Las transformaciones de un fandomen tiempos de aislamiento: El caso del Círculo de Lectores de Harry Potter Argentina; Fandom Transformation in Times of Isolation: The Case of Harry Potter Reading Club in Argentina Aller, Roberta; Cuestas, Paula En el artículo se muestran las transformaciones que atravesó un club de fans de Harry Potter, a partir de las medidas de aislamiento social dispuestas frente al avance del COVID-19. Se describen los orígenes del club, ligados a un momento de expansión de las tecnologías digitales y los encuentros "cara-a-cara" habitualmente organizados por el club. Como objetivo central, mediante una metodología de etnografía digital se analizan las nuevas dinámicas que lleva adelante el CHP en un contexto de obligada "virtualidad"; The article shows the transformations that a Harry Potter fan`s club went through as a result of the social isolation measures set out in the face of COVID-19’s spread. The origins of the club are described, bound to a time characterized by the expansion of digital technologies and the "face-to-face" gatherings habitually organized by the club. As a central objective, by a digital ethnography methodology, the new dynamics carried out by the CHP are analyzed in a context of mandatory "virtuality".

Trace element composition of amphibole and petrogenesis of hornblendites and plutonic suites of Cretaceous magmatic arcs developed in the Fuegian Andes, southernmost South America Torres García, M.F.; Calderón, M.; Ramírez de Arellano, C.; Hervé, Francisco; Opitz, J.; Theye, T.; Fanning, Christopher Mark; Pankhurst, Robert; Gonzalez Guillot, Mauricio Alberto; Fuentes, F.; Babinski, M. The evolution of continental crust in convergent margins can be explored in southernmost South America (54-56°S). Plutonic rocks of the Fuegian Batholith and the rear-arc satellite Ushuaia Pluton were emplaced within the magmatic arc and the Fuegian fold-and-thrust belt, respectively. They record subduction zone processes in two distinct tectonic settings during the evolution of the Rocas Verdes Basin. We report new U-Pb zircon geochronology, bulk rock chemistry, Sr-Nd isotope data, and EPMA and in-situ LA-ICP-MS analyses of amphibole from ‘hornblendites’ and gabbroic-granitoid suites in order to evaluate the origin and evolution of the magmatic plumbing systems in the upper plate of the subduction zone. Textural relationships and amphibole compositions in hornblendite indicate crystallization at lower crustal depths with pressures of 7-8 kbar in the Fuegian Batholith and of 5-6 kbar in the Ushuaia Pluton. Lower Cretaceous suites of hornblendite and calc-alkaline hornblende-gabbro, diorite and tonalite in the Fuegian Batholith have εNdt values ranging between +2 and +4. They were emplaced within an island arc coeval with mid-oceanic type spreading in the Rocas Verdes back-arc basin. Isotope ratios and amphibole compositions in hornblendite indicate crystallization from primitive and hydrous sub-alkaline basaltic melts with relatively low LREE/HREE and low alkali contents. The Late Cretaceous plutons in the fold-and-thrust belt were emplaced after the tectonic juxtaposition of Rocas Verdes ophiolitic complexes. The Ushuaia Pluton, consisting of clinopyroxene-hornblende cumulates, hornblende-gabbro, diorite and monzodiorite, was emplaced during the waning stage of Late Cretaceous magmatism. In this case hornblendite amphiboles show high contents of alkalis, LREE and incompatible elements with a strong crustal affinity (Th, Ba, Rb). The enriched incompatible trace element patterns indicate their derivation from K-rich transitional magmas formed in supra-subduction settings. Chemical variations in amphibole from hornblendites and spatially related plutonic rocks are evaluated in terms of fluid flux from the subducted slab and partial melting of the sub-arc mantle, ultimately controlled by the thermal state of the subducted slab and convergence rates.

