The evolution of the equation of mass conservation in fluid mechanics is studied. Following early hydraulic approximations, and progress by Daniel and Johann Bernoulli, its first expression as a partial differential equation was achieved by d’Alembert, and soon given definitive form by Euler. Later reworkings by Lagrange, Laplace, Poisson and others advanced the subject, but all based their derivations on the conserved mass of a moving fluid particle. Later, Duhamel and Thomson gave a simpler derivation, by considering mass flow into (...) and out of a fixed portion of space. The later propagation of these derivations in nineteenth-century British textbooks and treatises is also examined, including Maxwell’s on the kinetic theory of gases. (shrink)

We introduce a dynamic model for evolutionary games played on a network where strategy changes are correlated according to degree of influence between players. Unlike the notion of stochastic stability, which assumes mutations are stochastically independent and identically distributed, our framework allows for the possibility that agents correlate their strategies with the strategies of those they trust, or those who have influence over them. We show that the dynamical properties of evolutionary games, where such influence neighborhoods appear, differ dramatically from (...) those where all mutations are stochastically independent, and establish some elementary convergence results relevant for the evolution of social institutions. (shrink)

Circumcision is often claimed to be simpler, safer and more cost-effective when performed in the neonatal period as opposed to later in life, with a greater benefit-to-risk ratio. In the first part of this paper, we critically examine the evidence base for these claims, and find that it is not as robust as is commonly assumed. In the second part, we demonstrate that, even if one simply grants these claims for the sake of argument, it still does not follow that (...) neonatal circumcision is ethically permissible absent urgent medical necessity. Based on a careful consideration of the relevant evidence, arguments and counterarguments, we conclude that medically unnecessary penile circumcision—like other medically unnecessary genital procedures, such as ‘cosmetic’ labiaplasty—should not be performed on individuals who are too young (or otherwise unable) to provide meaningful consent to the procedure. (shrink)

Control measures, such as “lockdowns”, have been widely used to suppress the COVID-19 pandemic. Under some conditions, they prevent illness and save lives. But they also exact an economic toll. How should we balance the impact of such policies on individual lives and livelihoods (and other dimensions of concern) to determine which is best? A widely used method of policy evaluation, benefit–cost analysis (BCA), answers these questions by converting all the effects of a policy into monetary equivalents and then summing (...) them up. A different method, social welfare analysis, proceeds by determining the effects of a policy on individual wellbeing and then applying an aggregation formula to them to evaluate the overall effects of a policy. In this chapter, we survey these methods and argue that social welfare analysis has important advantages. One crucial advantage is that it enables ethical considerations relating to the impact of policies on individual wellbeing and its distribution to be incorporated into policy assessments in a transparent way. We illustrate this with a simple numerical model for evaluating pandemic policies that vary in terms of the stringency of the controls that they impose on individual behaviour, showing how the evaluation depends on the ethical significance accorded to their impact on the wellbeing of different age and income groups. (shrink)

The COVID-19 crisis has forced a difficult trade-off between limiting the health impacts of the virus and maintaining economic activity. Welfare economics offers tools to conceptualize this trade-off so that policy-makers and the public can see clearly what is at stake. We review four such tools: the Value of Statistical Life (VSL); the Value of Statistical Life Years (VSLYs); Quality-Adjusted Life-Years (QALYs); and social welfare analysis, and argue that the latter are superior. We also discuss how to choose policies that (...) differentially affect people’s wellbeing. We argue in favor of evaluating policies using a Social Welfare Function (SWF), which evaluates the possible distributions of wellbeing across individuals that may result from a policy. Such a function, we argue, should regard increases in the wellbeing of the less well-off as especially valuable. We then use a model to illustrate how such a framework can help evaluate two broad policy types in response to the pandemic: eradication of the virus, and more lenient control of the spread. Our model reveals how such evaluations depend on many empirical facts but also on key value judgments about the relative importance of health and on the extent of special concern for the worse off. The purpose of this brief is not to make precise recommendations, as conditions vary widely across countries and over time, but to provide a methodology. (shrink)

