The role of scientists at the human-nature interface on MaB protected areas; El rol de los científicos en la interface hombre-naturaleza en las áreas protegidas MaB López, Luciana; Rubio, María Clara; Rodriguez, Maria Daniela According to the theory of social metabolisms, human-nature interaction can generate “waste” that can act as environmental passives. The impact of scientists’ interaction with nature during their field researches is rarely ever discussed on literature. In this paper, we evaluate the externalities produced by scientific research on fauna based on a zoning system of a Man and Biosphere Reserve (MaB) in order to determine incompatibilities. We assume that the MaB zoning systems could prevent the generation of this type of waste done by scientists. We systematized all documents referred to Ñacuñán MaB Reserve in Argentina (60 years of records) and created a digital library. Afterward, we spatialized the investigations related to fauna and contrasted them with the current zoning system. The results showed that most of the researches were manipulatives and were conducted at the transition zone, followed by the northern core zone. Scientists do not always respect the activities allowed by zone. Sampling sites are frequently selected according to the proximity of their accommodation rather than to the permitted activities. Therefore, it is necessary to formulate new policies to avoid scientists’ liabilities and to encourage the build of knowledge and research on less studied zones, to promote conservation and sustainable development of MaB reserves.; Según la teoría de los metabolismos sociales, la interacción humano-naturaleza puede generar “residuos” que pueden actuar como pasivos ambientales. El impacto de los científicos que interactúan con la naturaleza en sus investigaciones de campo, raramente es discutido en la literatura. En este artículo, evaluamos las externalidades producidas por los científicos en sus investigaciones sobre fauna en función del sistema de zonificación de las Reservas del Hombre y la Biosfera (MaB) con el objetivo de determinar incompatibilidades. Suponemos que los sistemas de zonificación de MaB podrían evitar la generación de este tipo de residuos por parte de los científicos. Para ello se sistematizaron todos los documentos referidos a la Reserva MaB Ñacuñán en Argentina (más de 60 años de registros) y se creó una biblioteca digital. Luego espacializamos las investigaciones referidas a fauna y se contrastaron con el sistema de zonificación actual. Los resultados mostraron que la mayor parte de las investigaciones fueron manipulativas y se localizaron en la zona de transición, seguida de la zona del núcleo norte. Los científicos no siempre respetaron las actividades permitidas por zona, seleccionando sus sitios de muestro en función de la proximidad a su alojamiento. Por ello es necesario formular políticas para evitar las responsabilidades de los científicos y para orientar la generación de conocimientos en las zonas menos estudiadas a efectos de promover la conservación y el desarrollo sustentable de las Reservas MaB.

Biotecnología e innovación en Argentina: una aproximación desde la industria semillera; Biotechnology and innovation in Argentina: an approach from the seed industry Quadrana, Alejandra Paula El presente artículo se propone analizar los procesos de innovación en biotecnología en el contexto de un país periférico. Se decidió profundizar en la industria semillera atendiendo a la importancia relativa del sector dentro de las actividades biotecnológicas desarrolladas en Argentina y a su relevancia en tanto insumo estratégico de la producción agroalimentaria. En virtud de las transformaciones tecnológicas incorporadas a la semilla, se describe la evolución de la industria semillera en el país en el largo plazo. A partir de la aprobación comercial de semillas transgénicas en 1996, se identificaron distintas estrategias de innovación en el conjunto de actores que participan en la cadena de valor. En base al análisis se elaboró una tipología para dar cuenta de dichas estrategias, que pueden consistir en: empresas multinacionales importadoras de innovaciones radicales, empresas nacionales generadoras de innovaciones radicales o empresas nacionales generadoras de innovaciones incrementales. Por último se reflexiona sobre las oportunidades y los desafíos que presenta la actividad semillera dentro de una estrategia de desarrollo nacional.; This article analyzes the processes of innovation in biotechnology in the context of a peripheral country. It was decided to delve into the seed industry, taking into account the relative importance of the sector within the biotechnological activities carried out in Argentina and its relevance as a strategic input for agri-food production. Based on the technological transformations incorporated into the seed, the evolution of the seed industry in the country in the long term is described. After the commercial approval of transgenic seeds in 1996, three innovation strategies were identified in the set of actors that participate in the value chain. Based on the analysis, a typology was developed to account for these strategies, which may consist of: multinational companies that import radical innovations, national companies that generate radical innovations or national companies that generate incremental innovations. Finally, it reflects on the opportunities and challenges that seed activity presents within a national development strategy.

