El acercamiento al conocimiento de la naturaleza requiere una metodología adecuada. En este artículo presento la descripción madura que hace Peirce del método científico articulándolo a partir de los tres modos de inferencia. Esta descripción tiene la ventaja de ser muy clara, ya que asigna un tipo de inferencia distinto a cada etapa del método.

In the 19th century, the conflict thesis was forged to explain the science-religion relationship. This thesis presents religion as an obstacle to the development of science. Andrew White publishes a book that is at the origin of this thesis and Charles S. Peirce writes a review of this book in which he shows that there is nothing in religion that opposes scientific progress, but points to four human characteristics that offer difficulties in the face of radical novelties. It is interesting (...) to note how while the conflict thesis was forged, one of the greatest thinkers already shows the weakness of this thesis. (shrink)

La sobrecarga de información resulta un problema epistemológico que preocupa a distintas áreas del conocimiento tales como al campo de las ciencias cognitivas, en su intento por modelar sistemas capaces de detectar relevancia como a la ya olvidada enciclopedística, practicada durante los siglos XVI- XVIII y abocada a la organización, disposición y difusión de la información científica de la época. El presente artículo intenta dar cuenta del fracaso de estos dos campos de investigación a la hora de hallar soluciones ante (...) la problemática de la sobrecarga informacional. Para abordar nuestra cuestión clave, examinaremos particularmente las miradas relativamente pesimistas de H. Dreyfus y de Novalis. Los tratamientos de estos autores demuestran que la sobrecarga de información no puede, ni podrá ser resuelta, si no se recurre a otra vía de investigación por fuera de aquellas que se muestran como insuficientes, a saber: el modelo computacional de la mente (Dreyfus) y la operación enciclopedística clasificatoria (Novalis). (shrink)

This article aims to explore and to analyze three meanings of the project called “encyclopaedistics”, created by the German scientist and thinker Novalis. The examined definitions try to find the identity of this concept through their negative restrictions, namely the various aspects that cannot be applied to the author’s designed conception. In order to accomplish its purpose, this paper focuses on the study of the text entitled Das Allgemeine Brouillon. Materialien zur Enzyklopädistik, where Novalis sketches the notion of encyclopaedistics. This (...) unfinished work enables to discover the shape taken by such project, as well as to connect it with European Enlightenment and encyclopaedistics’s tradition from 16th to 18th centuries. (shrink)

We address a previous finding in the business ethics literature in which accounting professionals in higher rank levels, i.e., “manager” or “partner” of auditing firms, appear to have lower moral reasoning ability than their junior counterparts. Prior investigations have relied upon a similar methodology for estimating ethical beliefs, namely testing “moral reasoning ability” using either the Moral Judgment Interview or Defining Issues Test. In the present study, we use a multiple vignettes approach to test for the existence of the inverse (...) rank-ethical beliefs effect. With only 2 of the 30 vignettes resulting in both managers and partners being more accepting of the ethically charged behaviors, the results presented here using this alternative methodology are generally not supportive of the inverse rank-ethical beliefs phenomenon. We also use a multivariate analysis in order to control for demographic characteristics. Our results suggest that the most robust predictor of ethical attitudes among accounting practitioners is age, not rank within a firm. (shrink)

Conservation scholarship and policies are concerned with the viability of idealized ecological communities constructed using human metrics. We argue that the discipline of conservation assumes an epistemology and ethics of human sovereignty/dominion over animals that leads to violent actions against animals. We substantiate our argument by deconstructing a case study. In the context of recent bushfires in Australia, we examine recent legislation passed by the parliament of New South Wales, policy documents, and academic articles by conservationists that support breaking communities (...) of horses and/or killing 4,000 horses in Kosciuszko National Park, NSW. Theoretically framing our deconstruction against human sovereignty over animals and anthropocentrism, we affirm an intersectional, ecofeminist approach that values animals as relational and vulnerable agents. We uncover first the epistemic violence of categorizing horses as “pests,” and the anthropocentric nature of recently passed legislation in NSW. We analyze next the deficient ethics of NSW's government, and the argument that killing animals is justifiable when they suffer from starvation and dehydration. We close with a realistic proposal that does not involve breaking horses’ communities and/or killing horses, and a plea to the government of NSW and conservationists not to harm any horses in KNP. (shrink)

