The value circle. A profile of J. Richard Gaintner, MD.

This article describes how the arrival of CEO J. Richard Gaintner, MD, at Shands HealthCare signaled a time for refocusing the organization's direction and helping physicians to cope with the changes buffeting the industry. He saw angst and disenfranchisement, sentiments that characterized not only Shands and the University of Florida Health Science Center, but also the entire establishment of American scientific medicine. Gaintner believes--and continually preaches--that practicing medicine in a cost-effective manner will improve, not harm, the quality of care. His willingness to face reality objectively is perhaps his greatest asset in helping physicians deal with managed care. He conveys heartfelt empathy with the day-to-day conflicts they face. But he does not allow himself the temporary luxury of cynicism, and he refuses to accept negativity and pessimism in others. Rather, he asks that physicians and managers understand the system and develop the capacity to work within it and take responsibility for improving it. Beyond exhorting physicians to be accountable for the success of the enterprise, Gaintner creates mechanisms for meaningful physician participation in enterprise management.     

An Exposure‐Response Threshold for Lung Diseases and Lung Cancer Caused by Crystalline Silica

Whether crystalline silica (CS) exposure increases risk of lung cancer in humans without silicosis, and, if so, whether the exposure‐response relation has a threshold, have been much debated. Epidemiological evidence is ambiguous and conflicting. Experimental data show that high levels of CS cause lung cancer in rats, although not in other species, including mice, guinea pigs, or hamsters; but the relevance of such animal data to humans has been uncertain. This article applies recent insights into the toxicology of lung diseases caused by poorly soluble particles (PSPs), and by CS in particular, to model the exposure‐response relation between CS and risk of lung pathologies such as chronic inflammation, silicosis, fibrosis, and lung cancer. An inflammatory mode of action is described, having substantial empirical support, in which exposure increases alveolar macrophages and neutrophils in the alveolar epithelium, leading to increased reactive oxygen species (ROS) and nitrogen species (RNS), pro‐inflammatory mediators such as TNF‐alpha, and eventual damage to lung tissue and epithelial hyperplasia, resulting in fibrosis and increased lung cancer risk among silicotics. This mode of action involves several positive feedback loops. Exposures that increase the gain factors around such loops can create a disease state with elevated levels of ROS, TNF‐alpha, TGF‐beta, alveolar macrophages, and neutrophils. This mechanism implies a “tipping point” threshold for the exposure‐response relation. Applying this new model to epidemiological data, we conclude that current permissible exposure levels, on the order of 0.1 mg/m³, are probably below the threshold for triggering lung diseases in humans.     

Editorial: Women and work

Abstract

When compared to day workers, night-shift workers report that they eat fewer meals, have poorer appetites, are less satisfied with their eating habits, and eat at different times of the day. When demographic variables are held constant, there do not appear to be any significant differences between experienced day and night-shift workers in caffeine or alcohol consumption. Exceptions to and variations in these findings are probably due to the background influences of social and cultural variables. Eating and drinking behaviours do effect human performance and mood, but little relevant data have been gathered from experienced night-shift workers. There are no shiftworker data evaluating the effectiveness of the special diets or dietary recommendations that have been proposed for use by night-shift workers. Thus, attempts to manipulate night-shift worker eating and drinking habits require experimental test.     

Social Work Education

The authors assess the current state of social work education and make suggestions for its improvement, which include distinguishing between specialized and professional knowledge courses, teaching interpersonal skills for working with organizations and communities, differentiating subventionary and instrumental interventions, reformulating course content on policy and administration, dealing with the problems of social work’s expanding curriculum, broadening the range of activities and methods taught in social work research courses, providing incentives for collective faculty participation in curriculum development, and acknowledging the persistent anti-intellectual undercurrent in social work.     

Estimable functions in the nonlinear model

When the method of least squares is used to estimate the parameters in a general model and the generated system of normal equations is linearly dependent, the estimate of the vector of parameters which satisfies the criterion is not unique. However, there exist certain functions of the estimated vector of parameters which are invariant to the least squares solution obtained from the normal equations. We define those invariant functions to be estimable, and present a technique to determine the functions of the parameters which are estimable for the general model. The method results in solving either a linear first order partial differential equation or a system of linear first order partial differential equations corresponding, respectively, to a single or multiple dependency between columns of the Jacobian matrix of the mean of the model. The usual results concerning estimability for linear models are a special case of the general results developed.     

The Function of Avoidance in Improving the Understanding of Disaster Recovery

Functional avoidance as an intermittent coping mechanism is a necessary component in disaster recovery. By temporarily avoiding losses after disaster, survivors can secure basic needs and begin rebuilding. It is not until recovery projects are completed that mental health outcomes become apparent. Many individuals begin a healthy grieving process; however, for others, where avoidance extends past the completion of normalizing tasks it becomes pathological. This study presents the concept of functional avoidance and investigates the point at which it becomes dysfunctional using case examples and data from a mental health clinic. Findings suggest increased emotional distress, depression, and posttraumatic stress disorder over 3 years after Hurricane Katrina.     

Pseudo maximum likelihood estimation for the dirichlet-multinomial distribution

Pseudo maximum likelihood estimation (PML) for the Dirich-let-multinomial distribution is proposed and examined in this pa-per. The procedure is compared to that based on moments (MM) for its asymptotic relative efficiency (ARE) relative to the maximum likelihood estimate (ML). It is found that PML, requiring much less computational effort than ML and possessing considerably higher ARE than MM, constitutes a good compromise between ML and MM. PML is also found to have very high ARE when an estimate for the scale parameter in the Dirichlet-multinomial distribution is all that is needed.