Reconstitution reveals how myosin-VI self- organises to generate a dynamic mechanism of membrane sculpting Rogez, Benoit; Würthner, Laeschkir; Petrova, Anastasiia B.; Zierhut, Felix B.; Saczko Brack, Dario; Huergo, María Ana Cristina; Batters, Christopher; Frey, Erwin; Veigel, Claudia One enigma in biology is the generation, sensing and maintenance of membrane curvature. Curvature-mediating proteins have been shown to induce specific membrane shapes by direct insertion and nanoscopic scaffolding, while the cytoskeletal motors exert forces indirectly through microtubule and actin networks. It remains unclear, whether the manifold direct motorprotein–lipid interactions themselves constitute another fundamental route to remodel the membrane shape. Here we show, combining super-resolution-fluorescence microscopy and membrane-reshaping nanoparticles, that curvature-dependent lipid interactions of myosin-VI on its own, remarkably remodel the membrane geometry into dynamic spatial patterns on the nano- to micrometer scale. We propose a quantitative theoretical model that explains this dynamic membrane sculpting mechanism. The emerging route of motorprotein–lipid interactions reshaping membrane morphology by a mechanism of feedback and instability opens up hitherto unexplored avenues of membrane remodelling and links cytoskeletal motors to early events in the sequence of membrane sculpting in eukaryotic cell biology.

A combinatorial analysis of the permutation and non-permutation flow shop scheduling problems Rossit, Daniel Alejandro; Vásquez, Óscar C.; Tohmé, Fernando; Frutos, Mariano; Safe, Martín D. In this paper we introduce a novel approach to the combinatorial analysis of flow shop scheduling problems for the case of two jobs, assuming that processing times are unknown. The goal is to determine the dominance properties between permutation flow shop (PFS) and non-permutation flow shop (NPFS) schedules. In order to address this issue we develop a graph-theoretical approach to describe the sets of operations that define the makespan of feasible PFS and NPFS schedules (critical paths). The cardinality of these sets is related to the number of switching machines at which the sequence of the previous operations of the two jobs becomes reversed. This, in turn, allows us to uncover structural and dominance properties between the PFS and NPFS versions of the scheduling problem. We also study the case in which the ratio between the shortest and longest processing times, denoted ρ, is the only information known about those processing times. A combinatorial argument based on ρ leads to the identification of the NPFS schedules that are dominated by PFS ones, restricting the space of feasible solutions to the NPFS problem. We also extend our analysis to the comparison of NPFS schedules (with different number of switching machines). Again, based on the value of ρ, we are able to identify NPFS schedules dominated by other NPFS schedules.

Oral administration of lipoteichoic acid from Lactobacillus rhamnosus GG overcomes UVB-induced immunosuppression and impairs skin tumor growth in mice Friedrich, Adrián David; Campo, Valeria Evelyn; Cela, Eliana Maiten; Morelli, Adrian E.; Shufesky, William J.; Tckacheva, Olga A.; Leoni, Juliana; Paz, Mariela Laura; Larregina, Adriana T.; Gonzalez Maglio, Daniel Horacio There is increasing evidence of the relevant connection and regulation between the gut and skin immune axis. In fact, oral administration of lipoteichoic acid (LTA) from Lactobacillus rhamnosus GG (LGG) prevents the development of UV‐induced skin tumors in chronically exposed mice. Here we aim to evaluate whether this LTA is able to revert UV‐induced immunosuppression as a mechanism involved in its anti‐tumor effect and whether it has an immunotherapeutic effect against cutaneous squamous cell carcinoma. Using a mouse model of contact hypersensitivity, we demonstrate that LTA overcomes UV‐induced skin immunosuppression. This effect was in part achieved by modulating the phenotype of lymph node resident dendritic cells (DC) and the homing of skin migratory DC. Importantly, oral LTA reduced significantly the growth of established skin tumors once UV radiation was discontinued, demonstrating that it has a therapeutic, besides the already demonstrated preventive antitumor effect. The data presented here strongly indicates that oral administration of LTA represents a promising immunotherapeutic approach for different conditions in which the skin immune system is compromised.