Organic chemistry in harmony with our sensations; La química orgánica en armonía con nuestras sensaciones Guntero, Vanina Alejandra; Peralta, Micaela Belén; Ferretti, Cristián Alejandro; Mancini, Pedro Maximo Emilio; Kneeteman, Maria Nelida In this work the development and the results of a practical work are shown. The practical work has been designed for the teaching of organic chemistry in a high school teaching course. The selected theme is related to the perfume industry. Its main goal was related to promoting the study of the chemical discipline. This work was carried out within five weeks. It contemplates the fundamental abilities of reading, writing, orality and critical thinking. The results obtained indicate that it was possible to consolidate contents, relate them to others previously developed, improve the writing and presentation of reports, develop collaborative work, and improve skills in the handling of laboratory material.

Evaluación teórica del comportamiento de celdas solares de perovskita invertida totalmente inorgánicas Pinzón Rueda, Carlos Alberto; Martinez, Nahuel; Casas, Guillermo; Alvira, Fernando Carlos; Cappelletti, Marcelo Angel En este trabajo se llevó a cabo, por medio de simulaciones numéricas, un estudio teórico de celdas solares de perovskita totalmente inorgánicas con estructura invertida ITO/HTL/CsPbIxBr3−x/ETL/Ag, utilizando cuatro diferentes materiales como capa HTL (NiO, Cu2O, CuSCN y CuI) y tres diferentes materiales como capa ETL (ZnO, TiO2 y SnO2). Fueron investigados los efectos sobre la eficiencia de conversión de energía (PCE) de los dispositivos, frente a la variación de parámetros de la capa de perovskita, tales como espesor, densidad de átomos aceptores y densidad de defectos, con el fin de determinar las condiciones óptimas de diseño para lograr mayores eficiencias que las actuales. Los resultados obtenidos muestran que la celda solar de perovskita totalmente inorgánica de estructura invertida ITO/CuI/CsPbIxBr3−x/ZnO/Ag tiene la mayor PCE, alcanzando un valor óptimo teórico de 27.1% para una longitud de difusión de portadores minoritarios de 100 µm, lo que requiere una disminución drástica de la densidad de defectos en la capa de perovskita.

Teoría y Praxis: Dos enfoques rivales Olivares, Nicolàs Emanuel En diversos trabajos J. Habermas ha explicitado y defendido una particular conexión de tipo dialéctica entre los conceptos de teoría y praxis la cual hunde sus raíces en el controversial proyecto de retomar la senda iluminista racional moderna como respuesta suficiente ante la crisis de legitimidad democrática sobrevenida por la vigencia contemporánea de políticas tecnocráticas libertarias. En el presente artículo nos proponemos evaluar críticamente la conexión habermasiana discursiva idealista entre los términos teoría y práctica advirtiendo que constituye una propuesta de solución ineficiente e indeseable ante dicha crisis. En su lugar proponemos la adopción de una conexión reflexiva neorepublicana de ambos términos la cual consideramos una respuesta hipotéticamente aceptable y sustentable ante las condiciones normativas no ideales vigentes y adecuadamente responsiva a la dominación política ejercida por ciertos países centrales sobre otros periféricos.; In several works J. Habermas has explained and defended a particular dialectical connection between the concepts of theory and praxis which sinks its roots in the controversial project of retaking the modern rationalist enlightenment path as a sufficient response to the crisis of democratic legitimacy produced by the contemporary libertarian technocratic policies. In this article we propose to critically asses the Habermasian idealistic discursive connection between ideal theory and non ideal practice warning that it constitutes an inefficient and undesirable proposal of solution to that crisis. Instead we defend the adoption of a neorepublican reflexive connection of both terms which we consider a hypothetically acceptable and sustainable response to the current non-ideal normative conditions.