Recent analysis of genome sequences has identified individuals that are healthy despite carrying severe disease‐associated mutations. A possible explanation is that these individuals carry a second genomic perturbation that can compensate for the detrimental effects of the disease allele, a phenomenon referred to as suppression. In model organisms, suppression interactions are generally divided into two classes: genomic suppressors which are secondary mutations in the genome that bypass a mutant phenotype, and dosage suppression interactions in which overexpression of a suppressor gene (...) rescues a mutant phenotype. Here, we describe the general properties of genomic and dosage suppression, with an emphasis on the budding yeast. We propose that suppression interactions between genetic variants are likely relevant for determining the penetrance of human traits. Consequently, an understanding of suppression mechanisms may guide the discovery of protective variants in healthy individuals that carry disease alleles, which could direct the rational design of new therapeutics. (shrink)

To assess the effectiveness of Visual Thinking Strategies in medical education curricula, a pretest–posttest experimental study design was used to evaluate the impact of participating in VTS workshops on first-year medical students. A total of forty-one intervention and sixty comparative students completed the study which included the analysis of clinical images followed by a measurement of word count, length of time analyzing images, and quality of written observations of clinical images. VTS training increased the total number of words used to (...) describe clinical images, the time spent analyzing the images, and the number of clinically relevant observations. (shrink)

We investigate the emergence of iconicity, specifically a bouba-kiki effect in miniature artificial languages under different functional constraints: when the languages are reproduced and when they are used communicatively. We ran transmission chains of participant dyads who played an interactive communicative game and individual participants who played a matched learning game. An analysis of the languages over six generations in an iterated learning experiment revealed that in the Communication condition, but not in the Reproduction condition, words for spiky shapes tend (...) to be rated by naive judges as more spiky than the words for round shapes. This suggests that iconicity may not only be the outcome of innovations introduced by individuals, but, crucially, the result of interlocutor negotiation of new communicative conventions. We interpret our results as an illustration of cultural evolution by random mutation and selection. (shrink)

ABSTRACT:A wide range of research uses patterns of genetic variation to infer genetic similarity between individuals, typically referred to as genetic ancestry. This research includes inference of human demographic history, understanding the genetic architecture of traits, and predicting disease risk. Researchers are not just structuring an intellectual inquiry when using genetic ancestry, they are also creating analytical frameworks with broader societal ramifications. This essay presents an ethics framework in the spirit of virtue ethics for these researchers: rather than focus on (...) rule following, the framework is designed to build researchers’ capacities to react to the ethical dimensions of their work. The authors identify one overarching principle of intellectual freedom and responsibility, noting that freedom in all its guises comes with responsibility, and they identify and define four principles that collectively uphold researchers’ intellectual responsibility: truthfulness, justice and fairness, anti-racism, and public beneficence. Researchers should bring their practices into alignment with these principles, and to aid this, the authors name three common ways research practices infringe these principles, suggest a step-by-step process for aligning research choices with the principles, provide rules of thumb for achieving alignment, and give a worked case. The essay concludes by identifying support needed by researchers to act in accord with the proposed framework. (shrink)

From the most prominent thinkers in Latin American philosophy, literature, politics, and social science comes a challenge to conventional theories of globalization. The contributors to this volume imagine a discourse in which revolution requires no temporalized march of progress or takeovers of state power but instead aims at local control and the material conditions for human dignity.

Human Resources Practices and unions coexist in some organisations to manage the employment relationships of the workers. In this study, we analyse how the presence/absence of unions and HRPs are combined in private European organisations, and which of these combinations are related to higher levels of wellbeing and the quality of labor relations. Data come from 24,503 workers of private organisations, obtained from the Sixth European Working Conditions Survey. Latent profiles analysis and different analyses of the variance suggested four different (...) profiles. The profile with the greatest presence of HRPs and union presence is related to the highest levels of employees' wellbeing and quality of labor relations in organisations, whereas those organisations with a low level of union presence or HRPs reached the worst levels in employees' wellbeing and quality of labor relations indicators. The results and their practical implications are discussed. (shrink)