The Scope of Traditional and Geometric Morphometrics for Inferences of Diet in Carnivorous Fossil Mammals Tarquini, Sergio Daniel; Chemisquy, Maria Amelia; Ladeveze, Sandrine; Prevosti, Francisco Juan Molar morphology is one of the most used proxies for paleoecological inferences in mammals. Since the XIX century, several authors associated dental morphological traits with the diet of an animal by means of qualitative and descriptive analyses. More recently, different studies of tooth function have associated various quantitative traits of tooth shape (i.e., morphometric ratios or angles) with the different items consumed by the animal. However, because different inferences of diet for the same species can be found in the literature, it is crucial to study the power of different proxies. In this work, we compared the utility of classic morphometric indices (relative lower grinding area, lower angle and angle α) and three-dimensional landmarks configuration to infer diet. Based on a previously published dataset from our working group, we calculated the classic morphometric indices and performed three classification methods: linear discriminant analysis, quadratic discriminant analysis, and weighted random forest. Our results demonstrate that when using the geometric morphometrics approach, the diet of species is better reclassified than when using morphometric indices. Furthermore, intraspecific variation appears fundamental when making paleoecological inferences. In inferring ecological characteristics of extinct animals, studying morphological variation in extant organisms is a safeguard to prevent misinterpretations when reconstructing past ecologies.

Distribution and diversity of leaf-cutting ants in Northeastern Argentina: species most associated with forest plantations Sánchez Restrepo, Andrés Fernando; Jiménez, Nadia Lis; Confalonieri, Viviana Andrea; Calcaterra, Luis Alberto Leaf-cutting ants (LCA) are considered one of the main herbivores and one of the most destructive pest insects of the Neotropics. Northeastern Argentina harbors the greatest species richness of these ants and in turn comprises the highest surface with forest plantations. Our aim was to establish which species of leaf-cutting ants are most commonly associated with forest plantations by analyzing their geographic distribution using published and unpublished species occurrence data. Also, estimate their potential areas of distribution along a latitudinal gradient that entirely encompasses northeastern Argentina using Ecological Niche Modeling. Only seven of the 20 species recorded were strongly associated with productive systems along the gradient, but only 2–3 species in each region could be considered high-risk species for forest plantations. High-risk species composition shows a turnover between regions. Our models show the potential distribution areas where LCA could become more abundant and dominant, and possibly causing a detrimental effect on the forest plantations in the studied region. We find that ecological niche models are useful tools to assess the environmental suitability of important LCA.

Analysis of a southern sub-polar short-term ozone variation event using a millimetre-wave radiometer Orte, Pablo Facundo; Wolfram, Elian Augusto; Salvador, Jacobo Omar; Mizuno, Akira; Bègue, Nelson; Bencherif, Hassan; Bali, Juan Lucas; D'Elia, Raul; Pazmiño, Andrea; Godin Beekmann, Sophie; Ohyama, Hirofumi; Quiroga, Jonathan Javier Subpolar regions in the Southern Hemisphere are influenced by the Antarctic polar vortex during austral spring, which induces high and short-term ozone variability at different altitudes, mainly into the stratosphere. This variation may affect considerably the total ozone column changing the harmful UV radiation that reaches the surface. With the aim of studying ozone with a high time resolution at different altitudes in subpolar regions, a millimetre-wave radiometer (MWR) was installed at the Observatorio Atmosférico de la Patagonia Austral (OAPA), Río Gallegos, Argentina (51.6∘ S, 69.3∘ W), in 2011. This instrument provides ozone profiles with a time resolution of ∼1 h, which enables studies of short-term ozone mixing ratio variability from 25 to ∼70 km in altitude. This work presents the MWR ozone observations between October 2014 and 2015, focusing on an atypical event of the polar vortex and Antarctic ozone hole influence over Río Gallegos detected from the MWR measurements at 27 and 37 km during November of 2014. During the event, the MWR observations at both altitudes show a decrease in ozone followed by a local peak of ozone amount of the order of hours. This local recovery is observed thanks to the high time resolution of the MWR mentioned. The advected potential vorticity (APV) calculated from the MIMOSA high-resolution advection model (Modélisation Isentrope du transport Méso-échelle de l'Ozone Stratosphérique par Advection) was also analysed at two isentropic levels (levels of constant potential temperature) of 675 and 950 K (∼27 and ∼37 km of altitude, respectively) to understand and explain the dynamics at both altitudes and correlate the ozone rapid recovery with the passage of a tongue with low PV values over Río Gallegos. In addition, the MWR dataset was compared for the first time with measurements obtained from the Microwave Limb Sounder (MLS) at individual altitude levels (27, 37 and 65 km) and with the differential absorption lidar (DIAL) installed in the OAPA to analyse the correspondence between the MWR and independent instruments. The MWR–MLS comparison presents a reasonable correlation with mean bias errors of +5 %, −11 % and −7 % at 27, 37 and 65 km, respectively. The MWR–DIAL comparison at 27 km also presents good agreement, with a mean bias error of −1 %.