Increasing activity in T CrB suggests nova eruption is impending Luna, Gerardo Juan Manuel; Sokoloski, J. L.; Mukai, Koji; Kuin, Paul M. Estimates of the accretion rate in symbiotic recurrent novae (RNe) often fall short of theoretical expectations by orders of magnitude. This apparent discrepancy can be resolved if the accumulation of mass by the white dwarf (WD) is highly sporadic, and most observations are performed during low states. Here we use a re-analysis of archival data from the Digital Access to a Sky Century @Harvard survey to argue that the most recent nova eruption in symbiotic RN T CrB, in 1946, occurred during—and was therefore triggered by—a transient accretion high state. Based on similarities in the optical light curve around 1946 and the time of the prior eruption, in 1866, we suggest that the WD in T CrB accumulates most of the fuel needed to ignite the thermonuclear runaways (TNRs) during accretion high states. A natural origin for such states is dwarf-nova like accretion-disk instabilities, which are expected in the presumably large disks in symbiotic binaries. The timing of the TNRs in symbiotic RNe could thus be set by the stability properties of their accretion disks. T CrB is in the midst of an accretion high state like the ones we posit led to the past two nova eruptions. Combined with the approach of the time at which a TNR would be expected based on the 80 yr interval between the prior two novae (2026 ± 3), the current accretion high state increases the likelihood of a TNR occurring in T CrB in the next few years.

Killer Yeasts for the Biological Control of Postharvest Fungal Crop Diseases Diaz, Mariana Andrea; Pereyra, Martina María; Picón Montenegro, Ernesto; Meinhardt, Friedhelm; Dib, Julian Rafael Every year and all over the world fungal decay of fresh fruit and vegetables frequently generates substantial economic losses. Synthetic fungicides, traditionally used to efficiently combat the putrefactive agents, emerged, however, as the cause of environmental and human health issues. Given the need to seek for alternatives, several biological approaches were followed, among those with killer yeasts stand out. Here, after the elaboration of the complex of problems, we explain the hitherto known yeast killer mechanisms and present the implementation of yeasts displaying such phenotype in biocontrol strategies for pre- or postharvest treatments to be aimed at combating postharvest fungal decay in numerous agricultural products.

Effects of lactic, malic and fumaric acids on Salmonella spp. counts and on chicken meat quality and sensory characteristics Fernández, Mariano; Rodriguez, Anabel; Fulco, Maira Micaela; Soteras, Trinidad; Mozgovoj, Marina Valeria; Cap, Mariana The aim of this work was to assess the effectiveness of dipping chicken breast in lactic, malic and fumaric acid 3% solutions for 15 s on Salmonella counts, as well as on chicken meat quality and sensory characteristics. All three treatments effectively reduced Salmonella counts. The values of Salmonella log reduction were 2.22, 1.55 and 1.30 log CFU/g for fumaric, malic and lactic treatments, respectively. Although fumaric acid was the most effective for reducing Salmonella counts, chicken meat quality and sensory characteristics were significantly affected, even in cooked samples. Conversely, malic and lactic acids treatments caused minimal changes in chicken meat quality and sensory characteristics compared to control samples. This study shows effective alternatives to reduce Salmonella contamination on chicken breast fillets, although further studies should be considered to improve the effects on quality and sensory attributes.