This paper presents an overview of the activation of background knowledge during text comprehension. We first review the cognitive processes involved in the activation of inferences during text comprehension, stressing the interaction between text and reader in the construction of situation models. Second, we review evidence for embodied theories of cognition and discuss how this new framework can inform our understanding of the nature and role of background knowledge. We then review the neuropsychological data on the activation of background knowledge (...) during text comprehension. Finally, the paper presents existing and future challenges in researching the role of background knowledge both at a conceptual and a methodological level. (shrink)

ABSTRACTMemory bias is a risk factor for depression. In two independent studies, the efficacy of one CBM-Memory session on negative memory bias and depressive symptoms was tested in vulnerable samples. We compared positive to neutral CBM-Memory trainings in highly-ruminating individuals and individuals with elevated depressive symptoms. In both studies, participants studied positive, neutral, and negative Swahili words paired with their translations. In five study–test blocks, they were then prompted to retrieve either only the positive or neutral translations. Immediately following the (...) training and one week later, we tested cued recall of all translations and autobiographical memory bias; and also measured mood, depressive symptoms, and rumination. Retrieval practice resulted in training-congruent recall both immediately after and one week after the training. Overall, there was no differential decrease in symptoms or difference in autobiographical memory bias between the tra... (shrink)

Patients with strokes to the Anterior Communicating Artery pose an important challenge to rehabilitation teams due to a particular mix of cognitive and behavioral impairments. These deficits often compromise engagement with rehabilitation, learning and generalization. The goal of this article is to describe the long-term presentation of a patient with an ACoA stroke as well as her rehabilitation needs and the many challenges experienced by the rehabilitation team when attempting to facilitate functional, vocational and psychosocial recovery. Based on this case, (...) and the existing literature, a neuropsychological rehabilitation framework to understand and address the specific problems and needs of this population is proposed. This framework demands rehabilitation teams to consider: the slow pattern of recovery of this population, the interaction between cognitive and behavioral impairments, the relevance of physical and social environments, the value of personal projects and the need to include psychological and relational interventions. (shrink)

Un grupo de especialistas se reunieron durante tres días en el XXII Seminario Interdisciplinar de Bioética organizado por la Cátedra de Bioética de la Universidad Pontificia Comillas de Madrid, no simplemente para abordar las cuestiones ...

Existe una línea temática moderna que vincula el trabajo sobre las fuentes clásicas del 3er conde de Shaftesbury con el mosaico filosófico que más tarde desarrollará Johann Georg Hamann: se trata del “proyecto socrático”, que aparece en el primero bajo la idea de unas Chartae socraticae y será motivación para que Hamann recoja el testigo en sus Memorabilia socratica. Se rastrea las raíces shaftesburianas del Sócrates de Hamann –surgidas de su lectura y traducción de juventud: Sensus communis y Carta sobre (...) el entusiasmo– para delimitar. (shrink)

La justificación del ejercicio de la crítica como un derecho fundamental en todo ordenamiento democrático viene despertando mayor interés en los últimos tiempos. El presente trabajo se propone analizar este tema desde la democracia deliberativa de J. Habermas, mostrando algunas similitudes, pero también señalando las diferencias conceptuales con la teoría crítica. La idea es identificar el alcance de la herencia conceptual de la Escuela de Frankfurt en la política deliberativa habermasiana, una conexión que en esta teoría siempre resulta solo implícita (...) pero no explícitamente reconocida como condición de validez y legitimidad democrática del ordenamiento político. (shrink)

La relación entre pragmatismo y teoría política viene siendo explorada de diversas maneras en numerosos trabajos que analizan el tema. La idea es explicitar qué recepción lleva a cabo la filosofía política de los presupuestos del pragmatismo. En este contexto, en el presente trabajo se analiza el tema desde la democracia deliberativa de J. Habermas, señalando de qué modo esta teoría política recepta tales presupuestos teniendo en cuenta el marco teórico del discurso argumentativo, que constituye la base filosófica sobre la (...) cual fundamenta su estructura teórica. Como resultado de este análisis es posible señalar las contribuciones de aquella teoría política para el mejoramiento de la calidad democrática del estado de derecho. (shrink)