The use of 3-axial accelerometers to evaluate sound production in European spiny lobster, Palinurus elephas Zenone, Arturo; Ceraulo, Maria; Ciancio Blanc, Javier Ernesto; Buscaino, Giuseppa; D'Anna, Giovanni; Grammauta, Rosario; Mazzola, Salvatore; Giacalone, Vincenzo Maximiliano The European spiny lobster Palinurus elephas emits sound (“rasp”), moving the base of their antennas, as response to the presence of predator and for interspecific communication. During the last decade, three-axial accelerometers have been used to mainly describe diel activity patterns, circadian rhythms and rate of energy consumption of different lobster species, but these devices can also record sound emission in terms of mechanical vibration of carapace. In order to evaluate the efficiency of accelerometers in recording sound production (rasp events and number of pulses inside each rasp) and in discriminating of that from other behavioural events, accelerometers were used in combination with hydrophone and during mesocosm free ranging conditions. Three-axial accelerometers were able to detect sound production events in P. elephas. All the rasp events (n = 405) recorded with hydrophones were also detected by the accelerometers considering its data sampled at different frequency (from 800 Hz to 12 Hz). However, the detection of the number of pulses within each rasp sound decreased with sampling frequency of accelerometer data (median of predictive error for 800 Hz = 0.33; median of predictive error for 12 Hz = 0.65). During mesocosm free condition, three behavioural categories were identified: walk, tail flip, and rasp, the last with averaged (15.16 ± 3.52 m/s2 ) and maximum (29.49 ± 9.37 m/s2 ) values of acceleration significantly higher than the other two. Findings from this study prove that accelerometers register only lobster body vibrations providing a clear signal that is not distorted by other noises in the environment. They also allowed to identify rasps for each tagged lobster, something not possible using hydrophones in both, aquaria or natural habitat. Accelerometer resulted an useful tool to detect behaviours even with low mobility species. Moreover, the possibility to couple accelerometer and other biologging techniques would help to improve our understanding of the behaviour of a large range of free-living species.

Prognostic significance of tumor subtypes in women with breast cancer according to stage: A population-based study Leone, José P.; Leone, Julieta; Zwenger, Ariel; Vallejo, Carlos T.; Leone, Bernardo A. Objectives: The contribution of tumor subtypes (TS) in each stage of breast cancer with the use of contemporary therapies is unclear. The aim of this study was to analyze differences in overall survival (OS) by TS according to stage compared with other factors. Materials and Methods: We evaluated women with breast cancer diagnosed between 2010 and 2013 with known estrogen receptor and progesterone receptor (together hormone receptor [HR]) status and human epidermal growth factor receptor 2 (HER2) status reported to the SEER program. Patient characteristics were compared between TS. Univariate and multivariate analyses were performed to determine the effect of each variable on OS. Breast cancer–specific survival was a secondary endpoint. Results: We included 166,054 patients. TS distribution was: 72.5% HR-positive/HER2-negative, 10.8% HR-positive/HER2-positive, 4.8% HR-negative/HER2-positive, and 12% triple-negative (TN). Patients with HR-positive/HER2-negative tumors were older, had a lower grade and presented with the earlier stage (all P< 0.0001). OS was significantly different according to TS in each stage (Pinteraction<0.0001). HR-positive/HER2-negative had the best OS in stage I (3-year OS, 97.2%). In contrast, HR-positive/HER2-positive had the best 3-year OS in stage II (94.5%), stage III (87.8%), and stage IV (54.8%). There was a 40.1% difference in OS at 3 years in stage IV between TN and HRpositive/HER2-positive. Multivariate analysis adjusted for age, race, grade, histology, and marital status confirmed these results. Conclusions: Although HR-positive/HER2-negative tumors had better clinicopathologic features, the HR-positive/HER2-positive group had the best OS in most stages. OS was significantly different by TS in each of the 4 stages and these results remained significant in the multivariate model.