Nanosystems Applied to HIV Infection: Prevention and Treatments Macchione, Micaela Alejandra; Aristizabal, Dariana; Figueroa, Francisco Nicolas; Muñoz Fernández, María Ángeles; Strumia, Miriam Cristina Sexually-transmitted infections (STIs) are a global health concern worldwide as they cause acute diseases, infertility, and significant mortality. Among the bacterial, viral, and parasitic pathogens that can be sexually transmitted, human immunodeficiency virus (HIV) has caused one of the most important pandemic diseases, which is acquired immune deficiency syndrome (AIDS). 32.7 million people have died from AIDS-related illnesses since the start of the epidemic. Moreover, in 2019, 38 million people were living with HIV worldwide. The need to deal with this viral infection becomes more obvious, because it represents not only a problem for public health, but also a substantial economic problem. In this context, it is necessary to focus efforts on developing methods for prevention, detection and treatment of HIV infections that significantly reduce the number of newly infected people and provide a better quality of life for patients. For several decades, biomedical research has been developed allowing quick solutions through the contribution of effective tools. One of them is the use of polymers as vehicles, drug carrier agents, or as macromolecular prodrugs. Moreover, nanosystems (NSs) play an especially important role in the diagnosis, prevention, and therapy against HIV infection. The purpose of this work is to review recent research into diverse NSs as potential candidates for prevention and treatment of HIV infection. Firstly, this review highlights the advantages of using nanosized structures for these medical applications. Furthermore, we provide an overview of different types of NSs used for preventing or combating HIV infection. Then, we briefly evaluate the most recent developments associated with prevention and treatment alternatives. Additionally, the implications of using different NSs are also addressed.

Seasonality dictates changes in the ecological interactions among spatial dominants Gastaldi, Marianela; Firstater, Fausto Nahuel; Romero, María Alejandra; Pereyra, Patricio Javier; Narvarte, Maite Andrea Marine coasts are dynamic environments where spatial-physical gradients interact with seasonality. In the Patagonia in particular, high temperatures and strong winds lead to stressing physical conditions that shape intertidal communities. In a previous study, we found that the interaction between the sponge Hymeniacidon perlevis and the macroalga Ulva lactuca was context-dependent, switching from positive at the harsher intertidal to negative at the milder subtidal environment. Temporal variation in the physical variables, however, may also affect species performance and interaction strength. Since Patagonian shores are strongly seasonal environments, we evaluated how the interactions (competitive or cooperative) among these twospatially dominant species changed over a temporal-stress gradient throughout a year. We predicted that the macroalga would facilitate the sponge in seasons with more severe environmental conditions, whereas negative or neutral interactions would prevail when environmental conditions were milder. Our results demonstrated that the sign and intensity of the interaction between Hymeniacidon and Ulva changed over the seasons and coincided with a hump-shaped model, involving a neutral interaction in the milder seasons of autumn and winter, then switching to a positive one in the inclement springtime, and finally shifting to a negative relationship in the harshness of the summer. The amelioration of stressful conditions through shading did not satisfactorily explain the underlying mechanism for this varying interaction, an aspect that still remains unclear. Nevertheless, several mechanisms are discussed both within the context of the stress gradient hypothesis and the specific physiological constraints of intertidal organisms.

