Mathematical models of transmission and control of infectious agents

2021 ◽  
pp. 241-258
Author(s):  
Alex Welte ◽  
Cari van Schalkwyk
Keyword(s):  
Public Health ◽  
Mathematical Modelling ◽  
Mathematical Models ◽  
Statistical Modelling ◽  
Model Construction ◽  
Primary Data ◽  
Infectious Agents ◽  
The Common ◽  
And Control ◽  
Epidemiological Situation

Indeed, the ‘heavy lifting’ of healthcare is in the care of patients, the development and distribution of vaccines, drugs and devices, and the conception and implementation of sensible systems and policies. However, in recent decades, spectacular increases in the availability of computational capacity have paved the way for mathematical modelling to play an ever-increasing role in many aspects of public health, by supporting formal analyses at various scales of the processes involved. This chapter explores a particular kind of ‘modelling’—and it is not the common (bio)statistical kind. We focus on what we would call ‘dynamical’ modelling (as opposed to ‘statistical’ modelling). This essentially entails the reduction, to mathematics, of key facts and principles inherent in the ‘processes’ or ‘mechanisms’ in an epidemiological situation. We can then manipulate these mathematical constructs, in search of insights that, while ultimately implied in the model construction, are not superficially apparent from our primary data and our intuition.

Keeping the Focus on Public Health: The Struggles of a Tobacco Prevention Task Force

2003 ◽  
Vol 30 (6) ◽  
pp. 771-788 ◽  
Author(s):  
Jacquie A. Shillis ◽  
Beverly A. Hall ◽  
Gail G. Sneden ◽  
Nell H. Gottlieb
Keyword(s):  
Public Health ◽  
Task Force ◽  
Tobacco Prevention ◽  
Policy Success ◽  
Public Health Officials ◽  
The Common ◽  
And Control ◽  
Future Program ◽  
Product Sets

This case study examines a nonlegislative task force as it struggled to reach internal consensus despite external-political constraints. The study highlights the convergence of politics and science, revealing complex issues likely to be confronted by advocates and public health officials. Three themes capture participants’experiences: context, sizing up the opportunities and constraints; task force process, tacit strategy to operate outside the political context and play the science card; and aftermath, a glass half full. The task force took advantage of ambiguous parameters, crafting a comprehensive statewide plan to reduce tobacco use and breaking out of the common public health paradigm of allowing budget considerations to drive program design. These internal victories could not sustain a policy success in the legislature. However, the group’s product sets science-based standards for future program development, and the task force’s process provides valuable insights into other states developing tobacco prevention and control policies.

scholarly journals Mathematical modelling and phylodynamics for the study of dog rabies dynamics and control: A scoping review

2021 ◽  
Vol 15 (5) ◽  
pp. e0009449
Author(s):  
Maylis Layan ◽  
Simon Dellicour ◽  
Guy Baele ◽  
Simon Cauchemez ◽  
Hervé Bourhy
Keyword(s):  
Mathematical Modelling ◽  
Mathematical Models ◽  
Scoping Review ◽  
Control Strategies ◽  
Domestic Dog ◽  
Interdisciplinary Approaches ◽  
Dynamics And Control ◽  
And Control ◽  
The Impact

Background Rabies is a fatal yet vaccine-preventable disease. In the last two decades, domestic dog populations have been shown to constitute the predominant reservoir of rabies in developing countries, causing 99% of human rabies cases. Despite substantial control efforts, dog rabies is still widely endemic and is spreading across previously rabies-free areas. Developing a detailed understanding of dog rabies dynamics and the impact of vaccination is essential to optimize existing control strategies and developing new ones. In this scoping review, we aimed at disentangling the respective contributions of mathematical models and phylodynamic approaches to advancing the understanding of rabies dynamics and control in domestic dog populations. We also addressed the methodological limitations of both approaches and the remaining issues related to studying rabies spread and how this could be applied to rabies control. Methodology/principal findings We reviewed how mathematical modelling of disease dynamics and phylodynamics have been developed and used to characterize dog rabies dynamics and control. Through a detailed search of the PubMed, Web of Science, and Scopus databases, we identified a total of n = 59 relevant studies using mathematical models (n = 30), phylodynamic inference (n = 22) and interdisciplinary approaches (n = 7). We found that despite often relying on scarce rabies epidemiological data, mathematical models investigated multiple aspects of rabies dynamics and control. These models confirmed the overwhelming efficacy of massive dog vaccination campaigns in all settings and unraveled the role of dog population structure and frequent introductions in dog rabies maintenance. Phylodynamic approaches successfully disentangled the evolutionary and environmental determinants of rabies dispersal and consistently reported support for the role of reintroduction events and human-mediated transportation over long distances in the maintenance of rabies in endemic areas. Potential biases in data collection still need to be properly accounted for in most of these analyses. Finally, interdisciplinary studies were determined to provide the most comprehensive assessments through hypothesis generation and testing. They also represent new avenues, especially concerning the reconstruction of local transmission chains or clusters through data integration. Conclusions/significance Despite advances in rabies knowledge, substantial uncertainty remains regarding the mechanisms of local spread, the role of wildlife in dog rabies maintenance, and the impact of community behavior on the efficacy of control strategies including vaccination of dogs. Future integrative approaches that use phylodynamic analyses and mechanistic models within a single framework could take full advantage of not only viral sequences but also additional epidemiological information as well as dog ecology data to refine our understanding of rabies spread and control. This would represent a significant improvement on past studies and a promising opportunity for canine rabies research in the frame of the One Health concept that aims to achieve better public health outcomes through cross-sector collaboration.