Two prevailing paradigms explain the diversity of sex-determining modes in reptiles. Many researchers, particularly those who study reptiles, consider genetic and environmental sex-determining mechanisms to be fundamentally different, and that one can be demonstrated experimentally to the exclusion of the other. Other researchers, principally those who take a broader taxonomic perspective, argue that no clear boundaries exist between them. Indeed, we argue that genetic and environmental sex determination in reptiles should be seen as a continuum of states represented by species (...) whose sex is determined primarily by genotype, species where genetic and environmental mechanisms coexist and interact in lesser or greater measure to bring about sex phenotypes, and species where sex is determined primarily by environment. To do otherwise limits the scope of investigations into the transition between the two and reduces opportunities to use studies of reptiles to advance understanding of vertebrate sex determination generally. © 2004 Wiley Periodicals, Inc. (shrink)

Medical and public health research includes surveys, interviews, and biospecimens — techniques that do not present substantial risks to subjects. Consequently, this research is exempt from regulation under the Federal Common Rule. Nevertheless, at many institutions, exempt research is frequently subject to the same regulatory process that is required for non-exempt research, requiring the consumption of time and resources for review by Institutional Review Board members or staff. The federal government has indicated an intention to reform and centralize this system, (...) but has not yet specified the form that it will use instead. By examining the policies of the top 50 research institutions, this article assesses institutional practices surrounding exempt research, quantifies the extent of exempt-research review requirements, documents a problem of “over-compliance,” and makes recommendations for reform. (shrink)

Contingencies of the early nuclear arms race Content Type Journal Article Pages 1-23 DOI 10.1007/s11016-010-9495-z Authors S. S. Schweber, Department of the History of Science, Harvard University, Science Center 371, Cambridge, MA 02138, USA Alex Wellerstein, Department of the History of Science, Harvard University, Science Center 371, Cambridge, MA 02138, USA Ethan Pollock, Department of History, Box N, Brown University, Providence, RI 02912, USA Barton J. Bernstein, History Department, Building 200, Stanford University, Stanford, CA 94305-2024, USA Michael D. Gordin, (...) History Department, 305 Dickinson Hall, Princeton University, Princeton, NJ 08544, USA Journal Metascience Online ISSN 1467-9981 Print ISSN 0815-0796. (shrink)

Social scientists have not integrated relevant knowledge from the biological sciences into their explanations of human behavior. This failure is due to a longstanding antireductionistic bias against the natural sciences, which follows on a commitment to the view that social facts must be explained by social laws. This belief has led many social scientists into the error of reifying abstract analytical constructs into entities that possess powers of agency. It has also led to a false nature-culture dichotomy that effectively undermines (...) the place of biology in social scientific explanation. Following the principles of methodological individualism, we show how behavioral explanations supported by data and theory from the neurosciences can be used to correct the errors of reificationist thinking in the social sciences. We outline a mechanistic approach to the explanation of human behavior with the hope that the biological sciences will begin to find greater acceptance among social scientists. (shrink)

Online crowdsourcing platforms have rapidly become a popular source of data collection. Despite the various advantages these platforms offer, there are substantial concerns regarding not only data validity issues, but also the ethical, societal, and global ramifications arising from the prevalent use of online crowdsourcing platforms. This paper seeks to expand the dialogue by examining both the “internal” aspects of crowdsourcing research practices, such as data quality issues, reporting transparency, and fair compensation, and the “external” aspects, in terms of how (...) the widespread use of crowdsourcing data collection shapes the nature of scientific communities and our society in general. Online participants in research studies are informal workers who provide labor in exchange for remuneration. The paper thus highlights the need for researchers to consider the markedly different political, economic, and socio-cultural characteristics of the Global North and the Global South when undertaking crowdsourcing research involving an international sample; such consideration is crucial for both increasing research validity and mitigating societal inequities. We encourage researchers to scrutinize the value systems underlying this popular data collection research method and its associated ethical, societal, and global ramifications, as well as provide a set of recommendations regarding the use of crowdsourcing platforms. (shrink)

