Los nahuas de Tzintzuntzan-Huitzitzilan, Michoacán: historia, mito y legitimación de un señorío prehispánico

Los nahuas de Tzintzuntzan-Huitzitzilan, Michoacán: historia, mito y legitimación de un señorío prehispánico. La historiografía moderna sobre el Michoacán de fines del siglo xv y principios del siglo xvi enfatiza el éxito político-económico de los tarascos y de su principal linaje uacúsecha pero dedica relativamente poca atención a los demás grupos étnicos que radicaban en la región. Este artículo trata de la naturaleza y fuerza de las tradiciones históricas nahuas de Michoacán, con especial atención para el caso de Tzintzuntzan-Huitzitzilan, lugar que al momento de la conquista española era la capital del señorío uacúsecha. La presencia de los nahuas y su interacción con los tarascos no sólo llegaron a formar parte de las diversas visiones locales del pasado sino también tal vez hayan influido las miradas históricas de los vecinos nahuas del occidente y centro de México, quienes en sus narraciones de origen, migración y establecimiento de sus propios señoríos frecuentemente establecían una relación directa con el poblamiento de Michoacán. Estas tradiciones históricas claramente cumplen fines de legitimación y constituyen una compleja mezcla de registros de determinados sucesos, representaciones cosmológicas, así como símbolos religiosos y políticos.Les Nahua de Tzintzuntzan-Huitzitzilan, Michoacán: histoire, mythe et légitimation d’une seigneurie préhispanique. L’historiographie moderne sur le Michoacán de la fin du xve siècle et du début du xvie siècle accorde beaucoup d’importance au succès politico-économique des Tarasques et de leur lignage principal uacúsecha. En revanche, elle consacre relativement peu d’attention aux autres groupes ethniques qui habitaient la région. Cet article traite de la nature et de la force des traditions historiques nahua du Michoacán, particulièrement celles de Tzintzuntzan-Huitzitzilan, capitale de la seigneurie uacúsecha. La présence des Nahua et leur interaction avec les Tarasques font non seulement partie des diverses visions locales du passé, mais ont aussi probablement influé sur les vues historiques des voisins nahua de l’ouest et du centre du Mexique. Ces derniers établissaient fréquemment, dans les narrations d’origine, de migration et de fondation de leurs seigneuries, une relation directe avec le peuplement du Michoacán. Ces traditions historiques avaient clairement une intention de légitimation et constituent un mélange complexe de registres de faits précis, de représentations cosmologiques, ainsi que de symboles religieux et politiques.The Nahuas of Tzintzuntzan-Huitzitzilan, Michoacán: history, myth and legitimization of a Prehispanic señorío. Modern historiography on 15th and early 16th century Michoacán emphasizes the political-economical success of the Tarascans and their uacúsecha lineage but pays relatively little attention to other ethnic groups that lived in the region. This article deals with the nature and strength of the historical traditions of the Nahuas in Michoacán, paying special attention to the case of Tzintzuntzan-Huitzitzilan, a place which at the time of the Spanish conquest was the capital of the uacúsecha señorío. The presence of the Nahuas and their interaction with the Tarascans not only became part of the diverse local visions of the past but possibly also influenced the historical views of the Nahua neighbors from West and Central México. The latter frequently established a direct relation with the population of Michoacán in narratives about origin, migration and foundation of their own señoríos. These historical traditions clearly served the purpose of legitimization and constitute a complex blend of registered events, cosmological representations, as well as religious and political symbolism

Multivalent interaction and selectivities in selectin binding of functionalized gold colloids decorated with carbohydrate mimetics

Colloidal gold particles with functionalized organic shells were applied as novel selectin binders. The ligand shell was terminated with different monocyclic carbohydrate mimetics as simplified analogs of the sLe(x) unit found in biological selectin ligands. The multivalent presentation of the sulfated selectin binding epitopes on the gold particles led to extremely high binding affinities towards L- and P-selectin and IC(50) values in the subnanomolar range. Depending on the ring size of the sulfated carbohydrate mimetic, its substitution pattern and its configuration, different selectivities for either L-selectin or P-selectin were obtained. These selectivities were not found for gold particles with simple acyclic sulfated alcohols, diols and triols in the ligand shell. In addition, the influence of the particle size and the thickness of the hydrophobic organic shell were systematically investigated

Multibridge VO2-Based Resistive Switching Devices in a Two-Terminal Configuration