scholarly journals Mathematical Modelling of Epidemiology

2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Shreya Nagunuri ◽  
William Tavernetti
Keyword(s):  
Infectious Diseases ◽  
Mathematical Modelling ◽  
Mathematical Models ◽  
Applied Mathematics ◽  
Computer Models ◽  
Sir Model ◽  
And Control

In order to combat the spread of infectious diseases, scientists from a combination of fields have started to develop mathematical models to represent these diseases. With computer models and applied mathematics, one can predict and control various diseases. We present the evolution and implementation of different models used in mathematical modelling as well as a demonstration of the SIR model in MATLAB.

scholarly journals Step Rate Thresholds Associated with Moderate and Vigorous Physical Activity in Adults

2018 ◽  
Vol 15 (11) ◽  
pp. 2454 ◽  
Author(s):  
Myles O’Brien ◽  
Matthew Kivell ◽  
William Wojcik ◽  
Ghislain d’Entremont ◽  
Derek Kimmerly ◽  
...  
Keyword(s):  
Public Health ◽  
Physical Activity ◽  
Mathematical Modelling ◽  
Mathematical Models ◽  
Indirect Calorimetry ◽  
Vigorous Physical Activity ◽  
The Public ◽  
Step Rate ◽  
Public Health Message ◽  
Public Message

Adults are recommended to engage in 150 min of moderate (MPA) to vigorous (VPA) aerobic physical activity per week, with the public health message of obtaining 3000 steps in 30 min. There is a paucity of research on step rate thresholds that correspond to absolute MVPA (moderate = 3 METs, vigorous = 6 METs) with no research evaluating adult relative MVPA (moderate = 40% VO2max, vigorous = 60% VO2max). Anthropometric differences also influence intensity-related step rate thresholds. The purpose of this study was to identify step rates across a range of walking intensities so that mathematical models incorporating anthropometric factors could be used to identify individualized MVPA step rate thresholds. Forty-three adults (25♀; age = 39.4 ± 15.2 years) completed a staged treadmill walking protocol with pedometers and indirect calorimetry: six-minutes at 2.4, 3.2, 4.0, 5.6, 6.4, 7.2 km/h. Mathematical modelling revealed absolute and relative MPA step rate thresholds of ~100 steps/minute (spm) and ~125 spm, respectively. VPA corresponded to step rates of ~133 spm and ~139 spm for absolute and relative thresholds respectively. The current public message of 3000 steps in 30 min is valid for absolute MPA. However, VPA is achieved at higher thresholds than previously reported, more than 130 spm for healthy adults.

Analysis of the Management and Control System of Trade Receivables on the Effectiveness of the Corporate Cash Flow on PT. Enseval Putera Megatrading, tbk

2020 ◽  
Vol 2 (1) ◽  
pp. 75-87
Author(s):  
Syarifah Nuriah ◽  
Abdul Rakhman Laba ◽  
Muhammad Sobarsyah
Keyword(s):  
Control System ◽  
Cash Flow ◽  
Primary Data ◽  
Ratio Analysis ◽  
Financial Ratio ◽  
Accounts Receivable ◽  
Corporate Capital ◽  
Financial Ratio Analysis ◽  
Data Source ◽  
And Control

This study aims to determine the management and control system of trade receivables on the effectiveness of the cash flow company’s at PT. Enseval Putera Megatrading, Tbk. The data source used in this study is the primary data source, obtained directly from the company. The analytical method used for testing the management and control system of receivables on the effectiveness of cash flow is the analysis of financial ratios. In this study, the data used for analysis are qualitative data analysis and financial ratio analysis, namely the activity ratio (RTO, ACP, Arrears Ratio, and Billing Ratio). The results showed that (1) RTO of PT. Enseval Putera Megatrading, the highest rate in 2017 was 189 times, while the lowest RTO was in 2015 which was 115 times. This shows the normal level of turnover. The faster the payment terms, the better for the company, because the faster the working capital embedded in receivables returns to capital or cash, which means the higher the receivables turnover. (2) ACP or the average age of collection of receivables applied by companies, especially the value in 2017 is 2 days. This means that the company has been effective in managing its accounts receivable because the standard for collecting receivables set by the company is the repayment limit or due date no later than 7 (seven) to 90 (Ninety) calendar days from the billing statement received by the service user. (3) The Arrears Ratio, namely from 2014-2018, the largest was only 1.11%. This shows that the lower the arrears ratio, the better for the company, which means the company is able to handle its receivables properly. (4) Billing Ratio shows that from 2014-2018 the lowest that is 98.88% shows the greater the value of collectible receivables means the greater the percentage value of the collection ratio so that the better for the company because of the greater return on corporate capital. Then it can be concluded that the Billing Ratio of PT. Enseval Putera Megatrading, it's not working effectively.

