La subtitulación aficionada de animación japonesa: una aproximación intertextual

El presente artículo constituye una aproximación a la subtitulación aficionada de animación japonesa (saaj) desde la perspectiva de la intertextualidad. Se busca, en lo esencial, mostrar la idoneidad del marco teórico adoptado para el estudio de actividades discursivas de la compleja naturaleza de la saaj y proporcionar la base para una consideración adecuada de esta práctica en particular

Multivector Field Formulation of Hamiltonian Field Theories: Equations and Symmetries

We state the intrinsic form of the Hamiltonian equations of first-order Classical Field theories in three equivalent geometrical ways: using multivector fields, jet fields and connections. Thus, these equations are given in a form similar to that in which the Hamiltonian equations of mechanics are usually given. Then, using multivector fields, we study several aspects of these equations, such as the existence and non-uniqueness of solutions, and the integrability problem. In particular, these problems are analyzed for the case of Hamiltonian systems defined in a submanifold of the multimomentum bundle. Furthermore, the existence of first integrals of these Hamiltonian equations is considered, and the relation between {\sl Cartan-Noether symmetries} and {\sl general symmetries} of the system is discussed. Noether's theorem is also stated in this context, both the ``classical'' version and its generalization to include higher-order Cartan-Noether symmetries. Finally, the equivalence between the Lagrangian and Hamiltonian formalisms is also discussed.Comment: Some minor mistakes are corrected. Bibliography is updated. To be published in J. Phys. A: Mathematical and Genera

Active commuting and the health of workers

Introduction: Research has shown that commuting is related to the health of workers, and that mode choice may have a range of effects on this relationship. We analyze the relationship between active commuting (walking and cycling) and the health status reported by US workers. Methods: We use the 2014–2016 Eating and Health (EH) Module of the American Time Use Survey (ATUS). We estimate Ordinary Least Squares models on a measure of subjective health that is the self-reported assessment of individual general health status, and on the body mass index. Results: longer commutes by bicycle are significantly related to higher levels of subjective health and to lower body mass index, while commuting by walking is only weakly related to both health measures. We test the robustness of our results to possible measurement error in commuting times, to the exclusion of compensating factors, to the estimation method, and to the inclusion of time devoted to leisure-based physical activities. Conclusions: Our results may help policy makers in evaluating the importance of infrastructures that facilitate the use of bicycles as a means of transport, boosting investment in these infrastructures, especially in larger cities

La transición de la ortografía casera a la académica en un corpus de folletos políticos chilenos (1880-1939)

This article aims at contributing to the documentation of the transition from the spelling system known as ortografía chilena (‘Chilean orthography’) or ortografía casera (‘domestic orthography’) to that of the Royal Spanish Academy in Chile by studying the collection of political pamphlets made available to the public digitally by the Library of the National Congress of Chile. The analysis of 35 pamphlets printed between 1880 and 1939 shows a progressive adoption of the academic model, which by 1910 already seemed widely predominant. Thus, the possibility is raised that the 1927 decree establishing the adoption of the academic orthography was but the official reaffirmation of a tendency noticeable in the country since almost two decades before, at least as far as the genre under study is concerned.Este artículo busca contribuir en la documentación de la transición de la ortografía llamada chilena o casera a la de la Real Academia Española en Chile a través del estudio de la colección de folletos políticos que la Biblioteca del Congreso Nacional de Chile ha puesto a disposición del público en formato digital. El análisis de 35 folletos impresos entre 1880 y 1939 muestra una progresiva adopción del modelo académico, el cual ya a partir de la década de 1910 se muestra como ampliamente predominante. En consecuencia, se plantea la posibilidad de que el decreto de 1927 que estableció la adopción de la ortografía académica no fuera más que la reafirmación oficial de una tendencia observable hacía ya casi dos décadas en el país, al menos por lo que respecta al género en estudio

Quantum Conductance Steps in Solutions of Multiwalled Carbon Nanotubes

We have prepared solutions of multiwalled carbon nanotubes in Aroclor 1254, a mixture of polychlorinated biphenyls. The solutions are stable at room temperature. Transport measurements were performed using a scanning--tunneling probe on a sample prepared by spin--coating of the solution on gold substrates. Conductance steps were clearly seen. An histogram of a high number of traces shows maximum peaks at integer values of the conductance quantum $G_0 = 2e^2/h$, demonstrating ballistic transport at room temperature along the carbon nanotube over distances longer than $1.4\mu m$.Comment: 4 pages and 2 figure

The shift from plant-plant facilitation to competition under severe water deficit is spatially explicit

The stress-gradient hypothesis predicts a higher frequency of facilitative interactions as resource limitation increases. Under severe resource limitation, it has been suggested that facilitation may revert to competition, and identifying the presence as well as determining the magnitude of this shift is important for predicting the effect of climate change on biodiversity and plant community dynamics. In this study, we perform a meta-analysis to compare temporal differences of species diversity and productivity under a nurse plant (Retama sphaerocarpa) with varying annual rainfall quantity to test the effect of water limitation on facilitation. Furthermore, we assess spatial differences in the herbaceous community under nurse plants in situ during a year with below-average rainfall. We found evidence that severe rainfall deficit reduced species diversity and plant productivity under nurse plants relative to open areas. Our results indicate that the switch from facilitation to competition in response to rainfall quantity is nonlinear. The magnitude of this switch depended on the aspect around the nurse plant. Hotter south aspects under nurse plants resulted in negative effects on beneficiary species, while the north aspect still showed facilitation. Combined, these results emphasize the importance of spatial heterogeneity under nurse plants for mediating species loss under reduced precipitation, as predicted by future climate change scenarios. However, the decreased water availability expected under climate change will likely reduce overall facilitation and limit the role of nurse plants as refugia, amplifying biodiversity loss

On the k-Symplectic, k-Cosymplectic and Multisymplectic Formalisms of Classical Field Theories

The objective of this work is twofold: First, we analyze the relation between the k-cosymplectic and the k-symplectic Hamiltonian and Lagrangian formalisms in classical field theories. In particular, we prove the equivalence between k-symplectic field theories and the so-called autonomous k-cosymplectic field theories, extending in this way the description of the symplectic formalism of autonomous systems as a particular case of the cosymplectic formalism in non-autonomous mechanics. Furthermore, we clarify some aspects of the geometric character of the solutions to the Hamilton-de Donder-Weyl and the Euler-Lagrange equations in these formalisms. Second, we study the equivalence between k-cosymplectic and a particular kind of multisymplectic Hamiltonian and Lagrangian field theories (those where the configuration bundle of the theory is trivial).Comment: 25 page

Effect of Mg Alloying Addition on Dissolution Behavior of Oxide Films in Al-Si-Mg Alloys

Cyclic polarization measurements were carried out for Al-10%Si- X%Mg (X: 3%, 6% and 9.5%) alloys in borate solutions with and without additions of 50 mM NaCl. The voltammetric response exhibited some features of oxide film growth consistent with the high field conduction model. However, higher currents and distortions in the voltammetric wave shape compared to those for pure Al were ascribed to a possible incorporation of alloying elements in the oxide film, rendering it more defective, and to the strong electrochemical activity of Mg2Si particles.Cyclic polarization measurements were carried out for Al-10%Si- X%Mg (X: 3%, 6% and 9.5%) alloys in borate solutions with and without additions of 50 mM NaCl. The voltammetric response exhibited some features of oxide film growth consistent with the high field conduction model. However, higher currents and distortions in the voltammetric wave shape compared to those for pure Al were ascribed to a possible incorporation of alloying elements in the oxide film, rendering it more defective, and to the strong electrochemical activity of Mg2Si particles