Biología reproductiva de Boana pulchella y Boana punctata (Anura: Hylidae) en poblaciones simpátricas de humedales templados; Reproductive biology of Boana pulchella and Boana punctata (Anura: Hylidae) in sympatric populations of temperate wetlands Antoniazzi, Carolina Elizabet; López, Javier Alejandro; Ghirardi, Romina; Armando, Andrea Paola Boana pulchella habita principalmente climas templados y B. punctata principalmente climas tropicales, lo que permitiría suponer la presencia de estrategias reproductivas diferentes, aún en la región en la que sus poblaciones son simpátricas. En el presente estudio se analizaron y compararon los ciclos reproductivos, parámetros reproductivos y desarrollo de cuerpos grasos (CG) de Boana pulchella y B. punctata en humedales templados del río Paraná Medio. Boana pulchella presentó óvulos maduros de marzo a diciembre. En machos no hubo variación del volumen testicular a lo largo del año y el mayor desarrollo de CG de los machos se observó en invierno. Esta especie presentó un patrón reproductivo continuo. La vitelogénesis de B. punctata se inició en enero, alcanzando el mayor desarrollo ovárico en febrero (verano) y decreciendo hacia mayo (otoño). Los machos presentaron crecimiento testicular en verano, decreciendo hacia otoño y los CG presentaron su máximo desarrollo en enero para ambos sexos. Esta especie mostró un patrón reproductivo continuo. Ambas especies presentaron dimorfismo sexual con hembras que poseen una relación proporcional entre la talla y la inversión reproductiva. Boana pulchella presentó un mayor esfuerzo reproductivo (ER = 20,48 ± 12,9) y factor de tamaño ovárico (FTO = 25,73) que B. punctata (ER = 10,06 ± 4,45; FTO = 8,99). También se encontraron diferencias interespecíficas en la masa ovárica, complemento ovárico y volúmen testicular, siendo estas variables proporcionalmente mayores en B. pulchella. Las diferencias observadas en las poblaciones simpátricas podrían relacionarse con el desarrollo de estrategias reproductivas bajo diferentes presiones evolutivas; Boana pulchella mainly inhabits temperate climates while B. punctata mainly inhabits tropical climates, which would allow assuming the presence of different reproductive strategies, even in the region in which their populations are sympatric. In the present study, we analyzed and compared the reproductive cycles, reproductive parameters, and fat bodies development of Boana pulchella and B. punctata inhabiting in sympatry in temperate wetlands of the Middle Paraná River. Boana pulchella presented mature ovaries from March to December. There was no seasonal variation in testicular size of males, and their fat bodies development was greater during winter. This species exhibited a continuous breeding pattern. The vitellogenesis of B. punctata began in January (summer), reaching higher ovarian development in February (summer) and decreasing to May (autumn). Testicles of males grew in summer and decline in autumn. Fat bodies presented their developmental peak in January for both sexes. This species exhibited a prolonged breeding season. Both species showed sexual dimorphism with larger females having a greater inversion in reproduction. Boana pulchella showed greater reproductive effort (RE = 20.48 ± 12.9) and ovarian size factor (OSF = 25.73) than B. punctata (RE = 10.06 ± 4.45; OSF = 8.99). We also found interspecific differences in ovarian mass, ovarian complement, and testicular volume, these variables being proportionally greater in B. pulchella. Observed differences in sympatric populations could reside in the development of reproductive strategies under different evolutionary pressures.

Improving the efficiency of a Savonius wind turbine by designing a set of deflector plates with a metamodel-based optimization approach Storti, Bruno Alberto; Dorella, Jonathan Jesus; Roman, Nadia Denise; Peralta, Ignacio; Albanesi, Alejandro Eduardo Savonius wind turbines are the most suitable devices used in urban areas to produce electrical power. This is due to their simplicity, ease of maintenance, and acceptable power output with a low speed and highly variable wind profile. However, their efficiency is low, and the development of optimization tools is necessary to increase the total power output. This work presents a metamodel-based method to optimize the size and shape of a set of deflector plates to reduce the reverse moment of the turbine, using a genetic algorithm combined with an artificial neural network, reducing the computational cost. A parametrization of the deflectors geometry is proposed, and a Computational Fluid Dynamics model was implemented to train and validate the artificial neural network. The method was applied to design the deflectors of an actual 8-blade, 1[kW], 2.5[m] height turbine. Results showed an efficiency increment of 30%, from 0.215, to 0.279 in the turbine with the optimized deflectors. Furthermore, it is capable of producing power at 4[m/s], while the reference design had null power at that point. This methodology demanded 159 h, a substantial reduction of the computational cost of up to 97% in contrast to the classical simulation-based optimization approach.

