Comparison of PFAS soil remediation alternatives at a civilian airport using cost-benefit analysis.

Contamination of soil and water systems by per- and polyfluoroalkyl substances (PFAS) due to uncontrolled use of aqueous film-forming foams (AFFFs) at firefighting training sites at civilian and military airports is a universal issue and can lead to significant human health and environmental impacts. Remediation of these sites is often complex but necessary to alleviate the PFAS burden and minimise the risks of exposure by eliminating the hotspot/source from which the PFAS spreads. This study presents a probabilistic cost-benefit analysis (CBA) for evaluating PFAS remediation alternatives, which includes monetisation of both direct costs and benefits as well as externalities. The method is applied for a case study to compare five remediation alternatives for managing PFAS contaminated soil at Stockholm Arlanda Airport in Sweden. The social profitability, or the net present value (NPV), of each remediation alternative was calculated in comparison to two reference alternatives - 'total excavation' of the site (Alt 0) or 'do nothing'. Sensitivity analyses and model scenarios were tested to account for uncertainties, including small or large PFAS spreading and simulating different values for the magnitude of annual avoided cost of inaction (i.e., aggregate benefit) from PFAS remediation. In comparison to total excavation, four of the five studied remediation alternatives resulted in a positive mean NPV. Excavation and stabilization/solidification of the hotspot on-site combined with stabilization using activated carbon for the rest of site (Alt 2) had the highest NPV for both spreading scenarios, i.e., Alt 2 was the most socially profitable alternative. Simulations of the annual avoided cost of inaction enabled estimation of the breakeven point at which a remediation alternative becomes socially profitable (NPV > 0) compared to 'do nothing'. Alt 2 had the lowest breakeven point: 7.5 and 5.75 millions of SEK/year for large and small spreading, respectively.

Identifying governance strategies that effectively support ecosystem services, resource sustainability, and biodiversity.

Conservation scientists, national governments, and international conservation groups seek to devise, and implement, governance strategies that mitigate human impact on the environment. However, few studies to date have systematically investigated the performance of different systems of governance in achieving successful conservation outcomes. Here, we use a newly-developed analytic framework to conduct analyses of a suite of case studies, linking different governance strategies to standardized scores for delivering ecosystem services, achieving sustainable use of natural resources, and conserving biodiversity, at both local and international levels. Our results: (i) confirm the benefits of adaptive management; and (ii) reveal strong associations for the role of leadership. Our work provides a critical step toward implementing empirically justified governance strategies that are capable of improving the management of human-altered environments, with benefits for both biodiversity and people.

The life and work of Niels Kaj Jerne as a source of ethical reflection.

Niels Kaj Jerne, one of the leading theoreticians in 20th century immunology, was awarded the 1984 medical Nobel Prize for the natural selection theory of antibody formation, the haemolytic plaque technique, and the idiotypic network theory. A number of reasons for remembering Jerne are discussed, and three aspects of his life and work from three different life-phases are analysed. Drawing upon the classical tradition for writing biographies as 'ethical exemplars', the paper concludes that a major reason for remembering Jerne is that his life story addresses fundamental questions about how to live as a scientist in contemporary culture.

Ecology. The value of nature and the nature of value.

Ecosystems are capital assets: When properly managed, they yield a flow of vital goods and services. Relative to other forms of capital, however, ecosystems are poorly understood, scarcely monitored, and--in many important cases--undergoing rapid degradation. The process of economic valuation could greatly improve stewardship. This potential is now being realized with innovative financial instruments and institutional arrangements.

Time spent on waiting lists for medical care: an insurance approach.

In this paper, we develop a simple model of the benefits and costs of being on a waiting list. The model shows that complex factors are in operation, implying that a shorter waiting time need not necessarily be preferred to a longer waiting time. We also present an empirical study, where a sample of Swedes are offered the possibility of purchasing private insurance, thus reducing waiting time for surgery beyond the three-month guarantee offered by the public sector health care system. Respondents could choose between two insurance contracts. A 'spike' model, where the probability of a zero WTP is strictly positive, was developed and estimated to obtain demand functions for private insurance.

The structure and dynamics of immunology, 1951-1972: a prosopographical study of international meetings.

Immunology underwent a major change in direction during the 1950s and 1960s, from immunochemistry to immunobiology. A quantitative analysis of the participants at a large number of immunological meetings held during this critical period reveals much about the inner dynamics of the discipline. This new approach enables us to define the scientific leadership of the discipline and of its emerging subdisciplines, the interests of "mainstream" immunology, and when fields such as transplantation and allergy begin to join the mainstream. It is also suggested that some of these meetings, in addition to reflecting changes within the field, may have contributed substantially to these changes. Further, many of these meetings served to promote the institutionalization of the discipline and of its subdisciplines.

Participation in scientific meetings: a new prosopographical approach to the disciplinary history of science--the case of immunology, 1951-72.

To handle the enormous amount of sources in modern and contemporary science, the historian can use different quantitative methods, particularly varieties of citation analysis. So far, all these methods have been based on publication data. Taking as its point of departure the fact that meetings constitute a pervasive, yet neglected, aspect of science, this paper introduces analysis of participation in scientific meetings. The strength of this new prosopographical method is illustrated by an analysis of international immunological meetings in the period 1951-72. Frequency of participation in meetings seems to be correlated to professional standing in immunology. By means of cluster analysis of participation data, the subdisciplinary structure and dynamics of immunology can be reconstructed.

How to write the recent history of immunology--is the time really ripe for a narrative synthesis?

In June 1992 historians and immunologists met at the International School of Biological Sciences on Ischia, Italy to discuss aspects of the recent history of immunology. This paper takes issue with some of the historiographical recommendations in the report from the meeting by Horace F. Judson and Ian Mackay ('History in the Bay of Naples', Immunology Today, November 1992).