Abstract Vanadium dioxide exhibits a hysteretic insulator‐to‐metal transition (IMT) near room temperature, forming the foundation for various forms of resistive switching devices. Usually, these are realized in the form of two‐terminal bridge‐like structures. The authors show here that by incorporating multiple, parallel VO2 bridges in a single two‐terminal device, a wider range of possible characteristics can be obtained, including a manifold of addressable resistance states. Different device configurations are studied, in which the number of bridges, the bridge dimensions, and the interbridge distances are varied. The switching characteristics of the multibridge devices are influenced by the thermal cross‐talk between the bridges. Scanning thermal microscopy (SThM) is used to image the current distributions at various voltage/current bias conditions. This work presents a route to realize devices exhibiting highly nonlinear, multistate current–voltage characteristics, with potential applications in, e.g., tunable electronic components and novel, neuromorphic information processing circuitry

Beyond domain alignment: Revealing the effect of intrinsic magnetic order on electrochemical water splitting

To reach a long term viable green hydrogen economy, rational design of active oxygen evolution reaction (OER) catalysts is critical. An important hurdle in this reaction originates from the fact that the reactants are singlet molecules, whereas the oxygen molecule has a triplet ground state with parallel spin alignment, implying that magnetic order in the catalyst is essential. Accordingly, multiple experimentalists reported a positive effect of external magnetic fields on OER activity of ferromagnetic catalysts. However, it remains a challenge to investigate the influence of the intrinsic magnetic order on catalytic activity. Here, we tuned the intrinsic magnetic order of epitaxial La$_{0.67}$Sr$_{0.33}$MnO$_{3}$ thin film model catalysts from ferro- to paramagnetic by changing the temperature in-situ during water electrolysis. Using this strategy, we show that ferromagnetic ordering below the Curie temperature enhances OER activity. Moreover, we show a slight current density enhancement upon application of an external magnetic field and find that the dependence of magnetic field direction correlates with the magnetic anisotropy in the catalyst film. Our work thus suggests that both the intrinsic magnetic order in La$_{0.67}$Sr$_{0.33}$MnO$_{3}$ films and magnetic domain alignment increase their catalytic activity. We observe no long-range magnetic order at the catalytic surface, implying that the OER enhancement is connected to the magnetic order of the bulk catalyst. Combining the effects found with existing literature, we propose a unifying picture for the spin-polarized enhancement in magnetic oxide catalysts.Comment: The following article will be submitted to Applied Physics Reviews. Main text (incl. references) 19 pages, 8 figures. Supplementary text 9 pages, 13 figure

The effect of intrinsic magnetic order on electrochemical water splitting

To reach a long term viable green hydrogen economy, rational design of active oxygen evolution reaction (OER) catalysts is critical. An important hurdle in this reaction originates from the fact that the reactants are singlet molecules, whereas the oxygen molecule has a triplet ground state with parallel spin alignment, implying that magnetic order in the catalyst is essential. Accordingly, multiple experimentalists reported a positive effect of external magnetic fields on OER activity of ferromagnetic catalysts. However, it remains a challenge to investigate the influence of the intrinsic magnetic order on catalytic activity. Here, we tuned the intrinsic magnetic order of epitaxial La0.67Sr0.33MnO3 thin film model catalysts from ferro- to paramagnetic by changing the temperature in situ during water electrolysis. Using this strategy, we show that ferromagnetic ordering below the Curie temperature enhances OER activity. Moreover, we show a slight current density enhancement upon application of an external magnetic field and find that the dependence of magnetic field direction correlates with the magnetic anisotropy in the catalyst film. Our work, thus, suggests that both the intrinsic magnetic order in La0.67Sr0.33MnO3 films and magnetic domain alignment increase their catalytic activity. We observe no long-range magnetic order at the catalytic surface, implying that the OER enhancement is connected to the magnetic order of the bulk catalyst. Combining the effects found with existing literature, we propose a unifying picture for the spin-polarized enhancement in magnetic oxide catalysts.</p

Controlling genetic heterogeneity in gene-edited hematopoietic stem cells by single-cell expansion

Gene editing using engineered nucleases frequently produces unintended genetic lesions in hematopoietic stem cells (HSCs). Gene-edited HSC cultures thus contain heterogeneous populations, the majority of which either do not carry the desired edit or harbor unwanted mutations. In consequence, transplanting edited HSCs carries the risks of suboptimal efficiency and of unwanted mutations in the graft. Here, we present an approach for expanding gene-edited HSCs at clonal density, allowing for genetic profiling of individual clones before transplantation. We achieved this by developing a defined, polymer-based expansion system and identifying long-term expanding clones within the CD201 +CD150 +CD48 -c-Kit +Sca-1 +Lin - population of precultured HSCs. Using the Prkdc scid immunodeficiency model, we demonstrate that we can expand and profile edited HSC clones to check for desired and unintended modifications, including large deletions. Transplantation of Prkdc-corrected HSCs rescued the immunodeficient phenotype. Our ex vivo manipulation platform establishes a paradigm to control genetic heterogeneity in HSC gene editing and therapy