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.

La Agricultura familiar en Santa Cruz, Patagonia Argentina: caracterización de los núcleos agrícolas familiares; Family Farming in Santa Cruz, Patagonia Argentina: Characterization of family agricultural nuclei Birgi, Jorge Alberto; Peri, Pablo Luis; Ceconello, Marcos Mauricio; Gargaglione, Veronica Beatriz La agricultura familiar abarca a un grupo grande de personas que tienen distintos orígenes y una amplia diversidad cultural, pero que mantienen en común la producción de alimentos como forma de vida. El objetivo del presente trabajo fue caracterizar a la agricultura familiar de la provincia de Santa Cruz, determinando aspectos cualitativos, productivos y condiciones de producción de los núcleos de agricultura familiar. Se estudió el sector agrícola familiar de la provincia utilizando como base el análisis de 258 planillas del Registro Nacional de Agricultura Familiar relevadas durante los años 2014-2016. De dicho análisis surge que el tamaño medio de los predios en Santa Cruz es de 5 ha, se dedican principalmente a la agricultura y a la producción pecuaria, con predominio de la avicultura. En general, los productores realizan diversas actividades productivas en simultáneo. Se destaca por superficie implantada, la producción de forrajes, frutales, frutas finas y hortícolas de hoja. El presente trabajo es el primero en visibilizar numerosos aspectos de la agricultura familiar en Santa Cruz y presenta información inédita acerca de los núcleos de agricultura familiar en la provincia, contemplando a muchos productores que no figuran como tales en otros relevamientos como ser el Censo Agropecuario Nacional. Contar con este tipo de información resulta fundamental para las instituciones y los diversos actores sociales a fin de de monitorear su evolución en el tiempo y desarrollar políticas para su desarrollo y fortalecimiento.; Family farming encompasses a large group of people who have different origins and broad cultural diversity, but who keep food production in common as a way of life. The aim of this study was to characterize family farming in the province of Santa Cruz, determining qualitative and productive aspects and also production conditions of the family farming nucleus. The family agricultural sector of the province was studied using the analysis of 258 forms of the National Registry of Family Agriculture surveyed during the years 2014-2016. From this analysis it appears that the average size of the farms in Santa Cruz is 5 ha, they are mainly dedicated to agriculture and livestock production, being poultry the main activity. In general, producers carry out various productive activities simultaneously. It stands out for its implanted area, the production of forage, fruit trees, fine fruits and leafy vegetables. This work is the first to make numerous aspects of family farming in Santa Cruz visible and presents unpublished information about family farming centers in the province, considering many producers who are not listed as such in other surveys, such as the National Agricultural Census. Having this kind of information is essential for institutions and others social actors in order to monitor their evolution over time and develop policies for their development and strengthening.

