White matter tracts are known to be susceptible to injury following concussion. The objective of this study was to determine whether contact play in sport could alter white matter metabolite levels in female varsity athletes independent of changes induced by long-term exercise. Metabolite levels were measured by single voxel proton magnetic resonance spectroscopy in the prefrontal white matter at the beginning and end of season in contact and non-contact varsity athletes. Sedentary women were scanned once, at a time equivalent to (...) the Off-Season time point. Metabolite levels in non-contact athletes did not change over a season of play, or differ from age matched sedentary women except that non-contact athletes had a slightly lower myo-inositol level. The contact athletes had lower levels of myo-inositol and glutamate, and higher levels of glutamine compared to both sedentary women and non-contact athletes. Lower levels of myo-inositol in non-contact athletes compared to sedentary women indicates long-term exercise may alter glial cell profiles in these athletes. The metabolite differences observed between contact and non-contact athletes suggest that non-contact athletes should not be used as controls in studies of concussion in high-impact sports because repetitive impacts from physical contact can alter white matter metabolite level profiles. It is imperative to use athletes engaged in the same contact sport as controls to ensure a matched metabolite profile at baseline. (shrink)

Many recent studies of norm emergence employ the "prisoner's dilemma" (PD) paradigm, which focuses on the free-rider problem that can block the cooperation required for the emergence of social norms. This paper proposes an expansion of the PD paradigm to include a closely related game termed the "altruist's dilemma" (AD). Whereas egoistic behavior in the PD leads to collectively irrational outcomes, the opposite is the case in the AD: altruistic behavior (e.g., following the Golden Rule) leads to collectively irrational outcomes, (...) whereas egoistic behavior leads to Pareto-optimal outcomes. The analysis shows that PDs can be converted into ADs either by increasing cooperation costs or by diminishing marginal gains from cooperation; therefore ADs are as empirically abundant as PDs. In addition, the analysis shows that altruists are not the only type of actors who fall prey to the AD; egoists can fall into this trap as well if they possess a capacity for interpersonal control. Where group solidarity is defined analytically in terms of the extent of cooperation in both PDs and ADs, this paper presents a model based on rational choice to account for variations in solidarity. According to the proposed analysis, levels of group solidarity depend on the balance in the group between compliant control, which increases cooperation, and oppositional control, which reduces it. That balance, in turn, depends on the allocation of power within the group. (shrink)

We analyze the effects of uncertainty on WTA, WTP and the WTA–WTP gap. Extending the approach of Weber (Econom Lett 80:311–315, 2003) to the case of lotteries, we develop an exact expression for the WTA–WTP gap that allows identification of its magnitude under different utility specifications. Reinterpreting and extending results by Gabillon(Econom Lett 116:157–160, 2012), we also identify generally the relationship between an agent’s utility of income and the gap’s algebraic sign, as well as the effects of risk increases on (...) WTA and WTP. Finally, we derive the limit behavior of the gap as income or risk increase. (shrink)

The goals of public education, as well as conceptions of human intelligence and learning, are undergoing a transformation through the application of military-sponsored information technologies and information processing models of human thought. Recent emphases in education on thinking skills, learning strategies, and computer-based technologies are the latest episodes in the postwar military agenda to engineer intelligent components, human and artificial, for the optimal performance of complex technological systems. Public education serves increasingly as a “human factors” laboratory and production site for (...) this military enterprise, whose high performance technologies and command and control paradigms have also played central roles in the emergence of the information economy. (shrink)

The perturbative approach to quantum field theory has long been viewed with suspicion by philosophers of science. This article offers a diagnosis of its conceptual problems. Drawing on Norton’s discussion of the notion of approximation I argue that perturbative QFT ought to be understood as producing approximations without specifying an underlying QFT model. This analysis leads to a reassessment of common worries about perturbative QFT. What ends up being the key issue with the approach on this picture is not mathematical (...) rigour, or the threat of inconsistency, but the need for a physical explanation of its empirical success. 1Three Worries about Perturbative Quantum Field Theory2The Perturbative Formalism 2.1Expanding the S-matrix2.2Perturbative renormalization3Approximations and Models4Perturbative Quantum Field Theory Produces Approximations5The Real Problem. (shrink)

The paper examines constraints and preferences employed by people in learning decision rules from preclassified examples. Results from four experiments with human subjects were analyzed and compared with artificial intelligence (AI) inductive learning programs. The results showed the people's rule inductions tended to emphasize category validity (probability of some property, given a category) more than cue validity (probability that an entity is a member of a category given that it has some property) to a greater extent than did the AI (...) programs. Although the relative proportions of different rule types (e.g., conjunctive vs. disjunctive) changed across experiments, a single process model provided a good account of the data from each study. These observations are used to argue for describing constraints in terms of processes embodied in models rather than in terms of products or outputs. Thus AI induction programs become candidate psychological process models and results from inductive learning experiments can suggest new algorithms. More generally, the results show that human inductive generalizations tend toward greater specificity than would be expected if conceptual simplicity were the key constraint on inductions. This bias toward specificity may be due to the fact that this criterion both maximizes inferences that may be drawn from category membership and protects rule induction systems from developing over‐generalizations. (shrink)