Identification of the geographic origins of people buried in the cemetery of the Salesian Mission of Tierra del Fuego through the analyses of mtDNA and stable isotopes Motti, Josefina María Brenda; Winingear, S.; Valenzuela, Luciano Oscar; Nieves Colón, M. A.; Harkins, K. M.; Garcia Laborde, Pamela; Bravi, Claudio Marcelo; Guichon, Ricardo Anibal; Stone, A. C. Considering that the treatment of dead bodies constitutes an expression of the symbolic world, the objective of this work is to obtain greater knowledge about the regional geographic origins of the individuals buried in the post-European contact Salesian Mission “La Candelaria” of Tierra del Fuego. Historical data report that two groups of people made use of this cemetery: Native Americans from Southern Patagonia (indigenous) on one hand, and colonists and missionaries (non-indigenous) on the other hand. We used two new lines of evidence: mtDNA sequences and oxygen isotope data (δ18O), to identify these groups and assess whether the location of the individuals in the cemetery shows patterns that could be associated with group affiliation. Of the 26 individuals we tested, our results indicate that 85% of the individuals were local, i.e. Natives from Southern Patagonia and a 15% of the individuals came from outside this region (non-local). In the excavated sector of the cemetery, no trends were identified in the location and disposition of burials that could be associated with group affiliation. We found no differences in burial treatment that could indicate difference among individuals of European origin, migrants from nearby areas, and Natives from Southern Patagonia. While variability in the geographic origins of the people was expected considering the historical data, the fact that people with different geographic origins were buried together, without spatial separation within this section of the cemetery was not. The non-existence of spatial separation between indigenous and non-indigenous people may be related to the main objective of the missionary process: the evangelization of indigenous people. In this sense, all the individuals buried in the cemetery went through Christianization and their bodies were treated without observable differences between them.

Intervenciones sobre la lengua en la Argentina de finales de los 1920: Babel y el castellano (1928) de Arturo Capdevila, entre la prensa y el libro Ennis, Juan Antonio El presente trabajo propone un recorrido por una obra particularmente influyente en la historia de los debates sobre la lengua en Argentina: Babel y el castellano (1928), de Arturo Capdevila, considerándola desde su gestación en las columnas publicadas por su autor en el periódico La Prensa de Buenos Aires a partir de 1925. El análisis atiende asimismo a la articulación que estas intervenciones, por parte de un escritor versátil aunque lego en materia de ciencias del lenguaje, encuentran en sus distintas manifestaciones con campos y discursos en proceso de consolidación y diferenciación en la época en el país, como el de la literatura y los estudios lingüísticos, así como a los ecos que estas hallan en desarrollos posteriores, especialmente en el campo de la lingüística profesional.; The following paper attempts to give an insight into a particularly influential work in the history of language-ideological debates in Argentina: Babel y el castellano (1928), by Arturo Capdevila, considering it from its very origin in the columns published by its author in the Buenos Aires’ newspaper La Prensa from 1925 to 1927. The analysis also points to the way in which these interventions by a versatile writer –although a layman in the field of language sciences– deal with fields and discourses which were going through several processes of consolidation and differentiation in Argentina at the time (such as literature and linguistic studies). It also highlights the echoes that Capdevila’s texts find in later developments, especially in the field of professional linguistics.

Explicit solutions for distributed, boundary and distributed-boundary elliptic optimal control problems Bollati, Julieta; Gariboldi, Claudia Maricel; Tarzia, Domingo Alberto We consider a steady-state heat conduction problem in a multidimensional bounded domainfor the Poisson equation with constant internal energy g and mixed boundary conditions given by a constant temperature b in the portion 1 of the boundary and a constant heat flux q in the remaining portion2 of the boundary.Moreover, we consider a family of steady-state heat conduction problems with a convective condition on the boundary 1 with heat transfer coefficient α and external temperature b. We obtain explicitly, for a rectangular domain in R2, an annulus in R2 and a spherical shell in R3, the optimal controls, the system states and adjoint states for the following optimal control problems: a distributed control problem on the internal energy g, a boundary optimal control problem on the heat flux q, a boundary optimal control problem on the external temperature b and a distributed-boundary simultaneous optimal control problem on the source g and the flux q. These explicit solutions can be used for testing new numerical methods as a benchmark test. In agreement with theory, it is proved that the system state, adjoint state, optimal controls and optimal values corresponding to the problem with a convective condition on 1 converge, when α → ∞, to the corresponding system state, adjoint state, optimal controls and optimal values that arise from the problem with a temperature condition on 1. Also, we analyze the order of convergence in each case, which turns out to be 1/α being new for these kind of elliptic optimal control problems.