Crítica al discurso representativista como desenmascaramiento de la metafísica; Criticism of the representative discourse as an unmasking of the metaphysics Bisang, Sebastián Pablo; Fava, Fernando Juan Los cuestionamientos nietzscheanos al pensamiento metafísico desde el rechazo a la concepción tradicional del lenguaje, se entienden a partir de la asimilación crítica que Nietzsche realiza de pensadores inscriptos en la órbita del neokantismo como podrían considerarse a Schopenhauer, Hartmann o Lange. Durante los años 1865-1872, de un modo muy intuitivo, con fórmulas heredadas de su admirado maestro Schopenhauer, y bajo el influjo del proyecto cultural wagneriano, Nietzsche va combinando su bagaje cultural con lecturas de pensadores de cuño crítico como Lange o Hartmann. Ensayando su propio pensamiento desde bocetos no exentos de tensiones y confrontaciones, como también de intuiciones geniales. Un universo de lecturas que poco tiempo después (1873) el joven catedrático de Basilea, reorientará desde los aspectos tropológicos del lenguaje, a partir de su recepción de Die Sprache als Kunst de G. Gerber. En el siguiente artículo, nos proponemos trazar una génesis de su crítica al “pensamiento metafísico” desde la reconstrucción de sus preocupaciones tempranas en torno al conocimiento. Focalizándonos en los Nachgelassene Fragmente de este período (1865-1875), intentaremos reconstruir la poliédrica recepción nietzscheana de la crítica epistemológica asumida por Lange, el valor de lo instintivo-inconsciente en la configuración de las representaciones sostenida por Hartmann y el carácter ilusorio del conocimiento propuesto por Schopenhauer. Un entramado de ideas que bien reflejan los póstumos de esta etapa y que, si tomamos como hilo genealógico-interpretativo sus preocupaciones lingüísticas, se revelarán como la verdadera geología del mapa conceptual explayado en Über Wahrheit und Lüge im aussermoralischen Sinne. Escrito en el que Nietzsche no sólo sintetiza, concretiza y clarifica este camino de búsqueda, sino que prefigura los parámetros, la cartografía, de su pensamiento maduro.; The Nietzschean questions to metaphysical thought from the rejection of the traditional conception of language, are understood from the critical assimilation that Nietzsche makes of thinkers enrolled in the orbit of neo-Kantianism as Schopenhauer, Hartmann or Lange. During the years 1865-1872, in a very intuitive way, with formulas inherited from his admired teacher Schopenhauer, and under the influence of the Wagnerian cultural project, Nietzsche combines his cultural background with readings of critical thinkers such as Lange or Hartmann. Rehearsing his own thinking from sketches that are not without tension and confrontations, as well as great insights. A universe of readings that a short time later (1873) the young professor from Basel, reoriented from the tropological aspects of language, from his reception of Die Sprache als Kunst by G. Gerber. In the following article, we propose to trace a genesis of his critique of "metaphysical thought" from the reconstruction of his early concerns about knowledge. Focusing on the Nachgelassene Fragmente of this period (1865-1875), we will try to reconstruct the multifaceted Nietzschean reception of the epistemological critique assumed by Lange, the value of the instinctual-unconscious in the configuration of representations sustained by Hartmann and the illusory character of knowledge proposed by Schopenhauer. A network of ideas that well reflect the posthumous fragments of this stage and that, if we take their linguistic concerns as a genealogical-interpretative thread, will reveal themselves as the true geology of the conceptual map expanded in Über Wahrheit und Lüge im aussermoralischen Sinne. Work in which Nietzsche not only synthesizes, concretizes and clarifies this path of search, but prefigures the parameters, the cartography, of his mature thought.

Microemprendedores familiares y espíritu de empresa desde una mirada sociológica Seid, Gonzalo Javier En este artículo se analizan, a partir de los conceptos de la teoría de las clases sociales de Bourdieu, cuatro historias de personas que viven en Buenos Aires cuyas familias han tenido un microemprendimiento. Las historias se analizan como trayectorias de clase social, es decir, se observan las distintas especies de capital en juego y su transformación a través de tiempo. También se hace referencia a las disposiciones subjetivas y las estrategias familiares, con el fin de confrontarlas con los principios habitualmente aceptados para la administración racional de los negocios. Por último, se reflexiona sobre la mirada sociológica de los microemprendimientos familiares y su relación con los saberes de las disciplinas económicas.; Based on Bourdieu's theory of social classes, we analyze four life stories of people living in Buenos Aires whose families have had a micro-enterprise. The stories are interpreted as social class pathways, since we are interested in different kinds of capital at stake and their transformation over time. Moreover, we analyze subjective dispositions and family strategies, in order to confront them with the commonly accepted principles for the rational administration of business. Lastly, we reflect on the sociological view of family microenterprises and its connection with the knowledge of economic disciplines.; Este artigo analisa, com base nos conceitos da teoria das classes sociais de Bourdieu, quatro histórias de pessoas que vivem em Buenos Aires cujas famílias tiveram uma microempresa. As histórias são analisadas como trajetórias de classe social, ou seja, são observadas as diferentes espécies de capital em jogo e sua transformação ao longo do tempo. Também é feita referência a disposições subjetivas e estratégias familiares, a fim de confrontá-las com os princípios comumente aceitos para a administração racional dos negócios. Por fim, reflete sobre a visão sociológica das microempresas familiares e sua relação com o conhecimento das disciplinas econômicas.

