsoid ◽  
The Impact ◽  
Maximum Minimum ◽  
Simple Analytical Formula

This paper studies the collision problem of a robot manipulator and presents a method to minimize the impact force by pre-impact configuration designing. First, a general dynamic model of a robot manipulator capturing a target is established by spatial operator algebra (SOA) and a simple analytical formula of the impact force is obtained. Compared with former models proposed in literatures, this model has simpler form, wider range of applications, O(n) computation complexity, and the system Jacobian matrix can be provided as a production of the configuration matrix and the joint matrix. Second, this work utilizes the impulse ellipsoid to analyze the influence of the pre-impact configuration and the impact direction on the impact force. To illustrate the inertia message of each body in the joint space, a new concept of inertia quasi-ellipsoid (IQE) is introduced. We find that the impulse ellipsoid is constituted of the inertia ellipsoids of the robot manipulator and the target, while each inertia ellipsoid is composed of a series of inertia quasi-ellipsoids. When all inertia quasi-ellipsoids exhibit maximum (minimum) coupling, the impulse ellipsoid should be the flattest (roundest). Finally, this paper provides the analytical expression of the impulse ellipsoid, and the eigenvalues and eigenvectors are used as measurements to illustrate the size and direction of the impulse ellipsoid. With this measurement, the desired pre-impact configuration and the impact direction with minimum impact force can be easily solved. The validity and efficiency of this method are verified by a PUMA robot and a spatial robot.

The Basics of Microbiology

2021 ◽  
Author(s):  
Werner Solbach
Keyword(s):  
Infectious Diseases ◽  
Defense Mechanisms ◽  
Wide Spectrum ◽  
Severe Disease ◽  
Laboratory Diagnosis ◽  
Asymptomatic Infection ◽  
The Body ◽  
Sufficient Evidence ◽  
Effective Measure ◽  
Hygiene Measures

Microorganisms constitute 70 percent of the biomass on Planet Earth. Comparatively few species are adapted to colonize human surfaces and form a complex Meta-Organism with manyfold mutual benefits. Occasionally, microorganisms may overcome the barriers of the skin and mucosal surfaces and may multiply locally or in multiple sites inside the body. This process is called infection. Infections can be caused by bacteria, viruses, parasites, helminths, and fungi. Immediately after infection, numerous defense mechanisms of the immune system are activated to combat replication of the microbes. There is a balance between microorganism and human defense mechanisms, which may lead to either asymptomatic infection or result in a wide spectrum of symptoms from mild to severe disease and even death. The most important factors in the diagnosis of infectious diseases are a careful history, physical examination and the appropriate collection of body fluids and tissues. Laboratory diagnosis requires between 2 and 72 hours. Wherever possible, antibiotics should only be used when sufficient evidence of efficacy is available. Then, however, they should be used as early as possible and in high doses. In addition to everyday hygiene measures, vaccination is the most effective measure to prevent infectious diseases.

scholarly journals Quantifying the impact of social groups and vaccination on inequalities in infectious diseases using a mathematical model

BMC Medicine ◽  
2018 ◽  
Vol 16 (1) ◽  
Author(s):  
James D. Munday ◽  
Albert Jan van Hoek ◽  
W. John Edmunds ◽  
Katherine E. Atkins
Keyword(s):  
Mathematical Model ◽  
Infectious Diseases ◽  
Social Groups ◽  
The Impact

Dynamics between infectious diseases with two susceptibility conditions: A mathematical model.

2019 ◽  
Vol 309 ◽  
pp. 66-77 ◽  
Author(s):  
J.P. Gutiérrez-Jara ◽  
F.D. Córdova-Lepe ◽  
M.T. Muñoz-Quezada
Keyword(s):  
Mathematical Model ◽  
Infectious Diseases

INFLUENCE OF ASYMPTOMATIC PEOPLE ON MALARIA TRANSMISSION: A MATHEMATICAL MODEL FOR A LOW-TRANSMISSION AREA CASE

2020 ◽  
Vol 28 (01) ◽  
pp. 167-182
Author(s):  
IULIA MARTINA BULAI ◽  
STÉPHANIE DEPICKÈRE ◽  
VITOR HIRATA SANCHES
Keyword(s):  
Mathematical Model ◽  
Mortality Rate ◽  
Malaria Transmission ◽  
Equilibrium Points ◽  
Asymptomatic Infection ◽  
Human Populations ◽  
High Morbidity ◽  
Low Transmission ◽  
Transmission Area ◽  
Using Data

Malaria remains a primary parasitic disease in the tropical world, generating high morbidity and mortality in human populations. Recently, community surveys showed a high proportion of asymptomatic cases, which are characterized by a low parasitemia and a lack of malaria symptoms. Until now, the asymptomatic population is not treated for malaria and thus remains infective for a long time. In this paper, we introduce a four-dimensional mathematical model to study the influence of asymptomatic people on malaria transmission in low-transmission areas, specifically using data from Brazil. The equilibrium points of the system are calculated, and their stability is analyzed. Via numerical simulations, more in-depth analyzes of the space of some crucial parameters on the asymptomatic population are done, such as the per capita recovery rates of symptomatic and asymptomatic people, the ratio of the density of mosquitoes to that of humans, the mortality rate of mosquitoes and the probability of undergoing asymptomatic infection upon an infectious mosquito bite. Our results indicate that the disease-free equilibrium is inside the stability region if asymptomatic people are treated and/or the ratio of the density of mosquitoes to that of humans is decreased and/or the mortality rate of mosquitoes is increased.

