Working Unusual Hours and Its Relationship to Job Satisfaction: A Study of European Maritime Pilots

Our study focuses on maritime pilotage in seven European countries and analyzes the level of job satisfaction and its predictors. Like most existing studies in the field of job satisfaction, we show that job satisfaction is an outcome of the work of maritime pilots. Stressful working conditions, such as working unsocial hours and irregular working patterns, create strains that together with intervening factors related to work, family, or the work environment ultimately reduce job satisfaction. However, our results indicate that although negative physical and social consequences are important, they are neither the strongest nor the only variables determining job satisfaction. Another effect seems more important in European maritime pilotage: Job satisfaction is instead a predictor of how much pressure and stress pilots can handle. Despite health problems and a reduction in their quality of life due to working unusual hours, most maritime pilots do not regret their choice of profession. Factors to ameliorate the working conditions are also identified. The most important parameters include alterations in working time systems, working conditions which minimize physical strain, fairness regarding payment, flexibility within the compensation system, an intensification of the possibilities for involvement and participation, an extended degree of co-determination, and the distribution of the ownership of the pilot stations.     

The Statistical Analysis of Preference Data

A new statistic and a new method of analysis are proposed for data where a sample of respondents provides a preference ordering of some treatments. The new preference statistic is compared with the Friedman statistic, particularly for an example where 12 home owners each ranked four grasses. The new analysis provides a more natural and less misleading assessment of where the differences occur than an analysis based on the rank sums of the Friedman statistic. The new analysis is also more robust to deviations from the classical location problem, is not related to election methods known to have undesirable characteristics and adheres to the Condorcet criterion for election methods.     

Terrestrial vertebrates in urban ecosystems: developing hypotheses for the Gwynns Falls Watershed in Baltimore,Maryland

We review the literature on terrestrial vertebrates in urban and urbanizing areas in terms of the new paradigm in ecology that focuses on the origin, spatial pattern, and current influences of habitat patches. Studies of terrestrial vertebrates have documented differences in species composition along an urban-rural gradient and have identified some of the key land use features associated with these differences. We use information from a database developed for the Gwynns Falls Watershed in Baltimore City and County, Maryland to demonstrate how a study of forest-dependent breeding birds could be used to identify mechanisms that account for differences in the bird communities of forest patches in urban areas, and to provide useful information to planners and managers involved in wildlife conservation and management.     

Semiparametric mixture models and repeated measures: the multinomial cut point model

Summary.  Suppose that we have m repeated measures on each subject, and we model the observation vectors with a finite mixture model.  We further assume that the repeated measures are conditionally independent. We present methods to estimate the shape of the component distributions along with various features of the component distributions such as the medians, means and variances. We make no distributional assumptions on the components; indeed, we allow different shapes for different components.     

Regular physical exercise in patients with type II diabetes mellitus

It is widely accepted that regular physical exercise helps diabetic patients control blood glucose, reduce cardiovascular risk factors, and prevent other related complications. In spite of the undoubted benefits of regular physical exercise, diabetic patients with chronic complications should be aware of potential hazards of practicing exercise. To avoid some harmful consequences of acute exercise, it is necessary to adopt a vigilant attitude with these risk patients and to carefully adjust type and intensity of exercise to the individual situation. This article intends to summarize and analyze the current literature concerning the preventive and therapeutic effects of regular exercise in diabetic patients, pointing out its physiological influence on blood glucose regulation, and to analyze the potential risks of acute physical exercise and the precautions given to patients with a variety of complications.     

Estimation of Polygons and Areas

Abstract.  In forestry the problem of estimating areas is central. This paper addresses area estimation through fitting of a polygon to observed coordinate data. Coordinates of corners and points along the sides of a simple closed polygon are measured with independent random errors. This paper focuses on procedures to adjust the coordinates for estimation of the polygon and its area. Different new techniques that consider different amounts of prior information are described and compared. The different techniques use restricted least squares, maximum likelihood and the expectation maximization algorithm. In a simulation study it is shown that the root mean square errors of the estimates are decreased when coordinates are adjusted before estimation. Minor further improvement is achieved by using prior information about the order and the distribution of the points along the sides of the polygon. This paper has its origin in forestry but there are also other applications.