Campo adentro y ciudad afuera: Posiciones de género en el cine de Julia Solomonoff; Field inside and city outside: Julia Solomonoff´s cinema gender positions Martinelli, Lucas Sebastián Este ensayo analiza las posiciones y las significaciones del cine de Julia Solomonoff para considerar los aspectos que una perspectiva fílmica puede otorgar a cierta política de los cuerpos ficcionales como un terreno de disputas y problemáticas relativas al género, la sexualidad y la migración. Hermanas (2005), El último verano de la boyita (2009) y Nadie nos mira (2017) son largometrajes que proponen modelos especiales para considerar las formas de politicidad que el cine puede asumir respecto a cuestiones sociales y, de este modo, extender la experiencia estética hacia una implicancia de lo común.; This essay analyzes the space incursions and the meanings of Julia Solomonoff’s cinema to consider the aspects that a filmic perspective can grant to a certain politics of fictional bodies as a field of disputes and problems related to gender, sexuality and migration. Hermanas (2005), El último verano de la boyita (2009) y Nadie nos mira (2017) are feature films that propose special models to consider the forms of politics that cinema can assume regarding social issues and, in this way, extend the field of aesthetic towards a common implication.

Controls of forage selective defoliation by sheep in arid rangelands Oñatibia, Gastón Rafael; Golluscio, Rodolfo; Texeira González, Marcos Alexis; Paruelo, José Selective grazing by domestic livestock is a major control of plant community structure and dynamics in drylands. However, grazing impact predictions supporting management decisions are frequently based on average biomass consumption, neglecting selectivity. We evaluated the relative importance of grazing pressure, total and each species density, and plant dead biomass proportion as drivers of selective defoliation by sheep in three dominant native grass species in Patagonian steppes. Species were Poa ligularis, Festuca pallescens, and Pappostipa speciosa, which a priori present different preference degree by sheep. The relevance of these drivers for differently preferred species has not been simultaneously studied. We recorded the defoliation frequency and degree of the three species (dependent variables) throughout 112 field surveys. Besides, we recorded grazing management and vegetation structure descriptors (independent variables). Poa ligularis was highly defoliated (90% of plants), and grazing pressure was the leading driver (asymptotic exponential relationship). For F. pallescens, almost 70% of plants were defoliated, and defoliation non-linearly increased as grazing pressure rose and linearly decreased as both its dead biomass proportion and P. ligularis density increased. For P. speciosa, defoliation was low (20% of plants) and linearly decreased as both its dead biomass proportion and the density of the other two species increased. Grazing pressure played a negligible role in this species. These patterns confirmed that P. ligularis, F. pallescens, and P. speciosa, respectively, present high, intermediate, and low preference degree by sheep. In conclusion, our findings suggest that (1) selective defoliation can be satisfactorily predicted as function of grazing pressure, species densities, and plant dead biomass proportion; (2) grazing pressure becomes a more relevant driver as species preference rises and its effect on defoliation is markedly non-linear; (3) the dead biomass proportion and the abundance of highly preferred species are the leading factors determining less preferred species defoliation; and (4) grazing pressure management by itself is not enough to reduce the high defoliation of preferred species and increase the defoliation of non-preferred species. This knowledge is critical for developing effective management practices to control forage species defoliation in rangelands worldwide where species with different preference by herbivores coexist.

On the first step in zinc deposition – A case of nonlinear coupling with the solvent Quaino, Paola Monica; Colombo, Estefanía; Juárez, Fernanda; Santos, Elizabeth; Belletti, Gustavo Daniel; Groß, Axel; Schmickler, Wolfgang The deposition of zinc from aqueous solutions is of great practical importance, and it also serves as a prototype for the deposition of divalent ions. Both experiment and theory agree, that it takes place in two steps. Previous theoretical work [1] had suggested that the step, Zn+++e-→Zn+ takes place in the outer sphere, but gave a prohibitively high energy of activation of the order of 1.4 eV, in accord with the enigma of metal deposition postulated by Gileadi [2]. In this work the treatment of the reactant – solvent interaction is substantially improved by introducing nonlinear terms based on molecular dynamics. Our calculations suggest that the first steps follows an inner sphere path with a much lower energy of activation, which results in a physically adsorbed Zn+ ion. The second step then occurs on the electrode surface. These findings are in line with experimental data.

