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)

PURPOSE:To report the localization of a gene causing drusen and macular degeneration in a previously undescribed North American family. METHODS:Genetic mapping studies were performed using linkage analysis in a single family with drusen and atrophic macular degeneration. RESULTS:The clinical manifestations in this family ranged from fine macular drusen in asymptomatic middle-aged individuals to atrophic macular lesions in two children and two elderly patients. We mapped the gene to chromosome 6q14 between markers D6S2258 and D6S1644. CONCLUSIONS:In a family with autosomal dominant (...) drusen and atrophic macular degeneration, the gene maps to a 3.2-cM region on chromosome 6q14. This locus appears to be distinct from, but adjacent to, the loci for cone-rod dystrophy 7 (CORD7) and North Carolina macular dystrophy (MCDR1). Future identification of the gene responsible for the disease in this family will provide a better understanding of macular degeneration. (shrink)

Neuronal growth and remodelling are guided by both intracellular gene programs and extracellular stimuli. The growth cone is one site where the effects of these extrinsic and intrinsic factors converge upon the mechanical determinants of cell shape. We review the growth cone as a transduction device, converting extracellular signals into mechanical forces. A variety of soluble, extracellular matrix and membrane bound molecules control growth cone behavior. In addition, GAP‐43 is discussed as a possible component of the Intraneuronal (...) gene program which modulates growth cone activity. The GTP‐binding protein, Go, is a major growth cone membrane protein that may transduce signals not only from outside the cell, but from within as well. This may provide a molecular site in the growth cone for the coordination of a genetic growth program with environmental signals. (shrink)

A simplified definition of point local clocks and the relationship between an inertial reference frame and a class of such clocks, at rest with respect to each other, are used for an algebraic determination of the geometry of Minkowski's space-time on the set of point events. The group of all automorphisms that preserve the time ordering induced by the set of all equivalent local clocks is shown to be generated by the inhomogeneous orthochronous Lorentz group and dilatations, consistently with a (...) well-known result of E. C. Zeeman. The existence of a universal limit velocity and of an invariant clock cone through any event is among the implications of our proof, thus effectively exploiting a suggestion due to F. Severi. (shrink)

This paper proposes that we should think of epistemic agents as having, as one of their intellectual activities, a gatekeeping task: To decide in light of various criteria which ideas they should consider and which not to consider. When this task is performed with excellence, it is conducive to the acquisition of epistemic goods such as truth and knowledge, and the reduction of falsehoods. Accordingly, it is a worthy contender for being an intellectual virtue. Although gatekeeping may strike one simply (...) as the virtue of open- mindedness, I argue that it is not; gatekeeping does not favor a characteristic disposition to be willing to consider novel or opposing ideas. In fact, being told that an agent is excellent at gatekeeping reveals nothing about how frequently she considers or refuses to consider ideas. This paper will introduce and motivate the notion of gatekeeping, and offer some preliminary arguments in support of its candidacy as an intellectual virtue. (shrink)

Open peer commentary on the article “Second-Order Science: Logic, Strategies, Methods” by Stuart A. Umpleby. Upshot: The evaluation of what we knew is an urgent and evolving issue. The issues discussed by Umpleby have been raised earlier, particularly in the social sciences. Arguably, in some quarters they are exaggerated. But an awareness of observer effects is of great importance and is greatly enhanced by second-order cybernetics applied more widely as second-order science.

Considering the lack of substantive scientific or theoretical studies about ethics in small and medium sized enterprises (SMEs) in Latin America, this paper examines the context of an existent paradox, based upon the perspective of experts and academicians of Latin America and the Caribbean. These countries live different realities, due to their respective European cultural influences, as well as to racial and economic issues. Such facts impact the size and characteristics of their industries. On the other hand, the SMEs face (...) more similarities in the region, so they will be treated as a group in the discussion of ethics and corporate social responsibility (CSR) in Latin American SMEs. As this topic has not been sufficiently investigated in this geographic area, the objective of this exploratory study is to offer a contribution for future research. It raises the main dilemmas and intends to explain how legislation and common practices enable and perhaps lead SMEs to choose unethical strategies to survive and compete in the market. These enterprises are growing in number and in job creation, but do not participate in the Gross National Product in the same proportion. Informality, tax evasion and corruption are gradually caused or erode morality in business, but can contribute to corporate social responsibility in the region. The paper tries to show positive and negative aspects of apparently unethical practices and discusses challenging ways to solve complex problems that are common in most Latin America. (shrink)

A frequent objection to the fine-tuning argument has been that although certain necessary conditions for life were admittedly exceedingly improbable, still, the many possible alternative sets of conditions were all equally improbable, so that no special significance is to be attached to the realization of the conditions of life. Some authors, however, have rejected this objection as fallacious. The object of this paper is to state the objection to the fine-tuning argument in a more telling form than has been done (...) hitherto, and to meet the charge of fallacy. (shrink)