La percepción del tiempo: un abordaje psicofisiológico; A percepção do tempo: uma abordagem psicofisiológica; La perception du temps: une approche psychophysiologique; Time perception: a psychophysiological approach Squillace, Mario Rodolfo; Picón Janeiro, Jimena Cristina; Menéndez, Javier; Azzollini, Susana Celeste La cronobiología ha establecido la presencia de relojes internos en los organismos que miden diferentes frecuencias o ritmos. Este artículo aborda en una revisión cómo son esos relojes en el caso de la percepción subjetiva del paso del tiempo. A partir del modelo temprano de un marcapasos general para la estimación del tiempo hoy se concibe la presencia de modelos intrínsecos con mecanismos y áreas cerebrales diferenciadas. Si la estimación del tiempo requiere procesos controlados u automáticos será procesada por sistemas distintos; así como las tareas que implican procesamiento temporal de origen sensorial o motor. Poblaciones de neuronas procesan diferentes tareas de estimación temporal. Los mecanismos de rampa y de relojes poblacionales son propuestas teóricas de lo que ocurre a nivel sináptico y de redes neurales. Finalmente, se discuten factores que afectan la estimación subjetiva de la percepción del tiempo. Se ha mostrado que la edad, la motivación, la atención y el estado emocional afectan la velocidad con que se percibe el tiempo. La motivación intrínseca, la atención centrada en la tarea y el estado de baja activación emocional provocan enlentecimiento de la percepción del tiempo lo que lleva a su subestimación. Por otra parte, la motivación extrínseca, la atención focalizada en el paso del tiempo y la alta activación emocional provocan el efecto contrario, la percepción acelerada del tiempo, lo que provoca su sobreestimación.; A cronobiologia estabeleceu a presença de relógios internos nos organismos que medem diferentes frequências ou ritmos. Esse artigo aborda em uma revisão como esses relógios são no caso da percepção subjetiva da passagem do tempo. Partindo do modelo inicial de um marcapasso geral para estimativa de tempo, atualmente, se concebe a presença de modelos intrínsecos com áreas e mecanismos cerebrais diferenciados. Hipotetiza-se que se a estimativa de tempo requer processos controlados, ou automáticos, ela poderá ser processada por diferentes sistemas; bem como tarefas que envolvem processamento temporal de origem sensorial ou motora. Populações de neurônios processam diferentes tarefas de estimativa temporal. Os mecanismos de rampa e os relógios populacionais são propostas teóricas do que acontece no nível da rede sináptica e neural. Finalmente, os fatores que afetam a estimativa subjetiva da percepção do tempo, ainda, são discutidos. Encontrou-se que a idade, a motivação, a atenção e o estado emocional afetam a velocidade com que o tempo é percebido. A motivação intrínseca, a atenção voltada para a tarefa e o estado de baixa ativação emocional causam um abrandamento na percepção do tempo, levando à sua subestimação. Por outro lado, a motivação extrínseca, a atenção voltada para a passagem do tempo e a alta ativação emocional causam o efeito oposto a percepção acelerada do tempo que causa sua superestimação.; La chronobiologie a établi la présence d'horloges internes dans des organismes qui mesurent différentes fréquences ou rythmes. Cet article aborde dans une revue comment ces horloges sont dans le cas de la perception subjective du passage du temps. À partir du modèle précoce d'un stimulateur cardiaque général pour l'estimation du temps, on conçoit aujourd'hui la présence de modèles intrinsèques avec des zones et des mécanismes cérébraux différenciés. Si l'estimation de temps nécessite des processus contrôlés ou automatiques, elle sera traitée par différents systèmes; ainsi que les tâches qui impliquent un traitement temporel d'origine sensorielle ou motrice. Les populations de neurones traitent différentes tâches d'estimation temporelle. Les mécanismes de rampe et les horloges de population sont des propositions théoriques de ce qui se passe au niveau des réseaux synaptiques et neuronaux. Enfin, les facteurs qui affectent l'estimation subjective de la perception du temps sont discutés. Il a été démontré que l'âge, la motivation, l'attention et l'état émotionnel affectent la vitesse à laquelle le temps est perçu. La motivation intrinsèque, l'attention focalisée sur la tâche et l'état de faible activation émotionnelle provoquent un ralentissement de la perception du temps, ce qui conduit à sa sous-estimation. En revanche, la motivation extrinsèque, l'attention focalisée sur le passage du temps et la forte activation émotionnelle provoquent l'effet inverse, la perception accélérée du temps, qui provoque sa surestimation.; Chronobiology has established the presence of internal clocks in the organisms that measure at different frequencies or rhythms. This article addresses in a review how these clocks are in the case of the subjective perception of the passage of time. Today, the presence of intrinsic models with different brain areas and mechanisms is conceived from the early model of a general pacemaker for time estimation. If the time estimate requires controlled or automatic processes, it will be processed by different systems. As well as, tasks that involve temporal processing of sensory or motor origin. Neuron populations process different temporal estimation tasks. The ramp mechanisms and population clocks are theoretical proposals of what happens at the synaptic and neural network level. Finally, factors that affect the subjective estimation of time perception are discussed. Age, motivation, attention, and emotional state have been shown to affect the speed with which time is perceived. Intrinsic motivation, attention focused on the task and the state of low emotional activation cause the slowing of the perception of time, leading to its underestimation. On the other hand, extrinsic motivation, attention focused on the passage of time and high emotional activation cause the opposite effect, accelerated perception of time, leading to its overestimation.