In Silico Study of the Interaction between Casein with Tocopherols: Preliminary Evaluation of Lipophilic Substrate Inclusion on Proteic Matrix Guntero, Vanina Alejandra; Gutierrez, Leandro Gabriel; Kneeteman, Maria Nelida; Ferretti, Cristián Alejandro Bovine casein is a family of milk proteins with hydrophilic and hydrophobic regions thatshow block distribution within the protein chain. These amphiphilic properties offer great potentialas a material for use as a matrix for transporting active materials such as tocopherol. In this work,we aimed to evaluate the interaction of α1-casein, the main fraction of casein, with vitamin E bydocking calculations. Docking studies were conducted using SwissDock and DockThor servers.Using specific scoring functions based on energy terms, the best protein?ligand binding modelswere obtained. The observed interactions between vitamin E and amino acid residues consisted ofseveral hydrophobic interactions (e.g., with Tyr119, Ala144, Trp179, Met211, Pro212). A few hydrogen bonds were observed between the phenyl group of vitamin E and the carboxylate group ofthe glutamic acid residue (e.g., with Glu85, Glu148). In conclusion, the results suggest that there isa major interaction of vitamin E with random coil structure and interaction with segments formedby α-helix and β-sheet. This implies that in random coil segments there is a predominance of hydrophobic domains.

Microbiota diversity change as quality indicator of soils exposed to intensive periurban agriculture Raiger Iustman, Laura Judith; Almasqué, Facundo Joaquín; Vullo, Diana Lia In Argentina, periurban agriculture is performed by farmers with inadequate training in the use of pesticides and chemical fertilizers, developing horticulture with serious soil deterioration. The aim of this work was to monitor bacterial diversity of a horticultural soil (S) and a reference soil (R) as quality index for the design of future restoration strategies. As crops changed together with the agrochemical applications, sample collection was before harvest for strawberries, post-harvest for red peppers, pre-harvest broccoli crop and of a resting soil in treatment with poultry litter as a fertilizing amendment. Bacterial diversity was analysed by the use of high throughput sequencing of the V1–V3 region of the 16S rRNA gene. Analysis of R soils seemed relatively constant in time, enriched in Alphaproteobacteria and Acidobacteria consistent with a reference to soil health. The effect of the intensive use of S soils was proved by differences in Chloroflexi, Bacteroidetes and Proteobacteria relative abundances. The main evidence of the alteration of S soils was the increase in Bacteroidetes and Betaproteobacteria. A weak recuperation trend of S soil microbiota was registered during a post-harvest inactive period. A strong influence of the soil use routine—consisting in high crop rotation and short time-rest cycles—on microbial community structure was verified. These results indicate the microbiota perturbation, caused by the intense use of periurban agriculture soils and will contribute for further actions to improve environment quality.

Chinese cooperation with Africa in health infrastructure in the context of Coronavirus Crisis: BRI’s new emerging priority? Giaccaglia, Clarisa; Dussort, María Noel; Marchetti, Agustina The aim of this paper is to analyse infrastructure cooperation projects China has carried out in Sub-Saharan Africa in the period 2013-2020, considering that since Xi Jinping’s assumption China has spread more cooperation initiatives in infrastructure projects in the framework of the BRI. We focus on Chinese cooperation in health infrastructure, since COVID-19 global health emergency highlighted the lack of multilateral cooperation and gave China once again the opportunity to consolidate itself as a big player in the international system, this time in health issues.