The moral importance of the ‘intention–foresight’ distinction has long been a matter of philosophical controversy, particularly in the context of end-of-life care. Previous empirical research in Australia has suggested that general physicians and surgeons may use analgesic or sedative infusions with ambiguous intentions, their actions sometimes approximating ‘slow euthanasia’. In this paper, we report findings from a qualitative study of 18 Australian palliative care medical specialists, using in-depth interviews to address the use of sedation at the end of life. The (...) majority of subjects were agnostic or atheistic. In contrast to their colleagues in acute medical practice, these Australian palliative care specialists were almost unanimously committed to distinguishing their actions from euthanasia. This commitment appeared to arise principally from the need to maintain a clear professional role, and not obviously from an ideological opposition to euthanasia. While some respondents acknowledged that there are difficult cases that require considered reflection upon one's intention, and where there may be some ‘mental gymnastics,’ the nearly unanimous view was that it is important, even in these difficult cases, to cultivate an intention that focuses exclusively on the relief of symptoms. We present four narratives of ‘terminal’ sedation – cases where sedation was administered in significant doses just before death, and may well have hastened death. Considerable ambiguities of intention were evident in some instances, but the discussion around these clearly exceptional cases illustrates the importance of intention to palliative care specialists in maintaining their professional roles. (shrink)

In Bester’s article (2018) challenging the use of the harm principle and advocating sole reliance on the use of a best interest standard (BIS) in pediatric decision-making, we believe that the auth...

Physicists use different theories to describe the world on different scales. In particular, they use the standard model of particle physics at very high energies, but move to various effective field theories, such as quantum electrodynamics, when modelling lower energy scattering processes. One way to explain this methodological fact is pragmatic in spirit. According to this view, physicists move to an effective field theory at lower energies in order to extract predictions and qualitative understanding which would be difficult or impossible (...) to extract directly from a more fundamental theory. By contrast, another way of accounting for the methodological data is metaphysical in spirit. On this view, the reason that physicists use different theories at different scales is that the world actually exhibits different nomic structure on different scales. These two positions have recently been thrown into sharp relief in a debate between Woodward (2016) and Batterman (2021), with Woodward taking the pragmatist line and Batterman the metaphysical line. One difficulty with the metaphysical answer is that its content is unclear: in what sense exactly could an effective field theory provide a better representation of the nomic structure of the world in its domain of applicability than our world’s fundamental theory? This talk attempts to provide an answer to this question by developing a simple metaphysical model. I start by assuming a set of possible worlds which are nomically possible according to some fundamental theory (I suggest that one is free to adopt either a Humean or Non-Humean view of these fundamental nomic necessities). I then introduce an equivalence relation between possible worlds: two worlds are scale-E equivalent if they assign the same values to physical quantities below energy scale E (up to some finite level of precision P). The key question now is whether this relation induces equivalence classes on the set of nomically possible worlds. I argue that in the case of current quantum field theories this does indeed occur, as evidenced by the possibility of “integrating out” high energy degrees of freedom in the renormalisation group framework. The formation of equivalence classes in the fundamental theory's possibility space indicates that some of its high energy features do not make a difference to its low energy dynamical behaviour. This suggests the following reading of the claim that an effective field theory provides a better representation of the nomic structure of the world in its domain of applicability: the solutions of the effective field theory stand in one-to-one correspondence with equivalence classes induced by the scale-E equivalence relation, whereas the fundamental theory overcounts the physical possibilities which are relevant at scale E. In this sense, the effective field theory provides a more natural representation of low energy physics than the fundamental theory. I conclude by explaining how this metaphysical model offers a reduction compatible understanding of multiple realisability, once again pointing to renormalisation group results in quantum field theory to support this. (shrink)

The orthodox characterization of spontaneous symmetry breaking in statistical mechanics appeals to novel properties of systems with infinite degrees of freedom, namely, the existence of multiple equilibrium states. This raises the same puzzles about the status of the thermodynamic limit fueling recent debates about phase transitions. I argue that there are prospects of explaining the success of the standard approach to SSB in terms of the properties of large finite systems. Consequently, despite initial appearances, the need to account for SSB (...) phenomena does not offer decisive support to claims about the explanatory and representational indispensability of the thermodynamic limit. (shrink)

Proximate selfish goals reflect the machinations of more fundamental goals such as self-protection and reproduction. Evolutionary life history theory allows us to make predictions about which goals are prioritized over others, which stimuli release which goals, and how the stages of cognitive processing are selectively influenced to better achieve the aims of those goals.