El artículo analiza el problema de la relación entre ética y política teniendo en cuenta para ello el trabajo de J. De Zan sobre la “Significación moral de la democracia”. La idea es complementar, no sin señalamientos críticos, dicho trabajo identificando, en primer lugar, el sentido reconstructivo del planteamiento teórico de la democracia deliberativa de J. Habermas. Para este propósito, se explicita también una parte de sus fundamentos filosóficos, como es la pragmática universal del lenguaje, cuya tematización de las pretensiones (...) universales de validez del discurso argumentativo permite identificar el carácter moralmente constitutivo de la racionalidad argumentativa, y por lo tanto de la democracia deliberativa. Aunque de un modo indirecto, este trabajo se propone discutir críticamente también con el actual posicionamiento habermasiano sobre el tema. (shrink)

This paper presents an overview of the activation of background knowledge during text comprehension. We first review the cognitive processes involved in the activation of inferences during text comprehension, stressing the interaction between text and reader in the construction of situation models. Second, we review evidence for embodied theories of cognition and discuss how this new framework can inform our understanding of the nature and role of background knowledge. We then review the neuropsychological data on the activation of background knowledge (...) during text comprehension. Finally, the paper presents existing and future challenges in researching the role of background knowledge both at a conceptual and a methodological level. (shrink)

Issu d'un colloque organisé en octobre 2005 à l'Ecole normale supérieure cet ouvrage collectif replace l'oeuvre de J. Derrida au sein de la tradition philosophique. Il interroge ses concepts, sa relation à certaines figures de cette tradition, la transition qu'elle effectue entre plusieurs moments philosophiques. Cet hommage s'attache à commenter l'oeuvre du philosophe mais aussi à la continuer.