Objetos durables, mundos inestables: Modos de hacer y prácticas referenciales en las sociedades precoloniales de la región de Soto, Córdoba, Argentina.; Durable objects, unstable worlds: Ways of doing and referential practices in pre-colonial societies of the Soto region, Córdoba, Argentina Laguens, Andres Gustavo Se intenta una aproximación a los modos del habitar y la producción y reproducción de los mundos locales de las sociedades precoloniales de la localidad de Villa de Soto, Córdoba, Argentina. Se reflexiona cómo distintas materialidades y formas de hacer se entrelazan en un juego de referencias mutuas, que ponen en realce ciertos modos locales de entender y estar en el mundo. Encontramos una relación estrecha entre las formas de hacer cerámica en base a cestas y redes y otras materialidades tales como las de otros estilos cerámicos, las marcas corporales como se manifiestan en estatuillas de cerámica, algunos objetos líticos y el tratamiento de los cuerpos humanos, que permite postular la existencia local de ciertos principios relacionales en las interacciones entre las personas, las cosas y el mundo, que giran en torno a la noción de inestabilidad crónica y la vigencia de prácticas socio-materiales que apuntan a su opuesto, la perduración, congruente con cosmologías nativas sudamericanas, como el perspectivismo.; An approach is attempted to the ways of living and the production and reproduction of the local worlds of the pre-Hispanic agro-pottery societies of the town of Villa de Soto, Córdoba, Argentina. It reflects on how different materialities and ways of doing are intertwined in a game of mutual references, which highlight certain local ways of understanding and being in the world. We find a close relationship between the ways of making ceramics based on baskets and nets, and other materialities such as other ceramic styles, body marks as manifested in ceramic statuettes, some lithic objects and the treatment of human bodies, which allows us to postulate the local existence of certain relational principles in interactions between people, things and the world, which revolve around the notions of chronic instability and the validity of socio-material practices pointing to its opposite, permanence, congruent with native South American cosmologies, such as perspectivism.

On the strain-induced martensitic transformation process of the commercial AISI 304 stainless steel during cyclic loading Farias, Francisco David; Alvarez, Iris; Armas, Alberto Franklin Low-cycle fatigue tests were performed on metastable austenitic steel at two initial material states, the as-received, with a high crystal defect density, and the solution treated one, with fewer crystal defects. Cyclic curves have shown different hardening behavior depending on the initial material states. To understand these differences, the back and friction stresses were studied from the hysteresis loop analysis. The correlation of these results with the volume fraction of induced martensite and the observed microstructure revealed that the cyclic hardening behavior strongly depends on the existence of potential martensite nucleation sites.

Células madre/estromales mesenquimales: su potencial terapéutico en medicina; Mesenchymal stem/stromal cells: their therapeutic potential in medicine Domínguez, Luciana María; Fiore, Esteban Juan; Mazzolini Rizzo, Guillermo Daniel La terapia celular y la medicina regenerativa son áreas en gran desarrollo en la investigación biomédica. En la mayoría de los tejidos existen mecanismos de auto-reparación llevados a cabo, principalmente, por células madre o progenitoras residentes con capacidad para diferenciarse y reemplazar a las células dañadas o para secretar factores tróficos que induzcan el proceso regenerativo. Dado que estos mecanismos de reparación no siempre son suficientes, se postula que la terapia celular puede contribuir a la regeneración de los tejidos sometidos a injuria. Las células madre/estromales mesenquimales (MSCs, del inglés Mesenchymal Stem/Stromal Cells) son un tipo de progenitor adulto multipotente, que tienen la capacidad de expandirse in vitro con facilidad cuando son aisladas de su nicho in vivo, migrar selectivamente a los tejidos lesionados, modular y evadir el sistema inmunológico, y secretar factores tróficos que ayudan a la reparación tisular. Asimismo, la fácil manipulación ex vivo permitiría también usarlas como vehículos de genes terapéuticos. Las principales fuentes de obtención son la médula ósea, el tejido adiposo y cordón umbilical. Los numerosos estudios pre-clínicos y clínicos han demostrado que las MSCs parecieran ser seguras tanto para uso autólogo como alogénico. En este trabajo se resumen las propiedades de las MSCs y su potencial terapéutico para una amplia gama de enfermedades, también presentamos los distintos ensayos clínicos avanzados que las posicionan en el ámbito biomédico como una herramienta interesante para la regeneración de tejidos y el tratamiento de enfermedades inflamatorias.; Cell therapy and regenerative medicine are currently active areas for biomedical research. In most tissues, there are self-repair mechanisms carried out mainly by resident stem cells that can differentiate and replace dead cells or secrete trophic factors that stimulate the regenerative process. These mechanisms often fail in degenerative diseases; thus it is postulated that exogenous cell therapy can contribute to tissue regeneration and repair. Mesenchymal stem cells (MSCs) are multipotent adult stem/progenitor cells, which could be easily expanded in vitro and have the ability to selectively migrate toward injured tissues, evade the immune system recognition, and secrete trophic factors to support tissue repair. Furthermore, MSCs could be engineered for the delivery of therapeutic genes. The main sources for MSCs are bone marrow, adipose tissue, and umbilical cord. A number of pre-clinical and clinical studies have shown that MSCs therapy is safe for both autologous and allogeneic uses. This review summarizes information about the properties of MSCs and their therapeutic potential for a broad spectrum of diseases. We also present here the last data about clinical trials that position the use of MSCs as an interesting tool for tissue regeneration and the treatment of inflammatory diseases.