Perros indígenas en el Noreste argentino Castro, Juan Carlos; Bonomo, Mariano; González Venanzi, Lucio; Cornero, Silvia Elena El registro de Canis familiaris en contextos arqueológicos resulta cada vez más frecuente en Sudamérica. En este escenario, este trabajo discute su rol económico y social dentro de las sociedades indígenas prehispánicas. Se presentan nuevos hallazgos de perros procedentes de cinco sitios arqueológicos del Noreste argentino. La muestra estudiada incluye siete especímenes craneales y uno poscraneal correspondientes a individuos jóvenes y adultos, de tamaños medianos (13-23 kg). Algunos de los especímenes presentan huellas de corte y marcas de carnívoros. Tres nuevas fechas taxón ubican a la muestra entre aproximadamente 2500 y 900 cal aP. Se concluye que C. familiaris presenta edades y tamaños ligeramente mayores a los registrados previamente. Asimismo, la evidencia antrópica indica procesamiento y consumo de esta especie. Las dataciones extienden el rango cronológico conocido previamente para este taxón en Argentina, Brasil y Uruguay. Su presencia se vincula a cazadores-recolectores-pescadores y horticultores, con una marcada adaptación fluvial durante el Holoceno tardío.; The recording of Canis familiaris specimens in archaeological sites of South America has occurred with increasing regularity. In this scenario, this article discusses their economic and social role within prehispanic indigenous societies. It presents new remains of dogs originating from five archaeological sites in the Northeast Argentina region. The sample studied includes seven cranial specimens and one postcranial belonging to young and adult individuals of medium body size (13–23 kg). Some of the specimens present anthropic cut marks and carnivore marks. Three new taxonomic dates place the sample between about 2500 and 900 14C cal BP. The conclusion is that C. familiaris presents slightly greater ages and sizes than previous records show. Likewise, anthropic evidence indicates the processing and consumption of the species. The new 14C dates extend the chronological range previously known for indigenous dogs in Argentina, Brazil, and Uruguay. Their presence is linked to hunter-gatherer-fishers and horticulturalists, with a pronounced fluvial adaptation during the late Holocene.

La labor etnográfica en dos organismos estatales de administración de conflictos: Una mirada sobre los documentos y los casos; Etnographic work in two state conflicto managment agencies: A view on documents and cases; Trabalho etnográfico em duas agências estatais de gestão de conflitos: Um olhar sobre os documentos e casos Pizarro, Matías Rafael; Larrea, Natalia Jimena El objetivo de este artículo es reflexionar acerca de la producción documental y el estudio de casos a partir de la labor etnográfica desarrollada en dos organismos estatales de administración de conflictos en la ciudad de Olavarría, provincia de Buenos Aires, durante el año 2018. Por un lado, destacamos la importancia que los documentos comprenden como pistas, y también prácticas, para explorar la niñez y la vecindad como formas sociales objeto de regulación estatal. En este sentido, se describe y analiza el modo en que las formas de documentar del Estado impactan en la tramitación de conflictos vecinales y en la administración de situaciones asociadas a la niñez con derechos vulnerados. Por otro lado, nos ocupamos de señalar las potencialidades y límites que implica para el desarrollo y continuidad de nuestras investigaciones un abordaje metodológico centrado en casos.; The aim of this paper is to reflect on the documentary production and case studies based on the ethnographic work developed in two state agencies of conflict management in the city of Olavarría, Province of Buenos Aires, during the year 2018. On the one hand, we highlight the importance that the documents have as clues, and also practices, to explore childhood and neighbourhood as social forms subject to state regulation. In this sense, we describe and analyze the way in which the State’s forms of documentation impact the processing of neighborhood conflicts and the administration of situations associated with children “with violated rights”. On the other hand, we point out the potential and limits that a case-based methodological approach implies for the development and continuity of our research.; O objectivo deste artigo é reflectir sobre a produção documental e estudos de caso baseados no trabalho etnográfico desenvolvido em duas agências estatais de gestão de conflitos na cidade de Olavarría, Província de Buenos Aires, durante o ano de 2018. Por um lado, salientamos a importância que os documentos têm como pistas, e também como práticas, para explorar a infância e a vizinhança como formas sociais sujeitas a regulação estatal. Neste sentido, descrevemos e analisamos a forma como as formas de documentação do Estado têm impacto no tratamento dos conflitos de vizinhança e na administração de situações associadas a crianças “com direitos violados”. Por outro lado, salientamos também o potencial e os limites que uma abordagem metodológica baseada em casos concretos implica para o desenvolvimento e a continuidade da nossa investigação.

