We characterize strict Mittag-Leffler modules in terms of free realizations of positive primitive formulas, and rings over which projectives are trivial in terms of various notions of separability of strict Mittag-Leffler modules. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Context: The dominant approach to the study of perception is representational/computational, with an emphasis on the achievements of the brain and the nervous system, which are taken to construct internal models of the world. Alternatives include ecological, embedded, embodied, and enactivist approaches, all of which emphasize the centrality of action in understanding perception. Problem: Despite sharing many theoretical commitments that lead to a rejection of the classical approach, the alternatives are characterized by important contrasts and points of divergence. Here we (...) focus on the enactive and ecological approaches, in particular, on how they construe the status of the environment and the content of perception. Method: We begin with a review of James Gibson’s ecological psychology, highlighting it as a psychology for all organisms not just humans. Against this backdrop, we consider enactivist arguments against direct perception - a central assertion of the ecological approach - and in favor of interpreting the activity of perceptual agents as a kind of construction of a perceptually meaningful world. Results: We assess the merits of this interpretation and we conclude that it cannot be grounded on fundamental principles such as thermodynamics and organism-environment mutuality. Implications: As a consequence, enactivism remains close to representationalism and entails a form of dualism. Constructivist content: We advance a criticism of the constructivist foundations of the enactive approach to perception. Perception-action mutuality at the heart of enactivism does not require mental construction; indeed, perception-action mutuality obviates construction. (shrink)

The requirement of gauge invariance for the Schwinger-DeWitt equations, interpreted as a manifestly covariant quantum theory for the evolution of a system in spacetime, implies the existence of a five-dimensional pre-Maxwell field on the manifold of spacetime and “proper time” τ. The Maxwell theory is contained in this theory; integration of the field equations over τ restores the Maxwell equations with the usual interpretation of the sources. Following Schwinger's techniques, we study the Green's functions for the five-dimensional hyperbolic field equations (...) for both signatures ± [corresponding to O(4, 1) or O(3, 2) symmetry of the field equations] of the proper time derivative. The classification of the Green's functions follows that of the four-dimensional theory for “massive” fields, for which the “mass” squared may be positive or negative, respectively. The Green's functions for the five-dimensional field are then given by the Fourier transform over the “mass” parameter. We derive the Green's functions corresponding to the principal part ΔP and the homogeneous function Δ 1 ; all of the Green's functions can be expressed in terms of these, as for the usual field equations with definite mass. In the O(3, 2) case, the principal part function has support for x2⩾τ2, corresponding to spacelike propagation, as well as along the light cone x2=0 (for τ=0). There can be no transmission ofinformation in spacelike directions, with this propagator, since the Maxwell field, obtained by integration over τ, does not contain this component of the support. Measurements are characterized by such an integration. The spacelike field therefore can dynamically establish spacelike correlations. (shrink)

Physicians have an ethical responsibility to their patients to offer the best available medical care. This responsibility conflicts with their role as gatekeepers of the limited health care resources available for all patients collectively. It is ethically untenable to expect doctors to face this trade-off during each patient encounter; the physician cannot be expected to compromise the wellbeing of the patient in the office in favour of anonymous patients elsewhere. Hence, as in other domains of public policy where individual and (...) collective interests conflict, some form of collective solution is required. Collective solutions may take the form of placing explicit resource constraints on resources available to physicians, or clinical practice guidelines that recognise cost-effective care as acceptable. Such solutions will be politically and ethically sustainable only if patients as citizens of the larger population accept the need for rationing of limited resources in health care. (shrink)

The Search for the Legacy of the USPHS Syphilis Study at Tuskegee is a collection of essays from experts in a variety of fields seeking to redefine the legacy of the infamous Tuskegee Syphilis Study. The essayists place the legacy of the study within the evolution of racial and ethnic relations in the United States. Contributors include two leading historians on the study, two former United States Surgeons General, and other prominent scholars from a wide range of fields.

Most criticism and exposition of John Rawls’s political theory has focused on his account of distributive justice rather than on his support for liberalism. Because of this, much of his argument for protecting the basic liberties remains under explained. Specifically, Rawls claims that representative citizens would agree to guarantee those social conditions necessary for the exercise and development of the two moral powers, but he does not adequately explain why protecting the basic liberties would guarantee these social conditions. This gap (...) in his argument leads to two problems. First, the Rawlsian argument for the priority of liberty would fail if the gap could not be filled. His argument would still support the protection of individual freedoms, but these freedoms would be treated like other primary goods and regulated by the difference principle. Second, without a full argument, there is not sufficient reason to favor Rawls’s left-liberal conception of the basic liberties over a more right-leaning conception that would prioritize the protection of free-market rights. To address these two problems, this paper fills in the gap in order to better explain Rawls’s full argument for egalitarian liberalism. (shrink)

The use of platelet rich plasma as a novel treatment is discussed in the context of a qualitative research study comprising 38 interviews with sports medicine practitioners and other stakeholders working within the English Premier League during the 2013–16 seasons. Analysis of the data produced several overarching themes: conservatism versus experimentalism in medical attitudes; therapy perspectives divergence; conflicting versions of appropriate evidence; subcultures; community beliefs/practices; and negotiation of medical decision-making. The contested evidence base for the efficacy of PRP is presented (...) in the context of a broader professional shift towards evidence based medicine within sports medicine. Many of the participants while accepting this shift are still committed to casuistic practices where clinical judgment is flexible and does not recognize a context-free hierarchy of evidentiary standards to ethically justifiable practice. We also discuss a tendency in the data collected to consider the use of deceptive, placebo-like, practices among the clinician participants that challenge dominant understandings of informed consent in medical ethics. We conclude that the complex relation between evidence and ethics requires greater critical scrutiny for this emerging specialism within the medical community. (shrink)

This paper describes the matrimonial and reproductive behaviour of Italians who migrated to Belgium after the Second World War. Migrants were either already married, or later became married, to other Italians. Among the children of migrants, men equally chose Italian or Belgian wives but women tended to prefer Italian partners. Italian-Belgian marriages were more frequent among the better educated groups. Family size is smaller among migrants marrying after migration and in heterogamous marriages. Significant differences in birth intervals are found when (...) marriage occurred before or after migration, between generations, and between homogamous and heterogamous marriages. (shrink)

Nielsen's model presents a new isomorphic brain-mind viewpoint, according to which the sole dream generator is found in a REM-on (explicit or covert REM) mechanism. Such a model cannot explain the dreamlike activity during SWS (slow wave sleep), SO (sleep onset) and in the last period of sleep. Moreover the hypothesis contrasts with Solms's data, which show that dreaming is present also in case of destruction of the REM generator. [Nielsen; Solms].

Plamondon & Alimi's model will gain substantially in credibility when it is able to come up with predictions for new (rather than old) experimental results that discriminate between various models. Moreover, the present model is nothing more than a descriptive not an explanation for motor performance. A link to the contribution of various neuronal mechanisms involved in motor control and of muscle properties to the performance of the model is crucial.