The current times call for reforms in educational processes. The Covid-19 pandemic had an unforeseen impact on the educational system in all countries. This need for change requires new pedagogies and new methods for teaching and learning. Understanding the need for change is essential for the formulation of adaptive proposals, as well as for the generation of training activities to complement the teaching curriculum. New educational practices lead to a vision of educational quality, with new approaches that allow the continuous (...) integration of knowledge and permanent interaction with the student. This paper presents an analysis of the new teaching methodologies in times of confinement due to the pandemic caused by Covid-19. Keywords: Teaching methodologies, educational system, learning process. References [1]É. Tremblay-Wragg, C. Raby, L. Ménard y I. Plante, «El uso de estrategias didácticas diversificadas por cuatro profesores universitarios: ¿qué contribución a la motivación de aprendizaje de sus alumnos?,» Docencia en educación superior, vol. 26, nº 21, 2021. [2]L. Czerniewicz, R. Mogliacci, S. Walji, A. Cliff, B. Swinnerton y N. Morris, «Enseñanza y aprendizaje académico en el nexo: desagregación, mercantilización y digitalización en la educación superior,» Teaching in Higher Education, vol. 26, nº 2021, p. 16, 2021. [3]S. Dogan y A. Adam, «Aumentar el efecto del desarrollo profesional en la instrucción efectiva a través de comunidades profesionales,» Docentes y docencia: teoría y práctica, vol. 26, nº 3-4, pp. 326-349, 2020. [4]I. M. Torres Salas, «La enseñanza tradicional de las ciencias versus las nuevas tendencias educativas,» Educare, vol. 14, nº 1, pp. 131-142, 2010. [5]B. Fabio, J. Antonio Palomino y J. González Henríquez, «Evaluación y contraste de los métodos de enseñanza tradicional y lúdico,» Revista de Educación física y deportes, vol. 13, nº 94, pp. 29-36, 2008. [6]Y. Benítez y C. Mora, «Enseñanza tradicional vs aprendizaje activo,» Revista Cubana de Física, vol. 27, nº 2A, pp. 175-179, 2010. [7]P. Morales Bueno y V. Landa Fitzgerald, «Aprendizaje basado en problemas,» Theoria, vol. 13, nº 1, pp. 145-157, 2004. [8]R. Gil-Galván, I. Martín-Espinosa y F. Gil-Galván, «University student perceptions of competences acquired through problem-based learning,» Educación XXI, vol. 24, nº 1, pp. 271-295, 2020. [9]E. Ortiz Cermeño, «El aprendizaje basado en problemas,» Perfiles Educativos, vol. 41, nº 164, pp. 208-213, 2019. [10]E. Araos-Baeriswyl, C. Moll-Manzur, Á. Paredes y J. Landeros, «Aprendizaje invertido: un enfoque pedagógico en tiempos de pandemia,» Rev. Atención Primaria, vol. 53, nº 1, p. 117, 2021. [11]V. León-Carrascosa, M. Belando-Montoro y S. Sánchez-Serrano, «Design and validation of a questionnaire to evaluate the service-learning methodology,» Rev.Estudios sobre educación, vol. 39, nº 1, pp. 247-266, 2020. [12]J. Collado-Ruano, M. Ojeda, M. Malo y D. Amino, «Educación, arte e interculturalidad: El cine documental como lenguaje comunicativo y tecnología innovadora para el aprendizaje de la metodología I + D + I,» Rev. Texto livre, vol. 13, nº 3, pp. 376-393, 2020. [13]P. M. Bueno y V. Landa Fitzgerald, «Aprendizaje basado en problemas,» Theoria, vol. 13, nº 1, pp. 145-157, 2004. [14]J. A. Martí, M. Heydrich, M. Rojas y A. Hernández, «Aprendizaje basado en proyectos: Una experiencia de innovación docente,» Universidad EAFIT, vol. 46, nº 158, pp. 11-21, 2010. [15]L. Rojas y N. M. Jaimes, «Canvas LMS y el trabajo colaborativo como metodología de aprendizaje en entornos virtuales,» de Congreso Ibérico de Sistemas y Tecnologías de la Información, CISTI, Bogotá, Colombia, 2020. [16]B. Bordel y P. Mareca, «Results and Trends in educational MOOCs in the engineering area with MIRIADAX platform. A case study,» de 15th Iberian Conference on Information Systems and Technologies, CISTI 2020; Seville; Sevilla, España, 2020. [17]K. Vermeir y G. Kelchtermans, «Innovative practice as interpretative negotiation.A case-study on the kamishibai in Kindergarten.,» Teachers and Teaching: Theory and Practice, vol. 26, nº 3-4, pp. 248-263, 2020. [18]B. Tucker, «The Flipped Classroom: Online instruction at home frees class time for learning,» Education Next, vol. 1, nº 1, pp. 82-84, 2012. [19]M. V. Ledo, N. R. Michelena, N. N. Cao, I. d. R. M. Suárez y M. N. Vialart Vidal, « Aula invertida, nueva estrategia didáctica,» Educación Médica Superior, vol. 30, nº 3, pp. 678-688, 2016. [20]Metodologías activas por medio de las TIC, [Online]. Available: https://www.campuseducacion.com/blog/recursos/articulos-campuseducacion metodologias-activas-por-medio-de-las-tic/?cn-reloaded=1. [Last access: February 14, 2021]. (shrink)

Also known as the "Portuguese Aristotle", Pedro da Fonseca S. J. (1527-1599) was a prominent figure in early modern Scholasticism and particularly in the history of the Society of Jesus. He took part in the writing of the Society's Ratio Studiorum and laid the groundwork for the publication of the famous Cursus Conimbricensis (1592-1606). Furthermore, he was the author of an influential handbook of logic and dialectics (the Institutionum Dialecticarum, 1564), in addition to being one of the most important and (...) recognized commentators on Aristotle's Metaphysics in the sixteenth century (by his unfinished Commentaria, 1577-1612). This volume is the first collection of essays in English devoted to Fonseca, to his intellectual production, and his thought. The book gathers nine essays from scholars worldwide, among which are some of the most important current specialists in early modern Scholasticism, in Portuguese Aristotelianism, and the history of the Society of Jesus. So the volume presents, for the first time, a reliable portrait of the institutional role and the thought of Fonseca about many important questions of Western Metaphysics, as well as the reception of his work in the early modern age. (shrink)