Comparison of different analytical methods to evaluate the heat shock protein (HSP) response in fruits: Application to tomatoes subjected to stress treatments Polenta, Gustavo Alberto; Guidi, Silvina Mabel; Ambrosi, Vanina; Denoya, Gabriela Inés Heat shock proteins (HSP) are synthesized in living tissues exposed to transient increase in temperature and play a central role in the protective response against heat and other stresses. In fruits, this response to heat treatment provides resistance to a physiological alteration known as chilling injury. Despite the physiological importance of this group of proteins, publications comparing different methodological alternatives for their analysis are rather scarce. In the present paper, we conducted a comparative study using different electrophoretic and immunological techniques to evaluate the HSP response in fruits. Proteins were extracted from tomato fruit exposed to an HSP-inducing temperature (38º C) for different times (0, 3, 20, and 27 hours). Different alternatives of analysis (SDS-PAGE, SDS-PAGE followed by IEF, western blot, and dot blot) were performed, and their potential application discussed. The study was complemented with a practical application, in which tomatoes were subjected to heat and anaerobic treatments and then stored in a chill-inducing temperature. This application evidences the relevance of knowing the level of proteins attained by stress treatments which correlates with the acquired tolerance.

Obsidiana negra en la costa norte de Santa Cruz: interacciones humanas y aprovisionamiento lítico; Black obsidian in the north coast of Santa Cruz: human interactions and lithic procurement Ambrustolo, Pablo Los análisis geoquímicos realizados sobre artefactos de obsidiana negra de la costa norte de Santa Cruz evidencian la circulación a larga distancia, al menos desde el Holoceno medio, de las tres variedades de esta materia prima reconocidas en la fuente Pampa del Asador, ubicada aproximadamente a 400 km hacia el oeste de la mencionada área. Estudios de arqueología distribucional realizados a escala regional, sostienen que las frecuencias relativas de artefactos de obsidiana, sus tamaños y proporción de reserva cortical, decrecerían desde el oeste hacia el este, a medida que se alejan de la potencial fuente de abastecimiento. En un trabajo previo planteamos que el registro de evidencias de talla inicial de rodados de obsidiana, sumado a la identificación de artefactos con elevados porcentajes de corteza, sugería que la obtención de piezas de dicha materia prima se habría dado bajo morfologías de rodado. En función del hallazgo de guijarros de obsidiana negra, los cuales presentan dimensiones similares a los registrados en la propia fuente, sostenemos que el aprovisionamiento de los mismos se habría dado a través de variados mecanismos vinculados, entre otros factores, con el establecimiento y fortalecimiento de relaciones sociales en el marco de circuitos de movilidad que vincularían la costa y el interior.; Geochemical analyzes performed on black obsidian artifacts from the north coast of Santa Cruz show the long-distance circulation, at least from the middle Holocene, of the three varieties of this raw material recognized at the Pampa del Asador source, located approximately 400 km west of the mentioned area. Studies of distributional archeology conducted at regional level, argue that the relative frequencies of obsidian artifacts, their sizes and proportion of cortical reserve, would decrease from the west to the east, as they move away from the potential procurement source. In a previous paper, we suggested that the record of evidence of initial knapping events of obsidian pebbles, added to the identification of artifacts with high percentages of cortex, suggested that obtaining pieces of said raw material would have been under pebbles morphologies. Based on the finding of black obsidian pebbles, which have similar dimensions to those recorded at the source itself, we proposal that their procurement would have occurred through various mechanisms linked, among other factors, with the establishment and strengthening of social relations within the framework of mobility circuits that would link the coast and the interior.