Testing the demand-control-support model among health-care professionals: A structural equation model

This paper reports a further empirical validation of the Demand-Control-Support Model (DCS model), which was developed by Johnson and colleagues (1988, 1989). Data were collected from a heterogeneous group of health-care professionals (nurses and nurses' aides; n = 249). Three major refinements were made to the validation of the DCS Model. First, all relationships in the model were estimated simultaneously by means of covariance structure modelling (LISREL 8). Second, the control dimension was refined substantially, using a psychometrically more sound assessment of the workers' autonomy. Third, the model was applied to the work of health-care professionals. The data did not confirm the assumption that both job strain and motivation are multiplicative functions of job demands, autonomy and social support. First, the results suggested that high levels of autonomy attenuate the increase of emotional exhaustion due to job demands. These results partially supported Karasek's Job Demand-Control Model (Karasek 1979). Second, high levels of social support proved to attenuate the increase of emotional exhaustion due to autonomy. Finally, the main effect of autonomy on job challenge implied that an increase in autonomy is accompanied by an increase in job challenge (and, consequently, job involvement). In addition, low job demands and a high amount of work-related support seem to reduce feelings of exhaustion and, consequently, health complaints.     

Simplicial Pivoting Algorithms for a Tractable Class of Integer Programs

We present a tractable class of integer feasibility problems. This class of max-closed IP problems was studied in somewhat restricted form by Glover, Pnueli, Hochbaum and Chandrasekaran and has a logic counterpart known as the class of Horn formulas. First we modify the existing algorithms in order to avoid the related recognition problem. Then we show that in order to solve these max-closed IP problems, simplicial path following methods can be used. This is important because these methods are flexible with respect to starting conditions, which make them more suitable than the top-down truncation algorithms that have been suggested.     

The EFOM 12C energy supply model within the EC modelling system

This article describes the EC-EFOM 12C model in general and refers where possible to existing documentation. It also reports on the first completed experimental case study and on planned future analysis. This model was developed in one of the research programs undertaken by the European Commission aimed primarily at multinational studies. Data are obtained from research carried out by an interactive network of national implementation teams working with a central group at the Commission. The energy system used is an oriented network carrying the primary energy over intermediate stages till finally meeting consumers' demand. The numerical information, constituting the attributes that characterise the various energy transformation processes, is stored in the European energy data base. About 225 transformation processes distributed over 17 subsystems characterised for six time periods up till 2020 for all EC countries are involved. The management of the data base is performed by an interactive software and this data base is designed for use in simulation studies and for linear programming optimisation with various objective functions. The model has been used in a parallel case study to explore substitution possibilities between an investment policy reducing the primary energy imports and one where these investments are restrained at the cost of having to import more primary energy. Results are shown and briefly discussed. Finally the relationship of this EFOM 12C model with the other EC models developed in the same research subprogram is outlined.     

Maintaining strategic momentum: The CEO''s agenda

How does the chief executive of a large complex organization maintain strategic momentum? This represents a great challenge when there are no obvious external threats, and no obvious reasons for having a concerted action. Floris Maljers, Charles Baden-Fuller and Frans van den Bosch explore the inherent tensions which exist between stability and change. Change is necessary to maintain success, but too much change is disastrous. The authors argue that there are several possible solutions to this paradox, including that of generating periods of intense activity followed by periods of comparative stability and incremental improvement. Using the introspection of one of the CEOs of Unilever, who held office from 1984 to 1994, the authors examine how these tensions were played out and resolved.     

Environmental stressors: the mental health impacts of living near industrial activity

A growing literature examines whether the poor, the working class, and people of color are disproportionately likely to live in environmentally hazardous neighborhoods. This literature assumes that environmental characteristics such as industrial pollution and hazardous waste are detrimental to human health, an assumption that has not been well tested. Drawing upon the sociology of mental health and environmental inequality studies, we ask whether industrial activity has an impact on psychological well-being. We link individual-level survey data with data from the US. Census and the Toxic Release Inventory and find that residential proximity to industrial activity has a negative impact on mental health. This impact is both direct and mediated by individuals' perceptions of neighborhood disorder and personal powerlessness, and the impact is greater for minorities and the poor than it is for whites and wealthier individuals. These results suggest that public health officials need to take seriously the mental health impacts of living near industrial facilities.     

Dimensions Of Well-Being And Their Measurement: The Spf-Il Scale

What are the dimensions of well-being? That is, what universal goals need to be realized by individuals in order to enhance their well-being? Social production function (SPF) theory asserts that the universal goals affection, behavioral confirmation, status, comfort and stimulation are the relevant dimensions of subjective well-being. Realization of these substantive goals and the perspective on opportunities to realize these goals in the future contributes to the affective and cognitive component of well-being. The theoretical elaboration of this theory has been published elsewhere. This paper provides a measurement instrument for the dimensions of well-being. To measure levels of affection, behavioral confirmation, status, comfort and stimulation and empirically validate the dimensions of well-being, the SPF-IL scale was developed. This paper presents findings from a pilot study (n=145), the main study (n=1094), a test–retest examination (n=163), and a validation study (n=725). The measurement model was tested by means of structural equation modeling. Confirmatory factor analysis supported the dimensional structure of well-being indicating construct validity. The overall fit of the model was sufficient, in spite of the somewhat problematic measurement of status, and the test–retest study showed an acceptable level of stability. As for the content validity of the dimensions and their measurement, various sub-studies showed that the SPF-IL scale is a valid instrument, doing at least as well as popular measures of overall well-being but also specifying its dimensions.     

Reclassifying causes of death to study the epidemiological transition in The Netherlands, 1875–1992

This article describes a method for reclassifying causes of death in the Netherlands for the period 1875–1992. Two criteria should be met to obtain a useful classification to study the epidemiological transition. First, the categories should be nosologically continuous over the period under study and second, there should be enough detail in causes which are important in the context of the epidemiological transition viz. communicable diseases, non-communicable diseases and external causes of death. A method developed by Vallin and Meslé (1988), which involves ‘dual correspondence tables’ and ‘fundamental associations’, was used to create nosologically continuous categories. These categories were tested for statistical continuity during the transition years of one ICD-revision to the next, using ordinary least squares regression analysis. The reclassification procedure resulted in a nested classification consisting of three levels of refinement of causes of death: 27 causes, 1875–1992; 65 causes, 1901–1992; and 92 causes, 1931–1992. On the basis of this classification, 43% of all deaths in 1875–79 and 98% of all deaths in 1992 could be allocated to either communicable diseases, non-communicable diseases or external causes.