Determinación de la eficacia de antihelmínticos para el tratamiento de la gastroenteritis verminosa en caprinos de la provincia de Tucumán; Determination of the efficacy of anthelmintics used in the control of gastrointestinal nematodes of goats from Tucumán, Argentina Chocobar, Marianna Laura Elis; Diambra, Priscila; Terán Alurralde, María del Rosario; Bustos, María José; Prado, María José; Gonzalez Moreno, Candelaria; Fernández, Jorge Luis; Salinas, Carmen; Solaligue, Paola Blanca del Valle; Rosa, Ramiro José En la Argentina, el 93% de la producción caprina en la Argentina es desarrollada por pequeños productores deagriculturas de subsistencia, quienes, por lo general, utilizan antihelmínticos sin asesoramiento profesional, lo que, probablemente, hallevado al desarrollo de resistencia, comprometiendo seriamente la sustentabilidad del control de nematodos. El objetivo de esteestudio es determinar la eficacia de la ivermectina, el albendazol y el levamisol para el tratamiento de la gastroenteritis verminosa encuatro grupos de ocho caprinos cada uno, mediante el Test de Reducción del Conteo de Huevos (TRCH). Los resultados demostraronun 100% de reducción del número de HPG para los grupos tratados con albendazol y levamisol y un 17% de reducción para el grupotratado con ivermectina, con respecto al grupo control, lo que permite inferir que existe resistencia a este fármaco.; Almost 93% of goat production in Argentina is developed by small farmers, who generally use anthelmintics without professional advice, which has led to the development of resistance, seriously compromising the sustainability of nematode control. This study aims to determine the efficacy of ivermectin, albendazole and levamisole for the treatment of verminous gastroenteritis in four groups of eight goats each, using the Faecal Egg Count Reduction Test (FECRT). The results showed a 100% reduction in the number of EPG for the groups treated with albendazole and levamisole and a 17% reduction for the group treated with ivermectin, compared to the control group, which allows us to infer that there is resistance to this drug.

Translational activity of the splicing factor SRSF1 is required for development and cilia function Haward, Fiona; Maslon, Magdalena; Yeyati, Patricia; Bellora, Nicolás; Hansen, Jan; Aitken, Stuart; Lawson, Jennifer; von Kriegsheim, Alex; Wachten, Dagmar; Mill, Pleasantine; Adams, Ian; Caceres, Javier Shuttling RNA-binding proteins coordinate nuclear and cytoplasmic steps of gene expression. SR proteins regulate pre-mRNA splicing in the nucleus and a subset of them, including SRSF1, shuttles between the nucleus and cytoplasm affecting post-splicing processes. However, the physiological significance of this remains unclear. Here, we used genome editing to knock-in a nuclear retention signal (NRS) in Srsf1 to create a mouse model harboring an SRSF1 protein that is retained exclusively in the nucleus. Srsf1NRS/NRS mutants displayed small body size, hydrocephalus and immotile sperm, all traits associated with ciliary defects. We observed reduced translation of a subset of mRNAs and decreased abundance of proteins involved in multiciliogenesis, with disruption of ciliary ultrastructure and motility. These results highlight the physiological requirement of splicing factor shuttling to reprogram gene expression networks at the level of mRNA translation in the context of high cellular demand for cilia function.

