A reappraisal of how oral rehydration therapy affected mortality in Egypt

Oral rehydration therapy is the key low-cost child survival intervention used to deal with diarrheal illness in developing countries. The existence of a low-cost, highly efficacious technological fix (oral rehydration salts) for the life-threatening dehydration that accompanies diarrhea provided a strong rationale for making oral rehydration therapy a cornerstone of diarrheal disease control programs. The Egyptian oral rehydration therapy program has been quoted as having the most spectacular success in reducing infant and child mortality. But there is a need to differentiate between the efficacy of oral rehydration therapy in clinical settings and in community use. The National Control of Diarrheal Diseases Project (NCDDP) was launched in Egypt in 1983. A pilot program was followed by national promotion starting in February 1984. As early as 1985, opinions were being expressed about the favorable impact of NCDDP activities on child mortality. There is no doubt that the NCDDP greatly increased both awareness of the dangers of dehydration consequent upon diarrhea in children and knowledge of oral rehydration therapy. But survey data on the use of oral rehydration therapy during diarrheal episodes show such use to be far from universal (with use in fewer than 50 percent of episodes). Futher, ethnographic studies show appropriate use, in terms of timing and quantity, to be the exception rather than the rule. The maximum theoretical effect of the NCDDP on child mortality would be to eliminate all deaths from diarrhea, a reduction of about 50 percent. The maximum effect that could realistically be expected is a reduction of less than 20 percent. Analysis of a time series of infant mortality from vital registration data indicates an abrupt, statistically-significant change in level in 1985 amounting to a once-off decline of about 15 percent. In the absence of other changes taking place at about the right time that might explain this drop, it is concluded that the NCDDP probably was responsible. Thus, although many of the claims made for the impact of the NCDDP on child mortality in Egypt appear to have been greatly exaggerated, it does seem likely, in the absence of alternative explanations, that the program significantly reduced infant mortality in the mid-1980s.Early Child and Children's Health,Health Monitoring&Evaluation,Health Systems Development&Reform,Demographics,Statistical&Mathematical Sciences

Cycling: An Increasingly Untouched Source of Physical and Mental Health

Cost savings associated with increased gasoline prices and lower levels of urban sprawl have been cited in terms of personal savings, environmental awareness, reduced costs through lower travel times and congestion, and reduced income inequality. Cost savings in terms of improved health, however, are often not cited yet represent another dimension of savings associated with reduced urban sprawl and gas prices. Cycling is a form of exercise that can also be used as a mode of transportation if the surrounding environment facilitates such use. According to the United States Department of Transportation, 73 percent of adults want new bicycle facilities such as bike lanes, trails, and traffic signals. Using data from the 1990, 1995, and 2001 waves of the Nationwide Personal Transportation Survey, in addition to data from the Behavioral Risk Factor Surveillance System (1996-2000), I propose to analyze the effects of variations in the built environment in the form of urban sprawl and in real gasoline prices on cycling as a form of physical activity. Using bivariate probit and propensity score methods, I show how cycling can lead to improved physical health outcomes. This is turn may carry policy implications in terms of improved public awareness and city planning.

Employer-Provided Health Insurance and the Incidence of "Job-Lock": Is There a Consensus?

Several recent developments in health care in the United States include declining health care coverage, particularly that provided by employers, and a noticeable shift in the burden of medical care costs to employees. If these developments cause employees to feel locked into their jobs, optimal job matches in the labor force will not take place. Partly in response, the federal government has passed laws protecting health coverage for workers who switch jobs, with the passage of the Consolidated Omnibus Budget Reconciliation Act of 1986 and later the Health Insurance Portability and Accountability Act in 1996. In this paper we summarize the current literature on the topic and present some findings using the National Health Interview Survey, focusing on the 1997-2003 period. Our findings are consistent with recent assertions that there is some evidence of job-lock. Working Paper 06-5

Model-based design of transverse wall oscillations for turbulent drag reduction

Over the last two decades, both experiments and simulations have demonstrated that transverse wall oscillations with properly selected amplitude and frequency can reduce turbulent drag by as much as 40%. In this paper, we develop a model-based approach for designing oscillations that suppress turbulence in a channel flow. We utilize eddy-viscosity-enhanced linearization of the turbulent flow with control in conjunction with turbulence modeling to determine skin-friction drag in a simulation-free manner. The Boussinesq eddy viscosity hypothesis is used to quantify the effect of fluctuations on the mean velocity in the flow subject to control. In contrast to the traditional approach that relies on numerical simulations, we determine the turbulent viscosity from the second order statistics of the linearized model driven by white-in-time stochastic forcing. The spatial power spectrum of the forcing is selected to ensure that the linearized model for the uncontrolled flow reproduces the turbulent energy spectrum. The resulting correction to the turbulent mean velocity induced by small amplitude wall movements is then used to identify the optimal frequency of drag reducing oscillations. In addition, the control net efficiency and the turbulent flow structures that we obtain agree well with the results of numerical simulations and experiments. This demonstrates the predictive power of our model-based approach to controlling turbulent flows and is expected to pave the way for successful flow control at higher Reynolds numbers than currently possible.Comment: To appear in J. Fluid Mech. (35 pages, 17 figures