(Con)memoraciones utópicas y epístolas íntimas para Problemática Educativa; Utopic commemorations and intimate epistles for Problemática Educativa (Education Issues) Aguirre, Jonathan Ezequiel; Branda, Silvia Adriana; Cadaveira, Gabriela Carmen; Cañueto, Gladys Noemi; de Laurentis, Claudia Graciela; Galluzzi, María Concepción; Genzano, Florencia; Laquidain, Melina; Porta Vazquez, Luis Gabriel; Proasi, Laura Virginia; Ramallo, Francisco; Villarrreal, Magalí Este artículo se trata de una escritura, en gran medida colectiva, que detiene las rígidas temporalidades en epístolas, cuyos flujos (con)funden pasado, presente y futuro. A partir de una serie de cartas íntimas que aquí devienen públicas, descomponemos la historia de la cátedra Problemática Educativa de la Facultad de Humanidades de la Universidad Nacional de Mar del Plata. Como un modo de (con)memorar sus veintidós años y valorar su concentración en la inmediatez del campo de la ciencias de la educación, estas (carto)grafías testimonian registros no rectos y activan mutaciones con la memoria. La indivisibilidad entre lo íntimo, lo comunitario y la educación, abrazan un ejercicio académico contingente y viral que no sólo contagia contenido y forma, sino que también apela alformalismo de los estudios performáticos para desidentificar una comunidad de aprendizaje.

Nuevas fuentes de resistencia a la podredumbre carbonosa de la soja causada por Macrophomina phaseolina; New sources of resistance to Charcoal rot of soybean caused by Macrophomina phaseolina Reznikov, Sebastian; Bleckwedel, Juliana; Claps, María Paula; de Lisi, Vicente; Gonzalez, Victoria del Valle; Escobar, Marcela; Ledesma Rodriguez, Fernando; Devani, Mario Rodolfo; Castagnaro, Atilio Pedro; Ploper, Leonardo Daniel La podredumbre carbonosa de la soja [Glycine max (L.) Merr.], ocasionada por el hongo polífagoMacrophomina phaseolina (Tassi) Goid., es una enfermedad que ocasiona pérdidas económicamente importantes en elmundo. En el noroeste de Argentina esta patología es limitante para la producción de soja cuando se presentancondiciones de altas temperaturas y estrés hídrico. Debido a la importancia económica y a la falta de genotiposcomerciales de soja resistentes a esta enfermedad, se planteó como objetivo evaluar el comportamiento de las líneasavanzadas de soja del programa de mejoramiento genético de la Estación Experimental Agroindustrial Obispo Colombres(EEAOC) frente a la podredumbre carbonosa, en ensayos a campo inoculados con el hongo. Se evaluaron losparámetros de severidad e índice de unidades formadoras de colonias de M. phaseolina (IUFC) en estadio fenológico R7del cultivo. Se evaluaron 12 líneas de soja en la campaña 2016/2017 y 24 líneas en el ciclo agrícola 2017/2018. Laslíneas que presentaron los mejores comportamientos frente a M. phaseolina en los ciclos agrícolas evaluados fueron:D38M3-13/182, D51N59-14/247 y Munasqa RR, las cuales se comportaron como moderadamente resistentes cuando seevaluó el parámetro severidad, y como resistentes según el parámetro IUFC. Estas líneas podrían ser utilizadas en losprogramas de mejoramiento genético como progenitores para incorporar la resistencia frente a esta enfermedad, ymejorar así el manejo de la podredumbre carbonosa de la soja en el noroeste de Argentina de forma eficaz y amigablecon el ambiente.; Charcoal rot of soybean [Glycine max (L.) Merr.], caused by the polyphagous fungus Macrophomina phaseolina (Tassi) Goid., is an economically important disease worldwide. In northwestern Argentina this pathology is limiting for soybean production when high temperatures and water stress prevail in the season. Due to its economic importance and the lack of commercial genotypes of soybean resistant to this disease, the objective of this work was to evaluate the reaction against charcoal rot of advanced lines from Estación Experimental Agroindustrial Obispo Colombres (EEAOC) breeding program, in field trials inoculated with the fungus. The parameters evaluated at the R7 stage were severity and a colony-forming unit index of M. phaseolina (CFUI). Twelve soybean lines were evaluated in the 2016/2017 growing season and 24 lines in the 2017/2018 season. These evaluations indicated that D38M3-13/182, D51N59-14/247 and Munasqa RR were moderately resistant when severity was considered, and as resistant based on the CFUI. These lines could be used in genetic improvement programs as parents to enhance resistance to this disease and thus improve the management of charcoal rot of soybeans in northwestern Argentina in an efficient and environmentally friendly way.