The effectiveness of information retrieval technology in electronic discovery (E-discovery) has become the subject of judicial rulings and practitioner controversy. The scale and nature of E-discovery tasks, however, has pushed traditional information retrieval evaluation approaches to their limits. This paper reviews the legal and operational context of E-discovery and the approaches to evaluating search technology that have evolved in the research community. It then describes a multi-year effort carried out as part of the Text Retrieval Conference to develop evaluation methods (...) for responsive review tasks in E-discovery. This work has led to new approaches to measuring effectiveness in both batch and interactive frameworks, large data sets, and some surprising results for the recall and precision of Boolean and statistical information retrieval methods. The paper concludes by offering some thoughts about future research in both the legal and technical communities toward the goal of reliable, effective use of information retrieval in E-discovery. (shrink)

Heroin use poses a significant health and economic burden to society, and individuals with heroin dependence are responsible for a significant amount of crime. Owing to its efficacy and cost-effectiveness, methadone maintenance therapy (MMT) is offered as an optional alternative to imprisonment for drug offenders in several jurisdictions. Some object to such 'MMT offers' on the basis that they involve coercion and thus invalidate the offender's consent to MMT. While we find these arguments unpersuasive, we do not attempt to build (...) a case against them here. Instead, we explore whether administration of MMT following acceptance of an MMT offer might be permissible even on the assumption that MMT offers are coercive, and in such a way that the resulting MMT is non-consensual. We argue that non-consensual MMT following an MMT offer is typically permissible. We first offer empirical evidence to demonstrate the substantial benefits to the offender and society of implementing non-consensual MMT in the criminal justice system. We then explore and respond to potential objections to such uses of MMT. These appeal respectively to harm, autonomy, bodily and mental interference, and penal theoretic considerations. Finally, we introduce and dismiss a potential response to our argument that takes a revisionist position, rejecting prevailing incarceration practices. (shrink)

Jay Asher’s novel Thirteen Reasons Why and its Netflix adaptation have enjoyed widespread popularity. While they draw needed attention to issues like bullying and teen estrangement, they may have an unintended effect: they mislead about the etiology of suicide and even glamorize it to a degree. The medical literature has shown that suicide is almost always the result of psychiatric disorder, not provocative stress, in much the same way an asthmatic crisis is primarily the result of an underlying medical condition, (...) not an allergic stimulus. Both the novel and Netflix series ignore this premise and even belittle the idea. Thus, while the story has artistic merits, it also has the potential to be destructive if accessed by young readers and viewers seeking guidance. Approximately ten percent of teens suffer from depression, and suicide recently surpassed homicide as the second-leading cause of death among persons ages ten to twenty-four in the United States. A more balanced view addressing these misconceptions is provided for teens, parents, and mental health professionals. (shrink)

To increase donations of nutritious food, Ontario introduced a tax credit for farmers who donate agricultural products to food banks in 2013. This research seeks to investigate the role of Ontario’s Food Donation Tax Credit for Farmers in addressing both food loss and waste and food insecurity through a case study of fresh produce rescue in Windsor-Essex, Ontario. This research also documents the challenges associated with rescuing fresh produce from farms, as well as alternatives to donating. Interviews with food banks, (...) producers and key informants revealed that perceptions of the tax credit, and the credit’s ability to address FLW and food insecurity, contrasted greatly with the initial perceptions of the policymakers who created the tax credit. In particular, the legislators did not anticipate the logistical challenges associated with incentivizing this type of donation, nor the limitations of a donation-based intervention to provide food insecure Ontarians with access to fresh, nutritious food. (shrink)

In this article, we offer a detailed study of two important episodes in the early history of high-energy physics, namely the development of the Chew and the Nambu-Jona-Lasinio models. Our study reveals that both models resulted from the combination of an old Hamiltonian, which had been introduced by earlier researchers, and two new approximation methods developed by Chew and by Nambu and Jona-Lasinio. These new approximation methods, furthermore, were the key component behind the models’ success. We take this historical investigation (...) to support two philosophical theses about the manner in which scientific modelling operates in high-energy physics. Both of these theses run counter to a view that is commonly accepted among philosophers of science: the view that all approximations can be embedded within an equivalent idealized system, and that whatever role the former might play in scientific modelling is therefore parasitic on the much more substantial work performed by the latter. Our first thesis, which we call “Distinctness,” states that approximation methods constitute an independent category of theoretical output from idealized systems. We thus believe that approximations and idealized systems constitute two independent types of objects, both of which are essential to the practice of modelling. Our second, more radical thesis is called “Content Determination.” Our claim here is that approximation methods can in fact be essential to assigning determinate physical content to the idealized systems with which they jointly operate. As we show, this is due to the fact that quantum field theory allows for a very thin characterization of idealized systems only, making the use of approximations necessary to supply additional content. We conclude the paper with a few reflections about the manner in which our two theses can be used to articulate David Kaiser’s views on the “vanishing of scientific theory” in physics after WWII. (shrink)

This study employs the uses and gratification approach to investigate how different forms of Facebook use are linked to bridging social capital and bonding social capital. A survey of 152 college students was conducted to address research questions and to test hypotheses. Factor analysis identified six unique uses and gratifications: (a) information seeking, (b) entertainment, (c) communication, (d) social relations, (e) escape, and (f) Facebook applications. Findings reveal that intensity of Facebook use and the use of Facebook for social relations (...) are positive predictors of bridging social capital, whereas the use of Facebook for escape is negatively linked to bonding social capital. (shrink)