De la dictadura democrática a la dictadura del proletariado: el debate en el Partido Bolchevique sobre las Tesis de Abril de Lenin Murphy, Kevin; Gaido, Daniel Fernando A principios de abril de 1917, Lenin asombró tanto a sus amigos como a sus enemigos cuando, después de llegar a la estación Finlandia, leyó su tesis defendiendo la transición de la Revolución rusa de su primera etapa burguesa a una segunda etapa durante la cual el poder se transferiría a manos del proletariado. Esta nueva política iba en contra de la perspectiva política de lo que Lenin llamaba ahora el ‘viejo bolchevismo’ (la cual, a pesar de rechazar un frente común con la burguesía y abogar por una alianza del proletariado y el campesinado, limitaba la revolución a la consecución de metas democrático-burguesas) y señaló su acercamiento a la perspectiva de la revolución permanente bosquejada por primera vez por Trotsky y otros pensadores marxistas durante la revolución de 1905. Este rearme del Partido Bolchevique dio lugar a furiosas polémicas en sus filas en abril de 1917 y a un giro brusco en sus políticas, que documentamos en el presente artículo.; In early April 1917 Lenin astonished both friends and foes when, after arriving at the Finland station, he read his thesis advocating the transition of the Russian Revolution from its first, bourgeois stage, to a second stage during which power would be transferred into the hands of the proletariat. This new policy went counter to the political perspective of what Lenin called ‘old Bolshevism’—which, while rejecting a common front with the bourgeoisie and advocating an alliance of the proletariat and the peasantry, nevertheless limited the revolution to the attainment of bourgeois-democratic goals—and signaled his approach to the perspective of permanent revolution first outlined by Trotsky and a number of Marxist thinkers during the revolution of 1905. This rearming of the Bolshevik Party gave rise to furious polemics in its ranks in April 1917 and to a sharp turn in its policies, which we document in the present article.