Strengthening of occupational health promotion by the German Prevention Health Care Act

2019 ◽  
pp. 188-190
Author(s):  
Diana Hart
Keyword(s):  
Public Health ◽  
Health Care ◽  
Health Promotion ◽  
Primary Prevention ◽  
Occupational Health ◽  
Life Expectancy ◽  
Prevention And Control ◽  
Occupational Health Promotion ◽  
And Control

All countries are faced with the problem of the prevention and control of non-communicable diseases (NCD): implement prevention strategies eff ectively, keep up the momentum with long term benefi ts at the individual and the population level, at the same time tackling hea lth inequalities. Th e aff ordability of therapy and care including innovative therapies is going to be one of the key public health priorities in the years to come. Germany has taken in the prevention and control of NCDs. Germany’s health system has a long history of guaranteeing access to high-quality treatment through universal health care coverage. Th r ough their membership people are entitled to prevention and care services maintaining and restoring their health as well as long term follow-up. Like in many other countries general life expectancy has been increasing steadily in Germany. Currently, the average life expectancy is 83 and 79 years in women and men, respectively. Th e other side of the coin is that population aging is strongly associated with a growing burden of disease from NCDs. Already over 70 percent of all deaths in Germany are caused by four disease entities: cardiovascular disease, cancer, chronic respiratory disease and diabetes. Th ese diseases all share four common risk factors: smoking, alcohol abuse, lack of physical activity and overweight. At the same time, more and more people become long term survivors of disease due to improved therapy and care. Th e German Government and public health decision makers are aware of the need for action and have responded by initiating and implementing a wide spectrum of activities. One instrument by strengthening primary prevention is the Prevention Health Care Act. Its overarching aim is to prevent NCDs before they can manifest themselves by strengthening primary prevention and health promotion in diff erent sett ings. One of the main emphasis of the Prevention Health Care Act is the occupational health promotion at the workplace.

FINANCIAL CONTROLLING IN THE SYSTEM OF FINANCIAL MANAGEMENT

2018 ◽  
Vol 28 (1) ◽  
pp. 137-141
Author(s):  
Petya Yordanova – Dinova
Keyword(s):  
Comparative Analysis ◽  
Financial Management ◽  
Financial Stability ◽  
Business Environment ◽  
Innovative Approach ◽  
Financial Sustainability ◽  
The Common ◽  
The Difference ◽  
Effective Use ◽  
And Control

This paper explores the comparative analysis of the financial controlling, who is a result from the common controlling concept and the financial management. In the specialized literature, financial controlling is seen as an innovative approach to financial management. It is often presented as the most promising instrument of financial diagnostics. Generally speaking, financial controlling is seen as a process of managing the company`s assets which are valued in monetary measures. The difference between the financial management and the financial controlling is that the second covers all functions of management, analysis and control of finances, aiming at maximizing their effective use and increasing the value of the enterprise. Financial controlling is often seen as a function of the common practice of financial management. Its objective is to preserve the financial stability and financial sustainability of enterprises operating in a highly aggressive business environment.

The Semantics of Evidentials

2017 ◽  
Author(s):  
Sarah E. Murray
Keyword(s):  
Recent Work ◽  
Common Ground ◽  
Formal Semantics ◽  
Empirical Support ◽  
Propositional Content ◽  
Primary Data ◽  
Truth Conditional ◽  
The Common ◽  
Issue Content

This book gives a compositional, truth‐conditional, crosslinguistic semantics for evidentials set in a theory of the semantics for sentential mood. Central to this semantics is a proposal about a distinction between what propositional content is at‐issue, roughly primary or proffered, and what content is not‐at‐issue. Evidentials contribute not‐at‐issue content, more specifically what I will call a not‐at‐issue restriction. In addition, evidentials can affect the level of commitment a sentence makes to the main proposition, contributed by sentential mood. Building on recent work in the formal semantics of evidentials and related phenomena, the proposed semantics does not appeal to separate dimensions of illocutionary meaning. Instead, I argue that all sentences make three contributions: at‐issue content, not‐at‐issue content, and an illocutionary relation. At‐issue content is presented, made available for subsequent anaphora, but is not directly added to the common ground. Not‐at‐issue content directly updates the common ground. The illocutionary relation uses the at‐issue content to impose structure on the common ground, which, depending on the clause type (e.g., declarative, interrogative), can trigger further updates. Empirical support for this proposal comes from Cheyenne (Algonquian, primary data from the author’s fieldwork), English, and a wide variety of languages that have been discussed in the literature on evidentials.

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