De Fontanarrosa a Lacan: el exilio argentino en la colección Libros de Hoy de El Diario de Caracas Falcón, Alejandrina El propósito general de este trabajo es contribuir al conocimiento sobre la historia del exilio político y sus vínculos con la edición en América Latina a finales del siglo XX. Su propósito específico es la reconstrucción de la actividad editorial de argentinos exiliados en Venezuela a partir de un caso testigo: la colección Libros de Hoy publicada por el Diario de Caracas y dirigida por Ana María Miler y Daniel Divinsky, directivos de Ediciones de La Flor.

Synthesis and Two-Dimensional Chiral Surface Self-Assembly of a π-Conjugated System with Three-Fold Symmetry: Benzotri(7-Azaindole) Rodriguez, Luis Miguel; Gómez, Paula; Más Montoya, Miriam; Abad, José; Tárraga, Alberto; Cerdá, Jorge I.; Méndez, Javier; Curiel, David The synthesis of a novel expanded π-conjugated system, namely benzotri(7-azaindole), BTAI, is reported. Its C3h symmetry along with the integration of six complementary donor and acceptor N−H⋅⋅⋅N hydrogen bonds in the conjugated structure promote the 2D self-assembly on Au(111) over extended areas. Besides, a perfect commensurability with the gold lattice endows the physisorbed molecular film with a remarkable stability. The structural features of BTAI result in two levels of surface chirality: Firstly, the molecules become chiral upon adsorption on the surface. Then, due to the favorable N−H⋅⋅⋅N hydrogen bond-directed self-assembly, along with the relative molecular rotation with respect to the substrate, supramolecular chirality manifests in two mirror enantiomorphous domains. Thus, the system undergoes spontaneous chiral resolution. LEED and STM assisted by theoretical simulations have been employed to characterize in detail these novel 2D conglomerates with relevant chiral properties for systems with C3h symmetry.

The expansin EXP1 gene in the elongation zone is induced during soybean embryonic axis germination and differentially expressed in response to ABA and PEG treatments Montechiarini, Nidia Helga; Delgado Benarroch, Luciana; Morandi, Eligio Natalio; Carrillo, Nestor Jose; Gosparini, Carlos Omar During soybean seed germination, the expansive growth potential of the embryonic axes is driven by water uptake while cell wall loosening occurs in cells from the elongation zone (EZ). Expansins are regarded as primary promoters of cell wall remodelling in all plant expansion processes, with the expression profiles of the soybean expansins supporting their cell or tissue specificity. Therefore, we used embryonic axes isolated from whole seed and focused on the EZ to study seed germination. Using a suite of degenerate primers, we amplified an abundantly expressed expansin gene at the EZ during soybean embryonic axis germination, which was identified as EXP1 by in silico analyses. Expression studies showed that EXP1 was induced under germination conditions in distilled water and down-regulated by abscisic acid (ABA), which inhibits soybean germination by physiologically restraining expansion. Moreover, we also identified a time window of ABA responsiveness within the first 6 h of incubation in water, after which ABA lost control of both EXP1 expression and embryonic axis germination, thus confirming the early role of EXP1 in the EZ during this process. By contrast, EXP1 levels in the EZ increased even when germination was impaired by osmotically limiting the water availability required to develop the embryonic axes' growth potential. We propose that these higher EXP1 levels are involved in the fast germination of soybean embryonic axes as soon as water availability is re-established. Taken together, our results show strong EXP1 expression in the EZ and postulate EXP1 as a target candidate for soybean seed germination control.

Synthesis and catalytic application of silver nanoparticles supported on lactobacillus Kefiri S-Layer proteins Bolla, Patricia Araceli; Huggias, Sofia; Serradell, María de los Ángeles; Ruggera, José Fernando; Casella, Mónica Laura Research on nanoparticles obtained on biological supports is a topic of growing interest in nanoscience, especially regarding catalytic applications. Silver nanoparticles (AgNPs) have been studied due to their low toxicity, but they tend to aggregation, oxidation, and low stability. In this work, we synthesized and characterized AgNPs supported on S-layer proteins (SLPs) as bidimensional regularly arranged biotemplates. By different reduction strategies, six AgNPs of variable sizes were obtained on two different SLPs. Transmission electron microscopy (TEM) images showed that SLPs are mostly decorated by evenly distributed AgNPs; however, a drastic reduction by NaBH4 led to large AgNPs whereas a smooth reduction with H2 or H2 /NaBH4 at low concentration leads to smaller AgNPs, regardless of the SLP used as support. All the nanosystems showed conversion values between 75–80% of p-nitrophenol to p-aminophenol, however, the increment in the AgNPs size led to a great decrease in Kapp showing the influence of reduction strategy in the performance of the catalysts. Density functional theory (DFT) calculations indicated that the adsorption of p-nitrophenolate species through the nitro group is the most favored mechanism, leading to p-aminophenol as the only feasible product of the reaction, which was corroborated experimentally.