La mercantilización del agro y la resistencia contra el extractivismo agrícola sojero en Argentina; The commodification of agriculture and resistance against agricultural agricultural extractivism in Argentina Barzola, Erika Judith La invención de América Latina, hace más de 500 años, posibilitó, entre otras cosas, el ejercicio de un biopoder sobre los cuerpos y las naturalezas por parte de las potencias hegemónicas que, no sólo construyó naturalezas susceptibles de ser sacrificadas, sino también cuerpos subalternizados por la dominación. Esta lógica de poder y dominación se ha extendido a través del paso de los años y puede ser rastreada a lo largo de la historia del continente, a partir de considerar el rol de la región en la geopolítica mundial de los recursos naturales y el papel que los cuerpos considerados subalternos han ido ocupando. A lo largo de este escrito, buscamos evidenciar el ejercicio del biopoder y de la dominación a partir de reflexionar sobre las transformaciones que fue sufriendo el agro argentino, desde la década del ´70 en adelante, como consecuencia de la llamada “revolución verde”. Esta “revolución”, no fue otra cosa más que la formulación de políticas, por parte de los países hegemónicos, tendientes a resolver el problema del hambre mundial posterior a la Segunda Gran Guerra. En este contexto histórico, América Latina fue sometida a una nueva jugada colonial que la colocó como una región subdesarrollada, la que debía seguir los estándares de los países centrales en pos de alcanzar el desarrollo. Para el caso de la agricultura, estos estándares se anclaban en la modernización, la cientifización y la tecnificación, eliminando las prácticas ancestrales de producción de alimentos y despolitizando los debates en torno a qué producir, cómo hacerlo, para quién hacerlo, etc., colocando la discusión en un plano meramente científico-técnico. Este es el marco en el que el agro argentino comenzó a vislumbrar la incidencia del capitalismo financiero en la agricultura, iniciándose el paso a un modelo agrícola extractivista basado principalmente en el cultivo extensivo de soja transgénica. Frente a estos cambios, numerosas comunidades y organizaciones campesino-indígenas protagonizan acciones colectivas contra-hegemónicas en defensa de sus estilos de vida, medios de vida, territorios y bienes comunes. En este contexto y a lo largo de esta crito, nos interesa analizar las consecuencias socio-ambientales de la mercantilización de la naturaleza de la mano de la incidencia del capital financiero en el agro argentino y las resistencias que han ido emergiendo a lo largo de los años. Para ello, centramos nuestras reflexiones en torno a la expansión del modelo extractivista sojero y la resistencia del colectivo “Malvinas Lucha por la Vida” quién se enfrentó a la multinacional Monsanto y logro expulsarla de su territorio. Esta experiencia de lucha y resistencia contribuyó a poner de manifiesto la crisis del modelo civilizatorio y productivo, lo que condujo a la comunidad a revalorizar no sólo su territorio, sino también a plantear la necesidad de un modelo alternativo de agricultura que sea respetuoso de la soberanía alimentaria de los pueblos.; The invention of Latin America, more than 500 years ago, enabled, among other things, the exercise of a biopower over bodies and natures by the hegemonic powers that, not only built natures that could be sacrificed, but also subalternized bodies For domination. This logic of power and domination has spread over the years and can be traced throughout the history of the continent, considering the role of the region in the global geopolitics of natural resources and the role that the bodies considered subordinates have been occupying. Throughout this paper, we seek to demonstrate the exercise of biopower and domination from reflecting on the transformations that Argentina's agriculture was going through, from the 1970s onwards, as a consequence of the so-called "green revolution." This "revolution" was nothing more than the formulation of policies by the hegemonic countries, aimed at solving the problem of world hunger after the Second Great War. In this historical context, Latin America was subjected to a new colonial move that placed it as an underdeveloped region, which should follow the standards of the central countries in pursuit of development. In the case of agriculture, these standards were anchored in modernization, scientificization and technification, eliminating ancestral practices of food production and depoliticizing debates about what to produce, how to do it, who to do it for, etc., placing the discussion on a purely scientific-technical level. This is the framework in which Argentine agriculture began to glimpse the incidence of financial capitalism in agriculture, beginning the transition to an extractive agricultural model based mainly on the extensive cultivation of transgenic soybeans. Faced with these changes, numerous communities and peasant-indigenous organizations are leading collective anti-hegemonic actions in defense of their lifestyles, livelihoods, territories and commons. In this context and beyond this belief, we are interested in analyzing the socio-environmental consequences of the commodification of the nature of the hand of the incidence of financial capital in Argentine agriculture and the resistances that have been emerging over the years. . To this end, we focus on some reflections on the expansion of the extractive model on the strength and resistance of the collective “Malvinas Lucha por la Vida” that confronted the multinational Monsanto and the attempt to expel it from its territory. This experience of lucha and resistance contributed to maintaining the crisis of the civilizational and productive model, which led the community to revalue in the territory alone, and also to plant the need for an alternative model of agriculture that is the sovereignty of the country. would feed them los pueblos.

Aperturas y cierres en la interacción digital escrita: fórmulas de saludo en español bonaerense; Openings and closings in written digital interaction: forms of greeting in buenos aires spanish Cantamutto, Lucía Marina El artículo describe, desde una perspectiva sociolingüística e interaccional, uno de los actos de habla expresivos centrales en la interacción por textos breves en el discurso digital y de gran relevancia dentro de las estrategias pragmáticas: el saludo. Por un lado, el saludo de inicio, así como el empleo de fórmulas de tratamiento en función vocativa, son claves de contextualización para que los interactuantes identifiquen el punto en el que quedó la interacción previamente. Por otro, el saludo de despedida presenta una menor incidencia en la interacción digital escrita dada la posibilidad de mantener siempre abierto el canal de comunicación. El objetivo es caracterizar los recursos y estrategias que emplean los hablantes en las instancias de preparación, apertura y terminación conversacional en el intercambio de SMS. El estudio, que se realizó a partir de un corpus de 6700 SMS recolectados entre 2008-2016 en la ciudad de Bahía Blanca, analiza la variación existente según diferentes dominios de uso y variables sociolingüísticas. Se observa la preferencia por formas vocativas en detrimento de los saludos de inicio y la competencia entre el saludo de despedida y otros acto de habla expresivos, como la manifestación de agradecimiento.; From a socio-linguistic and interactional perspective, the article describes one of the core expressive speech act in digital discourse texting with high relevance in pragmatic strategies: greetings. On the one hand, the use of greetings and forms of address in vocative function as contextualization keys allows interactants identify how interaction was previously. On the other hand, the closings present a lower incidence in written digital interaction due to the possibility to keep the communication channel open. The objective is to characterize the resources and strategies employed by speakers in the stages of preparation, opening and termination in texting conversation. The study, conducted based on a corpus of 6700 SMS collected between 2008 and 2016 in Bahia Blanca, analyses the existing variation according to different domains of usage and sociolinguistic variables. The results shows the preference for vocative forms rather than greetings and the competition between closings and other expressive speech acts, like expression of gratitude.