Apriete, empaste y juzgamiento: la trama de relaciones detrás de un juicio a policías exonerados; Extort, fouiling and judging: the network of relationships behind a trial of exonerated police officers Bover, Tomás A partir del trabajo de campo realizado durante el juicio oral a ocho jefes policiales en una causa conocida como “la causa de los sobres” propongo analizar un conjunto de relaciones institucionales que conforman una trama policial-política y judicial. El objetivo de este artículo es poner en cuestión las nociones de “autonomía” y “autogobierno” policial, para dar cuenta de cómo la policía se encuentra formando parte de una imbricada trama de instituciones y pensar que “la policía”, “la justicia” y “la política” no pueden ser vistas como bloques monolíticos y separados. En segundo lugar, a partir de las nociones de apriete, empaste y juzgamiento analizo el tipo de relaciones - de complicidad, colaboración, conflicto y otras - que producen la mencionada trama entre instituciones.; Based on the field work carried out during the oral trial of eight police chiefs in a case known as "the cause of the envelopes", I propose to analyze a set of institutional relations that make up a police-political and judicial network. The objective of this article is to question the notions of police "autonomy" and "self-government", to account for how the police are forming part of an interwoven fabric of institutions and to think that "the police", "justice" and “politics” cannot be seen as monolithic and separate blocks. Second, From the notions of squeezing, filling and judging, the type of relationships, complicity, collaboration, conflict and others that produce the aforementioned are analyzed. plot between institutions.

Key Role of Oxygen-Vacancy Electromigration in the Memristive Response of Ferroelectric Devices Ferreyra, Cristian Daniel; Rengifo Morocho, Miguel Andrés; Sanchez, Maria Jose; Everhardt, Arnoud S.; Noheda, Beatriz; Rubi, Diego Ferroelectric memristors are intensively studied due to their potential implementation in data storage and processing devices. In this work we show that the memristive behavior of metal-ferroelectric-oxide-metal devices relies on the competition of two effects: the modulation of metal-ferroelectric interface barriers by the switchable ferroelectric polarization and the electromigration of oxygen vacancies, with the depolarizing field playing a fundamental role in the latter. We simulate our experimental results with a phenomenological model that includes both effects and we reproduce several nontrivial features of the electrical response, including resistance relaxations observed after external poling. Besides providing insight into the underlying physics of these complex devices, our work suggests that it is possible to combine nonvolatile and volatile resistive changes in single ferroelectric memristors, an issue that could be useful for the development of neuromorphic devices.