Root anatomy of 37 species of Asplenium (Aspleniaceae) from Argentina: Contributions to the systematics and phylogeny of the genus Luna, María Luján; Ganem, Maria Alejandra; Grossi, Mariana Andrea; Giudice, Gabriela Elena Asplenium L. (Aspleniaceae) is a large fern genus whose systematics is based mainly in leaf and reproductive characters. In Aspleniaceae, the root anatomy allows delimit the two genera, Asplenium and Hymenasplenium Hayata. Various root subtypes are recognized in Asplenium, according to the layers and number of asplenium sclereids that constitute the inner cortex. In order to assess the potential use of root features in the taxonomy and the phylogenetic relationships within Asplenium, the roots of the 37 species inhabiting Argentina were studied. Observations were carried out employing light microscopy. Various root subtypes were registered. Only in few instances the root subtypes were shared by closely phylogenetically related species, being in the majority of cases homoplastic characters. The root subtype was not related to the plant habit.

Los divergentes en un escenario de polarización: Un estudio exploratorio sobre los ''nopolarizados'' encontroversias sobre noticias de delitos en la televisión argentina; The ''divergent'' in a polarized scenario: An exploratory study on the ''non-polarized'' in controversies aboutcrime news on Argentine televisión Kessler, Gabriel; Focas, Brenda Marisa; Ortiz de Zarate, Juan Manuel; Feuerstein, Esteban Zindel El artículo se propone contribuir al debate sobre polarización política en América Latina, buscando matices a la imagen de la división de toda la sociedad en dos polos. En particular, presentamos a los “divergentes”, individuos que en contextos de interacción en los que se generan controversias polarizadas adoptan posiciones de ambas comunidades. Nos basamos en una investigación con grupos focales, respecto a la recepción de noticias sobre delitos de noticieros televisivos en la Ciudad Autónoma de Buenos Aires. Utilizamos una metodología mixta que integra análisis cualitativo y la aplicación de un método de detección de polarización semántica entre una Comunidad 1 (Kirchneristas u Oficialistas en mayo de 2020) y una Comunidad 2 (Opositores). De este modo, nos focalizamos en los divergentes. El principal rasgo en común entre los divergentes, es lo que llamamos “distancia reflexiva” con los medios, pero construimosluego una tipología con las diferencias entre los mismos divergentes. Al adoptar esta distancia reflexiva, elaboran una tercera posición tomando contenidos de ambas comunidades. El artículo muestra que la tercera posición frente a la polarización, se expresa sobre todo como una posición frente a los medios, más que en tanto construcción de un tercer relato diferenciado de los otros dos.; The article aimsto contribute to the debate on political polarization in Latin America, discussing the idea of the division of the whole society into two poles. We present the «divergent», individuals who, in contexts of interaction in which polarized controversies are generated, adopt positions of both communities. It is an exploratory study based on a mixed methodology: focus groups on crime in Buenos Aires and computational analysis of semantic polarization. Using a mixed methodology thatintegrates qualitative analysis and the application of a method to detect semantic polarization between Community 1 (Kirchneristas or Pro-Government on May 2020) and a Community 2 (Opponents) focuses on the «divergent». The main feature in common among the divergent is the «reflexive distance» from the media. This distance can be adopted in different ways such as a) moderate skepticism. b) appreciation of objectivity against polarization, c) positive consideration of polarization as pluralism and/or d) a disinterest in public affairs. By adopting this reflective distance, the divergent elaborates a third position, taking content from both communities. The article shows that the «third position» is more one of attitude towards the media than the building of a third differentiated political narrative.