Group Theoretic Approach to the Exponential Cosine Screened Coulomb Potential

1985 ◽  
Vol 40 (5) ◽  
pp. 453-455 ◽  
Author(s):  
Barnana Roy
Keyword(s):  
Perturbation Method ◽  
Coulomb Potential ◽  
Analytical Formula ◽  
Theoretic Approach ◽  
Energy Eigenvalues ◽  
Screened Coulomb Potential ◽  
Simple Analytical Formula

Perturbation method, using the properties of SO (2,1) algebra is applied to get a simple analytical formula for energy eigenvalues of the exponential cosine screened Coulomb potential.

Comparison between different proximity potentials and the double-folding model for spherical–deformed interacting nuclei

2016 ◽  
Vol 94 (1) ◽  
pp. 102-111 ◽  
Author(s):  
M. Ismail ◽  
I.A.M. Abdul-Magead
Keyword(s):  
Coulomb Barrier ◽  
Analytical Formula ◽  
Orientation Angle ◽  
Heavy Ion ◽  
Folding Model ◽  
Deformation Parameters ◽  
Double Folding Model ◽  
Double Folding ◽  
Coulomb Part ◽  
Simple Analytical Formula

The Coulomb barrier parameters have been calculated for a spherical–deformed interacting pair of nuclei using 14 different versions of the proximity approaches and a simple analytical formula for the Coulomb part of the heavy ion potential. The results of these proximity versions have been compared with more accurate results obtained from the double-folding model (DFM). We have considered the interacting pair 48Ca + 238Pu as an example and assumed the presence of the quadrupole, octupole, and hexadecapole deformation parameters for 238Pu. The orientation angle dependence of the Coulomb barrier parameters has been computed for different sets of deformation parameters. We found that the proximity types named Prox77, BW Prox91, AW Prox95, Bass Prox77, and Bass Prox80 are the best ones of the available 14 versions of the proximity approaches for calculating the nuclear part of the interaction potential for a spherical–deformed pair of nuclei.

Four-probe Magnetoresistance of Current-perpendicular-to-plane Structures

2005 ◽  
Vol 906 ◽  
Author(s):  
Hua Zhou ◽  
Mark W. Covington ◽  
Michael A. Seigler
Keyword(s):  
Finite Element ◽  
Current Flow ◽  
Three Dimensional ◽  
Analytical Formula ◽  
Unified Approach ◽  
Uniform Current ◽  
Current Perpendicular To Plane ◽  
Numerical Finite Element ◽  
Simple Analytical Formula ◽  
Probe Geometry

AbstractThe resistance and magnetoresistance (MR) of three-dimensional current-perpendicular-to-plane (CPP) structures have been calculated via numerical finite element solutions of the Laplace equation. This model accounts for the non-uniform current paths in a four-probe geometry that can yield MR that differs from the intrinsic MR of the isolated CPP pillar with spatially uniform current flow. We calculated the four-probe MR for various geometries and resistivities of both the normal metal leads and the magnetoresistive pillar. From a single, unified approach, we are able to consistently account for the disparate behavior that has been previously published. In particular, we identify conditions that produce four-probe MR that differs from the intrinsic MR of the CPP pillar and highlight those situations where the four-probe resistance is negative. Finally, we present a simple analytical formula for the MR ratio that is applicable to narrow CPP pillars with wide, thin leads.

An analytical formula for estimating the bending angle by laser forming

2006 ◽  
Vol 220 (2) ◽  
pp. 243-247 ◽  
Author(s):  
H Shen ◽  
Z Yao ◽  
Y Shi ◽  
J Hu
Keyword(s):  
Experimental Data ◽  
Solid Mechanics ◽  
Present Model ◽  
Analytical Formula ◽  
Laser Forming ◽  
Compatibility Conditions ◽  
Bending Angle ◽  
Metal Plates ◽  
External Forces ◽  
Simple Analytical Formula

Laser forming of metal plates offers the advantages of requiring no external forces and thus reduced cost and increased flexibility. It also enables forming of some materials and shapes that are impossible by using the traditional methods. Based on the conventional equilibrium and compatibility conditions used in solid mechanics, a simple analytical formula for predicting the bending angle is derived. The present model is compared with other models and available experimental data, from which the superiority of the present model is demonstrated.

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