Evaluation of the cryoprotective effect of seminal plasma on llama (Lama glama) spermatozoa Fumuso, Fernanda Gabriela; Giuliano, Susana María; Chaves, Maria G.; Neild, Debora Margarita; Miragaya, Marcelo; Carretero, Maria Ignacia In South American camelids, sperm survival is low after thawing and poor results are obtained when artificial insemination is performed with cryopreserved semen. The aim of this study was to evaluate the effect of different percentages (10% and 50%) of seminal plasma added prior to the process of cryopreservation and also to evaluate the absence of seminal plasma on llama sperm survival after freezing and thawing. A total of 15 ejaculates from five adult llama males (n = 5; r = 3) were evaluated. A significant decrease in sperm motility, viability, membrane function and intact acrosomes was observed in thawed samples (0%, 10% and 50%) when compared to raw semen. Neither morphology nor chromatin condensation was altered in all thawed samples (p > 0.05), but a significant increase (p < 0.05) in the percentage of spermatozoa with fragmented DNA was observed after thawing all samples compared to raw semen. Higher percentages of total and progressive sperm motility were observed when 0% and 10% of seminal plasma were used compared to 50%. However, no statistical differences were established for sperm viability, membrane function, morphology, acrosome status and DNA quality between thawed treatments. To conclude, neither of the percentages of seminal plasma used showed superiority nor cryoprotective effect on llama sperm survival.

Understanding the Role of Protic Ionic Liquids (PILs) in Reactive Systems: Rational Selection of PILs for the Design of Green Synthesis Strategies for Allylic Amines and β‐Amino Esters Bravo, Maria Virginia; Fernandez, Jose Luis; Adam, Claudia Guadalupe; Della Rosa, Claudia Daniela The reactive behaviour of protic ionic liquids (PILs) has been shown to be governed not only by their chemical structures but also by their global compositions, which include the presence of free acids and bases at equilibrium with ionic pairs. Six PILs composed of primary, secondary, or tertiary alkyl ammonium cations with two couterions, nitrate or acetate, were tested in model reactions with unsaturated substrates. The free species that were naturally present in these liquids were identified by cyclic voltammetry. Only tributylammonium nitrate was found to be mostly composed just of the ionic pair; the other five PILs also contain variable amounts of free acid and amine. In reactive systems, these free species determine the products of the reaction. In particular, allylic amines and β-amino esters were obtained in good yields (91 and 75 %, respectively) by reaction of conjugated dienes and acrylates in the presence of PILs. By taking into account the actual composition of each PIL, it was possible to direct the reaction path towards a specific product with good yields, to ensure acid catalysis, to avoid polymerization of the substrate, and to promote phase transfer of products. These results establish some useful guidelines for the rational design of new PIL-based one-step synthetic strategies.

A stem anseriform from the early Palaeocene of Antarctica provides new key evidence in the early evolution of waterfowl Tambussi, Claudia Patricia; Degrange, Federico Javier; de Mendoza, Ricardo Santiago; Sferco, Marta Emilia; Santillana, Sergio Nestor A new Anseriformes, Conflicto antarcticus gen. et sp. nov., represented by associated bones of a single individual, from the early Palaeocene of Antarctica is described. The new taxon is unlike any other known member of the order. Conflicto antarcticus is a medium-sized (2 kg) stem anseriform. The forelimb and pectoral girdle bones suggest that it was a flying bird, and the bones of the hindlimb show that it had elongated legs. The os quadratum represents a unique combination of features; some are similar to the features of the ancestral quadrate for galloanserines and some are similar to Anseriformes, but features such as the presence of three foramina are exclusive among Neornithes. The incisura or foramen nervi suracoracoidei is absent in C. antarcticus, as in most anatids and all Galliformes. Phylogenetic analysis shows that C. antarcticus + Anatalavis oxfordi is the most basal stem Anseriformes clade. This implies that the duck-type beak must have developed at an early stage of anseriform evolution. Conflicto antarcticus represents one (and possibly the most) substantial record of a non-marine Palaeocene bird from the Southern Hemisphere and supports the hypothesis that Neognathae had already diversified in the earliest Palaeocene.