Item Banking for an adaptive measurement of Neuroticism Abal, Facundo Juan Pablo; Lozzia, Gabriela Susana; Auné, Sofía Esmeralda; Attorresi, Horacio Felix The psychometric properties of a bank of 36 items are presented measuring Neuroticism based on the Five-Factor Model. These items pertain to the facets that were identified by the work of McCrae and Costa. The sample was comprised of 1133 adult subjects that reside in the Buenos Aires Metropolitan Area in Argentina. Women accounted for 52.1% of those subjects with an average age of 29.5 years (SD = 11.32). In order to get the items calibrated according to Item Response Theory (Graded Response Model), acquire the bank’s information functions and assess the estimated associations with other instruments, 70% of the cases were randomly selected. An adaptive administration simulation was made with the remaining 30% so as to test two stopping rules: a) using 18 items and b) standard error of ≤ 0.25. Correlations greater than .95 were found between the estimated bank scores and the two adaptive versions. The advantages of using the adaptive Neuroticism measurement over other well-renowned instruments that use conventional large formats, as well as abbreviated ones, are discussed.

Visibilizando la concepción del tiempo Qom en instituciones educativas del Gran Chaco Argentino; Making the Qom's conception of time visible in educational institutions of Argentina's Great Chaco Chadwick, Geraldine; Bonan, María Leonor; Castorina, José Antonio El objetivo general de este proyecto fue indagar sobre las concepciones de tiempo diurno y nocturno que circulan por las aulas multiculturales de diferentes instituciones educativas de la Provincia de Chaco, Argentina. Con este fin, se eligió anclar en la etnia Qom que forma parte de la familia lingüística Guaycurú. A través de una investigación-acción se decidió generar diferentes actividades a implementar en escuelas secundarias a las que asisten estudiantes, mayoritariamente de la etnia Qom. Se obtuvieron registros mediante producciones escritas, observaciones, etc. Finalmente, se analizaron los resultados obtenidos, mediante los cuales se observa una concepción de tiempo cíclica donde cobran vital relevancia la observación de las posiciones aparentes del Sol a lo largo del día, la luminosidad atmosférica durante la noche y el canto de aves específicas para ambos momentos. La realización de las tareas propuestas promovió el acceso a un fenómeno desde los conocimientos ancestrales, ofreciendo una mirada diversa sobre los fenómenos naturales.; The general objective of this project was to investigate day and night time conceptions that circulate in multicultural classrooms of different educational institutions of the Province of Chaco, Argentina. To that end, the Qom ethnic group has been chosen, which is part of the Guaycurú family language. Through action research, it was decided that different activities would be generated and implemented in secondary schools attended by students, mostly from the Qom ethnic group. Records were obtained through written annotations, observations, etc. Finally, the obtained results show a cyclic time conception, where the observation of apparent positions of the Sun throughout the day, atmospheric luminosity during the night, and specific bird songs for both moments are of vital relevance. The completion of the proposed tasks promoted access to a phenomenon dating back to ancestral knowledge, offering a diverse view on natural phenomena.

Relevant out-of-Time-order correlator operators: footprints of the classical dynamics Bergamasco, Pablo D.; Carlo, Gabriel Gustavo; Rivas, Alejandro Mariano Fidel The out-of-time-order correlator (OTOC) has recently become relevant in different areas where it has been linked to scrambling of quantum information and entanglement. It has also been proposed as a good indicator of quantum complexity. In this sense, the OTOC-RE theorem relates the OTOCs summed over a complete basis of operators to the second Renyi entropy. Here we have studied the OTOC-RE correspondence on physically meaningful bases like the ones constructed with the Pauli, reflection, and translation operators. The evolution is given by a paradigmatic bi-partite system consisting of two perturbed and coupled Arnold cat maps with different dynamics. We show that the sum over a small set of relevant operators is enough in order to obtain a very good approximation for the entropy and, hence, to reveal the character of the dynamics. In turn, this provides us with an alternative natural indicator of complexity, i.e., the scaling of the number of relevant operators with time. When represented in phase space, each one of these sets reveals the classical dynamical footprints with different depth according to the chosen basis.

Ninguna semilla nace sola Serpe, Paula Carolina; Sosa, Andrea Patricia La agroecología no es una moda pasajera: en Argentina lleva al menos treinta años de organización. Movimientos sociales, científicxs y productorxs vienen construyendo una nueva certeza: esta forma de producir nos alimenta mejor, genera trabajo y cuida nuestra salud. También tienen demandas, como la lucha por la tierra y políticas que promuevan otro modelo de agricultura. Paula Serpe y Andrea Sosa recorrieron chacras, hablaron con productores, participaron de verdurazos y, a la vuelta, escribieron esta crónica.