A comparison of approaches for estimating the effect of women's education on the probability of using modern contraceptive methods in Malawi

The aim of this study is to estimate the effect of education on the probability of married Malawian women using modern contraceptive methods by accounting for both observed and unobserved confounders. We conduct a sensitivity analysis and compare the results of naive models with instrumental variable models to account for the potential endogeneity of education. Our findings demonstrate conflicting results between the two modelling approaches. The naive models report smaller education effects on the probability of using modern contraceptive methods compared to instrumental variable models. We also find that by relaxing the functional form assumption on the effect of continuous covariates, using a flexible instrumental variable model, the education's effect follows a positive, nonlinear pattern. This finding is not observed with a classic instrumental variable model.     

The contribution of ergonomics to risk analysis in the design process: the case of a future control room

The aim of this paper is to highlight how ergonomics contributes to risk analysis and risk management in a design project for a new reactor, the French EPR (European Pressurized Reactor). An iterative ergonomics design process has been conducted over the last 10 years through a Human Factors Engineering program at the French energy company EDF. A parallel has been drawn between a risk management process and this ergonomics process based on International Organization for Standardization (ISO) publications such as ISO/IEC Guide 73, ISO Guide 51, etc. The contribution of ergonomics to risk analysis is illustrated by an example: the automatic diagnosis, which is a very important technical device for safety. Five main types of risk have been identified via ergonomic analyses during the different design stages. Counter-measures have been implemented and their efficacy tested within the scope of new campaigns to assess human factors. However, the management of risks in such a design project requires the participation both of the different design entities involved in the project and of other experts in aspects of risk management, such as human reliability. The organization of collaborative participation remains a challenge to be addressed.     

Getting down to business: defining competencies for entry-level youth workers

In January 2004, the National Collaboration for Youth approved a list of core competencies needed by entry-level youth development workers for effective youth development practice. This chapter provides an overview of these competencies, explaining why and how the list was created, outcomes, and recommendations for next steps.     

A comparative analysis of public sector restructuring in the U.S., Canada, Mexico, and the Caribbean

We examine public sector restructuring in North America and selected Commonwealth Caribbean nations. Although all the countries studied experienced significant restruc-turing in response to public debt pressures, there were major differences across coun-tries in the magnitude, pace, form, and the manner in which restructuring decisions were made. These differences reflect the state of economic development and institu-tional characteristics, e.g., the role of the state and the industrial relations system. In developing countries, international lending institutions played a major role in trans-forming the role of the state. In developed countries, the inherent stability of the eco-nomic systems and institutional pressures led to a gradualist approach to restructuring.     

Electrophysiological Signals of Familiarity and Recency in the Infant Brain

Electrophysiological work in nonhuman primates has established the existence of multiple types of signals in the temporal lobe that contribute to recognition memory, including information regarding a stimulus’s relative novelty, familiarity, and recency of occurrence. We used high‐density event‐related potentials (ERPs) to examine whether young infants represent these distinct types of information about previously experienced items. Twenty‐four different highly familiar and initially novel items were each repeated exactly once either immediately ( Experiment 1 ), or following one intervening item ( Experiment 2 ). A late slow wave (LSW) component of the ERP exhibited neural responses consistent with recency signals over right‐central leads, but only when there were no intervening stimuli between repetitions. The LSW also exhibited responses consistent with familiarity signals over anterior‐temporal leads, but only when there were intervening stimuli between repetitions. A mid‐latency negative component (i.e., the Nc) also distinguished familiar from novel items, but did not exhibit a pattern of responding consistent with familiarity signals. These findings suggest that infants encode information about a variety of objects from their natural environments into long‐term memory, and can discriminate between familiar and unfamiliar items, and between recently seen and new items, very quickly (within 1 sec). They also suggest that infants represent information about not only whether a stimulus is familiar or unfamiliar but also whether it has been seen recently.     

Attitudes of Mexican Americans toward irregular immigration

This inquiry focuses on the attitudes of 314 Mexican Americans toward issues relating to current US immigration policy. Telephone and personal interviews were conducted in Hidalgo and Travis counties, Texas, with Mexican-Americans. Virtually all respondent groups oppose an increased rate of immigration, consider illegal immigration to be an important problem, support stricter enforcement of immigration laws, and believe that undocumented workers take jobs no one else wants. Half of the respondents identify illegal immigration as a regional rather than a personal problem. At the same time, the data suggest significant differences in both direction and intensity of attitudes between Mexican Americans of different generations, income, occupational levels, and region. There is general opposition to the requirement of a national identity card, but widespread support for penalizing employers of undocumented workers and for granting amnesty to undocumented workers. These findings allow an examination of the extent to which the Mexican American leadership, which has been overwhelmingly opposed to the Simpson-Mazzoli bill, accurately reflects the views of the Mexican American people. The leadership and the population at large agree on 2 of the 3 issues, amnesty and the national identity card, but disagree on employer sanctions. 1st, it may be that the leadership holds the kinds of jobs for which undocumented workers are unlikely to compete, so they may not feel threatened. 2nd, they may feel that instituting employer sanctions will create incentives for employers to discriminate in their hiring practices against all Latino-looking job applicants. Non-elite Mexican Americans who support employer sanctions may believe that the only way they can compete for jobs is to make it impossible for elites to be hired. Both groups appear to fear that, regardless of the specifics of immigration reform, Mexican Americans are likely to encounter increased discrimination in the job market.     

Examination of computer task exposures in radiologists: a work systems approach

Radiologists are intensive computer users as they review and interpret radiological examinations using the Picture Archiving and Communication Systems (PACS). Since their computer tasks require the prolonged use of pointing devices, a high prevalence of Musculoskeletal Disorders (MSDs) is reported. The first phase of this study involved conducting a Cognitive Work Analysis in conjunction with a Participatory Ergonomics approach to perform a total work system analysis. We also conducted an ergonomic survey as well as collected computer use data, specifically for the mouse and keyboard. The goal of the study was to reduce the physical exposures for radiologists. This paper presents Phase I results describing the analyses and redesign process of the radiologists tasks, training design, computer use, and selected survey results.     

Revising a Prognostic Index Developed for Classification Purposes: an Application to Gastric Cancer Data

A prognostic index (PI) is usually derived from a regression model as a weighted mean of the covariates, with weights (partial scores) proportional to the parameter estimates. When a PI is applied to patients other than those considered for its development, the issue of assessing its validity on the new case series is crucial. For this purpose, Van Houwelingen (2000) proposed a method of validation by calibration, which limits overfitting by embedding the original model into a new one, so that only a few parameters will have to be estimated. Here we address the problem of PI validation and revision with the above approach when the PI has classification purposes and it represents the linear predictor of a Weibull model, derived from an accelerated failure time parameterization instead of a proportional hazards one, as originally described by Van Houwelingen. We show that the Van Houwelingen method can be applied in a straightforward manner, provided that the parameterization originally used in the PI model is appropriately taken into account. We also show that model validation and revision can be carried out by modifying the cut-off values used for prognostic grouping without affecting the partial scores of the original PI. This procedure can be applied to simplify the clinician's use of an established PI for classification purposes.