Factors controlling the spread of HIV in heterosexual communities in developing countries: patterns of mixing between different age and sexual activity classes

1993 ◽  
Vol 342 (1300) ◽  
pp. 137-159 ◽  
Keyword(s):  
Developing Countries ◽  
Sexual Activity ◽  
Supply And Demand ◽  
Model Development ◽  
Sensitivity Analyses ◽  
Major Influence ◽  
Mathematical Framework ◽  
Sex Structure ◽  
Mixing Patterns ◽  
Demographic Impact

The paper describes the development and analysis of a mathematical model of the spread and demographic impact of HIV in heterosexual communities in developing countries. The model extends previous work in this area by the representation of patterns of mixing between and within different age and sexual activity classes in a two sex structure. Summary parameters are derived to represent different mixing patterns, ranging from assortative via random to disassortative, as are methods to ensure that particular mixing patterns between different age and sexual classes (stratified on the basis of rates of sexual partner change) meet constraints that balance the supply and demand for sexual partners as AIDS induced mortality influences the demographic structure of a population. Analyses of model behaviour rely on numerical methods due to the complexity of the mathematical framework, and sensitivity analyses are conducted to assess the significance of different assumptions and different parameter assignments. Simulated patterns of HIV spread across the two sexes and various age classes are compared with observed patterns in Uganda. The principle conclusion of the study is that the pattern of mixing between age and sexual activity classes, combined with the assumptions made to balance supply and demand between the sexes have a very major influence on the predicted pattern of HIV spread and the demographic impact of AIDS. The paper ends with a discussion of future needs in model development and data acquisition.

The cost implication of primary prevention in the HOPE 3 trial

2019 ◽  
Vol 5 (3) ◽  
pp. 266-271
Author(s):  
Andre Lamy ◽  
Eva Lonn ◽  
Wesley Tong ◽  
Balakumar Swaminathan ◽  
Hyejung Jung ◽  
...  
Keyword(s):  
Developing Countries ◽  
Primary Prevention ◽  
Cost Saving ◽  
Developed Countries ◽  
Sensitivity Analyses ◽  
Clinical Trial Registration ◽  
Pressure Lowering ◽  
The Cost ◽  
Care Costs ◽  
Country Specific

Abstract Aims The Heart Outcomes Prevention Evaluation-3 (HOPE-3) found that rosuvastatin alone or with candesartan and hydrochlorothiazide (HCT) (in a subgroup with hypertension) significantly lowered cardiovascular events compared with placebo in 12 705 individuals from 21 countries at intermediate risk and without cardiovascular disease. We assessed the costs implications of implementation in primary prevention in countries at different economic levels. Methods and results Hospitalizations, procedures, study and non-study medications were documented. We applied country-specific costs to the healthcare resources consumed for each patient. We calculated the average cost per patient in US dollars for the duration of the study (5.6 years). Sensitivity analyses were also performed with cheapest equivalent substitutes. The combination of rosuvastatin with candesartan/HCT reduced total costs and was a cost-saving strategy in United States, Canada, Europe, and Australia. In contrast, the treatments were more expensive in developing countries even when cheapest equivalent substitutes were used. After adjustment for gross domestic product (GDP), the costs of cheapest equivalent substitutes in proportion to the health care costs were higher in developing countries in comparison to developed countries. Conclusion Rosuvastatin and candesartan/HCT in primary prevention is a cost-saving approach in developed countries, but not in developing countries as both drugs and their cheapest equivalent substitutes are relatively more expensive despite adjustment by GDP. Reductions in costs of these drugs in developing countries are essential to make statins and blood pressure lowering drugs affordable and ensure their use. Clinical trial registration HOPE-3 ClinicalTrials.gov number, NCT00468923.

scholarly journals Multibody Kinematics Optimization for the Estimation of Upper and Lower Limb Human Joint Kinematics: A Systematized Methodological Review

2018 ◽  
Vol 140 (3) ◽  
Author(s):  
Mickaël Begon ◽  
Michael Skipper Andersen ◽  
Raphaël Dumas
Keyword(s):  
Degrees Of Freedom ◽  
Inertial Sensors ◽  
Model Development ◽  
Simulated Data ◽  
Ground Truth ◽  
Joint Kinematics ◽  
Sensitivity Analyses ◽  
Geometrical Parameters ◽  
Joint Models ◽  
Human Joint

Multibody kinematics optimization (MKO) aims to reduce soft tissue artefact (STA) and is a key step in musculoskeletal modeling. The objective of this review was to identify the numerical methods, their validation and performance for the estimation of the human joint kinematics using MKO. Seventy-four papers were extracted from a systematized search in five databases and cross-referencing. Model-derived kinematics were obtained using either constrained optimization or Kalman filtering to minimize the difference between measured (i.e., by skin markers, electromagnetic or inertial sensors) and model-derived positions and/or orientations. While hinge, universal, and spherical joints prevail, advanced models (e.g., parallel and four-bar mechanisms, elastic joint) have been introduced, mainly for the knee and shoulder joints. Models and methods were evaluated using: (i) simulated data based, however, on oversimplified STA and joint models; (ii) reconstruction residual errors, ranging from 4 mm to 40 mm; (iii) sensitivity analyses which highlighted the effect (up to 36 deg and 12 mm) of model geometrical parameters, joint models, and computational methods; (iv) comparison with other approaches (i.e., single body kinematics optimization and nonoptimized kinematics); (v) repeatability studies that showed low intra- and inter-observer variability; and (vi) validation against ground-truth bone kinematics (with errors between 1 deg and 22 deg for tibiofemoral rotations and between 3 deg and 10 deg for glenohumeral rotations). Moreover, MKO was applied to various movements (e.g., walking, running, arm elevation). Additional validations, especially for the upper limb, should be undertaken and we recommend a more systematic approach for the evaluation of MKO. In addition, further model development, scaling, and personalization methods are required to better estimate the secondary degrees-of-freedom (DoF).

