Bullying behaviour in secondary schools: what roles do teachers play?

Teachers have an important role to play in the management and prevention of bullying. Although many anti‐bullying programmes advocate a ‘whole school approach’, they tend to focus on student‐student behaviours and rarely examine the nature of other relationships which exist in the school. This study examines bullying between students and teachers at two time points. Thirty per cent of students said they were bullied by teachers at both times. Numbers reporting they bullied teachers were 28 per cent and 16 per cent, respectively. The paper explores the important role that teachers play in dealing with bullying in a school setting by modelling appropriate behaviours and dealing with it effectively. If teachers are victimised by or engage in bullying students this has implications for the ethos within the school and may also impact on the success of anti‐bullying programmes. Copyright © 2008 John Wiley & Sons, Ltd.     

Use of a mixture model for the analysis of contraceptive-use duration among long-term users

This paper introduces a mixture model that combines proportional hazards regression with logistic regression for the analysis of survival data, and describes its parameter estimation via an expectation maximization algorithm. The mixture model is then applied to analyze the determinants of the timing of intrauterine device (IUD) discontinuation and long-term IUD use, utilizing 14 639 instances of IUD use by Chinese women. The results show that socio-economic and demographic characteristics of women have different influences on the acceleration or deceleration of the timing of stopping IUD use and on the likelihood of long-term IUD use.     

Opportunities for making ends meet and upward mobility: differences in organizational deprivation across urban and suburban poor neighborhoods

Objectives. Given the recent rise of poverty in U.S. suburbs, this study asks: What poor neighborhoods are most disadvantageous, those in the city or those in the suburbs? Building on recent urban sociological work demonstrating the importance of neighborhood organizations for the poor, we are concerned with one aspect of disadvantage—the lack of availability of organizational resources oriented toward the poor. By breaking down organizations into those that promote mobility versus those that help individuals meet their daily subsistence needs, we seek to explore potential variations in the type of disadvantage that may exist.Methods. We test whether poor urban or suburban neighborhoods are more likely to be organizationally deprived by breaking down organizations into three types: hardship organizations, educational organizations, and employment organizations. We use data from the 2000 U.S. County Business Patterns and the 2000 U.S. Census and test neighborhood deprivation using logistic regression models.Results. We find that suburban poor neighborhoods are more likely to be organizationally deprived than are urban poor neighborhoods, especially with respect to organizations that promote upward mobility. Interesting racial and ethnic composition factors shape this more general finding.Conclusion. Our findings suggest that if a poor individual is to live in a poor neighborhood, with respect to access to organizational resources, he or she would be better off living in the central city. Suburban residence engenders isolation from organizations that will help meet one's daily needs and even more so from those offering opportunities for mobility.     

The effect of habitual exercise on respiratory- muscle function in older adults

Older adults' participation in habitual exercise might be affected by alterations to respiratory mechanics such as decreased respiratory-muscle strength. This reduction can cause a decrease in efficiency of the ventilatory pump, potentially compromising exercise participation. This research examined the role of habitual exercise in respiratory-muscle function and the associated implications for exercise performance. Seventy-two healthy older adults (36 men, 64.9 +/- 8.6 years, 177.2 +/- 8.4 cm, 82.5+/- 11.9 kg; 36 women, 64.9 +/- 9.5 years, 161.7+/- 6.4 cm, 61.6 +/- 9.2 kg) undertook respiratory-function and walking-performance tests. Active men and women achieved higher scores than their inactive counterparts for all tests except spirometry, where no differences were evident. The results indicate that a significant amount of the elevated fitness level might be accounted for by increased endurance capacity of the inspiratory muscles. Inactive older individuals might be at risk for inadequate respiratory-muscle strength, so interventions should be considered.     

Anesthesia Patient Risk: A Quantitative Approach to Organizational Factors and Risk Management Options

The risk of death or brain damage to anesthesia patients is relatively low, particularly for healthy patients in modern hospitals. When an accident does occur, its cause is usually an error made by the anesthesiologist, either in triggering the accident sequence, or failing to take timely corrective measures. This paper presents a pilot study which explores the feasibility of extending probabilistic risk analysis (PRA) of anesthesia accidents to assess the effects of human and management components on the patient risk. We develop first a classic PRA model for the patient risk per operation. We then link the probabilities of the different accident types to their root causes using a probabilistic analysis of the performance shaping factors. These factors are described here as the "state of the anesthesiologist" characterized both in terms of alertness and competence. We then analyze the effects of different management factors that affect the state of the anesthesiologist and we compute the risk reduction benefits of several risk management policies. Our data sources include the published version of the Australian Incident Monitoring Study as well as expert opinions. We conclude that patient risk could be reduced substantially by closer supervision of residents, the use of anesthesia simulators both in training and for periodic recertification, and regular medical examinations for all anesthesiologists.     

Estimating operational costs in an electric utility

Generation expansion planning in the electric utility industry requires consideration of uncertainties in both the demand and supply of electric power. The expected demand is usually expressed via a load-duration curve, while, on the supply side, each generating unit has a given nameplate capacity and a predicted reliability. This paper focuses on considerations of the supply-side uncertainties and their effects on estimating operating costs in electric utility planning. However, the methods and analysis developed in this paper may be applicable to a wider class of production planning problems which deal with any nonstorable product with time varying demand. Two methods for estimating the energy generation from each generating unit are compared. The first is the method of probabilistic simulation, while the second involves a heuristic technique usually denoted the derating method. A bias inherent in the derating method is examined by comparing it with a probabilistic simulation method. The bias is examined for various load curve shapes. In certain cases, a closed form expression for the bias is obtained. However, a closed form expression of the bias for an arbitrary load curve is difficult to achieve. In these situations some examples are studied in which the trend of the relative bias among plants in the loading order is examined. Finally, the bias is examined using actual 1977 load and supply data for some New England utilities.