In this study a combination of computer tools for coupling and virtual screening is detailed, in 108 active molecules and 3620 decoys to find stabilizers for G quadruplex. To have more precise results, combinations of coupling programs with fifteen energy scoring functions were applied. The validation and evaluation of the metrics was done with the CompScore genetic algorithm. The results showed an increase in BEDROC and EF of 50% compared to other strategies, as well as reflecting early recognition of active (...) molecules. From these results it is possible to work with the molecules that showed a good early recognition and evaluate their effect as G4 stabilizers. This ensures more efficient and accurate results in the preclinical stage for the development of anticancer drugs. Keywords: Enrichment metrics; telomere; G quadruplex ; CompScore. References [1]M. Porru, P. Zizza, M. Franceschin, C. Leonetti and A. Biroccio. «EMICORON: A multi-targeting G4 ligand with a promising preclinical profile» 2017. Biochimica et Biophysica Acta - General Subjects, 1861, 1362–1370. [Online]. Available: https://doi.org/10.1007/s00294-018-0836-6. [2]K. Tomita. «How long does telomerase extend telomeres? Regulation of telomerase release and telomere length homeostasis». Current Genetics, 64, 1177–1181. 2018. [Online]. Available: https://doi.org/10.1016/j.bbagen. 2016.11.010. [3]M. Jafri, S. Ansari, M. Alqahtani and J. Shay. «Roles of telomeres and telomerase in cancer, and advances in telomerase-targeted therapies. Genome Medicine., 2016. [Online]. Available: https://doi.org/10.3390/ijms19020482. [4]J. Huppert and S. Balasubramanian. «G-quadruplexes in promoters throughout the human genome». 35, 406–413. 2007. [Online]. Available: https://doi.org/10.1016/j.bbapap.2017.06.012. [5]S. Joy, Vijayakumar, S. Choi and H. Sunhye. «Role of computer-aided drug design in modern drug discovery». Archives of Pharmacal Research. 2015. [Online]. Available: https://doi.org/10.1007/s12272-015-0640-5. [6]S. Asamitsu, S. Obata, Z. Yu, T. Bando and H. Sugiyama. «Recent Progress of Targeted G-Quadruplex-Preferred Ligands Toward Cancer Therapy». Molecules, 24, 429. 2019. [En línea]. Available: https://doi.org/10.3390/molecules24030429. [7]R. Monsen and J. Trent. «Biochimie G-quadruplex virtual drug screening : A review». Biochimie, 152, 134–148. 2018. [Online]. Available: https://doi.org/10.1039/c9cc06748e. [8]J. Beauvarlet, P. Bensadoun, E. Darbo, G. Labrunie, E. Richard, I. Draskovic and M. Djavaheri-mergny. «Modulation of the ATM / autophagy pathway by a G-quadruplex ligand tips the balance between senescence and apoptosis in cancer cells». 1–18. 2019. [Online]. Available: https://doi.org/10.1093/nar/gkz095. [9].Z. Crees, J. Girard, Z. Rios, G. Botting, K. Harrington and C. Shearrow. « Oligonucleotides and G-quadruplex stabilizers: targeting telomeres and telomerase in cancer therapy».2014. [Online]. Available: https://doi.org/10.2174/1381612820666140630100702. [10].M. Meier, A. Moya-torres, N. Krahn, M. Mcdougall, L. Orriss, E. Mcrae and T. Patel. «Structure and hydrodynamics of a DNA Gquadruplex with a cytosine bulge»., 1–13. 2018. [Online]. Available: https://doi.org/10.1093/nar/gky307. (shrink)

In General Relativity in Hamiltonian form, change has seemed to be missing, defined only asymptotically, or otherwise obscured at best, because the Hamiltonian is a sum of first-class constraints and a boundary term and thus supposedly generates gauge transformations. Attention to the gauge generator G of Rosenfeld, Anderson, Bergmann, Castellani et al., a specially _tuned sum_ of first-class constraints, facilitates seeing that a solitary first-class constraint in fact generates not a gauge transformation, but a bad physical change in electromagnetism or (...) General Relativity. The change spoils the Lagrangian constraints, Gauss's law or the Gauss-Codazzi relations describing embedding of space into space-time, in terms of the physically relevant velocities rather than auxiliary canonical momenta. But the resemblance between the gauge generator G and the Hamiltonian H leaves still unclear where objective change is in GR. Insistence on Hamiltonian-Lagrangian equivalence, a theme emphasized by Castellani, Sugano, Pons, Salisbury, Shepley and Sundermeyer among others, holds the key. Taking objective change to be ineliminable time dependence, one recalls that there is change in vacuum GR just in case there is no time-like vector field xi^a satisfying Killing's equation L_xi g_mn=0, because then there exists no coordinate system such that everything is independent of time. Throwing away the spatial dependence of GR for convenience, one finds explicitly that the time evolution from Hamilton's equations is real change just when there is no time-like Killing vector. The inclusion of a massive scalar field is simple. No obstruction is expected in including spatial dependence and coupling more general matter fields. Hence change is real and local even in the Hamiltonian formalism. The considerations here resolve the Earman-Maudlin standoff over change in Hamiltonian General Relativity: the Hamiltonian formalism is helpful, and, suitably reformed, it does not have absurd consequences for change and observables. Hence the classical problem of time is resolved. The Lagrangian-equivalent Hamiltonian analysis of change in General Relativity is compared to Belot and Earman's treatment. The more serious quantum problem of time, however, is not automatically resolved due to issues of quantum constraint imposition. (shrink)