Research has repeatedly confirmed that farmer field schools can serve as a bridge between science and farm practice, enhancing simultaneously rural social energy. However, even though social capital is a burgeoning topic in FFS research, it is not clear whether and how it mediates FFS performance. In this mixed-methods study, using data from two FFS projects conducted in Greece, we examined if social capital among trainees facilitates the co-creation of knowledge and the co-development of agricultural innovations by farmers. A thematic (...) analysis was performed to analyse qualitative data, whereas regression models were employed for the quantitative strand of analysis. Results revealed that social capital evolves progressively during FFS, enabling the achievement of the project’s aims by enhancing in-group communication, establishing affective ties, instilling a sense of community, and triggering motivational contagion among participants. Statistical analyses confirmed that the “softest” sides of social capital significantly contribute to knowledge and innovation co-production. Although this work was based on data derived only from two FFS projects that took place in Greece, our findings underline the importance of social capital for the success of any FFS project and emphasise the need for identifying routes to nurture social capital within FFS. (shrink)

Scholars have long pointed to the power of music as a primary source in instruction for bringing past actors into sharper view and engender deeper connections with the past. By employing Dimitri Shostakovich's 7th Symphony, composed amidst the Nazi siege of Leningrad during the Second World War, we sought to explore, more precisely, the nature of how music, as a primary source, enhances the study of history among students. Through the formulation, execution, and assessment of a two-day lesson with students (...) in five secondary history classes, three of which listened to the symphony and two of which did not, we found that the incorporation of the symphony resulted in students’ enhanced empathetic understanding of the past. Implications include details regarding profound opportunities for, as well as challenges to, cultivating historical empathy through the use of music as a primary source. (shrink)

Active inference offers a unified theory of perception, learning, and decision-making at computational and neural levels of description. In this article, we address the worry that active inference may be in tension with the belief–desire–intention model within folk psychology because it does not include terms for desires at the mathematical level of description. To resolve this concern, we first provide a brief review of the historical progression from predictive coding to active inference, enabling us to distinguish between active inference formulations (...) of motor control and active inference formulations of decision processes. We then show that, despite a superficial tension when viewed at the mathematical level of description, the active inference formalism contains terms that are readily identifiable as encoding both the objects of desire and the strength of desire at the psychological level of description. We demonstrate this with simple simulations of an active inference agent motivated to leave a dark room for different reasons. Despite their consistency, we further show how active inference may increase the granularity of folk-psychological descriptions by highlighting distinctions between drives to seek information versus reward—and how it may also offer more precise, quantitative folk-psychological predictions. Finally, we consider how the implicitly conative components of active inference may have partial analogues in other systems describable by the broader free energy principle to which it conforms. (shrink)

The terminology surrounding the dispute between higher-order and first-order theories of consciousness is piled so high that it sometimes obscures the view. When the debris is cleared away, there is a real prospect.

Anything is similar to anything, provided the respects of similarity are allowed to be gerrymandered or gruesome, as Goodman observed.2 But similarity in non-gruesome or—as I shall say—genuine respects is much less ecumenical. Colors, it seems, provide a compelling illustration of the distinction as applied to similarities among properties.3 For instance, in innumerable gruesome respects, blue is more similar to yellow than to purple. But in a genuine respect, blue is more similar to purple than to yellow (genuinely more similar, (...) as I shall sometimes put it). (shrink)

Potential conflicts between the roles of physicians and researchers have been described at the theoretical level in the bioethics literature (Czoli, et al., 2011). Physicians and researchers are generally in mutually distinct roles, responsible for patients and participants respectively. With increasing emphasis on integration of research into clinical settings, however, the role divide is sometimes unclear. Consequently, physician–researchers must consider and negotiate salient ethical differences between clinical– and research–based obligations (Miller et al, 1998). This paper explores the subjective experiences and (...) perspectives of 30 physician–researchers working in three Canadian paediatric settings. Drawing on qualitative interviews, it identifies ethical challenges and strategies used by physician–researchers in managing dual roles. It considers whether competing obligations could have both positive and adverse consequences for both physician–researchers and patients. Finally, we discuss how empirical work, which explores the perspectives of those engaged in research and clinical practice, can lead the way to understanding and promoting best practice. (shrink)

in Angelique M. Rietsma and Jonathan D. Moreno eds., Ethical Guidelines for Innovative Surgery. (Hagerstown, MD: University Publishing Group) 19-52. [PDF].