Th22 response induced by Mycobacterium tuberculosis strains is closely related to severity of pulmonary lesions and bacillary load in patients with multi-drug-resistant tuberculosis Imperiale, Belén Rocío; García, Ana; Minotti, Alejandro Adolfo; González Montaner, Pablo; Moracho Lucila; Morcillo, N.; Palmero, Domingo Juan; Sasiain, Maria del Carmen; de la Barrera, Silvia Susana The role of interleukin-22 (IL-22) in the pathogenesis or tissue repair in human tuberculosis (TB) remains to be established. Here, we aimed to explore the ex-vivo and in-vitro T helper 22 (Th22) response in TB patients and healthy donors (HD) induced by different local multi-drug-resistant (MDR) Mvcobacterium tuberculosis (Mtb) strains. For this purpose, peripheral blood mononuclear cells from drug-susceptible (S-TB) MDR-TB patients and HD were stimulated with local MDR strains and the laboratory strain H37Rv. IL-22 and IL-17 expression and senescent status were assessed in CD4+ and CD8+ cells by flow cytometry, while IL-22 amount was measured in plasma and culture supernatants by enzyme-linked immunosorbent assay (ELISA). We found lower IL-22 amounts in plasma from TB patients than HD, together with a decrease in the number of circulating T cells expressing IL-22. In a similar manner, all Mtb strains enhanced IL-22 secretion and expanded IL-22+ cells within CD4+ and CD8+ subsets, being the highest levels detected in S-TB patients. In MDRTB, low systemic and Mtb-induced Th22 responses associated with high sputum bacillary load and bilateralism of lung lesions, suggesting that Th22 response could be influencing the ability of MDR-TB patients to control bacillary growth and tissue damage. In addition, in MDR-TB patients we observed that the higher the percentage of IL-22+ cells, the lower the proportion of programmed cell death 1 (PD-1)+ or CD57+ T cells. Furthermore, the highest proportion of senescent T cells was associated with severe lung lesions and bacillary load. Thus, T cell senescence would markedly influence Th22 response mounted by MDR-TB patients.

A pandemia covid19 na Arxentina Oviedo, Eduardo Daniel Breve análisis del impacto de la pandemia en Argentina, especialmente en la enseñanza universitaria argentina, con descripción de la experiencia en el dictado de clases en la Universidad Nacional de Rosario.

Electron tunneling at the molecularly thin 2D perovskite and graphene van der Waals interface Leng, Kai; Wang, Lin; Shao, Yan; Abdelwahab, Ibrahim; Grinblat, Gustavo Sergio; Verzhbitskiy, Ivan; Li, Runlai; Cai, Yongqing; Chi, Xiao; Fu, Wei; Song, Peng; Rusydi, Andrivo; Eda, Goki; Maier, Stefan A.; Loh, Kian Ping Quasi-two-dimensional perovskites have emerged as a new material platform for optoelectronics on account of its intrinsic stability. A major bottleneck to device performance is the high charge injection barrier caused by organic molecular layers on its basal plane, thus the best performing device currently relies on edge contact. Herein, by leveraging on van der Waals coupling and energy level matching between two-dimensional Ruddlesden-Popper perovskite and graphene, we show that the plane-contacted perovskite and graphene interface presents a lower barrier than gold for charge injection. Electron tunneling across the interface occurs via a gate-tunable, direct tunneling-to-field emission mechanism with increasing bias, and photoinduced charge transfer occurs at femtosecond timescale (~50 fs). Field effect transistors fabricated on molecularly thin Ruddlesden-Popper perovskite using graphene contact exhibit electron mobilities ranging from 0.1 to 0.018 cm2V−1s−1 between 1.7 to 200 K. Scanning tunneling spectroscopy studies reveal layer-dependent tunneling barrier and domain size on few-layered Ruddlesden-Popper perovskite.