Discriminative power of acoustic features for jaw movement classification in cattle and sheep Galli, Julio Ricardo; Milone, Diego Humberto; Cangiano, Carlos Alberto; Martínez, César Ernesto; Lacambra, Emilio; Chelotti, Jose Omar; Rufiner, Hugo Leonardo Measuring foraging behaviour and pasture intake of ruminants is useful but difficult. Acoustic monitoring is one of the most promising methods for this task. In this work, we test its potential to classify jaw movements (JM) according to type (bite, chew, chew-bite), activity (grazing or rumination), and forage species being consumed. Experiments with cows and sheep grazing and ruminating several forages were conducted. First, each JM was manually identified, classified and described by two sets of sound features: i) one containing energy bands of the spectrum (EB), and ii) one containing four complementary (or global) variables (Cv). Two models were evaluated, one with EB alone and the other one combining EB and Cv. Jaw movements were correctly classified by type with 73.0% and 78.5% average accuracy. Accuracy wasbetter for cows than sheep (85 vs 66%). Simultaneous identification of the type of JM and plant species was about 78%. Classification accuracy of activity based on chews averaged 68.5% and 77.0% for rumination and grazing. Models including global variables performed better than using only the spectrum. Acoustic monitoring is a very promising method for further development, particularly to study diet selection.

Leishmaniasis in the Argentine Republic: Temporal and geographical distribution from 2013 to 2017 Germano, Maria Jose; Salomón, María Cristina; Neira, Gisela Natalia; Lozano, Esteban Sebastián; Mackern Oberti, Juan Pablo; Cargnelutti, Diego Esteban Objective: To assess the temporal and geographical distribution of confirmed cases of cutaneous, mucocutaneous and visceral leishmaniasis in the Argentine Republic from 2013 to 2017. Methods: A retrospective study was carried out using data collected from the Integrated Surveillance Bulletin database of the National System of Health Surveillance. Confirmed cases of cutaneous, mucocutaneous and visceral leishmaniasis up to the 52nd epidemiological week of each year was included. Results: In the 5 years period, 1 295 confirmed leishmaniasis cases were reported in the Argentine Republic. One thousand twenty-eight (1 028) cases corresponded to cutaneous leishmaniasis (87.10%), being the most common type of leishmaniasis. Mucocutaneous leishmaniasis was in the second place in the country with 115 cases reported, mostly in the Northwest and Northeast regions. A total of 52 individuals with visceral leishmaniasis were identified and Misiones Province was the most affected. Conclusions: It is important to analyze the temporal and geographical distribution of leishmaniasis in order to provide an adequate management and surveillance.

Color Source for the First Argentinian Flags Picone, Andrea Lorena; Romano, Rosana Mariel; Della Védova, Carlos Omar In this work, a historical controversy of more than 200 years is settled by the study of the oldest preserved Argentinian flag. The results of the present work reinforce the hypothesis of a number of historians who consider it to be the first flag that was originally hoisted on February 27, 1812, on the banks of the Paraná River. The work consists of a study of the original textile. Through chemical analysis and implementation of different types of analyses, techniques, and spectroscopies such as UV−vis, UV−vis diffuse reflectance spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy, scanning electron microscopy−energy-dispersive X-ray spectroscopy, and resonance Raman, the original characteristics of the flag of Macha were determined. The flag was colored with indigotin from Europe (from Isatis tinctoria) and made of silk; it is white, blue, and white in a horizontal arrangement. It was not treated with tin, and its blue color was subsequently adopted by the Central American Confederation and later by various states of Central America. According to related contemporaneous stories, its preservation was due to the watchfulness of the patriots.

Prognostic significance of α‐ and β2‐adrenoceptor gene expression in breast cancer patients Rivero, Ezequiel Mariano; Martinez, Leandro Marcelo; Bruque, Carlos David; Gargiulo, Lucía; Bruzzone, Ariana; Luthy, Isabel Alicia Breast cancer is the most frequently diagnosed and leading cause of cancer death among women worldwide. It was classified within molecular intrinsic subtypes: luminal A, luminal B, human epidermal growth factor receptor 2‐enriched and basal‐like. Epinephrine and norepinephrine, released during stress, bind to adrenoceptors. α2‐adrenoceptors are encoded by the ADRA2A , ADRA2B and ADRA2C genes and β2 by ADRB2 .