Purpose: Yerkish is an artificial language created in 1971 for the specific purpose of exploring the linguistic potential of nonhuman primates. The aim of this paper is to remind the research community of some important issues and concepts related to Yerkish that seem to have been forgotten or appear to be distorted. These are, particularly, its success, its promising aspects for future research and last but not least that it was Ernst von Glasersfeld who invented Yerkish: he coined the term (...) “lexigrams,” created the first 120 of them and designed the grammar that regulated their combination. Design: The first part of this paper begins with a short outline of the context in which the Yerkish language originated: the original LANA project. It continues by presenting the language itself in more detail: first, its design, focusing on its “lexigrams” and its “correlational” grammar, and then its use by the chimpanzee Lana in formulating sentences. The second part gives a brief introduction to the foundation of Yerkish in Silvio Ceccato’s Operational Methodology, particularly his idea of the correlational structure of thought and concludes with the main insights that can be derived from the Yerkish experiment seen in the light of Operational Methodology. Findings: Lana’s success in language learning and the success of Yerkish during the past decades are probably due to the characteristics of Yerkish, particularly its foundation in operational methodology. The operation of correlation could be what constitutes thinking in a chimpanzee and an attentional system could be what delivers the mental content that correlation assembles into triads and networks. Research implications: Since no other assessment or explanation of Lana’s performances has considered these foundational issues, a new research project or program should validate the above-mentioned hypotheses, particularly the correlational structure of chimpanzee thinking. (shrink)

O texto busca refletir criticamente sobre alguns fenômenos sociais contemporâneos, fortemente imbricados, notadamente as tendências contemporâneas de entrincheiramento e achatamento do eu; o reforço da iconomania e da compulsiva produção de avatares de si, em meio a bolhas narcísicas digitais, franqueadas pelas recentes tecnologias de informação e comunicação; e a virtual destruição da intimidade e da privacidade, diante da emergência de panópticos digitais e da vigilância algorítmica. Para tanto, toma-se como ponto de partida proposições apresentadas por Christopher Lasch em sua (...) obra _The Minimal Self: Psychic Survival in Troubled Times_, publicada originalmente em 1984, em particular a própria noção de mínimo eu, as quais são, então, entretecidas com argumentos de Christophe Dejours, Günther Anders, Theodor Adorno, Hebert Marcuse, Jonathan Crary, entre outros. Em acréscimo, busca-se salientar a ancoragem desses processos à hodierna dinâmica de acumulação de capital, a partir da crítica da economia política, perspectiva que atravessa todo o texto, bem como assinalar a atualidade do pensamento de Lasch. (shrink)

In the Dialogues Hume attaches great importance to an objection to the design argument which states, negatively, that from phenomena which embody evil as well as good there can be no analogical inference to the morally perfect deity of traditional theism and, positively, that the proper conclusion as regards moral character is an indifferent designer. The first section of this paper sets out Hume's points, and the next three offer an updating of Hume's objection which will apply to Swinburne's Bayesian (...) form of the design argument. The final section concludes that Hume's objection, suitably developed, holds against most of the main theistic arguments, even in their Bayesian form. (shrink)

Open peer commentary on the target article “Arguments Opposing the Radicalism of Radical Constructivism” by Gernot Saalmann. First paragraph: I appreciate Saalmann’s recognition that “there are considerable differences amongst the authors” and that these “have changed their opinions in the course of time” (§3); but given this, what are the consequences for an outline of the theses of radical constructivism (RC)? Which approach is best for outlining a theory of knowing under these hindering conditions? My suggestion would be to use (...) a method specifically developed for this kind of situation and to present it explicitly, or, if it does not yet exist, to develop one. (shrink)

Open peer commentary on the target article “Who Conceives of Society?” by Ernst von Glasersfeld. First paragraph: Issues such as social interaction and communication play an essential role in my recent approach to knowledge management called “Knowledge Cooperation”, conceived as “the participative cultivation of knowledge in a voluntary, informal social group”. Radical Constructivism provides a substantial support to the foundations of this approach, which aims at equilibrating intellectual and social capital. So I warmly welcome Ernst von Glasersfeld’s clarification of the (...) constructivist position in regard to “society.”. (shrink)

Open peer commentary on the target article “How and Why the Brain Lays the Foundations for a Conscious Self” by Martin V. Butz. Excerpt: Avoiding the term “representation” would make the article much more consistent with a radical constructivist way of thinking. It would also open up unexpected opportunities for realizing the potential of some of its most interesting ideas, such as the connection between anticipatory drive and attention (§31).

Open peer commentary on the article “Constructivism and Computation: Can Computer-Based Modeling Add to the Case for Constructivism?” by Manfred Füllsack. Upshot: Füllsack’s article offers many interesting ideas but falls short of elucidating the relationship between constructivism and computation. It could profit by taking into consideration stronger constructivist foundations such as the distinction between machine and organism, the relationship between reality and the observer, and Ceccato’s theory of attention.