Trends in Global Oil Investments Over the Past 20 Years

2021 ◽  
pp. 34-49
Author(s):  
Ekaterina Shirobokova ◽  
Fe Amor Parel Gudmundsson
Keyword(s):  
Developing Countries ◽  
Soviet Union ◽  
Former Soviet Union ◽  
Supply And Demand ◽  
Energy Resource ◽  
Modern Society ◽  
Developed Countries ◽  
Oil Demand ◽  
Former Ussr ◽  
The Relationship

Today, energy is an irreplaceable resource without which it is impossible to imagine the life of modern society. Oil, as the most important energy resource, has a significant impact on both individual economies and the world economy. The main objective of this chapter is to identify the relationship between oil supply and oil demand of developed and developing countries on the example of OECD and Former Soviet Union countries. The changes that took place in supply and demand in the oil market from 2000 to 2020 are investigated. The chapter uses graphic and mathematical analysis. It is clear with a fair amount of confidence that the oil demand in developed countries is higher than their supply, and the supply of oil in developing countries is rather more than demand. Also, the chapter draws attention to investments in the oil industry, including on the example of Russia as a former USSR country, analyzes their current state, and draws appropriate conclusions.

Evaluating Alternative Explanations

2019 ◽  
pp. 208-229
Author(s):  
Jonas B. Bunte
Keyword(s):  
Developing Countries ◽  
Interest Rate ◽  
Supply And Demand ◽  
Relative Importance ◽  
Demand Side ◽  
Humanitarian Emergencies ◽  
Debt Crises ◽  
The Interest Rate

This chapter evaluates alternative explanations for differences in borrowing portfolios across developing countries. The analysis suggests that borrowing portfolios result from the interaction of supply- and demand-side factors, through their relative importance differs across creditors. Loans from private creditors are more heavily shaped by creditors’ preferences, while recipient preferences strongly affect borrowing from public creditors. The analysis finds no evidence that recognizing Taiwan negatively affects the loan volume obtained from China. Recipient governments do not appear to decide among creditors based on the interest rate of loans offered. Borrowing portfolios do not depend on the use to which the loan is put as differences in borrowing portfolios across coalitions remain irrespective of infrastructure needs, humanitarian emergencies, and debt crises. This suggests that recipients do not use particular creditors for specific projects. Lastly, domestic political considerations appear more important in determining governments’ borrowing decisions than their ideological alignment with creditor governments.

Study on Compilation and Application of Engineering Cost Index for Construction Project in China

2013 ◽  
Vol 357-360 ◽  
pp. 2233-2237 ◽  
Author(s):  
Hong Ke ◽  
Rui Zhu Wu ◽  
Gao Feng Luo
Keyword(s):  
Developing Countries ◽  
Market Economy ◽  
Transition Period ◽  
Supply And Demand ◽  
Cost Index ◽  
Control Engineering ◽  
Construction Market ◽  
The Core ◽  
Engineering Cost ◽  
Edge Tool

Engineering cost index is one of the core tools to reflect the change of supply and demand in construction market and the level of productivity development. This paper comprehensively analyzes the actuality of compilation and application of engineering cost index from some representative provinces and cities in China, and systematically introduces and contrasts the application of engineering cost index in developed and developing countries or regions, providing reference for the engineering cost index during the transition to market economy in our country in the transition period, making it the edge tool to control engineering cost in a reasonable way.

Pseudo-Dynamic Modeling to Evaluate a Remote Gas-to-Liquids Process

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
Glen Hay ◽  
John Nighswander
Keyword(s):  
Steady State ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Model Development ◽  
Liquid Fuels ◽  
Sensitivity Analyses ◽  
Small Scale ◽  
Process Viability ◽  
Gas To Liquids ◽  
Steady State Simulation

A project team was given the task of evaluating various technology options for design of a small-scale gas-to-liquids (GTL) process operated remotely at or near an individual gas source. For this study, small-scale plants were considered those producing between 100 and 500 barrels per day of liquid fuels. In addition, being remote enforced limitations on utility sources available to the plant site such as water and grid power. A secondary goal was development of a dynamic model of the plant to use in operator training. To accomplish these objectives, the authors investigated the suitability of a process-simulation application. The conceptual design of the GTL unit included many different possibilities, such as front-end design, back-end design, heat integration, and recycling of materials. Complications associated with plant start-up and shutdown, utilities, process reliability, and economics were included in the decision-making process. The authors present selective results from a steady-state model and sensitivity studies. Considerations for the development of the dynamic model included both a fully rigorous dynamic model and a pseudo-dynamic steady-state-based model; results of the latter model are provided. The study concluded that an industrial steady-state simulation tool provided sufficient flexibility to complete the material and energy-balance calculations, sensitivity analyses, and pseudo-dynamic modeling. This study yielded significant insights into the importance of model assumptions and their impact on the overall process viability. The pseudo-dynamic model also provided insight for improving the process control design. During the work completed the authors determined that the object-oriented structure adopted for the model enabled an efficient, rapid model development.

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