In Dirac-Bergmann constrained dynamics, a first-class constraint typically does not _alone_ generate a gauge transformation. By direct calculation it is found that each first-class constraint in Maxwell's theory generates a change in the electric field E by an arbitrary gradient, spoiling Gauss's law. The secondary first-class constraint p^i,_i=0 still holds, but being a function of derivatives of momenta, it is not directly about E. Only a special combination of the two first-class constraints, the Anderson-Bergmann -Castellani gauge generator G, leaves E (...) unchanged. This problem is avoided if one uses a first-class constraint as the generator of a _canonical transformation_; but that partly strips the canonical coordinates of physical meaning as electromagnetic potentials and makes the electric field depend on the smearing function, bad behavior illustrating the wisdom of the Anderson-Bergmann Lagrangian orientation of interesting canonical transformations. The need to keep gauge-invariant the relation dot{q}- dH/dp= -E_i -p^i=0 supports using the primary Hamiltonian rather than the extended Hamiltonian. The results extend the Lagrangian-oriented reforms of Castellani, Sugano, Pons, Salisbury, Shepley, _etc._ by showing the inequivalence of the extended Hamiltonian to the primary Hamiltonian even for _observables_, properly construed in the sense implying empirical equivalence. Dirac and others have noticed the arbitrary velocities multiplying the primary constraints outside the canonical Hamiltonian while apparently overlooking the corresponding arbitrary coordinates multiplying the secondary constraints _inside_ the canonical Hamiltonian, and so wrongly ascribed the gauge quality to the primaries alone, not the primary-secondary team G. Hence the Dirac conjecture about secondary first-class constraints rests upon a false presupposition. The usual concept of Dirac observables should also be modified to employ the gauge generator G, not the first-class constraints separately, so that the Hamiltonian observables become equivalent to the Lagrangian ones such as the electromagnetic field F. (shrink)

Change and local spatial variation are missing in canonical General Relativity's observables as usually defined, an aspect of the problem of time. Definitions can be tested using equivalent formulations of a theory, non-gauge and gauge, because they must have equivalent observables and everything is observable in the non-gauge formulation. Taking an observable from the non-gauge formulation and finding the equivalent in the gauge formulation, one requires that the equivalent be an observable, thus constraining definitions. For massive photons, the de Broglie-Proca (...) non-gauge formulation observable A_{\mu} is equivalent to the Stueckelberg-Utiyama gauge formulation quantity A_{\mu} + \partial_{\mu} \phi, which must therefore be an observable. To achieve that result, observables must have 0 Poisson bracket not with each first-class constraint, but with the Rosenfeld-Anderson-Bergmann-Castellani gauge generator G, a tuned sum of first-class constraints, in accord with the Pons-Salisbury-Sundermeyer definition of observables. The definition for external gauge symmetries can be tested using massive gravity, where one can install gauge freedom by parametrization with clock fields X^A. The non-gauge observable g^{\mu\nu} has the gauge equivalent X^A,_{\mu} g^{\mu\nu} X^B,_{\nu}. The Poisson bracket of X^A,_{\mu} g^{\mu\nu} X^B,_{\nu} with G turns out to be not 0 but a Lie derivative. This non-zero Poisson bracket refines and systematizes Kuchař's proposal to relax the 0 Poisson bracket condition with the Hamiltonian constraint. Thus observables need covariance, not invariance, in relation to external gauge symmetries. The Lagrangian and Hamiltonian for massive gravity are those of General Relativity + \Lambda + 4 scalars, so the same definition of observables applies to General Relativity. Local fields such as g_{\mu\nu} are observables. Thus observables change. Requiring equivalent observables for equivalent theories also recovers Hamiltonian-Lagrangian equivalence. (shrink)