Measuring the Quality of Banking Regulation in Egypt

The free market economy most countries pursue nowadays is never entirely free from government intervention. Policy makers devote special attention to the regulation of financial markets and with the current financial crisis, the quality of the banking regulations need to be reconsidered. This paper aims to provide a tool to measure the quality of banking regulation and supervision. This is usually a difficult task because it is a qualitative analysis and is arbitrary. However, a regulation index has been modelled that is similar to the concept of a cost-benefit analysis. The input index resembles the cost signifying the efforts made by governments and supervisors to measure the intensity of the regulation. The output index resembles the benefit which shows the outcome of the governments’ efforts. Finally, applying this index on Egypt filled a research gap in this area.Banking regulation, Quality index, Egypt

Controlling the onset of turbulence by streamwise traveling waves. Part 1: Receptivity analysis

We examine the efficacy of streamwise traveling waves generated by a zero-net-mass-flux surface blowing and suction for controlling the onset of turbulence in a channel flow. For small amplitude actuation, we utilize weakly nonlinear analysis to determine base flow modifications and to assess the resulting net power balance. Receptivity analysis of the velocity fluctuations around this base flow is then employed to design the traveling waves. Our simulation-free approach reveals that, relative to the flow with no control, the downstream traveling waves with properly designed speed and frequency can significantly reduce receptivity which makes them well-suited for controlling the onset of turbulence. In contrast, the velocity fluctuations around the upstream traveling waves exhibit larger receptivity to disturbances. Our theoretical predictions, obtained by perturbation analysis (in the wave amplitude) of the linearized Navier-Stokes equations with spatially periodic coefficients, are verified using full-scale simulations of the nonlinear flow dynamics in companion paper, Lieu, Moarref & Jovanovi\'c (2010).Comment: To appear in J. Fluid Mec

Incentives in Obesity and Health Insurance

The obesity rate in the United States has risen significantly in the past few decades. While a number of economic causes for the rise in obesity have been explored, little attention has been on the role of health insurance per se. This paper examines obesity in the context of a model where health insurance status can influence body weight. We attempt to isolate the effects of ex ante moral hazard, where people with health insurance may change their behaviors towards weight control. We use data from the Behavioral Risk Factor Surveillance System from 1993 to 2002 to determine the potential effect of having health insurance on measures of body weight. In our analyses, we control for a variety of confounding factors that may influence body weight and address the endogenous nature of health insurance. Our results show evidence that having insurance is associated with higher body mass (particularly for those above the poverty threshold) and an increased probability of being overweight. However, we find no evidence that having insurance affects the probability of being obese.

Steady-state analysis and stability of synchronous reluctance motors considering saturation effects

This paper investigates the influence of the magnetic saturation on the performance of a Synchronous Reluctance Motor (SynRM) at steady-state. In addition, the stability limits for the SynRM are studied using a suggested more accurate method. The saturation and cross-saturation effects on both direct (d) and quadrature (q) axis flux linkages are considered. A Finite Element Method (FEM) is used to obtain an accurate representation for the dq-axis flux linkages relations. In order to reduce the calculation time of the finite element analysis, a look-up table (LUT) for the dq-axis flux linkages is generated based on the FEM to be used for simulating the SynRM characteristics. It is found that the magnetic saturation in the adopted motor results in an enlarged region of stable operation of the SynRM by about 200 % compared with the unsaturated case. The results show the importance of including the saturation factors on the performance of the SynRM and its stability limits. Hence, the magnetic saturation effect will not only reflect on the stability of the motor but also on the whole drive system

The Effects of Retirement on Physical and Mental Health Outcomes

While numerous studies have examined how health affects retirement behavior, few have analyzed the impact of retirement on subsequent health outcomes. This study estimates the effects of retirement on health status as measured by indicators of physical and functional limitations, illness conditions, and depression. The empirics are based on seven longitudinal waves of the Health and Retirement Study, spanning 1992 through 2005. To account for biases due to unobserved selection and endogeneity, panel data methodologies are used. These are augmented by counterfactual and specification checks to gauge the robustness and plausibility of the estimates. Results indicate that complete retirement leads to a 5-16 percent increase in difficulties associated with mobility and daily activities, a 5-6 percent increase in illness conditions, and 6-9 percent decline in mental health, over an average post-retirement period of six years. Models indicate that the effects tend to operate through lifestyle changes including declines in physical activity and social interactions. The adverse health effects are mitigated if the individual is married and has social support, continues to engage in physical activity post-retirement, or continues to work parttime upon retirement. Some evidence also suggests that the adverse effects of retirement on health may be larger in the event of involuntary retirement. With an aging population choosing to retire at earlier ages, both Social Security and Medicare face considerable shortfalls. Eliminating the embedded incentives in public and private pension plans, which discourage work beyond some point, and enacting policies that prolong the retirement age may be desirable, ceteris paribus. Retiring at a later age may lessen or postpone poor health outcomes for older adults, raise wellbeing, and reduce the utilization of health care services, particularly acute care. Working Paper 07-3