Mineralization of formic acid from catalytic nitrate reduction effluent by UV-based and electrochemical processes Miranda Zoppas, Fernanda; Wohlmuth da Silva, Salatiel; Favarini Beltrame, Thiago; Marchesini, Fernanda Albana; Bernardes, Andrea Moura; Miro, Eduardo Ernesto In this work, UV-based and electrochemical processes were proposed for formic acid (FA) mineralization, from an effluent generated on the nitrate catalytic reduction reaction. The results show that although direct photolysis (DP) does not have the ability to mineralize FA, heterogeneous photocatalysis (HP), photo-assisted electrochemical oxidation (PEO) and electrochemical oxidation (EO) have. In fact, it has been shown that FA mineralization is governed by the electrochemical process. When nitrate was added in the FA solution, all process exhibited an increase in FA mineralization, mainly for DP. For UV-based process, this fact can be linked to the nitrate photolysis generating hydroxyl radicals (HO•). On the other hand, the mineralization increase observed on the EO process, is associated with the increase in charge transfer, considering that the generation of oxidants is a rate-limiting-step, showing pseudo-zero-order constants for DP and HP, and pseudo-first-order for PEO and EO. The best results of FA mineralization with the smallest energy consumption was obtained by the electrochemical process. Besides, EO was not negatively influenced by the addition of nitrate.

Revisitando las intersecciones entre feminismo y sindicalismo. El caso de Mujeres Sindicalistas (Argentina, 2016-2019); Revisiting the intersections between feminism and unionism. The case of Mujeres Sindicalistas (Argentina, 2016-2019) Natalucci, Ana Laura; Ríos, Victoria; Vaccari, Samantha En los últimos años en Argentina, se produjeron dos fenómenos que por varios años transitaron caminos paralelos pero que finalmente encontraron puntos de intersección. Se tratan del proceso de revitalización sindical y de la activación del ciclo de movilización feminista. La emergencia del Ni Una Menos en 2015 fue decisivo para la visibilidad de la violencia machista y la formación de colectivos que cuestionaron las desigualdades de género. Asimismo, desde 2016 emergieron espacios y colectivos de mujeres en las organizaciones sindicales que trastocaron esta dinámica. ¿Cuáles fueron las relaciones entre el ciclo de movilización feminista y la emergencia y desarrollo de colectivos de mujeres sindicalistas a partir de la interseccionalidad entre clase, trabajo y género? ¿De qué modos las experiencias de clase y de género han incidido en la conformación de colectivos de mujeres en los nucleamientos sindicales? El objetivo del artículo es comprender la intersección entre feminismo y sindicalismo, específicamente por la creación de colectivos de mujeres en sindicatos. A partir de las nociones de interseccionalidad estructural e interseccionalidad política indagamos sobre la experiencia de Mujeres Sindicalistas perteneciente a la CFT/CGT. El período analizado se extiende entre 2016 y 2019. Nuestro argumento es que, aunque ya había mujeres que participaban de los sindicatos, la novedad de esta experiencia puede encontrarse en el establecimiento de puentes al interior del sindicalismo como entre este y otras organizaciones feministas. En términos metodológicos se siguió una estrategia multimétodo informada de la Teoría Fundamentada.; In the last years in Argentina, two events occurred that for several years travelled parallel make ways but that finally found intersection points. They are about the process of union revitalization and the activation of the feminist mobilization cycle. The emergence of Ni Una Menos in 2015 was decisive for the visibility of male violence and the formation of groups that questioned gender inequalities. Likewise, since 2016, women's spaces and groups emerged in union organizations that upset this dynamic. What were the relationships between the cycle of feminist mobilization and the emergence and development of groups of women trade unionists based on the intersectionality between class, work and gender? In what ways have class and gender experiences influenced the formation of women's collectives in the unions? The aim of the paper is to understand the intersection between feminism and unionism, specifically by creating women's collectives in union organizations. Starting from the notions of structural intersectionality and political intersectionality, we inquired about the experience of Mujeres Sindicalistas belonging to the CFT / CGT. The period analyzed is extended between 2016 and 2019. Our argument is that, although there were already women who participated in unions, the novelty of this experience can be found in the establishment of bridges within unionism, as between it and other feminist organizations. In methodological terms, we follow a multi-method strategy, informed by the Grounded Theory.