Change and local spatial variation are missing in Hamiltonian general relativity according to the most common definition of observables as having 0 Poisson bracket with all first-class constraints. But other definitions of observables have been proposed. In pursuit of Hamiltonian–Lagrangian equivalence, Pons, Salisbury and Sundermeyer use the Anderson–Bergmann–Castellani gauge generator G, a tuned sum of first-class constraints. Kuchař waived the 0 Poisson bracket condition for the Hamiltonian constraint to achieve changing observables. A systematic combination of the two reforms might (...) use the gauge generator but permit non-zero Lie derivative Poisson brackets for the external gauge symmetry of General Relativity. Fortunately one can test definitions of observables by calculation using two formulations of a theory, one without gauge freedom and one with gauge freedom. The formulations, being empirically equivalent, must have equivalent observables. For de Broglie-Proca non-gauge massive electromagnetism, all constraints are second-class, so everything is observable. Demanding equivalent observables from gauge Stueckelberg–Utiyama electromagnetism, one finds that the usual definition fails while the Pons–Salisbury–Sundermeyer definition with G succeeds. This definition does not readily yield change in GR, however. Should GR’s external gauge freedom of general relativity share with internal gauge symmetries the 0 Poisson bracket, or is covariance sufficient? A graviton mass breaks the gauge symmetry, but it can be restored by parametrization with clock fields. By requiring equivalent observables, one can test whether observables should have 0 or the Lie derivative as the Poisson bracket with the gauge generator G. The latter definition is vindicated by calculation. While this conclusion has been reported previously, here the calculation is given in some detail. (shrink)

Machine generated contents note: Cajal and Consciousness: Introduction. By PEDRO C. MARIJUAN1 -- Part I. Consciousness, One Hundred Years after Textura -- Progress in the Neural Sciences in the Century after Cajal (and the Mysteries -- That Remain). By THOMAS D. ALBRIGHT, THOMAS M. JESSELL, -- ERIC R. KANDEL, AND MICHAEL I. POSNER11 -- Part II. Biological Complexity and the Emergence of Consciousness -- Consciousness, Reduction, and Emergence: Some Remarks. -- By MURRAY GELL-MANN41 -- The Epistemic Paradox of Mind and (...) Matter. By HAROLD J. MOROWITZ50 -- The Conscious Cell. BY LYNN MARGULIS55 -- Complexity and Tinkering. By FRANCOIS JACOB71 -- Consciousness, the Brain, and Spacetime Geometry. By STUART HAMEROFF. 74 -- Consciousness, the Brain, and Spacetime Geometry: An Addendum-Some -- New Developments on the Orch OR Model for Consciousness. -- By ROGER PENROSE105 -- Part III. From Primary to Higher-level Consciousness -- Consciousness: The Remembered Present. By GERALD EDELMAN111 -- Consciousness and the Binding Problem. By WOLF SINGER123 -- Cajal on Neurons, Molecules, and Consciousness. By JEAN-PIERRE CHANGEUX 147 -- A Neuronal Model of a Global Workspace in Effortful Cognitive Tasks. By -- STANISLAS DEHAENE, MICHEL KERSZBERG, AND JEAN-PIERRE -- CHANGEUX152 -- Consciousness and the Brain: The Thalamocortical Dialogue in Health and -- Disease. By RODOLFO LLINAS AND URS RIBARY166 -- The Neuroanatomy of Phenomenal Vision: A Psychological Perspective. -- ByPETRA STOERIG176 -- Co-evolution of Human Consciousness and Language. By MICHAEL A. ARBIB 195 -- From Computing with Numbers to Computing with Words-From -- Manipulation of Measurements to Manipulations of Perceptions. -- By LOTFI A. ZADEH221 -- Part IV. Closing Remarks -- Who Was Cajal? By ALBERTO PORTERA-SANCHEZ253 -- Index of Contributors259 -- Subject Index261. (shrink)