Altruism,the free rider problem and group size

This paper is a survey of recent theoretical work on the influence of group size, perceived effectiveness or noticeability of one's behavior on a group member's altruistic responses. Experiments on this problem are analyzed and evaluated, and problems for future research are outlined.This paper is a revised version of a paper originally presented at the March 1973 meetings of the Public Choice Society. In preparing this paper I have benefited from criticisms and suggestions made by a number of people and I wish to take this opportunity to thank them. Among them are John Bonin, Barry Groffman, Bob O'Gorman, Don Moon, George Reynolds and Harrison Wagner.     

The Greater Complexity of Lived Race: An Extension of Harris and Sim*

Objectives. Harris and Sim (2002) recently demonstrated the complexity of lived race by exploring patterns of racial self‐identification. They raised important sociological questions about the role of context in racial self‐identification, but offered an incomplete picture of ethnic fluidity by excluding Hispanics from their analyses. We address this limitation with data on Hispanics from the National Longitudinal Study of Adolescent Health (Add Health). Methods. Our social‐psychological approach, using compositional analysis, focuses on the lived experience of race and ethnicity as qualitatively similar conceptual categories. Results. Informed by the cognitive process of social categorization, we find that considerably more individuals show fluidity in racial and ethnic self‐identification across contexts than suggested by Harris and Sim. Conclusions. Harris and Sim's thesis is even more strongly supported by these findings than in their original analysis, and our findings reinforce their challenge to the assumed stability of racial and ethnic measurement in sociology. We conclude by proposing a change in the measurement of race/ethnicity in America.     

全球经济及其理论辨析

由关贸总协定、世界贸易组织、世界银行、欧共体、美洲自由贸易区等国际协定和跨国公司体现的世界经济一体化是由私有化进程和打破区域垄断的自由主义经济目标推动的不可逆转的趋势。在这一过程之中经济和经济学成了世界的结构信息。经济学的两个预设———自私自利的经济人和人的世界———非人世界的二元论是全球经济的深层理论基石。经济人的实践活动造成贫富不均 ,二元论把人溺爱成肆无忌惮地破坏环境的动物。人类应该冷静思索这一新的世界形势 ,提出合理对策     

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.     

Rough-cut capacity planning for remanufacturing firms

Capacity planning is a critical element of any successful production planning and control system. A method of rough-cut capacity planning is developed, based on the bill-of-resources approach, that can be used to plan for capacity required for firms in a remanufacturing including overhaul repair operations environment. The modified bill-of-resources approach developed takes into account two major stochastic elements inherent in this environment; probabilistic material replacement factors and probabilistic routing files. A detailed example from an actual repair overhaul operation is presented to illustrate the technique.     

Emergency Planning for Hazardous Industrial Areas: A Brazilian Case Study

One of the characteristics of modern industrial development is the emergence of a new typology of accidents whose effects can be spread, in space as well as in time, well beyond the borders of the installations where they occur, sometimes impacting the local population and the environment in a catastrophic fashion. This is the result of a number of factors that have changed the risk profile of modern industrial activities. For a number of reasons, the developing countries have proved to be more vulnerable to industrial disasters. Three of the most catastrophic industrial accidents—Bhopal, San Juan de Ixhuatepec, and Cubatão—occurred in developing countries, claiming thousands of lives. During the 1970s and 1980s the higher degree of public visibility of industrial hazards as a result of serious accidents, led to the creation, especially in the more industrialized countries, of regulations for greater control over industrial activities, either by means of new laws or by updating existing legislation. Some of these regulations were designed to improve the response to accidents with potential impacts outside the industrial sites. This article attempts to describe the current status and identify the shortcomings of off‐site emergency planning for hazardous industrial areas in Brazil. The most important problems are the lack of specific legislation and the absence of awareness and active participation of public authorities. The experience of an off‐site emergency planning process for a Brazilian industrial area is presented. This experience illustrates how difficult it is to prepare and implement emergency planning processes in an industrializing country.     

Forging Diaspora: Afro-Cubans and African Americans in a World of Empire and Jim Crow

ABSTRACT

Drawing on social histories of rumour, this article challenges notions of white and Afrikaner homogeneity which persist in the scholarship on late and post-apartheid South Africa. In so doing, it demonstrates the revisionist potential of rumour as a historical source, while reinserting class in a scholarship which privileges race as salient historical feature. The article focuses on Arrie Paulus, apartheid South Africa’s most prominent white trade unionist, infamous as the personification of working-class racism. Yet this defender of race-based privilege and staunch Afrikaner nationalist was haunted by a rumour: Paulus, it was whispered, was not actually white. The rumour circulated in reform-era South Africa and persists in the post-apartheid present. By examining the rumour surrounding Paulus’s racial and ethnic origins in terms of the functions it fulfilled within the particular contexts in which it appeared, this article exposes longstanding tensions around the politics of class characterizing Afrikaner society since the 1970s.