A framework of decision making for technological change

The first article in this series2 drew a distinction between the costs of line operations- or current outputs—and those costs devoted to investment, or future outputs. As investment encompasses technological change—in practice it is dominated by it—this article examines some of the broader issues underlying decisions to invest and describes in outline a study being made of the economic criteria that are relevant to such decisions. In the longer term the objective is to develop a procedure or framework of criteria to assist the process of decision making; and this would include a frame of reference—a set of statistical time-series and analyses designed for the purpose.     

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.     

Cognitive and Affective Factors Which Influence Downtown Behaviors

Abstract

Data collected on perceptions of downtown Atlanta are used to explore the impact of cognitive and affective assessments of place on the frequency with which individuals go downtown for shopping, business or professional services, and for entertainment activities. Findings include: (1) social background variables generally exert only weak effects on cognitive and affective responses to downtown Atlanta; (2) affective identification with downtown exerts a positive, significant, and powerful effect on the frequency of using downtown for shopping and business activities; (3) non-Whites, city residents, and singles are more likely to go downtown for entertainment activities than Whites, suburbanites, and married respondents; and (4) images of downtown, affective identification, and positive assessments of downtown municipal services encourage participation in downtown entertainment activities. The analysis strongly suggests that behaviors are influenced by the meanings and evaluations people create for an area.     

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.